Safety system and method for configuring air conditioning system

Abstract

A safety system for a heat pump system is provided, the safety system comprising: a plurality of valve units, each of the plurality of valve units having a refrigerant piping portion with a control valve; a refrigerant leak detector; and a housing (400e) housing the valves and the refrigerant leak detector and having a first opening (420) and a second opening (430). The safety system further comprises a connection structure and a discharge structure, the connection structure being connected to an interior space of the housing via the first opening and the second opening, the discharge structure being connected to one of the housing and a connection mechanism and configured to discharge air from the interior space of the housing where a refrigerant leak has occurred. The housing has a first transverse surface and a second transverse surface facing different directions, the first opening being formed in the first transverse surface, and the second opening being formed in the second transverse surface.

Description

Technical Field

[0001] The present invention relates to a safety system for a heat pump system and a method for constructing an air-conditioning system including the safety system. Background Art

[0002] In a heat pump system, such as an air conditioning system for multiple target spaces, each of the liquid refrigerant piping and gas refrigerant piping of the heat pump circuit is branched into multiple sub-piping systems. The branch sub-piping systems are typically equipped with valves to partition the sub-piping systems.

[0003] At the same time, each valve used in a heat pump system can often become a refrigerant leak point, necessitating regular inspection and, as needed, repair. Consequently, to facilitate monitoring and maintenance, heat pump system piping is often designed to house multiple valves in a single location. For example, EP 3091314A1 proposes integrating multiple valves for refrigerant sub-piping within a single housing to form a valve unit. This not only reduces the burden of monitoring and maintenance but also prevents refrigerant leaks from any valve from spreading to the surrounding area.

[0004] However, due to the number of valves, piping layout, space constraints, and other factors, it is sometimes difficult to house all valves in a single housing. If the valves are separated into multiple separate housings, opening each housing to inspect any valves for refrigerant leaks is cumbersome and time-consuming. Furthermore, if a refrigerant leak occurs at any valve, by the time monitoring / maintenance personnel arrive and open the housing, the interior space of the housing housing the valves will have already been infiltrated with a significant amount of leaked refrigerant. For example, some refrigerants used are flammable or even slightly flammable. Therefore, from a safety perspective, opening such a housing is undesirable. Summary of the Invention

[0005] An object of the present invention is to provide a safety system and a method for constructing an air conditioning system, which can improve the safety of a heat pump system with respect to refrigerant leakage from a valve even when a plurality of valve units should be arranged at different positions.

[0006] A first aspect of the present invention provides a safety system, which includes: a plurality of valve units for a heat pump system, each of the plurality of valve units having at least one liquid refrigerant piping portion and at least one gas refrigerant piping portion; at least one liquid control valve arranged in the liquid refrigerant piping portion, at least one gas control valve arranged in the gas refrigerant piping portion, a shell, the shell accommodating at least the liquid control valve and the gas control valve and forming at least two openings, and a refrigerant leakage detector, the refrigerant leakage detector being configured to detect the occurrence of refrigerant leakage in the internal space of the shell; a connecting structure, the connecting structure connecting the internal space of the shell via the opening; and a discharge structure, the discharge structure being connected to one of the shells or the connecting structure, and the safety system being configured to discharge air from the internal space of the shell where refrigerant leakage has occurred.

[0007] With this configuration, even if refrigerant leaks from the valves in any valve unit, the housing housing the valves prevents or suppresses the leaked refrigerant from spreading to the surrounding area. Furthermore, by discharging air from the interior space to the space outside the housing, the concentration of leaked refrigerant in the interior space of the housing can be reduced. Furthermore, during normal operation of the heat pump system, the housing can be substantially closed, and refrigerant leak detection can be performed based on the refrigerant concentration in this substantially closed space.

[0008] Therefore, the occurrence of refrigerant leakage in the valve unit can be quickly detected, and the operation of the discharge mechanism can be initiated at an early stage. This can more safely prevent the concentration of leaked refrigerant from increasing both in the housing where the refrigerant leak has occurred and in the surrounding area of ​​the housing. This allows monitoring and maintenance personnel to safely monitor, maintain, or repair the valve. This improves the safety of the heat pump system with respect to refrigerant leakage.

[0009] Furthermore, the exhaust structure is commonly used for multiple valve units. Therefore, even when valves are arranged in separate housings, the safety of the heat pump system can be improved while preventing an increase in system installation costs. This also reduces the space required to arrange the safety system.

[0010] Here, the external space to which air is discharged by the discharge structure is preferably not an external space directly surrounding any housing, or an indoor space where people or animals may enter or live. The external space is preferably an outdoor space. The heat pump system to which multiple valve units belong may include multiple separate heat pump circuits. In other words, the pipelines of the valve units do not need to be connected to each other. In each valve unit, the piping part, the valve and the housing can be manufactured together. Therefore, it is easier to design the valve unit to enhance its performance, such as the airtightness of the housing. It also becomes easier to optimize the size of the valve unit and the position of the maintenance door of the housing. Therefore, not only safety can be improved, but also the maintainability and functionality of the valve unit can be improved. Alternatively, the housing can be a modified housing to be assembled around the existing valve.

[0011] According to a preferred embodiment of the safety system as described above, the housing of each valve unit has a first transverse surface and a second transverse surface facing different directions, and in each valve unit, a first opening as one of the openings is formed in the first transverse surface, and a second opening as the other of the openings is formed in the second transverse surface.

[0012] With the above configuration, the first and second openings are formed in the transverse surface. This prevents the connection structure from protruding upward or downward from the housing. This reduces the height range for arranging the valve units and the connection structure connecting them. Here, the term "arrangement space" for an element refers to, for example, a rectangular parallelepiped space that can accommodate the element.

[0013] In addition, the transverse surfaces having the first opening and the second opening face in different directions. This prevents multiple elements of the connection structure (e.g., pipes) from protruding from the same surface of the same housing, thereby avoiding clogging of the elements. In other words, the connection structure can be easily arranged along a single plane to reduce the height range of the layout space. This is particularly advantageous when two valve units directly connected to each other via the connection structure (hereinafter referred to as "adjacent valve units") are arranged closely side by side. Therefore, the safety system according to the present invention can be easily installed even in a limited space (e.g., a relatively small space).

[0014] Here, the "lateral surface" of the housing refers to the outside of the housing that faces in a substantially horizontal direction when in use (i.e., in a state in which the valve unit is installed for use). The lateral surface can be defined by at least one plate forming part of the housing. The lateral surface can be a surface that is substantially orthogonal to a reference plane that defines the space in which the valve unit is installed. Such a reference plane can be the floor of the space, or when the valve unit is installed in a ceiling space, the upper surface of the ceiling. Therefore, when the space is inclined relative to the horizontal plane due to, for example, an inclined ceiling, the reference plane can also be inclined, and the lateral surface can also be a surface that is inclined according to the inclination of the reference plane. The "different directions" of the first lateral surface and the second lateral surface can be orthogonal directions or opposite directions, but are not limited to these directions.

[0015] According to a preferred embodiment of the safety system as described above, the housing of each valve unit has a substantially box shape, and the first lateral surface and the second lateral surface are opposite surfaces of the housing.

[0016] The above configuration makes it easy to arrange multiple valve units and the connecting structures connecting them in a straight line. This minimizes the width of the space required to arrange the valve units. Here, "width of the arrangement space" refers to, for example, the length of the arrangement space in a direction perpendicular to the direction in which the valve units are aligned. This is particularly advantageous when three or more valve units are arranged in series.

[0017] According to another preferred embodiment of the safety system as described above, wherein the first and second transverse surfaces are opposing surfaces, the first and second openings at least partially overlap each other when viewed from a direction substantially perpendicular to the first and second transverse surfaces.

[0018] With the above configuration, when adjacent valve units are arranged so that the first transverse surface of one of the adjacent valve units and the second transverse surface of the other adjacent valve units face each other, the first opening of the first transverse surface and the second opening of the second transverse surface can be easily made to overlap with each other when viewed from a direction generally perpendicular to the first and second transverse surfaces. More specifically, this positional relationship of the first opening and the second opening can be achieved simply by arranging the adjacent valve units so that the first and second transverse surfaces are parallel to each other and the perimeters of the first and second transverse surfaces coincide when viewed from a direction generally perpendicular to the first and second transverse surfaces.

[0019] As a result, adjacent first and second openings to be connected by the connecting structure can be positioned closer together, without requiring the connecting structure to be significantly wound around. This allows adjacent valve units to be arranged closer together. Consequently, the space required to arrange adjacent valve units and the area of ​​the connecting structure between them can be reduced.

[0020] According to another preferred embodiment of any one of the safety systems described above, the shell of each valve unit has a bottom surface perpendicular to the first lateral surface and the second lateral surface, and the shell is constructed so that the centers of the first opening and the second opening, the ends closer to the bottom surface and / or the ends farther away from the bottom surface are at the same distance from the bottom surface.

[0021] With the above configuration, simply by arranging the two valve units so that their bottom surfaces are at the same distance from a specific plane, the first opening of one valve unit and the second opening of the other valve unit can be easily positioned at the same distance from the specific plane. This arrangement allows the connection structure to be arranged along the specific plane. Furthermore, since the height positions of the first opening and the second opening can be standardized for all valve units, the production cost of the safety system can be reduced.

[0022] Here, the "bottom surface" refers to the outer surface of the housing that faces downward during use. The bottom surface may be defined by at least one plate forming part of the housing. The "specific plane" may be a horizontal plane or a reference plane as described above. Therefore, if the space in which the valve unit is installed is tilted relative to the horizontal plane, the "bottom surface" may also tilt according to the inclination of the space.

[0023] According to another preferred embodiment of any one of the safety systems described above, wherein the centers of the first opening and the second opening, the ends closer to the bottom surface and / or the ends farther away from the bottom surface are at the same distance from the bottom surface, at least the first valve unit and the second valve unit as two of the valve units are arranged adjacent to each other so that the bottom surfaces of the first valve unit and the second valve unit are flush with each other.

[0024] With this configuration, there's no need to wrap the connecting structure around the specific plane described above to bridge the positional difference between the first and second openings of the first and second valve units relative to the specific plane. This allows adjacent valve units to be placed closer together. As a result, the space required to arrange adjacent valve units and the area of ​​the connecting structure between them can be reduced. Furthermore, since the bottom surfaces of the first and second valve units are aligned, the height range of the space required to arrange adjacent valve units can also be reduced.

[0025] According to another preferred embodiment of any one of the safety systems as described above, the first transverse surface and the second transverse surface are opposite surfaces of the shell, the shell of each valve unit has a third transverse surface perpendicular to the first transverse surface and the second transverse surface, and the above-mentioned shell is constructed so that the centers of the first opening and the second opening, the ends closer to the third transverse surface and / or the ends farther away from the third transverse surface are at the same distance from the third transverse surface.

[0026] With the above configuration, simply by arranging the two valve units so that their third transverse surfaces are at the same distance from the specific transverse surface, the first opening of one valve unit and the second opening of the other valve unit can be easily positioned at the same distance from the specific transverse surface. This arrangement allows the connection structure to be arranged along the specific transverse surface. Furthermore, since the height positions of the first and second openings can be standardized for all valve units, the production cost of the safety system can be reduced. Here, the "specific transverse surface" may be, but is not limited to, a vertical plane or a wall plane defining the space in which the valve units are to be installed.

[0027] According to another preferred embodiment of any one of the safety systems described above, wherein the centers of the first opening and the second opening, the ends closer to the third transverse plane and / or the ends farther away from the third transverse plane are at the same distance from the third transverse plane, at least the first valve unit and the second valve unit as two of the valve units are arranged adjacent to each other so that the third surface of the first valve unit and the third surface of the second valve unit are flush with each other.

[0028] With this configuration, there's no need to wrap the connecting structure around the specific transverse surface described above to bridge the positional difference between the first and second openings of the first and second valve units relative to the specific transverse surface. This allows adjacent valve units to be arranged closer together. As a result, the space required to arrange adjacent valve units and the area of ​​the connecting structure between them can be reduced. Furthermore, since the third surface of the first valve unit is aligned with the third surface of the second valve unit, the width of the space available to arrange the valve units can also be reduced.

[0029] According to another preferred embodiment of any one of the safety systems described above, each of the above-mentioned valve units also has a main liquid refrigerant piping portion and a main gas refrigerant piping portion, the above-mentioned liquid refrigerant piping portion branches off from the above-mentioned main liquid refrigerant piping portion, and the above-mentioned gas refrigerant piping portion branches off from the above-mentioned main gas refrigerant piping portion, in each of the above-mentioned valve units, one end of the above-mentioned main liquid refrigerant piping portion and one end of the above-mentioned main gas refrigerant piping portion protrude from the above-mentioned first lateral surface, and the other end of the above-mentioned main liquid refrigerant piping portion and the other end of the above-mentioned gas refrigerant piping portion protrude from the above-mentioned second lateral surface, the above-mentioned safety system also includes: at least one liquid refrigerant connecting pipe, the above-mentioned liquid refrigerant connecting pipe connecting the main liquid refrigerant piping portion of the first valve unit and the main liquid refrigerant piping portion of the second valve unit, the above-mentioned first valve unit and the above-mentioned second valve unit being two valve units; and at least one gas refrigerant connecting pipe, the above-mentioned gas refrigerant connecting pipe connecting the main gas refrigerant piping portion of the first valve unit and the main gas refrigerant piping portion of the second valve unit.

[0030] By the above-mentioned construction, the main liquid refrigerant piping portion and the main gas refrigerant piping portion (hereinafter referred to as the "main piping portion") of two adjacent valve units are connected in series through the liquid refrigerant connecting piping and the gas refrigerant connecting piping (hereinafter referred to as the "connecting piping"). The end portion of the main piping portion protrudes from the transverse surface formed with the first opening and the second opening. Therefore, when the two valve units are arranged so that the first transverse surface of one of the adjacent valve units and the second transverse surface of the other face each other, both the connecting piping and the connecting structure can be arranged in the space between the two valve units. Therefore, the width of the arrangement space of the valve units, the connecting piping and the connecting structure can be reduced. In addition, since the connecting piping and the connecting structure connecting two adjacent valve units can be arranged in parallel, the connecting structure between the valve units can be simplified.

[0031] According to another preferred embodiment of any one of the safety systems described above, the ends of the main liquid refrigerant piping portion and the main gas refrigerant piping portion protrude from the first lateral surface and the second lateral surface, the shell of each valve unit has a piping outlet surface different from the first lateral surface and the second lateral surface; and one end of the liquid refrigerant piping portion and one end of the gas refrigerant piping portion protrude from the piping outlet surface.

[0032] Through the above-mentioned construction, the ends of the liquid refrigerant piping portion and the gas refrigerant piping portion (hereinafter referred to as the "sub-piping portion") protrude from surfaces other than the first and second transverse surfaces. This avoids clogging of the protruding piping portions and the connecting structure in the space between two adjacent valve units. This allows adjacent valve units to be arranged closer. In addition, since the sub-piping portion protrudes from one transverse surface, it is possible to prevent the sub-piping portion from protruding upward or downward from the housing. This can reduce the height range of the arrangement space of the valve units.

[0033] According to another preferred embodiment of any one of the above-mentioned safety systems, the housing of each valve unit has a drain pan, which is provided with a drain outlet protruding from the edge of the drain pan, and the housing is configured so that the drain pan can switch between at least two states in which the drain outlet protrudes in different directions.

[0034] By means of the above-mentioned construction, the position of the drain outlet can be easily switched between at least two different positions. This is advantageous when the position of the drain pipe to which the drain outlet is connected is restricted. By setting the position of the drain outlet closer to the position of the drain pipe, they can be conveniently connected. The drain pan and the lower part of the shell to which the drain pan is attached (hereinafter referred to as the "lower shell part") have corresponding shapes and are provided with a fixing structure for detachably fixing the drain pan relative to the lower shell part. The shapes of the drain pan and the lower shell part and the arrangement and construction of the fixing structure may be point-symmetrical.

[0035] According to a preferred variant of the safety system as described above, the discharge structure comprises a common duct connected to one of the housings or the connection structure and a ventilator arranged in the common duct.

[0036] With the above configuration, when refrigerant leakage occurs in the housing, air can be effectively discharged from the interior space of the housing. The ventilator can be configured to blow air to push air out of the housing, or to draw air in to extract air from the housing. The common duct can extend to an outdoor space, and the ventilator can be arranged in or attached to the common duct. The ventilator can also be configured to further discharge air surrounding at least one of the housings, such as air in a ceiling or duct shaft.

[0037] According to another preferred variation of the safety system having a common duct and a ventilator as described above, the common duct has a first end and a second end, the ventilator is arranged at the second end of the common duct or at a position close to the second end and is configured to draw air in the common duct toward the second end, and the common duct is connected to one of the housings or the connecting structure on a side of the first end opposite to the ventilator.

[0038] With the above configuration, when the air is discharged, the interior space of the housing, the connection structure, and most of the common pipe are kept under pressure, thereby preventing the air containing the refrigerant from leaking to the surrounding area.

[0039] According to another preferred variant of the safety system having a second end portion of the common pipe as described above, the second end portion of the common pipe is open to an outdoor space.

[0040] With the above configuration, the air containing the refrigerant can be discharged to the outdoor space, thereby further improving the safety of the heat pump system.

[0041] According to another preferred variation of any of the safety systems having a common pipe and a ventilator as described above, the safety system further includes: a first controller configured to control the ventilator to start operating when a refrigerant leak occurs in any of the valve units.

[0042] With the above configuration, when refrigerant leakage occurs, the air containing the refrigerant can be discharged in a safer manner.

[0043] According to another preferred variation of any of the safety systems having the first controller as described above, each refrigerant leak detector is configured to output detection result information, and the first controller is configured to receive the detection result information output from any of the refrigerant leak detectors and identify in which valve unit the refrigerant leak has occurred based on the received detection result.

[0044] With the above configuration, it is possible to identify a valve unit in which a refrigerant leak has occurred, and to control the ventilator based on the determination result. The detection result information indicates whether a refrigerant leak has occurred in the corresponding valve unit and may indicate the identity of the valve unit in which the refrigerant leak has occurred (hereinafter referred to as a "refrigerant leakage valve unit").

[0045] According to another preferred variant of any of the safety systems described above, the connection structure comprises a plurality of individual conduits respectively connected to the second opening of the housing and also commonly connected to a common conduit.

[0046] With the above configuration, the internal spaces of the housings are connected in parallel. In other words, each internal space is connected to the discharge structure without being interrupted by any other housing. Therefore, the static pressure capacity required by the ventilator can be reduced.

[0047] According to another preferred variation of any of the safety systems with separate pipes as described above, each valve unit further has a damper, which is configured to prevent air from passing through the first opening when the damper is closed and to allow air to pass through the first opening when the damper is open, and the first controller is configured to control the damper so that when the ventilator is operated due to the occurrence of refrigerant leakage, the damper of the valve unit in which the refrigerant leakage occurs is opened, and the damper of the valve unit in which the refrigerant leakage does not occur is closed.

[0048] Preferably, all dampers are closed during normal operation of the heat pump system to quickly detect refrigerant leaks and prevent leaked refrigerant from spreading to the surrounding area. At the same time, if the dampers are closed, the first opening cannot be used as an air inlet for external air or an exhaust outlet for internal air, and even if the ventilator is operating, it is difficult to replace the air in the internal space of the housing. In this regard, the above-mentioned configuration opens the dampers of the valve unit with refrigerant leakage to effectively discharge air while achieving rapid detection of refrigerant leaks. In addition, one or more other dampers remain closed, thereby limiting the valve units affected by air discharge to those with refrigerant leakage. Generally, it is rare for refrigerant leaks to occur simultaneously in different valve units. Therefore, the air volume capacity required for the ventilator can be reduced. Each damper can be directly attached to the first opening, or arranged away from the first opening and connected to the first opening via a pipe.

[0049] According to another preferred variation of any of the safety systems with separate pipes and dampers as described above, the first controller includes a plurality of unit controllers respectively configured in the valve units and a central controller configured to communicate with the unit controllers, each refrigerant leakage detector is configured to send detection result information to the central controller via the corresponding unit controller, and the above-mentioned central controller is configured to determine whether refrigerant leakage has occurred in any of the valve units based on the detection result information received from the above-mentioned valve units, and when refrigerant leakage has occurred in any of the valve units, a damper opening command is sent to the damper of the valve unit where the refrigerant leakage has occurred via the corresponding unit controller, and the ventilator is controlled to start operation.

[0050] This configuration allows for the identification of refrigerant leaking valve units, and based on the resulting information, centralized control of the ventilator and damper can be performed more safely. The detection result information indicates whether a refrigerant leak has occurred in the valve unit and can also indicate the identification of the leaking valve unit. The damper opening command instructs the damper to open and can also indicate the identity of the valve unit in which the damper should be opened.

[0051] According to another preferred embodiment of any one of the safety systems described above, the connecting structure includes at least one connecting pipe, which connects the first opening of the first valve unit and the second opening of the second valve unit, wherein the first valve unit and the second valve unit are two of the valve units, and the discharge structure is connected to the second opening of the first valve unit.

[0052] Through the above construction, the interior space of the housing is connected in series to the discharge structure. In other words, at least one interior space is connected to the discharge structure via one or more other housings. This reduces the total length of the piping connecting the housing to the discharge structure, thereby reducing the installation cost of the system. The shared piping and the ventilator can be integrated into a single component. If a housing has a portion exposed to the outdoor space, this single component can be configured in that portion. In addition, since the valve units are connected in series, the space required to arrange the valve units and the width of the connection structure can be minimized.

[0053] According to another preferred embodiment of any one of the safety systems having the connecting pipe as described above, the first valve unit and the second valve unit are arranged such that a first lateral surface of the first valve unit and a second lateral surface of the second valve unit face each other.

[0054] The above-mentioned structure makes it easy to connect the first opening of the first valve unit and the second opening of the second transverse surface. As a result, the connecting structure connecting the first opening and the second opening can be arranged in the space between the first valve unit and the second valve unit. Therefore, the width of the arrangement space of the valve units and the connecting structure can be reduced. Preferably, the first transverse surface and the second transverse surface are roughly parallel. In this case, it is also preferred that the centers and / or edges of the first opening and the second opening in the same direction are in roughly the same position in a plane parallel to the first transverse surface and the second transverse surface. Therefore, there is no need to wrap the connecting structure around, and the first valve unit and the second valve unit can be arranged closer.

[0055] According to another preferred embodiment of any one of the safety systems having a common pipe, a connecting pipe and a ventilator as described above, the safety system further includes: a baffle, which is configured to prevent air from passing through the terminal first opening when the baffle is closed, and to allow air to pass through the terminal first opening when the baffle is open, and the terminal first opening is an opening of one of the valve units connected in series with the ventilator by at least one connecting pipe and is not connected to the connecting pipe; and a second controller, which is configured to control the opening of the baffle when the ventilator is operating due to a refrigerant leakage in any valve unit connected in series.

[0056] Preferably, the damper is closed during normal operation of the heat pump system to quickly detect refrigerant leaks and prevent the leaked refrigerant from spreading to the surrounding area. At the same time, if the damper is closed, the first terminal opening cannot be used as an air inlet for external air or an exhaust outlet for internal air, and even if the ventilator is operating, it is difficult to replace the air in the internal space of the housing. In this regard, the above-mentioned configuration opens the damper when a refrigerant leak occurs, effectively exhausting air from all valve units connected in series, while simultaneously enabling rapid detection of refrigerant leaks. The damper can be directly attached to the first opening, or arranged remotely from the first opening and connected to the first opening via a pipe, etc.

[0057] According to another preferred embodiment of any one of the safety systems having a common pipe, a connecting pipe, a ventilator and a controller as described above, the above-mentioned safety system further includes a baffle unit, which is configured to be attachable to the first opening of any valve unit, and when the baffle unit is attached to the first opening, blocks air from passing through the first opening when the baffle is closed, and allows air to pass through the first opening when the baffle is open.

[0058] With the above configuration, the baffle can be attached to any valve unit, depending on the order in which the valve units are connected by the connecting structure. In other words, all valve units can be produced with the same configuration, thereby reducing the production cost of the safety system. The baffle unit can include a housing having two opposing openings, and the baffle can be attached to one of the openings. The housing can be provided with a fixing structure, such as a screw fastener, for removably securing the housing of the baffle unit relative to the first surface of the housing, such that the housing opening is aligned with the first opening.

[0059] The second aspect of the present invention provides an air-conditioning system, which includes: any one of the safety systems described above; a heat source side unit, the heat source side unit having a compressor and a heat source side heat exchanger; a plurality of utilization side units, the plurality of utilization side units respectively having a utilization side heat exchanger; a liquid refrigerant pipeline, the liquid refrigerant pipeline extending between the heat source side unit and the utilization side unit and having a liquid refrigerant piping portion; a gas refrigerant pipeline, the gas refrigerant pipeline extending between the heat source side unit and the utilization side unit and having a gas refrigerant piping portion; and an expansion mechanism, the expansion mechanism being arranged in the liquid refrigerant pipeline.

[0060] With the above configuration, it is possible to obtain an air conditioning system that has high safety against refrigerant leakage at the valve.

[0061] The third aspect of the present invention provides a method for constructing an air-conditioning system, the air-conditioning system comprising: any one of the safety systems described above; a heat source side unit, the heat source side unit having a compressor and a heat source side heat exchanger; a plurality of utilization side units, the plurality of utilization side units respectively having a utilization side heat exchanger; a liquid refrigerant pipeline, the liquid refrigerant pipeline extending between the heat source side unit and the utilization side unit and having a liquid refrigerant piping portion; a gas refrigerant pipeline, the gas refrigerant pipeline extending between the heat source side unit and the utilization side unit and having a gas refrigerant piping portion; and an expansion mechanism, the expansion mechanism being arranged in the liquid refrigerant pipeline, the method comprising: installing the valve unit, the connecting structure, the discharge structure and the utilization side unit on the same floor of the building; and connecting the valve unit through the connecting structure, and connecting the discharge structure to one of the shells or the connecting structure.

[0062] Through the above method, an air-conditioning system can be obtained, which includes: any one of the safety systems described above; a heat source side unit, the heat source side unit having a compressor and a heat source side heat exchanger; a plurality of utilization side units, the plurality of utilization side units respectively having a utilization side heat exchanger; a liquid refrigerant pipeline, the liquid refrigerant pipeline extending between the heat source side unit and the utilization side unit and having a liquid refrigerant piping portion; a gas refrigerant pipeline, the gas refrigerant pipeline extending between the heat source side unit and the utilization side unit and having a gas refrigerant piping portion; and an expansion mechanism, the expansion mechanism being arranged in the liquid refrigerant pipeline, wherein the valve unit, the connecting structure and the utilization side units are installed on the same floor of a building.

[0063] As described above, valve units that enhance safety against refrigerant leakage in an air-conditioning system can be arranged closely side by side. Consequently, the length of connection structures, such as connecting pipes, can be shortened. Furthermore, the valve units can be arranged in confined spaces within a building, such as spaces on the same floor as the target space to be air-conditioned by the utilization-side units of the air-conditioning system. When the valve units are arranged close to the utilization-side units, the total length of the refrigerant piping between each valve unit and the utilization-side unit connected to it can be reduced. Furthermore, when the valve units and utilization-side units are arranged approximately on the same horizontal plane, the layout of the refrigerant piping between the valve units and the utilization-side units can be simplified. For example, the number of exhaust sections in the refrigerant piping can be reduced. Furthermore, since the exhaust structures are also arranged approximately on the same horizontal plane, the total length of piping used in the safety system can be shortened. Consequently, an air-conditioning system with enhanced safety against refrigerant leakage can be achieved at a low cost.

[0064] According to a preferred embodiment of the method for constructing an air-conditioning system as described above, the installation includes: installing the utilization side unit in a first space to be air-conditioned by the utilization side unit; and installing the valve unit, connecting structure and discharge structure of the safety system in a second space adjacent to the first space.

[0065] In the air conditioning system achieved by the above method, the utilization-side unit is installed in a first space to be air-conditioned by the utilization-side unit, and the connecting structure for the valve unit and the safety system is installed in a second space adjacent to the first space. The valve unit can be placed in a limited space within a building, such as a space adjacent to the target space. This further reduces the total length and number of exhaust sections in the refrigerant piping. Furthermore, since the exhaust structure is also placed in the same space as the valve unit, the total length of piping used in the safety system can be shortened. Consequently, the installation cost of the air conditioning system can be further reduced.

[0066] A fourth aspect of the present invention provides a method for constructing an air-conditioning system, the air-conditioning system comprising: any one of the safety systems described above; a heat source side unit, the heat source side unit having a compressor and a heat source side heat exchanger; a plurality of utilization side units, the plurality of utilization side units respectively having a utilization side heat exchanger; a liquid refrigerant pipeline, the liquid refrigerant pipeline extending between the heat source side unit and the utilization side unit and having a liquid refrigerant piping portion; a gas refrigerant pipeline, the gas refrigerant pipeline extending between the heat source side unit and the utilization side unit and having a gas refrigerant piping portion; and an expansion mechanism, the expansion mechanism being arranged in the liquid refrigerant pipeline, the method comprising: installing valve units on different floors of a building; arranging a connecting structure to connect the valve units on different floors; and connecting a discharge structure to the connecting structure.

[0067] Through the above method, an air-conditioning system can be obtained, which includes: any one of the safety systems described above; a heat source side unit, the heat source side unit having a compressor and a heat source side heat exchanger; a plurality of utilization side units, the plurality of utilization side units respectively having a utilization side heat exchanger; a liquid refrigerant pipeline, the liquid refrigerant pipeline extending between the heat source side unit and the utilization side unit and having a liquid refrigerant piping portion; a gas refrigerant pipeline, the gas refrigerant pipeline extending between the heat source side unit and the utilization side unit and having a gas refrigerant piping portion; and an expansion mechanism, the expansion mechanism being arranged in the liquid refrigerant pipeline, wherein the valve unit is installed in different floors of a building, the connecting structure connects the valve units on different floors, and the discharge structure is connected to the connecting structure.

[0068] As described above, the valve unit that improves refrigerant leakage safety in an air conditioning system can prevent the connection structure from protruding upward or downward from the housing. This reduces the height range of the valve unit's layout space. Furthermore, different floors can share a common discharge structure. Consequently, an air conditioning system with improved refrigerant leakage safety can be achieved at a low cost.

[0069] A reference example of a safety system includes: a plurality of valve units for a heat pump system, each of the plurality of valve units having: at least one liquid refrigerant piping portion; at least one gas refrigerant piping portion; at least one liquid control valve arranged in the liquid refrigerant piping portion; at least one gas control valve arranged in the gas refrigerant piping portion; a shell, the shell accommodating at least the liquid control valve and the gas control valve and formed with at least two openings; and a refrigerant leak detector, the refrigerant leak detector being configured to detect the occurrence of refrigerant leakage in the internal space of the shell; a connecting structure, the connecting structure being connected to the internal space of the shell via the opening; and a discharge structure, the discharge structure being connected to one of the shells or the connecting structure and being configured to discharge air from the internal space of the shell where the refrigerant leakage has occurred.

[0070] With this configuration, even if refrigerant leaks from the valves in any valve unit, the housing housing the valves prevents or suppresses the leaked refrigerant from spreading to the surrounding area. Furthermore, by discharging air from the interior space to the space outside the housing, the concentration of leaked refrigerant in the interior space of the housing can be reduced. Furthermore, during normal operation of the heat pump system, each housing can be substantially closed, and refrigerant leak detection can be performed based on the refrigerant concentration in this substantially closed space.

[0071] Therefore, the occurrence of refrigerant leakage in the valve unit can be quickly detected, and the operation of the discharge mechanism can be initiated at an early stage. This can more safely prevent the concentration of leaked refrigerant from increasing both in the housing where the refrigerant leak has occurred and in the surrounding area of ​​the housing. This allows monitoring and maintenance personnel to safely monitor, maintain, or repair the valve. This improves the safety of the heat pump system with respect to refrigerant leakage.

[0072] Furthermore, the exhaust structure is commonly used for a plurality of valve units. Therefore, even when valves are arranged at separate locations, the safety of the heat pump system can be improved while preventing an increase in the installation cost of the system.

[0073] Here, the external space to which air is discharged by the discharge structure is preferably not an external space directly surrounding any housing, or an indoor space where people or animals may enter or live. The external space is preferably an outdoor space. The heat pump system to which multiple valve units belong may include multiple separate heat pump circuits. In other words, the pipelines of the valve units do not need to be connected to each other. In each valve unit, the piping part, the valve and the housing can be manufactured together. Therefore, it is easier to design the valve unit to enhance its performance, such as the airtightness of the housing. It also becomes easier to optimize the size of the valve unit and the position of the maintenance door of the housing. Therefore, not only safety can be improved, but also the maintainability and functionality of the valve unit can be improved. Alternatively, the housing can be a modified housing to be assembled around the existing valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] Figure 1 is a schematic configuration diagram of an air conditioning system having a valve unit according to a first embodiment of the present invention.

[0075] Figure 2 yes Figure 1 The schematic structure diagram of the valve unit is shown.

[0076] Figure 3 is a schematic configuration diagram of a safety system according to a first embodiment.

[0077] Figure 4 It means by Figure 3 A flow chart of the operations performed by the unit controller is shown.

[0078] Figure 5 It means by Figure 3 A flowchart of the operations performed by the central controller is shown.

[0079] Figure 6 is a schematic configuration diagram of a safety system according to a second embodiment of the present invention.

[0080] Figure 7 It means by Figure 6 A flowchart of the operations performed by the central controller is shown.

[0081] Figure 8 is a schematic configuration diagram of a safety system according to a third embodiment of the present invention.

[0082] Figure 9 is Figure 9 The grouping table used by the central controller is shown.

[0083] Figure 10 is a schematic configuration diagram of a safety system according to a fourth embodiment of the present invention.

[0084] Figure 11is a grouping table used by the central controller according to the fourth embodiment of the present invention.

[0085] Figure 12 is a schematic configuration diagram of a valve unit according to a modification of the present embodiment.

[0086] Figure 13 Yes Figure 2 A schematic configuration diagram of a first arrangement mode of the first opening and the second opening is shown.

[0087] Figure 14 2 is a schematic configuration diagram showing a second arrangement pattern of the first openings and the second openings.

[0088] Figure 15 is a schematic configuration diagram showing a third arrangement pattern of the first openings and the second openings.

[0089] Figure 16 2 is a schematic configuration diagram showing a fourth arrangement pattern of the first openings and the second openings.

[0090] Figure 17 is a schematic configuration diagram of an air conditioning system having a valve unit according to a fifth embodiment of the present invention.

[0091] Figure 18 is a schematic configuration diagram of a safety system according to a fifth embodiment.

[0092] Figure 19 It is a perspective view of a valve unit according to a fifth embodiment.

[0093] Figure 20 is a perspective view of a valve unit according to a fifth embodiment, with a top plate removed.

[0094] Figure 21 is a top perspective view of a valve unit according to a fifth embodiment, with the top plate removed.

[0095] Figure 22 yes Figure 21 A front plan view of the baffle unit is shown.

[0096] Figure 23 It is a rear perspective view of the baffle unit.

[0097] Figure 24 It is a front perspective view of the baffle unit.

[0098] Figure 25 This is a perspective view of the drain pan of the valve unit.

[0099] Figure 26 Schematic diagram showing the arrangement of adjacent valve units.

[0100] Figure 27 is a schematic configuration diagram of an air conditioning system according to a first modification of the fifth embodiment.

[0101] Figure 28 is a schematic configuration diagram of an air conditioning system according to a second modification of the fifth embodiment. DETAILED DESCRIPTION

[0102] Preferred embodiments of an air conditioning system and a safety system according to the present invention will be described with reference to the accompanying drawings.

[0103] (First embodiment)

[0104] (Structure of air conditioning system)

[0105] The air-conditioning system according to the first embodiment of the present embodiment is a multi-connected air-conditioning system having a so-called three-pipe structure, and includes a heat-source-side unit and a plurality of usage-side units.

[0106] Figure 1 is a schematic configuration diagram of an air conditioning system according to a first embodiment.

[0107] like Figure 1 As shown, the air conditioning system 100 includes a heat source side unit 110 and a plurality of utilization side units 120, and the plurality of utilization side units 120 are connected to the heat source side unit 120 via refrigerant piping. The utilization side units 120 are divided into a plurality of unit families 121, such as a first unit family 121_1 to a third unit family 121_3. However, the number of unit families 121 is not limited to three, and may be two, four, or more. The number of utilization side units 120 belonging to each unit family 121 is also not limited.

[0108] The heat source side unit 110 includes a compressor, a condenser, and an evaporator (heat source side heat exchanger) (not shown). A liquid refrigerant pipe 131, a low-pressure gas refrigerant pipe 132, and a high-pressure gas refrigerant pipe 133 extend from the heat source side unit 110. The liquid refrigerant pipe 131 communicates with each of the condenser and the evaporator. The low-pressure gas refrigerant pipe 132 communicates with the suction port of the compressor. The high-pressure gas refrigerant pipe 133 communicates with the discharge port of the compressor.

[0109] The liquid refrigerant pipe 131 branches toward the first through third unit clusters 121_1 through 121_3 into a plurality of heat source-side liquid pipes 141. The low-pressure gas refrigerant pipe 132 branches toward the first through third unit clusters 121_1 through 121_3 into a plurality of heat source-side low-pressure gas pipes 142. The high-pressure gas refrigerant pipe 133 branches toward the first through third unit clusters 121_1 through 121_3 into a plurality of heat source-side high-pressure gas pipes 143.

[0110] For each unit cluster 121, the heat source-side liquid pipe 141 branches into a plurality of utilization-side liquid refrigerant pipes 151 toward the utilization-side unit 120 belonging to the unit cluster 121. For each unit cluster 121, the heat source-side low-pressure gas pipe 142 branches into a plurality of utilization-side gas refrigerant pipes 152 toward the utilization-side unit 120 belonging to the unit cluster 121. For each unit cluster 121, the heat source-side high-pressure gas pipe 143 branches toward the utilization-side unit 120 belonging to the unit cluster 121, and each branch pipe merges with a corresponding utilization-side gas refrigerant pipe 152.

[0111] Each of the utilization-side units 120 includes a utilization-side heat exchanger (not shown). The utilization-side heat exchanger communicates with the corresponding utilization-side liquid refrigerant pipe 151 and utilization-side gas refrigerant pipe 152 for each utilization-side unit 120.

[0112] In other words, in the air conditioning system 100, the liquid refrigerant line and the gas refrigerant line extend between the heat source-side unit 110 and the utilization-side unit 120, branching toward the unit clusters 121 and then toward the utilization-side unit 110 in each unit cluster 121, thereby forming a heat pump circuit. Thus, heat / cold heat can be supplied from the heat source-side unit 110 to each utilization-side unit 120 via circulating refrigerant.

[0113] The air conditioning system 100 also includes first through third valve units 200_1, 200_3 for the first through third unit families 121_1, 120_3, respectively. For each unit family 121, a branch point toward the corresponding utilization-side unit 120 is configured in the corresponding valve unit 200. The first through third valve units 200_1, 200_3 have substantially the same structure. Therefore, in the following description, the term "valve unit 200" refers to any one of the first through third valve units 200_1, 200_3. Details of the valve units 200 will be described below.

[0114] The air conditioning system 100 includes a safety system for improving the safety of the air conditioning system 100 (heat pump system) in terms of refrigerant leakage. The first valve unit 200_1 to the third valve unit 200_3 are part of the safety system. The details of the safety system will be described below.

[0115] (Structure of valve unit)

[0116] Figure 2 2 is a schematic structural diagram of the valve unit 200 .

[0117] like Figure 2As shown, the valve unit 200 includes a multi-branch selector 300, a housing 400, a baffle 440, a refrigerant leak detector 500, and a unit controller 600. The housing 400 accommodates the multi-branch selector 300. The refrigerant leak detector 500 and the unit controller 600 are disposed in the interior space 401 of the housing 400. However, the unit controller 600 may be disposed on the housing 400 or outside the housing 400.

[0118] The multi-branch selector 300 includes a heat source-side liquid piping section 310, multiple utilization-side liquid piping sections 311, a low-pressure gas piping section 320, multiple low-pressure gas sub-piping sections 321, multiple utilization-side gas piping sections 330, a high-pressure gas piping section 340, multiple high-pressure gas sub-piping sections 341, multiple bypass pipes 351, and multiple refrigerant heat exchangers 352. The multi-branch selector 300 also includes multiple low-pressure gas control valves 361, multiple high-pressure gas control valves 362, multiple expansion mechanisms 363, multiple liquid shutoff valves 364, and multiple gas shutoff valves 365.

[0119] The number of the utilization-side liquid piping section 311, the low-pressure gas sub-piping section 321, the utilization-side gas piping section 330, the high-pressure gas sub-piping section 341, the bypass piping 351, the refrigerant heat exchanger 352, the low-pressure gas control valve 361, the high-pressure gas control valve 362, the expansion mechanism 363, the liquid shutoff valve 364, and the gas shutoff valve 365 may be the same as the number of the utilization-side units 120 belonging to the corresponding unit family 121 (see FIG. Figure 1 ).

[0120] The heat source side liquid piping section 310, the low pressure gas piping section 320 and the high pressure gas piping section 340 are parts of the corresponding heat source side liquid piping 141, the heat source side low pressure gas piping 142 and the heat source side high pressure gas piping 143 (see FIG. Figure 1 The utilization side liquid piping portion 311 is a portion of the corresponding utilization side liquid refrigerant piping 151 (see Figure 1 The low-pressure gas sub-pipe 321, the high-pressure gas sub-pipe 341 and the utilization-side gas piping portion 330 are part of the corresponding utilization-side gas refrigerant piping 152 (see FIG. Figure 1 One of the usage-side liquid piping sections 311 and one of the usage-side gas piping sections 330 communicate with the same usage-side heat exchanger in one of the usage-side units 120 .

[0121] In the multi-branch selector 300, the heat source-side liquid piping section 310 branches into the usage-side liquid piping section 311, the low-pressure gas piping section 320 branches into the low-pressure gas sub-pipes 321, and the high-pressure gas piping section 340 branches into the high-pressure gas sub-pipes 341. One of the low-pressure gas sub-pipes 321 and one of the high-pressure gas sub-pipes 341 are connected to one of the usage-side gas piping sections 330. Alternatively, each low-pressure gas piping section 320 branches into the usage-side gas piping section 330 via the low-pressure gas sub-pipe 321, and each high-pressure gas piping section 340 branches into the usage-side gas piping section 330 via the high-pressure gas sub-pipe 341. Alternatively, each usage-side gas piping section 330 branches into the low-pressure gas piping section 320 and the high-pressure gas piping section 340 via the low-pressure gas sub-pipe 321 and the high-pressure gas sub-pipe 341.

[0122] The bypass pipes 351 are connected to the usage-side liquid pipe section 311 and the low-pressure gas pipe section 320 . In other words, one of the bypass pipes 351 branches from the usage-side liquid pipe section 311 and merges with the low-pressure gas pipe section 320 .

[0123] The expansion mechanisms 363 are respectively disposed in the bypass pipes 351. Each expansion mechanism 363 is configured to decompress and expand the refrigerant flowing out of the corresponding usage-side liquid piping portion 311 in the bypass pipe 351. Each expansion mechanism 363 may be an electric expansion valve.

[0124] The refrigerant heat exchangers 352 are each provided in the bypass piping 351. Each refrigerant heat exchanger 352 is configured to perform heat exchange between the refrigerant flowing through one of the utilization-side liquid piping sections 311 and the refrigerant that has been decompressed and expanded by the corresponding expansion mechanism 363 and is flowing through the corresponding bypass piping 351. In other words, each refrigerant heat exchanger 352 is combined with the corresponding utilization-side liquid piping section 311, the bypass piping 351, and the expansion mechanism 363 to form a subcooling system. Each refrigerant heat exchanger 352 can have two flow channels, which respectively form a portion of the utilization-side liquid piping section 311 and a portion of the bypass piping 351, and heat conduction occurs between them.

[0125] Low-pressure gas control valves 361 are disposed in the low-pressure gas sub-piping 321. Each low-pressure gas control valve 361 is configured to switch between an open state and a closed state, that is, to determine whether to allow refrigerant to flow between the low-pressure gas piping section 320 and the corresponding user-side gas piping section 330. The state of each low-pressure gas control valve 361 is controlled by the unit controller 600 according to the desired operating mode of the corresponding user-side unit 120. Each low-pressure gas control valve 361 may be an electric valve.

[0126] High-pressure gas control valves 362 are disposed in each of the high-pressure gas sub-piping sections 341. Each high-pressure gas control valve 362 is configured to switch between an open state and a closed state, that is, to determine whether to allow refrigerant to flow between the high-pressure gas piping section 340 and the corresponding utilization-side gas piping section 330. The state of each high-pressure gas control valve 362 is controlled by the unit controller 600 according to the desired operating mode of the corresponding utilization-side unit 120. Each high-pressure gas control valve 362 may be an electric valve and preferably has a micro-channel formed therein.

[0127] Liquid shutoff valves 364 are each disposed in the user-side liquid piping section 311. Gas shutoff valves 365 are each disposed in the user-side gas piping section 330. The liquid shutoff valves 364 and gas shutoff valves 365 disposed in the user-side liquid piping section 311 and the user-side gas piping section 330, which communicate with the same user-side heat exchanger, define a user-side piping section that extends between the two and includes at least the user-side heat exchanger. Each of the liquid shutoff valves 364 and gas shutoff valves 365 can be an electrically operated valve.

[0128] The housing 400 may have a generally box shape and be large enough to accommodate at least the multi-branch selector 300 and the refrigerant leak detector 500 therein. The housing 400 may be made of a metal plate, a carbon fiber plate, a flame-retardant resin plate, etc. The housing 400 is formed with a plurality of piping holes 410 .

[0129] The multiple piping holes 410 are configured to allow the piping extending from the multi-branch selector 300 (hereinafter referred to as "extension piping") to pass through. In other words, the multiple piping holes 410 are formed at locations corresponding to the locations of the extension piping, and the diameter of each piping hole is larger than the diameter of the corresponding extension piping. Here, these extension piping include the heat source-side liquid piping section 310, the low-pressure gas piping section 320, the high-pressure gas piping section 340, the utilization-side liquid piping section 311, and the utilization-side gas piping section 330.

[0130] Each extension pipe may have a pipe connecting component 370 for connecting to the corresponding external pipe, i.e., the corresponding heat source side liquid pipe 141, heat source side low-pressure gas pipe 142, heat source side high-pressure gas pipe 143, utilization side liquid refrigerant pipe 151 or other portion of the utilization side gas refrigerant pipe 152 (see FIG. Figure 1 ). Preferably, the pipe connection component 370 is arranged outside the housing 400.

[0131] The housing 400 is further formed with a first opening 420 and a second opening 430. Preferably, the first opening 420 and the second opening 430 are arranged on opposite sides of the housing 400 relative to the central portion of the interior space 401.

[0132] Especially when using a refrigerant heavier than atmospheric air, such as R32, it is preferable that both the first opening 420 and the second opening 430 be arranged closer to the top of the housing 400. This can prevent leaked refrigerant from spreading to the surrounding area of ​​the housing 400 in a safer manner, thereby quickly detecting the occurrence of a refrigerant leak in the housing 400. However, it is also possible to arrange the first opening 420 closer to the bottom of the housing 400 while arranging the second opening 430 closer to the top of the housing 400, thereby effectively draining the refrigerant accumulated at the bottom. In any case, the arrangement of the first opening 420 and the second opening 430 is not limited to the above.

[0133] The baffle 440 is directly attached to the first opening 420. Alternatively, the baffle 440 may be arranged away from the first opening 420 inside or outside the housing 400 and connected to the first opening 420 via a duct. The baffle 440 is configured to block air from passing through the first opening 420 when the baffle 440 is closed, and to allow air to pass through the first opening 420 when the baffle 440 is open. More specifically, the baffle 440 includes a flap 441 and a motor (not shown) for moving the flap to switch between a closed position, in which the flap closes the first opening 420, and an open position, in which the flap does not close the first opening 420. As described later, the motor is controlled by the unit controller 600. As Figure 2 As shown, the damper 440 may be a normally closed damper that is closed during normal operation of the air conditioning system 100 , ie, when no refrigerant leakage occurs.

[0134] The second opening 430 is configured to allow air to pass between the internal space 401 and the external space outside the housing 400. As described later, a duct is connected to the second opening 420 outside the housing 400. The second opening 440 may be provided with a baffle that is controlled to move synchronously with the baffle 440 of the first opening 420.

[0135] It is also preferred that the housing 400 has a maintenance door configured to allow monitoring / maintenance personnel to check the status of the multi-branch selector 300, the refrigerant leak detector 500, and the unit controller 600 and / or repair them as needed through the open door.

[0136] The insulator 450 is applied to the shell 400 so that the internal space 401 of the shell 400 is roughly isolated from the external space outside the shell 400 at the portion other than the first opening 420 and the second opening 430. The insulator 450 may include a tubular insulator that is respectively assembled into the gap between the outer surface of the extension piping of the multi-branch selector 300 and the inner edge of the piping hole 410. Each insulator 450 may be a foam tube, foam wrapping, foam filler, caulking material, tape, etc. A foam tube having a cutting line extending in the axial direction thereof is easy to fit into the gap. The thickness of the foam tube is preferably equal to or slightly larger than the gap between the outer surface of the corresponding extension piping and the inner surface of the corresponding piping hole 410. Before assembling the shell 400, the insulator 450 may be attached to the extension piping.

[0137] The insulator 450 can also be applied to other gaps in the shell 400, such as the gap between the flap 441 in the closed position and the outer shell of the baffle 440, the gap between the outer shell of the baffle 440 and the edge of the first opening 420, and the gap between the maintenance door of the shell 400 and the door frame.

[0138] The refrigerant leak detector 500 is configured to detect the occurrence of refrigerant leakage in the internal space 401 of the corresponding housing 400. The refrigerant leak detector 500 is configured to detect the refrigerant concentration in the air surrounding the refrigerant leak detector 500 and continuously or periodically output a detector signal indicating a detection value Vs corresponding to the detected concentration to the unit controller 600. The refrigerant leak detector 500 may be a semiconductor gas sensor that reacts to the refrigerant used in the air conditioning system 100. In the case of a refrigerant heavier than atmospheric air, such as R32 refrigerant, the refrigerant leak detector 500 is preferably disposed in the internal space 401 at or near the inner bottom surface of the housing 400.

[0139] As will be described later, the unit controller 600 determines whether a refrigerant leak has occurred in the corresponding housing 400 (hereinafter referred to as "refrigerant leak") based on the detection value Vs of the refrigerant leak detector 500. Therefore, the detection value Vs is detection result information indicating whether a refrigerant leak has occurred in the corresponding valve unit 200.

[0140] The unit controller 600 is configured to control the operation of the valve unit 200 via a wired communication path and / or a wireless communication path (partially not shown) between the unit controller 600 and the mechanical equipment in the valve unit 200. In particular, the unit controller 600 is configured to receive a detector signal from the refrigerant leak detector 500 and determine whether a refrigerant leak has occurred based on the detector signal. When it is determined that a refrigerant leak has occurred, the unit controller 600 is configured to output a leakage signal to the central controller described later. The leakage signal indicates the unit ID (identification) of the valve unit 200 equipped with the leakage detector 500 and indicates that a refrigerant leakage has occurred in the valve unit with the unit ID indicated by the leakage signal. In other words, the leakage signal is detection result information indicating whether a refrigerant leakage has occurred in the corresponding valve unit 200.

[0141] The unit controller 600 is further configured to receive a damper opening command described later from the central controller. When the unit controller 600 receives the damper opening command indicating the unit ID of the valve unit 200 to which the unit controller 600 belongs, the damper 440 is controlled to open.

[0142] The unit controller 600 may also be configured to switch the open / close state of each of the low-pressure gas control valve 361 and the high-pressure gas control valve 362, and / or control the opening degree of each expansion mechanism 363 (see FIG. Figure 2 ), so that the desired cooling / heating operation can be performed in each utilization side unit 120 (see Figure 1 ).

[0143] For example, for a utilization-side unit 120 that should perform a cooling operation, the corresponding low-pressure gas control valve 361 is opened, and the corresponding high-pressure gas control valve 362 and expansion mechanism 363 are closed. For a utilization-side unit 120 that should perform a heating operation, the corresponding high-pressure gas control valve 362 and expansion mechanism 363 are opened, and the corresponding low-pressure gas control valve 361 is closed. The unit controller 600 can perform such an operation based on a signal indicating the desired operating mode of the corresponding utilization-side unit 120. Such a signal can be sent from the heat source-side unit 110, the corresponding utilization-side unit 120, and / or an information output device (not shown) used by monitoring / maintenance personnel.

[0144] The unit controller 600 may be divided into a first controller having a function of controlling the multi-branch selector 300 and a second controller having a function of determining refrigerant leakage and controlling the damper 440. In this case, it is preferable that the first controller and the second controller have different power supplies.

[0145] The unit controller 600 includes an arithmetic circuit, such as a CPU (Central Processing Unit), a working memory used by the CPU, such as RAM (Random Access Memory), and a recording medium, such as ROM (Read Only Memory), which stores control programs and information used by the CPU, although these are not shown. The unit controller 600 is configured so that the CPU, executing the control program, performs information processing and signal processing to control the operation of the valve unit 200.

[0146] The housing 400 , the first opening 420 , the second opening 430 , the baffle 440 , the insulator 450 , the refrigerant leak detector 500 , and the unit controller 600 are part of a safety system of the air conditioning system 100 .

[0147] (Safety System Structure)

[0148] Figure 3 is a schematic configuration diagram of a safety system according to a first embodiment.

[0149] like Figure 3 As shown, the safety system 700 of the air conditioning system 100 according to the first embodiment includes first to third valve units 200_1 to 200_3, first to third individual pipes 710_1 to 710_3, a common pipe 720, a ventilator 730, and a central controller 800. The first to third valve units 200_1 to 200_3 respectively have a first internal space 401_1 of the first housing 400_1 to a third internal space 401_3 of the third housing 400_3. Here, the first to third valve units 200_1 to 20_3 are omitted (see FIG. 1 ). Figure 2 )'s multi-branch selector 300.

[0150] The first through third individual conduits 710_1, 710_3 correspond to the first through third valve units 200_1, 200_3, respectively. The first through third individual conduits 710_1, 710_3 have substantially the same structure as the corresponding individual conduits 710. Therefore, in the following description, the term "individual conduit 710" refers to any of the first through third individual conduits 710_1, 710_3. An individual conduit 710 is connected at one end to the second opening 430 of the housing 400 of the corresponding valve unit 200. The individual conduit 710a is further connected to the common conduit 720 at the other end of the individual conduit 710b. In other words, the first through third individual conduits 710_1, 710_3 are collectively connected to the common conduit 720.

[0151] The ventilator 730 is disposed at or near one end of the common duct 720 (hereinafter referred to as the "second end") and is configured to draw air in the common duct 720 toward the second end. Preferably, the second end of the common duct 720 is open to the outdoor space. Figure 3 As shown, it is also preferred that the ventilator 730 is disposed at the second end. The operation of the ventilator 730 is controlled by the central controller 800. For example, when the ventilator 730 receives a ventilator start command from the central controller 800, the ventilator 730 begins to operate. The ventilator can be a fan. The ventilator 730 can be provided with a check valve configured to prevent air from passing through the ventilator 730 when the ventilator 730 is not in operation.

[0152] The common duct 720 is connected to the first through third individual ducts 710_1, 710_3 at the other end of the common duct 720 (hereinafter referred to as the "first end") relative to the ventilator 730. Thus, the entire structure of the first through third individual ducts 710_1, 710_3, and the common duct 720 forms a branched duct. Any of the branched portions of this structure can be considered the first end of the common duct 720. For example, the portion between the point where the duct branches toward the first valve unit 200_1 and the point where the duct branches toward the second valve unit 200_2 can be considered any one of a portion of the common duct 720, a portion of the second individual duct 710_2, and a portion of the third individual duct 710_3.

[0153] Thus, the first to third individual ducts 710_1 to 710_3 form a connection structure that connects the first to third inner spaces 401_1 to 401_3 via the first to third second openings 430_1 to 430_3, respectively. Regarding the first openings 420, the extension duct may be connected to all or part of each of the first openings 420 on the outside of the corresponding housing 400.

[0154] When any of the first to third baffles 440_1, 440_3 are opened, an air path AP is formed, extending from the external space outside the corresponding housing 400 to the ventilator 730. This air path AP passes through the first opening 420, the corresponding internal space 401, the second opening 430, and the individual ducts 710 and the shared duct 720 when the baffles 440 are open. If the ventilator 730 is operating in this state, with the baffles 440 open, the air in the internal space 401 of the housing 400 is discharged by the suction force of the ventilator 730. Meanwhile, with the baffles 440 closed, the air path AP is not formed. Therefore, even if the ventilator 730 is operating, the air in the internal space 401 of the housing 400 is not discharged by the suction force of the ventilator 730 when the baffles 440 are closed. Figure 3 A case where only the first shutter 440_1 is opened is described.

[0155] Therefore, the common duct 720 and the ventilator 730 form a discharge structure that is connected to the connection structure described above and is configured to discharge air from the internal space 401 of the housing 400 when the damper 440 is opened.

[0156] For example, the central controller 800 is configured in the heat source side unit 110 (see Figure 1 The central controller 800 may be a part of a system controller (not shown) for controlling the air conditioning operation of the air conditioning system 100 .

[0157] The central controller 800 is connected to the first to third unit controllers 600_1 to 600_3 and the ventilator 730 via a communication path 801. The communication path 801 can connect the first to third unit controllers 600_1 to 600_3 and the ventilator 730 in series to the central controller 800 through wired and / or wireless communication, as shown in FIG. Figure 3 shown.

[0158] When a refrigerant leak occurs in any of the first through third valve units 200_1 through 200_3, the central controller 800 is configured to control the ventilator 730 to start operating (turn on). Furthermore, the central controller 800 is configured to collaborate with the first through third unit controllers 600_1 through 600_3 to identify which of the first through third valve units 200_1 through 200_3 is leaking refrigerant and control the first through third dampers 440_1 through 440_3. More specifically, the central controller 800 is configured to control the first through third dampers 440_1 through 440_3 so that, when the ventilator 730 is operating due to a refrigerant leak, the damper 440 of the valve unit 200 experiencing the refrigerant leak opens, while the other dampers 440 close. Thus, the exhaust structure described above can exhaust air from the interior space 401 of the housing 400 in the event of a refrigerant leak.

[0159] Although not shown, central controller 800 includes a computing circuit, such as a CPU; a working memory, such as RAM, for use by the CPU; and a recording medium, such as ROM, for storing control programs and information used by the CPU. Central controller 800 is configured to perform information and signal processing by the CPU executing the control program to control at least the operation of the safety system of air conditioning system 100.

[0160] (Unit controller operation)

[0161] The unit controllers 600 are configured to detect the occurrence of refrigerant leakage in the corresponding housings 400. When refrigerant leakage occurs, the unit controllers 600 are further configured to notify the central controller 800 of the detection result and control the opening of the corresponding dampers 440, which are normally closed under the control of the central controller 800. More specifically, the unit controllers 600 are configured to perform the following operations.

[0162] Figure 4 is a flowchart representing operations performed by the unit controller 600.

[0163] In step S1010, the unit controller 600 obtains a detection value Vs from the detector signal output from the refrigerant leak detector 500. The unit controller 600 may passively receive the detector signal continuously or periodically output from the refrigerant leak detector 500, or actively request the refrigerant leak detector 600 to periodically output the detector signal. The obtained detection value Vs substantially reflects the change in the refrigerant concentration in the housing 400.

[0164] In step S1020, the unit controller 600 compares the acquired detection value Vs with the detection value threshold Vth and determines whether the detection value Vs is less than the detection value threshold Vs. The unit controller 600 may obtain a moving average value of the detection value Vs within a specific time period and use the moving average value as the detection value Vs for comparison with the detection value threshold Vth.

[0165] The detection value threshold Vth is pre-stored in the unit controller 600. This detection value threshold Vth may be determined experimentally or the like to minimize false detection and oversight of refrigerant leaks. Preferably, the detection value threshold Vth is set to a value less than 25% of the lower flammability limit (LFL) of the refrigerant being used.

[0166] If the detection value Vs is equal to or greater than the detection value threshold Vth (S1020: No), the unit controller 600 proceeds to step S1030, described later. If the detection value Vs is less than the detection value threshold Vth (S1020: Yes), the unit controller 600 proceeds to step S1040, described later. It can be said that the refrigerant leak detector 500 transmits the detection result information to the central controller 800 via the corresponding unit controller 600 through steps S1010 to S1030.

[0167] In step S1030, the unit controller 600 sends a leakage signal to the central controller 800. The leakage signal indicates the unit ID of the valve unit 200 to which the unit controller 600 belongs (hereinafter referred to as the "self-unit ID"). The unit controller 600 can send the leakage signal directly to the central controller 800, or indirectly to the central controller 800 via one or more other unit controllers 600. In the latter case, the unit controller 600 sends the leakage signal to the other unit controllers 600, and the leakage signal is relayed in series by the unit controllers 600. For example, when the communication path 801 is as shown in FIG. Figure 3 In the illustrated arrangement, the unit controller 600_3 of the third valve unit 200_3 sends a leakage signal directly to the central controller 800 , and the unit controller 600_2 of the second valve unit 200_2 sends leakage information to the central controller 800 via the controller 600_3 of the third valve unit 200_3 .

[0168] The unit controller 600 may determine the controller to which the leakage signal should be sent based on network information related to the communication path between the unit controller 600 and the central controller 800. The network information may be pre-stored in the unit controller 600 or obtained by querying other unit controllers 600 and / or the central controller 800.

[0169] In step S1040, the cell controller 600 determines whether a leakage signal transmitted from another cell controller 600 is received at the cell controller 600. If a leakage signal is received (S1040: Yes), the cell controller 600 proceeds to step S1050. If a leakage signal is not received (S1040: No), the cell controller 600 proceeds to step S1060 described later.

[0170] In step S1050, the unit controller 600 forwards the received leakage signal to the central controller 800. The unit controller 600 may send the received leakage signal directly to the central controller 800, or indirectly to the central controller 800 via one or more other unit controllers 600. The unit controller 600 may determine the controller to which the received leakage signal should be sent based on the network information as described above.

[0171] In step S1060, the unit controller 600 determines whether a ventilator start-up command has been received. As will be described later, the ventilator start-up command is a command sent from the central controller 800. If a ventilator start-up command has been received (S1060: Yes), the unit controller 600 proceeds to step S1070. If a ventilator start-up command has not been received (S1060: No), the unit controller 600 proceeds to step S1080, described later.

[0172] In step S1070, the unit controller 600 forwards the received ventilator start command to the ventilator 730. The unit controller 600 may send the received ventilator start command directly to the ventilator 730, or indirectly to the ventilator 730 via one or more other unit controllers 600. The unit controller 600 may determine the unit controller 600 to which the ventilator start command should be sent based on the network information as described above.

[0173] In step S1080, the unit controller 600 determines whether the unit controller 600 has received a shutter opening command transmitted from the central controller 800. If the shutter opening command has been received (S1080: Yes), the unit controller 600 proceeds to step S1090. If the shutter opening command has not been received (S1080: No), the unit controller 600 proceeds to step S1110, which will be described later.

[0174] In step S1090, the unit controller 600 further determines whether the received damper opening command specifies the valve unit 200 to which the unit controller 600 belongs (hereinafter referred to as the "own valve unit") as the valve unit whose damper 440 should be opened. The unit controller 600 can make this determination based on whether the received damper opening command specifies the own unit ID. If the damper opening command does not specify the own valve unit (S1090: No), the unit controller 600 proceeds to step S1100. If the damper opening command specifies the own valve unit (S1090: Yes), the unit controller 600 proceeds to step S1120, described later.

[0175] In step S1100, the cell controller 600 forwards the received shutter open command to other cell controllers 600 that have not received the shutter open command. The cell controller 600 may determine the cell controller 600 to which the received shutter open command should be sent based on the network information as described above.

[0176] In step S1110, the unit controller 600 determines whether the operation has been terminated. This can be done by a user, another device, or the unit controller 600 itself. If the operation has not been terminated (S1110: No), the unit controller 600 returns to step S1010 to repeat the above acquisition and determination steps. If the operation has been terminated (S1110: Yes), the unit controller 600 terminates its operation.

[0177] In step S1120, the unit controller 600 controls the damper 440 of the valve unit 200 to open and then terminates its operation. For example, the unit controller 600 controls the state of the damper 440 by controlling the power supply to the damper 440. The unit controller 600 can output the alarm information through sound, light, visual images, and / or communication signals from a speaker, a light, a display device, and / or a communication interface provided to the unit controller 600.

[0178] Steps S1040 and S1050 may be performed before steps S1010 to S1030. Steps S1080 to S1100 may also be performed before steps S1040 and S1050.

[0179] Through the above operation, when refrigerant leakage occurs in its own valve unit 200, each unit controller 600 can report the occurrence of refrigerant leakage to the central controller 800, and when the central controller 800 has indicated it, control the damper 440 of its own valve unit 200 to open.

[0180] (Central controller operation)

[0181] The central controller 800 is configured to control the ventilator 730 to start operating when a refrigerant leak is reported in any valve unit 200. The central controller 800 is also configured to control the damper 440 in the valve unit 200 with the refrigerant leak to open by instructing the corresponding unit controller 600. More specifically, the central controller 800 is configured to perform the following operations.

[0182] Figure 5 is a flow chart representing operations performed by the central controller 800 .

[0183] In step S2010, the central controller 800 determines whether the central controller 800 receives a leakage signal sent from one of the unit controllers 600. Figure 4 In step S1030, the central controller 800 receives a signal from the central controller 800. If a leakage signal is received (S2010: Yes), the central controller 800 proceeds to step S2030 described later. If no leakage signal is received (S2010: No), the central controller 800 proceeds to step S2020 described later.

[0184] In step S2020, central controller 800 determines whether operation termination has been specified. This specification can be made by a user, another device, or central controller 800 itself. If operation termination has not been specified (S2020: No), central controller 800 returns to step S2010 to repeat the above determination step. If operation termination has been specified (S2020: Yes), central controller 800 terminates its operation.

[0185] In step S2030, the central controller 800 obtains the unit ID indicated by the received leakage signal from the leakage signal. The unit ID indicates the originator of the leakage signal, that is, the valve unit 200 with refrigerant leakage. Thus, the central controller 800 can identify the valve unit 200 with refrigerant leakage.

[0186] In step S2040, the central controller 800 sends a ventilator start command to the ventilator 730 to start the ventilator 730. The ventilator start command can be sent directly to the ventilator 730 or relayed to the ventilator 730 by one or more unit controllers 600. For example, the central controller 800 controls the ventilator 730 by controlling the power supply to the ventilator 730.

[0187] In step S2050, the central controller 800 sends a damper opening command to at least the initiator of the received leakage signal, wherein the damper opening command specifies the initiator as the valve unit 200 whose damper 440 should be opened. The central controller 800 can make this designation by using the unit ID of the initiator. The damper opening command can be directly sent to the unit controller 600 of the valve unit 200 where the refrigerant is leaking, or can be relayed to the unit controller 600 in series by one or more unit controllers 600. The central controller 800 then terminates its operation. It can be said that by Figure 4 In step S2050 and step S1120 , the central controller 800 sends a damper opening command to the damper 440 of the valve unit 200 where the refrigerant is leaking via the corresponding unit controller 600 .

[0188] The central controller 800 may output the alarm information through sound, light, visual images, and / or communication signals from a speaker, an electric light, a display device, and / or a communication interface provided to the central controller 800. In this case, it is preferable that the alarm information indicates the refrigerant-leaking valve unit 200 by outputting the unit ID of the refrigerant-leaking valve unit 200 or other information from which the refrigerant-leaking valve unit 200 can be identified, such as information indicating the position of the valve unit 200.

[0189] Step S2040 may be performed before step S2030, and step S2050 may also be performed before step S240. However, it is preferred that the operation of the ventilator 730 be started before the corresponding damper 440 is opened. The central controller 800 may control the timing of sending the damper opening command so that the corresponding damper 440 is opened only when the performance of the ventilator 730 reaches a sufficiently high level. This prevents the internal air in the corresponding housing 400 from flowing out through the first opening 420 even if the damper 440 is opened.

[0190] Through the above operation, when refrigerant leakage occurs in any valve unit 200 , the central controller 800 can control the ventilator 730 to start operating, and cooperate with the unit controller 600 to control the damper 440 in the valve unit 200 where the refrigerant is leaking to open.

[0191] (Advantageous Effects of First Embodiment)

[0192] As described above, the air conditioning system 100 according to the first embodiment includes a plurality of multi-branch selectors 300 and has a safety system 700. The safety system 700 includes a plurality of housings 400 that respectively accommodate the multi-branch selectors 300, and each housing 400 is provided with a refrigerant leak detector 500. The safety system 700 also includes a plurality of separate pipes 710, which serve as a connection structure for connecting the internal space 401 of the housing 400 via the second opening 430 of the housing 400. The safety system 700 also includes a common pipe 720 and a ventilator 730 as a discharge structure connected to the connection structure. The discharge structure is configured to discharge air from the internal space 401 of the housing 400 where the refrigerant leak has occurred when the occurrence of refrigerant leakage is detected.

[0193] Thus, when a refrigerant leak occurs in any of the multi-branch selectors 300, the safety system 700 can appropriately and quickly detect the refrigerant leak and discharge the air in the housing 400 covering the multi-branch selector to the exterior, thereby reducing the concentration of leaked refrigerant in the interior space 401 of the housing 400. This improves the safety of the air conditioning system 100 against refrigerant leaks in the multi-branch selectors 300 arranged at different locations. Furthermore, the air in one or more of the other housings 400 is not discharged. Consequently, the required air volume capacity of the ventilator 730 can be reduced, thereby reducing the size of the ventilator 730 and / or the number of ventilators 730.

[0194] (Variation of the First Embodiment)

[0195] In the first embodiment described above, the unit controllers 600 are connected in series to the central controller 800. However, all or part of the unit controllers 600 may be individually connected to the central controller 800 via separate communication paths. With respect to the individually connected unit controllers 600, the central controller 800 can distinguish the unit controller 600 from one or more other unit controllers 600 through the separate communication paths and appropriately transmit the shutter opening command simply by responding to the sender of the leakage signal.

[0196] In the first embodiment, the leakage signal indicates the unit ID of the valve unit 200 in which the refrigerant leak has occurred. However, if the unit controller 600 is configured to record the transmission of the leakage signal and recognize the damper opening command as a response to the transmitted leakage signal only when the damper opening command is received within a predetermined time of the transmission, the leakage signal does not necessarily indicate any unit ID. If the central controller 800 and the unit controller 600 communicate with each other using different time slots allocated to the unit controller 600, the leakage signal does not necessarily indicate any unit ID either.

[0197] Alternatively, when the unit controller 600 receives detection result information indicating that a refrigerant leak has occurred in its own valve unit 200, the unit controller 600 may control the damper 440 of its own valve unit 300 to open. In this case, the central controller 800 does not need to send a damper opening command to the unit controller 600. The unit controller 600 may control the damper 440 to open after a predetermined time has passed after the leakage signal is transmitted, so that the damper 440 opens after the ventilator 730 starts operating.

[0198] The connection path of the communication path 801 is not limited to Figure 3 For example, all or some of the unit controllers 600 and ventilators 730 may be directly connected to the central controller 800 via separate wired / wireless communication pathways.

[0199] (Second embodiment)

[0200] (Safety System Structure)

[0201] In the first embodiment of the present invention described above, the internal spaces 401 of the housing 400 are connected in parallel. On the other hand, in the second embodiment of the present invention described below, the internal spaces 401 of the housing 400 are connected in series.

[0202] The safety system according to the second embodiment can also be applied to an air conditioning system having the same configuration as the air conditioning system of the first embodiment. The configuration of each valve unit of the safety system according to the second embodiment can be the same as that of the first embodiment. The same reference numerals as those of the first embodiment are attached to substantially the same elements and steps as those of the first embodiment, and their descriptions are omitted.

[0203] Figure 6 is a schematic configuration diagram of a safety system according to a second embodiment.

[0204] like Figure 6 As shown, the air conditioning system 100 according to the second embodiment (see Figure 1 The safety system 700a of the embodiment includes first to third valve units 200_1 to 200_3, first and second connecting pipes 740a_1 and 740a_2, a common pipe 720a, a ventilator 730, and a central controller 800a. The safety system 700a does not have the separate pipe 710 of the first embodiment.

[0205] The first connecting pipe 740a_1 is connected to the second opening 430_2 of the housing 400_2 of the second valve unit 200_2 on one side and to the first opening 420_1 of the housing 400_1 of the first valve unit 200_1 on the other side. The second connecting pipe 740a_2 is connected to the second opening 430_3 of the housing 400_3 of the third valve unit 200_3 on one side and to the first opening 420_2 of the housing 400_2 of the first valve unit 200_2 on the other side.

[0206] Therefore, the first connection duct 740a_1 and the second connection duct 740a_2 form a connection structure connecting the first inner space 401_1 to the third inner space 401_3 via the first openings 420_1 , 420_2 and the second openings 430_2 , 430_3 .

[0207] The common pipe 720a is connected to the second opening 430_1 of the housing 400_1 of the first valve unit 200_1. The ventilator 730 is disposed at or near one end (hereinafter referred to as the "second end") of the common pipe 720 and is configured to draw air in the common pipe 720b toward the second end. Preferably, the second end of the common pipe 720a is open to the outdoor space. Figure 6 As shown, it is also preferred that the ventilator 730 is disposed at the second end. The static pressure capacity of the ventilator 730 of the second embodiment may be different from that of the ventilator 730 of the first embodiment. The extension duct may be connected to the first opening 420_3 of the third valve unit 200_3 outside the corresponding housing 400_3. The first opening 420_3 of the third valve unit 200_3 is the first opening 420 farthest from the ventilator 730 along the air path AP extending above the housing 400 and leading to the ventilator 730.

[0208] Therefore, the common duct 720a and the ventilator 730 form a discharge structure that is connected to the connection structure described above and is configured to discharge air from the internal space 401 of the housing 400 when all the dampers 440 are open.

[0209] The location, connection to other elements, and physical configuration of the central controller 800a may be the same as those of the central controller 800 according to the first embodiment. However, the operation of the central controller 800a is slightly different from that of the central controller 800 of the first embodiment. The central controller 800a is configured to control the dampers 440 of all valve units 200 to open when the ventilator 730 is operating due to refrigerant leakage.

[0210] (Central controller operation)

[0211] When refrigerant leakage is reported in any valve unit 200, the central controller 800a is configured to control the ventilator 730 to start operating similarly to the first embodiment. At the same time, the central controller 800a is configured to control the dampers 440 of all valve units 200 to open.

[0212] Figure 7 is a flow chart representing operations performed by the central controller 800a.

[0213] like Figure 7 As shown, the central controller 800a executes Figure 5 The central controller 800a performs step S2050a instead of Figure 5 S2050.

[0214] In step S2050a, the central controller 800a sends a damper-opening command to all valve units 200. More specifically, the central controller 800a sends the damper-opening command to all valve units 200 that are connected in series to the initiator of the leak signal. The central controller 800a can perform this designation using the unit ID of the valve unit 200. The central controller 800a then terminates its operation. The central controller 800a can output an alarm message and / or control the timing of sending the damper-opening command, as described in the first embodiment.

[0215] When all the first baffles 440_1 to the third baffles 440_3 (see Figure 6 ) is opened, an air path AP is formed extending from the external space outside the housing 400_3 of the third valve unit 200_3 to the ventilator 730. This air path AP passes through the first opening 420_3, the internal space 401_3, and the second opening 430_3 of the third valve unit 200_3, the second connecting duct 740a_2, the first opening 420_2, the internal space 401_2, and the second opening 430_2 of the second valve unit 200_2, the first connecting duct 740a_1, the first opening 420_1, the internal space 401_1, and the second opening 430_1 of the first valve unit 200_1, and the common duct 720a. If the ventilator 730 is operated in this state, the air in the internal space 401 of the housing 400 of the first to third valve units 200_1, 200_3 is discharged by the suction force of the ventilator 730.

[0216] (Advantageous Effects of Second Embodiment)

[0217] Thus, the air conditioning system 100 according to the second embodiment includes a plurality of multi-branch selectors 300 and has a safety system 700a. The safety system 700a includes a plurality of housings 400 that respectively accommodate the multi-branch selectors 300, and each housing 400 is provided with a refrigerant leak detector 500. The safety system 700a also includes a plurality of connecting pipes 740a, which serve as a connecting structure that connects the internal space 401 of the housing 400 via the first opening 420 and the second opening 430 of the housing 400. The safety system 700a also includes a common pipe 720a and a ventilator 730 as a discharge structure connected to the connection structure. The discharge structure is configured to discharge air from the internal space 401 of all housings 400, including the housing 400 where the refrigerant leak has occurred, when the occurrence of refrigerant leakage is detected.

[0218] Thus, when refrigerant leakage occurs in any of the multi-branch selectors 300, safety system 700a can appropriately and quickly detect the refrigerant leak and discharge the air in housing 400, which covers the multi-branch selector, to the outside space, thereby reducing the concentration of leaked refrigerant in interior space 401 of housing 400. Consequently, the safety of the air conditioning system against refrigerant leakage from valves in multi-branch selectors 300 arranged at different locations can be improved. Furthermore, compared to the configuration of the first embodiment, the total length of the piping connecting housing 400 to ventilator 730 can be reduced, thereby reducing the installation cost of the system.

[0219] (Variation of the Second Embodiment)

[0220] In the second embodiment described above, the ventilator 730 is connected to one of the housings 400 via the common duct 720a. However, the common duct 720a having a short length and the ventilator 730 may be integrated into a single element. If one of the housings has a portion exposed to the outdoor space, such a single element may be configured in that portion.

[0221] In the second embodiment, the leakage signal indicates the originator of the leakage signal through the unit ID of the valve unit 200 where the refrigerant leakage occurred, and the central controller 800a identifies the refrigerant leaking valve unit 200. However, the leakage signal does not necessarily indicate the originator of the leakage signal, let alone the unit ID, and the central controller 800a does not necessarily identify the refrigerant leaking valve unit 200.

[0222] The connection path of the communication path 801 is not limited to Figure 6 For example, all or some of the unit controllers 600 and ventilators 730 may be directly connected to the central controller 800a via separate wired / wireless communication pathways.

[0223] (Third embodiment)

[0224] As a third embodiment of the present invention, a configuration combining the configurations according to the first and second embodiments is described. The safety system according to the third embodiment can be applied to an air conditioning system having the same configuration as the air conditioning systems according to the first and second embodiments. The configuration of each valve unit in the safety system according to the third embodiment can be the same as that of the first and second embodiments. The same reference numerals as those in the first and second embodiments are used for substantially the same elements and steps as those in the first and second embodiments, and their descriptions are omitted.

[0225] Figure 8 is a schematic configuration diagram of a safety system according to a third embodiment.

[0226] like Figure 8 As shown, the air conditioning system 100 according to the third embodiment (see Figure 1 ) includes first to third valve units 200_1, 200_3, first and second individual pipes 710_1, 710_2, a second connecting pipe 740a_2, a common pipe 720b, a ventilator 730, and a central controller 800b. Safety system 700b does not include the third individual pipe 710_3 of the first embodiment and the first connecting pipe 740a_1 of the second embodiment.

[0227] The first individual conduit 710_1 connects the second opening 430_1 of the housing 400_1 of the first valve unit 200_1 to the common conduit 720b. The second individual conduit 710_2 connects the second opening 430_2 of the housing 400_2 of the second valve unit 200_2 to the common conduit 720b. The second connecting conduit 740a_2 connects the second opening 430_3 of the housing 400_3 of the third valve unit 200_3 to the first opening 420_2 of the housing 400_2 of the second valve unit 200_2.

[0228] Therefore, the first and second individual ducts 710_1 and 710_2 and the second connecting duct 740a_2 form a connecting structure connecting the first to third inner spaces 401_1 and 401_3 via the first and second openings 420_2 and 430_1 , 430_2 , and 430_3 .

[0229] The ventilator 730 is disposed in the common duct 720b at or near one end (hereinafter referred to as the "second end") of the common duct 720b and is configured to draw air in the common duct 720b toward the second end. Figure 8As shown, it is preferred that the ventilator 730 is disposed at the second end. The static pressure capacity of the ventilator 730 may be different from that of the ventilator 730 of the first embodiment and the second embodiment.

[0230] Therefore, the common pipe 720b and the ventilator 730 form the following discharge structure: the discharge structure is connected to the connection structure as described above, and is configured to discharge air from the internal space 401_1 of the shell 400_1 of the first valve unit 400_1 when the baffle 440_1 of the first valve unit 200_1 is opened, and to discharge air from the internal space 401_2 of the shell 400_2 of the second valve unit 200_2 and the internal space 401_3 of the shell 400_3 of the third valve unit 200_3 when the baffle 440_2 of the second valve unit 200_2 and the baffle 440_3 of the third valve unit 200_3 are both opened.

[0231] The location, connection to other components, and physical configuration of the central controller 800b may be the same as those of the central controller 800 according to the first embodiment. The central controller 800b is also configured to perform substantially the same operations as the central controller 800 according to the first embodiment. The central controller 800b controls all or part of the one or more dampers 440 of the valve unit 200 to open when the ventilator 730 is operating due to refrigerant leakage.

[0232] However, the operation of the central controller 800b is slightly different from that of the central controller 800 according to the first embodiment and the central controller 800a according to the second embodiment. The central controller 800b has a grouping table that defines the relationship between each valve unit 200 and the damper 440 to be opened when refrigerant leakage occurs in the valve unit 200. The central controller 800b is configured to determine the valve unit 200 whose damper 440 should be opened based on the grouping table.

[0233] Figure 9 is the grouping table used by the central controller 800b.

[0234] like Figure 9 As shown, the grouping table 910b associates one or more valve units 200 serving as destinations 912b of the damper opening command with each valve unit 200 serving as initiator 911b of the leakage signal. The destination 912b is the one or more valve units 200 whose dampers 440 should be opened when a refrigerant leak occurs in the valve unit 200 serving as the initiator 911b.

[0235] In other words, the grouping table 910b indicates the groups of valve units 200. In a group including a plurality of valve units 200, the interior space 401 of the housing 400 is connected in series to the ventilator 730. Between different groups, the interior space 401 of the housing 400 is connected in parallel to the ventilator 730. The valve units 200 can be defined in the grouping table 910b by their unit IDs.

[0236] For example, if the unit ID "U1" of the first valve unit 200_1 is used as the initiator 911b, only the unit ID "U1" of the first valve unit 300_1 is associated with the destination 912b. If the unit ID "U2" of the second valve unit 200_2 and the unit ID "U3" of the third valve unit 200_3 are used as the initiator 911b, the unit ID "U2" of the second valve unit 200_3 and the unit ID "U3" of the third valve unit 200_2 are associated with the destination 912b. The grouping table 910b is pre-stored in the central controller 800b. The central controller 800b can accept manual settings for the grouping table 910b.

[0237] However, the structure of the grouping table 910b is not limited to Figure 9 For example, the grouping table 910 can simply define groups of valve units 200, such that valve units 200 connected in series to the ventilator 730 via a connection structure form a group. A single valve unit 200 with no other valve units 200 connected in series to the ventilator 730 via a connection structure can also form a group. Each group can be defined using an identifier of the unit controller 600.

[0238] The central controller 800b executes Figure 5 Steps S2010 to S2050 are substantially the same as those in step S2030 or S2050. However, in step S2030 or S2050, the central controller 800a determines the valve unit 200 whose damper 440 should be opened based on the originator 911b of the received leakage signal and the grouping table 910b. Therefore, when, for example, a refrigerant leak occurs in the first valve unit 200_1, the central controller 800b transmits a damper opening command specifying the first valve unit 300_1.

[0239] Therefore, if Figure 8As shown, only the baffle 440_1 of the first valve unit 200_1 is opened to form an air path AP that passes through the first opening 420_1 of the first valve unit 200_1, the interior space 401_1, the second opening 430_1, the first individual duct 710_1, and the shared duct 720b. The baffle 440_2 of the second valve unit 200_2 and the baffle 440_3 of the third valve unit 200_3 remain closed. Therefore, the ventilator 730 draws air from the interior space 401_1 of the first valve unit 200_1, but does not draw air from the interior space 402_2 of the second valve unit 200_2 or the interior space 401_3 of the third valve unit 200_3.

[0240] Thus, the air conditioning system 100 according to the third embodiment includes the safety system 700b in which the housings 400 connected in series are further connected in parallel to another housing 400. Even with such a connection structure having a complicated configuration, it is possible to discharge air from the internal space 401 of the housing 400 where refrigerant leakage has occurred while reducing the static pressure capacity required for the ventilator 730.

[0241] The modifications mentioned in the first and second embodiments can be applied to the safety system 700b according to the third embodiment. It should be noted that the grouping table 910b and the determination of the valve unit 200 to open its damper 440 based on the grouping table 910a described above can also be applied to the first and second embodiments.

[0242] The connection path of the communication path 801 is not limited to Figure 8 For example, all or some of the unit controllers 600 and ventilators 730 may be directly connected to the central controller 800b via separate wired / wireless communication pathways.

[0243] Other configurations combining the first and second embodiments are also contemplated. For example, the second opening 430_2 of the second valve unit 200_2 and the third opening 430_3 of the third valve unit 200_3 may be connected in parallel to the first opening 420 of the first valve unit 200 via branch pipes. In such a configuration, the branch pipes function as both the individual pipes 710_2 and 710_3 of the first embodiment and the connecting pipes 740a_1 and 740a_2 of the second embodiment.

[0244] In any case, the central controller 800b is configured to open all one or more dampers 440 present on the pipeline extending from the ventilator 730, passing through the interior space 401 of the housing 400 having the refrigerant leak, and reaching the exterior space of the housing 400. Preferably, the central controller 800b keeps the other one or more dampers closed.

[0245] (Fourth embodiment)

[0246] As a fourth embodiment of the present invention, a configuration including multiple sets of connection structures and exhaust structures is described. The safety system according to the fourth embodiment can be applied to an air conditioning system having the same configuration as the air conditioning systems of the first to third embodiments. The configuration of each valve unit of the safety system according to the fourth embodiment can be the same as that of the first to third embodiments. The same reference numerals as those of the first to third embodiments are used for substantially the same elements and steps as those of the first to third embodiments, and their descriptions are omitted.

[0247] Figure 10 is a schematic configuration diagram of a safety system according to a fourth embodiment.

[0248] like Figure 10 As shown, the air conditioning system 100 according to the fourth embodiment (see Figure 1 )'s security system 700c includes a first segment 701c_1, a second segment 701c_2 and a central controller 800c.

[0249] The first section 701c_1 includes a first valve unit 200_1 and a second valve unit 200_2, a first separate pipe 710_1 and a third separate pipe 710_2, a first common pipe 720_1 and a first ventilator 730_1. However, the number of valve units 200 in each section 701c is not limited to two and may be one, three or more. Similar to the first embodiment, the first valve unit 200_1 and the second valve unit 200_2 are connected in parallel to each other and are commonly connected to the first common pipe 720_1 via the first separate pipe 710_1 and the second separate pipe 710_2. The unit controller ( Figure 10 Not shown, see Figure 3 ) is connected to the central controller 800c via communication path 801.

[0250] The second section 701c_2 includes the third valve unit 200_3 and the fourth valve unit 200_4, a connecting pipe 740a, a second common pipe 720_2, and a second ventilator 730_2. Similar to the second embodiment, the third valve unit 200_3 and the fourth valve unit 200_4 are connected to each other via the connecting pipe 740b and are connected in series with the second common pipe 720_2. The unit controllers ( Figure 10 Not shown, see Figure 6 ) is connected to the central controller 800c via communication path 801.

[0251] The location, connection to other elements, and physical structure of the central controller 800c may be the same as those of the central controller 800b according to the third embodiment. The central controller 800c is also configured to perform substantially the same operations as the central controller 800b according to the third embodiment. The central controller 800c controls one or more dampers 440 ( 440 ) of all or part of the valve unit 200 when the ventilator 730 is in operation due to a refrigerant leak. Figure 10 Not shown, see Figure 3 and Figure 6 ) is opened. Similar to the central controller 800b of the third embodiment, the central controller 800c determines the valve unit 200 whose damper 440 should be opened based on the grouping table.

[0252] However, the central controller 800c uses a different type of grouping table to further determine the ventilators that should start operating. More specifically, the central controller 800c is configured to control only the ventilators of the section where the refrigerant leakage has occurred to start operating.

[0253] Figure 11 is a grouping table used by the central controller 800c.

[0254] like Figure 11 As shown, in addition to one or more destinations 912b of the damper opening command, the grouping table 910c also associates a ventilator 913c that should be operated with each valve unit 200 as the initiator 911b of the leakage signal. In other words, the grouping table 910c indicates the sections 701c. In each section, the internal space 401 ( Figure 10 Not shown, see Figure 2 ) are connected to the same ventilator, but are not connected to ventilators in another section. The ventilators may be defined in the grouping table 910c by their ventilator ID.

[0255] For example, when the unit ID "U1" of the first valve unit 200_1 is the initiator 911b, the unit ID "U1" of the first valve unit 200_1 as the destination 912b is associated with the ventilator ID "F1" of the first ventilator 730_1 as the ventilator to be operated 913c. When the unit ID "U2" of the second valve unit 200_2 is the initiator 911b, the unit ID "U2" of the second valve unit 200_2 as the destination 912b is associated with the ventilator ID "F1" of the first ventilator 730_1 as the ventilator to be operated 913c. With the unit ID "U3" of the third valve unit 200_3 and the unit ID "U4" of the fourth valve unit 200_4 serving as the initiator 911b, the unit ID "U3" of the third valve unit 200_3 and the unit ID "U4" of the fourth valve unit 200_4, serving as the destination 912b, are associated with the ventilator ID "F2" of the second ventilator 730_2, serving as the ventilator to be operated 913c. The grouping table 910c is pre-stored in the central controller 800c. The central controller 800c can accept manual settings for the grouping table 910c.

[0256] However, the structure of the grouping table 910c is not limited to Figure 11 For example, the grouping table 910 can simply define groups of valve units 200, such that valve units 200 connected in series to the same ventilator 730 via a connection structure form a group, and the group is associated with the corresponding ventilator 730. A single valve unit 200 with no other valve units 200 connected in series to the ventilator 730 via a connection structure can also form a group. Each group can be defined using the identifier of the unit controller 600.

[0257] The central controller 800c executes Figure 5 However, in step S2030 or S2040, the central controller 800c determines the ventilator that should start operating based on the initiator of the received leakage signal and the group table 910c, and in step S2030 or S2050, determines one or more valve units 200 whose dampers 440 should be opened based on the initiator of the received leakage signal and the group table 910c.

[0258] Therefore, when, for example, a refrigerant leak occurs in the first valve unit 200_1, the central controller 800c sends a ventilator start command to the first ventilator 730_1 to start its operation, and also sends a damper opening command specifying the first valve unit 300_1. As a result, only the first ventilator 730_1 among the ventilators operates, and only the damper of the first valve unit 200_1 among the valve units 200 opens. The ventilator start command may specify the ventilator ID of the ventilator to be started.

[0259] Thus, the air conditioning system 100 according to the fourth embodiment includes a safety system 700c divided into multiple sections 701c controlled by a shared central controller 800c. When refrigerant leakage occurs in any valve unit 200, the central controller 800c is configured to control only the ventilation fan in the section 701c where the refrigerant leak has occurred to start operating, and to control only the damper or dampers 440 to be opened to discharge air from the leaking valve unit 200. This allows for proper air discharge while reducing power consumption.

[0260] When the valves of the air conditioning system 100 are arranged at widely separated locations, extending piping from all valve units 200 to the same common ventilator increases the total piping length and the static pressure capacity required by the ventilator. Furthermore, due to limitations imposed by the installation location, it may be difficult to draw a continuous piping system to cover all valve units 200. In such cases, multiple safety systems can be deployed. However, providing a central controller for each safety system is uneconomical. Therefore, the safety system 700c according to the fourth embodiment can improve the safety of the air conditioning system 100 against refrigerant leakage from the valves at a low cost, even if the valves are arranged at widely separated locations.

[0261] The connection path of the communication path 801 is not limited to Figure 10 For example, the third valve unit 200_3 and the fourth valve unit 200_4 of the second section 701c_2 and the second ventilator 730_2 can be connected to the central controller 800c via another communication path 801 independent of the first section 701c_1, or can be indirectly connected to the central controller 800c via one or more unit controllers 600 of the first section 701c_1. All or part of the unit controllers 600 and the ventilator 730 can be directly connected to the central controller 800c via separate wired / wireless communication paths. The connection path of the housing 400 of the valve unit 200 through the pipeline is also not limited to Figure 10 Pathway shown.

[0262] (Other Modifications of the First to Fourth Embodiments)

[0263] The configuration and operation of the security systems 700, 700a, 700b, 700c as described above may be modified according to circumstances.

[0264] For example, the valve unit 200 may have a configuration including the heat source-side liquid piping section 310, the utilization-side liquid piping section 311, the low-pressure gas piping section 320, the low-pressure gas sub-piping section 321, the high-pressure gas piping section 340, the high-pressure gas sub-piping section 341, the utilization-side gas piping section 330, the low-pressure gas control valve 361, and the high-pressure gas control valve 362, but may not include all or part of the set of the bypass piping 351, the refrigerant heat exchanger 352, and the expansion mechanism 363. Furthermore, all or part of the gas shutoff valve 365 may be omitted.

[0265] Furthermore, the air conditioning system 100 may include a heat pump system having a so-called double-pipe configuration. In this case, the piping contained in the housing 400 would not be the multi-branch selector 300. However, the valve unit 200 includes at least a liquid refrigerant piping section, a gas refrigerant piping section, a liquid control valve disposed in the liquid refrigerant piping section, and a gas control valve disposed in the gas refrigerant piping section. Each of the liquid control valve and the gas control valve may be any type of valve for controlling the refrigerant flow rate in the corresponding piping section.

[0266] For example, any of the security systems 700, 700a, 700b, 700c may include: Figure 12 The valve unit 200d shown replaces Figure 2 Valve unit 200. With Figure 2 Compared with the structure shown, the valve unit 200d, which is a variation of the present embodiment, does not have the high-pressure gas piping section 340, the low-pressure gas sub-piping 321, the high-pressure gas sub-piping 341, the bypass piping 351, the refrigerant heat exchanger 352, the low-pressure gas control valve 361, the high-pressure gas control valve 362 and the expansion mechanism 363.

[0267] Furthermore, any of the valve units described above may have a configuration in which the heat source-side liquid piping portion 310 and the one or more gas piping portions 320 and 340 do not branch toward the two or more utilization-side units 120 of the air conditioning system 100 but instead direct toward only one of the utilization-side units 120. Even in such a configuration, each valve in the refrigerant piping portion disposed within the housing 400 will be a refrigerant leakage point, and therefore, safety against refrigerant leakage should be improved.

[0268] The housing 400 of any of the above-described embodiments and variations may include multiple housing components that can be attached and detached from one another. In this case, the housing components may be configured such that each piping hole 410 is formed between two or more adjacent housing components. Thus, when the housing components are assembled, each extension pipe can be easily fitted into the corresponding piping hole 410.

[0269] The method for assembling the safety system 700 / 700a / 700b / 700c may include the following steps: for each valve unit 200 / 200d, arranging corresponding housing components around at least the liquid control valve and the gas control valve of the valve unit 200 / 2000d; for each valve unit 200 / 200d, securing the corresponding housing components to each other; providing a refrigerant leak detector 500 for each valve unit 200 / 200d; arranging a connection structure to connect the interior space 401 of the housing 400; and connecting a drain structure to one of the connection structure or the housing 400. Thus, the housing 400 can be retrofitted to an existing valve of a heat pump system. Insulators 450 may also be used to fill gaps between adjacent housing components.

[0270] The unit controller 600 of each valve unit 200 may have other functions. For example, the unit controller 600 may be further configured to, when a refrigerant leak occurs in any of the utilization side pipe sections, shut off the liquid stop valve 364 and the gas stop valve 365 (see FIG. Figure 2 ) is controlled to be closed. Thus, the utilization-side pipe section can be distinguished from the rest of the heat pump circuit. Alternatively or additionally, when a refrigerant leak is detected in any valve unit 200, the unit controller 600 can shut down the air conditioning system 100 by, for example, stopping the operation of the compressor in the heat source-side unit and the operation of the utilization-side unit 120. This can minimize further refrigerant leakage.

[0271] The position, orientation, and number of the ventilators 730 are not limited to those described in the first to fourth embodiments. For example, the ventilators 730 may be arranged to blow air toward the interior space 401 of the housing 400 where a refrigerant leak has occurred. This allows air containing refrigerant to be discharged from the corresponding first opening 420 even when the damper 440 is open. Furthermore, additional ventilators may be provided in the individual ducts 710, the connecting ducts 740a, and / or the shared ducts 720, 720a between the ventilator 730 and any of the interior spaces 401 to enhance suction force.

[0272] If the refrigerant used is heavier than air and thus allows the first opening 420 to be formed in the upper portion of the housing 400, the baffle 440 for the first opening 420 is not necessarily required. If the isolation of the internal space 401 of the housing 400 is sufficient without any special insulating body 450, such insulating body 450 may be omitted.

[0273] All or part of the unit controller 600 may be separated from the corresponding valve unit 200. In this case, the valve unit 200 should have a communication interface so that the unit controller 600 can obtain the detection value Vs of the refrigerant leak detector 500 and control the operation of the mechanical equipment of the valve unit 200 including the damper 440.

[0274] All or part of the unit controller 600 may be integrated into the central controller 800 / 800a / 800b / 800c. For example, the central controller 800 / 800a / 800b / 800c may compare the detection value Vs with the detection value threshold value Vth. Conversely, all or part of the central controller 800 / 800a / 800b / 800c may be integrated into the unit controller 600. For example, each unit controller 600 may determine whether to open the damper 440 of its own valve unit 200.

[0275] If the discharge of the internal air is continuously or periodically performed under the control of, for example, the unit controller 600, it is not necessarily necessary to perform the detection of the refrigerant leakage, and therefore, the refrigerant leak detector 500 is not required. In this case, it is not necessarily necessary to Figure 4 、 Figure 5 and Figure 7 Furthermore, if ventilation of the interior air through the connection structure is due to natural convection or air flow induced by an external mechanism, the ventilator 730 is not necessarily required.

[0276] (Position pattern of the first opening and the second opening)

[0277] As described above, the outer shape of the housing of each valve unit is not limited to any specific shape, and the arrangement of the first opening and the second opening in the housing is not limited to any specific arrangement. For example, when the outer shape of the housing is box-shaped and the first opening is formed in one of the four lateral surfaces of the housing, the arrangement of the first opening and the second opening can be roughly divided into four patterns.

[0278] Figures 13 to 16 are schematic configuration diagrams showing first to fourth modes of arrangement of a first opening and a second opening having a duct connected thereto.

[0279] In the first mode P1, the first opening 420 and the second opening 430 are respectively formed on two opposing lateral surfaces of the housing 400. In the second mode P2, the first opening 420 and the second opening 430 are respectively formed on two adjacent lateral surfaces of the housing 400. In the third mode P3, the first opening 420 is formed on one lateral surface of the housing 400, and the second opening 430 is formed on the top surface of the housing 400. In the fourth mode P4, the first opening 420 is formed on one lateral surface of the housing 400, and the second opening 430 is formed on the bottom surface of the housing 400.

[0280] In the first and second modes P1 and P2, neither the common conduit 720a nor the connecting conduit 740a protrudes upward or downward from the housing 200. Therefore, these modes help reduce the height of the space required to arrange the valve unit 200 and the conduits connected thereto. Furthermore, in the first mode P1, the connecting conduit 740a (or the connecting conduit 740b and the common conduit 720a) is arranged in a straight line. Therefore, this mode further helps reduce the width of the space required to arrange the valve unit 200 and the conduits connected thereto.

[0281] However, it should be noted that the arrangement of the first opening 420 and the second opening 430 is not limited to the above four modes. For example, the first opening 420 may be formed on the top surface or the bottom surface of the housing 400.

[0282] (Fifth embodiment)

[0283] (Structure of air conditioning system)

[0284] As a fifth embodiment of the present invention, the following configuration is described: a first opening 420 and a second opening 430 are formed on two opposite lateral surfaces of a housing 400, such as Figure 13 As shown in the first mode P1 described above.

[0285] The safety system according to the fifth embodiment can be similar to the safety system 700a according to the second embodiment. However, its piping configuration differs from that of the second embodiment. The construction of the safety system also differs slightly from that of the second embodiment. These differences will be described below; unless otherwise noted, the other construction is the same as that of the second embodiment. The same reference numerals as those of the second embodiment are attached to substantially identical elements, and their descriptions are omitted.

[0286] Figure 17 is a schematic configuration diagram of an air conditioning system according to a fifth embodiment.

[0287] like Figure 17As shown, like the second embodiment, the air conditioning system 100e according to the fifth embodiment includes a heat source-side unit 110, a utilization-side unit 120 connected to the heat source-side unit 110 via refrigerant piping, and first to third valve units 200e_1 to 200e_3 of the first to third unit families 121_1 to 121_3 for the utilization-side units 120. However, unlike the second embodiment, the pipelines of the first to third valve units 200e_1 to 200e_3 are connected in series in this order. It should be noted that the number of valve units 200e is not limited to three.

[0288] Each valve unit 200e includes a main liquid refrigerant piping section 381e, a main low-pressure gas refrigerant piping section 382e, and a main high-pressure gas refrigerant piping section 383e. The liquid refrigerant piping section 311 branches from the main liquid refrigerant piping section 381e, the low-pressure gas sub-piping section 321 branches from the main low-pressure gas refrigerant piping section 382e, and the high-pressure gas sub-piping section 341 branches from the main high-pressure gas refrigerant piping section 383a. The main liquid refrigerant piping section 381e, the main low-pressure gas refrigerant piping section 382e, and the main high-pressure gas refrigerant piping section 383e (hereinafter collectively referred to as "main piping sections") correspond to the heat source-side liquid piping section 310, the low-pressure gas sub-piping section 320, and the high-pressure gas piping section 340, respectively, described in the first embodiment. The main liquid refrigerant piping section 381e, the main low-pressure gas refrigerant piping section 382e and the main high-pressure gas refrigerant piping section 383e of one of the valve units 200e (for example, the third valve unit 200e_3) are respectively connected to the liquid refrigerant piping 131, the low-pressure gas refrigerant piping 132 and the high-pressure gas refrigerant piping 133.

[0289] The air conditioning system 100e also includes at least one set of liquid refrigerant connecting pipes 161e, low-pressure gas refrigerant connecting pipes 162e, and high-pressure gas connecting pipes 163e (hereinafter collectively referred to as "connecting pipes"). Between two valve units 200e, the liquid refrigerant connecting pipe 161e connects to the main liquid refrigerant piping section 381e, the low-pressure gas refrigerant connecting pipe 162e connects to the main low-pressure gas refrigerant piping section 382e, and the high-pressure gas connecting pipe 163e connects to the main high-pressure gas refrigerant piping section 383e. In other words, a set of main piping sections 381e, 382e, and 383e in one valve unit 200e is connected to another set of main piping sections 381e, 382e, and 383e in the other valve unit 200e via the set of connecting pipes 161e, 162e, and 163e.

[0290] Such a pair of valve units 200e directly connected by a set of connecting pipes 161e, 162e, 163e is preferably adjacent valve units 200a directly connected by a connecting pipe 740a, namely the first valve unit 200e_1 and the second valve unit 200e_2, or the second valve unit 200e_2 and the third valve unit 200e_3.

[0291] Figure 18 FIG. 7 is a schematic structural diagram of a security system 700e.

[0292] As in the second embodiment, the interior spaces 401_1, 401_2, 401_3 of the first housings 400e_1 to 400e_3 of the first to third valve units 200e_1 to 200e_3 are connected in series via the first openings 420_1, 420_2 and the second openings 430_2, 430_3 in sequence through the first connecting pipe 740a_1 and the second connecting pipe 740a_2. The common pipe 720a provided with the ventilator 730 is also connected to the second opening 430_1 of the first valve unit 200e_1. However, unlike the second embodiment, no ventilator is provided. Figure 6 The first to third baffles 440_1 to 440_3 are shown. In contrast, a baffle unit 440e having a baffle 440 is attached to the first opening 420_3 of the third valve unit 200e_3. The baffle 440 of the baffle unit 440e is connected to the controller 600_3 of the third valve unit 200e_3 via wired and / or wireless communication.

[0293] The damper 440 may be a normally closed damper. When the damper 440 is closed and the ventilator 730 is stopped, the air in all housings 400e_1, 400e_2, and 400e_3 becomes stagnant. Therefore, a refrigerant leak in any of the housings 400e_1, 400e_2, and 400e_3 can be quickly detected. The central controller 800a or the unit controller 600_3 of the third valve unit 200e_3, which is farthest from the common pipe 720a in the valve unit 200e, is configured to control the damper 440 to open when the ventilator 730 is operating due to a refrigerant leak in any of the housings 400e_1, 400e_2, and 400e_3.

[0294] If refrigerant leakage can be detected in any one of the internal spaces 401_1, 401_2, 401_3, and the ventilator 730 is started and the damper 440 is opened when refrigerant leakage is detected, some of the refrigerant leakage detectors 500_1, 500_2, 500_3, unit controllers 600_1, 600_2, 600_3 and central controller 800a can be omitted.

[0295] The first to third valve units 200e_1 to 200e_3 may have the same configuration. Therefore, in the following description, the term "valve unit 200e" refers to any one of the first to third valve units 200e_1 to 200e_3.

[0296] (Structure of valve unit)

[0297] Figure 19 It is a perspective view of the valve unit 200e.

[0298] like Figure 19 As shown, the housing 400e of the valve unit 200e has a roughly box-shaped (i.e., rectangular parallelepiped shape). The housing 400e has a first transverse surface 461e, a second transverse surface 462e, a pipe outlet surface 463e, a box side surface 464e, a top surface 465e, and a bottom surface 466e (not shown) that form the six faces of the rectangular parallelepiped respectively. The first transverse surface 461e and the second transverse surface 462e face opposite directions and are roughly parallel to each other. The pipe outlet surface 463e and the box side surface 464e are also transverse surfaces that face opposite directions and are roughly parallel to each other. The top surface 465e and the bottom surface 466e face opposite directions and are roughly parallel to each other. Each of the pipe outlet surface 463e, the box side surface 464e, the top surface 465e, and the bottom surface 466e is roughly perpendicular to each of the first transverse surface 461e and the second transverse surface 462e.

[0299] The valve unit 200 may have four or more suspension elements 467e (partially not shown) for suspending the housing 400e from a portion of the building structure, such as the underside of a building ceiling, using metal hangers and bolts. Preferably, two suspension elements 467e are secured to the housing 400e on the first transverse surface 461e, while the remaining suspension elements 467e are secured to the housing 400e on the second transverse surface 462e. The housing 400e is made of multiple panels, including a top panel 468e forming the top surface 465e and a bottom panel 469e forming the bottom surface 466e. The panels may be metal panels, carbon fiber panels, flame-retardant resin panels, or the like.

[0300] Figure 20 is a perspective view of the valve unit 200e with the top plate 468e removed.

[0301] like Figure 20 As shown, the valve unit 200e includes a multi-branch selector 300e. Although substantially the same as the multi-branch selector 300 of the second embodiment (same as the first embodiment, see Figure 2), but the multi-branch selector 300e of this embodiment also includes the main piping sections 381e, 382e, and 383e as described above, to replace the heat source side liquid piping section 310, the low-pressure gas sub-piping section 320, and the high-pressure gas sub-piping section 340.

[0302] Most of the multi-branch selector 300e is accommodated in the internal space 401 of the shell 400e. However, the ends of some pipes protrude outward from the shell 400e. One end of the main liquid refrigerant piping portion 381e, one end of the main low-pressure gas refrigerant piping portion 382e and one end of the main high-pressure gas refrigerant piping portion 383e (partially not shown) protrude from the first transverse surface 461e of the shell 400e. The other ends of these main piping portions 381e, 382e, 383e protrude from the second transverse surface 462e of the shell 400e. The ends of the utilization-side liquid piping portion 311 and the utilization-side gas piping portion 330 protrude from the piping transverse surface 463e of the shell 400e. Preferably, each of these piping ends is perpendicular to the transverse surface of the sleeve 400e from which the above-mentioned piping ends protrude.

[0303] The valve unit 200e also includes a switch box 601e in which the unit controller 600 is housed. The switch box 601e forms the box side surface 464e of the housing 400e and is arranged between the first transverse surface 461e and the second transverse surface 462e of the housing 400e. The multi-branch selector 300e is arranged between the piping transverse surface 463e of the housing 400e and the switch box 601e. In the following, the "internal space 401" refers to the space that is the internal space of the housing 400e but does not include the space occupied by the switch box 601e when in use. The space occupied by the switch box 601e when in use is referred to as the "box installation space".

[0304] The first opening 420 and the second opening 430 are positioned not to be blocked by the switch box 601e, and thus are open toward the inner space 401 of the housing 400e even when the switch box 601a is located at the box installation space.

[0305] Figure 21 is a top perspective view of the valve unit 200e with the top plate 468e removed.

[0306] The multi-branch selector 300e is fixed to the housing 400e, thereby being stable relative to the housing 400e. The housing 400e has a drain pan 470e below the multi-branch selector 300e. The drain pan 470e is configured on the bottom plate 469e of the housing 400e, and the above-mentioned bottom plate 469e forms a part of the bottom surface 466e of the housing 400e. The switch box 601e has a box bottom plate 611e, which forms the rest of the bottom surface 466e of the housing 400e. In other words, the bottom plate 469e and the box bottom plate 611e are flush with each other and form the bottom surface 466e of the housing 400e. However, the box bottom plate 611e can be recessed relative to the bottom plate 469e, or slightly protrude downward relative to the bottom plate 469.

[0307] The switch box 601e also has an outer plate 612e forming the box side 464e of the housing 400e and an inner plate 613e housed in the housing 400e. The outer plate 612e is fixed to one edge of the box bottom plate 611e at a right angle and extends upward to the top plate 468e of the housing 400e (see FIG. Figure 19 and Figure 20 The inner side plate 613e is fixed to the other edge of the bottom plate 611e at a right angle and extends upward to the top plate 468e of the housing 400e (see Figure 19 and Figure 20 The inner plate 613e is parallel to the outer plate 612e, that is, parallel to the box side 464e of the housing 400e. The unit controller 600 is housed and fixed in the space 601e (hereinafter referred to as the "box interior space") between the outer plate 612e and the inner plate 613e. The inner plate 613e separates the box interior space 602e of the switch box 601e from the interior space 401 of the housing 400e.

[0308] Preferably, the valve unit 200e includes an insulator 614e that covers a majority of the inner plate 613e on the side facing the interior space 401 of the housing 400e (i.e., the side facing the multi-branch selector 300e). The insulator 614e may be a thermal insulation board adhered to the inner plate 613e. The housing 400e may include another insulator, such as a thermal insulation board, that covers a majority of the inner surface of the board forming the first transverse surface 461e, the second transverse surface 462e, the pipe outlet surface 463e, and the top plate 468e. The drain pan 470e may also include an insulating layer, such as a thermal insulation board.

[0309] When the switch box 601e is removed, the interior space 401 of the housing 400e is open to the outside via the box installation space. This box installation space allows monitoring / maintenance personnel to monitor, maintain, or repair the multi-branch selector 300e. Therefore, the housing 400e is configured so that the switch box 601e can be detachably attached to the rest of the valve unit 200e. More specifically, the housing 400e is configured so that the switch box 601e can slide downward relative to the rest of the valve unit 200e, excluding the switch box 601a.

[0310] For example, the switch box 601e has a pair of plates or rods fixed to at least one of the box bottom plate 611e, the outer plate 612e, and the inner plate 613e. The pair of plates or rods extends parallel to the first transverse surface 461e and the second transverse surface 462e of the housing 400e and faces the inner surface of the housing 400e. A pair of grooves are formed in the pair of plates or rods. In other words, the switch box 601e has a groove extending in a plane parallel to the first transverse surface 461e and the second transverse surface 462e of the housing 400e. The housing 400e can have a pair of rod members, such as bolts, that protrude inwardly into the box installation space at relatively low positions. Such rod members can be fixed to the plates forming the first transverse surface 461e and the second transverse surface 462e of the housing 400e.

[0311] Therefore, the pair of rod members of the housing 400e respectively engage with the pair of grooves of the switch box 601e. The grooves have the same elongated shape, allowing the rod members to slide simultaneously along the grooves in the same direction. Thus, the switch box 601e can move along a path corresponding to the shape of the grooves. The grooves extend to a relatively high position, allowing most of the switch box 601e to be pulled out of the box installation space. The upper ends of the grooves are closed, allowing the switch box 601e to be suspended from the rest of the valve unit 200e at a lower position.

[0312] The slot can have an L-shape that extends toward the bottom surface 466 and then curves outward toward the box side 464e. This allows the switch box 601e to slide outward and laterally and then downward. Furthermore, this L-shape stabilizes the position of the switch box 601e in its normal position. Preferably, the valve unit 200e includes a fixing structure, such as a screw fastener, for securing the switch box 601e in its normal position relative to the rest of the valve unit 200a.

[0313] When the multi-branch selector 300e is controlled by the unit controller 600 via a signal cable (not shown), it is preferable to form a cable opening 615e in the inner plate 613e (and the isolator 614e) so that the box interior space 602e communicates with the interior space 401. Thus, the signal cable can be passed through the cable opening 615c. The signal cable should be long enough to prevent it from falling or falling off even when the switch box 601e is completely pulled out of the box installation space.

[0314] The configuration of the switch box 601e is not limited to the above-described structure. For example, if the impact of heat from the multi-branch selector 300e on the unit controller 600 is relatively small, the inner plate 613e and / or the insulator 614e may be omitted. The structure for sliding the switch box 601e downward relative to the remaining portion of the valve unit 200e, excluding the switch box, is also not limited to the above-described structure. For example, a pair of rod members may be provided in the switch box 601e, and a pair of grooves that engage with the rod members may be provided in the housing 400e.

[0315] The refrigerant leak detector 500 can be located within the interior space 401 of the housing 400e, the interior space 602e of the switch box 601e, or the interior space of a detector box protruding from the housing 400e. However, it is more preferable to locate the refrigerant leak detector 500 within the interior space 602e or the interior space of the protruding detector box, as these spaces are shielded from the heat emitted by the multi-branch selector 300e by the plates and insulators. The temperature in the interior space 401 can become very high during operation of the air conditioning system 100e, potentially causing the refrigerant leak detector 500 to malfunction.

[0316] When the refrigerant leak detector 500 is disposed in the box interior space 602e, a detector hole 510e may be formed in the inner plate 613e (and the insulator 614e) so that the space in which the detector hole 510a is disposed communicates with the interior space 401. When the refrigerant leak detector 500 is disposed in a detector box protruding from the housing 400e, the detector hole 510e may be formed in the plate provided with the detector box (and any insulator applied to the plate) so that the interior space of the detector box communicates with the interior space 401. Such a plate may be a plate forming the first lateral surface 461e or the second lateral surface 462e of the housing 400e.

[0317] As described above, the safety system 700e according to this embodiment includes a baffle unit 440e. The baffle unit 440e is configured to be attachable to the first opening 420 of the housing 400e of any valve unit 200e. A pipe connector 442e for connecting a pipe can be attached to the second opening 430. If the connecting pipe 740a is to be connected to the first opening 420, another pipe connector 442e can be attached to the first opening 420. If the connecting pipe 740a is not connected to the first opening 420, the baffle unit 440e can be attached to the first opening 420 directly or indirectly via a pipe or the like.

[0318] Figures 22 to 24 They are a front plan view, a rear perspective view, and a front perspective view of the baffle unit 440e, respectively.

[0319] Baffle unit 440e includes baffle 440 and a generally box-shaped baffle housing 443e. However, the shape of baffle housing 443e is not limited thereto. Baffle housing 443e includes two opposing plates: a duct side plate 444e and a unit side plate 445e. Duct side plate 444e is formed with a duct side opening 446e, and unit side plate 445e is formed with a unit side opening 447e. A duct connector 442e can be attached to duct side opening 446e.

[0320] The baffle unit 440e also includes a rotating plate 448e and a motor unit 449e that form the baffle 440. The rotating plate 448e is configured to rotate along the unit side plate 445e and close the unit side opening 447e when in a first position, and to open the unit side opening 447e when in a second position. In other words, when the rotating plate 448e is in the first position, the baffle 440 is closed, and when the rotating plate 448e is in the second position, the baffle 440 is opened. The motor unit 449e is configured to control the rotation of the rotating plate 448e under the control of the unit controller 600 or the central controller 800a to switch between the first and second positions. The baffle unit 440e is fixed to the housing 400e on the first transverse surface 461e so that the unit side opening 447e and the first opening 420 at least partially overlap. Preferably, in a state where the baffle unit 440e is fixed to the housing 400e, the periphery of the first opening 420 and the periphery of the duct-side opening 446e coincide when viewed from a direction perpendicular to the first lateral surface 461e.

[0321] Therefore, the baffle 440 of the baffle unit 440e is configured to block air from passing through the first terminal opening when the baffle 440 is closed, and to allow air to pass through the second terminal opening when the baffle 440 is open. Here, the first terminal opening refers to the first opening 420, which is an opening of one of the valve units 200e connected via at least one connecting pipe 740a connected in series with the ventilator 730, and which is not connected to any other valve unit 200a via the connecting pipe 740b. Preferably, the housing 400e and the baffle unit 440e are configured so that the baffle unit 440e can be detachably attached to the first opening 420 of any valve unit 200e.

[0322] like Figure 18 As shown, the interior space 401_1 of the first housing 400e_1 and the interior space 401_3 of the third housing 400e_3 are connected in series and lead to the ventilator 730 via a common duct 720a. When the ventilator 730 operates due to refrigerant leakage in any of the valve units 200e_1, 200e_2, and 200e_3, the damper 440 of the damper unit 440e is controlled to open. As a result, the first opening 420 of the third valve unit 200e_3 serves as an air intake for external air, promoting ventilation of the air in the housings 400e_1, 400e_2, and 400e_3.

[0323] As described above, the valve unit 200e has a drain pan 470e below the multi-branch selector 300e. The drain pan 470e and the bottom plate 469e on which the drain pan 470e is disposed are part of the housing 400e but are detachably attached to the rest of the housing 400e.

[0324] Figure 25 It is a perspective view of the drain pan 470e.

[0325] like Figure 25 As shown, drain pan 470e includes a drain plate 471e, a wall portion 472e, and a drain outlet 473e. Drain pan 470e includes a drain pan bottom surface 474e, which is the bottom surface of drain pan 470a and contacts the upper surface of bottom plate 469e of housing 400e when drain pan 470e is placed on bottom plate 469e. Drain pan 470e may include a drain pan bottom plate (not shown) forming drain pan bottom surface 474e. When viewed from a direction perpendicular to drain pan bottom surface 474 (hereinafter referred to as the "vertical direction"), the perimeter of drain plate 471e roughly coincides with the perimeter of interior space 401 of housing 400e. As described above, interior space 401 does not include the tank installation space. Wall portion 472e is formed along the perimeter of drain plate 471e and extends upward to surround the upper surface of drain plate 471 facing multi-branch selector 300e.

[0326] Drain outlet 473e protrudes from the edge of drain pan 470e. More specifically, drain outlet 473e is configured to discharge liquid (including refrigerant) from the upper surface of drain plate 471e through an opening or groove formed in drain plate 472e or wall portion 472e to the exterior of housing 400e when the liquid accumulates on the upper surface of drain plate 471e. Drain outlet 473e may be in the form of a pipe that penetrates wall portion 472e. Preferably, drain outlet 473e is disposed on an edge extending along first transverse surface 461e or second transverse surface 462e. It is also preferred that the upper surface of drain plate 471e be inclined downwardly toward drain outlet 473e.

[0327] The housing 400e is configured so that the drain pan 470e can switch between at least two positions in which the drain outlet 473e protrudes in different directions. As described above, the drain pan 470e is disposed on the bottom plate 469e of the housing 400e. The bottom plate 469e is secured to the plate of the housing 400e that forms the first transverse surface 461e and the second transverse surface 462e by screws. Thus, the position and protruding direction of the drain outlet 473e can be changed 180 degrees simply by removing the screws, removing the bottom plate 469e and the drain pan 470e from the plate that forms the first transverse surface 461e and the second transverse surface 462e, rotating the drain pan 470e on the upper surface of the bottom plate 469e, attaching the bottom plate 469e and the drain pan 470e to the plate that forms the first transverse surface 461e and the second transverse surface 461e, and securing the screws. The housing 400e may be formed with recesses so that the discharge outlet 473e may be fitted into one recess regardless of the protruding direction of the discharge outlet 473e.

[0328] (Arrangement of adjacent valve units)

[0329] The box shape of the housing 400e facilitates compact arrangement of multiple valve units 200e. In addition, the arrangement of the first opening 420 and the second opening 430 relative to the first and second lateral surfaces 461e and 462e as opposed lateral surfaces further facilitates compact arrangement of adjacent valve units 200e.

[0330] Figure 26 Schematic diagram showing the arrangement of adjacent valve units. Here, the first valve unit 200e_1 and the second valve unit 200e_2 are examples of two adjacent valve units.

[0331] like Figure 26As shown, the first valve unit 200e_1 and the second valve unit 200e_2 can be arranged adjacent to each other so that their bottom surfaces 466e are flush with each other. This can minimize the height range H of the arrangement space of the housing 400e of the first valve unit 200e_1 and the second valve unit 200e_2. Here, the height range H refers to the range in a direction perpendicular to any bottom surface 466e.

[0332] The first valve unit 200e_1 and the second valve unit 200e_2 can also be arranged so that their third transverse surfaces are flush with each other. The third transverse surface can be the housing side surface 464e. In this case, the width W of the arrangement space of the housing 400e of the first valve unit 200e_1 and the second valve unit 200e_2 can be minimized. Here, the width W refers to the range in a direction perpendicular to any third transverse surface (for example, a direction perpendicular to any housing side surface 464e).

[0333] Hereinafter, this arrangement, in which the bottom surfaces 466e of the first valve unit 200e_1 and the second valve unit 200e_2 are flush with each other, their third lateral surfaces are flush with each other, and the second surface 462e of the first valve unit 200e_1 and the first surface 461e of the second valve unit 200e_2 face each other, is referred to as an "aligned arrangement." This aligned arrangement allows the connecting conduit 740a to be arranged within the space between adjacent valve units 200e. Consequently, the arrangement space for adjacent valve units 200e and the connecting conduit 740a therebetween can be kept compact.

[0334] Furthermore, the housing 400e can be configured such that the centers of the first and second openings 420, 430, their ends closer to the third transverse plane (e.g., the side surface 464e), and / or their ends further from the third transverse plane (hereinafter referred to as "corresponding points") are located at the same distance from the third transverse plane. For example, the distance dw1 from the center of the first opening 420 to the side surface 464e and the distance dw2 from the center of the second opening 430 to the side surface 464e can be substantially equal. Additionally or alternatively, the housing 400e can be configured such that the centers, their ends closer to the bottom surface 466e, and / or their ends further from the bottom surface 467e (hereinafter referred to as "corresponding points") are located at the same distance from the bottom surface 468e. For example, the distance dh1 from the center of the first opening 420 to the bottom surface 466e and the distance dh2 from the center of the second opening 430 to the top surface 466e can be substantially equal. In any case, it is preferable that the periphery of the first opening 420 and the periphery of the second opening 430 coincide when viewed from a direction perpendicular to the first lateral surface 461 e and the second lateral surface 462 e (hereinafter referred to as “lateral direction”).

[0335] This arrangement of the first opening 420 and the second opening 430 is advantageous when adjacent valve units 200e are in an aligned arrangement as described above. Figure 26 In the alignment arrangement shown, when viewed from a direction perpendicular to the first lateral surface 461e of the first valve unit 200e_1 and the second lateral surface 462e of the second valve unit 200e_2 (hereinafter referred to as the "alignment direction"), the position (or periphery) of the second opening 430 of the first valve unit 200e_1 is consistent with the first opening 420 of the second valve unit 200e_2.

[0336] When observing from the alignment direction, when the positions (or peripheries) of the first opening 420 and the second opening 430 of adjacent valve units 200e are consistent, the connecting pipe 740a connected to the pipe connector 442e attached to the first opening 420 and the second opening 430 can be a simple linear shape. Therefore, the distance between adjacent valve units 200e can be minimized. In addition, the length and installation burden of the connecting pipe 740a can be reduced. However, the positional relationship between the first opening 420 and the second opening 430 is not limited to the positional relationship as described above. For example, the first opening 420 and the second opening 430 can be arranged so that when observed from the lateral direction, the first opening 420 and the second opening 420 of each valve unit 200e only partially overlap each other.

[0337] As for the pipeline, it is preferable that, when viewed from the transverse direction, the positions of the ends of the main pipe portions 381e, 382e, 383e protruding from the first transverse surface 461e are also consistent with the positions of the other ends of the same main pipe portions 381e, 382e, 383e protruding from the second transverse surface 462e (see FIG. Figure 20 Therefore, the connecting pipes 161e, 162e, 163e connecting the main pipe sections 381e, 382e, 383e of the adjacent valve units 200e may also be simple linear shapes (see Figure 17 ).

[0338] (Advantageous Effects of the Fifth Embodiment)

[0339] As described above, the valve unit 200e according to the fifth embodiment is advantageous in making the layout space of at least a portion of the safety system 700e more compact and reducing the cost of the safety system 700e. This compact layout space increases the installation flexibility of the air conditioning system 100e including the safety system 700e. For example, the valve unit 200e can be placed in a limited space near the location where the utilization-side unit 120 is located.

[0340] Therefore, at least two valve units 200e, the connecting pipe 740a connecting them, and the utilization-side unit 120 belonging to the at least two valve units 200e can be installed on the same floor of a building. In this case, it is preferable that the common pipe 720a and the ventilator 730 (i.e., the exhaust structure) to be connected to one of the valve units 200e or the connecting pipe 740a are also installed on the same floor.

[0341] In addition, when the utilization side unit 120 is installed in the target space (the first space to be air-conditioned by the utilization side unit 120a), at least two valve units 200e and the connecting pipe 740a may be installed in an adjacent space (the second space) adjacent to the target space. In this case, it is preferred that the common pipe 720a and the ventilator 730 are also installed in the same adjacent space. Alternatively, all the utilization side units 120, at least two valve units 200e, the connecting pipes 740a therebetween, the common pipe 720a and the ventilator 730 may also be installed in the target space. Here, both the room to be air-conditioned by the utilization side unit 120 and the ceiling space directly above the room may be regarded as a single "target space".

[0342] Alternatively, at least two valve units 200e may be installed on different floors of a building. In this case, the connecting pipe 740a connecting them is arranged on different floors, and the common pipe 720a having the ventilator 730 is connected to the connecting pipe 740b. The ventilator 730 may be installed on one of the different floors of the building or on another different floor.

[0343] It should also be noted that the configuration of the piping of the air conditioning system 100e is not limited to a particular configuration. Variations in the system layout and piping configuration and other modifications are described below.

[0344] (First Modification of the Fifth Embodiment)

[0345] Figure 27 is a schematic configuration diagram of an air conditioning system according to a first modified example of the fifth embodiment. Figure 27 The dotted line in the figure represents the building structure where the air conditioning system is installed.

[0346] like Figure 27As shown, an air conditioning system 100f including a security system 700f according to a first variation is installed in a building 920f. The building 920f has a ground floor 921f, a second floor 922f, and a top floor 923f. Each of the ground floor 921f and the second floor 922f has at least one target space 924f and at least one non-target space 925f. Each of the ground floor 921f and the second floor 922f can have a first ceiling space 926f located directly above the target space 924f behind the ceiling and / or a second ceiling space 927f located directly above the non-target space 925f behind the ceiling. However, the first ceiling space 926f can be considered as part of the target space 924fb, and the second ceiling space 927f can be considered as part of the non-target space 925f, particularly when there is no ceiling in the building.

[0347] A utilization-side unit 120 is installed in each target space 924f. The utilization-side unit 120 may be a ceiling-mounted air conditioner having an air outlet on its bottom surface. In this case, the utilization-side unit 120 may be installed in the first ceiling space 926f along the ceiling, with its bottom surface exposed to the target space 924f through an opening formed in the ceiling. The utilization-side unit 120 may be suspended from the bottom surface of the building's ceiling using a metal hanger or the like.

[0348] Multiple valve units 200f of the safety system 700f are installed in each second ceiling space 927f. The valve units 200f, the connecting pipes 740a connecting them, and the utilization-side unit 120 connected to the valve units 200f are installed on the same floor. The common pipe 720a and the ventilator 730 connected to one of the valve units 200f or the connecting pipe 740a are also installed in the second ceiling space 927f on the same floor.

[0349] In addition, if Figure 27As shown, it is preferable to configure a safety system 700f for each floor. For example, for each of the ground floor 921f and the second floor 922f, two valve units 200f, a connecting pipe 740a connecting the two valve units 200f, a common pipe 720a connected to one of the two valve units 200f, and a ventilator 730 configured in the common pipe 720b are installed in the same second ceiling space 927f. Alternatively, for each of the ground floor 921f and the second floor 922f, at least a portion of the common pipe 720a and the ventilator 730 configured in that portion can be installed in a separate space from the second ceiling space 927f but on the same floor as the other components of the safety system 700f. This reduces the total length of the pipes connecting the housing 400e to the discharge structure, thereby reducing the system's installation costs. Furthermore, if a refrigerant leak occurs in any valve unit 200f, the leaked refrigerant can be efficiently discharged from the valve unit 200b in a short period of time.

[0350] Here, the configuration of the refrigerant pipe 130f of the first modification is similar to that of the first to fourth embodiments (see Figure 1 ). In other words, the refrigerant pipeline of the valve unit 200f is connected in parallel with the heat source side unit 110. Therefore, the valve unit 200f has a heat source side liquid piping portion 310, a low-pressure gas sub-piping portion 320 and a high-pressure gas piping portion 340 (hereinafter referred to as the "branch main piping portion"), instead of the main piping portions 381e, 382e, 383e. The structure of the other parts of the valve unit 200f can be the same as that of the valve unit 200e. The ends of the branch main piping portions 310, 320, 340 preferably protrude from the first surface 461e or the second surface 462e of the shell 400e. These ends of the valve unit 200f are connected to the liquid refrigerant piping 131, the low-pressure gas refrigerant piping 132 and the high-pressure gas refrigerant piping 133 of the heat source side unit 110 (see Figure 1 ).

[0351] The valve unit 200 f and each of the usage-side units 120 belonging thereto are connected via a usage-side liquid refrigerant pipe 151 and a usage-side gas refrigerant pipe 152 (hereinafter referred to as “usage-side pipe”).

[0352] The valve unit 200f is preferably arranged on approximately the same horizontal plane as the utilization-side unit 120 connected to the valve unit 200f. Furthermore, the valve unit 200f is preferably arranged so that the pipe outlet surface 463e faces the direction forming the first ceiling space 926f. This simplifies the layout of the utilization-side pipes 151 and 152. Furthermore, since the second ceiling space 927f is adjacent to the first ceiling space 926f, the utilization-side pipes 152 and 151 can be minimized.

[0353] When the arrangement space of the valve units 200f and the connecting pipes 740a therebetween is small, such an arrangement of the space can be easily realized. As described above, when the corresponding points of the first opening 420 and the second opening 430 of each valve unit 200f are at approximately the same position when viewed from the lateral direction and / or when the adjacent valve units 200f are at the same position as above, the arrangement of the valve units 200f and the connecting pipes 740a therebetween is easily realized. Figure 26 This smaller arrangement space is easily achieved with the aligned arrangement shown.

[0354] although Figure 27 While the example in which the utilization side unit 120 is installed in the first ceiling space 926f separate from the target space 924f and the valve unit 200f is installed in the second ceiling space 927f separate from the non-target space 925f is shown, the arrangement of the units is not limited thereto. The valve unit 200f and the connecting pipe 740a connecting them can be installed in any of the target space 924f, the first ceiling space 926f, and the non-target space 925f, instead of or in addition to the second ceiling space. For example, the utilization side unit 120 and the valve unit 200f can be installed in the same target space 924f. In any case, it is preferred that each security system 700f be configured for each floor.

[0355] As described above, the arrangement of the first opening 420 and the second opening 430 of the valve unit 200e and the aligned arrangement of the valve unit 200e facilitate the design and installation of the air conditioning system 100f. It should be noted that the entire structure comprising not only the air conditioning system 100f but also at least the valve unit 200f and one or more spaces connected to the valve unit 200f, including the utilization-side unit 120, can be considered an air conditioning system. The building structure forming the one or more spaces can also be considered part of the air conditioning system.

[0356] Any of the safety systems 700e and 700f according to the first embodiment and the first modification thereof may include a plurality of valve units 200e and 200f. Figure 8 The safety system 700b of the third embodiment shown is also connected in parallel with the exhaust structure.

[0357] (Second Modification of the Fifth Embodiment)

[0358] The valve unit according to the fifth embodiment can also be applied to Figure 3 and Figure 8 The system configuration shown is one in which the interior spaces 401 of at least two valve units are connected in parallel to each other.

[0359] Figure 28 is a schematic configuration diagram of an air conditioning system according to a second modification of the fifth embodiment.

[0360] For example, an air conditioning system 100g including a safety system 700g according to the second variation is installed in a building having the same structure as the building 920f of the first variation. The air conditioning system 100g includes multiple valve units 200f and multiple utilization-side units 120. The multiple valve units 200f have the same structure as the valve units 200f of the first variation. The arrangement of the valve units 200f, utilization-side units 120, refrigerant piping 130f, and utilization-side pipes 151 and 152 can be the same as that of the first variation. However, the connection structure for connecting the internal space of the housing 400e of the valve units 200f differs from that of the first variation.

[0361] In a second variation, a connecting structure connects valve units 200f above the ground floor 921f and the second floor 922f. More specifically, the air conditioning system 100g includes a plurality of individual ducts 710 connected to valve units 200f on different floors, and a common duct 720a connected to each individual duct 710. Thus, at least a portion of the individual ducts 710 and / or the common duct 720a extends vertically. The individual ducts 710 and / or the common duct 720a may pass through the ceiling of the building 920f, pass through and run along the outer walls of the building 920f, and / or run in a vertical shaft extending above different floors of the building 920f. The common duct 720a may extend to the top floor 923f, and the ventilator 730 may be located on the top floor 923f.

[0362] Even with this configuration, since no pipes protrude directly upward or downward from valve unit 200f, the height range of the space required to arrange valve unit 200f and the pipes connected thereto can be reduced. Consequently, as with the first variant described above, this can facilitate the design and installation of air conditioning system 100g. This configuration is advantageous when valve units 200f on the same floor are located far from one another. It should be noted that the entire structure comprising not only air conditioning system 100g but also at least valve unit 200f and one or more spaces connected thereto, including the utilization-side unit 120, can be considered an air conditioning system. The building structure forming one or more spaces can also be considered part of the air conditioning system.

[0363] Needless to say, if Figure 27 and Figure 28 The arrangement of the utilization side unit 120 and the valve unit 200f in the building 920f shown can be applied to a building having Figure 17 In other words, the piping structure of any of the air conditioning systems 100f and 100g is not limited to the piping structure described above.

[0364] Furthermore, the configuration of the air conditioning system 100f according to the first modification and the configuration of the air conditioning system 100g according to the second modification may also be similar to that according to the third embodiment. Figure 8 For example, the second variant of the safety system 700g may include Figure 8 As with the safety system 700b of the third embodiment shown, a plurality of valve units 200f are connected in series with the exhaust structure.

[0365] (Third Modification of Fifth Embodiment)

[0366] The relative positional relationship between adjacent valve units is not limited to the relationship described above. For example, adjacent valve units can be arranged so that their piping outlet surfaces 463e face different directions (e.g., opposite directions). In this case, the adjacent valve units can be positioned and configured so that their main piping sections 381e, 382e, and 383e are connected in a straight line. With this configuration, the housing 400e protrudes in different directions (e.g., opposite directions) relative to the pipelines of the main piping sections 381e, 382e, and 383e.

[0367] (Other Modifications of the Fifth Embodiment)

[0368] In the above description of the fifth embodiment, it is assumed that the housings 400e of all valve units are identical in shape and size. However, the dimensions of the housings 400e may vary between valve units. Furthermore, the third transverse surface, from which corresponding points of the first opening 420 and the second opening 430 are approximately equidistant, may be the piping outlet surface 463e of the housing 400e, instead of the tank side surface 464e.

[0369] Any of the air conditioning systems 100e, 100f, 100g may include a heat pump system having a so-called double-pipe structure. Figure 12 As shown, the piping housed in the housing 400e is not the multi-branch selector 300. Furthermore, the heat source-side liquid piping section 310 and the one or more gas piping sections 320 and 340 do not necessarily need to branch toward two or more utilization-side units 120, but rather only toward one of the utilization-side units 120. However, when the valve unit includes at least a liquid refrigerant piping section, a gas refrigerant piping section, a liquid control valve disposed in the liquid refrigerant piping section, and a gas control valve disposed in the gas refrigerant piping section within the housing, the safety system can improve safety against refrigerant leaks in the air conditioning system.

[0370] Any valve unit 200e, 200f may have a configuration in which the first opening 420 and the second opening 430 are respectively formed in two adjacent lateral surfaces of the housing 400e, such as Figure 14 As shown in the second mode P2.

[0371] The shapes of the first opening 420 and the second opening 430 are not limited to those shown in the drawings. The first opening 420 and the second opening 430 may be, for example, rectangular in shape. In any case, it is preferred that the first opening 420 and the second opening 430 be substantially the same in shape and size when viewed from a transverse direction.

[0372] The shape of the housing 400e is not limited to a box shape, but may include any polyhedron having at least two transverse faces facing in different directions. Preferably, these transverse faces are substantially parallel to each other so as to form opposing faces of the housing.

[0373] When viewed in the lateral direction, the positions of corresponding points of the first opening 420 and the second opening 430 may be different. Even such a configuration is advantageous when adjacent valve units are arranged such that their bottom surfaces and / or their third lateral surfaces are offset by a predetermined positional difference.

[0374] The ends of the main piping sections 381e, 382e, and 383e may protrude from a surface of the housing other than the first and second transverse surfaces 461e and 462e. Alternatively, all ends of the main piping sections 381e, 382e, and 383e may protrude from one of the first and second transverse surfaces 461e and 462e. The ends of the utilization-side liquid piping section 311 and the utilization-side gas piping section 330 may also protrude from a surface of the housing other than the piping outlet surface 463.

[0375] The housing does not necessarily need to enable the switch box 601e to slide downward relative to a portion of the valve unit other than the switch box 601a. ​​In this case, the position of the switch box 601e is not limited to Figure 21 In addition, the valve units 200e and 200f do not necessarily need to have the switch box 601e, and the unit controller 600 can be simply arranged in the housing 400e. In any case, it is preferable to arrange a heat insulation plate between the unit controller 600 and the space where the valve is arranged.

[0376] In the case where serial connection of multiple valve units 200e is not required, for example, when only a single valve unit 200e is used, the pipe connector 442e and the pipe side plate 444e of the baffle unit 440e can be removed from the baffle assembly. In addition, the pipe connector 442e can be detachably attached to the housing 400e, so that when the baffle unit 440e is attached to the first opening 420 as an optional kit, the pipe connector 441e can be removed from the first opening 420.

[0377] and Figure 6As in the second embodiment shown, a baffle 440 may be provided at the first opening 420 connected to the connecting duct 740a, in place of the baffle unit 440e. Alternatively, if the air flow through the first terminal opening is low, any baffle may be omitted from the first opening 420, at least when the ventilator is not running.

[0378] If ventilation of the internal air through the connection structure is due to natural convection or air flow caused by an external mechanism, the ventilator 730 can be omitted. In this case, it is preferred that when refrigerant leakage occurs in the internal space 401 of any valve unit between the first opening of the terminal and the common pipe 720a, the unit controller 600 or the central controller 800a controls the damper 440 at the first opening of the terminal, and preferably controls another damper 440 arranged in the common pipe 720b to open.

[0379] The housing 400e does not necessarily need to be configured so that the drain pan 470e can be switched between at least two states in which the drain outlet 473e protrudes in different directions. In addition, the drain pan 470e may be a simple plate without the drain outlet 473e.

[0380] The number of unit clusters 121 (i.e., the number of valve units 200e, 200f), the number of utilization-side units 120 belonging to each unit cluster 121, the number of valve units 200a, 200f connected in series, the number of target spaces 924f, and the number of floors on which the valve units 200b, 200f are installed are not limited to the numbers described above. The location of the refrigerant leak detector 500 is also not limited to the location described above.

[0381] Any other changes or modifications of the first to fourth embodiments described above may also be applied to the fifth embodiment, the first modification, the second modification, and the third modification, as long as they are not incompatible.

[0382] Although only selected embodiments and variations have been chosen to illustrate the present invention, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made without departing from the scope of the present invention as defined in the appended claims. For example, unless otherwise specifically stated, the size, shape, position or orientation of the various components may be changed as needed and / or desired, as long as these changes do not substantially affect their intended function. Unless otherwise specifically stated, components shown as being directly connected or in contact with each other may have an intermediate structure configured between them, as long as these changes do not substantially affect their intended function. Unless otherwise specifically stated, the function of one element may be performed by two elements, and vice versa. The structure and function of one embodiment may be adopted in another embodiment. All advantages do not need to appear in a particular embodiment at the same time. Thus, the foregoing description of the embodiments of the present invention provided is for illustration only.

[0383] [Reference Signs List]

[0384] 100, 100e, 100f, 100g: air conditioning system;

[0385] 110: heat source side unit;

[0386] 120: Utilize the side unit;

[0387] 121: unit family;

[0388] 130f: refrigerant pipeline;

[0389] 131: Liquid refrigerant piping;

[0390] 132: low-pressure gas refrigerant piping;

[0391] 133: High-pressure gas refrigerant piping;

[0392] 141: heat source side liquid piping;

[0393] 142: low-pressure gas piping on the heat source side;

[0394] 143: heat source side high pressure gas piping;

[0395] 151: Utilization side liquid refrigerant piping;

[0396] 152: gas refrigerant pipe on the utilization side;

[0397] 161e: Liquid refrigerant connecting pipe;

[0398] 162e: low-pressure gas refrigerant connecting pipe;

[0399] 163e: High-pressure gas connecting pipe;

[0400] 200, 200d, 200e, 200f: valve unit;

[0401] 300, 300e: multi-branch selector;

[0402] 310: heat source side liquid piping part;

[0403] 311: Utilization side liquid piping portion (liquid refrigerant piping portion);

[0404] 320: low-pressure gas piping section (gas refrigerant piping section);

[0405] 321: low-pressure gas sub-pipe (gas refrigerant piping part);

[0406] 330: Utilization side gas piping portion (gas refrigerant piping portion);

[0407] 340: high-pressure gas piping portion (gas refrigerant piping portion);

[0408] 341: high-pressure gas sub-pipe (gas refrigerant piping portion);

[0409] 351: Bypass piping;

[0410] 352: Refrigerant heat exchanger;

[0411] 361: Low pressure gas control valve (gas control valve);

[0412] 362: High pressure gas control valve (gas control valve);

[0413] 363: expansion mechanism;

[0414] 364: Liquid stop valve (liquid control valve);

[0415] 365: Gas shut-off valve (gas control valve);

[0416] 370: Piping connection parts;

[0417] 381e: Main liquid refrigerant piping section;

[0418] 382e: Main low-pressure gas refrigerant piping section;

[0419] 383e: Main high-pressure gas refrigerant piping section;

[0420] 400, 400e: housing;

[0421] 401: interior space;

[0422] 410: Piping hole;

[0423] 420: First opening;

[0424] 430: Second opening;

[0425] 440: baffle;

[0426] 440e: baffle unit;

[0427] 441: Wings;

[0428] 442e: Pipeline connectors;

[0429] 443e: baffle housing;

[0430] 444e: Pipe side panel;

[0431] 445e: unit side panel;

[0432] 446e: Pipe side opening;

[0433] 447e: unit side opening;

[0434] 448e: rotating plate;

[0435] 449e: Motor unit;

[0436] 450: Isolate;

[0437] 461e: first transverse plane;

[0438] 462e: second transverse plane;

[0439] 463e: Pipe outlet surface (third transverse surface);

[0440] 464e: box side (third transverse surface, fourth transverse surface);

[0441] 465e: top surface;

[0442] 466e: Bottom;

[0443] 467e: Suspension elements;

[0444] 468e: top plate;

[0445] 469e: bottom plate;

[0446] 470e: drain pan;

[0447] 471e: Drain board;

[0448] 472e: siding;

[0449] 473e: drainage outlet;

[0450] 474e: bottom surface of drain pan;

[0451] 500: Refrigerant leak detector;

[0452] 510e: detector hole;

[0453] 600: unit controller (controller);

[0454] 601e: switch box;

[0455] 602e: box interior space;

[0456] 611e: box bottom plate;

[0457] 612e: lateral plate;

[0458] 613e: inner side panel;

[0459] 614e: Isolate;

[0460] 615e: Cable opening;

[0461] 700, 700a, 700b, 700c, 700e, 700f, 700g: security system;

[0462] 701c: Section;

[0463] 710: separate pipeline (connecting structure);

[0464] 720, 720a, 720b: common pipeline (discharge structure);

[0465] 730: Ventilator (discharge structure);

[0466] 740a: connecting pipe (connecting structure);

[0467] 800, 800a, 800b, 800c: central controller (controller);

[0468] 801: Communication path;

[0469] 910b, 910c: grouping table;

[0470] 920f: buildings;

[0471] 921f: Ground floor;

[0472] 922f: second floor;

[0473] 923f: Top floor;

[0474] 924f: target space;

[0475] 925f: non-target space;

[0476] 926f: First ceiling space; 927f: Second ceiling space; 928f: Outdoor space.

[0477] [Citation List]

[0478] [Patent Document]

[0479] [Patent Document 1] EP3091314A1

Claims

1. A security system comprising: A first valve unit and a second valve unit for a heat pump system, each of the first valve unit and the second valve unit having at least one liquid refrigerant piping portion, at least one gas refrigerant piping portion, at least one liquid control valve disposed in the liquid refrigerant piping portion, at least one gas control valve disposed in the gas refrigerant piping portion, a housing that accommodates at least the liquid control valve and the gas control valve and is formed with at least two openings, and a refrigerant leak detector configured to detect occurrence of refrigerant leakage in the interior space of the housing; a connecting structure, the connecting structure being a pipe connecting an interior space of the first housing and an interior space of the second housing via one of the openings of the first housing and one of the openings of the second housing, wherein the first housing is a housing of the first valve unit and the second housing is a housing of the second valve unit; as well as a discharge structure connected to the other of the openings of the first housing or the connection structure, and the safety system is configured to discharge air from the interior space of the housing where the refrigerant leakage has occurred, The housing of each of the first valve unit and the second valve unit has a first lateral surface and a second lateral surface facing in different directions, In each of the first valve unit and the second valve unit, a first opening as one of the openings is formed in the first lateral surface, and a second opening as the other of the openings is formed in the second lateral surface.

2. The security system according to claim 1, wherein: The housing of each of the first valve unit and the second valve unit has a substantially box shape, The first lateral surface and the second lateral surface are opposing surfaces of the housing.

3. The security system according to claim 2, wherein: The first opening and the second opening at least partially overlap each other when viewed from a direction generally perpendicular to the first and second lateral faces.

4. The security system according to claim 1, wherein: The housing of each of the first valve unit and the second valve unit has a bottom surface perpendicular to the first lateral surface and the second lateral surface, The housing is configured such that centers, ends closer to the bottom surface, and / or ends farther from the bottom surface of the first and second openings are at the same distance from the bottom surface.

5. The security system according to claim 4, wherein: The first valve unit and the second valve unit are arranged adjacent to each other such that a bottom surface of the first valve unit and a bottom surface of the second valve unit are flush with each other.

6. The security system according to claim 1, wherein: The housing of each of the first valve unit and the second valve unit has a third transverse surface perpendicular to the first transverse surface and the second transverse surface, The housing is configured such that the centers, ends closer to the third transverse plane, and / or ends farther from the third transverse plane of the first opening and the second opening are at the same distance from the third transverse plane.

7. The security system according to claim 6, wherein: The first valve unit and the second valve unit are arranged adjacent to each other such that a third surface of the first valve unit and a third surface of the second valve unit are flush with each other.

8. The security system according to claim 1, wherein: Each of the first valve unit and the second valve unit further has: a main liquid refrigerant piping portion from which the liquid refrigerant piping portion branches; and a main gas refrigerant piping portion, the gas refrigerant piping portion branching from the main gas refrigerant piping portion, In each of the first valve unit and the second valve unit, one end of the main liquid refrigerant piping portion and one end of the main gas refrigerant piping portion protrude from the first lateral surface, and the other end of the main liquid refrigerant piping portion and the other end of the main gas refrigerant piping portion protrude from the second lateral surface, The safety system further comprises: at least one liquid refrigerant connecting pipe connecting the main liquid refrigerant piping portion of the first valve unit and the main liquid refrigerant piping portion of the second valve unit; and At least one gas refrigerant connecting pipe that connects the main gas refrigerant piping portion of the first valve unit and the main gas refrigerant piping portion of the second valve unit.

9. The security system according to claim 8, wherein: The housing of each of the first valve unit and the second valve unit has a pipe outlet surface different from the first lateral surface and the second lateral surface, One end of the liquid refrigerant piping portion and one end of the gas refrigerant piping portion protrude from the piping outlet surface.

10. The security system according to claim 1, wherein: The housing of each of the first valve unit and the second valve unit has a drain pan provided with a drain outlet protruding from an edge of the drain pan, The housing is configured such that the drain pan is switchable between at least two states in which the drain outlet protrudes in different directions.

11. The security system according to claim 1, wherein: The discharge structure includes: a common pipe connected to the other of the openings of the first housing or the connection structure; and A ventilator is arranged in the common duct.

12. The security system according to claim 11, wherein: The common conduit has a first end and a second end, The ventilator is disposed at or near the second end of the common duct and is configured to draw air in the common duct toward the first end. The common duct is connected to the other of the openings of the first housing or the connection structure at the first end portion on a side opposite to the ventilator.

13. The security system according to claim 12, wherein: The second end portion of the common pipe is open to an outdoor space.

14. The security system according to claim 11, wherein: The safety system further comprises: A first controller is configured to control the ventilation fan to start operating when refrigerant leakage occurs in any one of the first valve unit and the second valve unit.

15. The security system according to claim 14, wherein: Each of the refrigerant leak detectors is configured to output detection result information, The first controller is configured to receive detection result information output from any one of the refrigerant leak detectors, and identify in which of the first valve unit and the second valve unit the refrigerant leakage has occurred based on the received detection result.

16. The security system according to claim 1, wherein: The connection structure includes a plurality of individual pipes, which are respectively connected to the second opening of the housing and are also commonly connected to the common pipe.

17. The security system according to claim 14, wherein: Each of the first valve unit and the second valve unit further has: a baffle configured to block air from passing through the first opening when the baffle is closed and to allow air to pass through the first opening when the baffle is open, The first controller is configured to control the damper so that, when the ventilator operates due to occurrence of refrigerant leakage, the damper of one of the first valve unit and the second valve unit in which refrigerant leakage occurs is opened, while the damper of the other of the first valve unit and the second valve unit in which refrigerant leakage does not occur is closed.

18. The security system according to claim 17, wherein: The first controller includes: a plurality of unit controllers, wherein the plurality of unit controllers are respectively configured in the first valve unit and the second valve unit; and a central controller configured to communicate with the unit controllers, Each of the refrigerant leak detectors is configured to send detection result information to the central controller via the corresponding unit controller. The central controller is configured to determine whether refrigerant leakage has occurred in either of the first valve unit and the second valve unit based on the detection result information received from the first valve unit and the second valve unit, and when refrigerant leakage has occurred in either of the first valve unit and the second valve unit, send a damper opening command to the damper of one of the first valve unit and the second valve unit where the refrigerant leakage has occurred via the corresponding unit controller, and control the ventilator to start operation.

19. The security system of claim 1, wherein: The connection structure includes: at least one connecting pipe connecting the first opening of the first valve unit and the second opening of the second valve unit, The discharge structure is connected to the second opening of the first valve unit.

20. The security system of claim 12, wherein: The first valve unit and the second valve unit are arranged such that the first lateral surface of the first valve unit and the second lateral surface of the second valve unit face each other.

21. The safety system of claim 12, comprising said common duct and said ventilator, wherein: The safety system further comprises: a damper configured to block air from passing through a terminal first opening when the damper is closed and to allow air to pass through a terminal second opening when the damper is open, the terminal first opening being an opening of one of the first valve unit and the second valve unit connected in series with the ventilator by the at least one connecting duct and not connected to the connecting duct; and A second controller is configured to control the damper to open when the ventilator operates due to refrigerant leakage in any valve unit connected in series.

22. The security system of claim 21, wherein: The safety system further comprises: a baffle unit configured to be attachable to the first opening of either the first valve unit or the second valve unit, and to block air from passing through the first opening when the baffle is closed, and to allow air to pass through the first opening when the baffle is open, in a state where the baffle unit is attached to the first opening.

23. An air conditioning system comprising: The safety system according to any one of claims 1 to 22; a heat source side unit, the heat source side unit including a compressor and a heat source side heat exchanger; a plurality of utilization-side units, each of the plurality of utilization-side units comprising a utilization-side heat exchanger; a liquid refrigerant pipeline extending between the heat source side unit and the utilization side unit and including the liquid refrigerant piping portion; a gas refrigerant pipeline extending between the heat source side unit and the utilization side unit and including the gas refrigerant piping portion; and An expansion mechanism is disposed in the liquid refrigerant pipeline.

24. A method for constructing an air conditioning system, The air conditioning system comprises: The safety system according to any one of claims 1 to 22; a heat source side unit, the heat source side unit including a compressor and a heat source side heat exchanger; a plurality of utilization-side units, each of the plurality of utilization-side units comprising a utilization-side heat exchanger; a liquid refrigerant pipeline extending between the heat source side unit and the utilization side unit and including the liquid refrigerant piping portion; a gas refrigerant pipeline extending between the heat source side unit and the utilization side unit and including the gas refrigerant piping portion; as well as an expansion mechanism, the expansion mechanism being arranged in the liquid refrigerant pipeline, The method comprises: installing the first valve unit, the second valve unit, the connection structure, the discharge structure, and the utilization-side unit on the same floor of a building; as well as The first valve unit and the second valve unit are connected by the connection structure, and the discharge structure is connected to the other one of the openings of the first housing or the connection structure.

25. A method for constructing the air conditioning system according to claim 24, characterized in that: Installation includes: installing the utilization-side unit in a first space to be air-conditioned by the utilization-side unit; and The first valve unit, the second valve unit, the connection structure, and the exhaust structure of the safety system are installed in a second space adjacent to the first space.

26. A method for constructing an air conditioning system, characterized in that: The air conditioning system comprises: The safety system according to any one of claims 1 to 22; a heat source side unit, the heat source side unit including a compressor and a heat source side heat exchanger; a plurality of utilization-side units, each of the plurality of utilization-side units comprising a utilization-side heat exchanger; a liquid refrigerant pipeline extending between the heat source side unit and the utilization side unit and including the liquid refrigerant piping portion; a gas refrigerant pipeline extending between the heat source side unit and the utilization side unit and including the gas refrigerant piping portion; and an expansion mechanism, the expansion mechanism being arranged in the liquid refrigerant pipeline, The method comprises: installing the first valve unit and the second valve unit in different floors of a building; arranging the connection structure to connect the first valve unit and the second valve unit above different floors; and The drain structure is connected to the connection structure.

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