heat pump

Abstract

This disclosure relates to a heat pump. The heat pump (1) comprises a refrigerant circuit (10) for circulating a refrigerant, which includes a compressor (11), a heat source heat exchanger (12), an expansion valve (13), and an intermediate heat exchanger (20); a heat medium circuit (30) for circulating a heat medium, which includes a pump (36) and an intermediate heat exchanger (20); an outdoor unit (100) which includes an outdoor unit casing (101) housing at least the heat source heat exchanger (12), the compressor (11), and the expansion valve (13); an indoor unit (300) which includes an indoor unit casing (301) housing at least the pump (36); and a heat exchanger unit (200) which includes a container (201) housing the intermediate heat exchanger (20). The heat source heat exchanger (12), compressor (11), expansion valve (13), and intermediate heat exchanger (20) are connected to each other via refrigerant piping (14), and the intermediate heat exchanger (20) and pump (36) are connected to each other via heat transfer fluid piping (37). The container (201) of the heat exchanger unit (200) is separate from the indoor unit casing (301) and the outdoor unit casing (101), and is located outside the indoor unit casing (301) and the outdoor unit casing (101).

Description

Technical Field

[0001] The present disclosure relates to a heat pump, and more particularly to a separated configuration of an intermediate heat exchanger of a heat pump. The present disclosure also relates to the relative arrangement between the intermediate heat exchanger and the gas-liquid separator of the heat pump.

Background Art

[0002] A heat pump generally has a refrigerant circuit in which a refrigerant circulates and a heat medium circuit in which a heat medium circulates. The refrigerant circuit is configured such that the refrigerant takes in heat from the outdoor external environment by a heat source heat exchanger. The heat is then transferred to the heat medium in the heat medium circuit through an intermediate heat exchanger. Finally, the heat is transferred to a utilization-side heat exchanger such as a radiator or floor heating. Thus, the heat is transferred from the outdoors to the indoors, for example, inside a building.

[0003] The development of heat pumps faces various challenges due to environmental and technical requirements. On the one hand, heat pumps should function as efficiently as possible. On the other hand, the refrigerant used in heat pumps must avoid environmental risks such as the possibility of ozone layer depletion and global warming.

[0004] To meet such requirements, it has been proposed to use propane as the refrigerant (R290) of the heat pump. This refrigerant is efficient and environmentally friendly. However, since propane is flammable, there is still some risk of fire.

[0005] It has also been proposed to use carbon dioxide (CO2, R744) in heat pumps. This refrigerant is efficient and environmentally friendly. However, there is also some risk. When carbon dioxide leaks, it accumulates at the bottom of the room, and for example, when a part of the refrigerant piping of the heat pump is installed indoors, it displaces air, posing a risk of suffocation to people.

[0006] To minimize these risks, several legal regulations and international standards have been established, such as those concerning the maximum amount of refrigerant used in heat pump systems and the required diffusion height of refrigerant that may leak within the heat pump system. Examples of such standards include the EN 378 series and the IEC 60335 1 and IEC 60335 2 40 standards.

[0007] In addition to these regulations, heat pumps employ certain safety measures to prevent harm to people in the event of a refrigerant leak. One such safety measure is described in European Patent Application Publication No. 3598039 (EP 3 598 039 A1). A container isolated from the internal space of the heat pump's indoor unit is located within the indoor unit's casing. The container houses the load-side heat exchanger (or intermediate heat exchanger). If refrigerant leaks in or within the load-side heat exchanger, the container prevents the leaked refrigerant from entering the indoor unit space, where electronic components and other potentially ignition sources are located.

[0008] However, even if a container housing the load-side heat exchanger is provided within the indoor unit casing, if there is a leak in the container, the leaked refrigerant may come into contact with something that could ignite the heat pump inside the indoor unit.

[0009] Furthermore, heat pumps employ certain safety measures in the form of safety devices to prevent harm to people in the event of a refrigerant leak. One such safety device is a double-wall plate heat exchanger, as described in European Patent Application Publication No. 3598039. If there is a leak in one wall of the plate heat exchanger, the second wall prevents the refrigerant from entering the heat transfer circuit through that leak. However, such double-wall plate heat exchangers are expensive. Therefore, other heat pumps employ a gas-liquid separator as a safety device. The gas-liquid separator is part of the heat transfer circuit. If a leak occurs, usually in the intermediate heat exchanger, and the refrigerant leaks into the heat transfer circuit, the gaseous refrigerant is separated from the liquid heat transfer medium (usually water) by the gas-liquid separator and released or discharged to the outside of the heat pump in a controlled manner. Such a gas-liquid separator is disclosed, for example, in European Patent Application Publication No. 4075078 (EP 4 075 078 A1).

[0010] However, if a gas-liquid separator is to be installed in a heat pump as a safety device, additional space is required because the gas-liquid separator constitutes an additional component, for example, in the indoor unit of the heat pump. Generally, however, it is desirable to make the units of a heat pump, such as the outdoor unit and the indoor unit, as small as possible, and this is especially true for the indoor unit of the heat pump. Considering the above, it is desirable to provide a heat pump equipped with a heat transfer medium circuit having a gas-liquid separator, and having a configuration that is highly space-efficient. [Overview of the project]

[0011] Considering the above, the purpose of this disclosure is to provide a heat pump with improved safety.

[0012] This objective is achieved by the heat pump described in claim 1. Optional features and preferred embodiments of the heat pump are described in the dependent claims.

[0013] In the first aspect, the heat pump comprises a refrigerant circuit that circulates a refrigerant comprising a compressor, a heat source heat exchanger, an expansion valve, and an intermediate heat exchanger; a heat transfer medium circuit that circulates a heat transfer medium comprising a pump and an intermediate heat exchanger; an outdoor unit comprising an outdoor unit casing housing at least a heat source heat exchanger, a compressor, and an expansion valve; an indoor unit comprising an indoor unit casing housing at least a pump; and a heat exchanger unit comprising a container housing an intermediate heat exchanger. The heat source heat exchanger, compressor, expansion valve, and intermediate heat exchanger are connected to each other via refrigerant piping. The intermediate heat exchanger and the pump are connected to each other via heat transfer medium piping. The container of the heat exchanger unit is separate from the indoor unit casing and the outdoor unit casing and is located outside the indoor unit casing and the outdoor unit casing.

[0014] Furthermore, since the container for the heat exchanger unit housing the intermediate heat exchanger is separate from the indoor and outdoor unit casings and located outside of them, if refrigerant leaks in or within the intermediate heat exchanger, the leaked refrigerant can be further removed from the indoor or outdoor unit space where potential ignition sources such as the heat pump's electronic components are located, compared to a configuration where the container housing the intermediate heat exchanger is located inside the indoor or outdoor unit of the heat pump. This improves the safety of the heat pump.

[0015] Furthermore, in the case of a heat pump with a split configuration in which the heat source heat exchanger, expansion valve, and compressor constitute part of the outdoor unit of the heat pump and are integrally arranged in the outdoor unit casing, and the intermediate heat exchanger is located indoors, the container of the heat exchanger unit housing the intermediate heat exchanger is located outside the indoor unit casing. Therefore, compared to a configuration in which the container housing the intermediate heat exchanger is located inside the indoor unit, the refrigerant piping connecting the components of the outdoor unit to the intermediate heat exchanger can be shortened. As a result, the amount of refrigerant in the heat pump can be reduced, and therefore the heat pump can be made less expensive.

[0016] The refrigerant can include propane. The refrigerant can be R290. Furthermore, the refrigerant can also be R32.

[0017] The heat source heat exchanger can be, for example, an evaporator in which a refrigerant exchanges heat with the outside air.

[0018] An intermediate heat exchanger can also serve as a condenser in a refrigerant circuit. The term "intermediate" indicates that the intermediate heat exchanger is a heat exchanger between the heat source side heat exchanger of the refrigerant circuit and the user side heat exchanger, which can be installed indoors in a building and used as a radiator or underfloor heating system.

[0019] The intermediate heat exchanger can be a plate heat exchanger. The shape of the intermediate heat exchanger can be generally a rectangular prism or a box shape.

[0020] A heat transfer circuit can include water as the heat transfer medium.

[0021] Pumps are sometimes called heat transfer pumps. Pumps are generally configured to circulate the heat transfer fluid within a heat transfer circuit.

[0022] Outdoor units are generally placed outdoors, that is, outside of buildings and other structures.

[0023] The outdoor unit casing of the outdoor unit may include a machine room and an air chamber. The machine room can house the compressor, expansion valve, and electronic components of the heat pump. The air chamber can house the heat source heat exchanger, blower fan, and bell mouth.

[0024] The shape of the outdoor unit casing can be, for example, a rectangular parallelepiped or box shape with six exterior walls: two side walls, a front wall, a rear wall, a top wall, and a bottom wall, when the outdoor unit casing is considered to be in the installed state, that is, when the outdoor unit casing is installed in a building or the like.

[0025] The indoor unit is generally installed indoors, that is, inside a building or the like. The interior of the building can generally be separated from the exterior of the building by walls.

[0026] The shape of the indoor unit casing can be, for example, a rectangular parallelepiped or box shape having six outer walls. Alternatively, the shape of the indoor unit casing can be substantially cylindrical, for example, an elongated cylindrical shape. Alternatively, the indoor unit casing can also have a portion having a substantially cylindrical shape and a portion having a rectangular parallelepiped or box shape.

[0027] Here, the term "substantially" means not only including the exact shape, direction, angle value, positional relationship, etc. of the shape, direction, angle, positional relationship, etc., but also including small changes in the angle value and positional relationship around that shape or that direction, for example, 5% in the case of a predetermined value.

[0028] The heat exchanger unit including the container for housing the intermediate heat exchanger can be regarded as a separate unit with respect to the outdoor unit and the indoor unit of the heat pump, or can also be regarded as belonging to the outdoor unit or the indoor unit. Therefore, the heat exchanger unit, and thus the container, can be installed outdoors or indoors.

[0029] The shape of the container for housing the intermediate heat exchanger can be, for example, a substantially rectangular parallelepiped shape or box shape having six outer walls. The container can also have a shape that conforms to the outer shape of the intermediate heat exchanger and, in some cases, other components housed in the container such as a gas-liquid separator.

[0030] The container can be formed of a plastic material such as acrylonitrile styrene acrylate.

[0031] When a heat exchanger unit, and therefore a container, is located outdoors, a portion of the heat transfer fluid piping can also be located outdoors. In this case, the heat transfer fluid piping can be equipped with measures to prevent the heat transfer fluid from freezing, especially if the heat transfer fluid is water. For example, the heat transfer fluid piping can be insulated around the portion of the piping that is located outdoors.

[0032] When a heat exchanger unit, and therefore a container, is located indoors, a portion of the refrigerant piping can be located indoors. In this case, the refrigerant piping can be equipped with measures to prevent heat dissipation from the refrigerant piping into the surrounding air. For example, the refrigerant piping can be equipped with insulation around it. Alternatively, as a safety measure in case of a leak, the refrigerant piping can be double-walled or equipped with a sheath around it. Insulation can also be provided in combination with the sheath.

[0033] Generally, when a heat exchanger unit is placed outdoors, the refrigerant piping can be shortened and the amount of refrigerant can be reduced compared to when the heat exchanger unit is placed indoors, thus making the heat pump less expensive. Specifically, the closer the heat exchanger unit's container is to the outdoor unit casing, the shorter the refrigerant piping becomes. Also, when the heat exchanger unit is placed outdoors, any leaked refrigerant such as propane is diluted in the air, thus reducing the risk of fire. On the other hand, when the heat exchanger unit is placed indoors, the heat transfer fluid piping is entirely indoors, and only the refrigerant piping is placed outdoors. In this case, the difference in elevation between the location of the outdoor unit and the location where the refrigerant piping enters the interior of the building can be made larger.

[0034] The characteristic that the container is separate from the indoor and outdoor unit casings can also include the fact that the container is independent of the indoor and outdoor unit casings. For example, the container can be an independent entity, and none of its outer walls form part of the outer wall of the indoor or outdoor unit casing. For example, the container can be moved or positioned independently of the outdoor and indoor unit casings.

[0035] In the second aspect, the heat exchanger unit container is spaced apart from the indoor unit casing and the outdoor unit casing.

[0036] The characteristic that the heat exchanger unit's container is separated from both the indoor and outdoor unit casings can be interpreted as meaning that the container is not attached to either the indoor or outdoor unit casing.

[0037] For example, the container can be spaced apart from the indoor unit casing such that the horizontal distance between the container and the indoor unit casing is up to 25m (inclusive of 25m) when viewed horizontally with respect to the building on which the heat pump is installed. Similarly, the container can be spaced apart from the outdoor unit casing such that the horizontal distance between the container and the outdoor unit casing is up to 50m (inclusive of 50m) when viewed horizontally. Furthermore, the container can be spaced apart from the outdoor unit casing such that the vertical distance between the container and the outdoor unit casing is up to 30m (inclusive of 30m) when viewed vertically with respect to the building.

[0038] This configuration allows the heat exchanger unit's container to be positioned close to the building wall when placed indoors, while simultaneously allowing the indoor unit to be placed elsewhere indoors, including away from the building wall where the refrigerant piping enters the building. Consequently, the refrigerant piping between the outdoor unit's components and the heat exchanger unit's components can be kept as short as possible. This reduces the amount of refrigerant in the heat pump, resulting in a lower-cost heat pump. This is in contrast to the case where the indoor unit is positioned away from the building wall and the container is located within the indoor unit casing. In that case, long refrigerant pipes are required to connect the indoor and outdoor units, and therefore, a large amount of refrigerant needs to be filled into the heat pump.

[0039] Furthermore, this configuration allows the heat exchanger unit to be positioned independently of the outdoor and indoor unit casings at any desired location, thus increasing the flexibility of the heat pump.

[0040] In a third aspect, the heat pump may further include a hot water tank. The heat transfer medium circuit may further include a coil that is immersed in the water contained in the hot water tank and exchanges heat with the water. The indoor unit may include a tank chamber that houses the hot water tank and the coil, and a machine chamber that houses at least the pump. The machine chamber may be located at the top of the tank chamber. The container of the heat exchanger unit may be attached to the machine chamber of the indoor unit casing.

[0041] The hot water tank and coil can be a hot water tank and coil known in heat pumps of the art.

[0042] The water stored in the hot water tank can also be used as household water for radiators, underfloor heating in buildings, and other systems.

[0043] To facilitate heat exchange between the water in the hot water tank and the heat transfer medium in the coil, the coil can be made of metal.

[0044] The characteristic of having the machine room located at the top of the tank room can be considered in the vertical direction when the heat pump is installed, that is, when the heat pump is installed in a building or similar structure.

[0045] The tank chamber and the machine chamber can be separated from each other, for example, by a partition plate. The tank chamber and the machine chamber may each have separate casings, and the casings of the tank chamber and the machine chamber can be combined to form an indoor unit casing. Alternatively, the tank chamber and the machine chamber can be formed integrally, with at least one outer wall of the indoor unit casing covering both the tank chamber and the machine chamber.

[0046] The characteristic that the heat exchanger unit's container is attached to the machine room section of the indoor unit casing can mean that the entire container, or a large portion of the container, is attached to the machine room section. The term "large portion" can be understood as more than 50% of the container. More than 50% can be related to the external dimensions of the container when viewed in the vertical direction.

[0047] This configuration allows for a compact design of the indoor unit containing the heat exchanger while improving the safety of the heat pump.

[0048] In the fourth aspect, the heat transfer fluid circuit may be further equipped with safety devices as a safety measure against refrigerant leakage into the heat transfer fluid circuit, and these safety devices may be housed within the container of the heat exchanger unit.

[0049] Safety devices can generally be understood as devices specifically configured to prevent refrigerant leaking in or within an intermediate heat exchanger from entering the heat transfer medium circuit.

[0050] When the safety device is housed within the heat exchanger unit's casing, both the intermediate heat exchanger and the safety device are housed within the casing. In this case, the casing can have a shape that conforms to the external configuration of the intermediate heat exchanger and the safety device.

[0051] In this configuration, the safety devices provide additional safety measures against refrigerant leaks, further improving the safety of the heat pump.

[0052] In the fifth aspect, the safety device can be a gas-liquid separator.

[0053] A gas-liquid separator generally has the following function: When a leak typically occurs in the intermediate heat exchanger, and the refrigerant leaks into the heat transfer circuit, the gaseous refrigerant is separated from the liquid heat transfer medium (usually water) by the gas-liquid separator and released or discharged to the outside of the heat pump in a controlled manner.

[0054] The gas-liquid separator can be a conventional gas-liquid separator as known in the art. Generally, the gas-liquid separator can have a cylindrical, particularly elongated cylindrical, body, or a rectangular parallelepiped shape. Thus, the gas-liquid separator can have a longitudinal axis extending in a direction parallel to the direction of gravity when the gas-liquid separator is installed, i.e., when the heat pump is installed. The gas-liquid separator is generally configured to separate a gas-liquid mixture internally. For this reason, the gas-liquid separator needs to have a certain height so that a steady state can be formed in which the liquid heat transfer medium accumulates at the bottom of the gas-liquid separator and the gaseous refrigerant accumulates at the top of the gas-liquid separator.

[0055] This configuration further improves the safety of the heat pump. Furthermore, gas-liquid separators are typically less expensive than other types of safety devices, such as double-walled plate heat exchangers. Therefore, it is possible to improve the safety of the heat pump while minimizing its cost.

[0056] In the sixth aspect, the gas-liquid separator may be equipped with a gas purge valve.

[0057] A gas purge valve can generally be installed to release gas accumulated in a gas-liquid separator to the outside of the gas-liquid separator in a controlled manner.

[0058] A gas purge valve can be installed on the upper side of the gas-liquid separator.

[0059] In this configuration, the gas accumulated in the gas-liquid separator can be released in a controlled manner, further improving the safety of the heat pump.

[0060] In the seventh aspect, the intermediate heat exchanger can be a double-walled plate heat exchanger, which is a safety device.

[0061] Generally, a double-wall plate heat exchanger has two walls that separate the refrigerant from the heat transfer medium. If there is a leak in the first wall of the plate heat exchanger, the second wall prevents the refrigerant from entering the heat transfer medium circuit through that leak.

[0062] This configuration further improves the safety of the heat pump. Furthermore, double-wall plate heat exchangers are generally smaller than a combination of a plate heat exchanger and a gas-liquid separator. Therefore, the safety of the heat pump can be improved while minimizing the external dimensions of the heat exchanger unit.

[0063] In the eighth aspect, the container can be in the shape of a box having a first side wall, a second side wall opposite the first side wall, a rear wall extending between the first and second side walls, a top wall connected to the upper ends of the first, second, and rear walls, a front wall opposite the rear wall, and a bottom wall opposite the top wall. The rear wall can be made closer to the outdoor unit than the front wall. The refrigerant pipe connection points into which the refrigerant piping enters the container can be located on the top wall, rear wall, first side wall, second side wall, or bottom wall of the container.

[0064] The shape of the box can be a rectangular prism, or substantially a rectangular prism, or a cube, or substantially a cube.

[0065] The first side wall, second side wall, front wall, top wall, rear wall, and bottom wall of the container can be the outer surface of the container. The first side wall, second side wall, front wall, top wall, rear wall, and bottom wall of the container can be flat surfaces or surfaces with steps.

[0066] The top wall can be positioned to face the bottom wall in the vertical direction, as if the heat pump were installed, that is, as if the heat pump were installed in a building or the like.

[0067] The characteristic that the rear wall is closer to the outdoor unit than the front wall means that, when the container is located indoors, the rear wall is the wall of the container that directly faces the building wall (or similar) through which the refrigerant piping enters the building.

[0068] A refrigerant pipe connection point can be understood as the area within or within a container where the refrigerant piping enters or penetrates the container. A refrigerant pipe connection point can also be called a refrigerant pipe connection location.

[0069] The refrigerant pipe connection point may include two penetration points in the refrigerant piping: a first penetration point in the refrigerant pipe through which the refrigerant flows into the intermediate heat exchanger, and a second penetration point in the refrigerant pipe through which the refrigerant flows out of the intermediate heat exchanger.

[0070] This configuration allows for the refrigerant piping to be as short as possible, thereby reducing the overall cost of the heat pump.

[0071] In the ninth aspect, the heat transfer pipe connection point where the heat transfer pipe enters the container can be located on the front wall, bottom wall, first side wall, second side wall, or top wall of the container.

[0072] A heat transfer fluid pipe connection point can be understood as the area within or within a container where the heat transfer fluid pipe enters or penetrates the container. A heat transfer fluid pipe connection point can also be called a heat transfer fluid pipe connection location.

[0073] The heat transfer medium pipe connection point may include two penetration points in the heat transfer medium piping: a first penetration point in the heat transfer medium pipe through which the heat transfer medium flows into the intermediate heat exchanger, and a second penetration point in the heat transfer medium pipe through which the heat transfer medium flows out of the intermediate heat exchanger.

[0074] This configuration allows for the shortest possible length of heat transfer fluid piping, thereby reducing the overall cost of the heat pump.

[0075] In the tenth aspect, a first duct can be provided in the container, and the first duct allows the inside of the container to communicate with the outside, where the outdoor unit is located. The refrigerant pipe connection point can be located inside the first duct.

[0076] The first duct can be a tubular or pipe-shaped element. The first duct can also be formed integrally with the container. Alternatively, the first duct can be a separate element connected to the container, for example, using a sealing member.

[0077] The first duct may have a circular, elliptical, and / or oblong cross-section. The shape of the cross-section of the first duct may also vary along the length of the first duct from the container to the outside.

[0078] The duct can be made of polyvinyl chloride or metal.

[0079] If the container is installed indoors, i.e., inside a building, the first duct can penetrate the building wall, thereby connecting the inside of the container to the outside. In this case, it is necessary to make a hole in the wall that is approximately the same size as the outer diameter of the first duct. The location in the wall where the first duct penetrates can be sealed, for example, using a sealant that blocks air and / or refrigerant.

[0080] Since the refrigerant pipe connection point can be located within the first duct, there is no need to create additional holes in the building wall to guide the refrigerant piping from outdoors to indoors. Furthermore, safety is improved in the event of a refrigerant leak from the piping.

[0081] This configuration further improves the safety of the heat pump. This is because if refrigerant leaks in or within the intermediate heat exchanger, the leaked refrigerant may accumulate in the container and flow out to the outside via the first duct. For example, if the container is installed indoors, flammable refrigerants such as propane can be directed outdoors, reducing the risk of fire inside the building. Furthermore, to further improve the safety of the heat pump, it is also conceivable that leaked refrigerant could be pumped out of the container via the first duct by, for example, a specialized maintenance worker.

[0082] In the eleventh aspect, the first duct can be located at the top of the container, and the second duct can be located at the bottom of the container. The second duct allows the inside of the container to communicate with the outside.

[0083] The second duct can have the same configuration and characteristics as the first duct.

[0084] The top and bottom of the container can be defined as the top and bottom when the container is in its installed state, i.e., when the heat pump is in its installed state, as viewed in the vertical direction.

[0085] This configuration further improves the safety of the heat pump. In particular, by providing a first duct and a second duct in the container, and allowing both the first and second ducts to communicate the inside of the container with the outside, natural ventilation of the container becomes possible. Natural ventilation means that no additional means such as a pump is required to guide the leaked refrigerant accumulated inside the container to the outside. This is because outside air enters the container through one of the ducts, for example through the first duct, and exits the container through the other duct, for example through the second duct, thereby creating natural ventilation of the container and allowing the leaked refrigerant to be discharged outdoors.

[0086] In the twelfth aspect, the inside of the container can be airtightly sealed from the outside.

[0087] In this context, airtight sealing can mean any sealing used between different parts of a container, such as when the container includes a lid or when the first and / or second ducts are not integrally formed with the container, so that neither air nor refrigerant can pass through or escape from the container.

[0088] This configuration further improves the heat pump's safety against refrigerant leaks.

[0089] In the 13th aspect, the first duct can be positioned at the top of the container. An air intake opening can be provided in the container. The air intake opening allows the inside of the container to communicate with the interior, where the interior is located. A fan can be positioned at the outdoor end of the first duct. The fan is configured to generate an airflow into the container from the air intake opening through the first duct to the outside.

[0090] In this configuration, the container can be placed indoors. "Indoors" refers to the indoor space of a building or other structure where the indoor unit is placed.

[0091] The air intake opening can be a hole provided in at least one of the outer walls of the container. The air intake opening can be equipped with a one-way valve or a check valve to allow, for example, air to pass only from outside the container, i.e., from inside (the indoor space of a building) to the inside of the container, while blocking air from passing from inside the container to outside the air intake opening.

[0092] An air intake opening can also be placed at the bottom of the container to promote airflow throughout the entire box.

[0093] The outdoor end of the first duct can be one end of the first duct penetrating the building wall, and the other end of the first duct can be connected to a container, for example, integrally.

[0094] The fan can generally be configured to blow the gas inside the container to the outside, which creates negative pressure inside the container, drawing gas from indoors into the container through the air intake opening, thus guiding the airflow through the container from the air intake opening to the outdoor end of the first duct.

[0095] This configuration further improves the safety of the heat pump. In particular, by operating the fan, airflow is forcibly created inside the container, providing forced ventilation of the container, unlike natural ventilation, and expelling any leaked refrigerant to the outside.

[0096] In the fourteenth aspect, a refrigerant leak detector can be installed inside the container. The operation of the fan can be made dependent on the refrigerant leak detector signal.

[0097] For example, a refrigerant leak detector can be an optical detector configured to detect refrigerant in a container, such as leaked refrigerant.

[0098] The fan can be activated when the refrigerant leak detector detects refrigerant in the container, for example, when the amount of refrigerant in the container is higher than a predetermined value. In this case, the refrigerant leak detector can output a refrigerant leak detection signal.

[0099] A control unit can also be provided to control the refrigerant leak detector and the fan, and to enable communication between the refrigerant leak detector and the fan.

[0100] In this configuration, the fan does not need to operate continuously, but only when a leaked refrigerant is detected. This saves power and therefore increases the efficiency of the heat pump.

[0101] In the 15th aspect, the container of the heat exchanger unit can be configured to be mounted on the wall of a building or on the floor of a building within the wall of a building.

[0102] The container can be configured to be mounted on the wall of a building or on the floor of a building within the wall of a building, either outdoors or indoors.

[0103] When the container is installed indoors on the wall of a building or on the floor within the wall of a building, the distance between the wall and the container can be up to 50 cm (including 50 cm), preferably up to 30 cm (including 30 cm), in order to shorten the refrigerant piping as much as possible.

[0104] For example, a container may have a mounting structure for holding it. The mounting structure may be configured to be attached to a building wall, for example, using screws.

[0105] The container can be configured to be mounted on the building wall to the building floor by a container equipped with a stand, frame, or platform on which the container rests. The stand, frame, or platform can be fixed to the floor using screws or the like.

[0106] In this configuration, the container can be easily placed on the building wall, and even when the container is placed indoors, the length of the refrigerant piping can be shortened.

[0107] In the sixteenth aspect, the heat pump comprises a refrigerant circuit having a compressor, a heat source heat exchanger, an expansion valve, and an intermediate heat exchanger, and a heat transfer medium circuit having an intermediate heat exchanger and a gas-liquid separator. The intermediate heat exchanger may have a first side wall, a second side wall facing the first side wall, a front wall extending between the first and second side walls, a top wall connected to the upper ends of the first, second, and front walls, a rear wall facing the front wall in the front-rear direction, and a bottom wall facing the top wall in the up-down direction. The intermediate heat exchanger may have a first inlet opening and a first outlet opening for the heat transfer medium. The first inlet opening and the first outlet opening are provided in the front wall. The gas-liquid separator may have a second inlet opening and a second outlet opening for the heat transfer medium. A heat transfer medium connecting pipe may be provided between the first outlet opening and the second inlet opening, thereby enabling the heat transfer medium to flow from the intermediate heat exchanger to the gas-liquid separator. Most of the gas-liquid separator can be placed in an area adjacent to the intermediate heat exchanger. This area extends vertically from the top wall to the bottom wall of the intermediate heat exchanger, and also extends in the front-to-back direction from the rear wall of the intermediate heat exchanger to the foremost point of the heat transfer medium connecting pipe.

[0108] Since most of the gas-liquid separator can be placed in an area adjacent to the intermediate heat exchanger, the gas-liquid separator and the intermediate heat exchanger can be arranged relatively compactly. This results in a heat pump configuration with high space efficiency. For example, if most of the gas-liquid separator is placed above or below the intermediate heat exchanger, the arrangement of these two components will not be compact, and space efficiency will be low. This is because the intermediate heat exchanger is usually one of the largest components in a heat pump unit, such as the indoor unit of the heat pump, and the height of the heat pump unit casing, such as the indoor unit casing, may be slightly higher than the height of the intermediate heat exchanger. If the gas-liquid separator is placed above or below the intermediate heat exchanger, the heat pump unit casing must be made correspondingly taller solely for the purpose of housing the gas-liquid separator within the heat pump unit casing. Therefore, such a configuration cannot be compact and space efficiency will be low.

[0109] Furthermore, since most of the gas-liquid separator can be placed in an area adjacent to the intermediate heat exchanger, the gas-liquid separator can also be placed in close proximity to the intermediate heat exchanger. The advantages of this are not limited to the fact that less piping is needed to connect the intermediate heat exchanger to the gas-liquid separator. Because the gas-liquid separator can be placed in close proximity to the intermediate heat exchanger, if a refrigerant leak occurs in or at the intermediate heat exchanger, the gaseous refrigerant that has leaked into the heat transfer medium circuit is quickly discharged to the gas-liquid separator. Therefore, if a leak detector is installed to detect leaked refrigerant, for example, the leak can be detected quickly. This improves the safety of the heat pump.

[0110] The heat pump can be a monoblock heat pump. In this configuration, the compressor, heat source heat exchanger, expansion valve, and intermediate heat exchanger form the outdoor unit of the heat pump and are all located within the outdoor unit casing. Alternatively, the heat pump can be a separate-component heat pump. In this configuration, the heat source heat exchanger, expansion valve, and compressor form the outdoor unit of the heat pump and are all located within the outdoor unit casing, while the intermediate heat exchanger is located indoors.

[0111] The heat source heat exchanger can be, for example, an evaporator in which a refrigerant exchanges heat with the outside air.

[0112] The refrigerant can also include propane or carbon dioxide. Furthermore, the refrigerant can be R32 or R410A.

[0113] A heat transfer circuit can include water as the heat transfer medium.

[0114] The gas-liquid separator can be a conventional gas-liquid separator as known in the prior art. Generally, the gas-liquid separator can have a cylindrical, especially elongated cylindrical, body, or a rectangular parallelepiped shape. Thus, the gas-liquid separator can have a longitudinal axis that extends in a direction parallel to the direction of gravity when the gas-liquid separator is installed, i.e., when the heat pump is installed. The gas-liquid separator is generally configured to separate a gas-liquid mixture internally. For this reason, the gas-liquid separator needs to have a certain height so that a steady state can be formed in which the liquid heat transfer medium accumulates at the bottom of the gas-liquid separator and the gaseous refrigerant accumulates at the top of the gas-liquid separator.

[0115] An intermediate heat exchanger can also serve as a condenser in a refrigerant circuit. The term "intermediate" indicates that the intermediate heat exchanger is a heat exchanger between the heat source side heat exchanger of the refrigerant circuit and the user side heat exchanger, which can be installed indoors in a building and used as a radiator or underfloor heating system.

[0116] The intermediate heat exchanger can be a plate heat exchanger. The shape of the intermediate heat exchanger can be generally a rectangular prism or a box shape.

[0117] The first side walls, second side walls, front wall, top wall, rear wall, and bottom wall of the intermediate heat exchanger can be the outer surfaces of the intermediate heat exchanger, and these outer surfaces can include, for example, an additional external enclosure for the intermediate heat exchanger that houses components of the intermediate heat exchanger and components that are unique to the intermediate heat exchanger. Such components may include, for example, piping and plates if the intermediate heat exchanger is a plate heat exchanger.

[0118] The second side wall can face the first side wall such that the first and second side walls are parallel or substantially parallel to each other. The same applies to the rear wall facing the front wall in the front-to-back direction, and the bottom wall facing the top wall in the up-to-down direction.

[0119] The term "effectively" used here refers not only to precise directional and angular values ​​and positional relationships, but also to small changes in the surrounding directional or angular values ​​and positional relationships, such as a 5% change in a given value.

[0120] The vertical direction can be parallel to the direction of gravity when the heat pump is installed in a desired location such as a building. The front-to-back direction can be perpendicular to the vertical direction, or substantially perpendicular. The direction in which the second side wall faces the first side wall can be perpendicular to the vertical direction and the front-to-back direction, or substantially perpendicular.

[0121] The first inlet opening can be an opening that allows the heat transfer medium to enter the intermediate heat exchanger and exchange heat with the refrigerant in the refrigerant circuit. The first outlet opening can be an opening that allows the heat transfer medium, which has exchanged heat with the refrigerant in the intermediate heat exchanger, to exit the intermediate heat exchanger. The first inlet opening and the first outlet opening of the intermediate heat exchanger can be spaced apart from each other in the vertical direction.

[0122] The second inlet opening can be an opening that allows the heat transfer medium to enter the gas-liquid separator. The second outlet opening can be an opening that allows the heat transfer medium to exit the gas-liquid separator. In the case of a cylindrical gas-liquid separator, the second inlet opening can be provided on the side of the cylinder, and the second outlet opening can be provided on the bottom of the cylinder. Furthermore, in the case of a cylindrical gas-liquid separator, the second inlet opening can be provided on the side of the cylinder, and the second outlet opening can also be provided on the side of the cylinder.

[0123] The heat transfer medium connecting pipe can be a single, integrated piece, or a one-piece pipe, or it can be composed of multiple pipe segments that combine with each other to form the heat transfer medium connecting pipe. Such pipe segments can be properly assembled using pipe joints.

[0124] The term "mostly" in "mostly the gas-liquid separator" can be understood as the portion greater than 50% of the gas-liquid separator. "Greater than 50%" can also be related to the external dimensions of the gas-liquid separator or the volume it occupies.

[0125] The arrangement area can generally be understood as a three-dimensional space adjacent to the intermediate heat exchanger, and can be understood as a three-dimensional space enclosed vertically by a plane containing the top wall or the uppermost part of the top wall of the intermediate heat exchanger and a plane containing the bottom wall or the lowermost part of the bottom wall of the intermediate heat exchanger. Furthermore, this space can be enclosed in the front-to-back direction by a plane containing the rear wall or the rearmost part of the rear wall of the intermediate heat exchanger and a plane containing the foremost point of the heat transfer medium connecting pipe that can be parallel or substantially parallel to the plane containing the rear wall of the intermediate heat exchanger.

[0126] The placement area can be the area adjacent to the first side wall of the intermediate heat exchanger, or the area adjacent to the second side wall.

[0127] In the 17th aspect, the second inlet opening and the second outlet opening can be spaced apart from each other in the first direction. The gas-liquid separator can have a maximum length in the first direction and a maximum width in a direction perpendicular to the first direction. At least 50%, preferably at least 70%, more preferably at least 80%, and most preferably at least 90% of the maximum length and maximum width can be located in the installation area.

[0128] The first direction can be parallel to or substantially parallel to the vertical direction. The vertical direction is the direction defined above with respect to the intermediate heat exchanger.

[0129] The maximum length of the gas-liquid separator can be understood as the maximum length of the gas-liquid separator when considering the external dimensions in the first direction. The maximum width of the gas-liquid separator can be understood as the maximum width of the gas-liquid separator when considering the external dimensions in the direction perpendicular to the first direction.

[0130] The maximum length of the gas-liquid separator in the first direction may include the length in the first direction of a gas purge valve, which may be installed, for example, above the gas-liquid separator. The gas purge valve may be installed to release the gas accumulated in the gas-liquid separator to the outside of the gas-liquid separator.

[0131] In this configuration, the gas-liquid separator and the intermediate heat exchanger are arranged more compactly relative to each other. The larger the ratio of the maximum length to the maximum width of the installation area, the more compact the arrangement of the gas-liquid separator and the intermediate heat exchanger becomes.

[0132] In the 18th aspect, the second side wall can face the first side wall in the left-right direction. The arrangement area can be further extended in the left-right direction from one of the first and second side walls to a point 35 cm or less away from the other of the first and second side walls.

[0133] The left-right direction can be perpendicular to, or substantially perpendicular to, the up-down and front-back directions.

[0134] In this configuration, the three-dimensional space of the arrangement area adjacent to the intermediate heat exchanger can be further enclosed laterally by a plane that is parallel or substantially parallel to the first or second side wall of the intermediate heat exchanger, and this plane is located at a distance of 35 cm or less from the first or second side wall, respectively.

[0135] In this configuration, the gas-liquid separator is positioned even closer to the intermediate heat exchanger, allowing for a more compact arrangement of the gas-liquid separator relative to the intermediate heat exchanger. Also, as explained above, this configuration requires fewer pipes connecting the intermediate heat exchanger and the gas-liquid separator. Because the gas-liquid separator can be positioned close to the intermediate heat exchanger, if a refrigerant leak occurs in or within the intermediate heat exchanger, the gaseous refrigerant that has leaked into the heat transfer medium circuit is quickly discharged to the gas-liquid separator, thus allowing for quicker leak detection and improving the safety of the heat pump.

[0136] Furthermore, the space between the gas-liquid separator and the intermediate heat exchanger can be left free of other components of the heat pump.

[0137] Other components of a heat pump may include piping, electronic components, heat transfer fluid pumps, valves, and so on.

[0138] In this configuration, the gas-liquid separator can be placed even closer to the intermediate heat exchanger, resulting in the aforementioned benefits such as a more compact design, reduced piping, and rapid discharge of gaseous refrigerant into the gas-liquid separator.

[0139] In a further embodiment, the second inlet opening and the second outlet opening can be provided in the gas-liquid separator so as to open in a direction intersecting the first direction, preferably at an angle of 90° or substantially 90°.

[0140] For example, in the case of a gas-liquid separator having an elongated cylindrical shape, the gas-liquid separator can have a longitudinal axis, and the first direction can be parallel to the longitudinal axis of the gas-liquid separator. In this configuration, if the second inlet opening and the second outlet opening are provided in the gas-liquid separator so as to open in a direction intersecting the first direction, the second inlet opening and the second outlet opening will open toward the side of the gas-liquid separator.

[0141] In this configuration, for example, the second inlet opening opens to the side of the gas-liquid separator and the second outlet opening opens to the bottom of the gas-liquid separator, and a more compact design of the gas-liquid separator is achieved compared to a configuration where the piping connecting the second inlet and second outlet openings extends from the side and bottom of the gas-liquid separator. In such a case, a larger space is required for the piping. For this reason, this configuration allows for a more compact overall configuration of the intermediate heat exchanger and gas-liquid separator.

[0142] In the 19th aspect, the heat pump may further include a heat transfer medium inlet pipe connected to a first inlet opening of an intermediate heat exchanger to allow the heat transfer medium to flow into the intermediate heat exchanger, and a heat transfer medium outlet pipe connected to a second outlet opening of a gas-liquid separator to allow the heat transfer medium to flow out of the gas-liquid separator. The heat transfer medium inlet pipe and the heat transfer medium outlet pipe may be arranged on the same side of the intermediate heat exchanger, preferably parallel to each other or substantially parallel to each other.

[0143] The heat transfer medium inlet pipe and heat transfer medium outlet pipe can be understood as piping segments of a heat transfer medium circuit that are directly connected to the first inlet opening of the intermediate heat exchanger and the second outlet opening of the gas-liquid separator, respectively.

[0144] The feature that the heat transfer medium inlet pipe and the heat transfer medium outlet pipe can be arranged on the same side of the intermediate heat exchanger, preferably parallel or substantially parallel to each other, can mean that a portion of the heat transfer medium inlet pipe and a portion of the heat transfer medium outlet pipe can be arranged on the same side of the intermediate heat exchanger, preferably parallel or substantially parallel to each other. Such portions can be portions of the pipe that are further away from the first inlet opening or the second outlet opening than the portions of the pipe that are connected to the first inlet opening and the second outlet opening, respectively.

[0145] The feature that the heat transfer medium inlet pipe and the heat transfer medium outlet pipe can be located on the same side of the intermediate heat exchanger means that each pipe, or a portion thereof, is located on the same side of a plane that includes one of the surfaces of the intermediate heat exchanger and is parallel to the corresponding surface of the intermediate heat exchanger.

[0146] In this configuration, the heat transfer medium inlet and outlet pipes are located on the same side of the intermediate heat exchanger, requiring less space and allowing for a more compact overall configuration of the intermediate heat exchanger and gas-liquid separator.

[0147] In more detail, the heat transfer medium inlet and outlet pipes can be positioned such that their respective centers lie in a plane where they are substantially perpendicular or parallel to each other in the vertical direction.

[0148] The centerline of a pipe can be understood as a line that extends in the same direction as the pipe and passes through the center of each cross-section along the pipe. In the case of a cylindrical pipe with a circular cross-section, the distance from the pipe wall to the centerline is the same along the circumference of the pipe.

[0149] For example, a portion of the heat transfer medium inlet pipe and a portion of the heat transfer medium outlet pipe can be positioned such that their respective centerlines lie in a plane that is substantially perpendicular or parallel in the vertical direction. Such portions can be portions of the pipe that are further away from the first inlet opening or the second outlet opening than the portions of the pipe that are connected to the first inlet opening and the second outlet opening, respectively.

[0150] The feature that the centerlines of the heat transfer medium inlet and outlet are located in a plane that is substantially perpendicular or parallel in the vertical direction includes, for example, configurations in which the centerlines of the heat transfer medium inlet and outlet are parallel or perpendicular in the vertical direction. When the centerlines of the heat transfer medium inlet and outlet are perpendicular in the vertical direction, the heat transfer medium inlet and outlet can be arranged adjacent to each other in the front-to-back direction or adjacent to each other in the vertical direction.

[0151] In this configuration, the heat transfer medium inlet and outlet pipes are located on the same side of the intermediate heat exchanger, and the centerlines of the heat transfer medium inlet and outlet pipes are in the same plane, thus requiring less space and allowing for a more compact overall configuration of the intermediate heat exchanger and gas-liquid separator.

[0152] In the 20th aspect, the gas-liquid separator is positioned adjacent to the first or second side wall of the intermediate heat exchanger.

[0153] For example, the entire gas-liquid separator or a large portion of the gas-liquid separator can be placed in a region adjacent to the first or second side wall of the intermediate heat exchanger, which extends vertically from the top wall to the bottom wall of the intermediate heat exchanger and also extends in the front-to-back direction from the rear wall to the front wall of the intermediate heat exchanger.

[0154] In this configuration, the intermediate heat exchanger and the gas-liquid separator are arranged more compactly relative to each other, thus reducing the overall size of the intermediate heat exchanger and the gas-liquid separator. This arrangement is preferable when the intermediate heat exchanger and the gas-liquid separator are installed within the indoor unit casing of the heat pump, and there is only a small amount of space to accommodate the intermediate heat exchanger together with the gas-liquid separator.

[0155] In the 21st aspect, the first outlet opening of the intermediate heat exchanger and the second inlet opening of the gas-liquid separator can be opened in the same direction.

[0156] For example, the intermediate heat exchanger and the gas-liquid separator can be arranged such that the first outlet opening and the second inlet opening are at the same height when viewed in the vertical direction.

[0157] In this configuration, the intermediate heat exchanger and the gas-liquid separator are arranged more compactly relative to each other, allowing for a smaller overall configuration of the intermediate heat exchanger and gas-liquid separator. Furthermore, since their respective openings face the same direction, the length of the heat transfer medium connecting pipes can be shortened.

[0158] In addition, the heat transfer medium connecting tube can have a U-shape.

[0159] U-shapes can include rounded shapes and angular shapes, such as U-shapes that include two 90° angles.

[0160] This configuration allows for a simple and compact connection between the intermediate heat exchanger and the gas-liquid separator.

[0161] In the 22nd aspect, the gas-liquid separator can be positioned adjacent to the end of the intermediate heat exchanger, which is formed by the front wall and the first or second side wall of the intermediate heat exchanger.

[0162] For example, the entire gas-liquid separator or a large portion of the gas-liquid separator can be positioned in a region adjacent to the end of the intermediate heat exchanger, which is formed by the front wall and the first or second side wall of the intermediate heat exchanger, and which extends vertically from the top wall to the bottom wall of the intermediate heat exchanger and in the front-to-back direction from the front wall of the intermediate heat exchanger to the foremost point of the heat transfer medium connecting pipe.

[0163] In this configuration, the intermediate heat exchanger and the gas-liquid separator are compactly arranged relative to each other, thus improving the overall spatial efficiency of the intermediate heat exchanger and gas-liquid separator configuration. Such an arrangement is preferable when the intermediate heat exchanger and gas-liquid separator are installed within the indoor unit casing of the heat pump, and there is ample space to accommodate the intermediate heat exchanger together with the gas-liquid separator.

[0164] In addition, the first outlet opening of the intermediate heat exchanger and the second outlet opening of the gas-liquid separator can be opened in directions that intersect each other, preferably at an angle of 90° or substantially at an angle of 90°.

[0165] For example, the intermediate heat exchanger and the gas-liquid separator can be arranged such that the first outlet opening and the second inlet opening are at the same height when viewed in the vertical direction.

[0166] In this configuration, the intermediate heat exchanger and the gas-liquid separator are compactly arranged relative to each other, thus improving the overall spatial efficiency of the intermediate heat exchanger and gas-liquid separator. Furthermore, since the openings of each component intersect with each other, the length of the heat transfer medium connecting pipes can be shortened.

[0167] In addition, the heat transfer medium connecting tube can have an L-shape.

[0168] L-shapes can include rounded shapes and angular shapes, such as L-shapes that include a single 90° angle.

[0169] This configuration allows for a simple and compact connection between the intermediate heat exchanger and the gas-liquid separator.

[0170] In addition, an inlet opening connecting pipe can be provided between the heat transfer medium connecting pipe and the second inlet opening of the gas-liquid separator. The inlet opening connecting pipe may have a length of at least 5 cm.

[0171] The inlet opening connecting pipe can be an integral part of the heat transfer medium connection section, or it can be a separate pipe segment.

[0172] The connecting pipe at the inlet opening can also be a straight pipe.

[0173] The inlet opening connecting pipe can be made of copper.

[0174] In this configuration, specifically, an inlet opening connecting pipe is provided between the heat transfer medium connecting pipe and the second inlet opening of the gas-liquid separator, and the inlet opening connecting pipe has a length of at least 5 cm, thereby promoting the proper functioning of the gas-liquid separator.

[0175] In addition, the heat pump may further include a container capable of housing an intermediate heat exchanger and a gas-liquid separator. This container may be separate from the casing of the heat source unit.

[0176] The heat source unit can be the outdoor unit of the heat pump. Optionally, or additionally, the container can be separate from the casing of the indoor unit of the heat pump.

[0177] The container can be housed within the indoor unit casing of the heat pump or within the outdoor unit casing of the heat pump. The container can be placed outside the indoor and outdoor unit casings, or at a distance from them. The container can be attached inside or outside the indoor or outdoor unit casing.

[0178] The container can be placed outdoors or indoors, for example, outside or inside a building.

[0179] The container may have a substantially rectangular parallelepiped shape or an L-shaped configuration, depending on the relative positional relationship between the intermediate heat exchanger and the gas-liquid separator. The container may have a shape that conforms to the external form of the intermediate heat exchanger and the gas-liquid separator.

[0180] The container can be formed from plastic materials such as acrylonitrile styrene acrylate.

[0181] This configuration further improves the safety of the heat pump. This is because, in the event of a refrigerant leak in or within the intermediate heat exchanger, or if refrigerant is discharged from the gas-liquid separator to the outside of the heat transfer medium circuit, the refrigerant will be contained in a container, keeping it away from ignition sources such as the heat pump's electronic components. Furthermore, the container provides an additional safety measure against refrigerant leaks, allowing for the use of a larger amount of refrigerant in the refrigerant circuit while complying with regulations and standards.

[0182] Furthermore, the internal space of the container can be airtightly sealed from the outside.

[0183] In this context, airtight sealing can mean any sealing used between different parts of a container, such as when the container includes a lid, so that neither air nor refrigerant can pass through or escape from the container.

[0184] For example, when the heat transfer medium inlet and outlet pipes are located on the same side of the intermediate heat exchanger, and a tightly sealed rectangular container with multiple side walls is used as a heat pump, the heat transfer medium inlet and outlet pipes can pass through the container through the same side wall and the same opening. In this configuration, compared to a configuration where the heat transfer medium inlet and outlet pipes are not located on the same side of the intermediate heat exchanger and pass through the container through different side walls and therefore multiple openings, only one opening in the side wall of the container needs to be tightly sealed.

[0185] This configuration further improves the heat pump's safety against refrigerant leaks.

[0186] In the 23rd aspect, the heat exchanger unit can be placed indoors.

[0187] Further aspects of this disclosure will be understood from the following description of specific embodiments with reference to the accompanying drawings. [Brief explanation of the drawing]

[0188] [Figure 1] This is a schematic diagram of the heat pump related to this disclosure. [Figure 2] Figure 1 is a schematic perspective view of an embodiment of the heat pump. [Figure 3] Figure 1 is a perspective view of an embodiment of the indoor unit of the heat pump. [Figure 4] This is a schematic perspective view showing a portion of the indoor unit of Figure 3, which has a heat exchanger unit. [Figure 5] Figure 1 is a perspective view of an embodiment of the heat exchanger unit of the heat pump. [Figure 6] Figure 5 is a perspective view of the intermediate heat exchanger and gas-liquid separator of the heat exchanger unit. [Figure 7] Figure 5 is a perspective view of the heat exchanger unit. [Figure 8] Figure 7 is a perspective view of the heat exchanger unit from a different direction. [Figure 9]Figure 7 is a perspective view of the heat exchanger unit from a different direction. [Figure 10] Figure 7 is a perspective view of the heat exchanger unit from a different direction. [Figure 11] Figure 1 is a schematic diagram showing a part of the heat pump embodiment. [Figure 12] Figure 1 is a schematic diagram showing a part of the heat pump embodiment. [Figure 13] This is a schematic diagram of the heat pump related to this disclosure. [Figure 14] This is a perspective view of an intermediate heat exchanger and a gas-liquid separator according to a first embodiment of the present disclosure. [Figure 15] Figure 14 is a front view of the intermediate heat exchanger and gas-liquid separator. [Figure 16] Figure 14 is a top view of the intermediate heat exchanger and gas-liquid separator. [Figure 17] Figure 14 is a bottom view of the intermediate heat exchanger and gas-liquid separator. [Figure 18] This is a perspective view of an intermediate heat exchanger and a gas-liquid separator housed in a container according to a second embodiment of the present disclosure. [Figure 19] This is a perspective view of an intermediate heat exchanger and a gas-liquid separator housed in a container according to a third embodiment of the present disclosure. [Figure 20] Figure 19 is a top view of the intermediate heat exchanger, gas-liquid separator, and container. [Figure 21] This is a cross-sectional perspective view of the intermediate heat exchanger and gas-liquid separator shown in Figure 14, housed in a container. [Modes for carrying out the invention]

[0189] Embodiments relating to the present disclosure will be described in detail below with reference to the accompanying drawings, using exemplary examples to illustrate the disclosure. Further modifications of the specific individual features described in this context may be combined with other features of the embodiments described to form further embodiments of the present disclosure.

[0190] Throughout the drawing, the same or similar elements should be referred to by the same reference numeral.

[0191] Figure 1 is a schematic diagram of a heat pump 1 according to this disclosure. The heat pump 1 comprises a refrigerant circuit 10 for circulating a refrigerant and a heat transfer medium circuit 30 for circulating a heat transfer medium. The refrigerant circuit 10 includes a compressor 11, a heat source heat exchanger 12 which is an evaporator in this embodiment, an expansion valve 13, and an intermediate heat exchanger 20 which is a condenser in this embodiment. The heat transfer medium circuit 30 includes a pump 36, an intermediate heat exchanger 20, and an optional gas-liquid separator 31 shown in Figure 1. The heat transfer medium in the heat transfer medium circuit 30 is circulated by the pump 36. The user-side heat exchanger of the heat pump 1, which can be a radiator or floor heating system, is not shown.

[0192] In the embodiment shown in Figure 1, the compressor 11, the heat source heat exchanger 12, and the expansion valve 13 form part of an outdoor unit 100, which includes an outdoor unit casing 101 that houses the compressor 11, the heat source heat exchanger 12, and the expansion valve 13. The outdoor unit 100 is located outdoors. On the other hand, in the embodiment shown in Figure 1, the intermediate heat exchanger 20, the gas-liquid separator 31, and the pump 36 are located indoors. The heat pump 1 includes an indoor unit 300 which includes an indoor unit casing 301 that houses at least the pump 36. The heat pump 1 further includes a heat exchanger unit 200 which includes a container 201 that optionally houses the intermediate heat exchanger 20 and the gas-liquid separator 31. One outdoor unit 100 and the other indoor unit 300 and heat exchanger unit 200 are separated by a building wall or the like.

[0193] The heat source heat exchanger 12, the compressor 11, the expansion valve 13, and the intermediate heat exchanger 20 are connected to each other via refrigerant piping 14. The intermediate heat exchanger 20, the gas-liquid separator 31, and the pump 36 are connected to each other via heat transfer fluid piping 37.

[0194] As shown in Figure 1, the container 201 of the heat exchanger unit 200 is separate from the indoor unit casing 301 and the outdoor unit casing 101, and is located outside the indoor unit casing 301 and the outdoor unit casing 101.

[0195] The container 201 of the heat exchanger unit 200, which houses the intermediate heat exchanger 20, is separate from the indoor unit casing 301 and the outdoor unit casing 101, and is located outside the indoor unit casing 301 and the outdoor unit casing 101. Therefore, if refrigerant leaks in or within the intermediate heat exchanger 20, the leaked refrigerant can be further removed from the indoor unit space or the outdoor unit space where potential ignition sources such as electronic components of the heat pump 1 are located, compared to a configuration where the container housing the intermediate heat exchanger is located inside the indoor unit or the outdoor unit of the heat pump. This improves the safety of the heat pump 1.

[0196] Furthermore, in Figure 1, the heat pump 1 is a divided heat pump 1 in which the heat source heat exchanger 12, expansion valve 13, and compressor 11 form part of the outdoor unit 100 of the heat pump 1 and are together arranged inside the outdoor unit casing 101, while the intermediate heat exchanger 20 is arranged inside. Since the container 201 of the heat exchanger unit 200 that houses the intermediate heat exchanger 20 is located outside the indoor unit casing 301, the refrigerant piping 14 connecting the components of the outdoor unit 100 to the intermediate heat exchanger 20 can be shortened compared to a configuration in which the container housing the intermediate heat exchanger is located inside the indoor unit. As a result, the amount of refrigerant in the heat pump 1 can be reduced, and the heat pump 1 can be made less expensive.

[0197] Figure 2 is a schematic perspective view of an embodiment of the heat pump 1 shown in Figure 1. Both the outdoor unit casing 101 of the outdoor unit 100 and the indoor unit casing 301 of the indoor unit 300 have a substantially rectangular parallelepiped shape.

[0198] The container 201 and the first duct 208 are shown translucently so that the components housed within them are visible. The container 201 of the heat exchanger unit 200 has a box shape, which will be described in more detail below. Furthermore, the container 201 includes the first duct 208, which will be described in more detail below. As shown in Figure 2, a portion of the refrigerant piping 14 is located within the first duct 208. The container 201 houses the intermediate heat exchanger 20 and the gas-liquid separator 31. As shown in Figure 2, the heat transfer medium piping 37 enters the container 201 from one of the same outer walls.

[0199] In the embodiment shown in Figure 2, the container 201 of the heat exchanger unit 200 is spaced apart from the indoor unit casing 301 of the indoor unit 300 and the outdoor unit casing 101 of the outdoor unit 100.

[0200] In Figure 2, the container 201 is assumed to be installed indoors. In this case, the container 201 of the heat exchanger unit 200 can be placed close to the building wall, while the indoor unit 300 can be placed in another location indoors, including a location away from the building wall where the refrigerant piping 14 enters the building. Therefore, the refrigerant piping 14 between the components of the outdoor unit 100 and the components of the heat exchanger unit 200 can be made as short as possible. This reduces the amount of refrigerant in the heat pump 1, resulting in a lower-cost heat pump 1.

[0201] Furthermore, in this configuration, the heat exchanger unit 200 can be positioned independently of the outdoor unit casing 101 and the indoor unit casing 301 at any desired location, thus increasing the flexibility of the heat pump 1.

[0202] Figure 3 is a perspective view of an embodiment of the indoor unit 300 of the heat pump 1 shown in Figure 1. The indoor unit 300 has an indoor unit casing 301. The indoor unit 300 comprises a tank chamber 302 and a machine chamber 303. The machine chamber 303 is located at the top of the tank chamber 302. In the embodiment shown in Figure 3, the tank chamber 302 and the machine chamber 303 are integrally formed, and at least one outer wall of the indoor unit casing 301 covers both the tank chamber 302 and the machine chamber 303.

[0203] Figure 4 is a schematic perspective view showing a portion of the indoor unit 300 of Figure 3, which has a heat exchanger unit 200. The tank chamber 302 houses a hot water tank 3021. The heat transfer medium circuit 30 further comprises a coil 3022 that is immersed in the water contained in the hot water tank 3021 and exchanges heat with the water. The water in the hot water tank 3021 can be household water.

[0204] The machine room 303 houses the pump 36 of the heat transfer fluid circuit 30. Further components of the machine room 303, such as electronic components, are omitted for the sake of simplicity in the illustration.

[0205] In the embodiment shown in Figure 4, the container 201 of the heat exchanger unit 200 is attached to the machine room section 303 of the indoor unit casing. In this embodiment, the heat exchanger unit 200 can be considered as the "backpack" of the indoor unit 300.

[0206] This configuration allows for a compact design of the indoor unit 300, which includes the heat exchanger unit 200, while improving the safety of the heat pump 1.

[0207] Figure 5 is a perspective view of an embodiment of the heat exchanger unit 200 of the heat pump 1 in Figure 1. The container 201 and the first duct 208 are shown transparently, allowing the components housed inside to be seen. In contrast to the heat exchanger unit 200 shown in Figure 2, the (optional) gas-liquid separator 31 is located on the opposite side of the intermediate heat exchanger 20. Also, the heat transfer medium piping 37 penetrates the container 201 through its bottom wall, rather than through its side wall.

[0208] The gas-liquid separator 31, together with the intermediate heat exchanger 20, constitutes a safety device as a safety measure against refrigerant leakage into the heat transfer medium circuit 30, which is housed in the container 201 of the heat exchanger unit 200.

[0209] Additionally or alternatively, the intermediate heat exchanger 20 may be a double-walled plate heat exchanger, and (further) safety devices may be configured.

[0210] Figure 6 is a perspective view of the intermediate heat exchanger 20 and gas-liquid separator 31 of the heat exchanger unit 200 shown in Figure 5. As can be seen from Figure 6, the gas-liquid separator 31 is further equipped with a gas purge valve 313. The gas purge valve 313 can be provided to release the gas accumulated in the gas-liquid separator 31 to the outside of the gas-liquid separator 31 in a controlled manner. In the embodiment shown in Figure 6, the gas purge valve 313 is provided on the upper side of the gas-liquid separator 31.

[0211] Figures 7, 8, 9, and 10 are perspective views of the heat exchanger unit 200 of Figure 5 from different directions, i.e., different viewpoints. The container 201 has the shape of a box, having a first side wall 202, a second side wall 203 opposite the first side wall 202, a rear wall 204 extending between the first side wall 202 and the second side wall 203, a top wall 205 connected to the upper ends of the first side wall 202, the second side wall 203, and the rear wall 204, a front wall 206 opposite the rear wall 204, and a bottom wall 207 opposite the top wall 205.

[0212] In the heat pump 1, the rear wall 204 of the container 201 is closer to the outdoor unit 100 than the front wall 206; in other words, the rear wall 204 is directly facing the inside of a wall, such as a building.

[0213] As can be seen from Figure 10, the refrigerant pipe connection point 141 where the refrigerant piping 14 enters the container 201 is located on the top wall 205 of the container 201. Alternatively, the refrigerant pipe connection point 141 could be located on the rear wall 204, the first side wall 202, the second side wall 203, or the bottom wall 207 of the container 201.

[0214] As shown in Figures 7, 8, and 9, the heat transfer pipe connection point 371, where the heat transfer pipe 37 enters the container 201, is located on the bottom wall 207 of the container 201. Alternatively, the heat transfer pipe connection point 371 can be located on the front wall 206, the first side wall 202, the second side wall 202, or the top wall 205 of the container 201.

[0215] Furthermore, a first duct 208 is provided in the container 201. Figures 7, 8, 9, and 10 show only a portion of the first duct 208. In this embodiment, the first duct 208 is provided in the top wall 205 of the container 201. The first duct 208 enables the inside of the container 201 to communicate with the outside. The outside is the location where the outdoor unit 100 is installed. As shown in Figure 10, the refrigerant pipe connection point 141 is located inside the first duct 208.

[0216] Figure 11 is a schematic diagram showing a part of the heat pump 1 embodiment shown in Figure 1. The first duct 208 is located at the top of the container 201. An air intake opening 210 is provided in the container 201, and in this embodiment, at the bottom of the container 201. The air intake opening 210 allows the inside of the container 201 to communicate with the indoors. The indoors is the location where the indoor unit 300 is installed.

[0217] A fan 211 is positioned at the outdoor end of the first duct 208. The fan 211 is configured to generate an airflow into the container 201 from the air intake opening 210 through the first duct 208 to the outside. Specifically, by operating the fan 211, an airflow is forcibly created inside the container 201, providing forced ventilation of the container 201, unlike natural ventilation, and discharging any leaked refrigerant to the outside.

[0218] Furthermore, a refrigerant leak detector 212 is provided inside the container 201. The operation of the fan 211 depends on the refrigerant leak detector signal. The fan 211 starts operating when the refrigerant leak detector 212 detects refrigerant in the container 201, for example, when the amount of refrigerant in the container 201 is higher than a predetermined refrigerant amount value. In this case, the refrigerant leak detector 212 outputs a refrigerant leak detector signal.

[0219] In the embodiment shown in Figure 11, the container 201 of the heat exchanger unit 200 is installed indoors on the building wall and on the building floor.

[0220] Figure 12 is a schematic diagram showing a part of the heat pump 1 embodiment shown in Figure 1. The first duct 208 is located at the top of the container 201. The second duct 209 is provided at the bottom of the container 201, and the second duct 209 enables the inside of the container 201 to communicate with the outside.

[0221] In particular, by providing a first duct 208 and a second duct 209 in the container 201, and enabling both the first duct 208 and the second duct 209 to communicate the inside of the container 201 with the outside, natural ventilation of the container 201 becomes possible, thereby allowing leaked refrigerant to be discharged outdoors. For example, air can enter the container 201 through the first duct 208 and exit the container 201 through the second duct 209, thereby providing natural ventilation of the container and discharging leaked refrigerant outdoors.

[0222] In this case, to further improve the safety of the heat pump 1, the inside of the container 201 can also be hermetically sealed from the outside of the container 201.

[0223] In the embodiment shown in Figure 12, the container 201 of the heat exchanger unit 200 is installed indoors on the wall of the building.

[0224] Figure 13 is a schematic diagram of a heat pump 1 according to the present disclosure. The heat pump 1 comprises a refrigerant circuit 10 and a heat transfer medium circuit 30. The refrigerant circuit 10 includes a compressor 11, a heat source heat exchanger 12 which is an evaporator in this embodiment, an expansion valve 13, and an intermediate heat exchanger 20 which is a condenser in this embodiment. The heat transfer medium circuit 30 includes an intermediate heat exchanger 20 and a gas-liquid separator 31. The heat transfer medium in the heat transfer medium circuit 30 is circulated by a pump 36. The heat exchanger on the user side of the heat pump, which can be a radiator or floor heating system, is not shown.

[0225] In the embodiment shown in Figure 13, the compressor 11, the heat source heat exchanger 12, and the expansion valve 13 form part of a heat source unit 100, which has a heat source unit casing 101 that houses the compressor 11, the heat source heat exchanger 12, and the expansion valve 13. The heat source unit 100 is located outdoors as the outdoor unit of the heat pump 1. The intermediate heat exchanger 20, the gas-liquid separator 31, and the pump 36 are installed indoors and form part of the indoor unit of the heat pump 1. The outdoor unit and the indoor unit are separated by a building wall.

[0226] Figure 14 is a perspective view of an intermediate heat exchanger 20 and a gas-liquid separator 31 according to a first embodiment of the present disclosure. The intermediate heat exchanger 20 has a first side wall 21, a second side wall 22 (not visible in Figure 14) that is opposite to the first side wall 21 in the left-right direction, a front wall 23 that extends between the first side wall 21 and the second side wall 22, a top wall 24 that is connected to the upper ends of the first side wall 21, the second side wall 22 and the front wall 23, a rear wall 25 (not visible in Figure 14) that is opposite to the front wall 23 in the front-rear direction, and a bottom wall 26 (not visible in Figure 14) that is opposite to the top wall 24 in the up-down direction.

[0227] The intermediate heat exchanger 20 has a first inlet opening 27 that allows the heat transfer medium to flow into the intermediate heat exchanger 20, and a first outlet opening 28 that allows the heat transfer medium to flow out of the intermediate heat exchanger 20 after exchanging heat with the refrigerant within the intermediate heat exchanger 20. The first inlet opening 27 and the first outlet opening 28 are provided in the front wall 23 of the intermediate heat exchanger 20. Furthermore, the front wall 23 is provided with additional inlet and outlet openings for allowing the refrigerant to flow into and out of the intermediate heat exchanger 20.

[0228] The gas-liquid separator 31 has a second inlet opening 311 that allows the heat transfer medium flowing out of the intermediate heat exchanger 20 to flow into the gas-liquid separator 31, and a second outlet opening 312 that allows the heat transfer medium to flow out of the gas-liquid separator 31. In the illustrated embodiment, the second inlet opening 311 and the second outlet opening 312 are spaced apart from each other in a first direction FD (shown in Figure 15). In this embodiment, the first direction FD is parallel to the vertical direction. The second inlet opening 311 and the second outlet opening 312 are provided in the gas-liquid separator 31 so as to open in a direction intersecting the first direction FD, and in this embodiment, in a direction parallel to the front-rear direction.

[0229] Furthermore, the first outlet opening 28 of the intermediate heat exchanger 20 and the second inlet opening 311 of the gas-liquid separator 31 open in the same direction, that is, in this embodiment, in the front-to-back direction.

[0230] A heat transfer medium connecting pipe 32 is provided between the first outlet opening 28 and the second inlet opening 311, allowing the heat transfer medium to flow from the intermediate heat exchanger 20 to the gas-liquid separator 31. In the first embodiment, the heat transfer medium connecting pipe 32 is a single, integrated pipe. The heat transfer medium connecting pipe 32 also has a U-shape.

[0231] Furthermore, as shown in Figure 14, the heat transfer medium inlet pipe 33 is connected to the first inlet opening 27 of the intermediate heat exchanger 20, allowing the heat transfer medium to flow into the intermediate heat exchanger 20, and the heat transfer medium outlet pipe 34 is connected to the second outlet opening 312 of the gas-liquid separator 31, allowing the heat transfer medium to flow out of the gas-liquid separator 31.

[0232] Figure 15 is a front view of the intermediate heat exchanger 20 and gas-liquid separator 31 shown in Figure 14, and Figure 16 is a top view of the intermediate heat exchanger 20 and gas-liquid separator 31 shown in Figure 14. As shown in Figures 3 and 4, most of the gas-liquid separator 31 is located in the arrangement area AR adjacent to the intermediate heat exchanger 20. The arrangement area AR extends vertically from the top wall 24 to the bottom wall 26 of the intermediate heat exchanger 20, and also extends in the front-to-back direction from the rear wall 25 of the intermediate heat exchanger 20 to the foremost point of the heat transfer medium connecting pipe 32.

[0233] As described above, since most of the gas-liquid separator 31 is located in the arrangement area AR adjacent to the intermediate heat exchanger 20, the gas-liquid separator 31 and the intermediate heat exchanger 20 are arranged relatively compactly. This results in a configuration of the heat pump 1 with high spatial efficiency.

[0234] Furthermore, since most of the gas-liquid separator 31 is located in the arrangement area AR adjacent to the intermediate heat exchanger 20, the gas-liquid separator 31 can be positioned close to the intermediate heat exchanger 20. The advantages of this are not limited to the fact that there is less piping to connect the intermediate heat exchanger 20 to the gas-liquid separator 31. Because the gas-liquid separator 31 can be positioned close to the intermediate heat exchanger 20, if a refrigerant leak occurs in or in the intermediate heat exchanger, the gaseous refrigerant that has leaked into the heat transfer medium circuit 30 is quickly discharged to the gas-liquid separator 31. Therefore, if a leak detector is installed to detect leaked refrigerant, for example, the leak can be detected quickly. This improves the safety of the heat pump 1.

[0235] More specifically, in the embodiments shown in Figures 3 and 4, the gas-liquid separator 31 has a maximum length Lmax in the first direction FD and a maximum width Wmax in the direction perpendicular to the first direction FD. The portion of the gas-liquid separator exceeding 50% of its maximum length Lmax and maximum width Wmax is located in the arrangement area AR. Also, as can be seen from Figures 3 and 4, the gas-liquid separator 31 is positioned adjacent to the first side wall 21 of the intermediate heat exchanger 20. There are no other components of the heat pump 1 in the space between the gas-liquid separator 31 and the intermediate heat exchanger 20. This allows for an even more compact arrangement of the gas-liquid separator 31 and the intermediate heat exchanger 20.

[0236] The placement area AR can be extended from the first side wall 21 in the left-right direction to a position of 35 cm or less from the first side wall 21. Alternatively, the gas-liquid separator 31 can be placed on the opposite side of the intermediate heat exchanger 20, and the placement area AR can be extended from the second side wall 22 in the left-right direction to a position of 35 cm or less from the second side wall 22.

[0237] As shown in Figure 16, the inlet opening connecting pipe 35 is provided between the heat transfer medium connecting pipe 32 and the second inlet opening 311 of the gas-liquid separator 31. The inlet opening connecting pipe 35 has a length of at least 5 cm to facilitate the proper functioning of the gas-liquid separator 31. In this embodiment, the inlet opening connecting pipe 35 and the heat transfer medium connecting pipe 32 are integrally formed as a one-piece pipe.

[0238] As shown in Figures 2 and 3, the heat transfer medium inlet pipe 33 and the heat transfer medium outlet pipe 34 are located on the same side of the intermediate heat exchanger 20. That is, in the first embodiment, both the heat transfer medium inlet pipe 33 and the heat transfer medium outlet pipe 34 are located on the side of the intermediate heat exchanger 20 that is below the bottom wall 26 of the intermediate heat exchanger 20 when viewed in the vertical direction. Specifically, a portion of the heat transfer medium inlet pipe 33 and a portion of the heat transfer medium outlet pipe 34 are both located on the side of the intermediate heat exchanger 20 that is below the bottom wall 26 of the intermediate heat exchanger 20 when viewed in the vertical direction. These portions are the portions of the pipe that are further away from the first inlet opening 27 or the second outlet opening 312 than the portions of the pipe that are connected to the first inlet opening 27 or the second outlet opening 312, respectively. More specifically, the portions of the heat transfer medium inlet pipe 33 and the heat transfer medium outlet pipe 34 located on the side of the intermediate heat exchanger 20 that is below the bottom wall 26 of the intermediate heat exchanger 20 when viewed in the vertical direction are located parallel to each other.

[0239] Figure 17 is a bottom view of the intermediate heat exchanger 20 and gas-liquid separator 31 shown in Figure 14. As shown in Figure 17, the heat transfer medium inlet pipe 33 and the heat transfer medium outlet pipe 34 are positioned such that their centerlines CLin and CLout lie in a plane that is substantially parallel in the vertical direction. Specifically, a portion of the heat transfer medium inlet pipe 33 and a portion of the heat transfer medium outlet pipe 34 are both positioned such that their centerlines CLin and CLout lie in a plane that is parallel in the vertical direction. These portions are the portions of the pipe that are further away from the first inlet opening 27 and the second outlet opening 312 than the portions of the pipe that are connected to the first inlet opening 27 and the second outlet opening 312, respectively. In Figure 17, this plane is shown by a dashed line passing through the centerlines CLin and CLout.

[0240] Figure 21 is a cross-sectional perspective view showing the intermediate heat exchanger 20 and gas-liquid separator 31 of Figure 14 housed in a container 201 according to the first embodiment.

[0241] The container 201 houses or accommodates the intermediate heat exchanger 20 and the gas-liquid separator 31. The container 201 has a substantially rectangular parallelepiped shape with multiple side walls that conform to the external shape of the configuration of the intermediate heat exchanger 20 and the gas-liquid separator 31. The container 201 can be separate from the casing 101 of the heat source unit 100.

[0242] As can be seen from Figure 21, the heat transfer medium inlet pipe 33 and the heat transfer medium outlet pipe 34 are located on the same side of the intermediate heat exchanger 20, so the heat transfer medium inlet pipe 33 and the heat transfer medium outlet pipe 34 penetrate the container 201 through the same side wall and the same opening. In this configuration, if an airtight container is required, only one opening in the side wall of the container 201 that needs to be airtight is needed.

[0243] Figure 18 is a perspective view of an intermediate heat exchanger 20 and a gas-liquid separator 31 housed in a container 201 according to a second embodiment of the present disclosure. In the second embodiment, the gas-liquid separator 31 is positioned adjacent to the second side wall 22 of the intermediate heat exchanger 20.

[0244] In the second embodiment, the heat transfer medium inlet pipe 33 and the heat transfer medium outlet pipe 34 are located on the side of the intermediate heat exchanger 20 adjacent to the second side wall 22 of the intermediate heat exchanger 20, when viewed in the left-right direction. Specifically, a portion of the heat transfer medium inlet pipe 33 and a portion of the heat transfer medium outlet pipe 34 are both located parallel to each other on the side of the intermediate heat exchanger 20 adjacent to the second side wall 22 of the intermediate heat exchanger 20. These portions are the portions of the pipe that are further away from the first inlet opening 27 or the second outlet opening 312 than the portions of the pipe that are connected to the first inlet opening 27 or the second outlet opening 312, respectively. More specifically, the centerlines CLin of the portion of the heat transfer medium inlet pipe 33 and CLout of the portion of the heat transfer medium outlet pipe 34 lie in a plane perpendicular to the vertical direction.

[0245] In the second embodiment, the heat transfer medium connecting pipe has an angular U-shape and consists of multiple pipe segments that together form a U-shape. The inlet opening connecting pipe 35 is another pipe segment provided between the heat transfer medium connecting pipe 32 and the second inlet opening 311.

[0246] The container 201 houses or accommodates the intermediate heat exchanger 20 and the gas-liquid separator 31. The container 201 has a substantially rectangular parallelepiped shape with multiple side walls that conform to the external shape of the configuration of the intermediate heat exchanger 20 and the gas-liquid separator 31. The container 201 can be separate from the casing 101 of the heat source unit 100.

[0247] As can be seen from Figure 18, the heat transfer medium inlet pipe 33 and the heat transfer medium outlet pipe 34 are located on the same side of the intermediate heat exchanger 20, so the heat transfer medium inlet pipe 33 and the heat transfer medium outlet pipe 34 penetrate the container 201 through the same side wall and the same opening. In this configuration, if an airtight container is required, only one opening in the side wall of the container 201 that needs to be airtight is needed.

[0248] Figure 19 is a perspective view of an intermediate heat exchanger 20 and a gas-liquid separator 31 housed in a container 201 according to a third embodiment of the present disclosure. Figure 20 is a top view of the intermediate heat exchanger 20, gas-liquid separator 31 and container 201 of Figure 19. As can be seen from the figure, the gas-liquid separator 31 is positioned adjacent to the end of the intermediate heat exchanger 20, which is formed by the front wall 23 and the second side wall 22 of the intermediate heat exchanger 20. The first outlet opening 28 of the intermediate heat exchanger 20 and the second outlet opening 312 of the gas-liquid separator 31 open in directions that intersect each other at a 90° angle. In the third embodiment, the heat transfer medium connecting pipe 32 has an L-shape. In Figures 7 and 8, the inlet opening connecting pipe 35 is omitted.

[0249] The paragraphs listed for each of the following items also constitute part of this disclosure. (Item 1) A refrigerant circuit (10) having a compressor (11), a heat source heat exchanger (12), an expansion valve (13), and an intermediate heat exchanger (20), A heat transfer medium circuit (30) having an intermediate heat exchanger (20) and a gas-liquid separator (31), Equipped with, The intermediate heat exchanger (20) has a first side wall (21), a second side wall (22) facing the first side wall (21), a front wall (23) extending between the first side wall (21) and the second side wall (22), a top wall (24) connected to the upper ends of the first side wall (21), the second side wall (22), and the rear wall (23), a rear wall (25) facing the front wall (23) in the front-rear direction, and a bottom wall (26) facing the top wall (24) in the vertical direction. The intermediate heat exchanger (20) has a first inlet opening (27) and a first outlet opening (28) for the heat transfer medium, and the first inlet opening (27) and the first outlet opening (28) are provided on the front wall (23). The gas-liquid separator (31) has a second inlet opening (311) and a second outlet opening (312) for the heat transfer medium. A heat transfer medium connecting pipe (32) is provided between the first outlet opening (28) and the second inlet opening (311), allowing the heat transfer medium to flow from the intermediate heat exchanger (20) to the gas-liquid separator (31). Most of the gas-liquid separator (31) is located in an arrangement area (AR) adjacent to the intermediate heat exchanger (20), and the arrangement area (AR) extends vertically from the top wall (24) to the bottom wall (26) of the intermediate heat exchanger (20), and also extends in the front-to-back direction from the rear wall (25) of the intermediate heat exchanger (20) to the foremost point of the heat transfer medium connecting pipe (32). Heat pump (1). (Item 2) The second inlet opening (311) and the second outlet opening (312) are spaced apart from each other in the first direction (FD). The gas-liquid separator (31) has a maximum length (Lmax) in the first direction (FD) and a maximum width (Wmax) in the direction perpendicular to the first direction (FD). At least 50% of the maximum length (Lmax) and maximum width (Wmax) are located within the arrangement area (AR). The heat pump (1) described in item 1. (Item 3) The second side wall (22) is opposite the first side wall (21) in the left-right direction. The arrangement area (AR) extends further in the left-right direction from one of the first side wall (21) and the second side wall (22) to a point 35 cm or less away from the one of the first side wall (21) and the second side wall (22). A heat pump as described in item 1 or 2 (1). (Item 4) The space between the gas-liquid separator (31) and the intermediate heat exchanger (20) is a space free of other components of the heat pump (1). A heat pump (1) as described in any one of the preceding items. (Item 5) The second inlet opening (311) and the second outlet opening (312) are provided in the gas-liquid separator (31) so as to open in a direction intersecting the first direction (FD). A heat pump (1) as described in any one of items 2 through 4. (Item 6) A heat transfer medium inlet pipe (33) is connected to the first inlet opening (27) of the intermediate heat exchanger (20), allowing the heat transfer medium to flow into the intermediate heat exchanger (20), A heat transfer fluid outlet pipe (34) is connected to the second outlet opening (312) of the gas-liquid separator (31), allowing the heat transfer fluid to flow out of the gas-liquid separator (31), Furthermore, The heat transfer medium inlet pipe (33) and the heat transfer medium outlet pipe (34) are located on the same side of the intermediate heat exchanger (20). A heat pump (1) as described in any one of the preceding items. (Item 7) The heat transfer medium inlet pipe (33) and the heat transfer medium outlet pipe (34) are positioned such that their centerlines (CLin) and CLout are located in a plane that is substantially perpendicular or parallel in the vertical direction. Heat pump (1) as described in item 6. (Item 8) The gas-liquid separator (31) is positioned adjacent to the first side wall (21) or the second side wall (22) of the intermediate heat exchanger (20). A heat pump (1) as described in any one of the preceding items. (Item 9) The first outlet opening (28) of the intermediate heat exchanger (20) and the second inlet opening (311) of the gas-liquid separator (31) open in the same direction. A heat pump (1) as described in any one of the preceding items. (Item 10) The heat transfer medium connecting pipe (32) has a U-shape. A heat pump (1) as described in any one of the preceding items. (Item 11) The gas-liquid separator (31) is positioned adjacent to the end of the intermediate heat exchanger (20) formed by the front wall (23) and the first side wall (21) or the second side wall (22) of the intermediate heat exchanger (20). A heat pump (1) described in any one of items 1 through 7. (Item 12) The first outlet opening (28) of the intermediate heat exchanger (20) and the second outlet opening (312) of the gas-liquid separator (31) are opening in directions that intersect each other. Heat pump (1) as described in item 11. (Item 13) The heat transfer medium connecting pipe (32) has an L-shape. Heat pump (1) as described in item 12. (Item 14) The inlet opening connecting pipe (35) is provided between the heat transfer medium connecting pipe (32) and the second inlet opening (311) of the gas-liquid separator (31). The inlet opening connecting pipe (35) has a length of at least 5 cm. A heat pump (1) as described in any one of the preceding items. (Item 15) A container (201) containing an intermediate heat exchanger (20) and a gas-liquid separator (31), Furthermore, The container (201) is separate from the casing (101) of the heat source unit (100). A heat pump (1) as described in any one of the preceding items. (Item 16) The internal space of the container (201) is hermetically sealed from the outside of the container (201). The heat pump (1) according to item 15.

Explanation of symbols

[0250] 1 Heat pump 10 Refrigerant circuit 11 Compressor 12 Heat source heat exchanger 13 Expansion valve 20 Intermediate heat exchanger 30 Heat medium circuit 36 Pump 31 Gas-liquid separator 100 Outdoor unit 101 Outdoor unit casing 300 Indoor unit 301 Indoor unit casing 200 Heat exchanger unit 201 Container 14 Refrigerant pipe 37 Heat medium pipe 302 Tank chamber part 3021 Hot water tank 3022 Coil 303 Machine room part 313 Gas purge valve 202 The first side wall of the container 201 203 The second side wall of the container 201 204 The rear wall of the container 201 205 The top wall of the container 201 206 The front wall of the container 201 207 The bottom wall of the container 201 141 Refrigerant pipe connection point 371 Heat medium pipe connection point 208 First duct 209 Second duct 210 Air intake opening 211 Fan 212 Refrigerant leak detector 21 The first side wall of the intermediate heat exchanger 20 22 The second side wall of the intermediate heat exchanger 20 The front wall of the intermediate heat exchanger 20 The top wall of the intermediate heat exchanger 20 The rear wall of the intermediate heat exchanger 20 The bottom wall of the intermediate heat exchanger 20 The first inlet opening The first outlet opening The second inlet opening The second outlet opening The heat medium connecting pipe The heat medium inlet pipe The heat medium outlet pipe The inlet opening connecting pipe The heat source unit (outdoor unit 100) The casing of the heat source unit (outdoor unit casing 101) AR arrangement area FD The first direction Lmax The maximum length of the gas-liquid separator Wmax The maximum width of the gas-liquid separator CLin The center line of the heat medium inlet pipe CLout The center line of the heat medium outlet pipe

Prior art documents

Patent documents

[0251]

Patent Document 1

Patent Document 2

Claims

1. A refrigerant circuit (10) for circulating a refrigerant includes a compressor (11), a heat source heat exchanger (12), an expansion valve (13), and an intermediate heat exchanger (20), A heat transfer medium circuit (30) for circulating a heat transfer medium, comprising a pump (36) and an intermediate heat exchanger (20), An outdoor unit (100) comprising an outdoor unit casing (101) that houses at least the heat source heat exchanger (12), the compressor (11), and the expansion valve (13), An indoor unit (300) comprising an indoor unit casing (301) that houses at least the pump (36), A heat exchanger unit (200) comprising a container (201) for housing the intermediate heat exchanger (20), Equipped with, The heat source heat exchanger (12), the compressor (11), the expansion valve (13), and the intermediate heat exchanger (20) are connected to each other via refrigerant piping (14), and the intermediate heat exchanger (20) and the pump (36) are connected to each other via heat transfer medium piping (37). The container (201) of the heat exchanger unit (200) is separate from the indoor unit casing (301) and the outdoor unit casing (101), and is located outside the indoor unit casing (301) and the outdoor unit casing (101). Heat pump (1).

2. The container (201) of the heat exchanger unit (200) is spaced apart from the indoor unit casing (301) and the outdoor unit casing (101). The heat pump (1) according to claim 1.

3. Hot water tank (3021), Furthermore, The heat transfer circuit (30) further comprises a coil (3022) that is immersed in the water contained in the hot water tank (3021) and exchanges heat with the water. The aforementioned indoor unit (300) is A tank chamber (302) housing the hot water tank (3021) and the coil (3022), At least the machine room section (303) that houses the pump (36), the machine room section (303) which is located at the top of the tank room section (302), It is equipped with, The container (201) of the heat exchanger unit (200) is attached to the machine room section (303) of the indoor unit casing (301). The heat pump (1) according to claim 1.

4. The heat transfer medium circuit (30) includes a safety device as a safety measure against leakage of refrigerant into the heat transfer medium circuit (30). Furthermore, The safety device is housed within the container (201) of the heat exchanger unit (200). A heat pump (1) according to any one of claims 1 to 3.

5. The safety device is a gas-liquid separator (31). The heat pump (1) according to claim 4.

6. The gas-liquid separator (31) is equipped with a gas purge valve (313). The heat pump (1) according to claim 5.

7. The aforementioned intermediate heat exchanger (20) is a double-walled plate heat exchanger which is the safety device. A heat pump (1) according to any one of claims 4 to 6.

8. The container (201) has the shape of a box, having a first side wall (202), a second side wall (203) facing the first side wall (202), a rear wall (204) extending between the first side wall (202) and the second side wall (203), a top wall (205) connected to the upper ends of the first side wall (202), the second side wall (203), and the rear wall (204), a front wall (206) facing the rear wall (204), and a bottom wall (207) facing the top wall (205), wherein the rear wall (204) is closer to the outdoor unit (100) than the front wall (206), The refrigerant pipe connection point (141) where the refrigerant piping (14) enters the container (201) is located on the top wall (205), the rear wall (204), the first side wall (202), the second side wall (203), or the bottom wall (207) of the container (201). A heat pump (1) according to any one of the preceding claims.

9. The heat transfer pipe connection point (371) where the heat transfer pipe (37) enters the container (201) is located on the front wall (206), the rear wall (207), the first side wall (202), the second side wall (202), or the top wall (205) of the container (201). The heat pump (1) according to claim 8.

10. A first duct (208) is provided in the container (201), and the first duct (208) enables the inside of the container (201) to communicate with the outdoors, where the outdoor unit (100) is located. The refrigerant pipe connection point (141) is located within the first duct (208). The heat pump (1) according to claim 8 or 9.

11. The first duct (208) is located at the top of the container (201), The second duct (209) is provided at the bottom of the container (201), The second duct (209) allows the inside of the container (201) to communicate with the outside. The heat pump (1) according to claim 10.

12. The inside of the container (201) is airtightly sealed from the outside of the container (201). A heat pump (1) according to any one of the preceding claims.

13. The first duct (208) is located at the top of the container (201), An air intake opening (210) is provided in the container (201), and the air intake opening (210) allows the inside of the container (201) to communicate with the indoors, where the indoors is the location where the indoor unit (300) is placed. A fan (211) is positioned at the outdoor end of the first duct (208), and the fan (211) is configured to generate an airflow into the container (201) from the air intake opening (210) through the first duct (208) to the outside. The heat pump (1) according to claim 10.

14. A refrigerant leak detector (212) is provided inside the container (201), The operation of the aforementioned fan (211) depends on the refrigerant leak detector signal. The heat pump (1) according to claim 13.

15. The container (201) of the heat exchanger unit (200) is configured to be attached to the wall of a building or to the floor of a building on the wall of a building. A heat pump (1) according to any one of the preceding claims.

16. The refrigerant circuit (10) includes the compressor (11), the heat source heat exchanger (12), the expansion valve (13), and the intermediate heat exchanger (20), The system comprises the intermediate heat exchanger (20) and the heat transfer medium circuit (30) having the gas-liquid separator (31), The intermediate heat exchanger (20) has a first side wall (21), a second side wall (22) facing the first side wall (21), a front wall (23) extending between the first side wall (21) and the second side wall (22), a top wall (24) connected to the upper ends of the first side wall (21), the second side wall (22), and the rear wall (23), a rear wall (25) facing the front wall (23) in the front-rear direction, and a bottom wall (26) facing the top wall (24) in the vertical direction. The intermediate heat exchanger (20) has a first inlet opening (27) and a first outlet opening (28) for the heat transfer medium, and the first inlet opening (27) and the first outlet opening (28) are provided in the front wall (23). The gas-liquid separator (31) has a second inlet opening (311) and a second outlet opening (312) for the heat transfer medium. A heat transfer medium connecting pipe (32) is provided between the first outlet opening (28) and the second inlet opening (311), allowing the heat transfer medium to flow from the intermediate heat exchanger (20) to the gas-liquid separator (31). Most of the gas-liquid separator (31) is located in an arrangement area (AR) adjacent to the intermediate heat exchanger (20), and the arrangement area (AR) extends vertically from the top wall (24) to the bottom wall (26) of the intermediate heat exchanger (20), and also extends in the front-rear direction from the rear wall (25) of the intermediate heat exchanger (20) to the foremost point of the heat transfer medium connecting pipe (32). The heat pump (1) according to claim 5 or 6.

17. The second inlet opening (311) and the second outlet opening (312) are spaced apart from each other in the first direction (FD). The gas-liquid separator (31) has a maximum length (Lmax) in the first direction (FD) and a maximum width (Wmax) in the direction perpendicular to the first direction (FD). At least 50% of the maximum length (Lmax) and the maximum width (Wmax) are located in the placement area (AR). The heat pump (1) according to claim 16.

18. The second side wall (22) is opposite the first side wall (21) in the left-right direction. The arrangement area (AR) extends further in the left-right direction from one of the first side wall (21) and the second side wall (22) to a point 35 cm or less away from the one of the first side wall (21) and the second side wall (22). The heat pump (1) according to claim 16 or 17.

19. A heat transfer medium inlet pipe (33) is connected to the first inlet opening (27) of the intermediate heat exchanger (20), allowing the heat transfer medium to flow into the intermediate heat exchanger (20), A heat transfer medium outlet pipe (34) is connected to the second outlet opening (312) of the gas-liquid separator (31), allowing the heat transfer medium to flow out of the gas-liquid separator (31), Furthermore, The heat transfer medium inlet pipe (33) and the heat transfer medium outlet pipe (34) are located on the same side of the intermediate heat exchanger (20). A heat pump (1) according to any one of claims 16 to 18.

20. The gas-liquid separator (31) is positioned adjacent to the first side wall (21) or the second side wall (22) of the intermediate heat exchanger (20). A heat pump (1) according to any one of claims 16 to 19.

21. The first outlet opening (28) of the intermediate heat exchanger (20) and the second inlet opening (311) of the gas-liquid separator (31) open in the same direction. A heat pump (1) according to any one of claims 16 to 20.

22. The gas-liquid separator (31) is positioned adjacent to the end of the intermediate heat exchanger (20) formed by the front wall (23) of the intermediate heat exchanger (20) and the first side wall (21) or the second side wall (22). A heat pump (1) according to any one of claims 16 to 19.

23. The heat exchanger unit (200) is installed indoors. A heat pump (1) according to any one of the preceding claims.

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