Heat source unit and refrigeration device

Abstract

This heat source unit, which is a constituent of a refrigeration device (1) provided with a showcase (50) having a first utilization heat exchanger (54) connected to a refrigerant circuit (11), comprises compression elements (21, 22, 23), a first pressure reducing mechanism (14) and a heat source heat exchanger (13) which are connected to the refrigerant circuit (11), a detecting unit (90) which detects the business status of a store having the showcase (50), and a control unit (C1) which controls the operation of the refrigeration device (1), wherein the control unit (C1) executes a first operation for restricting the operation of the refrigeration device (1) when it is detected that the store is outside business hours.

Description

Heat source unit and refrigeration device

[0001] The present disclosure relates to a heat source unit and a refrigeration device.

[0002] In stores such as grocery stores, food and beverages in showcases are refrigerated or frozen by refrigeration devices. Patent Document 1 discloses a control method for controlling the capacity of the refrigeration device in accordance with the cooling load of the showcase.

[0003] Japanese Patent Application Laid-Open No. 2018-4146

[0004] Incidentally, to keep the food and beverages in the showcases refrigerated or frozen, the refrigeration equipment needs to operate 24 hours a day. However, if the showcases continue to be cooled at the same load as when the store is open outside of business hours, even though no customers are visiting, it will be impossible to reduce power consumption.

[0005] An object of the present disclosure is to achieve energy savings in refrigeration devices outside of store opening hours.

[0006] The first aspect is a heat source unit constituting a refrigeration system (1) including a showcase (50) having a first utilization heat exchanger (54) connected to a refrigerant circuit (11), the heat source unit including: a compression element (21, 22, 23), a first pressure reduction mechanism (14), and a heat source heat exchanger (13) connected to the refrigerant circuit (11); a detection unit (90) that detects the business status of a store that includes the showcase (50); and a control unit (C1) that controls the operation of the refrigeration system (1), and the control units (C1, C3) execute a first operation that limits the operation of the refrigeration system (1) when it is detected that the store is outside business hours.

[0007] In the first aspect, the first operation suppresses the operation of the refrigeration device (1) outside of business hours, thereby realizing energy savings. In particular, since food or beverages that can be stored at room temperature do not need to be refrigerated outside of business hours, the first operation can contribute to energy savings in the refrigeration device (1).

[0008] A second aspect is the first aspect, wherein the first operation is an operation in which the duration of the thermo-off state of the refrigeration device (1) is longer than the duration of the thermo-off state during business hours of the store.

[0009] In the second mode, the duration of the thermo-off state, during which the operation of the compression elements (21, 22, 23) is restricted, is longer outside business hours than during business hours, thereby realizing energy conservation in the refrigeration system (1). In particular, the first operation is performed for products that do not require refrigeration or freezing. This is because, although the temperature inside the showcase (50) is likely to rise when the thermo-off standby time is long, this does not affect the products that do not require refrigeration or freezing.

[0010] In a third aspect, in the first or second aspect, the control unit (C1, C3) sets a first temperature at which thermo-off of the refrigeration device (1) ends in a first operation to be higher than the first temperature during business hours of the store.

[0011] In the third aspect, the temperature at which the thermostat switches from OFF to ON is set higher outside business hours than during business hours, thereby lengthening the time during which operation of the compression elements (21, 22, 23) is restricted.

[0012] A fourth aspect is any one of the first to third aspects, wherein, in the first operation, the control unit (C1, C3) sets a target evaporation temperature of the refrigerant in the first utilization heat exchanger (54) higher than a target evaporation temperature of the refrigerant in the first utilization heat exchanger (54) during business hours of the store.

[0013] In the fourth aspect, the difference between the evaporation temperature of the first utilization heat exchanger (54) and the target evaporation temperature is smaller outside business hours than during business hours, which makes it difficult for the rotation speed of the compression element (21, 22, 23) to increase, thereby achieving energy conservation in the refrigeration system (1).

[0014] A fifth aspect is any one of the first to fourth aspects, wherein the first operation is an operation in which the rate of increase in the operation frequency of the compression elements (21, 22, 23) is lower than the rate of increase in the operation frequency of the compression elements (21, 22, 23) when the store is outside business hours.

[0015] In the fifth aspect, the increase in the operating frequency of the compression elements (21, 22, 23) is slower outside business hours than during business hours, thereby achieving energy conservation in the refrigeration system (1).

[0016] A sixth aspect is any one of the first to fifth aspects, wherein the control units (C1, C3) do not execute the first operation when it is detected that the store (T) has started business.

[0017] In the sixth aspect, the first operation can be prevented from being executed during store opening hours.

[0018] A seventh aspect is any one of the first to sixth aspects, wherein the detection unit (90) detects that a first member (59) that suppresses a change in the air temperature inside the showcase (50) has been attached to the showcase (50), and the control units (C1, C3) determine that the store (T) is outside business hours when it is detected that the first member (59) has been attached to the showcase (50).

[0019] In the seventh aspect, the first operation can be performed even for products that require refrigeration or freezing by attaching the first member (59) to the showcase (50). Furthermore, when the attachment of the first member (59) is detected, the first operation can be performed automatically.

[0020] An eighth aspect is any one of the first to seventh aspects, wherein the refrigeration device (1) has a plurality of the showcases (50), and the control units (C1, C3) perform the first operation on a target showcase (50) among the plurality of the showcases (50).

[0021] In the eighth aspect, the first operation can be performed only in the target showcase (50), which is useful when the storage temperatures of products differ from showcase to showcase.

[0022] A ninth aspect is a refrigeration system including the heat source unit (10) of any one of the first to eighth aspects and the showcase (50).

[0023] In the ninth aspect, it is possible to provide a refrigeration system (1) that performs the first operation outside business hours.

[0024] A tenth aspect is the ninth aspect, wherein the showcase (50) is provided with a transparent panel (70) and a heating section (75) that suppresses fogging on the transparent panel (70), and the control section (C1, C3) limits the operation of the heating section (75) in the first operation.

[0025] In the tenth aspect, the operation of the heating section (75) is stopped during the first operation, thereby reducing power consumption outside business hours, thereby achieving energy conservation in the refrigeration system (1).

[0026] An eleventh aspect is the ninth or tenth aspect, wherein the showcase (50) includes a second pressure reduction mechanism (53) connected to the refrigerant circuit (11), and the control unit (C1, C3) controls the second pressure reduction mechanism (53) during the first operation so that the degree of superheat of the refrigerant sucked from the first utilization heat exchanger (54) to the compression element (21, 22, 23) becomes higher than the degree of superheat before the start of the first operation.

[0027] In the eleventh aspect, the second pressure reducing mechanism (53) is throttled, making it difficult for the refrigerant to flow, thereby suppressing low pressure and making it difficult for the rotation speed of the compression elements (21, 22, 23) to increase.

[0028] A twelfth aspect is any one of the ninth to eleventh aspects, further comprising an indoor unit (60) for air-conditioning an indoor space of the store (T), wherein the indoor unit (60) has a second utilization heat exchanger (64) connected to the refrigerant circuit (11), and the compression element (21, 22, 23) has a first compressor (21) for compressing refrigerant flowing out of the first utilization heat exchanger (54) and a second compressor (22) for compressing refrigerant flowing out of the second utilization heat exchanger (64), and the control units (C1, C3) increase the operating frequency of the first compressor (21) when prioritizing temperature regulation in the showcase (50) over air-conditioning of the indoor space in the first operation.

[0029] FIG. 1 is a piping system diagram of a refrigeration device according to an embodiment. FIG. 2A is a schematic diagram showing the configuration of a showcase according to an embodiment. FIG. 2B is a diagram corresponding to FIG. 2A showing a state in which the showcase cover is closed. FIG. 3 is a block diagram showing the relationship between each control unit and equipment of the refrigeration device. FIG. 4 is a piping system diagram corresponding to FIG. 1 showing the flow of refrigerant in refrigeration operation. FIG. 5 is a piping system diagram corresponding to FIG. 1 showing the flow of refrigerant in cooling / refrigeration operation. FIG. 6 is a piping system diagram corresponding to FIG. 1 showing the flow of refrigerant in heating / refrigeration operation. FIG. 7 is a flowchart showing the flow of a first operation. FIG. 8 is a diagram corresponding to FIG. 2A of a showcase according to a fourth modified example.

[0030] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the following embodiments are essentially preferred examples and are not intended to limit the scope of the present invention, its applications, or its uses. Furthermore, each configuration of the embodiments, modifications, other examples, etc. described below can be combined or partially substituted within the scope of the present invention.

[0031] (1) Configuration of the Refrigeration Device As shown in FIG. 1, the refrigeration device (1) of the present disclosure is applied to a store (T) that retails food and beverages, such as a supermarket. A showcase (50) is arranged in a sales area inside the store (T). Products that require refrigeration or freezing are displayed inside the showcase (50). A plurality of showcases (50) are arranged inside the store (T).

[0032] The refrigeration system (1) has an outdoor unit (10), an indoor unit (60), and a plurality of showcases (50). The outdoor unit (10) is placed outside the store. The indoor unit (60) conditions the indoor space of the store (T). The showcases (50) cool the air inside the showcases (50). In this way, the refrigeration system (1) simultaneously cools the inside of the showcases (50) and conditions the space inside the store (T).

[0033] The refrigeration system (1) has a refrigerant circuit (11) that performs a refrigeration cycle. The outdoor unit (10), the indoor unit (60), and a plurality of showcases (50) are connected by interconnecting pipes (2, 3, 4, 5) that form the refrigerant circuit (11). The plurality of showcases (50) are connected in parallel to the outdoor unit (10).

[0034] (2) Outdoor Unit The outdoor unit (10) is an example of a heat source unit (10). The outdoor unit (10) includes compression elements (21, 22, 23), switching units (TV1, TV2), an outdoor heat exchanger (13), an outdoor expansion valve (14), a gas-liquid separator (15), a cooling heat exchanger (16), and an intercooler (17), which are connected to a refrigerant circuit (11). The outdoor unit (10) includes an outdoor fan (12) and a cooling fan (17a).

[0035] (2-1) Compression Elements The compression elements (21, 22, 23) are configured as a so-called two-stage compression type. Specifically, the compression elements (21, 22, 23) include a first compressor (21), a second compressor (22), and a third compressor (23). The first compressor (21) and the second compressor (22) constitute a low-stage compressor, and the third compressor (23) constitutes a high-stage compressor. The refrigerant compressed and discharged by the first compressor (21) is sucked into and compressed by the third compressor (23). The refrigerant compressed and discharged by the second compressor (22) is sucked into and compressed by the third compressor (23).

[0036] The first compressor (21) is a compressor corresponding to the showcase (50). The first compressor (21) compresses the refrigerant flowing out from an indoor heat exchanger (54) described later. The second compressor (22) is a compressor corresponding to the indoor unit (60). The second compressor (22) compresses the refrigerant flowing out from an indoor heat exchanger (64) described later.

[0037] The first to third compressors (21 to 23) are rotary compressors whose compression mechanisms are driven by motors. Each of the compressors (21 to 23) is a variable displacement compressor whose operating frequency or rotation speed is adjustable. Each of the compressors (21 to 23) is, for example, a rotary, scroll, or screw type.

[0038] (2-2) Switching Unit The switching units (TV1, TV2) switch the flow path of the refrigerant in the refrigerant circuit (11). The switching units (TV1, TV2) have a first three-way valve (TV1) and a second three-way valve (TV2).

[0039] The first three-way valve (TV1) has a first port (P1) connected to the first pipe (31), which is a high-pressure line, a second port (P2) connected to the third pipe (33), which is a low-pressure line, and a third port (P3) communicating with the indoor gas line (35).

[0040] The second three-way valve (TV2) has a first port (P1) connected to the second pipe (32) which is a high-pressure line, a second port (P2) connected to the fourth pipe (34) which is a low-pressure line, and a third port (P3) which communicates with the outdoor gas line (36).

[0041] The first three-way valve (TV1) and the second three-way valve (TV2) are switched between a first state (a state indicated by a solid line in FIG. 1) and a second state (a state indicated by a broken line in FIG. 1).

[0042] (2-3) Outdoor Heat Exchanger The outdoor heat exchanger (13) is a fin-and-tube air heat exchanger. The outdoor fan (12) transports outdoor air to the outdoor heat exchanger (13). In the outdoor heat exchanger (13), heat is exchanged between the refrigerant flowing through the outdoor heat exchanger (13) and the outdoor air. The outdoor heat exchanger (13) is an example of a heat source heat exchanger (13).

[0043] A gas end of the outdoor heat exchanger (13) is connected to the outdoor gas line (36), and a liquid end of the outdoor heat exchanger (13) is in communication with the outdoor flow path (O).

[0044] (2-4) Outdoor Expansion Valve The outdoor expansion valve (14) is connected to the outdoor flow path (O). The outdoor flow path (O) is disposed in the outdoor unit (10) and constitutes the refrigerant circuit (11). The outdoor expansion valve (14) reduces the pressure of the refrigerant condensed in the outdoor heat exchanger (13). The outdoor expansion valve (14) is an example of a first pressure reducing mechanism (14). The outdoor expansion valve (14) is an electronic expansion valve whose opening is variable.

[0045] (2-5) Gas-Liquid Separator The gas-liquid separator (15) separates the refrigerant into a gas refrigerant and a liquid refrigerant. The gas-liquid separator (15) is connected to the outdoor flow path (O). A gas vent pipe (not shown) communicating with the injection flow path (38) is connected to the gas-liquid separator (15).

[0046] (2-6) Cooling Heat Exchanger The cooling heat exchanger (16) cools the refrigerant (mainly liquid refrigerant) separated in the gas-liquid separator (15). The cooling heat exchanger (16) has a first flow path (16a) and a second flow path (16b). The refrigerant flowing out of the gas-liquid separator (15) is divided into the first flow path (16a) and the second flow path (16b). The refrigerant reduced in pressure by the pressure reducing valve (40) flows through the second flow path (16b). The refrigerant flowing through the first flow path (16a) is cooled by exchanging heat with the refrigerant flowing through the second flow path (16b).

[0047] The second flow path (16b) communicates with an injection flow path (38). The injection flow path (38) is connected to an intermediate-pressure flow path (41) through which refrigerant of an intermediate pressure between the low-pressure compressor and the high-pressure compressor flows. In other words, the injection flow path (38) is connected to the suction side or suction pipe of the third compressor (23).

[0048] (2-7) Intercooler The intercooler (17) cools the intermediate-pressure refrigerant. The intercooler (17) is connected to the intermediate-pressure flow path (41). The intercooler (17) is provided on the discharge sides of the first compressor (21) and the second compressor (22) and on the suction side of the third compressor (23). The intercooler (17) is a fin-and-tube air heat exchanger. The intercooler (17) exchanges heat between the outdoor air transported by the cooling fan (17a) and the refrigerant flowing through the intercooler (17).

[0049] (2-8) Check Valves Seven check valves (CV1 to CV7) are connected to the refrigerant circuit (11). Each check valve (CV1 to CV7) allows the refrigerant to flow in the direction of the arrow shown in Fig. 1 and restricts the refrigerant to flow in the direction opposite to the arrow.

[0050] (3) Indoor Unit The indoor unit (60) has an indoor expansion valve (63) and an indoor heat exchanger (64) connected to the refrigerant circuit (11). The indoor unit (60) has an indoor fan (62). The indoor expansion valve (63) is an electronic expansion valve with a variable opening. The indoor heat exchanger (64) is a fin-and-tube air heat exchanger. The indoor heat exchanger (64) exchanges heat between the indoor air transported by the indoor fan (62) and the refrigerant flowing through the indoor heat exchanger (64). The indoor heat exchanger (64) is an example of a second utilization heat exchanger (64).

[0051] (4) Showcase Figure 2 shows an example of a showcase (50). The showcase (50) includes a casing (55), an internal heat exchanger (54), an internal fan (52), an internal expansion valve (53), and a cover (59).

[0052] The casing (55) is generally box-shaped. An opening (56) is formed in the front surface of the casing (55). The opening (56) is formed over substantially the entire front surface of the casing (55). A partition member (57) is provided within the casing (55). The partition member (57) divides the internal space (S) within the casing (55) into a first air passage (A1) and a second air passage (A2). The partition member (57) extends downward from above near the center of the internal space (S) in the front-rear direction, and then extends forward in the lower part of the internal space (S).

[0053] The first air passage (A1) is formed toward the front of the interior space (S). A display shelf (58) is provided in the first air passage (A1). The display shelf (58) is a board on which products are placed. The display shelf (58) extends forward from the partition member (57). A plurality of display shelves (58) may be arranged in the vertical and horizontal directions of the partition member (57).

[0054] The second air passage (A2) is formed toward the rear of the internal space (S). The second air passage (A2) and the first air passage (A1) communicate with each other at an upper portion of the internal space (S). The second air passage (A2) and the first air passage (A1) communicate with each other at a lower portion of the internal space (S). In the internal space (S), air flows in the direction of the arrows shown in FIG. 2.

[0055] The second air passage (A2) is provided with an internal heat exchanger (54), an internal expansion valve (53), and an internal fan (52). The internal heat exchanger (54) is an example of a first utilization heat exchanger (54). The internal expansion valve (53) is an example of a second pressure reduction mechanism (53).

[0056] The internal heat exchanger (54) is connected to the refrigerant circuit (11). The internal heat exchanger (54) is a fin-and-tube air heat exchanger. The internal fan (52) transports internal air, which is the air in the showcase, to the internal heat exchanger (54). In the internal heat exchanger (54), heat is exchanged between the internal air and the refrigerant flowing through the indoor heat exchanger (64).

[0057] The internal expansion valve (53) is connected to the refrigerant circuit (11). The internal expansion valve (53) is an electronic expansion valve whose opening is variable.

[0058] The cover (59) is a member that opens and closes the opening (56). The cover (59) is an example of a first member (59). The cover (59) is a sheet-like member large enough to cover the opening (56). The cover (59) may be made of a material having heat insulating properties.

[0059] With the cover (59) covering the opening (56), the temperature of the air inside the refrigerator is less likely to rise suddenly even when the operation of the refrigeration system (1) is stopped. In other words, the cover (59) suppresses changes in the temperature of the air inside the showcase (50). This suppresses a temperature rise inside the showcase (50) even when the capacity of the refrigeration system (1) is reduced, thereby reducing the power consumption of the refrigeration system (1).

[0060] The cover 59 is removed from the opening 56 immediately before, at, or after the opening of the store (FIG. 2A). Specifically, the cover 59 is placed at the top end of the opening 56 while wrapped around a rotatably supported support member 61.

[0061] The cover 59 is attached to the showcase 50 so as to cover the opening 56 immediately before, at, or after the store's closing time (FIG. 2B). Specifically, the support member 61 is rotated to extend the cover 59 downward to cover the opening 56.

[0062] In this manner, the cover (59) is attached to the opening (56) of the showcase (50) when business hours end, and the cover (59) is removed from the opening (56) of the showcase (50) when business hours begin.

[0063] (5) Sensors The refrigeration system (1) includes a plurality of sensors. The plurality of sensors include a refrigerant temperature sensor (86), an internal temperature sensor (88), and a first sensor (90). The refrigerant temperature sensor (86) and the internal temperature sensor (88) are provided in the showcase (50). The refrigerant temperature sensor (86) detects the evaporation temperature of the refrigerant in the internal heat exchanger (54). The internal temperature sensor (88) detects the air temperature inside the showcase (50). The first sensor (90) detects that the cover (59) has been attached to the showcase (50). Specifically, the first sensor (90) detects whether the cover (59) has opened or closed the opening (56). More specifically, the first sensor (90) detects whether the cover (59) has completely covered the opening (56). In this way, the first sensor (90) detects the business status of the store (T). The first sensor (90) is an example of a detection section (90).

[0064] (6) Remote Controller As shown in Fig. 1, the air conditioner (1) has a remote controller (100). A user can select an operation mode such as cooling operation, heating operation, or refrigerant discharge operation by operating the remote controller (100).

[0065] (7) Control Unit As shown in Fig. 3, the air conditioning apparatus (1) has an outdoor control unit (C1), an indoor control unit (C2), and an internal control unit (C3). The outdoor control unit (C1), the indoor control unit (C2), and the internal control unit (C3) are configured to be able to communicate with each other via wired or wireless communication. The outdoor control unit (C1) and the internal control unit (C3) are examples of the control units (C1, C3) of the present disclosure.

[0066] The outdoor control unit (C1), indoor control unit (C2), and inside control unit (C3) each include an MCU (Micro Controller Unit), an electric circuit, and an electronic circuit. The MCU includes a CPU (Central Processing Unit), a memory, and a communication interface. The memory stores various programs to be executed by the CPU.

[0067] The outdoor control unit (C1) is provided in the outdoor unit (10). The outdoor control unit (C1) of the outdoor unit (10) controls the switching between operation and stop of the compressor (21), the rotation speed of the compressor (21), the switching between operation and stop of the outdoor fan (12), the rotation speed of the outdoor fan (12), the opening of the outdoor expansion valve (14), etc.

[0068] The indoor control section (C2) is provided in the indoor unit (60). The indoor control section (C2) controls switching between operation and stop of the indoor fan (62), the rotation speed of the indoor fan (62), and the like.

[0069] The internal control section (C3) is provided in the showcase (50). The internal control section (C3) controls switching between on and off of the internal fan (52), the rotation speed of the internal fan (52), and the like.

[0070] (8) Operation An example of the operation of the refrigeration system (1) will be described below. In the following, the showcase (50) performs a refrigeration operation. The indoor unit (60) switches between a cooling operation and a heating operation.

[0071] (8-1) Refrigeration Operation In the cooling operation shown in Fig. 4, the first three-way valve (TV1) is in the second state, and the second three-way valve (TV2) is in the first state. The outdoor expansion valve (14) is opened to a predetermined opening, the opening of the indoor expansion valve (53) is adjusted by controlling the degree of superheat, the indoor expansion valve (63) is fully closed, and the opening of the pressure reducing valve (40) is adjusted appropriately. The outdoor fan (12) and the indoor fan (52) are operated, and the indoor fan (62) is stopped. The first compressor (21) and the third compressor (23) are operated, and the second compressor (22) is stopped.

[0072] The refrigerant compressed by the first compressor (21) is cooled in the intercooler (17) and then drawn into the third compressor (23). The refrigerant compressed by the first compressor (21) dissipates heat in the outdoor heat exchanger (13), flows through the gas-liquid separator (15), and is cooled in the first flow path (16a) of the cooling heat exchanger (16). The refrigerant in the second flow path (16b) that has cooled the refrigerant in the first flow path (16a) flows through the injection flow path (38) and is drawn into the first compressor (21). The refrigerant cooled in the first flow path (16a) of the cooling heat exchanger (16) is decompressed by the internal expansion valve (53) and then evaporates in the internal heat exchanger (54). This cools the air inside the showcase (50). The refrigerant evaporated in the cooling heat exchanger (16) is drawn into the first compressor (21) and compressed again.

[0073] (8-2) Cooling / Refrigeration Operation In the cooling / refrigeration operation shown in Fig. 5, the first three-way valve (TV1) is in the second state, and the second three-way valve (TV2) is in the first state. The outdoor expansion valve (14) is opened to a predetermined opening, the openings of the internal expansion valve (53) and the indoor expansion valve (63) are adjusted by superheat control, and the opening of the pressure reducing valve (40) is appropriately adjusted. The outdoor fan (12), the internal fan (52), and the indoor fan (62) are operated. The first compressor (21), the second compressor (22), and the third compressor (23) are operated.

[0074] The refrigerant compressed in the first compressor (21) and the second compressor (22) is sucked into the third compressor (23). The refrigerant compressed in the first compressor (21) dissipates heat in the outdoor heat exchanger (13), flows through the gas-liquid separator (15), and is cooled in the first flow path (16a) of the cooling heat exchanger (16). The refrigerant in the second flow path (16b) that has cooled the refrigerant in the first flow path (16a) flows through the injection flow path (38) and is sucked into the third compressor (23).

[0075] The refrigerant cooled in the first flow path (16a) of the cooling heat exchanger (16) is divided into the showcase (50) and the indoor unit (60). The refrigerant decompressed by the internal expansion valve (53) evaporates in the internal heat exchanger (54). The refrigerant evaporated in the internal heat exchanger (54) is drawn into the first compressor (21) and compressed again. The refrigerant decompressed by the indoor expansion valve (63) evaporates in the indoor heat exchanger (64). The refrigerant evaporated in the indoor heat exchanger (64) is drawn into the second compressor (22) and compressed again.

[0076] (8-3) Heating / Refrigeration Operation In the heating / refrigeration operation shown in Fig. 6, the first three-way valve (TV1) is set to the first position, and the second three-way valve (TV2) is set to the second position. The indoor expansion valve (63) is opened to a predetermined opening, the openings of the internal expansion valve (53) and the outdoor expansion valve (14) are adjusted by superheat control, and the opening of the pressure reducing valve (40) is appropriately adjusted.

[0077] The outdoor fan (12), the internal fan (52), and the indoor fan (62) are operated, and the first compressor (21), the second compressor (22), and the third compressor (23) are operated.

[0078] The refrigerant compressed in the first compressor (21) and the second compressor (22) is sucked into the third compressor (23). The refrigerant compressed in the third compressor (23) dissipates heat in the indoor heat exchanger (64). This heats the indoor air. The refrigerant that dissipates heat in the indoor heat exchanger (64) flows through the gas-liquid separator (15) and is cooled in the first flow path (16a) of the cooling heat exchanger (16). The refrigerant in the second flow path (16b) that has cooled the refrigerant in the first flow path (16a) flows through the injection flow path (38) and is sucked into the third compressor (23). A portion of the refrigerant cooled in the first flow path (16a) of the cooling heat exchanger (16) is decompressed by the outdoor expansion valve (14) and then evaporates in the outdoor heat exchanger (13). The refrigerant evaporated in the outdoor heat exchanger (13) is sucked into the second compressor (22) and compressed again.

[0079] The remainder of the refrigerant cooled in the first flow path (16a) of the cooling heat exchanger (16) is reduced in pressure by the internal expansion valve (53) and then evaporated in the internal heat exchanger (54). This cools the air inside the compartment. The refrigerant evaporated in the internal heat exchanger (54) is sucked into the first compressor (21) and compressed again.

[0080] (9) First Operation When it is detected that the store (T) is outside of business hours, the outdoor control unit (C1) executes a first operation that restricts the operation of the refrigeration device (1). The first operation includes an outdoor first operation executed by the outdoor unit (10) and an indoor first operation executed by the showcase (50).

[0081] (9-1) Outdoor First Operation The outdoor first operation is an operation in which the duration of the thermo-off state of the refrigeration device (1) is longer than the duration of the thermo-off state during the business hours of the store (T).

[0082] Specifically, when the temperature inside the showcase (50) is close to the set temperature, the refrigeration system (1) alternates between thermo-off and thermo-on. When the temperature inside the showcase (50) falls below a predetermined temperature that is lower than the set temperature, the thermo-off state is executed. In the thermo-off state, the operation of the first compressor (21) and the third compressor (23) is reduced or temporarily stopped. The thermo-off state continues for a certain period of time. For example, the duration of the thermo-off state executed outside business hours is set to three minutes, and the duration of the thermo-off state executed during business hours is set to one minute. In this way, the power consumption of the compression elements (21-23) is reduced by extending the duration of the thermo-off state.

[0083] (9-2) First In-compartment Operation The first in-compartment operation is an operation in which the in-compartment expansion valve (53) is controlled so that the degree of superheat of the refrigerant sucked from the in-compartment heat exchanger (54) into the first compressor (21) is greater than the degree of superheat during business hours. In other words, in the first in-compartment operation, the opening degree of the in-compartment expansion valve (53) outside business hours is smaller than the opening degree of the in-compartment expansion valve (53) during business hours. This reduces the amount of refrigerant flowing through the in-compartment heat exchanger (54), thereby reducing the amount of refrigerant sucked into the first compressor (21).

[0084] (10) Operation of the Control Unit An example of the operation of the control unit (C1) in the first operation will be described with reference to FIG. 7. In the following example, air conditioning in the store (T) is not performed outside the business hours of the store (T). That is, the operation of the indoor unit (60) is stopped outside the business hours. In other words, refrigeration operation is performed outside the business hours.

[0085] In step S01, the outdoor control unit (C1) determines whether or not the business hours of the store (T) have ended (whether or not it is outside of business hours). Specifically, the outdoor control unit (C1) determines whether or not it has received a first signal from the first sensor (90) indicating that the cover (59) has covered the opening (56).

[0086] In step S02, the outdoor control unit (C1) determines whether all showcases (50) are subject to the first operation. For example, a showcase (50) displaying frozen goods, fresh foods, or other products needs to maintain a constant temperature inside for 24 hours to maintain quality. Such showcases (50) are not suitable for the first operation. Therefore, the outdoor control unit (C1) determines whether there is a showcase (50) that is not suitable for the first operation, and if there is a showcase (50) that is not suitable for the first operation, identifies that showcase (50). For example, each showcase (50) is assigned a unique ID, and the outdoor control unit (C1) identifies the ID of a showcase (50) that is associated with an inability to perform the first operation from among all IDs.

[0087] If it is determined that all the showcases (50) are to be subjected to the first operation (YES in step S02), step S03 is executed. If it is determined that all the showcases (50) are not to be subjected to the first operation (NO in step S02), step S04 is executed.

[0088] In step S03, the outdoor control section (C1) executes the outdoor first operation, whereby the duration of the thermo-off state becomes longer than the duration of the thermo-off state during business hours.

[0089] In step S04, the outdoor control section (C1) transmits an instruction to perform the first indoor operation to the indoor control section (C3).

[0090] In step S05, the indoor control section (C2) executes the first indoor operation. As a result, the opening degree of the indoor expansion valve (53) becomes smaller than the opening degree of the indoor expansion valve (53) during business hours. Specifically, the indoor control section (C2) controls the indoor expansion valve (53) so that the opening degree of the indoor expansion valve (53) becomes the smallest.

[0091] In step S06, the outdoor control unit (C1) determines whether or not there is a showcase (50) that is a target of the first operation. If it is determined that there is a showcase (50) that is a target of the first operation (YES in step S06), step S07 is executed. If it is determined that there is no showcase (50) that is a target of the first operation (NO in step S06), the first operation is not executed and this flow ends.

[0092] In Step S07, the outdoor control section (C1) transmits an instruction to perform the first indoor operation to the indoor control section (C2) of the showcase (50) that is the target of the first operation.

[0093] In step S08, the outdoor control unit (C1) determines whether business hours of the store (T) have started (whether it is outside business hours). Specifically, the outdoor control unit (C1) determines whether the first signal indicating that the cover (59) has covered the opening (56) has been received. If it is determined that business hours of the store (T) have started (YES in step S08), step S09 is executed. If it is determined that business hours of the store (T) have not started (NO in step S08), step S08 is executed again.

[0094] In step S09, the outdoor control unit (C1) stops the first operation. In this way, the outdoor control unit (C1) does not execute the first operation when it is detected that the business hours of the store (T) have started. In other words, the outdoor control unit (C1) does not execute the first operation during the business hours of the store (T).

[0095] (11) Features (11-1) Feature 1 The outdoor unit (10) of the present embodiment includes a first sensor (90) that detects the business status of the store (T). When it is detected that the store (T) is outside of business hours, the outdoor control unit (C1) executes a first operation that limits the operation of the refrigeration device (1).

[0096] The first operation mode reduces the operation of the refrigeration device (1) outside of business hours, thereby realizing energy savings. In particular, food or beverage products that can be stored at room temperature do not need to be refrigerated outside of business hours, so the first operation mode can contribute to energy savings in the refrigeration device (1).

[0097] (11-2) Feature 2 The first operation of the present embodiment is an operation in which the duration of the thermo-off state of the refrigeration device (1) is longer than the duration of the thermo-off state during the opening hours of the store (T).

[0098] In this way, the waiting time for the thermostat to be turned off is extended outside business hours, and the time for which the operation of the first compressor (21) and the third compressor (23) is restricted is also extended. This allows energy conservation of the refrigeration system (1). In particular, the first operation is performed for products that do not require refrigeration or freezing. If the duration of the thermostat being turned off is extended, the temperature inside the showcase (50) is likely to rise, but the quality of the products that do not require refrigeration or freezing is unlikely to be affected.

[0099] (11-3) Feature 3: When the outdoor control unit (C1) of the present embodiment detects that the store (T) is outside of business hours, the outdoor control unit (C1) does not execute the first operation. In this way, the first operation is not executed during business hours of the store (T), and therefore, it is possible to suppress an increase in the temperature of the refrigerated or frozen products in the showcase (50).

[0100] (11-4) Feature 4 In this embodiment, the outdoor control unit (C1) controls the internal expansion valve (53) in the first operation so that the degree of superheat of the refrigerant drawn from the internal heat exchanger (54) into the first compressor (21) is greater than the degree of superheat before the first operation is started. In other words, the outdoor control unit (C1) controls the opening degree of the internal expansion valve (53) in the first operation to be smaller than that before the first operation is started. This reduces the amount of refrigerant flowing through the refrigerant, thereby reducing the amount of refrigerant drawn into the first compressor (21). As a result, the rotational speed of the first compressor (21) and therefore the rotational speed of the third compressor (23) can be reduced.

[0101] (11-5) Feature 5 The first sensor (90) of the present embodiment detects that a cover (59) for suppressing a change in the air temperature inside the showcase (50) has been attached to the showcase (50). When the outdoor control unit (C1) detects that the cover (59) has been attached to the showcase (50), it determines that the store (T) is closed.

[0102] The cover (59) is attached to the opening (56) of the showcase (50) after business hours, and therefore, when the first sensor (90) detects that the cover (59) has been attached to the showcase (50), it can be determined that the store (T) is no longer open. This allows the first operation to be automatically performed.

[0103] (12) Modifications Modifications of the refrigeration system (1) of the present disclosure will be described below. Configurations different from the refrigeration system (1) of the above embodiment will be described below.

[0104] (12-1) Modification 1 The outdoor first operation of Modification 1 differs from the outdoor first operation of the above embodiment. In the outdoor first operation of Modification 1, the outdoor control unit (C1) sets the target evaporation temperature of the refrigerant in the internal heat exchanger (54) to be higher than the target evaporation temperature of the refrigerant in the internal heat exchanger (54) before it is detected that the store (T) is outside its business hours.

[0105] In other words, the outdoor control unit (C1) sets the target evaporation temperature of the refrigerant in the internal heat exchanger (54) after the start of the first operation higher than that before the start of the first operation (before the end of business hours). For example, if the target evaporation temperature of the internal heat exchanger (54) during business hours is set to -10°C, the target evaporation temperature of the internal heat exchanger (54) in the first operation is set to 0°C.

[0106] As a result, the difference between the evaporation temperature of the internal heat exchanger (54) and the target evaporation temperature is smaller outside business hours in the showcase (50) than during business hours, and thus, an increase in the rotation speed of the first compressor (21) is suppressed during the first operation, thereby achieving energy conservation in the refrigeration system (1).

[0107] (12-2) Modification 2 The outdoor first operation of Modification 2 differs from the outdoor first operation of the above embodiment. In the outdoor first operation of Modification 2, the rate of increase in the operating frequency of the compression elements (21, 22, 23) is lower than the rate of increase in the operating frequency of the compression elements (21, 22, 23) during business hours of the store (T). In other words, the outdoor control unit (C1) sets the rate of increase in the operating frequency of the compression elements (21, 22, 23) in the first operation to be lower than the rate of increase in the operating frequency of the compression elements (21, 22, 23) before the start of the first operation. This results in a slower increase in the operating frequency of the compression elements (21, 22, 23) outside business hours than during business hours, thereby achieving energy conservation in the refrigeration system (1). Here, the compression elements (21, 22, 23) are a first compressor (21) and a third compressor (23) corresponding to the internal heat exchanger (54).

[0108] (12-3) Modification 3 The outdoor first operation of Modification 3 differs from the outdoor first operation of the above embodiment. The outdoor control unit (C1) of Modification 3 sets the first temperature at which the thermo-off state of the refrigeration device (1) ends during the first operation to be higher than the first temperature before the closing of the store (T) is detected. In other words, the outdoor control unit (C1) sets the first temperature at which the thermo-off state is switched to the thermo-on state during the first operation to be higher than the first operation before the first operation starts.

[0109] By setting the temperature at which the thermostat switches from off to on higher outside business hours than during business hours, the time during which the operation of the first compressor (21) and the third compressor (23) corresponding to the in-compartment heat exchanger (54) is restricted can be extended.

[0110] (12-4) Modification 4 The first internal operation of Modification 4 is a control for reducing the heat generation of the heating section (75) that suppresses fogging of the door (70) of the showcase (50).

[0111] Specifically, as shown in FIG. 8 , the showcase (50) has a door (70) having transparent glass. The door (70) is an example of a transparent panel (70). The door (70) is provided on the front surface of the casing (55). The door (70) is provided so as to be able to open and close the opening (56) of the casing (55). The glass portion of the door (70) is provided over substantially the entire area of ​​the door (70). Therefore, even when the door (70) is closed, the products placed in the showcase (50) can be viewed from outside.

[0112] The showcase (50) is provided with a heating section for suppressing fogging on the door (70). The heating section (75) heats the door (70), thereby suppressing fogging on the door (70) due to the temperature difference between the inside and outside of the cabinet.

[0113] The outdoor control unit (C1) of the outdoor unit (10) controls the operation of the heating unit (75). The outdoor control unit (C1) operates the heating unit (75) during business hours of the store (T). When the outdoor control unit (C1) detects that the store (T) is closed, the outdoor control unit (C1) limits the operation of the heating unit (75). In other words, the outdoor control unit (C1) limits the operation of the heating unit (75) in the first operation. Specifically, the outdoor control unit (C1) may stop the operation of the heating unit (75) or may reduce the amount of heat generated by the heating unit (75) during the first operation compared to before the first operation.

[0114] (13) Other Embodiments The above-described embodiment and each of the above-described modifications may be configured as follows.

[0115] The detection unit (90) of the present disclosure may detect that the store (T) has closed or is outside of business hours. For example, the detection unit (90) may detect that the lights in the store (T) have been turned off or that the entrance door to the store (T) has been locked. The first sensor (90) may also detect the presence or absence of personnel in the store (T). In this case, this may be detected using video of the inside of the store (T) captured by a camera installed in the store (T). The detection unit (90) may also detect the opening and closing times of the store (T). The detection unit (90) may also detect a signal to start security in the store (T) at night or on holidays.

[0116] In step S02 of the first operation in the above embodiment, the outdoor control unit (C1) may determine, based on the type of product, whether or not the showcase (50) in which the product is displayed is a target for the first operation. The type of product may be determined based on an image captured by a camera or a barcode attached to the product.

[0117] The refrigeration system (1) may have a communication controller (not shown) arranged outside the refrigeration system (1). The communication controller is communicably connected to the outdoor control unit (C1) and the indoor control unit (C3) of the refrigeration system (1). The communication controller may execute steps S02 and S06 in the first operation, for example.

[0118] In the outdoor first operation, at least one of the outdoor first operation described in the above embodiment and the outdoor first operation described in each modified example may be performed. A plurality of the outdoor first operations described in the above embodiment and the outdoor first operations described in each modified example may be combined.

[0119] When all the showcases (50) are subjected to the first operation, only the outdoor first operation or only the indoor first operation may be executed as the first operation.

[0120] The outdoor control unit (C1) may execute the first indoor operation, that is, in the flow of the first operation, steps S05 and S07 may be executed by the outdoor control unit (C1).

[0121] In the first operation, an operation may be performed to fully close the internal expansion valve (53) of the showcase (50) that is the target of the first operation, so that the refrigerant flows through the showcase (50) that is the target of the first operation, but the refrigerant does not flow through the showcase (50) that is the target of the first operation.

[0122] In the first operation, when priority is given to adjusting the temperature inside the showcase (50) over air conditioning inside the store (T) in the first operation, the outdoor control unit (C1) may increase the operating frequency of the second compressor (22). Outside the business hours of the store (T), the air conditioning load inside the store (T) is relatively low. Therefore, when it is detected that the store (T) is outside its business hours, the outdoor control unit (C1) may increase the operating frequency of the first compressor (21). In particular, when it is detected that the store (T) is outside its business hours, the air conditioning capacity of the indoor unit (60) is reduced from the air conditioning capacity during business hours, thereby reducing the power consumption of the refrigeration system (1) outside of business hours.

[0123] In the flow of the first operation of the above embodiment, the indoor unit (60) may be operated. That is, the cooling operation or the heating operation may be performed during the first operation. In this case, the second compressor (22) may be the target of the first operation.

[0124] The refrigeration system of the above embodiment does not necessarily have to include the indoor unit (60). In this case, the refrigeration system (1) may be of a single-stage compression type or a two-stage compression type. In the case of a single-stage compression type, the compression element (21, 22, 23) includes a first compressor (21).

[0125] In the first outdoor operation of the above embodiment, the rotation speed of one of the first compressor (21) and the third compressor (23) may be controlled to be reduced.

[0126] The refrigerant circuit (11) of the above embodiment may have a bypass flow path (not shown) that bypasses the third compressor (23). In this case, the bypass flow path connects the suction pipe and discharge pipe of the third compressor (23). In such a refrigerant circuit (11), the third compressor (23) can be stopped to switch to single-stage compression. In the single-stage compression, the rotation speed of the first compressor (21) may be controlled in the first outdoor operation.

[0127] Although the embodiments and modifications have been described above, it will be understood that various modifications in form and detail are possible without departing from the spirit and scope of the claims. Furthermore, the above embodiments and modifications may be combined or substituted as appropriate as long as the functionality of the subject matter of the present disclosure is not impaired. The terms "first," "second," etc., described above, are used to distinguish the terms to which these terms are attached, and do not limit the number or order of the terms.

[0128] INDUSTRIAL APPLICABILITY As described above, the present disclosure is useful for heat source units and refrigeration devices.

[0129] REFRIGERATION SYSTEM 1 Refrigeration unit 10 Outdoor unit (heat source unit) 11 Refrigerant circuit 13 Outdoor heat exchanger (heat source heat exchanger) 14 Outdoor expansion valve (first pressure reducing mechanism) 21 First compressor 21, 22, 23 Compression element 22 Second compressor 50 Showcase 53 Indoor expansion valve (second pressure reducing mechanism) 54 Indoor heat exchanger (first utilization heat exchanger) 59 Cover (first member) 60 Indoor unit 64 Indoor heat exchanger (second utilization heat exchanger) 75 Heating unit 90 First sensor (detection unit) C1 Outdoor control unit (control unit) T Store

Claims

1. A heat source unit constituting a refrigeration system (1) having a showcase (50) having a first utilization heat exchanger (54) connected to a refrigerant circuit (11), the heat source unit comprising: a compression element (21, 22, 23), a first pressure reduction mechanism (14), and a heat source heat exchanger (13) connected to the refrigerant circuit (11); a detection unit (90) that detects the business status of a store that has the showcase (50); and a control unit (C1) that controls the operation of the refrigeration system (1), wherein the control units (C1, C3) execute a first operation that limits the operation of the refrigeration system (1) when it is detected that the store is outside of business hours.

2. The heat source unit according to claim 1, wherein the first operation is an operation in which the duration of thermo-off of the refrigeration device (1) is longer than the duration of thermo-off during the opening hours of the store.

3. The heat source unit according to claim 1 or 2, wherein the control unit (C1, C3) sets a first temperature at which thermo-off of the refrigeration device (1) ends during the first operation to be higher than the first temperature during business hours of the store.

4. The heat source unit according to any one of claims 1 to 3, wherein in the first operation, the control unit (C1, C3) sets a target evaporation temperature of the refrigerant in the first utilization heat exchanger (54) higher than the target evaporation temperature of the refrigerant in the first utilization heat exchanger (54) during business hours of the store.

5. The heat source unit according to any one of claims 1 to 4, wherein the first operation is an operation in which the rate of increase in the operating frequency of the compression elements (21, 22, 23) is lower than the rate of increase in the operating frequency of the compression elements (21, 22, 23) during business hours of the store.

6. The heat source unit according to any one of claims 1 to 5, wherein the control unit (C1, C3) does not execute the first operation when it is detected that the store (T) has started business.

7. The heat source unit according to any one of claims 1 to 6, wherein the detection section (90) detects that a first member (59) that suppresses a change in the air temperature inside the showcase (50) has been attached to the showcase (50), and the control sections (C1, C3) determine that it has been detected that the store (T) is outside its business hours when it has detected that the first member (59) has been attached to the showcase (50).

8. The heat source unit according to any one of claims 1 to 7, wherein the refrigeration device (1) has a plurality of the showcases (50), and the control units (C1, C3) execute the first operation on a target showcase (50) among the plurality of the showcases (50).

9. A refrigeration system comprising the heat source unit (10) according to any one of claims 1 to 8 and the showcase (50).

10. The refrigeration system according to claim 9, wherein the showcase (50) is provided with a transparent panel (70) and a heating section (75) that suppresses fogging on the transparent panel (70), and the control section (C1, C3) limits operation of the heating section (75) in the first operation.

11. The refrigeration system according to claim 9 or 10, wherein the showcase (50) includes a second pressure reduction mechanism (53) connected to the refrigerant circuit (11), and the control unit (C1, C3) controls the second pressure reduction mechanism (53) in the first operation so that the degree of superheat of the refrigerant drawn from the first utilization heat exchanger (54) into the compression element (21, 22, 23) becomes higher than the degree of superheat before the start of the first operation.

12. The refrigeration system according to any one of claims 9 to 11, further comprising an indoor unit (60) for air-conditioning an indoor space of the store (T), wherein the indoor unit (60) has a second utilization heat exchanger (64) connected to the refrigerant circuit (11), wherein the compression element (21, 22, 23) has a first compressor (21) for compressing refrigerant flowing out of the first utilization heat exchanger (54) and a second compressor (22) for compressing refrigerant flowing out of the second utilization heat exchanger (64), and wherein the control units (C1, C3) increase the operating frequency of the first compressor (21) when, in the first operation, priority is given to adjusting the temperature in the showcase (50) over air-conditioning of the indoor space.

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