Refrigeration device

Abstract

The controller (60) controls the second expansion mechanism (33) and the pressure adjustment mechanism (34) under operating conditions in which the heat source-side heat exchanger (13) functions as a radiator, the first use-side heat exchanger (21) and the second use-side heat exchanger (31) functions as evaporators, and the first use-side heat exchanger (21) may frost. Therefore, the second utilization-side heat exchanger (31) is not frosted.

Description

Technical Field

[0001] The present disclosure relates to a refrigeration device. Background Art

[0002] Patent Document 1 discloses a transport refrigeration device. The refrigeration device includes a refrigerant circuit including a compressor, a condenser, an expansion valve, and an evaporator, and a secondary battery (battery) as a power source for the refrigeration device.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Publication No. 2010-188940 Summary of the invention

[0006] -Technical problem to be solved by the invention-

[0007] The inventor of the present application has created a structure for adjusting the battery temperature by using a refrigeration device. Specifically, a first utilization side heat exchanger and a second utilization side heat exchanger are arranged in parallel in the refrigerant circuit. The first utilization side heat exchanger, which functions as an evaporator, cools the first object, while the second utilization side heat exchanger, which functions as an evaporator, adjusts the temperature of the second object.

[0008] On the other hand, during such operation, there may be an operating condition that may cause frost on the first use-side heat exchanger. Under such operating conditions, since the evaporation temperature of the first use-side heat exchanger is relatively low, the evaporation temperature of the second use-side heat exchanger is also reduced. As a result, there is a problem that not only the first use-side heat exchanger but also the second use-side heat exchanger is frosted, causing adverse effects on the second object.

[0009] An object of the present disclosure is to provide a refrigeration device capable of suppressing frost formation on a second utilization-side heat exchanger.

[0010] -Technical solutions to solve technical problems-

[0011] The refrigeration device of the first aspect includes a refrigerant circuit R and a controller 60. The refrigerant circuit R includes a compressor 12, a heat source side heat exchanger 13, a first refrigerant flow path P1, and a second refrigerant flow path P2, the heat source side heat exchanger 13 is arranged in series with the compressor 12, the first refrigerant flow path P1 is arranged in series with the compressor 12 and the heat source side heat exchanger 13, and the first refrigerant flow path P1 has a first expansion mechanism 23 and a first utilization side heat exchanger 21, the second refrigerant flow path P2 is arranged in parallel with the first refrigerant flow path P1, and the second refrigerant flow path P2 has a second expansion mechanism 33, a second utilization side heat exchanger 31, and a pressure regulating mechanism 34.

[0012] Under operating conditions where the heat source side heat exchanger 13 acts as a radiator, the first utilization side heat exchanger 21 and the second utilization side heat exchanger 31 act as evaporators, and the first utilization side heat exchanger 21 may be frosted, the controller 60 controls the second expansion mechanism 33 and the pressure regulating mechanism 34 to prevent the second utilization side heat exchanger 31 from frosting.

[0013] In the first aspect, under the operating condition where the first use-side heat exchanger 21 may be frosted, the controller 60 controls the second expansion mechanism 33 and the pressure regulating mechanism 34. Thus, the evaporation temperature of the first use-side heat exchanger 21 and the evaporation temperature of the second use-side heat exchanger 31 can be adjusted respectively, and the frost of the second use-side heat exchanger 31 can be suppressed.

[0014] According to a second aspect, in addition to the first aspect, the second utilization-side heat exchanger 31 adjusts the temperature of the battery B.

[0015] If the second usage-side heat exchanger 31 is frosted, it becomes difficult to maintain the temperature of the battery B at a predetermined temperature using the second usage-side heat exchanger 31. In the second aspect, since frosting of the second usage-side heat exchanger 31 can be suppressed, reliability of temperature regulation of the battery B can be ensured.

[0016] According to a third aspect, based on the first or second aspect, the first utilization-side heat exchanger (21) cools the air in the storage.

[0017] In the third aspect, since the first use-side heat exchanger 21 cools the air in the storage, the evaporation temperature of the first use-side heat exchanger 21 tends to be relatively low, resulting in frost formation on the first use-side heat exchanger 21. In contrast, the controller 60 controls the second expansion mechanism 33 and the pressure regulating mechanism 34 so that the second use-side heat exchanger 31 is not frosted, thereby making it possible to perform an operation in which the temperature in the storage is low by using the first use-side heat exchanger 21 and frost formation on the second use-side heat exchanger 31 is suppressed.

[0018] In the fourth aspect, based on any one of the first to third aspects, the controller 60 controls the refrigerant circuit R to perform a defrost operation in which the refrigerant in the refrigerant circuit R is used to melt the frost on the first utilization side heat exchanger 21, and the refrigerant circuit R is configured to suppress the refrigerant from flowing to the second utilization side heat exchanger 31 during the defrost operation.

[0019] In the fourth aspect, during the defrosting operation for melting the frost on the first use-side heat exchanger 21, the refrigerant circuit R suppresses the refrigerant from flowing to the second use-side heat exchanger 31. Therefore, it is possible to suppress the temperature of the second use-side heat exchanger 31 from rising due to the refrigerant, and further suppress the temperature rise of the temperature control object of the second use-side heat exchanger 31.

[0020] A fifth aspect is based on the fourth aspect, and the controller (60) controls the refrigerant circuit (R) to perform a first action, a second action, or a third action as the defrosting operation.

[0021] The first action is to make the high-pressure refrigerant ejected from the compressor 12 bypass the heat source side heat exchanger 13 and flow to the first utilization side heat exchanger 21. The second action is to make the high-pressure refrigerant ejected from the compressor 12 release heat in the first utilization side heat exchanger 21 and evaporate in the heat source side heat exchanger 13. The third action is to make the high-pressure refrigerant ejected from the compressor 12 flow sequentially through the heat source side heat exchanger 13 and the first utilization side heat exchanger 21 whose corresponding fans 14 are in a stopped state.

[0022] In the sixth aspect, based on the fifth aspect, the refrigerant circuit R includes a bypass flow path 36, one end of the bypass flow path 36 is connected to the discharge side of the compressor 12, and the other end of the bypass flow path 36 is connected to the first refrigerant flow path P1 at a position between the first expansion mechanism 23 and the first utilization side heat exchanger 21, and the high-pressure refrigerant discharged from the compressor 12 under the first action flows through the bypass flow path 36.

[0023] In the sixth aspect, in the first operation of the defrosting operation, the high-pressure refrigerant discharged from the compressor 12 flows through the first usage side heat exchanger 21 via the bypass flow path 36. Thus, frost on the first usage side heat exchanger 21 can be melted by the high-pressure refrigerant.

[0024] According to the seventh aspect, based on the sixth aspect, in the first refrigerant flow path P1, a check valve 39 is provided between the connection end between the bypass flow path 36 and the first refrigerant flow path P1 and the branch portion 17 between the first refrigerant flow path P1 and the second refrigerant flow path P2, for prohibiting the refrigerant from flowing from the connection end to the branch portion 17.

[0025] In the seventh aspect, in the first operation, the refrigerant flowing out of the bypass flow path 36 can be prevented from flowing into the second refrigerant flow path P2 by the check valve 39. This prevents the high-pressure refrigerant from flowing into the second usage-side heat exchanger 31 during the defrosting operation.

[0026] According to an eighth aspect, based on any one of the fourth to seventh aspects, during the defrosting operation, the controller 60 reduces the opening of the second expansion valve 33 as the second expansion mechanism 33. It should be noted that "reducing the opening of the second expansion valve" mentioned here also includes making the opening of the second expansion valve 33 zero, in other words, completely closing the second expansion valve.

[0027] In the eighth aspect, since the opening degree of the second expansion valve ( 33 ) is reduced during the defrosting operation, it is possible to suppress the refrigerant from flowing into the second usage-side heat exchanger ( 31 ).

[0028] A ninth aspect is based on any one of the fourth to eighth aspects, wherein during the defrosting operation, the controller 60 reduces the opening of the pressure regulating valve 34 as the pressure regulating mechanism. It should be noted that "reducing the opening of the pressure regulating valve" mentioned here also includes making the opening of the pressure regulating valve 34 zero, in other words, completely closing the pressure regulating valve.

[0029] In the ninth aspect, since the opening degree of the pressure regulating valve ( 34 ) is reduced during the defrosting operation, it is possible to suppress the refrigerant from flowing into the second usage-side heat exchanger ( 31 ).

[0030] According to a tenth aspect, based on any one of the first to ninth aspects, the first expansion mechanism 23 is any one of an electronic expansion valve, a thermal expansion valve, and a capillary tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a simplified structural diagram of a vehicle and a refrigeration device involved in the embodiment;

[0032] Figure 2 is a schematic structural diagram of a refrigerant circuit of a refrigeration device according to an embodiment;

[0033] Figure 3 is a block diagram of main devices of a refrigeration device according to an embodiment;

[0034] Figure 4 is a control flow chart of a refrigeration device according to an embodiment;

[0035] Figure 5 is a schematic structural diagram of a refrigerant circuit of a refrigeration device according to Modification 1;

[0036] Figure 6is a schematic structural diagram of a refrigerant circuit of a refrigeration device according to Modification 2;

[0037] Figure 7 is a schematic structural diagram of a refrigerant circuit of a refrigeration device according to Modification 3;

[0038] Figure 8 This is a schematic diagram of the configuration of a refrigerant circuit of a refrigeration device according to Modification 4. DETAILED DESCRIPTION

[0039] The following is a detailed description of the embodiments of the present disclosure with reference to the accompanying drawings. It should be noted that the present disclosure is not limited to the embodiments shown below, and various changes can be made without departing from the technical concept of the present disclosure. The drawings are used to briefly illustrate the present disclosure, so for easy understanding, the size, ratio or quantity may be exaggerated or simplified as needed.

[0040] (1) Vehicle

[0041] like Figure 1 As shown, the vehicle 1 involved in the embodiment is a truck. The vehicle 1 is a refrigerated truck having a cab 2 and a cold storage 3 provided behind the cab 2. A driver's cab 2a is formed in the cab 2. A cargo room 3a is formed in the cold storage 3. Objects such as food are stored in the cargo room 3a. The vehicle 1 has a refrigeration device 10 for cooling the air in the cold storage 3.

[0042] (2) Overall structure of refrigeration unit

[0043] The refrigeration device 10 of this embodiment has a battery B, which is used as a driving source. The refrigeration device 10 has a refrigerant circuit R filled with a refrigerant. The refrigerant circuit R performs a vapor compression refrigeration cycle. The refrigeration device 10 has a first unit 11, a second unit 20, and a third unit 30. The first unit 11 is arranged above the cockpit 2. The first unit 11 constitutes a heat source unit located in the outdoor space O. The second unit 20 is arranged in the cargo room 3a. The second unit 20 constitutes a cooling unit. The third unit 30 is arranged in a battery room 30a separated from the cargo room 3a by a partition member 4. The third unit 30 constitutes a battery temperature adjustment unit.

[0044] The first unit 11 includes a compressor 12, an outdoor heat exchanger 13, and an outdoor fan 14. The second unit 20 includes an in-store heat exchanger 21 and an in-store fan 22. The third unit 30 includes a battery B, a battery-side heat exchanger 31, and a battery-side fan 32. It should be noted that the third unit 30 may also be configured without the battery-side fan 32.

[0045] (2-1) Structure of refrigerant circuit

[0046] like Figure 2 As shown, the refrigerant circuit R includes a compressor 12, an outdoor heat exchanger 13, an internal heat exchanger 21, and a battery side heat exchanger 31 as main devices. The refrigerant circuit R includes a first expansion valve 23, a second expansion valve 33, and a pressure regulating valve 34.

[0047] The compressor 12 compresses the sucked refrigerant and discharges the compressed refrigerant. The compressor 12 is a scroll type, a rotary type, a swing piston type, etc. The compressor 12 is connected in series with the gas end of the outdoor heat exchanger 13 via a discharge pipe 15 .

[0048] The outdoor heat exchanger 13 is an example of a heat source side heat exchanger. The outdoor heat exchanger 13 is provided in the outdoor space O or in a flow path for outdoor air to flow. The outdoor heat exchanger 13 exchanges heat between the outdoor air and the refrigerant. The outdoor heat exchanger 13 is a fin-tube heat exchanger. The liquid end of the outdoor heat exchanger 13 is connected to the first pipe P1 and the second pipe P2 via the main liquid pipe 16.

[0049] The outdoor fan 14 is arranged near the outdoor heat exchanger 13. The outdoor fan 14 sends outdoor air so that the outdoor air flows in the outdoor heat exchanger 13.

[0050] The first tube P1 and the second tube P2 are connected in parallel to each other in the refrigerant circuit R. One end of the first tube P1 and the second tube P2 is connected to the end of the main liquid pipe 16, that is, the branch portion 17. The other ends of the first tube P1 and the second tube P2 are connected to the suction pipe 18 of the compressor 12. The first tube P1 is an example of a first refrigerant flow path. The second tube P2 is an example of a second refrigerant flow path.

[0051] The first expansion valve 23 and the internal heat exchanger 21 are connected to the first pipe P1 in order from the liquid side to the gas side. The first expansion valve 23 is an example of a first expansion mechanism. The first expansion valve 23 is composed of an electronic expansion valve with adjustable opening.

[0052] The internal heat exchanger 21 is an example of a first user-side heat exchanger. The internal heat exchanger 21 is provided in the cargo room 3a. The internal heat exchanger 21 performs heat exchange between the air in the cargo room 3a and the refrigerant. The internal heat exchanger 21 is a fin-tube heat exchanger.

[0053] The internal fan 22 is disposed near the internal heat exchanger 21. The internal fan 22 sends the air in the cargo room 3a so that the air in the cargo room 3a flows in the internal heat exchanger 21.

[0054] The second expansion valve 33, the battery side heat exchanger 31, and the pressure regulating valve 34 are connected to the second pipe P2 in order from the liquid side to the gas side. The second expansion valve 33 is an example of a second expansion mechanism. The second expansion valve 33 is composed of an electronic expansion valve with an adjustable opening. The pressure regulating valve 34 is an example of a pressure regulating mechanism that regulates the evaporation pressure of the battery side heat exchanger 31. The pressure regulating valve 34 is composed of an electronic expansion valve, for example.

[0055] The battery side heat exchanger 31 is an example of a second utilization side heat exchanger. The battery side heat exchanger 31 is arranged inside the housing 35 of the third unit 30. The battery side heat exchanger 31 performs heat exchange between the air delivered by the battery side fan 32 and the refrigerant. It should be noted that it is also possible to omit the battery side fan 32 and make the battery side heat exchanger 31 contact with the battery B. In this case, heat exchange is directly performed between the battery side heat exchanger 31 and the battery B without passing through the air.

[0056] (2-2) Specific information of the third unit

[0057] The third unit 30 of this embodiment is arranged in the battery chamber 30a. The third unit 30 has a housing 35. The housing 35 is formed in a hollow box shape. The housing 35 is composed of a heat insulating member. The housing 35 accommodates the battery B, the battery side heat exchanger 31 and the battery side fan 32. The battery side heat exchanger 31 can be arranged separately from the battery B, or can be arranged in contact with the battery B.

[0058] The battery B functions as a power source for the refrigeration device 10. The battery B supplies power to the compressor 12, the outdoor fan 14, the in-compartment fan 22, and the battery-side fan 32. The battery B supplies power to the first expansion valve 23, the second expansion valve 33, the pressure regulating valve 34, and various sensors (described in detail later).

[0059] As a type of battery B, there is a lithium-ion battery, for example. Battery B needs to maintain its temperature within an appropriate temperature range. The temperature range is, for example, 10°C to 30°C. In particular, for lithium-ion batteries, the need for temperature management is greater. If the temperature of battery B is too low, the charge and discharge characteristics deteriorate. If the temperature of battery B increases, the deterioration of battery B will accelerate.

[0060] (2-3) Sensor

[0061] The refrigeration device 10 includes a plurality of sensors including an internal temperature sensor 51 , a battery-side temperature sensor 52 , a suction temperature sensor 53 , and a suction pressure sensor 54 .

[0062] The internal temperature sensor 51 is disposed in the cargo room 3a and detects the temperature of the internal air in the cold storage 3. The battery side temperature sensor 52 is mounted on the surface of the battery side heat exchanger 31. The battery side temperature sensor 52 detects the surface temperature of the battery side heat exchanger 31.

[0063] The suction temperature sensor 53 is provided on the suction pipe 18. The suction temperature sensor 53 detects the temperature of the refrigerant sucked into the compressor 12. The suction pressure sensor 54 detects the pressure of the refrigerant sucked into the compressor 12. The suction temperature sensor 53 and the suction pressure sensor 54 constitute a superheat detection unit for obtaining the superheat of the refrigerant flowing out of the internal heat exchanger 21.

[0064] (2-4) Controller

[0065] like Figure 2 and Figure 3 As shown, the refrigeration device 10 includes a controller 60. The controller 60 includes a microcomputer mounted on a control substrate and a storage device (specifically, a semiconductor memory) storing software for operating the microcomputer.

[0066] The controller 60 controls the refrigerant circuit R. Specifically, the controller 60 controls the start / stop of the compressor 12 and the rotation speed of the compressor 12. The controller 60 controls the start / stop of the outdoor fan 14, the indoor fan 22, and the battery-side fan 32. The controller 60 controls the rotation speeds of the outdoor fan 14, the indoor fan 22, and the battery-side fan 32. The controller 60 controls the openings of the first expansion valve 23, the second expansion valve 33, and the pressure regulating valve 34.

[0067] The controller 60 obtains the degree of superheat of the refrigerant flowing out of the internal heat exchanger 21 based on the detection values ​​of the suction temperature sensor 53 and the suction pressure sensor 54. Here, the degree of superheat is a value obtained by subtracting the saturation temperature corresponding to the detection pressure of the suction pressure sensor 54 from the detection temperature of the suction temperature sensor 53.

[0068] Under operating conditions where the internal heat exchanger 21 may be frosted, the controller 60 controls the second expansion valve 33 and the pressure regulating valve 34 so that the battery-side heat exchanger 31 is not frosted. The details of this control will be described later.

[0069] (3) Operation

[0070] Reference Figure 2 The basic operation of the refrigeration device 10 will be described.

[0071] When the refrigeration system is in operation, the controller 60 operates the compressor 12, the outdoor fan 14, the in-compartment fan 22, and the battery-side fan 32. The controller 60 adjusts the opening degrees of the first expansion valve 23 and the second expansion valve 33.

[0072] The refrigerant compressed in the compressor 12 flows through the outdoor heat exchanger 13. The refrigerant releases heat to the outdoor air and condenses in the outdoor heat exchanger 13. The condensed refrigerant flows through the main liquid pipe 16 and then is divided into the first pipe P1 and the second pipe P2.

[0073] The refrigerant flowing into the first pipe P1 is decompressed by the first expansion valve 23 and then flows through the internal heat exchanger 21. In the internal heat exchanger 21, the refrigerant absorbs heat from the air in the cargo room 3a and evaporates. The air in the cargo room 3a is cooled by the internal heat exchanger 21.

[0074] The refrigerant flowing into the second pipe P2 is decompressed by the second expansion valve 33 and then flows through the battery side heat exchanger 31. In the battery side heat exchanger 31, the refrigerant absorbs heat from the air in the housing 35 and evaporates. The air in the housing 35 is cooled by the battery side heat exchanger 31. Thus, the temperature of the battery B is adjusted to a predetermined temperature.

[0075] The refrigerant evaporated in the internal heat exchanger 21 and the battery-side heat exchanger 31 is sucked into the compressor 12 through the suction pipe 18 and is compressed again.

[0076] (4) Features

[0077] (4-1) Technical issues

[0078] During the operation of the refrigeration device 10, as described above, while the internal heat exchanger 21 cools the interior of the refrigerator, the battery side heat exchanger 31 adjusts the temperature of the battery B. Here, the internal heat exchanger 21 is disposed in the cold storage 3 of the refrigerator or freezer, and cools the air in the refrigerator to a relatively low temperature. Therefore, during the above operation, operating conditions that may cause the internal heat exchanger 21 to frost may be met. Specifically, sometimes the operation may be performed in which the evaporation temperature of the internal heat exchanger 21 is below 0 degrees. Therefore, under operating conditions in which the outdoor heat exchanger 13 functions as a radiator (condenser), the internal heat exchanger 21 and the battery side heat exchanger 31 function as evaporators, and the internal heat exchanger 21 may frost, the evaporation temperature of the battery side heat exchanger 31 may also become below 0 degrees, resulting in the problem of frost on the battery side heat exchanger 31.

[0079] If the surface of battery-side heat exchanger 31 is covered with frost, the heat exchange performance of battery-side heat exchanger 31 is reduced. As a result, the temperature of battery B cannot be adjusted to a predetermined temperature, and the performance of battery B is impaired.

[0080] In response to this, a countermeasure can be taken to defrost the battery-side heat exchanger 31 , but this countermeasure will complicate the structure and control of the refrigeration device.

[0081] Furthermore, if the battery-side heat exchanger 31 is heated by some measure, the temperature of the battery B will rise. As a result, problems such as shortening the life of the battery B, increasing the frequency of replacement of the battery B, and impairing the reliability of the refrigeration device 10 will also occur.

[0082] (4-2) Control to suppress frost formation on the battery side heat exchanger

[0083] In order to solve the above technical problems, the controller 60 performs the following control. Figure 4 The control is described. In step S11, the controller 60 adjusts the rotation speed of the compressor 12 according to the air temperature Ti in the warehouse and the target temperature Tis in the warehouse. Here, the air temperature Ti is detected by the temperature sensor 51 in the warehouse. The target temperature Tis in the warehouse is determined according to the operating mode such as the refrigeration mode / freezing mode of the refrigeration device and the set temperature input by the user. The controller 60 adjusts the rotation speed of the compressor 12 according to, for example, the difference ΔT (=Ti-Tis) between the air temperature Ti and the target temperature Tis in the warehouse. In other words, the controller 60 adjusts the rotation speed of the compressor 12 according to the cooling load in the warehouse. It should be noted that the controller 60 can also adjust the rotation speed of the compressor 12 so that the evaporation temperature Te1 of the heat exchanger 21 in the warehouse is close to the target evaporation temperature Tes. In this case, the target evaporation temperature Tes is determined according to the air temperature Ti and the target temperature Tis in the warehouse. The evaporation temperature Te1 is a saturation temperature corresponding to the pressure detected by, for example, the suction pressure sensor 54.

[0084] In step S12, the controller 60 adjusts the opening of the first expansion valve 23. The opening of the first expansion valve 23 is adjusted according to the superheat SH of the refrigerant sucked into the compressor 12. Specifically, the controller 60 adjusts the opening of the first expansion valve 23 to maintain the superheat SH at the target superheat. As described above, the superheat is obtained based on the detection values ​​of the suction temperature sensor 53 and the suction pressure sensor.

[0085] In step S13, the controller 60 adjusts the opening of the second expansion valve 33 and the pressure regulating valve 34. Specifically, the controller 60 adjusts the opening of the second expansion valve 33 and the pressure regulating valve 34 so that the temperature of the battery side heat exchanger 31 (battery temperature Tb) is close to the battery target temperature Tbs. Here, the battery temperature Tb is detected by the battery side temperature sensor 52. The battery target temperature Tbs is the optimal temperature of the battery B. The battery target temperature Tbs is a specified temperature higher than the temperature (for example, 0°C) at which the battery side heat exchanger 31 is frosted. The battery target temperature Tbs is a specified temperature higher than the target temperature in the warehouse, for example, set to 20°C.

[0086] exist Figure 4 In step S11, for example, when the in-store target temperature Tis is -5°C, the evaporation temperature Te1 of the in-store heat exchanger 21 reaches a specified temperature lower than -5°C. In this case, the refrigeration device 10 will perform an operation that may cause frost on the in-store heat exchanger 21. In response to this, in step S13, the controller 60 controls the opening of the second expansion valve 33 and the pressure regulating valve 34 so that the battery temperature Tb approaches the battery target temperature Tbs. Here, the battery target temperature Tbs is higher than the temperature at which the battery-side heat exchanger 31 frosts. Therefore, in this embodiment, under operating conditions where the in-store heat exchanger 21 may frost, frost on the battery-side heat exchanger 31 can be suppressed.

[0087] It should be noted that, in step 13, for example, the controller 60 adjusts the opening of the second expansion valve 33 so that the superheat of the refrigerant flowing out of the battery side heat exchanger 31 reaches a predetermined target value. At the same time, the controller 60 adjusts the opening of the pressure regulating valve 34 so that the battery target temperature Tbs reaches the target battery temperature Tb.

[0088] (4-3) Effects of Implementation

[0089] In the above-mentioned embodiment, under the operating conditions where the outdoor heat exchanger 13 acts as a radiator, the in-store heat exchanger 21 and the battery-side heat exchanger 31 act as evaporators, and the in-store heat exchanger 21 may be frosted, the controller 60 controls the opening of the second expansion valve 33 and the pressure regulating valve 34 to prevent the battery-side heat exchanger 31 from frosting.

[0090] Therefore, the air in the storage can be cooled to a relatively low temperature by the internal heat exchanger 21, and frost formation on the battery side heat exchanger 31 can be suppressed. As a result, the temperature of the battery B can be adjusted to a desired temperature by the battery side heat exchanger 31, and the performance of the battery B can be maintained.

[0091] Furthermore, since there is no need for equipment for defrosting the battery side heat exchanger 31, it is possible to simplify and reduce the cost of the refrigeration device 10. Furthermore, since it is possible to suppress the temperature rise of the battery side heat exchanger 31 due to defrosting, it is possible to avoid shortening the life of the battery B due to the temperature rise of the battery side heat exchanger 31. As a result, the reliability of the refrigeration device 10 can be ensured.

[0092] (5) Modifications of the Embodiments

[0093] The above-mentioned embodiment may also adopt the following modified structures. It should be noted that the differences from the above-mentioned embodiment will be described below.

[0094] (5-1) Modification 1

[0095] Figure 5 The refrigeration device 10 of the first modification shown is obtained by adding a bypass flow path 36 to the refrigerant circuit R of the embodiment. The bypass flow path 36 is a flow path for sending the high-pressure refrigerant discharged from the compressor 12 to the internal heat exchanger 21 by bypassing the outdoor heat exchanger 13 .

[0096] One end of the bypass flow path 36 is connected to the discharge pipe 15 . The other end of the bypass flow path 36 of Modification 1 is connected to the first pipe P1 . Specifically, the other end of the bypass flow path 36 is connected between the first expansion valve 23 and the internal heat exchanger 21 .

[0097] The refrigerant circuit R has a first switch valve 37 and a second switch valve 38. The first switch valve 37 is provided on the gas pipeline between the compressor 12 and the outdoor heat exchanger 13. Specifically, the first switch valve 37 is provided at a position of the gas pipeline between the connection end connected to the bypass flow path 36 and the gas end of the outdoor heat exchanger 13. The second switch valve 38 is provided on the bypass flow path 36. The first switch valve 37 and the second switch valve 38 are respectively composed of electromagnetic switch valves. The first switch valve 37 and the second switch valve 38 constitute a switching mechanism, which switches the flow path for sending the high-pressure refrigerant ejected from the compressor 12 to the outdoor heat exchanger 13 and the flow path for sending the high-pressure refrigerant ejected from the compressor 12 to the bypass flow path 36. The switching mechanism may be, for example, a three-way valve.

[0098] The refrigeration device 10 of Modified Example 1 performs a defrosting operation to melt the frost on the internal heat exchanger 21. The refrigeration device 10 of Modified Example 1 performs a first action as a defrosting operation. The first action is an action to make the high-pressure refrigerant ejected from the compressor 12 bypass the outdoor heat exchanger 13 and flow to the internal heat exchanger 21. The first action is a so-called hot gas defrosting action.

[0099] In the normal operation of the refrigeration device 10, the controller 60 opens the first on-off valve 37 and closes the second on-off valve 38. Thus, the refrigerant circuit R performs the same refrigeration cycle as in the above embodiment.

[0100] In the defrosting operation (first operation) of the refrigeration device 10, the controller 60 closes the first on-off valve 37 and opens the second on-off valve 38. The controller 60 operates the compressor 12 and the internal fan 22, and stops the outdoor fan 14 and the battery-side fan 32. The controller 60 closes the first expansion valve 23, the second expansion valve 33, and the pressure regulating valve 34.

[0101] In the first operation, the refrigerant discharged from the compressor 12 flows through the bypass flow path 36 and then flows in the internal heat exchanger 21. In the internal heat exchanger 21, the high-pressure refrigerant releases heat to the surface of the internal heat exchanger 21. As a result, the frost on the surface of the internal heat exchanger 21 melts. The refrigerant that has passed through the internal heat exchanger 21 is sucked into the compressor 12.

[0102] The refrigerant circuit R of Modification 1 is configured to suppress the refrigerant from flowing to the battery-side heat exchanger 31 during the defrosting operation (first operation). Specifically, the refrigerant circuit R suppresses the refrigerant from flowing to the battery-side heat exchanger 31 by the following configurations 1) to 4).

[0103] 1) The other end of the bypass flow path 36 is connected to the first pipe P1. For example, if the other end of the bypass flow path 36 is connected to the main liquid pipe 16, the high-pressure refrigerant is likely to flow to the second pipe P2. In contrast, by connecting the other end of the bypass flow path 36 to the first pipe P1, it is possible to suppress the high-pressure refrigerant from flowing to the second pipe P2.

[0104] 2) The refrigerant circuit R has a first expansion valve 23 whose opening degree becomes smaller during the defrosting operation. By reducing the opening degree of the first expansion valve 23, it is possible to suppress the refrigerant that has flowed through the bypass flow path 36 from flowing from the first pipe P1 to the second pipe P2. During the defrosting operation, the controller 60 can completely close the first expansion valve 23, or reduce the opening degree of the first expansion valve 23 to a specified opening degree greater than zero.

[0105] 3) The refrigerant circuit R has a second expansion valve 33 whose opening degree becomes smaller during the defrosting operation. By reducing the opening degree of the second expansion valve 33, it is possible to suppress the refrigerant that has flowed through the bypass flow path 36 from flowing from the first pipe P1 to the second pipe P2. During the defrosting operation, the controller 60 can completely close the second expansion valve 33, or reduce the opening degree of the second expansion valve 33 to a specified opening degree greater than zero.

[0106] 4) The refrigerant circuit R has a pressure regulating valve 34 whose opening degree becomes smaller during the defrosting operation. By reducing the opening degree of the pressure regulating valve 34, it is possible to suppress the refrigerant that has flowed through the first pipe P1 from flowing to the second pipe P2. During the defrosting operation, the controller 60 can completely close the pressure regulating valve 34 or reduce the opening degree of the pressure regulating valve 34 to a specified opening degree greater than zero.

[0107] It should be noted that the refrigerant circuit R may be configured to satisfy at least one of the above conditions 1) to 4).

[0108] Preferably, the controller 60 reduces the opening of the first expansion valve 23 , the second expansion valve 33 , or the pressure regulating valve 34 immediately before the compressor 12 is started. This can prevent the refrigerant discharged from the compressor 12 from flowing to the battery side heat exchanger 31 .

[0109] During the defrosting operation, when the high-pressure refrigerant flows through the battery-side heat exchanger 31, the temperature of the battery B rises, resulting in a shortened life of the battery B. In contrast, in Modification 1, during the defrosting operation, the suppression unit 1) to 4) can suppress the high-pressure refrigerant from flowing to the battery-side heat exchanger 31. As a result, the life of the battery B can be extended, and the reliability of the refrigeration device 10 can be ensured.

[0110] (5-2) Modification 2

[0111] Figure 6 The refrigeration device 10 of the modified example 2 shown is obtained by adding a check valve 39 to the first pipe P1 of the modified example 1. The check valve 39 is provided between the connection end of the bypass flow path 36 and the first pipe P1 and the branching portion 17 of the first pipe P1 and the second pipe P2. The check valve 39 prohibits the refrigerant from flowing from the connection end of the bypass flow path 36 and the first pipe P1 to the branching portion 17. The check valve 39 allows the refrigerant to flow from the branching portion 17 to the connection end of the bypass flow path 36 and the first pipe P1.

[0112] The check valve 39 is a suppressing part that suppresses the high-pressure refrigerant from flowing to the battery-side heat exchanger 31 during the defrosting operation. Specifically, in the first operation, the check valve 39 prohibits the refrigerant that has flowed out of the bypass flow path 36 from flowing to the second pipe P2 side. As a result, the temperature rise of the battery-side heat exchanger 31 caused by the defrosting operation can be reliably suppressed.

[0113] (5-3) Modification 3

[0114] exist Figure 7 In the refrigeration device 10 of the variant example 3 shown, the other end of the bypass flow path 36 is connected to a position different from that of the variant example 1. Specifically, the other end of the bypass flow path 36 is connected to the main liquid pipe 16. On the other hand, in the defrost operation (first action), the controller 60 opens the first expansion valve 23 at a specified opening degree (for example, a fully open opening degree) and completely closes the second expansion valve 33. The high-pressure refrigerant ejected from the compressor 12 passes through the bypass flow path 36 and the first expansion valve 23, and then flows in the internal heat exchanger 21. In the internal heat exchanger 21, the frost on the surface of the internal heat exchanger 21 is melted by the refrigerant. The refrigerant that has flowed through the internal heat exchanger 21 is sucked into the compressor 12.

[0115] In the third modification, the controller 60 closes the second expansion valve 33 and the pressure regulating valve 34 , thereby being able to suppress the high-pressure refrigerant from flowing to the battery-side heat exchanger 31 .

[0116] (5-4) Modification 4

[0117] Figure 8The refrigeration device 10 of the modified example 4 shown is obtained by providing a four-way reversing valve 40 in the refrigerant circuit R of the embodiment. The four-way reversing valve 40 is a flow path switching mechanism for switching the positive cycle and the reverse cycle of the refrigerant circuit R. The positive cycle corresponds to the refrigeration cycle during normal operation of the above-mentioned embodiment. The reverse cycle corresponds to the refrigeration cycle of the second action of the defrosting operation described in detail later. The four-way reversing valve 40 is switched to the first state ( Figure 8 The solid line shows the state), and is switched to the second state ( Figure 8 The state shown by the dotted line).

[0118] The four-way reversing valve 40 in the first state connects the discharge pipe 15 of the compressor 12 with the gas end side of the outdoor heat exchanger 13, and connects the suction pipe 18 of the compressor 12 with the gas end sides of the in-storage heat exchanger 21 and the battery-side heat exchanger 31. The four-way reversing valve 40 in the second state connects the discharge pipe 15 of the compressor 12 with the gas end sides of the in-storage heat exchanger 21 and the battery-side heat exchanger 31, and connects the suction pipe 18 of the compressor 12 with the gas end side of the outdoor heat exchanger 13.

[0119] In Modification 4, the controller 60 controls the refrigerant circuit R to perform a second operation as a defrosting operation in which the high-pressure refrigerant discharged from the compressor 12 releases heat in the internal heat exchanger 21 and evaporates in the outdoor heat exchanger 13. The second operation is a so-called reverse cycle defrosting operation.

[0120] In the defrosting operation (second operation) of the refrigeration device 10, the controller 60 sets the four-way reversing valve 40 to the second state. The controller 60 operates the compressor 12, the outdoor fan 14, and the in-compartment fan 22, and stops the battery-side fan 32. The controller 60 appropriately adjusts the opening of the first expansion valve 23. The controller 60 closes the second expansion valve 33 and the pressure regulating valve 34.

[0121] In the second action, the refrigerant ejected from the compressor 12 flows through the internal heat exchanger 21. In the internal heat exchanger 21, the high-pressure refrigerant releases heat to the surface of the internal heat exchanger 21. As a result, the frost on the surface of the internal heat exchanger 21 melts. The refrigerant that has passed through the internal heat exchanger 21 is decompressed by the first expansion valve 23 and flows through the outdoor heat exchanger 13. In the outdoor heat exchanger 13, the refrigerant absorbs heat from the outdoor air and evaporates. The refrigerant that has passed through the outdoor heat exchanger 13 is sucked into the compressor 12.

[0122] The refrigerant circuit R of the modification 4 is configured such that, in the defrosting operation (second operation), the refrigerant is prevented from flowing into the battery side heat exchanger 31. Specifically, by reducing the opening of the pressure regulating valve 34, the high-pressure refrigerant can be prevented from flowing into the battery side heat exchanger 31. By reducing the opening of the second expansion valve 33, the refrigerant can be prevented from flowing into the battery side heat exchanger 31.

[0123] (5-5) Modification 5

[0124] The refrigeration device 10 of the modification example 5 is Figure 2 In the same refrigerant circuit R as the above embodiment shown, the controller 60 controls the refrigerant circuit R to perform the third action as a refrigeration device in defrosting operation. In the third action, the high-pressure refrigerant ejected from the compressor 12 is sequentially flowed through the outdoor heat exchanger 13 and the internal heat exchanger 21 whose corresponding outdoor fan 14 is in a stopped state. The third action is a so-called positive cycle defrosting action.

[0125] In the defrosting operation (third operation) of the refrigeration device 10, the controller 60 operates the compressor 12 and the internal fan 22, and stops the outdoor fan 14 and the battery-side fan 32. The controller 60 fully opens the first expansion valve 23. The controller 60 closes the second expansion valve 33 and the pressure regulating valve 34.

[0126] In the third operation, the refrigerant discharged from the compressor 12 passes through the outdoor heat exchanger 13 and the first expansion valve 23, and then flows through the internal heat exchanger 21. In the internal heat exchanger 21, the high-pressure refrigerant releases heat to the surface of the internal heat exchanger 21. As a result, the frost on the surface of the internal heat exchanger 21 melts. The refrigerant that has passed through the internal heat exchanger 21 is sucked into the compressor 12.

[0127] The refrigerant circuit R of the modified example 5 is configured such that, in the defrosting operation (third operation), the refrigerant is prevented from flowing into the battery side heat exchanger 31. Specifically, by reducing the opening of the second expansion valve 33, the refrigerant can be prevented from flowing into the battery side heat exchanger 31. By reducing the opening of the pressure regulating valve 34, the high-pressure refrigerant can be prevented from flowing into the battery side heat exchanger 31.

[0128] (6) Other Implementation Methods

[0129] In the above-described embodiment and each modified example, the following configuration may be adopted.

[0130] The refrigeration device 10 is applied to the vehicle 1, but can also be applied to transportation vehicles such as railways and airplanes. The refrigeration device 10 is not necessarily applied to transportation vehicles, but can also be a stationary refrigeration device. The refrigeration device 10 can also be an air conditioning device that performs air conditioning in a room.

[0131] The battery B may supply power to devices other than the refrigeration device. For example, the battery B may supply power to a driving device of the vehicle 1 or to an air conditioner that performs air conditioning on the cabin 2a.

[0132] The first utilization-side heat exchanger may be an air-conditioning heat exchanger that cools or heats the air in the cab 2a.

[0133] The second utilization side heat exchanger may also adjust the temperature of an object other than the battery. The object may be, for example, an electrical component such as a converter or a power device. The electrical component is preferably provided in the power supply circuit of the refrigeration device 10 .

[0134] The first expansion mechanism may not be an electronic expansion valve but may be a thermal expansion valve or a capillary tube. The first expansion mechanism may be an expander that expands the refrigerant inside the cylinder.

[0135] The second expansion mechanism may not be an electronic expansion valve but may be a thermal expansion valve or a capillary tube. The second expansion mechanism may be an expander that expands the refrigerant inside the cylinder.

[0136] The above embodiments and variations are described, but it should be understood that various changes can be made to the methods and specific circumstances without departing from the spirit and scope of the claims. The elements of the above embodiments, variations and other embodiments can also be appropriately combined or replaced.

[0137] - Industrial Applicability -

[0138] In summary, the present disclosure is useful for refrigeration devices.

[0139] - Explanation of symbols -

[0140] 10 Refrigeration unit

[0141] 12 Compressor

[0142] 13Outdoor heat exchanger (heat source side heat exchanger)

[0143] 17 Branches

[0144] 21 Internal heat exchanger (first utilization side heat exchanger)

[0145] 23. First expansion valve (first expansion mechanism)

[0146] 31 Battery side heat exchanger (second utilization side heat exchanger)

[0147] 33 Second expansion valve (second expansion mechanism)

[0148] 34 Pressure regulating valve (pressure regulating mechanism)

[0149] 36 Bypass flow path

[0150] 39 Check valve

[0151] 60 Controller

[0152] B Battery

[0153] P1 first pipe (first refrigerant flow path)

[0154] P2 second pipe (second refrigerant flow path)

[0155] R Refrigerant circuit

Claims

1. A refrigeration device, characterized in that: The refrigeration device comprises a refrigerant circuit (R) and a controller (60). The refrigerant circuit (R) includes a compressor (12), a heat source side heat exchanger (13), a first refrigerant flow path (P1) and a second refrigerant flow path (P2). The heat source side heat exchanger (13) is arranged in series with the compressor (12). The first refrigerant flow path (P1) is arranged in series with the compressor (12) and the heat source side heat exchanger (13), and the first refrigerant flow path (P1) has a first expansion mechanism (23) and a first utilization side heat exchanger (21). The second refrigerant flow path (P2) is provided in parallel with the first refrigerant flow path (P1), and the second refrigerant flow path (P2) includes a second expansion mechanism (33), a second utilization side heat exchanger (31) and a pressure regulating mechanism (34). Under operating conditions where the heat source side heat exchanger (13) functions as a radiator, the first utilization side heat exchanger (21) and the second utilization side heat exchanger (31) function as evaporators, and the first utilization side heat exchanger (21) is likely to be frosted, the controller (60) controls the second expansion mechanism (33) and the pressure regulating mechanism (34) so ​​that the second utilization side heat exchanger (31) is not frosted.

2. The refrigeration device according to claim 1, characterized in that: The second utilization-side heat exchanger (31) adjusts the temperature of the battery (B).

3. The refrigeration device according to claim 1 or 2, characterized in that: The first utilization-side heat exchanger (21) cools the air in the storage.

4. The refrigeration device according to any one of claims 1 to 3, characterized in that: The controller (60) controls the refrigerant circuit (R) to perform a defrosting operation for melting frost on the first utilization side heat exchanger (21) using the refrigerant in the refrigerant circuit (R). The refrigerant circuit (R) is configured to suppress the refrigerant from flowing to the second utilization side heat exchanger (31) during the defrosting operation.

5. The refrigeration device according to claim 4, characterized in that: The controller (60) controls the refrigerant circuit (R) to perform a first action, a second action, or a third action as the defrosting operation. In the first action, the high-pressure refrigerant discharged from the compressor (12) bypasses the heat source side heat exchanger (13) and flows to the first utilization side heat exchanger (21). In the second operation, the high-pressure refrigerant discharged from the compressor (12) releases heat in the first utilization-side heat exchanger (21) and evaporates in the heat source-side heat exchanger (13). In the third action, the high-pressure refrigerant discharged from the compressor (12) flows sequentially through the heat source side heat exchanger (13) whose corresponding fan (14) is in a stopped state and the first utilization side heat exchanger (21).

6. The refrigeration device according to claim 5, characterized in that: The controller (60) is configured to execute the first action as the defrosting operation. The refrigerant circuit (R) includes a bypass flow path (36), one end of which is connected to the discharge side of the compressor (12), and the other end of which is connected to a portion of the first refrigerant flow path (P1) located between the first expansion mechanism (23) and the first utilization side heat exchanger (21), and the high-pressure refrigerant discharged from the compressor (12) under the first action flows through the bypass flow path (36).

7. The refrigeration device according to claim 6, characterized in that: In the first refrigerant flow path (P1), a check valve (39) is provided between a connection end between the bypass flow path (36) and the first refrigerant flow path (P1) and a branch portion (17) between the first refrigerant flow path (P1) and the second refrigerant flow path (P2) for preventing the refrigerant from flowing from the connection end to the branch portion (17).

8. The refrigeration device according to any one of claims 4 to 7, characterized in that: During the defrosting operation, the controller (60) reduces the opening degree of the second expansion valve (33) serving as the second expansion mechanism (33).

9. The refrigeration device according to any one of claims 4 to 8, characterized in that: During the defrosting operation, the controller (60) reduces the opening degree of the pressure regulating valve (34) serving as the pressure regulating mechanism.

10. The refrigeration device according to any one of claims 1 to 10, characterized in that: The first expansion mechanism (23) is any one of an electronic expansion valve, a thermal expansion valve, and a capillary tube.

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