Refrigerant circuit device

Abstract

To reduce power consumption even in a case when a commodity of a second commodity storage apparatus is heated while cooling a commodity of a first commodity storage apparatus.SOLUTION: A refrigerant circuit device includes a compressor 11, a condenser 12, a first refrigerant circuit constitution portion 20A and the like disposed in an exclusive cooling showcase 2A and the like, and a second refrigerant circuit constitution portion 30 disposed in a cooling / heating showcase 2C and having a second expansion mechanism 31 and an internal heat exchanger 32. The second refrigerant circuit constitution portion 30 includes: a first bypass passage 33 for circulating a part of the refrigerant from the condenser 12 to the internal heat exchanger 32 while bypassing the second expansion mechanism 31; and a second bypass passage 35 for making the refrigerant from the internal heat exchanger 32 bypass a part of an outlet passage to be thermally insulated and expanded. A control portion 50 is disposed to perform a heating operation for heating the commodity by circulating the refrigerant exchanging heat by the internal heat exchanger 32 to the second bypass passage 35 while circulating a part of the refrigerant condensed by the condenser 12 to the first bypass passage 33, when a predetermined heating condition is satisfied.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a refrigerant circuit device, and more particularly to a refrigerant circuit device applied to a plurality of product storage devices such as showcases.

Background Art

[0002] Conventionally, as a refrigerant circuit device applied to a plurality of showcases installed in a store, one having the refrigerant circuit proposed in Patent Document 1 is known. The refrigerant circuit is configured by connecting a compressor, a condenser, a first refrigerant circuit component, and a second refrigerant circuit component with refrigerant pipes, and refrigerant is enclosed therein.

[0003] The compressor constitutes a refrigerator separate from the above-mentioned showcase, and compresses and discharges the sucked refrigerant. The condenser constitutes a refrigerator together with the compressor, and condenses the refrigerant compressed by the compressor.

[0004] The first refrigerant circuit component is installed in a cooling-only showcase and has a first expansion valve and a first evaporator. The first expansion valve adiabatically expands a part of the refrigerant condensed by the condenser. The first evaporator evaporates the refrigerant adiabatically expanded by the first expansion valve and sucks it into the compressor. Such a first refrigerant circuit component can cool the products stored in the cooling-only showcase with the air cooled by the first evaporator.

[0005] The second refrigerant circuit component is installed in a cooling and heating showcase and has a second expansion valve and a second evaporator. The second expansion valve adiabatically expands a part of the refrigerant condensed by the condenser. The second evaporator evaporates the refrigerant adiabatically expanded by the second expansion valve and sucks it into the compressor together with the refrigerant that has passed through the first evaporator. Such a second refrigerant circuit component can cool the products stored in the cooling and heating showcase with the air cooled by the second evaporator.

Prior Art Documents

[0006] [Patent Document 1] Japanese Patent Publication No. 2007-187337 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] Incidentally, although not explicitly stated in Patent Document 1, in the refrigerant circuit device described above, when heating products stored in a cooling and heating showcase, the refrigerant condensed in the condenser was restricted from flowing to the second refrigerant circuit component. Therefore, in the cooling and heating showcase, the air was heated by a built-in heater, and the products were heated using that heated air.

[0008] Therefore, when cooling products in a dedicated cooling showcase while simultaneously heating them in a cooling / heating showcase, it was necessary to circulate the refrigerant in a refrigerant circuit while simultaneously driving a heater separately, which resulted in increased power consumption.

[0009] In view of the above circumstances, the present invention aims to provide a refrigerant circuit device that can reduce power consumption even when cooling the products in the first product storage device while heating the products in the second product storage device. [Means for solving the problem]

[0010] To achieve the above objective, the refrigerant circuit device according to the present invention comprises a first refrigerant circuit component for cooling the product, having a compressor that compresses and discharges the refrigerant drawn in; a condenser that condenses the refrigerant compressed by the compressor; a first expansion mechanism installed in a first product storage device for storing the product and adiabatically expands a portion of the refrigerant condensed in the condenser; and an evaporator that evaporates the refrigerant adiabatically expanded in the first expansion mechanism and draws it into the compressor; and a second refrigerant circuit component installed in a second product storage device for storing the product and adiabatically expands a portion of the refrigerant condensed in the condenser; and an internal heat exchanger that exchanges heat with the ambient air for the refrigerant adiabatically expanded in the second expansion mechanism and draws it into the compressor via the evaporator, or draws it into the compressor together with the refrigerant that has passed through the evaporator, wherein the second refrigerant circuit component bypasses the second expansion mechanism and draws a portion of the refrigerant condensed in the condenser into the internal heat exchanger The device is characterized by comprising: a first bypass path through which the refrigerant flows; a first switching mechanism that can selectively switch between a first delivery state that allows a portion of the refrigerant condensed in the condenser to flow through the second expansion mechanism, a second delivery state that allows the refrigerant to flow through the first bypass path, and a restricting state that restricts the flow through the second refrigerant circuit component; a second bypass path provided in such a manner that it bypasses a portion of the outlet path through which the refrigerant that has undergone heat exchange in the internal heat exchanger flows, and having a third expansion mechanism in the middle that adiabatically expands the flowing refrigerant; and a second switching mechanism that can selectively switch between a third delivery state that allows the refrigerant that has undergone heat exchange in the internal heat exchanger to flow only through the outlet path, and a fourth delivery state that allows the refrigerant to flow via the second bypass path; and a control unit that performs a heating operation to heat the products in the second product storage device by setting the first switching mechanism to the second delivery state and the second switching mechanism to the fourth delivery state when predetermined heating conditions are satisfied.

[0011] Furthermore, the present invention is characterized in that, in the above-mentioned refrigerant circuit device, the amount of heat exchanged by the internal heat exchanger is smaller than the amount of heat exchanged by the evaporator.

[0012] Furthermore, the present invention is characterized in that, in the above-mentioned refrigerant circuit device, the first refrigerant circuit component is provided in greater quantities than the second refrigerant circuit component.

[0013] Furthermore, the present invention is characterized in that, in the refrigerant circuit device described above, the control unit performs the heating operation when the internal temperature of the product storage area of ​​the second product storage device falls below a preset temperature while the first switching mechanism is in the restricted state, and the ambient temperature of the second product storage device falls below the preset temperature.

[0014] Furthermore, the present invention is characterized in that, in the above-mentioned refrigerant circuit device, the control unit performs the heating operation when a predetermined time has elapsed with the first switching mechanism in the restricted state, and the temperature of the air that passes around the internal heat exchanger and is blown into the product storage area of ​​the second product storage device falls below a preset temperature.

[0015] Furthermore, the present invention is characterized in that, in the above-mentioned refrigerant circuit device, the control unit, when performing the heating operation, drives a heating means installed near the internal heat exchanger to supplementarily heat the air that has passed around the internal heat exchanger. [Effects of the Invention]

[0016] According to the present invention, the second refrigerant circuit component includes a first bypass path that bypasses the second expansion mechanism and allows a portion of the refrigerant condensed in the condenser to flow to the internal heat exchanger, a first switching mechanism that can selectively switch between a first delivery state that allows a portion of the refrigerant condensed in the condenser to flow through the second expansion mechanism, a second delivery state that allows it to flow through the first bypass path, and a restricting state that restricts it from flowing through the second refrigerant circuit component, and is provided in a manner that bypasses a portion of the outlet path through which the refrigerant that has undergone heat exchange in the internal heat exchanger flows, and the flowing refrigerant undergoes adiabatic expansion. The system includes a second bypass path with a third expansion mechanism in the middle, and a second switching mechanism that can selectively switch between a third delivery state in which the refrigerant that has undergone heat exchange in the internal heat exchanger flows only through the outlet path, and a fourth delivery state in which it flows via the second bypass path. The control unit performs a heating operation in which, when predetermined heating conditions are met, it sets the first switching mechanism to the second delivery state and the second switching mechanism to the fourth delivery state to heat the products in the second product storage unit. This eliminates the need to drive a heater separately while circulating the refrigerant in the refrigerant circuit, as in conventional systems. Therefore, it has the effect of reducing power consumption even when cooling the products in the first product storage unit while heating the products in the second product storage unit. [Brief explanation of the drawing]

[0017] [Figure 1] Figure 1 is a schematic explanatory diagram showing a refrigerant circuit device according to an embodiment of the present invention. [Figure 2] Figure 2 is an explanatory diagram showing the circulation of refrigerant in the refrigerant circuit shown in Figure 1. [Figure 3] Figure 3 is an explanatory diagram showing the circulation of refrigerant in the refrigerant circuit shown in Figure 1. [Figure 4] Figure 4 is a flowchart showing the processing details of the heating operation start determination process performed by the control unit shown in Figure 1, etc. [Figure 5] Figure 5 is an explanatory diagram showing the circulation of refrigerant in the refrigerant circuit shown in Figure 1. [Figure 6] Figure 6 is a flowchart showing a modified example of the heating operation start determination process performed by the control unit shown in Figure 1, etc.

Best Mode for Carrying Out the Invention

[0018] Hereinafter, referring to the accompanying drawings, a preferred embodiment of the refrigerant circuit device according to the present invention will be described in detail.

[0019] FIG. 1 is an explanatory diagram schematically showing a refrigerant circuit device according to an embodiment of the present invention. The refrigerant circuit device 10 illustrated here is applied to a showcase system and includes a refrigerant circuit 10a and a control unit 50.

[0020] Here, the showcase system includes a refrigerator 1, a plurality (two in the illustrated example) of cooling-only showcases (first product storage devices) 2A and 2B, and a cooling and heating showcase (second product storage device) 2C. Hereinafter, elements provided in the cooling-only showcases 2A and 2B will be appropriately labeled with "A" and "B" in the reference numerals, and elements provided in the cooling and heating showcase 2C will be appropriately labeled with "C" in the reference numerals for explanation.

[0021] The refrigerant circuit 10a is a circuit configured by connecting a compressor 11, a condenser 12, first refrigerant circuit components 20A and 20B, and a second refrigerant circuit component 30 with a refrigerant pipe 13, and refrigerant is enclosed therein.

[0022] The compressor 11 constitutes the refrigerator 1. This compressor 11 is driven in response to a command given from the control unit 50, and when driven, it sucks and compresses the refrigerant and discharges it as a high-temperature and high-pressure refrigerant.

[0023] The condenser 12 also constitutes the refrigerator 1 like the compressor 11. This condenser 12 condenses the refrigerant compressed by the compressor 11 by exchanging heat with the ambient air.

[0024] Multiple first refrigerant circuit components 20A and 20B are provided (two in the example in Figure 1), and each is installed in a dedicated cooling showcase 2A and 2B. These first refrigerant circuit components 20A and 20B include first expansion mechanisms 21A and 21B and evaporators 22A and 22B.

[0025] The first expansion mechanisms 21A and 21B are composed of, for example, an electronic expansion valve, a thermostatic expansion valve, a capillary tube, etc., and their inlets are connected to the condenser 12 through the refrigerant pipeline 13. These first expansion mechanisms 21A and 21B adiabatically expand a portion of the refrigerant condensed in the condenser 12.

[0026] The evaporators 22A and 22B are installed in the air passages 3A and 3B of the cooling-dedicated showcases 2A and 2B. These air passages 3A and 3B are connected to the storage chambers 4A and 4B where the products are stored, via an intake and an outlet (neither of which are shown), and air is circulated between them and the storage chambers 4A and 4B by the operation of blower fans 5A and 5B installed in the air passages 3A and 3B.

[0027] Although not explicitly shown in the diagram, storage compartments 4A and 4B are equipped with multiple shelves for placing goods, arranged vertically, to store goods. Air blown out from the outlet is drawn into the intake, forming an air curtain near the front opening of storage compartments 4A and 4B.

[0028] The evaporators 22A and 22B described above evaporate the refrigerant, which has been adiabatically expanded in the first expansion mechanisms 21A and 21B, by exchanging heat with the surrounding air, thereby causing the refrigerant to evaporate and be drawn into the compressor 11. In these evaporators 22A and 22B, the evaporation of the refrigerant cools the air passing through the air passages 3A and 3B, thereby cooling the products stored in the storage compartments 4A and 4B.

[0029] The second refrigerant circuit component 30 is installed in the showcase 2C for cooling and heating. This second refrigerant circuit component 30 is connected to the refrigerator 1 (compressor 11 and condenser 12) in parallel with the first refrigerant circuit components 20A and 20B, and includes a second expansion mechanism 31, an internal heat exchanger 32, a first bypass path 33, a first switching mechanism 34, a second bypass path 35, and a second switching mechanism 36.

[0030] The second expansion mechanism 31 is composed of, for example, an electronic expansion valve, a thermostatic expansion valve, or a capillary tube, and is connected to the condenser 12 through the refrigerant pipeline 13. This second expansion mechanism 31 adiabatically expands a portion of the refrigerant condensed in the condenser 12.

[0031] The internal heat exchanger 32 is installed in the air passage 3C of the cooling and heating showcase 2C. This air passage 3C is connected to the storage chamber 4C for storing goods through an intake and an outlet (neither of which are shown), and air is circulated between the air passage 3C and the storage chamber 4C by driving a blower fan 5C installed in the air passage 3C.

[0032] Although not explicitly shown in the diagram, storage compartment 4C is designed to store goods by having multiple shelves arranged vertically for placing goods, and an air curtain is formed near the front opening of storage compartment 4C as air blown out from the outlet is drawn into the intake.

[0033] The above-mentioned internal heat exchanger 32 exchanges heat between the refrigerant, which has adiabatically expanded in the second expansion mechanism 31, and the surrounding air, and then draws it into the compressor 11. The heat exchange rate of such an internal heat exchanger 32 is set to be smaller than the heat exchange rate of the evaporators 22A and 22B of the first refrigerant circuit components 20A and 20B.

[0034] The first bypass route 33 is composed of a pipeline that branches off from the refrigerant pipeline 13 connected to the inlet side of the second expansion mechanism 31 and merges with the refrigerant pipeline 13 connected to the outlet side of the second expansion mechanism 31. This first bypass route 33 is intended to bypass the second expansion mechanism 31 and allow a portion of the refrigerant condensed in the condenser 12 to flow to the internal heat exchanger 32.

[0035] The first switching mechanism 34 is configured with an inlet valve 34a and a first bypass valve 34b. The inlet valve 34a is configured, for example, with a solenoid valve and is installed in the refrigerant pipeline 13 connected to the inlet side of the second expansion mechanism 31, closer to the second expansion mechanism 31 than the branching point with the first bypass route 33. This inlet valve 34a opens and closes in response to a command given by the control unit 50, allowing the flow of refrigerant when open and restricting the flow of refrigerant when closed.

[0036] The first bypass valve 34b is installed in the first bypass path 33. This first bypass valve 34b opens and closes in response to commands from the control unit 50, allowing the flow of refrigerant when open and restricting the flow of refrigerant when closed.

[0037] In this way, the first switching mechanism 34 opens the inlet valve 34a and closes the first bypass valve 34b, thereby entering a first discharge state in which a portion of the refrigerant condensed in the condenser 12 is allowed to flow through the second expansion mechanism 31.

[0038] Furthermore, the first switching mechanism 34 closes the inlet valve 34a while opening the first bypass valve 34b, thereby entering a second discharge state in which a portion of the refrigerant condensed in the condenser 12 flows through the first bypass path 33.

[0039] Furthermore, the first switching mechanism 34 closes the inlet valve 34a and the first bypass valve 34b, thereby restricting a portion of the refrigerant condensed in the condenser 12 from flowing through the second refrigerant circuit component 30.

[0040] In other words, the first switching mechanism 34 can be selectively switched between a first discharge state, a second discharge state, and a regulated state by opening and closing the inlet valve 34a and the first bypass valve 34b.

[0041] The second bypass route 35 is composed of a pipeline that branches off from the refrigerant pipeline 13 connected to the outlet side of the internal heat exchanger 32 and merges with the refrigerant pipeline 13 at a point downstream from the branching point. This second bypass route 35 is provided in such a manner that it bypasses a portion of the refrigerant pipeline (outlet route) 13 through which the refrigerant that has undergone heat exchange in the internal heat exchanger 32 flows.

[0042] A third expansion mechanism 35a is provided along the second bypass path 35. The third expansion mechanism 35a is composed of, for example, a capillary tube and causes the circulating refrigerant to undergo adiabatic expansion.

[0043] The second switching mechanism 36 is configured to include an outlet valve 36a and a second bypass valve 36b. The outlet valve 36a is configured, for example, as a solenoid valve, and is installed in the refrigerant pipeline 13 connected to the outlet side of the internal heat exchanger 32, between the branching point and the merging point with the second bypass route 35. This outlet valve 36a opens and closes in response to a command given by the control unit 50, allowing the flow of refrigerant when open and restricting the flow of refrigerant when closed.

[0044] The second bypass valve 36b is installed upstream of the third expansion mechanism 35a in the second bypass path 35. This second bypass valve 36b opens and closes in response to commands from the control unit 50, allowing the flow of refrigerant when open and restricting the flow of refrigerant when closed.

[0045] In this way, the second switching mechanism 36 opens the outlet valve 36a and closes the second bypass valve 36b, thereby entering a third discharge state in which the refrigerant that has undergone heat exchange in the internal heat exchanger 32 flows only through the refrigerant pipeline (outlet path) 13 connected to the outlet side of the internal heat exchanger 32.

[0046] Furthermore, the second switching mechanism 36 closes the outlet valve 36a while opening the second bypass valve 36b, thereby entering a fourth delivery state in which the refrigerant that has undergone heat exchange in the internal heat exchanger 32 is circulated via the second bypass path 35.

[0047] In other words, the second switching mechanism 36 can selectively switch between the third discharge state and the fourth discharge state by opening and closing the outlet valve 36a and the second bypass valve 36b.

[0048] The control unit 50 is electrically connected to the compressor 11, the first switching mechanism 34 (inlet valve 34a and first bypass valve 34b), and the second switching mechanism 36 (outlet valve 36a and second bypass valve 36b) as described above, and is also electrically connected to the heater 41, the internal temperature sensor 42, the ambient temperature sensor 43, and the blow-out temperature sensor 44.

[0049] The heater 41 is installed near the internal heat exchanger 32 in the air passage 3C of the cooling and heating showcase 2C. This heater 41 is driven in response to commands given by the control unit 50, and when driven, it heats the air passing around it.

[0050] The internal temperature sensor 42 is installed in the storage compartment 4C of the cooling and heating showcase 2C. This internal temperature sensor 42 detects the internal temperature of the storage compartment 4C and outputs the detection result as a detection signal to the control unit 50.

[0051] The ambient temperature sensor 43 is installed outside the cooling and heating showcase 2C. This ambient temperature sensor 43 detects the ambient temperature around the cooling and heating showcase 2C and outputs the detection result as a detection signal to the control unit 50.

[0052] The air outlet temperature sensor 44 is installed near the air outlet of the cooling and heating showcase 2C. This air outlet temperature sensor 44 detects the temperature of the air blown out from the air outlet of the cooling and heating showcase 2C and outputs the detection result as a detection signal to the control unit 50.

[0053] The control unit 50 comprehensively controls the operation of each part of the refrigerant circuit device 10 according to programs and data stored in the storage unit 51, which is electrically connected to the compressor 11, and includes an input processing unit 50a, a comparison unit 50b, a determination unit 50c, and an output processing unit 50d.

[0054] Furthermore, the control unit 50 may be implemented, for example, by causing a processing unit such as a CPU (Central Processing Unit) to execute a program, i.e., by software; by hardware such as an IC (Integrated Circuit); or by using a combination of software and hardware.

[0055] The input processing unit 50a receives detection signals from the internal temperature sensor 42, the ambient temperature sensor 43, and the outlet temperature sensor 44. The comparison unit 50b compares the various temperatures input through the input processing unit 50a with the set temperature (for example, 15-20°C) included in the set temperature information stored in the storage unit 51. The determination unit 50c determines, based on the comparison result via the comparison unit 50b, whether the refrigerant circuit device 10 satisfies the heating conditions for heating operation, and thereby makes a determination to start heating operation. The output processing unit 50d outputs drive commands or open / close commands to the compressor 11, the first switching mechanism 34 (inlet valve 34a and first bypass valve 34b), and the second switching mechanism 36 (outlet valve 36a and second bypass valve 36b).

[0056] In the refrigerant circuit device 10 having the above configuration, when cooling products stored in the cooling and heating showcase 2C, that is, when cooling products stored in all showcases 2A, 2B, and 2C, the refrigerant is circulated as follows.

[0057] The control unit 50 switches the first switching mechanism 34 to the first discharge state (inlet valve 34a: open, first bypass valve 34b: closed) and switches the second switching mechanism 36 to the third discharge state (outlet valve 36a: open, second bypass valve 36b: closed). As a result, the refrigerant in the refrigerant circuit 10a circulates as shown in Figure 2.

[0058] The refrigerant, compressed by the compressor 11 and condensed in the condenser 12, flows through the first refrigerant circuit components 20A, 20B and the second refrigerant circuit component 30. The refrigerant that flows through the first refrigerant circuit components 20A, 20B undergoes adiabatic expansion in the first expansion mechanisms 21A, 21B, and then flows through the evaporators 22A, 22B, where it evaporates through heat exchange with the surrounding air and is subsequently drawn back into the compressor 11. As the refrigerant evaporates in the evaporators 22A, 22B in this manner, the air circulating between the storage compartments 4A, 4B and the air passages 3A, 3B is cooled by the operation of the blower fans 5A, 5B, thereby cooling the products in the storage compartments 4A, 4B.

[0059] Furthermore, the refrigerant that flows through the second refrigerant circuit component 30 undergoes adiabatic expansion in the second expansion mechanism 31 before flowing to the internal heat exchanger 32, where it exchanges heat with the surrounding air and evaporates. After that, it merges with the refrigerant that has flowed through the evaporators 22A and 22B and is drawn into the compressor 11. As the refrigerant evaporates in the internal heat exchanger 32 in this way, the air circulating between the storage compartment 4C and the air passage 3C is cooled by the operation of the blower fan 5C, thereby cooling the products in the storage compartment 4C.

[0060] On the other hand, when the refrigerant circuit device 10 adjusts the temperature of the products stored in the cooling and heating showcase 2C to, for example, a temperature range of about 15-20°C, it circulates the refrigerant as follows.

[0061] The control unit 50 switches the first switching mechanism 34 to a restricted state (inlet valve 34a: closed, first bypass valve 34b: closed). As a result, the refrigerant in the refrigerant circuit 10a circulates as shown in Figure 3.

[0062] The refrigerant compressed by the compressor 11 and condensed in the condenser 12 flows only through the first refrigerant circuit components 20A and 20B, and its flow to the second refrigerant circuit component 30 is restricted. The refrigerant that flows through the first refrigerant circuit components 20A and 20B undergoes adiabatic expansion in the first expansion mechanisms 21A and 21B, then flows to the evaporators 22A and 22B, where it evaporates through heat exchange with the surrounding air and is subsequently drawn into the compressor 11. As the refrigerant evaporates in the evaporators 22A and 22B in this manner, the air circulating between the storage compartments 4A and 4B and the air passages 3A and 3B is cooled by the operation of the blower fans 5A and 5B, thereby cooling the products in the storage compartments 4A and 4B.

[0063] In the cooling and heating showcase 2C, the blower fan 5C drives air circulation between the storage chamber 4C and the air passage 3C. However, since no refrigerant flows through the internal heat exchanger 32, the internal temperature of the storage chamber 4C rises in a manner that approximates the ambient temperature.

[0064] The control unit 50 then performs a heating operation start determination process to determine whether or not to start the heating operation while the first switching mechanism 34 remains in the restricted state.

[0065] Figure 4 is a flowchart showing the processing details of the heating operation start determination process performed by the control unit 50 shown in Figure 1, etc.

[0066] In this heating operation start determination process, the control unit 50 waits for input of the internal temperature and ambient temperature via the input processing unit 50a (steps S101, S102). That is, the control unit 50 checks for the presence or absence of a detection signal from the internal temperature sensor 42 via the input processing unit 50a, and for the presence or absence of a detection signal from the ambient temperature sensor 43 via the input processing unit 50a. If the input of a detection signal from the internal temperature sensor 42 cannot be confirmed (step S101: No), and if the input of a detection signal from the ambient temperature sensor 43 cannot be confirmed (step S102: No), these processes are repeated.

[0067] When the internal temperature and ambient temperature are input through the input processing unit 50a (step S101: Yes, step S102: Yes), the control unit 50 reads the set temperature information from the storage unit 51 through the comparison unit 50b and compares whether the internal temperature is below the set temperature included in the set temperature information (step S103).

[0068] If the internal temperature is not below the set temperature (step S103: No), that is, if the internal temperature is above the set temperature, the control unit 50 returns to the previous step without performing the process described later and terminates the current process. As a result, the state in which the flow of refrigerant to the second refrigerant circuit component 30 is restricted without performing heating operation continues.

[0069] If the internal temperature is below the set temperature (step S103: Yes), the control unit 50 compares whether the ambient temperature is below the set temperature through the comparison unit 50b (step S104).

[0070] If the ambient temperature is not below the set temperature (step S104: No), that is, if the ambient temperature is above the set temperature, the control unit 50 returns to the previous step without performing the process described later and terminates the current process. As a result, the state in which the flow of refrigerant to the second refrigerant circuit component 30 is restricted without performing heating operation continues.

[0071] On the other hand, if the ambient temperature is below the set temperature (step S104: Yes), the control unit 50 determines through the determination unit 50c that the predetermined heating conditions are satisfied and decides to start the heating operation (step S105), and then returns to the previous step to end the current process.

[0072] Having determined that heating operation should begin, the control unit 50 switches the first switching mechanism 34 to the second discharge state (inlet valve 34a: closed, first bypass valve 34b: open) and switches the second switching mechanism 36 to the fourth discharge state (outlet valve 36a: closed, second bypass valve 36b: open). As a result, the refrigerant in the refrigerant circuit 10a circulates as shown in Figure 5.

[0073] The refrigerant compressed in the compressor 11 and condensed in the condenser 12 flows through the first refrigerant circuit components 20A, 20B and the second refrigerant circuit component 30. The refrigerant flowing through the first refrigerant circuit components 20A and 20B is the same as that shown in Figure 3, so its explanation is omitted here.

[0074] The refrigerant flowing through the second refrigerant circuit component 30 flows to the internal heat exchanger 32 via the first bypass path 33, where it exchanges heat with the surrounding air. Here, the refrigerant flowing through the internal heat exchanger 32 is at a higher temperature than the air passing through the air passage 3C, so it dissipates heat. The refrigerant that has dissipated heat in the internal heat exchanger 32 then passes through the second bypass path 35, undergoes adiabatic expansion by the third expansion mechanism 35a along the way, and then merges with the refrigerant that has flowed through the evaporators 22A and 22B before being drawn into the compressor 11.

[0075] As the refrigerant releases heat in the internal heat exchanger 32, the air circulating between the storage compartment 4C and the air passage 3C is heated by the operation of the blower fan 5C, thereby warming the products in the storage compartment 4C. By warming the products in the storage compartment 4C in this way, the products can be brought to approximately the set temperature.

[0076] As described above, according to the refrigerant circuit device 10, which is an embodiment of the present invention, the control unit 50 performs a heating operation in which, when predetermined heating conditions are met, the first switching mechanism 34 is set to the second supply state and the second switching mechanism 36 is set to the fourth supply state to heat the products in the cooling and heating showcase 2C. Therefore, as in the conventional method, it is not necessary to circulate the refrigerant in the refrigerant circuit while driving the heater separately. Accordingly, even when cooling the products in the cooling-only showcases 2A and 2B while heating the products in the cooling and heating showcase 2C, power consumption can be reduced.

[0077] Here, as described above, the heat exchange rate of the internal heat exchanger 32 is smaller than that of the evaporators 22A and 22B of the first refrigerant circuit components 20A and 20B. Therefore, even if the refrigerant that has flowed through the internal heat exchanger 32 is adiabatically expanded by the third expansion mechanism 35a and then drawn into the compressor 11 together with the refrigerant that has passed through the evaporators 22A and 22B, it is possible to avoid the occurrence of liquid backflow in the compressor 11.

[0078] According to the refrigerant circuit device 10 described above, when performing heating operation, the control unit 50 may drive the heater 41 to supplementarily heat the air that has passed around the internal heat exchanger 32. This allows the internal temperature of the storage chamber 4C to approximate the set temperature at an earlier stage.

[0079] Although preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications can be made.

[0080] In the embodiment described above, the heating operation start determination process was performed based on the internal temperature and ambient temperature, but the heating operation start determination process may also be performed as follows.

[0081] Figure 6 is a flowchart showing a modified example of the heating operation start determination process performed by the control unit 50 shown in Figure 1, etc.

[0082] In this heating operation start determination process, the control unit 50 determines whether a predetermined time has elapsed since the first switching mechanism 34 was set to the restricted state (step S111). If the predetermined time has elapsed (step S111: Yes), the control unit 50 waits for the discharge temperature input through the input processing unit 50a (step S112). That is, the control unit 50 checks for the presence or absence of a detection signal input from the discharge temperature sensor 44 through the input processing unit 50a, and if the input of a detection signal from the discharge temperature sensor 44 cannot be confirmed (step S112: No), this process is repeated.

[0083] When the discharge temperature is input through the input processing unit 50a (step S112: Yes), the control unit 50 reads the set temperature information from the storage unit 51 through the comparison unit 50b and compares whether the discharge temperature is lower than the set temperature included in the set temperature information (step S113).

[0084] If the discharge temperature is not below the set temperature (step S113: No), that is, if the discharge temperature is above the set temperature, the control unit 50 returns to the previous step without performing the process described later and terminates the current process. As a result, the flow of refrigerant to the second refrigerant circuit component 30 is restricted without performing a heating operation.

[0085] If the discharge temperature is below the set temperature (step S113: Yes), the control unit 50 determines through the determination unit 50c that the predetermined heating conditions are satisfied and decides to start the heating operation (step S114), and then returns to the previous step to end the current process.

[0086] In the above-described embodiment, the first refrigerant circuit components 20A and 20B were provided in greater numbers than the second refrigerant circuit components 30. However, in the present invention, the number of first refrigerant circuit components may be the same as the number of second refrigerant circuit components, and it is sufficient that the heat exchange rate of the internal heat exchanger is smaller than the heat exchange rate of the evaporator.

[0087] In the above-described embodiment, the refrigerant that flowed through the internal heat exchanger 32 merged with the refrigerant that flowed through the evaporators 22A and 22B and was drawn into the compressor 11. However, in the present invention, the refrigerant that flowed through the internal heat exchanger may be drawn into the compressor via the evaporator constituting the first refrigerant circuit component.

[0088] In the embodiment described above, the second switching mechanism 36 was configured to include an outlet valve 36a and a second bypass valve 36b. However, in the present invention, the second switching mechanism may be configured to include a three-way valve provided at the branching point between the refrigerant pipeline (outlet path) connected to the outlet side of the internal heat exchanger and the second bypass path.

[0089] In the embodiments described above, a refrigerant circuit device 10 applied to a showcase system was described, but the present invention may also be applied to other merchandise storage equipment. [Explanation of Symbols]

[0090] 1…Refrigeration unit, 2A, 2B…Cooling-only display case, 2C…Cooling and heating display case, 3A, 3B, 3C…Air passage, 4A, 4B, 4C…Storage room, 5A, 5B, 5C…Blower fan, 10…Refrigerant circuit device, 10a…Refrigerant circuit, 11…Compressor, 12…Condenser, 13…Refrigerant piping, 20A, 20B…First refrigerant circuit component, 21A, 21B…First expansion mechanism, 22A, 22B…Evaporator, 30…Second refrigerant circuit component, 31…Second expansion mechanism, 32…Internal heat exchanger 33...First bypass path, 34...First switching mechanism, 34a...Inlet valve, 34b...First bypass valve, 35...Second bypass path, 35a...Third expansion mechanism, 36...Second switching mechanism, 36a...Outlet valve, 36b...Second bypass valve, 41...Heater, 42...Internal temperature sensor, 43...Ambient temperature sensor, 44...Outlet temperature sensor, 50...Control unit, 50a...Input processing unit, 50b...Comparison unit, 50c...Determination unit, 50d...Output processing unit, 51...Storage unit.

Claims

1. A compressor that compresses and discharges the refrigerant that has been drawn in, A condenser for condensing the refrigerant compressed by the compressor, A first refrigerant circuit component for cooling the product, comprising: a first product storage device for storing the product, which has a first expansion mechanism for adiabatically expanding a portion of the refrigerant condensed in the condenser, and an evaporator for evaporating the refrigerant adiabatically expanded in the first expansion mechanism and drawing it into the compressor; A second refrigerant circuit component is installed in a second product storage device for storing products and has a second expansion mechanism that adiabatically expands a portion of the refrigerant condensed in the condenser, and an internal heat exchanger that exchanges heat with the ambient air for the refrigerant adiabatically expanded by the second expansion mechanism and is drawn into the compressor via the evaporator, or drawn into the compressor together with the refrigerant that has passed through the evaporator, and adjusts the temperature of the products. A refrigerant circuit device equipped with, The second refrigerant circuit component is, A first bypass path that bypasses the second expansion mechanism and allows a portion of the refrigerant condensed in the condenser to flow to the internal heat exchanger, A first switching mechanism that can selectively switch between a first delivery state in which a portion of the refrigerant condensed in the condenser is allowed to flow through the second expansion mechanism while restricting its flow through the first bypass path, a second delivery state in which a portion of the refrigerant is allowed to flow through the first bypass path while restricting its flow through the second expansion mechanism, and a restricting state in which a portion of the refrigerant is restricted from flowing through the second refrigerant circuit component, A second bypass path is provided in such a manner that it bypasses a portion of the outlet path through which the refrigerant that has undergone heat exchange in the aforementioned internal heat exchanger flows, and has a third expansion mechanism in the middle that causes the flowing refrigerant to undergo adiabatic expansion, A second switching mechanism that can selectively switch between a third delivery state in which the refrigerant that has undergone heat exchange in the internal heat exchanger is circulated only through the outlet path, and a fourth delivery state in which it is circulated via the second bypass path. Equipped with, A refrigerant circuit device characterized by comprising a control unit that, when predetermined heating conditions are met, performs a heating operation in which the first switching mechanism is set to the second supply state and the second switching mechanism is set to the fourth supply state to heat the products in the second product storage device.

2. The refrigerant circuit device according to claim 1, characterized in that the amount of heat exchanged by the internal heat exchanger is smaller than the amount of heat exchanged by the evaporator.

3. The refrigerant circuit device according to claim 2, characterized in that the first refrigerant circuit component is provided in greater quantities than the second refrigerant circuit component.

4. The refrigerant circuit device according to any one of claims 1 to 3, characterized in that the control unit performs the heating operation when the internal temperature of the product storage area of ​​the second product storage device falls below a preset temperature while the first switching mechanism is in the restricted state, and the ambient temperature of the second product storage device falls below the preset temperature.

5. The refrigerant circuit device according to any one of claims 1 to 3, characterized in that the control unit performs the heating operation when a predetermined time has elapsed with the first switching mechanism in the restricted state, and the temperature of the air that passes around the internal heat exchanger and is blown into the product storage area of ​​the second product storage device falls below a preset temperature.

6. The refrigerant circuit device according to any one of claims 1 to 3, characterized in that when the heating operation is performed, the control unit drives a heating means installed near the internal heat exchanger to supplementarily heat the air that has passed around the internal heat exchanger.

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