JP2012002427A - Refrigerant circuit device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigerant circuit device which can favorably perform a cooling/heating operation while reducing power consumption even when the amount of the refrigerant in a refrigerant circuit corresponds to the amount necessary for a single heating operation.SOLUTION: The refrigerant circuit device includes: a main route 20 connecting an inside heat exchanger 24, a compressor 21 and an outside heat exchanger 22; a high-pressure refrigerant introducing route 30 supplying the refrigerant from the compressor 21 to a prescribed inside heat exchanger 24; and return routes 40, 50 returning the refrigerant from the inside heat exchanger 24 to the main route 20 via a heating-side heat exchanger 42. The first return route 40 is branched in an upstream side of a return valve 44 in a first return piping 41. The circuit device includes: a variable flow rate expansion mechanism 47 provided in a branch piping 46 that joins the first return route in a downstream side of the branch; and a controller 80 that closes the return valve 44 on carrying out a cooling/heating operation and controls the opening of the variable flow rate expansion mechanism 47 to render the refrigerant temperature in an entrance side of the heating-side heat exchanger 42 to be equal to the outside air temperature.

Description

  The present invention relates to a refrigerant circuit device, and more particularly, to a refrigerant circuit device including a refrigerant circuit having a heat pump function.

  Conventionally, the following is known as a refrigerant circuit device including a refrigerant circuit having a heat pump function. That is, a refrigerant circuit having a main path, a high-pressure refrigerant introduction path, a heat radiation path, and a return path is provided.

  The main path is configured in an annular shape by sequentially connecting the internal heat exchanger, the compressor, the external heat exchanger, and the expansion mechanism through the refrigerant pipe. The internal heat exchanger is disposed inside a target room. The compressor sucks the refrigerant that has passed through the internal heat exchanger, compresses the sucked refrigerant, and discharges it in a high-temperature and high-pressure state. The external heat exchanger introduces and condenses the refrigerant compressed by the compressor. The expansion mechanism depressurizes the refrigerant condensed in the external heat exchanger and adiabatically expands it.

  In such a main path, the refrigerant compressed by the compressor is condensed by the external heat exchanger, and the condensed refrigerant is adiabatically expanded by the expansion mechanism and evaporated by the internal heat exchanger. The refrigerant evaporated in the internal heat exchanger is sucked by the compressor, compressed again, and circulated. Thereby, the internal air of the chamber in which the internal heat exchanger is disposed is cooled.

  The high-pressure refrigerant introduction path introduces the refrigerant compressed by the compressor, and supplies it to the one disposed in the chamber to be heated among the internal heat exchangers constituting the main path. In this way, the refrigerant is condensed. Thereby, the internal air of the chamber in which the internal heat exchanger is disposed is heated.

  The heat radiation path introduces the refrigerant condensed in the internal heat exchanger and supplies it to the external heat exchanger. As a result, in the external heat exchanger, the passing refrigerant exchanges heat with ambient air and evaporates.

  The return path is a mode in which the refrigerant evaporated in the external heat exchanger is introduced and returned to the main path in a mode of being sent to the compressor. As a result, the refrigerant that has passed through the return path reaches the main path and is then sent to the compressor.

  In the refrigerant circuit device having such a configuration, when only cooling the internal air of a corresponding chamber (when performing a single cooling operation), the refrigerant may be circulated only in the main path. On the other hand, when cooling the internal air of one chamber and heating the internal air of the other chamber (when performing cooling heating operation), a part of the refrigerant compressed by the compressor is circulated in the main path, In addition, another part of the refrigerant may be circulated in the order of the high-pressure refrigerant introduction path, the heat radiation path, and the return path. Furthermore, when only heating the internal air of the corresponding chamber (when performing heating only operation), the refrigerant compressed by the compressor is passed through the high-pressure refrigerant introduction path, the heat radiation path, and the return path in this order. It may be circulated so as to return to (for example, see Patent Document 1).

JP 2000-304397 A

  By the way, in the case where the cooling heating operation is performed and the case where the heating single operation is performed, the amount of necessary refrigerant differs because the volume of the pipe through which the refrigerant flows in the refrigerant circuit is different. More specifically, the required amount of refrigerant is larger in the case of performing the cooling and heating operation than in the case of performing the single heating operation.

  Therefore, in the refrigerant circuit device proposed in Patent Document 1 described above, if the amount of refrigerant in the refrigerant circuit matches the required amount during the heating single operation, the amount of refrigerant becomes insufficient during the cooling heating operation, and the internal heat exchanger As a result, the condensing temperature is lowered, leading to an increase in the driving time of the compressor and an increase in power consumption.

  In view of the above circumstances, the present invention can perform the cooling and heating operation satisfactorily while reducing the power consumption even if the amount of refrigerant in the refrigerant circuit corresponds to the necessary amount for the heating single operation. An object is to provide a refrigerant circuit device.

  In order to achieve the above-mentioned object, a refrigerant circuit device according to claim 1 of the present invention sucks the refrigerant that has passed through the internal heat exchanger disposed inside the target chamber and the internal heat exchanger. The main path configured by sequentially connecting the compressor that compresses the refrigerant and the external heat exchanger that condenses the refrigerant compressed by the compressor with refrigerant piping, and the introduction valve provided in itself opens, High-pressure refrigerant introduction that condenses the refrigerant in the internal heat exchanger by introducing the refrigerant compressed by the compressor and supplying it to the internal heat exchanger disposed in the chamber to be heated A path, a return path for returning the refrigerant condensed in the internal heat exchanger to the upstream side of the internal heat exchanger in the main path through the heating side heat exchanger, and at least one of the main path and the return path The refrigerant provided and condensed in the external heat exchanger and the heating side A refrigerant circuit device including an expansion mechanism that adiabatically expands any of the refrigerant that has passed through the exchanger, and is disposed in the middle of the pipe from the internal heat exchanger to the heating side heat exchanger, and opens itself In the case of allowing the refrigerant to flow from the internal heat exchanger to the heating side heat exchanger, in the case where the refrigerant is closed, the refrigerant is transferred from the internal heat exchanger to the heating side heat exchanger. When the return valve is closed, the refrigerant condensed in the internal heat exchanger is introduced, and the refrigerant is supplied by a variable flow rate expansion mechanism that can control the flow rate. In the case of performing a cooling heating operation with a branch path that is adiabatically expanded and supplied to the heating side heat exchanger, the return valve is closed, and the refrigerant temperature on the inlet side of the heating side heat exchanger is set to the outside air temperature. Said variable flow expander to be equal Characterized in that a control means for adjusting the degree of opening.

  According to the refrigerant circuit device of the present invention, when the cooling heating operation is performed, the control means closes the return valve and the variable flow rate so that the refrigerant temperature on the inlet side of the heating side heat exchanger becomes equal to the outside air temperature. Since the opening degree of the expansion mechanism is adjusted, the liquid refrigerant condensed in the internal heat exchanger of the chamber to be heated can be adiabatically expanded to form a gas-liquid two-phase refrigerant. Moreover, since the refrigerant temperature at the inlet of the heating side heat exchanger is made equal to the outside air temperature, the degree of superheat of the refrigerant (gas-liquid two-phase refrigerant) passing through the heating side heat exchanger can be made zero. Thereby, while being able to make the refrigerant | coolant in the path | route from a variable flow volume expansion mechanism to an expansion mechanism into the high pressure state of a gas-liquid two phase, the heat dissipation loss in a heating side heat exchanger can be reduced. Thus, since the refrigerant in the path from the variable flow rate expansion mechanism to the expansion mechanism can be in a gas-liquid two-phase high-pressure state, the amount of refrigerant enclosed in the refrigerant circuit corresponds to the necessary amount for the heating single operation. Even so, a sufficient amount of refrigerant can be secured from the compressor of the refrigerant circuit to the internal heat exchanger of the chamber to be heated, and the condensation temperature in the internal heat exchanger can be increased. it can. Thereby, the drive time of a compressor can be reduced. Therefore, even if the amount of refrigerant in the refrigerant circuit corresponds to the necessary amount for the heating single operation, there is an effect that the cooling and heating operation can be performed satisfactorily while reducing the power consumption.

FIG. 1 is a sectional view showing a case where an internal structure of a vending machine to which a refrigerant circuit device according to an embodiment of the present invention is applied is viewed from the front. FIG. 2 shows the internal structure of the vending machine shown in FIG. 1, and is a cross-sectional side view of the right commodity storage. FIG. 3 is a conceptual diagram conceptually showing the refrigerant circuit device applied to the vending machine shown in FIGS. 1 and 2. FIG. 4 is a conceptual diagram showing the flow of the refrigerant when the single heating operation is performed in the refrigerant circuit device shown in FIG. 3. FIG. 5 is a conceptual diagram showing the flow of the refrigerant when performing the cooling heating operation (HCC operation) in the refrigerant circuit device shown in FIG. 3.

  Exemplary embodiments of a refrigerant circuit device according to the present invention will be explained below in detail with reference to the accompanying drawings.

  FIG. 1 is a sectional view showing a case where an internal structure of a vending machine to which a refrigerant circuit device according to an embodiment of the present invention is applied is viewed from the front. The vending machine illustrated here includes a main body cabinet 1.

  The main body cabinet 1 has a rectangular shape with an open front surface. The main body cabinet 1 is provided with three independent commodity containers 3 partitioned by, for example, two heat insulating partition plates 2 in a side-by-side manner. This product storage 3 is for storing products such as canned beverages and beverages containing plastic bottles while maintaining them at a desired temperature, and has a heat insulating structure.

  FIG. 2 shows the internal structure of the vending machine shown in FIG. 1 and is a cross-sectional side view of the right product storage case 3. Here, the internal structure of the right product storage 3 (hereinafter also referred to as the right storage 3a) is shown, but the central product storage 3 (hereinafter also referred to as the intermediate storage 3b) and the left product storage 3 are shown. The internal structure (hereinafter also referred to as the left warehouse 3c as appropriate) has substantially the same configuration as the right warehouse 3a. In the present specification, the right side indicates the right side when the vending machine is viewed from the front, and the left side indicates the left side when the vending machine is viewed from the front.

  As shown in FIG. 2, an outer door 4 and an inner door 5 are provided on the front surface of the main body cabinet 1. The outer door 4 is for opening and closing the front opening of the main body cabinet 1, and the inner door 5 is for opening and closing the front surface of the commodity storage 3. The inner door 5 is divided into upper and lower parts, and the upper door 5a opens and closes when a product is replenished.

  The product storage 3 is provided with a product storage rack 6, a carry-out mechanism 7 and a carry-out shooter 8. The commodity storage rack 6 is for storing commodities in a manner arranged in the vertical direction. The carry-out mechanism 7 is provided at the lower part of the product storage rack 6 and is used to carry out the products at the bottom of the product group stored in the product storage rack 6 one by one. The carry-out shooter 8 is for guiding the product carried out from the carry-out mechanism 7 to the product take-out port 4 a provided in the outer door 4.

  FIG. 3 is a conceptual diagram conceptually showing the refrigerant circuit device applied to the vending machine shown in FIGS. 1 and 2. The refrigerant circuit device illustrated here includes a refrigerant circuit 10 having a main path 20, a high-pressure refrigerant introduction path 30, a first return path 40, and a second return path 50. The refrigerant circuit 10 has a refrigerant (for example, R134a) sealed therein.

  The main path 20 is configured by sequentially connecting a compressor 21, an external heat exchanger 22, and an internal heat exchanger 24 through a refrigerant pipe 25.

  The compressor 21 is disposed in the machine room 9 as shown in FIG. The machine room 9 is a room inside the main body cabinet 1, partitioned from the product storage 3 and below the product storage 3. The compressor 21 sucks the refrigerant through the suction port, compresses the sucked refrigerant to be in a high-temperature and high-pressure state (high-temperature and high-pressure refrigerant), and discharges it from the discharge port.

  As shown in FIG. 2, the external heat exchanger 22 is disposed in the machine room 9 similarly to the compressor 21. When the refrigerant | coolant compressed with the compressor 21 passes, this external heat exchanger 22 condenses this refrigerant | coolant.

  A three-way valve 261 is provided in the refrigerant pipe 25 that connects the external heat exchanger 22 and the compressor 21. The three-way valve 261 will be described later.

  A plurality of (three in the illustrated example) heat exchangers 24 in the cabinet are provided, which are disposed in the lower interior of each commodity storage 3 and on the front side of the rear duct D (see FIG. 2). is there. The refrigerant pipe 25 connecting the internal heat exchanger 24 and the external heat exchanger 22 is branched at a first branch point P1 in the middle of the internal heat exchanger 24 and the internal heat exchanger 24 disposed in the right warehouse 3a. On the entrance side of the internal heat exchanger 24 (hereinafter also referred to as the internal heat exchanger 24b) disposed in the internal storage 3b on the entrance side of the right internal heat exchanger 24a (hereinafter also referred to as the internal internal heat exchanger 24b) It is connected to the inlet side of the internal heat exchanger 24 (hereinafter also referred to as the left internal heat exchanger 24c) disposed inside the left warehouse 3c.

  Further, in this refrigerant pipe 25, expansion mechanisms 231, 232,... On the way from the first branch point P1 to each of the right internal heat exchanger 24a, the central internal heat exchanger 24b, and the left internal heat exchanger 24c. 233 is provided. The expansion mechanisms 231, 232, and 233 are variable in flow rate that can adjust the opening according to a command given from the controller 80, and can be in a fully closed state. The expansion mechanisms 231, 232, and 233 are for adiabatic expansion by reducing the pressure of the passing refrigerant.

  The refrigerant piping 25 connected to the outlet side of the internal heat exchanger 24 joins at the first joining point P <b> 2 in the middle, and is connected to the compressor 21 via the accumulator 27. Here, the accumulator 27 is for storing the liquid-phase refrigerant and allowing the gas-phase refrigerant to pass through when the refrigerant passing therethrough is a gas-liquid mixed refrigerant. Note that outlet-side low-pressure solenoid valves 262b and 262c are arranged in the middle of the refrigerant pipe 25 from the outlet side of the inner-chamber heat exchanger 24b and the left-chamber heat exchanger 24c to the first junction P2. The outlet-side low-pressure solenoid valves 262b and 262c are openable and closable valve bodies. When the opening command is given from the controller 80, the outlet-side low-pressure solenoid valves 262b and 262c are opened to allow passage of the refrigerant, while when the closing command is given. Is closed to restrict the passage of refrigerant.

  In such a main path 20, reference numeral 28 in FIG. 3 is an internal heat exchanger. The internal heat exchanger 28 exchanges heat between the high-pressure refrigerant and the low-pressure refrigerant.

  The high-pressure refrigerant introduction path 30 is connected to the three-way valve 261 and branches in the middle, one of which is connected to the refrigerant pipe 25 on the inlet side of the internal heat exchanger 24b and the other is the inlet of the left internal heat exchanger 24c. It is the path | route comprised by the high voltage | pressure refrigerant | coolant inlet piping 31 each joined to the refrigerant | coolant piping 25 of the side. The high-pressure refrigerant introduction path 30 is a path for introducing the refrigerant (high-pressure refrigerant) compressed by the compressor 21.

  Here, the three-way valve 261 is a first sending state in which the refrigerant compressed by the compressor 21 is sent to the external heat exchanger 22 and a second sending state in which the refrigerant compressed by the compressor 21 is sent to the high-pressure refrigerant introduction path 30. It is a switching valve that can be switched alternatively between. The switching operation of the three-way valve 261 is performed according to a command given from the controller 80.

  In the high-pressure refrigerant introduction pipe 31, high-pressure introduction valves 321 and 322 are provided on the downstream side of the branch point, respectively. The high-pressure introduction valves 321 and 322 are valve bodies that can be opened and closed. When the opening command is given from the controller 80, the high-pressure introduction valves 321 and 322 are opened and allow the refrigerant to pass therethrough. Thus, the passage of the refrigerant is restricted.

  That is, when the refrigerant compressed by the compressor 21 is supplied through the high-pressure refrigerant introduction path 30, the inner-compartment heat exchanger 24 b and the left-compartment heat exchanger 24 c It heats the internal air of the product storage 3 (the central storage 3b and the left storage 3c).

  The first return path 40 is branched in the middle of each of the refrigerant pipes 25 connected to the outlet side of the internal heat exchanger 24b and the left internal heat exchanger 24c, and merges at the second junction P3. This is a path constituted by the first return pipe 41 connected to the inlet side of the heating side heat exchanger 42 arranged in a mode adjacent to the external heat exchanger 22. The first return path 40 is for supplying the refrigerant condensed in at least one of the internal heat exchanger 24 b and the left internal heat exchanger 24 c to the heating side heat exchanger 42.

  The heating-side heat exchanger 42 is disposed in a form adjacent to the external heat exchanger 22, and heat is exchanged between the refrigerant passing through itself and the ambient air to radiate the refrigerant. is there. That is, the first return path 40 introduces the refrigerant condensed in the internal heat exchanger 24 and sends it to the heating side heat exchanger 42, and the heating side heat exchanger 42 radiates the refrigerant. .

  From a branch point with the refrigerant pipe 25 connected to the outlet side of the middle return heat exchanger 24b and the left return heat exchanger 24c in the middle of the first return pipe 41 constituting the first return path 40. On the way to the second junction P3, check valves 431 and 432 are provided, respectively.

  The first return path 40 is provided with a return valve 44 and a branch path 45. The return valve 44 is provided in the middle of the first return pipe 41. The return valve 44 is a valve body that can be opened and closed. When the opening command is given from the controller 80, the return valve 44 opens and allows the refrigerant to pass therethrough, but closes when the closing command is given. It regulates the passage of refrigerant.

  The branch path 45 is connected in a manner that branches from a branch point upstream of the return valve 44 in the first return pipe 41 and joins at a junction point downstream of the return valve 44 in the first return pipe 41. The branch pipe 46 is provided with a variable flow rate expansion mechanism 47.

  The variable flow rate expansion mechanism 47 has a variable flow rate that can adjust the opening degree in accordance with a command given from the opening degree adjustment control unit 81 of the controller 80, and can be in a fully closed state. The variable flow rate expansion mechanism 47 depressurizes the refrigerant passing therethrough and adiabatically expands the refrigerant.

  The second return path 50 is connected to the outlet side of the heating side heat exchanger 42 and is connected to the refrigerant pipe 25 constituting the main path 20, that is, the external heat exchanger 22 (in the illustrated example, the internal heat exchanger 28). The second return pipe 51 is connected to the third junction P4 of the refrigerant pipe 25 between the first branch point P1. The second return path 50 is for introducing the refrigerant radiated by the heating side heat exchanger 42 and returning it to the upstream side of the internal heat exchanger 24 of the main path 20. It is arranged. The capillary tube 52 decompresses the refrigerant passing through the second return pipe 51 and adiabatically expands the refrigerant.

  In addition to the above configuration, the refrigerant circuit 10 having the above-described configuration includes a first bypass path 60, a second bypass path 70, an outside air temperature sensor S1, and a heating side heat exchanger inlet temperature sensor S2.

  The first bypass path 60 branches off from a branch point in the middle of the second return pipe 51 from the heating side heat exchanger 42 to the capillary tube 52, and is in the middle of the refrigerant pipe 25 between the internal heat exchanger 28 and the accumulator 27. It is comprised by the 1st bypass piping 61 provided in the aspect which merges. Such a first bypass pipe 61 is provided with a first bypass valve 62. The first bypass valve 62 is a valve body that can be opened and closed. The first bypass valve 62 is opened when the opening command is given from the controller 80 and allowed to pass through the refrigerant. On the other hand, the first bypass valve 62 is closed when the closing command is given. This restricts the passage of refrigerant.

  The second bypass path 70 branches off from a branch point in the middle of the refrigerant pipe 25 extending from the external heat exchanger 22 to the internal heat exchanger 28, and the refrigerant pipe 25 extending from the first junction P <b> 2 to the internal heat exchanger 28. It is comprised by the 2nd bypass piping 71 provided in the aspect which merges in the middle merge point. Such a second bypass pipe 71 is provided with a second bypass valve 72. The second bypass valve 72 is a valve body that can be opened and closed. When the opening command is given from the controller 80, the second bypass valve 72 opens and allows the refrigerant to pass therethrough, but when the closing command is given, the second bypass valve 72 closes. This restricts the passage of refrigerant.

  The outside air temperature sensor S1 is disposed outside the vending machine to which the refrigerant circuit device is applied. The outside air temperature sensor S1 detects an outside air temperature, and the detected outside air temperature is sent to the opening adjustment control unit 81 of the controller 80 as an outside air temperature signal.

  The heating side heat exchanger inlet temperature sensor S <b> 2 is disposed in the first return pipe 41 in the vicinity of the inlet side of the heating side heat exchanger 42. The heating side heat exchanger inlet temperature sensor S2 detects a refrigerant temperature entering the heating side heat exchanger 42, and the detected refrigerant temperature is sent to the opening adjustment control unit 81 of the controller 80 as a refrigerant temperature signal. To be sent.

  Here, the opening degree adjustment control unit 81 of the controller 80 adjusts the opening degree of the variable flow rate expansion mechanism 47, and more specifically, the outside air detected by the outside temperature sensor S1 when performing the cooling and heating operation. The opening degree of the variable flow rate expansion mechanism 47 is adjusted so that the temperature and the refrigerant temperature detected by the heating side heat exchanger inlet temperature sensor S2 are the same. In addition, when performing the single heating operation, the opening adjustment control unit 81 opens the variable flow rate expansion mechanism 47 so that the refrigerant temperature detected by the heating side heat exchanger inlet temperature sensor S2 is included in a desired range. The degree is adjusted. That is, the opening degree of the variable flow rate expansion mechanism 47 is adjusted so that the refrigerant passing through the heating side heat exchanger 42 can evaporate by performing a heat exchanger with the ambient air.

  The refrigerant circuit device having the above-described configuration cools or heats the product stored in the product storage 3 as follows.

  First, the case where the heating single operation (here, the operation of heating the internal air of only the left chamber 3c) is described. In this case, the controller 80 causes the three-way valve 261 to be in the second delivery state, fully closes the expansion mechanisms 231, 232, 233, the outlet side low pressure solenoid valves 262b, 262c, the high pressure introduction valve 321, the return valve 44, and the second The bypass valve 72 is closed, and the high-pressure introduction valve 322 and the first bypass valve 62 are opened. Further, the opening adjustment control unit 81 of the controller 80 adjusts the opening of the variable flow rate expansion mechanism 47 to a desired size. As a result, the refrigerant compressed by the compressor 21 circulates as shown in FIG.

  In other words, the refrigerant compressed by the compressor 21 flows into the high-pressure refrigerant introduction pipe 31 via the three-way valve 261 in the second delivery state, passes through the high-pressure refrigerant introduction pipe 31 and passes through the left-side heat exchanger. 24c. The refrigerant that has reached the left internal heat exchanger 24c exchanges heat with the internal air of the left internal 3c while passing through the heat exchanger, and dissipates heat to the internal air to condense. Thereby, the internal air of the left warehouse 3c is heated. The heated internal air circulates inside each of the left warehouses 3c by driving the internal blower fan F1, whereby the products stored in the left warehouse 3c are heated to the circulating internal air.

  The refrigerant condensed in the left-side internal heat exchanger 24 c passes through the first return pipe 41 constituting the first return path 40 and reaches the branch pipe 46. The refrigerant passing through the branch pipe 46 is adiabatically expanded by the variable flow rate expansion mechanism 47, and the adiabatically expanded refrigerant reaches the heating side heat exchanger 42. The refrigerant reaching the heating side heat exchanger 42 evaporates while passing through the heating side heat exchanger 42 by exchanging heat with the ambient air. The refrigerant evaporated in the heating side heat exchanger 42 passes through the first bypass pipe 61 through the second return pipe 51, is sucked into the compressor 21 through the accumulator 27, and is compressed by the compressor 21. The above-described circulation is repeated.

  Next, the case where the HCC operation (cooling heating operation for heating the internal air of the left warehouse 3c and cooling the internal air of the right warehouse 3a and the middle warehouse 3b) is described. In this case, the controller 80 sets the three-way valve 261 to the second delivery state, fully closes the expansion mechanism 233, the outlet side low pressure electromagnetic valve 262c, the high pressure introduction valve 321, the return valve 44, the first bypass valve 62, and the second The bypass valve 72 is closed, and the opening degree of the expansion mechanisms 231 and 232 is set to a desired size to open the outlet side low pressure solenoid valve 262b and the high pressure introduction valve 322. Further, the opening adjustment control unit 81 of the controller 80 performs variable flow rate expansion so that the outside air temperature detected by the outside air temperature sensor S1 and the refrigerant temperature detected by the heating side heat exchanger inlet temperature sensor S2 are the same. The opening degree of the mechanism 47 is adjusted. As a result, the refrigerant compressed by the compressor 21 circulates as shown in FIG.

  In other words, the refrigerant compressed by the compressor 21 flows into the high-pressure refrigerant introduction pipe 31 via the three-way valve 261 in the second delivery state, passes through the high-pressure refrigerant introduction pipe 31 and passes through the left-side heat exchanger. 24c. The refrigerant that has reached the left internal heat exchanger 24c exchanges heat with the internal air of the left internal 3c while passing through the heat exchanger, dissipates heat to the internal air, condenses, and becomes a liquid refrigerant. Thereby, the internal air of the left warehouse 3c is heated. The heated internal air circulates inside each of the left warehouses 3c by driving the internal blower fan F1, whereby the products stored in the left warehouse 3c are heated to the circulating internal air.

  The refrigerant (liquid refrigerant) condensed in the left-side heat exchanger 24 c passes through the first return pipe 41 constituting the first return path 40 and reaches the branch pipe 46. The refrigerant passing through the branch pipe 46 is adiabatically expanded by the variable flow rate expansion mechanism 47 to become a gas-liquid two-phase refrigerant and reaches the heating side heat exchanger 42.

  Here, the opening degree of the variable flow rate expansion mechanism 47 is determined by the opening degree adjustment control unit 81 of the controller 80, the outside air temperature detected by the outside air temperature sensor S1, and the refrigerant temperature detected by the heating side heat exchanger inlet temperature sensor S2. Are adjusted to the same size, the refrigerant (gas-liquid two-phase refrigerant) passing through the heating side heat exchanger 42 does not evaporate or the like equal to the outside air temperature. That is, the superheat degree of the refrigerant passing through the heating side heat exchanger 42 becomes zero.

  The refrigerant that has passed through the heating-side heat exchanger 42 passes through the second return pipe 51, adiabatically expands in the capillary tube 52, becomes a low-pressure refrigerant, flows into the main path 20 from the third junction P4, and has an opening degree. It passes through the expansion mechanisms 231 and 232 adjusted to a desired size. The refrigerant that has passed through the expansion mechanisms 231 and 232 reaches the right internal heat exchanger 24a and the internal heat exchanger 24b, and evaporates in the right internal heat exchanger 24a and the internal heat exchanger 24b, respectively. Then, heat is taken from the internal air of each product container 3 to cool the internal air. The cooled internal air circulates inside each product storage 3 by driving each internal blower fan F1, thereby cooling the products stored in each product storage 3 (right store 3a and middle store 3b). Is done. The refrigerant evaporated in the right internal heat exchanger 24a and the internal internal heat exchanger 24b is sucked into the compressor 21 through the accumulator 27, is compressed by the compressor 21, and repeats the circulation described above.

  In the refrigerant circuit device according to the present embodiment as described above, the opening degree adjustment control unit 81 of the controller 80 is detected by the outside air temperature sensor S1 when performing cooling heating operation such as HCC operation. Since the opening degree of the variable flow rate expansion mechanism 47 is adjusted so that the outside air temperature and the refrigerant temperature detected by the heating side heat exchanger inlet temperature sensor S2 are the same, the liquid refrigerant condensed in the left internal heat exchanger 24c. Can be expanded adiabatically into a gas-liquid two-phase refrigerant. Moreover, since the refrigerant temperature at the inlet of the heating side heat exchanger 42 is made equal to the outside air temperature, the degree of superheat of the refrigerant (gas-liquid two-phase refrigerant) passing through the heating side heat exchanger 42 can be made zero. Thereby, the refrigerant in the path from the variable flow rate expansion mechanism 47 to the capillary tube 52 can be brought into a gas-liquid two-phase high-pressure state, and heat dissipation loss in the heating side heat exchanger 42 can be reduced.

  Thus, since the refrigerant in the path from the variable flow rate expansion mechanism 47 to the capillary tube 52 can be in a gas-liquid two-phase high pressure state, the amount of the refrigerant sealed in the refrigerant circuit 10 becomes the necessary amount for the heating single operation. Even if it corresponds, the refrigerant quantity from the compressor 21 of the refrigerant circuit 10 to the internal heat exchanger 24 (the left internal heat exchanger 24) of the chamber to be heated can be sufficiently secured, The condensation temperature in the internal heat exchanger 24 can be increased. Thereby, the drive time of the compressor 21 can be reduced.

  Therefore, according to the refrigerant circuit device of the first embodiment, even if the refrigerant amount in the refrigerant circuit 10 corresponds to the necessary amount for the heating single operation, the cooling heating operation is performed while reducing the power consumption. Can be performed satisfactorily.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to this, and various modifications can be made.

  In the above-described embodiment, the capillary tube 52 is provided in the second return pipe 51 and is adiabatically expanded by the capillary tube 52. However, in the present invention, the capillary tube 52 of the second return pipe 51 is an essential component. Instead, adiabatic expansion may be performed by the expansion mechanisms 231, 232, and 233 provided on the upstream side of the internal heat exchangers 24.

  In the embodiment described above, the internal heat exchanger 28 is provided. However, in the present invention, the internal heat exchanger may not be provided.

  As described above, the refrigerant circuit device according to the present invention is useful for vending machines that sell products such as canned beverages and plastic bottled beverages.

DESCRIPTION OF SYMBOLS 1 Main body cabinet 10 Refrigerant circuit 20 Main path 21 Compressor 22 External heat exchanger 231 Expansion mechanism 232 Expansion mechanism 233 Expansion mechanism 24 Internal heat exchanger 24a Right internal heat exchanger 24b Central internal heat exchanger 24c Left warehouse Internal heat exchanger 25 Refrigerant pipe 261 Three-way valve 263b Outlet side low pressure solenoid valve 263c Outlet side low pressure solenoid valve 30 High pressure refrigerant introduction path 31 High pressure refrigerant introduction pipe 321 High pressure refrigerant introduction valve 322 High pressure introduction valve 40 First return path 41 First return pipe 42 Heating side heat exchanger 44 Return valve 45 Branch path 46 Branch pipe 47 Variable flow rate expansion mechanism 50 Second return path 51 Second return pipe 52 Capillary tube 60 First bypass path 61 First bypass pipe 62 First bypass valve 70 First 2 Bypass path 71 Second bypass pipe 72 Second bypass valve 80 Controller 81 Opening adjustment controller S1 Outside air temperature sensor S2 Heating side heat exchanger inlet temperature sensor

Claims (1)

An internal heat exchanger disposed inside the target chamber, a compressor that sucks and compresses the refrigerant that has passed through the internal heat exchanger, and external heat exchange that condenses the refrigerant compressed by the compressor A main path configured by sequentially connecting the vessel with refrigerant piping,
By introducing the refrigerant compressed by the compressor by opening an introduction valve provided in itself, and supplying the refrigerant disposed in the chamber to be heated among the internal heat exchangers, A high-pressure refrigerant introduction path for condensing the refrigerant in the internal heat exchanger;
A return path for returning the refrigerant condensed in the internal heat exchanger to the upstream side of the internal heat exchanger in the main path through the heating side heat exchanger;
A refrigerant provided in at least one of the main path and the return path, and an expansion mechanism that adiabatically expands either the refrigerant condensed in the external heat exchanger or the refrigerant that has passed through the heating side heat exchanger In the circuit device,
It is arranged in the middle of the pipe from the internal heat exchanger to the heating side heat exchanger, and allows the refrigerant to flow from the internal heat exchanger to the heating side heat exchanger when it opens. On the other hand, a return valve that restricts the flow of refrigerant from the internal heat exchanger to the heating-side heat exchanger when it is closed,
When the return valve is closed, the refrigerant condensed in the internal heat exchanger is introduced, and the refrigerant is adiabatically expanded by a variable flow rate expansion mechanism capable of controlling the flow rate provided in itself, and the heating side heat exchanger A branch path to supply to
Control means for closing the return valve and adjusting the opening of the variable flow rate expansion mechanism so that the refrigerant temperature on the inlet side of the heating side heat exchanger becomes equal to the outside air temperature when performing cooling heating operation; A refrigerant circuit device comprising:

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