JP6387672B2 - Refrigerant circuit device - Google Patents

Description

  The present invention relates to a refrigerant circuit device, and more particularly to a refrigerant circuit device applied to, for example, a vending machine.

  2. Description of the Related Art Conventionally, a refrigerant circuit device that is applied to, for example, a vending machine and realizes a refrigeration cycle or a heat pump cycle, in which an ejector is used, is known. The ejector uses low-pressure refrigerant (high-pressure refrigerant) supplied from a radiator to depressurize the low-pressure refrigerant discharged from an evaporator disposed in each commodity storage of the vending machine body. (Low-pressure refrigerant) is sucked, the sucked low-pressure refrigerant is mixed with the high-pressure refrigerant, and the low-pressure refrigerant is pressurized and then discharged.

  In the refrigerant circuit device using such an ejector, the low-pressure refrigerant sucked by the ejector is discharged after being boosted, and the discharged refrigerant is separated into a gas-phase refrigerant and a liquid-phase refrigerant by a gas-liquid separator. The liquid-phase refrigerant separated by the gas-liquid separator is sent to each evaporator, while the gas-phase refrigerant separated by the gas-liquid separator is sucked by the compressor.

  Such a refrigerant circuit device has an advantage that the pressure of the refrigerant sucked by the compressor can be increased, thereby improving the operation efficiency of the compressor (see, for example, Patent Document 1).

Japanese Patent No. 4526500

  By the way, in the refrigerant circuit device described above, the ejector sucks the refrigerant that has passed through all the evaporators disposed in each commodity storage, mixes it with the high-pressure refrigerant, and then converts the refrigerant in the gas-liquid two-phase state into the evaporator. Discharge to the side and compressor side. At that time, if the liquid refrigerant returns to the compressor side, the compression efficiency may be reduced, or the compressor may be broken. Therefore, it is necessary to dispose a gas-liquid separator on the discharge side of the ejector, separate the gas-liquid two-phase refrigerant into a gas-phase refrigerant and a liquid-phase refrigerant by the gas-liquid separator, and suck the gas-phase refrigerant into the compressor was there. However, the arrangement of the gas-liquid separator increases the number of parts and increases the manufacturing cost.

  In view of the above circumstances, an object of the present invention is to provide a refrigerant circuit device capable of reducing the manufacturing cost by reducing the number of gas-liquid separators.

In order to achieve the above object, a refrigerant circuit device according to the present invention is provided in each of the target chambers and evaporates the supplied refrigerant to cool the internal air of the corresponding target chambers. A heat exchanger, a compressor that sucks and compresses the refrigerant evaporated in at least one of the plurality of in-compartment heat exchangers, and is provided outside and supplied to each target chamber In the refrigerant circuit device comprising a refrigerant circuit having an external heat exchanger that dissipates the radiated refrigerant, among the refrigerant radiated by the external heat exchanger, one of the two branched at the branch point is adiabatically expanded. And an expansion mechanism for supplying a refrigerant to a low-load heat exchanger disposed in a target chamber having the smallest volume among the plurality of internal heat exchangers, and the other of the refrigerant branched into two at the branch point The cold discharged from the low load heat exchanger by reducing the pressure. An ejector for delivering these refrigerants were mixed, and the allowed to mix at least one internal heat exchanger except for a low load heat exchanger refrigerant by sucking, reaching the branch point from the cabinet external heat exchanger When the valve is disposed and opened, the refrigerant is allowed to pass therethrough. When the valve is closed, the valve restricts the passage of the refrigerant, and the valve is opened and closed at a predetermined opening / closing ratio. And a control means for making it possible .

  According to the present invention, in the refrigerant circuit device, the control unit calculates a deviation between a preset target temperature of the target chamber and a room temperature of the target chamber, and performs PID calculation based on the deviation. The valve is opened and closed according to the open / close ratio.

  According to the present invention, the expansion mechanism adiabatically expands one of the refrigerant radiated by the external heat exchanger into two at the branch point, and has the smallest cooling load among the plurality of internal heat exchangers. Since the refrigerant is supplied to the low load heat exchanger, the refrigerant supplied to the low load heat exchanger evaporates to become a gas phase refrigerant. In addition, the ejector decompresses the other of the refrigerant branched into two at the branch point, sucks the vapor-phase refrigerant that has evaporated in the low load heat exchanger, mixes these refrigerants, and removes the low load heat exchanger Since the refrigerant mixed in at least one internal heat exchanger is sent out, the refrigerant sent out to the internal heat exchanger can be evaporated, whereby the heat load (cooling load) is minimized and the refrigerant flow rate is minimized. A low-load heat exchanger that requires only a small amount is placed on the side that is sucked into the ejector, and other heat exchangers inside the cabinet are placed on the side that is discharged to the ejector, so that a gas-liquid separator that has been conventionally required The gas-phase refrigerant can be returned to the compressor without using. Therefore, the production cost can be reduced by reducing the number of parts by reducing the number of gas-liquid separators.

FIG. 1 is an explanatory diagram showing a case where the internal structure of a vending machine to which the refrigerant circuit device according to the first embodiment of the present invention is applied is viewed from the front. FIG. 2 is a cross-sectional side view of a vending machine to which the refrigerant circuit device according to Embodiment 1 of the present invention is applied. 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 schematic diagram showing the configuration of the ejector shown in FIG. FIG. 5 is an explanatory diagram showing the flow of the refrigerant when the CCC operation is performed. FIG. 6 is an explanatory diagram showing the flow of the refrigerant when the HCC operation is performed. FIG. 7 is a conceptual diagram conceptually showing the refrigerant circuit device according to the second embodiment of the present invention. FIG. 8 is an explanatory diagram showing a characteristic control system of the refrigerant circuit device according to the second embodiment. FIG. 9 is a flowchart showing the processing contents of the valve opening / closing control processing performed by the control unit shown in FIG.

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

<Embodiment 1>
1 and 2 each show a vending machine to which the refrigerant circuit device according to Embodiment 1 of the present invention is applied, and FIG. 1 is an explanatory diagram showing a case where the internal structure is viewed from the front, FIG. 2 is a sectional side view. The vending machine illustrated here includes a main body cabinet 1.

  The main body cabinet 1 is formed as a rectangular heat insulator having an open front surface. The main body cabinet 1 is provided with an outer door 2 and inner doors 3a and 3b on the front surface thereof, and three independent commodity storage boxes 5 partitioned by, for example, two heat insulating partition plates 4 in the left and right. It is provided in a side-by-side manner.

  More specifically, the outer door 2 is for opening and closing the front opening of the main body cabinet 1, and the inner doors 3 a and 3 b are for opening and closing the front surface of the commodity storage 5. The inner doors 3a and 3b are divided into upper and lower parts, and the upper door 3a opens and closes when a product is replenished. The commodity storage 5 is for storing commodities such as canned drinks and plastic bottled drinks while maintaining a desired temperature.

  The product storage 5 is provided with a product storage rack 6, a payout 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 payout mechanism 7 is provided in the lower part of the product storage rack 6 and is used to carry out the products at the lowest level of the product group stored in the product storage rack 6 one by one. The carry-out shooter 8 guides the product delivered from the delivery mechanism 7 to a product outlet (not shown) provided in the outer door 2 through a product outlet 3c provided in the lower inner door 3b. belongs to.

  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 in which a refrigerant is sealed. The refrigerant circuit 10 includes a main path 20, a high-pressure refrigerant introduction path 30, and a return path 40. Yes.

  The main path 20 is configured by connecting a compressor 21, an external heat exchanger 22, an internal heat exchanger 23, an expansion mechanism 24, and an ejector 25 through a refrigerant pipe 26.

  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 and partitioned from the product storage 5 and below the product storage 5. 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-pressure refrigerant), and discharges it from the discharge port.

  The external heat exchanger 22 is disposed in the machine room 9 like the compressor 21, and includes a first external heat exchanger 22a and a second external heat exchanger 22b. In addition, an outside air blower fan F1 is disposed in the vicinity of the outside heat exchanger 22.

  When the refrigerant compressed by the compressor 21 passes through its own flow path, the first external heat exchanger 22a exchanges heat with ambient air to dissipate heat. A three-way valve 271 is provided in the refrigerant pipe 26 that connects the external heat exchanger 22 and the compressor 21. The three-way valve 271 will be described later.

  The second external heat exchanger 22b is integrated with the first external heat exchanger 22a in a state where the fin member thermally connected to the flow path of the second external heat exchanger 22b is shared with the first external heat exchanger 22a. It is structured. The second external heat exchanger 22b is configured to dissipate heat by exchanging heat between the refrigerant passing through the flow path, that is, the heat dissipated by the first external heat exchanger 22a, with the ambient air.

  A plurality (three in the illustrated example) of the internal heat exchangers 23 are provided, and each of the internal heat exchangers 23 is disposed in front of the rear duct D in the low internal region of each commodity storage 5. In the vicinity of each internal heat exchanger 23, an internal blower fan F2 is disposed.

  For these internal heat exchangers 23, the internal heat exchanger 23 disposed in the right product storage 5 (hereinafter also referred to as the right storage 5a) is referred to as the right internal heat exchanger 23a, and the central product The in-compartment heat exchanger 23 disposed in the storage 5 (hereinafter also referred to as “inside storage 5b”) is referred to as “internal storage heat exchanger 23b”, and the left product storage 5 (hereinafter also referred to as “left storage 5c”). The disposed internal heat exchanger 23 is referred to as a left internal heat exchanger 23c. And in each goods storage 5, the volume of the inner warehouse 5b is the smallest compared with the right warehouse 5a and the left warehouse 5c, and thereby, the inner heat exchanger 23b has the lowest heat load (cooling load). It is a load heat exchanger.

  In these internal heat exchangers 23, the refrigerant pipes 26 connected to the respective outlet sides of the right internal heat exchanger 23a and the left internal heat exchanger 23c join at a first junction P1 on the way. The compressor 21 is connected to the compressor 21 in a manner communicating with the suction port of the compressor 21.

  The expansion mechanism 24 is composed of, for example, an electronic expansion valve, a capillary tube, or the like, and adiabatically expands the refrigerant that passes therethrough. The expansion mechanism 24 branches at the first branch point Q1 in the middle of the refrigerant pipe 26 connected to the outlet side of the external heat exchanger 22 (second external heat exchanger 22b), and the internal heat Arranged in the refrigerant line 26 connected to the inlet side of the exchanger 23b.

  As shown in FIG. 4, the ejector 25 is a two-phase flow ejector, and includes a nozzle portion 251, a mixing portion 252, and a diffuser portion 253.

  The nozzle unit 251 is a part that accelerates the high-pressure refrigerant (driving flow) sucked through the high-pressure refrigerant inlet 254 by reducing the pressure. By accelerating the high-pressure refrigerant in this way, the low-pressure refrigerant (suction flow) can be sucked through the refrigerant suction port 255. The nozzle portion 251 is provided with a nozzle valve 251a. The nozzle valve 251a is a valve body for adjusting the nozzle diameter for depressurizing the high-pressure refrigerant.

  The mixing unit 252 is a part that mixes the high-pressure refrigerant accelerated by the nozzle unit 251 and the low-pressure refrigerant sucked through the refrigerant suction port 255.

  The diffuser unit 253 is a part that pressurizes the refrigerant (mixed refrigerant) mixed in the mixing unit 252. The pressurized mixed refrigerant is discharged through a discharge port (not shown).

  The high-pressure refrigerant inlet 254 communicates with the other refrigerant pipe 26 branched at the first branch point Q1, and the refrigerant inlet 255 is connected to the outlet side of the internal heat exchanger 23b. It communicates with the refrigerant pipe 26. Moreover, the said discharge port is connected to the refrigerant | coolant pipe line 26 connected to the inlet side of the heat exchanger 23a on the right side, and the heat exchanger 23c on the left side. Here, the refrigerant pipe 26 connecting the ejector 25, the right-side heat exchanger 23a, and the left-side heat exchanger 23c is branched into two at the second branch point Q2 in the middle, and one of them is the right side. It is connected to the inlet side of the internal heat exchanger 23a, and the other is connected to the inlet side of the left internal heat exchanger 23c. And the electromagnetic valve 272 is provided in the middle of the refrigerant line 26 from the 2nd branch point Q2 to the left internal heat exchanger 23c. The electromagnetic valve 272 is a valve body that opens and closes in response to a command given from a control unit (not shown).

  The ejector 25 having such a configuration reduces the internal heat of the inside by depressurizing a part of the high-pressure refrigerant (high-pressure refrigerant) radiated by the external heat exchanger 22 (second external heat exchanger 22b). The low-pressure refrigerant (low-pressure refrigerant) discharged from the exchanger 23b is sucked, the sucked low-pressure refrigerant is mixed with the high-pressure refrigerant from the external heat exchanger 22, and the pressure is increased and then discharged.

  The high-pressure refrigerant introduction path 30 is configured by a high-pressure refrigerant introduction pipe 31 having one end connected to the three-way valve 271 and the other end connected to the inlet side of the heating heat exchanger 32 disposed in the left warehouse 5c. ing. The high-pressure refrigerant introduction path 30 is for introducing the high-pressure refrigerant compressed by the compressor 21 into the heating heat exchanger 32.

  Here, the three-way valve 271 is between a first delivery state in which the high-pressure refrigerant compressed by the compressor 21 is delivered to the first external heat exchanger 22a and a second delivery state in which the high-pressure refrigerant is delivered to the heating heat exchanger 32. The valve body can be switched alternatively. The switching operation of the three-way valve 271 is performed according to a command given from the control unit.

  The return path 40 has one end connected to the outlet side of the heating heat exchanger 32 and the other end connected to the refrigerant pipe 26 constituting the main path 20, that is, the first external heat exchanger 22a and the second external heat. It is comprised by the return line 41 connected to the 2nd junction P2 of the refrigerant line 26 between the exchangers 22b. The return path 40 is for returning the refrigerant that has passed through the heating heat exchanger 32 to the main path 20. In addition, the code | symbol 42 in FIG. 3 is a check valve.

  In the refrigerant circuit device having the above-described configuration, the internal temperature of each commodity storage 5 can be adjusted to a desired temperature state by controlling the three-way valve 271 and the electromagnetic valve 272 through the control unit. In this way, the product stored in the product storage 5 can be cooled or heated. Here, in the case of performing the CCC operation (operation for cooling the internal air of all the product containers 5) and the HCC operation (heating the internal air of the left warehouse 5c and cooling the internal air of the right warehouse 5a and the middle warehouse 5b). The case where the operation is performed will be described as a representative example.

  First, the case where the CCC operation is performed will be described. In this case, the control unit sets the three-way valve 271 to the first delivery state and opens the electromagnetic valve 272.

  As a result, the refrigerant compressed by the compressor 21 passes through the three-way valve 271 in the first delivery state and reaches the first external heat exchanger 22a as shown in FIG. The refrigerant that has reached the first external heat exchanger 22a performs heat exchange with ambient air (outside air) while passing through the first external heat exchanger 22a, and dissipates heat. The refrigerant radiated by the first external heat exchanger 22a reaches the second external heat exchanger 22b, and further exchanges heat with ambient air while passing through the second external heat exchanger 22b. The refrigerant radiated by the second external heat exchanger 22b branches into two at the first branch point Q1.

  One of the refrigerants branched into two at the first branch point Q1 reaches the expansion mechanism 24. The refrigerant that has reached the expansion mechanism 24 is adiabatically expanded and sent to the internal heat exchanger 23b as a low-pressure refrigerant. The refrigerant (low-pressure refrigerant) sent to the internal heat exchanger 23b passes through a refrigerant flow path (not shown) and exchanges heat with ambient air (internal air of the internal 5b) to cool the internal air. The cooled air circulates in the interior by driving the internal blower fan F2 disposed in the vicinity of the internal heat exchanger 23b, and the product accommodated in the internal 5b is thereby cooled by the circulating air. .

  On the other hand, the other of the refrigerant branched into two at the first branch point Q1 is sent to the ejector 25. The refrigerant (high-pressure refrigerant) sent to the ejector 25 enters the nozzle portion 251 through the high-pressure refrigerant introduction port 254, is depressurized and accelerates. As a result, the refrigerant (low-pressure refrigerant) that has passed through the internal heat exchanger 23 b is sucked through the refrigerant inlet 255. Then, in the mixing unit 252 of the ejector 25, the accelerated high-pressure refrigerant and the sucked low-pressure refrigerant are mixed to become a mixed refrigerant and reach the diffuser unit 253, and the mixed refrigerant is pressurized by the diffuser unit 253. After being discharged.

  The mixed refrigerant discharged from the ejector 25 branches at the second branch point Q2, and is sent to the right-inside heat exchanger 23a and the left-inside heat exchanger 23c. The refrigerant (low-pressure refrigerant) sent to the right internal heat exchanger 23a and the left internal heat exchanger 23c passes through a refrigerant passage (not shown) and exchanges heat with ambient air (internal air). Cool down. The cooled air circulates in the interior by driving the internal blower fan F2 disposed in the vicinity of each internal heat exchanger 23, and the products accommodated in the right compartment 5a and the left compartment 5c thereby circulate the air. It is cooled by. The refrigerant that has passed through the right-side heat exchanger 23a and the left-side heat exchanger 23c merges at the first merge point P1, and then is sucked into the compressor 21 and repeats the cycle of circulating through the refrigerant circuit 10.

  Next, a case where the HCC operation is performed will be described. In this case, the control unit causes the three-way valve 271 to be in the second delivery state, and closes the electromagnetic valve 272.

  As a result, as shown in FIG. 6, the refrigerant compressed by the compressor 21 passes through the three-way valve 271 in the second delivery state and is sent to the heating heat exchanger 32 through the high-pressure refrigerant introduction pipe 31.

  The refrigerant (high-pressure refrigerant) sent to the heating heat exchanger 32 passes through a refrigerant flow path (not shown) and exchanges heat with ambient air (internal air) to heat the internal air. The heated air circulates in the interior by driving the internal blower fan F2, and thereby the product stored in the left compartment 5c is heated by the circulating air.

  The refrigerant that has passed through the heat exchanger 32 for heating reaches the second junction P2 after passing through the return pipe 41, and enters the main path 20 at the second junction P2. The refrigerant that has entered the main path 20 passes through the second external heat exchanger 22b. While passing through the second external heat exchanger 22b, heat is exchanged with ambient air to dissipate heat. The refrigerant radiated by the second external heat exchanger 22b branches into two at the first branch point Q1.

  One of the refrigerants branched into two at the first branch point Q1 reaches the expansion mechanism 24. The refrigerant that has reached the expansion mechanism 24 is adiabatically expanded and sent to the internal heat exchanger 23b as a low-pressure refrigerant. The refrigerant (low-pressure refrigerant) sent to the internal heat exchanger 23b passes through a refrigerant flow path (not shown) and exchanges heat with ambient air (internal air of the internal 5b) to cool the internal air. The cooled air circulates in the interior by driving the internal blower fan F2 disposed in the vicinity of the internal heat exchanger 23b, and the product accommodated in the internal 5b is thereby cooled by the circulating air. . At that time, in order to surely evaporate all the refrigerant passing through the internal heat exchanger 23b, temperature sensors are installed at the inlet and the outlet of the internal heat exchanger 23b, and the temperature at the outlet with respect to the saturation temperature of the inlet. You may adjust the rotation speed of a compressor and the valve opening degree of an ejector at any time so that it may raise.

  On the other hand, the other of the refrigerant branched into two at the first branch point Q1 is sent to the ejector 25. The refrigerant (high-pressure refrigerant) sent to the ejector 25 enters the nozzle portion 251 through the high-pressure refrigerant introduction port 254, is depressurized and accelerates. As a result, the refrigerant (low-pressure refrigerant) that has passed through the internal heat exchanger 23 b is sucked through the refrigerant inlet 255. Then, in the mixing unit 252 of the ejector 25, the accelerated high-pressure refrigerant and the sucked low-pressure refrigerant are mixed to become a mixed refrigerant and reach the diffuser unit 253, and the mixed refrigerant is pressurized by the diffuser unit 253. After being discharged.

  The mixed refrigerant discharged from the ejector 25 is sent to the right-side heat exchanger 23a. The refrigerant (low pressure refrigerant) sent to the right-side heat exchanger 23a passes through a refrigerant flow path (not shown) and exchanges heat with ambient air (internal air) to cool the internal air. The cooled air circulates in the interior by the drive of the internal blower fan F2 disposed in the vicinity of the right internal heat exchanger 23a, and thereby the products accommodated in the right internal 5a are cooled by the circulating air. . At that time, in order to surely evaporate all the refrigerant passing through the right internal heat exchanger 23a, temperature sensors are installed at the inlet and the outlet of the internal heat exchanger 23a, and the temperature at the outlet is equal to the saturation temperature of the inlet. You may adjust the rotation speed of a compressor and the valve opening degree of an ejector at any time so that it may raise. The refrigerant that has passed through the right-side heat exchanger 23 a is sucked into the compressor 21 and repeats the cycle of circulating through the refrigerant circuit 10.

  According to the refrigerant circuit device according to the first embodiment as described above, the expansion mechanism 24 adiabatically expands one of the refrigerant radiated by the external heat exchanger 22 into two at the branch point, In addition, since the refrigerant is supplied to the internal heat exchanger 23b, the refrigerant supplied to the internal heat exchanger 23b evaporates to become a gas phase refrigerant. In addition, the ejector 25 decompresses the other of the refrigerant radiated by the external heat exchanger 22 at the bifurcation point, and sucks the vapor-phase refrigerant after being evaporated in the internal heat exchanger 23b. These refrigerants are mixed, and the refrigerant mixed in at least one of the right-side heat exchanger 23a and the left-side heat exchanger 23c is sent out. The internal heat exchanger 23b, which can be evaporated and thereby has the smallest heat load (cooling load) and requires a small amount of refrigerant flow, is arranged on the side sucked by the ejector 25, and the other right internal heat By arranging the exchanger 23a and the left-side heat exchanger 23c on the side discharged to the ejector 25, the gas-phase refrigerant can be returned to the compressor without using a gas-liquid separator that has been conventionally required. . Accordingly, the manufacturing cost can be reduced by reducing the number of parts by reducing the number of gas-liquid separators.

<Embodiment 2>
FIG. 7 is a conceptual diagram conceptually showing the refrigerant circuit device according to the second embodiment of the present invention, and FIG. 8 is an explanatory diagram showing a characteristic control system of the refrigerant circuit device according to the second embodiment. It is. In addition, the same code | symbol is attached | subjected to what has the structure similar to the refrigerant circuit apparatus which is Embodiment 1 mentioned above, and the description is omitted suitably.

  The refrigerant circuit device illustrated here has a refrigerant circuit 10 ′ in which a refrigerant is sealed, and includes a valve 28, an internal temperature sensor S 1, and a control unit 50.

  The valve 28 is disposed in the refrigerant pipe 26 between the second external heat exchanger 22b and the first branch point Q1 in the main path 20 ′. The valve 28 is a valve body that can be opened and closed by a command given from the control unit 50. When the valve 28 is opened, the refrigerant passes from the second external heat exchanger 22b toward the expansion mechanism 24 and the ejector 25. On the other hand, when closed, the passage of the refrigerant from the second external heat exchanger 22b toward the expansion mechanism 24 and the ejector 25 is restricted.

  The in-compartment temperature sensor S1 is disposed inside each commodity storage 5 and detects the internal temperature (internal temperature) of the commodity storage 5 in which it is disposed. The internal temperature detected by the internal temperature sensor S1 is given to the control unit 50 as an internal temperature signal.

  The control unit 50 controls the valve 28 according to programs and data stored in the memory 55, and includes an input processing unit 51, a calculation processing unit 52, and an output processing unit 53. Although the control unit 50 that controls the valve 28 is shown here, in the present invention, such a processing unit controls the three-way valve 271, the electromagnetic valve 272, the compressor 21, and the like in addition to the valve 28. It may be.

  The input processing unit 51 performs input processing of signals and commands from the internal temperature sensors S1 and the vending machine control unit 60. The vending machine control unit 60 controls the overall operation of the vending machine to which the refrigerant circuit device is applied.

  The calculation processing unit 52 obtains a deviation between the internal temperature of the target product storage 5 input through the input processing unit 51 and the target temperature of the product storage 5 stored in the memory 55, and based on the deviation. The PID calculation is performed to calculate the opening / closing ratio (duty ratio) of the valve 28. The output processing unit 53 gives a command to the valve 28.

  In such a refrigerant circuit device according to the second embodiment, when performing the above-described CCC operation or HCC operation, valve opening / closing control processing is performed at preset time intervals.

  FIG. 9 is a flowchart showing the processing contents of the valve opening / closing control processing performed by the control unit shown in FIG.

  In this valve opening / closing control process, the control unit 50 receives the internal temperature signal from the internal temperature sensor S1 through the input processing unit 51 (step S101: Yes), that is, the commodity storage 5 to be cooled (right here) When the internal temperature of the internal storage 5a is detected by the internal temperature sensor S1, the open / close ratio is calculated through the calculation processing unit 52 (step S102). More specifically, the control unit 50 reads out the target temperature of the product storage 5 (right storage 5a) in which the internal temperature sensor S1 is arranged from the memory 55 through the calculation processing unit 52, and the read target temperature, A deviation from the internal temperature input in step S101 is obtained, and a PID calculation is performed based on the deviation to calculate an opening / closing ratio (duty ratio) of the valve.

  The control unit 50 having calculated the opening / closing ratio of the valve 28 gives an instruction to the valve 28 through the output processing unit 53 according to the opening / closing ratio to open / close the valve 28 (step S103), and then returns the procedure to this time. Terminate the process.

  According to this, the refrigerant | coolant flow volume with respect to the ejector 25 can be continuously controlled by opening and closing the valve | bulb 28 with a predetermined opening / closing ratio.

  As described above, according to the refrigerant circuit device according to the second embodiment, the expansion mechanism 24 adiabatically expands one of the refrigerant radiated by the external heat exchanger 22 into two at the branch point. And since a refrigerant | coolant is supplied to the heat exchanger 23b in a store | warehouse | chamber, the refrigerant | coolant supplied to the heat exchanger 23b in a store | warehouse | chamber evaporates and becomes a gaseous-phase refrigerant | coolant. In addition, the ejector 25 decompresses the other of the refrigerant radiated by the external heat exchanger 22 at the bifurcation point, and sucks the vapor-phase refrigerant after being evaporated in the internal heat exchanger 23b. These refrigerants are mixed, and the refrigerant mixed in at least one of the right-side heat exchanger 23a and the left-side heat exchanger 23c is sent out. The internal heat exchanger 23b, which can be evaporated and thereby has the smallest heat load (cooling load) and requires a small amount of refrigerant flow, is arranged on the side sucked by the ejector 25, and the other right internal heat By arranging the exchanger 23a and the left-side heat exchanger 23c on the side discharged to the ejector 25, the gas-phase refrigerant can be returned to the compressor without using a gas-liquid separator that has been conventionally required. . Accordingly, the manufacturing cost can be reduced by reducing the number of parts by reducing the number of gas-liquid separators.

  Further, according to the refrigerant circuit device, the valve 28 disposed in the refrigerant pipe 26 extending from the external heat exchanger 22 to the first branch point Q1 expands from the external heat exchanger 22 when opened. While permitting the refrigerant to pass toward the mechanism 24 and the ejector 25, when closed, it restricts and controls the passage of the refrigerant from the external heat exchanger 22 toward the expansion mechanism 24 and the ejector 25. The unit 50 obtains a deviation between a preset target temperature of the product storage 5 and the temperature in the product storage 5 and opens and closes the valve 28 according to a PID calculation based on the deviation. Therefore, the refrigerant flow rate with respect to the ejector 25 can be continuously controlled without processing and assembling the shape of the nozzle portion and the nozzle valve with high accuracy as in the prior art. Thereby, it is possible to satisfactorily realize the flow rate control even in the low flow rate region while suppressing an increase in manufacturing cost.

  The preferred embodiments 1 and 2 of the present invention have been described above, but the present invention is not limited to these, and various modifications can be made.

  In Embodiments 1 and 2 described above, the internal heat exchanger 23b has been described as a low load heat exchanger. However, in the present invention, any of the internal heat exchangers is a low load heat exchanger. Needless to say, the circuit configuration of the refrigerant circuit can be changed as appropriate according to the setting of the low load heat exchanger.

  In Embodiments 1 and 2 described above, the refrigerant circuits 10 and 10 ′ capable of the heat pump cycle are shown. However, in the present invention, the refrigerant circuits may be applied only to the refrigeration cycle.

DESCRIPTION OF SYMBOLS 10 Refrigerant circuit 20 Main path | route 21 Compressor 22 External heat exchanger 23 Internal heat exchanger 24 Expansion mechanism 25 Ejector 26 Refrigerant line 271 Three-way valve 272 Solenoid valve 28 Valve 30 High-pressure refrigerant introduction path 31 High-pressure refrigerant introduction line 32 Heat exchanger for heating 40 Return path 41 Return line 50 Control section 51 Input processing section 52 Calculation processing section 53 Output processing section 55 Memory S1 Internal temperature sensor

Claims (2)

A plurality of internal heat exchangers disposed inside each target chamber and evaporating the supplied refrigerant to cool the internal air of the corresponding target chamber;
A compressor that sucks and compresses the refrigerant evaporated in at least one of the plurality of internal heat exchangers;
In the refrigerant circuit device including the refrigerant circuit that is disposed outside the target chambers and has an external heat exchanger that dissipates the supplied refrigerant.
One of the refrigerants radiated by the external heat exchanger is bifurcated at the branching point and is adiabatically expanded, and the low load disposed in the target chamber having the smallest volume among the plurality of internal heat exchangers An expansion mechanism for supplying refrigerant to the heat exchanger;
At least one of the refrigerants excluding the low-load heat exchanger is sucked out by mixing the refrigerant discharged from the low-load heat exchanger by depressurizing the other of the refrigerants branched into two at the branch point. An ejector for sending out the refrigerant mixed in the internal heat exchanger ;
A valve that is disposed in a path from the external heat exchanger to the branch point, and that allows the refrigerant to pass when opened, and restricts the refrigerant from passing when closed. When,
Control means for opening and closing the valve at a predetermined opening and closing rate;
Refrigerant circuit device characterized by comprising a. The control means obtains a deviation between a preset target temperature of the target room and the room temperature of the target room, and opens and closes the valve at an opening / closing ratio calculated by performing PID calculation based on the deviation. The refrigerant circuit device according to claim 1 , wherein

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