JP2018185069A - Coolant circuit arrangement - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid the generation of a liquid back phenomenon while adjusting the refrigeration capacity to a desired size.SOLUTION: A coolant circuit arrangement comprises: a main circuit 30 in which a chiller 34, a compressor 31, a radiator 32, an auxiliary radiator 33, a first capillary tube 38 and second capillary tubes 40a, 40b and 40c are sequentially connected by a refrigerant pipe line 35; a refrigerant circuit 20 having a heater 46 installed in a commodity storage 3 and connected to an introduction pipe line 45 branched from the refrigerant pipe line 35 on the discharge side of the compressor 31, a feedback pipe line 47 for connecting between the heater 46 and the refrigerant pipe line 35 on the entrance side of the auxiliary radiator 33; and a control part 50 for controlling the refrigerating capacity in an outdoor blower fan F1 for sending external air to the radiator 32 and the auxiliary radiator 33 when driven, an outlet temperature sensor S for detecting the temperature of the refrigerant sucked into the compressor 31, and a cooler 34 for increasing or decreasing the air blowing rate of the outdoor blower fan F1 according to the change in the refrigerant temperature detected through the outlet temperature sensor S.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a refrigerant circuit device, and more particularly to a refrigerant circuit device provided with 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 circuit, an introduction line, a heater, and a return line is provided.

  The main circuit has a tubular shape in which a cooler, a compressor, a radiator, an auxiliary radiator, and an expansion mechanism are sequentially connected via a refrigerant pipe. The cooler is installed in the target room. The compressor is installed outside the chamber. The compressor sucks refrigerant (for example, carbon dioxide) that has passed through the cooler, compresses the sucked refrigerant, and discharges it in a high-temperature and high-pressure state. Like the compressor, the radiator is installed outside the chamber, and the refrigerant compressed by the compressor exchanges heat with ambient air to dissipate heat. The auxiliary radiator is installed in the vicinity of the radiator and radiates heat by exchanging heat of the refrigerant radiated by the radiator with ambient air. An expansion mechanism decompresses and thermally expands the refrigerant radiated by the auxiliary radiator.

  In such a main circuit, the refrigerant compressed by the compressor radiates heat by the radiator and the auxiliary radiator, and the radiated refrigerant is adiabatically expanded by the expansion mechanism and evaporated by the cooler. The refrigerant evaporated in the cooler is sucked by the compressor, compressed again, and circulated. Thereby, the internal air of the chamber in which the cooler is installed is cooled.

  The introduction pipe is a pipe provided in a manner branched from the refrigerant pipe on the outlet side of the compressor. The heater is connected to the introduction pipe line and is installed in a chamber to be heated among the chambers in which the cooler is installed. When the refrigerant compressed by the compressor is supplied through the introduction pipe line, the heater dissipates the refrigerant and heats the internal air of the chamber.

  The return pipe is provided in such a manner that the heater and the refrigerant pipe on the inlet side of the auxiliary radiator are connected. This return pipe sends out the refrigerant radiated by the heater to the main circuit.

  In the refrigerant circuit device having such a configuration, when only the cooling of the internal air of the chamber is performed (when the cooling single operation is performed), the refrigerant is circulated only in the main circuit. On the other hand, when the internal air of one chamber is cooled to heat the internal air of another chamber (when heat pump operation is performed), the refrigerant compressed by the compressor is sent to the heater, and the heater is The refrigerant that has passed is sent to the auxiliary radiator, and then passed through the expansion mechanism and the cooler. Thereby, the internal air of the room | chamber in which the heater was installed can be heated, and the internal air of the room | chamber in which the cooler was installed can be cooled.

  In such a refrigerant circuit device, when performing heat pump operation, outside air is sent to the radiator and the auxiliary radiator in accordance with the refrigerant temperature at the outlet of the auxiliary radiator in order to keep the pressure of the high-pressure refrigerant within a predetermined range. The air volume of the outside air blowing fan to be controlled is controlled (for example, see Patent Document 1).

Japanese Patent No. 5024198

  However, in the above-described refrigerant circuit device, the amount of air sent from the outside air blower fan that sends outside air to the radiator and the auxiliary radiator is controlled in accordance with the refrigerant temperature at the outlet of the auxiliary radiator. When the refrigeration capacity becomes excessive, it is difficult to detect the so-called liquid back phenomenon in which the compressor sucks the liquid phase refrigerant, and as a result it is difficult to avoid the liquid back phenomenon. there were.

  In order to avoid the occurrence of such a liquid back phenomenon, an inverter compressor capable of changing the rotation speed is applied as a compressor, or an electronic expansion valve capable of adjusting the opening degree is applied as an expansion mechanism. However, the inverter compressor and the electronic expansion valve are expensive, resulting in an increase in manufacturing cost, which is not preferable.

  In view of the above circumstances, an object of the present invention is to provide a refrigerant circuit device capable of avoiding the occurrence of a liquid back phenomenon while adjusting the refrigeration capacity to a desired size.

  In order to achieve the above object, a refrigerant circuit device according to the present invention includes a cooler, a compressor that sucks and compresses the refrigerant from the cooler, and a radiator that dissipates heat from the refrigerant compressed by the compressor. An auxiliary radiator that radiates the refrigerant passing on the downstream side of the radiator and an expansion mechanism that adiabatically expands the refrigerant radiated by the auxiliary radiator are sequentially connected through a refrigerant pipe, and the cooler Connected to the main circuit for evaporating the refrigerant and cooling the internal air of the chamber in which the cooler is installed, and the inlet pipe provided in a manner branched from the refrigerant pipe on the outlet side of the compressor and heated A heater that is installed in a target chamber and is supplied with a refrigerant compressed by the compressor through the introduction pipe, and radiates the refrigerant to heat the internal air of the chamber; and A refrigerant pipe on the inlet side of the auxiliary radiator; In a refrigerant circuit device having a refrigerant circuit that is provided in a connected manner and has a return circuit that delivers a refrigerant radiated by the heater to the main circuit, and is installed in the vicinity of the radiator and is driven The outside air blowing means for sending the outside air of the chamber to the radiator and the auxiliary radiator, the refrigerant temperature detecting means for detecting the temperature of the refrigerant sucked by the compressor, and the refrigerant temperature detecting means. Control means for controlling the refrigerating capacity of the cooler by increasing or decreasing the amount of air blown by the outside air blowing means according to a change in refrigerant temperature.

  In the refrigerant circuit device according to the present invention, the main circuit includes an internal heat exchanger for exchanging heat between the refrigerant radiated by the auxiliary radiator and the refrigerant evaporated by the cooler, and the refrigerant temperature detection The means detects the temperature of the refrigerant that passes through the internal heat exchanger and is sucked into the compressor.

  In the refrigerant circuit device according to the present invention, the heater is installed in any chamber in which the cooler is installed.

  In the refrigerant circuit device according to the present invention, the refrigerant is carbon dioxide.

  According to the present invention, the control means converts the outside air of the chamber into the radiator and the auxiliary radiator according to the change in the refrigerant temperature detected by the refrigerant temperature detection means that detects the temperature of the refrigerant sucked into the compressor. Since the refrigerating capacity in the cooler is controlled by increasing / decreasing the air volume of the outside air blowing means to be sent out, the refrigerating capacity can be approximated to a desired size. In addition, the control means can directly obtain the temperature of the refrigerant sucked into the compressor, and the liquid phase refrigerant can be prevented from being sucked into the compressor. Therefore, it is possible to avoid the occurrence of the liquid back phenomenon while adjusting the refrigeration capacity to a desired size.

FIG. 1 is an explanatory diagram 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 according to the embodiment of the present invention. FIG. 4 is a schematic diagram schematically showing a characteristic control system of the refrigerant circuit device according to the embodiment of the present invention. FIG. 5 is a flowchart showing the processing contents of the external fan driving control performed by the control unit. FIG. 6 is a flowchart showing the processing contents of the air flow variable control shown in FIG. FIG. 7 is a flowchart showing the processing contents of the air flow rate adjustment control shown in FIG. FIG. 8 is a Mollier diagram (Ph diagram) showing a change in state of the refrigerant in the refrigerant circuit device according to the embodiment of the present invention.

  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 an explanatory diagram 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 is formed as a rectangular housing having an opening 1a (see FIG. 2) on the front surface. The main body cabinet 1 is provided with three independent commodity storage boxes 3 partitioned by two heat insulating partition plates 2 in the left and right sides, for example. These merchandise containers 3 are rooms for storing merchandise such as canned beverages and beverages containing plastic bottles in a state maintained at a desired temperature, and have 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 commodity storage. 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 opening 1 a on the front surface 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 commodity storage 3 is provided with a storage rack 6, a payout mechanism 7 and a shooter 8. The storage rack 6 is used for storing products in a manner of being arranged in the vertical direction. The payout mechanism 7 is provided at the lower part of the storage rack 6 and is used for paying out the products at the bottom of the product group stored in the storage rack 6 one by one. The shooter 8 is for guiding the product delivered from the delivery mechanism 7 to the product outlet 4a provided in the outer door 4 through the product outlet 5c provided in the lower door 5b of the inner door 5. It is.

  FIG. 3 is a conceptual diagram conceptually showing a refrigerant circuit device according to an embodiment of the present invention, and FIG. 4 schematically shows a characteristic control system of the refrigerant circuit device according to an embodiment of the present invention. It is a schematic diagram shown.

  The refrigerant circuit device illustrated here includes a refrigerant circuit 20 in which a refrigerant such as carbon dioxide is enclosed, an outlet temperature sensor S, an external fan F1, and a control unit 50. The refrigerant circuit 20 includes a main circuit 30, an introduction pipe 45, a heater 46, and a return pipe 47.

  The main circuit 30 is configured by connecting a compressor 31, a radiator 32, an auxiliary radiator 33, and a cooler 34 through a refrigerant pipe 35. The refrigerant pipe 35 is formed by appropriately connecting refrigerant pipes.

  The compressor 31 is installed 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 31 is driven in accordance with a command given from the control unit 50. When driven, the compressor 31 sucks the refrigerant through the suction port, compresses the sucked refrigerant, and is in a high-temperature and high-pressure state (high-pressure refrigerant). And discharged from the discharge port.

  The radiator 32 is installed in the machine room 9 similarly to the compressor 31, that is, installed outside the commodity storage 3 that is a chamber. The radiator 32 is configured to cause heat exchange between the refrigerant compressed by the compressor 31 and the ambient air and the ambient air to dissipate the refrigerant. A three-way valve 36 is provided in the refrigerant pipe 35 connecting the radiator 32 and the compressor 31. The three-way valve 36 will be described later.

  The auxiliary radiator 33 is installed in the machine room 9 in a manner adjacent to the radiator 32. The auxiliary radiator 33 has a smaller capacity than the radiator 32, but, like the radiator 32, exchanges heat between the refrigerant passing therethrough and the surrounding air to radiate the refrigerant.

  A plurality of coolers 34 (three in the illustrated example) are provided, and are disposed in the lower internal area of each product storage 3 and on the front side of the rear duct 10. In the vicinity of each cooler 34, an internal fan F2 is disposed. The internal blower fan F2 is driven in accordance with a command given from the control unit 50, and circulates the internal air of the product storage case 3 when driven.

  The refrigerant pipe 35 connecting the cooler 34 and the auxiliary radiator 33 is branched into three by a distributor 37 provided in the middle, and the cooler 34 (hereinafter, right cooling) installed in the right warehouse 3a. The inlet side of the cooler 34 (hereinafter also referred to as the intermediate cooler 34b) installed in the storage 3b and the cooler 34 (hereinafter also referred to as the left cooler 34c) installed in the left storage 3c. Are connected to each.

  In the refrigerant pipe 35, a first capillary tube 38 is provided on the way from the auxiliary radiator 33 to the distributor 37, and from the distributor 37 to the left cooler 34c, the intermediate cooler 34b, and the right cooler 34a. In the middle of the process, electromagnetic valves 39a, 39b, 39c and second capillary tubes 40a, 40b, 40c are provided.

  The first capillary tube 38 is for adiabatic expansion by reducing the pressure of the refrigerant passing therethrough. The electromagnetic valves 39a, 39b, and 39c are valves that open and close in response to a command given from the control unit 50. When the solenoid valves 39a, 39b, and 39c are opened, the refrigerant is allowed to pass therethrough. It regulates the passage of Similar to the first capillary tube 38, the second capillary tubes 40a, 40b, and 40c are for adiabatic expansion by depressurizing the refrigerant that passes therethrough. The first capillary tube 38 and the second capillary tubes 40 a, 40 b, 40 c constitute an expansion mechanism that adiabatically expands the refrigerant radiated by the auxiliary radiator 33.

  The refrigerant pipe 35 connected to the outlet side of the cooler 34 joins at the first joining point P <b> 1 and is connected to the compressor 31.

  In such a main circuit 30, reference numeral 41 in FIG. 3 is an internal heat exchanger. The internal heat exchanger 41 passes a refrigerant (high-pressure refrigerant) passing from the auxiliary radiator 33 toward the first capillary tube 38 and a refrigerant (low-pressure refrigerant) passing from the first junction P1 toward the compressor 31. Heat exchange.

  One end of the introduction pipe 45 is connected to the three-way valve 36. That is, the introduction pipe 45 is provided in a manner that branches from the refrigerant pipe 35 on the outlet side of the compressor 31. The introduction pipe 45 is formed by appropriately connecting refrigerant pipes similarly to the refrigerant pipe 35.

  The three-way valve 36 is between a first sending state in which the refrigerant compressed by the compressor 31 is sent to the radiator 32 and a second sending state in which the refrigerant compressed by the compressor 31 is sent to the introduction conduit 45. The valve can be switched alternatively. The switching operation of the three-way valve 36 is performed according to a command given from the control unit 50.

  The heater 46 is connected to the introduction pipe line 45 and is installed in the left warehouse 3c. When the refrigerant compressed by the compressor 31 is supplied through the introduction pipe line 45, the heater 46 radiates the refrigerant and heats the internal air of the left chamber 3c. The heater 46 may be installed integrally with the left cooler 34c, or may be installed separately from the left cooler 34c.

  The return pipe 47 has one end connected to the outlet side of the heater 46 and the other end joined to the refrigerant pipe 35 connecting the radiator 32 and the auxiliary radiator 33 at the second junction P2. Connected with. That is, the return line 47 sends out the refrigerant radiated by the heater 46 to the main circuit 30. The introduction pipe 45 is formed by appropriately connecting refrigerant pipes similarly to the refrigerant pipe 35 and the introduction pipe 45.

  The outlet temperature sensor S is provided in the vicinity of the low-pressure refrigerant outlet of the internal heat exchanger 41 in the main circuit 30 (refrigerant circuit 20). The outlet temperature sensor S is a refrigerant temperature detection unit that detects the temperature of the refrigerant (low-pressure refrigerant) that has passed through the internal heat exchanger 41, that is, the temperature of the refrigerant sucked into the compressor 31. The outlet temperature sensor S sends the detected refrigerant temperature (hereinafter also referred to as outlet temperature) to the control unit 50 as an outlet temperature signal.

  The outside blower fan F <b> 1 is installed near the radiator 32 in the machine room 9. This outside blower fan F <b> 1 is driven in accordance with a command given from the control unit 50, and when driven, sends outside air that is outside air of the product storage case 3 to the radiator 32 and the auxiliary radiator 33. The outside air blowing means.

  The control unit 50 comprehensively controls the operation of each unit in accordance with programs and data stored in the memory 59. The control unit 50 includes an input processing unit 51, a determination processing unit 52, a comparison processing unit 53, a setting processing unit 54, and a drive processing unit 55. For example, the control unit 50 may cause a processing device such as a CPU (Central Processing Unit) to execute a program, that is, may be realized by software, or may be realized by hardware such as an IC (Integrated Circuit). Alternatively, software and hardware may be used in combination.

  The input processing unit 51 receives an outlet temperature signal given from the outlet temperature sensor S and a command signal from the vending machine control unit 100 and inputs the outlet temperature and the command. Here, the vending machine control unit 100 controls the overall operation of the vending machine to which the refrigerant circuit device is applied. The input processing unit 51 appropriately stores the outlet temperature input from the outlet temperature sensor S in the memory 59.

  The determination processing unit 52 determines whether or not the outlet temperature input through the input processing unit 51 is within a predetermined air flow rate variable temperature range T (T1 <T <T2). The determination processing unit 52 determines whether or not the outlet temperature input through the input processing unit 51 is within a preset target temperature range U (T3 ≦ U ≦ T4). Here, the lower limit temperature T3 of the target temperature range U is higher than the temperature T1 that defines the air flow rate variable temperature range T, and the upper limit temperature T4 of the target temperature range U is lower than the temperature T2 that defines the air flow rate variable temperature range T.

  The comparison processing unit 53 compares the outlet temperature input through the input processing unit 51 with the previous outlet temperature stored in the memory 59 in the air flow rate variable control described later.

  The setting processing unit 54 sets the ratio (duty ratio) of the blowing amount of the outside blowing fan F1 according to a predetermined table.

  The drive processing unit 55 sends out a drive command or a drive stop command to the external blower fan F1 to drive or stop the external blower fan F1.

  The refrigerant circuit device having the above-described configuration cools and heats the product stored in the product storage 3 as follows. Here, the case where the HCC operation (heat pump operation for heating the internal air of the left warehouse 3c and cooling the internal air of the right warehouse 3a and the central warehouse 3b) is described.

  In this case, the control unit 50 brings the three-way valve 36 into the second delivery state, closes the electromagnetic valve 39c, and further opens the electromagnetic valves 39a and 39b. As a result, the refrigerant compressed by the compressor 31 flows into the introduction pipe 45 via the three-way valve 36 in the second delivery state, and passes through the introduction pipe 45 to reach the heater 46. While passing through the heater 46, the refrigerant that has reached the heater 46 exchanges heat with the internal air of the left warehouse 3c to dissipate heat. Thereby, the internal air of the left warehouse 3c is heated. The heated internal air circulates in the left warehouse 3c by driving the internal blower fan F2, whereby the product stored in the left warehouse 3c is heated by the circulating internal air.

  The refrigerant radiated by the heater 46 flows through the return pipe 47 and reaches the auxiliary radiator 33 through the second junction P2. The refrigerant reaching the auxiliary radiator 33 exchanges heat with ambient air to further dissipate heat, and then passes through the internal heat exchanger 41. The refrigerant that has passed through the internal heat exchanger 41 in this way is decompressed by the first capillary tube 38 and adiabatically expanded, and is branched into two by the distributor 37. The refrigerant branched into two is depressurized by the second capillary tubes 40a and 40b and adiabatically expanded, and then reaches the right cooler 34a and the middle cooler 34b. The right cooler 34a and the middle cooler 34b evaporate, respectively. Then, heat is taken from the internal air of each commodity storage 3, and the internal air is cooled. The cooled internal air is circulated through the interior of each product storage 3 by driving each internal blower fan F2, 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 cooler 34a and the middle cooler 34b merges at the first merge point P1, passes through the internal heat exchanger 41, is sucked into the compressor 31, is compressed by the compressor 31, and is circulated as described above. repeat.

  In such a refrigerant circuit device, when the control unit 50 inputs a control command given from the vending machine control unit 100 through the input processing unit 51, the outside blower fan drive control is performed in parallel with the HCC operation. .

  FIG. 5 is a flowchart showing the processing contents of the external fan driving control performed by the control unit.

  In this external blower fan drive control, the control unit 50 sets the air flow rate to 100% through the setting processing unit 54 (step S110). Thus, the control part 50 which set the ventilation volume to 100% sends a drive command to the external ventilation fan F1 so that it may become the air volume of this ratio (100%) through the drive process part 55 (step S140), and is built-in. It waits for a predetermined time (for example, 10 seconds) through the clock (step S170). That is, in the execution of the outside fan driving control, the control unit 50 drives the outside fan B1 at 100% airflow until a predetermined time elapses.

  When the predetermined time has elapsed (step S170: Yes), the control unit 50 repeatedly performs the air flow rate variable control every predetermined time (for example, 15 to 20 seconds) (step S200).

  FIG. 6 is a flowchart showing the processing contents of the air flow variable control shown in FIG. In this air flow rate variable control, the control unit 50 waits for input of the outlet temperature from the outlet temperature sensor S through the input processing unit 51 (step S201). When the outlet temperature is input from the outlet temperature sensor S through the input processing unit 51 (step S201: Yes), the control unit 50 determines whether or not the outlet temperature is in the ventilation amount variable temperature range T through the determination processing unit 52. Determination is made (step S202, step S203).

  When the outlet temperature is equal to or lower than the maximum temperature T1 that is lower than the air flow rate variable temperature range T (step S202: Yes), that is, when the outlet temperature is lower than the air flow rate variable temperature range T, the control unit 50 sends it through the setting processing unit 54. The air volume is set to 0% (step S204), a drive stop command is sent to the external fan F1 through the drive processing unit 55 (step S205), and then the procedure is returned to end the current air volume variable control. To do.

  According to this, the heat radiation amount of the refrigerant in the auxiliary radiator 33 can be reduced, and the refrigerant capacity in the cooler 34 (the right cooler 34a and the middle cooler 34b) can be decreased. This will be described in more detail. When the outlet temperature is equal to or lower than T1, the temperature of the refrigerant sucked into the compressor 31 is very low, and the refrigerating capacity in the cooler 34 becomes excessive. As described above, if the refrigerating capacity is excessive, there is a possibility of generating a liquid back phenomenon in which the refrigerant that has passed through the cooler 34 is sucked into the compressor 31 in a liquid phase state. Therefore, by stopping driving of the external fan F1, the refrigeration capacity in the cooler 34 can be reduced while reducing the amount of refrigerant radiated in the auxiliary radiator 33, and the occurrence of the liquid back phenomenon can be avoided. it can.

  When the outlet temperature is equal to or higher than the minimum temperature T2 that exceeds the ventilation volume variable temperature range T (step S202: No, step S203: Yes), that is, when the outlet temperature exceeds the ventilation volume variable temperature range T, the control unit 50 sets The air flow rate is set to 100% through the processing unit 54 (step S206), and a drive command is sent to the external fan B1 through the drive processing unit 55 so that the air flow rate is 100% (step S207). Thereafter, the procedure is returned to end the current air flow rate variable control.

  According to this, the heat radiation amount of the refrigerant in the auxiliary radiator 33 can be increased and the refrigeration capacity in the cooler 34 can be increased. This will be described in more detail. When the outlet temperature is equal to or higher than T2, the temperature of the refrigerant sucked into the compressor 31 is very high, and not only the refrigerating capacity in the cooler 34 is insufficient. In the refrigerant circuit 20, there is a possibility that the refrigerant pressure in an area where the refrigerant becomes high pressure (high pressure area) becomes excessive. Thus, when the refrigerant pressure in the high pressure region in the refrigerant circuit 20 becomes excessive, the compressor 31 and the like are stopped as a high pressure abnormality, and as a result, the HCC operation cannot be performed. Therefore, by driving the external fan F1 so that the air flow rate becomes 100%, the refrigerant circuit 20 increases the refrigerating capacity in the cooler 34 while increasing the heat radiation amount of the refrigerant in the auxiliary heat radiator 33. The pressure of the refrigerant at a high pressure can be kept within a predetermined range.

  By the way, when the outlet temperature is in the air flow rate variable temperature range T (step S202: No, step S203: No), the control unit 50 determines whether the outlet temperature is in the target temperature range U through the determination processing unit 52. (Step S208, Step S209).

  That is, when the outlet temperature is not less than the lower limit temperature T3 of the target temperature range U and not more than the upper limit temperature T4 (step S208: Yes, step S209: Yes), the control unit 50 controls the air flow rate through the setting processing unit 54. The maintenance setting is made (step S210), and then the procedure is returned to end the current air flow rate variable control.

  As a result, the amount of air blown by the outside blower fan F1 is maintained, and the outlet temperature can be maintained within the target temperature range U.

  On the other hand, when the outlet temperature deviates from the target temperature range U, that is, when the outlet temperature is lower than the lower limit temperature T3 (step S208: No), or when the outlet temperature exceeds the upper limit temperature T4 (step S209: No), The control unit 50 performs the air volume adjustment control (step S220).

  FIG. 7 is a flowchart showing the processing contents of the air flow rate adjustment control shown in FIG. In this air flow rate adjustment control, the control unit 50 reads the previous outlet temperature (hereinafter also referred to as the previous temperature) stored in the memory 59 by the previous air flow rate variable control from the memory 59 through the comparison processing unit 53 (step S221). ), The outlet temperature and the previous temperature are compared (step S222, step S223).

  When the outlet temperature is higher than the previous temperature (step S222: Yes), the control unit 50 sets the air flow rate to increase by a predetermined ratio (for example, about 5%) through the setting processing unit 54 (step S224).

  Then, the control unit 50 sends a drive command to the external fan F1 through the drive processing unit 55 so as to achieve the air flow rate set in step S224 (step S225), and then returns the procedure to this time. By terminating the air flow adjustment control, the current air flow variable control is terminated.

  As a result, the amount of air blown by the outside blower fan F1 is increased by a predetermined ratio, whereby the amount of heat dissipated by the auxiliary radiator 33 is increased, whereby the refrigeration capacity of the cooler 34 can be increased. This will be described in more detail.

  FIG. 8 is a Mollier diagram (Ph diagram) showing a change in state of the refrigerant in the refrigerant circuit device according to the embodiment of the present invention.

  In FIG. 8, A is a refrigerant cycle targeted by the refrigerant circuit device. In such a cycle A, the length a until it intersects with the saturated vapor pressure curve D during the evaporation process in the cooler 34 indicates the refrigerating capacity.

  As described above, when the outlet temperature exceeds the previous temperature in step S222, since the refrigerating capacity is lower than the previous temperature, the refrigerant cycle at the present time is higher than the refrigerating capacity a of the target refrigerant cycle A. Becomes a small B. Then, the current refrigerant cycle B is approximated to the target refrigerant cycle A by increasing the amount of air blown by the outside blower fan F1 by a predetermined ratio and increasing the amount of heat released by the auxiliary radiator 33. Can do.

  When the outlet temperature is lower than the previous temperature (step S222: No, step S223: Yes), the control unit 50 sets the air flow rate to be reduced by a predetermined ratio (for example, about 5%) through the setting processing unit 54. (Step S226). Then, the control unit 50 sends a drive command to the outside blower fan F1 through the drive processing unit 55 so as to achieve the air flow rate set in step S226 (step S227), and then returns the procedure to this time. By terminating the air flow adjustment control, the current air flow variable control is terminated.

  As a result, the amount of air blown by the outside blower fan F1 is reduced by a predetermined ratio, and thereby the amount of heat released by the auxiliary radiator 33 is reduced, so that the refrigerating capacity of the cooler 34 can be reduced. This will be described in more detail.

  As described above, when the outlet temperature is lower than the previous temperature in step S222 and step S223, since the refrigeration capacity is increased from the previous time, the refrigerant cycle at the present time is higher than the refrigeration capacity a of the target refrigerant cycle A. The refrigerating capacity c is C. And the refrigerant | coolant cycle C at the present time is approximated to the target refrigerant | coolant cycle A by reducing the radiating amount of the auxiliary | assistant heat radiator 33 by decreasing the ventilation volume of the ventilation fan F1 outside a store | warehouse | chamber beforehand. Can do.

  When the outlet temperature matches the previous temperature (step S222: No, step S223: No), the control unit 50 maintains and sets the air flow rate through the setting processing unit 54 (step S228), and then returns the procedure to this time. The current air flow rate variable control is terminated by terminating the air flow amount adjustment control.

  As a result, the amount of air blown by the outside blower fan F1 is maintained, so that the amount of heat released by the auxiliary radiator 33 and the refrigeration capacity of the cooler 34 can be maintained. This will be described in more detail.

  As described above, when the outlet temperature matches the previous temperature in step S222 and step S223, the current refrigeration cycle matches the target refrigeration cycle A. Therefore, the current refrigerant cycle can be maintained in a state consistent with the target refrigerant cycle A by maintaining the heat radiation amount in the auxiliary radiator 33 and the refrigeration capacity in the cooler 34.

  When the control unit 50 that repeatedly performs such variable air flow control every predetermined time inputs a control stop command given from the vending machine control unit 100 through the input processing unit 51 (step S230: Yes), the drive processing unit A drive stop command is sent to the outside air blowing fan F1 through 55 (step S260), and then the procedure is returned to end the current outside air blowing fan drive control.

  As described above, according to the refrigerant circuit device according to the embodiment of the present invention, the controller 50 controls the amount of air blown from the outside fan F1 in accordance with the change in the outlet temperature detected through the outlet temperature sensor S. Since the refrigeration capacity in the cooler 34 is controlled by increasing / decreasing, the refrigeration capacity can be approximated to the target refrigeration capacity. And since the control part 50 inputs exit temperature, the temperature of the refrigerant | coolant suck | inhaled by the compressor 31 can be obtained directly, and it can suppress that a liquid phase refrigerant | coolant is attracted | sucked by the compressor 31. FIG. Therefore, the occurrence of the liquid back phenomenon can be avoided while adjusting the refrigeration capacity to a desired size.

  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 embodiment described above, the outlet temperature sensor S is provided in the vicinity of the outlet of the low-pressure refrigerant of the internal heat exchanger 41. However, in the present invention, the refrigerant temperature detecting means detects the temperature of the refrigerant sucked into the compressor. If it can be detected, the arrangement location is not particularly limited.

  In the embodiment described above, the heater 46 is installed in the left warehouse 3c. However, in the present invention, the chamber to be heated does not have to be installed with a cooler.

DESCRIPTION OF SYMBOLS 1 Main body cabinet 3 Commodity storage 20 Refrigerant circuit 30 Main circuit 31 Compressor 32 Radiator 33 Auxiliary radiator 34 Cooler 35 Refrigerant pipe line 38 1st capillary tube 40a, 40b, 40c 2nd capillary tube 41 Internal heat exchanger 45 Introductory line 46 Heater 47 Return line 50 Control unit 51 Input processing unit 52 Judgment processing unit 53 Comparison processing unit 54 Setting processing unit 55 Drive processing unit 59 Memory F1 External fan fan F2 Internal fan fan S Outlet temperature sensor

Claims (4)

A cooler, a compressor that sucks and compresses the refrigerant from the cooler, a radiator that dissipates the refrigerant compressed by the compressor, and an auxiliary radiator that dissipates the refrigerant passing downstream of the radiator And an expansion mechanism for adiabatic expansion of the refrigerant radiated by the auxiliary radiator, and sequentially connecting the refrigerant pipes to evaporate the refrigerant in the cooler to change the air inside the chamber in which the cooler is installed. A main circuit for cooling;
The refrigerant is connected to an introduction pipe provided in a manner branched from the refrigerant pipe on the outlet side of the compressor and is installed in a chamber to be heated, and the refrigerant compressed by the compressor is supplied through the introduction pipe. A heater that radiates the refrigerant and heats the internal air of the chamber,
A refrigerant having a refrigerant circuit provided with a mode for connecting the heater and a refrigerant pipe on the inlet side of the auxiliary radiator, and having a return pipe for sending the refrigerant radiated by the heater to the main circuit In the circuit device,
Outside air blowing means for sending outside air to the radiator and the auxiliary radiator when installed and driven in the vicinity of the radiator,
Refrigerant temperature detecting means for detecting the temperature of the refrigerant sucked into the compressor;
A refrigerant circuit comprising: control means for controlling the refrigerating capacity of the cooler by increasing or decreasing the amount of air blown by the outside air blowing means in accordance with a change in refrigerant temperature detected through the refrigerant temperature detecting means. apparatus. The main circuit includes an internal heat exchanger for exchanging heat between the refrigerant radiated by the auxiliary radiator and the refrigerant evaporated by the cooler,
The refrigerant circuit device according to claim 1, wherein the refrigerant temperature detecting unit detects a temperature of the refrigerant that passes through the internal heat exchanger and is sucked into the compressor.   The refrigerant circuit device according to claim 1, wherein the heater is installed in any chamber in which the cooler is installed.   The refrigerant circuit device according to claim 1, wherein the refrigerant is carbon dioxide.

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