JP2010043758A - Cooling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent abnormal rise of a high pressure-side pressure caused by clogging of capillary tubes in a cooling device using the capillary tubes as an expanding mechanism. <P>SOLUTION: The cooling device in which the plurality of capillary tubes as the expanding mechanism are arranged in parallel with each other, and valve devices for controlling the circulation of a refrigerant to each of the capillary tubes are respectively disposed in passages upstream of the capillary tubes, further includes a temperature detecting means for detecting the temperature of the refrigerant passing through an evaporator, and a control means for selectively opening the plurality of valve devices and switching the valve devices on the basis of a temperature detected by a temperature detecting means. The control means closes the opened valve device, and opens the other valve device, when it is determined that the temperature detected by the temperature detecting means is lower than a set value. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a cooling device, and more particularly, to a cooling device that cools the internal atmosphere of a heat insulating housing in, for example, a vending machine, a refrigerator, a freezer / refrigerator showcase, a beverage dispenser, and the like.

  Conventionally, a cooling device used to cool an internal atmosphere in a vending machine, a refrigerator, a freezer / refrigerated showcase, a beverage dispenser, and the like includes a compressor, a radiator (gas cooler), an expansion mechanism, and an evaporator. ing.

  The compressor compresses the sucked refrigerant into a high temperature and high pressure state. The radiator dissipates the refrigerant compressed by the compressor and liquefies it. The expansion mechanism decompresses and expands the refrigerant radiated by the radiator to form a low-temperature and low-pressure refrigerant, and a capillary tube or an electronic expansion valve is used. The evaporator evaporates the low-temperature and low-pressure refrigerant expanded under reduced pressure by the expansion mechanism. Such a compressor, a radiator, an expansion mechanism, and an evaporator are sequentially connected by piping to form a refrigerant circulation path, and the refrigerant is circulated while changing the phase in the refrigerant circulation path. Thus, the portion where the evaporator is disposed is cooled because heat is taken away by evaporation of the refrigerant (see, for example, Patent Document 1).

JP 2002-130896 A

  By the way, in this kind of cooling device, usually, a part of the refrigerating machine oil that lubricates the friction part of the compressor is discharged from the compressor, flows through the refrigerant circulation path together with the refrigerant, and is returned to the compressor. In the expansion mechanism described above, the temperature of the refrigerant is drastically decreased by rapidly increasing the flow path resistance to expand the refrigerant. For this reason, the viscosity of the refrigerating machine oil increases rapidly in the expansion mechanism, and the refrigerating machine oil may be clogged in the piping of the expansion mechanism.

  When an electronic expansion valve is used as the expansion mechanism, clogging of refrigerating machine oil can be prevented by increasing the opening of the electronic expansion valve. On the other hand, the capillary tube is a fixed throttle, and the refrigerant flow rate cannot be adjusted. For this reason, once the refrigeration oil is clogged in the narrow pipe of the capillary tube, the refrigerant stops flowing, and the refrigerant accumulates on the high-pressure side of the refrigerant circulation path. There is a risk of causing an abnormal stop.

  In view of the above points, an object of the present invention is to prevent an abnormal increase in high-pressure side pressure that occurs when a capillary tube is clogged in a cooling device that uses a capillary tube as an expansion mechanism.

  In order to achieve the above object, a cooling device according to claim 1 of the present invention includes a compressor that compresses a refrigerant, a radiator that radiates the refrigerant compressed by the compressor, and a refrigerant that radiates heat using the radiator. A refrigerant circulation path formed by sequentially connecting a capillary tube for decompressing and expanding the evaporator and an evaporator for evaporating the refrigerant decompressed and expanded in the capillary tube with a pipe, and cooling a portion where the evaporator is disposed In the cooling device, a plurality of the capillary tubes are arranged in parallel, and a valve device for controlling the refrigerant flow to each capillary tube is arranged on the upstream path of each capillary tube, and passes through the evaporator. A temperature detecting means for detecting a temperature of the refrigerant to be selectively opened, and the plurality of valve devices are selectively opened, and the valve device is controlled based on the temperature detected by the temperature detecting means. Control means for performing replacement, and the control means closes the opened valve device when the temperature detected by the temperature detection means is determined to be lower than a set value, and other valves It is characterized by opening the device.

  The cooling device according to claim 2 of the present invention is the cooling device according to claim 1, wherein the control means detects the temperature detected by the temperature detection means after a predetermined time has elapsed since the switching control of the valve device. Is determined to not reach the set value, the drive of the compressor is stopped.

According to a third aspect of the present invention, there is provided a cooling device comprising a compressor for compressing a refrigerant, a radiator for radiating the refrigerant compressed by the compressor, and a capillary for decompressing and expanding the refrigerant radiated by the radiator. In a cooling device having a refrigerant circulation path in which a tube and an evaporator for evaporating the refrigerant decompressed and expanded in the capillary tube are sequentially connected by piping, and cooling a portion where the evaporator is disposed, A plurality of the evaporators are arranged in parallel via a distributor, a plurality of the capillary tubes are arranged in parallel between the radiator and the refrigerant distributor, and upstream of each capillary tube. In the path, a valve device for controlling the refrigerant flow to each capillary tube is disposed, and temperature detecting means for detecting the temperature of the refrigerant passing through each evaporator,
Control means for selectively opening the plurality of valve devices and switching the valve devices based on the temperatures detected by the temperature detection means, wherein the control means is detected by the temperature detection means. When it is determined that at least one of the temperatures is lower than the set value, the opened valve device is closed and the other valve device is opened.

  According to a fourth aspect of the present invention, there is provided the cooling device according to the third aspect, wherein the control unit is detected by the temperature detecting means even after a predetermined time has elapsed after switching the valve device. The drive of the compressor is stopped when it is determined that the temperature does not reach the set value.

  According to a fifth aspect of the present invention, there is provided a cooling device comprising: a compressor that compresses a refrigerant; a radiator that dissipates the refrigerant compressed by the compressor; and a capillary that decompresses and expands the refrigerant dissipated by the radiator. In a cooling device having a refrigerant circulation path in which a tube and an evaporator for evaporating the refrigerant decompressed and expanded in the capillary tube are sequentially connected by piping, and cooling a portion where the evaporator is disposed, A plurality of the evaporators are arranged in parallel via a distributor, a plurality of the capillary tubes are arranged in parallel between the refrigerant distributor and each evaporator, and an upstream side of each capillary tube is arranged. A valve device for controlling the refrigerant flow to each capillary tube is disposed in the path, and a temperature detecting means for detecting the temperature of the refrigerant passing through each evaporator and the plurality of valve devices are selectively opened. Control means for switching the valve device based on the temperature detected by the temperature detection means, wherein the control means is configured such that at least one of the temperatures detected by the temperature detection means is lower than a set value. When it is determined that the value is low, in the valve device connected to the evaporator, the opened valve device is closed and the other valve device is opened.

  The cooling device according to claim 6 of the present invention is the cooling device according to claim 5, wherein the control unit is detected by the temperature detection means even if a predetermined time has elapsed after switching the valve device. The drive of the compressor is stopped when it is determined that the temperature does not reach the set value.

  The cooling device of the present invention includes a plurality of capillary tubes that are expansion mechanisms arranged in parallel, and a valve device that controls the flow of the refrigerant to each capillary tube is disposed in the upstream path of each capillary tube. When the refrigerant temperature of the evaporator detected by the temperature detecting means becomes lower than the threshold value, the opened valve device is closed and the supply of the refrigerant to the capillary tube connected to the valve device is stopped. On the other hand, the other valve device is opened so that the refrigerant flows through the capillary tube connected to the valve device. For this reason, even if the refrigerating machine oil is clogged in the flow path of the capillary tube, the flow of the refrigerant in the refrigerant circulation path is not stopped by switching to another capillary tube. As a result, it is possible to prevent an abnormal increase in the high-pressure side pressure of the refrigerant circulation path and damage to the compressor.

  Hereinafter, preferred embodiments of a cooling device according to the present invention will be described in detail with reference to the accompanying drawings. In the following, for convenience of explanation, the cooling device will be described as being applied to a vending machine.

(Embodiment 1)
1 and 2 schematically show a vending machine to which the cooling device according to Embodiment 1 of the present invention is applied. FIG. 1 is a sectional view seen from the front, and FIG. 2 is a side view. FIG. The vending machine 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 for example, three independent commodity containers 5a partitioned by two heat insulating partition plates 4a and 4b, 5b and 5c are 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 3a and 3b are for opening and closing the front surfaces of the product containers 5a, 5b and 5c. is there. The inner doors 3a and 3b are divided into upper and lower parts, and the upper door opens and closes when a product is replenished. The product containers 5a, 5b, 5c are for storing the product W such as a canned beverage or a beverage containing a plastic bottle while maintaining the desired temperature.

  The product storage 5a, 5b, 5c is provided with a product storage rack 6, a carry-out mechanism 7 and a product carry-out shooter 8, respectively. The product storage rack 6 is for storing the products W in a manner of being arranged along 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 W at the lowest level of the product group stored in the product storage rack 6 one by one. The product carry-out shooter 8 is for guiding the product W carried out from the carry-out mechanism 7 to the product take-out port 3c.

  A cooling device 10 is disposed in the machine room 9 inside the main body cabinet 1 and outside the commodity storage 5a, 5b, 5c.

  FIG. 3 is a conceptual diagram of the cooling device 10 according to the first embodiment. Here, in FIG. 3, in order to make it easy to understand the flow of the refrigerant, the portion in which the refrigerant flows in the HCC mode in which the product storage 5a is heated and the product storage 5b and 5c is cooled is indicated by a solid line. The part which is not shown is shown with a broken line. The cooling device 10 illustrated in FIG. 3 has a refrigerant circulation path L.

  The refrigerant circulation path L is formed by sequentially connecting the compressor 20, the radiator (gas cooler) 30, the (internal heat exchanger 60), the expansion mechanism 40, the evaporators 50 a, 50 b, 50 c, and the internal heat exchanger 60 through the pipe 11. The main path 12 configured in a ring shape is branched from the main path 12 at a branch point p1 in the path from the compressor 20 to the radiator 30 and the heating heat exchanger 70 and the external heat exchanger 80 are connected. The bypass path 13 joins the main path 12 at a junction p2 in the middle of the path from the external heat exchanger 80 to the internal heat exchanger 60. In the main path 12, a solenoid valve 14 is provided on the way from the compressor 20 to the radiator 30. In the bypass path 13, an electromagnetic valve 15 is provided in the vicinity of the branch point p1. The electromagnetic valves 14 and 15 permit passage of the refrigerant in each path in the opened state, and restrict passage of the refrigerant in each path in the closed state. Reference numerals 16 and 17 in FIG. 3 denote check valves. As the refrigerant flowing through the pipe 11 in the cooling device 10, carbon dioxide is used which has non-flammability, safety and non-corrosion properties and has little influence on the ozone layer.

  The compressor 20 compresses the refrigerant (carbon dioxide) from the evaporator 50 into a high temperature and high pressure state. The compressor 20 is a two-stage compressor that performs a compression operation in two steps. More specifically, the compressor 20 includes a first compressor 21 that performs a first (first) compression operation and a second compressor 22 that performs a second (last) compression operation. An intermediate heat exchanger (not shown) is provided between them. The intermediate heat exchanger cools the refrigerant compressed by the first compression operation by the first compressor 21, that is, releases the heat to return the refrigerant to the second compressor 22, and is made of a metal such as stainless steel A fin tube type composed of piping and aluminum fins is used. Thus, by performing the compression operation twice through the intermediate heat exchanger, the refrigerant can be compressed to a desired high temperature and high pressure state with low power consumption. In the present embodiment, the refrigerant is compressed to about 4.9 MPa by the first compression by the first compressor 21, and the refrigerant is compressed to about 9.8 MPa by the second compression by the second compressor 22. To do.

  As the compressor 20, a reciprocating compressor, a rotary compressor, a scroll compressor, or an inverter compressor capable of adjusting the compression capacity thereof can be applied.

  In the compressor 20, refrigeration oil is used as the lubricating oil for the friction part inside the compressor 20. A part of the refrigerating machine oil is discharged from the compressor 20, circulated through the refrigerant circulation path L together with the refrigerant, and returned to the compressor 20.

  The radiator 30 radiates and liquefies the refrigerant that has been brought into a high-temperature and high-pressure state by the compressor 20. In the present embodiment, a fin tube type composed of a metal pipe such as copper and an aluminum fin is used as the radiator 30. A blower fan F1 for air volume adjustment is installed in the vicinity of the radiator 30.

  The expansion mechanism 40 discharges from the heat radiator 30 (or the external heat exchanger 80) and depressurizes the refrigerant that has passed through the internal heat exchanger 60 described later to adjust to a low temperature and low pressure state. The expansion mechanism 40 includes expansion paths 41 and 42 provided in parallel between the internal heat exchanger 60 and the refrigerant distributor 51, and capillary tubes 43 and 44 connected to the expansion paths 41 and 42, The expansion passages 41 and 42 are configured to include capillary solenoid valves (valve devices) 45 and 46 disposed on the upstream side of the capillary tubes 43 and 44. Hereinafter, the expansion path 41 is referred to as a first expansion path 41, the capillary tube 43 is referred to as a first capillary tube 43, the capillary electromagnetic valve 45 is referred to as a first capillary electromagnetic valve, the expansion path 42 is referred to as a second expansion path 42, and a capillary tube 44. The second capillary tube 44 and the capillary solenoid valve 46 are referred to as a second capillary solenoid valve 46.

  The first capillary tube 43 and the second capillary tube 44 are pipes having a diameter smaller than that of the pipe 11 and spirally expand the refrigerant that has passed through an internal heat exchanger 60 described later under reduced pressure. The first capillary tube 43 and the second capillary tube 44 may have the same pipe resistance, or may have different pipe resistances.

  The first capillary solenoid valve 45 controls the refrigerant flow to the first capillary tube 41 by performing an opening / closing operation on the upstream side of the first capillary tube 43. That is, the first capillary solenoid valve 45 allows the refrigerant to pass through the first expansion path 41 in the open state, while restricting the refrigerant from passing through the first expansion path 41 in the closed state. .

  The second capillary solenoid valve 46 controls the refrigerant flow to the second capillary tube 44 by performing an opening / closing operation on the upstream side of the second capillary tube 44. That is, the second capillary solenoid valve 46 permits passage of the refrigerant in the second expansion path 42 in the open state, while restricting passage of the refrigerant in the second expansion path 42 in the closed state. .

  The first capillary solenoid valve 45 and the second capillary solenoid valve 46 described above are controlled by the control unit 90 described later so that one of them is opened and the other is closed.

  The evaporators 50a, 50b, and 50c are for evaporating the refrigerant adiabatically expanded to a low temperature and low pressure state by the expansion mechanism 40. As the refrigerant evaporates, the surrounding areas of the evaporators 50a, 50b, and 50c are cooled by removing heat. As shown in FIG. 3, each of the evaporators 50a, 50b, and 50c is connected to each path branched in three directions from the path on the outlet side of the expansion mechanism 40 via the refrigerant distributor 51, and is stored in the commodity storage box. In order to cool 5a, 5b, and 5c independently of each other, they are disposed inside the commodity storages 5a, 5b, and 5c, respectively. In the present embodiment, as the evaporators 50a, 50b, and 50c, fin tube types composed of copper tubes and aluminum fins are used.

  In individual paths to which the evaporators 50a, 50b, and 50c are connected, the solenoid valves 52a, 52b, and 52c for evaporators are provided at the upstream side of the evaporators 50a, 50b, and 50c. Then, by selectively opening the evaporator solenoid valves 52a, 52b, and 52c, the refrigerant from the expansion mechanism 40 is sent to the corresponding evaporators 50a, 50b, and 50c. On the other hand, the outlet side paths of the respective evaporators 50 a, 50 b, 50 c merge and are connected to the first compressor 21 of the compressor 20 via the internal heat exchanger 60.

  Further, in each path branched in three directions via the refrigerant distributor 51, between the evaporator solenoid valves 52a, 52b, 52c and the evaporators 50a, 50b, 50c, that is, the inlets of the evaporators 50a, 50b, 50c. Evaporation temperature sensors (temperature detection means) 53a, 53b, and 53c are provided on the side paths, respectively. The evaporation temperature sensor 53a detects the temperature of the refrigerant passing through the evaporator 50a, the evaporation temperature sensor 53b detects the temperature of the refrigerant passing through the evaporator 50b, and the evaporation temperature sensor 53c The temperature of the refrigerant passing through the evaporator 50c is detected. Hereinafter, the temperatures detected by the evaporation temperature sensors 53a, 53b, and 53c are referred to as the refrigerant evaporation temperature. The evaporation temperature sensors 53a, 53b, 53c give the detected temperature to the control unit 90 (see FIG. 4) as a detection signal. The controller 90 performs capillary solenoid valve switching control, which will be described later, based on the evaporation temperature received from the evaporation temperature sensors 53a, 53b, and 53c.

  The internal heat exchanger 60 exchanges heat between the high-pressure refrigerant from the radiator 30 and the low-pressure refrigerant from the evaporators 50a, 50b, and 50c. More specifically, the internal heat exchanger 60 is for exchanging heat between the high pressure side and the low pressure side of the refrigerant circuit L. The high pressure side of the refrigerant circulation path L is the main path 12 from the outlet side of the compressor 20 through the radiator 30 to the inlet side of the expansion mechanism 40 and the entire section of the bypass passage 13. Further, the low pressure side of the refrigerant circulation path L is from the outlet side of the expansion mechanism 40 to the inlet side of the compressor 20 through the evaporator 50 in the main path 12. Inside such an internal heat exchanger 60, a refrigerant pipe 61 through which the refrigerant sent from the radiator 30 or the external heat exchanger 80 flows, and a refrigerant pipe 62 through which the refrigerant evaporated by the evaporator 50 flows. Are arranged in such a manner that they have a distance allowing heat exchange with each other and are in a non-contact countercurrent manner.

  The heating heat exchanger 70 exchanges heat between the passing refrigerant and the ambient air, and is disposed inside the commodity storage 5a as shown in FIGS. The heating heat exchanger 70 serves as a radiator that dissipates the refrigerant compressed to a high temperature and high pressure by the compressor 20 and heats the internal atmosphere of the commodity storage 5a. As the heating heat exchanger 70, a fin tube type composed of a pipe made of metal such as copper and an aluminum fin can be used.

  The external heat exchanger 80 exchanges heat between the refrigerant passing therethrough and the ambient air, and is disposed in the machine room 9 that is outside the commodity storage 5a, 5b, 5c. This external heat exchanger 80 serves as a heat radiator that further dissipates the refrigerant that has been radiated and delivered by the heating heat exchanger 70 described above. The refrigerant radiated and cooled by the external heat exchanger 80 is sent to the internal heat exchanger 60. As this external heat exchanger 80, the fin tube type thing comprised with metal piping, such as copper, and an aluminum fin can be used.

  As shown in FIG. 2, a heater H, an internal fan F2, a circulation duct D, and the like are provided in the vicinity of the evaporators 50a, 50b, and 50c in each of the commodity storages 5a, 5b, and 5c. The heater H is for heating the air (internal atmosphere) of the product storage 5a, 5b, 5c, that is, for heating the product W stored in the product storage rack 6. Note that, as described above, since the internal atmosphere is heated by the heat released from the heating heat exchanger 70 in the commodity storage 5a, the heater H installed in the commodity storage 5a is used as an auxiliary. The internal fan F2 cools the evaporator 50 by blowing air (cold air) cooled by the evaporator 50 or air heated by the heating heat exchanger 70 or the heater H (warm air). Alternatively, high heat from the heating heat exchanger 70 or the heater H is transferred to the product W. The air blown by the internal blower fan F2 is circulated through the circulation duct D.

  Hereinafter, the flow of the refrigerant when the internal atmosphere of the product storage 5a is heated and the internal atmosphere of the product storage 5b, 5c is cooled (HCC mode) will be described with reference to FIG. In the HCC mode, the electromagnetic valve 15 is opened to allow the refrigerant to flow through the bypass path 13, and the evaporator electromagnetic valves 52b, 52c are opened to allow the refrigerant to flow through the evaporators 50b, 50c. On the other hand, the solenoid valve 14 and the evaporator solenoid valve 52a are closed. In the expansion mechanism 40, the first capillary solenoid valve 45 is opened, and the second capillary solenoid valve 46 is closed.

  The high-temperature and high-pressure refrigerant compressed by the compressor 20 flows through the bypass path 13 and reaches the heat exchanger 70 for heating. The refrigerant passing through the heating heat exchanger 70 is cooled by releasing heat by exchanging heat with the surrounding air. As a result, the internal atmosphere of the commodity storage 5a is heated by the heat released from the heat exchanger 70 for heating. The refrigerant delivered from the heating heat exchanger 70 reaches the external heat exchanger 80 and is further cooled by dissipating heat by exchanging heat with the surrounding air, and the refrigerant pipe 61 of the internal heat exchanger 60 is passed through. It passes through and reaches the first capillary tube 43 of the expansion mechanism 40. The refrigerant passing through the piping of the first capillary tube 43 is decompressed and expanded to become a low-temperature and low-pressure refrigerant, and is distributed in two directions by the refrigerant distributor 51 to reach the evaporators 50b and 50c. In the evaporators 50b and 50c, the refrigerant evaporates by exchanging heat with the surrounding air. As a result, the internal atmosphere of the product containers 5b and 5c is cooled by taking heat away. The refrigerant that has passed through the evaporators 50b and 50c merges at the outlet side path of the evaporators 50b and 50c, passes through the refrigerant pipe 62 of the internal heat exchanger 60, and returns to the first compressor 21.

  Next, the flow of the refrigerant when cooling the internal atmosphere of all the product containers 5a, 5b, 5c (CCC mode) will be described. In the CCC mode, the solenoid valve 14, the first capillary solenoid valve 45, and the evaporator solenoid valves 52a, 52b, and 52c are opened to circulate the refrigerant in the main path 12, while the solenoid valve 15 is closed and bypassed. The distribution of the refrigerant to the path 13 is restricted.

  The high-temperature and high-pressure refrigerant compressed by the compressor 20 flows through the main path 12 and reaches the radiator 30. The refrigerant passing through the radiator 30 dissipates heat by exchanging heat with ambient air, and reaches the first capillary tube 43 of the expansion mechanism 40 through the internal heat exchanger 60. The refrigerant passing through the first capillary tube 43 is expanded under reduced pressure to become a low-temperature and low-pressure refrigerant, and is distributed in three directions by the refrigerant distributor 51 to reach the evaporators 50a, 50b, and 50c. In the evaporators 50a, 50b, and 50c, the refrigerant evaporates by exchanging heat with the ambient air. As a result, the internal atmosphere of the product containers 5a, 5b, 5c is cooled by taking heat away. The refrigerant that has passed through the evaporators 50 a, 50 b, 50 c merges at the outlet side path of the evaporators 50 a, 50 b, 50 c, passes through the internal heat exchanger 60, and returns to the first compressor 21.

  In the cooling device 10 configured as described above, in order to prevent the refrigerating machine oil flowing in the pipe 11 together with the refrigerant from clogging in the pipe of the first capillary tube 43 or the second capillary tube 44, the first and second Switching control of the solenoid valves 45 and 46 for capillaries is performed. Normally, when the refrigeration oil begins to clog in the capillary tube, the temperature of the refrigerant passing through the evaporator decreases. Therefore, in the present embodiment, when the temperature of the refrigerant passing through the evaporator 50 becomes lower than the set value, the opened first capillary solenoid valve 45 is closed to the first capillary tube 43. While the supply of the refrigerant is stopped, the second capillary electromagnetic valve 46 is opened to control the flow of the refrigerant to the second capillary tube 44.

  As shown in FIG. 4, the control unit 90 (control means) that performs switching control of the first and second capillary solenoid valves 45 and 46 includes a setting storage unit 91, a comparison unit 92, and a solenoid valve switching processing unit 93. And a compressor drive processing unit 94.

  The setting storage unit 91 stores a set value of the evaporation temperature of the refrigerant and stores a program and the like necessary for selectively opening the first and second capillary solenoid valves 45 and 46. Here, the set value of the evaporation temperature of the refrigerant is about −15 ° C.

  The comparison unit 92 compares the evaporation temperature detected by each of the evaporation temperature sensors 53a, 53b, and 53c with the set value stored in the setting storage unit 91, and determines whether or not the detected evaporation temperature is lower than the set value. Is determined.

  The solenoid valve switching processing unit 93 performs switching processing between the first capillary solenoid valve 45 and the second capillary solenoid valve 46 based on the determination result of the comparison unit 92. That is, the electromagnetic valve switching processing unit 93 opens the capillary when the comparison unit 92 determines that all the evaporation temperatures detected by the evaporation temperature sensors 53a, 53b, and 53c are equal to or higher than a set value. The electromagnetic valve for solenoid (for example, the first capillary electromagnetic valve 45) is maintained in an open state, and the other capillary electromagnetic valve (for example, the second capillary electromagnetic valve 46) is maintained in a closed state. On the other hand, the electromagnetic valve switching processing unit 93 is opened when the comparison unit 92 determines that at least one of the evaporation temperatures detected by the evaporation temperature sensors 53a, 53b, and 53c is equal to or lower than a set value. The capillary solenoid valve (for example, the first capillary solenoid valve 45) is closed, and the other capillary solenoid valve (for example, the second capillary solenoid valve 46) is opened.

  The compressor drive processing unit 94 is determined by the comparison unit 92 that the evaporating temperature detected again does not reach the set value after a predetermined time has elapsed after the electromagnetic valve switching processing is performed by the electromagnetic valve switching processing unit 93. In this case, the driving of the compressor 20 is stopped.

  FIG. 5 is a schematic flowchart showing the contents of processing executed by the control unit 90 shown in FIG. Hereinafter, the control performed by the control unit 90 will be described with reference to FIGS. 5 and 3. In the following example, since the merchandise container 5a is heated and the merchandise containers 5b and 5c are cooled in the HCC mode, the electromagnetic valve 52a for the evaporator is closed. In the initial state, the first capillary solenoid valve 45 is opened and the second capillary solenoid valve 46 is closed.

  Each of the evaporating temperature sensors 53b and 53c detects the evaporating temperature of the refrigerant at regular intervals or every predetermined time, and transmits the detected evaporating temperature to the control unit 90 as a detection signal. The control unit 90 compares the detected evaporation temperature with the set value stored in the setting storage unit 91 through the comparison unit 92. When the evaporating temperatures detected by the evaporating temperature sensors 53b and 53c are both equal to or higher than the set value (step S1: No), the control unit 90 indicates that the first capillary tube 43 is operating normally. It is determined that the piping of the first capillary tube 43 is not clogged, and the first capillary electromagnetic valve 45 is maintained in the open state, and the second capillary electromagnetic valve 46 is maintained in the closed state.

  On the other hand, when any one of the evaporation temperatures detected by each of the evaporation temperature sensors 53b and 53c falls below the set value, for example, when the evaporation temperature detected by the evaporation temperature sensor 53b falls below the set value ( In step S1: Yes), the control unit 90 determines that the first capillary tube 43 is abnormal, that is, the piping of the first capillary tube 43 is clogged, and passes through the solenoid valve switching processing unit 93 for the first capillary. While the solenoid valve 45 is closed, the second capillary solenoid valve 46 is opened (step S2). As a result, the supply of the refrigerant to the first expansion path 41 and the first capillary tube 43 is stopped, and the refrigerant flows to the second expansion path 42 and the second capillary tube 44. Therefore, the high-pressure side of the refrigerant circulation path L It is possible to prevent an abnormal increase in pressure.

  After a predetermined time has elapsed after performing the above-described capillary solenoid valve switching processing, the control unit 90 receives the evaporating temperature of the refrigerant detected by the evaporating temperature sensor 53b, and compares it again with the set value through the comparing unit 92. To do. At this time, when the detected evaporation temperature reaches the set value (step S3: Yes), the control unit 90 operates the second capillary tube 44 switched from the first capillary tube 43 normally. It returns to step S1 and the subsequent processing is repeated.

  That is, when the evaporation temperatures detected by the evaporation temperature sensors 53b and 53c are both equal to or higher than the set value (step S1: No), the controller 90 operates the second capillary tube 44 normally. That is, it is determined that the piping of the second capillary tube 44 is not clogged, and the second capillary electromagnetic valve 46 is maintained in the open state, and the first capillary electromagnetic valve 45 is maintained in the closed state. On the other hand, when any one of the evaporating temperatures detected by the evaporating temperature sensors 53b and 53c falls below the set value (step S1: Yes), the control unit 90 indicates that the second capillary tube 44 is abnormal. That is, it is determined that the piping of the second capillary tube 44 has started to be clogged, and the second capillary electromagnetic valve 46 is closed through the electromagnetic valve switching processing unit 93 while the first capillary electromagnetic valve 45 is opened again. (Step S2). While the refrigerant is flowing through the second capillary tube 44, the temperature in the vicinity of the piping of the first capillary tube 43 that stopped the refrigerant flow rises to about room temperature. For this reason, the viscosity of the refrigerating machine oil staying in the piping of the first capillary tube 43 is reduced. Therefore, when the first capillary solenoid valve 45 is opened again and the refrigerant flows through the first capillary tube 43, the refrigerant flow is not hindered by the refrigerating machine oil.

  On the other hand, in step S3, the evaporation temperature detected by the evaporation temperature sensor 53b is compared again with the set value, and when this does not reach the set value (step S3: No), the control unit 90 performs the second capillary. It is determined that the tube 44 is abnormal, and the compressor 20 is stopped through the compressor drive processing unit 94 (step S4). By stopping the driving of the compressor 20 and stopping the circulation of the refrigerant in the refrigerant circulation path L, it is possible to prevent the compressor 20 from being damaged.

  In the above example, the case of the HCC mode in which the product container 5a is heated and the product containers 5b and 5c are cooled has been described. However, in the case of the CCC mode in which all the product containers 5a, 5b and 5c are cooled. Opens the evaporator electromagnetic valve 52a, and detects the evaporation temperature by the evaporation temperature sensors 53a, 53b, 53c.

  As described above, the cooling device according to the first embodiment has a plurality of capillary tubes, which are expansion mechanisms, arranged in parallel, and a capillary solenoid valve is arranged in the upstream path of each capillary tube. When the refrigerant temperature of the evaporator detected by the evaporation temperature sensor becomes lower than the set value, the opened capillary solenoid valve is closed and the refrigerant is supplied to the capillary tube connected thereto. On the other hand, the other solenoid valve for capillary is opened and the refrigerant is made to flow to the capillary tube connected thereto. For this reason, even if the refrigerating machine oil is clogged in the flow path of the capillary tube, the flow of the refrigerant in the refrigerant circulation path does not stop by switching to the other capillary tube. As a result, it is possible to prevent an abnormal increase in the high-pressure side pressure in the refrigerant circulation path.

  In addition, after a predetermined time has passed since the above-described capillary solenoid valve switching control, the temperature detected by the evaporation temperature sensor is compared again with the set value, and if this does not reach the set value, the compressor By configuring so as to stop the drive, it is possible to reliably prevent the compressor from being damaged.

(Embodiment 2)
Next, the cooling device in Embodiment 2 of this invention is demonstrated. In addition, the same code | symbol is attached | subjected about the same part as the cooling device 10 in Embodiment 1 mentioned above, and description is abbreviate | omitted. FIG. 6 is a conceptual diagram of cooling device 100 in the second embodiment. Here, in FIG. 6, in order to make it easy to understand the flow of the refrigerant, the portion in which the refrigerant flows in the HCC mode in which the product storage 5a is heated and the product storage 5b and 5c is cooled is indicated by a solid line. The part which is not shown is shown with a broken line.

  In the first embodiment described above, the expansion mechanism 40 is disposed between the internal heat exchanger 60 and the refrigerant distributor 51. However, in the present embodiment, the three directions are provided via the refrigerant distributor 51. The difference is that the expansion mechanisms 40a, 40b, and 40c are disposed in the branched paths.

  That is, the expansion mechanism 40a includes expansion paths 41a and 42a provided in parallel between the refrigerant distributor 51 and the evaporator 50a, capillary tubes 43a and 44a connected to the expansion paths 41a and 42a, In the expansion paths 41a and 42a, capillary solenoid valves 45a and 46a arranged on the upstream side of the capillary tubes 43a and 44a are provided. Similarly, the expansion mechanism 40b includes expansion paths 41b and 42b provided in parallel between the refrigerant distributor 51 and the evaporator 50b, and capillary tubes 43b and 44b connected to the expansion paths 41b and 42b. The expansion passages 41b and 42b include capillary solenoid valves 45b and 46b arranged on the upstream side of the capillary tubes 43b and 44b. Similarly, the expansion mechanism 40c includes expansion paths 41c and 42c provided in parallel between the refrigerant distributor 51 and the evaporator 50c, and capillary tubes 43c and 44c connected to the expansion paths 41c and 42c. The expansion passages 41c and 42c include capillary solenoid valves 45c and 46c disposed on the upstream side of the capillary tubes 43c and 44c. The capillary solenoid valves 45a to 46c in the second embodiment also serve as the evaporator solenoid valves described in the first embodiment.

  The control unit 90 determines that at least one of the temperatures detected by the evaporation temperature sensors 53a, 53b, and 53c that detect the refrigerant temperature (evaporation temperature) passing through each of the evaporators 50a, 50b, and 50c is lower than the set value. In this case, the capillary solenoid valve connected to the evaporator is controlled so that the opened capillary solenoid valve is closed and the other capillary solenoid valve is opened.

  Hereinafter, the control performed by the control unit 90 in the cooling device 100 of the second embodiment will be described with reference to FIGS. 5 and 6. In the following example, the product container 5a is heated and the product containers 5b and 5c are cooled in the HCC mode. Therefore, the first capillary solenoid valve 45a and the second capillary solenoid valve of the expansion mechanism 40a are used. 46a is closed. In the initial state, the first capillary solenoid valves 45b and 45c are opened, and the second capillary solenoid valves 46b and 46c are closed.

  Each of the evaporating temperature sensors 53b and 53c detects the evaporating temperature of the refrigerant at regular intervals or every predetermined time, and transmits the detected evaporating temperature to the control unit 90 as a detection signal. The control unit 90 compares the detected evaporation temperature with the set value stored in the setting storage unit 91 through the comparison unit 93. When the evaporating temperatures detected by the evaporating temperature sensors 53b and 53c are both equal to or higher than the set value (step S1: No), the controller 90 indicates that the first capillary tubes 43b and 43c are operating normally. The first capillary tubes 43b and 43c are determined not to be clogged, and the first capillary solenoid valves 45b and 45c are maintained in the open state, and the second capillary solenoid valves 46b and 46c are maintained in the closed state. To do.

  On the other hand, of the evaporation temperatures detected by the evaporation temperature sensors 53b and 53c, for example, when the temperature detected by the evaporation temperature sensor 53b is lower than the set value (step S1: Yes), the control unit 90 It is determined that the first capillary tube 43b is abnormal, that is, the piping of the first capillary tube 43b is clogged, and the first capillary electromagnetic valve 45b is closed through the electromagnetic valve switching processing unit 93, while the second capillary The electromagnetic valve 46b for operation is opened (step S2). As a result, the supply of the refrigerant to the first expansion path 41b and the first capillary tube 43b is stopped, and the refrigerant flows to the second expansion path 42b and the second capillary tube 44b. It is possible to prevent an abnormal increase in pressure. Note that the initial state is maintained for the expansion mechanism 40c having no abnormality.

  After a predetermined time has elapsed since the capillary solenoid valve switching process described above, the control unit 90 receives the evaporating temperature of the refrigerant detected by the evaporating temperature sensor 53b and compares it again with the set value. When the evaporation temperature detected by the evaporation temperature sensor 53b has reached the set value (step S3: Yes), the control unit 90 operates the second capillary tube 44b switched from the first capillary tube 43b normally. That is, it is determined that the piping of the second capillary tube 44b is not clogged, the process returns to step S1, and the subsequent processing is repeated.

  That is, when the evaporation temperatures detected by the evaporation temperature sensors 53b and 53c are both equal to or higher than the set value (step S1: No), the control unit 90 indicates that the second capillary tube 44b and the first capillary tube 43c are normal. It is determined that the piping of the second capillary tube 44b and the first capillary tube 43c is not clogged, and the second capillary solenoid valve 46b and the first capillary solenoid valve 45c are maintained in the open state. The first capillary solenoid valve 45b and the second capillary solenoid valve 46c are kept closed. On the other hand, of the evaporation temperatures detected by the evaporation temperature sensors 53b and 53c, for example, when the temperature detected by the evaporation temperature sensor 53b is lower than the set value (step S1: Yes), the control unit 90 It is determined that the second capillary tube 44b is abnormal, that is, the piping of the second capillary tube 44b is clogged, and the second capillary electromagnetic valve 46b is closed through the electromagnetic valve switching processing unit 93, while the first capillary tube The electromagnetic valve 45b is opened (step S2). In the second embodiment, since the capillary tube is installed in the commodity storage, the temperature in the vicinity of the piping of the first capillary tube 43b where the refrigerant flow has stopped has risen only to about 5 ° C. The viscosity of the refrigerating machine oil staying in the piping of the first capillary tube 43b becomes sufficiently small. Therefore, even if the first capillary solenoid valve 45b is opened again and the refrigerant flows through the first capillary tube 43b, the refrigerant flow is not hindered by the refrigerating machine oil.

  On the other hand, in step S3, the evaporation temperature detected by the evaporation temperature sensor 53b is compared again with the set value, and when this does not reach the set value (step S3: No), the control unit 90 performs the second capillary. It is determined that the tube 44b is abnormal, and the compressor 20 is stopped through the compressor drive processing unit 94 (step S4). By stopping the driving of the compressor 20 and stopping the circulation of the refrigerant in the refrigerant circulation path L, it is possible to prevent the compressor 20 from being damaged.

  As described above, the cooling device according to the second embodiment has a plurality of capillary tubes arranged in parallel between evaporators provided in a plurality of paths branched from the refrigerant distributor. Capillary solenoid valves that control the flow of refrigerant to each capillary tube are arranged on the upstream path of the capillary tube, and at least one of the refrigerant temperatures detected by the evaporation temperature sensor is lower than the set value. When it becomes low, the valve device connected to the evaporator is configured to close the open solenoid valve for the capillary and open the other solenoid valve for the capillary. For this reason, even if the refrigerating machine oil is clogged in the flow path of the capillary tube, the flow of the refrigerant in the refrigerant circulation path is not stopped by switching to another capillary tube. As a result, it is possible to prevent an abnormal increase in the high-pressure side pressure in the refrigerant circulation path.

  Further, after a predetermined time has elapsed since the above-described capillary solenoid valve switching control, the temperature detected by the evaporation temperature sensor is compared again with the set value, and if this does not reach the set value, the compressor By being configured to stop the drive of 20, it becomes possible to reliably prevent damage to the compressor.

  In the above-described embodiment, the capillary solenoid valve switching control is performed based on the evaporation temperature of the refrigerant. However, the present invention is not limited to this. For example, the capillary solenoid valve switching control is performed based on the degree of superheat of the refrigerant in the evaporator. Electromagnetic valve switching control may be performed. In this case, when the detected degree of superheat exceeds the set value, the capillary solenoid valve is switched. On the other hand, when the detected degree of superheat is lower than the set value, the open / close state of the capillary solenoid valve is maintained.

  Moreover, in embodiment mentioned above, although the some vending machine 5a, 5b, 5c was provided and the vaporizer 50a, 50b, 50c was arrange | positioned in each merchandise storage box, it was not necessarily illustrated. There is no need for multiple product bins and evaporators.

It is sectional drawing which looked at the vending machine to which the cooling device of this invention was applied from the front. It is sectional drawing which looked at the vending machine to which the cooling device of this invention was applied from the side. 1 is a conceptual diagram of a cooling device in Embodiment 1. FIG. It is a block diagram of the cooling device in the first and second embodiments. It is a schematic flowchart which shows the content of the process which a control part implements. 6 is a conceptual diagram of a cooling device in Embodiment 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main body cabinet 2 Outer door 3a, 3b Inner door 4a, 4b Thermal insulation partition plate 5a, 5b, 5c Product storage 6 Product storage rack 7 Carry-out mechanism 8 Product carry-out shooter 9 Machine room 10,100 Cooling device 11 Piping 12 Main path 13 Bypass path 14, 15 Solenoid valve 16, 17 Check valve 20 Compressor 21 First compressor 22 Second compressor 30 Radiator 40 Expansion mechanism 41, 42 First and second expansion paths 43 First capillary tube 44 Second Capillary tube 45, 45a, 45b, 45c First capillary solenoid valve 46, 46a, 46b, 46c Second capillary solenoid valve 50a, 50b, 50c Evaporator 51 Refrigerant distributor 52a, 52b, 52c Evaporator solenoid valve 53a, 53b, 53c Evaporation temperature sensor 60 Internal heat exchanger 61, 62 Refrigerant pipe line 70 Heat exchange for heating Vessel 80 external heat exchanger 90 control unit 91 setting storage unit 92 comparing unit 93 solenoid valve switch processing unit 94 compressor drive unit

Claims (6)

A compressor that compresses the refrigerant; a radiator that dissipates the refrigerant compressed by the compressor; a capillary tube that decompresses and expands the refrigerant dissipated by the radiator; and evaporates the refrigerant decompressed and expanded by the capillary tube In the cooling device that has a refrigerant circulation path formed by sequentially connecting the evaporator and the pipe to be cooled, and cools the portion where the evaporator is disposed,
A plurality of the capillary tubes are arranged in parallel, and a valve device for controlling the refrigerant flow to each capillary tube is arranged on the upstream path of each capillary tube,
Temperature detecting means for detecting the temperature of the refrigerant passing through the evaporator;
Control means for selectively opening the plurality of valve devices and switching the valve devices based on the temperature detected by the temperature detection means,
The control means includes
A cooling device characterized in that when it is determined that the temperature detected by the temperature detecting means is lower than a set value, the opened valve device is closed and the other valve device is opened. The control means includes
The drive of the compressor is stopped when it is determined that the temperature detected by the temperature detection means does not reach the set value after a predetermined time has elapsed since the switching control of the valve device. The cooling device according to claim 1. A compressor that compresses the refrigerant; a radiator that dissipates the refrigerant compressed by the compressor; a capillary tube that decompresses and expands the refrigerant dissipated by the radiator; and evaporates the refrigerant decompressed and expanded by the capillary tube In the cooling device that has a refrigerant circulation path formed by sequentially connecting the evaporator and the pipe to be cooled, and cools the portion where the evaporator is disposed,
Arranging a plurality of the evaporators in parallel via a refrigerant distributor;
A plurality of the capillary tubes are arranged in parallel between the radiator and the refrigerant distributor, and a valve device for controlling the refrigerant flow to each capillary tube is provided in the upstream path of each capillary tube. Arranged,
Temperature detecting means for detecting the temperature of the refrigerant passing through each evaporator;
Control means for selectively opening the plurality of valve devices and switching the valve devices based on the temperature detected by the temperature detection means,
The control means includes
A cooling device characterized by closing an opened valve device and opening another valve device when it is determined that at least one of the temperatures detected by the temperature detecting means is lower than a set value. . The controller is
The drive of the compressor is stopped when it is determined that the temperature detected by the temperature detecting means does not reach the set value even after a predetermined time has elapsed after the switching of the valve device. The cooling device according to claim 3. A compressor that compresses the refrigerant; a radiator that dissipates the refrigerant compressed by the compressor; a capillary tube that decompresses and expands the refrigerant dissipated by the radiator; and evaporates the refrigerant decompressed and expanded by the capillary tube In the cooling device that has a refrigerant circulation path formed by sequentially connecting the evaporator and the pipe to be cooled, and cools the portion where the evaporator is disposed,
Arranging a plurality of the evaporators in parallel via a refrigerant distributor;
A plurality of the capillary tubes are arranged in parallel between the refrigerant distributor and each evaporator, and a valve device for controlling the refrigerant flow to each capillary tube is provided on the upstream path of each capillary tube. Arranged,
Temperature detecting means for detecting the temperature of the refrigerant passing through each evaporator;
Control means for selectively opening the plurality of valve devices and switching the valve devices based on the temperature detected by the temperature detection means,
The control means includes
When it is determined that at least one of the temperatures detected by the temperature detecting means is lower than a set value, the valve device connected to the evaporator is closed and the other valve device is closed. A cooling device characterized by opening the device. The controller is
The drive of the compressor is stopped when it is determined that the temperature detected by the temperature detecting means does not reach the set value even after a predetermined time has elapsed after the switching of the valve device. The cooling device according to claim 5.

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