JP6690290B2 - Cooling system - Google Patents

Description

  The present invention relates to a cooling device, and more particularly, to a cooling device applied to an open flat type ice case that stores a product such as ice cream in a removable state.

  2. Description of the Related Art Conventionally, as an open flat type ice case for storing products such as ice cream in a state where the product can be taken out, one provided with a case body and a cooling unit is known.

  The case main body is a rectangular parallelepiped heat insulating case having an opening (hereinafter, also referred to as an upper surface opening) formed on the upper surface, and has a storage and an air passage. The storage is a room provided so as to face the upper surface opening and stores products.

  The air passage is formed so as to be partitioned from the storage, and communicates with the storage through the suction port and the air outlet. A blower fan is provided in this air passage. The blower fan drives the suction fan to suck the internal air of the storage into the air passage through the suction port, and after passing through the air passage, blows the air into the storage through the air outlet to form the storage and the air passage. The internal air is circulated between them.

  The cooling unit is configured by connecting an evaporator, a compressor, a condenser, and an expansion mechanism to the refrigerant pipeline. The evaporator is provided in the air passage.

  The compressor is provided in a machine room inside the case body and outside the storage and the air passage. When driven, this compressor sucks and compresses the refrigerant that has passed through the evaporator. The condenser is provided in the machine room and condenses the refrigerant compressed by the compressor. The expansion mechanism is provided in the machine room and adiabatically expands the refrigerant condensed in the condenser and sends it to the evaporator.

  In such a cooling unit, the compressor is driven to supply the refrigerant adiabatically expanded by the expansion mechanism to the evaporator. As a result, the evaporator causes heat exchange between the supplied refrigerant and the internal air passing through the air passage, and the refrigerant is evaporated to cool the internal air. As a result, the internal air of the storage is cooled, and the products stored in the storage are cooled.

  Further, in the ice case, since the internal air passing through the air passage contains water, frost adheres to the evaporator when cooling the internal air of the storage, and the removal for removing the frost is required. The frost operation is appropriately performed (for example, refer to Patent Document 1).

JP-A-6-42855

  By the way, although not explicitly disclosed in Patent Document 1, when performing a defrosting operation in an ice case, the heater heated in the air passage drives the heater while the heater disposed in the air passage is driven. It is common to drive the blower fan to pass.

  However, in the defrosting operation, it is necessary to prevent the temperature of the product stored in the storage container from rising and the quality of the product from deteriorating. Therefore, the heating amount by the heater and the blowing amount of the blower fan are It is necessary to limit it to some extent, and as a result, the time required for the defrosting operation is lengthened.

  In view of the above situation, it is an object of the present invention to provide a cooling device that can reduce the time required for defrosting operation.

  In order to achieve the above-mentioned object, a cooling device according to the present invention includes a first heat exchanger for exchanging heat between a supplied refrigerant and ambient air passing through, and an air passage through which internal air of a target chamber passes. Installed in the second heat exchanger for exchanging heat between the supplied refrigerant and the passing internal air, and expansion for adiabatically expanding the refrigerant passing through the first heat exchanger or the second heat exchanger A cooling unit configured by connecting a mechanism and a compressor that sucks and compresses the refrigerant that has passed through the first heat exchanger or the second heat exchanger with a refrigerant pipe line, and when performing normal operation When the internal air is cooled while the defrosting operation is performed by normally circulating the refrigerant compressed by the compressor in the order of the first heat exchanger, the expansion mechanism, and the second heat exchanger. The refrigerant compressed by the compressor is transferred to the second heat exchange. And a control means for removing frost adhering to the second heat exchanger by reversely circulating the expansion mechanism and the first heat exchanger in this order, the control means comprising: When performing the defrosting operation, the drive of the air blowing unit that blows and circulates air between the target chamber and the air passage is stopped, and a predetermined drive stop time elapses from the start of the reverse circulation. After that, or after the internal temperature of the target chamber reaches a predetermined reference temperature, the air blowing unit is driven.

  Further, the present invention is characterized in that, in the above cooling device, the control means drives a heating means arranged in the vicinity of the second heat exchanger when performing the defrosting operation.

  According to the present invention, when the control means performs the defrosting operation, the refrigerant compressed by the compressor is reversely circulated in the order of the second heat exchanger, the expansion mechanism, and the first heat exchanger to the target chamber. Since the driving of the air blowing means that blows and circulates air between the air passage and the air passage is stopped, the ambient temperature including the second heat exchanger can be raised in a relatively short time, and the second heat exchanger can be used. It is possible to remove the adhered frost. Then, the control means drives the blower means after a predetermined drive stop time has elapsed from the start of the reverse circulation or after the internal temperature of the target chamber reaches the predetermined reference temperature, so that the compressor is Air can be circulated between the target chamber and the air passage before the driving is stopped due to a high pressure abnormality or the like. As a result, frost and the like attached to the air passage around the second heat exchanger can be melted, and the compressor can be prevented from being stopped. Therefore, the time required for the defrosting operation can be shortened.

FIG. 1 is a vertical cross-sectional view showing a vertical cross section of an ice case to which a cooling device according to an embodiment of the present invention is applied. FIG. 2 is a conceptual diagram showing a part of the components of the cooling device shown in FIG. FIG. 3 is a block diagram schematically showing the control system of the cooling device. FIG. 4 is a flowchart showing the processing contents of the defrosting control processing executed by the control unit shown in FIG.

  Hereinafter, preferred embodiments of a cooling device according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a vertical cross-sectional view showing a vertical cross section of an ice case to which a cooling device according to an embodiment of the present invention is applied. The ice case illustrated here includes a case body 10.

  The case body 10 is a rectangular heat-insulating housing having an opening (hereinafter, also referred to as an upper surface opening) 10a formed on the upper surface. The case body 10 has a storage chamber (target chamber) 11 and an air passage 12 defined therein, and a cooling device 20 provided therein.

  The storage chamber 11 is a chamber defined so as to face the upper surface opening 10a, and is for storing a net-like basket-like object in which products such as ice cream are stored. A suction port 13 is formed in the upper rear part of the storage chamber 11, and an air outlet 14 is formed in the upper front part of the storage chamber 11.

  The suction port 13 is an opening for sucking air inside the storage chamber 11, and extends along the left-right direction of the storage chamber 11. The air outlet 14 is an opening for blowing air into the storage chamber 11. The air outlet 14 extends in the left-right direction of the storage chamber 11.

  The air passage 12 is an air passage for air from the suction port 13 to the air outlet 14. The air passage 12 communicates with the suction port 13 and is located outside the storage chamber 11 and behind the rear passage 12a, and outside the storage chamber 11 is below the lower passage 12b. The front passage 12c, which is located outside the vehicle 11 and in front of the air outlet 11, communicates with the air outlet 14, and is configured to communicate with each other.

  FIG. 2 is a conceptual diagram showing a part of the components of the cooling device 20 shown in FIG. 1, and FIG. 3 is a block diagram schematically showing a control system of the cooling device 20. As shown in FIGS. 2 and 3, the cooling device 20 includes a cooling unit 21 and a control unit (control means) 22.

  The cooling unit 21 includes a refrigerant circuit 30 and a blowing fan (blowing means) F. The refrigerant circuit 30 has a main path 30a, a high-pressure refrigerant introduction path 30b, a heat radiation path 30c, and a bypass path 30d, and the refrigerant is sealed inside.

  The main path 30a includes a compressor 31, a three-way valve 32, an outside heat exchanger (first heat exchanger) 33, a first expansion mechanism 34, and an inside heat exchanger (second heat exchanger) 35 as a refrigerant pipeline. It is configured by connecting appropriately at 36.

  The compressor 31 is arranged in the machine room 15 of the case body 10 as shown in FIG. The compressor 31 is driven according to a command given from the control unit 22, and when driven, sucks the refrigerant and compresses the sucked refrigerant to a high temperature and high pressure state (high temperature and high pressure refrigerant). It is what is discharged.

  The three-way valve 32 has one inlet 32a and two outlets (first outlet 32b, second outlet 32c), and the inlet 32a and the first outlet 32b according to a command given from the control unit 22. It is a switching valve that can be switched to either a first delivery state that communicates with and a second delivery state that communicates with the inlet 32a and the second outlet 32c. A refrigerant pipe line 36 connected to the compressor 31 is connected to the inlet 32a of the three-way valve 32.

  The outside heat exchanger 33 is arranged in the machine room 15 like the compressor 31 as shown in FIG. 1. The outside heat exchanger 33 exchanges heat between the passing refrigerant and the outside air passing around. An unillustrated external fan is provided near the external heat exchanger 33. The refrigerant pipe line 36 connected to the inlet of the outside heat exchanger 33 is connected to the first outlet 32b of the three-way valve 32.

  As shown in FIG. 1, the first expansion mechanism 34 is arranged in the machine chamber 15 like the compressor 31 and the outside heat exchanger 33. The first expansion mechanism 34 is composed of, for example, an electronic expansion valve, a capillary tube, or the like, and decompresses the refrigerant that has passed through the outside heat exchanger 33 to adiabatically expand it. The inlet of the first expansion mechanism 34 is connected to a refrigerant pipe 36 connected to the outlet of the outside heat exchanger 33, and a high-pressure solenoid valve 37 is provided in the refrigerant pipe 36. The high-pressure solenoid valve 37 opens and closes according to a command given from the control unit 22, and when opened, allows passage of the refrigerant from the outside heat exchanger 33 to the first expansion mechanism 34, When it is closed, the passage of the refrigerant from the outside heat exchanger 33 to the first expansion mechanism 34 is restricted.

  The internal heat exchanger 35 is arranged in the air passage 12 as shown in FIG. This internal heat exchanger 35 is connected to a refrigerant pipe 36 whose inlet is connected to the outlet of the first expansion mechanism 34, and a check valve 38 is provided in the middle of the refrigerant pipe 36. . The refrigerant pipe line 36 connected to the outlet of the internal heat exchanger 35 is connected to the inlet of the compressor 31, and a first low pressure solenoid valve 39 is provided in the middle thereof. The first low-pressure solenoid valve 39 opens and closes according to a command given from the control unit 22, and when opened, allows passage of the refrigerant from the internal heat exchanger 35 to the compressor 31, while When closed, the passage of the refrigerant from the internal heat exchanger 35 to the compressor 31 is regulated.

  The high-pressure refrigerant introduction path 30b has a high-pressure refrigerant conduit 40. The high-pressure refrigerant line 40 has one end connected to the second outlet 32c of the three-way valve 32 and the other end connected to the inlet of the internal heat exchanger 35, and is downstream of the check valve 38 of the refrigerant line 36. The first merging point P1 becomes The high-pressure refrigerant pipe 40 supplies the high-pressure refrigerant compressed by the compressor 31 to the internal heat exchanger 35 when the refrigerant is allowed to be introduced by the three-way valve 32.

  The heat radiation path 30c is configured to include a heat radiation conduit 41. The radiating pipe 41 is branched at a first branch point P2 in the middle of the refrigerant pipe 36 connected to the outlet side of the internal heat exchanger 35, and the refrigerant between the three-way valve 32 and the external heat exchanger 33. The refrigerant conduit 36 is connected in such a manner that it joins at the second confluence point P3 of the conduit 36.

  A second expansion mechanism 42 and a second low pressure electromagnetic valve 43 are provided in the middle of the heat radiation pipe 41. The second expansion mechanism 42 is composed of, for example, an electronic expansion valve, a capillary tube, or the like, and decompresses the refrigerant passing through the heat radiation conduit 41 to adiabatically expand it.

  The second low-pressure solenoid valve 43 is opened / closed in response to a command given from the control unit 22, and when opened, allows the refrigerant to pass through the heat dissipation pipe 41, and when closed, Is for restricting the passage of the refrigerant through the heat radiation conduit 41.

  The bypass path 30d is configured to include a bypass pipe line 44 and a bypass valve 45. The bypass pipeline 44 branches from the second branch point P4 on the upstream side of the high-pressure electromagnetic valve 37 in the refrigerant pipeline 36 connected to the outlet of the outside heat exchanger 33, and is connected to the inlet of the compressor 31. The refrigerant pipe 36 is connected to the refrigerant pipe 36 in such a manner that the refrigerant pipe 36 joins at the third joining point P5.

  The bypass valve 45 is a valve body that can be opened and closed, and when opened, allows the refrigerant to pass through the bypass pipeline 44, while when closed, the refrigerant passes through the bypass pipeline 44. It regulates that.

  The blower fan F is arranged at a predetermined portion of the lower passage 12b. The blower fan F is driven according to a command given from the control unit 22, and when driven, sucks the internal air of the storage chamber 11 through the suction port 13 and sucks the sucked internal air into the rear passage 12a. The lower passage 12b and the front passage 12c are delivered to the air outlet 14 in such a manner as to pass through the air passage 12 in this order, and blown out into the storage chamber 11 through the air outlet 14. It circulates air between and.

  The control unit 22 centrally controls the operation of each unit of the cooling device 20 in accordance with the programs and data stored in the memory 23, and includes an input processing unit 22a, a determination processing unit 22b, a compressor drive processing unit 22c, and a valve. The drive processing unit 22d and the fan drive processing unit 22e are provided. The control unit 22 may be realized by causing a processing device such as a CPU (Central Processing Unit) to execute a program, that is, by software, or by hardware such as an IC (Integrated Circuit). However, it may be realized by using software and hardware together.

  The input processing section 22a inputs a command signal given from the input means 24 such as a remote controller or a keyboard. In the present embodiment, for example, the defrosting start time information and the information regarding the defrosting time provided from the input means 24 are input and then stored in the memory 23. Further, the memory 23 stores information regarding the drive stop time.

  The drive stop time is a time for temporarily stopping the drive of the blower fan F in the defrosting control process described later. This drive stop time is a time determined in order to sufficiently heat the internal heat exchanger 35 and its surroundings, and its upper limit is set to end before the compressor 31 is stopped due to a high pressure abnormality or the like. The value is fixed.

  The determination processing unit 22b measures time through a built-in clock and determines whether or not the measured time has exceeded the drive stop time stored in the memory 23. The compressor drive processing unit 22c gives a drive command or a drive stop command to the compressor 31 to drive or stop the compressor 31. The valve drive processing unit 22d gives a switching command to the three-way valve 32 to bring it into the first delivery state or the second delivery state. The valve drive processing unit 22d gives an opening / closing command to the high pressure solenoid valve 37, the first low pressure solenoid valve 39, the second low pressure solenoid valve 43, and the bypass valve 45 to open and close them. The fan drive processing section 22e gives a drive command or a drive stop command to the blower fan F to drive or stop the blower fan F.

  In the cooling device 20 having the above-described configuration, when performing the normal operation, the control unit 22 sends a drive command to the compressor 31 through the compressor drive processing unit 22c and blows air through the fan drive processing unit 22e. A drive command is sent to the fan F.

  Further, the control unit 22 gives an opening command to the high-pressure solenoid valve 37 and the first low-pressure solenoid valve 39 to open the three-way valve 32 through the valve drive processing unit 22d in the first delivery state, and also opens the second low-pressure solenoid valve. A closing command is given to 43 and the bypass valve 45 to close them.

  By driving the blower fan F in this way, the internal air in the storage chamber 11 is sucked through the suction port 13 and passes through the air passage 12 in the order of the rear passage 12a, the lower passage 12b, and the front passage 12c. In this manner, the air is delivered to the air outlet 14 and is blown into the storage chamber 11 through the air outlet 14. Thereby, the internal air of the storage chamber 11 can be circulated between the inside of the storage chamber 11 and the air passage 12.

  By driving the compressor 31, in the cooling unit 21, the refrigerant compressed by the compressor 31 is normally circulated as follows.

  The refrigerant compressed by the compressor 31 passes through the three-way valve 32 in the first delivery state and reaches the outside heat exchanger 33 via the refrigerant pipeline 36. The refrigerant reaching the outside heat exchanger 33 radiates heat to the ambient air (outside air) while passing through the outside heat exchanger 33 and is condensed. The refrigerant condensed in the outside heat exchanger 33 is adiabatically expanded by the first expansion mechanism 34 to reach the inside heat exchanger 35, is evaporated in the inside heat exchanger 35, and is removed from the internal air passing through the air passage 12. It takes heat and cools the internal air. The refrigerant evaporated in the internal heat exchanger 35 is sucked into the compressor 31, then compressed, and repeatedly passes through the main path 30a.

  By performing such a normal operation, the internal air circulated between the storage chamber 11 and the air passage 12 by the blower fan F is cooled by the evaporator, and the internal air of the storage chamber 11 is thereby cooled. The products that are cooled and stored in the storage chamber 11 are cooled.

  When the current time has passed the defrosting start time stored in the memory 23, the control unit 22 performs the following defrosting control process. It is assumed that the compressor 31 and the blower fan F are driven as a premise of the defrosting control process.

  FIG. 4 is a flowchart showing the processing contents of the defrosting control processing executed by the control unit 22 shown in FIG.

  In this defrosting control process, the control unit 22 sends a drive stop command to the compressor 31 through the compressor drive processing unit 22c (step S101) to stop the drive of the compressor 31 and also through the fan drive processing unit 22e. A drive stop command is sent to the blower fan F (step S102) to stop the drive of the blower fan F.

  Then, the control unit 22 sends a switching command to the three-way valve 32 through the valve drive processing unit 22d, sends an open command to the second low pressure solenoid valve 43 and the bypass valve 45, and sends the first low pressure solenoid valve 39 and the high pressure solenoid valve 39. A close command is sent to the solenoid valve 37 (step S103, step S104, step S105).

  After performing the processes of steps S103 to S105, the control unit 22 sends a drive command to the compressor 31 through the compressor drive processing unit 22c (step S106) to drive the compressor 31.

  By driving the compressor 31 in this way, in the cooling unit 21, the refrigerant compressed by the compressor 31 circulates reversely as follows.

  The refrigerant compressed by the compressor 31 passes through the high pressure refrigerant pipeline 40 via the three-way valve 32 in the second delivery state. The refrigerant that has passed through the high-pressure refrigerant pipe 40 reaches the internal heat exchanger 35. The refrigerant that has reached the internal heat exchanger 35 exchanges heat with the internal air of the air passage 12 while passing through the internal heat exchanger 35, and radiates heat to the internal air to be condensed. Thereby, the air around the internal heat exchanger 35 is heated.

  The refrigerant condensed in the internal heat exchanger 35 reaches the radiating pipe 41, undergoes adiabatic expansion in the second expansion mechanism 42, and then reaches the external heat exchanger 33, and in the external heat exchanger 33, ambient air flows. Heat exchange with (outside air). The refrigerant that has passed through the outside heat exchanger 33 reaches the bypass pipeline 44, is sucked by the compressor 31 after passing through the bypass pipeline 44, and then repeatedly passes through the above-described path.

  At this time, the driving of the blower fan F is stopped, so that the circulation of the internal air of the storage chamber 11 between the storage chamber 11 and the air passage 12 is stopped. Therefore, the periphery of the inside heat exchanger 35 is heated by the heat radiation of the refrigerant in the inside heat exchanger 35. In this way, the surroundings of the internal heat exchanger 35 are heated, but since the air is not passed by the blower fan F, the heat radiation amount in the internal heat exchanger 35 is not sufficiently secured, and as a result, the compressor 31 The temperature of the refrigerant compressed and discharged from the tank also rises. As a result, the ambient temperature of the inside heat exchanger 35 including the heat exchanger 35 rises in a relatively short time. As a result, the frost attached to the internal heat exchanger 35 melts.

  Through the determination processing unit 22, the control unit 22 that has performed the above step S105 starts measuring time from the time when the reverse circulation of the refrigerant in the cooling unit 21 is started, and waits for the drive stop time read from the memory 23 to elapse. (Step S107).

  When it is determined through the determination processing unit 22b that the measurement time has exceeded the drive stop time (step S107: Yes), the control unit 22 stops the time measurement by the determination processing unit 22b and the compressor drive processing unit 22c. A drive stop command is sent to the compressor 31 through (step S108) to stop the drive of the compressor 31.

  The control unit 22 that has stopped driving the compressor 31 in this way sends a drive command to the blower fan F through the fan drive processing unit 22e (step S109), and waits for the defrosting time read from the memory 23 to elapse. (Step S110).

  By driving the blower fan F in this way, air circulates between the storage chamber 11 and the air passage 12, and thereby frost and the like attached to the air passage 12 around the internal heat exchanger 35 and the like. Can be melted.

  After that, when the defrost time has elapsed (step S110: Yes), the control unit 22 sends a drive stop command to the blower fan F through the fan drive processing unit 22e (step S111), and then returns the procedure. The defrosting control process this time is ended.

  As described above, in the cooling device 20 according to the present embodiment, when the control unit 22 performs the defrosting operation, the refrigerant compressed by the compressor 31 is used as the internal heat exchanger 35 and the second refrigerant. Since the expansion mechanism 42 and the outdoor heat exchanger 33 are circulated (reverse circulation) in this order, the drive of the blower fan F that circulates by circulating the air between the storage chamber 11 and the air passage 12 is stopped. The ambient temperature including the exchanger 35 can be raised in a relatively short time, and the frost adhering to the internal heat exchanger 35 can be removed. Then, the control unit 22 drives the blower fan F after a predetermined drive stop time has elapsed from the start of the reverse circulation, so that the storage chamber 11 and the storage chamber 11 can be driven before the compressor 31 is stopped due to a high pressure abnormality or the like. Air can be circulated to and from the air passage 12. Accordingly, frost and the like attached to the air passage 12 around the internal heat exchanger 35 can be melted, and the compressor 31 can be prevented from being stopped. Therefore, according to the cooling device 20, the time required for the defrosting operation can be shortened.

  Further, according to the cooling device 20 described above, by performing the defrosting operation, not only the internal heat exchanger 35 but also the frost around the internal heat exchanger 35 can be removed. The quality of the ice case applied by driving can be improved.

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

  In the above-described embodiment, in the defrost control process, in step S107, the blower fan F is driven after a predetermined drive stop time has elapsed from the start of the reverse circulation, but in the present invention, the reverse circulation is performed. After starting, the blower unit (blower fan F) may be driven after the internal temperature of the target chamber (storage chamber 11) detected by the temperature detection unit reaches a predetermined reference temperature.

  In the present invention, when a heating means such as a heater is provided near the second heat exchanger (in-compartment heat exchanger 35), the heating means may be driven when the defrosting operation is performed. Good. As a result, the ambient temperature including the second heat exchanger can be raised in a short period of time, and defrosting can be reliably performed.

11 storage room 12 air passage 20 cooling device 21 cooling unit 22 control unit (control means)
23 Memory 30 Refrigerant Circuit 30a Main Path 30b High Pressure Refrigerant Introduction Path 30c Heat Dissipation Path 30d Bypass Path 31 Compressor 32 Three-Way Valve 33 External Heat Exchanger (First Heat Exchanger)
34 1st expansion mechanism 35 Internal heat exchanger (2nd heat exchanger)
36 Refrigerant pipeline F Blower fan (Blower means)

Claims (2)

A first heat exchanger for exchanging heat between the supplied refrigerant and the ambient air passing through the surroundings, and a refrigerant installed and provided in the air passage through which the internal air of the target chamber passes, and the supplied refrigerant and the internal air passing therethrough. A second heat exchanger for exchanging heat between the two, an expansion mechanism for adiabatically expanding the refrigerant passing through the first heat exchanger or the second heat exchanger, the first heat exchanger or the second heat exchanger A cooling unit configured by connecting a compressor that sucks and compresses the refrigerant that has passed through with a refrigerant pipeline,
When the normal operation is performed, the refrigerant compressed by the compressor is normally circulated through the first heat exchanger, the expansion mechanism, and the second heat exchanger in this order to cool the internal air, When performing the defrosting operation, the refrigerant compressed by the compressor is reversely circulated in the order of the second heat exchanger, the expansion mechanism, and the first heat exchanger, so that the second heat exchanger A cooling device comprising: a control means for removing adhered frost,
When performing the defrosting operation, the control means stops driving of an air blowing means for blowing and circulating air between the target chamber and the air passage, and predetermined from the start of the reverse circulation. after driving stop time has elapsed the, or a shall by driving the blower means after the internal temperature of the target chamber reaches a predetermined reference temperature, predetermined from by further driving the air blowing means A cooling device , characterized in that the blowing means is stopped after the defrosting time has elapsed .   The cooling device according to claim 1, wherein the control unit drives a heating unit disposed near the second heat exchanger when performing the defrosting operation.

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