Cooling system

Abstract

To prevent damage to the products and to prevent the compressor from shutting down due to high pressure abnormalities. [Solution] A cooling system 1 is provided which a storage room 13A etc. is cooled by evaporation of refrigerant in the evaporator 34A etc. in the showcases 12A etc., and the showcases 12A etc. include doorless showcases 12A, 12E and showcases with doors 12B to 12D, and when the defrosting operation of doorless showcase 12A etc. is completed by the defrosting operation of one of the showcases with doors 12B to 12D when the defrosting operation of doorless showcase 12A etc. is completed by the controller control unit 52 driving the compressor 31 while forcibly ending the defrosting operation of one of the showcases with doors 12B to 12D.

Description

Technical Field

[0001] The present invention relates to a cooling system.

Background Art

[0002] Conventionally, as a cooling system installed in stores such as convenience stores and supermarkets, for example, a system equipped with a refrigerator and a plurality of showcases is known (see, for example, Patent Document 1).

[0003] The refrigerator is installed, for example, outside the store and has a compressor and a condenser. The compressor compresses the sucked refrigerant. The condenser condenses the refrigerant compressed by the compressor.

[0004] The plurality of showcases have a storage chamber in which a plurality of product placement shelves for placing products are provided in the vertical direction, and have an expansion valve and an evaporator that constitute a refrigerant circuit together with the refrigerator. The expansion valve adiabatically expands a part of the refrigerant condensed by the condenser, that is, the refrigerant condensed by the condenser and distributed and supplied. The evaporator evaporates the refrigerant adiabatically expanded by the expansion valve and sucks it into the compressor. In such a showcase, the products placed on the product placement shelves are cooled by introducing the air cooled by the evaporation of the refrigerant in the evaporator into the storage chamber.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] By the way, although not explicitly stated in Patent Document 1 above, in the cooling system, when performing a defrosting operation for removing the frost adhering to the evaporator of each showcase, the compressor is stopped from being driven.

[0007] The time required for this defrosting operation differs between a showcase without a door, where the front opening of the case body facing the storage compartment is always open, and a showcase with a door, where the front opening of the case body facing the storage compartment is opened and closed by a front door, which is normally closed by the front door.

[0008] In other words, in a doorless display case, outside air can be introduced through the front opening during defrosting, so the time required for defrosting is shorter than in a display case with a door, where the front opening is blocked by the front door and outside air cannot be introduced during defrosting.

[0009] When doorless and doorled display cases are mixed together, the doorless display cases tend to finish their defrosting cycle relatively early, which leads to the following problems.

[0010] In other words, if the compressor is driven when the defrosting operation of a doorless display case is completed, and there is only one doorless case that has completed the defrosting operation, and the refrigerant is such that it needs to be under high pressure in the refrigerant circuit, such as carbon dioxide, the refrigerant will be circulated between the chiller and the doorless case. This could result in insufficient volume being secured in the refrigerant circuit piping, potentially causing the compressor to shut down due to a high-pressure abnormality.

[0011] To prevent the compressor from shutting down due to a high-pressure malfunction, it is conceivable to activate the compressor when the defrosting operation of multiple display cases is completed. However, in display cases without doors, outside air could enter the storage compartment through the front opening, potentially damaging the merchandise.

[0012] In view of the above circumstances, the present invention aims to provide a cooling system that can prevent damage to goods and suppress the compressor from stopping due to high pressure abnormalities. [Means for solving the problem]

[0013] To achieve the above objective, the cooling system according to the present invention comprises a refrigerator having a compressor for compressing the refrigerant drawn in and a condenser for condensing the refrigerant compressed by the compressor; a plurality of cooling equipment having an expansion mechanism for adiabatically expanding a portion of the refrigerant condensed in the condenser and an evaporator for evaporating the refrigerant adiabatically expanded by the expansion mechanism and drawing it into the compressor; and a control unit that drives the compressor under normal conditions, but stops the compressor when a defrosting operation is performed in the plurality of cooling equipment to remove frost attached to the evaporator, and the plurality of cooling equipment... A cooling system that cools a predetermined cooling area by evaporation of a refrigerant in a container, wherein the plurality of cooling equipment comprises at least one first cooling equipment whose opening facing the cooling area is always open, and a plurality of second cooling equipment whose opening facing the cooling area is opened and closed by a door and normally closed by the door, and the control unit is characterized in that, when the defrosting operation of one of the first cooling equipment is completed by performing the defrosting operation, it performs a defrosting recovery operation in which it drives the compressor while forcibly terminating the defrosting operation of any one of the second cooling equipment.

[0014] Furthermore, the present invention is characterized in that, in the above-mentioned cooling system, when the control unit performs the defrosting recovery operation, it forcibly terminates the defrosting operation of a second cooling equipment that is different from the second cooling equipment that was forcibly terminated in the previous instance.

[0015] Furthermore, the present invention is characterized in that, in the above-mentioned cooling system, when the control unit performs the defrosting recovery operation, it forcibly terminates the defrosting operation of the second cooling equipment in accordance with a predetermined termination order.

[0016] Furthermore, the present invention is characterized in that, in the above-mentioned cooling system, the refrigerant is carbon dioxide.

[0017] Furthermore, the present invention is characterized in that, in the above-mentioned cooling system, the equipment to be cooled is a showcase for storing goods in the storage chamber which is the cooling area. [Effects of the Invention]

[0018] According to the present invention, a plurality of cooling required facilities include at least one first cooling required facility with an opening facing a cooling area that is always open, and a plurality of second cooling required facilities with an opening facing the cooling area that is opened and closed by a door body and is blocked by the door body in a normal state. When the defrosting operation of one first cooling required facility ends by performing the defrosting operation, the control unit performs a defrosting return operation of forcibly ending the defrosting operation of any one of the second cooling required facilities while driving the compressor. Therefore, it is possible to prevent damage to the product and suppress the compressor from stopping due to abnormal high pressure during driving.

Brief Description of the Drawings

[0019] [Figure 1] FIG. 1 is a block diagram schematically showing the configuration of a cooling system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram schematically showing the configuration of the controller shown in FIG. 1. [Figure 3] FIG. 3 is a flowchart showing the processing content of the defrosting operation control performed by the controller control unit shown in FIG. 1.

Embodiments for Carrying Out the Invention

[0020] Hereinafter, a preferred embodiment of the cooling system according to the present invention will be described in detail with reference to the accompanying drawings.

[0021] FIG. 1 is a block diagram schematically showing the configuration of a cooling system according to an embodiment of the present invention.

[0022] The cooling system 1 exemplified here is applied to a store such as a convenience store or a supermarket, and the refrigeration system 10 is connected to the controller 50 to be configured.

[0023] The refrigeration system 10 includes a refrigerator 11 and a plurality (for example, five) of showcases (refrigerated facilities) 12A to 12E. In the following, elements provided in the showcases 12A to 12E will be described by appropriately attaching "A", "B", "C", "D", "E" to the reference numerals.

[0024] The refrigerator 11 is installed, for example, outside the store and includes a compressor 31 and a condenser 32. The compressor 31 together with the condenser 32 is connected by refrigerant pipelines 35 to expansion mechanisms 33A to 33E and evaporators 34A to 34E, which will be described later, to form a refrigerant circuit 30 in which refrigerant is enclosed. Here, for example, carbon dioxide is used as the refrigerant.

[0025] This compressor 31 is driven in response to a command given from a controller 50. When driven, it sucks and compresses the refrigerant and discharges it as a high-temperature and high-pressure refrigerant. The condenser 32 condenses the refrigerant compressed by the compressor 31 by heat-exchanging it with the ambient air.

[0026] The plurality of showcases 12A to 12E are each installed inside the store and include storage chambers 13A to 13E in which a plurality of product placement shelves (not shown) for placing products are provided in multiple stages along the vertical direction, and showcase control units 14A to 14E. These plurality of showcases 12A to 12E each have expansion mechanisms 33A to 33E and evaporators 34A to 34E.

[0027] The expansion mechanisms 33A to 33E are composed of, for example, electronic expansion valves, etc., and the inlets are connected to the condenser 32 through the refrigerant pipelines 35. These expansion mechanisms 33A to 33E adiabatically expand a part of the refrigerant condensed by the condenser 32, that is, the refrigerant condensed by the condenser 32 and distributed and supplied.

[0028] The evaporators 34A to 34E evaporate the refrigerant, which has been adiabatically expanded in the expansion mechanisms 33A to 33E, by exchanging heat with the surrounding air, thereby drawing the refrigerant into the compressor 31. In other words, the refrigerant evaporated in the evaporators 34A to 34E merges with the refrigerant evaporated in the other evaporators 34A to 34E installed in the other showcases 12A to 12E and is then drawn into the compressor 31.

[0029] Such evaporators 34A to 34E are installed in an air passage (not shown) that communicates with storage chambers 13A to 13E. As a result, the air cooled by the evaporators 34A to 34E is supplied to the storage chambers 13A to 13E, cooling the internal atmosphere of the storage chambers 13A to 13E and cooling the products placed on each product display shelf. Thus, the storage chambers 13A to 13E correspond to a predetermined cooling area of ​​the showcase 12A to 12E.

[0030] The showcase control units 14A to 14E control the operating state of the showcases 12A to 12E by adjusting the opening of the expansion mechanisms 33A to 33E while acquiring temperature information of the storage chambers 13A to 13E and opening information of the expansion mechanisms 33A to 33E of the installed showcases 12A to 12E. The showcase control units 14A to 14E also send the operating state of the showcases 12A to 12E to the controller 50. Furthermore, the showcase control units 14A to 14E have the function of sending the acquired information to the controller 50.

[0031] By the way, in the example shown, three of the showcases 12B to 12D among the showcases 12A to 12E are equipped with front doors 15B to 15D. These front doors 15B to 15D open and close the front openings 16B to 16D that face the storage compartments 13A to 13E, and normally close the front openings 16B to 16D.

[0032] In other words, the front openings 16A and 16E facing the storage rooms 13A and 13E of the showcases 12A and 12E (first refrigerated equipment) are always open, while the front openings 16B and 16D facing the storage rooms 13B and 13D of the showcases 12B to 12D are opened and closed by the front doors (door bodies) 15B and 15D, and are normally closed by the front doors 15B and 15D. In the following explanation, showcases 12A and 12E will also be referred to as "showcases without doors 12A and 12E," and showcases 12B and 12D will also be referred to as "showcases with doors 12B and 12D."

[0033] Figure 2 is a schematic block diagram showing the configuration of the controller 50 shown in Figure 1. As shown in Figure 2, the controller 50 is configured to include an input / output unit 51 and a controller control unit 52.

[0034] The input / output unit 51 is, for example, an input / output device such as a touch panel, which inputs various setting information for the cooling system 1 and outputs various data such as the control status and control results of the cooling system 1.

[0035] The controller control unit 52 controls the refrigeration system 10 according to the programs and data stored in the storage unit 53. This controller control unit 52 includes a refrigeration unit control unit 521, an operation monitoring unit 522, a decision processing unit 523, and an output control unit 524.

[0036] The refrigeration unit control unit 521 controls the operation of the compressor 31 while acquiring data such as the suction pressure, discharge pressure, suction temperature, discharge temperature, and operating frequency of the compressor 31 in real time.

[0037] The operation monitoring unit 522 monitors the operating status of each showcase 12A to 12E. Specifically, it receives and monitors the operating status signals sent from the showcase control units 14A to 14E of each showcase 12A to 12E.

[0038] The decision processing unit 523 reads the showcase information 53a stored in the memory unit 53 and performs a process to determine which showcases with doors 12B to 12D will have their defrosting operation forcibly terminated in the defrosting operation control described later. This showcase information 53a is information regarding the order in which the showcases with doors 12B to 12D will have their defrosting operation forcibly terminated in the defrosting operation control.

[0039] Therefore, the processing in the decision processing unit 523 determines which door-equipped showcases 12B to 12D will have their defrosting operation forcibly terminated according to a predetermined termination order, and forcibly terminates the defrosting operation of a door-equipped showcase 12B to 12D that is different from the door-equipped showcase 12B to 12D that was forcibly terminated last time. The output control unit 524 outputs various commands to each showcase control unit 14A to 14E. The output control unit 524 also performs output control to the input / output unit 51.

[0040] Figure 3 is a flowchart showing the processing details of the defrosting operation control performed by the controller control unit 52 shown in Figure 1.

[0041] In this defrosting operation control, the controller control unit 52 determines whether or not the defrosting start time has elapsed using a clock (not shown) (step S101). If the defrosting start time has not elapsed (step S101: No), the controller control unit 52 repeats this determination process.

[0042] If the defrost start time has elapsed (Step S101: Yes), the controller control unit 52 outputs a defrost operation command to all showcase control units 14A to 14E via the output control unit 524 (Step S102), and also stops the compressor 31 via the chiller control unit 521 (Step S103).

[0043] As a result, the compressor 31 in the refrigerator 11 stops running, and the circulation of refrigerant in the refrigerant circuit 30 stops. In addition, in each of the showcases 12A to 12E, the showcase control units 14A to 14E set the opening of the expansion mechanisms 33A to 33E to zero, and a defrosting operation is performed in which an internal fan (not shown) drives the unit to pass air around the evaporators 34A to 34E, removing the frost that has accumulated on the evaporators 34A to 34E.

[0044] The controller control unit 52 then monitors the operating status of each showcase 12A to 12E by receiving signals sent from each showcase control unit 14A to 14E via the operation monitoring unit 522.

[0045] Incidentally, regarding the defrosting operation performed in each showcase 12A to 12E, the doorless showcases 12A and 12E finish earlier than the showcases with doors 12B to 12D. This is because, in the defrosting operation of the doorless showcases 12A and 12E, relatively warm outside air is introduced through the front openings 16A and 16E, which removes the frost that has accumulated on the evaporators 34A and 34E.

[0046] Having performed the processes in steps S102 and S103, the controller control unit 52 waits for an input indicating the end of the defrosting operation (step S104). That is, the controller control unit 52 determines, via the operation monitoring unit 522, whether or not a signal indicating the end of the defrosting operation has been received from the showcase control units 14A and 14E of any of the doorless showcases 12A and 12E.

[0047] If there is no input from the showcase control units 14A and 14E of the doorless showcases 12A and 12E indicating the end of the defrosting operation (step S104: No), the controller control unit 52 waits for the input indicating the end of the defrosting operation.

[0048] On the other hand, if an input indicating the end of defrosting operation is received from the showcase control units 14A and 14E of either of the doorless showcases 12A and 12E (step S104: Yes), the controller control unit 52 reads the showcase information 53a from the storage unit 53 via the decision processing unit 523 and determines which showcases with doors 12B to 12D will have their defrosting operation forcibly terminated (step S105). Note that in step S104, it is assumed that an input indicating the end of defrosting operation was received from the showcase control unit 14A of the doorless showcase 12A, and in step S105, it is assumed that it has been decided to forcibly terminate the defrosting operation of the showcase with door 12B.

[0049] As mentioned above, the showcase with a door 12B, whose defrosting operation is being forcibly terminated this time, is a separate unit from the showcases with doors 12C and 12D, whose defrosting operation was forcibly terminated last time.

[0050] The reason why the defrosting operation is forcibly terminated in showcases 12A to 12E is limited to showcases with doors 12B to 12D. This is because, under normal conditions, the front openings 16B to 16D of showcases with doors 12B to 12D are closed by the front doors 15B to 15D, resulting in less frost accumulating on the evaporators 34B to 34D compared to showcases without doors 12A and 12E.

[0051] Having performed the processing in step S105, the controller control unit 52 outputs a cooling operation command via the output control unit 524 to the corresponding showcase control units 14A and 14B of the showrooms 12A and 12B, which are the doorless showcase 12A for which the defrosting operation was terminated in step S104, and the doorled showcase 12B for which the defrosting operation is now to be forcibly terminated (step S106). As a result, the showcase control units 14A and 14B of the corresponding showcases 12A and 12B adjust the opening of the expansion mechanisms 33A and 33B to a predetermined size and output an operating status signal to the controller 50. Consequently, the controller control unit 52 monitors via the operation monitoring unit 522 that the corresponding showcases 12A and 12B have switched from defrosting operation to cooling operation.

[0052] Then, the controller control unit 52 drives the compressor 31 through the refrigerator control unit 521 (step S107) to perform the defrosting recovery operation, and then returns to the previous step to end the current process.

[0053] By performing this defrosting and recovery operation, the refrigerant compressed by the compressor 31 is condensed in the condenser 32 and then supplied to the doorless showcase 12A, where the defrosting operation has ended, and the doorled showcase 12B, where the defrosting operation has been forcibly terminated. These two showcases 12A and 12B undergo adiabatic expansion in the expansion mechanisms 33A and 33B and then evaporate in the evaporators 34A and 34B. The refrigerant evaporated in the evaporators 34A and 34B is drawn into the compressor 31, compressed, and circulates through the refrigerant circuit 30.

[0054] Incidentally, the air cooled by the evaporation of the refrigerant in evaporators 34A and 34B is sent to storage compartments 13A and 13B by the operation of an internal fan, thereby cooling the air inside storage compartments 13A and 13B.

[0055] Subsequently, the controller control unit 52, via the operation monitoring unit 522, outputs a cooling operation command via the output control unit 524 to each showcase 12C to 12E for which the defrosting operation has been completed, and sequentially initiates the cooling operation for the showcases 12C to 12E for which the defrosting operation has been completed.

[0056] As described above, according to the cooling system 1, which is an embodiment of the present invention, when the controller control unit 52 completes the defrosting operation of one doorless showcase 12A by performing a defrosting operation, it performs a defrosting recovery operation in which it forcibly terminates the defrosting operation of one of the doorled showcases 12B while driving the compressor 31. As a result, the goods in the storage compartment 13A of the doorless showcase 12A whose defrosting operation has been completed will not be damaged, and the volume of the refrigerant circuit 30 piping can be sufficiently secured. This prevents damage to the goods and also prevents the compressor 31 from stopping due to a high-pressure abnormality.

[0057] Furthermore, when the controller control unit 52 performs a defrosting recovery operation, it forcibly terminates the defrosting operation of a different showcase with doors 12B than the previously terminated showcases 12C and 12D. This avoids the concentration of forced terminations of defrosting operations on only one showcase with doors 12B to 12D, thereby suppressing a decrease in the cooling efficiency of that showcase with doors 12B to 12D.

[0058] Although preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications can be made.

[0059] In the defrosting operation control in the embodiment described above, in step S104, it is assumed that an input indicating the end of defrosting operation has been received from the showcase control unit 14A of the doorless showcase 12A, and in step S105, it is decided to forcibly terminate the defrosting operation of the showcase with a door 12B. However, the present invention is not limited to this, and in step S104, it may be assumed that an input indicating the end of defrosting operation has been received from the showcase control unit 14E of the doorless showcase 12E, and in step S105, it may be decided to forcibly terminate the defrosting operation of either the showcase with a door 12C or 12D.

[0060] In the defrosting operation control of the embodiment described above, the defrosting operation of any of the door-equipped showcases 12B to 12D was terminated. However, in the present invention, the defrosting operation to be terminated may be determined according to the volume of the storage compartments 13B to 13D of each door-equipped showcase 12B to 12D.

[0061] In the embodiment described above, the order in which the defrosting operation of the door-equipped showcases 12B to 12D was terminated was determined based on the showcase information 53a. However, in the present invention, any method may be used to determine the termination order, as long as it is possible to forcibly terminate the defrosting operation for a door-equipped showcase that is different from the door-equipped showcase whose defrosting operation was forcibly terminated in the previous instance.

[0062] In the embodiments described above, showcases 12A to 12E were given as an example of equipment requiring refrigeration, but in the present invention, equipment other than showcases may be used as equipment requiring refrigeration.

[0063] The configurations illustrated in the embodiments described above are functional schematics and do not necessarily have to be physically represented as shown. In other words, the forms of distribution and integration of each device and component are not limited to those shown, and all or part of them can be functionally or physically distributed and integrated in any unit according to various usage situations. [Explanation of Symbols]

[0064] 1...Cooling system, 10...Refrigeration system, 11...Refrigerator, 12A~12E...Showcase, 13A~13E...Storage room, 14A~14E...Showcase control unit, 15B~15D...Front door, 16A~16E...Front opening, 30...Refrigerant circuit, 31...Compressor, 32...Condenser, 33A~33E...Expansion mechanism, 34A~34E...Evaporator, 35...Refrigerant pipeline, 50...Controller, 51...Input / Output unit, 52...Controller control unit, 521...Refrigerator control unit, 522...Operation monitoring unit, 523...Decision processing unit, 524...Output control unit, 53...Storage unit, 53a...Showcase information.

Claims

1. A refrigerator having a compressor for compressing the refrigerant that has been drawn in, and a condenser for condensing the refrigerant that has been compressed by the compressor, Multiple refrigeration equipment having an expansion mechanism for adiabatically expanding a portion of the refrigerant condensed in the condenser, and an evaporator for evaporating the refrigerant adiabatically expanded in the expansion mechanism and drawing it into the compressor, A control unit that normally drives the compressor, but stops the compressor when performing a defrosting operation to remove frost accumulated on the evaporators of the multiple cooling equipment. Equipped with, A cooling system in which a predetermined cooling area is cooled by evaporation of a refrigerant in the evaporator in the aforementioned plurality of cooling equipment, The aforementioned multiple refrigeration equipment are, At least one first cooling equipment having an opening facing the cooling area that is always open, Multiple second cooling equipment units, the openings facing the aforementioned cooling area, are opened and closed by a door and are normally closed by the door. It has, The cooling system is characterized in that, when the control unit completes the defrosting operation of one of the first refrigerated equipment units by performing the defrosting operation, it performs a defrosting recovery operation in which it drives the compressor while forcibly terminating the defrosting operation of one of the second refrigerated equipment units.

2. The cooling system according to claim 1, characterized in that when the control unit performs the defrosting recovery operation, it forcibly terminates the defrosting operation of a second refrigerated equipment that is different from the second refrigerated equipment that was forcibly terminated in the previous instance.

3. The cooling system according to claim 2, characterized in that when the control unit performs the defrosting recovery operation, it forcibly terminates the defrosting operation of the second cooling equipment in a predetermined termination order.

4. The cooling system according to any one of claims 1 to 3, characterized in that the refrigerant is carbon dioxide.

5. The cooling system according to claim 4, characterized in that the refrigeration equipment is a showcase for storing goods in the storage chamber which is the cooling area.

Images