Cooling system

Abstract

A cooling system that can effectively utilize surplus power generated by a solar power generation device even when there is no storage battery that can sufficiently store the surplus power generated by the solar power generation device. [Solution] This cooling system 100 includes a solar power generation device 1, a compressor 30 that compresses a refrigerant, and a condenser 31 that condenses the refrigerant compressed by the compressor 30, and is powered by electricity supplied from the solar power generation device 1 and a commercial power source 6, a cooling equipment 3 that includes a first expansion valve 12 that expands the refrigerant condensed by the condenser 31 and a first evaporator 13 that evaporates the expanded refrigerant, and cools products for sale 91, and a control unit 4 that, when there is surplus electricity generated by the solar power generation device 1 that exceeds the power consumption of a load 7 including the refrigerator 2 connected to the solar power generation device 1, controls the compressor 30 to use the surplus electricity to perform heat storage operation to store cold energy.

Description

[Technical Field]

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

[0002] BACKGROUND ART Conventionally, cooling systems are known (see, for example, Patent Document 1).

[0003] The above-mentioned Patent Document 1 discloses an operation control system (cooling system). This operation control system controls the operation (operating modes) of multiple store equipment installed in various stores such as convenience stores and supermarkets. The operation control system includes store equipment including a solar power generation system, a storage battery, and electrical equipment, and a control unit. The electrical equipment includes a refrigerator and equipment that requires refrigeration (cooling facilities). The electrical equipment is configured to be able to operate either by power supply from a commercial power source or by discharging (discharged power) from the storage battery. The solar power generation system supplies generated electricity (power) to the storage battery as charging power. The storage battery stores the electricity generated by the solar power generation system so that it can be discharged to the electrical equipment. The power supplied to the storage battery is discharged (supplied) to the electrical equipment, and any power in excess of the discharged amount is stored. The control unit acquires weather information for the area where the store is located and controls the operation (operating modes) of the solar power generation system and the storage battery according to the acquired weather information. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2023-142821 Summary of the Invention [Problem to be solved by the invention]

[0005] Although not described in Patent Document 1, there are cases where a store equipped with a solar power generation device does not have a storage battery for storing the power generated by the solar power generation device. In such cases, since the power generated by the solar power generation device cannot be stored, for example, power generation by the solar power generation device is controlled to prevent reverse power flow caused when the amount of power generated by the solar power generation device exceeds the amount of power discharged (supplied) to electrical equipment. That is, when the power generated by the solar power generation device is likely to generate surplus power that exceeds the power consumption of loads including a refrigerator connected to the solar power generation device, control is performed to suppress power generation by the solar power generation device. Therefore, even when there is no storage battery capable of sufficiently storing the surplus power generated by the solar power generation device, it is desirable to effectively utilize the surplus power generated by the solar power generation device.

[0006] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a cooling system that can effectively utilize surplus power generated by a solar power generation system even when there is no storage battery that can sufficiently store the surplus power generated by the solar power generation system. [Means for solving the problem]

[0007] In order to achieve the above object, a cooling system according to one aspect of the present invention includes a solar power generation device, a refrigerator including a compressor that compresses a refrigerant and a condenser that condenses the refrigerant compressed by the compressor, and is operated by power supplied from the solar power generation device and a commercial power source, a first evaporator that evaporates the expanded refrigerant using a first expansion valve that expands the refrigerant condensed by the condenser, and is equipped with cooling equipment that cools products for sale, and a control unit that, when there is surplus power generated by the solar power generation device that exceeds the power consumption of a load including the refrigerator connected to the solar power generation device, controls the compressor to use the surplus power to perform heat storage operation to store cold heat.

[0008] In a cooling system according to one aspect of the present invention, as described above, the control unit is configured to perform a heat storage operation in which, when the power generated by the solar power generation device exceeds the power consumption of the load, including the refrigerator connected to the solar power generation device, the control unit uses the surplus power to operate the compressor and store cold heat. Thus, even if a storage battery for storing the power generated by the solar power generation device is not provided, when the power generated by the solar power generation device generates surplus power, the control unit can perform a heat storage operation without controlling the power generation by the solar power generation device, thereby storing cold heat using the surplus power. Therefore, when there is no surplus power from the solar power generation device, the cold heat stored using the surplus power can be used. Therefore, even if there is no storage battery capable of sufficiently storing the surplus power from the power generated by the solar power generation device, the surplus power from the solar power generation device can be effectively utilized.

[0009] In the cooling system according to the above aspect, the control unit is preferably configured to switch from heat storage operation to heat dissipation operation, in which the stored cold heat is dissipated using the surplus power when the state transitions from surplus power to no surplus power. With this configuration, the control unit can dissipate the stored cold heat using the surplus power by switching from heat storage operation to heat dissipation operation when the state transitions from no surplus power to no surplus power. Therefore, in a state where there is no surplus power, the cooling system can save energy by reducing the amount of power supplied from the commercial power system, while at least cooling the products sold by the cooling system. Therefore, even if there is no storage battery capable of sufficiently storing the surplus power generated by the solar power generation system, the surplus power generated by the solar power generation system can be effectively utilized.

[0010] In the cooling system according to the above aspect, the cooling equipment preferably further includes a display area for displaying products for sale and a work storage area accessible to workers and storing replenishment products to be replenished in the display area, and the control unit is configured to operate the compressor in the heat storage operation so that the temperature inside the cooling equipment reaches a heat storage operation temperature that is lower than the normal set temperature during normal operation, thereby storing cold heat in the replenishment products stored in the work storage area. With this configuration, in the heat storage operation, surplus electricity can be used by increasing the operating load of the compressor to raise the temperature inside the cooling equipment to a heat storage operation temperature that is lower than the normal set temperature, and cold heat can be stored in the replenishment products stored in the work storage area whose temperature has been lowered to the heat storage operation temperature. Therefore, by storing cold heat in the replenishment products stored in the work storage area, surplus electricity generated by the solar power generation device can be appropriately and effectively utilized even in a case where there is no storage battery capable of sufficiently storing the surplus electricity generated by the solar power generation device.

[0011] In this case, the control unit is preferably configured to switch from heat storage operation to heat dissipation operation in which, when there is no surplus power, the cold stored in the replenishment products is dissipated without circulating refrigerant through the first evaporator. With this configuration, by not circulating refrigerant through the first evaporator in the heat dissipation operation, the operating load on the compressor can be reduced and the power consumption of the compressor can be reduced. Therefore, the amount of power supplied from the commercial power system can be reduced, thereby easily achieving energy savings in the cooling system, while in the heat dissipation operation, the cold stored in the replenishment products can be dissipated to cool the products for sale.

[0012] In the configuration for switching from the heat storage operation to the heat dissipation operation in which the cold energy stored in the replenishment products is dissipated, preferably, the cooling equipment further includes a blower, and the control unit is configured to, in the heat storage operation, reverse the rotation of the blower, which rotates forward during normal operation, to cause the blower to blow air toward the work storage area. With this configuration, the reverse rotation of the blower in the heat storage operation causes the blower to blow air toward the work storage area, so that cold energy can be efficiently stored in the replenishment products stored in the work storage area without the need to add a new blower.

[0013] In this case, preferably, the cooling equipment further includes a first cold storage material, and the control unit is configured to, in the heat storage operation, blow air blown out from the first evaporator by the blower toward the work storage area via the first cold storage material, and to, in the heat release operation, release the cold stored in the replenishment products and the first cold storage material without allowing refrigerant to flow into the first evaporator. With this configuration, in the heat storage operation, cold can be stored in both the replenishment products and the first cold storage material by the cooled air blown out from the first evaporator, and in the heat release operation, cold can be released from both the replenishment products and the first cold storage material. Therefore, in the heat release operation, with a simple configuration, the products for sale can be further cooled by the cold released from both the replenishment products and the first cold storage material.

[0014] In the above-described configuration in which the cooling equipment includes a blower, the cooling equipment preferably includes a second evaporator that evaporates the expanded refrigerant by a second expansion valve that expands the refrigerant condensed by the condenser, a first cold storage material cooled by the second evaporator, and a first cold storage material cooling unit disposed in parallel with the first evaporator, and the control unit is configured to store cold energy in the first cold storage material by the second evaporator in the heat storage operation, and to release the cold energy stored in the first cold storage material to the replenishment products and the first cold storage material without allowing refrigerant to flow into the first evaporator and the second evaporator in the heat release operation. With this configuration, in the heat storage operation, cold energy can be stored in the first cold storage material by the second evaporator, and cold energy can be stored in the replenishment products by the cooled air blown out from the first evaporator. Therefore, in the heat storage operation, cold energy can be easily stored in the first cold storage material via the second evaporator. Furthermore, in the heat dissipation operation, cold heat can be dissipated from both the replenishment products and the first cold storage material, so that the products for sale can be further cooled by the cold heat dissipated from both the replenishment products and the first cold storage material.

[0015] The cooling system according to the above aspect preferably further includes a heat storage device including a third evaporator that evaporates the expanded refrigerant by a third expansion valve that expands the refrigerant condensed by the condenser, and a second cold storage material cooled by the third evaporator, and the control unit is configured to store cold heat in the second cold storage material by the third evaporator during the heat storage operation. With this configuration, by using surplus electricity during the heat storage operation, the second cold storage material can be cooled by the third evaporator in the heat storage device, and cold heat can be stored in the second cold storage material. Therefore, by storing cold heat in the second cold storage material, surplus electricity from the solar power generation device can be appropriately and effectively utilized even when there is no storage battery capable of sufficiently storing the surplus electricity from the solar power generation device.

[0016] In this case, the heat storage device preferably further includes a heat exchanger that performs heat exchange between the refrigerant condensed by the condenser and the second cold storage material, and the control unit is configured to switch from heat storage operation to heat dissipation operation in which, when there is no surplus power, the refrigerant flowing out of the condenser flows into the heat exchanger until the refrigerant flowing out of the heat exchanger exceeds a predetermined temperature, thereby supercooling the refrigerant by performing heat exchange between the second cold storage material and the refrigerant, and then flowing the supercooled refrigerant into the first evaporator. With this configuration, the supercooled refrigerant can be flowed into the first evaporator by performing heat exchange between the second cold storage material and the refrigerant. The specific enthalpy of the refrigerant can be reduced by supercooling, thereby improving the cooling effect of the first evaporator. Therefore, the operating load of the compressor can be reduced by the amount of the improved cooling effect, thereby reducing the power consumption of the compressor (the amount of power supplied from the commercial power system). Therefore, energy conservation of the cooling system can be achieved during heat dissipation operation.

[0017] In the configuration in which the heat storage device further includes a heat exchanger and the control unit switches to heat dissipation operation in which the refrigerant flowing out of the condenser flows into the heat exchanger, preferably, the configuration further includes a switching valve that switches the flow path of the refrigerant flowing out of the refrigerator, the cooling equipment includes multiple cooling equipment, and the control unit controls the switching of the switching valve so that, in the heat storage operation, the heat storage device and the multiple cooling equipment are connected in parallel in the flow path of the refrigerant on the high pressure side, and, in the heat dissipation operation, the heat storage device is connected in series to the multiple cooling equipment connected in parallel in that order in the flow path of the refrigerant on the high pressure side. With this configuration, by switching the switching valve by the control unit, in the heat storage operation, the third evaporator of the heat storage device and the multiple cooling equipment are connected in parallel, so that cold energy can be stored in the second cold storage material by circulating the refrigerant through the third evaporator of the heat storage device, and merchandise can be cooled by circulating the refrigerant through the multiple cooling equipment. Furthermore, by switching the switching valve by the control unit, the supercooler of the heat storage device is connected in series with the multiple cooling devices connected in parallel in this order during heat dissipation operation, so that the refrigerant supercooled in the heat exchanger of the heat storage device can flow into the multiple cooling devices. Therefore, the supercooled refrigerant can be used to cool the products for sale in the multiple cooling devices.

[0018] In the configuration including the heat storage device, the heat storage device preferably further includes a second cold storage material that is an ice slurry, and a heat storage tank in which the second cold storage material is disposed. With this configuration, the second cold storage material that is an ice slurry can be stored in the heat storage tank, and cold can be uniformly transferred by the second cold storage material that has fluidity. Therefore, in the heat exchange between the second cold storage material that is an ice slurry and the refrigerant, the refrigerant can be efficiently supercooled, thereby improving the heat storage performance.

[0019] In the above-described configuration in which the heat storage device includes a second cold storage material that is an ice slurry and a heat storage tank, the heat storage device preferably further includes a third evaporator disposed inside the heat storage tank, a metal tubular member disposed in contact with and surrounded by the third evaporator, and a screw member that rotates to scrape ice generated inside the tubular member to the outside of the tubular member when water or an aqueous solution stored inside the heat storage tank is cooled by the third evaporator through the tubular member, thereby generating the second cold storage material that is an ice slurry. With this configuration, the ice generated inside the tubular member is scraped to the outside of the tubular member by the screw member, thereby continuously generating the second cold storage material that is an ice slurry. As a result, the second cold storage material that is an ice slurry can be efficiently generated.

[0020] In the above configuration including a heat storage device, the heat storage device is preferably provided inside the cooling equipment. With this configuration, the heat storage device is provided inside the first cooling equipment, which is kept at a relatively low temperature. This allows the second cold storage material of the heat storage device to exchange heat with the air outside the heat storage device, thereby preventing a decrease in the cold stored in the second cold storage material. Furthermore, when the second cold storage material of the heat storage device exchanges heat with the air outside the heat storage device, the cold stored in the second cold storage material can be used to cool the inside of the cooling equipment, which should be kept at a relatively low temperature. As a result, energy loss in the cooling system can be reduced. [Effects of the Invention]

[0021] According to the present invention, as described above, it is possible to provide a cooling system that can effectively utilize surplus power generated by a solar power generation device even when there is no storage battery that can sufficiently store the surplus power generated by the solar power generation device. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a schematic diagram of a store in which a cooling system according to a first embodiment is installed. [Figure 2] 1 is a block diagram of a cooling system according to a first embodiment. [Figure 3] 1 is a refrigerant circuit diagram showing a schematic configuration of a refrigeration cycle according to a first embodiment. [Figure 4] FIG. 4 is a schematic diagram showing the flow of air in the first cooling facility. [Figure 5] FIG. 3 is a refrigerant circuit diagram showing the flow of refrigerant when a heat storage operation and a normal operation are performed according to the first embodiment. [Figure 6] FIG. 3 is a refrigerant circuit diagram showing the flow of refrigerant when a heat radiation operation is performed according to the first embodiment. [Figure 7] 4 is a time chart for explaining operation switching control by the control unit according to the first embodiment. [Figure 8] 4 is a flowchart illustrating operation switching control by a control unit according to the first embodiment. [Figure 9] FIG. 6 is a refrigerant circuit diagram showing a schematic configuration of a refrigeration cycle according to a second embodiment. [Figure 10] FIG. 2 is a schematic diagram showing a heat sink. [Figure 11] FIG. 10 is a refrigerant circuit diagram showing a schematic configuration of a refrigeration cycle according to a third embodiment. [Figure 12] FIG. 10 is a block diagram of a cooling system according to a fourth embodiment. [Figure 13] FIG. 10 is a refrigerant circuit diagram showing a schematic configuration of a refrigeration cycle according to a fourth embodiment. [Figure 14] FIG. 10 is a refrigerant circuit diagram showing the flow of refrigerant when a heat storage operation is performed according to a fourth embodiment. [Figure 15] FIG. 10 is a refrigerant circuit diagram showing the flow of refrigerant when a heat radiation operation is performed according to a fourth embodiment. [Figure 16] FIG. 10 is a refrigerant circuit diagram showing the flow of refrigerant during normal operation according to a fourth embodiment. [Figure 17] FIG. 2 is a pH diagram for explaining the state of the refrigerant during heat dissipation operation and normal operation. [Figure 18] 10 is a time chart for explaining operation switching control by a control unit according to a fourth embodiment. [Figure 19]10 is a flowchart illustrating operation switching control by a control unit according to a fourth embodiment. [Figure 20] FIG. 10 is a refrigerant circuit diagram showing a schematic configuration of a refrigeration cycle according to a fifth embodiment. [Figure 21] FIG. 10 is a refrigerant circuit diagram showing the flow of refrigerant when a heat storage operation is performed according to a fifth embodiment. [Figure 22] FIG. 11 is a refrigerant circuit diagram showing the flow of refrigerant when a heat radiation operation is performed according to a fifth embodiment. [Figure 23] FIG. 10 is a refrigerant circuit diagram showing a schematic configuration of a refrigeration cycle according to a sixth embodiment. [Figure 24] FIG. 13 is a refrigerant circuit diagram showing the flow of refrigerant when a heat storage operation is performed according to a sixth embodiment. [Figure 25] 6 is a time chart for explaining operation switching control by a control unit according to a first modified example. [Figure 26] FIG. 10 is a refrigerant circuit diagram showing a schematic configuration of a refrigeration cycle according to a second modified example. [Figure 27] FIG. 10 is a schematic diagram showing a heat storage device according to a third modified example. DETAILED DESCRIPTION OF THE INVENTION

[0023] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

[0024] [First embodiment] A cooling system 100 according to a first embodiment will be described with reference to FIGS.

[0025] (Store overview and cooling system configuration) 1 and 2, the cooling system 100 includes a solar power generation device 1, a refrigerator 2, a cooling facility 3, and a control unit 4. The cooling system 100 of this embodiment is not provided with a storage battery capable of storing surplus power generated by the solar power generation device 1.

[0026] Referring to FIG. 1, a store 90 in which a cooling system 100 is installed will be described. A control unit 4, a cooling facility 3, and a plurality of storage units 5 are arranged inside the store 90. The cooling facility 3 includes a first cooling facility 10 and a plurality of second cooling facilities 20. A solar power generation system 1 and a freezer 2 are arranged outside the store 90. The store 90 is not particularly limited, but may be, for example, a convenience store, a supermarket, or a drugstore. The first cooling facility 10 is an example of the "cooling facility" in the claims.

[0027] In this specification, the vertical direction connecting the ceiling and floor of the store 90 is referred to as the Z direction, with the ceiling side being referred to as the Z1 side and the floor side being referred to as the Z2 side. The front-to-rear direction of the store 90, which is perpendicular to the Z direction, is referred to as the Y direction, with the side where the entrance is located being referred to as the front side (Y1 side) and the side opposite the front side being referred to as the rear side (Y2 side). The left-to-right direction perpendicular to the Y and Z directions is referred to as the X direction. In the X direction, when viewed from the Y1 side to the Y2 side, the right side is referred to as the X1 side and the left side is referred to as the X2 side. Note that FIG. 1 schematically illustrates the arrangement of the cooling system 100.

[0028] The control unit 4 is configured to control the first cooling equipment 10, the second cooling equipment 20, the freezer 2, etc. The control unit 4 is configured, for example, by a processor such as a CPU (Central Processing Unit) and a memory such as a RAM (Random Access Memory). The control unit 4 is located, for example, in the back yard of the store 90.

[0029] The control unit 4 is configured to switch between heat storage operation, heat dissipation operation, and normal operation. Details of the heat storage operation, heat dissipation operation, and normal operation, and details of operation switching control by the control unit 4 will be described later. The control unit 4 is also configured to control power generation by the solar power generation device 1 based on data on the amount of power supply, data on the amount of power generated, and data on the amount of power consumed, acquired by the power measurement unit 8a (see FIG. 2), so as to prevent reverse power flow from occurring to the commercial power source 6 (see FIG. 2). The amount of power supply, amount of power generated, and amount of power consumed will be described later.

[0030] The first cooling equipment 10 is configured to display merchandise 91 for sale (see FIG. 4) and to cool the displayed merchandise 91 for sale. The first cooling equipment 10 includes a first cooling section 11. The first cooling section 11 (see FIG. 3) includes a first expansion valve 12, a first evaporator 13, and a blower 14. The first cooling section 11 (see FIG. 4) is disposed on the ceiling side of the work storage area 10b. The first cooling section 11 circulates cool air within the first cooling equipment 10 by the air blown by the blower 14. Details of the first cooling section 11 will be described later.

[0031] The first refrigeration equipment 10 has a display area 10a and a work storage area 10b within the first refrigeration equipment 10. The display area 10a includes a plurality of shelf sections 10c, and is an area where products for sale 91 are displayed on the plurality of shelf sections 10c. Products for sale 91 (see FIG. 4), such as canned drinks, bottled drinks, and PET bottled drinks, are displayed on the shelf sections 10c.

[0032] The work storage area 10b is an area where workers can work and where replenishment products 92 (see FIG. 4) to be replenished in the display area 10a are stored. The work storage area 10b is an area inside the first cooling equipment 10 other than the area where the multiple shelf sections 10c are provided. In the work storage area 10b, workers perform tasks such as displaying sales products 91 on the shelf sections 10c and carrying in replenishment products 92 to be stored inside the first cooling equipment 10. The replenishment products 92 are products that are replenished to the shelf sections 10c when, for example, the remaining number of sales products 91 displayed on the shelf sections 10c becomes low. The replenishment products 92 are stored in the work storage area 10b. The work storage area 10b also stores sales products 91 to be sold in the second cooling equipment 20.

[0033] Furthermore, a door 10d is provided on the X2 side of the shelf 10c. Customers of the store 90 can open the door 10d to remove products 91 for sale displayed on the shelf 10c from the shelf 10c. Furthermore, an entrance / exit 10e is provided on the Y1 side of the first cooling equipment 10. The first cooling equipment 10 is a so-called walk-in type cooling equipment in which workers can work and replenish products 92 can be stored.

[0034] A first temperature sensor 15 is provided inside the first cooling equipment 10. The first temperature sensor 15 is configured to measure the temperature inside the first cooling equipment 10. The first temperature sensor 15 is also configured to transmit the measured temperature inside the first cooling equipment 10 to the control unit 4.

[0035] The second cooling equipment 20 is configured to display merchandise 91 for sale and to cool the displayed merchandise 91 for sale. The second cooling equipment 20 includes a second cooling section 21. The second cooling section 21 (see FIG. 3) includes a second cooling section expansion valve 22, a second cooling section evaporator 23, and a fan 24. That is, each of the multiple second cooling equipment 20 includes a second cooling section 21 including a second cooling section expansion valve 22 and a second cooling section evaporator 23. Details of the second cooling section 21 will be described later. The second cooling equipment 20 has an opening (not shown) on the front side (Y1 direction side). The second cooling equipment 20 is a so-called open-type cooling equipment. Note that although the number of second cooling equipment 20 is six in FIG. 1, the number of second cooling equipment 20 is not particularly limited. The number of second cooling equipment 20 may be two to five, or may be seven or more. The number of second cooling equipment 20 may also be one.

[0036] The storage section 5 is an article storage section where products such as foodstuffs are stored, and products that are to be stored at room temperature are stored.

[0037] The chiller 2 is connected to the first cooling equipment 10 and the second cooling equipment 20, and constitutes a refrigeration cycle 70. The chiller 2 includes a compressor 30 and a condenser 31. The chiller 2 is provided outside (outdoors) of the store 90. The chiller 2 is provided, for example, on the roof of the store 90 or adjacent to the store 90. The chiller 2 is operated by power supplied from the solar power generation device 1 and a commercial power source 6 (see FIG. 2). Details of the chiller 2 and the refrigeration cycle 70 will be described later.

[0038] 2, the solar power generation device 1 includes, for example, a solar panel 32 and a power conversion unit 33. The solar panel 32 includes a plurality of cells. The solar panel 32 is installed, for example, on the roof of a store 90. The power conversion unit 33 is configured to convert the power generated by the solar panel 32 into power that can be used by a load 7 connected to the solar power generation device 1 within the store 90.

[0039] The load 7 may include, for example, a refrigerator 2, a first cooling equipment 10, a second cooling equipment 20, and store equipment 9 including cooking facilities, beverage brewing equipment, an air conditioning system, and lighting. The cooking facilities are, for example, a fryer for cooking fried foods. The beverage brewing equipment is, for example, a device for producing beverages including coffee and juice. The air conditioning system is an air conditioning system for cooling and heating the store 90. The lighting is, for example, LEDs (Light Emitting Diodes) installed in the store 90.

[0040] The power distribution unit 8 is configured to receive power from the commercial power source 6 and the solar power generation device 1. The power supplied to the power distribution unit 8 is then supplied from the power distribution unit 8 to each of the loads 7. The power distribution unit 8 also includes a power measurement unit 8a. The power measurement unit 8a measures the amount of power supplied from the commercial power source 6, the amount of power generated by the solar power generation device 1, and the amount of power consumed by the loads 7, and transmits data on the measured amount of power supplied, the amount of power generated, and the amount of power consumed to the control unit 4.

[0041] (Configuration of refrigeration cycle in cooling system) Next, the configuration of the refrigeration cycle 70 in the cooling system 100 according to this embodiment will be described with reference to FIG.

[0042] The cooling system 100 includes a refrigeration cycle 70. The refrigeration cycle 70 cools air by circulating a refrigerant. In this embodiment, the air cooled by the refrigeration cycle 70 cools the replenishment products 92 and the sales products 91 in the first cooling equipment 10, and also cools the sales products 91 in the second cooling equipment 20.

[0043] The refrigeration cycle 70 includes a compressor 30, a condenser 31, a first expansion valve 12, a first evaporator 13, a second cooling section expansion valve 22, and a second cooling section evaporator 23. The compressor 30 and the condenser 31 are included in the refrigerator 2. The first expansion valve 12 and the first evaporator 13 are included in the first cooling section 11. The second cooling section expansion valve 22 and the second cooling section evaporator 23 are included in the second cooling section 21. The refrigerant circulates through the refrigeration cycle 70 by flowing through a refrigerant flow path provided in the refrigeration cycle 70. One example of the refrigerant is R448A, but the type of refrigerant is not particularly limited.

[0044] The compressor 30 is configured to compress a refrigerant. Specifically, the compressor 30 compresses a low-pressure refrigerant vapor into a high-pressure gas-phase refrigerant.

[0045] The condenser 31 is configured to condense the high-pressure refrigerant vapor compressed in the compressor 30 into a high-pressure liquid-phase refrigerant. The condenser 31 is disposed downstream of the compressor 30. A blower fan (not shown) is provided near the condenser 31. In the condenser 31, heat is removed from the refrigerant by air sent by the blower fan.

[0046] The first evaporator 13 of the first cooling section 11 and each of the multiple second cooling section evaporators 23 are provided in parallel downstream of the condenser 31 and upstream of the compressor 30. A first branch section 71 that branches the refrigerant flow path is provided downstream of the condenser 31 and upstream of the first evaporator 13 and the multiple second cooling section evaporators 23. The first branch section 71 branches into a flow path through which the refrigerant flowing out of the condenser 31 flows into the first expansion valve 12 and a flow path through which the refrigerant flowing out of the condenser 31 flows into the second cooling section expansion valve 22. The refrigerant flows into the first evaporator 13 via the first branch section 71 and the first expansion valve 12, and the refrigerant flows into each of the multiple second cooling section evaporators 23 via the first branch section 71 and the second cooling section expansion valve 22.

[0047] The first expansion valve 12 is configured to expand the high-pressure liquid-phase refrigerant flowing out from the condenser 31 to produce a low-pressure, low-temperature liquid-phase refrigerant. The first expansion valve 12 is, for example, an electronic expansion valve, and its opening degree is adjusted based on the control of the control unit 4. Alternatively, the opening degree of the first expansion valve 12 is adjusted by the first cooling equipment 10 based on a command from the control unit 4. Note that the first expansion valve 12 is not limited to an electronic expansion valve, and may be, for example, a combination of a temperature expansion valve and a solenoid valve. The first expansion valve 12 is arranged downstream of the first branch unit 71 and upstream of the first evaporator 13.

[0048] The first evaporator 13 is configured to cool the air in the first refrigeration equipment 10 by evaporating the refrigerant expanded by the first expansion valve 12. As shown in Fig. 4(a), during normal operation, in the first evaporator 13, the low-pressure, low-temperature liquid-phase refrigerant flowing out from the first expansion valve 12 becomes low-pressure gas-phase refrigerant, and absorbs heat from the air in the first refrigeration equipment 10 supplied by the forward rotating blower 14. As a result, the merchandise 91 in the first refrigeration equipment 10 is cooled by the air that has absorbed the heat.

[0049] The second cooling section expansion valve 22 is configured to expand the high-pressure liquid-phase refrigerant flowing out from the condenser 31 to produce a low-pressure, low-temperature liquid-phase refrigerant. The second cooling section expansion valve 22 is, for example, an electronic expansion valve, and its opening degree is adjusted based on the control of the control unit 4. Alternatively, the opening degree of each of the multiple second cooling section expansion valves 22 is adjusted by each of the multiple second cooling devices 20 based on commands from the control unit 4. Note that the second cooling section expansion valve 22 is not limited to an electronic expansion valve and may be, for example, a combination of a temperature expansion valve and a solenoid valve. The second cooling section expansion valve 22 is arranged downstream of the first branch section 71 and upstream of the second cooling section evaporator 23.

[0050] The second cooling section evaporator 23 is configured to cool the air in the second cooling equipment 20 by evaporating the refrigerant expanded by the second cooling section expansion valve 22. In the second cooling section evaporator 23, the low-pressure, low-temperature liquid-phase refrigerant flowing out from the second cooling section expansion valve 22 becomes a low-pressure gas-phase refrigerant, and absorbs heat from the air in the second cooling equipment 20. As a result, the air that has absorbed the heat and been cooled circulates through the second cooling equipment 20 via the fan 24, thereby cooling the products for sale in the second cooling equipment 20.

[0051] (The control unit switches between heat storage operation, heat dissipation operation, and normal operation.) The heat storage operation, heat dissipation operation, and normal operation in this embodiment will be described with reference to FIGS.

[0052] (Heat storage operation) The heat storage operation will be described with reference to Figures 4(b) and 5. The control unit 4 is configured to perform a heat storage operation in which cold heat is stored by operating the compressor 30 using the surplus power when there is surplus power generated by the solar power generation device 1 that exceeds the power consumption of the load 7 including the chiller 2 connected to the solar power generation device 1. Specifically, when there is surplus power generated by the solar power generation device 1, the control unit 4 performs a heat storage operation in which cold heat is stored by further operating the compressor 30.

[0053] More specifically, the control unit 4 is configured to use surplus power during the heat storage operation to increase the operating load of the compressor 30 to raise the temperature inside the first cooling equipment 10 to a heat storage operation temperature that is lower than the normal set temperature during normal operation, thereby storing cold heat in the replenishment products 92 stored in the work storage area 10b. Also, as shown in FIG. 4(b), during the heat storage operation, the control unit 4 is configured to rotate the blower 14 in the reverse direction, which rotates forward during normal operation, so that the blower 14 blows air toward the work storage area 10b.

[0054] As shown in Fig. 5, the heat storage operation is an operation mode in which the interior of the first cooling equipment 10 is cooled by air cooled by the first evaporator 13, and the interior of the second cooling equipment 20 is cooled by air cooled by the second cooling section evaporator 23. In this case, the refrigerant compressed by the compressor 30 flows through the condenser 31, and then flows through the first branch section 71 to the first expansion valve 12 and the first evaporator 13, or flows through the first branch section 71 to the second cooling section expansion valve 22 and the second cooling section evaporator 23, and is then drawn into the compressor 30. The refrigerant is then compressed by the compressor 30 and repeats the above-mentioned circulation.

[0055] When surplus power is generated by the solar power generation device 1 that exceeds the power consumption of the load 7, including the chiller 2, connected to the solar power generation device 1, based on data on the amount of power supply, data on the amount of power generated, and data on the amount of power consumed measured by the power measurement device 8a, the control device 4 uses the surplus power to increase the operating load of the compressor 30 in order to set the temperature inside the first cooling device 10 to a heat-storage operating temperature that is lower than the normal set temperature during normal operation. The control device 4 increases the operating load of the compressor 30 by using the surplus power by performing feedback control based on the temperature inside the first cooling device 10 measured by the first temperature sensor 15 in order to set the temperature inside the first cooling device 10 to a heat-storage operating temperature that is lower than the normal set temperature during normal operation.

[0056] 4(a), in normal operation, the blower 14 rotates forward, and the air cooled by the first evaporator 13 is sent toward the display area 10a where the sales products 91 are displayed. In contrast, as shown in FIG. 4(b), in heat storage operation, the control unit 4 controls the blower 14 to rotate in the reverse direction, and the air cooled by the first evaporator 13 is sent toward the work storage area 10b where the replenishment products 92 are stored. In addition, in heat storage operation, the control unit 4 increases the rotation speed of the blower 14 above the rotation speed during normal operation.

[0057] The control unit 4 uses surplus power to increase the operating load of the compressor 30 to reach the heat storage operating temperature, and also reverses the rotation of the blower 14 and increases the rotation speed of the blower 14, thereby storing cold heat in the replenishment products 92 stored in the work storage area 10b during the heat storage operation. Also, through the heat storage operation, cold heat is stored in the sales products 91 stored in the display area 10a.

[0058] In this embodiment, the temperature of the refrigerant flowing into the first evaporator 13 is, for example, 0°C to -15°C. Specifically, the temperature of the refrigerant flowing into the first evaporator 13 is, for example, -5°C to -6°C. The temperature of the refrigerant flowing into the first evaporator 13 is not limited to 0°C to -15°C. The normal set temperature of the first cooling equipment 10 during normal operation is, for example, a temperature below the target product temperature of 5°C. The target product temperature of the products displayed in the first cooling equipment 10 is not limited to 5°C. The heat storage operation temperature in the first cooling equipment 10 is a temperature higher than 0°C and lower than the normal set temperature. The heat storage operation temperature in the first cooling equipment 10 is, for example, 2°C to 3°C.

[0059] (heat dissipation operation) The heat dissipation operation will be described with reference to Figures 4(a) and 6. When the state changes from one in which there is surplus power to one in which there is no surplus power, the control unit 4 is configured to switch from the heat storage operation to the heat dissipation operation in which the stored cold heat is dissipated using the surplus power to cool at least the products for sale 91 of the first cooling equipment 10.

[0060] Specifically, when there is no surplus electricity, the control unit 4 is configured to switch from heat storage operation to heat dissipation operation, in which the refrigerant is not circulated through the first evaporator 13 and the cold heat stored in the replenishment product 92 is dissipated until the temperature inside the first cooling equipment 10 reaches the normal set temperature.

[0061] As shown in FIG. 6 , the heat radiation operation is an operating mode in which the interior of the first cooling unit 10 is cooled by the cold stored in the replenishment product 92 during the heat storage operation, and the interior of the second cooling unit 20 is cooled by the air cooled by the second cooling unit evaporator 23. In the heat radiation operation, the control unit 4 fully closes the first expansion valve 12. Therefore, the refrigerant compressed by the compressor 30 flows through the condenser 31, then through the first branching unit 71 to the second cooling unit expansion valve 22 and the second cooling unit evaporator 23, and is then drawn into the compressor 30. Because the first expansion valve 12 is fully closed, the refrigerant that has flowed through the condenser 31 does not flow from the first branching unit 71 to the first evaporator 13 via the first expansion valve 12. The refrigerant is then compressed by the compressor 30 and repeats the above-described cycle.

[0062] When there is no surplus power in the power generated by the solar power generation device 1 that exceeds the power consumption of the load 7, including the chiller 2 connected to the solar power generation device 1, based on data on the amount of power supply, data on the amount of power generated, and data on the amount of power consumed measured by the power measurement device 8a, the control device 4 switches from the heat storage operation to the heat dissipation operation in which the cold heat stored in the replenishment product 92 is dissipated without circulating refrigerant through the first evaporator 13. In the heat dissipation operation, the inside of the first cooling equipment 10 is cooled not by air cooled by the first evaporator 13, but by dissipating the cold heat stored in the replenishment product 92. Therefore, the control device 4 reduces the operating load of the compressor 30.

[0063] Furthermore, the control unit 4 performs the heat radiation operation until the temperature inside the first cooling equipment 10 acquired by the first temperature sensor 15 reaches the normal set temperature. Furthermore, as shown in Fig. 4(a), during the heat radiation operation, the control unit 4 rotates the blower 14 in the forward direction and reduces the rotation speed of the blower 14 below the rotation speed during the normal operation and the heat storage operation, or stops the blower 14. Note that the control unit 4 may stop the blower 14 during the heat radiation operation.

[0064] In the heat dissipation operation, the first expansion valve 12 is fully closed by the control unit 4, so that the refrigerant does not flow into the first evaporator 13, but the cold stored in the replenishment product 92 during the heat storage operation is dissipated inside the first cooling equipment 10 using surplus power, thereby cooling the air inside the first cooling equipment 10 and cooling the sales product 91 of the first cooling equipment 10. Note that if the first expansion valve 12 is a combination of a temperature expansion valve and a solenoid valve, the solenoid valve is closed in the heat dissipation operation.

[0065] (Normal operation) Normal operation will now be described. When the temperature inside the first cooling equipment 10 acquired by the first temperature sensor 15 reaches the normal set temperature, the control unit 4 switches from heat dissipation operation to normal operation. As shown in Fig. 5, normal operation is an operation mode in which, even though there is no surplus power, the compressor 30 is operated using at least the power supplied from the commercial power source 6, thereby cooling the inside of the first cooling equipment 10 with air cooled by the first evaporator 13 and cooling the inside of the second cooling equipment 20 with air cooled by the second cooling unit evaporator 23.

[0066] In normal operation, the control unit 4 increases the operating load of the compressor 30 more than during heat radiation operation in order to set the temperature inside the first cooling equipment 10 to the normal set temperature during normal operation. The control unit 4 also increases the rotation speed of the blower 14 more than during heat radiation operation.

[0067] In normal operation, the refrigerant compressed by the compressor 30 flows through the condenser 31, and then flows through the first expansion valve 12 and the first evaporator 13 via the first branch section 71, or flows through the second cooling section expansion valve 22 and the second cooling section evaporator 23 via the first branch section 71, and is then drawn into the compressor 30. The refrigerant is then compressed by the compressor 30 and repeats the above-described circulation.

[0068] The control unit 4 is configured to switch from normal operation to heat storage operation when the power generated by the solar power generation device 1 generates surplus power that exceeds the power consumption of the load 7, including the refrigerator 2 connected to the solar power generation device 1, based on data regarding the amount of power supplied, data regarding the amount of power generated, and data regarding the amount of power consumed measured by the power measurement unit 8a.

[0069] (Operation switching control by the control unit) The operation switching control by the control unit 4 will be described with reference to FIG. 7. At time t0, the solar power generation system 1 is not generating power, or there is no surplus power among the power generated by the solar power generation system 1. Therefore, normal operation is performed at time t0. Specifically, the control unit 4 operates the compressor 30 using power supplied from at least the commercial power source 6, thereby cooling the interior of the first cooling system 10 with air cooled by the first evaporator 13 so that the temperature inside the first cooling system 10 reaches the normal set temperature, and cooling the interior of the second cooling system 20 with air cooled by the second cooling unit evaporator 23. Note that from time t1 to time t2, a defrosting operation is performed to remove frost adhering to the first evaporator 13 and the second cooling unit evaporator 23. The normal operation is performed until surplus power is generated.

[0070] At time t3, the power generated by the solar power generation device 1 exceeds the power consumption of the load 7, including the chiller 2 connected to the solar power generation device 1. Therefore, from time t3, normal operation is replaced by heat storage operation. Specifically, based on the data on the amount of power supply, the data on the amount of power generated, and the data on the amount of power consumed measured by the power measurement unit 8a, the control unit 4 determines that the power generated by the solar power generation device 1 exceeds the power consumption of the load 7, including the chiller 2 connected to the solar power generation device 1, at time t3. Therefore, the control unit 4 uses the surplus power to increase the operating load of the compressor 30 to raise the temperature inside the first cooling equipment 10 to a heat storage operation temperature that is lower than the normal set temperature during normal operation. As a result, during the heat storage operation, cold heat is stored in the replenishment products 92 stored in the work storage area 10b. The heat storage operation is continued until there is no surplus power.

[0071] At time t4, the power generated by the solar power generation device 1 changes from a state in which there is surplus power to a state in which there is no surplus power. Therefore, from time t4, heat dissipation operation is performed instead of heat storage operation. Specifically, based on the data on the amount of power supply, the data on the amount of power generated, and the data on the amount of power consumed measured by the power measurement unit 8a at time t4, the control unit 4 determines that there is no surplus power in the power generated by the solar power generation device 1 that exceeds the power consumption of the load 7, including the chiller 2 connected to the solar power generation device 1. Therefore, the control unit 4 does not circulate refrigerant through the first evaporator 13, but rather dissipates the cold energy stored in the replenishment product 92. In addition, the control unit 4 reduces the operating load of the compressor 30. As a result, in the heat dissipation operation, the interior of the first cooling equipment 10 is cooled not by air cooled by the first evaporator 13, but by dissipating the cold energy stored in the replenishment product 92. From time t5 to time t6, a defrosting operation is performed to remove frost adhering to the first evaporator 13 and the second cooling section evaporator 23. The heat dissipation operation is performed until the temperature inside the first cooling equipment 10 acquired by the first temperature sensor 15 reaches the normal set temperature.

[0072] At time t7, the temperature inside the first cooling device 10 acquired by the first temperature sensor 15 reaches the normal set temperature. Therefore, from time t7, the heat dissipation operation is replaced with normal operation. The normal operation is continued until surplus power is generated.

[0073] (Operation switching control process by the control unit) The operation switching process by the control unit 4 will be described with reference to Fig. 8. The process shown in Fig. 8 starts when normal operation starts. The order of the processing steps can be reversed or executed simultaneously as long as there are no contradictions.

[0074] In step S1, if the control unit 4 determines, based on the data regarding the amount of power supplied, the data regarding the amount of power generated, and the data regarding the amount of power consumed measured by the power measuring unit 8a, that the power generated by the solar power generation device 1 will generate surplus power that exceeds the power consumed by the load 7, including the refrigerator 2 connected to the solar power generation device 1 (Yes in step S1), the processing proceeds to step S2, and if it determines that surplus power will not be generated (No in step S1), the processing repeats the judgment of step S1.

[0075] In step S2, the control unit 4 switches from normal operation to heat storage operation, after which the process proceeds to step S3.

[0076] In step S3, if the control unit 4 determines that there is no surplus power based on the data regarding the amount of power supplied, the data regarding the amount of power generated, and the data regarding the amount of power consumed measured by the power measuring unit 8a (Yes in step S3), the processing proceeds to step S4, and if it determines that surplus power will be generated (No in step S3), the processing repeats the determination in step S3.

[0077] In step S4, the control unit 4 switches from the heat storage operation to the heat release operation, and then the process proceeds to step S5.

[0078] In step S5, if the control unit 4 determines that the temperature inside the first cooling equipment 10 acquired by the first temperature sensor 15 has reached the normal set temperature (Yes in step S5), the processing proceeds to step S6, and if the control unit 4 determines that the temperature inside the first cooling equipment 10 has not reached the normal set temperature (No in step S5), the processing repeats the judgment of step S5.

[0079] In step S6, the control unit 4 switches from the heat radiation operation to the normal operation, after which the process returns to step S1.

[0080] (Effects of the first embodiment) In the first embodiment, the following effects can be obtained.

[0081] In the first embodiment, as described above, when the power generated by the solar power generation device 1 exceeds the power consumed by the load 7, including the chiller 2 connected to the solar power generation device 1, the control unit 4 is configured to perform a heat storage operation using the surplus power to operate the compressor 30 and store cold heat. As a result, even if a storage battery for storing the power generated by the solar power generation device 1 is not provided, when surplus power is generated by the solar power generation device 1, the control unit 4 can store cold heat using the surplus power by performing a heat storage operation without controlling the power generation by the solar power generation device 1. Therefore, when there is no surplus power from the solar power generation device 1, the cold heat stored using the surplus power can be used. Therefore, even if there is no storage battery capable of sufficiently storing the surplus power from the power generated by the solar power generation device 1, the surplus power from the solar power generation device 1 can be effectively used.

[0082] Furthermore, in the first embodiment, as described above, when the state transitions from one in which there is surplus power to one in which there is no surplus power, the control unit 4 is configured to switch from the heat storage operation to the heat dissipation operation in which the stored cold heat is dissipated using the surplus power to cool at least the products for sale 91 of the first cooling equipment 10. As a result, by switching from the heat storage operation to the heat dissipation operation when there is no surplus power, the control unit 4 can dissipate the stored cold heat using the surplus power. Therefore, when there is no surplus power, it is possible to cool at least the products for sale 91 of the first cooling equipment 10 while achieving energy conservation in the cooling system 100 by reducing the amount of power supplied from the commercial power source 6. Therefore, even when there is no storage battery capable of sufficiently storing the surplus power generated by the solar power generation device 1, the surplus power generated by the solar power generation device 1 can be effectively utilized.

[0083] Furthermore, in the first embodiment, as described above, the first cooling equipment 10 further includes a display area 10a for displaying products for sale 91 and a work storage area 10b in which a worker can work and which stores replenishment products 92 to be replenished in the display area 10a, and the control unit 4 is configured to operate the compressor 30 in the heat storage operation so that the temperature inside the first cooling equipment 10 becomes a heat storage operation temperature that is lower than the normal set temperature during normal operation, thereby storing cold energy in the replenishment products 92 stored in the work storage area 10b. As a result, in the heat storage operation, surplus electricity can be used by increasing the operating load of the compressor 30 to make the temperature inside the first cooling equipment 10 become a heat storage operation temperature that is lower than the normal set temperature, and cold energy can be stored in the replenishment products 92 stored in the work storage area 10b, the temperature of which has been lowered to the heat storage operation temperature. Therefore, by storing cold heat in the replenishment products 92 stored in the work storage area 10b, the surplus electricity generated by the solar power generation device 1 can be appropriately and effectively utilized even if there is no storage battery capable of sufficiently storing the surplus electricity generated by the solar power generation device 1.

[0084] Furthermore, in the first embodiment, as described above, when there is no surplus power, the control unit 4 is configured to switch from the heat storage operation to the heat release operation in which the cold energy stored in the replenishment products 92 is released without circulating the refrigerant through the first evaporator 13. As a result, by not circulating the refrigerant through the first evaporator 13 during the heat release operation, the operating load on the compressor 30 can be reduced and the power consumption of the compressor 30 can be reduced. Therefore, the amount of power supplied from the commercial power source 6 can be reduced, thereby easily achieving energy savings in the cooling system 100, while during the heat release operation, the cold energy stored in the replenishment products 92 can be released to cool the products for sale 91.

[0085] Furthermore, in the first embodiment, as described above, the first cooling equipment 10 includes the blower 14, and the control unit 4 is configured to cause the blower 14 to blow air toward the work storage area 10b during the heat storage operation by rotating the blower 14 in the reverse direction, which rotates in the forward direction during normal operation. As a result, by rotating the blower 14 in the reverse direction during the heat storage operation, the blower 14 blows air toward the work storage area 10b, so that cold energy can be efficiently stored in the replenishment products 92 stored in the work storage area 10b without adding a new blower.

[0086] [Second embodiment] Next, a cooling system 100 according to a second embodiment of the present invention will be described with reference to Fig. 9. Unlike the first embodiment, the second embodiment will describe an example in which a first cold storage material 81 is provided in the first cooling section 11 of the first cooling equipment 10. Note that the same components as those in the first embodiment will be denoted by the same reference numerals, and descriptions thereof will be omitted.

[0087] 9, the first cooling equipment 10 includes a first cold storage material 81. Specifically, the first cooling section 11 of the first cooling equipment 10 includes a first expansion valve 12, a first evaporator 13, a blower 14, and the first cold storage material 81.

[0088] As an example, the first cold storage material 81 is a latent heat type cold storage material that stores cold energy by changing its phase from liquid to solid and releases the stored cold energy by changing its phase from solid to liquid. The first cold storage material 81 includes, for example, a hydrate or a paraffin-based material that contains water as the main component and an additive. The phase change temperature (freezing point) of the first cold storage material 81 is, for example, 2°C, which is the heat storage operating temperature in the first cooling equipment 10. The phase change temperature of the first cold storage material 81 is not particularly limited.

[0089] Furthermore, a heat dissipation plate 16 (see FIG. 10) provided with a plurality of fins 16a is arranged on one surface of the first cold storage material 81 so as to be in contact with the first cold storage material 81. The plurality of fins 16a are arranged so as to protrude in the opposite direction from the first cold storage material 81. The plurality of fins 16a can improve the cold storage capacity of the first cold storage material 81 and the heat dissipation capacity of the cold stored in the first cold storage material 81.

[0090] The first cold storage material 81 is disposed on the ceiling side of the work storage area 10b (see FIG. 4). The first cold storage material 81 is disposed at a position where air blown out from the first evaporator 13 by the blower 14 rotating forward flows through.

[0091] The control unit 4 is configured to, during the heat storage operation, cause the blower 14 to blow the air blown out from the first evaporator 13 toward the work storage area 10b via the first cold storage material 81. That is, as shown in FIG. 4(b), during the heat storage operation, the control unit 4 controls the air cooled by the first evaporator 13 to be sent toward the work storage area 10b where the replenishment products 92 are stored via the first cold storage material 81. Furthermore, during the heat storage operation, the control unit 4 increases the rotation speed of the blower 14 above the rotation speed during normal operation.

[0092] In order to reach the heat storage operation temperature, the control unit 4 uses surplus power to increase the operating load of the compressor 30 and also increases the rotation speed of the blower 14, so that during the heat storage operation, cold heat is stored in the first cold storage material 81 and in the replenishment products 92 stored in the work storage area 10b. Furthermore, due to the heat storage operation, cold heat is also stored in the sales products 91 stored in the display area 10a.

[0093] Furthermore, the control unit 4 is configured to radiate the cold stored in the replenishment products 92 and the first cold storage material 81 during the heat radiation operation without causing refrigerant to flow into the first evaporator 13. That is, during the heat radiation operation, the inside of the first cooling equipment 10 is not cooled by air cooled by the first evaporator 13, but is cooled by radiating the cold stored in the first cold storage material 81 and the replenishment products 92. Furthermore, the control unit 4 reduces the operating load of the compressor 30.

[0094] During heat dissipation operation, surplus electricity generated during heat storage operation is used to dissipate the cold heat stored in the first cold storage material 81 and the replenishment products 92 inside the first cooling equipment 10, thereby cooling the air inside the first cooling equipment 10 and the products for sale 91 in the first cooling equipment 10.

[0095] The other configurations of the second embodiment are the same as those of the first embodiment.

[0096] (Effects of the second embodiment) In the second embodiment, as described above, the first cooling equipment 10 includes the first cold storage material 81, and the control unit 4 is configured to, in the heat storage operation, cause the blower 14 to blow air blown out from the first evaporator 13 toward the work storage area 10b via the first cold storage material 81, and to, in the heat release operation, release the cold stored in the replenishment products 92 and the first cold storage material 81 without allowing refrigerant to flow into the first evaporator 13. As a result, in the heat storage operation, cold can be stored in both the replenishment products 92 and the first cold storage material 81 by the cooled air blown out from the first evaporator 13, and in the heat release operation, cold can be released from both the replenishment products 92 and the first cold storage material 81. Therefore, in the heat release operation, with a simple configuration, the sales products 91 can be further cooled by the cold released from both the replenishment products 92 and the first cold storage material 81.

[0097] The other effects of the second embodiment are the same as those of the first embodiment.

[0098] [Third embodiment] Next, a cooling system 100 according to a third embodiment of the present invention will be described with reference to Fig. 11. Unlike the first embodiment in which the first cooling section 11 of the first cooling equipment 10 is provided with a first cold storage material 81, the second embodiment will describe an example in which the first cooling section 11 of the first cooling equipment 10 is provided with a first cold storage material cooling section 17 including the first cold storage material 81. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and descriptions thereof will be omitted.

[0099] 11, the first cooling equipment 10 includes a first cold storage material cooling unit 17. Specifically, the first cooling unit 11 of the first cooling equipment 10 includes a first expansion valve 12, a first evaporator 13, a blower 14, and the first cold storage material cooling unit 17 including a first cold storage material 81.

[0100] The first cold storage material cooling unit 17 cools the first cold storage material 81 by circulating a refrigerant. In this embodiment, the first cold storage material 81 cooled by the first cold storage material cooling unit 17 cools the air in the first cooling equipment 10, thereby cooling the replenishment products 92 and the sales products 91. Note that the first cold storage material cooling unit 17 may be configured not to include the first cold storage material 81, but to include a cold storage material different from the first cold storage material 81.

[0101] The first cold storage material cooling section 17 is disposed on the ceiling side of the work storage area 10b. The first cold storage material cooling section 17 is provided in parallel with the first evaporator 13. That is, the first cold storage material cooling section 17 and the first evaporator 13 of the first cooling section 11 are provided in parallel downstream of the condenser 31 and upstream of the compressor 30. A second branch section 72 that branches the refrigerant flow path is provided downstream of the condenser 31 and upstream of the first cold storage material cooling section 17. The refrigerant flows into the first cold storage material cooling section 17 via the second branch section 72.

[0102] The first cold storage material cooling section 17 includes a second expansion valve 18, a second evaporator 19, and a first cold storage material 81.

[0103] The second expansion valve 18 is configured to expand the high-pressure liquid-phase refrigerant flowing out from the condenser 31 to produce a low-pressure, low-temperature liquid-phase refrigerant. The second expansion valve 18 is, for example, an electronic expansion valve, and its opening degree is adjusted under the control of the control unit 4. Note that the second expansion valve 18 is not limited to an electronic expansion valve, and may be, for example, a combination of a thermal expansion valve and a solenoid valve. The second expansion valve 18 is disposed downstream of the second branch unit 72 and upstream of the second evaporator 19.

[0104] The second evaporator 19 is configured to cool the first cold storage material 81 by evaporating the refrigerant expanded by the second expansion valve 18. During cold storage operation, in the second evaporator 19, the low-pressure, low-temperature liquid-phase refrigerant flowing out from the second expansion valve 18 becomes a low-pressure gas-phase refrigerant, and absorbs heat from the first cold storage material 81, thereby cooling the first cold storage material 81. During heat release operation, the cooled first cold storage material 81 cools the air in the first cooling equipment 10, thereby cooling the replenishment products 92 and the sales products 91.

[0105] The second evaporator 19 includes a metal plate (not shown) and a refrigerant flow path provided inside the metal plate. A first cold storage material 81 is disposed on one side of the metal plate. The refrigerant flow path may have a structure that bends multiple times inside the evaporator in order to efficiently store cold energy in the first cold storage material 81. The structure of the second evaporator 19 is not particularly limited.

[0106] A heat sink 16 having a plurality of fins 16a is disposed on the surface of the first cold storage material 81 opposite to the metal plate so as to come into contact with the first cold storage material 81.

[0107] In the heat storage operation, the refrigerant compressed by the compressor 30 flows through the condenser 31, and then flows through the first expansion valve 12 and the first evaporator 13 via the first branch section 71, or flows through the second expansion valve 18 and the second evaporator 19 via the second branch section 72, or flows through the second cooling section expansion valve 22 and the second cooling section evaporator 23 via the second branch section 72, and is then drawn into the compressor 30. The refrigerant is then compressed by the compressor 30 and repeats the above-described circulation. In the heat dissipation operation, the refrigerant compressed by the compressor 30 flows through the condenser 31, and then flows through the second branch section 72 through the second cooling section expansion valve 22 and the second cooling section evaporator 23, and is then drawn into the compressor 30. Because the first expansion valve 12 and the second expansion valve 18 are fully closed, the refrigerant that has circulated through the condenser 31 does not flow from the first branch part 71 through the first expansion valve 12 into the first evaporator 13, and does not flow from the second branch part 72 through the second expansion valve 18 into the second evaporator 19. The refrigerant is then compressed by the compressor 30 and repeats the above-described circulation.

[0108] The control unit 4 is configured to store cold energy in the first cold storage material 81 by the second evaporator 19 during the heat storage operation. That is, during the heat storage operation, the control unit 4 controls the refrigerant to flow through the second evaporator 19 via the second expansion valve 18, whereby the second evaporator 19 stores cold energy in the first cold storage material 81.

[0109] Furthermore, the control unit 4 is configured to dissipate the cold stored in the replenishment products 92 and the first cold storage material 81 during the heat dissipation operation without causing refrigerant to flow into the first evaporator 13 and the second evaporator 19. That is, during the heat dissipation operation, the inside of the first cooling equipment 10 is not cooled by air cooled by the first evaporator 13, but is cooled by dissipating the cold stored in the replenishment products 92 and the first cold storage material 81. Furthermore, the control unit 4 reduces the operating load of the compressor 30.

[0110] During heat dissipation operation, surplus electricity generated during heat storage operation is used to dissipate the cold heat stored in the replenishment products 92 and the first cold storage material 81 inside the first cooling equipment 10, thereby cooling the air inside the first cooling equipment 10 and the products for sale 91 in the first cooling equipment 10.

[0111] The other configurations of the third embodiment are the same as those of the first embodiment.

[0112] (Effects of the third embodiment) In the third embodiment, as described above, the first cooling equipment 10 includes the second evaporator 19 that evaporates the expanded refrigerant by the second expansion valve 18 that expands the refrigerant condensed by the condenser 31, the first cold storage material 81 that is cooled by the second evaporator 19, and the first cold storage material cooling unit 17 that is provided in parallel with the first evaporator 13, and the control unit 4 is configured to store cold energy in the first cold storage material 81 by the second evaporator 19 in the heat storage operation, and to release the cold energy stored in the replenishment product 92 and the first cold storage material 81 in the heat release operation without allowing refrigerant to flow into the first evaporator 13 and the second evaporator 19. As a result, in the heat storage operation, cold energy can be stored in the first cold storage material 81 by the second evaporator 19, and cold energy can be stored in the replenishment product 92 by the cooled air blown out from the first evaporator 13. Therefore, in the heat storage operation, cold energy can be easily stored in the first cold storage material 81 via the second evaporator 19. Furthermore, in the heat release operation, cold energy can be released from both the replenishment products 92 and the first cold storage material 81. Therefore, in the heat release operation, the products for sale 91 can be further cooled by the cold energy released from both the replenishment products 92 and the first cold storage material 81.

[0113] The other effects of the third embodiment are the same as those of the first embodiment.

[0114] [Fourth embodiment] Next, a cooling system 100 according to a fourth embodiment of the present invention will be described with reference to Fig. 1 and Fig. 12 to Fig. 19. Unlike the first embodiment, in the fourth embodiment, an example will be described in which the cooling system 100 includes a heat storage device 40. Note that the same components as those in the first embodiment will be assigned the same reference numerals, and descriptions thereof will be omitted.

[0115] (Cooling system configuration) 1, 12, and 13, the cooling system 100 includes a solar power generation device 1, a refrigerator 2, a heat storage device 40, a first switching valve 75, a cooling facility 3, and a control unit 4. Note that the cooling system 100 of this embodiment is also not provided with a storage battery capable of storing surplus power generated by the solar power generation device 1.

[0116] A control unit 4, a cooling system 3, and multiple storage units 5 are arranged inside the store 90. The cooling system 3 includes a first cooling system 10 and multiple second cooling systems 20. A solar power generation system 1, a refrigerator 2, a heat storage system 40, and a first switching valve 75 are arranged outside the store 90. The first switching valve 75 and the heat storage system 40 may be arranged inside the store 90 and outside the first cooling system 10 and the second cooling system 20. The first cooling system 10 and the multiple second cooling systems 20 are examples of "cooling systems" in the claims. The first evaporator 13 of the first cooling system 10 and the second cooling section evaporator 23 of the second cooling system 20 are examples of "first evaporators" in the claims. The first expansion valve 12 of the first cooling system 10 and the second cooling section expansion valve 22 of the second cooling system 20 are examples of "first expansion valves" in the claims. The first switching valve 75 is an example of the "switching valve" in the claims.

[0117] 13, the heat storage device 40 includes a third expansion valve 41, a third evaporator 42, a heat exchanger 43, a second cold storage material 82, a heat storage tank 44, and a second temperature sensor 46 (see FIG. 12). The third expansion valve 41, the third evaporator 42, and the heat exchanger 43 will be described in detail later.

[0118] The second cold storage material 82 is cooled by the evaporation of the refrigerant that has flowed into the third evaporator 42 via the third expansion valve 41. The second cold storage material 82 also exchanges heat with the refrigerant that has flowed into the heat exchanger 43, thereby supercooling the refrigerant by latent heat.

[0119] The second cold storage material 82 is, for example, a latent heat type cold storage material that stores cold energy by changing its phase from liquid to solid and releases the stored cold energy by changing its phase from solid to liquid. The second cold storage material 82 is, for example, ice slurry. Ice slurry is a solution containing several tens of volume percent ice and, unlike ice, has fluidity. As described above, for example, since the temperature of the refrigerant flowing into the first evaporator 13 is −5°C to −6°C, the phase change temperature of the second cold storage material 82 is, for example, −2°C to −3°C. Note that the second cold storage material 82 is not limited to ice slurry and may be, for example, water, a hydrate containing water as the main component and an additive, or a paraffin-based material. The phase change temperature of the second cold storage material 82 is not limited to −2°C to −3°C and can be set appropriately depending on the temperature of the refrigerant flowing into the first evaporator 13 and the second cooling unit evaporator 23.

[0120] The second cold storage material 82 contains an ice crystal growth inhibitor that inhibits the growth of ice crystals. This prevents the fluidity of the second cold storage material 82 from decreasing due to the growth of ice crystals, thereby enabling consistent and efficient transfer of cold. The second cold storage material 82 also contains a freezing point depressant that adjusts the phase change temperature of the second cold storage material 82. This allows the phase change temperature (freezing point) of the second cold storage material 82 to be adjusted to a desired phase change temperature. Note that the second cold storage material 82 does not necessarily need to contain the ice crystal growth inhibitor or the freezing point depressant.

[0121] A second cold storage material 82 is disposed in the heat storage tank 44. The heat storage tank 44 has, for example, a box shape. The heat storage tank 44 includes an upper portion, a bottom portion, and side portions connecting the upper portion and the bottom portion. The upper portion, bottom portion, and side portions are configured to include a heat insulating member 45 that blocks the second cold storage material 82 from the outside air and restricts the transfer of heat. Inside the heat storage tank 44, a third evaporator 42, a heat exchanger 43, and a second cold storage material 82 accommodated so as to surround the third evaporator 42 and the heat exchanger 43 are disposed. The heat storage tank 44 is provided, for example, on the roof of the store 90 or adjacent to the store 90. The heat storage tank 44 is also provided with an agitator (not shown) for agitating the second cold storage material 82. The agitator may not be provided in the heat storage tank 44.

[0122] The second temperature sensor 46 (see FIG. 12 ) is configured to detect the temperature of the refrigerant flowing out from the heat exchanger 43. The second temperature sensor 46 is provided in the heat storage tank 44 near the flow path through which the refrigerant flowing out from the heat exchanger 43 flows. The location of the second temperature sensor 46 is not particularly limited. The second temperature sensor 46 may be provided downstream of the heat exchanger 43 and near the refrigerant flow path upstream of the first expansion valve 12 or the second cooling section expansion valve 22, for example. The second temperature sensor 46 is configured to transmit the detected temperature of the refrigerant flowing out from the heat exchanger 43 to the control unit 4.

[0123] The control unit 4 is configured to switch between the heat storage operation, the heat dissipation operation, and the normal operation. Details of the heat storage operation, the heat dissipation operation, and the normal operation, and details of the operation switching control by the control unit 4 will be described later.

[0124] The refrigerator 2 is connected to the heat storage device 40, the first cooling equipment 10, and the second cooling equipment 20, and forms a refrigeration cycle .

[0125] (Configuration of refrigeration cycle in cooling system) Next, the configuration of the refrigeration cycle 70 in the cooling system 100 according to this embodiment will be described.

[0126] The cooling system 100 includes a refrigeration cycle 70. The refrigeration cycle 70 includes a compressor 30, a condenser 31, a first switching valve 75, a third expansion valve 41, a third evaporator 42, a heat exchanger 43, a first expansion valve 12, a first evaporator 13, a second cooling section expansion valve 22, and a second cooling section evaporator 23. The refrigerant circulates through the refrigeration cycle 70 by flowing through a refrigerant flow path provided in the refrigeration cycle 70. The refrigerant is R448A, for example, but the type of refrigerant is not particularly limited. Note that the configurations of the compressor 30, the condenser 31, the first expansion valve 12, the first evaporator 13, the second cooling section expansion valve 22, and the second cooling section evaporator 23 are the same as those in the first embodiment, and therefore will not be described here.

[0127] The first switching valve 75 is configured to switch the flow path of the refrigerant flowing out from the refrigerator 2. The first switching valve 75 is arranged downstream of the condenser 31. The first switching valve 75 is, for example, a three-way valve. The first switching valve 75 switches between a high-pressure side refrigerant flow path during heat storage operation and a high-pressure side refrigerant flow path during heat release operation. Specifically, the first switching valve 75 connects the heat storage device 40, the first cooling equipment 10, and the second cooling equipment 20 in parallel in the high-pressure side refrigerant flow path during heat storage operation. Furthermore, the first switching valve 75 connects the heat storage device 40, the first cooling equipment 10 connected in parallel, and the second cooling equipment 20 in series in that order in the high-pressure side refrigerant flow path during heat release operation. More specifically, the first switching valve 75 switches between a flow path in which the refrigerant flowing out of the condenser 31 flows into the third evaporator 42, the first evaporator 13 or the second evaporator 19 during heat storage operation, and a flow path in which the refrigerant flowing out of the condenser 31 flows into the heat exchanger 43 during heat dissipation operation.

[0128] In normal operation, the first switching valve 75 switches to the same flow path as that in the heat storage operation. However, because the third expansion valve 41 is fully closed under the control of the control unit 4, in normal operation the refrigerant that flows out of the condenser 31 does not flow into the third evaporator 42 but flows into the first evaporator 13 or the second cooling section evaporator 23 via the first switching valve 75.

[0129] Further, a third branch section 73 that branches the refrigerant flow path is provided downstream of the condenser 31. The third branch section 73 branches into a flow path in which the refrigerant flowing out of the condenser 31 flows into the third evaporator 42 via the third expansion valve 41, and a flow path in which the refrigerant flowing out of the condenser 31 flows into the first evaporator 13 or the second cooling section evaporator 23. The third branch section 73 is disposed downstream of the first switching valve 75.

[0130] The third expansion valve 41 is configured to expand the high-pressure liquid-phase refrigerant flowing out from the condenser 31 to produce a low-pressure, low-temperature liquid-phase refrigerant. The third expansion valve 41 is, for example, an electronic expansion valve, and its opening degree is adjusted under the control of the control unit 4. Note that the third expansion valve 41 is not limited to an electronic expansion valve, and may be, for example, a combination of a temperature expansion valve and a solenoid valve. The third expansion valve 41 is disposed downstream of the third branching unit 73 and upstream of the third evaporator 42.

[0131] The third evaporator 42 is configured to cool the second cold storage material 82 by evaporating the refrigerant expanded by the third expansion valve 41. In other words, the third evaporator 42 is configured to store cold energy in the second cold storage material 82.

[0132] The heat exchanger 43 is configured to perform heat exchange between the refrigerant condensed by the condenser 31 and the second cold storage material 82. Specifically, the heat exchanger 43 is configured so that the refrigerant flowing out from the condenser 31 flows into it, and thereby performs heat exchange between the second cold storage material 82 and the refrigerant, thereby supercooling the refrigerant by the latent heat of the second cold storage material 82. Then, the refrigerant supercooled by the heat exchanger 43 by the latent heat of the second cold storage material 82 flows into the first evaporator 13 of the first cooling equipment 10 and each of the multiple second cooling unit evaporators 23 of the second cooling equipment 20.

[0133] (The control unit switches between heat storage operation, heat dissipation operation, and normal operation.) The heat storage operation, heat dissipation operation, and normal operation in this embodiment will be described with reference to FIGS.

[0134] (Heat storage operation) The heat storage operation will be described with reference to Fig. 14. The control unit 4 is configured to perform a heat storage operation in which, when the power generated by the solar power generation device 1 has surplus power that exceeds the power consumption of the load 7 including the chiller 2 connected to the solar power generation device 1, the compressor 30 is operated using the surplus power to store cold heat.

[0135] Specifically, in the heat storage operation, the control unit 4 is configured to use surplus power to store cold energy in the second cold storage material 82 by the third evaporator 42. In addition, in the heat storage operation, the control unit 4 is configured to control the switching of the first switching valve 75, thereby connecting the heat storage device 40, the first cooling equipment 10, and the second cooling equipment 20 in parallel in the high-pressure side refrigerant flow path.

[0136] The heat storage operation is an operation mode in which the refrigerant flowing into the third evaporator 42 via the third expansion valve 41 evaporates, thereby storing cold energy in the second cold storage material 82. In this operation, the refrigerant compressed by the compressor 30 flows through the condenser 31, and then flows through the third expansion valve 41 and the third evaporator 42 via the first switching valve 75 and the third branch section 73, or flows through the first expansion valve 12 and the first evaporator 13 via the first switching valve 75, the third branch section 73, and the first branch section 71, or flows through the second cooling section expansion valve 22 and the second cooling section evaporator 23 via the first switching valve 75, the third branch section 73, and the first branch section 71, and is then drawn into the compressor 30. The refrigerant is then compressed by the compressor 30 and repeats the above-described circulation. Note that the first switching valve 75 prevents the refrigerant flowing out of the condenser 31 from flowing into the heat exchanger 43.

[0137] Based on data on the amount of power supplied, the amount of power generated, and the amount of power consumed measured by the power measuring unit 8a, when surplus power is generated by the solar power generation device 1 that exceeds the power consumption of the load 7 including the chiller 2 connected to the solar power generation device 1, the control unit 4 uses the surplus power to increase the operating load of the compressor 30 in order to flow refrigerant into the third evaporator 42 via the third expansion valve 41.

[0138] The control unit 4 uses surplus electricity to increase the operating load of the compressor 30 so that refrigerant flows into the third evaporator 42 through the third expansion valve 41, and during heat storage operation, cold energy is stored in the second cold storage material 82 by the third evaporator 42.

[0139] (heat dissipation operation) The heat dissipation operation will be described with reference to Fig. 15. When the state changes from one in which there is surplus power to one in which there is no surplus power, the control unit 4 is configured to switch from the heat storage operation to the heat dissipation operation in which the stored cold heat is dissipated using the surplus power to cool at least the products for sale 91 of the first cooling equipment 10 and the second cooling equipment 20.

[0140] Specifically, when there is no surplus power, the control unit 4 is configured to switch from the heat storage operation to the heat dissipation operation in which the refrigerant flowing out from the condenser 31 is caused to flow into the heat exchanger 43 until the temperature of the refrigerant flowing out from the heat exchanger 43 exceeds a predetermined temperature, thereby performing heat exchange between the second cold storage material 82 and the refrigerant to supercool the refrigerant by latent heat, and then causing the supercooled refrigerant to flow into the first evaporator 13 and the second cooling unit evaporator 23. Furthermore, the control unit 4 is configured to control the switching of the first switching valve 75 in the heat dissipation operation to connect the heat storage device 40, the first cooling equipment 10 connected in parallel, and the second cooling equipment 20 in series in that order in the high-pressure side refrigerant flow path.

[0141] The heat radiation operation is an operation mode in which the refrigerant is supercooled by latent heat due to heat exchange between the refrigerant and the second cold storage material 82, which stores cold energy during the heat storage operation, and flows into the first evaporator 13 and the second cooling section evaporator 23, thereby cooling the interiors of the first cooling equipment 10 and the second cooling equipment 20. In this operation, the refrigerant compressed by the compressor 30 flows through the condenser 31, flows through the heat exchanger 43 via the first switching valve 75, and then flows through the first expansion valve 12 and the first evaporator 13 via the first branching section 71, or flows through the second cooling section expansion valve 22 and the second cooling section evaporator 23 via the first branching section 71, and is then drawn into the compressor 30. The refrigerant is then compressed by the compressor 30 and repeats the above-described circulation. Note that the first switching valve 75 prevents the refrigerant flowing out of the condenser 31 from flowing into the third evaporator 42.

[0142] Based on the data on the amount of power supply, the amount of power generated, and the amount of power consumed measured by the power measuring unit 8a, when there is no surplus power generated by the solar power generation device 1 that exceeds the power consumption of the load 7, including the chiller 2 connected to the solar power generation device 1, the control unit 4 switches from the heat storage operation to the heat dissipation operation in which the refrigerant is not circulated through the third evaporator 42, and the refrigerant is supercooled by latent heat due to heat exchange between the refrigerant and the second cold storage material 82, which has stored cold during the heat storage operation, and flows into the first evaporator 13 and the second cooling section evaporator 23. In the heat dissipation operation, the supercooled refrigerant flows into the first evaporator 13 of the first cooling equipment 10 and the second cooling section evaporator 23 of the second cooling equipment 20. The operating load of the compressor 30 can be reduced by the amount of improvement in the cooling effect of the first evaporator 13 and the second cooling section evaporator 23 due to the supercooled refrigerant.

[0143] Here, the improvement of the cooling effect in the first evaporator 13 and the second cooling section evaporator 23 by the supercooled refrigerant will be described with reference to Fig. 17. Fig. 17(a) is a pH diagram for explaining the state of the refrigerant in heat dissipation operation in which the refrigerant that has flowed out of the condenser 31 flows through the heat exchanger 43. Fig. 17(b) is a pH diagram for explaining the state of the refrigerant in normal operation in which the refrigerant that has flowed out of the condenser 31 does not flow through the heat exchanger 43.

[0144] In the heat radiation operation shown in Fig. 17(a), the refrigerant that has flowed out of the condenser 31 flows through the heat exchanger 43, thereby enabling the refrigerant to be more subcooled than in the normal operation shown in Fig. 17(b). That is, in the heat radiation operation shown in Fig. 17(a), the specific enthalpy of the refrigerant can be made smaller than in the normal operation shown in Fig. 17(b), thereby improving the cooling effect. Therefore, the operating load of the compressor 30 can be reduced by the amount of the improved cooling effect.

[0145] Furthermore, the control unit 4 performs the heat dissipation operation until the temperature of the refrigerant flowing out of the heat exchanger 43, acquired by the second temperature sensor 46 (see FIG. 12), exceeds a predetermined temperature. The predetermined temperature is a temperature at which the refrigerant cannot be sufficiently supercooled by heat exchange with the second cold storage material 82.

[0146] During heat dissipation operation, the refrigerant is supercooled by the cold energy stored in the second cold storage material 82 using surplus electricity during heat storage operation, and flows into the first evaporator 13 of the first cooling equipment 10 and the second cooling section evaporator 23 of the second cooling equipment 20, thereby cooling the air within the first cooling equipment 10 and the products for sale 91 of the first cooling equipment 10, and also cooling the air within the second cooling equipment 20 and the products for sale 91 of the second cooling equipment 20.

[0147] (Normal operation) Normal operation will be described with reference to Fig. 16. The control unit 4 switches from heat dissipation operation to normal operation when the temperature of the refrigerant flowing out from the heat exchanger 43 acquired by the second temperature sensor 46 (see Fig. 12) exceeds a predetermined temperature. The normal operation is the same as the normal operation in the first embodiment, and therefore a description thereof will be omitted here. Note that the control unit 4 switches from normal operation to heat storage operation when surplus power is generated by the photovoltaic power generation device 1 that exceeds the power consumption of the load 7 including the chiller 2 connected to the photovoltaic power generation device 1, based on data related to the amount of power supply, data related to the amount of power generated, and data related to the amount of power consumed, all measured by the power measurement unit 8a.

[0148] (Operation switching control by the control unit) The operation switching control by the control unit 4 will be described with reference to Fig. 18. For ease of explanation, Fig. 18 does not show the temperature inside the first cooling equipment 10, and only shows the temperature inside the second cooling equipment 20.

[0149] At time t8, the solar power generation device 1 is not generating power, or there is no surplus power generated by the solar power generation device 1. Therefore, normal operation is performed at time t8. Specifically, the control unit 4 operates the compressor 30 using at least the power supplied from the commercial power source 6, thereby cooling the interior of the first cooling device 10 with air cooled by the first evaporator 13 so that the temperature inside the first cooling device 10 reaches the normal set temperature, and cooling the interior of the second cooling device 20 with air cooled by the second cooling section evaporator 23. Because the third expansion valve 41 is fully closed, no refrigerant flows into the third evaporator 42. Note that from time t9 to time t10, a defrosting operation is performed to remove frost adhering to the first evaporator 13 and the second cooling section evaporator 23. Normal operation is performed until surplus power is generated.

[0150] At time t11, the power generated by the solar power generation device 1 exceeds the power consumption of the load 7, including the chiller 2 connected to the solar power generation device 1, to generate surplus power. Therefore, from time t11, normal operation is replaced with heat storage operation. Specifically, based on the data on the amount of supplied power, the data on the amount of generated power, and the data on the amount of power consumed measured by the power measurement unit 8a, the control unit 4 determines that the power generated by the solar power generation device 1 exceeds the power consumption of the load 7, including the chiller 2 connected to the solar power generation device 1, to generate surplus power at time t11. Therefore, the control unit 4 increases the operating load of the compressor 30 so that the refrigerant flows into the third evaporator 42 via the third expansion valve 41. As a result, cold energy is stored in the second cold storage material 82 during the heat storage operation. The heat storage operation is continued until there is no surplus power.

[0151] At time t12, the power generated by the solar power generation device 1 changes from a state in which there is surplus power to a state in which there is no surplus power. Therefore, from time t12, heat dissipation operation is performed instead of heat storage operation. Specifically, at time t12, based on the data on the amount of supplied power, the data on the amount of generated power, and the data on the amount of consumed power measured by the power measurement unit 8a, the control unit 4 determines that there is no surplus power in the power generated by the solar power generation device 1 that exceeds the power consumption of the load 7, including the chiller 2 connected to the solar power generation device 1. Therefore, by switching the first switching valve 75, the refrigerant flowing out of the condenser 31 flows into the heat exchanger 43, and heat is exchanged between the second cold storage material 82 and the refrigerant, thereby supercooling the refrigerant by latent heat. In addition, the control unit 4 reduces the operating load of the compressor 30.

[0152] As a result, during the heat dissipation operation, the refrigerant that has been supercooled by heat exchange between the refrigerant and the second cold storage material 82, in which cold energy has been stored during the heat storage operation, flows into the first evaporator 13 and the second cooling section evaporator 23, thereby cooling the air in the first cooling equipment 10 and the merchandise 91 for sale in the first cooling equipment 10, and also cooling the air in the second cooling equipment 20 and the merchandise 91 for sale in the second cooling equipment 20. Note that from time t13 to time t14, a defrosting operation is performed to remove frost that has adhered to the first evaporator 13 and the second cooling section evaporator 23. The heat dissipation operation is performed until the temperature of the refrigerant flowing out of the heat exchanger 43, detected by the second temperature sensor 46, exceeds a predetermined temperature.

[0153] At time t15, the temperature of the refrigerant flowing out of the heat exchanger 43, detected by the second temperature sensor 46, exceeds a predetermined temperature. Therefore, from time t15, the heat dissipation operation is replaced with normal operation. The normal operation is continued until surplus power is generated.

[0154] (Operation switching control process by the control unit) The operation switching process by the control unit 4 will be described with reference to Fig. 19. The process shown in Fig. 19 is started when normal operation starts. The order of the processing steps can be reversed or executed simultaneously as long as there are no contradictions.

[0155] In step S11, if the control unit 4 determines, based on the data regarding the amount of power supplied, the data regarding the amount of power generated, and the data regarding the amount of power consumed measured by the power measuring unit 8a, that the power generated by the solar power generation device 1 will generate surplus power that exceeds the power consumed by the load 7, including the refrigerator 2 connected to the solar power generation device 1 (Yes in step S11), the processing proceeds to step S12, and if it determines that surplus power will not be generated (No in step S11), the processing repeats the judgment of step S11.

[0156] In step S12, the control unit 4 switches from normal operation to heat storage operation, after which the process proceeds to step S13.

[0157] In step S13, if the control unit 4 determines that there is no surplus power based on the data regarding the amount of power supplied, the data regarding the amount of power generated, and the data regarding the amount of power consumed measured by the power measuring unit 8a (Yes in step S13), the processing proceeds to step S14, and if it determines that surplus power will be generated (No in step S13), the processing repeats the determination in step S13.

[0158] In step S14, the control unit 4 switches from the heat storage operation to the heat release operation, and then the process proceeds to step S15.

[0159] In step S15, if the control unit 4 determines that the temperature of the refrigerant flowing out of the heat exchanger 43 acquired by the second temperature sensor 46 exceeds a predetermined temperature (Yes in step S15), the processing proceeds to step S16, and if the control unit 4 determines that the temperature of the refrigerant flowing out of the heat exchanger 43 does not exceed the predetermined temperature (No in step S15), the processing repeats the determination in step S15.

[0160] In step S16, the control unit 4 switches from the heat radiation operation to the normal operation, after which the process returns to step S11.

[0161] The other configurations of the fourth embodiment are the same as those of the first embodiment.

[0162] (Effects of the fourth embodiment) In the fourth embodiment, the following effects can be obtained.

[0163] In the fourth embodiment, as described above, the control unit 4 is configured to perform a heat storage operation in which, when the power generated by the solar power generation device 1 exceeds the power consumed by the load 7, including the chiller 2 connected to the solar power generation device 1, the compressor 30 is operated using the surplus power to store cold heat. As a result, even if a storage battery for storing the power generated by the solar power generation device 1 is not provided, when surplus power is generated by the solar power generation device 1, the control unit 4 can perform a heat storage operation without controlling the power generation by the solar power generation device 1, thereby storing cold heat using the surplus power. Therefore, when there is no surplus power from the solar power generation device 1, the cold heat stored using the surplus power can be used. Therefore, even if there is no storage battery capable of sufficiently storing the surplus power from the power generated by the solar power generation device 1, the surplus power from the solar power generation device 1 can be effectively used.

[0164] Furthermore, in the fourth embodiment, as described above, when the state transitions from one in which there is surplus power to one in which there is no surplus power, the control unit 4 is configured to switch from the heat storage operation to the heat dissipation operation in which the stored cold heat is dissipated using the surplus power to cool at least the products for sale 91 of the first cooling equipment 10 and the plurality of second cooling equipment 20. Thus, by switching from the heat storage operation to the heat dissipation operation when there is no surplus power, the control unit 4 can dissipate the stored cold heat using the surplus power. Therefore, when there is no surplus power, the cooling system 100 can save energy by reducing the amount of power supplied from the commercial power source 6, while cooling at least the products for sale 91 of the first cooling equipment 10 and the plurality of second cooling equipment 20. Therefore, even when there is no storage battery capable of sufficiently storing the surplus power generated by the solar power generation device 1, the surplus power generated by the solar power generation device 1 can be effectively utilized.

[0165] Furthermore, in the fourth embodiment, as described above, the heat storage device 40 includes the third evaporator 42 that evaporates the expanded refrigerant by the third expansion valve 41 that expands the refrigerant condensed by the condenser 31, and the second cold storage material 82 that is cooled by the third evaporator 42, and the control unit 4 is configured to store cold heat in the second cold storage material 82 by the third evaporator 42 during the heat storage operation. As a result, by using surplus electricity during the heat storage operation, the second cold storage material 82 can be cooled by the third evaporator 42 in the heat storage device 40, and cold heat can be stored in the second cold storage material 82. Therefore, by storing cold heat in the second cold storage material 82, surplus electricity generated by the solar power generation device 1 can be appropriately and effectively utilized even when there is no storage battery that can sufficiently store the surplus electricity generated by the solar power generation device 1.

[0166] Furthermore, in the fourth embodiment, as described above, the heat storage device 40 includes the heat exchanger 43 that performs heat exchange between the refrigerant condensed by the condenser 31 and the second cold storage material 82. The control unit 4 is configured to switch from the heat storage operation to the heat release operation in which, when there is no surplus power, the refrigerant flowing out from the condenser 31 flows into the heat exchanger 43 until the temperature of the refrigerant flowing out from the heat exchanger 43 exceeds a predetermined temperature. The heat exchange between the second cold storage material 82 and the refrigerant supercools the refrigerant, and the supercooled refrigerant flows into the first evaporator 13 and the second cooling section evaporator 23. This allows the supercooled refrigerant to flow into the first evaporator 13 and the second cooling section evaporator 23 by performing heat exchange between the second cold storage material 82 and the refrigerant. The specific enthalpy of the refrigerant can be reduced by supercooling, thereby improving the cooling effect in the first evaporator 13 and the second cooling section evaporator 23. Therefore, the operating load of the compressor 30 can be reduced by the amount of the improved cooling effect, thereby reducing the power consumption of the compressor 30 (the amount of power supplied from the commercial power supply 6 system).As a result, energy conservation of the cooling system 100 can be achieved during the heat dissipation operation.

[0167] Furthermore, in the fourth embodiment, as described above, the system further includes a first switching valve 75 for switching the flow path of the refrigerant flowing out from the refrigerator 2, and the cooling equipment 3 includes a first cooling equipment 10 and a plurality of second cooling equipment 20. The control unit 4 controls the switching of the first switching valve 75 so that, in heat storage operation, the heat storage device 40, the first cooling equipment 10, and the plurality of second cooling equipment 20 are connected in parallel in the flow path of the high-pressure refrigerant, and, in heat dissipation operation, the heat storage device 40, the first cooling equipment 10 connected in parallel, and the plurality of second cooling equipment 20 are connected in series in that order in the flow path of the high-pressure refrigerant. As a result, by switching the first switching valve 75 by the control unit 4, the third evaporator 42 of the heat storage device 40 is connected in parallel to the first cooling equipment 10 and the multiple second cooling equipment 20 in the heat storage operation, so that cold heat is stored in the second cold storage material 82 by circulating refrigerant through the third evaporator 42 of the heat storage device 40, and merchandise for sale 91 can be cooled by circulating refrigerant through the first cooling equipment 10 and the multiple second cooling equipment 20. Furthermore, by switching the first switching valve 75 by the control unit 4, in the heat release operation, the supercooler of the heat storage device 40, the first cooling equipment 10 connected in parallel, and the multiple second cooling equipment 20 are connected in series in this order, so that refrigerant supercooled in the heat exchanger 43 of the heat storage device 40 can flow into the first cooling equipment 10 and the multiple second cooling equipment 20. Therefore, the merchandise for sale 91 can be cooled in the first cooling equipment 10 and the multiple second cooling equipment 20 using the supercooled refrigerant.

[0168] Furthermore, in the fourth embodiment, as described above, the heat storage device 40 includes the second cold storage material 82, which is an ice slurry, and the heat storage tank 44 in which the second cold storage material 82 is disposed. This allows the second cold storage material 82, which is an ice slurry having fluidity, to be stored in the heat storage tank 44, and cold can be uniformly transferred by the second cold storage material 82, which has fluidity. Therefore, in the heat exchange between the refrigerant and the second cold storage material 82, which is an ice slurry having fluidity, the refrigerant can be efficiently supercooled, and the heat storage performance can be improved.

[0169] [Fifth embodiment] Next, a cooling system 100 according to a fifth embodiment of the present invention will be described with reference to Figures 20 to 22. Unlike the above-described fourth embodiment, the fifth embodiment describes an example in which a heat storage device 40 is provided inside the first cooling equipment 10, and a heat exchanger 43 of the heat storage device 40 and a first evaporator 13 of the first cooling equipment 10 are connected in series in the flow path of the high-pressure refrigerant. Note that the same components as those in the above-described fourth embodiment are denoted by the same reference numerals, and their description will be omitted.

[0170] (Cooling system configuration) As shown in FIGS. 1 and 20 , the cooling system 100 includes a solar power generation device 1, a refrigerator 2, a heat storage device 40, a cooling facility 3, and a control unit 4. The control unit 4, the cooling facility 3, a plurality of storage sections 5, and the heat storage device 40 are arranged inside a store 90. The cooling facility 3 includes a first cooling facility 10 and a plurality of second cooling facilities 20. The heat storage device 40 is arranged inside the first cooling facility 10. The solar power generation device 1 and the refrigerator 2 are arranged outside the store 90. Note that, unlike the fourth embodiment, the present embodiment does not include a first switching valve 75.

[0171] (Configuration of refrigeration cycle in cooling system) Next, the configuration of the refrigeration cycle 70 in the cooling system 100 according to this embodiment will be described with reference to FIG.

[0172] A fourth branch section 74 that branches the refrigerant flow path is provided downstream of the condenser 31. The fourth branch section 74 branches into a flow path through which the refrigerant that has flowed out of the condenser 31 flows into the heat exchanger 43 and a flow path through which the refrigerant that has flowed out of the condenser 31 flows into the second cooling section evaporator 23.

[0173] The refrigerant that flows into the heat exchanger 43 via the fourth branch portion 74 flows out of the heat exchanger 43 and then flows into the first evaporator 13 via the first expansion valve 12. The refrigerant that flows into the first evaporator 13 flows out of the first evaporator 13 and then is sucked into the compressor 30. That is, in the high-pressure side refrigerant flow path, the third evaporator 42 of the heat storage device 40, the heat exchanger 43 of the heat storage device 40, and the second cooling section evaporator 23 of the second cooling equipment 20 are connected in parallel. Also, in the high-pressure side refrigerant flow path, the heat exchanger 43 of the heat storage device 40 and the first evaporator 13 of the first cooling equipment 10 are connected in series in this order.

[0174] (The control unit switches between heat storage operation, heat dissipation operation, and normal operation.) The heat storage operation, heat dissipation operation, and normal operation in this embodiment will be described with reference to FIGS.

[0175] (Heat storage operation) 21, the heat storage operation is an operation mode in which the refrigerant flowing into the third evaporator 42 via the third expansion valve 41 evaporates, thereby storing cold energy in the second cold storage material 82. In this case, the refrigerant compressed by the compressor 30 flows through the condenser 31, and then flows through the third expansion valve 41 and the third evaporator 42 via the third branch section 73, or flows through the heat exchanger 43, the first expansion valve 12, and the first evaporator 13 via the third branch section 73 and the fourth branch section 74, or flows through the second cooling section expansion valve 22 and the second cooling section evaporator 23 via the third branch section 73 and the fourth branch section 74, and is then drawn into the compressor 30. The refrigerant is then compressed by the compressor 30 and repeats the above-described circulation.

[0176] The control unit 4 uses surplus electricity to increase the operating load of the compressor 30 so that refrigerant flows into the third evaporator 42 through the third expansion valve 41, and during heat storage operation, cold energy is stored in the second cold storage material 82 by the third evaporator 42.

[0177] (heat dissipation operation) The heat dissipation operation will be described with reference to Fig. 22. When the state changes from one with surplus power to one without surplus power, the control unit 4 is configured to switch from the heat storage operation to the heat dissipation operation in which the refrigerant is supercooled by latent heat by performing heat exchange between the second cold storage material 82 and the refrigerant in the heat exchanger 43 and the supercooled refrigerant flows into the first evaporator 13 until the temperature of the refrigerant flowing out of the heat exchanger 43 exceeds a predetermined temperature.

[0178] The heat radiation operation is an operation mode in which the inside of the first cooling equipment 10 is cooled by the refrigerant supercooled by latent heat due to heat exchange between the refrigerant and the second cold storage material 82, which has stored cold during the heat storage operation, and then flows into the first evaporator 13. In this operation, the refrigerant compressed by the compressor 30 flows through the condenser 31, flows through the heat exchanger 43 via the fourth branch section 74, and then flows through the first expansion valve 12 and the first evaporator 13 in this order, or flows through the second cooling section expansion valve 22 and the second cooling section evaporator 23 in this order via the fourth branch section 74, and is then drawn into the compressor 30. The refrigerant is then compressed by the compressor 30 and repeats the above-described circulation. Note that the control unit 4 fully closes the third expansion valve 41, so the refrigerant flowing out of the condenser 31 does not flow into the third evaporator 42.

[0179] During heat dissipation operation, the refrigerant is supercooled by the cold energy stored in the second cold storage material 82 using surplus electricity during heat storage operation, and is then flowed into the first evaporator 13 of the first cooling equipment 10, thereby cooling the air within the first cooling equipment 10 and cooling the products 91 for sale at the first cooling equipment 10.

[0180] (Normal operation) The flow of the refrigerant during normal operation is the same as the flow of the refrigerant during heat dissipation operation, and therefore a description thereof will be omitted here. Note that, during normal operation, the refrigerant is not supercooled in the heat exchanger 43.

[0181] The other configurations of the fifth embodiment are the same as those of the fourth embodiment.

[0182] (Effects of the fifth embodiment) In the fifth embodiment, the following effects can be obtained.

[0183] In the fifth embodiment, as described above, the heat storage device 40 is provided inside the first cooling equipment 10. By providing the heat storage device 40 inside the first cooling equipment 10, which is kept at a relatively low temperature, the second cold storage material 82 of the heat storage device 40 exchanges heat with the air outside the heat storage device 40, and it is possible to prevent a decrease in the cold stored in the second cold storage material 82. Furthermore, when the second cold storage material 82 of the heat storage device 40 exchanges heat with the air outside the heat storage device 40, the cold stored in the second cold storage material 82 can be used to cool the inside of the first cooling equipment 10, which should be kept at a relatively low temperature. As a result, it is possible to reduce energy loss in the cooling system 100.

[0184] The other effects of the fifth embodiment are the same as those of the fourth embodiment.

[0185] [Sixth embodiment] Next, a cooling system 600 according to a sixth embodiment of the present invention will be described with reference to Figures 1, 23, and 24. Unlike the fourth embodiment, the sixth embodiment describes an example in which a heat storage device 640 is provided inside the first cooling equipment 10. Note that the same components as those in the fourth embodiment are denoted by the same reference numerals, and descriptions thereof will be omitted.

[0186] (Cooling system configuration) As shown in FIGS. 1 and 23 , the cooling system 600 includes a solar power generation device 1, a chiller 2, a heat storage device 640, a first switching valve 75, a cooling facility 3, and a control unit 4. The control unit 4, the cooling facility 3, a plurality of storage units 5, the heat storage device 640, and the first switching valve 75 are arranged inside a store 90. The first switching valve 75 may be arranged outside the store 90. The cooling facility 3 includes a first cooling facility 610 and a plurality of second cooling facilities 20. The heat storage device 40 is arranged inside the first cooling facility 610. The solar power generation device 1 and the chiller 2 are arranged outside the store 90.

[0187] (Configuration of refrigeration cycle in cooling system) 23, in a refrigeration cycle 670 in a cooling system 600, the third branch portion 73 is disposed upstream of the first switching valve 75. That is, the order of the third branch portion 73 and the first switching valve 75 between the condenser 31 and the first branch portion 71 is reversed from that of the refrigeration cycle 70 in the fourth embodiment. Note that, other than the order of the third branch portion 73 and the first switching valve 75 between the condenser 31 and the first branch portion 71, the configuration is the same as that of the refrigeration cycle 70 in the fourth embodiment, and therefore description thereof will be omitted here.

[0188] (Configuration of heat storage device) As shown in FIG. 23, similar to the heat storage device 40 of the fourth embodiment, the heat storage device 640 includes a third expansion valve 41, a third evaporator 42, a heat exchanger 43, a second cold storage material 82, a heat storage tank 44, and a second temperature sensor 46 (see FIG. 12).

[0189] As shown in FIG. 24, the heat storage device 640 includes a cylindrical member 651 , a screw member 652 , a screw drive motor 653 , a bypass flow path 654 , and an ice amount sensor 655 .

[0190] The cylindrical member 651 is disposed so as to be in contact with the third evaporator 42 and surrounded by the third evaporator 42. The cylindrical member 651 is made of metal. The cylindrical member 651 has cylindrical side and top surfaces and is open on the lower side. The portion of the third evaporator 42 that contacts the cylindrical member 651 has a spiral shape. A plurality of through holes 651a that connect the inside and outside of the cylindrical member 651 are formed in the top surface and the upper part of the side surface of the cylindrical member 651. This allows water or an aqueous solution outside the cylindrical member 651 to be supplied to the inside and upper part of the cylindrical member 651 via the plurality of through holes 651a.

[0191] The screw member 652 rotates to scrape out ice generated inside the cylindrical member 651 by the water or aqueous solution stored inside the heat storage tank 44 being cooled by the third evaporator 42 through the cylindrical member 51, to the outside of the cylindrical member 651 to generate ice slurry, which is the second cold storage material 82. The screw member 652 rotates to scrape out the ice generated inside the cylindrical member 651 downward.

[0192] The screw member 652 is configured to rotate inside the cylindrical member 651 so that an end 652a of the screw member 652 on the cylindrical member 651 side and an inner circumferential surface 651b of the cylindrical member 651 are maintained at a predetermined distance L or less. This makes it possible to prevent the thickness of ice generated inside the cylindrical member 651 from becoming excessively large. This makes it possible to prevent the water or aqueous solution inside the cylindrical member 651 from being difficult to cool by the third evaporator 42 through the cylindrical member 651, which would be caused by the ice having a lower thermal conductivity than the metal cylindrical member 651 becoming too thick. As a result, the second cold storage material 82, which is ice slurry, can be generated more efficiently.

[0193] The screw drive motor 653 is a drive source that rotates the screw member 652 .

[0194] Ice amount sensor 655 is provided at the bottom of heat storage tank 44. Ice amount sensor 655 detects whether the amount of ice (second cold storage material 82, which is ice slurry) inside heat storage tank 44 has reached a predetermined threshold. Note that ice amount sensor 655 may be provided at a location other than the bottom of heat storage tank 44, as long as it can detect whether the amount of ice (second cold storage material 82, which is ice slurry) inside heat storage tank 44 has reached the predetermined threshold.

[0195] One end of bypass flow path 654 is arranged outside cylindrical member 651 and at the bottom of heat storage tank 44, and the other end is arranged inside cylindrical member 651 and at the top of cylindrical member 651. As a result, even if second cold storage material 82, which is ice slurry, accumulates at the top of heat storage tank 44 and water or aqueous solution outside cylindrical member 651 is difficult to supply to the inside of cylindrical member 651 through through-hole 651a, water or aqueous solution outside cylindrical member 651 and at the bottom of heat storage tank 44 can be supplied to the inside and top of cylindrical member 651 through bypass flow path 654.

[0196] (Operation of the heat storage device) As shown in Figure 24, in the heat storage operation, the high-temperature, high-pressure refrigerant supplied from the refrigerator 2 is decompressed and expanded by the third expansion valve 41 (see Figure 23) and flows into the third evaporator 42. The refrigerant that has flowed into the third evaporator 42 evaporates in the third evaporator 42, thereby cooling a cylindrical member 651 that comes into contact with the third evaporator 42 and is arranged so as to be surrounded by the third evaporator 42. The cooling of the cylindrical member 651 cools the water or aqueous solution inside the cylindrical member 651, and ice is produced inside the cylindrical member 651. Note that the refrigerant that has flowed into the evaporator 42 that is arranged so as to come into contact with the third evaporator 42 evaporates in the third evaporator 42, and thus the water or aqueous solution outside the third evaporator 42 is also cooled, and ice is also produced outside the cylindrical member 651.

[0197] By rotating screw member 652 with screw drive motor 653, the water or aqueous solution produced inside cylindrical member 651 is scraped downward, producing second cold storage material 82 which is ice slurry. Second cold storage material 82 which is ice slurry is sent out from the lower side of cylindrical member 651 to the outside of cylindrical member 651, and moves to the upper part of heat storage tank 44 by buoyancy outside cylindrical member 651. As second cold storage material 82 which is ice slurry is produced inside cylindrical member 651, and as second cold storage material 82 which is ice slurry continues to be sent out from the lower side of cylindrical member 651 to the outside of cylindrical member 651, second cold storage material 82 which is ice slurry accumulates inside heat storage tank 44. When the ice amount sensor 655 detects that the amount of ice (second cold storage material 82, which is ice slurry) inside the heat storage tank 44 reaches a predetermined threshold, the rotation of the screw member 652 is stopped, thereby stopping the production of the second cold storage material 82, which is ice slurry.

[0198] In the heat dissipation operation, the refrigerant is caused to flow through the heat exchanger 43 arranged inside the heat storage tank 44, and heat is exchanged between the refrigerant and the second cold storage material 82, which is a slurry, to cool the refrigerant flowing through the heat exchanger 43. In order to promote the heat exchange between the refrigerant and the second cold storage material 82, which is a slurry, the screw member 652 is rotated by the screw drive motor 653, causing convection inside the heat storage tank 44.

[0199] The other configurations of the sixth embodiment are the same as those of the fourth embodiment.

[0200] (Effects of the sixth embodiment) As described above, in the sixth embodiment, the heat storage device 640 includes water or an aqueous solution stored inside the heat storage tank 44, the third evaporator 42 disposed inside the heat storage tank 44, a metallic cylindrical member 651 disposed in contact with and surrounded by the third evaporator 42, and a screw member 652 that rotates to scrape ice generated inside the cylindrical member 651 as the water or aqueous solution is cooled by the third evaporator 42 through the cylindrical member 651 to the outside of the cylindrical member 651. As a result, the ice generated inside the cylindrical member 651 is scraped to the outside of the cylindrical member 651 by the screw member 652, thereby continuously generating the second cold storage material 82, which is an ice slurry. As a result, the second cold storage material 82, which is an ice slurry, can be efficiently generated.

[0201] Furthermore, in the sixth embodiment, as described above, the heat storage device 640 is provided inside the first cooling equipment 610. Thus, by providing the heat storage device 640 inside the first cooling equipment 610, which is kept at a relatively low temperature, the second cold storage material 82 of the heat storage device 640 exchanges heat with the air outside the heat storage device 640, and it is possible to prevent a decrease in the cold stored in the second cold storage material 82. Furthermore, when the second cold storage material 82 of the heat storage device 640 exchanges heat with the air outside the heat storage device 640, the cold stored in the second cold storage material 82 can be used to cool the inside of the first cooling equipment 610, which should be kept at a relatively low temperature. As a result, it is possible to reduce energy loss in the cooling system 600.

[0202] The other effects of the sixth embodiment are the same as those of the fourth embodiment.

[0203] (Variation) The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims rather than the description of the above embodiments, and further includes all modifications (variations) within the meaning and scope of the claims.

[0204] For example, in the first to third embodiments described above, during the heat storage operation, cold heat is stored in the replenishment products 92 stored in the work storage area 10b of the first cooling equipment 10, and during the heat dissipation operation, the cold heat stored in the replenishment products 92 is dissipated, and in the fourth and fifth embodiments described above, during the heat storage operation, cold heat is stored in the second cold storage material 82 of the heat storage device 40, and during the heat dissipation operation, the refrigerant is supercooled by latent heat through heat exchange between the second cold storage material 82 in which the cold heat has been stored and the refrigerant. However, the present invention is not limited to this. 25, the control unit 4 may be configured to use surplus power in the heat storage operation to operate the compressor 30 so that the temperature inside the first cooling equipment 10 reaches a heat storage operation temperature that is lower than the normal set temperature during normal operation, thereby storing cold energy in the replenishment products 92 stored in the work storage area 10b, and to cause the third evaporator 42 included in the heat storage device 40 to store cold energy in the second cold storage material 82. Then, the control unit 4 may be configured to release the cold energy stored in the replenishment products 92 in the heat release operation, and to supercool the refrigerant by latent heat through heat exchange between the refrigerant and the second cold storage material 82 in which the cold energy has been stored.

[0205] In the first modification, the cooling system 100 includes a heat storage device 40 .

[0206] (Operation switching control by the control unit) The operation switching control by the control unit 4 will be described with reference to FIG.

[0207] At time t16, no power is generated by the solar power generation device 1, or no surplus power is generated in the power generated by the solar power generation device 1. Therefore, normal operation is performed at time t16. From time t17 to time t18, a defrosting operation is performed to remove frost adhering to the first evaporator 13 and the second cooling section evaporator 23. The normal operation is performed until surplus power is generated.

[0208] At time t19, surplus power is generated by the solar power generation device 1, exceeding the power consumption of the load 7, including the refrigerator 2 connected to the solar power generation device 1. Therefore, from time t19, normal operation is replaced with heat storage operation. Specifically, at time t19, the control unit 4 uses the surplus power to increase the operating load of the compressor 30 in order to raise the temperature inside the first cooling equipment 10 to a heat storage operation temperature that is lower than the normal set temperature during normal operation. As a result, during the heat storage operation, cold heat is stored in the replenishment products 92 stored in the work storage area 10b.

[0209] Furthermore, at time t19, the control unit 4 increases the operating load of the compressor 30 so as to cause the refrigerant to flow into the third evaporator 42 via the third expansion valve 41. As a result, in the heat storage operation, cold energy is stored in the second cold storage material 82. The heat storage operation is performed until there is no surplus power.

[0210] At time t20, the power generated by the solar power generation device 1 changes from a state in which there is surplus power to a state in which there is no surplus power. Therefore, from time t20, the heat storage operation is replaced with a heat dissipation operation in which the cold energy stored in the replenishment products 92 is dissipated. Specifically, at time t20, the control unit 4 dissipates the cold energy stored in the replenishment products 92 without circulating refrigerant through the first evaporator 13. The control unit 4 also reduces the operating load of the compressor 30. From time t21 to time t22, a defrosting operation is performed to remove frost adhering to the first evaporator 13 and the second cooling unit evaporator 23. The heat dissipation operation in which the cold energy stored in the replenishment products 92 is dissipated is performed until the temperature inside the first cooling equipment 10, acquired by the first temperature sensor 15, reaches the normal set temperature.

[0211] At time t23, the temperature inside the first cooling equipment 10 acquired by the first temperature sensor 15 reaches the normal set temperature. Therefore, from time t23, a heat radiation operation is performed in the heat exchanger 43 to supercool the refrigerant using latent heat. Specifically, at time t23, the control unit 4 switches the switching valve to allow the refrigerant flowing out of the condenser 31 to flow into the heat exchanger 43, thereby performing heat exchange between the second cold storage material 82 and the refrigerant, thereby supercooling the refrigerant using latent heat. The control unit 4 also reduces the operating load of the compressor 30. The heat radiation operation in which the refrigerant is supercooled using latent heat in the heat exchanger 43 is performed until the temperature of the refrigerant flowing out of the heat exchanger 43 acquired by the second temperature sensor 46 exceeds a predetermined temperature. When the temperature of the refrigerant flowing out of the heat exchanger 43 acquired by the second temperature sensor 46 exceeds the predetermined temperature, the heat radiation operation in which the refrigerant is supercooled using latent heat in the heat exchanger 43 is replaced with normal operation. The normal operation is performed until surplus power is generated.

[0212] In addition, in the above-described fifth embodiment, an example has been described in which the refrigerant that has circulated through the heat exchanger 43 via the fourth branch portion 74 flows into the first evaporator 13 via the first expansion valve 12, but the present invention is not limited to this. For example, as in a cooling system 100 of a second modified example shown in Fig. 26, the refrigeration cycle 70 may be configured to include a second switching valve 76 that switches between a high-pressure side refrigerant flow path during heat dissipation operation and a high-pressure side refrigerant flow path during normal operation.

[0213] (Configuration of refrigeration cycle in cooling system) Next, the configuration of the refrigeration cycle 70 in the cooling system 100 according to a second modification will be described with reference to FIG.

[0214] The refrigeration cycle 70 includes a second switching valve 76. The second switching valve 76 is configured to switch the flow path of the refrigerant flowing out from the refrigerator 2. The second switching valve 76 is disposed downstream of the fourth branch portion 74. The second switching valve 76 is, for example, a three-way valve. The second switching valve 76 switches between a high-pressure side refrigerant flow path during heat radiation operation and a high-pressure side refrigerant flow path during normal operation. Specifically, the second switching valve 76 switches between a flow path in which the refrigerant that flows out of the condenser 31 and through the fourth branch portion 74 flows into the heat exchanger 43, the first expansion valve 12, and the first evaporator 13 in that order during heat radiation operation, and a flow path in which the refrigerant that flows out of the condenser 31 and through the fourth branch portion 74 flows into the first expansion valve 12 and the first evaporator 13 in that order during normal operation, without flowing through the heat exchanger 43.

[0215] (The control unit switches between heat storage operation, heat dissipation operation, and normal operation.) The heat storage operation, heat release operation, and normal operation in the second modified example will be described.

[0216] (Heat storage operation) Since this is the same as the heat storage operation in the fifth embodiment, a description thereof will be omitted here.

[0217] (heat dissipation operation) In the heat dissipation operation, under the control of the control unit 4, the second switching valve 76 switches the flow path so that the refrigerant that has flowed out of the condenser 31 and passed through the fourth branch portion 74 flows sequentially through the heat exchanger 43, the first expansion valve 12, and the first evaporator 13. The refrigerant compressed by the compressor 30 flows through the condenser 31 and the fourth branch portion 74, passes through the heat exchanger 43 via the second switching valve 76, and then passes through the first expansion valve 12 and the first evaporator 13, or passes through the fourth branch portion 74, passes through the second cooling section expansion valve 22, and the second cooling section evaporator 23, and is then drawn into the compressor 30. The refrigerant is then compressed by the compressor 30 and repeats the above-described circulation.

[0218] (Normal operation) In normal operation, the control unit 4 controls the second switching valve 76 to switch the flow path so that the refrigerant that flows out of the condenser 31 and through the fourth branch portion 74 flows into the first expansion valve 12 and the first evaporator 13 in this order without passing through the heat exchanger 43. More specifically, in normal operation, the refrigerant does not flow through the heat storage tank 44. The refrigerant compressed by the compressor 30 flows through the condenser 31 and the fourth branch portion 74, and then flows through the first expansion valve 12 and the first evaporator 13 in this order via the second switching valve 76, or flows through the fourth branch portion 74 and then flows through the second cooling section expansion valve 22 and the second cooling section evaporator 23 in this order, and is then drawn into the compressor 30. The refrigerant is then compressed by the compressor 30 and repeats the above-described circulation. In the refrigeration cycle 70 of the second modified example, unlike the refrigeration cycle 70 of the fifth embodiment, in normal operation, the refrigerant does not flow through the heat exchanger 43 and the heat storage tank 44.

[0219] In addition, in the first to third embodiments, examples have been shown in which the heat storage operation is configured to store cold heat in replenishment products stored in the work storage area, and the heat dissipation operation is configured to dissipate the cold heat stored in the replenishment products, but the present invention is not limited to this. For example, the heat storage operation may be configured to store cold heat in at least one of replenishment products stored in the work storage area or sales products displayed in the display area, and the heat dissipation operation may be configured to dissipate the cold heat stored in the heat storage operation in at least one of the replenishment products or sales products.

[0220] In addition, in the first to sixth embodiments, the cooling equipment includes the first cooling equipment and the second cooling equipment, but the present invention is not limited to this. For example, the cooling equipment may be configured to include the first cooling equipment but not the second cooling equipment.

[0221] Furthermore, in the first to sixth embodiments, when there is surplus power in the power generated by the solar power generation device that exceeds the power consumption of the load connected to the solar power generation device, the surplus power is used to operate the compressor to perform heat storage operation to store cold heat, but the present invention is not limited to this. For example, when there is surplus power in the total power of inexpensive power generated by a power supplier other than the store using renewable energy and purchased by the store and the power generated by the store's solar power generation device that exceeds the power consumption of the load connected to the solar power generation device, the surplus power may be used to operate the compressor to perform heat storage operation to store cold heat.

[0222] Furthermore, in the above first to third embodiments, an example has been shown in which the control unit switches from heat radiation operation to normal operation when the temperature inside the first cooling equipment acquired by the first temperature sensor reaches the normal set temperature, but the present invention is not limited to this. For example, the control unit may be configured to switch from heat radiation operation to heat storage operation when the temperature inside the first cooling equipment acquired by the first temperature sensor reaches the normal set temperature and there is surplus power in the power generated by the solar power generation device that exceeds the power consumption of a load including a refrigerator connected to the solar power generation device, based on data on the amount of supplied power, data on the amount of generated power, and data on the amount of consumed power measured by the power measurement unit.

[0223] Furthermore, in the fourth to sixth embodiments, the control unit switches from the heat radiation operation to the normal operation when the temperature of the refrigerant flowing out of the heat exchanger acquired by the second temperature sensor exceeds a predetermined temperature, but the present invention is not limited to this. For example, the control unit may be configured to switch from the heat radiation operation to the heat storage operation when the temperature of the refrigerant flowing out of the heat exchanger acquired by the second temperature sensor exceeds a predetermined temperature and there is surplus power in the power generated by the solar power generation device that exceeds the power consumption of a load including a refrigerator connected to the solar power generation device, based on data on the amount of supplied power, data on the amount of generated power, and data on the amount of consumed power measured by the power measurement unit.

[0224] In addition, in the first to sixth embodiments, the cooling system is not provided with a storage battery capable of storing surplus power generated by the solar power generation device, but the present invention is not limited to this. For example, the cooling system may be provided with a capacitor that stores power generated by the solar power generation device, and may be configured to supply the power generated by the solar power generation device to a load connected to the solar power generation device via the capacitor.

[0225] Furthermore, in the sixth embodiment, an example was described in which water or an aqueous solution generated inside the cylindrical member 651 in the heat storage device 640 was scraped downward, but the present invention is not limited to this. For example, as in a cooling system 900 of a third modified example shown in FIG. 27 , the heat storage device 940 may be configured so that water or an aqueous solution generated inside the cylindrical member 951 is scraped upward. As shown in FIG. 27 , in the third modified example, the cylindrical member 951 has a cylindrical side surface and is open at the upper and lower sides. Alternatively, the lower side of the cylindrical member 951 may not be open, and multiple through holes 951 a connecting the inside and outside of the cylindrical member 951 may be formed in the lower surface and lower parts of the side surface of the cylindrical member 951. The screw member 952 rotates to scrape ice generated inside the cylindrical member 951 upward.

[0226] Furthermore, in the sixth embodiment, the heat storage device 640 includes water or an aqueous solution stored inside the heat storage tank 44, a third evaporator 42 arranged inside the heat storage tank 44, a metallic tubular member 651 arranged in contact with the third evaporator 42 and surrounded by the third evaporator 42, and a screw member 652 that rotates to scrape ice generated inside the tubular member 651 as the water or aqueous solution is cooled by the third evaporator 42 through the tubular member 651 to the outside of the tubular member 651. However, the heat storage devices of the fourth and fifth embodiments may be configured to include a tubular member 651 and a screw member 652, similar to the heat storage device of the sixth embodiment.

[0227] In the fifth and sixth embodiments, the heat storage device is disposed inside the first cooling equipment, but the present invention is not limited to this. For example, the heat storage device may be disposed inside the second cooling equipment. [Explanation of symbols]

[0228] 1. Solar power generation equipment 2. Freezer 3 Cooling equipment 4. Control section 6 Commercial power supply 7 Load 10, 610 1st cooling equipment (cooling equipment) 10a display area 10b Working storage area 12 First expansion valve 13 First evaporator 14 Blower 18 Second expansion valve 19 Second evaporator 20 2nd cooling equipment (cooling equipment) 30 Compressor 31 Condenser 40, 640, 940 Heat storage device 41 Third expansion valve 42 Third evaporator 43 Heat exchanger 44 Heat storage tank 651, 951 Cylindrical member 652, 952 screw members 75 First switching valve (switching valve) 81 1st cold storage material 82 Second cold storage material 91 Products for Sale 92 Replenishment products 100, 600, 900 Cooling System

Claims

1. A solar power generation device; a refrigerator including a compressor that compresses a refrigerant and a condenser that condenses the refrigerant compressed by the compressor, the refrigerator being operated by power supplied from the solar power generation device and a commercial power source; a cooling facility for cooling merchandise for sale, the cooling facility including a first evaporator for evaporating the expanded refrigerant by a first expansion valve for expanding the refrigerant condensed by the condenser; a control unit that, when there is surplus power generated by the solar power generation device that exceeds the power consumption of a load including the refrigerator connected to the solar power generation device, controls the compressor to operate using the surplus power to perform a heat storage operation to store cold heat.

2. 2. The cooling system according to claim 1, wherein the control unit is configured to switch from the heat storage operation to a heat dissipation operation in which, when a state in which there is surplus power changes to a state in which there is no surplus power, the operation dissipates the cold heat stored using the surplus power to cool at least the products for sale in the cooling equipment.

3. The cooling equipment further includes a display area for displaying the products for sale within the cooling equipment, and a work storage area that can be worked on by a worker and that stores replenishment products to be replenished in the display area, The cooling system of claim 1, wherein the control unit is configured to operate the compressor during the heat storage operation so that the temperature inside the cooling equipment becomes a heat storage operation temperature that is lower than the normal set temperature during normal operation, thereby storing cold heat in the replenishment products stored in the work storage area.

4. The cooling system of claim 3, wherein the control unit is configured to switch from the heat storage operation to a heat dissipation operation in which, when there is no surplus electricity, the refrigerant is not circulated through the first evaporator and the stored cold heat is dissipated in the replenishment product.

5. The cooling facility further includes a blower; The cooling system according to claim 4, wherein the control unit is configured to rotate the blower, which rotates forward during the normal operation, in reverse during the heat storage operation, thereby causing the blower to blow air toward the work storage area.

6. The cooling device further includes a first cold storage material; The control unit In the heat storage operation, the air blown out from the first evaporator by the blower is blown toward the work storage area through the first cold storage material, and The cooling system according to claim 5, wherein in the heat dissipation operation, the cold stored in the replenishment product and the first cold storage material is dissipated without the refrigerant flowing into the first evaporator.

7. the cooling equipment includes a second evaporator that evaporates the expanded refrigerant by a second expansion valve that expands the refrigerant condensed by the condenser, a first cold storage material that is cooled by the second evaporator, and a first cold storage material cooling unit that is provided in parallel with the first evaporator; The control unit In the heat storage operation, cold energy is stored in the first cold storage material by the second evaporator, and The cooling system of claim 5, wherein the cooling system is configured to radiate the cold stored in the replenishment product and the first cold storage material without causing the refrigerant to flow into the first evaporator and the second evaporator during the heat radiation operation.

8. The system further includes a heat storage device including a third evaporator that evaporates the refrigerant expanded by a third expansion valve that expands the refrigerant condensed by the condenser, and a second cold storage material that is cooled by the third evaporator, The cooling system according to any one of claims 1 to 4, wherein the control unit is configured to store cold energy in the second cold storage material by the third evaporator during the heat storage operation.

9. the heat storage device further includes a heat exchanger that exchanges heat between the refrigerant condensed by the condenser and the second cold storage material, 9. The cooling system of claim 8, wherein the control unit is configured to switch from the heat storage operation to a heat dissipation operation in which, when there is no surplus power, the refrigerant flowing out of the condenser flows into the heat exchanger, thereby supercooling the refrigerant by performing heat exchange between the second cold storage material and the refrigerant, and flowing the supercooled refrigerant into the first evaporator, until the temperature of the refrigerant flowing out of the heat exchanger exceeds a predetermined temperature.

10. a switching valve for switching a flow path of the refrigerant flowing out from the refrigerator, the cooling equipment includes a plurality of the cooling equipment; 10. The cooling system according to claim 9, wherein the control unit is configured to control the switching of the switching valve so that, in the heat storage operation, the heat storage device and the plurality of cooling equipments are connected in parallel in the high-pressure side refrigerant flow path, and, in the heat dissipation operation, the heat storage device and the plurality of cooling equipments connected in parallel are connected in series in the high-pressure side refrigerant flow path.

11. The cooling system according to claim 8 , wherein the heat storage device further includes the second cold storage material being ice slurry, and a heat storage tank in which the second cold storage material is disposed.

12. 12. The cooling system according to claim 11, wherein the heat storage device further includes: the third evaporator disposed inside the heat storage tank; a metallic tubular member disposed in contact with and surrounded by the third evaporator; and a screw member that rotates to scrape ice generated inside the tubular member by cooling the water or aqueous solution stored inside the heat storage tank by the third evaporator through the tubular member to the outside of the tubular member so as to generate the second cold storage material, which is the ice slurry.

13. The cooling system according to claim 8 , wherein the heat storage device is provided inside the cooling facility.

Images