Control device, waste heat recovery refrigeration system, control method, and program

Abstract

To provide a method capable of improving total efficiency of a load device utilizing exhaust heat of a refrigeration machine and the refrigeration machine.SOLUTION: A controller of an exhaust heat recovery refrigeration machine system including: a first exhaust heat recovery unit for supplying heat recovered by heat exchange with a first refrigerant circulating in a refrigerant circuit of a refrigeration machine for cooling a refrigeration chamber and / or a second refrigerant circulating in a refrigerant circuit of the refrigeration machine for cooling a freezing chamber to an air conditioner; and a second exhaust heat recovery unit for supplying the heat recovered by heat exchange with the first refrigerant and / or the second refrigerant to a water heater, controls whether heat exchange with the first refrigerant is performed or not and whether heat exchange with the second refrigerant is performed or not in each of the first exhaust heat recovery unit and the second exhaust heat recovery unit according an outside air temperature.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a control device, an exhaust heat recovery refrigeration system, a control method, and a program.

Background Art

[0002] Patent Document 1 discloses a heat pump system including a refrigerator having a capacity-variable compressor, an evaporator, etc., a water medium circuit that recovers the exhaust heat of the refrigerant circuit by exchanging heat with the refrigerant circulating in the refrigerant circuit of the refrigerator, and an auxiliary heat source that heats the water medium circulating in the water medium circuit. In this heat pump system, when the difference between the outlet temperature of the water medium in the refrigerant-water heat exchanger and the target outlet temperature is equal to or greater than a threshold value, control is disclosed to cause the auxiliary heat source to operate. According to the heat pump system disclosed in Patent Document 1, the exhaust heat of the refrigerant circuit recovered by the water medium circuit can be supplied to loads such as heating and hot water supply.

[0003] Patent Document 1 mentions the operation of combining a refrigerator with a water heater or a refrigerator with heating, but there is no mention of under what conditions the exhaust heat of the refrigerator can be used for operations such as heating and hot water supply to improve the overall operation efficiency of the system including the refrigerator and heating.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] There is a need for a method to improve the overall operation efficiency of a system including a refrigerator and a load-side device (such as an air conditioner or a water heater) that utilizes the exhaust heat of the refrigerator.

[0006] Therefore, an object of the present invention is to provide a control device, an exhaust heat recovery refrigeration system, a control method, and a program that can solve the above-described problems.

Means for Solving the Problems

[0007] According to one aspect of the present disclosure, a control device exchanges heat with a first refrigerant circulating in a refrigerant circuit of a first refrigerator that cools a refrigerating chamber and / or a second refrigerant circulating in a refrigerant circuit of a second refrigerator that cools the refrigerating chamber to recover heat, and supplies the recovered heat to an air conditioning unit. The control device also includes a second exhaust heat recovery device that exchanges heat with the first refrigerant and / or the second refrigerant to recover heat and supplies the recovered heat to a hot water supply unit. In the first exhaust heat recovery device, it is possible to switch whether to exchange heat for each of the first refrigerant and the second refrigerant. In the second exhaust heat recovery device, it is configured to be able to switch whether to exchange heat for each of the first refrigerant and the second refrigerant. The control device of the exhaust heat recovery refrigeration system includes a heat recovery control unit that controls whether to exchange heat with the first refrigerant and controls whether to exchange heat with the second refrigerant in each of the first exhaust heat recovery device and the second exhaust heat recovery device according to the outside air temperature. When the outside air temperature becomes equal to or lower than a predetermined first threshold temperature, the heat recovery control unit controls the first exhaust heat recovery device and the second exhaust heat recovery device so as not to perform heat exchange of the first refrigerant.

[0008] According to one aspect of the present disclosure, an exhaust heat recovery refrigeration system includes a first refrigerator for cooling a refrigerating chamber, a second refrigerator for cooling the refrigerating chamber, an air conditioning unit, a hot water supply unit, a first heat exchange circuit that exchanges heat between a first refrigerant circulating in a first refrigerant circuit of the first refrigerator and a first water medium, a second heat exchange circuit that exchanges heat between a second refrigerant circulating in a second refrigerant circuit of the second refrigerator and the first water medium, a circuit for supplying heat of the heat-exchanged first water medium to the air conditioning unit, a valve provided in the first heat exchange circuit for switching whether the first water medium flows through the first heat exchange circuit, a valve provided in the second heat exchange circuit for switching whether the first water medium flows through the second heat exchange circuit, a first exhaust heat recovery device including the same, a third heat exchange circuit that exchanges heat between the first refrigerant and a second water medium, a fourth heat exchange circuit that exchanges heat between the second refrigerant and the second water medium, a circuit for supplying heat of the heat-exchanged second water medium to the hot water supply unit, a valve provided in the third heat exchange circuit for switching whether the second water medium flows through the third heat exchange circuit, a valve provided in the fourth heat exchange circuit for switching whether the second water medium flows through the fourth heat exchange circuit, a second exhaust heat recovery device including the same, and a control device according to any one of claims 1 to 5.

[0009] According to one aspect of the present disclosure, the control method includes a first waste heat recovery device that exchanges heat with a first refrigerant circulating in a refrigerant circuit of a first refrigerator for cooling a refrigerating chamber and / or a second refrigerant circulating in a refrigerant circuit of a second refrigerator for cooling the refrigerating chamber to recover heat, and supplies the recovered heat to an air conditioning unit, and a second waste heat recovery device that exchanges heat with the first refrigerant and / or the second refrigerant to recover heat, and supplies the recovered heat to a hot water supply unit. In the first waste heat recovery device, it is possible to switch whether to exchange heat for each of the first refrigerant and the second refrigerant. In the second waste heat recovery device, it is configured to be able to switch whether to exchange heat for each of the first refrigerant and the second refrigerant. The control method of the waste heat recovery refrigerator system is to control whether to exchange heat with the first refrigerant and whether to exchange heat with the second refrigerant in each of the first waste heat recovery device and the second waste heat recovery device according to the outside air temperature. When the outside air temperature becomes equal to or lower than a predetermined first threshold temperature, the first exhaust heat recovery device and the second exhaust heat recovery device are controlled so as not to perform heat exchange of the first refrigerant.

[0010] According to one aspect of the present disclosure, the program causes a computer to include a first waste heat recovery device that exchanges heat with a first refrigerant circulating in a refrigerant circuit of a first refrigerator for cooling a refrigerating chamber and / or a second refrigerant circulating in a refrigerant circuit of a second refrigerator for cooling the refrigerating chamber to recover heat, and supplies the recovered heat to an air conditioning unit, and a second waste heat recovery device that exchanges heat with the first refrigerant and / or the second refrigerant to recover heat, and supplies the recovered heat to a hot water supply unit. In the first waste heat recovery device, it is possible to switch whether to exchange heat for each of the first refrigerant and the second refrigerant. In the second waste heat recovery device, it is configured to be able to switch whether to exchange heat for each of the first refrigerant and the second refrigerant. The control method of the waste heat recovery refrigerator system is to control whether to exchange heat with the first refrigerant and whether to exchange heat with the second refrigerant in each of the first waste heat recovery device and the second waste heat recovery device according to the outside air temperature. When the outside air temperature becomes equal to or lower than a predetermined first threshold temperature, the process of controlling the first exhaust heat recovery device and the second exhaust heat recovery device so as not to perform heat exchange of the first refrigerant to execute.

Advantages of the Invention

[0011] According to the control device, exhaust heat recovery refrigeration system, control method, and program of the present disclosure, it is possible to improve the operating efficiency of the entire system including both a load device that utilizes the exhaust heat of the refrigerator and the refrigerator.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3A

Figure 3B

Figure 4

Modes for Carrying Out the Invention

[0013] <Embodiment> Hereinafter, an exhaust heat recovery refrigeration system according to an embodiment of the present disclosure will be described with reference to FIGS. 1 to 4. (Configuration) FIG. 1 is a diagram showing an example of an exhaust heat recovery refrigeration system according to an embodiment. The exhaust heat recovery refrigeration system 100 is used in a store such as a supermarket, and includes a refrigerator 1a that cools a refrigerated showcase, a refrigerator 1b that cools the refrigerated showcase, an air conditioning unit 30, a hot water supply unit 40, an exhaust heat recovery device 10 that recovers the exhaust heat of the refrigerator 1a and the refrigerator 1b and supplies it to the hot water supply unit 40 of the store, an exhaust heat recovery device 20 that recovers the exhaust heat of the refrigerator 1a and the refrigerator 1b and supplies it to the air conditioning unit 30 of the store, a system controller 50, and temperature sensors 60a to 60d. The temperature sensors 60a to 60d measure the outside air temperature. The outside air temperature is the ambient temperature around the locations where the devices such as the refrigerators 1a and 1b, the air conditioner of the air conditioning unit 30, and the water heater 41 are installed. The temperature sensor 60a is provided near the installation location of the refrigerator 1a and measures the ambient temperature of the refrigerator 1a. The temperature sensor 60b is provided near the installation location of the refrigerator 1b and measures the ambient temperature of the refrigerator 1b. The temperature sensor 60c is provided near the installation location of an air conditioner (not shown) and measures the ambient temperature of the air conditioner. The temperature sensor 60d is provided near the installation location of the water heater 41 and measures the ambient temperature of the water heater 41. The outside air temperature measured by the temperature sensor 60a is transmitted to the control unit 7a and the system controller 50. The outside air temperature measured by the temperature sensor 60b is transmitted to the control unit 7b and the system controller 50. The outside air temperature measured by the temperature sensor 60c is transmitted to the control unit 35 and the system controller 50. The outside air temperature measured by the temperature sensor 60d is transmitted to the control unit 46 and the system controller 50.

[0014] The refrigerator 1a includes a compressor 2a, a gas cooler 3a, an expansion valve 4a, an evaporator 5a, a refrigerant pipe 6a connecting these components, and a control unit 7a. The compressor 2a compresses and discharges the refrigerant. Between the compressor 2a and the gas cooler 3a, the heat exchanger 11a of the exhaust heat recovery unit 10 and the heat exchanger 21a of the exhaust heat recovery unit 20 are connected (inserted), and the refrigerant of the refrigerator 1a flows through the heat exchanger 11a and the heat exchanger 21a. In the heat exchanger 11a, the heat of the high-temperature and high-pressure refrigerant is recovered by the refrigerant (water) of the exhaust heat recovery unit 10 and supplied to the hot water supply unit 40. In the heat exchanger 21a, the heat of the high-temperature and high-pressure refrigerant is recovered by the refrigerant (water) of the exhaust heat recovery unit 20 and supplied to the air conditioning unit 30. The refrigerant that has passed through the heat exchanger 11a and the heat exchanger 21a exchanges heat with air in the gas cooler 3a to dissipate heat and is condensed. The condensed refrigerant is decompressed and expanded by the expansion valve 4a and supplied to the evaporator 5a. The refrigerant supplied to the evaporator 5a absorbs the heat of the refrigerated showcase and cools the air in the refrigerated showcase. The refrigerant vaporized in the evaporator 5a is sucked into the compressor 2a. The refrigerant is compressed by the compressor 2a and circulates through the above-mentioned path again. For example, CO2 is used as the refrigerant of the refrigerator 1a. The CO2 refrigerant becomes a supercritical state in the normal temperature range of about 31°C. The control unit 7a operates in a state where the CO2 refrigerant becomes supercritical at high pressure when the outside air temperature measured by the temperature sensor 60a is equal to or higher than a predetermined threshold value, or when heat recovery is performed by the exhaust heat recovery unit 10 or the exhaust heat recovery unit 20, and operates in a state where the high pressure becomes subcritical in other cases.

[0015] The refrigerator 1b includes a compressor 2b, a gas cooler 3b, an expansion valve 4b, an evaporator 5b, a refrigerant pipe 6b connecting these components, and a control unit 7b. The compressor 2b compresses and discharges the refrigerant. Between the compressor 2b and the gas cooler 3b, the heat exchanger 11b of the waste heat recovery unit 10 and the heat exchanger 21b of the waste heat recovery unit 20 are connected (inserted), and the refrigerant of the refrigerator 1b flows through the heat exchanger 11b and the heat exchanger 21b. In the heat exchanger 11b, the heat of the high-temperature and high-pressure refrigerant is recovered by the refrigerant (water) of the waste heat recovery unit 10 and supplied to the hot water supply unit 40. In the heat exchanger 21b, the heat of the high-temperature and high-pressure refrigerant is recovered by the refrigerant (water) of the waste heat recovery unit 20 and supplied to the air conditioning unit 30. The refrigerant that has passed through the heat exchanger 11b and the heat exchanger 21b exchanges heat with air in the gas cooler 3b to dissipate heat and is condensed. The condensed refrigerant is decompressed and expanded by the expansion valve 4b and supplied to the evaporator 5b. The refrigerant supplied to the evaporator 5b absorbs the heat of the refrigerated showcase and cools the air in the refrigerated showcase. The refrigerant vaporized in the evaporator 5b is sucked into the compressor 2b. The CO2 refrigerant is compressed by the compressor 2b and circulates through the above-mentioned path again. For example, CO2 is used as the refrigerant of the refrigerator 1b. When the outside air temperature measured by the temperature sensor 60b is equal to or higher than a predetermined threshold value, the control unit 7b operates in a state where the CO2 refrigerant becomes supercritical at high pressure, and in other cases, it operates in a state where the high pressure becomes subcritical. Similar to the case of the refrigerator 1a, when heat recovery is performed by the waste heat recovery unit 10 or the waste heat recovery unit 20, the control unit 7b may operate in a state where it becomes supercritical at high pressure regardless of the outside air temperature measured by the temperature sensor 60b. Comparing the refrigerators 1a and 1b, the evaporation temperature of the refrigerator 1a is higher, and the refrigerant temperature at high pressure of the refrigerator 1b is higher.

[0016] The heat recovery unit 10 includes a heat exchanger 11a, a heat exchanger 11b, a pump 13, a heat exchanger 14, a pipe 15a that branches from the pipe 15b and connects to the heat exchanger 11a on the upstream side of the flow direction of the water medium from the heat exchanger 11b and connects to the pipe 15b on the downstream side of the flow direction of the water medium of the heat exchanger 11b, a valve 12a provided in the pipe 15a, a pipe 15b that connects the heat exchanger 11b, the pump 13, and the heat exchanger 14 and circulates the water medium among them, a valve 12b provided between the branch point of the pipe 15b on the upstream side of the flow direction of the water medium in the pipe 15a and the heat exchanger 11b, and a control unit 16. The control unit 16 controls the start and stop of the pump 13 and the opening and closing of the valves 12a and 12b. (1) When the pump 13 is started, the valve 12a is in the open state, and the valve 12b is in the closed state, the water medium circulates through the pipe 15a. In the heat exchanger 11a, heat is absorbed from the CO2 refrigerant of the refrigerator 1a, and the temperature of the water medium rises. The heated water medium flows through the pipe 15a, merges into the pipe 15b, flows through the pipe 15b, and reaches the heat exchanger 14. In the heat exchanger 14, heat exchange is performed between the water medium flowing through the pipe 15b and the water medium on the hot water supply unit 40 side to raise the temperature of the water medium on the hot water supply unit 40 side. (2) When the pump 13 is started, the valve 12a is in the closed state, and the valve 12b is in the open state, the water medium circulates through the pipe 15b. In the heat exchanger 11b, heat is absorbed from the CO2 refrigerant of the refrigerator 1b, and the temperature of the water medium rises. The heated water medium flows through the pipe 15b and reaches the heat exchanger 14. In the heat exchanger 14, heat exchange is performed between the water medium flowing through the pipe 15b and the water medium on the hot water supply unit 40 side to raise the temperature of the water medium on the hot water supply unit 40 side. (3) When the pump 13 is started, the valve 12a is in the open state, and the valve 12b is in the open state, heat exchange is performed in both the heat exchanger 11a and the heat exchanger 11b, the water medium flowing through the heat recovery unit 10 is heated, and in the heat exchanger 14, the water medium on the hot water supply unit 40 side is heated.

[0017] The heat recovery unit 20 includes a heat exchanger 21a, a heat exchanger 21b, a pump 23, a pipe 24b that branches from the pipe 24a on the upstream side of the flow direction of the water medium from the heat exchanger 21a and is connected to the heat exchanger 21b, and is connected to the pipe 24a on the downstream side of the flow direction of the water medium in the heat exchanger 21a, a valve 22b provided in the pipe 24b, a pipe 24a that connects the heat exchanger 21a, the pump 23, and the air conditioning unit 30 side and circulates the water medium among them, a valve 22a provided between the branch point of the pipe 24a on the upstream side of the flow direction of the water medium in the pipe 24a and the heat exchanger 21a, and a control unit 25. The control unit 25 controls the start and stop of the pump 23 and the opening and closing of the valves 22a and 22b. (1) When the pump 23 is started, the valve 22a is in the open state, and the valve 22b is in the closed state, the water medium circulates through the pipe 24a and the air conditioning unit 30. In the heat exchanger 21a, it absorbs heat from the CO2 refrigerant of the refrigerator 1a, and the temperature of the water medium rises. The heated water medium flows through the pipe 24a and reaches the tank 33 of the air conditioning unit 30. The warm water in the tank 33 is supplied to an air conditioner (not shown), and the water returned from the air conditioner reaches the tank 32. The pump 23 of the heat recovery unit 20 sucks water from the tank 32 of the air conditioning unit 30 and sends it to the heat exchanger 21a. (2) When the pump 23 is started, the valve 22a is in the closed state, and the valve 22b is in the open state, the water medium reaches the heat exchanger 21b through the pipe 24b. In the heat exchanger 21b, it absorbs heat from the CO2 refrigerant of the refrigerator 1b, and the temperature of the water medium rises. The heated water medium flows through the pipe 24b, merges with the pipe 24a, and reaches the tank 33 of the air conditioning unit 30, and is supplied to an air conditioner (not shown). The pump 23 sucks water from the tank 32 and sends it to the heat exchanger 21b. (3) When the pump 23 is started, the valve 22a is in the open state, and the valve 22b is in the open state, heat exchange is performed in both the heat exchanger 21a and the heat exchanger 21b. The water medium flowing through the heat recovery unit 20 is heated up and supplied to the tank 33 for use in air conditioning. The water after use is sent to the tank 32. In the heat recovery unit 20, the water in the tank 32 is sent to the heat exchanger 21a and / or the heat exchanger 21b to recover the exhaust heat of the refrigerators 1a and 1b and heat up the water medium.

[0018] The air conditioning unit 30 includes a heat source machine 31 for air conditioning, a tank 32, a tank 33, a pump 34, and a control unit 35. The heat source machine 31 and the tank 32 are connected by a pipe 352. The heat source machine 31 and the tank 33 are connected by a pipe 353. The tank 33 is connected to an air conditioner (not shown) by a pipe 354, and the hot water in the tank 33 is supplied to the air conditioner (not shown) by driving the pump 34 provided in the pipe 354. The control unit 35 controls the heat source machine 31 and the pump 34. Further, the control unit 35 acquires and stores information on the amount and temperature of the hot water stored in the tank 33 and the heat storage amount. For example, a temperature sensor 331 and a flow rate sensor 332 are provided in the flow path on the inlet side of the tank 33 for the water medium supplied from the exhaust heat recovery device 20. A temperature sensor 333 and a flow rate sensor 334 are provided in the flow path on the inlet side of the tank 33 for the water medium supplied from the heat source machine 31. A temperature sensor 335 and a flow rate sensor 336 are provided in the flow path on the outlet side of the tank 33 for the hot water supplied to the air conditioner (not shown). Also, a temperature sensor 321 is provided in the flow path from the tank 32 to the pump 23, a temperature sensor 322 is provided in the flow path from the tank 32 to the heat source machine 31, and a temperature sensor 351a is provided in the flow path of the pipe 351. The control unit 35 acquires the temperatures measured by the temperature sensors 321, 322, 331, 333, 335, 351a and the flow rates measured by the flow rate sensors 332, 334, 336. The control unit 35 acquires and stores, as information on the temperature of the hot water stored in the tank 33, the temperature measured by the temperature sensor 335 at each time. The control unit 35 acquires and stores, as information on the amount of the hot water stored in the tank 33, the value obtained by temporally integrating the value obtained by subtracting the flow rate measured by the flow rate sensor 336 from the sum of the flow rate measured by the flow rate sensor 332 and the flow rate measured by the flow rate sensor 334 at each time. The control unit 35 calculates the exhaust heat recovery amount by (the temperature measured by the temperature sensor 331 at each time - the temperature measured by the temperature sensor 321 at each time) × the flow rate measured by the flow rate sensor 332 at each time, and calculates the output from the heat source machine 31 by (the temperature measured by the temperature sensor 333 at each time - the temperature measured by the temperature sensor 322 at each time) × the flow rate measured by the flow rate sensor 334 at each time.Further, the control unit 35 calculates the amount of heat actually consumed on the load side by (the temperature measured by the temperature sensor 335 at each time - the temperature measured by the temperature sensor 351a at each time) × the flow rate measured by the flow rate sensor 336 at each time. The control unit 35 temporally integrates the value obtained by subtracting the amount of heat actually consumed on the load side from the sum of the calculated waste heat recovery amount and the output from the heat source machine 31 to calculate the heat storage amount in the tank 33. The control unit 35 operates the heat source machine 31 according to the operation mode (cooling, heating, stop, etc.) of the air conditioner and the load. For example, when the air conditioner is in the heating mode, the heat source machine 31 heats the water in the tank 32 and supplies the heated hot water to the tank 33. The tank 33 is supplied with the hot water generated by the heat source machine 31 and the hot water recovered by the waste heat recovery device 20. The hot water in the tank 33 is supplied to an air conditioner (not shown), heat is released by a fan coil unit or the like of the air conditioner, and the water medium that has become low temperature is returned to the tank 32 through the pipe 351. The water medium returned to the tank 32 is heated by the heat source machine 31 and the waste heat recovery device 20, and the heated hot and cold water is stored in the tank 33. The control unit 35 adjusts the operation load of the heat source machine 31 according to the amount and temperature of the hot water stored in the tank 33. For example, even when the set temperature for heating is the same, when the amount of hot water stored in the tank 33 is small, the heat source machine 31 is operated at a higher load compared to the case where the heat storage amount in the tank 33 is large, and when the heat storage amount in the tank 33 is large, the load of the heat source machine 31 is reduced for operation (utilization of heat storage). Also, when the outside air temperature measured by the temperature sensor 60c is high, the heat source machine 31 can be operated at a higher load than the load required by the air conditioner to generate a large amount of heated water medium and store surplus hot water in the tank 33. The stored hot water can be used, for example, when the outside air temperature drops. Thereby, the operation load of the heat source machine 31 when the outside air temperature drops can be reduced. For example, by increasing the load a little during the day when the outside air temperature is high (when the operation load is low) to store surplus heat, and using the stored heat for heating the store after evening, the operation efficiency over a predetermined period (for example, one day) can be improved.

[0019] The hot water supply unit 40 includes a hot water heater 41, a three-way valve 42, a three-way valve 43, a tank 44, a pump 45, and a control unit 46. The three-way valve 42 is connected to a water supply pipe 451, a pipe 452, and a pipe 454. The pipe 452 connects the three-way valve 42 and the tank 44, and a heat exchanger 14 of the waste heat recovery unit 10 is provided in the middle thereof. The pipe 454 connects the three-way valve 42 and the hot water heater 41. A pipe 453 branches from the pipe 454, and the pipe 453 connects the branch point of the pipe 454 and the three-way valve 43. A pipe 456 connects the tank 44 and the three-way valve 43. The remaining port of the three-way valve 43 is connected to a pipe 457 for supplying hot and cold water. The hot water heater 41 and the tank 44 are connected by a pipe 455. The tap water supplied through the pipe 451 is divided by the three-way valve 42 and supplied to the hot water heater 41 through the pipe 454. The hot water heater 41 boils the tap water and supplies hot water to the tank 44 through the pipe 455. On the other hand, the tap water divided by the three-way valve 42 and sent to the pipe 452 absorbs heat by performing heat exchange with the water-cooling medium flowing through the waste heat recovery unit 10 in the heat exchanger 14 and is sent to the tank 44. The tank 44 is supplied with the warm water generated by the hot water heater 41 and the warm water heat-recovered by the waste heat recovery unit 10. The warm water stored in the tank 44 flows through the pipe 456, is mixed with the tap water supplied through the pipe 453 at the three-way valve 43, and then is supplied to the equipment using the warm water through the pipe 457. A pump 45 is provided in the pipe 457, and the warm water is supplied to the load side by driving the pump 45. The control unit 46 operates the hot water heater 41 according to the demand for hot and cold water and stores warm water in the tank 44. In addition, the control unit 46 acquires and stores information on the amount and temperature of the warm water stored in the tank 44 and the heat storage amount. For example, a temperature sensor 441 and a flow rate sensor 442 are provided in the flow path on the inlet side of the tank 44 of the water medium heat-exchanged by the heat exchanger 14 of the waste heat recovery unit 10. A temperature sensor 443 and a flow rate sensor 444 are provided in the flow path on the inlet side of the tank 44 of the water medium supplied from the hot water heater 41. A temperature sensor 445 and a flow rate sensor 446 are provided in the flow path on the outlet side of the warm water in the tank 44. The control unit 46 acquires the temperatures measured by the temperature sensors 441, 443, 445 and the flow rates measured by the flow rate sensors 442, 444, 446.The control unit 46 acquires and stores, as information on the temperature of the hot water stored in the tank 44, the temperature measured by the temperature sensor 445 at each time. The control unit 46 acquires and stores, as information on the amount of hot water stored in the tank 44, the value obtained by temporally integrating the value obtained by subtracting the flow rate measured by the flow sensor 446 from the sum of the flow rates measured by the flow sensor 442 and the flow sensor 444 at each time. The control unit 46 calculates the heat storage amount of the tank 44 by temporally integrating the value obtained by multiplying the value obtained by subtracting the flow rate measured by the flow sensor 446 from the sum of the flow rates measured by the flow sensor 442 and the flow sensor 444 at each time by the temperature difference between the predetermined reference temperature and the temperature measured by the temperature sensor 445. The control unit 46 adjusts the operation load of the water heater 41 according to the amount, temperature, and heat storage amount of the hot water stored in the tank 44. For example, when the hot water heated by the heat exchanger 14 is supplied to the tank 44, the control unit 46 reduces the load of the water heater 41 according to the heat storage amount of the hot water heat-recovered by the exhaust heat recovery unit 10 (utilization of heat storage). Also, for example, when the outside air temperature measured by the temperature sensor 60d is high, the water heater 41 can be operated at a higher load than the required load to generate a large amount of hot water and store surplus hot water in the tank 44. The stored hot water is used when the demand for hot water is high or when the outside air temperature or the water temperature measured by the temperature sensor 60d is low. Thereby, the operation load of the water heater 41 at high load can be reduced.

[0020] The exhaust heat recovery refrigeration system 100 shown in FIG. 1 schematically shows the basic configuration, and may further include other components. For example, in FIG. 1, the heat exchangers 11a, 21a, etc. incorporated in the refrigerators 1a, 1b are one each for the air conditioning unit 30 and the water heater unit 40, but a plurality of heat exchangers may be incorporated in the refrigerators 1a, 1b respectively.

[0021] FIG. 2 is a diagram showing an example of a system controller according to an embodiment. The system controller 50 is connected to the control units 7a, 7b, 16, 25, 35, 46 and the temperature sensor 60 in FIG. 1. The system controller 50 communicates with the control units 7a, 7b, 16, 25, 35, 46 to control the operations of the refrigerators 1a, 1b, the waste heat recovery units 10, 20, the air conditioning unit 30, and the hot water supply unit 40 so as to improve the efficiency of the entire waste heat recovery refrigeration system 100. The system controller 50 includes an outside air temperature acquisition unit 51, a determination unit 52, a first refrigerator control unit 53, a second refrigerator control unit 54, a first heat recovery control unit 55, a second heat recovery control unit 56, an air conditioning unit control unit 57, a hot water supply unit control unit 58, and a storage unit 59.

[0022] The outside air temperature acquisition unit 51 acquires the outside air temperature measured by each of the temperature sensors 60a to 60d. The determination unit 52 makes a determination regarding the waste heat recovery control from the refrigerators 1a and 1b based on a predetermined setting. The predetermined setting defines under what conditions the waste heat recovered from the refrigerators 1a and 1b is used for heating or hot water supply and under what conditions the waste heat is not used. Conditions for improving the overall operating efficiency of the waste heat recovery refrigeration system 100 are set in this setting. Improving the operating efficiency means, for example, operating while reducing the energy consumption of the waste heat recovery refrigeration system 100 as much as possible. For example, when the outside air temperature measured by the temperature sensor 60a or the like is X1°C or higher and the refrigerators 1a and 1b are operated according to their respective loads, if the efficiency of the entire system can be improved by using the waste heat of the refrigerators 1a and 1b rather than operating the air conditioning unit 30 and the hot water supply unit 40 independently without operating the waste heat recovery units 10 and 20, the determination unit 52 determines to operate the waste heat recovery units 10 and 20 when the outside air temperature becomes X1°C or higher. An example of this determination will be described later with reference to FIGS. 3A and 3B. The determination unit 52 acquires information regarding the states of the respective devices obtained from the control units 7a, 7b, 16, 25, 35, 46 through the first refrigerator control unit 53, the second refrigerator control unit 54, the first heat recovery control unit 55, the second heat recovery control unit 56, the air conditioning unit control unit 57, and the hot water supply unit control unit 58, and makes these determinations.

[0023] The first refrigerator control unit 53 communicates with the control unit 7a of the refrigerator 1a to obtain the operation mode of the refrigerator 1a. The first refrigerator control unit 53 instructs the control unit 7a of the operation mode of the refrigerator 1a. For example, when the loads of the air conditioning unit 30 and the hot water supply unit 40 are high and increasing the amount of recovered exhaust heat can improve the efficiency of the entire exhaust heat recovery refrigerator system 100, the first refrigerator control unit 53 instructs the control unit 7a to increase the operation load. The control unit 71a instructed to increase the operation load increases the rotation speed of the compressor 2a and raises the discharge temperature of the CO2 refrigerant so that the heat exchange amount in the heat exchangers 11a and 21a increases.

[0024] The second refrigerator control unit 54 communicates with the control unit 7b of the refrigerator 1b to obtain the operation mode of the refrigerator 1b. The second refrigerator control unit 54 instructs the control unit 7b of the operation mode of the refrigerator 1b. For example, when the loads of the air conditioning unit 30 and the hot water supply unit 40 are high and increasing the amount of recovered exhaust heat can improve the efficiency of the entire exhaust heat recovery refrigerator system 100, the second refrigerator control unit 54 instructs the control unit 7b to increase the operation load. The control unit 7b instructed to increase the operation load increases the rotation speed of the compressor 2a and raises the discharge temperature of the CO2 refrigerant so that the heat exchange amount in the heat exchangers 11b and 21b increases.

[0025] The first heat recovery control unit 55 communicates with the control unit 16 of the exhaust heat recovery unit 10 to obtain information regarding the operating state of the exhaust heat recovery unit 10, such as whether the pump 13 is operating or stopped, whether the valves 12a and 12b are in the open state or the closed state, and whether the temperature of the water-cooling medium on the outlet side or the inlet side of the pump 13 has reached the target temperature. The first heat recovery control unit 55 controls the operation of the exhaust heat recovery unit 10. For example, when the hot water supply unit 40 is stopped and there is no need to supply the exhaust heat of the refrigerators 1a and 1b, the first heat recovery control unit 55 instructs the control unit 16 to stop the pump 13. Based on this instruction, the control unit 16 stops the pump 13. For example, when the exhaust heat of the refrigerator 1a for refrigeration is not supplied to the hot water supply unit 40, the first heat recovery control unit 55 instructs the control unit 16 to stop the exhaust heat recovery from the refrigerator 1a. Based on this instruction, the control unit 16 controls the pump 13 to be in the operating state, the valve 12a to be in the closed state, and the valve 12b to be in the open state. For example, when the temperature of the water-cooling medium is lower than the target temperature, the first heat recovery control unit 55 instructs an increase in the rotational speed of the pump 13, and the control unit 16 controls the pump 13 based on this instruction.

[0026] The second heat recovery control unit 56 communicates with the control unit 25 of the exhaust heat recovery unit 20 to obtain information regarding the operating state of the exhaust heat recovery unit 20, such as whether the pump 23 is started or stopped, whether the valves 22a and 22b are in the open state or the closed state, and whether the temperature of the water-cooling medium on the outlet side or the inlet side of the pump 23 has reached the target temperature. The second heat recovery control unit 56 controls the operation of the exhaust heat recovery unit 20. For example, when the air conditioning unit 30 is stopped or operating in a cooling mode, etc., and there is no need to supply the exhaust heat of the refrigerators 1a and 1b, the second heat recovery control unit 56 instructs the control unit 25 to stop the pump 23. Based on this instruction, the control unit 25 stops the pump 23. For example, when the exhaust heat of the refrigerator 1a for refrigeration is not supplied to the air conditioning unit 30, the second heat recovery control unit 56 instructs the control unit 25 to stop the exhaust heat recovery from the refrigerator 1a. Based on this instruction, the control unit 25 controls the pump 23 to be in the operating state, the valve 22a to be in the closed state, and the valve 22b to be in the open state. For example, when the temperature of the water-cooling medium is lower than the target temperature, the second heat recovery control unit 56 instructs to increase the rotational speed of the pump 23, and the control unit 25 controls the pump 23 based on this instruction.

[0027] The air conditioning unit control unit 57 communicates with the control unit 35 to obtain information regarding the operating state of the air conditioning unit 30, such as whether it is in a cooling operation, a heating operation, stopped, performing an operation using the recovered exhaust heat, performing a heat storage operation, the water temperature and water volume of the tank 33, etc. The air conditioning unit control unit 57 controls the air conditioning unit 30. For example, when the outside air temperature measured by the temperature sensor 60c is high, etc., the air conditioning unit control unit 57 instructs the control unit 35 to perform heat storage in the tank 33 in addition to responding to the air conditioning load. For example, the air conditioning unit control unit 57 instructs the control unit 35 to perform an operation using the exhaust heat recovered by the exhaust heat recovery unit 20. For example, in the air conditioning unit 30, a control method for utilizing the exhaust heat in advance is defined, and the control unit 35 executes an operation using the exhaust heat based on this control method.

[0028] The hot water supply unit control unit 58 communicates with the control unit 46 to obtain information regarding the operating state of the hot water supply unit 40, such as whether it is operating, stopped, performing an operation using waste heat, performing a heat storage operation, the water temperature and water volume of the tank 44, and the like. The hot water supply unit control unit 58 controls the hot water supply unit 40. For example, when the outside air temperature measured by the temperature sensor 60d is high, in addition to responding to the hot water supply load to the control unit 46, the hot water supply unit control unit 58 instructs the tank 44 to perform heat storage. For example, the hot water supply unit control unit 58 instructs the control unit 46 to perform an operation that utilizes the waste heat recovered by the waste heat recovery device 10. For example, in the hot water supply unit 40, a control method for using waste heat in advance is defined, and the control unit 46 executes an operation that utilizes waste heat based on this control method.

[0029] The storage unit 59 stores the outside air temperature measured by the temperature sensors 60a to 60d obtained by the outside air temperature acquisition unit 51, various programs that exhibit the functions of the system controller 50, the determination conditions used by the determination unit 52, data of the processing process, and the like.

[0030] (Operation) Next, with reference to FIGS. 3A and 3B, an example of waste heat recovery control for improving the efficiency of the entire waste heat recovery refrigeration system 100 will be described. (Utilization of Waste Heat for Hot Water Supply Unit) FIG. 3A is a first flowchart showing an example of waste heat recovery control according to the embodiment. First, the determination unit 52 determines whether the model of the water heater 41 is a heat pump type (step S1). The heat pump type water heater 41 originally has good operating efficiency. On the other hand, when the water heater 41 is an electric heating wire type unit driven by electricity or a boiler using fossil fuel, etc., the operating efficiency tends to be lower than that of the heat pump type water heater 41. In the case of a water heater 41 other than the heat pump type, rather than covering all loads with an inefficient water heater 41, increasing the operating load of the refrigerators 1a and 1b with good operating efficiency, increasing and recovering the exhaust heat, and using the recovered exhaust heat to operate the water heater 41 may improve the overall system efficiency. Step S1 is a determination condition based on such a concept. When the model of the water heater 41 is not a heat pump type (step S1; No), the determination unit 52 decides to use the exhaust heat of the refrigerator 1a for refrigeration, use the exhaust heat of the refrigerator 1b for refrigeration, and operate the water heater 41 according to the load (step S9). The first heat recovery control unit 55 instructs the control unit 16 to start the pump 13 and control the valves 12a and 12b to be in the open state based on the decision of the determination unit 52. The control unit 16 starts the pump 13 and sets the valves 12a and 12b to the open state. The hot water unit control unit 58 instructs the control unit 46 to perform an operation using the exhaust heat recovered by the exhaust heat recovery device 10 based on the decision of the determination unit 52. The control unit 46 operates the water heater 41 in the instructed mode. Also, the first refrigerator control unit 53 instructs the control unit 7a to increase the operating load of the refrigerator 1a. The control unit 7a increases the rotational speed of the compressor 2a to increase the refrigerant discharge temperature and discharge pressure. The second refrigerator control unit 54 instructs the control unit 7b to increase the operating load of the refrigerator 1b. The control unit 7b increases the rotational speed of the compressor 2b to increase the refrigerant discharge temperature and discharge pressure.

[0031] When the model of the water heater 41 is a heat pump type (step S1; Yes), the determination unit 52 determines whether there is a heat storage tank (tank 44) in the hot water supply system (hot water supply unit 40) (step S2). The determination of whether there is a heat storage tank includes not only physically determining whether a heat storage tank is provided, but also determining whether the temperature and amount of water stored in the heat storage tank can be used to reduce the load of the water heater 41. The determination unit 52 determines whether the hot water in the tank 44 can be used to reduce the load of the water heater 41 based on the water volume and the temperature of the hot water in the tank 44 acquired from the control unit 46. For example, for example, the determination unit 52 may determine that the hot water in the tank 44 can be used to reduce the load if the water temperature in the tank 44 is equal to or higher than a predetermined temperature and the water volume is equal to or more than a predetermined amount. If a heat storage tank is physically provided in the hot water supply unit 40 and the hot water in the heat storage tank can be used to reduce the load of the water heater 41, the determination in step S2 is Yes; otherwise, it is No.

[0032] When there is no heat storage tank (step S2; No), the determination unit 52 determines whether the outside air temperature is equal to or higher than a predetermined temperature (XX °C) based on the outside air temperature measured by the temperature sensor 60a acquired by the outside air temperature acquisition unit 51 (step S4). Regardless of the outside air temperature, the high-pressure refrigerant temperature of the refrigerator 1b for refrigeration becomes high (a temperature at which heat recovery is possible). On the other hand, in the refrigerator 1a for refrigeration, if the outside air temperature is high, the operating load is high, so the high-pressure refrigerant temperature becomes high. However, if the outside air temperature is low, the high-pressure refrigerant temperature does not become high enough for heat recovery. In this case, in order to utilize the exhaust heat, if the refrigerator 1b is operated so as to increase the high-pressure refrigerant temperature while matching the load required by the refrigerated showcase, the exhaust heat can be utilized, but the efficiency of the entire system may instead decrease. Therefore, when the outside air temperature is lower than the predetermined temperature (XX °C), only the exhaust heat of the refrigerator 1b for refrigeration is used for the hot water supply unit 40, and exhaust heat recovery is not performed from the refrigerator 1a for refrigeration. That is, when the outside air temperature is equal to or higher than the predetermined temperature (XX °C) (step S4; Yes), the determination unit 52 determines to utilize the exhaust heat of the refrigerator 1a for refrigeration, utilize the exhaust heat of the refrigerator 1b for refrigeration, and operate the water heater 41 according to the load (step S7). The first heat recovery control unit 55 instructs the control unit 16 to start the pump 13 and open the valves 12a and 12b based on the determination of the determination unit 52. The control unit 16 starts the pump 13 and opens the valves 12a and 12b. The hot water supply unit control unit 58 instructs the control unit 46 to perform an operation using the exhaust heat of the refrigerators 1a and 1b recovered by the exhaust heat recovery device 10 based on the determination of the determination unit 52. The control unit 46 operates the water heater 41 in the instructed operation mode (an operation mode in which the load is reduced by utilizing the exhaust heat of the refrigerator 1a and the refrigerator 1a and the water heater 41 is operated).

[0033] When the outside air temperature measured by the temperature sensor 60a is less than a predetermined temperature (XX °C) (step S4; No), the determination unit 52 determines not to use the exhaust heat of the refrigerator freezer 1a for refrigeration, to use the exhaust heat of the refrigerator freezer 1b for refrigeration, and to operate the water heater 41 according to the load (step S8). Based on the determination of the determination unit 52, the first heat recovery control unit 55 instructs the control unit 16 to start the pump 13, close the valve 12a, and open the valve 12b. The control unit 16 starts the pump 13, closes the valve 12a, and opens the valve 12b. The water heater unit control unit 58 instructs the control unit 46 to perform an operation using the exhaust heat of the refrigerator freezer 1b recovered by the exhaust heat recovery device 10 based on the determination of the determination unit 52. The control unit 46 operates the water heater 41 in the instructed operation mode (using only the exhaust heat of the refrigerator freezer 1b).

[0034] When there is a heat storage tank (step S2; Yes), the determination unit 52 determines whether the outside air temperature is equal to or higher than a predetermined temperature (XX °C) based on the outside air temperature measured by the temperature sensor 60a acquired by the outside air temperature acquisition unit 51 (step S3). When the outside air temperature is equal to or higher than the predetermined temperature (XX °C) (step S3; Yes), the determination unit 52 determines to use the exhaust heat of the refrigerator freezer 1a for refrigeration and to use the exhaust heat of the refrigerator freezer 1b for refrigeration (step S5). Based on the determination of the determination unit 52, the first heat recovery control unit 55 instructs the control unit 16 to start the pump 13 and open the valves 12a and 12b. The control unit 16 starts the pump 13 and opens the valves 12a and 12b. When the outside air temperature is less than the predetermined temperature (XX °C) (step S3; No), the determination unit 52 determines not to use the exhaust heat of the refrigerator freezer 1a for refrigeration and to use the exhaust heat of the refrigerator freezer 1b for refrigeration (step S6). The control unit 16 starts the pump 13, closes the valve 12a, and opens the valve 12b.

[0035] When there is a heat storage tank (step S2; Yes), following steps S5 and S6, the determination unit 52 determines whether the current time is a time period with a high outside air temperature (the outside air temperature measured by the temperature sensor 60d) within a day (step S10). For example, if the current time is between 11:00 and 15:00, the determination unit 52 determines that it is a time period with a high outside air temperature, and if it is any other time, it determines that it is a time period with a low outside air temperature. The time period with a high outside air temperature can be arbitrarily set for each region and each season. In the case of a time period with a high outside air temperature (step S10; Yes), the determination unit 52 decides to utilize the waste heat of the refrigerators 1a and 1b (depending on the determination in steps S5 and S6), operate the water heater 41 according to the hot water supply load, and further perform heat storage (step S11). The hot water supply unit control unit 58 instructs the control unit 46 to perform heat storage in the tank 44 in addition to corresponding to the hot water supply load. The control unit 46 operates the water heater 41 in the instructed predetermined operation mode (for example, when the outside air temperature is XX °C or higher, while reducing the load by utilizing the waste heat of the refrigerators 1a and 1b, increasing the load for heat storage).

[0036] In the case of a time period with a low outside air temperature (step S10; No), the determination unit 52 decides to utilize the waste heat of the refrigerators 1a and 1b (depending on the determination in steps S5 and S6), and operate the water heater 41 according to the hot water supply load while utilizing the heat stored in the heat storage tank (step S12). The hot water supply unit control unit 58 instructs the control unit 46 to perform an operation using the stored heat. The control unit 46 operates the water heater 41 in the instructed predetermined operation mode (for example, when the outside air temperature is less than XX °C, operating the water heater 41 by utilizing the waste heat of the refrigerator 1b and the heat stored in the heat storage tank (tank 44)).

[0037] Following the determination regarding the hot water supply unit 40, the determination unit 52 makes a determination regarding the air conditioning unit 30. Next, referring to FIG. 3B, the waste heat recovery control regarding the air conditioning unit 30 will be described. FIG. 3B is a second flowchart showing an example of the waste heat recovery control according to the embodiment. The determination unit 52 determines whether there is a heat storage tank (tank 33) in the air conditioning system (air conditioning unit 30) (step S21). Similar to the case of the hot water supply system, in addition to physically determining whether the tank 33 exists, the determination unit 52 determines whether the hot and cold water in the tank 33 can be used to reduce the load on the heat source machine 31 based on, for example, the water volume in the tank 33 and the temperature of the hot and cold water acquired from the control unit 35. If a heat storage tank is physically provided in the air conditioning unit 30 and the hot and cold water in the heat storage tank can be used to reduce the load on the heat source machine 31, the determination in step S21 is Yes; otherwise, it is No.

[0038] When there is no heat storage tank (step S21; No), the determination unit 52 determines whether the air conditioning mode of the air conditioning unit 30 is the heating mode (step S23). The determination unit 52 determines whether it is the heating mode based on the operation mode of the heat source machine 31 acquired by the air conditioning unit control unit 57 from the control unit 35. This determination may be made based on, for example, the current season and the outside air temperature measured by the temperature sensor 60c. For example, the determination unit 52 may determine that it is the heating mode if it is currently winter (it may also be spring or autumn) and the outside air temperature is below a predetermined value; otherwise, it is not the heating mode. Also, the determination unit 52 may determine that it is the heating mode if the outside air temperature is below a predetermined value regardless of the season, and it is not the heating mode if the outside air temperature is above the predetermined value. When it is not the heating mode (step S23; No), the determination unit 52 decides not to utilize the exhaust heat of the refrigerators 1a and 1b and to operate the heat source machine 31 according to the air conditioning load (step S27). The second heat recovery control unit 56 instructs the control unit 35 to stop the pump 23 based on the decision of the determination unit 52. The control unit 35 stops the pump 23. The air conditioning unit control unit 57 instructs the control unit 35 to operate in a mode according to the air conditioning load (cooling load) based on the decision of the determination unit 52. The control unit 35 operates the heat source machine 31 in the instructed mode.

[0039] In the case of the heating mode (step S23; Yes), the determination unit 52 determines to utilize the exhaust heat of the refrigerators 1a and 1b and operate the heat source machine 31 according to the air conditioning load (heating load) (step S26). Based on the determination of the determination unit 52, the second heat recovery control unit 56 instructs the control unit 35 to start the pump 23 and set the valves 22a and 22b to the open state. The control unit 35 starts the pump 23 and sets the valves 22a and 22b to the open state. The air conditioning unit control unit 57 instructs the control unit 35 to perform operation according to the heating load based on the determination of the determination unit 52. The control unit 35 operates the heat source machine 31 in the instructed mode.

[0040] When there is a heat storage tank (step S21; Yes), the determination unit 52 determines whether the air conditioning mode of the air conditioning unit 30 is the heating mode (step S22). This determination is the same as in step S23. When it is not the heating mode (step S22; No), the determination unit 52 determines not to utilize the exhaust heat of the refrigerators 1a and 1b (step S25). Based on the determination of the determination unit 52, the second heat recovery control unit 56 instructs the control unit 25 to stop the pump 23. The control unit 25 stops the pump 23. Subsequently, the determination unit 52 determines whether the current time is a time zone with a low outside air temperature (the outside air temperature measured by the temperature sensor 60c) within a day (step S29). This determination is the same as in step S10.

[0041] When it is a time zone with a low outside air temperature (step S29; Yes), the determination unit 52 determines to operate the heat source machine 31 according to the air conditioning load and further perform heat storage in the tank 33 (step S32). The air conditioning unit control unit 57 instructs the control unit 35 to perform heat storage in the tank 33 in addition to responding to the air conditioning load (cooling load). The control unit 35 operates the heat source machine 31 in the instructed predetermined operation mode (for example, an operation mode in which the heat source machine 31 is operated according to the cooling load without using the exhaust heat of the refrigerators 1a and 1b and the operation load is increased for heat storage).

[0042] When it is not a time period with a low outside air temperature (step S29; No), the determination unit 52 determines to operate the heat source machine 31 according to the air conditioning load (cooling load) while using the heat stored in the heat storage tank (step S33). The air conditioning unit control unit 57 instructs the control unit 35 to perform an operation using heat storage. The control unit 35 operates the water heater 41 in a specified operation mode (for example, an operation mode in which the heat source machine 31 is operated using the heat stored in the heat storage tank (tank 33) without using the exhaust heat of the refrigerators 1a and 1b).

[0043] Note that when the air conditioning unit 30 is stopped, steps S27, S29, S32, and S33 are not executed. Also, when the air conditioning mode is not the heating mode, the air conditioning unit 30 does not use the exhaust heat. Therefore, more heat can be supplied to the hot water supply unit 40 via the exhaust heat recovery device 10. Thus, when the air conditioning mode is not the heating mode, the operating load of the water heater 41 can be reduced more compared to the case where the air conditioning mode is the heating mode.

[0044] When the air conditioning mode is the heating mode (step S22; Yes), the determination unit 52 determines to use the exhaust heat of the refrigerators 1a and 1b (step S24). The second heat recovery control unit 56 instructs the control unit 35 to start the pump 23 and set the valves 22a and 22b to the open state based on the determination of the determination unit 52. The control unit 35 starts the pump 23 and sets the valves 22a and 22b to the open state.

[0045] Subsequently, the determination unit 52 determines whether the current time is a time period when the outside air temperature (the outside air temperature measured by the temperature sensor 60c) is high (step S28). This determination is the same as in step S10. In the case of a time period when the outside air temperature is high (step S28; Yes), the determination unit 52 determines to utilize the exhaust heat of the refrigerators 1a and 1b, operate the heat source machine 31 according to the heating load, and further increase the operation load of the heat source machine 31 to perform heat storage (step S30). The air conditioner unit control unit 57 instructs the control unit 35 to perform heat storage in the tank 33 in addition to coping with the heating load. The control unit 35 operates the heat source machine 31 in the instructed predetermined operation mode (for example, an operation mode in which the load is reduced by utilizing the exhaust heat of the refrigerators 1a and 1b while increasing the load for heat storage).

[0046] In the case where it is not a time period when the outside air temperature is high (step S28; No), the determination unit 52 determines to utilize the exhaust heat of the refrigerators 1a and 1b, and operate the heat source machine 31 according to the heating load while utilizing the heat stored in the heat storage tank (tank 33) (step S31). The air conditioner unit control unit 57 instructs the control unit 35 to perform an operation using the heat storage. The control unit 35 operates the heat source machine 31 in the instructed predetermined operation mode (for example, an operation mode in which the heat source machine 31 is operated according to the heating load by utilizing the exhaust heat of the refrigerators 1a and 1b and the heat storage in the heat storage tank (tank 33)).

[0047] As described above, according to the present embodiment, the operations of the exhaust heat recovery devices 10 and 20 are switched so that the exhaust heat of the refrigerators 1a and 1b can be utilized to improve the operation efficiency of the entire exhaust heat recovery refrigerator system 100 according to the outside air temperature and the like. Thereby, the operation efficiency of the exhaust heat recovery refrigerator system 100 can be improved. Further, when the outside air temperature is high or the like, by performing heat storage in the heat storage tanks (tanks 33 and 44), even if the operation efficiency decreases during heat storage, the operation efficiency over a predetermined period can be improved.

[0048] Note that the control illustrated in FIGS. 3A and 3B is merely an example and is not limited thereto. For example, in FIG. 3B, the heat source machine used in the air conditioner unit 30 determines whether it is a heat pump type. If it is not a heat pump type, the operating loads of the refrigerators 1a and 1b may be increased, and the exhaust heat of the refrigerators 1a and 1b may be utilized.

[0049] FIG. 4 is a diagram showing an example of the hardware configuration of the system controller according to the embodiment. The computer 900 includes a CPU 901, a main storage device 902, an auxiliary storage device 903, an input / output interface 904, and a communication interface 905. The system controller 50 is implemented in the computer 900. And each of the above-described functions is stored in the auxiliary storage device 903 in the form of a program. The CPU 901 reads the program from the auxiliary storage device 903 and expands it in the main storage device 902, and executes the above processing according to the program. Further, the CPU 901 secures a storage area in the main storage device 902 according to the program. Further, the CPU 901 secures a storage area in the auxiliary storage device 903 for storing data being processed according to the program.

[0050] A program for realizing all or part of the functions of the system controller 50 may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be read into a computer system and executed to perform the processing by each functional unit. Here, the "computer system" shall include hardware such as an OS and peripheral devices. Also, the "computer system" shall include a homepage providing environment (or display environment) if the WWW system is being used. Further, the "computer-readable recording medium" refers to portable media such as CDs, DVDs, USBs, etc., and storage devices such as hard disks built into a computer system. Also, when this program is distributed to the computer 900 via a communication line, the computer 900 that has received the distribution may expand the program in the main storage device 902 and execute the above processing. Also, the above program may be for realizing a part of the functions described above, or may be capable of realizing the functions described above in combination with a program already recorded in the computer system.

[0051] In addition, without departing from the spirit of the present invention, it is possible to appropriately replace the components in the above-described embodiments with well-known components. Also, the technical scope of this invention is not limited to the above-described embodiments, and various changes can be made without departing from the spirit of the present invention.

[0052] <Supplementary Note> The control device, waste heat recovery refrigeration system, control method, and program described in each embodiment are understood as follows, for example.

[0053] (1) The control device (system controller 50) according to the first aspect recovers heat by exchanging heat with a first refrigerant circulating in a refrigerant circuit of a first refrigerator 1a that cools a refrigerating chamber (refrigerated showcase) and / or a second refrigerant circulating in a refrigerant circuit of a second refrigerator 1b that cools the refrigerating chamber (refrigerated showcase), and supplies the recovered heat to an air-conditioning unit 30. A first waste heat recovery device 20, and a second waste heat recovery device 10 that recovers heat by exchanging heat with the first refrigerant and / or the second refrigerant and supplies the recovered heat to a hot water supply unit 40. In the first waste heat recovery device 20, it is possible to switch whether to exchange heat for each of the first refrigerant and the second refrigerant. The second waste heat recovery device is configured to be able to switch whether to exchange heat for each of the first refrigerant and the second refrigerant. A control device for a waste heat recovery refrigerator system 100, which controls whether to exchange heat with the first refrigerant and controls whether to exchange heat with the second refrigerant in each of the first waste heat recovery device and the second waste heat recovery device according to the outside air temperature, and includes a heat recovery control unit (first heat recovery control unit 55, second heat recovery control unit 56). Thereby, according to the efficiency of the waste heat recovery refrigerator system 100, the operating states of the first waste heat recovery device and the second waste heat recovery device can be switched. As a result, the operating efficiency of the waste heat recovery refrigerator system 100 can be improved.

[0054] (2) The control device (system controller 50) according to the second aspect is the control device of (1), and when the outside air temperature is equal to or higher than a predetermined first threshold temperature (the first threshold temperature is a temperature at which it can be determined that it is not in the heating mode) or when the operation of the air-conditioning unit is other than the heating mode, the heat recovery control unit controls the first waste heat recovery device 20 not to exchange heat between the first refrigerant and the second refrigerant. Based on the outside air temperature, when it can be determined that it is not in the heating mode, the waste heat recovery device 20 is stopped. Thereby, a large amount of waste heat can be supplied to the hot water supply unit 40.

[0055] (3) The control device (system controller 50) according to the third aspect is the control device of (1) to (2), and when the outside air temperature becomes equal to or lower than a predetermined second threshold temperature, the heat recovery control unit controls so as not to perform heat exchange of the first refrigerant in the first exhaust heat recovery device and the second exhaust heat recovery device. When the outside air temperature is low, heat recovery is stopped without unreasonably increasing the load of the refrigerator 1a for refrigeration. Thereby, the operation efficiency of the exhaust heat recovery refrigerator system 100 can be improved.

[0056] (4) The control device (system controller 50) according to the fourth aspect is the control device of (1) to (3), and the exhaust heat recovery refrigerator system 100 further includes a heat source machine 31 of the air conditioning unit 30, a water heater 41 of the hot water supply unit 40, a first tank 33 for storing the heat medium heated by the heat source machine 31, and a second tank 44 for storing the hot water heated by the water heater 41. The control device further includes a heat source machine control unit (air conditioning unit control unit 57) for controlling the heat source machine 31 and a water heater control unit (hot water supply unit control unit 58) for controlling the water heater 41. When the outside air temperature becomes equal to or higher than a predetermined third threshold temperature, the heat source machine control unit increases the operation load of the heat source machine (steps S28, 29), and when the outside air temperature becomes equal to or higher than a predetermined fourth threshold temperature, the water heater control unit increases the operation load of the water heater (step S10). By performing heat storage in the tank according to the outside air temperature, the operation efficiency of the exhaust heat recovery refrigerator system 100 over a predetermined period can be improved instead of the operation efficiency at each moment.

[0057] (5) The control device (system controller 50) according to the fifth aspect is the control device of (1) to (4), the waste heat recovery refrigeration system further includes the first refrigerator and the second refrigerator, and the control device further includes a first refrigerator control unit that controls the first refrigerator and a second refrigerator control unit that controls the second refrigerator. When the hot water supply unit or the air conditioning unit is other than a heat pump type, the first refrigerator control unit increases the operating load of the first refrigerator more than when operating to cool the refrigerating chamber to a predetermined set temperature, and the second refrigerator control unit increases the operating load of the second refrigerator more than when operating to cool the freezing chamber to a predetermined set temperature. When it is more efficient for the system as a whole to improve the operating loads of the highly efficient refrigerators 1a and 1b, the operating loads of the refrigerators 1a and 1b are increased to improve the operating efficiency of the waste heat recovery refrigeration system 100.

[0058] (6) The waste heat recovery refrigeration system 100 according to the sixth aspect includes a first refrigerator that cools a refrigerating chamber, a second refrigerator that cools the refrigerating chamber, an air conditioning unit, a hot water supply unit, a first heat exchange circuit that exchanges heat between a first refrigerant circulating in a first refrigerant circuit of the first refrigerator and a first water medium, a second heat exchange circuit that exchanges heat between a second refrigerant circulating in a second refrigerant circuit of the second refrigerator and the first water medium, a circuit that supplies the heat of the heat-exchanged first water medium to the air conditioning unit, a valve provided in the first heat exchange circuit that switches whether the first water medium flows through the first heat exchange circuit, a valve provided in the second heat exchange circuit that switches whether the first water medium flows through the second heat exchange circuit, a first waste heat recovery device including these, a third heat exchange circuit that exchanges heat between the first refrigerant and a second water medium, a fourth heat exchange circuit that exchanges heat between the second refrigerant and the second water medium, a circuit that supplies the heat of the heat-exchanged second water medium to the hot water supply unit, a valve provided in the third heat exchange circuit that switches whether the second water medium flows through the third heat exchange circuit, a valve provided in the fourth heat exchange circuit that switches whether the second water medium flows through the fourth heat exchange circuit, a second waste heat recovery device including these, and a control device according to any one of claims 1 to 5. Thereby, according to the efficiency of the waste heat recovery refrigeration system 100, the operating states of the first waste heat recovery device and the second waste heat recovery device can be switched. As a result, the operating efficiency of the waste heat recovery refrigeration system 100 can be improved.

[0059] (7) The control method according to the seventh aspect recovers heat by exchanging heat with a first refrigerant circulating in a refrigerant circuit of a first refrigerator that cools a refrigerating chamber and / or a second refrigerant circulating in a refrigerant circuit of a second refrigerator that cools the refrigerating chamber, and supplies the recovered heat to an air conditioning unit. The control method also includes a second waste heat recovery unit that recovers heat by exchanging heat with the first refrigerant and / or the second refrigerant and supplies the recovered heat to a hot water supply unit. In the first waste heat recovery unit, it is possible to switch whether to exchange heat for each of the first refrigerant and the second refrigerant. In the second waste heat recovery unit, it is configured to be able to switch whether to exchange heat for each of the first refrigerant and the second refrigerant. The control method of the waste heat recovery refrigerator system is to control whether to exchange heat with the first refrigerant and control whether to exchange heat with the second refrigerant in each of the first waste heat recovery unit and the second waste heat recovery unit according to the outside air temperature.

[0060] (8) The program according to the eighth aspect causes a computer to execute a control method of a waste heat recovery refrigerator system including a first waste heat recovery unit that recovers heat by exchanging heat with a first refrigerant circulating in a refrigerant circuit of a first refrigerator that cools a refrigerating chamber and / or a second refrigerant circulating in a refrigerant circuit of a second refrigerator that cools the refrigerating chamber, and supplies the recovered heat to an air conditioning unit, and a second waste heat recovery unit that recovers heat by exchanging heat with the first refrigerant and / or the second refrigerant and supplies the recovered heat to a hot water supply unit. In the first waste heat recovery unit, it is possible to switch whether to exchange heat for each of the first refrigerant and the second refrigerant. In the second waste heat recovery unit, it is configured to be able to switch whether to exchange heat for each of the first refrigerant and the second refrigerant. The control method is to control whether to exchange heat with the first refrigerant and control whether to exchange heat with the second refrigerant in each of the first waste heat recovery unit and the second waste heat recovery unit according to the outside air temperature.

Description of Reference Numerals

[0061] 1a ··· Refrigerator, 1b ··· Refrigerator, 10 ··· Exhaust heat recovery device, 20 ··· Exhaust heat recovery device, 30 ··· Air conditioning unit, 40 ··· Water heater unit, 50 ··· System controller, 51 ··· Outdoor air temperature acquisition unit, 52 ··· Judgment unit, 53 ··· First refrigerator control unit, 54 ··· Second refrigerator control unit, 55 ··· First heat recovery control unit, 56 ··· Second heat recovery control unit, 57 ··· Air conditioning unit control unit, 58 ··· Water heater unit control unit, 59 ··· Memory unit, 60 ··· Temperature sensor, 100 ··· Exhaust heat recovery refrigeration system

Claims

1. A first waste heat recovery unit that recovers heat by exchanging heat with a first refrigerant circulating in a refrigerant circuit of a first refrigerator that cools a refrigerator compartment and / or a second refrigerant circulating in a refrigerant circuit of a second refrigerator that cools the refrigerator compartment, and supplies the recovered heat to an air conditioning unit; and a second waste heat recovery unit that recovers heat by exchanging heat with the first refrigerant and / or the second refrigerant, and supplies the recovered heat to a water heater unit. In the first waste heat recovery unit, it is possible to switch whether or not to exchange heat for each of the first refrigerant and the second refrigerant. In the second waste heat recovery unit, it is configured to be able to switch whether or not to exchange heat for each of the first refrigerant and the second refrigerant. A control device for an exhaust heat recovery refrigeration system, a heat recovery control unit that controls whether or not to exchange heat with the first refrigerant and controls whether or not to exchange heat with the second refrigerant in each of the first waste heat recovery unit and the second waste heat recovery unit according to the outside air temperature, comprising, when the outside air temperature is equal to or lower than a predetermined first threshold temperature, the heat recovery control unit controls the first waste heat recovery unit and the second waste heat recovery unit not to exchange heat with the first refrigerant, a control device.

2. When the heat recovery control unit can determine that the operation of the air conditioning unit is not in the heating mode based on the outside air temperature being equal to or higher than a predetermined second threshold temperature, or when the operation of the air conditioning unit is other than the heating mode, in the first waste heat recovery unit, heat exchange between the first refrigerant and the second refrigerant is not performed, and in the second waste heat recovery unit, at least heat exchange with the second refrigerant is controlled to be performed, The control device according to claim 1.

3. The exhaust heat recovery refrigeration system further includes a heat source machine of the air conditioning unit, a water heater of the water heater unit, a first tank that stores a heat medium heated by the heat source machine, and a second tank that stores hot water heated by the water heater, The control device further includes a heat source machine control unit that controls the heat source machine and a water heater control unit that controls the water heater, when the outside air temperature is equal to or higher than a predetermined third threshold temperature, the heat source machine control unit increases the operation load of the heat source machine, when the outside air temperature is equal to or higher than a predetermined fourth threshold temperature, the water heater control unit increases the operation load of the water heater, The control device according to claim 1 or claim 2.

4. The exhaust heat recovery refrigeration system further includes the first refrigerator and the second refrigerator. The control device further includes a first refrigerator control unit that controls the first refrigerator and a second refrigerator control unit that controls the second refrigerator. When the hot water supply unit or the air conditioning unit is other than a heat pump type, the first refrigerator control unit increases the operating load of the first refrigerator more than when operating to cool the refrigerating chamber to a predetermined set temperature, and the second refrigerator control unit increases the operating load of the second refrigerator more than when operating to cool the freezing chamber to a predetermined set temperature. The control device according to any one of claims 1 to 3.

5. A first refrigerator for cooling a refrigerating chamber; A second refrigerator for cooling a freezing chamber; An air conditioning unit; A hot water supply unit; A first heat exchange circuit that exchanges heat between a first refrigerant circulating in a first refrigerant circuit of the first refrigerator and a first water medium, a second heat exchange circuit that exchanges heat between a second refrigerant circulating in a second refrigerant circuit of the second refrigerator and the first water medium, a circuit that supplies the heat of the heat-exchanged first water medium to the air conditioning unit, a valve provided in the first heat exchange circuit that switches whether or not the first water medium flows through the first heat exchange circuit, and a valve provided in the second heat exchange circuit that switches whether or not the first water medium flows through the second heat exchange circuit, a first exhaust heat recovery device including; A third heat exchange circuit that exchanges heat between the first refrigerant and a second water medium, a fourth heat exchange circuit that exchanges heat between the second refrigerant and the second water medium, a circuit that supplies the heat of the heat-exchanged second water medium to the hot water supply unit, a valve provided in the third heat exchange circuit that switches whether or not the second water medium flows through the third heat exchange circuit, and a valve provided in the fourth heat exchange circuit that switches whether or not the second water medium flows through the fourth heat exchange circuit, a second exhaust heat recovery device including; The control device according to any one of claims 1 to 4; An exhaust heat recovery refrigeration system comprising.

6. A control method for an exhaust heat recovery refrigeration system including a first exhaust heat recovery device that recovers heat by exchanging heat with a first refrigerant circulating in a refrigerant circuit of a first refrigerator that cools a refrigerating chamber and / or a second refrigerant circulating in a refrigerant circuit of a second refrigerator that cools the refrigerating chamber, and supplies the recovered heat to an air conditioning unit, and a second exhaust heat recovery device that recovers heat by exchanging heat with the first refrigerant and / or the second refrigerant, and supplies the recovered heat to a hot water supply unit. In the first exhaust heat recovery device, it is possible to switch whether to exchange heat for each of the first refrigerant and the second refrigerant. In the second exhaust heat recovery device, it is configured to be able to switch whether to exchange heat for each of the first refrigerant and the second refrigerant, According to the outside air temperature, in each of the first exhaust heat recovery device and the second exhaust heat recovery device, control whether to exchange heat with the first refrigerant and control whether to exchange heat with the second refrigerant, When the outside air temperature is equal to or lower than a predetermined first threshold temperature, control is performed so that heat exchange of the first refrigerant is not performed in the first exhaust heat recovery device and the second exhaust heat recovery device, Control method.

7. On a computer, A control method for an exhaust heat recovery refrigeration system including a first exhaust heat recovery device that recovers heat by exchanging heat with a first refrigerant circulating in a refrigerant circuit of a first refrigerator that cools a refrigerating chamber and / or a second refrigerant circulating in a refrigerant circuit of a second refrigerator that cools the refrigerating chamber, and supplies the recovered heat to an air conditioning unit, and a second exhaust heat recovery device that recovers heat by exchanging heat with the first refrigerant and / or the second refrigerant, and supplies the recovered heat to a hot water supply unit. In the first exhaust heat recovery device, it is possible to switch whether to exchange heat for each of the first refrigerant and the second refrigerant. In the second exhaust heat recovery device, it is configured to be able to switch whether to exchange heat for each of the first refrigerant and the second refrigerant, According to the outside air temperature, in each of the first exhaust heat recovery device and the second exhaust heat recovery device, control whether to exchange heat with the first refrigerant and control whether to exchange heat with the second refrigerant, When the outside air temperature is equal to or lower than a predetermined first threshold temperature, a process of controlling so that heat exchange of the first refrigerant is not performed in the first exhaust heat recovery device and the second exhaust heat recovery device, A program for causing the above to be executed.

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