TWI736463B - Composite refrigeration system and controling method thereof - Google Patents

Abstract

A composite refrigeration system is suitable for being driven and controlled by a controller. The composite refrigeration system includes a first refrigeration system, a second refrigeration system, an ice storage tank, a third expansion valve, a heat exchanger and a fluid driver. The first refrigeration system includes a first compressor, a first condenser, a first expansion valve and a first evaporator. The second refrigeration system includes a second compressor, a second condenser, a second expansion valve and a second evaporators. The ice storage tank is arranged in parallel with the first condenser. One end of the third expansion valve is connected to the pipeline between the first condenser and the first expansion valve. The other end of the third expansion valve is connected to the ice storage tank.

Description

Compound refrigeration system and control method thereof

The invention relates to a refrigeration system and a control method thereof, in particular to a composite refrigeration system and a control method thereof.

Nowadays, general food vending places, such as supermarkets, convenience stores, etc., are equipped with food preservation cabinets such as open cabinets, refrigerators, and freezers. When the temperature in the food preservation cabinet is higher than an upper temperature limit, the control unit drives the compressor to produce cold air, and opens the intake valve to allow the refrigerant to pass through the evaporator, and the air in the cabinet is blown by the refrigerating fan. Through the evaporator, the heat exchange between the air in the cabinet and the evaporator can reduce the temperature in the cabinet and achieve the purpose of preservation.

Food preservation cabinets are divided into peak periods and off-peak periods according to consumers' shopping habits. Peak hours are when consumers spend more often, generally from 7 am to 11 pm. Off-peak hours are when consumers consume less, usually from 11pm to 7am. However, because the power consumption of food preservation cabinets is concentrated in peak hours, and the electricity price during peak hours is about 2 to 3 times higher than that of off-peak hours, the monthly electricity bills required by food vending establishments remain high.

The present invention is to provide a composite refrigeration system and a control method thereof, so as to transfer the peak power load and improve the stability of the power supply of the power system.

The compound refrigeration system disclosed in an embodiment of the present invention is suitable for being controlled by a controller. The composite refrigeration system includes a first refrigeration system, a second refrigeration system, an ice storage tank, a third expansion valve, a heat exchanger and a fluid driver. The first refrigeration system includes a first compressor, a first condenser, a first expansion valve, and a first evaporator. The first compressor, the first condenser, the first expansion valve and the first evaporator are connected in sequence through a pipeline to form a first cooling cycle (such as refrigeration). The second refrigeration system includes a second compressor, a second condenser, a second expansion valve, and a second evaporator. The second compressor, the second condenser, the second expansion valve, and the second evaporator are connected in sequence through pipelines to form a second cooling cycle (such as refrigeration). The ice storage tank is arranged in parallel with the first condenser. The first compressor, the ice storage tank, the first expansion valve, and the first evaporator are connected in sequence through a pipeline to form a third cooling cycle (such as cold-release refrigeration). One end of the third expansion valve is connected to the pipeline between the first condenser and the first expansion valve. The other end of the third expansion valve is connected to the ice storage tank. The first compressor, the first condenser, the ice storage tank, the third expansion valve and the ice storage tank are connected in sequence through a pipeline to form a fourth cooling cycle (such as cold storage). The fluid driver, the ice storage tank and the heat exchanger are connected in sequence through the pipeline to form a fifth cooling cycle (cooling release). The heat exchanger is arranged in parallel with the second condenser. The second compressor, the heat exchanger, the second expansion valve, and the second evaporator are connected in sequence through a pipeline to form a sixth cooling cycle (such as refrigeration).

The control method of the compound refrigeration system disclosed in another embodiment of the present invention includes the following steps. Provide compound refrigeration system. Determine whether the current time is in the off-peak period. If yes, it is determined whether the liquid level of the liquid in the ice storage tank reaches the preset upper limit. If it is, the combined refrigeration system is operated in the refrigerating and freezing mode. If not, the combined refrigeration system is operated in the cold storage and refrigeration mode. If not, the combined refrigeration system is operated in the cooling release mode.

According to the composite refrigeration system and its control method of the above embodiment, by combining the ice storage tank, refrigeration, and freezing, the composite refrigeration system can determine the refrigeration system according to the current time period, ice storage in the ice storage tank and the temperature of the refrigerator. Operation in freezing mode, cold storage and refrigeration mode, cold storage mode or cold release mode. In this way, the ice storage tank can store cold energy during off-peak hours when the electricity price is low, and then release the pre-stored cold energy in the ice storage tank for cold storage and freezing during the peak hours when the electricity price is higher, and then transfer the peak use Electric load, improve the stability of the power supply of the power system and reduce the cost of electricity.

The above description of the content of the present invention and the description of the following embodiments are used to demonstrate and explain the principle of the present invention, and to provide a further explanation of the scope of the patent application of the present invention.

10: Compound refrigeration system

20: Controller

100: The first refrigeration system

110: The first compressor

120: The first condenser

130: The first expansion valve

140: The first evaporator

150: reservoir

200: The second refrigeration system

210: second compressor

220: second condenser

230: second expansion valve

240: second evaporator

300: ice storage tank

310: tank

320: flow tube

400: Third expansion valve

500: heat exchanger

600: Fluid Drive

710: The first on-off valve

720: The second on-off valve

730: third on-off valve

740: The fourth on-off valve

810: The first switching valve

820: second switching valve

830: third switching valve

a~g: direction

F1~F6: direction

T1: The first thermometer

T2: Second thermometer

L: Level gauge

S100~S400: steps

Fig. 1 is a block diagram of the composite refrigeration system and controller according to the first embodiment of the present invention.

Fig. 2 is a system schematic diagram of the compound refrigeration system of Fig. 1.

Fig. 3 is a schematic diagram of the fluid flow of the first refrigeration system, the second refrigeration system, the ice storage tank, and the heat exchanger of Fig. 2.

4 to 7 are schematic diagrams of the operation mode of the compound refrigeration system of FIG. 2.

Fig. 8 is a control method of the compound refrigeration system of Fig. 2.

Please refer to Figure 1 to Figure 2. Fig. 1 is a block diagram of the composite refrigeration system and controller according to the first embodiment of the present invention. Fig. 2 is a system schematic diagram of the compound refrigeration system of Fig. 1. Fig. 3 is a schematic diagram of the fluid flow of the first refrigeration system, the second refrigeration system, the ice storage tank, and the heat exchanger of Fig. 2.

The composite refrigeration system 10 of this embodiment is applied to a supermarket or a convenience store, for example. The composite refrigeration system 10 is suitable for being driven by a controller 20, and includes a first refrigeration system 100, a second refrigeration system 200, an ice storage tank 300, a third expansion valve 400, a heat exchanger 500 and A fluid driver 600.

The first refrigeration system 100 is, for example, a refrigeration system, and its refrigeration temperature is about minus 10 degrees Celsius. The first refrigeration system 100 includes a first compressor 110, a first condenser 120, a first expansion valve 130 and a first evaporator 140. The first compressor 110, the first condenser 120, the first expansion valve 130, and the first evaporator 140 are connected in sequence through pipelines to form a first cooling cycle, so that the first evaporator 140 provides approximately minus 10 degrees Celsius. Degrees of cold energy are given to the refrigerator.

In this embodiment, the first refrigeration system 100 further includes an accumulator 150. The accumulator 150 is connected between the first condenser 120 and the first expansion valve 130.

The second refrigeration system 200 is, for example, a refrigeration system, and its freezing temperature is approximately minus 30 degrees Celsius. The second refrigeration system 200 includes a second compressor 210, a second condenser 220, a second expansion valve 230, and a second evaporator 240. The second compressor 210, the second condenser 220, the second expansion valve 230, and the second evaporator 240 are connected in sequence through pipelines to form a second cooling cycle, so that the second evaporator 240 provides approximately minus 30 degrees Celsius. Degrees of cold energy are given to the freezer.

The ice storage tank 300 is arranged in parallel with the first condenser 120. The first compressor 110, the ice storage tank 300, the first expansion valve 130, and the first evaporator 140 are connected in sequence through pipelines to form a third cooling cycle, so as to utilize the cold energy stored in the ice storage tank 300 for the refrigerating cabinet .

One end of the third expansion valve 400 is connected to the pipeline between the accumulator 150 and the first expansion valve 130. The other end of the third expansion valve 400 is connected to the ice storage tank 300. The first compressor 110, the first condenser 120. The third expansion valve 400 and the ice storage tank 300 are connected in sequence through a pipeline to form a fourth cooling cycle to store cold energy in the ice storage tank 300.

The fluid driver 600, the ice storage tank 300, and the heat exchanger 500 are sequentially connected through a pipeline to form a fifth cooling cycle to increase the heat exchange speed of the ice storage tank 300. In this embodiment, the heat exchanger 500 and the second condenser 220 are arranged in parallel, and the second compressor 210, the heat exchanger 500, the second expansion valve 230, and the second evaporator 240 are connected in sequence through a pipeline to form a The sixth cooling cycle is to use the cold energy stored in the ice storage tank 300 to the freezer.

Please refer to Figure 3. Fig. 3 is a schematic diagram of the fluid flow of the first refrigeration system, the second refrigeration system, the ice storage tank, and the heat exchanger of Fig. 2. In this embodiment, the ice storage tank 300 includes a tank body 310 and a plurality of flow tubes 320. The tank 310 communicates with the heat exchanger 500. The flow tubes 320 are located in the tank body 310 and have a spiral shape, and the flow tubes 320 are connected to the first refrigeration system 100. When ice cubes are stored in the ice storage tank 300, the first refrigeration system 100 and the second refrigeration system 200 can use the cold energy in the ice storage tank 300 to provide refrigeration and freezing functions. In detail, the high-temperature gaseous refrigerant produced by the first refrigeration system 100 flows into the flow tubes 320 along the direction F1. Then, the high-temperature gas refrigerant in the ice storage tank 300 exchanges heat with the cold energy stored in the ice storage tank 300 to be converted into a low-temperature liquid refrigerant. Then, the low-temperature liquid refrigerant flows back to the first refrigeration system 100 along the direction F2. In addition, the ice cubes of the tank body 310 of the ice storage tank 300 and the high-temperature gaseous refrigerant of the first refrigeration system 100 will melt into ice water after heat exchange. The ice water flows in the direction F4 to the heat exchanger 500 and heats with the heat exchanger 500. After being exchanged to form warm water, it flows back to the tank body 310 of the ice storage tank 300 in the direction F3. Then, the high-temperature gaseous refrigerant generated by the second refrigeration system 200 flows to the heat exchanger 500 in the direction F5, and after heat exchange with the ice water in the heat exchanger 500 to become a low-temperature liquid refrigerant, it flows back to the second refrigerant in the direction F6. Refrigeration system 200.

Since the ice in the tank body 310 of the ice storage tank 300 will adhere to the fluid 320 of the ice storage tank 300, and when the high-temperature gaseous refrigerant of the first refrigeration system 100 flows through the flow pipe 320, the ice storage tank 300 When the warm water of the heat exchanger 500 flows into the tank body 310, the ice in the tank body 310 of the ice storage tank 300 is melted from outside, so that the ice in the ice storage tank 300 is melted. The ice cubes in the tank body 310 achieve the effect of melting ice inside and outside, thereby avoiding the generation of ten thousand years of ice, so as to maximize the use of cold energy.

In this embodiment, the compound refrigeration system 10 may also include a first thermometer T1, a second thermometer T2, and a liquid level gauge L. The first thermometer T1 and the level gauge L are located in the ice storage tank 300 to detect the temperature and liquid level of the ice storage tank 300. The second thermometer T2 is located between the first evaporator 140 and the first compressor 110 to detect the temperature of the outlet end of the first evaporator 140, that is, the temperature of the refrigerator.

In this embodiment, the composite refrigeration system 10 may further include a first on-off valve 710, a second on-off valve 720, a third on-off valve 730, and a fourth on-off valve 740. The first on-off valve 710 is connected between the first condenser 120 and the third expansion valve 400. The second on-off valve 720 is connected between the first condenser 120 and the first expansion valve 130. One end of the third switch valve 730 is connected to the pipeline between the third expansion valve 400 and the ice storage tank 300. The other end of the third on-off valve 730 is connected to the pipeline between the second on-off valve 720 and the first expansion valve 130. The fourth switch valve 740 is connected between the ice storage tank 300 and the first compressor 110.

In this embodiment, the first on-off valve 710, the second on-off valve 720, the third on-off valve 730, and the fourth on-off valve 740 are solenoid valves as an example, but it is not limited thereto. In other embodiments, the first on-off valve 710, the second on-off valve 720, the third on-off valve 730, and the fourth on-off valve 740 may also be mechanical valves.

In this embodiment, the composite refrigeration system 10 may further include a first switching valve 810, a second switching valve 820, and a third switching valve 830. The first switching valve 810, the second switching valve 820, and the third switching valve 830 are three-way valves. The three channels of the first switching valve 810 are respectively connected to the first compressor 110, the first condenser 120 and the ice storage tank 300. The three channels of the second switching valve 820 are respectively connected to the second compressor 210, the second condenser 220 and the heat exchanger 500. The three channels of the third switching valve 830 are respectively connected to the ice storage tank 300, the heat exchanger 500 and the fluid driver 600.

In this embodiment, the first switching valve 810, the second switching valve 820, and the third switching valve 830 are three-way valves as an example, but not limited thereto. In other embodiments, each switching valve may be replaced by two solenoid valves, for example.

Please refer to Figure 4 to Figure 7. 4 to 7 are schematic diagrams of the operation mode of the compound refrigeration system of FIG. 2. The composite refrigeration system 10 of this embodiment is used to be controlled by the controller 20 to be in a cold storage and refrigeration mode, a cold storage mode, a cold storage and freezing mode, or a cold release mode.

As shown in FIG. 4, when the composite refrigeration system 10 is in the cold storage and refrigeration mode, the composite refrigeration system 10 operates in the first cooling cycle and the fourth cooling cycle to achieve the functions of refrigeration and cold storage at the same time. In detail, when the controller 20 controls the combined refrigeration system 10 to be in the cold storage and refrigeration mode, the controller 20 will disconnect the first switching valve 810 from the ice storage tank 300, the third switching valve 730 closes, and the second refrigeration system 200 stops running and the other on-off valves are opened. In this way, on the one hand, the first compressor 110 will drive the refrigerant to flow through the first condenser 120, the accumulator 150, the first expansion valve 130, and the first evaporator 140 in the direction a, and then return to the first compressor. 110 to form a first cooling cycle, and for example, to provide cold energy required by the refrigerating cabinet. In addition, the first compressor 110 on the other hand drives the refrigerant to flow through the first condenser 120, the accumulator 150, the third expansion valve 400, and the ice storage tank 300 in order along the direction b, and then return to the first compressor 110. A fourth cooling cycle is formed, and for example, the cold energy required by the ice storage tank 300 is provided, that is, ice cubes are stored in the ice storage tank 300.

In addition, in this embodiment, the controller 20 can also turn on the fluid driver 600 and cause the fluid driver 600 to drive the fluid to flow in the direction c, so as to disturb the fluid in the tank body 310 of the ice storage tank 300, thereby improving the ice storage tank 300 Heat exchange efficiency.

In this embodiment, the composite refrigeration system 10 is in the cold storage and refrigeration mode, and only operates in the first cooling cycle and the fourth cooling cycle, but it is not limited to this. In other embodiments, the compound refrigeration The system can also operate in the first cooling cycle, the fourth cooling cycle and the second cooling cycle at the same time to achieve the functions of refrigeration, freezing and cold storage at the same time.

As shown in FIG. 5, when the composite refrigeration system 10 is in the cold storage mode, the composite refrigeration system 10 operates in the fourth cooling cycle to achieve the function of cold storage. When the controller 20 controls the hybrid refrigeration system 10 to be in the cold storage mode, the controller 20 will disconnect the first switching valve 810 from the ice storage tank 300, the second switching valve 720 and the third switching valve 730, and the second cooling The system 200 stops running and the remaining on-off valves are opened. In this way, the first compressor 110 will only drive the refrigerant to flow through the first condenser 120, the accumulator 150, the third expansion valve 400, and the ice storage tank 300 in order along the direction b, and then return to the first compressor 110. A fourth cooling cycle is formed, and for example, the cold energy required by the ice storage tank 300 is provided, that is, ice cubes are stored in the ice storage tank 300.

As shown in FIG. 6, when the composite refrigeration system 10 is in the refrigerating and freezing mode, the composite refrigeration system 10 operates in a first cooling cycle and a second cooling cycle to achieve the functions of refrigeration and freezing. When the controller 20 controls the combined refrigeration system 10 to be in the refrigerating and freezing mode, the controller 20 will disconnect the first switching valve 810 from the ice storage tank 300, the first switching valve 710, the third switching valve 730, and the fourth switching valve. 740 is closed and the other on-off valves are opened. In this way, on the one hand, the hybrid refrigeration system 10 will drive the refrigerant through the first compressor 110 to flow through the first condenser 120, the accumulator 150, the first expansion valve 130, the first evaporator 140 and then in the direction a. It is returned to the first compressor 110 to form a first cooling cycle, and for example, provides cold energy required by the refrigerating cabinet. In addition, the hybrid refrigeration system 10 on the other hand drives the refrigerant through the second compressor 210 to flow through the second condenser 220, the second expansion valve 230, and the second evaporator 240 in order in the direction d, and then return to the second compressor. 210 to form a second cooling cycle, thereby providing cold energy required by the freezer, for example.

As shown in FIG. 7, when the composite refrigeration system 10 is in the cooling release mode, the composite refrigeration system 10 operates in the third cooling cycle, the fifth cooling cycle, and the sixth cooling cycle to achieve the functions of refrigeration and freezing.

When the controller 20 controls the combined refrigeration system 10 to be in the release mode, the controller 20 will disconnect the first switching valve 810 from the first condenser 120, the first switching valve 710, the second switching valve 720, and the fourth switch The valve 740 is closed and the remaining on-off valves are opened. In this way, on the one hand, the hybrid refrigeration system 10 will drive the refrigerant through the first compressor 110 to flow through the ice storage tank 300, the first expansion valve 130, and the first evaporator 140 in the direction e, and then return to the first compressor. 110 to form a third cooling cycle, and for example, the cold energy stored in the ice storage tank 300 can be used to provide the refrigerating cabinet. In addition, the composite refrigeration system 10 on the other hand drives the fluid to flow between the ice storage tank 300 and the heat exchanger 500 in the direction g through the fluid driver 600 to form a fifth cooling cycle. On the other hand, the composite refrigeration system 10 will drive the refrigerant through the second compressor 210 to flow through the heat exchanger 500, the second expansion valve 230, and the second evaporator 240 in order in the direction f, and then return to the second compressor 210 to form a second compressor 210. Six cooling cycles, for example, provide the cold energy required by the freezer.

In this way, the refrigerator and the freezer can use the cold energy in the ice storage tank 300 to provide the refrigeration function and the freezing function.

Please refer to Figure 2 and Figure 8. FIG. 8 is a control method of the compound refrigeration system of FIG. 2, and the control method is executed by the controller 20. First, a composite refrigeration system 10 as shown in FIG. 2 is provided. Next, as shown in step S100, it is determined whether the current time is in an off-peak period. If it is the off-peak period (the electricity price is cheaper), as shown in step S200, the liquid position obtained by the liquid level gauge L on the ice storage tank 300 is used to determine whether the liquid level of the liquid in the ice storage tank 300 reaches a preset upper level. Limit. If so, it means that the amount of ice in the ice storage tank 300 has reached the upper limit. Therefore, as shown in step S210, the combined refrigeration system 10 is operated in a refrigerating and freezing mode (as shown in FIG. 6). If not, it means that the amount of ice in the ice storage tank 300 has not reached the upper limit. Therefore, as shown in step S300, the combined refrigeration system 10 is temporarily operated in the cold storage and refrigeration mode (as shown in FIG. 4). Then, as shown in step S310, the temperature value obtained by the second thermometer T2 is used to determine whether the temperature at the outlet end of the first evaporator 140 of the compound refrigeration system 10 reaches a preset lower limit. If yes, it means that the temperature of the refrigerated cabinet has reached the refrigeration requirement, so as As shown in step S320, the combined refrigeration system 10 is operated in a cold storage mode (as shown in FIG. 5) to store excess cold energy in the ice storage tank 300. If not, it means that the temperature of the refrigerating cabinet has not yet reached the refrigeration demand. Therefore, as shown in step S300, the combined refrigeration system 10 is continued to operate in the cold storage refrigeration mode (as shown in FIG. 4).

Next, after the combined refrigeration system 10 is operated in the cold storage mode (as shown in FIG. 5) (step S320), as shown in step S330, the temperature value obtained by the second thermometer T2 is used to determine whether the combined refrigeration system 10 is Whether the temperature at the outlet end of the first evaporator 140 reaches a preset upper limit. If yes, it means that the temperature of the refrigerating cabinet has not yet reached the refrigeration demand, so step S100 needs to be re-executed to determine whether the current time is in the off-peak period, so as to continue to re-execute the refrigerating and freezing mode. If not, it means that the temperature of the refrigerating cabinet still meets the refrigeration demand, so as shown in step S320, the combined refrigeration system 10 is continued to operate in the cold storage mode.

Conversely, if it is a peak period (the electricity price is more expensive), as shown in step S400, the composite refrigeration system 10 is operated in the cooling release mode (as shown in FIG. The refrigeration and freezing functions can be exerted, and the electricity cost of the composite refrigeration system 10 can be saved. For example, if the off-peak electricity price is 1.8 yuan and the peak electricity price is 4.44 yuan, the combined refrigeration system 10 of this embodiment should save about 50,000 yuan a year in supermarkets or convenience stores, which means annual savings 10-15% electricity bill.

In addition, after step S400, as shown in step S410, it is determined whether the temperature of the liquid in the ice storage tank 300 of the hybrid refrigeration system 10 reaches a preset upper limit. If so, it means that the amount of ice cubes in the ice storage tank 300 is insufficient. Therefore, as shown in step S210, the combined refrigeration system 10 is turned to operate in a refrigeration mode. If not, it means that the ice storage in the ice storage tank 300 is still sufficient to support the cold energy required by the refrigeration and freezing functions. Therefore, as shown in step S400, the combined refrigeration system 10 is maintained to operate in the cooling release mode.

According to the composite refrigeration system and its control method of the above embodiment, by combining the ice storage tank, refrigeration, and freezing, the composite refrigeration system can determine the refrigeration system according to the current time period, ice storage in the ice storage tank and the temperature of the refrigerator. Operation in freezing mode, cold storage and refrigeration mode, cold storage mode or cold release mode. In this way, the ice storage tank can store cold energy during off-peak hours when the electricity price is low, and then release the pre-stored cold energy in the ice storage tank for cold storage and freezing during the peak hours when the electricity price is higher, and then transfer the peak use Electric load, improve the stability of the power supply of the power system and reduce the cost of electricity.

In addition, the ice storage tank is connected in parallel to the condenser of the refrigeration system. Compared with freezing, the temperature of refrigeration is higher, which makes the energy consumption of cold storage lower, thereby reducing the energy consumption of cold storage.

In addition, the composite refrigeration system of this embodiment can use existing refrigeration and refrigeration equipment without adding expensive equipment such as liquid refrigerant pumps, which greatly reduces the cost of introduction.

Although the present invention is disclosed in the foregoing embodiments as above, it is not intended to limit the present invention. Anyone familiar with similar art can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of patent protection for inventions shall be determined by the scope of patent applications attached to this specification.

10: Compound refrigeration system

100: The first refrigeration system

110: The first compressor

120: The first condenser

130: The first expansion valve

140: The first evaporator

150: reservoir

200: The second refrigeration system

210: second compressor

220: second condenser

230: second expansion valve

240: second evaporator

300: ice storage tank

400: Third expansion valve

500: heat exchanger

600: Fluid Drive

710: The first on-off valve

720: The second on-off valve

730: third on-off valve

740: The fourth on-off valve

810: The first switching valve

820: second switching valve

830: third switching valve

T1: The first thermometer

T2: Second thermometer

L: Level gauge

Claims (13)

A composite refrigeration system suitable for being driven by a controller. The composite refrigeration system includes: a first refrigeration system, including a first compressor, a first condenser, a first expansion valve, and a first evaporator The first compressor, the first condenser, the first expansion valve, and the first evaporator are connected in sequence through a pipeline to form a first cooling cycle; a second refrigeration system includes a second compressor Engine, a second condenser, a second expansion valve, and a second evaporator, the second compressor, the second condenser, the second expansion valve, and the second evaporator are connected in sequence through pipelines A second cooling cycle is formed; an ice storage tank, the ice storage tank is arranged in parallel with the first condenser, the first compressor, the ice storage tank, the first expansion valve and the first evaporator pass through the pipeline Sequentially connected to form a third cooling cycle; a third expansion valve, one end of the third expansion valve is connected to the pipeline between the first condenser and the first expansion valve, and the other of the third expansion valve One end is connected to the ice storage tank, the first compressor, the first condenser, the third expansion valve and the ice storage tank are connected in sequence through a pipeline to form a fourth cooling cycle; and a heat exchanger and A fluid driver, the fluid driver, the ice storage tank, and the heat exchanger are sequentially connected through pipes to form a fifth cooling cycle, and the heat exchanger and the second condenser are arranged in parallel, and the second compression The engine, the heat exchanger, the second expansion valve and the second evaporator are connected in sequence through a pipeline to form a sixth cooling cycle. The compound refrigeration system according to claim 1, wherein the compound refrigeration system is used to be controlled by the controller to be in a refrigeration and freezing mode, a cold storage mode or a refrigeration mode, and the compound refrigeration system is in the In the refrigeration and freezing mode, the compound refrigeration system operates in the first cooling cycle and the second cooling cycle. When the compound refrigeration system is in the cold storage mode, the compound refrigeration system operates in the The fourth cooling cycle operates. When the composite refrigeration system is in the cooling release mode, the composite refrigeration system operates in the third cooling cycle, the fifth cooling cycle, and the sixth cooling cycle. The compound refrigeration system according to claim 1, wherein the first refrigeration system is a refrigeration system, and the first refrigeration cycle is a refrigeration cycle, the second refrigeration system is a refrigeration system, and the second cooling cycle is a refrigeration cycle . The compound refrigeration system according to claim 1, wherein the compound refrigeration system is used to be driven by the controller to be in a cold storage and refrigeration mode, and when the compound refrigeration system is in the cold storage and refrigeration mode, the compound refrigeration system The refrigeration system operates in the first cooling cycle, the fourth cooling cycle, and the second cooling cycle. The compound refrigeration system according to claim 1, wherein the first refrigeration system further comprises a liquid accumulator connected between the first condenser and the first expansion valve, and the third expansion valve One end is connected to the pipeline between the accumulator and the first expansion valve. The composite refrigeration system according to claim 1, wherein the ice storage tank includes a tank body and a plurality of flow tubes, the tank body is connected to the heat exchanger, and the flow tubes are located in the tank body and are in a spiral shape, The flow pipes are all connected to the first refrigeration system. The compound refrigeration system according to claim 1, further comprising a first thermometer, a second thermometer, and a level gauge. The first thermometer and the level gauge are located in the ice storage tank, and the second thermometer is located in the ice storage tank. Between the first evaporator and the first compressor. The compound refrigeration system according to claim 1, further comprising a first on-off valve, a second on-off valve, a third on-off valve, and a fourth on-off valve, the first on-off valve is connected to the first condenser Between the third expansion valve and the third expansion valve, the second switch valve is connected between the first condenser and the first expansion valve, and one end of the third switch valve is connected between the third expansion valve and the ice storage tank The pipeline, the third on-off valve The other end is connected to the pipeline between the second on-off valve and the first expansion valve, and the fourth on-off valve is connected between the ice storage tank and the first compressor. The compound refrigeration system according to claim 1, further comprising a first switching valve, a second switching valve and a third switching valve, the first switching valve, the second switching valve and the third switching valve are A three-way valve, the three channels of the first switching valve are respectively connected to the first compressor, the first condenser and the ice storage tank, and the three channels of the second switching valve are respectively connected to the second compressor and the ice storage tank. The second condenser and the heat exchanger, and the three channels of the third switching valve are respectively connected to the ice storage tank, the heat exchanger and the fluid driver. A control method of a composite refrigeration system, which is suitable for being driven and executed by a controller, and includes the following steps: providing a composite refrigeration system as described in claim 1; judging whether the current time is in an off-peak period; if so, then Determine whether the height of the liquid in the ice storage tank reaches a preset upper limit; if so, make the hybrid refrigeration system operate in a refrigerating and freezing mode; and if not, make the hybrid refrigeration system operate in a storage The refrigeration mode is operated; and if not, the combined refrigeration system is operated in a cooling release mode. The control method of the composite refrigeration system according to claim 10, wherein after the step of operating the composite refrigeration system in a cold storage and refrigeration mode, the method further comprises: determining the output end of the first evaporator of the composite refrigeration system Whether the temperature reaches a preset lower limit; if so, make the combined refrigeration system operate in a cold storage mode; and If not, the combined refrigeration system is maintained to operate in the cold storage and refrigeration mode. The control method of the composite refrigeration system according to claim 11, wherein after the step of operating the composite refrigeration system in the cold storage mode, the method further comprises: determining the temperature at the outlet end of the first evaporator of the composite refrigeration system Whether it reaches a preset upper limit; if so, it is determined whether the current time is in the off-peak period; and if not, the combined refrigeration system is maintained to operate in the cold storage mode. The control method of the composite refrigeration system according to claim 10, wherein after the step of causing the composite refrigeration system to operate in the cooling release mode, the method further comprises: determining the temperature of the liquid in the ice storage tank of the composite refrigeration system Whether it reaches a preset upper limit; if so, the combined refrigeration system is made to operate in a refrigerating and freezing mode; and if not, the combined refrigeration system is maintained to operate in the cooling release mode.

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