Chilled water storage system capable of improving cold storage efficiency

Abstract

The chilled water storage system capable of improving the cold storage efficiency comprises a refrigeration main machine, a cold storage water tank, a cold storage and discharge pump and a heat exchanger, the refrigeration main machine and an air conditioner tail end form a refrigeration loop through a pipeline, the refrigeration loop comprises a refrigeration water supply pipe and a refrigeration water return pipe, and a refrigeration pump is arranged on the refrigeration water return pipe. The refrigeration host and the cold storage water tank are connected through a pipeline to form a cold storage loop, the cold storage loop comprises a cold storage water supply pipe and a cold storage water return pipe, the cold storage water pump is arranged in the cold storage water supply pipe and comprises a heat exchange pipeline, the heat exchanger and the refrigeration loop form a heat exchange loop through the heat exchange pipeline, and the heat exchange pipeline comprises a heat exchange water supply pipe and a heat exchange water return pipe. According to the chilled water storage system capable of improving the cold storage efficiency, the cold storage water in the cold storage water tank is fully refrigerated, and therefore the cold storage efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of water thermal energy storage, in particular to a water thermal energy storage system for improving the cold storage efficiency. Background Art

[0002] Water thermal energy storage realizes the storage of cold energy by using the sensible heat of water. Therefore, a reasonably designed cold storage system should obtain the maximum cold storage efficiency by maintaining the largest possible temperature difference of the stored water and preventing the mixing of cold water and hot water.

[0003] In the water thermal energy storage technology, the key issue is that the structure form of the cold storage tank should prevent the mixing of the stored cold water and the returned hot water. To achieve this goal, the commonly used method at present is the natural stratification method. That is, natural stratification is realized by the different densities of water at different temperatures. The system composition is to add a cold water storage tank to a conventional refrigeration system. During the cold storage cycle, the cold water sent by the refrigeration equipment enters the water storage tank through the bottom water distributor, and the hot water is discharged from the top. The water volume in the cold water storage tank remains unchanged. During the cold release cycle, the water flow direction is opposite, the cold water is sent from the bottom to the load demand side, and the returned hot water enters the cold water storage tank from the top water distributor. Generally, the cold storage efficiency is used to describe the cold storage effect of the cold water storage tank.

[0004] The thermocline is the temperature transition layer between cold water and hot water. A clear and stable thermocline can prevent the mixing of cold water and hot water, but the existence of the thermocline reduces the cold storage efficiency. Whether the cold storage system can work normally and stably at high efficiency mainly depends on the design of the top and bottom water distributors and the design of the water storage tank. The water distributor is used to evenly distribute the water flow entering the cold water storage tank, reduce the disturbance and damage to the thermocline.

[0005] However, no matter what form of water distributor is used, the appearance of the thermocline cannot be solved. Therefore, there will definitely be mixed water of the thermocline at the top of the cold water storage tank when the cold storage ends. Since the temperature of this mixed water is lower than the temperature of the cold storage hot water, this part of the mixed water generally cannot be used for heat exchange and cold storage. When it is forced to be pumped into the refrigeration main unit for refrigeration, it causes the refrigeration main unit to produce cold water with a temperature lower than the set temperature. At this time, the refrigeration main unit is forced to stop due to the set low-temperature water outlet protection function. Therefore, this mixed water generally generates in each cold storage and release process, and will continuously affect the cold storage efficiency in the long run. Summary of the Utility Model

[0006] The purpose of the utility model is to provide a water thermal energy storage system for improving the cold storage efficiency, so as to fully refrigerate the cold water stored in the cold water storage tank, thereby improving the cold storage efficiency.

[0007] The technical solution adopted by the water thermal energy storage system for improving the cold storage efficiency disclosed by the utility model is:

[0008] A water-cooled energy storage system for improving the energy storage efficiency, comprising a refrigeration main unit, a chilled water storage tank, a charging / discharging pump, and a heat exchanger. The refrigeration main unit and the air-conditioning terminal form a refrigeration loop through pipelines. The refrigeration loop includes a refrigeration supply pipe and a refrigeration return pipe. A chilled water pump is provided on the refrigeration return pipe, and the refrigeration supply pipe communicates with the refrigeration return pipe, and the refrigeration return pipe communicates with the refrigeration supply pipe. The refrigeration main unit and the chilled water storage tank are connected through pipelines to form a cold storage loop. The cold storage loop includes a cold storage supply pipe and a cold storage return pipe. The chilled water pump is arranged in the cold storage supply pipe, and the heat exchanger and the refrigeration main unit are connected in parallel at the water outlet end of the chilled water pump. The heat exchanger and the chilled water storage tank are connected in parallel at the water inlet end of the chilled water pump. It further includes a heat exchange pipeline. The heat exchanger forms a heat exchange loop with the refrigeration loop through the heat exchange pipeline. The heat exchange pipeline includes a heat exchange supply pipe and a heat exchange return pipe. One end of the heat exchange supply pipe communicates with the heat exchanger, and the other end of the heat exchange supply pipe communicates with the refrigeration return pipe. The heat exchange return pipe communicates with the heat exchanger, and the other end of the heat exchange return pipe communicates with the refrigeration supply pipe.

[0009] As a preferred solution, electric valves V1 and V4 are respectively arranged at both ends of the charging / discharging pump.

[0010] As a preferred solution, an electric valve V3 is provided on the cold storage return pipe, and an electric valve V2 is provided between the cold storage return pipe and the charging / discharging pump.

[0011] As a preferred solution, electric valves V5 and V6 are provided on both the refrigeration supply pipe and the refrigeration return pipe.

[0012] As a preferred solution, a connecting pipe is provided between the heat exchange return pipe and the heat exchange supply pipe, and an electric control valve VT3 is provided on the connecting pipe.

[0013] As a preferred solution, electric control valves VT1 and VT2 are respectively provided at the inlets of the heat exchange pipeline and the cold storage loop corresponding to both sides of the heat exchanger.

[0014] As a preferred solution, it further includes a cooling component. The cooling component includes a cooling tower and a cooling pump. The cooling tower forms a cooling loop with the refrigeration main body through pipelines, and the cooling pump is arranged on the cooling return pipeline.

[0015] The beneficial effects of a water-cooled energy storage system for improving the energy storage efficiency disclosed by the present utility model are as follows: The chilled water stored at the upper end of the chilled water storage tank is pumped out by a storage and discharge pump, enters the refrigeration main unit through a chilled water supply pipe for refrigeration, and the chilled water after refrigeration is discharged from the lower end of the chilled water storage tank through a chilled water return pipe. After the chilled water pumped out from the upper end of the chilled water storage tank passes through the chilled water pump, a part of it enters the heat exchanger, and the heat exchanger heats up a part of the chilled water. After the temperature rise, the chilled water flows back to the water inlet end of the chilled water pump, and the chilled water after temperature rise is mixed with the chilled water just coming out from the upper end of the chilled water storage tank, so as to increase the temperature of the chilled water in the chilled water supply pipe. After being refrigerated by the refrigeration main unit, the temperature of the chilled water is prevented from being too low, and the situation of low-temperature protection of the refrigeration main unit is avoided. At the same time, the chilled water in the thermocline can be refrigerated, so that the temperature of the chilled water in the chilled water storage tank is maintained at a relatively low level, and the energy storage efficiency is improved.

[0016] During the night energy storage operation of the chilled water storage tank, the chilled water in the refrigeration circuit is sent into the heat exchanger by a chilled water pump for further heat exchange and cooling, and can be cooled to the temperature required for the refrigeration system according to the demand. This not only solves the problems of slow response speed and early startup of the original refrigeration system, but also saves part of the air-conditioning operation cost during the low electricity price period at night. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of a water-cooled energy storage system for improving the energy storage efficiency of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] The present utility model will be further described and explained below in conjunction with specific embodiments and the accompanying drawings of the specification:

[0019] Please refer to Figure 1 , a water-cooled energy storage system for improving the energy storage efficiency, comprising a refrigeration main unit 10, a chilled water storage tank 20, a storage and discharge pump 21 and a heat exchanger 30. The refrigeration main unit 10 and the air-conditioning terminal 50 form a refrigeration circuit through pipelines. The refrigeration circuit includes a refrigeration supply pipe 11 and a refrigeration return pipe 12. A chilled water pump 13 is provided on the refrigeration return pipe 12, and the refrigeration supply pipe 11 communicates with the refrigeration return pipe 12, and the refrigeration return pipe 12 communicates with the refrigeration supply pipe 11. Electric valves V5 and V6 are provided on both the refrigeration supply pipe 11 and the refrigeration return pipe 12.

[0020] The refrigeration main unit 10 and the chilled water storage tank 20 are connected by pipelines to form a chilled water storage circuit. The chilled water storage circuit includes a chilled water supply pipe 22 and a chilled water return pipe 23. A chilled water pump is provided in the chilled water supply pipe 22, and the heat exchanger 30 and the refrigeration main unit 10 are connected in parallel at the water outlet end of the chilled water pump, and the heat exchanger 30 and the chilled water storage tank 20 are connected in parallel at the water inlet end of the chilled water pump.

[0021] In this embodiment, the temperature range of the chilled water storage tank 20 is set to 4°C - 11°C. To ensure the chilled storage efficiency of the chilled water storage tank 20, the temperature of the chilled water flowing back to the chilled water storage tank 20 is 4°C. Therefore, the minimum chilled temperature set by the chiller 10 is 4°C. Thus, it is necessary to ensure that the chilled water produced by the chiller 10 has a temperature not lower than 4°C.

[0022] In the above solution, electric valves V1 and V4 are respectively provided at both ends of the chilled water storage and discharge pump 21. The electric valves V1 and V4 are respectively used to control the opening or closing of the pipelines on both sides of the chilled water storage pump. An electric valve V3 is provided on the chilled water return pipe 23 to control whether the chiller 10 performs chilled storage work, and an electric valve V2 is provided between the chilled water return pipe 23 and the chilled water storage and discharge pump 21.

[0023] Through the chilled water supply pipe 11 and the chilled water return pipe, the chiller 10 forms a cooling effect with the air-conditioning terminal 50. And when the chiller 10 supplies cooling to the air-conditioning terminal 50, the electric valves V3 and V4 can be closed, and the electric valves V5 and V6 are opened, so as to ensure the cooling effect. On the contrary, when the air-conditioning terminal 50 stops working and the chilled water storage tank 20 performs chilled storage at night, the electric valves V5 and V6 are closed, and the electric valves V3 and V4 are opened to ensure that the chilled water of the chiller 10 flows into the chilled water storage tank 20.

[0024] In the chilled storage working mode, the flow direction of the chilled water is as follows:

[0025] The upper end of the chilled water storage tank 20 - electric valve V1 - chilled water pump - electric valve V4 - chiller 10 - electric valve V3 - the lower end of the chilled water storage tank 20. At the same time, part of the water is shunted at the chilled water pump. The chilled water pump - electric regulating valve VT1 - heat exchanger 30 - electric valve V1 - chilled water pump, realizing heating and mixing part of the chilled water in the chilled water storage tank 20 through the heat exchanger 30.

[0026] It also includes a heat exchange pipeline. The heat exchanger 30 forms a heat exchange loop with the refrigeration loop through the heat exchange pipeline. The heat exchange pipeline includes a heat exchange supply pipe 31 and a heat exchange return pipe 32. One end of the heat exchange supply pipe 31 is connected to the heat exchanger 30, the other end of the heat exchange supply pipe 31 is connected to the chilled water return pipe 12, the heat exchange return pipe 32 is connected to the heat exchanger 30, and the other end of the heat exchange return pipe 32 is connected to the chilled water supply pipe 11.

[0027] Due to the start-stop sequence requirements of the central air-conditioning system, when starting up, it is necessary to start the chilled water pump 13 in advance and then start the chiller 10, which will increase the ineffective working time of the chilled water pump and the response speed of cooling supply is slow. In order not to affect the use, the general solution is to start the central air-conditioning system in advance; when shutting down, it is necessary to stop the chiller 10 first and then turn off the chilled water pump. In this way, the chilled water pump circulates in the system, and the water temperature of the chilled water pipeline also continuously increases, resulting in an even slower response speed when the system supplies cooling the next day.

[0028] Therefore, when the cold storage water tank 20 stores cold at night, the chilled water in the refrigeration circuit is sent into the heat exchanger 30 through the chilled water pump 13 and continues to exchange heat and cool down. It can be cooled to the cold supply demand temperature of the refrigeration system according to the demand. This not only solves the problems of slow original cold supply response speed and early startup, but also saves part of the air conditioner operation cost by working during the low electricity price period at night.

[0029] A connecting pipe 33 is provided between the heat exchange return pipe 32 and the heat exchange supply pipe 31. An electric control valve VT3 is provided on the connecting pipe 33. Through the cooperation of the connecting pipe 33 and the electric control valve VT3, when the air-conditioning terminal 50 does not work, a heat exchange circuit is formed in the refrigeration circuit, achieving a better heat exchange effect.

[0030] Electric control valves VT1 and VT2 are provided at the inlets of the heat exchange pipelines and the cold storage circuit corresponding to both sides of the heat exchanger 30. The pipelines entering the heat exchanger 30 can be controlled to be opened or closed through the electric control valves VT1 and VT2.

[0031] A cooling assembly, the cooling assembly includes a cooling tower 40 and a cooling pump 41. The cooling tower 40 forms a cooling circuit with the refrigeration main body through a pipeline. The cooling pump 41 is arranged on the cooling circuit. The cooling water in the cooling tower 40 cools the refrigeration main unit 10 through the cooling circuit and realizes a circulating circuit.

[0032] The present utility model provides a water cold storage system for improving the cold storage efficiency. The cold storage water at the upper end of the cold storage water tank is pumped out through a cold storage and discharge pump, enters the refrigeration main unit through the cold storage supply pipe for refrigeration, and the chilled water after refrigeration is discharged from the lower end of the cold storage water tank through the cold storage return pipe. After the cold storage water pumped out from the upper end of the cold storage water tank passes through the cold storage water pump, part of it enters the cold side of the heat exchanger. The heat exchanger heats up part of the cold storage water. After the heating is completed, the cold storage water flows back to the water inlet end of the cold storage water pump, and the heated cold storage water is mixed with the cold storage water just coming out of the upper end of the cold storage water tank, thereby increasing the temperature of the cold storage water in the cold storage supply pipe. After being refrigerated by the refrigeration main unit, it can avoid being too cold and causing the situation of low-temperature protection of the refrigeration main unit. At the same time, it can also refrigerate the cold storage water in the thermocline layer, keep the cold storage water temperature in the cold storage water tank at a relatively low level, and improve the cold storage efficiency.

[0033] When the cold storage water tank stores cold at night, the chilled water in the refrigeration circuit is sent into the heat exchanger through the chilled water pump and continues to exchange heat and cool down. It can be cooled to the cold supply demand temperature of the refrigeration system according to the demand. This not only solves the problems of slow original cold supply response speed and early startup, but also saves part of the air conditioner operation cost by working during the low electricity price period at night.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A water thermal energy storage system for improving the energy storage efficiency, characterized in that, It includes a refrigeration host, a chilled water storage tank, a chilled water charging and discharging pump, and a heat exchanger. The refrigeration host and the air-conditioning terminal form a refrigeration circuit through pipelines. The refrigeration circuit includes a refrigeration supply pipe and a refrigeration return pipe. A chilled water pump is provided on the refrigeration return pipe, and the refrigeration supply pipe is communicated with the refrigeration return pipe, and the refrigeration return pipe is communicated with the refrigeration supply pipe. The refrigeration host and the chilled water storage tank are connected by pipelines to form a chilled water storage circuit. The chilled water storage circuit includes a chilled water storage supply pipe and a chilled water storage return pipe. The chilled water storage pump is arranged in the chilled water storage supply pipe, and the heat exchanger and the refrigeration host are connected in parallel at the water outlet end of the chilled water storage pump. The heat exchanger and the chilled water storage tank are connected in parallel at the water inlet end of the chilled water storage pump. It further includes a heat exchange pipeline. The heat exchanger forms a heat exchange circuit with the refrigeration circuit through the heat exchange pipeline. The heat exchange pipeline includes a heat exchange supply pipe and a heat exchange return pipe. One end of the heat exchange supply pipe is communicated with the heat exchanger, and the other end of the heat exchange supply pipe is communicated with the refrigeration return pipe. The heat exchange return pipe is communicated with the heat exchanger, and the other end of the heat exchange return pipe is communicated with the refrigeration supply pipe.

2. The water thermal energy storage system for improving the thermal energy storage efficiency according to claim 1, wherein, Electric valves V1 and V4 are respectively provided at both ends of the chilled water charging and discharging pump.

3. The water-cool thermal energy storage system for improving the cooling efficiency according to claim 2, wherein, An electric valve V3 is provided on the chilled water storage return pipe, and an electric valve V2 is provided between the chilled water storage return pipe and the chilled water charging and discharging pump.

4. A water thermal energy storage system for improving the thermal energy storage efficiency according to claim 1, wherein, Electric valves V5 and V6 are provided on both the refrigeration supply pipe and the refrigeration return pipe.

5. A water thermal energy storage system for improving the thermal energy storage efficiency as claimed in claim 1, wherein, A connecting pipe is provided between the heat exchange return pipe and the heat exchange supply pipe, and an electric regulating valve VT3 is provided on the connecting pipe.

6. A water thermal energy storage system for improving the thermal energy storage efficiency according to claim 1, wherein Electric regulating valves VT1 and VT2 are respectively provided at the inlets of the heat exchange pipeline and the chilled water storage circuit corresponding to both sides of the heat exchanger.

7. A water thermal energy storage system for improving the thermal energy storage efficiency according to claim 1, characterized in that, It further includes a cooling component. The cooling component includes a cooling tower and a cooling pump. The cooling tower forms a cooling circuit with the refrigeration main body through pipelines, and the cooling pump is arranged on the cooling return pipe.

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