Energy storage system and control method thereof

Abstract

The application relates to an energy storage system and a control method thereof, which comprises an energy supply system, an energy storage module and a user unit. By introducing the energy storage module, the matching of the energy supply side of the energy supply system and the demand of the user side is improved, the volume and cost of the energy supply system are reduced, the irreversible damage of the energy supply system caused by frequent start and stop is avoided, and the service life of the energy supply system is prolonged. By adopting the mode of flow distribution and energy distribution of the first energy carrying medium entering the energy storage system in a single loop, and by adopting the mode of the first energy carrying medium supplying energy for cooling the second energy carrying medium and adjusting the in-out position of the first energy carrying medium and the second energy carrying medium in the storage tank in a double loop, it is ensured that one way of the energy carrying medium can directly input the energy supply system to supply power for the user unit, so that the cold start can be quickly realized. Meanwhile, by utilizing the temperature difference and density difference of the energy carrying medium in the storage tank and the characteristics of natural convection, the temperature of the energy storage module is uniform, and the energy storage effect is good.

Description

Technical Field

[0001] This invention relates to the field of energy storage technology, and in particular to an energy storage system suitable for rapid cold start and its control method. Background Technology

[0002] User demand fluctuations are an unavoidable problem for energy supply systems. Simply increasing system power to meet peak user demand will increase system costs and reduce economic efficiency. On the other hand, some energy supply systems have significant operational inertia; frequently starting and stopping them to cope with user demand fluctuations can cause irreversible damage and shorten system lifespan.

[0003] Typically, user units have higher cooling demand at midday and lower demand at night, and the demand also varies among different users. For centralized hot water supply systems, user unit demand surges when there is demand for domestic hot water and drops sharply to zero when there is no demand. Both of these examples demonstrate fluctuations in user unit demand. Energy storage systems can effectively address these demand fluctuations, increasing the matching between energy supply and demand. For instance, in a "one-to-many" cooling system or combined cooling and heating system where multiple users share a single unit, peak shaving and valley filling can be achieved. Energy is released when user unit demand is high and stored when demand is low, thus increasing the matching between energy supply and demand.

[0004] However, the use of energy storage systems significantly increases cold start time and reduces user experience. Specifically, without energy storage, the power supply system can directly and quickly supply power to user units. However, with energy storage, the power supply system needs to lower or raise the temperature of the energy storage system before supplying power to user units, which greatly increases cold start time. Furthermore, the use of energy storage systems also requires consideration of the temperature distribution within the energy storage units. When the temperature distribution within the energy storage system is uneven, the energy storage efficiency decreases. Summary of the Invention

[0005] One objective of this invention is to provide an energy storage system and its control method, wherein the energy storage system can meet the demand fluctuations on the user side, can start up quickly in cold conditions, has good energy storage effect, and has a simple control method.

[0006] An energy storage system includes an energy supply system, an energy storage module, and a user unit connected in the same circuit. The user unit includes an inlet valve group connected to the energy supply system and the energy storage module, and a user-side energy supply device connected to the inlet valve group. A first energy-carrying medium output from the energy supply system flows into the user-side energy supply device via the inlet valve group to power the device. The first energy-carrying medium output from the user-side energy supply device flows into the energy storage module for a cold start phase, an energy release phase, or an energy storage phase, and finally flows back into the energy supply system, thus completing one working cycle of the energy storage system. The energy storage module is used to split the first energy-carrying medium into two outputs during the cold start phase: one output is directly input into the energy supply system, and the other output exchanges heat with the energy storage medium in the energy storage module, enabling the energy storage module to start quickly in the cold.

[0007] In one embodiment of the present invention, the energy storage module includes a storage tank connected to the user-side energy supply equipment, a liquid distribution device disposed in the storage tank, a cold start valve disposed in the upper half of the storage tank, and a storage tank outlet valve disposed at the bottom of the storage tank. The liquid distribution device is used to distribute the first energy-carrying medium flowing into the energy storage module during the cold start phase, such that one path of the first energy-carrying medium is directly input into the energy supply system via the cold start valve, and another path of the first energy-carrying medium flows into the storage tank, exchanges heat with the energy storage medium in the storage tank, and then flows into the energy supply system via the storage tank outlet valve. The energy storage module controls the switching of the cold start phase, the energy release phase, and the energy storage phase by controlling the opening mode of the cold start valve and the storage tank outlet valve.

[0008] In one embodiment of the present invention, the energy storage module further includes a first energy-carrying medium thermometer disposed between the energy supply system and the user unit and a storage tank thermometer disposed in the storage tank. The first energy-carrying medium thermometer is used to detect the temperature of the first energy-carrying medium, and the storage tank thermometer is used to detect the temperature of the storage tank. The energy storage module controls the opening degree of the cold start valve based on the comparison result between the temperature value measured by the first energy-carrying medium thermometer and a set value, and controls the opening and closing of the cold start valve based on the comparison result between the temperature value measured by the storage tank thermometer and a rated temperature value.

[0009] In one embodiment of the present invention, the energy storage module further includes a level gauge disposed in the storage tank, the level gauge being used to detect the level of the first energy-carrying medium in the storage tank, and the energy storage module controlling the opening degree of the storage tank outlet valve based on the level of the first energy-carrying medium in the storage tank.

[0010] In one embodiment of the present invention, the liquid dispensing device is a weir plate.

[0011] In one embodiment of the present invention, the liquid preparation device includes a thick tube and a thin tube inserted into the thick tube.

[0012] In one embodiment of the present invention, the liquid dispensing device is a three-way structure, which has an inlet for the first energy-carrying medium to flow in and two outlets with different diameters.

[0013] In one embodiment of the present invention, the energy storage module includes a cold start valve connected to the user-side power supply equipment and the power supply system, a storage tank inlet valve connected to the user-side power supply equipment, and a storage tank connected to the storage tank inlet valve and the power supply system. During the cold start phase, the first energy-carrying medium flowing out of the user-side power supply equipment is divided into two outputs. One output of the first energy-carrying medium flows into the power supply system via the cold start valve, and the other output of the first energy-carrying medium flows into the storage tank via the storage tank inlet valve. After exchanging heat with the energy storage medium in the storage tank, the first energy-carrying medium flows into the power supply system. The energy storage module controls the switching between the cold start phase, the energy release phase, and the energy storage phase by controlling the opening degree of the cold start valve and the storage tank inlet valve.

[0014] In one embodiment of the present invention, the energy storage module further includes a first energy-carrying medium thermometer disposed between the energy supply system and the user unit and a storage tank thermometer disposed in the storage tank. The first energy-carrying medium thermometer is used to detect the temperature of the first energy-carrying medium, and the storage tank thermometer is used to detect the temperature of the storage tank. The energy storage module controls the opening degree of the cold start valve and the storage tank inlet valve based on the comparison result between the temperature value measured by the first energy-carrying medium thermometer and the set value, and controls the opening and closing of the cold start valve based on the comparison result between the storage tank thermometer and the rated temperature value.

[0015] In one embodiment of the present invention, the energy storage module further includes a first heat exchanger disposed in the storage tank. The inlet of the first heat exchanger is located in the upper half of the storage tank and connected to the storage tank inlet valve, and the outlet of the first heat exchanger is located in the lower half of the storage tank and connected to the energy supply system. The first energy-carrying medium flows into the first heat exchanger from the upper half of the storage tank and flows out from the lower half of the storage tank.

[0016] In one embodiment of the present invention, the energy storage module further includes a first heat exchanger disposed in the storage tank. The inlet of the first heat exchanger is located in the lower half of the storage tank and connected to the storage tank inlet valve, and the outlet of the first heat exchanger is located in the upper half of the storage tank and connected to the energy supply system. The first energy-carrying medium flows into the first heat exchanger from the lower half of the storage tank and flows out from the upper half of the storage tank.

[0017] In one embodiment of the present invention, the first energy-carrying medium is any one of water, ethanol, ethylene glycol, heat transfer oil, and silicone oil.

[0018] In one embodiment of the present invention, the energy storage system further includes a bypass valve connected to the energy supply system and the energy storage module. When the flow rate of the first energy-carrying medium exceeds the flow rate required by the user-side energy supply device, the excess portion of the first energy-carrying medium flows out through the bypass valve and merges with the first energy-carrying medium flowing out of the user-side energy supply device.

[0019] An energy storage system includes an energy supply system, an energy storage module connected to the energy supply system, and a user unit connected to the energy storage module. The loop between the energy supply system and the energy storage module is independent of the loop between the energy storage module and the user unit. The user unit includes an inlet valve group connected to the energy supply system and the energy storage module, and a user-side energy supply device connected to the inlet valve group. The energy storage module includes a storage tank and a first energy-carrying medium heat exchanger and a second energy-carrying medium heat exchanger disposed in the storage tank. The first energy-carrying medium output from the energy supply system flows into the first energy-carrying medium heat exchanger, exchanges heat with the energy storage medium in the storage tank, and then flows back to the energy supply system. The second energy-carrying medium output from the energy storage module flows into the user-side energy supply device via the inlet valve group to supply energy to the user-side energy supply device. The second energy-carrying medium output from the user-side energy supply device flows into the second energy-carrying medium heat exchanger for a cold start stage, an energy release stage, or an energy storage stage, thereby completing one working cycle of the energy storage system.

[0020] In one embodiment of the present invention, the energy storage module further includes a weir plate structure, which is disposed in the lower half of the storage tank. The first energy-carrying medium heat exchanger is disposed in the upper half of the storage tank. During the cold start stage, the first energy-carrying medium and the energy storage medium in the upper half of the storage tank undergo a wall-to-wall heat exchange process. Under the action of the weir plate structure, the energy storage medium in the storage tank is distributed in a form where the upper part is a low-temperature fluid and the lower part is a normal-temperature fluid. The second energy-carrying medium output by the user-side energy supply equipment flows into the second energy-carrying medium heat exchanger from the lower half of the storage tank and flows out from the upper half of the storage tank.

[0021] In one embodiment of the present invention, the energy storage module further includes a weir plate structure, which is disposed in the upper half of the storage tank. The first energy-carrying medium heat exchanger is disposed in the lower half of the storage tank. During the cold start stage, the first energy-carrying medium and the energy storage medium in the lower half of the storage tank undergo an indirect heat exchange process. Under the action of the weir plate structure, the energy storage medium in the storage tank is distributed in a form where the lower part is a low-temperature fluid and the upper part is a normal-temperature fluid. The second energy-carrying medium output by the user-side energy supply equipment flows into the second energy-carrying medium heat exchanger from the upper half of the storage tank and flows out from the lower half of the storage tank.

[0022] In one embodiment of the present invention, the weir plate structure includes a plurality of weir plates of different lengths spaced apart inside the storage tank.

[0023] In one embodiment of the present invention, the energy storage module further includes a circulation pump disposed between the second energy-carrying medium heat exchanger and the user unit, wherein the second energy-carrying medium output by the energy storage module is pressurized by the circulation pump and flows into the user-side energy supply equipment.

[0024] In one embodiment of the present invention, the first energy-carrying medium, the second energy-carrying medium, and the energy storage medium are any one of water, ethanol, ethylene glycol, heat transfer oil, and silicone oil.

[0025] In one embodiment of the present invention, the energy storage system further includes a bypass valve connected to the user unit and the energy storage module. When the flow rate of the second energy-carrying medium exceeds the flow rate required by the user-side energy supply equipment, the excess portion of the second energy-carrying medium flows out through the bypass valve and merges with the second energy-carrying medium flowing out of the user-side energy supply equipment.

[0026] A control method for an energy storage system includes the following steps:

[0027] S110, the first energy-carrying medium of the energy supply system flows into the user-side energy supply equipment via the inlet valve group.

[0028] S120, the first energy-carrying medium output by the user-side energy supply equipment flows into the energy storage module, where a cold start phase, an energy release phase, or an energy storage phase are performed; and

[0029] S130, the first energy-carrying medium flows back to the energy supply system, completing one working cycle of the energy storage system.

[0030] In one embodiment of the present invention, step S120 includes the following steps:

[0031] S121. Control the energy storage module to enter the cold start stage: The energy storage module divides the first energy-carrying medium into two outputs, one of which is directly input into the energy supply system, and the other of which exchanges heat with the energy storage medium in the energy storage module to provide energy for the rapid cold start of the energy storage module.

[0032] S122. Control the energy storage module to enter the energy release stage: the first energy-carrying medium flows into the energy storage module, absorbs the energy of the energy storage medium in the energy storage module, and then flows out; and

[0033] S123. Control the energy storage module to enter the energy storage stage: the first energy carrier medium flows into the energy storage module and releases energy, and the energy storage medium of the energy storage module absorbs the energy released by the first energy carrier medium to realize the energy storage process.

[0034] In one embodiment of the present invention, step S121 includes the following steps:

[0035] S1211. Control the opening of the cold start valve of the energy storage module. The first energy-carrying medium flows into the storage tank of the energy storage module. Under the action of the liquid distribution device in the storage tank, most of the first energy-carrying medium flows directly out of the storage tank, and the remaining first energy-carrying medium flows out from the bottom of the storage tank through the storage tank outlet valve.

[0036] S1212, Detect the temperature of the first energy-carrying medium and the temperature of the energy storage module's tank, and detect the liquid level of the first energy-carrying medium in the tank; and

[0037] S1213. Control the opening degree of the cold start valve according to the comparison result between the temperature value of the first energy-carrying medium and the set value, control the opening and closing of the cold start valve according to the comparison result between the temperature of the storage tank and the rated temperature value, and control the opening degree of the storage tank outlet valve according to the liquid level of the first energy-carrying medium in the storage tank.

[0038] In one embodiment of the present invention, in step S122, the cold start valve is controlled to be closed, the first energy-carrying medium flows into the storage tank, absorbs the energy of the energy storage medium in the storage tank, and then flows out through the storage tank outlet valve.

[0039] In one embodiment of the present invention, in step S123, the cold start valve is controlled to be closed, the first energy-carrying medium flows into the storage tank and releases energy, and the energy storage medium in the storage tank absorbs the energy released by the first energy-carrying medium, thereby realizing the energy storage process.

[0040] In one embodiment of the present invention, step S121 includes the following steps:

[0041] S1211. Control the opening of the cold start valve and the storage tank inlet valve of the energy storage module, so that most of the first energy-carrying medium flows into the energy supply system through the cold start valve, and the remaining part of the first energy-carrying medium flows into the storage tank through the storage tank inlet valve, and flows out after exchanging heat with the energy storage medium in the storage tank.

[0042] S1212, Detect the temperature of the first energy-carrying medium and the temperature of the energy storage module's tank; and

[0043] S1213. Control the opening degree of the cold start valve and the tank inlet valve according to the comparison result between the temperature value of the first energy-carrying medium and the set value, and control the opening and closing of the cold start valve according to the comparison result between the temperature of the tank and the rated temperature value.

[0044] In one embodiment of the present invention, in step S122, the cold start valve is controlled to be closed, and the first energy-carrying medium flows into the first heat exchanger through the tank inlet valve, absorbs the energy of the energy storage medium in the tank, and then flows out from the first heat exchanger.

[0045] In one embodiment of the present invention, in step S123, the cold start valve is controlled to be closed, the first energy-carrying medium flows into the first heat exchanger through the tank inlet valve and releases energy, and the energy storage medium in the tank absorbs the energy released by the first energy-carrying medium to realize the energy storage process.

[0046] A control method for an energy storage system includes the following steps:

[0047] S210. The first energy-carrying medium output from the energy supply system flows into the first energy-carrying medium heat exchanger of the energy storage module, exchanges heat with the energy storage medium in the storage tank of the energy storage module, and then flows back to the energy supply system.

[0048] S220, The second energy-carrying medium output by the energy storage module flows into the user-side energy supply equipment through the inlet valve group of the user unit to supply energy to the user-side energy supply equipment;

[0049] S230, the second energy-carrying medium output by the user-side energy supply equipment flows into the second energy-carrying medium heat exchanger of the energy storage module for a cold start stage, an energy release stage, or an energy storage stage, thereby completing one working cycle of the energy storage system.

[0050] In one embodiment of the present invention, step S230 includes the following steps:

[0051] S231. Control the energy storage module to enter the cold start phase:

[0052] The first energy-carrying medium flows into the first energy-carrying medium heat exchanger from the upper half of the storage tank, and undergoes a wall-to-wall heat exchange process with the energy storage medium in the upper half of the storage tank. Under the action of the weir plate structure of the storage tank, the energy storage medium in the storage tank is distributed in the form of low temperature fluid in the upper half and normal temperature fluid in the lower half.

[0053] The second energy-carrying medium output by the user-side energy supply equipment flows into the second energy-carrying medium heat exchanger from the lower half of the storage tank, and is cooled by the low-temperature fluid-like energy storage medium in the upper half of the storage tank before flowing out from the upper half of the storage tank.

[0054] S232. Control the energy storage module to enter the energy release stage: the second energy-carrying medium flows into the storage tank, absorbs the energy of the energy storage medium in the storage tank, and then flows out; and

[0055] S233. Control the energy storage module to enter the energy storage stage: the second energy carrier medium flows into the storage tank and releases energy, and the energy storage medium in the storage tank absorbs the energy released by the second energy carrier medium to realize the energy storage process.

[0056] In one embodiment of the present invention, step S230 includes the following steps:

[0057] S231. Control the energy storage module to enter the cold start phase:

[0058] The first energy-carrying medium flows into the first energy-carrying medium heat exchanger from the lower half of the storage tank, and undergoes a wall-to-wall heat exchange process with the energy storage medium in the lower half of the storage tank. Under the action of the weir plate structure of the storage tank, the energy storage medium in the storage tank is distributed in the form of low temperature fluid in the lower half and normal temperature fluid in the upper half.

[0059] The second energy-carrying medium output by the user-side energy supply equipment flows into the second energy-carrying medium heat exchanger from the upper half of the storage tank, and is cooled by the low-temperature fluid-like energy storage medium in the lower half of the storage tank before flowing out from the lower half of the storage tank.

[0060] S232. Control the energy storage module to enter the energy release stage: the second energy-carrying medium flows into the storage tank, absorbs the energy of the energy storage medium in the storage tank, and then flows out; and

[0061] S233. Control the energy storage module to enter the energy storage stage: the second energy carrier medium flows into the storage tank and releases energy, and the energy storage medium in the storage tank absorbs the energy released by the second energy carrier medium to realize the energy storage process.

[0062] This invention introduces the energy storage module into the energy supply system and the user unit, enabling the energy storage module to release energy when the user unit's demand is high and store energy when the demand is low, thereby increasing the matching between the energy supply side and the user side's demand. Simultaneously, by introducing the energy storage module, the size and cost of the energy supply system are reduced, improving economic performance. Furthermore, by introducing the energy storage module, irreversible damage to the energy supply system caused by frequent start-stop cycles can be avoided, extending the service life of the energy storage system.

[0063] This invention employs an energy storage module to distribute the flow and energy of the first energy-carrying medium flowing into the energy storage module, ensuring that a portion of the energy-carrying medium always flows directly into the energy supply system. This allows the energy supply system to start quickly to supply energy to user units without cooling the entire energy storage module during cold starts, thus solving the problem of long cold start times in existing energy supply systems when introducing energy storage systems.

[0064] This invention employs a method where a first energy-carrying medium flows into a first energy-carrying medium heat exchanger for heat exchange, thereby supplying energy to cool the second energy-carrying medium flowing into the second energy-carrying medium heat exchanger. This allows the first energy-carrying medium to supply energy directly to the user unit without cooling or heating the entire storage tank during the cold start phase, thus achieving rapid energy supply during the cold start phase and solving the problem of long cold start times that exist when introducing energy storage systems into existing energy supply systems.

[0065] This invention achieves the pre-cooling and preheating process of the first energy-carrying medium by placing the storage tank after the user-side energy supply equipment, thereby reducing the equipment load. Furthermore, by employing a liquid distribution device, the energy storage system can switch from the cold start stage to the energy release stage and the energy storage stage solely based on the structure of the liquid distribution device, without relying on a control system.

[0066] This invention provides a simple energy storage system control strategy by adjusting the opening degree of the cold start valve based on the temperature of the first energy-carrying medium to ensure that the temperature of the first energy-carrying medium is equal to a set value, controlling the opening and closing of the cold start valve based on the tank temperature, and maintaining a constant tank liquid level by adjusting the tank outlet valve according to the tank liquid level; or, this invention adjusts the opening degree of the cold start valve and the tank inlet valve based on the temperature of the first energy-carrying medium to ensure that the temperature of the first energy-carrying medium is equal to a set value, and controlling the opening and closing of the cold start valve based on the tank temperature. This reduces the difficulty of controlling the energy storage system and improves its reliability.

[0067] This invention utilizes the natural convection generated by the temperature and density differences between the upper and lower parts of the energy storage medium in the energy storage module by setting inlet and outlet of the first and second energy storage mediums. This allows the energy storage medium in the storage tank to automatically churn and mix evenly, thereby ensuring the uniformity of the internal temperature of the storage tank. This invention solves the problem of uneven temperature distribution inside the storage tank by relying on mechanical structure and without the need for power input.

[0068] The further objects and advantages of the invention will become fully apparent from the following description and accompanying drawings. Attached Figure Description

[0069] Figure 1 This is a schematic block diagram of the energy storage system according to the first preferred embodiment of the present invention;

[0070] Figure 2 for Figure 1 The diagram shows the energy supply process of the first embodiment of the energy storage system.

[0071] Figure 3 for Figure 2 The diagram shown is a first structural schematic of the liquid distribution device for the energy storage system.

[0072] Figure 4 for Figure 2 The diagram shows a second structural schematic of the liquid distribution device for the energy storage system.

[0073] Figure 5 for Figure 2 The diagram shows a third structural representation of the liquid distribution device for the energy storage system.

[0074] Figure 6 for Figure 1 The diagram shows the energy supply process of the second embodiment of the energy storage system.

[0075] Figure 7 for Figure 1 The diagram shows the energy supply process of the third embodiment of the energy storage system.

[0076] Figure 8 This is a schematic block diagram of the energy storage system according to the second preferred embodiment of the present invention;

[0077] Figure 9 for Figure 8 The diagram shows the energy supply process of the first embodiment of the energy storage system.

[0078] Figure 10 for Figure 8 The diagram shows the energy supply process of the second embodiment of the energy storage system.

[0079] The reference numerals in the attached diagrams are as follows: Energy storage system 100; Energy supply system 20; Energy storage module 30; User unit 40; Inlet valve group 1; User-side energy supply equipment 2; Bypass valve 3; Storage tank 4; Cold start valve 5; Storage tank outlet valve 6; Storage tank inlet valve 7; Circulation pump 8; First energy-carrying medium heat exchanger 9; Second energy-carrying medium heat exchanger 10; Weir plate structure 11; Weir plate 111; Liquid distribution device 12; First energy-carrying medium thermometer 13; Storage tank thermometer 14; Liquid level gauge 15; First heat exchanger 16. In the attached diagrams, solid arrows indicate the direction of fluid flow, and dashed arrows indicate the direction of control signal transmission. Detailed Implementation

[0080] The following description is intended to disclose the present invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art. The basic principles of the invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the invention.

[0081] Those skilled in the art should understand that, in the disclosure of this invention, the terms "vertical," "horizontal," "up," "down," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting this invention.

[0082] It is understood that the term "a" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple, and the term "a" should not be understood as a limitation on the number.

[0083] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0084] like Figures 1 to 7As shown, the specific structure of the energy storage system 100 in the first preferred embodiment of the present invention is explained. Specifically, the energy storage system 100 in the first preferred embodiment of the present invention adopts a single-loop energy supply process. The energy storage system 100 includes an energy supply system 20, an energy storage module 30, and a user unit 40 connected in the same circuit. The user unit 40 includes an inlet valve group 1 connected to the energy supply system 20 and the energy storage module 30, and a user-side energy supply device 2 connected to the inlet valve group 1. The first energy-carrying medium output from the energy supply system 20 flows into the user-side energy supply device 2 via the inlet valve group 1 to supply energy to the user-side energy supply device 2. The first energy-carrying medium output from the user-side energy supply device 2 flows into the energy storage module 30 for a cold start stage, an energy release stage, or an energy storage stage, and finally flows back into the energy supply system 20, thereby completing one working cycle of the energy storage system 100. The energy storage module 30 is used to split the first energy-carrying medium into two outputs during the cold start stage. One output is directly input into the energy supply system 20, and the other output exchanges heat with the energy storage medium in the energy storage module 30, so that the energy storage module 30 can start up quickly.

[0085] It is worth mentioning that the energy storage system 100 also includes a bypass valve 3 connected to the energy supply system 20 and the energy storage module 30. When the flow rate of the first energy-carrying medium exceeds the flow rate required by the user-side energy supply device 2, the excess portion of the first energy-carrying medium flows out through the bypass valve 3 and merges with the first energy-carrying medium flowing out of the user-side energy supply device 2 before flowing into the energy supply system 20. It can be understood that the excess portion of the first energy-carrying medium can directly flow into the energy supply system 20 through the bypass valve 3.

[0086] The operation of the energy storage module 30 can be divided into a cold start phase and a normal operation phase. The normal operation phase can be further divided into an energy storage phase and an energy release phase. During the cold start phase, the temperature of the energy storage medium in the energy storage module 30 rises or falls from the ambient temperature to the rated temperature. During the normal operation phase, the energy storage module 30 alternates between energy storage and energy release processes to achieve peak shaving and valley filling, thus meeting fluctuating user demand. During the energy release phase, if the power supply of the energy supply system 20 is less than the power demand of the user unit 40, the energy storage module 30 releases energy to achieve valley filling. During the energy storage phase, if the power supply of the energy supply system 20 is greater than the power demand of the user unit 40, the energy storage module 30 stores excess energy to achieve peak shaving.

[0087] It is understood that by introducing the energy storage module 30 into the energy supply system 20 and the user unit 40, the present invention enables the energy storage module 30 to release energy when the user unit 40 has a large demand and store energy when the demand is small, thereby increasing the matching between the energy supply side of the energy supply system 20 and the demand of the user side. At the same time, by introducing the energy storage module 30, the volume and cost of the energy supply system 20 are reduced, improving economic performance. In addition, by introducing the energy storage module 30, irreversible damage to the energy supply system 20 caused by frequent start-stop is avoided, extending the service life of the energy storage system 100.

[0088] like Figures 2 to 5 As shown, the specific structure and energy supply process of the first preferred embodiment of the energy storage system 100 of the present invention are explained. Specifically, the energy storage module 30 includes a storage tank 4 connected to the user-side energy supply device 2, a liquid distribution device 12 disposed in the storage tank 4, a cold start valve 5 disposed in the upper half of the storage tank 4, and a storage tank outlet valve 6 disposed at the bottom of the storage tank 4. The liquid distribution device 12 is used to distribute the first energy-carrying medium flowing into the energy storage module 30 during the cold start phase, so that one path of the first energy-carrying medium is directly input into the energy supply system 20 via the cold start valve 5, and another path of the first energy-carrying medium flows into the storage tank 4, exchanges heat with the energy storage medium in the storage tank 4, and then flows into the energy supply system 20 via the storage tank outlet valve 6. The energy storage module 30 controls the switching of the cold start phase, the energy release phase, and the energy storage phase by controlling the opening mode of the cold start valve 5 and the storage tank outlet valve 6.

[0089] Specifically, such as Figure 2 As shown, during the cold start phase, the cold start valve 5 opens, and the first energy-carrying medium flows into the storage tank 4 from the upper part. Under the action of the liquid distribution device 12, most of the first energy-carrying medium flows directly out of the storage tank 4, and the remaining first energy-carrying medium flows out of the storage tank 4 from the bottom through the storage tank outlet valve 6. Therefore, the first energy-carrying medium can supply energy to the user unit 40 without cooling or heating the entire storage tank 4, realizing rapid energy supply during the cold start phase.

[0090] During normal operation, the cold start valve 5 is closed. During the energy release phase, the first energy-carrying medium flows into the storage tank 4 from the top layer, absorbs the energy of the energy storage medium in the storage tank 4, and then flows out from the bottom of the storage tank 4 through the storage tank outlet valve 6, thereby realizing the energy release process of the energy storage medium in the storage tank 4.

[0091] During the energy storage stage, the first energy-carrying medium flows into the storage tank 4 from the top layer, releases excess energy, and then flows out of the storage tank 4 from the bottom through the storage tank outlet valve 6, thus realizing the energy storage process of the energy storage medium in the storage tank 4.

[0092] Figure 3 , Figure 4 as well as Figure 5 The diagram illustrates three possible structures for the liquid preparation device 12. For example... Figure 3 As shown, the liquid distribution device 12 is a weir plate. By using a weir plate, most of the first energy-carrying medium can flow directly out of the storage tank 4, achieving rapid cold start. Figure 4 As shown, the liquid dispensing device 12 includes a thick pipe and a thin pipe. The thin pipe is inserted into the thick pipe, allowing most of the first energy-carrying medium to flow directly out of the storage tank 4, thus achieving rapid cold start. Figure 5 As shown, the liquid dispensing device 12 has a three-way structure. The three-way structure has an inlet for the first energy-carrying medium to flow in and two outlets with different diameters. By using outlet pipes of different diameters, most of the first energy-carrying medium can flow directly out of the storage tank 4, thus achieving rapid cold start.

[0093] It is understood that by using the liquid distribution device 12 to distribute the flow and energy of the first energy-carrying medium flowing into the energy storage module 30, the present invention ensures that most of the first energy-carrying medium always flows directly into the energy supply system 20. This allows the energy supply system 20 to start quickly to supply energy to the user unit 40 without cooling the entire energy storage module 30 during cold start, thus solving the problem of long cold start time when the existing energy supply system 20 is introduced into the energy storage system.

[0094] It is also understood that by placing the storage tank 4 after the user-side energy supply equipment 2, the present invention realizes the pre-cooling and preheating process of the first energy-carrying medium, reducing the equipment load. Furthermore, by using the liquid distribution device 12, the energy storage system 100 can switch from the cold start stage to the energy release stage and the energy storage stage without relying on the control system, but only on the structure of the liquid distribution device 12.

[0095] Furthermore, the energy storage module 30 also includes a first energy-carrying medium thermometer 13 disposed between the energy supply system 20 and the user unit 40 and a storage tank thermometer 14 disposed in the storage tank 4. The first energy-carrying medium thermometer 13 is used to detect the temperature of the first energy-carrying medium, and the storage tank thermometer 14 is used to detect the temperature of the storage tank 4. The energy storage module 30 controls the opening degree of the cold start valve 5 based on the comparison result between the temperature value measured by the first energy-carrying medium thermometer 13 and the set value, and controls the opening and closing of the cold start valve 5 based on the comparison result between the storage tank thermometer 14 and the rated temperature value.

[0096] It is worth mentioning that the energy storage module 30 also includes a level gauge 15 disposed in the storage tank 4. The level gauge 15 is used to detect the level of the first energy-carrying medium in the storage tank 4. The energy storage module 30 controls the opening degree of the storage tank outlet valve 6 based on the level of the first energy-carrying medium in the storage tank 4.

[0097] In other words, the energy storage module 30 can switch between the cold start phase, the energy storage phase, and the energy release phase by controlling the opening of the cold start valve 5 and the storage tank outlet valve 6. During the cold start phase, the opening of the cold start valve 5 is adjusted according to the temperature of the first energy-carrying medium to ensure that the temperature of the first energy-carrying medium equals a set value. When the temperature of the first energy-carrying medium deviates significantly from the set value, the opening of the cold start valve 5 increases; when the temperature of the first energy-carrying medium deviates slightly from the set value, the opening of the cold start valve 5 decreases. Furthermore, the energy storage module 30 adjusts the opening of the storage tank outlet valve 6 according to the liquid level of the storage tank 4 to maintain a constant liquid level in the storage tank 4. When the liquid level in the storage tank 4 is higher than the set value, the opening of the storage tank outlet valve 6 increases; when the liquid level in the storage tank 4 is lower than the set value, the opening of the storage tank outlet valve 6 decreases. When the temperature of the storage tank 4 reaches the rated temperature, the cold start phase ends, and the normal operation phase begins, at which point the cold start valve 5 is completely closed.

[0098] Understandably, temperature-based control is simple and easy to implement, ensuring the temperature uniformity of the energy storage module 30 and improving system reliability.

[0099] Optionally, the first energy-carrying medium may be water, ethanol, ethylene glycol, heat transfer oil, silicone oil, etc., and the present invention does not limit this.

[0100] The beneficial effects of this embodiment are as follows: 1) It solves the mismatch between the power supply of the power supply system 20 and the power demand of the user unit 40, reduces the size and cost of the power supply system 20, improves economic efficiency, avoids frequent start-stop of the power supply system 20, and thus extends its service life; 2) It solves the problem of long cold start time of existing energy storage systems, and the power supply system 20 can meet user needs without cooling the entire energy storage module 30; 3) It provides a simple energy storage system control strategy, reduces the difficulty of system control, and improves system reliability.

[0101] like Figure 6 As shown, the specific structure and energy supply process of the second embodiment of the energy storage system 100 of the first preferred embodiment of the present invention are explained. It is understood that, except for the different structure of the energy storage module 30, the structure of the energy storage system 100 in the second embodiment is the same as that of the energy storage system 100 in the first embodiment.

[0102] Specifically, in the second embodiment, the energy storage module 30 includes a cold start valve 5 connected to the user-side energy supply device 2 and the energy supply system 20, a storage tank inlet valve 7 connected to the user-side energy supply device 2, and a storage tank 4 connected to the storage tank inlet valve 7 and the energy supply system 20. During the cold start phase, the first energy-carrying medium flowing out of the user-side power supply device is divided into two outputs. One output of the first energy-carrying medium flows into the energy supply system 20 via the cold start valve 5, and the other output of the first energy-carrying medium flows into the storage tank 4 via the storage tank inlet valve 7. After exchanging heat with the energy storage medium in the storage tank 4, the first energy-carrying medium flows into the energy supply system 20. The energy storage module 30 controls the switching between the cold start phase, the energy release phase, and the energy storage phase by controlling the opening degree of the cold start valve 5 and the storage tank inlet valve 7.

[0103] During the cold start phase, the cold start valve 5 opens, allowing most of the first energy-carrying medium to flow into the energy supply system 20. The remaining first energy-carrying medium flows into the storage tank 4 through the storage tank inlet valve 7, where it undergoes a heat exchange process with the energy storage medium inside the storage tank 4. Therefore, the first energy-carrying medium can supply energy to the user unit 40 without cooling the entire storage tank 4, achieving rapid energy supply during the cold start phase.

[0104] During normal operation, the cold start valve 5 is closed. During the energy release phase, the first energy-carrying medium flows into the storage tank 4, absorbs the energy of the energy storage medium in the storage tank 4, and then flows out of the storage tank 4, thereby realizing the energy release process of the energy storage medium in the storage tank 4.

[0105] During the energy storage stage, the first energy-carrying medium flows into the storage tank 4, releases excess energy, and then flows out of the storage tank 4, thereby realizing the energy storage process of the energy storage medium in the storage tank 4.

[0106] Furthermore, the energy storage module 30 also includes a first energy-carrying medium thermometer 13 disposed between the energy supply system 20 and the user unit 40 and a storage tank thermometer 14 disposed on the storage tank 4. The first energy-carrying medium thermometer 13 is used to detect the temperature of the first energy-carrying medium, and the storage tank thermometer 14 is used to detect the temperature of the storage tank 4. The energy storage module 30 controls the opening degree of the cold start valve 5 and the storage tank inlet valve 7 based on the comparison result between the temperature value measured by the first energy-carrying medium thermometer 13 and the set value, and controls the opening and closing of the cold start valve 5 based on the comparison result between the storage tank thermometer 14 and the rated temperature value.

[0107] In other words, the energy storage system 100 only needs to control the opening degrees of the cold start valve 5 and the storage tank inlet valve 7 to switch between the cold start stage, the energy storage stage, and the energy release stage. During the cold start stage, the opening degrees of the cold start valve 5 and the storage tank inlet valve 7 are adjusted according to the temperature of the first energy-carrying medium to ensure that the temperature of the first energy-carrying medium equals a set value. When the temperature of the first energy-carrying medium deviates significantly from the set value, the opening degree of the cold start valve 5 increases, and the opening degree of the storage tank inlet valve 7 decreases; when the temperature of the first energy-carrying medium deviates slightly from the set value, the opening degree of the cold start valve 5 decreases, and the opening degree of the storage tank inlet valve 7 increases. When the temperature of the storage tank 4 reaches the rated temperature, the cold start stage ends, and the normal operation stage begins, at which point the cold start valve 5 is completely closed.

[0108] It is worth mentioning that the energy storage module 30 also includes a first heat exchanger 16 disposed in the storage tank 4. The inlet of the first heat exchanger 16 is located in the upper half of the storage tank 4 and connected to the inlet of the storage tank 4, and the outlet of the first heat exchanger 16 is located in the lower half of the storage tank 4 and connected to the energy supply system 20. The first energy-carrying medium flows into the first heat exchanger 16 from the upper half of the storage tank 4 and flows out from the lower half of the storage tank 4.

[0109] Understandably, during the energy storage stage, the temperature of the first energy-carrying medium entering the storage tank 4 is lower than its temperature leaving the storage tank 4. The first energy-carrying medium flows in from above the liquid phase and flows out from below. With this arrangement, the temperature of the energy storage medium above the liquid phase in the storage tank 4 is lower than that of the energy storage medium below, and its density is higher than that of the energy storage medium below. Due to natural convection, the energy storage medium below surges to the top, making the temperature distribution inside the storage tank 4 more uniform.

[0110] Optionally, the first energy-carrying medium is any one of water, ethanol, ethylene glycol, heat transfer oil, and silicone oil.

[0111] It is understood that in the first embodiment of the energy storage system 100, the flow rate and energy of the first energy-carrying medium are distributed by using the liquid distribution device 12 and by setting the cold start valve 5 and the storage tank outlet valve 6 on the output side of the storage tank 4, ensuring that most of the first energy-carrying medium can flow directly into the energy supply system 20 during the cold start phase, thereby achieving a rapid cold start of the energy storage system 100. In the second embodiment of the energy storage system 100, the flow rate and energy of the first energy-carrying medium are distributed by setting the cold start valve 5 and the storage tank inlet valve 7 on the input side of the storage tank 4, ensuring that most of the first energy-carrying medium can flow directly into the energy supply system 20 during the cold start phase, thereby achieving a rapid cold start of the energy storage system 100.

[0112] like Figure 7 As shown, the specific structure and energy supply process of the third embodiment of the energy storage system 100 of the first preferred embodiment of the present invention are explained. The third embodiment is a variation of the second embodiment. It is understood that, except for the different entry and exit positions of the first energy-carrying medium in the storage tank 4, the structure of the energy storage system 100 in the third embodiment is the same as that of the energy storage system 100 in the second embodiment.

[0113] Specifically, in the third embodiment, the inlet of the first heat exchanger 16 is located in the lower half of the storage tank 4 and connected to the inlet of the storage tank 4, and the outlet of the first heat exchanger 16 is located in the upper half of the storage tank 4 and connected to the power supply system 20. The first energy-carrying medium flows into the first heat exchanger 16 from the lower half of the storage tank 4 and flows out from the upper half of the storage tank 4.

[0114] Understandably, during the energy storage stage, the temperature of the first energy-carrying medium entering the storage tank 4 is higher than its temperature leaving the storage tank 4. The first energy-carrying medium flows in from below the liquid phase and flows out from above. With this arrangement, the temperature of the energy storage medium below the liquid phase in the storage tank 4 is higher than that of the energy storage medium above, and its density is lower than that of the energy storage medium above. Under the action of natural convection, the energy storage medium surges to the top, making the temperature inside the storage tank 4 more uniform.

[0115] The beneficial effects of the energy storage system 100 in the second and third embodiments are as follows: 1) It solves the mismatch between the power supply of the energy supply system 20 and the power demand of the user unit 40, reduces the size and cost of the energy supply system 20, improves economic efficiency, avoids frequent start-stop of the energy supply system 20, and thus extends its service life; 2) It solves the problem of long cold start time of existing energy storage systems, and the energy supply system 20 can meet user needs without cooling the entire energy storage module 30;

[0116] 3) A simple energy storage system control strategy is provided, which reduces the difficulty of system control and improves system reliability; 4) The problem of uneven temperature distribution inside the storage tank 4 can be solved by relying solely on mechanical structure without the need for power input.

[0117] It is understood that, in another aspect, the present invention also provides a control method for an energy storage system according to a first preferred embodiment, comprising the steps of:

[0118] S110, the first energy-carrying medium of the energy supply system 20 flows into the user-side energy supply equipment 2 via the inlet valve group 1.

[0119] S120, the first energy-carrying medium output by the user-side energy supply device 2 flows into the energy storage module 30, and a cold start phase, an energy release phase, or an energy storage phase are carried out in the energy storage module 30; and

[0120] S130, the first energy-carrying medium flows back to the energy supply system 20, completing one working cycle of the energy storage system 100.

[0121] Further, step S120 includes the following steps:

[0122] S121. Control the energy storage module 30 to enter the cold start stage: The energy storage module 30 divides the first energy-carrying medium into two outputs, one of which is directly input into the energy supply system 20, and the other of which exchanges heat with the energy storage medium in the energy storage module 30 to provide energy for the rapid cold start of the energy storage module 30.

[0123] S122. Control the energy storage module 30 to enter the energy release stage: the first energy-carrying medium flows into the energy storage module 30, absorbs the energy of the energy storage medium in the energy storage module 30, and then flows out; and

[0124] S123. Control the energy storage module 30 to enter the energy storage stage: the first energy carrier medium flows into the energy storage module 30 and releases energy, and the energy storage medium of the energy storage module 30 absorbs the energy released by the first energy carrier medium to realize the energy storage process.

[0125] In a first embodiment of the energy storage system 100 corresponding to the first preferred embodiment of the present invention, step S121 includes the following steps:

[0126] S1211. Control the opening of the cold start valve 5 of the energy storage module 30. The first energy-carrying medium flows into the storage tank 4 of the energy storage module 30. Under the action of the liquid distribution device 12 in the storage tank 4, most of the first energy-carrying medium flows directly out of the storage tank 4, and the remaining first energy-carrying medium flows out from the bottom of the storage tank 4 through the storage tank outlet valve 6.

[0127] S1212, Detect the temperature of the first energy-carrying medium and the temperature of the storage tank 4 of the energy storage module 30, and detect the liquid level of the first energy-carrying medium in the storage tank 4; and

[0128] S1213. Control the opening degree of the cold start valve 5 according to the comparison result between the temperature value of the first energy-carrying medium and the set value, control the opening and closing of the cold start valve 5 according to the comparison result between the temperature of the storage tank 4 and the rated temperature value, and control the opening degree of the storage tank outlet valve 6 according to the liquid level of the first energy-carrying medium in the storage tank 4.

[0129] Correspondingly, in step S122, the cold start valve 5 is closed, and the first energy-carrying medium flows into the storage tank 4, absorbs the energy of the energy storage medium in the storage tank 4, and then flows out through the storage tank outlet valve 6.

[0130] Correspondingly, in step S123, the cold start valve 5 is closed, the first energy-carrying medium flows into the storage tank 4 and releases energy, and the energy storage medium in the storage tank 4 absorbs the energy released by the first energy-carrying medium, thereby realizing the energy storage process.

[0131] In the second and third embodiments of the energy storage system 100 corresponding to the first preferred embodiment of the present invention, step S121 includes the following steps:

[0132] S1211. Control the opening of the cold start valve 5 and the storage tank inlet valve 7 of the energy storage module 30, so that most of the first energy-carrying medium flows into the energy supply system 20 through the cold start valve 5, and the remaining part of the first energy-carrying medium flows into the storage tank 4 through the storage tank inlet valve 7, and flows out after exchanging heat with the energy storage medium in the storage tank 4.

[0133] S1212, Detect the temperature of the first energy-carrying medium and the temperature of the storage tank 4 of the energy storage module 30; and

[0134] S1213. Control the opening degree of the cold start valve 5 and the tank inlet valve 7 according to the comparison result between the temperature value of the first energy-carrying medium and the set value, and control the opening and closing of the cold start valve 5 according to the comparison result between the temperature of the tank 4 and the rated temperature value.

[0135] Correspondingly, in step S122, the cold start valve 5 is closed, and the first energy-carrying medium flows into the first heat exchanger 16 through the storage tank inlet valve 7, absorbs the energy of the energy storage medium in the storage tank 4, and then flows out from the first heat exchanger 16.

[0136] Correspondingly, in step S123, the cold start valve 5 is closed, the first energy-carrying medium flows into the first heat exchanger 16 through the storage tank inlet valve 7 and releases energy, and the energy storage medium in the storage tank 4 absorbs the energy released by the first energy-carrying medium, thus realizing the energy storage process.

[0137] like Figures 8 to 10 As shown, the specific structure of the energy storage system 100 according to the second preferred embodiment of the present invention is explained. Specifically, the energy storage system 100 of the second preferred embodiment of the present invention adopts a dual-loop energy supply process. The energy storage system 100 includes an energy supply system 20, an energy storage module 30 connected to the energy supply system 20, and a user unit 40 connected to the energy storage module 30. The loop between the energy supply system 20 and the energy storage module 30 is independent of the loop between the energy storage module 30 and the user unit 40.

[0138] like Figure 9As shown, a first embodiment of the energy storage system 100 according to a second preferred embodiment of the present invention is specifically illustrated. Specifically, the energy storage system 100 includes an energy supply system 20, an energy storage module 30 connected to the energy supply system 20, and a user unit 40 connected to the energy storage module 30. The circuit between the energy supply system 20 and the energy storage module 30 is independent of the circuit between the energy storage module 30 and the user unit 40. The user unit 40 includes an inlet valve group 1 connected to the energy supply system 20 and the energy storage module 30, and a user-side energy supply device 2 connected to the inlet valve group 1. The energy storage module 30 includes a storage tank 4 and a first energy-carrying medium heat exchanger 9 and a second energy-carrying medium heat exchanger 9 disposed in the storage tank 4. The energy-carrying medium heat exchanger 10 is used in which the first energy-carrying medium output from the energy supply system 20 flows into the first energy-carrying medium heat exchanger 9, exchanges heat with the energy storage medium in the storage tank 4, and then flows back to the energy supply system 20; the second energy-carrying medium output from the energy storage module 30 flows into the user-side energy supply device 2 via the inlet valve group 1 to supply energy to the user-side energy supply device 2, and the second energy-carrying medium output from the user-side energy supply device 2 flows into the second energy-carrying medium heat exchanger 10 to carry out the cold start stage, energy release stage, or energy storage stage, thereby completing one working cycle of the energy storage system 100.

[0139] It is worth mentioning that the energy storage system 100 also includes a bypass valve 3 connected to the user unit 40 and the energy storage module 30. When the flow rate of the second energy-carrying medium exceeds the flow rate required by the user-side energy supply device 2, the excess portion of the second energy-carrying medium flows out through the bypass valve 3 and merges with the second energy-carrying medium flowing out of the user-side energy supply device 2 before flowing into the energy storage module 30. It can be understood that the excess portion of the second energy-carrying medium can directly flow into the energy storage module 30 through the bypass valve 3.

[0140] In addition, it is worth mentioning that the energy storage module 30 also includes a circulation pump 8 disposed between the second energy-carrying medium heat exchanger 10 and the user unit 40. The second energy-carrying medium output by the energy storage module 30 is pressurized by the circulation pump 8 and flows into the user-side energy supply equipment 2.

[0141] Furthermore, the energy storage module 30 also includes a weir plate structure 11, which is disposed in the lower half of the storage tank 4. The first energy-carrying medium heat exchanger 9 is disposed in the upper half of the storage tank 4. During the cold start stage, the first energy-carrying medium and the energy storage medium in the upper half of the storage tank 4 undergo a wall-to-wall heat exchange process. Under the action of the weir plate structure 11, the energy storage medium in the storage tank 4 is distributed in a form where the upper part is a low-temperature fluid and the lower part is a normal-temperature fluid. The second energy-carrying medium output by the user-side energy supply device 2 flows into the second energy-carrying medium heat exchanger 10 from the lower half of the storage tank 4 and flows out from the upper half of the storage tank 4.

[0142] It is worth mentioning that the weir plate structure 11 includes a plurality of weir plates 111 of different lengths spaced apart inside the storage tank 4.

[0143] Specifically, during the cold start phase, the first energy-carrying medium undergoes an indirect heat exchange process with the upper liquid-phase energy storage medium in the storage tank 4, resulting in a decrease in the temperature of the upper liquid. Under the action of the weir plate structure 11, most of the cryogenic fluid remains at the top, and the energy storage medium in the storage tank 4 is distributed with cryogenic fluid at the top and room temperature fluid at the bottom. The second energy-carrying medium enters the storage tank 4 from the bottom and undergoes an indirect heat exchange process with the liquid-phase energy storage medium. When the second energy-carrying medium flows through the bottom of the storage tank 4, the lower energy storage medium is at room temperature and cannot cool the second energy-carrying medium. When the second energy-carrying medium flows through the top of the storage tank 4, the upper energy storage medium is cryogenic and cools the second energy-carrying medium. Therefore, the first energy-carrying medium can supply energy to the user without cooling the entire storage tank 4, achieving rapid energy supply during the cold start phase. In other words, the first energy-carrying medium only needs to cool the upper half of the storage tank 4 so that the second energy-carrying medium can be cooled, allowing the second energy-carrying medium to directly supply energy to the user, thus achieving rapid energy supply during the cold start phase.

[0144] During the energy storage stage, since the first energy-carrying medium heat exchanger 9 is located above the liquid phase of the storage tank 4, the temperature of the energy storage medium in the upper part of the liquid phase of the storage tank 4 is lower than that of the lower part of the energy storage medium, and the density is greater than that of the lower part of the energy storage medium. Under the action of natural convection, the lower part of the energy storage medium surges to the top, making the temperature inside the storage tank 4 more uniform.

[0145] It is understood that the present invention utilizes the temperature and density difference between the upper and lower parts of the energy storage medium in the energy storage module 30 and takes advantage of the characteristics of natural convection to enable the energy storage medium in the storage tank 4 to automatically churn and mix evenly, thereby ensuring the uniformity of the internal temperature of the storage tank 4. The present invention relies on mechanical structure and does not require power input to solve the problem of uneven temperature distribution inside the storage tank 4.

[0146] Optionally, the first energy-carrying medium, the second energy-carrying medium, and the energy storage medium may be water, ethanol, ethylene glycol, heat transfer oil, silicone oil, etc., and the present invention does not limit them.

[0147] like Figure 10 As shown, a second embodiment of the energy storage system 100 according to a second preferred embodiment of the present invention is specifically illustrated. In the second preferred embodiment of the present invention, the second embodiment is a variation of the first embodiment. It is understood that, except for the different entry and exit positions of the second energy-carrying medium in the storage tank 4, the structure of the energy storage system 100 in the second embodiment is the same as that of the energy storage system 100 in the first embodiment.

[0148] Specifically, in the second embodiment, the weir plate structure 11 is disposed in the upper half of the storage tank 4, and the first energy-carrying medium heat exchanger 9 is disposed in the lower half of the storage tank 4. During the cold start stage, the first energy-carrying medium and the energy storage medium in the lower half of the storage tank 4 undergo a wall-to-wall heat exchange process. Under the action of the weir plate structure 11, the energy storage medium in the storage tank 4 is distributed in a form where the lower part is a low-temperature fluid and the upper part is a normal-temperature fluid. The second energy-carrying medium output by the user-side energy supply equipment 2 flows into the second energy-carrying medium heat exchanger 10 from the upper half of the storage tank 4 and flows out from the lower half of the storage tank 4.

[0149] In other words, during the cold start phase, the first energy-carrying medium undergoes an indirect heat exchange process with the liquid-phase energy storage medium in the lower part of the storage tank 4, causing the temperature of the lower liquid to rise. Under the action of the weir plate structure 11, most of the high-temperature fluid remains in the lower part, resulting in a distribution of the energy storage medium in the storage tank 4 with room-temperature fluid at the top and high-temperature fluid at the bottom. The second energy-carrying medium enters the storage tank 4 from the top and undergoes an indirect heat exchange process with the liquid-phase energy storage medium. When the second energy-carrying medium flows through the upper part of the storage tank 4, the upper energy storage medium is at room temperature and cannot heat the second energy-carrying medium. When the second energy-carrying medium flows through the lower part of the storage tank 4, the lower energy storage medium is at high temperature and heats the second energy-carrying medium. Therefore, the first energy-carrying medium can supply energy to the user without heating the entire storage tank 4, achieving rapid energy supply during the cold start phase.

[0150] During the energy storage stage, since the first energy-carrying medium heat exchanger 9 is located in the lower part of the liquid phase of the storage tank 4, the temperature of the energy storage medium in the upper part of the liquid phase of the storage tank 4 is lower than that of the lower part of the energy storage medium, and the density is greater than that of the upper part of the energy storage medium. Under the action of natural convection, the lower energy storage medium surges to the upper part, making the temperature inside the storage tank 4 more uniform.

[0151] It is understood that, in another aspect, the present invention also provides a control method for an energy storage system according to a second preferred embodiment, comprising the steps of:

[0152] S210, the first energy-carrying medium output from the energy supply system 20 flows into the first energy-carrying medium heat exchanger 9 of the energy storage module 30, exchanges heat with the energy storage medium in the storage tank 4 of the energy storage module 30, and then flows back to the energy supply system 20.

[0153] S220, the second energy-carrying medium output by the energy storage module 30 flows into the user-side energy supply device 2 through the inlet valve group 1 of the user unit 40, and supplies energy to the user-side energy supply device 2;

[0154] S230, the second energy-carrying medium output by the user-side energy supply device 2 flows into the second energy-carrying medium heat exchanger 10 of the energy storage module 30 for a cold start stage, an energy release stage, or an energy storage stage, thereby completing one working cycle of the energy storage system 100.

[0155] In the first embodiment of the energy storage system 100 corresponding to the second preferred embodiment of the present invention, step S230 includes the following steps:

[0156] S231. Control the energy storage module 30 to enter the cold start stage:

[0157] The first energy-carrying medium flows into the first energy-carrying medium heat exchanger 9 from the upper half of the storage tank 4, and undergoes a wall-to-wall heat exchange process with the energy storage medium in the upper half of the storage tank 4. Under the action of the weir plate structure 11 of the storage tank 4, the energy storage medium in the storage tank 4 is distributed in the form of low temperature fluid in the upper half and normal temperature fluid in the lower half.

[0158] The second energy-carrying medium output by the user-side energy supply device 2 flows into the second energy-carrying medium heat exchanger 10 from the lower half of the storage tank 4, and is cooled by the low-temperature fluid-like energy storage medium in the upper half of the storage tank 4 before flowing out from the upper half of the storage tank 4.

[0159] S232, Control the energy storage module 30 to enter the energy release stage: The second energy-carrying medium flows into the storage tank 4, absorbs the energy of the energy storage medium in the storage tank 4, and then flows out; and

[0160] S233. Control the energy storage module 30 to enter the energy storage stage: the second energy carrier medium flows into the storage tank 4 and releases energy, and the energy storage medium in the storage tank 4 absorbs the energy released by the second energy carrier medium to realize the energy storage process.

[0161] In a second embodiment of the energy storage system 100 corresponding to the second preferred embodiment of the present invention, step S230 includes the following steps:

[0162] S231. Control the energy storage module 30 to enter the cold start stage:

[0163] The first energy-carrying medium flows into the first energy-carrying medium heat exchanger 9 from the lower half of the storage tank 4, and undergoes a wall-to-wall heat exchange process with the energy storage medium in the lower half of the storage tank 4. Under the action of the weir plate structure 11 of the storage tank 4, the energy storage medium in the storage tank 4 is distributed in the form of low temperature fluid in the lower half and normal temperature fluid in the upper half.

[0164] The second energy-carrying medium output by the user-side energy supply device 2 flows into the second energy-carrying medium heat exchanger 10 from the upper half of the storage tank 4, and is cooled by the low-temperature fluid-like energy storage medium in the lower half of the storage tank 4 before flowing out from the lower half of the storage tank 4.

[0165] S232, Control the energy storage module 30 to enter the energy release stage: The second energy-carrying medium flows into the storage tank 4, absorbs the energy of the energy storage medium in the storage tank 4, and then flows out; and

[0166] S233. Control the energy storage module 30 to enter the energy storage stage: the second energy carrier medium flows into the storage tank 4 and releases energy, and the energy storage medium in the storage tank 4 absorbs the energy released by the second energy carrier medium to realize the energy storage process.

[0167] The beneficial effects of the energy storage system 100 in the second preferred embodiment of the present invention are as follows: 1) It solves the mismatch between the power supply of the energy supply system 20 and the power demand of the user unit 40, reduces the volume and cost of the energy supply system 20, improves economic efficiency, avoids frequent start-stop of the energy supply system 20, and thus extends its service life; 2) It solves the problem of long cold start time of existing energy storage systems, and the energy supply system 20 can meet user needs without cooling the entire energy storage module 30; 3) It provides a simple energy storage system control strategy, reduces the difficulty of system control, and improves system reliability; 4) It solves the problem of uneven temperature distribution inside the storage tank 4 by relying solely on mechanical structure without power input.

[0168] In summary, this invention provides an energy storage system and its control method that enables rapid cold start, uniform internal temperature, simple control, and can meet the fluctuating demand of the user side. By introducing an energy storage module, the matching between the energy supply side and the user side demand of the energy supply system is increased, the size and cost of the energy supply system are reduced, and irreversible damage caused by frequent start-stop operations is avoided, extending its service life. By employing flow and energy distribution of the first energy-carrying medium entering the energy storage system in a single loop, and by using the first energy-carrying medium to supply energy for cooling the second energy-carrying medium and adjusting the entry and exit positions of the first and second energy-carrying media in the storage tank in a dual loop, it is ensured that there is always one energy-carrying medium that can directly input into the energy supply system to power the user unit, enabling rapid cold start. At the same time, by utilizing the temperature and density differences of the energy-carrying medium in the storage tank and the characteristics of natural convection, the temperature of the energy storage module is uniform, resulting in good energy storage performance.

[0169] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0170] The above embodiments merely illustrate preferred implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention should be determined by the appended claims.

Claims

1. An energy storage system, characterized in that, The system includes an energy supply system, an energy storage module, and a user unit connected in the same circuit. The user unit includes an inlet valve group connected to the energy supply system and the energy storage module, and a user-side energy supply device connected to the inlet valve group. The first energy-carrying medium output from the energy supply system flows into the user-side energy supply device via the inlet valve group to power the device. The first energy-carrying medium output from the user-side energy supply device flows into the energy storage module for a cold start phase, an energy release phase, or an energy storage phase, and finally flows back into the energy supply system, thus completing one working cycle of the energy storage system. The energy storage module is used to split the first energy-carrying medium into two outputs during the cold start phase: one output is directly input into the energy supply system, and the other output exchanges heat with the energy storage medium in the energy storage module, enabling the energy storage module to start quickly in the cold.

2. The energy storage system according to claim 1, characterized in that, The energy storage module includes a storage tank connected to the user-side energy supply equipment, a liquid distribution device disposed in the storage tank, a cold start valve disposed in the upper half of the storage tank, and a storage tank outlet valve disposed at the bottom of the storage tank. The liquid distribution device is used to distribute the first energy-carrying medium flowing into the energy storage module during the cold start phase, so that one path of the first energy-carrying medium is directly input into the energy supply system via the cold start valve, and another path of the first energy-carrying medium flows into the storage tank, exchanges heat with the energy storage medium in the storage tank, and then flows into the energy supply system via the storage tank outlet valve. The energy storage module controls the switching of the cold start phase, the energy release phase, and the energy storage phase by controlling the opening mode of the cold start valve and the storage tank outlet valve.

3. The energy storage system according to claim 2, characterized in that, The energy storage module further includes a first energy-carrying medium thermometer disposed between the energy supply system and the user unit, and a storage tank thermometer disposed in the storage tank. The first energy-carrying medium thermometer is used to detect the temperature of the first energy-carrying medium, and the storage tank thermometer is used to detect the temperature of the storage tank. The energy storage module controls the opening degree of the cold start valve based on the comparison result between the temperature value measured by the first energy-carrying medium thermometer and the set value, and controls the opening and closing of the cold start valve based on the comparison result between the temperature value measured by the storage tank thermometer and the rated temperature value.

4. The energy storage system according to claim 3, characterized in that, The energy storage module also includes a level gauge installed in the storage tank. The level gauge is used to detect the level of the first energy-carrying medium in the storage tank. The energy storage module controls the opening degree of the storage tank outlet valve based on the level of the first energy-carrying medium in the storage tank.

5. The energy storage system according to any one of claims 2 to 4, characterized in that, The liquid preparation device is a weir plate.

6. The energy storage system according to any one of claims 2 to 4, characterized in that, The liquid preparation device includes a thick tube and a thin tube inserted into the thick tube.

7. The energy storage system according to any one of claims 2 to 4, characterized in that, The liquid dispensing device is a three-way structure, which has an inlet for the first energy-carrying medium to flow in and two outlets with different diameters.

8. The energy storage system according to claim 1, characterized in that, The energy storage module includes a cold start valve connected to the user-side power supply equipment and the power supply system, a storage tank inlet valve connected to the user-side power supply equipment, and a storage tank connected to the storage tank inlet valve and the power supply system. During the cold start phase, the first energy-carrying medium flowing out of the user-side power supply equipment is divided into two outputs. One output of the first energy-carrying medium flows into the power supply system via the cold start valve, and the other output of the first energy-carrying medium flows into the storage tank via the storage tank inlet valve. After exchanging heat with the energy storage medium in the storage tank, the first energy-carrying medium flows into the power supply system. The energy storage module controls the switching between the cold start phase, the energy release phase, and the energy storage phase by controlling the opening degree of the cold start valve and the storage tank inlet valve.

9. The energy storage system according to claim 8, characterized in that, The energy storage module further includes a first energy-carrying medium thermometer disposed between the energy supply system and the user unit, and a storage tank thermometer disposed in the storage tank. The first energy-carrying medium thermometer is used to detect the temperature of the first energy-carrying medium, and the storage tank thermometer is used to detect the temperature of the storage tank. The energy storage module controls the opening degree of the cold start valve and the storage tank inlet valve based on the comparison result between the temperature value measured by the first energy-carrying medium thermometer and the set value, and controls the opening and closing of the cold start valve based on the comparison result between the storage tank thermometer and the rated temperature value.

10. The energy storage system according to claim 9, characterized in that, The energy storage module further includes a first heat exchanger disposed inside the storage tank. The inlet of the first heat exchanger is located in the upper half of the storage tank and connected to the storage tank inlet valve, and the outlet of the first heat exchanger is located in the lower half of the storage tank and connected to the energy supply system. The first energy-carrying medium flows into the first heat exchanger from the upper half of the storage tank and flows out from the lower half of the storage tank.

11. The energy storage system according to claim 9, characterized in that, The energy storage module further includes a first heat exchanger disposed inside the storage tank. The inlet of the first heat exchanger is located in the lower half of the storage tank and connected to the storage tank inlet valve, and the outlet of the first heat exchanger is located in the upper half of the storage tank and connected to the energy supply system. The first energy-carrying medium flows into the first heat exchanger from the lower half of the storage tank and flows out from the upper half of the storage tank.

12. The energy storage system according to any one of claims 1 to 4, 8 to 11, characterized in that, The first energy-carrying medium is any one of water, ethanol, ethylene glycol, heat transfer oil, and silicone oil.

13. The energy storage system according to any one of claims 1 to 4, 8 to 11, characterized in that, The energy storage system also includes a bypass valve connected to the energy supply system and the energy storage module. When the flow rate of the first energy-carrying medium exceeds the flow rate required by the user-side energy supply equipment, the excess portion of the first energy-carrying medium flows out through the bypass valve and merges with the first energy-carrying medium flowing out of the user-side energy supply equipment.

14. A control method for an energy storage system according to any one of claims 10 to 11, characterized in that, Including the following steps: S110, the first energy-carrying medium of the energy supply system flows into the user-side energy supply equipment via the inlet valve group. S120, the first energy-carrying medium output by the user-side energy supply equipment flows into the energy storage module, and a cold start stage, an energy release stage, or an energy storage stage are carried out in the energy storage module. as well as S130, the first energy-carrying medium flows back to the energy supply system, completing one working cycle of the energy storage system.

15. The control method for the energy storage system according to claim 14, characterized in that, Step S120 includes the following steps: S121. Control the energy storage module to enter the cold start stage: The energy storage module divides the first energy-carrying medium into two outputs, one of which is directly input into the energy supply system, and the other of which exchanges heat with the energy storage medium in the energy storage module to provide energy for the rapid cold start of the energy storage module. S122. Control the energy storage module to enter the energy release stage: the first energy-carrying medium flows into the energy storage module, absorbs the energy of the energy storage medium in the energy storage module, and then flows out; as well as S123. Control the energy storage module to enter the energy storage stage: the first energy carrier medium flows into the energy storage module and releases energy, and the energy storage medium of the energy storage module absorbs the energy released by the first energy carrier medium to realize the energy storage process.

16. The control method for the energy storage system according to claim 15, characterized in that, Step S121 includes the following steps: S1211. Control the opening of the cold start valve of the energy storage module. The first energy-carrying medium flows into the storage tank of the energy storage module. Under the action of the liquid distribution device in the storage tank, most of the first energy-carrying medium flows directly out of the storage tank, and the remaining first energy-carrying medium flows out from the bottom of the storage tank through the storage tank outlet valve. S1212. Detect the temperature of the first energy-carrying medium and the temperature of the storage tank of the energy storage module, and detect the liquid level of the first energy-carrying medium in the storage tank; as well as S1213. Control the opening degree of the cold start valve according to the comparison result between the temperature value of the first energy-carrying medium and the set value, control the opening and closing of the cold start valve according to the comparison result between the temperature of the storage tank and the rated temperature value, and control the opening degree of the storage tank outlet valve according to the liquid level of the first energy-carrying medium in the storage tank.

17. The control method for the energy storage system according to claim 16, characterized in that, In step S122, the cold start valve is closed, and the first energy-carrying medium flows into the storage tank, absorbs the energy of the energy storage medium in the storage tank, and then flows out through the storage tank outlet valve.

18. The control method for the energy storage system according to claim 16, characterized in that, In step S123, the cold start valve is closed, the first energy-carrying medium flows into the storage tank and releases energy, and the energy storage medium in the storage tank absorbs the energy released by the first energy-carrying medium, thus realizing the energy storage process.

19. The control method for the energy storage system according to claim 15, characterized in that, Step S121 includes the following steps: S1211. Control the opening of the cold start valve and the storage tank inlet valve of the energy storage module, so that most of the first energy-carrying medium flows into the energy supply system through the cold start valve, and the remaining part of the first energy-carrying medium flows into the storage tank through the storage tank inlet valve, and flows out after exchanging heat with the energy storage medium in the storage tank. S1212, Detect the temperature of the first energy-carrying medium and the temperature of the energy storage module's tank; as well as S1213. Control the opening degree of the cold start valve and the tank inlet valve according to the comparison result between the temperature value of the first energy-carrying medium and the set value, and control the opening and closing of the cold start valve according to the comparison result between the temperature of the tank and the rated temperature value.

20. The control method for the energy storage system according to claim 19, characterized in that, In step S122, the cold start valve is closed, and the first energy-carrying medium flows into the first heat exchanger through the tank inlet valve, absorbs the energy of the energy storage medium in the tank, and then flows out of the first heat exchanger.

21. The control method for the energy storage system according to claim 19, characterized in that, In step S123, the cold start valve is closed, the first energy-carrying medium flows into the first heat exchanger through the tank inlet valve and releases energy, and the energy storage medium in the tank absorbs the energy released by the first energy-carrying medium, thus realizing the energy storage process.

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