A control system of a thermoelectric cold tri-generation immersed energy storage cabinet

Abstract

This invention relates to the field of energy storage cabinet technology, specifically to a combined heat, power, and cooling (CHP) immersion energy storage cabinet control system. The system includes an energy storage unit, a thermal management unit, a waste heat recovery unit, and a control unit. The energy storage unit comprises multiple battery modules connected in series. The thermal management unit includes liquid cooling modules corresponding to each battery module. Each liquid cooling module includes a battery compartment and a liquid cooling circulation branch. The battery compartment is filled with coolant, and the battery cells of the battery modules are immersed in the coolant. The coolant circulation branch includes a circulation pump and a plate heat exchanger. The waste heat recovery unit includes a cooling water circuit and a refrigerant circuit that exchange heat with the liquid cooling circulation branch through the plate heat exchanger. The control unit is communicatively connected to the energy storage unit, the thermal management unit, and the waste heat recovery unit. This energy storage cabinet control system enables precise temperature control of individual battery modules and achieves stable and efficient CHP (cogeneration) of energy storage, hot water supply, and cooling / ice making.

Description

Technical Field

[0001] This invention relates to the field of energy storage cabinet technology, and in particular to a control system for a combined heat, power and cooling (CHP) immersion energy storage cabinet. Background Technology

[0002] Electrochemical energy storage systems are widely used in grid peak shaving and renewable energy consumption. As the core carrier, the thermal safety of the batteries inside the energy storage cabinet directly affects the safety, efficiency and lifespan of the system. Traditional energy storage cabinet thermal management mainly adopts forced air cooling or liquid cooling by chiller units, which has the following obvious defects: 1) Poor temperature uniformity, large temperature difference inside the battery pack, affecting overall performance and lifespan; 2) Single form of energy utilization, the waste heat generated by battery charging and discharging is directly discharged into the environment through the radiator, resulting in energy waste; 3) Isolated system function, which can only realize electrical energy storage and cannot meet the comprehensive needs of users for multiple forms of energy such as cold and heat.

[0003] While some existing technologies attempt to recover battery waste heat for purposes such as heating or providing hot water, these solutions are typically complex in structure, poorly coupled with the battery thermal management system, and have simple control strategies. They are difficult to achieve dynamic, efficient, and coordinated control of the three energy flows (cold, heat, and electricity) while ensuring absolute battery safety (especially in immersion liquid cooling environments). Furthermore, existing systems generally lack intelligence and adaptive capabilities, and cannot perform globally optimal operation based on battery status, environmental conditions, and user needs. Summary of the Invention

[0004] In view of this, the purpose of this invention is to propose a control system for a combined heat, power and cooling (CHP) immersion energy storage cabinet to solve the above problems.

[0005] For the purposes described above, the present invention provides:

[0006] A control system for a combined heat, power, and cooling (CHP) immersion energy storage cabinet includes:

[0007] Energy storage unit, thermal management unit, waste heat recovery unit, and control unit;

[0008] The energy storage unit includes multiple battery modules connected in series;

[0009] The thermal management unit includes liquid cooling modules that correspond one-to-one with the battery modules. Each liquid cooling module includes a sealed battery compartment and an independent liquid cooling circulation branch. The battery compartment is filled with coolant, and the battery cells of the battery module are immersed in the coolant. The liquid cooling circulation branch includes a circulation pump and a plate heat exchanger located outside the battery compartment.

[0010] The waste heat recovery unit includes a cooling water circuit and a refrigerant circuit that exchange heat with the liquid cooling circulation branch through the plate heat exchanger.

[0011] The control unit is communicatively connected to the energy storage unit, the thermal management unit, and the waste heat recovery unit, and is used to coordinately control the operation of the thermal management unit and the waste heat recovery unit according to the thermal state of the energy storage unit.

[0012] Preferably, the plate heat exchanger is a three-channel plate heat exchanger, with the first channel connected to the liquid cooling circulation branch, the second channel connected to the cooling water circuit, and the third channel connected to the refrigerant circuit.

[0013] Preferably, the liquid cooling circulation branch further includes a first temperature sensor disposed in the battery compartment and a second temperature sensor disposed at the outlet of the first channel of the plate heat exchanger.

[0014] The control unit is configured to adjust the speed of the circulating pump and control the start and stop of the refrigerant circuit based on the detection data of the first temperature sensor and the second temperature sensor.

[0015] Preferably, the cooling water circuit includes a water storage tank, a water pump, a waste heat recovery heat exchanger, an air source heat pump, and an auxiliary heater. The cooling water circuit flows sequentially through the second channel of the plate heat exchanger, the waste heat recovery heat exchanger, the air source heat pump, and the auxiliary heater before returning to the water storage tank.

[0016] Preferably, the refrigerant circuit includes a compressor, a condenser, a throttling element, and a switching valve assembly. The third channel of the plate heat exchanger serves as the evaporator of the refrigerant circuit. The condensation waste heat of the condenser is discharged to a waste heat recovery heat exchanger for heat exchange. The switching valve assembly is used to switch the evaporator side of the refrigerant circuit to an air conditioning terminal or an ice maker.

[0017] Preferably, the control unit executes the following priority control strategy:

[0018] S1. Prioritize the control of the thermal management unit and the waste heat recovery unit to maintain the temperature of the coolant at the temperature threshold, and keep the temperature of the battery module within a safe range.

[0019] S2. Under the premise of satisfying step S1, control the waste heat recovery unit to meet a preset user load requirement;

[0020] S3. After satisfying steps S1 and S2, the remaining thermal energy is used for storage.

[0021] Preferably, the control unit is configured as follows:

[0022] The temperature threshold of the coolant is dynamically adjusted based on the state of charge and charge / discharge power of the battery module.

[0023] Preferably, the water storage tank is a pressurized water tank with a vacuum insulation jacket, and is equipped with a water temperature stratification detection sensor and an internal circulation pump for agitating the water.

[0024] Preferably, the system also includes an IoT gateway that is communicatively connected to the control unit. The control unit integrates a fault diagnosis module for locating faulty components based on data from various sensors and for uploading fault information and remotely receiving control commands through the IoT gateway.

[0025] Preferably, the control unit has a built-in energy efficiency optimization model based on machine learning. The energy efficiency optimization model is used to optimize the operating parameters of the circulating pump, the compressor and the auxiliary heater based on historical operating data, ambient temperature and user load prediction.

[0026] The beneficial effects of this invention are:

[0027] 1. The independent liquid cooling module set for each battery module realizes modularity, which can achieve precise temperature control of each battery module and keep the temperature difference of each battery module within 1.5℃ for a long time, thereby suppressing thermal runaway of the battery module and significantly improving the safety and life of the battery module.

[0028] 2. The three-channel plate heat exchanger enables staged heat exchange between cooling water and refrigerant on the coolant, allowing for precise temperature control of the coolant and further ensuring the stability of individual battery modules.

[0029] 3. The low-grade waste heat from the battery is used as the primary heat source for hot water production through a three-channel plate heat exchanger, and the medium-grade condensation waste heat in the cooling water circuit and refrigerant circuit is boosted by an air source heat pump and used as the secondary heat source for hot water production through a waste heat recovery heat exchanger, thus achieving a higher degree of energy recovery.

[0030] 4. Based on user needs, it can provide hot water and cooling / ice making services, achieving stable and efficient combined energy storage, hot water supply, and cooling / ice making. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic block diagram of the entire invention;

[0033] Figure 2 This is a schematic diagram of the overall structure of the present invention;

[0034] Figure 3 This is a schematic diagram of the refrigerant circuit in this invention;

[0035] Figure 4 This is a schematic diagram of the cooling water circuit in this invention;

[0036] Figure 5 This is a schematic diagram of the battery module and liquid cooling circulation branch in this invention.

[0037] The diagram is marked as follows:

[0038] 100. Energy storage unit; 110. Battery module; 200. Thermal management unit; 210. Battery compartment; 220. Liquid cooling circulation branch; 221. Circulation pump; 222. Plate heat exchanger; 223. First temperature sensor; 224. Second temperature sensor; 310. Cooling water circuit; 311. Water tank; 312. Water pump; 313. Waste heat recovery heat exchanger; 314. Air source heat pump; 315. Auxiliary heater; 320. Refrigerant circuit; 321. Compressor; 322. Condenser; 323. Throttling element; 324. Switching valve assembly; 400. Control unit. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0040] It should be noted that, unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0041] like Figure 1-2 As shown, a control system for a combined heat, power and cooling (CHP) immersion energy storage cabinet includes an energy storage unit 100, a thermal management unit 200, a waste heat recovery unit, and a control unit 400.

[0042] Among them, the energy storage unit 100 includes multiple battery modules 110 connected in series, which constitute the main body of the energy storage cabinet for storing electrical energy.

[0043] The thermal management unit 200 includes several liquid cooling modules that correspond one-to-one with the battery module 110. Each liquid cooling module includes a sealed battery compartment 210 and an independent liquid cooling circulation branch 220. The battery compartment 210 is filled with coolant (preferably silicon-based coolant). The battery cells of the battery module 110 are placed in the battery compartment 210 and immersed in the coolant. The coolant quickly and evenly absorbs the heat generated by the battery module 110. A first temperature sensor (preferably an NTC sensor attached to the surface of a representative battery cell) is arranged inside the battery compartment 210. A leakage sensor for detecting coolant leakage is provided at the bottom of the battery compartment 210.

[0044] The battery compartment 210 is connected to an external liquid-cooled circulation branch 220 via a pipe to form a closed loop. The liquid-cooled circulation branch 220 includes a circulation pump 221 (preferably a variable frequency micro circulation pump 221) and a plate heat exchanger 222 with three channels. The first channel of the plate heat exchanger 222 is connected to the liquid-cooled circulation branch 220. The circulation pump 221 drives the coolant to circulate between the battery compartment 210 and the first channel of the heat exchanger. A second temperature sensor 224 is provided at the outlet of the first channel of the plate heat exchanger 222. A flow sensor can also be provided on the liquid-cooled circulation branch 220 to cooperate with the second temperature sensor 224 to more accurately adjust the circulation flow rate of the coolant. Each thermal management unit 200 of the above structure corresponds to a battery module 110, realizing independent and precise temperature control of each battery module 110.

[0045] The waste heat recovery unit includes a cooling water circuit 310 and a refrigerant circuit 320. The second channel of the plate heat exchanger 222 is connected to the cooling water circuit 310, and the third channel of the plate heat exchanger 222 is connected to the refrigerant circuit 320, so that the cooling water circuit 310, the refrigerant circuit 320 and the liquid cooling circulation branch 220 exchange heat in the plate heat exchanger 222.

[0046] Specifically, the cooling water circuit 310 includes a pressurized water storage tank 311, a water pump 312, a waste heat recovery heat exchanger 313, an air source heat pump 314, and a PID-controlled auxiliary heater 315. The water storage tank 311 adopts a double-layer vacuum insulation sandwich structure and can be equipped with an electric auxiliary heating device, multiple layered temperature sensors, and an internal circulation pump to detect and optimize the water temperature distribution in the tank.

[0047] The flow of cooling water in cooling water circuit 310 is as follows:

[0048] Water pump 312 drives cooling water to flow out of water storage tank 311, first entering the second channel of plate heat exchanger 222, where it absorbs heat from the battery module 110 side again. Then, the cooling water flows through waste heat recovery heat exchanger 313, which is connected to the condenser 322 of refrigerant circuit 320 and the condenser side of air source heat pump 314 via a duct, allowing the waste heat generated by condensation in the condenser 322 of refrigerant circuit 320 and the condenser side of air source heat pump 314 to be discharged. The water undergoes heat exchange in the waste heat recovery heat exchanger 313, absorbing the condensing waste heat from the refrigerant circuit 320 and the air source heat pump 314. After that, the cooling water enters the condenser 322 of the air source heat pump 314 and is further heated. If the water temperature still does not reach the set value (e.g., 55°C) after the above steps, the auxiliary heater 315 will provide precise supplemental heating. Finally, the heated cooling water is returned to the storage tank 311 for storage and use by the user, thereby maximizing the recovery of medium and low grade heat energy in the system.

[0049] Specifically, the refrigerant circuit 320 is a vapor compression refrigeration cycle, including a compressor 321, a condenser 322, a throttling element 323 (such as an electronic expansion valve), and a switching valve group 324 for function switching (including a main solenoid valve and a standby solenoid valve). The third channel of the plate heat exchanger 222 is connected to the refrigerant circuit 320 and acts as the evaporator of the refrigerant circuit 320. The condenser 322 is coupled to the waste heat recovery heat exchanger 313.

[0050] Refrigerant circuit 320 mainly operates in the following three modes:

[0051] Mode 1: When the battery module 110 generates a large amount of heat and requires enhanced cooling, the control unit 400 controls the main solenoid valve and the backup solenoid valve to close. The refrigerant output by the compressor 321 flows through the condenser 322 and then flows through the throttling element 323. The throttling element 323 controls the flow rate of the refrigerant so that the refrigerant flows to the third channel of the plate heat exchanger 222, absorbs the heat from the battery module 110 side, and then returns to the compressor 321.

[0052] Mode 2: When the cooling demand of the battery module 110 is not large and the user has an air conditioning cooling demand (mainly to meet the cooling demand of the internal environment of the energy storage cabinet to reduce the ambient temperature inside the energy storage cabinet), the control unit 400 controls the main solenoid valve to open and the standby solenoid valve to close. The refrigerant flowing through the throttling element 323 flows through the main solenoid valve and enters the air conditioning terminal, and returns to the compressor 321 after the air conditioning cooling is achieved.

[0053] Mode 3: When the cooling demand of the battery module 110 is not large and the user has an ice-making demand, the control unit 400 controls the main solenoid valve to close and the backup solenoid valve to open. The refrigerant flowing through the throttling element 323 enters the ice-making device after passing through the backup solenoid valve, and returns to the compressor 321 after ice making.

[0054] Regardless of the three modes mentioned above, the condensation waste heat released by the refrigerant in the condenser 322 is recovered and utilized by the cooling water circuit 310 through the waste heat recovery heat exchanger 313, achieving zero waste heat emission.

[0055] The control unit 400 integrates a battery management system (BMS), an intelligent collaborative control module, and a fault diagnosis module, and is connected to an IoT gateway. The battery management module is used to collect the operating information of the battery module 110, the intelligent collaborative control module is used to control the operation of the thermal management unit 200 and the waste heat recovery unit, the fault diagnosis module is used to locate faulty components, and the material network gateway is used to upload fault information and remotely receive control commands. Based on the system's real-time data, the control unit 400 executes the following priority control strategy:

[0056] S1, First Priority (Safety): Based on the continuous high-precision monitoring of the battery module 110 and coolant temperatures by the first temperature sensor 223 and the second temperature sensor 224, the speed of the circulation pump 221 of each liquid cooling module is unconditionally adjusted to cool the battery module 110 through the coolant. When the temperature of the battery module 110 has not dropped to the safe range, the compressor 321 of the refrigerant circuit 320 is started to cool the coolant through the refrigerant entering the plate heat exchanger 222, thereby enhancing the cooling of the battery module 110 and ensuring that the temperature of all battery modules 110 is stable within the safe range. In addition, the control unit 400 dynamically calculates and adjusts the temperature threshold of the coolant based on the data such as voltage, current, SOC, and SOH of the battery module 110 collected by the battery management system and the ambient temperature. For example, a lower temperature threshold is used when charging at a high rate, and a higher temperature threshold is used in low-temperature environments to extend battery life.

[0057] S2, Second Priority (Demand): Under the premise of meeting the thermal safety of battery module 110, prioritize responding to the immediate demand set, such as supplying hot water at a certain temperature or cooling a specific area.

[0058] S3, Third Priority (Optimization): When the battery module 110 has sufficient heat dissipation capacity and there is no immediate external demand, the system automatically enters the energy optimization mode. For example, it can use excess heat to maintain the water temperature of the water storage tank 311, or start the ice-making device to store cold energy for subsequent high-load cooling needs.

[0059] In addition, the energy efficiency optimization model based on machine learning built into the control unit 400 optimizes the operating parameters of the circulation pump 221, compressor 321 and auxiliary heater 315 according to historical operating data, ambient temperature and user load prediction, so that the system energy efficiency improves over time. The fault diagnosis module built into the control unit 400 can quickly locate problems such as pump failure and sensor abnormality and execute preset fault-tolerant strategies. For example, when the circulation pump 221 of the thermal management unit 200 of a single battery module 110 fails, the series circuit of the battery module 110 is automatically shut down to ensure system safety. When the air heat source pump fails, the auxiliary heater 315 is automatically switched to the main heat source to maintain the stability of hot water supply.

[0060] With the above structure, the system operates as follows:

[0061] When the system is running, the heat generated by the battery module 110 is first absorbed by the coolant and transferred to the cooling water through the plate heat exchanger 222 to prepare hot water. If the heat generated by the battery module 110 is too large, the refrigerant circuit 320 is activated to enhance the cooling of the coolant and thus enhance the cooling of the battery module 110. At the same time, the condensation waste heat generated by the system is recovered through the waste heat recovery heat exchanger 313 for the preparation of hot water. The refrigerant circuit 320 can flexibly cool the internal environment of the energy storage cabinet or make ice externally as needed. The entire process is intelligently scheduled and controlled by the control unit 400 to achieve stable and efficient combined production of electric energy storage, hot water supply, and cooling / ice making.

[0062] By adopting the above structure and operating method, the following beneficial effects are achieved compared with existing technologies:

[0063] 1. The independent liquid cooling module set in each battery module 110 realizes modularity, which can achieve precise temperature control of each battery module 110, and keep the temperature difference of each battery module 110 stable within 1.5℃ for a long time, thereby suppressing thermal runaway of the battery module 110 and significantly improving the safety and life of the battery module 110.

[0064] 2. The three-channel plate heat exchanger 222 enables staged heat exchange between cooling water and refrigerant on the coolant, which allows for precise temperature control of the coolant and further ensures the stability of a single battery module 110.

[0065] 3. The low-grade waste heat from the battery is used as the primary heat source for hot water preparation through the three-channel plate heat exchanger 222, and the medium-grade condensation waste heat in the cooling water circuit 310 and refrigerant circuit 320 is boosted by the air source heat pump 314 through the waste heat recovery heat exchanger 313 and used as the secondary heat source for hot water preparation, thus achieving a higher degree of energy recovery.

[0066] 4. Based on user needs, it can provide hot water and cooling / ice making services, achieving stable and efficient combined energy storage, hot water supply, and cooling / ice making.

[0067] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in the details for the sake of brevity.

[0068] This invention is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A control system for a combined heat, power, and cooling (CHP) immersion energy storage cabinet, characterized in that, include: Energy storage unit, thermal management unit, waste heat recovery unit, and control unit; The energy storage unit includes multiple battery modules connected in series; The thermal management unit includes liquid cooling modules that correspond one-to-one with the battery modules. Each liquid cooling module includes a sealed battery compartment and an independent liquid cooling circulation branch. The battery compartment is filled with coolant, and the battery cells of the battery module are immersed in the coolant. The liquid cooling circulation branch includes a circulation pump and a plate heat exchanger located outside the battery compartment. The waste heat recovery unit includes a cooling water circuit and a refrigerant circuit that exchange heat with the liquid cooling circulation branch through the plate heat exchanger. The control unit is communicatively connected to the energy storage unit, the thermal management unit, and the waste heat recovery unit, and is used to coordinately control the operation of the thermal management unit and the waste heat recovery unit according to the thermal state of the energy storage unit.

2. The control system for a combined heat, power, and cooling (CHP) immersion energy storage cabinet according to claim 1, characterized in that, The plate heat exchanger is a three-channel plate heat exchanger, with its first channel connected to the liquid cooling circulation branch, the second channel connected to the cooling water circuit, and the third channel connected to the refrigerant circuit.

3. The control system for a combined heat, power, and cooling (CHP) immersion energy storage cabinet according to claim 2, characterized in that, The liquid cooling circulation branch also includes a first temperature sensor disposed in the battery compartment and a second temperature sensor disposed at the first channel outlet of the plate heat exchanger. The control unit is configured to adjust the speed of the circulating pump and control the start and stop of the refrigerant circuit based on the detection data of the first temperature sensor and the second temperature sensor.

4. The control system for a combined heat, power, and cooling (CHP) immersion energy storage cabinet according to claim 2, characterized in that, The cooling water circuit includes a water storage tank, a water pump, a waste heat recovery heat exchanger, an air source heat pump, and an auxiliary heater. The cooling water circuit flows sequentially through the second channel of the plate heat exchanger, the waste heat recovery heat exchanger, the air source heat pump, and the auxiliary heater before returning to the water storage tank.

5. The control system for a combined heat, power, and cooling (CHP) immersion energy storage cabinet according to claim 4, characterized in that, The refrigerant circuit includes a compressor, a condenser, a throttling element, and a switching valve assembly. The third channel of the plate heat exchanger serves as the evaporator of the refrigerant circuit. The condensation waste heat of the condenser is discharged to a waste heat recovery heat exchanger for heat exchange. The switching valve assembly is used to switch the evaporator side of the refrigerant circuit to an air conditioning terminal or an ice maker.

6. The control system for a combined heat, power, and cooling (CHP) immersion energy storage cabinet according to claim 1, characterized in that, The control unit executes the following priority control strategy: S1. Prioritize the control of the thermal management unit and the waste heat recovery unit to maintain the temperature of the coolant at the temperature threshold, and keep the temperature of the battery module within a safe range. S2. Under the premise of satisfying step S1, control the waste heat recovery unit to meet a preset user load requirement; S3. After satisfying steps S1 and S2, the remaining thermal energy is used for storage.

7. The control system for a combined heat, power, and cooling (CHP) immersion energy storage cabinet according to claim 6, characterized in that, The control unit is configured to: The temperature threshold of the coolant is dynamically adjusted based on the state of charge and charge / discharge power of the battery module.

8. The control system for a combined heat, power, and cooling (CHP) immersion energy storage cabinet according to claim 4, characterized in that, The water storage tank is a pressurized water tank with a vacuum insulation jacket, and is equipped with a water temperature stratification detection sensor and an internal circulation pump for agitating the water.

9. The control system for a combined heat, power, and cooling (CHP) immersion energy storage cabinet according to claim 1, characterized in that, It also includes an IoT gateway that communicates with the control unit. The control unit integrates a fault diagnosis module, which is used to locate faulty components based on data from various sensors, and to upload fault information and remotely receive control commands through the IoT gateway.

10. The control system for a combined heat, power, and cooling (CHP) immersion energy storage cabinet according to claim 5, characterized in that, The control unit has a built-in machine learning-based energy efficiency optimization model, which is used to optimize the operating parameters of the circulating pump, the compressor and the auxiliary heater based on historical operating data, ambient temperature and user load prediction.

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