Cooling and fire-fighting combined heat management system for energy storage cabinet

Abstract

The utility model belongs to the technical field of battery temperature management, and particularly relates to an energy storage cabinet cooling and fire fighting combined thermal management system which comprises a control system and a plurality of battery modules arranged in a PACK box, a temperature sensor and a liquid cooling assembly are arranged in the PACK box, and the temperature sensor is connected with the control system; the liquid cooling assembly is located at the bottom of the battery module, the liquid cooling assembly comprises a liquid cooling structure and a plurality of glass balls, a cold source assembly is arranged on the outer side of the PACK box, the cold source assembly is connected with the interior of the liquid cooling structure through a pipeline, and the cold source assembly is used for actively cooling the battery module by using a refrigerant conveyed into the liquid cooling structure; the glass ball is mounted on the surface of the liquid cooling structure; according to the heat management system, heat exchange and cooling can be carried out through a refrigerant in the liquid cooling structure and the battery module, meanwhile, thermal runaway of the battery can be prevented, fire extinguishing is carried out by triggering explosion of the glass balls, and the fire extinguishing requirement of the energy storage cabinet is met.

Description

Technical Field

[0001] The utility model belongs to the technical field of battery temperature management, and particularly relates to a combined thermal management system for energy storage cabinet cooling and fire fighting. Background Art

[0002] In recent years, energy storage technologies based on "battery + power electronics technology" have developed rapidly. The energy issue has received close international attention. To achieve carbon neutrality and solve the current energy supply problem, China has also introduced many policies to strongly support the development of clean energy. With the rapid development of the wind power and photovoltaic industries, energy storage has largely solved the problems of randomness and volatility of new energy power generation, playing a role of "filling valleys with peaks". The performance of energy storage depends to a large extent on the performance of the battery. Energy storage batteries apply electrochemical principles for charging and discharging operations. The direct conversion of chemical energy into electrical energy is the result of spontaneous oxidation, reduction and other chemical reactions inside the battery. Heat is generated during this chemical reaction process. The optimal operating temperature of the battery is between 25°C and 35°C. The battery is greatly affected by temperature. At too high or too low temperatures, there will be potential safety hazards for the battery. For example, too high a temperature will cause the battery to experience thermal runaway, and too low a temperature will cause damage to the internal structure of the battery or a decline in battery performance, which will affect the charge and discharge cycle times of the battery and reduce the service life of the battery. At the same time, too high a temperature will also cause thermal runaway and trigger safety problems. Therefore, thermal management of batteries in the energy storage industry is particularly important.

[0003] Currently, the systems for battery thermal management in the energy storage industry usually adopt air cooling and liquid cooling.

[0004] The air-cooled thermal management system in the energy storage industry is generally used for small area energy density. Natural cooling and forced cooling methods are selected according to the heat exchange amount. The forced air cooling system usually uses industrial air conditioners to transfer the heat in the energy storage cabinet to the outside of the cabinet. The disadvantage of the air-cooled system is that the design of the air duct is particularly important. If the design is not good, the temperature difference of the battery will be relatively large, affecting the service life of the battery, and at the same time, it is greatly affected by the external environmental temperature. Currently, the widely used system in the energy storage industry is the liquid-cooled one. The battery module exchanges heat with the ethylene glycol aqueous solution in the liquid-cooled structure. The advantages of the liquid-cooled system are fast cooling rate, good temperature uniformity, and extended service life of the battery.

[0005] However, chemical reactions occur inside the battery continuously to generate heat, and the heat accumulation leads to thermal runaway, causing fire or even explosion, presenting a relatively high fire hazard. A large amount of combustible gas is generated during the thermal runaway process, posing an explosion risk in the energy storage battery compartment (a confined space). Traditional fire extinguishing methods, such as gas fire extinguishing systems, aerosol fire extinguishing, and dry powder fire extinguishing systems, cannot meet the fire extinguishing requirements of the energy storage cabinet;

[0006] There is a need to design an energy storage cabinet thermal management system to improve the above problems. Summary of the Utility Model

[0007] The purpose of the present utility model is to overcome the defects of the prior art and provide a combined thermal management system for energy storage cabinet cooling and fire protection.

[0008] The present utility model provides a combined thermal management system for energy storage cabinet cooling and fire protection, including a control system and a plurality of battery modules arranged in a PACK box;

[0009] A temperature sensor and a liquid cooling component are arranged inside the PACK box, and the temperature sensor is connected to the control system;

[0010] The liquid cooling component is located at the bottom of the battery module. The liquid cooling component includes a liquid cooling structure and a plurality of glass balls. A cold source component is arranged outside the PACK box, and the cold source component is connected to the inside of the liquid cooling structure through a pipeline for actively cooling the battery module by using the refrigerant transported into the liquid cooling structure; the glass balls are installed on the surface of the liquid cooling structure, and the bottom of the glass balls is communicated with the inside of the liquid cooling structure for releasing the refrigerant by blasting the glass balls when thermal runaway occurs inside the battery for fire extinguishing and cooling;

[0011] A control valve is installed on the pipeline, and the control valve is connected to the control system;

[0012] The temperature sensor monitors the temperature of the battery module in real time. The control system adjusts the opening of the control valve according to the temperature of the battery module to cool the battery module. When thermal runaway occurs due to too high temperature of the battery module, the glass balls burst, and the refrigerant in the liquid cooling structure sprays out to increase the heat transfer rate and extinguish the fire.

[0013] Further, a plurality of refrigerant flow channels arranged side by side are arranged inside the liquid cooling structure. The cold source component includes a compressor, a condenser and a liquid storage tank connected in sequence; the liquid storage tank is communicated with the inlet of the refrigerant flow channel through an inlet pipeline. The control valve includes a proportional solenoid valve and an outlet electric valve, and the proportional solenoid valve is installed on the inlet pipeline; the inlet end of the compressor is communicated with the outlet of the refrigerant flow channel through an outlet pipeline, and the outlet electric valve is arranged on the outlet pipeline. The proportional solenoid valve and the outlet electric valve are respectively connected to the control system;

[0014] The outlet end of the compressor is connected to one end of the condenser, and a condenser fan is arranged on one side of the condenser;

[0015] The other end of the condenser is communicated with the liquid storage tank through a return pipeline.

[0016] Further, a gas-liquid separator is arranged at one end of the outlet pipeline close to the compressor to prevent liquid refrigerant from being sucked into the compressor.

[0017] Further, the refrigerant flow channel is of a rectangular structure.

[0018] Further, a sub-pipeline is installed in the middle of the inner side of the refrigerant flow channel, and the bottom of the glass ball communicates with the sub-pipeline.

[0019] Further, an electronic expansion valve is also provided on the return pipeline. The temperature sensing bulb of the electronic expansion valve is arranged at the air inlet end of the compressor. The control system is connected to the temperature sensing bulb and the electronic expansion valve of the electronic expansion valve, and is used to collect the temperature at the air inlet end of the compressor. The control system controls the opening degree of the electronic expansion valve based on the temperature at the air inlet end.

[0020] Further, a warning device is also included. The control system is connected to the warning device and is used to stop the operation of the energy storage cabinet and give a warning when the temperature of the battery module reaches the high-temperature protection value;

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] A liquid cooling structure and glass balls are arranged at the bottom of the battery module of the present invention. A cold source component is arranged on the outer side of the PACK box. The cold source component and the liquid cooling structure are connected through pipelines to form a refrigeration cycle loop, which is used to actively cool the battery module. The battery module exchanges heat with liquid nitrogen in the liquid cooling structure. The bottoms of several glass balls communicate with the inside of the liquid cooling structure and are used to release liquid nitrogen for fire extinguishing and cooling when a thermal runaway occurs inside the battery, preventing the battery thermal runaway and the rapid accumulation of combustible gases in the cabin from causing the battery to explode and burn; this thermal management system can not only exchange heat and cool down the battery module through the liquid nitrogen in the liquid cooling structure, but also prevent the battery thermal runaway from triggering the glass ball explosion for fire extinguishing, meeting the fire extinguishing requirements of the energy storage cabinet. It can not only effectively control the battery temperature within the normal range of operation, but also quickly carry out fire extinguishing treatment and prevent the spread of fire when the battery has a thermal runaway. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The following drawings only schematically illustrate and explain the present invention and are not used to limit the scope of the present invention, wherein:

[0024] Figure 1 : Schematic structural diagram of the energy storage cabinet of the present invention;

[0025] Figure 2 : Schematic structural diagram of the combined thermal management system for cooling and fire protection of the energy storage cabinet of the present invention;

[0026] In the figure: 1 - PACK box, 2 - battery module, 3 - glass ball, 4 - liquid cooling structure, 5 - proportional electric valve, 6 - outlet electric valve, 7 - gas-liquid separator, 8 - electronic expansion valve, 9 - liquid storage tank, 10 - compressor, 11 - temperature sensor, 12 - condenser, 13 - condenser fan. Detailed implementation manners

[0027] In order to make the purpose, technical solution, design method and advantages of the present utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings through specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0028] As Figure 1 - Figure 2 shown, the present utility model provides a combined thermal management system for energy storage cabinet cooling and fire protection, including a control system and a plurality of battery modules 2 arranged in the PACK box 1.

[0029] A temperature sensor 11 and a liquid cooling component are arranged inside the PACK box 1, and the temperature sensor is connected to the control system;

[0030] The liquid cooling component is located at the bottom of the battery module 2. The liquid cooling component includes a liquid cooling structure 4 and a plurality of glass balls 3. A cold source component is arranged outside the PACK box 1, and the cold source component is connected to the liquid cooling structure 4 through a pipeline for actively cooling the battery module 2 by using the refrigerant transported into the liquid cooling structure. And the glass balls 3 are installed on the surface of the liquid cooling structure 4, and the bottom of the glass balls 3 is communicated with the inside of the liquid cooling structure 4 for releasing the refrigerant for fire extinguishing and cooling when thermal runaway occurs inside the battery;

[0031] A control valve is installed on the pipeline, and the control valve is connected to the control system;

[0032] The temperature sensor 11 monitors the temperature of the battery module 2 in real time. The control system adjusts the opening of the control valve according to the temperature of the battery module 2 to cool the battery module 2. When thermal runaway occurs due to too high temperature of the battery module 2, the glass balls 3 burst, and the refrigerant in the liquid cooling structure 4 sprays out to increase the heat transfer rate and extinguish the fire; It also includes an early warning device, and the control system is connected to the early warning device for the energy storage cabinet body to stop and give an early warning when the battery module temperature reaches the high temperature protection value;

[0033] It should be noted that a liquid cooling structure 4 and glass balls 3 are arranged at the bottom of the battery module 2, and a cold source component is arranged outside the PACK box 1. The cold source component is connected to the liquid cooling structure 4 through a pipeline for actively cooling the battery module 2. The liquid nitrogen in the battery module 2 and the liquid cooling structure 4 exchanges heat, and the bottoms of a plurality of the glass balls 3 are communicated with the inside of the liquid cooling structure 4 for the glass balls 3 to burst and release liquid nitrogen for fire extinguishing and cooling when thermal runaway occurs inside the battery; This thermal management system can not only effectively control the battery temperature to operate within the normal range, but also quickly carry out fire extinguishing treatment and prevent the spread of fire when thermal runaway occurs in the battery.

[0034] Among them, compared with traditional fire extinguishing equipment, nitrogen fire extinguishing has better performance, lower cost and is more environmentally friendly. The thermal runaway of lithium batteries combined with the rapid accumulation of combustible gases in the cabin is the main cause of lithium battery explosion and combustion. The boiling point of liquid nitrogen is extremely low (-196°C), which can quickly absorb the heat of the battery and effectively reduce the battery temperature. Liquid nitrogen is non-conductive and can provide an inerting and explosion-suppressing effect, increasing safety; after liquid nitrogen is discharged, the ambient temperature near the discharge port can drop to -100°C, and the resulting extremely low temperature environment can block the propagation chain of lithium battery thermal runaway, protecting lithium batteries that have not yet experienced thermal runaway, and the low temperature environment will not damage the performance of lithium batteries;

[0035] Furthermore, a plurality of refrigerant flow channels arranged side by side are provided inside the liquid cooling structure 4. The cold source assembly includes a liquid storage tank 9, a compressor 10 and a condenser 12 connected in sequence; the liquid storage tank 9 is communicated with the refrigerant flow channel inlet through an inlet pipeline. The control valve includes a proportional solenoid valve 5 and an outlet electric valve 6. A proportional solenoid valve is provided on the inlet pipeline; the intake end of the compressor 10 is communicated with the outlet of the refrigerant flow channel through an outlet pipeline, and the outlet electric valve 6 is provided on the outlet pipeline. The proportional solenoid valve and the outlet electric valve 6 are respectively connected to the control system;

[0036] The outlet end of the compressor 10 is connected to one end of the condenser 12, and a condenser fan 13 is provided on one side of the condenser 12;

[0037] The other end of the condenser 12 is communicated with the liquid storage tank 9 through a return pipeline.

[0038] It should be noted that the control system adjusts the opening degrees of the proportional solenoid valve 5 and the outlet electric valve 6 according to the temperature of the battery module. The control system is connected to the proportional electric valve 5. The proportional electric valve 5 includes a motor, a reducer and a position feedback sensor. According to the battery temperature, a PID signal of the control system is sent to the proportional electric valve 5. The proportional electric valve 5 receives the signal. A motor, a reducer and a position feedback sensor are arranged in the proportional electric valve 5 to complete corresponding actions and adjust the opening degree of the valve of the proportional electric valve 5; the control system is connected to the outlet electric valve 6. The outlet electric valve 6 includes an electric actuator, which usually consists of a motor, a reducer and a controller. The motor is used as the power source, and the speed is reduced and the torque is increased through the reducer to meet the requirements of valve opening and closing. The controller is responsible for receiving the control signal of the control system and driving the motor to perform corresponding actions. The electric actuator can adjust the opening degree of the valve according to needs to achieve precise flow control;

[0039] Furthermore, a gas-liquid separator 7 is provided at one end of the outlet pipeline close to the compressor 10 to prevent liquid refrigerant from being sucked into the compressor 10;

[0040] It should be noted that the liquid storage tank 9 is connected to the middle of the refrigerant flow channel through an inlet pipe, and a proportional solenoid valve is provided on the inlet pipe; it is used to control the flow of liquid nitrogen; the air inlet end of the compressor 10 is connected to the middle of the refrigerant flow channel through an outlet pipe, and an outlet electric valve 6 is provided at one end of the outlet pipe close to the middle of the refrigerant flow channel to control the discharge of liquid nitrogen; when the battery temperature exceeds the set value, the proportional electric valve 5 will automatically adjust the opening degree according to the PID signal of the control system to maintain the battery temperature between 25℃ and -35℃; the boiling point of liquid nitrogen is extremely low (-196℃), which can quickly absorb the heat of the battery and effectively reduce the battery temperature. Liquid nitrogen is non-conductive and can provide inerting and explosion suppression, increasing safety; liquid nitrogen enters the liquid nitrogen pipeline in the liquid cooling structure 4 after being adjusted by the proportional electric valve 5 through the control system, and the liquid nitrogen becomes gaseous nitrogen after absorbing the heat generated by the battery, so that the temperature of the battery is reduced to the charging and discharging temperature. The gaseous nitrogen is compressed into high-temperature and high-pressure gas by the compressor 10. The high-temperature and high-pressure nitrogen is cooled by the condenser 12 and the fan and condensed into gaseous and liquid nitrogen. The gaseous and liquid nitrogen is converted back into liquid nitrogen after passing through the electronic expansion valve 8 and stored in the liquid storage tank 9. A gas-liquid separator 7 is installed at the air inlet of the compressor 10 to prevent liquid refrigerant from being sucked into the compressor 10.

[0041] Energy storage cabinet cooling and fire protection combined thermal management system with safety monitoring system and fire extinguishing effect;

[0042] The temperature sensor 11 monitors the temperature of the battery module 2 in real time. The control system adjusts the opening of the control valve according to the temperature of the battery module 2 to cool the battery module 2. When the temperature of the battery module 2 is too high and thermal runaway occurs, the glass ball 3 explodes, and the refrigerant in the liquid cooling structure 4 is ejected to increase the heat transfer rate and extinguish the fire. Specifically: the temperature sensor 11 monitors the battery temperature in real time. When the battery temperature reaches the high temperature protection value, the energy storage cabinet will shut down and issue an early warning. If the battery temperature continues to rise and the battery thermal runaway occurs, the glass ball 3 will be triggered to explode and spray liquid nitrogen to increase the heat transfer rate and extinguish the fire; wherein, when a battery thermal runaway occurs, the glass ball 3 closest to the runaway battery will explode and spray liquid nitrogen, and then all the glass balls 3 in the entire battery module will explode and open in sequence to increase the contact area and suffocation space between the liquid nitrogen and the thermal runaway battery. The control system is connected to the proportional electric valve 5, and the proportional electric valve 5 is adjusted to the maximum opening, and the outlet electric valve 6 of the liquid outlet will be completely closed to increase the injection pressure and heat exchange efficiency of the liquid nitrogen. Fire extinguishing effect: Through the efficient cooling and suffocation effect of liquid nitrogen, the system can quickly and effectively suppress the spread of fire and reduce the battery surface temperature to below -100°C, thereby ensuring that the thermal runaway battery will not reignite within 24 hours.

[0043] Therefore, the combined thermal management system for energy storage cabinet cooling and fire protection can not only effectively control the battery temperature within the normal range, but also quickly extinguish the fire and prevent the spread of fire when the battery undergoes thermal runaway.

[0044] Furthermore, the refrigerant flow channel is of a rectangular structure; the refrigeration working medium cools the battery module 2 actively through the refrigerant flow channel of the rectangular structure. A sub-pipe is installed in the middle of the inner side of the refrigerant flow channel, and the sub-pipe is located between the inlet pipe and the outlet pipe. The bottom of the glass sphere 3 is communicated with the sub-pipe of the liquid cooling structure 4; when thermal runaway occurs inside the battery, the glass sphere 3 bursts to release liquid nitrogen through the sub-pipe of the liquid cooling structure 4.

[0045] Furthermore, an electronic expansion valve 8 is also arranged on the return pipeline. The temperature sensing bulb of the electronic expansion valve is arranged at the air inlet end of the compressor 10. The control system is connected to the temperature sensing bulb of the electronic expansion valve and the electronic expansion valve 8, and is used to collect the temperature at the air inlet end of the compressor 10. The control system controls the opening degree of the electronic expansion valve based on the temperature at the air inlet end, and turns the nitrogen in gaseous and liquid states back into liquid nitrogen after passing through the electronic expansion valve and stores it in the liquid storage tank 9.

[0046] Wherein, one end of the inlet pipe close to the liquid cooling structure 4 and one end of the outlet pipe close to the liquid cooling structure 4 are both welded to the liquid cooling structure 4, which can withstand higher system pressure.

[0047] It should be noted that a liquid cooling structure 4 and glass spheres 3 are arranged at the bottom of the battery module 2 of the present application. A cold source assembly is arranged outside the PACK box 1. The cold source assembly and the liquid cooling structure 4 are connected through pipelines to form a refrigeration cycle loop, which is used to cool the battery module 2 by using the refrigeration working medium transported into the liquid cooling structure. The battery module 2 exchanges heat with the liquid nitrogen in the liquid cooling structure 4. The bottoms of several glass spheres 3 are communicated with the inside of the liquid cooling structure 4, and are used to release liquid nitrogen for fire extinguishing and cooling when the glass spheres 3 burst during thermal runaway inside the battery; this thermal management system meets the fire extinguishing requirements of the energy storage cabinet, prevents the battery from thermal runaway and the rapid accumulation of combustible gas in the cabin from causing battery explosion and combustion. It can not only effectively control the battery temperature within the normal range, but also quickly carry out fire extinguishing treatment and prevent the spread of fire when the battery undergoes thermal runaway.

[0048] The embodiments of the present invention have been described above. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles of the embodiments, practical applications or improvements to the technology in the market, or to enable other ordinary technicians in the technical field to understand the disclosed embodiments herein.

Claims

1. A combined thermal management system for energy storage cabinet cooling and fire protection, characterized in that: It includes a control system and several battery modules arranged in a PACK box; A temperature sensor and a liquid cooling assembly are provided inside the PACK box, and the temperature sensor is connected to the control system; The liquid cooling assembly is located at the bottom of the battery module, and the liquid cooling assembly includes a liquid cooling structure and a plurality of glass balls. A cold source assembly is arranged outside the PACK box, and the cold source assembly is connected to the inside of the liquid cooling structure through a pipeline, and is used to actively cool down the battery module by using the refrigerant transported to the liquid cooling structure; the glass balls are installed on the surface of the liquid cooling structure, and the bottom of the glass balls is connected to the inside of the liquid cooling structure, and is used for the glass balls to explode and release the refrigerant to extinguish the fire and cool down when thermal runaway occurs inside the battery; A control valve is installed on the pipeline, and the control valve is connected to the control system; The temperature sensor monitors the battery module temperature in real time, and the control system adjusts the control valve opening according to the battery module temperature to cool the battery module. When the battery module temperature is too high and thermal runaway occurs, the glass ball explodes, and the refrigerant in the liquid cooling structure sprays out to increase the heat transfer rate and extinguish the fire.

2. The energy storage cabinet cooling and fire protection combined thermal management system according to claim 1, characterized in that: The liquid cooling structure is provided with a plurality of refrigerant flow channels arranged side by side, the cold source assembly comprises a compressor, a condenser and a liquid storage tank connected in sequence; the liquid storage tank is communicated with the inlet of the refrigerant flow channel through an inlet pipe, the control valve comprises a proportional solenoid valve and an outlet electric valve, and the proportional solenoid valve is installed on the inlet pipe; the air inlet end of the compressor is communicated with the outlet of the refrigerant flow channel through an outlet pipe, the outlet electric valve is arranged on the outlet pipe, and the proportional solenoid valve and the outlet electric valve are respectively connected to the control system; The air outlet end of the compressor is connected to one end of the condenser, and a condenser fan is provided on one side of the condenser; The other end of the condenser is communicated with the liquid storage tank through a reflux pipeline.

3. The energy storage cabinet cooling and fire protection combined thermal management system according to claim 2, characterized in that: A gas-liquid separator is provided at one end of the outlet pipe close to the compressor to prevent liquid refrigerant from being sucked into the compressor.

4. The energy storage cabinet cooling and fire protection combined thermal management system according to claim 2, characterized in that: The refrigerant flow channel is a rectangular structure.

5. The energy storage cabinet cooling and fire protection combined thermal management system according to claim 4, characterized in that: A sub-pipeline is installed in the middle of the inner side of the refrigerant flow channel, and the bottom of the glass ball is connected to the sub-pipeline.

6. The energy storage cabinet cooling and fire protection combined thermal management system according to claim 2, characterized in that: An electronic expansion valve is also provided on the return pipeline. The temperature sensing package of the electronic expansion valve is provided at the air inlet end of the compressor. The control system is connected to the temperature sensing package of the electronic expansion valve and the electronic expansion valve for collecting the air inlet end temperature of the compressor. The control system controls the opening of the electronic expansion valve based on the air inlet end temperature.

7. The energy storage cabinet cooling and fire protection combined thermal management system according to claim 2, characterized in that: It also includes an early warning device, and the control system is connected to the early warning device, which is used to shut down the energy storage cabinet and issue an early warning when the temperature of the battery module reaches a high temperature protection value.

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