Energy storage battery immersed cooling experiment platform and temperature feedback control method

Abstract

The invention belongs to the technical field of energy storage batteries, and discloses an energy storage battery immersed cooling experiment platform and a temperature feedback control method, and the method comprises the steps: after a stable circulation cooling loop is formed, a PLC (Programmable Logic Controller) controls the rotating speed of a gear pump to obtain a normal cooling flow Qn; the normal cooling flow Qn is kept to be executed, and a normal working circulation cooling loop is formed; the data collector collects the flow, the temperature of the center point of the battery, the temperature of the cooling medium in the immersion container and the pressure in the immersion container in real time and conducts cooling medium temperature feedback partition control based on a preset temperature feedback partition control algorithm according to the real-time temperature of the energy storage battery. The core defects that in the prior art, an existing air cooling / cold plate liquid cooling / direct cooling technology is poor in temperature uniformity, a flowing dead zone exists in an immersed technology, and temperature and heat dissipation integrated utilization is insufficient are effectively overcome.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of energy storage batteries, and particularly relates to an energy storage battery immersion cooling experimental platform and a temperature feedback control method. BACKGROUND

[0002] Lithium iron phosphate batteries (LiFePO4, LFP) are widely used in energy storage power stations due to their long life, high temperature stability, fast charging speed and cost advantage, and are developing towards large capacity. However, the increase in battery volume and capacity exacerbates the problem of internal temperature non-uniformity. The cycle performance and safety of the battery are highly dependent on the temperature, and the optimal working temperature range is 15℃-35℃. Too low temperature will cause the ion migration rate to decrease, causing capacity attenuation and efficiency reduction; too high temperature is prone to trigger thermal runaway risk. Precise temperature control can optimize battery performance, expand application scenarios, and maximize battery aging delay and safety improvement.

[0003] The main challenges currently faced by energy storage battery thermal management applications include: high heat dissipation per unit volume of large energy storage square cell; high-density deployment of batteries in limited space in prefabricated cabins leads to difficulty in temperature uniformity control. The existing air cooling technology has insufficient cooling efficiency; although liquid cooling and direct cooling technology can achieve local rapid cooling, there are still local hot spot problems. Therefore, it is urgent to develop a high-efficiency uniform temperature, safety-oriented thermal management method and control method suitable for large-capacity, large-volume energy storage batteries.

[0004] Compared with power batteries, energy storage battery monomers have larger capacity and significantly increased volume. The existing mainstream thermal management technologies (air cooling, cold plate liquid cooling, and cold plate phase change direct cooling) are limited by the effective contact area between the battery and the cold source, and can only achieve local uniformity. At the same time, the axial and radial dimensions of the battery internal winding core are large, causing heat transfer delay and forming local high-temperature areas.

[0005] Although the immersion thermal management technology has potential, current applications still have limitations: the internal cooling medium flow may be limited, causing local thermal flow imbalance between batteries (hot spot problem). In addition, the existing immersion scheme fails to fully utilize its comprehensive advantages of "temperature and fire suppression integration", i.e., simultaneously achieving efficient temperature control and thermal runaway suppression and fire suppression functions.

[0006] Therefore, there is an urgent need to develop a new immersion thermal management platform and its control algorithm to solve the temperature uniformity and safety problems of large-capacity, large-volume energy storage batteries. SUMMARY

[0007] To overcome the problems in the related art, the present application discloses an immersion thermal management platform and a temperature feedback control method, specifically an energy storage battery immersion cooling experimental platform and a temperature feedback control method.

[0008] The technical solution is as follows: a temperature feedback control method of an immersion heat management platform, the method comprising: S1, injecting an immersion cooling medium into a high-low temperature water tank, and obtaining a constant temperature cooling medium at a normal temperature of 25 DEG C; S2, the constant temperature cooling medium flows into a plate heat exchanger through a low temperature inlet, flows out through a low temperature outlet and enters a gear pump, and a PLC programmable controller controls the rotating speed of the gear pump to obtain an initial flow Q 0; S3, the constant temperature cooling medium is transported through the gear pump and a gear flowmeter, and the initial flow Q 0 is set in advance and enters the immersion container through a pressure transmitter and an opened inlet ball valve; S4, the outlet ball valve is in a closed state, and when the cooling medium height in the immersion container exceeds the energy storage battery height, the outlet ball valve is opened; the charging and discharging machine is opened and charging and discharging working conditions are carried out; S5, the cooling medium flows through the outlet ball valve, enters the plate heat exchanger through a pipeline, and flows out through a hot outlet after heat dissipation through the plate heat exchanger, and flows back to the high-low temperature water tank through a high-low temperature water tank inlet, to form a circulating cooling loop; S6, after the stable circulating cooling loop is formed, the PLC programmable controller controls the rotating speed of the gear pump to obtain a normal cooling flow Q n ; S7, the normal cooling flow Q n is maintained, and a normal working circulating cooling loop is formed; a data collector collects flow, battery center point temperature, immersion container cooling medium temperature and immersion container pressure in real time, and carries out cooling medium temperature feedback partition control according to the real-time temperature of the energy storage battery and by using a preset temperature feedback partition control algorithm.

[0009] In step S7, the cooling medium temperature feedback partition control by using the preset temperature feedback partition control algorithm comprises: the battery temperature obtained by a temperature sensor T cell and the immersion container cooling medium temperature obtained by a PT100 temperature sensor T coolant are collected in real time by the data collector; the PLC programmable controller is used to collect temperature sensor signals and PT100 temperature sensor signals in real time and to process and obtain a battery target control temperature difference Δ T ; If the energy storage battery temperature T cell <15 DEG C and the immersion container cooling medium temperature T coolant ≥25 DEG C, the battery target control temperature difference Δ TReal-time flow adjustment is performed to complete low-temperature preheating; If the energy storage battery temperature is 15℃ ≤ T cell <35℃, the gear pump speed and the cooling liquid flow are adjusted to complete normal-temperature uniform heating; If the energy storage battery temperature is 35℃ ≤ T cell <100℃, the gradient pressurization mode of the gear pump is started to complete high-temperature cooling; If the energy storage battery temperature is T cell ≥ 100℃ or the pressure change rate of the immersion container is dp / dt > 50 kPa / s, the cooling liquid flow executes the locked flow Q h,max to complete the thermal runaway suppression.

[0010] In the low-temperature preheating, the high-low temperature water tank heats the cooling liquid to 30℃, and the cooling flow executes the normal cooling flow Q n , and the flow real-time adjustment is performed according to the energy storage battery target control temperature difference Δ T ; the execution speed is 1000 rpm, and the initial flow is Q n 0.66 L / min; If the temperature of the cooling medium in the immersion container is T coolant <25℃, the cooling flow executes the medium cooling flow Q m , the execution speed is 2000 rpm, and the medium cooling flow is Q m 1.32 L / min.

[0011] In the normal-temperature uniform heating, the high-low temperature water tank maintains the normal temperature of 25℃; if the energy storage battery target control temperature difference Δ T <1℃, the execution speed is 500 rpm, and the small cooling flow is Q s 0.33 L / min; If the energy storage battery target control temperature difference is 1℃ ≤ Δ T <2℃, the execution speed is 2000 rpm, and the medium cooling flow is Q m 1.32 L / min; If the battery target control temperature difference Δ T ≥ 2℃, the execution speed is 4000 rpm, and the large cooling flow is Q h 2.64 L / min.

[0012] In the high-temperature cooling process, the temperature of the high and low temperature water tank is controlled at 20°C, and the gradient pressure boosting mode of the gear pump is started: Q gradient Q m α ·( T cell -35) 2 , wherein α is the gain coefficient of flow regulation, α =0.1 L / min·℃ 2 ; Q gradient is the output flow after gradient pressure boosting, Q m is the medium cooling flow, T cell is the battery temperature; If the temperature of the cooling medium in the immersion container is T c >35°C, trigger pulse jet, pulse jet is 10 seconds Q h plus 10 seconds Q s cycle; In the heat runaway suppression process, the cooling medium in the high and low temperature water tank is rapidly cooled to 5°C, and the cooling flow is executed as a locked flow Q h,max , the rotation speed is 6000 rpm, and the locked flow Q h,max is 3.96 L / min; auxiliary use high and low temperature water tank configuration liquid nitrogen injection interface / system or perfluorohexone injection interface / system, heat runaway suppression.

[0013] The target cooling medium corrected flow includes: Q corrector = K p · Δ T + K i · ∫ Δ T dt + K d · d (Δ T ) / dt; , wherein: Δ T is the temperature difference between the battery temperature and the target control temperature, Δ T = T cell - T target ; T target is the target control temperature of the energy storage battery, Q ​​corrector a target cooling medium correction flow rate, K p a proportional term coefficient, K i an integral term coefficient, K d a differential term coefficient, t a time.

[0014] Another object of the present application is to provide an immersion heat management platform, which comprises a high-low temperature water tank, the high-low temperature water tank outlet is connected with a standard pagoda interface, and is connected with a plate heat exchanger low temperature inlet through a two-part standard specification pipeline; The cooling medium flows through the plate heat exchanger through a low temperature outlet, and the low temperature outlet is connected with a gear pump inlet through a pipeline; the fluid flows out through an outlet after working through the gear pump, flows into a gear flowmeter inlet through a fluid pipeline, flows out through a gear flowmeter outlet, passes through a pressure transmitter, and flows into an immersion container through an inlet ball valve; an energy storage battery is placed in the immersion container, and the cooling medium in the immersion container flows through an outlet ball valve through a pipeline; the cooling medium further flows into a plate heat exchanger high temperature inlet through a pipeline, flows through the plate heat exchanger through a high temperature outlet, and returns to the high-low temperature water tank through a high-low temperature water tank inlet.

[0015] The high-low temperature water tank is provided with a liquid nitrogen injection interface / system and a perfluorohexanone injection interface / system; A plurality of temperature sensors of the same specification are distributed at positive and negative electrode tabs of the energy storage battery and centers of large faces of the energy storage battery, and are used to collect temperatures of the positive and negative electrodes and centers of the two large faces of the energy storage battery; The PT100 temperature sensor measures the temperature of the cooling medium in the immersion container; The charge-discharge machine is used to simulate different working conditions of charging and discharging of the energy storage battery; The data collector is connected with the gear flowmeter signal, the pressure transmitter signal, the temperature sensor signal, the pressure sensor signal and the PT100 temperature sensor through an electric circuit to collect electric signals; The PLC programmable controller is used to obtain the temperature sensor signal and the PT100 temperature sensor signal in real time, and is based on a preset energy storage battery temperature, an energy storage battery target control temperature difference and an immersion container cooling medium temperature feedback partition control algorithm, and is used to control the temperature of the high-low temperature water tank and the rotating speed of the gear pump through temperature feedback, so as to obtain the best cooling medium temperature and flow rate.

[0016] The immersion container comprises a container main body, a rubber sealing ring and a container end cover; A third standard two-part threaded hole in the container main body is a cooling medium inlet and a first standard two-part threaded hole cooling medium outlet, which constitute a first cooling loop; The second standard two-part thread hole in the container body is a cooling medium inlet, and the fourth standard two-part thread hole is a cooling medium outlet, which can form a second cooling loop; The first standard three-part thread hole in the container body is a cooling medium inlet, and the third standard three-part thread hole is a cooling medium outlet, which can form a third cooling loop; The fourth standard three-part thread hole in the container body is a cooling medium inlet, and the second standard three-part thread hole is a cooling medium outlet, which forms a fourth cooling loop.

[0017] The PLC programmable controller is based on a preset energy storage battery temperature, an energy storage battery target control temperature difference, and a submerged container cooling medium temperature feedback partition control algorithm, which is used for temperature feedback control of high and low temperature water tank temperature and gear pump speed, obtains the best cooling medium temperature and flow, and further performs intelligent switching of the cooling loop, including: The first cooling loop and the second cooling loop are used in parallel, periodically pass through the inlet ball valve and the outlet ball valve to realize the conduction of the first cooling loop and the closing of the second cooling loop; or the conduction of the second cooling loop and the closing of the first cooling loop; for cooling medium to enter the interior of the submerged container in a horizontal or vertical direction and flow out, the third cooling loop and the fourth cooling loop are used in parallel, periodically pass through the inlet ball valve and the outlet ball valve to realize the conduction of the third cooling loop and the closing of the fourth cooling loop; or the conduction of the fourth cooling loop and the closing of the third cooling loop; to realize the horizontal or vertical entry of the cooling medium into the interior of the submerged container and flow out.

[0018] In combination with all the above technical solutions, the application has the following beneficial effects: First, efficient uniform temperature: through the unique multi-inlet / multi-outlet design of the submerged container and the switchable horizontal / vertical cooling loop, the flow distribution of the cooling medium in the container is significantly improved, the low-flow area (dead zone) is effectively eliminated, and the temperature uniformity of the large energy storage battery is greatly improved.

[0019] The temperature feedback partition control method proposed by the intelligent partition control realizes real-time dynamic adjustment of the cooling medium flow and temperature according to the battery temperature difference and the medium temperature, and the partition function realizes: Low-temperature preheating: avoids performance degradation of the battery at low temperature.

[0020] Normal temperature uniformity: maintains stable and efficient operation in the best working temperature zone.

[0021] High-temperature cooling: quickly suppresses temperature rise and prevents heat accumulation.

[0022] Thermal runaway suppression: provides powerful cooling at extremely high temperatures and has a fire suppression function.

[0023] Temperature and fire suppression integration: integrates efficient thermal management and thermal runaway suppression functions on the immersion cooling platform, and fully utilizes the comprehensive advantages of immersion cooling.

[0024] Flexible: Different pipe diameter cooling circuit design, facilitate the study of pipe specifications on system performance, provide design basis for practical engineering application.

[0025] Second, the application first designs a multi-loop dynamic flow field technology, through 4 groups of switchable cooling circuit (lateral / longitudinal flow + different pipe diameter), simply but effectively solves the flow dead zone problem of immersion cooling. The heat management and heat runaway suppression (liquid nitrogen / full fluorine ketone injection) are integrated in the same platform, the four-section control strategy (preheating / temperature equalization / cooling / heat runaway) and gradient supercharging method are proposed, and the adaptive control framework is provided. BRIEF DESCRIPTION OF DRAWINGS

[0026] The drawings incorporated into the specification and forming a part thereof, show embodiments consistent with the present disclosure, and together with the specification serve to explain the principles of the present disclosure; Figure 1 is the structure diagram of the immersion heat management platform provided by the embodiment of the application; Figure 2 is a schematic diagram of an immersion container provided by the embodiment of the application; Figure 3 is a schematic diagram of a container body provided by the embodiment of the application; Figure 4 is a schematic diagram of the position of the fourth standard two-part threaded hole in the container body provided by the embodiment of the application; Figure 5 is a container end cover diagram provided by the embodiment of the application; Figure 6 is a flow chart of the immersion heat management platform and temperature feedback control method provided by the embodiment of the application; Figure 7 is a dynamic process diagram of the immersion flow adaptive regulation of the cooling medium flow provided by the application; In the figure: 1, high and low temperature water tank; 2, plate heat exchanger; 3, gear pump; 4, gear flowmeter; 5, pressure transmitter; 6, inlet ball valve; 7, immersion container; 100, container body; 101, first standard hole; 102, second standard hole; 103, third standard hole; 104, fourth standard hole; 105, fifth standard hole; 106, sixth standard hole; 107, sealing ring groove; 108, first standard two-part threaded hole; 109, first standard three-part threaded hole; 110, second standard three-part threaded hole; 111, second standard two-part threaded hole; 112, third standard three-part threaded hole; 113, third standard two-part threaded hole; 114, fourth standard three-part threaded hole; 115, fourth standard two-part threaded hole; 200, rubber sealing ring; 300, container end cover; 301, first end cover standard hole; 302, second end cover standard hole; 303, third end cover standard hole; 304, fourth end cover standard hole; 305, fifth end cover standard hole; 306, sixth end cover standard hole; 307, end cover sealing ring groove; 308, first end cover standard two-part threaded hole; 309, second end cover standard two-part threaded hole; 310, third end cover standard two-part threaded hole; 311, fourth end cover standard two-part threaded hole; 312, end cover intermediate hole; 313, standard M20 threaded hole; 8, energy storage battery; 9, temperature sensor; 10, pressure sensor; 11, outlet ball valve; 12, PT100 temperature sensor; 13, charge and discharge machine; 14, data acquisition device; 15, PLC programmable controller. DETAILED DESCRIPTION

[0027] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below. In the following description, a large number of specific details are set forth in order to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the spirit of the present application, so the present application is not limited to the specific implementation disclosed below.

[0028] In view of the core problems of high heat dissipation per unit volume of large energy storage battery monomer and poor temperature uniformity caused by high-density deployment of batteries in limited space of prefabricated cabin, the innovation of the present application lies in: the present application proposes an immersion type heat management platform and a temperature feedback control method. Four groups of switchable cooling circuit structures are designed, the flow dead zone is completely eliminated by periodically switching the horizontal / vertical flow field, and full spatial domain uniform temperature is realized. Based on the temperature partition control algorithm (low temperature preheating / normal temperature uniformity / high temperature gradient pressurization + pulse injection mechanism / thermal runaway quenching), dynamic flow regulation and cooling medium temperature self-adaptive control are adopted to realize full temperature domain response. The integrated "temperature elimination" function (heat management + liquid nitrogen / full fluorohexone injection system) synchronously solves the long-existing problems of poor temperature uniformity, delayed safety response and low energy efficiency in the field of energy storage, and meets the heat management and safety requirements of large energy storage power station.

[0029] The present application innovatively proposes the following structure: Multi-circuit switchable design: at least two groups (such as 1 / 2 circuit and 3 / 4 circuit) of independent inlet and outlet pairs, and the cooling medium can flow horizontally or vertically by valve switching. This is the core hardware innovation to solve the flow dead zone and improve the uniformity.

[0030] Different pipe diameter design: including at least two pipe diameter specifications (such as 2-part pipe and 3-part pipe circuit), which is convenient for research and optimization, and has practicality and value.

[0031] The bottom surface is flush with the inlet: it is conducive to the complete emptying of the medium and is a practical detail design.

[0032] The present invention innovatively proposes: Temperature Zoning + Dual-Parameter Feedback: The battery temperature is divided into four key zones (low temperature, normal temperature, high temperature, and thermal runaway). The target battery temperature difference and the temperature of the cooling medium in the container are combined to coordinately and independently adjust two core control variables: the cooling medium temperature (set by the water tank) and the cooling medium flow rate (controlled by the pump speed). This dual-temperature parameter, zoned, coordinated control logic is significantly innovative.

[0033] Multifunctional integration: A set of control logic realizes four functions: low-temperature preheating, normal temperature equalization, high-temperature cooling, and thermal runaway suppression. In particular, the use of powerful cooling as a fire-fighting method to suppress thermal runaway embodies the design concept of "temperature and fire suppression in one".

[0034] Example 1, as Figure 1 As shown, the immersion thermal management platform provided by the embodiment of the present invention includes a high and low temperature water tank 1, a plate heat exchanger 2, a gear pump 3, a gear flowmeter 4, a pressure transmitter 5, an inlet ball valve 6, an immersion container 7, an energy storage battery 8, a temperature sensor 9, a pressure sensor 10, an outlet ball valve 11, a PT100 temperature sensor 12, a charger and discharger 13, a data collector 14, and a PLC programmable controller 15. Figure 1 The dashed line represents the pipeline connection, and the double-dotted line represents the circuit connection.

[0035] The outlet of the high and low temperature water tank 1 can be connected to a standard pagoda interface and connected to the low temperature inlet of the plate heat exchanger 2 through a two-way or other standard specification pipeline.

[0036] The plate heat exchanger 2 includes two inlets, namely a low-temperature inlet and a high-temperature inlet, and two outlets, namely a low-temperature outlet and a high-temperature outlet. The cooling medium flows through the plate heat exchanger 2 through the low-temperature outlet, which is connected to the inlet of the gear pump 3 by a pipeline. After the gear pump 3 performs work, the fluid flows out through the outlet, flows through the fluid pipeline, enters the inlet of the gear flowmeter 4, flows out through the outlet of the gear flowmeter 4, passes through the pressure transmitter 5, flows through the inlet ball valve 6, and enters the immersion container 7. The energy storage battery 8 is placed inside the immersion container 7, and the cooling medium in the immersion container 7 flows through the outlet ball valve 11 through the pipeline. It further enters the high-temperature inlet of the plate heat exchanger 2 through the pipeline, flows through the plate heat exchanger 2 through the high-temperature outlet, and returns to the high- and low-temperature water tank 1 through the inlet of the high- and low-temperature water tank 1.

[0037] The high and low temperature water tank 1 is equipped with a liquid nitrogen injection interface / system and a perfluorohexanone injection interface / system.

[0038] Four temperature sensors 9 of the same specification are distributed at the positive and negative tabs of the energy storage battery 8 and the center of the large face of the energy storage battery 8, for collecting the temperatures of the positive and negative tabs and the center of the large face of the energy storage battery 8.

[0039] The PT100 temperature sensor 12 can measure the temperature of the cooling medium inside the immersion container 7.

[0040] The charge and discharge machine 13 is used to simulate different working conditions of the energy storage battery 8 such as charging and discharging.

[0041] The data collector 14 is connected with the gear flowmeter 4, the pressure transmitter 5, the temperature sensor 9, the pressure sensor 10 and the PT100 temperature sensor 12 to collect electrical signals.

[0042] The PLC programmable controller 15 is mainly used to obtain the signals of the temperature sensor 9 and the PT100 temperature sensor 12 in real time, and based on the preset temperature of the energy storage battery 8, the target control temperature difference of the energy storage battery 8 and the temperature feedback partition control algorithm of the cooling medium inside the immersion container 7, the temperature feedback control high and low temperature tank 1 temperature and the gear pump 3 speed are used to obtain the best cooling medium temperature and flow, so as to obtain the best cooling effect.

[0043] As shown in Figure 2 , the immersion container 7 includes a container body 100, a rubber sealing ring 200 and a container end cover 300.

[0044] The container body 100, as shown in Figure 3 , Figure 4 , mainly includes a first standard hole 101, a second standard hole 102, a third standard hole 103, a fourth standard hole 104, a fifth standard hole 105, a sixth standard hole 106, a sealing ring groove body 107, a first standard two-part threaded hole 108, a second standard two-part threaded hole 111, a third standard two-part threaded hole 113, a fourth standard two-part threaded hole 115, a first standard three-part threaded hole 109, a second standard three-part threaded hole 110, a third standard three-part threaded hole 112 and a fourth standard three-part threaded hole 114.

[0045] The third standard two-part threaded hole 113 is a fluid inlet and the first standard two-part threaded hole 108 is a fluid outlet, which can form a first cooling circuit. The second standard two-part threaded hole 111 is a fluid inlet and the fourth standard two-part threaded hole 115 is a fluid outlet, which can form a second cooling circuit. The first standard three-part threaded hole 109 is a fluid inlet and the third standard three-part threaded hole 112 is a fluid outlet, which can form a third cooling circuit. The fourth standard three-equal thread hole 114 is a fluid inlet, and the second standard three-equal thread hole 110 is a fluid outlet, which can form a fourth cooling circuit.

[0046] The first cooling circuit and the second cooling circuit can be used in parallel, and the first circuit is turned on and the second circuit is turned off, or the second circuit is turned on and the first circuit is turned off, by the inlet ball valve 6 and the outlet ball valve 11, so that the cooling medium enters the immersion container horizontally or vertically and flows out, reduces the flow dead zone of the cooling medium, and promotes the circulation of the fluid in the immersion container.

[0047] Similarly, the third cooling circuit and the fourth cooling circuit can be used in parallel, and the third circuit is turned on and the fourth circuit is turned off, or the fourth circuit is turned on and the third circuit is turned off, by the inlet ball valve 6 and the outlet ball valve 11, so that the cooling medium enters the immersion container horizontally or vertically and flows out.

[0048] The main difference between the first cooling circuit, the second cooling circuit, the third cooling circuit, and the fourth cooling circuit is that the connection pipeline is different in thickness, which can be used for the influence of different inlet and outlet pipelines on the heat management system.

[0049] The fluid inlet first standard three-equal thread hole 109, the second standard two-equal thread hole 111, the third standard two-equal thread hole 113, and the fourth standard three-equal thread hole 114 are characterized in that the lower edge is combined with the bottom of the inner surface of the immersion container 7, so that the medium in the immersion container 7 is completely discharged by relying on the liquid level difference during replacement of the cooling medium or maintenance and other working conditions.

[0050] The container end cover 300 is shown in Figure 5 The container end cover 300 is shown in

[0051] The container main body 100 and the rubber sealing ring 200 are fixedly connected by the sealing ring groove 107 in a glue bonding manner.

[0052] The container main body 100 and the container end cover 300 are fixedly connected by six standard bolts through the first standard hole 101, the second standard hole 102, the third standard hole 103, the fourth standard hole 104, the fifth standard hole 105, the sixth standard hole 106, and the first end cover standard hole 301, the second end cover standard hole 302, the third end cover standard hole 303, the fourth end cover standard hole 304, the fifth end cover standard hole 305, and the sixth end cover standard hole 306.

[0053] The container body 100 is sealed with the container end cover 300 by a rubber sealing ring 200.

[0054] The first end cover standard two-part threaded hole 308, the second end cover standard two-part threaded hole 309, the third end cover standard two-part threaded hole 310, and the fourth end cover standard two-part threaded hole 311 on the container end cover 300 can be connected to a pressure sensor 10 or a temperature sensor 9, an outlet ball valve 11, and other devices according to actual needs.

[0055] The M20 threaded hole 313 is used to connect a Luer lock for leading out the line in the immersion container 7 to the charge-discharge machine 13 and the data collector 14.

[0056] Embodiment 2, as shown in the figure, the temperature feedback control method of the immersion heat management platform provided by the embodiment of the application comprises: Figure 6 S1, inject the immersion cooling medium into the high-low temperature water tank 1, and obtain the constant-temperature cooling medium at room temperature 25℃.

[0057] S2, the constant-temperature cooling medium flows in through the low-temperature inlet of the plate heat exchanger 2, flows out through the low-temperature outlet and enters the gear pump 3, and the PLC programmable controller 15 controls the rotating speed of the gear pump 3 to obtain the initial flow rate Q 0.

[0058] S3, the constant-temperature cooling medium is transported through the gear pump 3, passes through the gear flowmeter 4, and enters the immersion container 7 through the pressure transmitter 5 and the opened inlet ball valve 6 according to the pre-set initial flow rate Q 0.

[0059] S4, the outlet ball valve 11 is in a closed state, and when the cooling medium height in the immersion container 7 exceeds the battery height, the outlet ball valve 11 is opened. At this time, the charge-discharge machine 13 is opened and the charge-discharge working condition is carried out.

[0060] S5, the cooling medium flows through the outlet ball valve 11, enters the plate heat exchanger 2 through the pipeline, and flows back to the high-low temperature water tank through the high-low temperature water tank 1 inlet after the cooling medium is cooled by the plate heat exchanger 2 and flows out through the hot outlet, forming a circulating cooling loop.

[0061] S6, after the stable circulating cooling loop is formed, the PLC programmable controller 15 controls the rotating speed of the gear pump 3 to obtain the normal cooling flow rate Q n .

[0062] S7, the normal cooling flow rate is maintained Q n ​, forming a normal working cycle cooling circuit; the data collector 14 collects the flow rate, the battery center point temperature, the temperature of the cooling medium in the immersion container, and the pressure in the immersion container in real time, and according to the real-time temperature of the energy storage battery 8, uses a preset temperature feedback partition control algorithm to perform cooling medium temperature feedback partition control.

[0063] In step S7, the data collector 14 collects the flow rate, the battery center point temperature, the temperature of the cooling medium in the immersion container, and the pressure in the immersion container in real time, and according to the real-time temperature of the energy storage battery 8, uses a preset temperature feedback partition control algorithm to perform cooling medium temperature feedback partition control, including: In the preparation stage of the circulating cooling circuit, a constant temperature cooling medium is obtained at room temperature 25℃, and the flow rate of the gear pump 3 in the preparation stage is prepared at a preparation flow rate Q 0, and in this example, the preparation flow rate is executed at a speed of 3000 rpm Q 0 is 1.98 L / min. If the height of the immersion container is greater than the height of the battery, the outlet ball valve 11 is opened, and the PLC programmable controller 15 controls to a normal cooling flow rate Q n , and in this example, the normal cooling flow rate is executed at a speed of 1000 rpm Q n is 0.66 L / min; otherwise, the preparation flow rate is continued to be executed Q 0, and the outlet ball valve 11 remains closed.

[0064] The data collector 14 collects the battery temperature obtained by the temperature sensor 9 in real time T cell and the temperature of the cooling medium in the container obtained by the PT100 temperature sensor 12 T coolant . The PLC programmable controller 15 is used to collect the signals of the temperature sensor 9 and the PT100 temperature sensor 12 in real time, and process to obtain the battery target control temperature difference Δ T .

[0065] If the temperature of the energy storage battery is T cell <15℃ and the temperature of the cooling medium in the container is T coolant ≥25℃, the high and low temperature water tank 1 heats the cooling liquid to 30℃, and the cooling flow rate is executed at a normal cooling flow rate Q n , and in this example, the initial flow rate is executed at a speed of 1000 rpm Q n is 0.66 L / min, and the flow rate is adjusted in real time in combination with the battery target control temperature difference Δ T ; if the temperature of the cooling medium in the immersion container is T coolant<25℃, cooling flow executing medium cooling flow Q m , this example is to execute the speed 2000 rpm, medium cooling flow Q m 1.32 L / min, and combined with the battery target control temperature difference Δ T Flow real-time adjustment. Realize low temperature preheating function.

[0066] If the energy storage battery temperature 15℃ ≤ T cell <35℃, the high and low temperature water tank keeps normal temperature 25℃. If the battery target control temperature difference Δ T <1℃, execute the speed 500 rpm, small cooling flow Q s 0.33 L / min. If the energy storage battery target control temperature difference 1℃ ≤ Δ T <2℃, execute the speed 2000 rpm, medium cooling flow Q m 1.32 L / min. If the energy storage battery target control temperature difference Δ T ≥2℃, execute the speed 4000 rpm, large cooling flow Q h 2.64 L / min. Realize normal temperature equalization function.

[0067] If the energy storage battery temperature 35℃ ≤ T cell <100℃, the high and low temperature water tank control temperature is 20℃, start gradient boost mode: Q gradient = Q m + α ·( T cell -35) 2 , wherein α is the gain coefficient of flow adjustment ( α =0.1 L / min·℃ 2 ), which reflects the nonlinear growth demand of cooling intensity, that is, when the battery temperature exceeds 35℃, the cooling capacity required to increase by 1℃ is nonlinear. Q gradient is the output flow after gradient boost, Q m is the medium cooling flow, T cell is the battery temperature; if the container cooling medium temperature T c >35℃, trigger pulse jet (10s Qh +10s Q s Cycling). Realize high-temperature cooling function.

[0068] If the energy storage battery temperature T cell ≥ 100℃ or the pressure change rate in the immersion container dp / dt > 50 kPa / s, the cooling medium in the water tank is rapidly cooled to 5℃ (optionally liquid nitrogen is injected in the water tank to assist cooling), and the cooling flow executes a locked flow Q h,max , this example is to execute a rotational speed of 6000 rpm, and the locked flow Q h,max is 3.96 L / min. In addition, the liquid nitrogen injection interface / system or perfluorohexone injection interface / system configured by the high-low temperature water tank 1 is used to realize the thermal runaway suppression function.

[0069] Another example, the preset temperature feedback partition control algorithm includes: First, data acquisition and pretreatment.

[0070] Sampling frequency: synchronously collect the following data every 1s: (1) Battery temperature (T T cell ): 4 temperature sensor matrix data (2×2 grid distribution), take the weighted average value (battery large surface center point weight 0.35, battery positive and negative electrode edge point weight 0.15).

[0071] (2) Cooling medium temperature (T T c ): 12-PT100 sensor data, combined with historical 10s data to do exponential moving average (Exponential Moving Average) filtering.

[0072] (3) Pressure data (P p ): Real-time monitoring of the pressure change rate in the immersion container (P dp / dt ), auxiliary for predicting thermal runaway risk.

[0073] Second, the partition state machine and the multi-level temperature partition control strategy; Control core formula: Flow regulation: Q corrector = K p · Δ T + K i · ∫ ΔT dt + K d · d (Δ T ) / dt; Where: Δ T is the temperature difference between the battery temperature and the target control temperature, Δ T = T cell - T target ; T target To control the temperature of the energy storage battery target, Q corrector is the corrected flow rate of the target cooling medium, K p is the proportional term coefficient, K i is the integral term coefficient, K d is the differential term coefficient, t For time.

[0074] Multi-level temperature partition control strategy, PID parameters are dynamically adjusted with the partition; specifically: (1) Low temperature preheating: Control conditions: T cell <15℃ and T coolant ≥25℃, T coolant If the cooling medium temperature is the same, the action is executed: the water tank is heated to 30℃ (heating rate 2℃ / min) and the flow rate is Q n (Speed n n )+ Q corrector (PID fine-tuning K p =0.8, K i =0.05); Control conditions: T cell <15℃ and T coolant <25℃, then execute the action: the water tank is heated to 30℃ (heating rate 2℃ / min) and the flow rate Q m (Speed n m )+ Q corrector (PID fine-tuning K p =0.8, K i =0.05).

[0075] (2) Normal temperature equalization: Control condition: 15 °C ≤ T cell <35 °C, Action: Water bath constant temperature 25 °C, dynamic flow grading; when Δ T <1 °C: Q s (rpm n s ), when 1 °C ≤ Δ T <2 °C: Q m (rpm n m ), when Δ T ≥ 2 °C: Q h (rpm n h ).

[0076] (3) High temperature cooling: Control condition: T cell ≥ 35 °C, Action: Water bath cooling to 20 °C (cooling rate 3 °C / min), start gradient pressurization mode: Q gradient = Q m + g ·( T cell - 35) 2 , in which, g is the gain coefficient of flow regulation ( g = 0.1 L / min·°C 2 ); if T c > 35 °C, trigger pulse jet (10 s Q h + 10 s Q s cycle).

[0077] (4) Thermal runaway suppression: Control condition: T cell ≥ 100 °C or dp / dt > 50 kPa / s, Action: Water bath rapid cooling to 5 °C (optionally inject liquid nitrogen in water bath for auxiliary cooling), flow lock Q h,max (rpm n h,max ), inject flame retardant additives.

[0078] where, T coolant is the temperature of the cooling medium in the immersion container obtained by the 12-PT100 temperature sensor,Q is the flow rate of gear pump 3 (L / min), Q 0 is the preparation flow rate (L / min), Q n is the normal cooling flow rate (L / min), Q s is the minimum cooling flow rate (L / min), Q m For medium cooling flow (L / min), Q h For maximum cooling flow (L / min), Q h,max To lock the flow rate (L / min), n n Gear pump speed (rpm) for normal cooling flow, n s is the speed of the gear pump with small cooling flow (rpm), n m For medium cooling flow gear pump speed (rpm), n h is the maximum cooling flow gear pump speed (rpm), n h,max The gear pump speed (rpm) for the lock flow.

[0079] The flow rate of gear pump 3 is determined by its own mechanical structure parameters and speed: Q = K * D *2 m * B * n *10 -6； in, K It is the correction coefficient, which is generally 1.05~1.15 and needs to be corrected according to the actual gear pump; D is the pitch circle diameter (mm); m is the module (mm); B is the tooth width (mm); n is the rotation speed (rpm).

[0080] In this embodiment, the flow rate and speed of the gear pump 3 satisfy: Q =6.6×10 -4 * n ,in n is the rotation speed (rpm).

[0081] In another exemplary embodiment, after executing the partition state machine and the multi-level temperature partition control strategy, intelligent switching of the cooling circuit is required; During the example execution, the first cooling circuit and the second cooling circuit can be used in parallel, and the first cooling circuit can be turned on and the second cooling circuit can be turned off periodically (for example, every minute) through the inlet ball valve 6 and the outlet ball valve 11; or the second cooling circuit is turned on and the first cooling circuit is turned off; for realizing the cooling medium entering the immersion container horizontally or longitudinally and flowing out, reducing the cooling medium flow dead zone and promoting the circulation of the cooling medium in the immersion container. Similarly, the third cooling circuit and the fourth cooling circuit can be used in parallel, and the third cooling circuit can be turned on and the fourth cooling circuit can be turned off periodically (for example, every minute) through the inlet ball valve 6 and the outlet ball valve 11; or the fourth cooling circuit is turned on and the third cooling circuit is turned off; for realizing the cooling medium entering the immersion container horizontally or longitudinally and flowing out.

[0082] For example, the intelligent switching of the cooling circuit includes: (1) Switch the circuit combination every 60s (switch from the first cooling circuit on / the second cooling circuit off to the second cooling circuit on / the first cooling circuit off; or switch from the third cooling circuit on / the fourth cooling circuit off to the fourth cooling circuit on / the third cooling circuit off).

[0083] (2) Based on the standard deviation of the four temperature fields of the positive and negative tabs and the two center surfaces σ Dynamic adjustment period: If σ >2℃: The switching period is shortened to 30s; If σ <0.5℃: The switching period is extended to 120s.

[0084] (3) Pipe diameter selection logic: Low-viscosity cooling liquid (such as deionized water, perfluoroalkene) is preferentially used in two-pipe circuits (first / second circuits); High-viscosity cooling liquid (such as silicone oil) is automatically switched to three-pipe circuits (third / fourth circuits).

[0085] To further illustrate the effects of the embodiments of the present application, the following experiments are performed.

[0086] For a single 280 Ah lithium iron phosphate square cell energy storage battery, the working condition of continuous discharge at 1C rate for 1 hour (environmental temperature 25℃), two kinds of cooling technologies are compared and analyzed in detail, and the core index comparison is shown in Table 1.

[0087] Table 1 Core index comparison table

[0088] For example, Figure 7The dynamic process of submerged flow adaptive adjustment of cooling medium flow is shown, during 0-5 min: small cooling flow (0.33 L / min); at 12 min, the detection delta T =1.8℃, the flow is increased to medium cooling flow (1.32 L / min); at 28 min, the medium temperature rise triggers, and the pulse large cooling flow (2.64 L / min / 10 s) is started; at 45 min, the temperature is stable, and the flow is decreased back to medium cooling flow; at 55 min, the temperature rises at the end of discharge, and the medium cooling flow is continued to be maintained.

[0089] The submerged scheme of the present application exhibits accurate temperature control, has dynamic response capability through flow adaptive adjustment, and is the only one that controls the hotspot temperature within 30℃, integrates thermal runaway suppression function, T cell and automatically switches to 5℃ rapid cooling mode when the temperature is greater than 100℃.

[0090] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any modification, equivalent replacement and improvement made by those skilled in the art within the technical range disclosed by the present application, as long as it is within the spirit and principle of the present application, should be covered within the protection scope of the present application.

Claims

1. A temperature feedback control method for an immersion thermal management platform, the method comprising: The method comprises the following steps: S1, immerse the cooling medium into the high-low temperature water tank, and obtain constant temperature cooling medium at normal temperature 25℃; S2, the constant temperature cooling medium flows into the plate heat exchanger through the low temperature inlet, flows out through the low temperature outlet and enters the gear pump, and the PLC programmable controller controls the rotating speed of the gear pump to obtain the initial flow Q 0; S3, the constant temperature cooling medium is transported through the gear pump, through the gear flow meter, and the initial flow is set according to the pre-setting Q 0 enters the immersion container through the pressure transmitter and the opened inlet ball valve; S4, the outlet ball valve is in a closed state, and when the cooling medium height in the immersion container exceeds the energy storage battery height, the outlet ball valve is opened; the charging and discharging machine is opened and charging and discharging working conditions are carried out; S5, the cooling medium flows through the outlet ball valve, enters the plate heat exchanger through the pipeline, flows out through the heat outlet after the cooling medium is cooled by the plate heat exchanger, and flows back to the high-low temperature water tank through the high-low temperature water tank inlet, to form a circulating cooling loop; S6, after forming the stable circulating cooling loop, the PLC programmable controller controls the rotating speed of the gear pump to obtain normal cooling flow Q n ; S7, keep performing normal cooling flow Q n Form a normal working cycle cooling circuit; the data collector collects flow, battery center point temperature, cooling medium temperature in the immersion container, and pressure in the immersion container in real time, and performs cooling medium temperature feedback partition control according to the real-time temperature of the energy storage battery and by using a preset temperature feedback partition control algorithm.

2. The temperature feedback control method of the immersion thermal management platform of claim 1, wherein, In step S7, the cooling medium temperature feedback partition control is carried out by using the preset temperature feedback partition control algorithm, which comprises: Data acquisition unit real-time acquisition of battery temperature acquired by temperature sensor T cell and coolant temperature in the container acquired by PT100 temperature sensor T coolant PLC programmable logic controller for real-time acquisition of temperature sensor signal and PT100 temperature sensor signal and processing to obtain battery target control temperature difference Δ T ; If the energy storage battery temperature T cell <15℃ and the temperature of the cooling medium in the immersion container T coolant ≥25℃, in combination with the target control temperature difference Δ T Real-time flow adjustment is performed to complete low-temperature preheating; If the energy storage battery temperature is 15℃ ≤ T cell <35℃, adjust the gear pump speed and coolant flow rate to achieve normal temperature uniformity; If the energy storage battery temperature 35℃ ≤ T cell <100℃, start the gear pump gradient boost mode to complete high temperature cooling; If the energy storage battery temperature T cell ≥ 100°C or the rate of change of the pressure inside the immersion vessel dp / dt > 50 kPa / s, the flow of the cooling liquid is executed at the locked flow Q h,max , the thermal runaway suppression is completed.

3. The temperature feedback control method of the immersion thermal management platform of claim 2, wherein, In the low-temperature preheating, the high-low temperature tank heats the cooling liquid to 30℃, and the cooling flow executes the normal cooling flow Q n And the target control temperature difference Δ of the energy storage battery is combined T Flow real-time adjustment is performed; the initial flow Q n is 0.66 L / min; If the temperature of the cooling medium in the immersion vessel is T coolant <25°C, cooling flow rate Medium cooling flow rate Q m , the rotational speed 2000 rpm, medium cooling flow rate Q m 1.32 L / min.

4. The temperature feedback control method of the immersion thermal management platform of claim 2, wherein, In the process of completing the normal temperature, the high and low temperature water tank keeps normal temperature 25℃; if the target control temperature difference ΔT of the energy storage battery is 0.5℃, the rotation speed is 500rpm, and the small cooling flow is 0.33 L / min. T <1℃, execute rotation speed 500rpm, small cooling flow Q s 0.33 L / min; If the energy storage battery target control temperature difference is 1℃≤ΔT≤2℃, the rotation speed is 2000 rpm, and the medium cooling flow rate is executed T <2℃, the rotation speed is 2000 rpm, and the medium cooling flow rate is executed Q m 1.32 L / min; If the battery target control temperature difference ΔT T ≥ 2°C, the rotation speed 4000 rpm is executed, and the large cooling flow rate Q h is 2.64 L / min.

5. The temperature feedback control method of the immersion thermal management platform of claim 2, wherein, In the high-temperature cooling, the temperature of the high- and low-temperature water tanks is controlled at 20℃, and the gradient pressurization mode of the gear pump is started: Q gradient = Q m + α T cell -35) 2 , wherein α is a gain coefficient of flow rate regulation, α =0.1 L / min·℃ 2 ; Q gradient is an output flow rate after the gradient pressurization, Q m is a medium cooling flow rate, T cell is a battery temperature;​ If the temperature of the cooling medium within the immersion vessel is T c > 35°C, trigger pulsed jet, pulsed jet for 10 seconds Q h Add 10 seconds Q s Cycle; When thermal runaway is suppressed, the cooling medium in the high and low temperature water tanks is rapidly cooled to 5°C, and the cooling flow is locked. Q h,max , execution speed 6000 rpm, lock flow Q h,max The flow rate is 3.96 L / min; the liquid nitrogen injection interface / system or perfluorohexanone injection interface / system configured with high and low temperature water tanks is used to assist in suppressing thermal runaway.

6. The temperature feedback control method of the immersion thermal management platform of claim 2, wherein, Target cooling medium corrected flow rate includes: Q corrector = K p · Δ T + K i · ∫ Δ T dt + K d · d (Δ T ) / dt. wherein: Δ T is the temperature difference between the battery temperature and the target control temperature, Δ T = T cell - T target ; T target is the target control temperature of the energy storage battery, Q corrector is the target cooling medium corrected flow rate, K p is the proportional term coefficient, K i is the integral term coefficient, K d is the differential term coefficient, t is the time.

7. An immersion thermal management platform, characterized by, The platform implements the temperature feedback control method of the immersion heat management platform according to any one of claims 1-6, and the platform comprises a high-low temperature water tank (1), a standard pagoda interface connected to the outlet of the high-low temperature water tank (1), and a plate heat exchanger (2) connected to the low-temperature inlet of the plate heat exchanger (2) through a two-part standard pipeline; The cooling medium flows through the low-temperature outlet of the plate heat exchanger (2) and is connected to the inlet of a gear pump (3) through a pipeline; the fluid flows out through the outlet after working in the gear pump (3), flows into the inlet of a gear flowmeter (4) through a fluid pipeline, flows out through the outlet of the gear flowmeter (4), passes through a pressure transmitter (5), flows into an immersion container (7) through an inlet ball valve (6), and an energy storage battery (8) is placed in the immersion container (7); the cooling medium in the immersion container (7) flows through an outlet ball valve (11) through a pipeline; and further flows into the high-temperature inlet of the plate heat exchanger (2) through a pipeline, flows through the plate heat exchanger (2) through the high-temperature outlet, and returns to the high-low temperature water tank (1) through the inlet of the high-low temperature water tank (1).

8. The immersion thermal management platform of claim 7, wherein, The high-low temperature water tank (1) is provided with a liquid nitrogen injection interface / system and a perfluorohexone injection interface / system; A plurality of temperature sensors (9) of the same specification are distributed on the positive and negative electrode tabs of the energy storage battery (8) and the center of the large face of the energy storage battery (8), and are used to collect the temperatures of the positive and negative electrodes and the centers of the two large faces of the energy storage battery (8); A PT100 temperature sensor (12) is used to measure the temperature of the cooling medium in the immersion container (7); A charging and discharging machine (13) is used to simulate different working conditions of charging and discharging of the energy storage battery (8); A data collector (14) is connected to the gear flowmeter (4) signal, the pressure transmitter (5) signal, the temperature sensor (9) signal, the pressure sensor (10) signal and the PT100 temperature sensor (12) through a circuit to collect electrical signals; A PLC programmable controller (15) is used to obtain the temperature sensor (9) signal and the PT100 temperature sensor (12) signal in real time, and based on the preset energy storage battery (8) temperature, the energy storage battery (8) target control temperature difference and the immersion container (7) cooling medium temperature feedback partition control algorithm, the temperature feedback control high-low temperature water tank (1) temperature and the gear pump (3) speed are used for temperature feedback control, to obtain the best cooling medium temperature and flow.

9. The immersion thermal management platform of claim 7, wherein, The immersion container (7) comprises a container body (100), a rubber sealing ring (200), and a container end cover (300); The third standard two-part threaded hole (113) in the container body (100) is a cooling medium inlet and the first standard two-part threaded hole (108) is a cooling medium outlet, forming a first cooling circuit; The second standard two-part threaded hole (111) in the container body (100) is a cooling medium inlet and the fourth standard two-part threaded hole (115) is a cooling medium outlet, forming a second cooling circuit; The first standard three-part threaded hole (109) in the container body (100) is a cooling medium inlet and the third standard three-part threaded hole (112) is a cooling medium outlet, forming a third cooling circuit; The fourth standard three-part threaded hole (114) in the container body (100) is a cooling medium inlet and the second standard three-part threaded hole (110) is a cooling medium outlet, forming a fourth cooling circuit.

10. The immersion thermal management platform of claim 7, wherein, The PLC programmable controller (15) is based on the preset temperature of the energy storage battery (8), the target control temperature difference of the energy storage battery (8), and the temperature feedback partition control algorithm of the cooling medium in the immersion container (7), and is used for temperature feedback control of the high and low temperature water tank (1) and the gear pump (3) speed. After obtaining the best cooling medium temperature and flow, further intelligent switching of the cooling circuit is carried out, including: The first cooling circuit and the second cooling circuit are used in parallel, periodically passing through the inlet ball valve (6) and the outlet ball valve (11) to realize the conduction of the first cooling circuit and the closing of the second cooling circuit; or the conduction of the second cooling circuit and the closing of the first cooling circuit; for cooling medium to enter the immersion container horizontally or longitudinally and flow out; the third cooling circuit and the fourth cooling circuit are used in parallel, periodically passing through the inlet ball valve (6) and the outlet ball valve (11) to realize the conduction of the third cooling circuit and the closing of the fourth cooling circuit; or the conduction of the fourth cooling circuit and the closing of the third cooling circuit; to realize the horizontal or longitudinal entry of the cooling medium into the immersion container and the outflow.

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