Liquid-cooled lithium battery pack thermal management system and temperature adjusting method

Abstract

The invention discloses a liquid-cooled lithium battery pack thermal management system and a temperature adjusting method, and relates to the technical field of lithium battery thermal management, and the system comprises a liquid cooling circulation module which forms an insulation fluoride liquid closed circulation; the phase-change temperature adjusting module is integrated in the liquid storage tank to complete mixing adjustment; the multi-dimensional sensing module collects data and transmits the data to the intelligent control module; the detection feedback module forms closed-loop regulation and control; the auxiliary heat dissipation module is matched with the condenser for heat dissipation; the intelligent control module calculates and issues a regulation and control instruction on the basis of the industrial-grade embedded controller; a collaborative linkage heat management framework is constructed, data support is provided by relying on multi-dimensional perception, the intelligent control module optimizes the target phase change temperature of the cooling liquid in real time, the modules efficiently interact to avoid traditional problems, a multi-layer heat regulation and control system is further formed, cooling parameters can be adaptively optimized, closed-loop calibration is adopted to guarantee the execution effect, and the system is suitable for large-scale popularization and application. System adaptability and reliability are enhanced, and operation of the lithium battery pack is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of lithium battery thermal management technology, specifically to a liquid-cooled lithium battery pack thermal management system and temperature regulation method. Background Technology

[0002] With the rapid development of the new energy industry, lithium batteries, with their core advantages such as high energy density, long cycle life, and low pollution emissions, have become the core power source for various new energy equipment and are widely used in many important fields. The operating performance and service life of lithium batteries directly depend on their operating temperature environment. Temperature deviation from the suitable range will lead to rapid capacity decay, abnormal increase in internal resistance, and in severe cases, even thermal runaway and other safety risks. Therefore, thermal management systems have become an indispensable key supporting facility in lithium battery applications. Compared with traditional air-cooling technology, liquid-cooled thermal management systems have significant advantages such as high heat exchange efficiency, good temperature control uniformity, and low space occupancy, and have gradually become the mainstream thermal management solution for medium and high power lithium battery packs. However, with the continuous expansion of application scenarios, the operating environment faced by lithium batteries is becoming increasingly complex, and the fluctuation of operating conditions is becoming more frequent. This places higher demands on the dynamic adaptability, precise control level, and comprehensive reliability of thermal management systems. It is necessary to achieve comprehensive perception of the battery operating status and key environmental parameters, as well as the coordinated optimization of various parameters of the cooling system, in order to meet the stable operation requirements of lithium batteries in different scenarios.

[0003] Existing liquid-cooled lithium battery thermal management systems have many insurmountable limitations, failing to fully adapt to the complex and ever-changing demands of real-world applications. Most traditional systems rely solely on temperature data for regulation, neglecting key influencing factors such as changes in battery internal resistance and the coupling effect of ambient temperature and humidity. This results in a lack of comprehensiveness and scientific rigor in regulation decisions. The phase change characteristics of the cooling medium are often fixed and cannot be dynamically adjusted according to changes in battery operating conditions and environmental conditions, leading to deviations between cooling performance and actual requirements. Liquid cooling circuit flow regulation is mostly independent, lacking a coordinated regulation mechanism with the phase change temperature of the cooling medium, which can easily lead to insufficient heat dissipation or excessive energy consumption. Furthermore, traditional systems have a relatively limited sensing dimension, lacking precise monitoring of key state parameters such as cooling medium concentration and phase change temperature. The feedback regulation chain is incomplete, making it difficult to detect and correct regulation deviations in a timely manner. This results in lag in temperature control, making it unable to quickly respond to sudden environmental changes or drastic fluctuations in battery status. Long-term operation will accelerate battery aging and reduce the overall reliability and safety of the system. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a liquid-cooled lithium battery pack thermal management system and temperature regulation method. It integrates liquid cooling circulation, phase change temperature regulation, multi-dimensional sensing, detection feedback, auxiliary heat dissipation, and intelligent control modules to construct a collaborative architecture. The intelligent control module is equipped with two types of core algorithms. Combining data collected from multi-dimensional sensing, such as ambient temperature and humidity and battery internal resistance, it dynamically calculates the target phase change temperature of the coolant and the target flow rate of the liquid cooling loop. Through a complete process of parameter pre-configuration, data acquisition, calculation and control, closed-loop calibration, and dynamic adaptation, it achieves precise optimization and real-time adjustment of cooling parameters, efficiently responds to fluctuations in operating conditions and the environment, ensures the lithium battery pack is within a suitable temperature range, comprehensively improves operational safety and reliability, extends battery life, and is adaptable to various lithium battery application scenarios.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: In one aspect, a liquid-cooled lithium battery pack thermal management system, the system comprising: Liquid cooling circulation module: It consists of a liquid storage tank, a circulation pump and a condenser, forming an insulated closed circulation path for fluorinated liquid. It is integrated and linked with the phase change temperature regulation module and the auxiliary heat dissipation module, and receives instructions from the intelligent control module to adjust the circulation flow rate. Phase change temperature regulation module: Integrated into the liquid storage tank, it consists of a phase change regulator storage bottle, a high-precision metering pump, and a mixing chamber. It completes the mixing and regulation with the insulating fluorinated liquid and receives the control instructions from the intelligent control module to complete the quantitative addition and fine adjustment of the regulator. Multi-dimensional sensing module: Composed of an ambient temperature and humidity sensor and a battery internal resistance online monitoring module, it collects external temperature and humidity data, battery internal resistance and rate of change data of the lithium battery module, and transmits the data to the intelligent control module through an industrial bus. The detection feedback module is located inside the liquid storage tank and consists of a phase change temperature detection probe and a coolant concentration sensor. It detects the actual phase change temperature and mixing concentration of the cooling medium after adjustment and transmits the data to the intelligent control module, forming a closed-loop control relationship with the phase change temperature adjustment module. Auxiliary heat dissipation module: Located on the outside of the condenser, the core of which is a speed-adjustable cooling fan with two fixed speeds. It receives start / stop and speed commands from the intelligent control module and works with the condenser to dissipate heat from the cooling medium. Intelligent control module: Based on an industrial-grade embedded controller, it calculates the target phase change temperature of the cooling medium through a dynamic adaptation algorithm for coolant phase change temperature, and calculates the target circulation flow of the liquid cooling loop through a liquid cooling loop flow collaborative control algorithm. It is also electrically connected to the liquid cooling circulation module, phase change temperature adjustment module, multi-dimensional sensing module, detection feedback module, and auxiliary heat dissipation module, and issues corresponding control commands to each module.

[0006] Furthermore, the liquid storage tank of the liquid cooling circulation module is a sealed pressure vessel with an independent phase change modifier mixing chamber inside. A liquid level sensor and a pressure sensor are installed on the outer wall of the storage tank, with the detection end of the sensor extending into the medium inside the tank. The sensor is connected to the intelligent control module via a communication line and transmits monitoring data. The circulation pump is a variable frequency adjustable centrifugal pump with an integrated overcurrent and overheat protection unit. The protection unit is electrically connected to the intelligent control module and sends operating condition signals. The condenser is a shell-and-tube heat exchange structure with aluminum alloy fins and an anti-corrosion coating. A temperature sensor is installed at the medium inlet of the condenser.

[0007] Furthermore, the phase change regulator storage bottle of the phase change temperature regulation module is a light-proof and sealed storage container with a low liquid level alarm device at the bottom and a one-way valve at the outlet; the metering pump is a micro-flow high-precision plunger pump with an integrated liquid addition accumulation counting unit, and has three working modes: quantitative liquid addition, replenishment fine adjustment, and emergency pump stop; the mixing chamber is a sealed chamber with built-in spiral turbulence blades made of polytetrafluoroethylene, a flow regulating valve at the inlet of the mixing chamber, and a static mixer at the outlet.

[0008] Furthermore, the mathematical expression for the coolant phase change temperature dynamic adaptation algorithm built into the intelligent control module is as follows: Among them, among them, The target phase transition temperature for the coolant. The base value for phase transition temperature is used to match the ambient temperature and humidity. This is the correction factor for the rate of change of internal resistance. This is the normalization factor for the rate of change of battery internal resistance. This is the temperature and humidity coupling correction factor. This is the environmental temperature and humidity coupling normalization factor.

[0009] Furthermore, the mathematical expression for the liquid cooling circuit flow coordination control algorithm built into the intelligent control module is as follows: ;in, Q0 represents the dynamic target flow rate of the liquid cooling circuit, and Q0 represents the base flow rate of the liquid cooling circuit under rated operating conditions of the lithium battery module. The internal resistance feedforward weighting coefficient is used. This is the normalization factor for the rate of change of battery internal resistance. The reference threshold for the rate of change of battery internal resistance. This is the phase transition temperature deviation feedback weighting coefficient. This is the phase transition temperature deviation normalization factor. This is the humidity heat transfer gain weighting coefficient. This is the ambient humidity heat transfer gain factor.

[0010] On the other hand, a temperature regulation method for a liquid-cooled lithium battery pack thermal management system includes the following specific steps: S100, parameter pre-configuration: preset system control rules, threshold parameters and algorithm coefficients in the controller to complete the calibration and storage of thermal control reference parameters; S200, Data Acquisition: Continuously collects data on the external environment temperature and humidity of the lithium battery module, battery internal resistance and rate of change through a multi-dimensional sensing module, and transmits all collected data to the controller synchronously. S300, parameter calculation: After receiving the collected data, the controller preprocesses the data, calculates the target phase change temperature of the coolant through the coolant phase change temperature dynamic adaptation algorithm, calculates the target flow rate of the liquid cooling circuit through the liquid cooling circuit flow collaborative control algorithm, and integrates the target phase change temperature of the coolant and the target flow rate of the liquid cooling circuit to form a cooling parameter control scheme. S400, Regulation and Calibration: The controller issues regulation commands to each execution module according to the cooling parameter regulation scheme to complete phase change temperature regulation, auxiliary heat dissipation regulation and emergency flow regulation. Combined with the actual phase change temperature and mixed concentration data monitored by the detection feedback module, the controller performs closed-loop calibration and correction of the coolant phase change temperature and liquid cooling circuit flow. S500, Dynamic Adaptation: The multi-dimensional sensing module and detection feedback module continuously collect real-time data and transmit it to the controller. The controller continuously updates the target phase change temperature of the coolant and the target flow rate of the liquid cooling circuit based on the data fluctuations through the dynamic adaptation algorithm of coolant phase change temperature and the collaborative control algorithm of liquid cooling circuit flow rate. It repeatedly performs the control calibration operation to complete the dynamic self-adaptive control of cooling parameters.

[0011] Furthermore, the system control rules preset within the controller include matching rules between ambient temperature and humidity and the base value of the coolant phase change temperature. The base value of the coolant phase change temperature is 25°C when the ambient temperature is between -20°C and 10°C, 30°C when the ambient temperature is between 10°C and 25°C, 35°C when the ambient temperature is between 25°C and 40°C, and 40°C when the ambient temperature is between 40°C and 60°C. The preset threshold parameters include a temperature and humidity abrupt change judgment threshold, a phase change temperature deviation control threshold, and a battery internal resistance change rate threshold. The temperature and humidity abrupt change judgment threshold is... The threshold values ​​for ambient temperature change rate and ambient relative humidity change rate are defined. The phase change temperature deviation control threshold is the allowable deviation between the actual and target values ​​of the coolant phase change temperature. The battery internal resistance change rate threshold is the critical value of the change in battery internal resistance per unit time. The preset algorithm coefficients include the internal resistance change rate correction coefficient, temperature and humidity coupling correction coefficient, internal resistance feedforward weight coefficient, phase change temperature deviation feedback weight coefficient, and humidity heat transfer gain weight coefficient. After completing the input of all system control rules, threshold parameters, and algorithm coefficients, the thermal control reference parameters are calibrated, and all calibrated parameters are stored in the controller's storage unit, which is a component of the intelligent control module.

[0012] Furthermore, the multi-dimensional sensing module collects data at a frequency of 0.5 to 2 seconds per acquisition. The ambient temperature and humidity sensor collects the current ambient temperature, the ambient temperature one hour ago, and the real-time relative humidity outside the lithium battery module. The battery internal resistance online monitoring module collects the current internal resistance and the internal resistance one hour ago and calculates the rate of change of internal resistance. The multi-dimensional sensing module synchronously transmits all collected data to the controller via an industrial bus. During the transmission process, a data frame verification mechanism is used. The controller timestamps all received collected data and stores the data in the controller's cache unit according to the acquisition time order. The cache unit is a component of the intelligent control module. The cache unit stores the collected data according to a preset rule, which is to overwrite historical collected data that exceeds the storage capacity in chronological order.

[0013] Furthermore, the controller's preprocessing of the collected data includes removing abnormal collected data that exceeds the 3σ principle and replacing the abnormal collected data with valid collected data from the previous collection cycle. After preprocessing, the target phase change temperature of the coolant is first calculated using a dynamic adaptation algorithm for coolant phase change temperature. The rule for the target phase change temperature is that the calculated result is limited to the range of 25℃ to 40℃. Then, the target flow rate of the liquid cooling circuit is calculated using a liquid cooling circuit flow rate collaborative control algorithm. The rule for the target flow rate of the liquid cooling circuit is that the lower limit of the calculated result is 1.2 times the basic flow rate of the liquid cooling circuit under the rated operating conditions of the lithium battery module, and the upper limit is 2.0 times the basic flow rate of the liquid cooling circuit under the rated operating conditions of the lithium battery module. When the rate of change of ambient temperature and the rate of change of ambient relative humidity in the collected data reach the threshold for temperature and humidity sudden change judgment, the target flow rate of the liquid cooling circuit is executed at the lower limit value. The controller integrates the target phase change temperature of the coolant and the target flow rate of the liquid cooling circuit, and the integrated content is the cooling parameter control scheme.

[0014] Furthermore, the controller issues control commands to the phase change temperature adjustment module, liquid cooling circulation module, and auxiliary heat dissipation module according to the cooling parameter control scheme. The control commands issued to the phase change temperature adjustment module include the amount of liquid added, the liquid added rate, and the liquid added interval. The closed-loop calibration judgment rule is that when the deviation between the actual value of the coolant phase change temperature collected by the detection feedback module and the target phase change temperature of the coolant reaches the phase change temperature deviation control threshold, the controller issues a command to the phase change temperature adjustment module to add regulator. The control commands issued to the auxiliary heat dissipation module include fan start / stop and fan speed. The speed control rule for the variable-speed cooling fan of the auxiliary heat dissipation module is that the fan is turned off when the ambient relative humidity is below 60%, the fan speed is 1000 rpm when the ambient relative humidity is between 60% and 80%, and the fan speed is 1500 rpm when the ambient relative humidity is greater than or equal to 80%. The emergency flow control command issued to the liquid cooling circulation module is triggered when the rate of change of ambient temperature and the rate of change of ambient relative humidity reach the temperature and humidity sudden change judgment threshold, the controller issues a command to the liquid cooling circulation module to adjust the flow to the target flow of the liquid cooling loop.

[0015] Compared with existing technologies, this liquid-cooled lithium battery pack thermal management system and temperature regulation method have the following advantages: I. This invention integrates core modules such as liquid cooling circulation, phase change temperature regulation, multi-dimensional sensing, detection feedback, and intelligent control to construct a collaborative thermal management architecture. The multi-dimensional sensing module acquires key data on battery operating status and the environment, providing comprehensive support for control decisions. The intelligent control module is equipped with a dynamic adaptation algorithm for coolant phase change temperature, optimizing the target phase change temperature of the coolant in real time based on the collected data. This achieves precise matching between the phase change characteristics of the cooling medium and the battery operating conditions and environmental conditions. Simultaneously, the modules interact efficiently through an industrial bus and closed-loop control mechanism. The detection feedback module verifies the state of the cooling medium in real time and promptly corrects control deviations, avoiding problems such as temperature control lag and insufficient adaptability common in traditional thermal management systems. This ensures that the lithium battery pack remains within a suitable temperature range under complex operating conditions, improving the accuracy and stability of thermal management.

[0016] Second, this invention achieves dynamic adaptation of cooling flow rate and heat dissipation intensity through the coordinated design of liquid cooling circuit flow rate control algorithm and auxiliary heat dissipation module. Combined with the fine adjustment capability of phase change temperature adjustment module, a multi-dimensional and multi-level thermal control system is formed. Based on parameter pre-configuration, the system continuously updates the control scheme through continuous data acquisition and dynamic calculation, and completes the self-adaptive optimization of cooling parameters. It can flexibly cope with fluctuations in environmental conditions and battery operating status. The introduction of closed-loop calibration mechanism further ensures the execution effect of control commands, effectively balances cooling efficiency and energy consumption, and avoids excessive or insufficient heat dissipation. The overall architecture, through module integration and algorithm support, enhances the adaptability and reliability of thermal management system, providing strong protection for the safe operation, stable performance and extended service life of lithium battery packs.

[0017] Other advantages, objectives and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination or study, or may be learned from the practice of the invention. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0019] Figure 1 This is a diagram showing the composition and connection relationships of the thermal management system modules for a liquid-cooled lithium battery pack. Figure 2 This is a flowchart of the temperature regulation method for the thermal management system of a liquid-cooled lithium battery pack. Detailed Implementation

[0020] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0021] Example 1 Liquid-cooled lithium battery pack thermal management system.

[0022] This thermal management system uses an intelligent control module as its core control hub. Through electrical connections and signal interaction, it coordinates the operation of the liquid cooling circulation module, phase change temperature regulation module, multi-dimensional sensing module, detection and feedback module, and auxiliary heat dissipation module, forming a complete closed-loop thermal management system encompassing data acquisition, parameter calculation, command issuance, and feedback calibration. This ensures that the lithium battery pack temperature remains within a suitable range, guaranteeing stable battery performance and lifespan. Figure 1 As shown.

[0023] Module structure and connection relationships: The intelligent control module is based on an industrial-grade embedded controller, providing stable and reliable computation and control support. It incorporates a dynamic adaptation algorithm for coolant phase change temperature and a coordinated control algorithm for liquid cooling circuit flow, enabling precise calculation of key parameters adapted to real-time operating conditions. It also integrates storage and cache units. This module establishes bidirectional data transmission or command issuance channels with the other five modules via communication lines or electrical connections. It rapidly receives monitoring data from each sensing and feedback module and promptly issues precise control commands to the execution modules. It is the core of the system's overall coordination, ensuring consistent and coordinated actions across all modules.

[0024] The liquid-cooled circulation module consists of a sealed pressure vessel-type liquid storage tank, a variable frequency adjustable centrifugal pump, and a shell-and-tube condenser connected in series to form an insulated closed-loop circulation path for the fluorinated liquid. This prevents leakage of the cooling medium and external contamination, maintaining loop stability. The liquid storage tank has an independent phase change regulator mixing chamber, ensuring thorough mixing of the regulator and cooling medium without affecting the medium state in other areas of the tank. Level and pressure sensors mounted on the outer wall extend directly into the cooling medium inside the tank, transmitting level and pressure data in real-time to the intelligent control module via a communication line. This allows for timely monitoring of the medium state within the tank, preventing low levels or abnormal pressure from affecting the circulation. The circulation pump integrates overcurrent and overheat protection units, electrically connected to the intelligent control module. It can send pump operating status signals in real-time. When overcurrent or overheating abnormalities occur, the intelligent control module quickly receives the signal and triggers protection commands to prevent pump damage and ensure continuous circulation. The condenser uses aluminum alloy heat exchange fins with an anti-corrosion coating, balancing heat exchange efficiency and service life. A temperature sensor is installed at the medium inlet to collect the initial temperature of the cooling medium entering the heat exchange stage. This data is synchronously uploaded to the intelligent control module, providing a basis for subsequent heat exchange effect evaluation and control. Furthermore, this module, along with the phase change temperature regulation module, achieves precise mixing of the cooling medium and phase change regulator through a mixing chamber. It also works in synergy with the auxiliary heat dissipation module, mounted on the outside of the condenser, to receive flow adjustment commands from the intelligent control module, enabling dynamic adaptation of the circulating flow rate to meet different heat dissipation requirements.

[0025] Phase change temperature control module: Integrated into an independent mixing chamber within the storage tank, this module comprises a light-proof, sealed phase change regulator storage bottle, a micro-flow, high-precision plunger pump, and a sealed mixing chamber with built-in spiral baffles. It precisely controls the addition and mixing process of the phase change regulator, ensuring the cooling medium's phase change temperature reaches the target value. A low-level alarm is located at the bottom of the storage bottle. When the regulator level is insufficient, the alarm signal is transmitted to the intelligent control module via electrical connection, facilitating timely replenishment and preventing any impact on the control effect. Simultaneously, a one-way valve at the outlet prevents backflow of the cooling medium, ensuring the regulator's purity. The metering pump integrates a cumulative counting unit for the added volume, offering three operating modes: quantitative addition, fine-tuning, and emergency pump stop. It receives addition commands from the intelligent control module via a communication line, precisely controlling the regulator output to ensure the added volume meets calculation requirements. The turbulence blades in the mixing chamber are made of polytetrafluoroethylene, which has strong chemical stability and is not easy to stick to the medium, thus improving the uniformity of medium mixing. The inlet is equipped with a flow regulating valve, which can adjust the inlet rate according to the instructions of the intelligent control module. The outlet is equipped with a static mixer to further optimize the mixing effect, ensuring that the phase change modifier and the insulating fluorinated liquid are fully integrated before entering the liquid cooling circulation path, thus ensuring the stability of the phase change performance of the cooling medium.

[0026] The multi-dimensional sensing module consists of an ambient temperature and humidity sensor and a battery internal resistance online monitoring module. Both establish data transmission connections with the intelligent control module via an industrial bus, ensuring stable transmission and low latency. The ambient temperature and humidity sensor is installed in key external heat dissipation areas of the lithium battery module, accurately collecting current ambient temperature and humidity data to reflect the impact of the external environment on battery heat dissipation. The battery internal resistance online monitoring module is directly connected to the electrodes of the lithium battery module, collecting battery internal resistance data in real time and automatically calculating the rate of change of internal resistance. This indirectly reflects the battery's heating state through changes in internal resistance. All collected temperature, humidity, internal resistance, and rate of change data are synchronously sent to the intelligent control module through a stable transmission channel of the industrial bus, providing comprehensive and real-time raw data support for subsequent parameter calculations and ensuring that the calculation results closely match actual operating conditions.

[0027] The detection feedback module, located inside the storage tank along the cooling medium flow path, consists of a phase change temperature detection probe and a coolant concentration sensor. The detection signals from both are fed back to the intelligent control module in real time via a communication line, promptly reflecting the actual state of the cooling medium after adjustment. The phase change temperature detection probe directly contacts the mixed cooling medium, accurately detecting its actual phase change temperature to ensure reliable temperature data. The coolant concentration sensor monitors the mixed concentration of the phase change regulator and the insulating fluorinated liquid, ensuring the mixing ratio meets the control requirements. This module forms a closed-loop control relationship with the phase change temperature adjustment module. Its detection data is the core basis for the intelligent control module to correct the amount of regulator added, ensuring that the cooling medium performance always meets the target requirements.

[0028] Auxiliary heat dissipation module: The core is a speed-adjustable cooling fan, fixedly installed on the outside of the condenser, closely corresponding to the condenser's heat dissipation surface. It receives start / stop and speed commands from the intelligent control module via electrical connection. The fan has two fixed speed settings, and its operating status is directly related to the condenser's heat exchange efficiency. When the cooling medium requires enhanced heat dissipation, the intelligent control module starts the fan and adjusts its speed, working in conjunction with the condenser to dissipate and cool the cooling medium, improving heat dissipation efficiency, ensuring the heat dissipation effect of the liquid cooling cycle, and enabling the cooling medium to quickly return to a suitable temperature to meet the circulation heat dissipation requirements.

[0029] System working principle: After system startup, the multi-dimensional sensing module continuously collects data on the external environment temperature and humidity, battery internal resistance, and rate of change of the lithium battery module at a preset frequency of 0.5 to 2 seconds. This data is transmitted to the intelligent control module via an industrial bus. During transmission, a data verification mechanism ensures data accuracy, providing a high-quality data foundation for subsequent parameter calculations. Upon receiving the data, the intelligent control module, supported by an industrial-grade embedded controller, first performs preliminary analysis of the raw data. Then, it invokes the built-in coolant phase change temperature dynamic adaptation algorithm. Combining parameters such as the base value of the phase change temperature matching the ambient temperature and humidity, the internal resistance rate of change correction coefficient, and the temperature-humidity coupling correction coefficient, it calculates the dynamic target phase change temperature of the coolant under the current operating conditions. The mathematical expression for the coolant phase change temperature dynamic adaptation algorithm is as follows: ;in, The target phase transition temperature for the coolant. The base value for phase transition temperature is used to match the ambient temperature and humidity. This is the correction factor for the rate of change of internal resistance. This is the normalization factor for the rate of change of battery internal resistance. This is the temperature and humidity coupling correction factor. An environmental temperature and humidity coupling normalization factor is used to ensure that the phase change temperature adapts to the environment and battery state. Simultaneously, a liquid cooling circuit flow rate collaborative control algorithm is invoked. Based on the basic flow rate of the liquid cooling circuit under the rated operating conditions of the lithium battery module, the internal resistance feedforward weight coefficient, and the phase change temperature deviation feedback weight coefficient, the dynamic target flow rate of the liquid cooling circuit is calculated. The mathematical expression for the liquid cooling circuit flow rate collaborative control algorithm is as follows: ;in, Q0 represents the dynamic target flow rate of the liquid cooling circuit, and Q0 represents the base flow rate of the liquid cooling circuit under rated operating conditions of the lithium battery module. The internal resistance feedforward weighting coefficient is used. This is the normalization factor for the rate of change of battery internal resistance. The reference threshold for the rate of change of battery internal resistance. This is the phase transition temperature deviation feedback weighting coefficient. This is the phase transition temperature deviation normalization factor. This is the humidity heat transfer gain weighting coefficient. The ambient humidity heat transfer gain factor enables the flow rate to match the phase change temperature and heat dissipation requirements.

[0030] Subsequently, the intelligent control module sends control commands to each execution module: a flow adjustment command is sent to the liquid cooling circulation module, and the variable frequency circulation pump adjusts its operating power according to the command to achieve precise control of the target circulation flow rate and ensure that the circulation speed of the cooling medium meets the heat dissipation requirements; commands such as liquid addition amount and liquid addition rate are sent to the phase change temperature regulation module, and the metering pump injects a fixed amount of phase change regulator into the mixing chamber according to the command, which is fully mixed with the insulating fluorinated liquid to make the phase change temperature of the cooling medium reach the target value and ensure the cooling effect; commands such as fan start / stop and speed are sent to the auxiliary heat dissipation module to adjust the fan operation status according to the ambient humidity and other operating conditions, and work with the condenser to improve heat dissipation efficiency and quickly reduce the temperature of the cooling medium.

[0031] During the control process, the detection feedback module monitors the actual phase change temperature and mixing concentration of the cooling medium in real time and feeds the data back to the intelligent control module. The intelligent control module compares the actual detected value with the target value. If there is a deviation that reaches the phase change temperature deviation control threshold, it sends a supplementary fine-tuning command to the phase change temperature adjustment module to correct the mixing ratio and ensure that the phase change temperature of the cooling medium returns to the target value. At the same time, based on the actual operating status of the circulation flow, it fine-tunes the operating parameters of the circulation pump to form a closed-loop control, ensuring that the performance of the cooling medium always matches the heat dissipation requirements of the lithium battery pack, thereby achieving precise and stable control of the lithium battery pack temperature.

[0032] Example 2: Temperature regulation method for thermal management system of liquid-cooled lithium battery pack.

[0033] S100, Parameter Pre-configuration: Before system startup, the thermal management baseline parameters are pre-configured and calibrated. The intelligent control module, with an industrial-grade embedded controller at its core, pre-loads system control rules, threshold parameters, and algorithm coefficients. The control rules clearly define the matching relationship between ambient temperature and humidity and the base value of the coolant phase change temperature. The base value of the phase change temperature is 25℃ when the ambient temperature is between -20℃ and 10℃, 30℃ when it is between 10℃ and 25℃, 35℃ when it is between 25℃ and 40℃, and 40℃ when it is between 40℃ and 60℃, providing a clear reference for setting the phase change temperature under different ambient temperatures. The threshold parameters include the temperature and humidity change change judgment threshold, the phase change temperature deviation control threshold, and the battery internal resistance change rate threshold. The temperature and humidity change change judgment threshold is the critical value of the ambient temperature change rate and the critical value of the ambient relative humidity change rate, which can promptly identify extreme environmental changes. The phase change temperature deviation control threshold is the allowable deviation between the actual value and the target value of the coolant phase change temperature, ensuring the accuracy of temperature control. The battery internal resistance change rate threshold is the critical value of the change in battery internal resistance per unit time, which can promptly detect abnormal battery heating. The algorithm coefficients include the internal resistance change rate correction coefficient, the temperature and humidity coupling correction coefficient, the internal resistance feedforward weight coefficient, the phase change temperature deviation feedback weight coefficient, and the humidity heat transfer gain weight coefficient, which provide a guarantee for the accurate calculation of the algorithm. After all parameters are entered, the thermal control reference parameters are calibrated to ensure their accuracy and adaptability. The calibrated parameters are stored in the storage unit of the intelligent control module for easy retrieval by the controller during subsequent operation, providing a stable reference for control. Figure 2 As shown.

[0034] S200, Data Acquisition: After system startup, the multi-dimensional sensing module enters continuous data acquisition mode, with an acquisition frequency set to 0.5 to 2 seconds per acquisition. This allows for timely capture of dynamic changes in the environment and battery status, avoiding data lag that could affect control effectiveness. The ambient temperature and humidity sensor accurately acquires the current ambient temperature, the ambient temperature one hour ago, and the real-time relative humidity outside the lithium battery module, comprehensively reflecting the changing trends of ambient temperature and humidity and providing data support for temperature and humidity coupling-related calculations. The battery internal resistance online monitoring module is directly connected to the lithium battery module, acquiring the current battery internal resistance and the battery internal resistance one hour ago, and automatically calculating the rate of change of battery internal resistance. This indirectly reflects changes in the battery's heating state through changes in internal resistance. All collected data is transmitted to the intelligent control module via an industrial bus. During transmission, a data frame verification mechanism is used to effectively avoid data transmission errors and ensure data accuracy. After receiving the data, the intelligent control module timestamps each set of data and stores it in the cache unit in the order of collection time. The cache unit stores data according to preset rules. When the storage capacity reaches the upper limit, it automatically overwrites the oldest historical data in chronological order, making efficient use of cache space while ensuring that the latest data is retained, providing a real-time and complete data foundation for subsequent parameter calculations.

[0035] S300, Parameter Calculation: After receiving the collected data, the intelligent control module first performs data preprocessing, using the 3σ principle to eliminate abnormal collected data to avoid interference with the calculation results. For data determined to be abnormal, valid collected data from the previous collection cycle is used to replace it, ensuring the continuity of the calculation process and data reliability. After preprocessing, the intelligent control module calls the coolant phase change temperature dynamic adaptation algorithm, combining pre-matched parameters such as the basic phase change temperature value, internal resistance change rate correction coefficient, and temperature and humidity coupling correction coefficient, to calculate the dynamic target phase change temperature of the coolant. The mathematical expression of the coolant phase change temperature dynamic adaptation algorithm is as follows: ;in, The target phase transition temperature for the coolant. The base value for phase transition temperature is used to match the ambient temperature and humidity. This is the correction factor for the rate of change of internal resistance. This is the normalization factor for the rate of change of battery internal resistance. This is the temperature and humidity coupling correction factor. As an environmental temperature and humidity coupling normalization factor, the calculation results are strictly limited to the range of 25℃ to 40℃ to ensure the stability of the phase change performance of the cooling medium and avoid the effect of excessively high or low temperatures on heat dissipation. Simultaneously, a liquid cooling circuit flow rate collaborative control algorithm is invoked. Based on parameters such as the basic flow rate of the liquid cooling circuit under rated operating conditions of the lithium battery module, the internal resistance feedforward weight coefficient, and the phase change temperature deviation feedback weight coefficient, the dynamic target flow rate of the liquid cooling circuit is calculated. The mathematical expression for the liquid cooling circuit flow rate collaborative control algorithm is as follows: ;in, Q0 represents the dynamic target flow rate of the liquid cooling circuit, and Q0 represents the base flow rate of the liquid cooling circuit under rated operating conditions of the lithium battery module. The internal resistance feedforward weighting coefficient is used. This is the normalization factor for the rate of change of battery internal resistance. The reference threshold for the rate of change of battery internal resistance. This is the phase transition temperature deviation feedback weighting coefficient. This is the phase transition temperature deviation normalization factor. This is the humidity heat transfer gain weighting coefficient. The ambient humidity heat transfer gain factor is used. The calculation result has a lower limit of 1.2 times the basic flow rate and an upper limit of 2.0 times the basic flow rate, which ensures minimum heat dissipation requirements while avoiding excessive energy waste caused by excessive flow rate. If the rate of change of ambient temperature and the rate of change of ambient relative humidity in the collected data reach the threshold for sudden temperature and humidity changes, the intelligent control module will directly execute the target flow rate of the liquid cooling circuit at the lower limit value to quickly respond to extreme environmental changes and prevent the battery temperature from rising sharply. Subsequently, the calculated target phase change temperature of the coolant is integrated with the target flow rate of the liquid cooling circuit to form a complete cooling parameter control scheme, providing a clear basis for subsequent control commands.

[0036] S400, Regulation and Calibration: The intelligent control module issues precise control commands to each execution module based on the cooling parameter control scheme, ensuring that each module operates according to the predetermined target. It issues control commands including liquid addition volume, liquid addition rate, and liquid addition interval to the phase change temperature regulation module. The metering pump starts according to the commands and accurately outputs the phase change regulator, which is fully mixed with the insulating fluorinated liquid through the mixing chamber, gradually bringing the phase change temperature of the cooling medium closer to the target value. It issues fan start / stop and speed commands to the auxiliary heat dissipation module. The fan speed is adaptively adjusted according to the ambient relative humidity. When the ambient relative humidity is below 60%, the fan shuts off to reduce unnecessary energy consumption. Between 60% and 80%, the fan speed is 1000 rpm; when it is greater than or equal to 80%, the fan speed is 1500 rpm, working in conjunction with the condenser to complete heat dissipation, ensuring good heat dissipation effect under different humidity environments. It issues emergency flow control commands to the liquid cooling circulation module. When the temperature and humidity reach the sudden change threshold, the circulation pump adjusts its operating state according to the target flow lower limit, quickly improving heat dissipation capacity and ensuring stable flow in the cooling circuit. While each module executes the control commands, the detection and feedback module continuously monitors the actual phase change temperature and mixing concentration of the cooling medium and feeds the data back to the intelligent control module in real time. When the deviation between the actual phase change temperature and the target phase change temperature reaches the phase change temperature deviation control threshold, the intelligent control module immediately issues a command to the phase change temperature regulation module to add regulator, and performs closed-loop calibration and correction on the coolant phase change temperature and liquid cooling circuit flow rate to ensure that the control effect meets expectations and that the cooling medium is always in the best working state.

[0037] S500, Dynamic Adaptation: Throughout the temperature regulation process, the multi-dimensional sensing module and detection feedback module are constantly acquiring data, capturing real-time changes in ambient temperature and humidity, battery internal resistance fluctuations, and cooling medium performance changes, and simultaneously transmitting this data to the intelligent control module to ensure the controller can promptly grasp the latest operating conditions. Based on the fluctuations in this real-time data, the intelligent control module continuously calls the coolant phase change temperature dynamic adaptation algorithm and the liquid cooling loop flow collaborative control algorithm to dynamically update the target coolant phase change temperature and the target flow rate of the liquid cooling loop, ensuring that the parameters always closely match the real-time operating conditions. At the same time, it repeatedly executes various operations in the regulation and calibration phase, continuously optimizing the regulation commands to ensure that the cooling parameters are always precisely matched with the real-time heating state of the lithium battery pack and changes in the external environment, achieving dynamic self-adaptive regulation of cooling parameters. This ensures that the lithium battery pack operates stably within a suitable temperature range throughout the entire process, fully utilizing battery performance and extending battery life.

[0038] In summary, the temperature regulation method of this liquid-cooled lithium battery pack thermal management system achieves precise temperature control through five consecutive steps: parameter pre-configuration, data acquisition, parameter calculation, adjustment and calibration, and dynamic adaptation. Pre-configured parameters establish a baseline, high-frequency data acquisition ensures real-time performance, preprocessing and dedicated algorithms ensure accurate parameter calculation, closed-loop calibration corrects deviations, and dynamic adaptation keeps pace with changes in operating conditions. The entire process strictly adheres to preset rules and thresholds, relying on two core algorithms and the collaboration of various modules to quickly respond to environmental and battery state fluctuations while maintaining stable cooling effects. This prevents abnormal temperatures from affecting battery operation and provides reliable temperature protection for the safe and efficient operation of the lithium battery pack.

[0039] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A liquid-cooled lithium battery pack thermal management system, characterized in that, The system includes: Liquid cooling circulation module: It consists of a liquid storage tank, a circulation pump and a condenser, forming an insulated closed circulation path for fluorinated liquid. It is integrated and linked with the phase change temperature regulation module and the auxiliary heat dissipation module, and receives instructions from the intelligent control module to adjust the circulation flow rate. Phase change temperature regulation module: Integrated into the liquid storage tank, it consists of a phase change regulator storage bottle, a high-precision metering pump, and a mixing chamber. It completes the mixing and regulation with the insulating fluorinated liquid and receives the control instructions from the intelligent control module to complete the quantitative addition and fine adjustment of the regulator. Multi-dimensional sensing module: Composed of an ambient temperature and humidity sensor and a battery internal resistance online monitoring module, it collects external temperature and humidity data, battery internal resistance and rate of change data of the lithium battery module, and transmits the data to the intelligent control module through an industrial bus. The detection feedback module is located inside the liquid storage tank and consists of a phase change temperature detection probe and a coolant concentration sensor. It detects the actual phase change temperature and mixing concentration of the cooling medium after adjustment and transmits the data to the intelligent control module, forming a closed-loop control relationship with the phase change temperature adjustment module. Auxiliary heat dissipation module: Located on the outside of the condenser, the core of which is a speed-adjustable cooling fan with two fixed speeds. It receives start / stop and speed commands from the intelligent control module and works with the condenser to dissipate heat from the cooling medium. Intelligent control module: Based on an industrial-grade embedded controller, it calculates the target phase change temperature of the cooling medium through a dynamic adaptation algorithm for coolant phase change temperature, and calculates the target circulation flow of the liquid cooling loop through a liquid cooling loop flow collaborative control algorithm. It is also electrically connected to the liquid cooling circulation module, phase change temperature adjustment module, multi-dimensional sensing module, detection feedback module, and auxiliary heat dissipation module, and issues corresponding control commands to each module.

2. The liquid-cooled lithium battery pack thermal management system according to claim 1, characterized in that, The liquid cooling circulation module's storage tank is a sealed pressure vessel with an independent phase change regulator mixing chamber inside. A level sensor and a pressure sensor are mounted on the outer wall of the storage tank, with the sensor's detection end extending into the medium inside the tank. The sensors are connected to the intelligent control module via a communication line and transmit monitoring data. The circulation pump is a variable frequency adjustable centrifugal pump with integrated overcurrent and overheat protection units. These protection units are electrically connected to the intelligent control module and send operating condition signals. The condenser is a shell-and-tube heat exchange structure with aluminum alloy fins and an anti-corrosion coating. A temperature sensor is installed at the medium inlet of the condenser.

3. The liquid-cooled lithium battery pack thermal management system according to claim 1, characterized in that, The phase change temperature regulating module's phase change regulator storage bottle is a light-proof, sealed storage container with a low liquid level alarm device at the bottom and a one-way valve at the outlet. The metering pump is a micro-flow, high-precision plunger pump with an integrated liquid addition cumulative counting unit, providing three working modes: quantitative liquid addition, replenishment fine-tuning, and emergency pump stop. The mixing chamber is a sealed chamber with built-in spiral turbulence blades made of polytetrafluoroethylene. The mixing chamber inlet is equipped with a flow regulating valve, and the outlet is equipped with a static mixer.

4. The liquid-cooled lithium battery pack thermal management system according to claim 1, characterized in that, The mathematical expression for the coolant phase change temperature dynamic adaptation algorithm built into the intelligent control module is as follows: ;in, The target phase transition temperature for the coolant. The base value for phase transition temperature is used to match the ambient temperature and humidity. This is the correction factor for the rate of change of internal resistance. This is the normalization factor for the rate of change of battery internal resistance. This is the temperature and humidity coupling correction factor. This is the environmental temperature and humidity coupling normalization factor.

5. The liquid-cooled lithium battery pack thermal management system according to claim 1, characterized in that, The mathematical expression for the liquid cooling circuit flow coordination control algorithm built into the intelligent control module is as follows: ;in, Q0 represents the dynamic target flow rate of the liquid cooling circuit, and Q0 represents the base flow rate of the liquid cooling circuit under rated operating conditions of the lithium battery module. The internal resistance feedforward weighting coefficient is used. This is the normalization factor for the rate of change of battery internal resistance. The reference threshold for the rate of change of battery internal resistance. This is the phase transition temperature deviation feedback weighting coefficient. This is the phase transition temperature deviation normalization factor. This is the humidity heat transfer gain weighting coefficient. This is the ambient humidity heat transfer gain factor.

6. A temperature regulation method for a liquid-cooled lithium battery pack thermal management system, the method being applicable to the liquid-cooled lithium battery pack thermal management system according to any one of claims 1-5, characterized in that, The specific steps of this method are as follows: S100, parameter pre-configuration: preset system control rules, threshold parameters and algorithm coefficients in the controller to complete the calibration and storage of thermal control reference parameters; S200, Data Acquisition: Continuously collects data on the external environment temperature and humidity of the lithium battery module, battery internal resistance and rate of change through a multi-dimensional sensing module, and transmits all collected data to the controller synchronously. S300, parameter calculation: After receiving the collected data, the controller preprocesses the data, calculates the target phase change temperature of the coolant through the coolant phase change temperature dynamic adaptation algorithm, calculates the target flow rate of the liquid cooling circuit through the liquid cooling circuit flow collaborative control algorithm, and integrates the target phase change temperature of the coolant and the target flow rate of the liquid cooling circuit to form a cooling parameter control scheme. S400, Regulation and Calibration: The controller issues regulation commands to each execution module according to the cooling parameter regulation scheme to complete phase change temperature regulation, auxiliary heat dissipation regulation and emergency flow regulation. Combined with the actual phase change temperature and mixed concentration data monitored by the detection feedback module, the controller performs closed-loop calibration and correction of the coolant phase change temperature and liquid cooling circuit flow. S500, Dynamic Adaptation: The multi-dimensional sensing module and detection feedback module continuously collect real-time data and transmit it to the controller. The controller continuously updates the target phase change temperature of the coolant and the target flow rate of the liquid cooling circuit based on the data fluctuations through the dynamic adaptation algorithm of coolant phase change temperature and the collaborative control algorithm of liquid cooling circuit flow rate. It repeatedly performs the control calibration operation to complete the dynamic self-adaptive control of cooling parameters.

7. The temperature regulation method for a liquid-cooled lithium battery pack thermal management system according to claim 6, characterized in that, In step S100, the preset system control rules in the controller include matching rules between ambient temperature and humidity and the base value of the coolant phase change temperature. The base value of the coolant phase change temperature is 25°C when the ambient temperature is between -20°C and 10°C, 30°C when the ambient temperature is between 10°C and 25°C, 35°C when the ambient temperature is between 25°C and 40°C, and 40°C when the ambient temperature is between 40°C and 60°C. The preset threshold parameters include a temperature and humidity abrupt change judgment threshold, a phase change temperature deviation control threshold, and a battery internal resistance change rate threshold. The threshold values ​​are: the critical value for the rate of change of ambient temperature and the critical value for the rate of change of ambient relative humidity; the threshold value for the phase change temperature deviation control is the allowable deviation between the actual value and the target value of the coolant phase change temperature; and the threshold value for the rate of change of battery internal resistance is the critical value for the change of battery internal resistance per unit time. The preset algorithm coefficients include the internal resistance change rate correction coefficient, the temperature and humidity coupling correction coefficient, the internal resistance feedforward weight coefficient, the phase change temperature deviation feedback weight coefficient, and the humidity heat transfer gain weight coefficient. After completing the input of all system control rules, threshold parameters, and algorithm coefficients, the thermal control reference parameters are calibrated, and all calibrated parameters are stored in the controller's storage unit, which is a component of the intelligent control module.

8. The temperature regulation method for a liquid-cooled lithium battery pack thermal management system according to claim 6, characterized in that, In step S200, the multi-dimensional sensing module collects data at a frequency of 0.5 to 2 seconds each time. The ambient temperature and humidity sensor collects the current ambient temperature, the ambient temperature one hour ago, and the real-time relative humidity outside the lithium battery module. The battery internal resistance online monitoring module collects the current internal resistance and the internal resistance one hour ago and calculates the rate of change of internal resistance. The multi-dimensional sensing module synchronously transmits all collected data to the controller through the industrial bus. During the transmission process, a data frame verification mechanism is used. The controller timestamps all received collected data and stores the data in the controller's cache unit according to the collection time order. The cache unit is a component of the intelligent control module. The cache unit stores the collected data according to a preset rule, which is to overwrite historical collected data that exceeds the storage capacity in chronological order.

9. The temperature regulation method for a liquid-cooled lithium battery pack thermal management system according to claim 6, characterized in that, In step S300, the controller's preprocessing operation for the collected data includes removing abnormal collected data that exceeds the 3σ principle and replacing the abnormal collected data with valid collected data from the previous collection cycle. After preprocessing, the target phase change temperature of the coolant is first calculated using a dynamic adaptation algorithm for coolant phase change temperature. The target phase change temperature is set within the range of 25°C to 40°C. Then, the target flow rate of the liquid cooling circuit is calculated using a coordinated control algorithm for the liquid cooling circuit. The target flow rate is set at a lower limit of 1.2 times the basic flow rate of the liquid cooling circuit under the rated operating conditions of the lithium battery module, and an upper limit of 2.0 times the basic flow rate of the liquid cooling circuit under the rated operating conditions of the lithium battery module. When the rate of change of ambient temperature and the rate of change of ambient relative humidity in the collected data reach the threshold for sudden temperature and humidity changes, the target flow rate of the liquid cooling circuit is executed at the lower limit. The controller integrates the target phase change temperature of the coolant with the target flow rate of the liquid cooling circuit, and the integrated content is the cooling parameter control scheme.

10. The temperature regulation method for a liquid-cooled lithium battery pack thermal management system according to claim 6, characterized in that, In step S400, the controller sends control commands to the phase change temperature adjustment module, liquid cooling circulation module, and auxiliary heat dissipation module according to the cooling parameter control scheme. The control commands sent to the phase change temperature adjustment module include liquid addition amount, liquid addition rate, and liquid addition interval. The closed-loop calibration judgment rule is that when the deviation between the actual value of the coolant phase change temperature collected by the detection feedback module and the target phase change temperature of the coolant reaches the phase change temperature deviation control threshold, the controller sends a command to the phase change temperature adjustment module to add regulator. The control commands sent to the auxiliary heat dissipation module include fan start / stop and fan speed. The speed control rule for the variable-speed cooling fan of the auxiliary heat dissipation module is that the fan is off when the ambient relative humidity is below 60%, the fan speed is 1000 rpm when the ambient relative humidity is between 60% and 80%, and the fan speed is 1500 rpm when the ambient relative humidity is greater than or equal to 80%. The emergency flow control command issued to the liquid cooling circulation module is triggered when the rate of change of ambient temperature and the rate of change of ambient relative humidity reach the threshold for sudden temperature and humidity changes. In this case, the controller issues a command to the liquid cooling circulation module to adjust the flow rate to the target flow rate of the liquid cooling circuit.

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