Off-highway dump truck battery thermal management cooling system and method

Abstract

The invention discloses an off-highway dump truck battery thermal management cooling system and method, and belongs to the technical field of off-highway dump truck battery thermal management. The system comprises a battery heat management unit, a water outlet pipe, a battery water inlet diverter, a plurality of battery water inlet branches, a plurality of battery water outlet branches, a battery water outlet diverter, a water return pipe, a temperature sensor, a controller and an expansion water tank, the battery heat management unit comprises an electronic water pump, an electromagnetic valve, a heat dissipation water tank, a fan, a compressor, a condenser, an expansion water valve, a plate heat exchanger and a PTC heater, and three main modes including a battery pack heating mode, a battery pack cooling mode and a battery pack natural air cooling mode are switched. The method is mainly used for temperature regulation and control of the off-highway dump truck battery pack, ensures that the battery is in a safe working temperature interval under different working conditions, and improves the battery performance and prolongs the service life.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of off-highway dump truck battery thermal management. More specifically, the present application relates to an off-highway dump truck battery thermal management cooling system and method. BACKGROUND

[0002] Off-highway dump trucks are mainly used in heavy-load operation scenarios such as mines, and their operation characteristics are heavy load, short driving distance, and frequent start-stop operation. Traditional off-highway dump trucks with fuel engines have the problems of high energy consumption and large exhaust emissions, and cannot meet the demand for low energy consumption and low emissions in the green transformation of mines. Therefore, the market share of pure electric and hybrid off-highway dump trucks is gradually increasing. As the core power source of pure electric and hybrid off-highway dump trucks, the power battery will continuously generate a large amount of heat under heavy-load working conditions, and local high-temperature phenomena are prone to occur. If the temperature cannot be timely and effectively regulated, it will lead to shortened battery life and increased failure rate, so an efficient battery thermal management system is needed to ensure its safe and stable operation.

[0003] At present, the battery thermal management system of hybrid new energy off-highway dump trucks on the market mainly connects multiple battery packs in series through rubber pipes, and the water cooling unit sequentially delivers cooling liquid to the cooling pipelines of each battery pack. In this cooling mode, the temperature of the cooling liquid increases after flowing through the previous battery pack, resulting in a significantly higher water inlet temperature of the subsequent battery pack than that of the previous battery pack. This causes some battery packs to have excess heat dissipation power and some battery packs to have insufficient heat dissipation power, resulting in uneven temperature distribution among the battery packs in the battery pack. As the running time increases, the temperature difference gradually widens, which further affects the charging and discharging performance of the entire battery pack, ultimately leading to a decrease in the power output stability of the entire vehicle. In addition, long-term temperature imbalance can also exacerbate battery degradation, further shortening the service life of the battery. The existing system lacks targeted design to solve this temperature uniformity problem. SUMMARY

[0004] The present application provides an off-highway dump truck battery thermal management cooling system, which realizes uniform distribution of cooling liquid through multiple battery water inlet branches, multiple battery water outlet branches, a battery water inlet diverter, multiple battery water inlet branches, multiple battery water outlet branches, and a battery water outlet diverter, solves the problem of uneven temperature distribution of battery packs, prolongs the service life of the battery, and improves the charging and discharging performance.

[0005] The present application provides an off-highway dump truck battery thermal management cooling method, which realizes precise temperature control, reduces energy consumption, and ensures the safe and stable operation of the battery under complex working conditions by dynamically switching heating, cooling, and other modes and sub-modes according to driving / charging scenarios and extreme high-temperature startup emergency mode.

[0006] In order to achieve the purposes and other advantages according to the present application, a battery thermal management cooling system for off-highway dump truck is provided, comprising a battery thermal management unit, a water outlet pipe, a battery water inlet diverter, a plurality of battery water inlet branches, a plurality of battery water outlet branches, a battery water outlet diverter, a water return pipe, temperature sensors, a controller and an expansion tank, the plurality of temperature sensors are respectively arranged at the water outlet, the water inlet of the battery thermal management unit and the plurality of battery packs, at least one temperature sensor is arranged on each battery pack, and the controller controls the on-off or opening degree of each component according to the feedback of the temperature sensors; The battery thermal management unit comprises an electronic water pump, an electronic three-way valve, a heat dissipation water tank, a fan, a compressor, a condenser, an expansion water valve, a plate heat exchanger and a PTC heater. The water outlet of the battery thermal management unit is communicated with one end of the water outlet pipe, the other end of the water outlet pipe is communicated with the water inlet of the battery water inlet diverter, the plurality of water outlets of the battery water inlet diverter are respectively communicated with the water inlets of the plurality of battery water inlet branches one by one, a plurality of electromagnetic valves are connected in series in the plurality of battery water inlet branches, the water outlet of each battery water inlet branch is used for being communicated with the water inlet of the cooling water circuit of one battery pack one by one, the water outlet of each battery pack is communicated with the water inlet of one battery water outlet branch one by one, the water outlets of the plurality of battery water outlet branches are respectively communicated with the plurality of water inlets of the battery water outlet diverter one by one, the water outlet of the battery water outlet diverter is communicated with one end of the water return pipe, the other end of the water return pipe is communicated with the water inlet of the battery thermal management unit, the water return pipe is further communicated with a water supplement pipe and a degassing pipe, the expansion tank supplements the cooling liquid in the cooling circuit through the water supplement pipe, and the bubbles generated in the cooling circuit are discharged into the expansion tank through the degassing pipe.

[0007] Preferably, the other end of the water outlet pipe is communicated with the water inlets of the battery water inlet diverters through a distribution unit, the distribution unit comprises a water outlet three-way valve, the first interface of the water outlet three-way valve is communicated with the other end of the water outlet pipe, and the second interface and the third interface of the water outlet three-way valve are respectively communicated with the water inlets of the two battery water inlet diverters. The water outlet of the battery water outlet diverter is communicated with one end of the water return pipe through a collection unit, the collection unit comprises a water return three-way valve, the first interface of the water return three-way valve is communicated with one end of the water return pipe, and the second interface and the third interface of the water return three-way valve are respectively communicated with the water outlets of the two battery water outlet diverters.

[0008] The cooling method of the battery thermal management cooling system for off-highway dump truck comprises the following steps: Collecting the highest temperature of the battery pack in real time through the temperature sensor T max Collecting the average temperature of the battery pack in real time through the temperature sensor T mean Collecting the lowest temperature of the battery pack in real time through the temperature sensor T minthe battery thermal management unit outlet, the battery thermal management unit inlet, and the outdoor environment temperature, and transmits the collected temperature data to the controller to switch among the three main modes of the battery pack heating mode, the battery pack cooling mode, and the battery pack natural air cooling mode, wherein the battery pack cooling mode includes a refrigeration sub-mode and a self-circulation sub-mode; When the controller determines that the driving heating condition is met T min ≤5℃ and T max ≤8℃, or the direct current charging heating condition is met T min ≤12℃ and T mean ≤15℃, the controller controls the battery thermal management unit to enter the battery pack heating mode, at which time the controller starts the PTC heater and the electronic water pump to heat the battery pack by circulating the heated cooling liquid in the plate heat exchanger; When the controller determines T max ≥28℃ and T mean ≥24℃, the controller controls the battery thermal management unit to enter the battery pack cooling mode, at which time the controller starts the compressor, the fan, and the electronic water pump to enter the refrigeration sub-mode to cool the battery pack by circulating the cooling liquid in the plate heat exchanger after heat exchange, and when the controller determines T max <28℃, the controller only starts the electronic water pump to enter the self-circulation sub-mode to cool the battery pack by circulating the cooling liquid in the plate heat exchanger; When the controller determines that the outdoor environment temperature is ≤-15℃, the controller controls the battery thermal management unit to enter the battery pack natural air cooling mode, at which time the controller starts the fan and the electronic water pump to cool the battery pack by circulating the cooling liquid in the heat dissipation water tank.

[0009] Preferably, after entering the battery pack cooling mode in the driving scenario, the controller further determines to enter the refrigeration sub-mode or the self-circulation sub-mode according to the cooling liquid temperature at the battery thermal management unit outlet and the previous working mode, specifically including: When the cooling liquid temperature is ≥15℃, if the previous working mode is the shutdown mode, the battery pack heating mode, or the self-circulation sub-mode, the controller switches to the refrigeration sub-mode; if the previous working mode is the refrigeration sub-mode, the controller controls to remain in the refrigeration sub-mode; When the coolant temperature is 12-15℃, if the previous working mode is the shutdown mode or the battery pack heating mode, the controller switches to the self-circulation sub-mode; if the previous working mode is the self-circulation sub-mode, the controller controls to keep the self-circulation sub-mode; if the previous working mode is the refrigeration sub-mode, the controller decides the subsequent mode according to the refrigeration duration: if the refrigeration duration < 5min, the controller controls to keep the refrigeration sub-mode, if the refrigeration duration ≥ 5min, the controller switches to the self-circulation sub-mode. When the coolant temperature ≤ 12℃, if the previous working mode is the refrigeration sub-mode, the controller controls to keep the refrigeration sub-mode; otherwise, the controller switches to the self-circulation sub-mode.

[0010] Preferably, after entering the battery pack cooling mode in the charging scenario, the controller further decides the refrigeration sub-mode or the self-circulation sub-mode according to the coolant temperature at the outlet of the battery thermal management unit and the previous working mode, specifically including: When the coolant temperature ≥ 10℃, if the previous working mode is the shutdown mode, the battery pack heating mode or the self-circulation sub-mode, the controller switches to the refrigeration sub-mode; if the previous working mode is the refrigeration sub-mode, the controller controls to keep the refrigeration sub-mode. When the coolant temperature is 7-10℃, if the previous working mode is the shutdown mode or the battery pack heating mode, the controller switches to the self-circulation sub-mode; if the previous working mode is the self-circulation sub-mode, the controller controls to keep the self-circulation sub-mode; if the previous working mode is the refrigeration sub-mode, the controller decides the subsequent mode according to the refrigeration duration: if the refrigeration duration < 10min, the controller controls to keep the refrigeration sub-mode; if the refrigeration duration ≥ 10min, the controller switches to the self-circulation sub-mode. When the coolant temperature ≤ 7℃, if the previous working mode is the refrigeration sub-mode, the controller controls to keep the refrigeration sub-mode; otherwise, the controller switches to the self-circulation sub-mode.

[0011] Preferably, when the controller judges T max ≥ 38℃, the controller controls the battery thermal management unit to switch to the emergency mode, and forcibly starts the compressor, the fan and the electronic water pump to run for ≥ 15min, and then the controller switches the working mode according to the current scenario as the driving cooling or the charging cooling.

[0012] Preferably, the following mode closing steps are further included: In the battery pack heating mode, when the driving heating closing condition T min ≥ 10℃ or T mean ≥ 13℃, or the direct current charging heating closing conditionT min ≥17℃ or T mean When the temperature is ≥20℃, the controller will exit the battery pack heating mode. In battery pack cooling mode, when the controller determines T max ≤24℃ and T mean When the temperature is ≤22℃, the controller will exit the battery pack cooling mode. After emergency mode is activated, when the controller determines... T max ≤23℃ and T mean When the temperature is ≤21℃, the controller will exit the emergency mode. In the battery pack natural air cooling mode, when the controller determines that the coolant temperature at the outlet of the battery thermal management unit is >12℃ in the driving scenario or >7℃ in the charging scenario, the controller will exit the battery pack natural air cooling mode.

[0013] Preferably, the highest temperature of the battery pack is collected in real time by a temperature sensor. T max Average temperature T mean Minimum temperature T min Specifically, it includes: The controller uses a reference sampling frequency f 0. Collect temperature values ​​for each battery pack; Real-time calculation of the instantaneous temperature change rate of each battery pack within the current sampling period v i : in, T i,b For the first i The battery pack is currently the [number]th [number]. b Temperature at any moment T i,b-1 For the first i The temperature of the battery pack at the previous moment, Δ t s The sampling period; When the absolute value of the instantaneous temperature change rate of any battery pack | v i | Exceeds the preset rate of change threshold of the battery pack v ,th At that time, the controller increases the sampling frequency of the battery pack to f 1: wherein, k is a response coefficient greater than 1; the controller updates the temperature data at the boosted sampling frequency, and T max , T mean , T min and performs the subsequent mode determination.

[0014] Preferably, in the battery pack cooling mode and the battery pack natural air cooling mode, the controller periodically calculates the real-time maximum temperature difference Δ T of all battery packs, and calculates the change rate T of Δ α : wherein, Δ T n is the real-time maximum temperature difference of all battery packs in the current n period, Δ T n-1 is the real-time maximum temperature difference of all battery packs in the previous period, and Δ t T is the period length of temperature difference calculation; when Δ T th and its change rate α>0, the controller starts dynamic flow distribution: wherein, Q i is the dynamic heat dissipation power of the i th battery pack, Q 0i is the basic dynamic heat dissipation power of the i th battery pack, T i is the real-time temperature of the i th battery pack, T max，th , T min，th are the maximum and minimum values of the safe working temperature range of the battery pack, β is the temperature influence coefficient, gamma is the temperature difference change rate correction coefficient; The controller adjusts the opening degree of the electromagnetic valve to perform flow distribution until Δ T is reduced to the threshold value Δ T th and α ≤0.

[0015] Preferably, the controller adjusts the opening degree of the electromagnetic valve, and the specific step of flow distribution comprises: The controller generates a corresponding electromagnetic valve opening degree control signal according to the calculated flow demand of each battery pack Q i The controller sends control instructions to the electromagnetic valve at a frequency of 1 Hz to adjust the valve opening degree of each battery water inlet branch in real time; At the same time, the controller continuously monitors the value of Δ T and α until Δ T reduces to the threshold value Δ T th When Δ α ≤0, the electromagnetic valve opening degree is restored to the state before the equalization control.

[0016] The present application at least includes the following beneficial effects: First, the present application realizes uniform distribution of cooling liquid for multiple battery packs through multiple battery water inlet branches, multiple battery water outlet branches, a battery water inlet diverter, and a battery water outlet diverter, avoids local temperature imbalance, solves the problems of insufficient cooling liquid and bubble retention through the design of the water supply pipe and the degassing pipe, guarantees the stability of the circulation, the temperature sensor monitors the temperature of the key nodes in real time, the controller accurately controls each component, can maintain the safe temperature of the battery under high and low temperature environments, adapts to the complex working conditions of off-highway dump trucks, effectively prolongs the service life of the battery and improves the charging and discharging performance, and at the same time, the system components are mature industrial parts, easy to purchase and assemble.

[0017] Second, the present application sets differential heating conditions for driving and charging scenes, sets a natural air cooling mode for low temperature environments to avoid energy waste, and the heating mode guarantees the activity of the battery under low temperature, the cooling mode controls the temperature of the battery under high temperature, and the natural air cooling mode adapts to extreme low temperature, each mode is automatically switched by the controller without manual intervention, realizes full working condition temperature control coverage, improves the performance stability of the battery under different scenes, adapts to the operation needs of off-highway dump trucks, and guarantees the stability of the battery discharge efficiency.

[0018] Third, the present application dynamically adjusts the sampling frequency based on the battery temperature fluctuation data calculated by the instantaneous temperature change rate formula, the faster the temperature changes, the higher the sampling frequency, which ensures that the temperature fluctuation can be captured in real time, and when the temperature changes slowly, the base frequency is returned to avoid waste of controller computing power, ensure the real-time and accuracy of temperature data, update the temperature parameters based on the improved data, provide accurate basis for mode judgment, and enable the controller to quickly respond to battery temperature fluctuations.

[0019] ​Fourth, the present application adjusts the heat dissipation power of each battery pack, solves the problem of too large temperature difference of multiple battery packs, calculates the dynamic heat dissipation power by monitoring the maximum temperature difference and the change rate, combines the temperature and temperature difference change trend, ensures the accuracy of flow distribution, avoids overheating or overcooling of part of the battery pack, adjusts the opening of the electromagnetic valve of the corresponding high-temperature battery pack, realizes differentiated adjustment, solves the problems of insufficient heat dissipation of high-temperature battery pack and energy waste of low-temperature battery pack caused by traditional uniform water supply, especially adapts to the scene of part of the battery pack overheating when the off-highway dump truck is heavily loaded, and improves the overall safety of the battery pack.

[0020] Other advantages, objects, and features of the present application will be apparent to those skilled in the art from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 The structure diagram of the cooling system of one of the technical solutions of the present application; Figure 2 The principle diagram of the cooling system of one of the technical solutions of the present application; Figure 3 The pipe structure diagram of the cooling system of two groups of battery packs of one of the technical solutions of the present application; Figure 4 The structure diagram of the battery thermal management unit of one of the technical solutions of the present application. DETAILED DESCRIPTION

[0022] The present application will be further described in detail below with reference to the accompanying drawings, so that those skilled in the art can implement the present application according to the description.

[0023] It should be understood that the terms such as "have", "include" and "include" used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0024] It should be noted that, unless otherwise specified, the experimental methods described in the following embodiments are conventional methods, and the reagents and materials mentioned are commercially available. In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "setting" should be interpreted broadly. For example, they can refer to fixed connection or setting, detachable connection or setting, or integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. The terms "lateral," "longitudinal," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0025] Existing battery thermal management systems for off-highway dump trucks cannot achieve uniform distribution of coolant across multiple battery packs, resulting in rapid battery performance degradation and short lifespan, making them unsuitable for the complex operating conditions of off-highway dump trucks.

[0026] like Figures 1-2 As shown, the present invention provides a battery thermal management cooling system for off-highway dump trucks, including a battery thermal management unit 1, a water outlet pipe 6, a battery inlet water distributor 9, multiple battery water inlet branches, multiple battery water outlet branches, a battery water outlet distributor 10, a return water pipe 5, temperature sensors, a controller, and an expansion tank 2. Multiple temperature sensors are respectively installed at the water outlet and water inlet of the battery thermal management unit 1 and on multiple battery packs to collect the temperature of the coolant. Each battery pack is equipped with at least one temperature sensor to collect the temperature of each battery pack. The controller controls the on / off state or adjusts the opening degree of each component based on the feedback from the temperature sensors. The outlet of the battery thermal management unit 1 is connected to one end of the outlet pipe 6, and the other end of the outlet pipe 6 is connected to the inlet of the battery inlet diverter 9. Multiple outlets of the battery inlet diverter 9 are respectively connected to the inlets of multiple battery inlet branches. Multiple solenoid valves are connected in series to multiple battery inlet branches. The outlet of each battery inlet branch is connected to the cooling water inlet of a battery pack, and the cooling water outlet of each battery pack is connected to the inlet of a battery outlet branch. The outlets of multiple battery water outlet branches are connected to the multiple inlets of the battery water outlet distributor 10 one by one. The outlet of the battery water outlet distributor 10 is connected to one end of the return water pipe 5, and the other end of the return water pipe 5 is connected to the inlet of the battery thermal management unit 1. The return water pipe 5 is also connected to a water supply pipe 4 and a degassing pipe 3. The water supply pipe 4 supplies liquid, and the degassing pipe 3 discharges air bubbles. The expansion tank 2 supplies coolant to the cooling circuit through the water supply pipe 4, and the air bubbles generated in the cooling circuit are discharged into the expansion tank 2 through the degassing pipe 3.

[0027] When the off-highway dump truck starts, the controller first powers on to initialize, controls the electronic water pump to start, and the coolant begins to circulate in the system. The circulation path is: outlet of battery thermal management unit 1 → outlet pipe 6 → battery inlet distributor 9 → solenoid valve → battery inlet branch → cooling water circuit of battery pack → battery outlet branch → battery outlet distributor 10 → return pipe 5 → inlet of battery thermal management unit 1, forming a closed loop.

[0028] During the cycle, temperature sensors collect the temperature at each monitoring point in real time: temperature sensors at the unit's outlet and inlet collect the coolant temperature, and temperature sensors on the battery pack collect the temperature of each battery pack. All temperature data are transmitted to the controller in real time. The controller processes the collected battery pack temperatures and calculates the highest, average, and lowest temperatures of the battery pack. Combined with the coolant temperature and the outdoor ambient temperature (collected by an ambient temperature sensor located outside the vehicle's cab, with the same model as the battery pack temperature sensor), it determines the thermal management mode that needs to be activated.

[0029] The battery thermal management unit 1 regulates the temperature of the coolant as follows: like Figure 4 As shown, the battery thermal management unit 1 includes an electronic water pump, an electronic three-way valve, a heat sink, a fan, a compressor, a condenser, an expansion valve, a plate heat exchanger, a PTC heater (Positive Temperature Coefficient), and a controller. The controller also realizes the on / off control or opening degree adjustment of each sub-component of the battery thermal management unit 1. The expansion tank 2, the electronic water pump, and the first port of the electronic three-way valve are connected in sequence. The second port of the electronic three-way valve is connected to the cooling water tank. The cooling water tank is equipped with a fan facing opposite. The third port of the electronic three-way valve is connected to the plate heat exchanger. The plate heat exchanger is connected in series with the compressor, condenser, and expansion valve to form a refrigerant circuit. The end of the parallel pipeline between the cooling water tank and the plate heat exchanger is connected in series with the PTC heater and then connected to the battery.

[0030] When heating is required, the controller energizes the PTC heater to generate heat. The coolant flowing through the PTC heater is heated and then flows into the battery pack cooling water circuit, where it exchanges heat with the individual battery cells, transferring heat to the batteries and raising their temperature. When cooling is required, the controller shuts down the compressor, which then compresses the refrigerant. The refrigerant exchanges heat with the coolant in the plate heat exchanger, cooling the coolant. The cooled coolant then flows into the battery pack, absorbing heat from the batteries and achieving cooling. When the temperature reaches a certain level, the controller shuts down the compressor, and the self-circulating cooled coolant flows into the battery pack to absorb heat from the batteries, achieving cooling. When the temperature is extremely low, the controller shuts down the compressor, and the fan blows air into the radiator, carrying away the heat from the coolant in the radiator through airflow, thus cooling the coolant and dissipating heat from the batteries.

[0031] Meanwhile, during the entire circulation process, if the coolant level in the return pipe 5 is too low, the expansion tank 2 will replenish the coolant through the water supply pipe 4; the air bubbles generated during circulation will be discharged into the expansion tank 2 through the degassing pipe 3 to ensure smooth coolant circulation, avoid air bubbles from hindering heat exchange, ensure continuous and stable operation of the system, and provide a reliable temperature environment for off-highway dump truck battery packs.

[0032] In the above technical solution, multiple battery water inlet branches, multiple battery water outlet branches, battery water inlet distributor 9, and battery water outlet distributor 10 are used to achieve uniform distribution of coolant across multiple battery packs, avoiding local temperature imbalance. The design of water supply pipe 4 and degassing pipe 3 solves the problems of insufficient coolant and air bubble retention, ensuring circulation stability. Temperature sensors monitor the temperature of key nodes in real time, and the controller links various components for precise control, which can maintain the battery's safe temperature in high and low temperature environments, adapting to the complex working conditions of off-highway dump trucks, effectively extending battery life and improving charge and discharge performance. At the same time, the system components are all mature industrial parts, which are easy to procure and assemble, reducing the difficulty of implementation.

[0033] When dealing with two or more battery packs, a single inlet distributor is insufficient for efficient coolant distribution, and a single outlet distributor is insufficient for efficient coolant collection. This can easily lead to significant differences in water flow rates between different battery packs, further exacerbating temperature unevenness and affecting the overall thermal management performance of multiple battery packs. In another technical solution, such as... Figure 3As shown, the other end of the water outlet pipe 6 is connected to the inlet of the battery inlet distributor 9 through a distribution unit. The distribution unit includes a water outlet tee 8 to distribute coolant to multiple sets of inlet distributors. The first port of the water outlet tee 8 is connected to the other end of the water outlet pipe 6, and the second and third ports of the water outlet tee 8 are connected to the inlets of the two battery inlet distributors 9, respectively. The outlet of the battery water outlet distributor 10 is connected to one end of the return water pipe 5 through a collection unit. The collection unit includes a return water tee 7, which enables the coolant from multiple water outlet distributors to be collected into the return water pipe 5. The first port of the return water tee 7 is connected to one end of the return water pipe 5, and the second and third ports of the return water tee 7 are respectively connected to the outlets of the two battery water outlet distributors 10.

[0034] The unit's water outlet pipe 6 is connected to the battery inlet diverter 9, the unit's water outlet tee 8, and the battery inlet branch. The unit's water inlet pipe is also connected to the battery outlet diverter 10, the unit's return water tee 7, the battery outlet branch, the water supply pipe 4, and the degassing pipe 3.

[0035] After the electronic water pump starts, the coolant flows out from the outlet of the battery thermal management unit 1, flows through the outlet pipe 6 into the outlet tee 8 interface A' of the distribution unit, and inside the outlet tee 8, the coolant is evenly distributed to the interfaces B' and C', flowing into the two connecting pipes respectively, and then into the two battery inlet distributors 9. Each battery inlet distributor 9 further distributes the coolant to the four inlet branches, flowing into the four battery pack cooling water circuits of the corresponding group, and exchanging heat with the battery.

[0036] After heat exchange, the coolant flows out from the battery pack cooling water outlet and flows into the corresponding battery outlet distributor 10 through the outlet branch. The two outlet distributors collect the coolant from the four outlet branches of the group and then flow into the return water tee 7 interface B'' and interface C'' of the collection unit through the connecting pipe. Inside the return water tee 7, the two groups of coolant converge to interface A'', then flow into the return water pipe 5, and finally return to the inlet of the battery thermal management unit 1 to complete the circulation.

[0037] In the above technical solution, the addition of the distribution unit and the collection unit allows the system to adapt to two battery packs while achieving efficient distribution and collection of coolant through the outlet tee 8 and return tee 7, reducing the flow differences in the water paths of different battery packs and preventing localized overpressure. This further improves the temperature consistency of multiple battery packs. If the temperature of a certain battery pack is too high, the coolant flow in that branch can be appropriately increased by adjusting the opening of the solenoid valve. Compared with adding multiple independent diversion / collection structures, this design simplifies system complexity, reduces costs, and maintains coolant circulation efficiency, ensuring that both battery packs can obtain stable thermal management effects, thus adapting to the multi-battery pack configuration requirements of off-highway dump trucks.

[0038] Existing thermal management methods for off-highway dump truck batteries lack real-time and accurate monitoring and control of battery pack and coolant temperatures. They also struggle to maintain stable battery operating temperatures in high and low temperature environments, leading to energy waste and failing to meet the temperature control requirements of different scenarios such as driving and charging.

[0039] A cooling method for the thermal management cooling system of an off-highway dump truck battery includes the following steps: The highest temperature of the battery pack is collected in real time by a temperature sensor. T max Average temperature T mean Minimum temperature T min Specifically, the controller collects data from each temperature sensor at a frequency of 1Hz: it collects the temperature values ​​from all battery pack temperature sensors and calculates the battery pack's temperature. T max (The maximum temperature among all battery pack temperatures) T mean (Arithmetic mean of temperatures of all battery packs) T min The system measures the minimum temperature of all battery packs, including the coolant temperature at the outlet and inlet of the battery thermal management unit 1, as well as the outdoor ambient temperature. It transmits the collected temperature data to the controller, switching between three main modes: battery pack heating mode, battery pack cooling mode, and battery pack natural air cooling mode. In battery pack heating mode, the PTC heater heats the coolant to raise the battery pack temperature. Battery pack cooling mode lowers the battery pack temperature and includes a cooling sub-mode (compressor running, actively cooling the coolant) and a self-circulation sub-mode (compressor off, coolant only dissipates heat naturally through circulation). In battery pack natural air cooling mode, at extremely low temperatures, the compressor is turned off, and heat is dissipated through the radiator to cool the coolant. The system sequentially checks whether the conditions for heating mode, cooling mode, and natural air cooling mode are met, with the order being: heating mode first (prioritizing battery activity at low temperatures), followed by natural air cooling mode (compressor efficiency is low at extreme low temperatures), and finally cooling mode (active cooling is required at high temperatures). When the heating is activated while the off-highway dump truck is in motion, the controller determines that the heating conditions for driving are met. T min ≤5℃ and T max ≤8℃, or heating is activated when the battery pack is DC charged, meeting the DC charging heating conditions. T min ≤12℃ and T meanAt ≤15℃, the battery needs higher activity during charging, and the heating threshold is higher. The battery thermal management unit 1 is controlled to enter the battery pack heating mode. The third coolant circuit realizes the active heating of the battery. The controller controls the electronic three-way valve to connect the first port A and the third port C, the electronic water pump starts, the PTC heater starts, and other components are shut down (the plate heat exchanger only provides a coolant flow channel). The coolant in the expansion tank passes through the electronic water pump, electronic three-way valve, plate heat exchanger, and PTC heater. The PTC heater heats the coolant, and the heated coolant returns to the battery to heat the battery. This ensures the battery activity in low-temperature environments and avoids the decline in charge and discharge performance caused by low temperature. When the controller determines T max ≥28℃ and T mean When the temperature is ≥24℃, to avoid triggering a single high-temperature point and ensure overall cooling, the battery thermal management unit 1 is controlled to enter the battery cooling mode. At this time, the second coolant circuit achieves active cooling of the battery. The controller starts the compressor, fan, and electric water pump to enter the cooling sub-mode. The coolant cools the battery pack after heat exchange in the plate heat exchanger. Specifically, the electronic three-way valve switches to the first port A and the third port C, the electric water pump starts, the fan runs, the compressor starts, and the expansion valve is open. The refrigerant is compressed into a high-temperature, high-pressure gas by the compressor and cooled into a liquid by the condenser. It then enters the plate heat exchanger through the expansion valve to exchange heat with the coolant. The coolant in the expansion tank returns to the battery after being cooled by the plate heat exchanger via the electronic water pump and electronic three-way valve. Under high-temperature conditions, the battery temperature is controlled within a safe range. When the controller determines… T max At temperatures below 28℃, the third coolant circuit enables the battery's self-circulation cooling mode. In this mode, the controller only activates the electronic water pump to enter the self-circulation sub-mode. The coolant circulates in the plate heat exchanger to cool the battery pack. Specifically, the controller connects the first port A and the third port C of the electronic three-way valve, starts the electronic water pump, and shuts down other components (the plate heat exchanger and the PTC heater only provide a coolant flow channel). The coolant in the expansion tank, after self-circulation cooling via the electronic water pump, electronic three-way valve, plate heat exchanger, and PTC heater, returns to the battery to cool it. When the controller determines that the outdoor ambient temperature is ≤-15℃, the compressor's compression efficiency drops significantly, resulting in excessive energy consumption. Air cooling is suitable, so the controller controls the battery thermal management unit 1 to enter the battery pack's natural air cooling mode. The first coolant circuit achieves natural cooling of the battery. At this time, the controller starts the fan and the electric water pump, and the coolant circulates in the heat sink to cool the battery pack. Specifically, the controller controls the first port A and the second port B of the electronic three-way valve to connect, the electric water pump starts, the fan runs, and the coolant in the expansion tank returns to the battery after being cooled by the electric water pump, the electronic three-way valve, and the heat sink, thus providing natural cooling for the battery and balancing the low-temperature heat dissipation requirements with energy consumption.

[0040] In the above technical solution, three main modes and cooling sub-modes are dynamically switched by multi-dimensional temperature data. The natural air cooling mode is set for low-temperature environments to avoid energy waste, the heating mode ensures battery activity at low temperatures, the cooling mode controls battery temperature at high temperatures, and the natural air cooling mode is adapted to extreme low temperatures, achieving full-condition temperature control coverage, improving battery performance stability in different scenarios, and adapting to the needs of off-highway dump truck operations.

[0041] Existing thermal management methods for off-highway dump truck batteries are prone to over-cooling or under-cooling when the battery pack is cooled during driving scenarios. This increases energy consumption and fails to accurately maintain the battery's operating temperature, affecting the battery's performance stability during driving.

[0042] In another technical solution, after entering the battery pack cooling mode during driving, the controller further determines whether to enter either the cooling sub-mode or the self-circulation sub-mode based on the coolant temperature at the outlet of the battery thermal management unit 1 and the previous operating mode. In the driving cooling mode, the compressor and electric water pump operate simultaneously, actively cooling the coolant through the compressor to quickly reduce the battery temperature. This is suitable for scenarios with high coolant temperatures and where the battery requires strong heat dissipation. In the self-circulation sub-mode, the compressor is turned off, and the electric water pump operates, relying solely on the coolant circulating within the pipes for natural heat dissipation. This is suitable for scenarios with moderate coolant temperatures and where strong cooling is not required, thus reducing energy consumption. Specifically, this includes: When the coolant temperature at the outlet of battery thermal management unit 1 is ≥15℃, the battery discharge generates a strong amount of heat, and the heat dissipation capacity decreases. The compressor needs to be started for powerful cooling. If the previous working mode was the shutdown mode, battery pack heating mode, or self-circulation sub-mode, the controller will switch to the cooling sub-mode. If the previous working mode was the cooling sub-mode, the controller will maintain the cooling sub-mode. When the coolant temperature at the outlet of battery thermal management unit 1 is between 12-15℃, the coolant still has a certain natural heat dissipation capacity. Without compressor operation, the heat dissipation requirement can be met through the self-circulation sub-mode, reducing compressor energy consumption. If the previous operating mode was shutdown mode or battery pack heating mode, the controller switches to the self-circulation sub-mode. If the previous operating mode was self-circulation sub-mode, the controller maintains the self-circulation sub-mode. If the previous operating mode was cooling sub-mode, the controller determines whether to enter cooling sub-mode or self-circulation sub-mode based on the cooling duration. Frequent compressor starts and stops can shorten component lifespan. If the cooling duration is <5 minutes, the controller maintains the cooling sub-mode to balance heat dissipation requirements and component reliability. If the cooling duration is ≥5 minutes, the controller switches to the self-circulation sub-mode. When the coolant temperature at the outlet of the battery thermal management unit 1 is ≤12℃, if the previous working mode is the cooling sub-mode, the controller will maintain the cooling sub-mode to avoid repeated start-stop cycles that could damage components; otherwise, the controller will switch to the self-circulation sub-mode.

[0043] In the above technical solution, the battery discharge power fluctuates greatly during driving (heating increases sharply under heavy load and decreases under light load). The battery heat dissipation demand is reflected by the coolant temperature. Combined with the previous mode for precise control, when the coolant temperature is high, the cooling sub-mode is prioritized to cool down quickly. When the temperature is moderate, the self-circulation sub-mode is switched to save energy. At the same time, the continuity of the previous mode is considered to avoid frequent switching. The judgment on the duration of cooling prevents system fluctuations caused by repeated switching in a short period of time, ensuring that the battery temperature remains stable within a safe range during driving, reducing energy consumption and improving battery reliability during driving, and adapting to the dynamic heating characteristics of driving conditions.

[0044] Existing thermal management methods for off-highway dump truck batteries are prone to over-cooling or under-cooling during battery pack cooling in charging scenarios. This increases energy consumption and fails to accurately maintain the battery's operating temperature, affecting the battery's performance stability during charging.

[0045] In another technical solution, during the charging scenario, the battery only receives electrical energy and does not discharge externally. It generates only a small amount of heat due to its internal resistance, resulting in gradual heating and a slow temperature rise. After entering the battery pack cooling mode during the charging scenario, the controller further determines whether to enter a cooling sub-mode or a self-circulation sub-mode based on the coolant temperature at the outlet of the battery thermal management unit 1 and the previous operating mode. Specifically, this includes: When the coolant temperature at the outlet of battery thermal management unit 1 is ≥10℃, it can no longer meet the demand through natural heat dissipation and the compressor needs to be started. If the previous working mode was the shutdown mode, battery pack heating mode or self-circulation sub-mode, the controller switches to the cooling sub-mode; if the previous working mode was the cooling sub-mode, the controller maintains the cooling sub-mode. When the coolant temperature at the outlet of battery thermal management unit 1 is between 7-10℃, the natural heat dissipation of the coolant can match the low heat generation power of the battery during charging. Turning off the compressor can save thermal management energy consumption. If the previous working mode was the shutdown mode or the battery pack heating mode, the controller switches to the self-circulation sub-mode. If the previous working mode was the self-circulation sub-mode, the controller maintains the self-circulation sub-mode. If the previous working mode was the cooling sub-mode, the controller determines the subsequent mode based on the cooling duration: if the cooling duration is <10min, the controller maintains the cooling sub-mode to avoid ineffective switching and reduce the number of compressor start-stop cycles, thus improving component lifespan; if the cooling duration is ≥10min, the controller switches to the self-circulation sub-mode. When the coolant temperature at the outlet of battery thermal management unit 1 is ≤7℃, if the previous working mode is the cooling sub-mode, the controller will maintain the cooling sub-mode; otherwise, the controller will switch to the self-circulation sub-mode.

[0046] In the above technical solution, the battery has no discharge loss during charging. The cooling fluid temperature reflects the battery's heat dissipation needs. The cooling fluid temperature threshold is lowered to take advantage of the battery's gradual heating characteristics during charging. This better meets the battery's need for gentle temperature control during charging, minimizing energy consumption while ensuring battery charging safety and battery health.

[0047] If the battery pack is switched to the normal mode when the maximum temperature is too high, the best time to cool down may be missed, which may lead to battery thermal runaway and threaten battery safety and off-highway dump truck operation safety.

[0048] In another technical solution, when the controller determines... T max When the temperature reaches ≥38℃, the battery is close to the risk of thermal runaway. The battery thermal management unit 1 is switched to emergency mode to quickly cool down the battery and prevent thermal runaway. Specifically, after the emergency mode is triggered, regardless of the coolant temperature, outdoor ambient temperature, and the previous operating mode, the controller outputs a forced control signal to force the compressor and electric water pump to run for ≥15 minutes to ensure sufficient cooling, prioritizing battery safety and avoiding the risk of thermal runaway caused by the delay in switching from the normal mode. Subsequently, the controller switches the operating mode to vehicle cooling or charging cooling according to the current scenario, providing additional safety protection for off-highway dump truck batteries. This is especially suitable for extreme scenarios such as high-temperature operations in summer, reducing the probability of battery safety accidents and improving the overall safety of the system.

[0049] Existing thermal management methods for off-highway dump truck batteries involve continuous heating, cooling, emergency cooling, and natural air cooling. These methods continue to operate even when not in use, resulting in energy waste and potentially causing the battery to overheat or overcool due to continuous heating or cooling, thus damaging battery life.

[0050] Another technical solution also includes the following mode-closing steps: In battery pack heating mode, when the conditions for turning off the vehicle heating are met. T min ≥10℃ or T mean ≥13℃, or meet the DC charging heating shutdown conditions. T min ≥17℃ or T mean When the temperature is ≥20℃, the controller will exit the battery pack heating mode to ensure that the overall temperature is suitable or more conducive to charging efficiency, and to avoid the battery life being affected by excessive temperature. In battery pack cooling mode, when the controller determines T max ≤24℃ and T mean When the temperature is ≤22℃, the battery temperature drops to the lower limit of the safe range, and the controller exits the battery pack cooling mode. After emergency mode is activated, when the controller determines... T max ≤23℃ and T mean When the temperature is ≤21℃, the controller will exit the emergency mode. In the battery pack natural air cooling mode, when the controller determines that the coolant temperature at the outlet of the battery thermal management unit 1 is >12℃ in the driving scenario or >7℃ in the charging scenario, the controller will exit the battery pack natural air cooling mode.

[0051] The above technical solution clarifies the shutdown conditions for each mode, ensuring that heating, cooling, emergency, and natural air cooling modes shut down promptly after reaching preset temperature conditions, avoiding energy waste caused by continuous operation. For example, in heating mode, the PTC heater is turned off after the battery temperature reaches the target, and in cooling mode, the compressor is turned off after the temperature drops, preventing the battery from overheating or overcooling and further extending battery life. At the same time, the shutdown conditions can be precisely triggered by temperature sensors without manual intervention, improving the system's automation level and adapting to the unattended thermal management needs of off-highway dump trucks.

[0052] Existing off-highway dump truck battery thermal management methods use a fixed sampling frequency when collecting battery pack temperature. When the battery pack temperature changes abruptly, it cannot capture the temperature change in time, resulting in a delay in subsequent mode judgment, affecting the temperature control response speed, and failing to accurately monitor battery temperature fluctuations, which may cause temperature control strategy lag problems.

[0053] In another technical solution, the highest temperature of the battery pack is collected in real time using a temperature sensor. T max Average temperature Tmean Minimum temperature T min The rate of temperature change of a single battery pack is quantified by the ratio of the temperature difference between adjacent time points to the time interval, specifically including: (1) Calculation of instantaneous temperature change rate: The controller uses a reference sampling frequency f 0. Collect temperature values ​​for each battery pack; Real-time calculation of the instantaneous temperature change rate of each battery pack within the current sampling period v i Understand the degree of fluctuation in battery temperature: in, T i,b For the first i The battery pack is currently the [number]th [number]. b Temperature at any moment T i,b-1 For the first i The temperature of the battery pack at the previous moment, Δ t s The sampling period; In scenarios where battery temperature is stable, such as when off-highway dump trucks are lightly loaded or when the battery is stationary, the battery heats up gradually. T i,b-1 and T i,b The difference is small, and the calculated value is... v i A small absolute value of the rate of change indicates that the battery temperature is in a stable state and high-frequency sampling is not required. In scenarios involving sudden changes in battery temperature, such as when an off-highway dump truck suddenly experiences heavy loading, climbs a hill, or experiences a localized battery anomaly, the battery discharge power increases sharply. T i,b-1 and T i,b The difference expands rapidly, and the calculated v i Subsequently, it exceeded the preset threshold. v ,th This indicates that the battery temperature has entered a sudden change state, and the sampling frequency needs to be increased to capture real-time changes. (2) Dynamic sampling frequency adjustment: When the absolute value of the instantaneous temperature change rate of any battery pack | v i | Exceeds the preset rate of change threshold of the battery pack v ,th If this occurs, it indicates a sudden change in battery temperature, requiring a higher sampling frequency to capture the change. The controller then increases the sampling frequency of the battery pack to [a higher frequency]. f 1: in, k A response coefficient greater than 1 is used to amplify the adjustment range of the sampling frequency, ensuring sensitivity to sudden temperature changes. The controller updates the temperature data based on the increased sampling frequency. T max , T mean , T min The controller will then perform subsequent mode checks. If the condition is met for multiple consecutive cycles, the controller will automatically... f 1 Restore to f 0, to prevent long-term high-frequency sampling from consuming too much of the controller's computing power.

[0054] In the above technical solution, the sampling frequency is dynamically adjusted. The faster the temperature changes, the higher the sampling frequency is, ensuring that temperature fluctuations can be captured in real time. When the temperature changes slowly, the frequency returns to the reference frequency to avoid wasting the controller's computing power and ensure the real-time performance and accuracy of the temperature data. The temperature parameters are updated based on the improved data to provide accurate basis for mode judgment, enabling the controller to respond quickly to battery temperature fluctuations.

[0055] Existing thermal management methods for off-highway dump truck batteries fail to adjust flow rates when the temperature difference between battery packs is too large and continues to increase. This results in some battery packs being in unsafe temperature ranges for extended periods, affecting the overall performance and lifespan of the battery pack.

[0056] In another technical solution, in both battery pack cooling mode and battery pack natural air cooling mode, the rate and direction of temperature change in the battery pack are quantified by the ratio of the temperature difference between adjacent cycles to the time interval. (1) Calculation of the rate of change of temperature difference: The controller periodically calculates the real-time maximum temperature difference Δ of all battery packs. T And calculate Δ T rate of change α Determine the trend of temperature difference changes in the battery pack: Where, Δ T n For the current number n The real-time maximum temperature difference of all battery packs within the cycle, that is, the difference between the maximum and minimum temperatures of all battery packs within the current cycle. Δ T n-1 The maximum real-time temperature difference of all battery packs in the previous cycle, i.e., the [number]th cycle. n The difference between the maximum and minimum temperatures of all battery packs within a -1 cycle. Δ t TThe period for calculating the temperature difference is the time interval between two consecutive calculations of Δ by the controller. T The time interval; like α >0 indicates that the current cycle temperature difference Δ T n Greater than the previous period Δ T n-1 The temperature difference in the battery pack is continuing to widen, and dynamic flow distribution needs to be activated to suppress its expansion. like α ≤0 indicates that the temperature difference has not increased, and no additional flow rate adjustment is needed to avoid excessive intervention; (2) Calculation of dynamic heat dissipation power: To obtain more heat dissipation power (flow) for battery packs with higher temperatures and more significant temperature differences, when Δ T Continuously exceeding the threshold Δ T th And its rate of change α When the value is >0, the controller initiates dynamic traffic allocation: in, Q i For the first i The dynamic heat dissipation power of a battery pack, that is, the target heat dissipation power that the battery pack needs to be allocated, directly determines the coolant flow rate (the greater the power, the more flow rate is required). Q 0i For the first i The basic dynamic heat dissipation power of a battery pack is the initial heat dissipation power of the battery pack when the temperature difference is balanced (preset according to the battery pack capacity). T i For the first i Real-time temperature of each battery pack T max，th , T min，th These are the highest and lowest values ​​within the safe operating temperature range of the battery pack. β This is the temperature influence coefficient. gamma This is the correction factor for the rate of change of temperature difference; To normalize the temperature deviation calculation, the temperature deviation of different battery packs is normalized to the 0-1 range to avoid calculation errors caused by differences in the absolute value of temperature. T i = T min，th (Minimum safe temperature), this factor = 0 indicates that the battery pack temperature is at its lowest, and no additional flow is required. T i = T max，th(Maximum safe temperature): This factor = 1 indicates that the battery pack has the highest temperature and the flow rate needs to be increased to the maximum extent. When the temperature difference increases α Further increase the flow rate of the high-temperature battery pack to suppress the temperature difference from expanding further: like α >0,1+ gamma × α >1, which amplifies the effect of temperature-related factors, allowing high-temperature battery packs to obtain more flow; like α ≤0, 1+ gamma × α = 1, only retain the effect of temperature deviation, and avoid over-distributing flow; Based on base power Q 0i Based on the baseline, the battery pack needs to allocate more flow rate when the temperature is high or the temperature difference is large compared to the baseline state, while the battery pack does not need additional flow rate when the temperature is the lowest and the temperature difference is stable.

[0057] The controller distributes flow by adjusting the opening of the solenoid valve until Δ T Reduce to threshold Δ T th The following and α ≤0.

[0058] In the above technical solution, the flow distribution is dynamically adjusted. By monitoring the maximum temperature difference and the rate of change, the heat dissipation power of each battery pack is adjusted in a targeted manner to solve the problem of excessive temperature difference among multiple battery packs. The dynamic heat dissipation power is calculated in combination with the temperature and temperature difference change trend to ensure the accuracy of flow distribution and avoid some battery packs from overheating or overcooling. The flow adjustment is achieved by adjusting the solenoid valve, which improves the overall temperature consistency of the battery pack and extends the overall life of the battery pack.

[0059] Existing off-highway dump truck battery thermal management methods do not involve flow distribution, making it difficult to accurately and in real time adjust the flow of each branch, and unable to ensure that the temperature difference drops rapidly below the safety threshold.

[0060] In another technical solution, the controller distributes flow by adjusting the opening of the solenoid valve, and the specific steps include: The controller calculates the required flow rate for each battery pack. Q i ,Establish Q i - An opening mapping relationship is established to generate the solenoid valve opening control signal for each battery pack branch. Specifically, in a laboratory environment, the solenoid valve is connected in series with a flow sensor, and the valve opening is gradually adjusted (0-100%, 5% at a time). The actual coolant flow rate at the corresponding opening is recorded, and then combined with... , cThe specific heat capacity correlation coefficient of the coolant. q (for traffic), establish Q i A one-to-one mapping table of target flow rate and opening degree is stored in the controller. When a certain battery pack is calculated... Q i The controller calls the mapping relationship and queries it. Q i Corresponding to the opening degree, a control signal for the opening degree is then generated; The controller sends control commands to the solenoid valve at a frequency of 1Hz. The battery pack of the off-highway dump truck has multiple parallel branches. Q i Unlike other controllers, the controller sends individual commands to the solenoid valves of each battery water inlet branch to adjust the valve opening of each battery water inlet branch in real time. Meanwhile, the controller continuously monitors Δ at a frequency of 2Hz. T and α The value ensures timely capture of temperature difference changes, up to Δ. T Reduce to threshold Δ T th The following and α When the value is ≤0, the solenoid valve opening will be restored to the state before equalization control. Dynamic traffic allocation is a temporary emergency measure, not a long-term solution. When Δ T Reduce to threshold Δ T th The following and α When the temperature difference is ≤0, the battery pack temperature difference has converged to a safe range. There is no need to allocate additional flow to the high-temperature pack. The temperature difference is restored to a balanced opening, allowing the coolant flow to return to its initial balanced state. This resets the dynamic adjustment for the next temperature difference expansion and avoids uneven valve wear caused by long-term unbalanced flow.

[0061] The above technical solution clarifies the solenoid valve regulation, standardizes dynamic flow distribution, ensures the real-time nature of flow adjustment with a 1Hz command sending frequency, and promptly grasps temperature difference changes with a 2Hz monitoring frequency to avoid over- or under-adjustment, reduce human operation errors, ensure that the flow of each battery pack is accurately adapted to the needs, further guarantee the temperature balance of multiple battery packs, and improve the stability of system operation.

[0062] In summary, this invention significantly improves the precision of control through multi-dimensional optimization: on the one hand, it subdivides temperature ranges into multiple levels, differentiating the cooling activation threshold and inlet temperature range for driving and charging scenarios, effectively improving adaptability to different scenarios; on the other hand, it introduces the duration of the cooling mode as a basis for mode switching, for example, prioritizing the current mode when cooling is less than 5 minutes, avoiding frequent switching to enhance system stability; at the same time, it sets a special branch for emergency mode for extreme scenarios, triggering forced cooling logic at extreme high temperatures, and setting special shutdown conditions for the previous mode being emergency mode, improving the control chain in extreme scenarios; in addition, it achieves differentiated linkage of the previous mode state, setting completely different switching rules for different states such as shutdown / self-circulation / cooling / emergency mode switching (e.g., cooling → self-circulation less than 5 minutes), making the transition between the previous modes more complex and valuable for off-highway use, providing more solid technical support for the creativity of control strategies.

[0063] This invention adjusts the dynamic sampling frequency to collect battery pack temperature at a reference frequency, calculates the instantaneous temperature change rate, increases the frequency when the temperature exceeds a threshold, and restores the reference frequency after the temperature stabilizes, balancing data timeliness and computing power; it controls temperature difference and flow rate, periodically calculates the maximum temperature difference and change rate of all battery packs, and calculates the heat dissipation power of each pack and adjusts the solenoid valves when the temperature exceeds the threshold and the change rate is positive, suppressing the expansion of temperature difference; it refines execution, generates valve opening signals as needed, issues commands to adjust the opening once per second, monitors the temperature difference twice per second, and restores the valve equilibrium state after convergence, providing more solid technical support for the creativity of control strategies.

[0064] The number of devices and processing scale described herein are for the purpose of simplifying the description of the invention. Applications, modifications, and variations of the invention will be readily apparent to those skilled in the art.

[0065] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A battery thermal management cooling system for off-highway dump trucks, characterized in that, It includes a battery thermal management unit, a water outlet pipe, a battery inlet water distributor, multiple battery water inlet branches, multiple battery water outlet branches, a battery water outlet distributor, a return water pipe, temperature sensors, a controller, and an expansion tank. Multiple temperature sensors are respectively installed at the water outlet and water inlet of the battery thermal management unit and on multiple battery packs. Each battery pack is equipped with at least one temperature sensor. The controller controls the on / off state or adjusts the opening degree of each component based on the feedback from the temperature sensors. The battery thermal management unit includes an electronic water pump, an electronic three-way valve, a heat sink, a fan, a compressor, a condenser, an expansion valve, a plate heat exchanger, and a PTC heater. The outlet of the battery thermal management unit is connected to one end of the outlet pipe, and the other end of the outlet pipe is connected to the inlet of the battery inlet distributor. Multiple outlets of the battery inlet distributor are connected to the inlets of multiple battery inlet branches. Multiple solenoid valves are connected in series to multiple battery inlet branches. The outlet of each battery inlet branch is connected to the cooling water inlet of a battery pack. The cooling water outlet of each battery pack is connected to the inlet of a battery outlet branch. The outlets of multiple battery outlet branches are connected to the multiple inlets of the battery outlet distributor. The outlet of the battery outlet distributor is connected to one end of the return water pipe, and the other end of the return water pipe is connected to the inlet of the battery thermal management unit. The return water pipe is also connected to a water supply pipe and a degassing pipe. The expansion tank replenishes coolant to the cooling circuit through the water supply pipe, and the air bubbles generated in the cooling circuit are discharged into the expansion tank through the degassing pipe.

2. The off-highway dump truck battery thermal management cooling system according to claim 1, characterized in that, The other end of the water outlet pipe is connected to the inlet of the battery inlet diverter via a distribution unit. The distribution unit includes a water outlet tee. The first interface of the water outlet tee is connected to the other end of the water outlet pipe. The second and third interfaces of the water outlet tee are respectively connected to the inlets of the two battery inlet diverters. The outlet of the battery water outlet is connected to one end of the return water pipe through a collection unit. The collection unit includes a return water tee. The first port of the return water tee is connected to one end of the return water pipe, and the second and third ports of the return water tee are respectively connected to the outlets of the two battery water outlets.

3. The cooling method for the off-highway dump truck battery thermal management cooling system according to claim 1 or 2, characterized in that, Includes the following steps: The highest temperature of the battery pack is collected in real time by a temperature sensor. T max Average temperature T mean Minimum temperature T min The system collects the coolant temperature at the outlet and inlet of the battery thermal management unit, as well as the outdoor ambient temperature, and transmits the collected temperature data to the controller. It switches between three main modes: battery heating mode, battery cooling mode, and battery natural air cooling mode. The battery cooling mode includes a cooling sub-mode and a self-circulation sub-mode. When the controller determines that the vehicle heating conditions are met T min ≤5℃ and T max ≤8℃, or meet the conditions for DC charging heating. T min ≤12℃ and T mean When the temperature is ≤15℃, the battery thermal management unit is controlled to enter the battery pack heating mode. At this time, the controller starts the PTC heater and the electric water pump, and the heated coolant circulates in the plate heat exchanger to heat the battery pack. When the controller determines T max ≥28℃ and T mean When the temperature reaches ≥24℃, the battery thermal management unit enters the battery cooling mode. At this time, the controller starts the compressor, fan, and electric water pump to enter the cooling sub-mode. The battery pack is cooled by the coolant exchanging heat through the plate heat exchanger. When the controller determines… T max At temperatures below 28℃, the controller only activates the electronic water pump to enter the self-circulation sub-mode, where the coolant circulates in the plate heat exchanger to cool the battery pack. When the controller determines that the outdoor ambient temperature is ≤-15℃, it controls the battery thermal management unit to enter the battery pack natural air cooling mode. At this time, the controller starts the fan and electric water pump, and cools the battery pack by circulating the coolant in the heat sink.

4. The cooling method according to claim 3, characterized in that, After entering the battery pack cooling mode during driving, the controller further determines whether to enter the cooling sub-mode or the self-circulation sub-mode based on the coolant temperature at the battery thermal management unit outlet and the previous operating mode. Specifically, this includes: When the coolant temperature is ≥15℃, if the previous operating mode was the shutdown mode, battery pack heating mode, or self-circulation sub-mode, the controller will switch to the cooling sub-mode; if the previous operating mode was the cooling sub-mode, the controller will maintain the cooling sub-mode. When the coolant temperature is between 12-15℃, if the previous operating mode was the shutdown mode or the battery pack heating mode, the controller switches to the self-circulation sub-mode; if the previous operating mode was the self-circulation sub-mode, the controller maintains the self-circulation sub-mode; if the previous operating mode was the cooling sub-mode, the controller determines whether to enter the cooling sub-mode or the self-circulation sub-mode based on the cooling duration: if the cooling duration is <5min, the controller maintains the cooling sub-mode; if the cooling duration is ≥5min, the controller switches to the self-circulation sub-mode. When the coolant temperature is ≤12℃, if the previous operating mode is the refrigeration sub-mode, the controller will maintain the refrigeration sub-mode; otherwise, the controller will switch to the self-circulation sub-mode.

5. The cooling method according to claim 4, characterized in that, After entering the battery pack cooling mode during charging, the controller further determines whether to enter the cooling sub-mode or the self-circulation sub-mode based on the coolant temperature at the battery thermal management unit outlet and the previous operating mode. Specifically, this includes: When the coolant temperature is ≥10℃, if the previous operating mode was the shutdown mode, battery pack heating mode or self-circulation sub-mode, the controller switches to the cooling sub-mode; if the previous operating mode was the cooling sub-mode, the controller maintains the cooling sub-mode. When the coolant temperature is between 7-10℃, if the previous operating mode was the shutdown mode or the battery pack heating mode, the controller switches to the self-circulation sub-mode; if the previous operating mode was the self-circulation sub-mode, the controller maintains the self-circulation sub-mode; if the previous operating mode was the cooling sub-mode, the controller determines the subsequent mode based on the cooling duration: if the cooling duration is <10min, the controller maintains the cooling sub-mode; if the cooling duration is ≥10min, the controller switches to the self-circulation sub-mode. When the coolant temperature is ≤7℃, if the previous operating mode is the cooling sub-mode, the controller will maintain the cooling sub-mode; otherwise, the controller will switch to the self-circulation sub-mode.

6. The cooling method according to claim 5, characterized in that, When the controller determines T max When the temperature reaches ≥38℃, the battery thermal management unit is switched to emergency mode, and the compressor, fan and electric water pump are forcibly started and run for ≥15 minutes. After that, the controller switches the working mode to vehicle cooling or charging cooling according to the current scenario.

7. The cooling method according to claim 3, characterized in that, This also includes the following steps to disable the mode: In battery pack heating mode, when the conditions for turning off the vehicle heating are met. T min ≥10℃ or T mean ≥13℃, or meet the DC charging heating shutdown conditions. T min ≥17℃ or T mean When the temperature is ≥20℃, the controller will exit the battery pack heating mode. In battery pack cooling mode, when the controller determines T max ≤24℃ and T mean When the temperature is ≤22℃, the controller will exit the battery pack cooling mode. After emergency mode is activated, when the controller determines... T max ≤23℃ and T mean When the temperature is ≤21℃, the controller will exit the emergency mode. In the battery pack natural air cooling mode, when the controller determines that the coolant temperature at the outlet of the battery thermal management unit is >12℃ in the driving scenario or >7℃ in the charging scenario, the controller will exit the battery pack natural air cooling mode.

8. The cooling method according to claim 3, characterized in that, The highest temperature of the battery pack is collected in real time by a temperature sensor. T max Average temperature T mean Minimum temperature T min Specifically, it includes: The controller uses a reference sampling frequency f 0. Collect temperature values ​​for each battery pack; Real-time calculation of the instantaneous temperature change rate of each battery pack within the current sampling period v i : in, T i,b For the first i The battery pack is currently the [number]th [number]. b Temperature at any moment T i,b-1 For the first i The temperature of the battery pack at the previous moment, Δ t s The sampling period; When the absolute value of the instantaneous temperature change rate of any battery pack | v i | Exceeds the preset rate of change threshold of the battery pack v ,th At that time, the controller increases the sampling frequency of the battery pack to f 1: in, k A response coefficient greater than 1; The controller updates the temperature data based on the increased sampling frequency. T max , T mean , T min Then perform subsequent pattern judgments.

9. The cooling method according to claim 8, characterized in that, In both battery pack cooling mode and battery pack natural air cooling mode, the controller periodically calculates the real-time maximum temperature difference Δ of all battery packs. T And calculate Δ T rate of change α : Where, Δ T n For the current number n The real-time maximum temperature difference of all battery packs during the cycle, Δ T n-1 Δ represents the real-time maximum temperature difference of all battery packs in the previous cycle. t T The duration of the period calculated for the temperature difference; When ΔT continuously exceeds the threshold Δ T th And when its rate of change α > 0, the controller initiates dynamic flow allocation: in, Q i For the first i Dynamic heat dissipation power of each battery pack Q 0i For the first i The basic dynamic heat dissipation power of each battery pack T i For the first i Real-time temperature of each battery pack T max，th , T min，th These are the highest and lowest values ​​within the safe operating temperature range of the battery pack. β This is the temperature influence coefficient. γ This is the correction factor for the rate of change of temperature difference; The controller distributes flow by adjusting the opening of the solenoid valve until Δ T Reduce to threshold Δ T th The following and α ≤0.

10. The cooling method according to claim 9, characterized in that, The specific steps by which the controller distributes flow by adjusting the opening of the solenoid valve include: The controller calculates the required flow rate for each battery pack. Q i This generates the corresponding solenoid valve opening control signal; The controller sends control commands to the solenoid valve at a frequency of 1Hz to adjust the valve opening of each battery water inlet branch in real time. Meanwhile, the controller continuously monitors Δ at a frequency of 2Hz. T and α The value until Δ T Reduce to threshold Δ T th The following and α When the value is ≤0, the solenoid valve opening will be restored to the state before the equalization control.

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