Coolant control method, system, and vehicle

Abstract

This disclosure relates to a coolant control method, system, and vehicle, which can improve control accuracy while solving the coupling problem between coolant flow and air flow, thereby enhancing the stability of the fuel cell system. The coolant control method includes: acquiring the coolant outlet temperature of the fuel cell; when the coolant outlet temperature is greater than or equal to a preset threshold, controlling the valve opening of the electronic thermostat to be fully open; determining the number of working groups of the electronic fans based on the theoretical duty cycle value of each target electronic fan group, the coolant outlet temperature, the heat dissipation power value of the electronic fans, and the preset duty cycle threshold; and activating the electronic fans according to the number of working groups to dissipate heat from the flowing coolant, so that the coolant temperature reaches the preset target temperature.

Description

Technical Field

[0001] This disclosure relates to the field of fuel cell technology, and more specifically, to a coolant control method, system, and vehicle. Background Technology

[0002] With the global energy crisis, the development of fuel cell technology has received increasing attention. When a fuel cell is working, it generates a lot of heat and electricity. The heat generated helps to raise the temperature of the fuel cell stack, thereby improving its working efficiency. However, excessive heat will cause the stack temperature to rise continuously, destroying the activity of the catalyst and reducing the lifespan of the fuel cell. Therefore, it is necessary to remove excess heat in a timely and accurate manner to stabilize the stack at a suitable temperature and achieve continuous, stable and efficient operation of the fuel cell system.

[0003] The fuel cell cooling cycle system of related technologies cannot solve the problem of coupling between coolant flow and air flow while achieving precise temperature control, which will cause temperature fluctuations and affect the stability of the fuel cell system. Summary of the Invention

[0004] The purpose of this disclosure is to provide a coolant control method, system, and vehicle to solve the problem in related technologies that fail to achieve precise temperature control while simultaneously addressing the coupling between coolant flow and air flow, thereby improving the stability of fuel cell systems.

[0005] To achieve the above objectives, in a first aspect, this disclosure provides a coolant control method, the method comprising:

[0006] Obtain the coolant outlet temperature of the fuel cell;

[0007] When the coolant outlet temperature is greater than or equal to a preset threshold, the valve opening of the electronic thermostat is fully open, and the number of working groups of the electronic fan is determined according to the theoretical duty cycle value of each target electronic fan in the electronic fan, the coolant outlet temperature, the heat dissipation power value of the electronic fan and the preset duty cycle threshold.

[0008] The electronic fan is activated according to the number of working groups to dissipate heat from the flowing coolant, so that the temperature of the coolant reaches the preset target temperature.

[0009] Optionally, the theoretical duty cycle of each group of target electronic fans in the electronic fan is obtained in the following way:

[0010] Based on the difference between the coolant outlet temperature and the preset target temperature, and the rate of change of the coolant outlet temperature over a preset time interval, the duty cycle adjustment value is obtained through a fuzzy PID control algorithm.

[0011] The target duty cycle value of each group of target electronic fans is adjusted according to the duty cycle adjustment value to obtain the theoretical duty cycle value of each group of target electronic fans. The target duty cycle value is the duty cycle value obtained based on the ambient temperature and the theoretical heat dissipation of each group of target electronic fans.

[0012] Optionally, the step of activating the electronic fan according to the number of work groups to dissipate heat from the flowing coolant, so that the temperature of the coolant reaches the preset target temperature, includes:

[0013] The output duty cycle value of each target electronic fan group is determined based on the number of working groups of the electronic fan and the theoretical duty cycle value of the target electronic fan, and / or the output duty cycle value of each target electronic fan group is determined based on the fault information of the fuel cell.

[0014] The target electronic fans of the working group are started, and for each target electronic fan in the working group, the target electronic fan is controlled according to the corresponding output duty cycle value so that the temperature of the coolant reaches the preset target temperature value.

[0015] Optionally, determining the number of working groups of the electronic fans based on the theoretical duty cycle of each group of target electronic fans, the coolant outlet temperature, the heat dissipation power of the electronic fans, and a preset duty cycle threshold includes:

[0016] When the coolant outlet temperature meets the first preset condition and the heat dissipation power value of the electric fan meets the second preset condition, the number of working groups of the electric fan is controlled to be the first preset value.

[0017] When the theoretical duty cycle value meets the third preset condition and the heat dissipation power value of the electronic fan meets the second preset condition, the number of working groups of the electronic fan is controlled to be the second preset value, wherein the second preset value is less than the first preset value;

[0018] When at least one group of target electronic fans has a theoretical duty cycle value that is greater than or equal to different preset duty cycles, the number of working groups of the electronic fans is increased.

[0019] When at least two groups of target electronic fans have theoretical duty cycle values ​​that are less than or equal to different preset duty cycles, the number of working groups of the electronic fans is reduced.

[0020] Optionally, the electronic thermostat uses a fuzzy PID control algorithm to control the valve opening to increase or decrease.

[0021] Optionally, the method further includes:

[0022] Determine the ion concentration value of the coolant;

[0023] When the ion concentration of the coolant is greater than or equal to a first preset concentration value, the shut-off valve is opened to reduce the ion concentration of the coolant flowing through the deionizer by the water pump, wherein the shut-off valve is located between the deionizer and the water pump.

[0024] When the ion concentration of the coolant is less than or equal to a second preset concentration value, the shut-off valve is closed to keep the ion concentration of the coolant constant.

[0025] Secondly, this disclosure also provides a coolant control system, including:

[0026] Electronic thermostat, used to adjust the flow of coolant;

[0027] An electric fan is used to dissipate heat from the flowing coolant.

[0028] The controller is used to control the valve opening of the electronic thermostat to be fully open when the coolant outlet temperature is greater than or equal to a preset threshold, and to determine the number of working groups of the electronic fan according to the theoretical duty cycle value of each target electronic fan in the electronic fan group, the coolant outlet temperature, the heat dissipation power value of the electronic fan and the preset duty cycle threshold, and to start the electronic fan according to the number of working groups to dissipate heat from the flowing coolant so that the temperature of the coolant reaches the preset target temperature.

[0029] Optionally, the system further includes:

[0030] A water pump is used to control the circulation of the coolant;

[0031] A deionizer is used to control the ion concentration of the coolant;

[0032] A shut-off valve is installed between the deionizer and the water pump;

[0033] The controller is configured to open the shut-off valve when the ion concentration of the coolant is greater than or equal to a first preset concentration value, so as to reduce the ion concentration of the coolant flowing through the deionizer, and to close the shut-off valve when the ion concentration of the coolant is less than or equal to a second preset concentration value, so as to keep the ion concentration of the coolant constant.

[0034] Thirdly, this disclosure also provides a vehicle, including:

[0035] Fuel cells;

[0036] The coolant control system described in any one of the second aspects is used to control the coolant in the fuel cell.

[0037] The above technical solution allows the electronic thermostat valve to be fully open when the coolant outlet temperature is greater than or equal to a preset threshold. Based on the theoretical duty cycle of each target electronic fan group, the coolant outlet temperature, the fan's heat dissipation power, and the preset duty cycle threshold, the number of working groups for the electronic fans is determined, and the fans are activated according to this number to dissipate heat from the flowing coolant, ensuring the coolant temperature reaches the preset target temperature. Therefore, the fan does not operate when the electronic thermostat valve is not fully open; it only operates when the thermostat is fully open. This avoids system temperature fluctuations, ensuring system stability. It also achieves precise temperature control while resolving the coupling problem between coolant and airflow, thus improving the stability of the fuel cell system.

[0038] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0039] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0040] Figure 1 This is a flowchart illustrating a coolant control method according to an exemplary embodiment of the present disclosure;

[0041] Figure 2 This is a schematic diagram illustrating the principle of a fuzzy PID control algorithm according to an exemplary embodiment of the present disclosure;

[0042] Figure 3 This is a schematic diagram of a coolant control system according to an exemplary embodiment of the present disclosure;

[0043] Figure 4 This is a schematic diagram illustrating the control flow of the electronic fan working group number according to an exemplary embodiment of this disclosure;

[0044] Figure 5 This is a flowchart illustrating a coolant control method according to an exemplary embodiment of the present disclosure;

[0045] Figure 6 This is a schematic diagram of a coolant control system according to an exemplary embodiment of the present disclosure;

[0046] Figure 7 This is a block diagram illustrating a coolant control system according to an exemplary embodiment of this disclosure;

[0047] Figure 8This is a block diagram illustrating a coolant control system according to an exemplary embodiment of this disclosure. Detailed Implementation

[0048] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure.

[0049] Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims. It should be noted that in this disclosure, the terms "S101," "S102," etc., in the specification, claims, and drawings are used to distinguish steps and are not necessarily to be construed as performing method steps in a specific order or sequence.

[0050] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0051] With the global energy crisis, the development of fuel cell technology has received increasing attention. When a fuel cell operates, it generates a significant amount of heat and electricity. This heat helps raise the temperature of the fuel cell stack, thereby improving efficiency. However, excessive heat can cause the stack temperature to rise continuously, damaging the catalyst's activity and reducing the fuel cell's lifespan. Therefore, it is crucial to dissipate excess heat promptly and accurately, stabilizing the stack at a suitable temperature to ensure the continuous, stable, and efficient operation of the fuel cell system. A well-designed fuel cell cooling cycle system not only ensures the appropriate reaction temperature of the stack at all times, but its control methods can also precisely control the required reaction temperature and reduce the power consumption of the cooling cycle system.

[0052] In one related technology, different operating modes can be adopted at different operating temperatures. Temperature control of the fuel cell stack is achieved through a combination of large and small circulation systems and internal and external circulation systems, and different operating modes of the fuel cell stack cooling system are set according to changes in ambient temperature. This control method controls the system to operate in different modes by identifying temperature, thereby minimizing the power consumption of the cooling system. While the control scheme is simple and feasible, it does not achieve precise control of the system temperature.

[0053] Another related technology can determine whether the difference between the target temperature value of the coolant outlet and the real-time temperature value is less than a set temperature difference value, and start the fan strategy when the difference is less than the set temperature difference value. It can also dynamically adjust the number of fans by determining whether the actual output fan duty cycle is greater than the upper limit of the duty cycle. This can reduce the system cooling power consumption and improve the system control accuracy to a certain extent. However, it does not explain the calculation method between different numbers of fans and duty cycles, and it does not take into account the control problems caused by system failures.

[0054] The aforementioned technologies can improve the control of reaction temperature by the cooling system of fuel cell systems to a certain extent. However, from a practical application perspective, none of them have solved the coupling problem between coolant flow and air flow while achieving precise temperature control, which can lead to temperature fluctuations and affect the stability of the fuel cell system.

[0055] In view of this, the present disclosure provides a coolant control method to solve the problems in the related art, which can solve the coupling problem between coolant flow and air flow while achieving precise temperature control, thereby improving the stability of the fuel cell system.

[0056] Figure 1 This is a flowchart illustrating a coolant control method according to an exemplary embodiment of the present disclosure, with reference to... Figure 1 The method includes:

[0057] Step S101: Obtain the coolant outlet temperature of the fuel cell;

[0058] For example, the coolant outlet temperature of a fuel cell can be obtained by means of a temperature sensor or the like, but this disclosure does not limit this.

[0059] Step S102: When the coolant outlet temperature is greater than or equal to the preset threshold, the valve opening of the electronic thermostat is fully open, and the number of working groups of the electronic fan is determined according to the theoretical duty cycle value of each target electronic fan in the electronic fan group, the coolant outlet temperature, the heat dissipation power value of the electronic fan and the preset duty cycle threshold.

[0060] Step S103: Start the electric fan according to the number of working groups to dissipate heat from the flowing coolant so that the temperature of the coolant reaches the preset target temperature.

[0061] It should be understood that when the electronic thermostat valve is fully open, starting the electric fan can resolve the coupling problem between coolant flow and airflow. Specifically, the fully open valve increases the coolant flow, while the electric fan provides sufficient airflow, achieving a relatively high flow rate. In this way, the coolant and airflow have greater independence, relatively reducing their coupling effect. Furthermore, coupling problems arise in multivariable control. When multiple variables are simultaneously regulated or controlled, they may influence and interfere with each other's control processes. Such coupling effects can lead to unstable system response, difficulty in regulation, and undesirable control results. By adopting a single-variable control principle—that is, the fan does not operate when the electronic thermostat valve is not fully open, and only operates when the electronic thermostat is fully open—system temperature fluctuations and other issues can be avoided, ensuring system stability.

[0062] It should be understood that by setting a duty cycle threshold, one can avoid the electric fan from working to its limit before controlling the next electric fan to start. Furthermore, considering that the higher the duty cycle of an electric fan, the lower its efficiency, setting a duty cycle threshold can help control the fan to work in a relatively high efficiency range.

[0063] For example, the preset duty cycle threshold can be set according to the relationship between the actual speed and efficiency of the electric fan. For instance, the maximum duty cycle of the electric fan can be set to m and the minimum duty cycle to n, where m is less than or equal to the physical maximum value of the electric fan's duty cycle and n is greater than or equal to the physical minimum value of the electric fan's duty cycle. The preset duty cycle threshold can be set between n and m.

[0064] It should also be understood that the flow of coolant can be controlled by adjusting the opening of the electronic thermostat valve.

[0065] Specifically, the opening degree of the electronic thermostat valve can be adjusted using a fuzzy PID control algorithm. The fuzzy PID control algorithm takes the difference between the current state of the system and the set value (hereinafter referred to as error) as input, uses the error and the rate of change of error as input, performs fuzzy inference using fuzzy rules, and queries the fuzzy matrix table to adjust the parameters to meet the self-tuning requirements of the error and the rate of change of error at different times for the PID parameters, thereby improving the control accuracy of the system.

[0066] In this embodiment of the disclosure, the electronic thermostat uses a fuzzy PID control algorithm to control the valve opening degree to increase or decrease. For example, refer to... Figure 2 The temperature difference e between the target temperature and the actual temperature of the coolant, and the rate of change of the actual temperature over a preset time interval δ. eThe change in the electronic thermostat valve opening serves as the input to the fuzzy controller and as the controller output. Aiming to bring the coolant temperature to the optimal temperature for the current operating conditions, the flow direction of the coolant is controlled by adjusting the electronic thermostat valve opening, thereby improving the accuracy of coolant temperature control.

[0067] For example, the preset target temperature can be determined according to the actual operating conditions of the fuel cell. For instance, the target temperature of the coolant required by the fuel cell varies under different electrical densities, and this disclosure does not limit this.

[0068] For example, the preset threshold can be obtained by calibration. For instance, the measured data can be collected and analyzed and calibrated through experimental testing according to the actual situation. This disclosure does not limit this.

[0069] It should also be understood that, based on actual conditions, the first preset threshold and the second preset threshold can be obtained through calibration. Specifically, when the coolant outlet temperature is greater than or equal to the first preset threshold and less than the second preset threshold, the electric fan is in the off state, and the flow direction of the coolant can be controlled by the electronic thermostat to make the coolant temperature reach the preset target temperature; and when the coolant outlet temperature is greater than or equal to the second preset threshold, the valve opening of the electronic thermostat is controlled to be fully open, and the electric fan is started to dissipate heat from the flowing coolant to make the coolant temperature reach the preset target temperature value.

[0070] For example, refer to Figure 3 In the coolant control system shown in an exemplary embodiment of the present disclosure, the coolant of the fuel cell stack first passes through the water pump 301. When the coolant outlet temperature is detected to be greater than or equal to a first preset threshold and less than a second preset threshold, the electronic fan 304 is controlled to be turned off. Under the control of the electronic thermostat 302, the coolant flows simultaneously to both the heater 303 and the electronic fan 304, and finally flows back to the fuel cell stack.

[0071] When the coolant outlet temperature is detected to be greater than or equal to the second preset threshold, the valve opening of the electronic thermostat 302 is fully open, and the electronic fan 304 is started. All the coolant will flow to the passage where the electronic fan 304 is located, and finally flow back to the fuel cell stack.

[0072] When the coolant outlet temperature is detected to be lower than the first preset threshold, the electronic thermostat 302 is closed, and the coolant will flow entirely to the passage where the heater 303 is located, and eventually flow back to the fuel cell stack.

[0073] By comparing the coolant outlet temperature with a preset threshold using the above method, the electric fan and electronic thermostat can be controlled accordingly. Furthermore, based on the theoretical duty cycle of each target electric fan group, the coolant outlet temperature, the cooling power of the electric fan, and the preset duty cycle threshold, the number of working groups of electric fans can be determined. The electric fans are then activated according to the number of working groups to dissipate heat from the flowing coolant, ensuring the coolant temperature reaches the preset target temperature. Therefore, the fan does not operate when the electronic thermostat valve is not fully open; it only operates when the electronic thermostat is fully open. This avoids system temperature fluctuations, ensuring system stability. Simultaneously, it achieves precise temperature control and resolves the coupling problem between coolant flow and air flow, improving the stability of the fuel cell system.

[0074] In one possible approach, the theoretical duty cycle of each group of target electronic fans in an electronic fan system can be obtained as follows:

[0075] Based on the difference between the coolant outlet temperature and the preset target temperature, and the rate of change of the coolant outlet temperature over a preset time interval, a fuzzy PID control algorithm is used to obtain the duty cycle adjustment value. The target duty cycle value of each group of target electric fans is adjusted according to the duty cycle adjustment value to obtain the theoretical duty cycle value of each group of target electric fans. The target duty cycle value is the duty cycle value obtained based on the ambient temperature and the theoretical heat dissipation of each group of target electric fans.

[0076] It should be understood that by using the fuzzy PID control algorithm, the temperature difference between the preset target temperature of the coolant and the coolant outlet temperature, as well as the rate of change of the coolant outlet temperature over a preset time interval, can be used as the input to the fuzzy controller, and the duty cycle adjustment value can be used as the output of the controller.

[0077] It should be understood that the theoretical heat dissipation of each target electric fan can be adjusted through bench testing to obtain the actual value, which is more in line with the actual working conditions of the electric fan.

[0078] For example, the duty cycle adjustment value adjusts the target duty cycle value of each group of target electronic fans. The specific value can be obtained through calibration. For example, according to the actual situation, the measured data can be collected and analyzed through experimental testing and calibration can be performed. This disclosure embodiment does not limit this.

[0079] Using the above method, the duty cycle adjustment value can be obtained according to the fuzzy PID control algorithm, and the target duty cycle value of each group of target electronic fans can be adjusted to obtain the theoretical duty cycle value of each group of target electronic fans.

[0080] In one possible approach, electric fans are activated according to the number of workgroups to dissipate heat from the flowing coolant, so that the coolant temperature reaches a preset target temperature, including:

[0081] Based on the number of working groups of the electric fan and the theoretical duty cycle value of the target electric fan, determine the output duty cycle value of each target electric fan group, and / or, based on the fault information of the fuel cell, determine the output duty cycle value of each target electric fan group.

[0082] Start several target electronic fans in the work group, and control each target electronic fan in the work group according to the corresponding output duty cycle value so that the coolant temperature reaches the preset target temperature value.

[0083] It should be understood that the output duty cycle value of each group of target electric fans needs to take into account the number of working groups of fans. For example, when one group of electric fans is running, the output duty cycle value of the electric fan is the theoretical duty cycle value of that group of electric fans; when two groups of electric fans are running, the output duty cycle value of each group of electric fans is the theoretical duty cycle value of the second group of fans, and so on. When the i-th group of electric fans is running, the output duty cycle value of each group of electric fans is the theoretical duty cycle value of the i-th group of electric fans. This ensures the uniformity of airflow when multiple groups of electric fans are working simultaneously.

[0084] It should also be understood that when a fuel cell fault message appears during the system control process, such as: 1) the fuel cell outlet temperature exceeds the preset upper limit threshold, for example, the preset upper limit threshold can be set to 90℃;

[0085] 2) Fuel cell controller communication failure; 3) Fuel cell inlet and outlet temperature sensor failure. In this case, the i-group electric fans can be controlled to operate at a relatively high duty cycle N. set The system operates to ensure that the heat generated by the system can be dissipated normally. That is, when the above fault information is detected, all electric fans can be controlled to operate at a higher duty cycle until the system is shut down, at which point the electric fans will stop running. For example, N... set The value can be greater than the preset minimum duty cycle value of the electric fan, and less than or equal to the preset maximum duty cycle value of the electric fan. For example, N can be set. set The value is 90%.

[0086] By combining the number of working groups of the electric fans and the fault information of the fuel cell, the output duty cycle value of each target electric fan can be determined. The target electric fans can then be controlled according to the corresponding output duty cycle value, thereby dissipating heat from the flowing coolant and ensuring that the coolant temperature reaches the preset target temperature. Furthermore, the output duty cycle value can be determined in conjunction with fault conditions to ensure that the heat generated by the fuel cell system can be dissipated normally.

[0087] In one possible approach, the number of working groups of electric fans is determined based on the theoretical duty cycle value, coolant outlet temperature, heat dissipation power value of the electric fan, and a preset duty cycle threshold for each group of target electric fans, including:

[0088] When the coolant outlet temperature meets the first preset condition and the heat dissipation power value of the electric fan meets the second preset condition, the number of working groups controlling the electric fan is the first preset value.

[0089] When the theoretical duty cycle value meets the third preset condition and the heat dissipation power value of the electronic fan meets the second preset condition, the number of working groups controlling the electronic fan is the second preset value, wherein the second preset value is less than the first preset value.

[0090] When there are at least one group of target electronic fans whose theoretical duty cycle values ​​are greater than or equal to different preset duty cycles, the number of working groups of electronic fans is increased.

[0091] When there are at least two groups of target electronic fans whose theoretical duty cycle values ​​are less than or equal to different preset duty cycles, the number of working groups of electronic fans is reduced.

[0092] It should be understood that the heat dissipation power of the electronic fan is measured in real time, for example, using a dedicated heat dissipation power measuring instrument or sensor, and this disclosure does not limit this.

[0093] For example, if the first preset value is 1, then the number of working groups of the electric fan is 1; if the second preset value is 0, then the number of working groups of the electric fan is 0.

[0094] For example, when the theoretical duty cycle of the first group of fans is greater than or equal to the first preset duty cycle, the number of working groups of the electronic fans can be controlled to change from 1 group to 2 groups; when the theoretical duty cycle of the first group of electronic fans is greater than or equal to the second preset duty cycle and the theoretical duty cycle of the second group of electronic fans is greater than or equal to the third preset duty cycle, the number of working groups of the electronic fans can be controlled to change from 2 groups to 3 groups; when the theoretical duty cycle of the second group of electronic fans is greater than or equal to the fourth preset duty cycle and the theoretical duty cycle of the third group of electronic fans is greater than or equal to the fifth preset duty cycle, the number of working groups of the electronic fans can be controlled to change from 3 groups to 4 groups. For example, the first preset duty cycle can be set to 50%, the second preset duty cycle to 60%, the third preset duty cycle to 60%, the fourth preset duty cycle to 70%, the fifth preset duty cycle to 70%, etc., and this embodiment of the present disclosure does not limit this.

[0095] For example, when the theoretical duty cycle value of the fourth group of electronic fans is ≤ the sixth preset duty cycle and the theoretical duty cycle value of the third group of electronic fans is ≤ the seventh preset duty cycle, the number of working groups of electronic fans can be controlled to change from 4 groups to 3 groups; when the theoretical duty cycle value of the third group of electronic fans is ≤ the eighth preset duty cycle and the theoretical duty cycle value of the second group of electronic fans is ≤ the ninth preset duty cycle, the number of working groups of electronic fans can be controlled to change from 3 groups to 2 groups; when the theoretical duty cycle value of the second group of electronic fans is ≤ the tenth preset duty cycle threshold and the theoretical duty cycle value of the first group of electronic fans is ≤ the eleventh preset duty cycle, the number of working groups of electronic fans can be controlled to change from 2 groups to 1 group. For example, the sixth preset duty cycle threshold can be set to 50%, the seventh preset duty cycle to 50%, the eighth preset duty cycle to 40%, the ninth preset duty cycle to 40%, the tenth preset duty cycle to 30%, the eleventh preset duty cycle to 30%, etc., and this embodiment of the present disclosure does not limit this.

[0096] For example, when the theoretical duty cycle of the first group of electronic fans is less than or equal to the twelfth preset duty cycle and the heat dissipation power of the electronic fans is less than the first preset heat dissipation power value, the number of working groups of the electronic fans can be controlled to be 0, that is, the electronic fans stop working. For example, the twelfth preset duty cycle can be set to 20%, and the second preset heat dissipation power value can be set to 20KW. This disclosure does not limit this aspect.

[0097] For example, when the coolant outlet temperature is greater than a first preset threshold and the heat dissipation power of the electric fan is greater than a second preset heat dissipation power value, the number of working groups of the electric fan can be controlled to be 1. For example, the first preset heat dissipation power value can be set to 25KW. This embodiment of the present disclosure does not limit this.

[0098] The following reference Figure 4 The control flow for the number of working groups of an electronic fan, as illustrated in an exemplary embodiment of this disclosure, will be described. (Refer to...) Figure 4 In the initial state, by default, one set of electric fans is working.

[0099] When condition 1 is met, that is, when the theoretical duty cycle of the first group of electronic fans is greater than or equal to the first preset duty cycle, the number of working groups controlling the electronic fans changes from 1 group to 2 groups.

[0100] When condition 2 is met, that is, when the theoretical duty cycle of the first group of electronic fans is greater than or equal to the second preset duty cycle and the theoretical duty cycle of the second group of electronic fans is greater than or equal to the third preset duty cycle, the number of working groups controlling the electronic fans changes from 2 groups to 3 groups.

[0101] When condition 3 is met, that is, when the theoretical duty cycle of the second group of electronic fans is greater than or equal to the fourth preset duty cycle and the theoretical duty cycle of the third group of electronic fans is greater than or equal to the fifth preset duty cycle, the number of working groups controlling the electronic fans changes from 3 groups to 4 groups.

[0102] When condition 4 is met, that is, when the theoretical duty cycle of the fourth group of electronic fans is less than or equal to the sixth preset duty cycle and the theoretical duty cycle of the third group of electronic fans is less than or equal to the seventh preset duty cycle, the number of working groups controlling the electronic fans changes from 4 groups to 3 groups.

[0103] When condition 5 is met, that is, when the theoretical duty cycle of the third group of electronic fans is less than or equal to the eighth preset duty cycle and the theoretical duty cycle of the second group of electronic fans is less than or equal to the ninth preset duty cycle, the number of working groups controlling the electronic fans changes from 3 groups to 2 groups.

[0104] When condition 6 is met, that is, when the theoretical duty cycle of the second group of electronic fans is less than or equal to the tenth preset duty cycle and the theoretical duty cycle of the first group of electronic fans is less than or equal to the eleventh preset duty cycle, the number of working groups controlling the electronic fans changes from 2 groups to 1 group.

[0105] When condition 7 is met, that is, when the duty cycle of the first group of electronic fans is less than or equal to the twelfth preset duty cycle and the heat dissipation power of the electronic fans is less than the first preset heat dissipation power, the electronic fans are controlled to stop working.

[0106] When condition 8 is met, that is, when the coolant outlet temperature is greater than the first preset threshold and the heat dissipation power of the electric fan is greater than the second preset heat dissipation power value, control one set of electric fans to work.

[0107] Using the above method, the number of working groups of electronic fans can be determined based on the theoretical duty cycle value, coolant outlet temperature, heat dissipation power value and preset duty cycle threshold of each target electronic fan group. This can improve the working efficiency of the electronic fans and reduce power consumption to a certain extent.

[0108] The following reference Figure 5 A coolant control method illustrated in an exemplary embodiment of this disclosure will be described. (Refer to...) Figure 5 The coolant control method includes the following steps:

[0109] Step S501: The fuel cell generator operates at room temperature;

[0110] Step S502: The electronic thermostat is in working condition;

[0111] Step S503: Determine whether the coolant outlet temperature T is greater than or equal to the first preset threshold T1. If yes, proceed to step S505; otherwise, proceed to step S504.

[0112] Step S504: Turn off the electronic thermostat;

[0113] Step S505: Determine whether the coolant outlet temperature T is greater than or equal to the second preset threshold T2. If yes, proceed to step S506; otherwise, proceed to step S508.

[0114] Step S506: The electronic thermostat is in the fully open position;

[0115] Step S507: The electric fan is turned on;

[0116] Step S508: Control the coolant outlet temperature to maintain the target temperature.

[0117] The specific implementation methods for each of the above steps have been described in detail above and will not be repeated here. It should also be understood that, for the sake of simplicity, the above method embodiments are described as a series of actions; however, those skilled in the art should understand that this disclosure is not limited to the order of actions described above. Furthermore, those skilled in the art should also understand that the embodiments described above are preferred embodiments, and the steps involved are not necessarily essential to this disclosure.

[0118] By comparing the coolant outlet temperature with a preset threshold, the electronic fan and electronic thermostat can be controlled accordingly. This ensures that the coolant temperature reaches the preset target temperature while resolving the coupling problem between coolant flow and air flow, reducing temperature fluctuations and improving the stability of the fuel cell system.

[0119] In one possible embodiment, the coolant control method further includes:

[0120] Determine the ion concentration value of the coolant;

[0121] When the ion concentration of the coolant is greater than or equal to the first preset concentration value, the shut-off valve is opened to reduce the ion concentration of the coolant flowing through the deionizer from the water pump. The shut-off valve is located between the deionizer and the water pump.

[0122] When the ion concentration of the coolant is less than or equal to the second preset concentration value, the control shut-off valve is closed to keep the ion concentration of the coolant flowing through the deionizer by the water pump constant.

[0123] For example, the specific values ​​of the first preset concentration value and the second preset concentration value can be set according to the actual situation of the fuel cell, as long as the second preset concentration value is less than the first preset concentration value. This embodiment of the present disclosure does not limit this. It should be understood that the first preset concentration value and the second preset concentration value can form a hysteresis range. For example, if the first preset concentration value is set to 10 mol / L and the second preset concentration value is set to 7 mol / L, the shut-off valve can be controlled to open when the ion concentration of the coolant is >10 mol / L. After opening, the ion concentration of the coolant will decrease for a period of time. However, in order to ensure that the ion concentration of the coolant does not immediately increase, the shut-off valve is controlled to close when the ion concentration of the coolant drops below 7 mol / L.

[0124] Reference Figure 6 A shut-off valve 306 is installed between the deionizer 305 and the water pump 301. When the ion concentration of the coolant is greater than or equal to a first preset concentration value, the shut-off valve 306 is opened to reduce the ion concentration of the coolant flowing from the water pump 301 through the deionizer 305. When the ion concentration of the coolant is less than or equal to a second preset concentration value, the shut-off valve 306 is closed to keep the ion concentration of the coolant flowing from the water pump 301 through the deionizer 305 constant.

[0125] Therefore, the shut-off valve can be opened and closed according to different operating conditions to keep the ion concentration of the coolant within the required range, and the service life of the deionizer can be extended to a certain extent by setting the shut-off valve.

[0126] Based on the same inventive concept, this disclosure also provides a coolant control system, referring to... Figure 7 The coolant control system includes:

[0127] Electronic thermostat 701 is used to adjust the flow direction of coolant;

[0128] The electric fan 702 is used to dissipate heat from the flowing coolant;

[0129] The controller 703 is used to control the valve opening of the electronic thermostat 701 to be fully open when the coolant outlet temperature is greater than or equal to a preset threshold. It also determines the number of working groups of the electronic fan 702 based on the theoretical duty cycle value of each target electronic fan in the electronic fan 702, the coolant outlet temperature, the heat dissipation power value of the electronic fan 702, and the preset duty cycle threshold. The controller 703 then starts the electronic fan 702 according to the number of working groups to dissipate heat from the coolant flowing through it, so that the coolant temperature reaches the preset target temperature.

[0130] Optionally, refer to Figure 8 The coolant control system also includes:

[0131] Water pump 704 is used to control the circulation of coolant;

[0132] Deionizer 705 is used to control the ion concentration of the coolant;

[0133] The shut-off valve 706 is located between the deionizer 705 and the water pump 704;

[0134] The controller 703 is used to control the shut-off valve 706 to open when the ion concentration of the coolant is greater than or equal to a first preset concentration value, so as to reduce the ion concentration of the coolant flowing through the deionizer 705, and to control the shut-off valve 706 to close when the ion concentration of the coolant is less than or equal to a second preset concentration value, so as to keep the ion concentration of the coolant constant.

[0135] The above system can compare the coolant outlet temperature with a preset threshold, thereby controlling the electronic fan 702 and the electronic thermostat 701 accordingly. This can achieve the desired coolant temperature while resolving the coupling problem between coolant flow and air flow, thus improving the stability of the fuel cell system and extending the service life of the deionizer 705 to some extent.

[0136] Based on the same inventive concept, this disclosure also provides a vehicle, including:

[0137] Fuel cells;

[0138] The coolant control system described above is used to control the coolant in the fuel cell.

[0139] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0140] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0141] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A coolant control method characterized by, The method includes: Obtain the coolant outlet temperature of the fuel cell; When the coolant outlet temperature is greater than or equal to a preset threshold, the valve opening of the electronic thermostat is fully open. The number of working groups of the electronic fans is determined based on the theoretical duty cycle of each target electronic fan group, the coolant outlet temperature, the heat dissipation power of the electronic fan, and the preset duty cycle threshold. The theoretical duty cycle of each target electronic fan group is obtained as follows: based on the difference between the coolant outlet temperature and the preset target temperature, and the rate of change of the coolant outlet temperature over a preset time interval, a fuzzy PID control algorithm is used to obtain the duty cycle adjustment value. The target duty cycle of each target electronic fan group is adjusted according to the duty cycle adjustment value to obtain the theoretical duty cycle of each target electronic fan group. The target duty cycle value is the duty cycle value obtained based on the ambient temperature and the theoretical heat dissipation of each target electronic fan group. The electronic fan is activated according to the number of working groups to dissipate heat from the flowing coolant, so that the temperature of the coolant reaches the preset target temperature.

2. The method of claim 1, wherein, The step of activating the electronic fan according to the number of work groups to dissipate heat from the flowing coolant, so that the temperature of the coolant reaches a preset target temperature, includes: The output duty cycle value of each target electronic fan group is determined based on the number of working groups of the electronic fan and the theoretical duty cycle value of the target electronic fan, and / or the output duty cycle value of each target electronic fan group is determined based on the fault information of the fuel cell. The target electronic fans of the working group are started, and for each target electronic fan in the working group, the target electronic fan is controlled according to the corresponding output duty cycle value so that the temperature of the coolant reaches the preset target temperature.

3. The method of claim 1, wherein, The step of determining the number of working groups of the electronic fans based on the theoretical duty cycle of each target electronic fan group, the coolant outlet temperature, the heat dissipation power of the electronic fan, and a preset duty cycle threshold includes: When the coolant outlet temperature meets the first preset condition and the heat dissipation power value of the electric fan meets the second preset condition, the number of working groups of the electric fan is controlled to be the first preset value. When the theoretical duty cycle value meets the third preset condition and the heat dissipation power value of the electronic fan meets the second preset condition, the number of working groups of the electronic fan is controlled to be the second preset value, wherein the second preset value is less than the first preset value; When at least one group of target electronic fans has a theoretical duty cycle value that is greater than or equal to different preset duty cycles, the number of working groups of the electronic fans is increased. When at least two groups of target electronic fans have theoretical duty cycle values ​​that are less than or equal to different preset duty cycles, the number of working groups of the electronic fans is reduced.

4. The method of claim 1, wherein, The electronic thermostat uses a fuzzy PID control algorithm to control the valve opening degree to increase or decrease.

5. The method of any of claims 1-2, wherein, The method further includes: Determine the ion concentration value of the coolant; When the ion concentration of the coolant is greater than or equal to a first preset concentration value, the shut-off valve is opened to reduce the ion concentration of the coolant flowing through the deionizer by the water pump, wherein the shut-off valve is located between the deionizer and the water pump. When the ion concentration of the coolant is less than or equal to a second preset concentration value, the shut-off valve is closed to keep the ion concentration of the coolant constant.

6. A coolant control system characterized by comprising: include: Electronic thermostat, used to adjust the flow of coolant; An electric fan is used to dissipate heat from the flowing coolant. The controller is used to control the valve opening of the electronic thermostat to be fully open when the coolant outlet temperature is greater than or equal to a preset threshold, and to determine the number of working groups of the electronic fan according to the theoretical duty cycle value of each target electronic fan group, the coolant outlet temperature, the heat dissipation power value of the electronic fan and the preset duty cycle threshold, and to start the electronic fan to dissipate heat from the flowing coolant according to the number of working groups so that the temperature of the coolant reaches the preset target temperature; The theoretical duty cycle of each target electronic fan in the electronic fan group is obtained as follows: based on the difference between the coolant outlet temperature and the preset target temperature, and the rate of change of the coolant outlet temperature over a preset time interval, a fuzzy PID control algorithm is used to obtain the duty cycle adjustment value; the target duty cycle value of each target electronic fan group is adjusted according to the duty cycle adjustment value to obtain the theoretical duty cycle value of each target electronic fan group, wherein the target duty cycle value is the duty cycle value obtained based on the ambient temperature and the theoretical heat dissipation of each target electronic fan group.

7. The system of claim 6, wherein, The system also includes: A water pump is used to control the circulation of the coolant; A deionizer is used to control the ion concentration of the coolant; A shut-off valve is installed between the deionizer and the water pump; The controller is configured to open the shut-off valve when the ion concentration of the coolant is greater than or equal to a first preset concentration value, so as to reduce the ion concentration of the coolant flowing through the deionizer, and to close the shut-off valve when the ion concentration of the coolant is less than or equal to a second preset concentration value, so as to keep the ion concentration of the coolant constant.

8. A vehicle characterized by comprising: include: Fuel cells; The coolant control system according to claim 6 or 7 is used to control the coolant of the fuel cell.

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