Hydrogen fuel cell thermal management system, control method and vehicle

Abstract

The invention discloses a hydrogen fuel cell thermal management system, a control method and a vehicle, and belongs to the technical field of hydrogen fuel cell heat dissipation control. The hydrogen fuel cell thermal management system comprises a cell unit, a heat dissipation unit and an FCCU controller; according to the control method for the thermal management system of the hydrogen fuel cell, the Fan value corresponding to the calculation period is obtained by setting the calculation period Z and calculating the L value corresponding to each calculation period, so that the starting number, the starting and stopping sequence and the rotating speed of the radiators in the heat dissipation units are dynamically controlled, the battery units under different working conditions are matched with the corresponding heat dissipation efficiency, and the heat dissipation efficiency of the battery units is improved. And keeping the stack temperature of the battery unit within the target working temperature interval of the stack. The method is low in energy consumption, high in temperature control capability, high in heat dissipation efficiency and capable of shortening the calculation time and reducing the cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrogen fuel cell heat dissipation control, and in particular relates to a hydrogen fuel cell thermal management system, a control method and a vehicle. Background Art

[0002] A hydrogen fuel cell is a power generation device that directly converts the chemical energy of hydrogen and oxygen into electrical energy. It has the characteristics of no pollution, low noise, and high efficiency. Hydrogen fuel cells are often used in the fields of energy storage and vehicles as a driving energy source or energy storage energy for vehicles.

[0003] Since hydrogen fuel cell systems have higher power generation efficiency and longer life at stable operating temperatures, and high temperatures can cause irreversible damage to the fuel cell stack, maintaining the fuel cell stack at an allowable operating temperature is a key measure to ensure the normal operation of the fuel cell stack.

[0004] However, the temperature control method currently used in hydrogen fuel cell systems often causes the temperature fluctuation of the heat dissipation system to be large during the heat dissipation process, which not only increases energy consumption, but also makes the stack easily exceed the allowable operating temperature range of the stack during the temperature rise or fall, causing irreversible damage and affecting the performance and life of the battery; although the ordinary temperature control method can control the speed of several radiators in the heat dissipation system, it does not consider that when adjacent radiators are turned on at the same time, they will interfere with each other, resulting in the overall heat dissipation effect being affected; in addition, the algorithms involved in the current temperature control method are complex, resulting in a huge amount of calculation, thereby increasing the investment expenditure and time cost of the battery in the early debugging process. Therefore, there is an urgent need to provide a control method for the hydrogen fuel cell thermal management system that can solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide a hydrogen fuel cell thermal management system, control method and vehicle to address the above shortcomings, and to solve the problems of high energy consumption, poor temperature control ability, low heat dissipation efficiency, high debugging cost and long debugging time in the current hydrogen fuel cell heat dissipation method. To achieve the above purpose, the present invention provides the following technical solutions:

[0006] A hydrogen fuel cell thermal management system comprises a battery unit, a heat dissipation unit and an FCCU controller; the battery unit is provided with a parameter acquisition component for real-time acquisition of ambient temperature and stack temperature; the heat dissipation unit comprises a plurality of radiators; the plurality of radiators constitute at least two radiator rows arranged in sequence from left to right, and a plurality of radiator rows are staggered from top to bottom; the FCCU controller is electrically connected to a power generation unit and a heat dissipation unit, respectively; the FCCU controller dynamically controls the number of radiators opened, the start and stop sequence and the rotation speed in the heat dissipation unit by calculation, so that the battery units under different working conditions match the corresponding heat dissipation efficiency.

[0007] A control method for a hydrogen fuel cell thermal management system comprises the following steps:

[0008] S1: Number the i radiators in the cooling unit as 1-i; set the speed value F when the radiator stops rotating to 0, and the speed value F when the radiator rotates at full speed to 100, then the speed value of the i-th radiator is F i , and F i ∈[0, 100];

[0009] S2: preset the target operating temperature T of the battery stack of the battery cell 目 , Radiator start-up temperature T 启 and radiator deactivation temperature T 停 , start the battery unit and collect the ambient temperature value T in real time 环 and the stack temperature T 堆 , when the battery cell's T 堆 ≥T 启 When , enter step S3;

[0010] S3: Set the sum of the rotation speed values ​​of the n radiators as the total rotation speed value L of the cooling unit, and construct a cooling function, which is expressed as:

[0011] L=K×[(M+N)×P×Q+L last ];

[0012] In the above formula, M represents the correction value of the difference between the target temperature and the current temperature, N represents the correction value of the temperature rate and slope change, P represents the ambient temperature correction value, Q represents the fan speed correction value, L represents the fan speed correction value, and last Indicates the total speed value of the cooling unit in the previous calculation cycle;

[0013] Set the calculation cycle Z, and obtain the values ​​of K, M, N, P, and Q corresponding to each calculation cycle; then calculate the L value corresponding to each calculation cycle according to the heat dissipation function;

[0014] Among them, L last The initial value of is set to 0, and every time the next calculation cycle is entered, let L last The value of is equal to the L value in this calculation cycle;

[0015] S4: Construct the radiator control function and express it as:

[0016]

[0017] Obtain the L value corresponding to each calculation cycle Z and substitute it into the radiator control function, round down the calculated Fan value and take the remainder, and then obtain the integer value A and the remainder value B; then, let the FCCU controller turn on A radiators in ascending order, and set the speed values ​​F of these radiators to 100; at the same time, turn on the radiator with the number value A+1, and set the speed value F of the radiator to B, that is, F A+1 =B.

[0018] Furthermore, the step S3 specifically includes:

[0019] S31: Whenever a new calculation cycle is entered, the current stack temperature value T is re-obtained 堆 and ambient temperature T 环 ;

[0020] S32: For parameter K, set the initial value to 1 and determine the stack temperature value T in the current calculation cycle. 堆 With the preset heat sink enable temperature T 启 and radiator deactivation temperature T 停 The size between, when T 堆 ≤T 停 When K=0, when T 堆 ≥T 启 When K=1, when T 停 ≤T 堆 ≤T 启 , keep the current value unchanged.

[0021] Furthermore, the step S3 specifically includes:

[0022] S33: Set M = (T 目 -T 堆 )×Ka, where Ka represents the preset temperature difference coefficient value; then according to the stack temperature value T obtained in the calculation cycle 堆 and preset stack target operating temperature T 目 , calculate and obtain the M value corresponding to the calculation cycle;

[0023] The specific steps for obtaining the Ka value are as follows:

[0024] S331: Confirm that the battery unit is in a normal temperature environment, and turn off all radiators of the cooling unit;

[0025] S332: Start the battery unit at the maximum power of the battery, and the battery startup rate v 电 is the maximum startup rate v 电max , get the stack temperature value T when it is turned on 堆启 , so that all radiators start at a preset rate v 散Start at the same time and rotate at full speed, at this time Fan = Fan max ; Record the stack temperature from T 堆启 Rise to the preset stack target operating temperature T 目 The time required △t a ;

[0026] S333: Set the temperature difference coefficient base value Ka0, and then use the formula Calculate the value of Ka0;

[0027] S334: Multiply Ka0 by 1, 2, 4, 8 times, respectively, are substituted into the formula of parameter M to obtain 6 sets of M values; then let L = M, L last = 0, start and control the radiator of the heat dissipation unit according to the method described in step S4; record and plot each group of battery units from the time of starting to reaching T 目 The functional relationship diagram of the temperature change with time until the end of the experiment; wherein the functional relationship diagram is a sinusoidal function diagram of oscillation attenuation;

[0028] S335: Preset the maximum allowable operating temperature T of the battery stack 允 , judge and select in sub-step S334, the amplitude is the largest and the stack temperature does not exceed T 允 The Ka0 value corresponding to a set of data is a fixed value of Ka.

[0029] Furthermore, the step S3 specifically includes:

[0030] S34: For parameter N, set In the above formula, Kb represents the temperature variation coefficient, △T represents the temperature variation rate of the battery stack in each calculation cycle Z, and △t' represents the preset time value;

[0031] The specific steps for obtaining the Kb value are as follows:

[0032] S341: Confirm that the battery unit is in a normal temperature environment and press L=K×[(M+N)+L last ] is a formula for controlling the radiator of the cooling unit;

[0033] S342: Setting the base value Kb0 of the temperature variation coefficient, where the value of Kb0 is the Ka value obtained in sub-step S335;

[0034] S343: Start the battery unit according to the maximum power of the battery, and record the temperature change rate value △T of the battery stack in each calculation cycle Z. Wherein, T2 is the temperature value of the battery stack in the current calculation cycle, T1 is the temperature value of the battery stack in the previous calculation cycle, △t'=1s; then draw a functional relationship diagram of △T and time;

[0035] S344: Kb0 The 2, 4, and 8 times values ​​are respectively used as new Kb0 values, and are re-substituted into sub-step S343 for calculation, and then a functional relationship diagram of △T and time corresponding to each Kb0 value is plotted;

[0036] S345: Fit each group of function relationship graphs obtained in sub-steps S343 and S344 to obtain a corresponding fitted straight line graph; then, select a function relationship graph in which the included angle between the fitted straight line graph and the x-axis line in the corresponding function relationship graph is between 5° and 10° and obtain an alternative value of Kb;

[0037] The Kb value is selected as follows:

[0038] Determine the number of Kb candidate values. If there is only one Kb candidate value, then this value is used as the variation coefficient value Kb corresponding to the temperature change value △T of the stack; if there are multiple Kb candidate values, then select a value with an angle closer to 7.5° as the Kb value corresponding to the temperature change value △T of the stack. If the angles between the tangents corresponding to multiple candidate values ​​and the x-axis line are the same distance from 7.5°, then randomly select one as the Kb value; if there is no alternative value, then select a curve with an angle closest to 7.5° as the Kb value; and record the Kb value as Kb1;

[0039] S346: construct a linear equation of the fitting line, expressed as y=Cx+b; then substitute the coordinates of any two points in the functional relationship diagram of △T and time corresponding to the fitting line for calculation, obtain the C value and record it as C1, then set △T=C1, then the actual N value is N=C1×Kb;

[0040] S347: Set the battery startup rate v 电 They are the maximum starting rate v 电max , and Repeat steps S342 to S346 to perform the test, and obtain a one-to-one corresponding C value and Kb value, which are used as preset call values;

[0041] S348: When entering a new calculation cycle Z, the stack temperature change rate value △T is reacquired, and the C value and Kb value corresponding to the △T value are selected to obtain the corresponding N value in the calculation cycle.

[0042] Furthermore, the step S3 specifically includes:

[0043] S35: For parameter P, set Among them, T 环启 is the actual ambient temperature value obtained each time the battery unit is turned on, T 环理 It is the preset ideal ambient temperature value.

[0044] Furthermore, the step S3 specifically includes:

[0045] S36: Whenever a new calculation cycle is entered, determine which interval of the preset radiator total speed value interval R the L value obtained in the previous calculation cycle is in, and then calculate and obtain the Q value corresponding to the current calculation cycle;

[0046] The specific steps for obtaining the Q value are as follows:

[0047] S361: Build a heat dissipation power test platform, set the rated value of the heat dissipation power, and start the heat dissipation unit according to the heat dissipation start sequence set in S4; whenever the heat dissipation power of the heat dissipation system reaches 10%, 20%, 30%...100% of the rated value, record the corresponding total heat dissipation speed value S1, S2, S3...S 10 , and set the total speed base value

[0048] S362: Set the total radiator speed value interval R, and divide the interval into [0, S1], (S1, S2], (S2, S3], (S3, S4], (S4, S5], (S5, S6], (S6, S7], (S7, S8], (S8, S9], (S9, S 10 ]; sum the two end values ​​of each interval and divide by two to obtain the corresponding reference average value S of the total actual speed of the radiator in the corresponding interval 实 ;

[0049] S363: Constructing formula Determine which range of the preset radiator total speed value range R the L value obtained in the previous calculation cycle is in, and then substitute the corresponding S 实 The numerical value of is calculated to obtain the corresponding Q value.

[0050] Furthermore, in step S3, the time interval of the calculation cycle Z is set to 0.1s-1s.

[0051] Furthermore, in step S1, the order of numbering the radiators is: the middle first, then the two ends; the top first, then the bottom.

[0052] A vehicle adopts any one of the above control methods for a hydrogen fuel cell thermal management system.

[0053] The beneficial effects of the present invention are:

[0054] 1. The control method of the present invention calculates the L value corresponding to each calculation cycle by setting the calculation cycle Z and the dynamically changing parameters to obtain the Fan value corresponding to the calculation cycle, thereby realizing dynamic control of the heat dissipation unit, timely meeting the heat dissipation requirements of the battery unit under complex working conditions, and keeping the battery stack temperature of the battery unit within the target operating temperature range of the battery stack. The present invention has low energy consumption, strong temperature control ability, high heat dissipation efficiency, and can shorten calculation time and reduce costs.

[0055] 2. The present invention achieves a balance between use cost and heat dissipation efficiency by adjusting the time interval of the calculation cycle Z, thereby reducing investment as much as possible and improving economic benefits while ensuring the normal operation of the battery unit.

[0056] 3. The present invention controls the opening sequence of the radiators by staggered arrangement and numbering of the heat dissipation units and a control method. When the heat dissipation power is low, adjacent radiators can be turned on at different times as much as possible, thereby reducing mutual interference between adjacent radiators and improving heat dissipation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 It is a schematic diagram of the structure of the hydrogen fuel cell thermal management system of the present invention; DETAILED DESCRIPTION

[0058] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation methods, but the present invention is not limited to the following embodiments.

[0059] Embodiment 1:

[0060] See attached Figure 1. One aspect of the present invention discloses a hydrogen fuel cell thermal management system, including a battery unit, a heat dissipation unit and an FCCU controller; the battery unit is provided with a parameter acquisition component for real-time acquisition of ambient temperature and stack temperature; the heat dissipation unit includes a plurality of radiators; the plurality of radiators constitute at least two radiator rows arranged in sequence from left to right, and the plurality of radiator rows are staggered from top to bottom; the FCCU controller is electrically connected to the power generation unit and the heat dissipation unit respectively; the FCCU controller dynamically controls the number of radiators opened, the start-stop sequence and the speed of the radiators in the heat dissipation unit by calculation, so that the battery units under different working conditions match the corresponding heat dissipation efficiency. It can be seen from the above structure that the present invention uses the heat dissipation unit to dissipate heat for the battery unit, and the heat dissipation unit includes a plurality of radiators, and the plurality of radiators constitute at least two radiator rows arranged in sequence from left to right in the horizontal direction, and the plurality of radiator rows are staggered from top to bottom. Such an arrangement can avoid the top and bottom of the radiators in the upper and lower adjacent radiator rows being too close, affecting the overall heat dissipation efficiency when the plurality of radiator rows are opened at the same time. Specifically, the radiator can be a heat dissipation fan, and each fan is independently controlled by the FCCU controller. The FCCU controller is used to calculate and control the number of radiators in the heat dissipation unit, the start and stop sequence, and the speed to control the heat dissipation speed of the battery unit, thereby keeping the battery stack temperature within the target operating temperature range of the battery stack. In addition, during factory commissioning and normal use, the entire hydrogen fuel cell system can also be connected to a computer with fuel cell thermal control software to calculate, simulate, and test through the preset algorithm in the FCCU controller to obtain and optimize the various parameters required for the heat dissipation unit, thereby regulating the heat dissipation efficiency of the heat dissipation unit to meet the heat dissipation requirements of the battery unit under different working conditions.

[0061] Embodiment 2:

[0062] See attached Figure 1 Based on the first embodiment, the second aspect of the present invention discloses a control method for a hydrogen fuel cell thermal management system, comprising the following steps:

[0063] S1: Number the i radiators in the cooling unit as 1-i; set the speed value F when the radiator stops rotating to 0, and the speed value F when the radiator rotates at full speed to 100, then the speed value of the i-th radiator is F i , and F i ∈[0, 100];

[0064] S2: preset the target operating temperature T of the battery stack of the battery cell 目 , Radiator start-up temperature T 启 and radiator deactivation temperature T 停 , start the battery unit and collect the ambient temperature value T in real time 环 and the stack temperature T堆 , when the battery cell's T 堆 ≥T 启 When , enter step S3;

[0065] S3: Set the sum of the rotation speed values ​​of the n radiators as the total rotation speed value L of the cooling unit, and construct a cooling function, which is expressed as:

[0066] L=K×[(M+N)×P×Q+L last ];

[0067] In the above formula, M represents the correction value of the difference between the target temperature and the current temperature, N represents the correction value of the temperature rate and slope change, P represents the ambient temperature correction value, Q represents the fan speed correction value, L represents the fan speed correction value, and last Indicates the total speed value of the cooling unit in the previous calculation cycle;

[0068] Set the calculation cycle Z, and obtain the values ​​of K, M, N, P, and Q corresponding to each calculation cycle; then calculate the L value corresponding to each calculation cycle according to the heat dissipation function;

[0069] Among them, L last The initial value of is set to 0, and every time the next calculation cycle is entered, let L last The value of is equal to the L value in this calculation cycle;

[0070] S4: Construct the radiator control function and express it as:

[0071]

[0072] Obtain the L value corresponding to each calculation cycle Z and substitute it into the radiator control function, round down the calculated Fan value and take the remainder, and then obtain the integer value A and the remainder value B; then, let the FCCU controller turn on A radiators in ascending order, and set the speed values ​​F of these radiators to 100; at the same time, turn on the radiator with the number value A+1, and set the speed value F of the radiator to B, that is, F A+1 =B.

[0073] The control method of the present invention dynamically adjusts the total speed value L of the heat dissipation unit by designing the calculation cycle Z and the heat dissipation function L, so as to adapt to the complex and changeable hydrogen fuel cell working conditions, better meet the heat dissipation requirements, improve the control ability of the stack temperature, prevent the stack from exceeding the maximum allowable operating temperature during temperature control, and ensure the performance and service life of the battery. In addition, the control method of the present invention can also dynamically adjust the opening number, sequence and speed of each radiator in the heat dissipation unit according to the real-time working condition changes of the hydrogen fuel cell by setting the radiator control function Fan, and then dynamically adjust the heat dissipation efficiency of the heat dissipation unit. Under the condition that the working temperature of the hydrogen fuel cell stack is within the allowable range, on the one hand, the temperature control strategy is changed in real time to reduce the redundant energy consumption, thereby reducing the use cost. On the other hand, the opening sequence of several radiators is set by algorithm control, which can minimize the situation where adjacent radiators are turned on at the same time and interfere with each other, and further improve the heat dissipation efficiency.

[0074] Embodiment three:

[0075] See attached Figure 1 Based on the first embodiment, step S3 specifically includes:

[0076] S31: Whenever a new calculation cycle is entered, the current stack temperature value T is re-obtained 堆 and ambient temperature T 环 ;

[0077] S32: For parameter K, set the initial value to 1 and determine the stack temperature value T in the current calculation cycle. 堆 With the preset heat sink enable temperature T 启 and radiator deactivation temperature T 停 The size between, when T 堆 ≤T 停 When K=0, when T 堆 ≥T 启 When K=1, when T 停 ≤T 堆 ≤T 启 , keep the current value unchanged.

[0078] Parameter K is used as a control parameter to control whether the radiator in the cooling unit is turned on, with the radiator enabling temperature T 启 and radiator deactivation temperature T 停 As a restriction condition for whether to turn on or off, it can reduce energy consumption.

[0079] S33: Set M = (T 目 -T 堆 )×Ka, where Ka represents the preset temperature difference coefficient value; then according to the stack temperature value T obtained in the calculation cycle 堆and preset stack target operating temperature T 目 , calculate and obtain the M value corresponding to the calculation cycle;

[0080] The specific steps for obtaining the Ka value are as follows:

[0081] S331: Confirm that the battery unit is in a normal temperature environment, and turn off all radiators of the cooling unit;

[0082] S332: Start the battery unit at the maximum power of the battery, and the battery startup rate v 电 is the maximum startup rate v 电max , get the stack temperature value T when it is turned on 堆启 , so that all radiators start at a preset rate v 散 Start at the same time and rotate at full speed, at this time Fan = Fan max ; Record the stack temperature from T 堆启 Rise to the preset stack target operating temperature T 目 The time required △t a ;

[0083] S333: Set the temperature difference coefficient base value Ka0, and then use the formula Calculate the value of Ka0;

[0084] S334: Multiply Ka0 by 1, 2, 4, 8 times, respectively, are substituted into the formula of parameter M to obtain 6 sets of M values; then let L = M, L last = 0, control the heat dissipation unit to dissipate heat according to the method described in step S4; record and plot each group of battery units from the time of opening to reaching T 目 The functional relationship diagram of the temperature change with time until the end of the experiment; wherein the functional relationship diagram is a sinusoidal function diagram of oscillation attenuation;

[0085] S335: Preset the maximum allowable operating temperature T of the battery stack 允 , judge and select in sub-step S334, the amplitude is the largest and the stack temperature does not exceed T 允 The Ka0 value corresponding to a set of data is a fixed value of Ka.

[0086] By setting the parameter M and calculating and obtaining a fixed Ka value, the deviation between the target temperature and the actual operating temperature can be shortened, thereby optimizing the value of L.

[0087] S33: Set M = (T 目 -T 堆 )×Ka, where Ka represents the preset temperature difference coefficient value; then according to the stack temperature value T obtained in the calculation cycle 堆 and preset stack target operating temperature T 目, calculate and obtain the M value corresponding to the calculation cycle;

[0088] The specific steps for obtaining the Ka value are as follows:

[0089] S331: Confirm that the battery unit is in a normal temperature environment, and turn off all radiators of the cooling unit;

[0090] S332: Start the battery unit at the maximum power of the battery, and the battery startup rate v 电 is the maximum startup rate v 电max , get the stack temperature value T when it is turned on 堆启 , so that all radiators start at a preset rate v 散 Start at the same time and rotate at full speed, at this time Fan = Fan max ; Record the stack temperature from T 堆启 Rise to the preset stack target operating temperature T 目 The time required △t a ;

[0091] S333: Set the temperature difference coefficient base value Ka0, and then use the formula Calculate the value of Ka0;

[0092] S334: Multiply Ka0 by 1, 2, 4, 8 times, respectively, are substituted into the formula of parameter M to obtain 6 sets of M values; then let L = M, L last = 0, start and control the radiator of the heat dissipation unit according to the method described in step S4; record and plot each group of battery units from the time of starting to reaching T 目 The functional relationship diagram of the temperature change with time until the end of the experiment; wherein the functional relationship diagram is a sinusoidal function diagram of oscillation attenuation;

[0093] S335: Preset the maximum allowable operating temperature T of the battery stack 允 , judge and select in sub-step S334, the amplitude is the largest and the stack temperature does not exceed T 允 The Ka0 value corresponding to a set of data is a fixed value of Ka.

[0094] S34: For parameter N, set In the above formula, Kb represents the temperature variation coefficient, △T represents the temperature variation rate of the battery stack in each calculation cycle Z, and △t' represents the preset time value;

[0095] The specific steps for obtaining the Kb value are as follows:

[0096] S341: Confirm that the battery unit is in a normal temperature environment and press L=K×[(M+N)+L last ] is a formula for controlling the radiator of the cooling unit;

[0097] S342: Setting the base value Kb0 of the temperature variation coefficient, where the value of Kb0 is the Ka value obtained in sub-step S335;

[0098] S343: Start the battery unit according to the maximum power of the battery, and record the temperature change rate value △T of the battery stack in each calculation cycle Z. Wherein, T2 is the temperature value of the battery stack in the current calculation cycle, T1 is the temperature value of the battery stack in the previous calculation cycle, △t'=1s; then draw a functional relationship diagram of △T and time;

[0099] S344: Kb0 The 2, 4, and 8 times values ​​are respectively used as new Kb0 values, and are re-substituted into sub-step S343 for calculation, and then a functional relationship diagram of △T and time corresponding to each Kb0 value is plotted;

[0100] S345: Fit each group of function relationship graphs obtained in sub-steps S343 and S344 to obtain a corresponding fitted straight line graph; then, select a function relationship graph in which the included angle between the fitted straight line graph and the x-axis line in the corresponding function relationship graph is between 5° and 10° and obtain an alternative value of Kb;

[0101] The Kb value is selected as follows:

[0102] Determine the number of Kb candidate values. If there is only one Kb candidate value, then this value is used as the variation coefficient value Kb corresponding to the temperature change value △T of the stack; if there are multiple Kb candidate values, then select a value with an angle closer to 7.5° as the Kb value corresponding to the temperature change value △T of the stack. If the angles between the tangents corresponding to multiple candidate values ​​and the x-axis line are the same distance from 7.5°, then randomly select one as the Kb value; if there is no alternative value, then select a curve with an angle closest to 7.5° as the Kb value; and record the Kb value as Kb1;

[0103] S346: construct a linear equation of the fitting line, expressed as y=Cx+b; then substitute the coordinates of any two points in the functional relationship diagram of △T and time corresponding to the fitting line for calculation, obtain the C value and record it as C1, then set △T=C1, then the actual N value is N=C1×Kb;

[0104] S347: Set the battery startup rate v 电 They are the maximum starting rate v 电max , and Repeat steps S342 to S346 to perform the test, and obtain a one-to-one corresponding C value and Kb value, which are used as preset call values;

[0105] S348: When entering a new calculation cycle Z, the stack temperature change rate value △T is reacquired, and the C value and Kb value corresponding to the △T value are selected to obtain the corresponding N value in the calculation cycle.

[0106] Parameter N is the core parameter of this control method as the correction value of temperature rate and slope change. The value of N is positively correlated with the slope of temperature change, so the selection of Kb value is very critical. Due to the complex and changeable working conditions of hydrogen fuel cells, the change value of the stack temperature may be different in each period of time, and its value may be positive or negative, and may be larger or smaller. If ordinary heat dissipation methods are adopted, not only will the response speed be delayed, but also the stack temperature will fluctuate greatly, which is easy to exceed the allowed working range of the stack, such as exceeding the maximum allowed working temperature of the stack, causing irreversible damage to the battery, affecting the efficiency and service life of the battery. In addition, such a heat dissipation method will cause the speed of the radiator to change greatly, which will not only cause greater energy consumption, but also noise problems. Therefore, the present invention adopts a method of taking the corresponding Kb value for different stack temperature change rate values ​​△T, and reselects the Kb value in each calculation cycle, so as to obtain the parameter N that fits the current working conditions, which can more quickly and accurately regulate the stack temperature of the battery unit and improve the temperature control effect.

[0107] S35: For parameter P, set Among them, T 环启 is the actual ambient temperature value obtained each time the battery unit is turned on, T 环理 It is the preset ideal ambient temperature value.

[0108] The parameter P is used as an ambient temperature correction value to correct the actual ambient temperature and the ideal ambient temperature when the battery unit is working. The control method of the present invention is calculated by the formula By considering the effect of temperature difference on heat dissipation power as a linear correlation, while optimizing the calculation result of the L value, the complexity of the algorithm can be greatly reduced, thereby reducing the calculation time, reducing the cost required for the algorithm, and reducing the demand for FCCU chip computing power, which is easy to implement.

[0109] S36: Whenever a new calculation cycle is entered, determine which interval of the preset radiator total speed value interval R the L value obtained in the previous calculation cycle is in, and then calculate and obtain the Q value corresponding to the current calculation cycle;

[0110] The specific steps for obtaining the Q value are as follows:

[0111] S361: Build a heat dissipation power test platform, set the rated value of the heat dissipation power, and start the heat dissipation unit according to the heat dissipation start sequence set in S4; whenever the heat dissipation power of the heat dissipation system reaches 10%, 20%, 30%...100% of the rated value, record the corresponding total heat dissipation speed value S1, S2, S3...S 10 , and set the total speed base value

[0112] S362: Set the total radiator speed value interval R, and divide the interval into [0, S1], (S1, S2], (S2, S3], (S3, S4], (S4, S5], (S5, S6], (S6, S7], (S7, S8], (S8, S9], (S9, S 10 ]; sum the two end values ​​of each interval and divide by two to obtain the corresponding reference average value S of the total actual speed of the radiator in the corresponding interval 实 ;

[0113] S363: Constructing formula Determine which range of the preset radiator total speed value range R the L value obtained in the previous calculation cycle is in, and then substitute the corresponding S 实 The numerical value of is calculated to obtain the corresponding Q value.

[0114] Since the heat dissipation power and the fan speed are positively correlated, but not completely linearly correlated, the parameter Q is set as the fan speed correction value to optimize the value of L.

[0115] Embodiment 4:

[0116] See attached Figure 1 On the basis of the third embodiment, in the step S1, the heat sinks are numbered in the following order: the middle first, then the two ends; the top first, then the bottom.

[0117] The present invention designs a numbering sequence of "middle first, then both ends; top first, then bottom" for a number of radiators in order to prevent adjacent radiators from being turned on at the same time as much as possible when the heat dissipation power is low, reduce mutual interference between adjacent radiators, and thus improve heat dissipation efficiency. Furthermore, an opening sequence of left first then right or right first then left can be added after the first two numbering sequence methods. For example, the radiator of the heat dissipation unit is a fan, and there are ten of them, and then a structure of five fans in each row, a total of two rows, and the two rows of fans are staggered. The numbering sequence of the heat dissipation unit is as follows: first, the fan in the middle of the first row at the top is numbered 1, and the fan in the middle of the second row at the bottom is numbered 2; secondly, the fans at both ends of the first row are numbered 3 and 4, respectively, and then the fans at both ends of the second row are numbered 5 and 6, respectively; finally, the two fans left in the first row are numbered 7 and 8, and the two fans left in the second row are numbered 9 and 10.

[0118] Embodiment five:

[0119] See attached Figure 1 On the basis of the fourth embodiment, in the step S3, the time interval of the calculation cycle Z is set to 0.1s-1s.

[0120] The control method of the present invention sets the time interval of the calculation cycle Z to 0.1s-1s, and can select the heat dissipation interval according to the actual heat dissipation requirements of different hydrogen fuel cells to achieve a balance between the use cost and the heat dissipation efficiency, while ensuring the normal operation of the battery unit, reducing the investment as much as possible and improving the economic benefits.

[0121] Embodiment six:

[0122] See attached Figure 1 On the basis of the fifth embodiment, the control method of the present invention may further include the following steps: when the battery unit stops working, the calculation of the L value and the Fan value is stopped, and all radiators are turned off.

[0123] When the battery unit of the present invention needs to stop working under normal or abnormal circumstances, it directly exits the calculation and turns off the heat dissipation unit to prevent affecting other operations or control steps.

[0124] Embodiment seven:

[0125] See attached Figure 1 Based on the sixth embodiment, the third aspect of the present invention discloses a vehicle, which uses the control method of the hydrogen fuel cell thermal management system of the present invention to control the battery stack temperature of the vehicle in real time to ensure that the battery stack temperature does not exceed the allowable operating temperature range.

[0126] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A hydrogen fuel cell thermal management system, characterized in that: It comprises a battery unit, a heat dissipation unit and an FCCU controller; the battery unit is provided with a parameter acquisition component for real-time acquisition of ambient temperature and stack temperature; the heat dissipation unit comprises a plurality of radiators; the plurality of radiators constitute at least two radiator rows arranged in sequence from left to right, and a plurality of radiator rows are staggeredly arranged from top to bottom; the FCCU controller is electrically connected to the power generation unit and the heat dissipation unit respectively; the FCCU controller dynamically controls the opening number, start-stop sequence and rotation speed of the radiators in the heat dissipation unit through calculation, so that the battery units under different working conditions match the corresponding heat dissipation efficiency.

2. A control method for a hydrogen fuel cell thermal management system, characterized in that: The hydrogen fuel cell thermal management system according to claim 1 comprises the following steps: S1: Number the i radiators in the cooling unit as 1-i; set the speed value F when the radiator stops rotating to 0, and the speed value F when the radiator rotates at full speed to 100, then the speed value of the i-th radiator is F i , and F i ∈[0, 100]; S2: preset the target operating temperature T of the battery stack of the battery cell 目 , Radiator start-up temperature T 启 and radiator deactivation temperature T 停 , start the battery unit and collect the ambient temperature value T in real time 环 and the stack temperature T 堆 , when the battery cell's T 堆 ≥T 启 When , enter step S3; S3: Set the sum of the rotation speed values ​​of the n radiators as the total rotation speed value L of the cooling unit, and construct a cooling function, which is expressed as: L=K×[(M+N)×P×Q+L last ]; In the above formula, M represents the correction value of the difference between the target temperature and the current temperature, N represents the correction value of the temperature rate and slope change, P represents the ambient temperature correction value, Q represents the fan speed correction value, L represents the fan speed correction value, and last Indicates the total speed value of the cooling unit in the previous calculation cycle; Set the calculation cycle Z, and obtain the values ​​of K, M, N, P, and Q corresponding to each calculation cycle; then calculate the L value corresponding to each calculation cycle according to the heat dissipation function; Among them, L last The initial value of is set to 0, and every time the next calculation cycle is entered, let L last The value of is equal to the L value in this calculation cycle; S4: Construct the radiator control function and express it as: Obtain the L value corresponding to each calculation cycle Z and substitute it into the radiator control function, round down the calculated Fan value and take the remainder, and then obtain the integer value A and the remainder value B; then, let the FCCU controller turn on A radiators in ascending order, and set the speed values ​​F of these radiators to 100; at the same time, turn on the radiator with the number value A+1, and set the speed value F of the radiator to B, that is, F A+1 =B.

3. The control method of a hydrogen fuel cell thermal management system according to claim 2, characterized in that: The step S3 specifically includes: S31: Whenever a new calculation cycle is entered, the current stack temperature value T is re-obtained 堆 and ambient temperature T 环 ; S32: For parameter K, set the initial value to 1 and determine the stack temperature value T in the current calculation cycle. 堆 With the preset heat sink enable temperature T 启 and radiator deactivation temperature T 停 The size between, when T 堆 ≤T 停 When K=0, when T 堆 ≥T 启 When K=1, when T 停 ≤T 堆 ≤T 启 , keep the current value unchanged.

4. The control method of a hydrogen fuel cell thermal management system according to claim 3, characterized in that: The step S3 specifically includes: S33: Set M = T 目 -T 堆 )×Ka, where Ka represents the preset temperature difference coefficient value; then according to the stack temperature value T obtained in the calculation cycle 堆 and preset stack target operating temperature T 目 , calculate and obtain the M value corresponding to the calculation cycle; The specific steps for obtaining the Ka value are as follows: S331: Confirm that the battery unit is in a normal temperature environment, and turn off all radiators of the cooling unit; S332: Start the battery unit at the maximum power of the battery, and the battery startup rate v 电 is the maximum startup rate v 电max , get the stack temperature value T when it is turned on 堆启 , so that all radiators start at a preset rate v 散 Start at the same time and rotate at full speed, at this time Fan = Fan max ; Record the stack temperature from T 堆启 Rise to the preset stack target operating temperature T 目 The time required △t a ; S333: Set the temperature difference coefficient base value Ka0, and then use the formula Calculate the value of Ka0; S334: Multiply Ka0 by 1, 2, 4, 8 times, respectively, are substituted into the formula of parameter M to obtain 6 sets of M values; then let L = M, L last = 0, start and control the radiator of the heat dissipation unit according to the method described in step S4; record and plot each group of battery units from the time of starting to reaching T 目 The functional relationship diagram of the temperature change with time until the end of the experiment; wherein the functional relationship diagram is a sinusoidal function diagram of oscillation attenuation; S335: Preset the maximum allowable operating temperature T of the battery stack 允 , judge and select in sub-step S334, the amplitude is the largest and the stack temperature does not exceed T 允 The Ka0 value corresponding to a set of data is a fixed value of Ka.

5. The control method of a hydrogen fuel cell thermal management system according to claim 4, characterized in that: The step S3 specifically includes: S34: For parameter N, set In the above formula, Kb represents the temperature variation coefficient, △T represents the temperature variation rate of the battery stack in each calculation cycle Z, and △t' represents the preset time value; The specific steps for obtaining the Kb value are as follows: S341: Confirm that the battery unit is in a normal temperature environment and press L=K×[(M+N)+L last ] is a formula for controlling the radiator of the cooling unit; S342: Setting the base value Kb0 of the temperature variation coefficient, where the value of Kb0 is the Ka value obtained in sub-step S335; S343: Start the battery unit according to the maximum power of the battery, and record the temperature change rate value △T of the battery stack in each calculation cycle Z. Wherein, T2 is the temperature value of the battery stack in the current calculation cycle, T1 is the temperature value of the battery stack in the previous calculation cycle, △t'=1s; then draw a functional relationship diagram of △T and time; S344: Kb0 The 2, 4, and 8 times values ​​are respectively used as new Kb0 values, and are re-substituted into sub-step S343 for calculation, and then a functional relationship diagram of △T and time corresponding to each Kb0 value is plotted; S345: Fit each group of function relationship graphs obtained in sub-steps S343 and S344 to obtain a corresponding fitted straight line graph; then, select a function relationship graph in which the included angle between the fitted straight line graph and the x-axis line in the corresponding function relationship graph is between 5° and 10° and obtain an alternative value of Kb; The Kb value is selected as follows: Determine the number of Kb candidate values. If there is only one Kb candidate value, then this value is used as the variation coefficient value Kb corresponding to the temperature change value △T of the stack; if there are multiple Kb candidate values, then select a value with an angle closer to 7.5° as the Kb value corresponding to the temperature change value △T of the stack. If the angles between the tangents corresponding to multiple candidate values ​​and the x-axis line are the same distance from 7.5°, then randomly select one as the Kb value; if there is no alternative value, then select a curve with an angle closest to 7.5° as the Kb value; and record the Kb value as Kb1; S346: construct a linear equation of the fitting line, expressed as y=Cx+b; then substitute the coordinates of any two points in the functional relationship diagram of △T and time corresponding to the fitting line for calculation, obtain the C value and record it as C1, then set △T=C1, then the actual N value is N=C1×Kb; S347: Set the battery startup rate v 电 They are the maximum starting rate v 电max , and Repeat steps S342 to S346 to perform the test, and obtain a one-to-one corresponding C value and Kb value, which are used as preset call values; S348: When entering a new calculation cycle Z, the stack temperature change rate value △T is reacquired, and the C value and Kb value corresponding to the △T value are selected to obtain the corresponding N value in the calculation cycle.

6. The control method of a hydrogen fuel cell thermal management system according to claim 5, characterized in that: The step S3 specifically includes: S35: For parameter P, set Among them, T 环启 is the actual ambient temperature value obtained each time the battery unit is turned on, T 环理 It is the preset ideal ambient temperature value.

7. The control method of a hydrogen fuel cell thermal management system according to claim 6, characterized in that: The step S3 specifically includes: S36: Whenever a new calculation cycle is entered, determine which interval of the preset radiator total speed value interval R the L value obtained in the previous calculation cycle is in, and then calculate and obtain the Q value corresponding to the current calculation cycle; The specific steps for obtaining the Q value are as follows: S361: Build a heat dissipation power test platform, set the rated value of the heat dissipation power, and start the heat dissipation unit according to the heat dissipation start sequence set in S4; whenever the heat dissipation power of the heat dissipation system reaches 10%, 20%, 30%...100% of the rated value, record the corresponding total heat dissipation speed value S1, S2, S3...S 10 , and set the total speed base value S362: Set the total radiator speed value interval R, and divide the interval into [0, S1], (S1, S2], (S2, S3], (S3, S4], (S4, S5], (S5, S6], (S6, S7], (S7, S8], (S8, S9], (S9, S 10 ]; sum the two end values ​​of each interval and divide by two to obtain the corresponding reference average value S of the total actual speed of the radiator in the corresponding interval 实 ; S363: Constructing formula Determine which range of the preset radiator total speed value range R the L value obtained in the previous calculation cycle is in, and then substitute the corresponding S 实 The numerical value of is calculated to obtain the corresponding Q value.

8. The control method of a hydrogen fuel cell thermal management system according to claim 2, characterized in that: In step S3, the time interval of the calculation cycle Z is set to 0.1s-1s.

9. The control method of a hydrogen fuel cell thermal management system according to claim 2, characterized in that: In step S1, the order of numbering the radiators is: the middle first, then the two ends; the top first, then the bottom.

10. A vehicle, characterized in that: A control method for a hydrogen fuel cell thermal management system as claimed in any one of claims 2 to 9 is adopted.

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