Method and equipment for controlling ion concentration of coolant of fuel cell system and medium

Abstract

The invention relates to the technical field of new energy vehicle fuel cell system management, and particularly provides a fuel cell system cooling liquid ion concentration control method and device and a medium, and the method comprises the following steps: setting different conductivity intervals and control measures corresponding to the different conductivity intervals; the conductivity of the cooling liquid is monitored in real time; and according to the conductivity, the conductivity interval and corresponding control measures, the control of the ion concentration of the cooling liquid of the fuel cell system is realized, and the whole cooling loop is maintained in a safe conductivity range. Different conductivity intervals and control measures corresponding to the different conductivity intervals are set, and the ion concentration in the cooling liquid is monitored and controlled in real time, so that the system safety can be improved, the service life of a galvanic pile is prolonged, and the maintenance cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of fuel cell system management technology for new energy vehicles, and more specifically, to a method, device, and medium for controlling the ion concentration of coolant in a fuel cell system. Background Technology

[0002] For fuel cells, the output voltage and current density of a single cell, which consists of a set of electrodes and electrolyte plates, are relatively low during operation. To obtain higher voltage and power, multiple single cells are usually connected in series to form a fuel cell stack. Adjacent single cells are separated by bipolar plates, which serve to connect the upper and lower single cells in series and provide a gas flow path.

[0003] Currently, commercial fuel cell vehicles generally use water-based or glycol-based coolants for thermal management. However, after prolonged operation, due to material precipitation, stack corrosion, and other factors, the ion concentration in the coolant gradually increases, leading to: 1. Increased coolant conductivity poses a risk of fuel cell stack leakage; 2. Increased corrosion of metal components affects the lifespan of the fuel cell stack; 3. Scale buildup and blockage in the cooling channels affect heat dissipation efficiency; 4. Coolant needs to be replaced or replenished regularly, increasing operating and maintenance costs.

[0004] Existing deionization treatment methods mainly rely on periodically replacing the deionization tank or setting rigid thresholds for replenishment, which cannot be intelligently adjusted according to the actual operating status of the system, resulting in resource waste and frequent maintenance. Summary of the Invention

[0005] Based on this, in order to intelligently regulate the ion concentration of fuel cell coolant, the present invention provides a method, device, and medium for controlling the ion concentration of fuel cell system coolant, the specific technical solution of which is as follows: A method for controlling the ion concentration of coolant in a fuel cell system includes the following steps: Different conductivity ranges and corresponding control measures for different conductivity ranges were defined; Real-time monitoring of the conductivity of the coolant; Based on the conductivity, conductivity range, and corresponding control measures, the ion concentration of the coolant in the fuel cell system is controlled to ensure that the overall cooling circuit is maintained within a safe conductivity range.

[0006] The method for controlling the ion concentration of the coolant in the fuel cell system can improve system safety, extend stack life, and reduce maintenance costs by setting different conductivity ranges and corresponding control measures for different conductivity ranges, and by monitoring and controlling the ion concentration in the coolant in real time.

[0007] Preferably, the method for controlling the ion concentration of the coolant in the fuel cell system further includes the following steps: Acquire the cumulative operating time of the fuel cell system, the current real-time operating temperature of the stack, the baseline safety threshold for conductivity, the temperature influence factor, and the aging degradation coefficient; Based on the current real-time operating temperature of the fuel cell stack, the baseline safety threshold for conductivity, and the temperature influence factor, a temperature response term is obtained to characterize the nonlinear effect of temperature on conductivity. Based on the cumulative operating time of the fuel cell system and the aging degradation coefficient, an aging correction term is obtained to tighten the safety conductivity threshold as the material ages. The safe conductivity threshold is obtained based on the temperature response term and the aging correction term.

[0008] Preferably, the method for controlling the ion concentration of the coolant in the fuel cell system further includes the following steps: Obtain the current ion concentration, stack aging correction factor, corrosion rate function, ion exchange efficiency function, coolant temperature, and coolant flow rate; The corrosion rate function and coolant temperature are used to describe the rate of increase in corrosion ion concentration due to increased coolant temperature. The ion exchange efficiency is obtained based on the ion exchange efficiency function and the coolant flow rate to characterize the positive correlation with the coolant flow rate. The net change in ion concentration within a preset time window is obtained based on the rate of increase in corrosion ion concentration and the ion exchange efficiency. The net change in ion concentration is corrected according to the stack aging correction factor, and the ion concentration value at a future time is predicted based on the current ion concentration and the corrected net change in ion concentration.

[0009] Preferably, the method for controlling the ion concentration of the coolant in the fuel cell system further includes the following steps: The corrosion rate integral, which characterizes the cumulative corrosion effect, is obtained based on the corrosion rate function. Obtain the material constant used to characterize the corrosion resistance coefficient of the fuel cell stack and the total ion capacity used to characterize the maximum allowable ion carrying capacity of the system. Based on the corrosion rate integral, the material constant, and the total ion capacity, obtain the corrosion progress term used to calculate the proportion of the current corrosion progress to the total tolerance capacity of the system. The number of system start-stop cycles is obtained, and a start-stop loss index term representing the impact of the number of start-stop cycles on the lifespan of the fuel cell is obtained based on the number of system start-stop cycles; The predicted maintenance interval time for the fuel cell system is based on the corrosion progress term and the start-stop loss index term.

[0010] Preferably, the method for controlling the ion concentration of the coolant in the fuel cell system further includes the following steps: The rate of change of ion concentration is obtained based on the current ion concentration. The pressure difference change and flow rate change of the coolant circulation pipeline are obtained, and the flow resistance characteristic value of the coolant circulation pipeline is obtained based on the pressure difference change and flow rate change. Obtain the system health status baseline value, and obtain the coolant circulation pipeline fault index based on the ion concentration change rate, flow resistance characteristic value, and system health status baseline value.

[0011] A fuel cell system coolant ion concentration control device, used to implement the fuel cell system coolant ion concentration control method, comprising: The intelligent controller is used to set different conductivity ranges and corresponding control measures for different conductivity ranges, and to generate control commands based on the conductivity, conductivity range and corresponding control measures. An ion concentration sensor is used to monitor the conductivity of the coolant in real time. The execution module is used to respond to the control command and control the flow path of the coolant through the electric valve group, pump and proportional valve to control the ion concentration of the coolant in the fuel cell system and ensure that the overall cooling circuit is maintained within a safe conductivity range.

[0012] Preferably, the fuel cell system coolant ion concentration control device further includes: The first parameter acquisition module is used to acquire the cumulative operating time of the fuel cell system, the current real-time operating temperature of the stack, the baseline safety threshold of conductivity, the temperature influence factor, and the aging degradation coefficient. The temperature response term construction module is used to obtain a temperature response term that characterizes the nonlinear effect of temperature on conductivity based on the current real-time operating temperature of the fuel cell stack, the conductivity reference safety threshold, and the temperature influence factor. An aging correction term construction module is used to obtain an aging correction term for tightening the safety conductivity threshold as the fuel cell system ages, based on the cumulative operating time and aging degradation coefficient of the fuel cell system. The conductivity threshold acquisition module is used to acquire a safe conductivity threshold based on the temperature response term and the aging correction term.

[0013] Preferably, the fuel cell system coolant ion concentration control device further includes: The second parameter acquisition module is used to acquire the current ion concentration, stack aging correction factor, corrosion rate function, ion exchange efficiency function, coolant temperature, and coolant flow rate. An additional rate acquisition module is added, which is used to acquire the rate of increase in corrosion ion concentration due to the increase in coolant temperature based on the corrosion rate function and coolant temperature. The ion exchange efficiency acquisition module is used to acquire the ion exchange efficiency, which is positively correlated with the coolant flow rate, based on the ion exchange efficiency function and the coolant flow rate. The net change acquisition module is used to acquire the net change in ion concentration within a preset time window based on the rate of increase in corrosion ion concentration and ion exchange efficiency. The ion concentration prediction module is used to correct the net change in ion concentration according to the stack aging correction factor, and to predict the ion concentration value at a future time based on the current ion concentration and the corrected net change in ion concentration.

[0014] Preferably, the fuel cell system coolant ion concentration control device further includes: The corrosion rate integral acquisition module is used to acquire the corrosion rate integral, which characterizes the cumulative corrosion effect, based on the corrosion rate function. The corrosion progress term acquisition module is used to acquire the material constant used to characterize the corrosion resistance coefficient of the fuel cell stack and the total ion capacity used to characterize the maximum allowable ion carrying capacity of the system. Based on the corrosion rate integral, material constant and total ion capacity, a corrosion progress term is acquired to calculate the proportion of the current corrosion progress to the total tolerance capacity of the system. The start-stop loss index term acquisition module is used to acquire the number of system start-stop cycles and acquire the start-stop loss index term, which characterizes the impact of the number of start-stop cycles on the lifespan of the fuel cell, based on the number of system start-stop cycles. The maintenance interval prediction module is used to predict the maintenance interval of the fuel cell system based on the corrosion progress item and the start-stop loss index item.

[0015] A computer-readable storage medium storing a computer program that, when executed, implements the method for controlling the ion concentration of coolant in a fuel cell system. Attached Figure Description

[0016] The invention will be further understood from the following description taken in conjunction with the accompanying drawings. The components in the drawings are not necessarily drawn to scale, but rather the emphasis is on illustrating the principles of the embodiments. In different views, the same reference numerals designate corresponding parts.

[0017] Figure 1 This is a schematic diagram of the overall process of a method for controlling the ion concentration of a fuel cell system coolant in one embodiment of the present invention; Figure 2 This is a schematic diagram of the control process for dynamic adjustment of ion concentration in one embodiment of the present invention; Figure 3This is a flowchart illustrating a method for controlling the ion concentration of a fuel cell system coolant according to another embodiment of the present invention. Figure 1 ; Figure 4 This is a flowchart illustrating a method for controlling the ion concentration of a fuel cell system coolant according to another embodiment of the present invention. Figure 2 ; Figure 5 This is a flowchart illustrating a method for controlling the ion concentration of a fuel cell system coolant according to another embodiment of the present invention. Figure 3 ; Figure 6 This is a flowchart illustrating a method for controlling the ion concentration of a fuel cell system coolant according to another embodiment of the present invention. Figure 4 ; Figure 7 This is a schematic diagram of the overall structure of a fuel cell system coolant ion concentration control device according to an embodiment of the present invention; Figure 8 This is a logic control diagram of a fuel cell system coolant ion concentration control device according to an embodiment of the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to its embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the scope of protection of the invention.

[0019] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0021] In this invention, "first" and "second" do not represent a specific quantity or order, but are merely used to distinguish names.

[0022] like Figure 1As shown, an embodiment of the present invention provides a method for controlling the ion concentration of a fuel cell system coolant, which includes the following steps: S1, setting different conductivity ranges and corresponding control measures for different conductivity ranges.

[0023] For example, the conductivity range and corresponding control measures can be found in the table below:

[0024] S2, real-time monitoring of the conductivity of the coolant.

[0025] S3. Based on the conductivity, conductivity range and corresponding control measures, the ion concentration of the coolant in the fuel cell system is controlled to ensure that the overall cooling circuit is maintained within a safe conductivity range.

[0026] Specifically, after the system starts up, it periodically or in real time collects coolant conductivity data. The controller sets the conductivity range. When the conductivity deviates from the target value, the deionization module (such as ion exchange resin) is activated first for online purification. If the conductivity still does not recover after the deionization module is activated for online purification of the coolant, the system automatically starts deionized water replenishment or drains part of the coolant for dilution, so that the overall coolant circuit is maintained within a safe conductivity range (such as <30 S / cm). At the same time, the system operating status is recorded to provide support for predictive maintenance.

[0027] like Figure 2 The diagram shows the control flow chart for dynamic adjustment of ion concentration in a fuel cell system, illustrating the intelligent controller's monitoring, judgment, and response strategy for coolant conductivity. After the system starts operating, it collects real-time ion concentration information in the coolant. When the conductivity exceeds a set threshold, it first determines whether the ion exchange module can be activated for purification; if not, it activates the deionized water replenishment device to reduce the ion concentration. The system then continues to monitor the adjustment effect and enters the next round of sampling control, achieving closed-loop regulation and dynamic management.

[0028] In summary, the method for controlling the ion concentration of the coolant in the fuel cell system can improve system safety, extend stack life, and reduce maintenance costs by setting different conductivity ranges and corresponding control measures for different conductivity ranges, and by monitoring and controlling the ion concentration in the coolant in real time.

[0029] In one embodiment, such as Figure 3 As shown, the method for controlling the ion concentration of the coolant in the fuel cell system further includes the following steps: S4 obtains the cumulative operating time of the fuel cell system, the current real-time operating temperature of the stack, the baseline safety threshold of conductivity, the temperature influence factor, and the aging degradation coefficient.

[0030] S5, based on the current real-time operating temperature of the fuel cell stack Conductivity reference safety threshold and temperature influence factors Obtain the temperature response term used to characterize the nonlinear effect of temperature on conductivity.

[0031] For example, the temperature response term is represented as .in, This indicates the temperature-sensitive gain, typically between 1.2 and 1.8, used to amplify the intensity of the effect of temperature on the threshold. This indicates the preset critical temperature, which is generally between 65 and 80°C, such as 72°C.

[0032] Specifically, the current real-time operating temperature of the fuel cell stack reflects its current operating temperature and directly affects the ion deposition rate. The baseline safety threshold for conductivity is determined by the fuel cell stack material properties and is generally between 8 and 12 µS / cm. The temperature influence factor is used to control the sensitivity of the threshold adjustment to temperature changes and is generally between 0.05 and 0.1 °C⁻¹. exp is a natural exponential function. The baseline safety threshold for conductivity, the temperature influence factor, and the temperature-sensitive gain can all be calibration values, determined by fitting accelerated aging experimental data of the fuel cell stack.

[0033] Because corrosion is slow at low temperatures, the temperature response term approaches α in the low-temperature region (T < 70℃) to relax the threshold; while high temperatures accelerate ion precipitation, so the temperature response term approaches α / β in the high-temperature region (T > 75℃) to tighten the threshold. In the temperature response term, the sigmoid function... It can simulate the nonlinear effect of temperature on conductivity, especially the sensitive changes in the operating range of 65-80℃.

[0034] Thus, within the typical operating temperature range of fuel cells (65~80℃), based on this temperature response term, the safety conductivity threshold can be nonlinearly and adaptively adjusted with temperature.

[0035] S6, based on the cumulative operating time of the fuel cell system and aging degradation coefficient Obtain an aging correction term to tighten the safe conductivity threshold as the material ages.

[0036] Generally speaking, as fuel cell stack materials age, their corrosion resistance decreases (e.g., passivation layer wears down, bipolar plates thin), and their tolerance to ion concentrations decreases, thus requiring stricter control of the conductivity threshold. In other words, the more severe the aging, the more significant the decay of the conductivity threshold, in order to avoid accelerated corrosion and a surge in failure risk.

[0037] For example, the aging correction term is represented as .in, This indicates the time base, which is set to 100 hours by default. This is primarily used to avoid aging correction items from being in place. When the value is 0, divergence occurs. The aging degradation coefficient is used to quantify the contribution of operating time to threshold degradation, and is generally between 0.1 and 0.3. It can be set empirically or calibrated by fitting data from accelerated aging experiments on the fuel cell stack. The larger the value of the aging degradation coefficient, the more significant the aging effect.

[0038] Assuming the aging degradation coefficient is chosen to be 0.2, When α = 0, the aging correction term ≈ α, indicating that the conductivity threshold is lenient for new fuel cell stacks; when the cumulative operating time... Increase, such as At 5000h, the aging correction term =α / (50+1)^0.2≈1 / 2.18≈0.459α, indicating that the conductivity threshold tightens due to fuel cell aging. This dependence means that the more severe the fuel cell aging, the more significant the decrease in conductivity threshold, consistent with the law that corrosion resistance decreases after material aging.

[0039] S7. Obtain the safe conductivity threshold based on the temperature response term and the aging correction term.

[0040] For example, the safe conductivity threshold is expressed as It replaces the traditional fixed threshold and performs well in three typical operating conditions: 1. When the temperature is low during cold start, a higher threshold is allowed; 2. When running at full load, the control is tightened; 3. After long-term operation, the conductivity threshold tolerance is automatically reduced to avoid accelerated corrosion and a surge in failure risk.

[0041] In summary, by obtaining the aforementioned safe conductivity threshold It can solve the problems of excessive control of fixed threshold in low temperature range and insufficient protection in high temperature range, thereby realizing adaptive adjustment of threshold and avoiding the problems of accelerated corrosion and surge in failure risk caused by aging of fuel cell material.

[0042] In one embodiment, such as Figure 4 As shown, the method for controlling the ion concentration of the coolant in the fuel cell system further includes the following steps: S8 retrieves the current ion concentration, stack aging correction factor, corrosion rate function, ion exchange efficiency function, coolant temperature, and coolant flow rate.

[0043] S9, based on the corrosion rate function and the coolant temperature, obtain the rate of increase in corrosion ion concentration due to the increase in coolant temperature.

[0044] S10, based on the ion exchange efficiency function and the coolant flow rate, obtain the ion exchange efficiency used to characterize the positive correlation with the coolant flow rate.

[0045] S11, obtain the net change in ion concentration within a preset time window based on the rate of increase in corrosion ion concentration and ion exchange efficiency.

[0046] S12, the net change in ion concentration is corrected according to the stack aging correction factor, and the ion concentration value at a future time is predicted based on the current ion concentration and the corrected net change in ion concentration.

[0047] For example, the ion concentration value at some future time. Represented as .in, These represent, in order, the current ion concentration, stack aging correction factor, corrosion rate function, ion exchange efficiency function, coolant temperature, and coolant flow rate. This indicates that the predicted timeframe is short, and t represents the current time.

[0048] Specifically, the fuel cell stack aging correction factor can be understood as a coefficient related to the aging state of the fuel cell stack. Its value may increase as the stack's operating time increases, indicating that ion concentration is more likely to accumulate under the same conditions. The corrosion rate function represents the rate at which ion concentration increases due to corrosion of the fuel cell stack material at temperature T; the higher the temperature, the faster the corrosion rate. The ion exchange efficiency function represents the rate at which ions are removed by the ion exchange device at a given coolant flow rate; the higher the flow rate, the higher the ion exchange efficiency.

[0049] The fuel cell stack aging correction factor is typically between 1.0 and 1.2. For example, the fuel cell stack aging correction factor... The parameters 0.2 and 5000 are empirical values ​​and can be adjusted according to actual conditions. (Cumulative running time) The unit is hours.

[0050] Integral term This represents the net change in ion concentration over the time period [t, t+Δt]. Because as the fuel cell stack ages, the same corrosion conditions may lead to more ion deposition or a decrease in ion exchange efficiency, therefore... This can be understood as using an aging correction factor to correct the net change.

[0051] The corrosion rate function is usually expressed in the form of the Arrhenius equation, while the ion exchange efficiency function can be expressed in the form of a power function based on hydrodynamics and ion exchange characteristics. ,in, These represent the basic efficiency coefficient of the ion exchange device (which is related to the type and amount of exchange resin, and is generally between 0.8 and 1.0) and the flow rate effect index (usually taken as 0.5 to 0.8, indicating that as the flow rate increases, the efficiency improves, but not non-linearly).

[0052] Thus, based on functions The model predicts the ion concentration at time t+1 in the future. It not only considers the current state but also predicts future concentration changes through integration. It is based on corrosion chemistry mechanism (Arrhenius equation) and fluid dynamics model, rather than a simple statistical model. By introducing a fuel cell stack aging correction factor, the model can adapt to the fuel cell stack aging process and improve the accuracy of long-term prediction.

[0053] When it is predicted that the concentration will exceed the safety threshold in the future, the control system can start the deionization device in advance or adjust the coolant flow rate to avoid the concentration from exceeding the standard, thereby achieving proactive control of the ion concentration and reducing the risk of fuel cell corrosion.

[0054] In one embodiment, such as Figure 5 As shown, the method for controlling the ion concentration of the coolant in the fuel cell system further includes the following steps: S13, Obtain the corrosion rate integral, which characterizes the cumulative corrosion effect, based on the corrosion rate function.

[0055] S14, obtain the material constant used to characterize the corrosion resistance coefficient of the fuel cell stack and the total ion capacity used to characterize the maximum allowable ion carrying capacity of the system, and obtain the corrosion progress term used to calculate the proportion of the current corrosion progress to the total tolerance capacity of the system based on the corrosion rate integral, the material constant and the total ion capacity.

[0056] S15, obtain the number of system start-stop cycles, and obtain the start-stop loss index term, which characterizes the impact of the number of start-stop cycles on the lifespan of the fuel cell, based on the number of system start-stop cycles.

[0057] S16, predict the maintenance interval time of the fuel cell system based on the corrosion progress term and the start-stop loss index term.

[0058] For example, predicting maintenance intervals Represented as .in, These are represented, in order, as material constants, total ion capacity, corrosion rate integral, start-stop loss attenuation factor, and system start-stop count. These represent the corrosion progress term and the start-up and shutdown loss index term, respectively.

[0059] Because the thermal stress generated during each start-up and shutdown accelerates the aging of the sealing material, and the local concentration of residual ions during shutdown exacerbates the risk of pitting corrosion, the system exhibits a certain start-up and shutdown loss. The start-up and shutdown loss attenuation factor is generally between 0.01 and 0.05, which can be obtained through accelerated aging experiments.

[0060] Here, this embodiment quantifies the actual corrosion level in real time through the corrosion progress term, which can replace the crude measurement of maintenance time. It innovatively introduces the start-stop loss index term to compensate for the hidden losses of start-stop impact. By quantifying the cumulative corrosion effect and start-stop loss, it realizes the accurate prediction of the maintenance cycle of fuel cell system.

[0061] In one embodiment, such as Figure 6 As shown, the method for controlling the ion concentration of the coolant in the fuel cell system further includes the following steps: S17, Obtain the rate of change of ion concentration based on the current ion concentration.

[0062] S18, obtain the pressure difference change and flow rate change of the coolant circulation pipeline, and obtain the flow resistance characteristic value of the coolant circulation pipeline based on the pressure difference change and flow rate change.

[0063] S19, obtain the system health status benchmark value, and obtain the coolant circulation pipeline fault index based on the ion concentration change rate, flow resistance characteristic value and system health status benchmark value.

[0064] For example, the coolant circulation pipeline failure index is expressed as: .in, These are represented, in order, as the rate of change in ion concentration, the change in pressure difference, the change in flow rate, and the baseline value of the system health status. This is expressed as a flow resistance characteristic value.

[0065] Specifically, the pressure difference change is the pressure difference between the inlet and outlet of the cooling circuit, and the flow rate change is the deviation between the actual flow rate and the rated flow rate. The flow resistance characteristic value represents the rate of change of pressure difference per unit flow rate; an increase in this value generally indicates a blockage in the cooling pipes, while a decrease indicates coolant leakage. In the coolant circulation pipeline fault index function, The product can amplify the signal when there is a synchronous anomaly. For example, when there is a blockage, the concentration rises sharply and the pressure difference surges, which will lead to a significant increase in the fault indicators.

[0066] For example, the system health status baseline value can be expressed by formula calculate, These represent the new system calibration values ​​(0.15~0.25) and temperature coefficients (0.02~0.05℃), respectively. -1 ) and aging factors (0.01~0.03).

[0067] The new system calibration values ​​can be determined by fitting fault-free data, while the temperature coefficient is derived from the Arrhenius equation.

[0068] Different failure indices correspond to different failure types, and corresponding failure maintenance strategies can be adopted. Please refer to the table below for details:

[0069] Traditional fault monitoring often employs a single-parameter threshold method, which cannot distinguish between actual faults and operational disturbances (such as sudden temperature changes) under complex operating conditions, and struggles to pinpoint fault types (such as blockages / leakage / sensor failures). This embodiment, by fusing multiple parameters to obtain a fault index, can amplify fault signals, suppress noise signals, and determine fault types, thereby improving system sensitivity and robustness.

[0070] The fuel cell system coolant ion concentration control method further includes setting an optimization objective function, which is expressed as follows: .in, These represent the target concentration, circulation pump power, and deionized water replenishment volume, respectively. This is a weighting coefficient, which can be set and adjusted according to actual needs. This is the control vector. The purpose of setting this optimization objective function is to find the final control vector through multi-objective collaborative optimization, that is, to find the optimal balance point among the three objectives by solving for the Pareto optimal solution.

[0071] Specifically, the control vector includes, but is not limited to, the opening degree and rotational speed of the circulating pump. Of course, constraints can also be set, such as coolant ion concentration boundaries, upper limits for coolant volume change rate, and operating temperature ranges. Regarding the concentration weighting coefficient... It can be dynamically adjusted based on the fault index, that is, when the fault index increases or exceeds a preset threshold, the concentration weighting coefficient is automatically increased. This value improves the accuracy of coolant ion concentration control, prevents corrosion, and ensures the insulation safety of the fuel cell stack. For example, . The preset standard fault index threshold, This represents the adjustment coefficient, which can be set empirically, such as 0.2.

[0072] like Figure 7 As shown, an embodiment of the present invention also provides a fuel cell system coolant ion concentration control device for implementing the fuel cell system coolant ion concentration control method, which includes an intelligent controller, an ion concentration sensor, and an execution module.

[0073] The intelligent controller is used to set different conductivity ranges and corresponding control measures for each conductivity range, and generates control commands based on the conductivity, conductivity range, and corresponding control measures; the ion concentration sensor is used to monitor the conductivity of the coolant or key ions (such as Na+) in real time. + Cl -The concentration of the coolant is controlled by the execution module in response to the control command and by controlling the flow path of the coolant through the electric valve group, pump and proportional valve, so as to control the ion concentration of the coolant in the fuel cell system and ensure that the overall cooling circuit is maintained within a safe conductivity range.

[0074] Specifically, the fuel cell system coolant ion concentration control device further includes a coolant management unit, which comprises a deionized water tank, a conventional coolant tank, and an ion exchange module. The controller has a built-in algorithm module that combines operating time, temperature, and historical conductivity trends to predict the optimal replenishment ratio and timing.

[0075] See again Figure 7 The demonstration showcased the interconnections between the fuel cell stack, coolant circulation path, ion concentration sensor, deionized water replenishment module, ion exchange module, and intelligent control system (FCU). By monitoring the coolant conductivity in real time through sensors, the FCU can intelligently control deionized water replenishment or activate the ion exchange device based on the monitoring results, dynamically adjusting the ion concentration to ensure the long-term stable operation of the fuel cell system.

[0076] like Figure 8 The diagram shows the logic control of the coolant ion concentration control device in a fuel cell system. It illustrates the signal transmission and control relationships between the ion concentration sensor (T), the intelligent control module (FCU), and the execution module. The sensor collects the conductivity data of the coolant in real time and feeds it back to the control module. The intelligent control module determines whether the conductivity exceeds the set threshold and transmits instructions to the ion exchange module or the deionized water replenishment device to achieve dynamic adjustment and intelligent control of the ion concentration.

[0077] In summary, the fuel cell system coolant ion concentration control device has the following advantages: 1. Intelligent adjustment: The system can dynamically determine whether to start purification or replenishment based on the actual operating status; 2. Extend service life: Maintain coolant within the ideal conductivity range to prevent fuel cell corrosion; 3. Reduce operating and maintenance costs: Reduce the frequency of coolant replacement and avoid human error; 4. Supports predictive maintenance: Analyzes system health status through data recording; 5. High adaptability: It can be deployed in various fuel cell commercial vehicles, stationary power generation devices and other systems.

[0078] As a preferred technical solution, the fuel cell system coolant ion concentration control device further includes a first parameter acquisition module, a temperature response item construction module, an aging correction item construction module, and a conductivity threshold acquisition module.

[0079] The first parameter acquisition module is used to acquire the cumulative operating time of the fuel cell system, the current real-time operating temperature of the stack, the conductivity reference safety threshold, the temperature influence factor, and the aging degradation coefficient; the temperature response term construction module is used to acquire a temperature response term to characterize the nonlinear effect of temperature on conductivity based on the current real-time operating temperature of the stack, the conductivity reference safety threshold, and the temperature influence factor.

[0080] The aging correction term construction module is used to obtain an aging correction term for tightening the safe conductivity threshold as the fuel cell system ages, based on the cumulative operating time and aging decay coefficient; the conductivity threshold acquisition module is used to obtain the safe conductivity threshold based on the temperature response term and the aging correction term.

[0081] For example, the safe conductivity threshold is expressed as It replaces the traditional fixed threshold and performs well in three typical operating conditions: 1. When the temperature is low during cold start, a higher threshold is allowed; 2. When running at full load, the control is tightened; 3. After long-term operation, the conductivity threshold tolerance is automatically reduced to avoid accelerated corrosion and a surge in failure risk.

[0082] In summary, by obtaining the aforementioned safe conductivity threshold It can solve the problems of excessive control of fixed threshold in low temperature range and insufficient protection in high temperature range, thereby realizing adaptive adjustment of threshold and avoiding the problems of accelerated corrosion and surge in failure risk caused by aging of fuel cell material.

[0083] The fuel cell system coolant ion concentration control device also includes a second parameter acquisition module, an increase rate acquisition module, an exchange efficiency acquisition module, a net change acquisition module, and an ion concentration prediction module.

[0084] The second parameter acquisition module is used to acquire the current ion concentration, stack aging correction factor, corrosion rate function, ion exchange efficiency function, coolant temperature, and coolant flow rate; the increase rate acquisition module is used to acquire the rate of increase in corrosion ion concentration caused by the increase in coolant temperature based on the corrosion rate function and coolant temperature.

[0085] The ion exchange efficiency acquisition module is used to acquire the ion exchange efficiency, which is positively correlated with the coolant flow rate, based on the ion exchange efficiency function and the coolant flow rate. The net change acquisition module is used to acquire the net change in ion concentration within a preset time window based on the corrosion ion concentration increase rate and the ion exchange efficiency. The ion concentration prediction module is used to correct the net change in ion concentration based on the stack aging correction factor, and predict the ion concentration value at a future time based on the current ion concentration and the corrected net change in ion concentration.

[0086] For example, the ion concentration value at some future time. Represented as .in, These represent, in order, the current ion concentration, stack aging correction factor, corrosion rate function, ion exchange efficiency function, coolant temperature, and coolant flow rate. This indicates that the predicted timeframe is short, and t represents the current time.

[0087] Specifically, the fuel cell stack aging correction factor can be understood as a coefficient related to the aging state of the fuel cell stack. Its value may increase as the stack's operating time increases, indicating that ion concentration is more likely to accumulate under the same conditions. The corrosion rate function represents the rate at which ion concentration increases due to corrosion of the fuel cell stack material at temperature T; the higher the temperature, the faster the corrosion rate. The ion exchange efficiency function represents the rate at which ions are removed by the ion exchange device at a given coolant flow rate; the higher the flow rate, the higher the ion exchange efficiency.

[0088] The fuel cell stack aging correction factor is typically between 1.0 and 1.2. For example, the fuel cell stack aging correction factor... The parameters 0.2 and 5000 are empirical values ​​and can be adjusted according to actual conditions. (Cumulative running time) The unit is hours.

[0089] Integral term This represents the net change in ion concentration over the time period [t, t+Δt]. Because as the fuel cell stack ages, the same corrosion conditions may lead to more ion deposition or a decrease in ion exchange efficiency, therefore... This can be understood as using an aging correction factor to correct the net change.

[0090] The corrosion rate function is usually expressed in the form of the Arrhenius equation, while the ion exchange efficiency function can be expressed in the form of a power function based on hydrodynamics and ion exchange characteristics. ,in, These represent the basic efficiency coefficient of the ion exchange device (which is related to the type and amount of exchange resin, and is generally between 0.8 and 1.0) and the flow rate effect index (usually taken as 0.5 to 0.8, indicating that as the flow rate increases, the efficiency improves, but not non-linearly).

[0091] Thus, based on functions The model predicts the ion concentration at time t+1 in the future. It not only considers the current state but also predicts future concentration changes through integration. It is based on corrosion chemistry mechanism (Arrhenius equation) and fluid dynamics model, rather than a simple statistical model. By introducing a fuel cell stack aging correction factor, the model can adapt to the fuel cell stack aging process and improve the accuracy of long-term prediction.

[0092] When it is predicted that the concentration will exceed the safety threshold in the future, the control system can start the deionization device in advance or adjust the coolant flow rate to avoid the concentration from exceeding the standard, thereby achieving proactive control of the ion concentration and reducing the risk of fuel cell corrosion.

[0093] The fuel cell system coolant ion concentration control device also includes a corrosion rate integral acquisition module, a corrosion progress acquisition module, a start-stop loss index acquisition module, and a maintenance interval prediction module.

[0094] The corrosion rate integral acquisition module is used to acquire the corrosion rate integral, which characterizes the cumulative corrosion effect, based on the corrosion rate function; the corrosion progress term acquisition module is used to acquire the material constant, which characterizes the stack corrosion resistance coefficient, and the total ion capacity, which characterizes the maximum allowable ion carrying capacity of the system, and to acquire the corrosion progress term, which is used to calculate the proportion of the current corrosion progress to the total tolerance capacity of the system, based on the corrosion rate integral, the material constant, and the total ion capacity. The start-stop loss index acquisition module is used to acquire the number of system start-stop cycles, and acquire the start-stop loss index, which characterizes the impact of the number of start-stop cycles on the life of the fuel cell, based on the number of system start-stop cycles; the maintenance interval prediction module is used to predict the maintenance interval of the fuel cell system based on the corrosion progress item and the start-stop loss index.

[0095] For example, predicting maintenance intervals Represented as .in, These are represented, in order, as material constants, total ion capacity, corrosion rate integral, start-stop loss attenuation factor, and system start-stop count. These represent the corrosion progress term and the start-up and shutdown loss index term, respectively.

[0096] Because the thermal stress generated during each start-up and shutdown accelerates the aging of the sealing material, and the local concentration of residual ions during shutdown exacerbates the risk of pitting corrosion, the system exhibits a certain start-up and shutdown loss. The start-up and shutdown loss attenuation factor is generally between 0.01 and 0.05, which can be obtained through accelerated aging experiments.

[0097] Here, this embodiment quantifies the actual corrosion level in real time through the corrosion progress term, which can replace the crude measurement of maintenance time. It innovatively introduces the start-stop loss index term to compensate for the hidden losses of start-stop impact. By quantifying the cumulative corrosion effect and start-stop loss, it realizes the accurate prediction of the maintenance cycle of fuel cell system.

[0098] The present invention also provides a computer-readable storage medium storing a computer program that, when executed, implements the method for controlling the ion concentration of the coolant in a fuel cell system.

[0099] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0100] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for controlling the ion concentration of coolant in a fuel cell system, characterized in that, The method for controlling the ion concentration of the coolant in the fuel cell system includes the following steps: Different conductivity ranges and corresponding control measures for different conductivity ranges were defined; Real-time monitoring of the conductivity of the coolant; Based on the conductivity, conductivity range, and corresponding control measures, the ion concentration of the coolant in the fuel cell system is controlled to ensure that the overall cooling circuit is maintained within a safe conductivity range.

2. The method for controlling the ion concentration of coolant in a fuel cell system as described in claim 1, characterized in that, The method for controlling the ion concentration of the coolant in the fuel cell system further includes the following steps: Acquire the cumulative operating time of the fuel cell system, the current real-time operating temperature of the stack, the baseline safety threshold for conductivity, the temperature influence factor, and the aging degradation coefficient; Based on the current real-time operating temperature of the fuel cell stack, the baseline safety threshold for conductivity, and the temperature influence factor, a temperature response term is obtained to characterize the nonlinear effect of temperature on conductivity. Based on the cumulative operating time of the fuel cell system and the aging degradation coefficient, an aging correction term is obtained to tighten the safety conductivity threshold as the material ages. The safe conductivity threshold is obtained based on the temperature response term and the aging correction term.

3. The method for controlling the ion concentration of coolant in a fuel cell system as described in claim 2, characterized in that, The method for controlling the ion concentration of the coolant in the fuel cell system further includes the following steps: Obtain the current ion concentration, stack aging correction factor, corrosion rate function, ion exchange efficiency function, coolant temperature, and coolant flow rate; The corrosion rate function and coolant temperature are used to describe the rate of increase in corrosion ion concentration due to increased coolant temperature. The ion exchange efficiency is obtained based on the ion exchange efficiency function and the coolant flow rate to characterize the positive correlation with the coolant flow rate. The net change in ion concentration within a preset time window is obtained based on the rate of increase in corrosion ion concentration and the ion exchange efficiency. The net change in ion concentration is corrected according to the stack aging correction factor, and the ion concentration value at a future time is predicted based on the current ion concentration and the corrected net change in ion concentration.

4. The method for controlling the ion concentration of coolant in a fuel cell system as described in claim 3, characterized in that, The method for controlling the ion concentration of the coolant in the fuel cell system further includes the following steps: The corrosion rate integral, which characterizes the cumulative corrosion effect, is obtained based on the corrosion rate function. Obtain the material constant used to characterize the corrosion resistance coefficient of the fuel cell stack and the total ion capacity used to characterize the maximum allowable ion carrying capacity of the system. Based on the corrosion rate integral, the material constant, and the total ion capacity, obtain the corrosion progress term used to calculate the proportion of the current corrosion progress to the total tolerance capacity of the system. The number of system start-stop cycles is obtained, and a start-stop loss index term representing the impact of the number of start-stop cycles on the lifespan of the fuel cell is obtained based on the number of system start-stop cycles; The predicted maintenance interval time for the fuel cell system is based on the corrosion progress term and the start-stop loss index term.

5. The method for controlling the ion concentration of coolant in a fuel cell system as described in claim 4, characterized in that, The method for controlling the ion concentration of the coolant in the fuel cell system further includes the following steps: The rate of change of ion concentration is obtained based on the current ion concentration. The pressure difference change and flow rate change of the coolant circulation pipeline are obtained, and the flow resistance characteristic value of the coolant circulation pipeline is obtained based on the pressure difference change and flow rate change. Obtain the system health status baseline value, and obtain the coolant circulation pipeline fault index based on the ion concentration change rate, flow resistance characteristic value, and system health status baseline value.

6. A device for controlling the ion concentration of a fuel cell system coolant, used to implement the method for controlling the ion concentration of a fuel cell system coolant as described in any one of claims 1-5, characterized in that, The fuel cell system coolant ion concentration control device includes: The intelligent controller is used to set different conductivity ranges and corresponding control measures for different conductivity ranges, and to generate control commands based on the conductivity, conductivity range and corresponding control measures. An ion concentration sensor is used to monitor the conductivity of the coolant in real time. The execution module is used to respond to the control command and control the flow path of the coolant through the electric valve group, pump and proportional valve to control the ion concentration of the coolant in the fuel cell system and ensure that the overall cooling circuit is maintained within a safe conductivity range.

7. The fuel cell system coolant ion concentration control device as described in claim 6, characterized in that, The fuel cell system coolant ion concentration control device also includes: The first parameter acquisition module is used to acquire the cumulative operating time of the fuel cell system, the current real-time operating temperature of the stack, the baseline safety threshold of conductivity, the temperature influence factor, and the aging degradation coefficient. The temperature response term construction module is used to obtain a temperature response term that characterizes the nonlinear effect of temperature on conductivity based on the current real-time operating temperature of the fuel cell stack, the conductivity reference safety threshold, and the temperature influence factor. An aging correction term construction module is used to obtain an aging correction term for tightening the safety conductivity threshold as the fuel cell system ages, based on the cumulative operating time and aging degradation coefficient of the fuel cell system. The conductivity threshold acquisition module is used to acquire a safe conductivity threshold based on the temperature response term and the aging correction term.

8. The fuel cell system coolant ion concentration control device as described in claim 7, characterized in that, The fuel cell system coolant ion concentration control device also includes: The second parameter acquisition module is used to acquire the current ion concentration, stack aging correction factor, corrosion rate function, ion exchange efficiency function, coolant temperature, and coolant flow rate. An additional rate acquisition module is added, which is used to acquire the rate of increase in corrosion ion concentration due to the increase in coolant temperature based on the corrosion rate function and coolant temperature. The ion exchange efficiency acquisition module is used to acquire the ion exchange efficiency, which is positively correlated with the coolant flow rate, based on the ion exchange efficiency function and the coolant flow rate. The net change acquisition module is used to acquire the net change in ion concentration within a preset time window based on the rate of increase in corrosion ion concentration and ion exchange efficiency. The ion concentration prediction module is used to correct the net change in ion concentration according to the stack aging correction factor, and to predict the ion concentration value at a future time based on the current ion concentration and the corrected net change in ion concentration.

9. The fuel cell system coolant ion concentration control device as described in claim 8, characterized in that, The fuel cell system coolant ion concentration control device also includes: The corrosion rate integral acquisition module is used to acquire the corrosion rate integral, which characterizes the cumulative corrosion effect, based on the corrosion rate function. The corrosion progress term acquisition module is used to acquire the material constant used to characterize the corrosion resistance coefficient of the fuel cell stack and the total ion capacity used to characterize the maximum allowable ion carrying capacity of the system. Based on the corrosion rate integral, material constant and total ion capacity, a corrosion progress term is acquired to calculate the proportion of the current corrosion progress to the total tolerance capacity of the system. The start-stop loss index term acquisition module is used to acquire the number of system start-stop cycles and acquire the start-stop loss index term, which characterizes the impact of the number of start-stop cycles on the lifespan of the fuel cell, based on the number of system start-stop cycles. The maintenance interval prediction module is used to predict the maintenance interval of the fuel cell system based on the corrosion progress item and the start-stop loss index item.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed, implements the fuel cell system coolant ion concentration control method as described in any one of claims 1-5.

Images