Fuel cell coolant safety detection system and method

Abstract

The invention discloses a fuel cell coolant safety detection system and method, and relates to the technical field of fuel cells, and the fuel cell coolant safety detection system comprises an electric pile, a cooling circulation pipeline, a plurality of conductivity sensors and a data processing unit. The cooling circulation pipeline is connected to the electric pile, the plurality of conductivity sensors are divided into a plurality of groups, and at least two conductivity sensors in each group are arranged on a cooling liquid inlet side and a cooling liquid outlet side of at least one key component in a radiator, a deionizer and a PTC (Positive Temperature Coefficient) in the cooling circulation pipeline and are used for synchronously collecting conductivity signals of cooling liquid before and after the component works. All the conductivity sensors are in communication connection with a data processing unit, and the data processing unit receives and processes the signals. Compared with the prior art, the system carries out comparison monitoring before and after multiple components, component-level positioning and online evaluation on the conductivity change of the cooling liquid are achieved, the problems that pollution sources cannot be distinguished and faults are difficult to position in a traditional single-measuring-point monitoring mode are effectively solved, and the accuracy and safety of operation and maintenance of the fuel cell system are improved.

Description

Technical Field

[0001] This application relates to the field of fuel cell technology, and in particular to a fuel cell coolant safety detection system and method. Background Technology

[0002] As a highly efficient and clean energy conversion device, fuel cells must dissipate the heat generated during operation through a cooling system to maintain the stack within its optimal temperature range, ensuring its efficiency, lifespan, and safety. The electrical insulation properties of the coolant, as the medium for thermal management, are crucial. Excessively high conductivity significantly increases the risk of leakage or even short circuits within the stack, leading to decreased efficiency, power degradation, and potential safety hazards.

[0003] Currently, traditional solutions, which use a single measuring point to monitor the overall conductivity, cannot distinguish the specific source of conductivity changes, leading to difficulties in locating faulty components and delays in maintenance. Summary of the Invention

[0004] The purpose of this invention is to provide a fuel cell coolant safety detection system and method, which at least solves the problems of traditional solutions that use a single measuring point to monitor the overall conductivity, making it impossible to distinguish the specific source of conductivity changes, leading to difficulties in locating faulty components and delayed maintenance.

[0005] This invention provides the following solution:

[0006] According to one aspect of the present invention, a fuel cell coolant safety detection system is provided, comprising a fuel cell stack: a cooling circulation pipeline is connected to one side of the fuel cell stack, the cooling circulation pipeline is connected to a plurality of conductivity sensors, the plurality of conductivity sensors are divided into several groups, and at least two sensors in each group are respectively arranged in pairs on the coolant inlet and outlet sides of at least one component of the radiator, deionizer and PTC in the cooling circulation pipeline, for synchronously acquiring conductivity signals of the coolant before and after the corresponding component, and outputting conductivity signals; the plurality of conductivity sensors are communicatively connected to a data processing unit, the data processing unit receiving and processing the conductivity signals.

[0007] Furthermore, the cooling circulation pipeline includes a main circulation branch and a deionization branch, which are connected in parallel via a three-way valve and one of them can be selectively connected; in the main circulation branch, the coolant flows sequentially through the radiator, the filter screen and the water pump; a deionizer is connected in series in the deionization branch.

[0008] Furthermore, the plurality of conductivity sensors include a first group of sensors, which includes conductivity sensor four and conductivity sensor five respectively disposed on the coolant inlet side and outlet side of the radiator.

[0009] Furthermore, the plurality of conductivity sensors include a second set of sensors, the second set of sensors including conductivity sensor six and conductivity sensor seven respectively disposed on the coolant inlet side and outlet side of the deionizer, wherein conductivity sensor seven is disposed on the inlet side of the filter screen.

[0010] Furthermore, the cooling circulation pipeline also includes a heating branch connected in parallel. The heating branch is connected to the main circulation loop through a three-way valve and is connected in series with a water pump, a PTC and a heater core.

[0011] Furthermore, the plurality of conductivity sensors include a third group of sensors, which includes conductivity sensor one and conductivity sensor two respectively disposed on the coolant inlet side and outlet side of the PTC. The plurality of conductivity sensors also include conductivity sensor three disposed on the coolant outlet side of the heater core.

[0012] Furthermore, the plurality of conductivity sensors also includes a conductivity sensor eight disposed on the coolant outlet side of the water pump one.

[0013] Furthermore, the conductivity sensor is sealed and installed on the wall of the cooling circulation pipeline via a threaded connection.

[0014] Furthermore, the data processing unit is configured to: evaluate the impact of the component on the coolant conductivity based on the signal difference between two conductivity sensors on the inlet and outlet sides of the same functional component; and predict the remaining service life of the deionizer and generate an early warning signal based on the conductivity data collected by the multiple conductivity sensors.

[0015] According to two aspects of the present invention, a method for safety testing of fuel cell coolant is provided, comprising the following steps:

[0016] S1. Simultaneously acquire signals from pairs of conductivity sensors installed on the inlet and outlet sides of the coolant in at least one component in the radiator, deionizer and PTC.

[0017] S2. Process the paired signals corresponding to each component, and evaluate the impact of the component on the coolant conductivity based on the difference between its inlet and outlet signals.

[0018] S3. Based on the conductivity signals of the deionizer inlet and outlet sides, predict the remaining service life of the deionizer, and generate an early warning signal when the remaining service life is lower than a threshold.

[0019] The above solution achieves the following beneficial technical effects:

[0020] This application utilizes pairs of conductivity sensor groups installed at the inlet and outlet sides of key components such as radiators, deionizers, and PTCs to compare the conductivity signals of the coolant before and after each component's operation in real time. The data processing unit then analyzes the signals, enabling component-level location monitoring and evaluation of the coolant's insulation performance. This improves upon the problems of traditional solutions that rely on a single measuring point to monitor overall conductivity, making it impossible to distinguish the specific source of conductivity changes, leading to difficulties in locating faulty components and delayed maintenance.

[0021] This application sets up multiple conductivity sensors in groups before and after multiple key functional components in the cooling circulation pipeline, covering multiple potential sources of ion contamination such as radiators, deionizers, and heaters. This enables simultaneous online conductivity monitoring of multiple components, thereby improving the problem in traditional monitoring schemes where the limited number of conductivity sensors can only reflect the local or overall conductivity of the system, resulting in an inability to fully grasp the independent status of each component and insufficient system monitoring integrity.

[0022] This application acquires signals in real time through multiple conductivity sensors and communicates with a data processing unit. The data processing unit then processes and judges the conductivity status of the coolant in real time, thereby realizing online continuous monitoring and immediate feedback of the coolant's insulation performance. This improves upon the problems of traditional monitoring methods that rely on manual periodic offline testing or single-point sampling, which have long testing cycles and delayed feedback, making it difficult to detect conductivity abnormalities in a timely manner and achieve real-time safety monitoring.

[0023] This application establishes an integrated online detection system by installing multiple conductivity sensors in the cooling circulation pipeline and connecting them to a data processing unit. This system enables the automatic acquisition, transmission, and analysis of coolant conductivity data, thereby improving upon the traditional method which requires external equipment, manual detection, and data recording. This method is cumbersome, relies on human operation, and results in low monitoring efficiency and difficulty in achieving systematic and continuous monitoring. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of a fuel cell coolant safety detection system provided in a specific embodiment of the present invention.

[0025] Figure 2 This is a flowchart of a fuel cell coolant safety testing method provided in a specific embodiment of the present invention.

[0026] The components are as follows: 1. Fuel cell stack; 2. Water pump one; 3. Water pump two; 4. Three-way valve one; 5. Three-way valve two; 6. PTC; 7. Heater core; 8. Radiator; 9. Deionizer; 10. Filter screen; 11. Conductivity sensor one; 12. Conductivity sensor two; 13. Conductivity sensor three; 14. Conductivity sensor four; 15. Conductivity sensor five; 16. Conductivity sensor six; 17. Conductivity sensor seven; 18. Conductivity sensor eight. Detailed Implementation

[0027] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Figure 1 This is a schematic diagram of the structure of a fuel cell coolant safety detection system provided in a specific embodiment of the present invention.

[0029] Fuel cell coolant safety monitoring system, such as Figure 1 As shown, the device includes a fuel cell stack 1. A cooling circulation pipe is connected to one side of the fuel cell stack 1. The cooling circulation pipe is connected to multiple conductivity sensors 11-18. The multiple conductivity sensors 11-18 are divided into several groups. Each group has at least two sensors, which are respectively set in pairs on the coolant inlet and outlet sides of at least one of the components in the cooling circulation pipe, namely the radiator 8, the deionizer 9, and the PTC6. These sensors are used to synchronously collect the conductivity signals of the coolant before and after the corresponding components and output the conductivity signals. The multiple conductivity sensors 11-18 are communicatively connected to a data processing unit, which receives and processes the conductivity signals.

[0030] Specifically, conductivity sensors 11-18, arranged at the inlet and outlet sides of multiple key functional components in the cooling circulation pipeline, synchronously and in pairs collect the conductivity parameters of the coolant in real time. During circulation, the coolant flows through components such as the radiator 8, deionizer 9, and PTC6, and its conductivity may change due to material precipitation, corrosion, scaling, or variations in deionization efficiency of the components themselves. By placing sensors in pairs at the inlet and outlet ends of each component to be monitored, instantaneous data on the coolant conductivity before and after the application of a single variable to that component can be obtained. All conductivity sensors 11-18 transmit the collected conductivity signals to the data processing unit in real time.

[0031] After receiving signals from the conductivity sensors (groups 11-18), the data processing unit first compares and calculates the conductivity difference between the inlet and outlet of the component. This difference directly reflects the influence of the specific component on the coolant ion concentration under current operating conditions. For example, a significant increase in conductivity before and after radiator 8 may indicate internal corrosion or deposit release; if the outlet conductivity of deionizer 9 is not significantly lower than that at the inlet, it suggests a decrease or failure in its deionization capacity; changes in conductivity before and after PTC6 can be used to assess whether the heating process has triggered unnecessary ion precipitation.

[0032] Based on the aforementioned difference data, the data processing unit performs two core analytical functions. First, it performs fault location and performance evaluation. When the conductivity difference corresponding to a component exceeds a preset safety threshold, the system can determine that the component is the main contributor to the deterioration of the coolant's insulation performance, thus achieving rapid location of abnormal problems and avoiding the shortcomings of traditional single conductivity sensors 11-18, which cannot distinguish the source of contamination. Second, it performs lifespan prediction. The system continuously records the conductivity data at the inlet and outlet of the deionizer 9 and calculates the historical trend of its ion removal efficiency. Combining operating parameters such as coolant flow rate, temperature, and cumulative system operating time, the data processing unit can deduce the deionization resin performance degradation curve through a built-in attenuation model, thereby predicting its remaining effective lifespan. When the predicted lifespan is lower than the set threshold, the system generates a warning signal, indicating the need for maintenance or replacement.

[0033] This system solves the problem of blind monitoring of insulation performance in fuel cell cooling systems. Traditional methods typically use a single conductivity sensor (11-18) in the loop, which only provides information on the overall system conductivity level and cannot pinpoint the specific source of increased ion concentration, making troubleshooting difficult. This system, through a multi-point, paired deployment, enables independent measurement and isolated assessment of the impact on each critical component.

[0034] This system addresses the reactive nature of deionizer 9 maintenance. Existing systems often only trigger alarms and require replacement after the coolant conductivity exceeds acceptable levels, potentially jeopardizing the fuel cell stack 1 by then. This system proactively predicts the remaining lifespan of deionizer 9 through real-time monitoring and trend analysis, enabling planned and timely maintenance and preventing sudden failures.

[0035] This enhances the system's safety level. Through distributed real-time monitoring of the coolant conductivity, the system can promptly issue alarms when parameters at any monitoring point become abnormal, preventing internal short circuits, efficiency reduction, or permanent damage to the fuel cell stack due to decreased coolant insulation performance, thus ensuring the safe operation and lifespan of the fuel cell system.

[0036] The system's structural design directly supports the realization of the aforementioned functions. The cooling circulation piping is designed with a main circulation branch and a branch containing the deionizer 9, switched via a three-way valve. This ensures that the coolant flows through the deionizer 9 for purification under different operating modes. Simultaneously, the placement of conductivity sensors 11-18 covers all critical nodes that might affect conductivity. The conductivity sensors 11-18 are connected to the piping using threaded seals, guaranteeing long-term monitoring reliability and sealing. The integration of the data processing unit with the vehicle's existing control system (ECU) allows for the combination of data acquisition, analysis, and overall vehicle operating conditions, improving the accuracy of the predictive model and the efficiency of system collaboration.

[0037] This fuel cell coolant safety monitoring system, through its unique conductivity sensor 11-18 network layout and data processing method, achieves refined monitoring of coolant insulation performance, independent assessment of the impact on key components, and early prediction of the deionizer 9 lifespan, thereby systematically improving the safety and maintainability of fuel cell operation.

[0038] The cooling circulation pipeline includes a main circulation branch and a deionization branch. The main circulation branch and the deionization branch are connected in parallel through a three-way valve 4 and one of them can be selected to be open. In the main circulation branch, the coolant flows through the radiator 8, the filter screen 10 and the water pump 2 in sequence. The deionization branch is connected in series with a deionizer 9.

[0039] Specifically, the main circulation branch and the deionization branch are connected in parallel via a three-way valve 4. The three-way valve 4 switches its internal flow path according to control commands, allowing the coolant to selectively enter either the main circulation branch or the deionization branch, thus enabling selective conduction of the two circulation modes.

[0040] When the system operates in main circulation mode, the coolant is introduced into the main circulation branch via three-way valve 4. In this branch, the coolant first flows through radiator 8. At radiator 8, the coolant exchanges heat with the outside air, dissipating the heat it carries from the fuel cell stack 1 and lowering its temperature. Subsequently, the coolant flows through filter screen 10. Filter screen 10 physically traps and filters any mechanical impurities such as solid particles and flocculent precipitates that may be present in the coolant, preventing these impurities from circulating in the loop and causing blockage or wear to downstream components. The filtered coolant is then pumped back to the fuel cell stack 1 inlet by water pump 2, completing the main circulation. This mode is primarily used for efficient heat dissipation during normal operation of the fuel cell system.

[0041] When the system operates in deionization mode, the coolant is introduced into the deionization branch via three-way valve 4. In this branch, the coolant flows through deionizers 9 connected in series. Deionizers 9 are filled with ion exchange resin and other media. As the coolant flows through, the media adsorbs cations and anions in the water through ion exchange, thereby reducing the ion concentration and conductivity of the coolant. The purified coolant with low conductivity can then be guided back to the main circuit or directly pumped back to the fuel cell stack 1. This mode is mainly used to perform online purification when an increase in coolant conductivity is detected, restoring its insulation performance.

[0042] The effectiveness of this piping structure design lies in functional separation and on-demand switching. Decoupling the heat dissipation and deionization functions into two parallel paths avoids potential problems arising from connecting the radiator 8, filter 10, and deionizer 9 in series within a single loop. For example, it prevents impurities trapped by filter 10 from increasing the burden on deionizer 9 and also reduces system flow resistance. Through valve-controlled switching, the system can flexibly select its operating mode according to actual needs, without requiring all components to continuously operate to simultaneously fulfill two functions, thus optimizing system energy consumption and component lifespan.

[0043] This structure addresses the efficiency losses and design complexity issues caused by overly tight coupling between the existing coolant heat dissipation and purification paths. In highly integrated systems, if heat dissipation and purification functions are forcibly connected in series in the same non-switchable loop, achieving the necessary heat dissipation capacity and purification frequency may lead to redundant piping design, increased pumping power consumption, and compromised system thermal safety when the deionizer 9 requires maintenance or fails. The selective parallel branch scheme provided by this structure, while ensuring both core functions are implemented, offers greater flexibility in system operation, simplifies component configuration within each branch, and improves subsystem maintenance convenience, eliminating the need to interrupt the entire cooling cycle for maintenance or replacement of the deionizer 9.

[0044] Multiple conductivity sensors 11-18 include a first group of sensors, which includes conductivity sensor four 14 and conductivity sensor five 15 respectively disposed on the coolant inlet side and outlet side of the radiator 8.

[0045] Specifically, conductivity sensor 4 14 and conductivity sensor 5 15 are respectively installed on the inlet and outlet sides of the radiator 8, forming the first set of sensors. Their working principle is based on the synchronous measurement and comparison of the coolant conductivity parameters of the radiator 8, this specific heat exchange component, before and after operation.

[0046] When the coolant flows through the radiator 8, it comes into contact with its internal pipes and fin materials, exchanging heat. During this process, if the internal metal materials of the radiator 8 corrode, or if existing deposits are washed away or dissolved, metal ions or other conductive substances may be released into the coolant. Conductivity sensor 4 14 monitors the baseline conductivity of the coolant before it enters the radiator 8 in real time. Conductivity sensor 5 15 monitors the real-time conductivity of the coolant after it flows out of the radiator 8. The signals collected by conductivity sensors 4 14 and 5 15 are synchronously transmitted to the data processing unit.

[0047] After receiving signals from conductivity sensors 14 and 15, the data processing unit calculates the difference between the measured values ​​at the outlet and inlet sides. This difference characterizes the change in conductivity of the coolant as it passes through this specific section of the radiator 8. If the difference remains zero or within a very low baseline fluctuation range, it is determined that the radiator 8 has no substantial impact on the coolant ion concentration under current operating conditions. If the difference appears and continues to increase positively, exceeding the safety threshold set based on system materials and historical data, it indicates that conductive ions are continuously being released inside the radiator 8.

[0048] Through the above methods, conductivity sensors 14 and 15 achieve the isolated monitoring and quantitative assessment of the impact of the radiator 8's own condition on the coolant's insulation performance. It separates the contribution of the radiator 8 as a potential source of contamination from the overall conductivity change signal in the cooling circuit. Traditional single-location conductivity detection can only reflect the overall system conductivity level and cannot distinguish whether the change originates from the radiator 8, pipe corrosion, pump wear, or other components. This arrangement, through before-and-after comparison, directly obtains the conductivity increment data caused by the flow through the radiator 8.

[0049] This solution addresses the challenge of quickly locating and identifying the specific component responsible for increased coolant conductivity in complex, multi-component cooling systems. Previously, when overall system conductivity monitoring showed anomalies, maintenance personnel had to systematically check all possible components, a time-consuming process that could require system downtime. Using data from conductivity sensors 4.14 and 5.15, this solution immediately determines whether radiator 8 is the primary source of the current conductivity anomaly. If the difference is normal, radiator 8 can be largely ruled out, allowing the focus to shift to other components. If the difference is abnormal, radiator 8 can be directly inspected, cleaned, or replaced, enabling rapid fault location and precise maintenance, reducing unnecessary system downtime and maintenance costs. Furthermore, continuous monitoring of this difference data provides a direct data source for assessing the long-term corrosion rate and lifespan prediction of radiator 8 materials.

[0050] Multiple conductivity sensors 11-18 include a second group of sensors, which includes conductivity sensor six 16 and conductivity sensor seven 17 respectively disposed on the coolant inlet side and outlet side of deionizer 9, and conductivity sensor seven 17 disposed on the inlet side of filter screen 10.

[0051] Specifically, the second set of sensors consists of conductivity sensor six 16 and conductivity sensor seven 17, which are respectively installed on the coolant inlet side and outlet side of the deionizer 9, with conductivity sensor seven 17 located on the inlet side of the filter screen 10. Its working principle is based on the simultaneous measurement and comparison of the conductivity of the coolant at the inlet and outlet of the deionizer 9, to directly and in real-time evaluate the ion removal efficiency of the deionizer 9.

[0052] When the coolant flows through deionizer 9, the dissolved conductive ions are selectively adsorbed by the ion exchange resin within deionizer 9, thereby purifying the coolant and reducing its conductivity. Conductivity sensor 6 16 measures the conductivity of the coolant before it enters deionizer 9, reflecting the ion load level of the untreated coolant. Conductivity sensor 7 17 measures the conductivity of the coolant after it leaves deionizer 9 and before it enters filter 10, reflecting the purity of the deionized coolant. Conductivity sensor 6 16 and conductivity sensor 7 17 perform synchronous or quasi-synchronous measurements.

[0053] After receiving signals from conductivity sensors 16 and 17, the data processing unit performs calculations. The core calculation involves obtaining the difference between the outlet conductivity value and the inlet conductivity value, or further calculating the deionization efficiency. This difference or efficiency value directly and quantitatively reflects the actual operating performance of the deionizer 9 at the measurement moment. If the outlet value is significantly lower than the inlet value, and the efficiency value remains at a high level, it indicates that the deionizer 9 is working normally. If the outlet value is close to or even equal to the inlet value, or the efficiency value continues to decrease and falls below the set threshold, it indicates that the ion exchange capacity of the deionizer 9 has decreased or is approaching saturation and failure.

[0054] By positioning the conductivity sensor 717 on the inlet side of the filter 10, it ensures that it measures the state of the coolant immediately after it leaves the outlet of the deionizer 9. This arrangement avoids interference from additional conductivity changes that might occur as the coolant flows through other pipes or components after leaving the deionizer 9 and before reaching the conductivity sensor 717. This ensures that the conductivity value measured by the conductivity sensor 717 can be attributed most directly and accurately to the treatment effect of the deionizer 9, improving the accuracy and reliability of the performance evaluation of the deionizer 9.

[0055] The conductivity sensors 6.16 and 7.17 enable online, quantitative performance diagnosis and monitoring of the deionizer 9, the core purification component. Instead of simply monitoring whether the conductivity at a certain point in the system exceeds a certain absolute safety threshold, they dynamically monitor the operating efficiency of the deionizer 9 itself. This allows the system to grasp the performance degradation trend of the deionizer 9, rather than merely knowing whether it will eventually fail.

[0056] This solution addresses the limitations of traditional monitoring methods in providing early warnings and lifespan predictions for the performance status of deionizer 9. In systems with only single-point monitoring or without paired sensors deployed before and after deionizer 9, anomalies are typically only detected after the overall system conductivity exceeds the limit. By this time, deionizer 9 may have completely failed, and the coolant may no longer possess sufficient insulation properties, posing an immediate risk to fuel cell stack 1. Through the arrangement and calculation of conductivity sensors 616 and 717, the efficiency decline trend of deionizer 9 can be detected in advance, even when its performance is gradually deteriorating but its outlet conductivity has not yet exceeded the limit. Based on this efficiency trend data over time, combined with information such as the known processing capacity and cumulative processed liquid volume of deionizer 9, a model can be established to predict its remaining effective lifespan or the point at which regeneration / replacement is needed. This transforms maintenance from "emergency replacement after failure" to "planned maintenance based on performance prediction," significantly improving the proactive safety of system operation and the orderly nature of maintenance management.

[0057] The cooling circulation pipeline also includes a parallel heating branch, which is connected to the main circulation loop through a three-way valve 25, and is connected in series with a water pump 23, a PTC 6 and a heater core 7.

[0058] Specifically, the heating branch is connected in parallel to the main circulation loop via a three-way valve 25, and then connected in series with water pump 23, PTC 6, and the heater core 7. Its working principle involves loop switching, active heating, and heat distribution.

[0059] Three-way valve 25 switches according to control commands, diverting some or all of the coolant from the main circulation loop to the heating branch. Water pump 23 provides independent circulation power for the coolant flowing through this branch. When the coolant flows through PTC6, PTC6 is energized, converting electrical energy into heat energy to actively and precisely heat the coolant. The heated coolant then flows through heater core 7. As an air-liquid heat exchanger, heater core 7 uses a fan to drive air across its surface when the cabin needs heating, transferring the heat carried by the coolant to the air through the core, thus heating the cabin. After heat exchange, the coolant temperature decreases, and it then flows back to the main circulation loop or continues to circulate and be heated through three-way valve 25.

[0060] The effect of this branch structure is to provide active heating and warming functions independent of the main heat dissipation cycle. It realizes two main operating modes: one is the rapid heating mode, when the fuel cell system starts in a low-temperature environment, by opening this branch and closing or reducing the main heat dissipation cycle, the heat of the coolant can be quickly directed to the fuel cell stack 1, helping the fuel cell stack 1 to rise to a suitable operating temperature as soon as possible and improving cold start performance; the other is the waste heat heating mode, when the fuel cell stack 1 is running normally and the cabin needs heating, this branch can use the waste heat of the fuel cell stack 1 for cabin heating through the heater core 7, improving the overall energy utilization efficiency of the fuel cell system.

[0061] This design solves the problems of limited thermal management functionality and insufficient energy utilization in traditional cooling systems. In systems with only a single heat dissipation circuit, the fuel cell stack 1 relies on its own heat generation for temperature rise during low-temperature startup, which is slow. Furthermore, the coolant heat cannot be effectively used for cabin heating, typically requiring a separate electric heating system, increasing energy consumption and system complexity. This design, by adding a parallel heating branch and integrating the PTC6 and heater core 7, achieves both active heating and waste heat recovery in the coolant circuit. This allows the thermal management system to flexibly switch between heat dissipation and heating / warming modes or adjust them proportionally based on ambient temperature, fuel cell stack 1 operating conditions, and cabin requirements, optimizing the overall thermal balance and energy flow management of the system while avoiding the cost and space burden of setting up a separate fluid circuit for heating.

[0062] The multiple conductivity sensors 11-18 include a third group of sensors, which includes conductivity sensor one 11 and conductivity sensor two 12 respectively disposed on the coolant inlet side and outlet side of PTC6. The multiple conductivity sensors 11-18 also include conductivity sensor three 13 disposed on the coolant outlet side of heater core 7.

[0063] Specifically, the third set of sensors consists of conductivity sensor 11 and conductivity sensor 212 respectively installed on the inlet and outlet sides of the PTC6 coolant, and conductivity sensor 313 is added on the coolant outlet side of the heater core 7.

[0064] Conductivity sensors 11 and 12 simultaneously measure the conductivity of the coolant before and after flowing through PTC6. The difference between the two values ​​directly reflects the net impact of PTC6's operation on the coolant conductivity. Conductivity sensor 13 measures the coolant conductivity after flowing through the heater core 7. Since the coolant flows sequentially through PTC6 and heater core 7 in the heating branch, the value measured by conductivity sensor 13 is the final result after the combined effect of both. Comparing the measured value of conductivity sensor 13 with that of conductivity sensor 12 further distinguishes and quantifies the contribution of heater core 7 itself to the conductivity change.

[0065] This setup enables segmented monitoring and comprehensive evaluation of the heating branch. Independent monitoring of its operating status is achieved through conductivity sensors 11 before and after PTC6 and conductivity sensor 12 before and after it. By adding conductivity sensor 12 at the outlet of the heater core 7, not only is the final coolant state output from this branch to the main circuit obtained, but also, through joint analysis with upstream measuring points within the branch, the influence of the PTC6 and heater core 7—two components connected in series—can be technically isolated and evaluated separately.

[0066] This solution addresses the challenge of independently monitoring and differentiating the condition of downstream components in functional branches containing series-connected parts. Previously, monitoring only the area before and after PTC6 made it impossible to determine if the problem originated from the heater core 7 when that data was normal but the overall branch output was abnormal. This new arrangement, by adding an end-point measuring point, allows for independent assessment of the heater core 7's condition even when PTC6 is evaluated as normal. This enables precise fault location for two critical components within the heating branch, avoiding misdiagnosis or missed diagnosis due to insufficient monitoring points, and improving the accuracy of system diagnosis and the targeted nature of maintenance.

[0067] Multiple conductivity sensors 11-18 also include conductivity sensor 818 disposed on the coolant outlet side of water pump 2.

[0068] Specifically, water pump 2, as a key power component driving the flow of coolant throughout the main circulation loop, contains moving parts such as a rotating impeller, mechanical seals, and bearings. During long-term operation, these components may generate fine metal wear particles due to mechanical friction. Simultaneously, the pump body or impeller material may corrode. These wear particles or corrosion products are directly released into the coolant flowing through water pump 2. Conductivity sensor 818 is installed on the pipeline at the water pump outlet side to directly measure the conductivity value of the coolant after being pressurized and pumped by water pump 2, before it enters the subsequent loop. This measurement captures the instantaneous state of the coolant after flowing through this specific mechanical component, water pump 2.

[0069] The data processing unit receives the signal from the conductivity sensor 818. This signal is used for two main analyses: one is absolute value monitoring, which directly monitors the conductivity level of the coolant at the outlet of water pump 2 as a basic parameter of this node in the main circulation loop; the other is trend and correlation analysis, which compares and calculates the measured value with the measured values ​​at other locations in the loop in real time.

[0070] This setup allows for the targeted monitoring of the operating status of water pump 2 and its contribution to coolant contamination. Since water pump 2 is the primary moving mechanical component in the circuit and a potential source of metal particles, placing a monitoring point at its outlet directly captures changes in coolant conductivity caused by wear or corrosion of water pump 2 itself. This provides an independent observation window for the condition of water pump 2.

[0071] This solution addresses the limitations of traditional monitoring methods in providing online and indirect assessments of the mechanical wear condition of circulating water pump 2, as well as the difficulty in quickly tracing the source of particulate contamination in the system. In complex pipelines, if conductivity or particulate matter is only detected at the end of the system or at a single location, it is impossible to determine whether the contaminant originates from pump 2, radiator 8, or other parts when an anomaly is detected. By installing a conductivity sensor 818 at the outlet of pump 2, an abnormal increase in conductivity at that point, combined with the signal from the particulate matter sensor, can initially suggest abnormal wear or accelerated corrosion within pump 2. Conversely, if the outlet value of pump 2 is stable, but the value at the inlet of downstream radiator 8 increases, the pump can be preliminarily ruled out as a factor, and the focus shifts to radiator 8 and the piping between them. This provides crucial early diagnostic and location information for system maintenance, facilitating predictive maintenance and preventing the spread of wear-related particulate matter from pump 2 to the entire system, thus avoiding more serious consequences. Furthermore, long-term monitoring of the data at this point can also provide a reference for assessing the mechanical life of pump 2.

[0072] Multiple conductivity sensors 11-18 are sealed and installed on the wall of the cooling circulation pipeline via threaded connections.

[0073] Specifically, the threaded connection of multiple conductivity sensors 11-18 typically refers to the conductivity sensor 11-18 probe being machined with external threads, and the corresponding position on the cooling circulation pipe wall being welded or integrated with a pipe seat or connector with internal threads. During installation, the threaded portion of the conductivity sensor 11-18 is screwed into the internal thread of the pipe seat. Through the engagement and tightening of the threads, the conductivity sensor 11-18 probe is connected to the inside of the pipe, and the two are mechanically fixed. Sealing is typically achieved through one or more of the following methods: wrapping sealing materials such as PTFE tape around the threaded portion; placing an O-ring at the root of the conductivity sensor 11-18 thread, where the O-ring is compressed between the end faces to form a static seal when the conductivity sensor 11-18 is tightened to the specified torque; or using tapered threads, relying on the interference fit and plastic deformation of the thread engagement surface to achieve a seal. After installation, the sensitive element of the conductivity sensor 11-18 comes into direct contact with the coolant flowing in the pipeline through its front opening or water-permeable membrane to measure conductivity.

[0074] The first advantage of this installation method is that it provides a reliable and repeatable mechanical connection and sealing interface. The threaded connection has high structural strength, capable of withstanding pressure pulsations, fluid shocks, and vibrations during vehicle operation within the cooling system, preventing the conductivity sensor 11-18 from loosening or falling off due to vibration. Its sealing performance effectively prevents high-pressure coolant leakage from the installation interface, ensuring the long-term sealing reliability of the system. Secondly, this method achieves a standardized and modular interface between the conductivity sensor 11-18 and the piping. The threaded connection facilitates the on-site installation, removal, and replacement of the conductivity sensor 11-18. When a conductivity sensor 11-18 needs calibration, maintenance, or replacement due to failure, there is no need for destructive operations such as cutting or welding the piping. Simply use tools to unscrew the conductivity sensor 11-18 and tighten the new conductivity sensor 11-18 to the specified torque, greatly simplifying the maintenance process and reducing maintenance costs and time.

[0075] The technical problems addressed include insufficient sealing reliability, inconvenient maintenance, and potential impact on measurement accuracy associated with traditional conductivity sensor 11-18 installation methods. If an unsealed insertion installation or clamp fixation is used, coolant leakage or gas intrusion can easily occur under system pressure fluctuations, posing safety hazards and potentially affecting the accuracy of conductivity measurements due to changes in the fluid state at the measurement point. If the conductivity sensor 11-18 is permanently fixed to the pipeline by welding or other methods, replacement is extremely difficult once the sensor is damaged, potentially requiring the replacement of the entire pipeline. The threaded connection sealing installation ensures that the mechanical strength and sealing performance meet the stringent operating conditions of the vehicle cooling system while providing necessary maintainability. Furthermore, a well-designed threaded connection ensures that the conductivity sensor 11-18 electrodes are immersed in the coolant in the correct position and orientation, reducing interference from flow dead zones or eddies created during installation that could affect the representativeness of the measurement sample. This facilitates obtaining a more stable and reliable conductivity measurement signal, providing accurate basic data input for subsequent data processing and condition diagnosis.

[0076] The data processing unit is configured to: evaluate the impact of the component on the coolant conductivity based on the signal difference between two conductivity sensors on the inlet and outlet sides of the same functional component; and predict the remaining service life of the deionizer 9 and generate an early warning signal based on the conductivity data collected by multiple conductivity sensors 11-18.

[0077] Specifically, the data processing unit is configured to perform two core analytical functions: performance evaluation based on the difference between the sensor signals before and after the component, and deionizer 9 life prediction and early warning based on multi-sensor data.

[0078] The first function works as follows: For pairs of conductivity sensor groups installed at the inlet and outlet sides of specific functional components such as radiator 8, deionizer 9, and PTC6, the data processing unit synchronously or quasi-synchronously receives measurement signals from the same set of two sensors. The internal calculation module subtracts these two signal values ​​to obtain the instantaneous conductivity difference between the outlet and inlet of the component. This difference quantifies the net change in conductivity of the coolant as it flows through the specific component. The unit pre-stores reference difference ranges or allowable thresholds corresponding to different components. By continuously comparing the real-time calculated difference with the preset thresholds, the current impact of the component on the coolant conductivity is evaluated. If the difference continuously exceeds the allowable range, the component is deemed to be abnormal, such as releasing ions or experiencing performance degradation.

[0079] The second function works as follows: The data processing unit continuously receives and records measurement data from conductivity sensors installed on the inlet and outlet sides of deionizer 9. The unit calculates the instantaneous deionization efficiency of deionizer 9 at each monitoring moment, which can be characterized by formulas such as (inlet value - outlet value) / inlet value. The unit simultaneously records or receives operating parameters such as system running time, cumulative coolant flow rate, and temperature. A built-in prediction algorithm analyzes historical data sequences of deionization efficiency to identify trends of decline over time or cumulative processing volume. The algorithm combines the current efficiency value, trend slope, and a preset efficiency failure threshold to extrapolate and estimate the remaining effective operating time or remaining processing capacity of deionizer 9, i.e., its remaining service life. When the predicted remaining service life falls below the set warning threshold, the data processing unit generates and outputs a warning signal, which can be used to trigger dashboard indicator lights, audible alarms, or remote notifications.

[0080] The first technological achievement is the ability to isolate, quantify, and conduct online assessments of the status of critical components within the cooling system. By analyzing differences rather than absolute single-point values, the influence of fluctuations in system background conductivity is effectively eliminated, making the assessment conclusions direct and specific to the monitored component itself. The second technological achievement is the ability to predictively assess and proactively warn of the remaining lifespan of the consumable component, deionizer 9. This allows maintenance actions to be planned in advance based on predictions of component performance degradation, rather than passively waiting for complete failure leading to excessive coolant levels.

[0081] The first type of technical problem addressed is the ambiguity and lag in fault location inherent in traditional monitoring methods. In solutions that only monitor the conductivity of a single point in the system, it's impossible to distinguish whether an increase in conductivity originates from the radiator 8, PTC6, or other components. This solution, through differential analysis, can immediately correlate abnormal effects to specific components, achieving rapid fault location and accurate diagnosis, significantly shortening troubleshooting time. The second type of technical problem addressed by this configuration is the passivity and unpredictability of deionizer 9 maintenance. Traditional methods often only replace it after the coolant conductivity has exceeded the standard, at which point fuel cell stack 1 may already be at risk. This solution, through continuous performance trend analysis and lifespan prediction, can issue early replacement warnings in the early stages of deionizer 9 performance degradation before complete failure, shifting the maintenance mode from "post-fault response" to "predictive maintenance." This avoids unplanned downtime due to sudden failure of deionizer 9, reduces the risk of potential damage to fuel cell stack 1, and allows for more rational allocation of maintenance resources and plans. In summary, the configuration of this data processing unit transforms the raw data collected by the front-end sensor network into component status information and early warning information with direct maintenance guidance value, thereby improving the intelligence level and practical value of the entire coolant safety monitoring system.

[0082] Figure 2 This is a flowchart of a fuel cell coolant safety testing method provided in a specific embodiment of the present invention.

[0083] like Figure 2 The fuel cell coolant safety testing method shown includes the following steps:

[0084] S1. Simultaneously acquire signals from pairs of conductivity sensors 11-18 installed on the coolant inlet and outlet sides of at least one of the components: radiator 8, deionizer 9, and PTC6.

[0085] S2. Process the paired signals corresponding to each component, and evaluate the impact of the component on the coolant conductivity based on the difference between its inlet and outlet signals.

[0086] S3. Based on the conductivity signals at the inlet and outlet sides of the deionizer 9, predict the remaining service life of the deionizer 9, and generate a warning signal when the remaining service life is lower than a threshold.

[0087] Specifically, this method performs data processing and logical judgment based on synchronous signals collected by multiple conductivity sensors 11-18 arranged before and after key components. Real-time measurements from paired conductivity sensors 11-18 at the inlet and outlet sides of at least one of the components—radiator 8, deionizer 9, and PTC6—are acquired synchronously. This synchronous acquisition ensures the temporal consistency of the comparison data, avoiding errors introduced by fluctuations in coolant state over time. Subsequently, calculations are performed on each acquired signal set, with the core being the instantaneous difference between the outlet and inlet values. This difference directly quantifies the net change in conductivity as the coolant flows through that specific component, thus decomposing the overall conductivity change of the system and attributing it to specific individual components. For deionizer 9, the method further continuously records and analyzes its inlet and outlet conductivity values ​​to calculate its ion removal efficiency. Based on the decay trend of this efficiency value over time or accumulated treated liquid volume, its remaining effective working time or capacity is estimated using a preset lifespan prediction algorithm. When the predicted remaining lifespan is lower than a preset safety threshold, a warning signal is generated and output.

[0088] This represents a shift from "holistic monitoring" to "component-level diagnostics," and an upgrade in maintenance from reactive response to proactive prediction. By calculating and monitoring the difference in conductivity before and after a component's operation, it's possible to assess in real-time and independently whether the radiator 8 is corroding and releasing ions, whether the PTC6 is causing contamination during heating, and whether the immediate purification efficiency of the deionizer 9 meets standards. This allows any anomaly to be linked to the specific responsible component. Lifespan prediction based on the deionizer 9's performance degradation trend enables early warnings of replacement or maintenance before its efficiency drops to a dangerous level.

[0089] This method addresses the issues of vague fault diagnosis and reactive maintenance in existing fuel cell coolant management strategies. Traditional single-point threshold alarm methods can only indicate overall system anomalies, failing to pinpoint the specific faulty component, leading to aimless and time-consuming troubleshooting. Furthermore, for consumable components like the deionizer 9, whose performance gradually degrades, traditional methods only allow replacement after complete failure and excessive coolant conductivity, resulting in delayed maintenance and potentially exposing the fuel cell stack 1 to insulation degradation. This new method achieves rapid and accurate fault location through differential analysis and planned replacement of the deionizer 9 through trend prediction, thereby shortening troubleshooting time, avoiding potential operational risks caused by untimely maintenance, and improving system reliability and the scientific nature of maintenance management.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fuel cell coolant safety detection system, characterized in that, Includes fuel cell stack (1): A cooling circulation pipe is connected to one side of the fuel cell stack (1), and the cooling circulation pipe is connected to multiple conductivity sensors (11-18). The multiple conductivity sensors (11-18) are divided into several groups. At least two sensors in each group are respectively set on the coolant inlet and outlet sides of at least one of the components in the cooling circulation pipe, namely the radiator (8), the deionizer (9), and the PTC (6), for synchronously collecting the conductivity signals of the coolant before and after the corresponding components and outputting the conductivity signals. The multiple conductivity sensors (11-18) are communicatively connected to a data processing unit, which receives and processes the conductivity signals.

2. The fuel cell coolant safety detection system according to claim 1, characterized in that, The cooling circulation pipeline includes a main circulation branch and a deionization branch. The main circulation branch and the deionization branch are connected in parallel through a three-way valve (4) and one of them is selected to be open. In the main circulation branch, the coolant flows through the radiator (8), the filter screen (10) and the water pump (2) in sequence. The deionization branch is connected in series with a deionizer (9).

3. The fuel cell coolant safety detection system according to claim 1, characterized in that, The plurality of conductivity sensors (11-18) include a first group of sensors, which includes conductivity sensor four (14) and conductivity sensor five (15) respectively disposed on the coolant inlet side and outlet side of the radiator (8).

4. The fuel cell coolant safety detection system according to claim 1, characterized in that, The plurality of conductivity sensors (11-18) include a second group of sensors, the second group of sensors including conductivity sensor six (16) and conductivity sensor seven (17) respectively disposed on the coolant inlet side and outlet side of the deionizer (9), wherein the conductivity sensor seven (17) is disposed on the inlet side of the filter screen (10).

5. The fuel cell coolant safety detection system according to claim 1, characterized in that, The cooling circulation pipeline also includes a heating branch connected in parallel. The heating branch is connected to the main circulation loop through a three-way valve (5) and is connected in series with a water pump (3), a PTC (6) and a warm air core (7).

6. The fuel cell coolant safety detection system according to claim 1, characterized in that, The plurality of conductivity sensors (11-18) include a third group of sensors, which includes conductivity sensor one (11) and conductivity sensor two (12) respectively disposed on the coolant inlet side and outlet side of PTC (6). The plurality of conductivity sensors (11-18) also include conductivity sensor three (13) disposed on the coolant outlet side of heater core (7).

7. The fuel cell coolant safety detection system according to claim 1, characterized in that, The plurality of conductivity sensors (11-18) also include a conductivity sensor eight (18) disposed on the coolant outlet side of the water pump one (2).

8. The fuel cell coolant safety detection system according to claim 1, characterized in that, The conductivity sensor (11-18) is sealed and installed on the wall of the cooling circulation pipeline by means of a threaded connection.

9. The fuel cell coolant safety detection system according to claim 1, characterized in that, The data processing unit is configured to: evaluate the influence of the component on the conductivity of the coolant based on the signal difference between two conductivity sensors on the inlet and outlet sides of the same functional component; and predict the remaining service life of the deionizer (9) and generate an early warning signal based on the conductivity data collected by the plurality of conductivity sensors (11-18).

10. A method for safety testing of fuel cell coolant, characterized in that, The fuel cell coolant safety detection system according to any one of claims 1-9 includes the following steps: S1. Simultaneously acquire signals collected by pairs of conductivity sensors (11-18) on the coolant inlet and outlet sides of at least one of the components, namely the radiator (8), the deionizer (9) and the PTC (6); S2. Process the paired signals corresponding to each component, and evaluate the impact of the component on the coolant conductivity based on the difference between its inlet and outlet signals. S3. Based on the conductivity signals of the inlet and outlet sides of the deionizer (9), predict the remaining service life of the deionizer (9) and generate an early warning signal when the remaining service life is lower than a threshold.

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