A fuel cell stack temperature control system

Abstract

This invention discloses a fuel cell stack temperature control system, belonging to the field of fuel cell technology. It includes an air handling assembly, a cooling circulation assembly, and a flow regulation device. The air handling assembly includes an air compressor and an intercooler connected in sequence. External air is compressed by the air compressor, flows through the hot side of the intercooler, and is delivered to the cathode inlet, then flows out from the cathode outlet. The cooling circulation assembly includes a main loop located between the coolant inlet and coolant outlet, and a branch loop connected to the main loop. The main loop is equipped with a main water pump and a temperature control valve. Coolant is diverted from the main loop to the branch loop and then returns to the main loop via the cold side of the intercooler. The flow regulation device is located in the main loop and / or the branch loop to regulate the flow rate of coolant flowing through the cold side of the intercooler. By integrating the coordinated operation mechanism of the air handling assembly and the cooling circulation assembly, and in conjunction with the flow regulation device, high-precision dynamic control of the fuel cell stack operating temperature is achieved.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and in particular to a fuel cell stack temperature control system. Background Technology

[0002] As a highly efficient and clean energy conversion device, fuel cells have received widespread attention and application in many fields such as automobiles and distributed power generation. The fuel cell stack, as the core component of a fuel cell system, is highly dependent on a suitable operating temperature for its stable operation and performance.

[0003] In actual operation, fuel cells require oxygen from the air to supply the fuel cell stack as the oxidant needed for the electrochemical reaction. This is typically achieved by compressing outside air using an air compressor before feeding it into the cathode of the fuel cell stack. However, after compression, the temperature of the outside air rises, and with increasing pressure, the temperature can far exceed the upper limit of the air temperature required by the fuel cell stack cathode, necessitating additional cooling of the compressed air. Furthermore, the electrochemical reaction generates a significant amount of heat during this process. If this heat cannot be dissipated from the system in a timely and effective manner, the temperature of the fuel cell stack will rise rapidly. Excessively high temperatures not only accelerate the aging and degradation of the internal materials of the fuel cell but also reduce power generation efficiency and may even pose safety risks.

[0004] Currently available fuel cell stack temperature control systems typically employ basic cooling methods, such as simple air or water cooling. These methods often struggle to precisely adjust the cooling intensity based on the real-time heat generation and oxygen supply of the fuel cell stack. In practical applications, the cathode temperature is easily affected by changes or shifts in the atmospheric environment, which can prevent the fuel cell stack from achieving optimal performance. In some cases, improper thermal management can even lead to irreversible performance damage, impacting the reliability and durability of the fuel cell stack. Summary of the Invention

[0005] The purpose of this invention is to provide a fuel cell stack temperature control system to solve the technical problem of poor adaptability of fuel cell stack cooling systems in the prior art, which cannot adjust the cooling intensity in real time based on actual conditions.

[0006] Based on the above concept, the technical solution adopted by this invention is as follows:

[0007] A fuel cell stack temperature control system is applied to the main body of the fuel cell stack, the main body of the fuel cell stack having a coolant inlet, a coolant outlet, a cathode inlet, and a cathode outlet. The fuel cell stack temperature control system includes:

[0008] An air handling assembly includes an air compressor and an intercooler connected in sequence. Outside air is compressed by the air compressor, flows through the hot side of the intercooler, and is delivered to the cathode inlet and exits from the cathode outlet. A cooling circulation assembly includes a main circuit disposed between the coolant inlet and the coolant outlet, and a branch circuit connected to the main circuit. The main circuit is equipped with a main water pump and a temperature control valve. Coolant is diverted from the main circuit to the branch circuit and returns to the main circuit through the cold side of the intercooler. A flow regulating device is disposed in the main circuit and / or the branch circuit for regulating the flow rate of the coolant flowing through the cold side of the intercooler.

[0009] Preferably, the flow regulating device includes an auxiliary water pump, which is disposed in the branch circuit and located between the main water pump and the intercooler. The auxiliary water pump is used to regulate the flow rate of the coolant flowing through it.

[0010] Preferably, the flow regulating device includes a flow resistance regulating valve, which is disposed in the main circuit and located between the main water pump and the coolant inlet. The flow resistance regulating valve is used to regulate the flow rate of the coolant flowing through it, and the input end of the branch circuit is located between the main water pump and the flow resistance regulating valve.

[0011] Preferably, the output end of the branch circuit is located between the flow resistance regulating valve and the coolant inlet.

[0012] Preferably, the battery stack body further includes a package box purge inlet and a package box purge outlet. In the external air flowing through the hot side of the intercooler, a portion is transported to the cathode inlet, and another portion is transported to the package box purge inlet and flows out from the package box purge outlet.

[0013] Preferably, a first temperature sensor and a first pressure sensor are provided at the coolant inlet, and a second temperature sensor and a second pressure sensor are provided at the coolant outlet; and / or, a third temperature sensor and a third pressure sensor are provided at the cathode inlet, and a fourth temperature sensor and a fourth pressure sensor are provided at the cathode outlet.

[0014] Preferably, a humidification device is provided between the intercooler and the cathode inlet to increase the humidity of the external air flowing through it.

[0015] Preferably, a shut-off valve is provided between the intercooler and the cathode inlet, the shut-off valve being used to open or close the passage between the intercooler and the cathode inlet; and / or, a back pressure regulating valve is provided at the cathode outlet, the back pressure regulating valve being used to control the flow rate of the external air flowing out of the cathode outlet.

[0016] Preferably, the air handling assembly includes an air filter, an air flow meter, and an air temperature sensor. The air filter is connected to the input of the air compressor and is used to filter the outside air. The air flow meter and the air temperature sensor are disposed between the air filter and the air compressor.

[0017] Preferably, a radiator is connected in parallel between the temperature control valve and the main water pump, the radiator being used to reduce the temperature of the coolant flowing through it.

[0018] The beneficial effects of this invention are:

[0019] The fuel cell stack temperature control system proposed in this invention uses an air handling assembly that connects an air compressor and an intercooler in series. This allows the compressed, high-temperature external air flowing through the hot side of the intercooler to directly exchange heat with the coolant in the cooling circulation assembly. This rapidly eliminates the extra heat introduced during compression before the external air enters the cathode inlet, preventing the high-temperature external air from directly impacting the interior of the fuel cell stack. Simultaneously, the cooling circulation assembly employs a parallel topology of main and branch loops. A main water pump drives the coolant to circulate within the fuel cell stack to absorb the heat generated by the electrochemical reaction, while a portion of the coolant is directed to the cold side of the intercooler for secondary heat exchange via the branch loops. This split-flow design allows the same coolant flow path to simultaneously perform the dual functions of cooling the fuel cell stack and pre-cooling the cathode inlet air, improving coolant utilization. The flow regulation device dynamically adjusts the coolant flow rate through the cold side of the intercooler, precisely matching cooling requirements based on real-time operating conditions. When the air compressor load increases or the intake air temperature rises due to external environmental factors, the heat exchange efficiency of the intercooler can be improved by increasing the flow rate of the coolant in the branch circuit. Conversely, reducing the flow rate in the branch circuit under low load or low temperature conditions can avoid energy waste caused by over-cooling and maintain the uniformity of the internal temperature of the fuel cell stack. Through this adaptive flow distribution mechanism, combined with the closed-loop regulation of the overall temperature of the main circuit by the temperature control valve, the fuel cell stack temperature control system can simultaneously respond to the dual disturbances of heat generation fluctuations in the fuel cell stack and changes in intake air temperature. In summary, the fuel cell stack temperature control system provided by this invention, through the integrated collaborative operation mechanism of the air handling components and cooling circulation components, and in conjunction with the flow regulation device, achieves high-precision dynamic control of the fuel cell stack operating temperature. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the fuel cell stack temperature control system provided in Embodiment 1 of the present invention;

[0021] Figure 2 This is a schematic diagram of the structure of the fuel cell stack temperature control system provided in Embodiment 2 of the present invention;

[0022] Figure 3 This is a schematic diagram of the fuel cell stack temperature control system provided in Embodiment 3 of the present invention.

[0023] In the picture:

[0024] 100. Battery stack body; 101. Coolant inlet; 102. Coolant outlet; 103. Cathode inlet; 104. Cathode outlet; 105. Encapsulation box purge inlet; 106. Encapsulation box purge outlet; 1. Air handling unit; 11. Air compressor; 12. Intercooler; 13. Air filter; 14. Air flow meter; 15. Air temperature sensor; 2. Cooling circulation unit; 201. Main circuit; 202. Branch circuit; 21. Main water pump; 22. Temperature control valve; 23. Humidifier; 24. Shut-off valve; 25. Back pressure regulating valve; 26. Radiator; 27. Tailpipe; 31. Auxiliary water pump; 32. Flow resistance regulating valve; 41. First temperature sensor; 42. First pressure sensor; 51. Second temperature sensor; 52. Second pressure sensor; 61. Third temperature sensor; 62. Third pressure sensor; 71. Fourth temperature sensor; 72. Fourth pressure sensor. Detailed Implementation

[0025] Embodiments of the present invention are described in detail below. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0026] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0028] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. Example 1

[0029] This invention provides a fuel cell stack temperature control system that can compress, cool, and deliver external air to the cathode of the fuel cell stack to provide the oxygen required for the chemical reaction of the fuel cell, and to cool the fuel cell stack to ensure power generation efficiency.

[0030] See Figure 1 The fuel cell stack temperature control system provided in this embodiment of the invention is applied to the fuel cell stack body 100. The fuel cell stack body 100 has a coolant inlet 101, a coolant outlet 102, a cathode inlet 103 and a cathode outlet 104. The fuel cell stack temperature control system includes an air handling component 1, a cooling circulation component 2 and a flow regulation device. The air handling assembly 1 includes an air compressor 11 and an intercooler 12 connected in sequence. External air is compressed by the air compressor 11 and flows through the hot side of the intercooler 12 and is delivered to the cathode inlet 103 and flows out from the cathode outlet 104. The cooling circulation assembly 2 includes a main circuit 201 and a branch circuit 202 connected to the main circuit 201, which are disposed between the coolant inlet 101 and the coolant outlet 102. The main circuit 201 is equipped with a main water pump 21 and a temperature control valve 22. The coolant is diverted from the main circuit 201 to the branch circuit 202 and flows back to the main circuit 201 through the cold side of the intercooler 12. A flow regulating device is disposed in the main circuit 201 and / or the branch circuit 202 to regulate the flow rate of the coolant flowing through the cold side of the intercooler 12.

[0031] The fuel cell stack temperature control system proposed in this invention uses an air handling assembly 1 that connects an air compressor 11 and an intercooler 12 in series. This allows the compressed, high-temperature external air flowing through the hot side of the intercooler 12 to directly exchange heat with the coolant in the cooling circulation assembly 2. This rapidly eliminates the extra heat introduced during compression before the external air enters the cathode inlet 103, preventing the high-temperature external air from directly impacting the interior of the fuel cell stack body 100. Simultaneously, the cooling circulation assembly 2 employs a parallel topology of a main loop 201 and a branch loop 202. A main water pump 21 drives the coolant to circulate within the fuel cell stack body 100 to absorb the heat generated by the electrochemical reaction, and the branch loop 202 directs a portion of the coolant to the cold side of the intercooler 12 for secondary heat exchange. This split-flow design allows the same coolant flow path to simultaneously perform the dual functions of heat dissipation for the fuel cell stack body 100 and pre-cooling of the air entering the cathode inlet 103, improving coolant utilization. The flow regulation device dynamically adjusts the coolant flow rate through the cold side of the intercooler 12, enabling precise matching of cooling requirements based on real-time operating conditions. When the air compressor 11 load increases or the intake air temperature rises due to external environmental factors, the heat exchange efficiency of the intercooler 12 can be improved by increasing the flow rate of the coolant in the branch circuit 202. Conversely, reducing the flow rate of the branch circuit 202 under low load or low temperature conditions can avoid energy waste caused by over-cooling and maintain the uniformity of the internal temperature of the fuel cell stack body 100. Through this adaptive flow distribution mechanism, combined with the closed-loop regulation of the overall temperature of the main circuit 201 by the temperature control valve 22, the fuel cell stack temperature control system can synchronously respond to the dual disturbances of heat generation fluctuations and intake air temperature changes in the fuel cell stack body 100. In summary, the fuel cell stack temperature control system provided by this invention, through the integrated collaborative operation mechanism of the air handling component 1 and the cooling circulation component 2, and in conjunction with the flow regulation device, achieves high-precision dynamic control of the fuel cell stack operating temperature.

[0032] The specific structure and working principle of the temperature control system for this fuel cell stack are described below.

[0033] In operation, the temperature control system for this fuel cell stack first pressurizes and heats external air by entering the air compressor 11. It then flows through the hot-side channel of the intercooler 12, where it exchanges heat with the coolant flowing on the cold side of the intercooler 12. The cooled air is then transported to the cathode inlet 103 of the fuel cell stack body 100 to participate in the electrochemical reaction. Simultaneously, the main water pump 21 drives the coolant to flow from the coolant outlet 102, along the main loop 201, through the temperature control valve 22, and back to the coolant inlet 101, forming a main circulation to continuously absorb the reaction heat generated inside the fuel cell stack body 100. During the flow of the coolant through the main loop 201, a portion of the coolant is diverted through the branch loop 202 to the cold-side channel of the intercooler 12, where it absorbs heat from the compressed air through heat exchange before returning to the main loop 201. The flow regulation device dynamically adjusts the coolant distribution ratio of the main circuit 201 or the branch circuit 202 according to real-time operating conditions. When the output temperature of the air compressor 11 increases or the heat generation of the fuel cell stack 100 intensifies, the flow rate of the branch circuit 202 is increased to enhance the heat exchange capacity of the intercooler 12. At the same time, the temperature control valve 22 synchronously increases the flow rate of the main circuit 201 to improve the overall heat dissipation intensity. When the heat load decreases, the flow rate is adjusted in the opposite direction to reduce coolant consumption. Through the coordinated control of the flow rates of the main circuit 201 and the branch circuit 202, the system simultaneously completes the dual tasks of heat dissipation of the fuel cell stack 100 and pre-cooling of the intake air in a single cycle, ultimately achieving a dynamic balance of the fuel cell stack operating temperature.

[0034] The function of the main water pump 21 is to provide power for the flow of coolant in the cooling circulation assembly 2, causing the coolant to circulate in the main loop 201 and the branch loop 202. Its working principle is to mechanically draw coolant from the coolant outlet 102 and pressurize it to the coolant inlet 101, forming a forced circulation path. This achieves the circulation of coolant, thereby removing the heat generated by the fuel cell stack and the heat from the hot-side air of the intercooler 12.

[0035] Temperature control valve 22 is integrated into the main circuit 201 and is used to dynamically adjust the overall circulation intensity of the coolant in the main circuit 201 according to the actual temperature of the battery stack body 100. When the temperature of the battery stack body 100 rises, the opening of temperature control valve 22 increases to increase the flow rate in the main circuit 201 and accelerate heat dissipation; when the temperature drops below a set threshold, the valve of temperature control valve 22 is appropriately closed to reduce the circulation flow rate and avoid overcooling. This adjustment process works in conjunction with the flow regulation device of the branch circuit 202 to ensure the temperature stability of the battery stack body 100 while also taking into account the heat exchange requirements of the intake pre-cooling stage, achieving precise thermal balance under all operating conditions.

[0036] Preferably, a radiator 26 is connected in parallel between the temperature control valve 22 and the main water pump 21. The radiator 26 is used to reduce the temperature of the coolant flowing through it. After the coolant flows out of the coolant outlet 102 of the battery stack body 100, it is divided into two paths under the drive of the main water pump 21. One path flows through the temperature control valve 22 and returns directly to the coolant inlet 101, while the other path enters the parallel radiator 26 for forced cooling. The coolant flowing through the radiator 26 is cooled by heat exchange with the ambient air or an external cold source, and then flows back into the main circuit 201 and mixes with the uncooled coolant before flowing into the coolant inlet 101. When the heat generation of the battery stack body 100 is low, the temperature control valve 22 reduces its opening, allowing most of the coolant to flow preferentially through the radiator 26 for deep cooling, ensuring that the temperature of the battery stack body 100 does not drop excessively under low-temperature conditions. When heat generation increases dramatically, the temperature control valve 22 increases its opening, allowing more uncooled coolant to quickly return to the battery stack body 100. Simultaneously, the radiator 26 continuously processes the diverted coolant, preventing the main circuit 201 from experiencing a cumulative temperature rise due to insufficient heat dissipation capacity. The radiator 26, as an independent heat dissipation unit, complements the temperature control valve 22 of the main circuit 201. For example, in extremely high-temperature environments, even if the temperature control valve 22 is fully open (with no heat dissipation in the main circuit 201), effective cooling can still be achieved by increasing the diversion ratio through the radiator 26. When the radiator 26 fails due to a malfunction, the system can rely entirely on the temperature control valve 22 to regulate the flow rate in the main circuit 201 to maintain basic heat dissipation functions, improving the system's fault tolerance. By adjusting the flow ratio of the radiator 26, the temperature of the coolant entering the battery stack body 100 after mixing can be precisely controlled, avoiding the repeated heating energy consumption caused by excessive cooling of the coolant in the traditional series radiator 26.

[0037] In this embodiment, the flow regulating device includes an auxiliary water pump 31, which is disposed in the branch circuit 202 and located between the main water pump 21 and the intercooler 12. The auxiliary water pump 31 is used to regulate the flow rate of the coolant flowing through it.

[0038] Specifically, the auxiliary water pump 31 is located at the beginning of the coolant diversion in the branch circuit 202 (between the main water pump 21 and the intercooler 12). Its working principle is to directly control the flow rate of coolant entering the cold side of the intercooler 12 by adjusting the valve opening. When the temperature of the compressed air output by the air compressor 11 increases or the heat generation of the battery stack body 100 intensifies, the auxiliary water pump 31 increases its opening, diverting more coolant from the main circuit 201 to the branch circuit 202, thereby improving the heat exchange capacity of the intercooler 12 and rapidly reducing the temperature of the compressed air. Simultaneously, the remaining coolant in the main circuit 201 can still have its flow rate adjusted by the temperature control valve 22 to ensure the heat dissipation requirements of the battery stack body 100. Conversely, under low heat load conditions, the auxiliary water pump 31 decreases its opening to reduce the flow rate in the branch circuit 202, preventing excessive coolant from flowing through the intercooler 12 and causing energy waste.

[0039] This design, through the independent adjustment function of the auxiliary water pump 31, can precisely allocate the coolant ratio between the main circuit 201 and the branch circuit 202, thereby implementing decoupled control for the two stages of intake pre-cooling and heat dissipation of the battery stack body 100. For example, when the ambient temperature rises sharply, causing the initial temperature of the compressed air to be too high, the auxiliary water pump 31 can be used to quickly increase the flow rate of the branch circuit 202 to suppress the intake heat input, without significantly changing the overall flow rate of the main circuit 201, thus avoiding disturbance to the temperature stability of the battery stack body 100. This hierarchical control strategy not only simplifies the system response logic but also improves the reliability of dynamic adjustment by reducing control interference between the temperature control valve 22 and the auxiliary water pump 31. In addition, since the auxiliary water pump 31 acts directly on the fluid path of the branch circuit 202, its adjustment action is less sensitive to coolant pressure fluctuations, further enhancing the stability of flow control.

[0040] Specifically, a first temperature sensor 41 and a first pressure sensor 42 are installed at the coolant inlet 101, and a second temperature sensor 51 and a second pressure sensor 52 are installed at the coolant outlet 102. The first temperature sensor 41 and the first pressure sensor 42 at the coolant inlet 101 monitor the temperature and pressure of the coolant before it enters the battery stack body 100 in real time, while the second temperature sensor 51 and the second pressure sensor 52 at the coolant outlet 102 simultaneously detect the state of the coolant after heat dissipation. By using the temperature and pressure difference data between the inlet and outlet, the actual heat generated inside the battery stack body 100 and the coolant circulation resistance can be accurately calculated, providing a direct basis for subsequent coolant flow control and adjustment of the temperature control valve 22.

[0041] And / or, a third temperature sensor 61 and a third pressure sensor 62 are provided at the cathode inlet 103, and a fourth temperature sensor 71 and a fourth pressure sensor 72 are provided at the cathode outlet 104. The third temperature sensor 61 and the third pressure sensor 62 at the cathode inlet 103 continuously collect the temperature and pressure values ​​of the compressed air before it enters the cathode of the battery stack body 100. Combined with the detection results of the fourth temperature sensor 71 and the fourth pressure sensor 72 at the cathode outlet 104, the heat exchange efficiency and gas diffusion state of the airflow path can be dynamically evaluated.

[0042] Specifically, there are four possible combinations of temperature control valve 22 and auxiliary water pump 31:

[0043] When the third temperature sensor 61 at the cathode inlet 103 reports that the external air temperature at the cathode inlet 103 is lower than the cathode temperature setpoint, and the first temperature sensor 41 at the coolant inlet 101 reports that the temperature at the coolant inlet 101 is lower than the coolant temperature setpoint, the speed of the auxiliary water pump 31 is reduced, while ensuring that its speed is higher than or equal to the minimum operating speed. At this time, the coolant flow rate through the intercooler 12 is reduced, reducing the heat exchange in the intercooler 12, thereby increasing the temperature of the cathode inlet 103. Simultaneously, the opening of the temperature control valve 22 is reduced (by default, when the temperature control valve 22 is at its minimum opening, the external heat exchange system is cut off, and it is in a "small circulation state"; when the temperature control valve 22 is at its maximum opening, all flow passes through the external heat exchange system, and it is in a "large circulation state"), and the instantaneous opening is kept no less than the minimum opening, in order to increase the temperature of the reactor coolant inlet 101.

[0044] When the third temperature sensor 61 at the cathode inlet 103 indicates that the external air temperature at the cathode inlet 103 is higher than the cathode temperature setpoint, and the first temperature sensor 41 at the coolant inlet 101 indicates that the temperature at the coolant inlet 101 is higher than the coolant temperature setpoint, the speed of the auxiliary water pump 31 is increased, ensuring that its speed is lower than or equal to the maximum operating speed. At this time, the coolant flow through the intercooler 12 increases, increasing the heat exchange in the intercooler 12, thereby reducing the temperature of the cathode inlet 103. Simultaneously, the opening of the temperature control valve 22 is increased, and the instantaneous opening is kept no greater than the maximum opening, to further reduce the temperature of the coolant inlet 101.

[0045] When the third temperature sensor 61 at the cathode inlet 103 indicates that the external air temperature at the cathode inlet 103 is lower than the cathode temperature setpoint, but the first temperature sensor 41 at the coolant inlet 101 indicates that the temperature at the coolant inlet 101 is higher than the coolant temperature setpoint, the speed of the auxiliary water pump 31 is reduced, ensuring that its speed is higher than or equal to the minimum operating speed. At this time, the coolant flow through the intercooler 12 decreases, reducing heat exchange in the intercooler 12 and thus increasing the temperature of the cathode inlet 103. Simultaneously, the opening of the temperature control valve 22 is increased, and the instantaneous opening is kept no greater than the maximum opening, to reduce the temperature of the coolant inlet 101.

[0046] When the third temperature sensor 61 at the cathode inlet 103 indicates that the external air temperature at the cathode inlet 103 is higher than the cathode temperature setpoint, but the first temperature sensor 41 at the coolant inlet 101 indicates that the temperature at the coolant inlet 101 is lower than the coolant temperature setpoint, the speed of the auxiliary water pump 31 is increased, ensuring that its speed is lower than or equal to the maximum operating speed. At this time, the coolant flow through the intercooler 12 increases, increasing the heat exchange in the intercooler 12, thereby raising the temperature of the cathode inlet 103. Simultaneously, the opening of the temperature control valve 22 is reduced, and the instantaneous opening is kept no less than the minimum opening, to further increase the temperature of the coolant inlet 101.

[0047] The fuel cell stack temperature control system is equipped with a central controller (CCU), which is electrically connected to each sensor. The first temperature sensor 41 at the coolant inlet 101 uses a thermistor to sense the coolant temperature, converting temperature changes into electrical signals. After amplification and filtering by a signal conditioning circuit, the signals are sent to the CCU as digital signals via a data transmission line. The first pressure sensor 42 senses the coolant pressure through a pressure-sensitive element, similarly converting pressure changes into electrical signals, which are then processed and transmitted to the CCU. The second temperature sensor 51 and the second pressure sensor 52 at the coolant outlet 102 follow the same principle as the inlet sensors, collecting temperature and pressure data at the coolant outlet 102 and transmitting them to the CCU. The third temperature sensor 61 and the third pressure sensor 62 at the cathode inlet 103 detect the temperature and pressure of the compressed air entering the cathode, converting the sensed physical quantity changes into electrical signals, which are then processed and sent to the CCU. The fourth temperature sensor 71 and the fourth pressure sensor 72 at the cathode outlet 104 collect the temperature and pressure data of the air flowing out of the cathode and transmit them to the CCU as electrical signals.

[0048] After receiving data from the coolant inlet 101 and outlet sensors, the CCU uses its built-in algorithm software to calculate the actual heat generated inside the battery stack body 100 based on thermodynamic formulas and preset coolant specific heat capacity and mass parameters. Simultaneously, based on fluid mechanics principles, it assesses the coolant circulation resistance according to the pressure difference between coolant inlet 101 and coolant outlet 102, as well as relevant system piping parameters. For data from the cathode inlet 103 and outlet sensors, the CCU runs a gas analysis software module, combining preset air property parameters and utilizing heat exchange principles and gas diffusion models to analyze and compare the temperature and pressure changes of the air at cathode inlet 103 and cathode outlet 104, dynamically evaluating the heat exchange efficiency and gas diffusion state of the airflow path.

[0049] If calculations show an increase in heat generation from the battery stack while the coolant circulation resistance remains normal, the CCU determines that enhanced heat dissipation is needed. In this case, the CCU sends an electrical signal to the temperature control valve 22, increasing its opening, and simultaneously sends a signal to the main water pump 21, appropriately increasing its speed to accelerate coolant circulation and enhance heat dissipation. When the airflow path's heat exchange efficiency is assessed to be low, the CCU sends control commands to the air handling unit 1 based on the specific situation. For example, if it is determined that the intercooler 12 is not heat-exchanging enough, the CCU sends an electrical signal to the auxiliary water pump 31, increasing its opening to allow more coolant to flow through the cold side of the intercooler 12, thus improving the intercooler 12's cooling capacity for compressed air. If poor gas diffusion is detected, the CCU sends a command to the back pressure regulating valve 25, adjusting its opening to optimize the gas pressure environment within the battery stack body 100, ensuring smooth gas diffusion and maintaining the electrochemical reaction under suitable conditions.

[0050] Specifically, during the cold start phase, especially when the ambient temperature is extremely low, the fuel cell stack needs to rapidly heat up to its normal operating temperature. At this time, the system reduces the speed of the auxiliary water pump 31 to zero (i.e., stops it completely), causing the coolant flow through the cold side of the intercooler 12 to approach zero, thereby maximally suppressing the heat exchange effect of the intercooler 12. Since the compressed air output from the air compressor 11 cannot be cooled when flowing through the hot side of the intercooler 12, the heat it carries is completely retained. The high-temperature air is directly delivered to the cathode inlet 103, utilizing the heat generated during the compression process to heat the interior of the fuel cell stack body 100, thus shortening the temperature rise time during the cold start phase.

[0051] When the temperature of the battery stack body 100 gradually rises but remains below the target temperature, a threshold temperature for the auxiliary water pump 31 to activate is set (e.g., 80% of the target temperature). Below this threshold, the auxiliary water pump 31 maintains a small flow of coolant at its lowest speed, avoiding the risk of pipe freezing due to complete cessation and ensuring that the heat exchange of the intercooler 12 remains at an extremely low level, continuing to utilize the residual heat of compressed air to accelerate the temperature rise of the battery stack body 100. Simultaneously, the closed-loop control strategy of the auxiliary water pump 31 is still implemented during this stage, monitoring the temperature of the cathode inlet 103 in real time. If the detected temperature approaches or exceeds the set value, the speed of the auxiliary water pump 31 is gradually increased to restore the cooling function of the intercooler 12 and prevent overheating.

[0052] Specifically, during use, the CCU runs a self-test program to perform circuit connection and functional tests on all connected sensors and various actuators. The CCU reads preset low-temperature cold start parameters from its internal storage module, including the target start temperature, the minimum operating speed of the auxiliary water pump 31, the opening range of the temperature control valve 22, and the normal operating parameter range of each sensor, to complete the system initialization settings.

[0053] The first temperature sensor 41 at the coolant inlet 101 monitors the initial temperature of the coolant in real time and transmits the temperature data to the CCU in the form of an electrical signal. The CCU compares the received coolant temperature with a preset low-temperature cold start threshold. If the coolant temperature is lower than the threshold, the system is determined to be in a low-temperature cold start state, and the low-temperature cold start control strategy is then activated.

[0054] Once the control strategy is activated, the CCU sends a command to the air compressor 11, instructing it to operate at a specific starting speed to ensure that the compressed air can carry sufficient heat for heating the battery stack body 100. This starting speed is preset based on the heat required by the battery stack body 100 under low-temperature conditions and the performance of the air compressor 11.

[0055] Afterwards, the CCU control shut-off valve 24 is closed to prevent unheated cold air from entering the cathode and avoid heat loss from the battery stack.

[0056] At the same time, the CCU sends a signal to reduce the speed of the auxiliary water pump 31 to zero, so that the flow rate of the coolant flowing through the cold side of the intercooler 12 approaches zero, thereby suppressing the heat exchange effect of the intercooler 12 to the maximum extent and ensuring that the heat carried by the compressed air can be fully used for heating the inside of the battery stack body 100.

[0057] Furthermore, the CCU dynamically adjusts the rotation speed of the main water pump 21 based on the coolant temperature fed back by the first temperature sensor 41 and a preset heating rate model. In the initial stage, the rotation speed of the main water pump 21 is appropriately reduced to decrease the coolant circulation volume, allowing heat to accumulate inside the battery stack body 100 and accelerating the heating rate. As the temperature of the battery stack body 100 gradually rises, the CCU gradually increases the rotation speed of the main water pump 21 to ensure that the coolant can uniformly transfer heat and maintain the consistency of the internal temperature of the battery stack body 100.

[0058] Temperature control valve 22 is kept at a small opening, allowing the coolant to circulate slightly inside the battery stack body 100, reducing heat exchange with the external radiator 26, preventing the coolant temperature from dropping excessively, and ensuring the battery stack's heating efficiency.

[0059] During the cold start process, each sensor continuously feeds back data to the CCU in real time. The third temperature sensor 61 at the cathode inlet 103 monitors the air temperature entering the cathode, while the temperature sensors at the coolant inlet 101 and coolant outlet 102 monitor the coolant temperature changes, respectively.

[0060] Based on this real-time data, the CCU uses its built-in algorithm model to assess the temperature rise of the battery stack body 100. If the air temperature at the cathode inlet 103 is found to be too high, potentially causing localized overheating of the battery stack, the CCU will appropriately increase the speed of the auxiliary water pump 31, allowing a small amount of coolant to flow through the intercooler 12 to moderately cool the compressed air. If the overall temperature rise rate of the battery stack is too slow, the CCU will further optimize the speed of the air compressor 11 or adjust the operating status of the main water pump 21 and the temperature control valve 22 to accelerate the temperature rise process.

[0061] When the temperature reported by the first temperature sensor 41 at the coolant inlet 101 reaches the preset operating temperature threshold of the auxiliary water pump 31 (e.g., 80% of the target temperature), the CCU instructs the auxiliary water pump 31 to operate at its lowest speed to maintain a small amount of coolant flow. This avoids the risk of pipe freezing due to a complete shutdown and ensures that the heat exchange of the intercooler 12 is at an extremely low level, continuing to utilize the waste heat of compressed air to accelerate the heating of the fuel cell stack.

[0062] Simultaneously, the CCU initiates a closed-loop control strategy for the cathode inlet 103 temperature. It compares the cathode inlet 103 temperature fed back by the third temperature sensor 61 with the set value in real time. If the detected temperature is close to or exceeds the set value, the CCU gradually increases the speed of the auxiliary water pump 31 to restore the cooling function of the intercooler 12 and prevent the battery stack from overheating.

[0063] As the temperature of the fuel cell stack continues to rise and approaches the target operating temperature, the CCU gradually adjusts the operating status of each component to smoothly transition it to normal operation. For example, the opening of the temperature control valve 22 is gradually increased to allow the coolant to circulate more freely and enhance heat exchange with the external radiator 26; the speeds of the auxiliary water pump 31 and the air compressor 11 are precisely adjusted according to the actual heat generated by the fuel cell stack and the air intake temperature to ensure that the fuel cell stack can operate stably and efficiently after reaching the operating temperature.

[0064] Preferably, the branch loop 202 has a parallel dual-channel structure, including a conventional cooling channel and a heat storage channel. The heat storage channel is filled with a phase change material whose solid-liquid phase change temperature matches the optimal operating temperature of the fuel cell stack. The inlet ends of the two channels are connected to the input end of the branch loop 202 through a three-way switching valve, and the outlet ends converge into the output end of the branch loop 202. When the main body of the fuel cell stack 100 needs to be heated rapidly, the three-way switching valve directs the branch coolant to the heat storage channel. As it flows through the phase change material, it absorbs the latent heat stored in it. The heated coolant then enters the cold side of the intercooler 12 to exchange heat with the compressed air, causing the air temperature at the cathode inlet 103 to rise rapidly. When enhanced heat dissipation is required, the system switches to the conventional cooling channel, and the coolant flows through the intercooler 12 to efficiently cool down through sensible heat exchange. During normal operation of the fuel cell, the phase change material absorbs the waste heat of the coolant and stores thermal energy (such as when the coolant in the branch circuit 202 flows through the heat storage channel during the high temperature operation of the main body 100 of the fuel cell stack, the phase change material absorbs heat and melts). During cold start or low temperature conditions, it releases heat (the phase change material releases heat upon solidification), thus achieving time-space distribution of energy and improving the system's temperature rise response speed. In addition, the dual-channel switching mechanism works in synergy with the temperature control valve 22 of the main circuit 201. For example, during a cold start in winter, the system switches to the heat storage channel and reduces the opening of the temperature control valve 22, allowing the high-temperature coolant to concentrate on heating the main body 100 of the fuel cell stack, which can save energy compared to the traditional single-channel solution.

[0065] Specifically, the switching logic of the three-way switching valve is linked with the temperature sensor network. When the third temperature sensor 61 detects that the temperature of the cathode inlet 103 is lower than the cathode temperature set value and the temperature of the coolant inlet 101 is also low, the controller prioritizes switching to the heat storage channel and adjusts the auxiliary water pump 31 to increase the total flow of the branch, using the phase change material to store heat and quickly increase the intake temperature. When the battery stack body 100 enters steady-state operation, it automatically switches back to the normal channel and restores the branch flow reference value.

[0066] Preferably, a humidification device 23 is provided between the intercooler 12 and the cathode inlet 103 to increase the humidity of the external air flowing through it. The compressed air, which flows through the hot side of the intercooler 12 and is initially cooled, absorbs moisture and increases humidity as it flows through the humidification device 23 before entering the cathode, raising the air humidity to the optimal range required for the electrochemical reaction. This process works in conjunction with temperature control. The intercooler 12 first cools the high-temperature compressed air to a suitable temperature range, preventing excessive evaporation of humidified moisture due to high temperature. The humidification device 23 then precisely replenishes the humidity based on this temperature, ensuring that the air entering the cathode simultaneously meets both temperature and humidity requirements. By compensating for humidity downstream of the intercooler 12, moisture loss caused by temperature changes during air compression and cooling can be offset. Furthermore, the sequential arrangement of the humidification device 23 and the intercooler 12 forms a graded processing logic of "temperature adjustment first, then humidity adjustment", which avoids the waste of water caused by high-temperature humidification (high-temperature air has a strong moisture absorption capacity and requires more water to be consumed), and also prevents the risk of freezing that may be caused by low-temperature humidification (if humidification is done first and then cooling is done, water may condense during the subsequent cooling). In addition, the humidification process can utilize the waste heat of the system or the waste heat of the coolant circulation to achieve the cascade utilization of thermal energy and reduce the dependence on external humidification energy.

[0067] The humidification device 23 can be an existing membrane humidifier, steam jet humidifier, or other existing equipment. Its specific structure and working principle will not be described in detail here.

[0068] A shut-off valve 24 is provided between the intercooler 12 and the cathode inlet 103. The shut-off valve 24 is used to open or close the passage between the intercooler 12 and the cathode inlet 103, which can flexibly control the external air passage into the cathode inlet 103. When the fuel cell stack is under specific operating conditions, such as the initial start-up, shutdown phase, or when the system needs maintenance, the passage between the intercooler 12 and the cathode inlet 103 can be cut off by closing the shut-off valve 24, preventing air from entering the cathode, which helps to protect the internal structure of the fuel cell stack body 100.

[0069] And / or, a back pressure regulating valve 25 is provided at the cathode outlet 104. The back pressure regulating valve 25 is used to control the flow rate of external air flowing out of the cathode outlet 104, and to precisely control the flow rate of external air flowing out of the cathode outlet 104. By reasonably adjusting the external air flow rate, the gas pressure environment inside the fuel cell stack body 100 can be optimized, ensuring that the electrochemical reaction takes place under suitable pressure conditions, thereby improving the power generation efficiency and performance stability of the fuel cell stack.

[0070] In addition, the battery stack body 100 also includes a packaged box purge inlet 105 and a packaged box purge outlet 106. A portion of the external air flowing through the hot side of the intercooler 12 is delivered to the cathode inlet 103, and the other portion is delivered to the packaged box purge inlet 105 and exits from the packaged box purge outlet 106. The compressed air, pressurized by the air compressor 11 and flowing through the hot side of the intercooler 12, is divided into two independent airflows. The main airflow is delivered to the cathode inlet 103 via a conventional path to participate in the electrochemical reaction, while the other split airflow is guided to the packaged box purge inlet 105. After flowing through the inside of the packaged box, the split airflow is discharged from the purge outlet to the outside of the system. During this process, it continuously carries away accumulated water vapor, unreacted residual gases, or any impurities that may be present inside the packaged box, thereby maintaining the dryness and cleanliness of the inside of the box. This design utilizes the pressure and residual heat characteristics carried by the compressed air itself to achieve active gas replacement of the packaged box without adding an additional purge power source.

[0071] Furthermore, the air handling assembly 1 includes an air filter 13, an air flow meter 14, and an air temperature sensor 15. The air filter 13 is connected to the input of the air compressor 11 and is used to filter external air. The air flow meter 14 and the air temperature sensor 15 are disposed between the air filter 13 and the air compressor 11. The air compressor 11 draws in external air filtered by the air filter 13 from the atmospheric environment, and the air flow meter 14 and the air temperature sensor 15 measure the flow rate and temperature of the filtered external air entering the air compressor 11, respectively. The compressed external air is cooled by the intercooler 12.

[0072] When the fuel cell system is operating, the shut-off valve 24 is opened, and external air filtered by the air filter 13 is drawn into the air compressor 11 and compressed. The compressed external air is cooled by the intercooler 12 and split into fuel cell stack package purging air and fuel cell stack cathode gas. The fuel cell stack package purging air flows into the package purging inlet 105 and exits the package purging outlet 106. Based on the humidification requirements of the gas at the cathode inlet 103, the cooled compressed air enters the humidification device 23 for humidification (this component is not present in systems without external humidification), and then passes through the shut-off valve 24, the third temperature sensor 61, and the third pressure sensor 62 before entering the cathode inlet 103. The external air exiting the fuel cell stack flows out through the cathode outlet 104, and the temperature and pressure of the external air are measured by the fourth temperature sensor 71 and the fourth pressure sensor 72, respectively. The back pressure regulating valve 25 controls the pressure of the cathode of the battery stack body 100 according to the pressure target, and merges with the purge gas of the fuel cell package box downstream of the back pressure regulating valve 25 before entering the tailpipe 27 and being discharged to the atmosphere.

[0073] More specifically, the hot-side outlet of the intercooler 12 is connected to the cathode inlet 103 via a retractable bellows section. An air pressure sensor is also installed at the input end of the air compressor 11. The retractable bellows section is connected to the air pressure sensor signal. When the air pressure sensor detects a high-altitude, low-pressure environment, it drives the bellows to contract to shorten the flow path length from the intercooler 12 to the cathode inlet 103. This reduces heat loss and pressure drop of compressed air during transportation, ensuring that sufficient compressed air can efficiently enter the cathode inlet 103 and maintain the stable electrochemical reaction. At the same time, the speed of the air compressor 11 is adjusted to compensate for the decrease in intake air density, ensuring that the quality and flow rate of the compressed air entering the battery stack body 100 meet the reaction requirements and avoid affecting the power generation efficiency due to insufficient intake air. When the air pressure sensor detects a low-altitude, high-pressure environment, it drives the bellows to extend to increase the heat dissipation area of ​​the flow channel, which helps the compressed air to dissipate heat naturally during transportation, reducing the cooling burden on the intercooler 12; and simultaneously increases the flow rate of the coolant on the cold side of the intercooler 12, enhancing the cooling effect of the intercooler 12, thus providing dual protection for the appropriate air temperature entering the cathode inlet 103.

[0074] Preferably, the air handling assembly 1 further includes a multi-stage temperature regulation module, which is located between the hot-side outlet of the intercooler 12 and the cathode inlet 103. When the compressed air, initially cooled by the intercooler 12, flows through the multi-stage temperature regulation module, it can be further temperature-regulated according to the real-time temperature requirements of the cathode inlet 103. When the ambient temperature is extremely low, the coolant flow rate on the cold side of the intercooler 12 is preferentially reduced to decrease heat exchange, so that the compressed air maintains a higher temperature at the outlet of the intercooler 12, and then is precisely reheated by the multi-stage temperature regulation module. When the ambient temperature is high, the intercooler 12 cools the air with maximum efficiency, and the multi-stage temperature regulation module is in a closed or low-power state.

[0075] The multi-stage temperature control module can be an existing electric heater, heat pump, or heat exchange gas-to-gas heater. Its working principle and specific structure will not be elaborated here. Example 2

[0076] Figure 2 Embodiment 2 is shown, wherein components that are the same as or corresponding to those in Embodiment 1 are represented by the same reference numerals as those in Embodiment 1. For simplicity, only the differences between Embodiment 2 and Embodiment 1 are described. The differences are as follows:

[0077] The flow regulation device includes a flow resistance regulating valve 32, which is located in the main circuit 201 and between the main water pump 21 and the coolant inlet 101. The flow resistance regulating valve 32 is used to regulate the flow rate of the coolant flowing through it. The input end of the branch circuit 202 is located between the main water pump 21 and the flow resistance regulating valve 32.

[0078] Specifically, the flow resistance regulating valve 32 is installed on the main circuit 201 between the main water pump 21 and the coolant inlet 101. The input end of the branch circuit 202 is located at the branch point downstream of the main water pump 21 and upstream of the flow resistance regulating valve 32. When the opening of the flow resistance regulating valve 32 decreases, the flow resistance of the main circuit 201 decreases, resulting in a decrease in pressure at the branch point. Consequently, the pressure difference between the branch circuit 202 and the main circuit 201 decreases, thus naturally reducing the flow rate of the branch circuit 202. Conversely, when the opening of the flow resistance regulating valve 32 increases, the flow resistance of the main circuit 201 increases, the pressure difference of the branch circuit 202 increases, driving more coolant from the branch point into the branch circuit 202 and flowing through the cold side of the intercooler 12. Through the throttling-branching coupling effect of the flow resistance regulating valve 32 on the fluid in the main circuit 201, the active regulation of the main circuit 201 and the passive response of the branch circuit 202 are organically combined to form a flow distribution mechanism with self-balancing characteristics.

[0079] More specifically, regarding the coordination between the flow resistance regulating valve 32 and the auxiliary water pump 31, there are four possible scenarios:

[0080] When the third temperature sensor 61 at the cathode inlet 103 reports that the external air temperature at the cathode inlet 103 is lower than the cathode temperature setpoint, and the first temperature sensor 41 at the coolant inlet 101 reports that the temperature at the coolant inlet 101 is lower than the coolant temperature setpoint, the opening of the flow resistance regulating valve 32 is reduced (the opening is the minimum opening when the flow resistance is minimum, and the opening is the maximum opening when the flow resistance is maximum), and its opening is kept higher than or equal to the minimum opening. At this time, the flow resistance (inlet-outlet pressure difference) distributed in the entire intercooler 12 branch circuit 202 is reduced, the coolant flow rate through the intercooler 12 is reduced, the heat exchange of the intercooler 12 is reduced, thereby increasing the temperature of the cathode inlet 103. At the same time, the opening of the temperature control valve 22 is reduced and the instantaneous opening is not less than the minimum opening, so as to increase the temperature of the reactor coolant inlet 101.

[0081] When the third temperature sensor 61 at the cathode inlet 103 reports that the external air temperature at the cathode inlet 103 is higher than the cathode temperature setpoint, and the first temperature sensor 41 at the coolant inlet 101 reports that the temperature at the coolant inlet 101 is higher than the coolant temperature setpoint, the opening of the flow resistance regulating valve 32 is increased, ensuring that its opening is less than or equal to the maximum opening. At this time, the flow resistance (inlet-outlet pressure difference) distributed in the branch circuit 202 of the entire intercooler 12 increases, the coolant flow rate through the intercooler 12 increases, and the heat exchange of the intercooler 12 is enhanced, thereby reducing the temperature of the cathode inlet 103. At the same time, the opening of the temperature control valve 22 is increased, and the instantaneous opening is kept no greater than the maximum opening, so as to reduce the temperature of the coolant inlet 101.

[0082] When the third temperature sensor 61 at the cathode inlet 103 reports that the external air temperature at the cathode inlet 103 is lower than the cathode temperature setpoint, but the first temperature sensor 41 at the coolant inlet 101 reports that the temperature at the coolant inlet 101 is higher than the coolant temperature setpoint, the opening of the flow resistance regulating valve 32 is reduced, ensuring that its opening is greater than or equal to the minimum opening. At this time, the flow resistance (inlet-outlet pressure difference) distributed throughout the intercooler 12 branch circuit 202 decreases, the coolant flow rate through the intercooler 12 decreases, reducing the heat exchange of the intercooler 12, thereby increasing the temperature of the cathode inlet 103. Simultaneously, the opening of the temperature control valve 22 is increased, and the instantaneous opening is kept no greater than the maximum opening, to reduce the temperature of the coolant inlet 101.

[0083] When the third temperature sensor 61 at the cathode inlet 103 reports that the external air temperature at the cathode inlet 103 is higher than the cathode temperature setpoint, but the first temperature sensor 41 at the coolant inlet 101 reports that the temperature at the coolant inlet 101 is lower than the coolant temperature setpoint, the opening of the flow resistance regulating valve 32 is increased, ensuring that its opening is less than or equal to the maximum opening. At this time, the flow resistance (inlet-outlet pressure difference) distributed throughout the intercooler 12 branch circuit 202 increases, the coolant flow rate through the intercooler 12 increases, and the heat exchange of the intercooler 12 is enhanced, thereby reducing the temperature of the cathode inlet 103. Simultaneously, the opening of the temperature control valve 22 is reduced, and the instantaneous opening is not less than the minimum opening, in order to increase the temperature of the coolant inlet 101.

[0084] Preferably, the output end of the branch loop 202 is located between the flow resistance regulating valve 32 and the coolant inlet 101. The output end of the branch loop 202 is located in the main loop 201 section between the flow resistance regulating valve 32 and the coolant inlet 101. When the system is in a low-temperature cold start state, the flow resistance regulating valve 32 is controlled to be less than or equal to the maximum opening. At this time, the flow rate of the main loop 201 is greatly reduced, while the branch loop 202 obtains a higher proportion of coolant flow rate due to the increased pressure difference at the branch point. The coolant flowing through the cold side of the intercooler 12 absorbs heat from the compressed air and its temperature rises. It then flows directly into the main loop 201 section adjacent to the coolant inlet 101, mixes with a small amount of unheated coolant in the main loop 201, and forms a mixed coolant with a raised temperature that enters the coolant inlet 101. Through a special coolant branch loop 202 topology, a high proportion of branch flow can be actively maintained in low-temperature environments, continuously introducing the heat recovered by the intercooler 12 into the battery stack body 100. This avoids heat loss caused by the coolant repeatedly flowing through the radiator 26 in traditional systems, thereby improving the temperature uniformity inside the battery stack body 100. This design eliminates the need for additional electric heating devices, achieving self-supply of the cold start heat source solely through flow path topology optimization. This simplifies the system structure and avoids energy loss from auxiliary heating. For example, during a cold start at an extremely low temperature of -30℃, the compressed air output by the air compressor 11 can reach a temperature of over 80℃. After absorbing heat through the intercooler 12, the coolant in branch loop 202 reaches a temperature of 40-50℃, which, when directly injected into the inlet of the battery stack body 100, allows its core area to break through the freezing point within minutes, outperforming the start-up performance of traditional series cooling architectures. In addition, under normal operating conditions, the flow resistance regulating valve 32 returns to its normal opening, and the preheated coolant output from the branch circuit can still maintain a suitable inlet temperature after mixing with the coolant in the main circuit 201, thus achieving seamless switching between cold start mode and steady-state operation mode. Example 3

[0085] Figure 3 Embodiment 3 is shown, in which components that are the same as or corresponding to those in Embodiments 1 and 2 are referred to using the same reference numerals as those in Embodiment 1. For simplicity, only the differences between Embodiment 3 and Embodiments 1 and 2 are described. The differences are as follows:

[0086] The flow regulation device includes an auxiliary water pump 31 and a flow resistance regulating valve 32. The auxiliary water pump 31 is located in the branch circuit 202 and between the main water pump 21 and the intercooler 12. The auxiliary water pump 31 is used to regulate the flow rate of the coolant flowing through it. The flow resistance regulating valve 32 is located in the main circuit 201 and between the main water pump 21 and the coolant inlet 101. The flow resistance regulating valve 32 is used to regulate the flow rate of the coolant flowing through it. The input end of the branch circuit 202 is located between the main water pump 21 and the flow resistance regulating valve 32.

[0087] It is understandable that the technical solution of Embodiment 3 constructs a dual regulation mechanism for the flow of the main circuit 201 and the branch circuit 202 by simultaneously setting up an auxiliary water pump 31 and a flow resistance regulating valve 32. Its specific operating principle and process integrate the collaborative control logic of Embodiments 1 and 2. When the system is running, the auxiliary water pump 31 directly affects the heat exchange of the intercooler 12 by actively adjusting the flow of the branch circuit 202, while the flow resistance regulating valve 32 indirectly adjusts the flow distribution ratio of the branch circuit 202 by changing the flow resistance of the main circuit 201. The two form a complementary flow distribution strategy. For example, when the cathode inlet temperature fluctuates rapidly, the auxiliary water pump 31 prioritizes rapid coarse adjustment of the branch flow, while the flow resistance regulating valve 32 performs fine correction of the main circuit 201 flow. The dynamic balance of coolant distribution is achieved through the coordinated action of the two valves. This design, by superimposing the control dimensions of Embodiments 1 and 2, further enhances the system's adaptability to complex operating conditions. Its specific implementation is based on the teachings of the aforementioned embodiments and will not be repeated here.

[0088] The above embodiments merely illustrate the basic principles and characteristics of the present invention. The present invention is not limited to the above embodiments. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A fuel cell stack temperature control system, applied to a fuel cell stack body (100), the fuel cell stack body (100) having a coolant inlet (101), a coolant outlet (102), a cathode inlet (103), and a cathode outlet (104), characterized in that, The fuel cell stack temperature control system includes: An air handling unit (1) includes an air compressor (11) and an intercooler (12) connected in sequence. After being compressed by the air compressor (11), the outside air flows through the hot side of the intercooler (12) and is delivered to the cathode inlet (103), and flows out from the cathode outlet (104). The cooling circulation assembly (2) includes a main circuit (201) disposed between the coolant inlet (101) and the coolant outlet (102) and a branch circuit (202) connected to the main circuit (201). The branch circuit (202) has a parallel dual-channel structure, including a conventional cooling channel and a heat storage channel. The inlet ends of the two channels are connected to the input end of the branch circuit (202) through a three-way switching valve, and the outlet ends converge into the output end of the branch circuit (202). The main circuit (201) is equipped with a main water pump (21) and a temperature control valve (22). The coolant is diverted from the main circuit (201) to the branch circuit (202) and flows back to the main circuit (201) through the cold side of the intercooler (12). A radiator (26) is connected in parallel between the temperature control valve (22) and the main water pump (21). The radiator (26) is used to reduce the temperature of the coolant flowing through it. A flow regulating device is provided in the main circuit (201) and / or the branch circuit (202) for regulating the flow rate of the coolant flowing through the cold side of the intercooler (12); The flow regulating device includes an auxiliary water pump (31), which is located in the branch circuit (202) and between the main water pump (21) and the intercooler (12). The auxiliary water pump (31) is used to regulate the flow rate of the coolant flowing through it. The flow regulation device includes a flow resistance regulating valve (32), which is disposed in the main circuit (201) and located between the main water pump (21) and the coolant inlet (101). The flow resistance regulating valve (32) is used to regulate the flow rate of the coolant flowing through it. The input end of the branch circuit (202) is located between the main water pump (21) and the flow resistance regulating valve (32). The output end of the branch circuit (202) is located between the flow resistance regulating valve (32) and the coolant inlet (101).

2. The fuel cell stack temperature control system according to claim 1, characterized in that, The battery stack body (100) also includes a package box purge inlet (105) and a package box purge outlet (106). A portion of the external air flowing through the hot side of the intercooler (12) is transported to the cathode inlet (103), and another portion is transported to the package box purge inlet (105) and flows out from the package box purge outlet (106).

3. The fuel cell stack temperature control system according to claim 1, characterized in that, A first temperature sensor (41) and a first pressure sensor (42) are provided at the coolant inlet (101), and a second temperature sensor (51) and a second pressure sensor (52) are provided at the coolant outlet (102). And / or, a third temperature sensor (61) and a third pressure sensor (62) are provided at the cathode inlet (103), and a fourth temperature sensor (71) and a fourth pressure sensor (72) are provided at the cathode outlet (104).

4. The fuel cell stack temperature control system according to claim 1, characterized in that, A humidification device (23) is provided between the intercooler (12) and the cathode inlet (103) to increase the humidity of the external air flowing through it.

5. The fuel cell stack temperature control system according to claim 1, characterized in that, A shut-off valve (24) is provided between the intercooler (12) and the cathode inlet (103). The shut-off valve (24) is used to open or close the passage between the intercooler (12) and the cathode inlet (103). And / or, a back pressure regulating valve (25) is provided at the cathode outlet (104), the back pressure regulating valve (25) being used to control the flow rate of the external air flowing out of the cathode outlet (104).

6. The fuel cell stack temperature control system according to claim 1, characterized in that, The air handling assembly (1) includes an air filter (13), an air flow meter (14), and an air temperature sensor (15). The air filter (13) is connected to the input end of the air compressor (11) and is used to filter the external air. The air flow meter (14) and the air temperature sensor (15) are disposed between the air filter (13) and the air compressor (11).

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