A non-humidifier fuel cell system for a passenger car

Abstract

The present application relates to hydrogen fuel cell vehicle technology field, disclose a kind of passenger car's humidifier-free fuel cell system, including hydrogen fuel cell stack, air subsystem, hydrogen subsystem and cooling subsystem, fuel cell stack is used to carry out electrochemical reaction and generate electric energy;Air subsystem is connected with hydrogen fuel cell stack, for hydrogen fuel cell stack supplies air;Hydrogen subsystem is connected with hydrogen fuel cell stack, for hydrogen fuel cell stack supplies hydrogen;The intercooler of air subsystem is connected with the preheater of hydrogen subsystem;Cooling subsystem is connected with hydrogen fuel cell stack, for hydrogen fuel cell cooling, cooling subsystem is connected with intercooler, cooling subsystem is connected with preheater.The overall structure of the present application is more compact, reduces the complexity and failure rate of system, reduces downtime risk, system performance has also been obviously promoted, system runs smoothly and noise and vibration level is lower, power output is stable and high efficiency.

Description

Technical Field

[0001] This invention relates to the field of hydrogen fuel cell vehicle technology, and more specifically to a humidifier-free fuel cell system for passenger vehicles. Background Technology

[0002] With the increasing urgency of energy transition and environmental protection demands, hydrogen fuel cell vehicles, with their high efficiency and cleanliness, have become an important direction for the development of the automotive industry. As the core component of hydrogen fuel cell vehicles, the performance and design of the fuel cell play a crucial role in the overall vehicle's operation. Traditional fuel cell systems are typically equipped with a humidifier, a key component whose main function is to humidify the reactant gases that will participate in the electrochemical reaction. This is because, during the operation of the fuel cell, appropriate humidity of the reactant gases is indispensable for maintaining the smooth progress of the electrochemical reaction. Insufficient humidity of the reactant gases can lead to a decline in the performance of the proton exchange membrane, thereby affecting the power generation efficiency and stability of the entire fuel cell. The humidifier aims to solve this problem, ensuring that the reactant gases are within a suitable humidity range.

[0003] However, the use of humidifiers also brings a series of drawbacks that cannot be ignored. First, the addition of humidifiers makes the overall architecture of the fuel cell system more complex and cumbersome. The difficulty of connecting and coordinating various components such as pipes, valves, and the humidifier itself increases significantly. This not only reduces the system's reliability to some extent but also brings considerable inconvenience to the system's assembly, debugging, and subsequent maintenance. Second, the humidifier itself has a certain cost; its purchase and installation costs are included in the total cost of the fuel cell system, increasing the overall system cost and limiting the large-scale commercialization of hydrogen fuel cell vehicles. Third, the humidifier consumes additional energy to achieve its humidification function. While this energy consumption may seem small, it accumulates significantly over long-term operation, affecting the energy conversion efficiency of the fuel cell system. Furthermore, the humidifier increases the system's size and weight, which is not ideal for hydrogen fuel cell vehicles, which already have specific requirements for space layout and lightweight design, potentially negatively impacting the vehicle's overall design and performance.

[0004] With the continuous development and advancement of hydrogen fuel cell vehicle technology, the industry's requirements for performance, cost, and compactness are constantly increasing. Against this backdrop, developing a fuel cell system that does not require a humidifier has gradually become a research hotspot and trend. This novel fuel cell system aims to eliminate the various drawbacks of traditional humidifiers, ensuring suitable humidity of the reaction gas without relying on one, maintaining the efficient and stable operation of the fuel cell's electrochemical reaction, and thus propelling hydrogen fuel cell vehicles towards greater efficiency, economy, and compactness. This is of crucial practical significance for enhancing the market competitiveness of hydrogen fuel cell vehicles and accelerating their commercial application. Therefore, this invention proposes a novel humidifier-free fuel cell system for passenger vehicles to address the problems existing in the prior art. Summary of the Invention

[0005] To address the problems of humidifiers in existing hydrogen fuel cell vehicle systems, such as complexity, high cost, high energy consumption, and difficult maintenance, this invention provides a humidifier-free fuel cell system for passenger vehicles.

[0006] The technical solution adopted by the present invention to achieve the above objectives is: a humidifier-free fuel cell system for passenger vehicles, comprising...

[0007] Hydrogen fuel cell stacks are used to generate electricity through electrochemical reactions.

[0008] An air subsystem, connected to the hydrogen fuel cell stack, is used to supply air to the hydrogen fuel cell stack;

[0009] A hydrogen subsystem, which is connected to the hydrogen fuel cell stack, is used to supply hydrogen to the hydrogen fuel cell stack.

[0010] The intercooler of the air subsystem is connected to the preheater of the hydrogen subsystem.

[0011] A cooling subsystem is connected to the hydrogen fuel cell stack and is used to cool the hydrogen fuel cell. The cooling subsystem is connected to the intercooler and the preheater.

[0012] According to some embodiments of the present invention, a humidifier-free fuel cell system for a passenger vehicle includes an air subsystem further comprising an air filter, an air compressor, and a muffler. The air filter is connected to the air compressor via a first pipeline, the air compressor is connected to the intercooler via a second pipeline, the intercooler is connected to the muffler via a third pipeline, the intercooler is connected to the air inlet of the hydrogen fuel cell stack via an air delivery pipeline, and the air delivery pipeline is connected to the third pipeline. The muffler is connected to the air outlet of the hydrogen fuel cell stack via an air exhaust pipeline, and the air exhaust pipeline is connected to the third pipeline.

[0013] According to some embodiments of the present invention, a humidifier-free fuel cell system for a passenger vehicle is provided, wherein a flow meter is provided on the first pipeline and an air pressure sensor is provided on the air delivery pipeline.

[0014] According to some embodiments of the present invention, a humidifier-free fuel cell system for a passenger vehicle includes a bypass pipe between the air supply pipe and the air exhaust pipe, and a bypass throttle valve is provided on the bypass pipe.

[0015] According to some embodiments of the present invention, a humidifier-free fuel cell system for a passenger vehicle is provided on the third pipeline, wherein an air main throttle valve and a back pressure throttle valve are provided, the air main throttle valve is disposed between the intercooler and the air delivery pipeline, and the back pressure throttle valve is disposed between the air exhaust pipeline and the muffler.

[0016] According to some embodiments of the present invention, a humidifier-free fuel cell system for a passenger vehicle, wherein the third pipeline is also connected to the housing of the hydrogen fuel cell stack via a purge pipeline, the purge pipeline being connected between the intercooler and the main air throttle valve, and the housing of the hydrogen fuel cell stack being connected to the third pipeline via an exhaust pipeline, the exhaust pipeline being connected between the back pressure throttle valve and the muffler.

[0017] According to some embodiments of the present invention, a humidifier-free fuel cell system for a passenger vehicle includes a hydrogen subsystem further comprising a hydrogen interface, a water distributor, and a hydrogen circulation pump. The hydrogen interface is connected to the preheater via a fourth pipeline. The preheater is connected to the hydrogen inlet of the hydrogen fuel cell stack via a hydrogen delivery pipeline. The water distributor is connected to the hydrogen outlet of the hydrogen fuel cell stack via a hydrogen discharge pipeline. The hydrogen outlet of the water distributor is connected to the muffler via a hydrogen discharge pipeline. The drain outlet of the water distributor is connected to the muffler via a drain pipeline. The water distributor is connected to the hydrogen circulation pump via a fifth pipeline. The hydrogen circulation pump is connected to the hydrogen delivery pipeline via a hydrogen circulation pipeline.

[0018] According to some embodiments of the present invention, a humidifier-free fuel cell system for a passenger vehicle includes a first hydrogen pressure sensor, a high-pressure hydrogen solenoid valve, a proportional valve, and a second hydrogen pressure sensor sequentially arranged on the hydrogen delivery pipeline. The hydrogen circulation pipeline is connected between the second hydrogen pressure sensor and the hydrogen fuel cell stack. The hydrogen discharge pipeline is equipped with a hydrogen discharge solenoid valve, and the drainage pipeline is equipped with a drainage solenoid valve.

[0019] According to some embodiments of the present invention, a humidifier-free fuel cell system for a passenger vehicle includes a cooling subsystem comprising a main cooling fan, a deionizer, an expansion tank, and a PTC heater. The inlet of the main cooling fan is connected to the cooling water outlet of the hydrogen fuel cell stack via a cooling water outlet pipeline, and the outlet of the main cooling fan is connected to the cooling water inlet of the hydrogen fuel cell stack via a cooling water inlet pipeline. The cooling water inlet pipeline is equipped with a water pump. The inlet of the deionizer is connected to the cooling water outlet pipeline via a sixth pipeline, and the outlet of the deionizer is connected to the inlet of the expansion tank via a seventh pipeline. The outlet of the expansion tank is connected to the cooling water inlet pipeline via an eighth pipeline, which connects the water pump and the main cooling fan. The inlet of the PTC heater is connected to the cooling water outlet pipeline via a ninth pipeline, which connects the eighth pipeline and the main cooling fan. The outlet of the PTC heater is connected to the cooling water inlet pipeline via a tenth pipeline, and a three-way valve is provided at the connection between the tenth pipeline and the cooling water inlet pipeline.

[0020] According to some embodiments of the present invention, a humidifier-free fuel cell system for a passenger vehicle includes a conductivity meter on the cooling water inlet pipeline, the conductivity meter being disposed between the three-way valve and the main cooling fan; an outlet pressure-temperature sensor on the cooling water outlet pipeline, the outlet pressure-temperature sensor being disposed between the cooling water outlet of the hydrogen fuel cell stack and the deionizer; a preheater connected to the cooling water outlet pipeline via an eleventh pipeline, the eleventh pipeline being connected between the outlet pressure-temperature sensor and the deionizer; an inlet pressure-temperature sensor on the cooling water inlet pipeline, the inlet pressure-temperature sensor being disposed between the water pump and the cooling water inlet of the hydrogen fuel cell stack; and an intercooler connected to the cooling water inlet pipeline via a twelfth pipeline, the twelfth pipeline being connected between the water pump and the inlet pressure-temperature sensor.

[0021] This invention discloses a humidifier-free fuel cell system for passenger vehicles, which simplifies the overall system structure. By eliminating the humidifier, the number of components in the fuel cell system is reduced, resulting in a more compact overall structure. This not only reduces system complexity and failure rate but also effectively reduces the risk of system downtime due to humidifier failure. The humidifier-free design of this invention significantly reduces the system's hardware costs, and further reduces energy consumption costs during operation because it eliminates the need for the energy required for humidifier operation. Furthermore, system performance is significantly improved. Through comprehensive and coordinated optimization of the hydrogen fuel cell stack, air subsystem, hydrogen subsystem, and cooling subsystem, the system operates smoothly with low noise and vibration levels, stable power output, and high efficiency, fully meeting the stringent performance requirements of fuel cell systems in the passenger vehicle sector. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a humidifier-free fuel cell system for a passenger vehicle according to an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the output power test results of the fuel cell system according to an embodiment of the present invention;

[0024] Figure 3 This is a schematic diagram of the stability test results of the fuel cell system according to an embodiment of the present invention.

[0025] In the diagram: 1. Hydrogen fuel cell stack; 2. Air filter; 3. Flow meter; 4. Air compressor; 5. Intercooler; 6. Main air throttle valve; 7. Bypass throttle valve; 8. Back pressure throttle valve; 9. Muffler; 10. Air pressure sensor; 11. Hydrogen inlet; 12. Preheater; 13. First hydrogen pressure sensor; 14. High-pressure hydrogen solenoid valve; 15. Proportional valve; 16. Second hydrogen pressure sensor; 17. Hydrogen circulation pump; 18. Water distributor; 19. Hydrogen discharge solenoid valve; 20. Drain solenoid valve; 21. Main cooling fan; 22. Conductivity meter; 23. PTC heater; 24. Three-way valve; 25. Expansion tank; 26. Deionizer; 27. Water pump; 28. Stack inlet pressure-temperature sensor; 29. ​​Stack outlet pressure-temperature sensor. Detailed Implementation

[0026] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0027] In the description of this invention, it should be noted that the terms "upper," "lower," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. The terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0028] This embodiment provides a humidifier-free fuel cell system suitable for passenger vehicles, particularly MPVs, employing a 50kW fuel cell system to simplify system structure, reduce cost, decrease size and weight, and ensure good performance of the fuel cell system without relying on a humidifier. Figure 1 As shown, the system includes a hydrogen fuel cell stack 1, an air subsystem, a hydrogen subsystem, and a cooling subsystem. The hydrogen fuel cell stack 1 is used to generate electricity through an electrochemical reaction. The air subsystem is connected to the hydrogen fuel cell stack 1 and is used to supply air to the hydrogen fuel cell stack 1. The hydrogen subsystem is connected to the hydrogen fuel cell stack 1 and is used to supply hydrogen to the hydrogen fuel cell stack 1. The intercooler 5 of the air subsystem is connected to the preheater 12 of the hydrogen subsystem. The cooling subsystem is connected to the hydrogen fuel cell stack 1 and is used to cool the hydrogen fuel cell. In addition, the cooling subsystem is also connected to the intercooler 5 and the preheater 12.

[0029] As a preferred embodiment, and more specifically, the air subsystem further includes an air filter 2, an air compressor 4, and a silencer 9. The outlet of the air filter 2 is connected to the inlet of the air compressor 4 via a first pipeline. The air filter 2 filters air impurities, ensuring the cleanliness of the air entering the air compressor 4. The air compressor 4 compresses air, increasing air pressure to provide sufficient oxygen for the hydrogen fuel cell stack 1. A flow meter 3 is also installed on the first pipeline to monitor air flow, allowing the system to monitor and regulate air volume in real time. The outlet of the air compressor 4 is connected to the inlet of the intercooler 5 via a second pipeline. The outlet of the intercooler 5 is connected to the inlet of the silencer 9 via a third pipeline. The intercooler 9... The air delivery pipeline is connected to the air inlet of the hydrogen fuel cell stack 1. An air pressure sensor 10 is also installed on the air delivery pipeline. The air pressure sensor 10 can monitor the air pressure entering the hydrogen fuel cell stack 1 in real time and feed it back to the system. The system uses the obtained pressure data to adjust the parameters of the air compressor 4. The air delivery pipeline is also connected to a third pipeline. The intercooler 5 cools the high-temperature air discharged from the air compressor 4, increasing the air density and facilitating the reaction in the hydrogen fuel cell stack 1. The silencer 9 is connected to the air outlet of the hydrogen fuel cell stack 1 via an air exhaust pipeline, which is also connected to the third pipeline. The silencer 9 reduces the noise generated by the air compressor 4, improving the noise level in the system's operating environment. An air pressure sensor 10 is also installed on the air delivery pipeline.

[0030] As a preferred embodiment, and more specifically, a bypass pipe is provided between the air supply pipe and the air exhaust pipe. A bypass throttle valve 7 is provided on the bypass pipe. When the air pressure sensor 10 detects excessive air inlet pressure, the system opens the bypass throttle valve 7, allowing air to be directly discharged. A main air throttle valve 6 and a back pressure throttle valve 8 are provided on the third pipeline. The main air throttle valve 6 is located between the intercooler 5 and the air supply pipe, and the back pressure throttle valve 8 is located between the air exhaust pipe and the muffler 9. The back pressure throttle valve 8 can adjust the exhaust back pressure, optimize the exhaust flow, and improve the overall system performance.

[0031] As a preferred embodiment, and more specifically, the third pipeline is also connected to the housing of the hydrogen fuel cell stack 1 via a purge pipeline. The purge pipeline is connected between the intercooler 5 and the main air throttle valve 6. The housing of the hydrogen fuel cell stack 1 is connected to the third pipeline via an exhaust pipeline, which is connected between the back pressure throttle valve 8 and the muffler 9. The purge pipeline is used to remove residual gaseous impurities from the hydrogen fuel cell stack 1, keeping it clean and ensuring the high efficiency of the electrochemical reaction. The exhaust pipeline discharges the exhaust gas from the hydrogen fuel cell stack 1 after operation, maintaining system pressure balance and ensuring stable system operation.

[0032] As a preferred embodiment, and more specifically, the hydrogen subsystem further includes a hydrogen interface 11, a water separator 18, and a hydrogen circulation pump 17. The hydrogen interface 11 is connected to the preheater 12 via a fourth pipeline. The hydrogen interface 11 is used to introduce external hydrogen and serves as the inlet for the system's hydrogen supply. The preheater 12 is connected to the hydrogen inlet of the hydrogen fuel cell stack 1 via a hydrogen delivery pipeline. The preheater 12 can preheat the hydrogen to prevent it from becoming too cold and affecting the reaction of the hydrogen fuel cell stack 1. The water separator 18 is connected to the hydrogen outlet of the hydrogen fuel cell stack 1 via a hydrogen discharge pipeline. The hydrogen discharge port of the water separator 18 is connected to the silencer 9 via a hydrogen discharge pipeline, and the drain port of the water separator 18 is connected to the silencer 9 via a drain pipeline. The water separator 18 can separate liquid water from the hydrogen, preventing liquid water from entering the hydrogen fuel cell stack 1 and affecting its performance, and can also separate unreacted hydrogen. The water separator 18 is connected to the hydrogen circulation pump 17 via the fifth pipeline. The hydrogen circulation pump 17 is connected to the hydrogen delivery pipeline via the hydrogen circulation pipeline. The hydrogen circulation pump 17 can recycle unreacted hydrogen, improve hydrogen utilization, reduce costs, and also increase the humidity of the hydrogen entering the stack.

[0033] In a preferred embodiment, and more specifically, a first hydrogen pressure sensor 13, a high-pressure hydrogen solenoid valve 14, a proportional valve 15, and a second hydrogen pressure sensor 16 are sequentially installed on the hydrogen delivery pipeline. A hydrogen circulation pipeline connects the second hydrogen pressure sensor 16 and the hydrogen fuel cell stack 1. A hydrogen discharge solenoid valve 19 is installed on the hydrogen discharge pipeline, and a drainage solenoid valve 20 is installed on the drainage pipeline. The first hydrogen pressure sensor 13 monitors the pressure of the hydrogen delivery pipeline in real time, providing data support for system regulation and ensuring stable hydrogen pressure. The high-pressure hydrogen solenoid valve 14 controls the high-pressure on / off of hydrogen, ensuring the safety and reliability of the hydrogen supply. The proportional valve 15 precisely adjusts the hydrogen flow rate based on the data from the first and second hydrogen pressure sensors 13 and 16, matching the hydrogen supply to the actual needs of the hydrogen fuel cell stack 1 and improving system operating efficiency. The second hydrogen pressure sensor 16 monitors the hydrogen pressure again, further ensuring that the hydrogen pressure entering the hydrogen fuel cell stack 1 meets the requirements. The hydrogen discharge solenoid valve 19 is installed on the hydrogen discharge pipeline, enabling timely discharge of unreacted hydrogen and maintaining pressure balance within the hydrogen fuel cell stack 1. The drain solenoid valve 20 is used to remove liquid water from the hydrogen, preventing moisture from accumulating in the system and affecting performance, and ensuring the purity and dryness of the hydrogen.

[0034] As a preferred embodiment, and more specifically, the cooling subsystem includes a main cooling fan 21, a deionizer 26, an expansion tank 25, and a PTC heater 23. The inlet of the main cooling fan 21 is connected to the cooling water outlet of the hydrogen fuel cell stack 1 via a cooling water outlet pipeline, and the outlet of the main cooling fan 21 is connected to the cooling water inlet of the hydrogen fuel cell stack 1 via a cooling water inlet pipeline. The main cooling fan 21 can effectively dissipate the heat from the cooling water and maintain the system temperature. The cooling water inlet pipeline is equipped with a water pump 27. The inlet of the deionizer 26 is connected to the cooling water outlet pipeline via a sixth pipeline, and the outlet of the deionizer 26 is connected to the expansion tank 25 via a seventh pipeline. The inlet of water tank 25 is connected to deionizer 26, which removes the conductivity of cooling water to ensure its purity. The outlet of expansion tank 25 is connected to cooling water inlet pipeline via the eighth pipeline. Expansion tank 25 is used to store cooling water and monitor the liquid level for easy replenishment. The eighth pipeline connects water pump 27 and main cooling fan 21. The inlet of PTC heater 23 is connected to cooling water outlet pipeline via the ninth pipeline, which is connected between the eighth pipeline and main cooling fan 21. The outlet of PTC heater 23 is connected to cooling water inlet pipeline via the tenth pipeline, and a three-way valve 24 is installed at the connection between the tenth pipeline and cooling water inlet pipeline. PTC heater 23 can heat cooling water at low temperatures in hydrogen fuel cell stack 1, which is beneficial for low-temperature start-up of hydrogen fuel cell stack 1. Water pump 27 provides power for cooling water circulation, ensuring smooth circulation of cooling water. Three-way valve 24 is used to control the flow direction of cooling water, allowing cooling water to flow through PTC heater 23 or main cooling fan 21 as needed.

[0035] As a preferred embodiment, more specifically, a conductivity meter 22 is installed on the cooling water inlet pipeline, and the conductivity meter 22 is located between the three-way valve 24 and the main cooling fan 21. The conductivity meter 22 can monitor the conductivity of the cooling water in real time, which facilitates timely understanding of the purity of the cooling water and ensures the normal operation of the cooling system. An outlet pressure-temperature sensor 29 is installed on the cooling water outlet pipeline, and the outlet pressure-temperature sensor 29 is located between the cooling water outlet of the hydrogen fuel cell stack 1 and the deionizer 26. The outlet pressure-temperature sensor 29 can monitor the pressure and temperature of the cooling water when it leaves the stack, providing key data for system regulation. The preheater is connected to the cooling water outlet pipeline through an eleventh pipeline, and the eleventh pipeline is connected between the outlet pressure-temperature sensor 29 and the deionizer 26, which can utilize the heat of the cooling water to preheat the water entering the hydrogen fuel cell stack 1. The hydrogen gas is introduced to increase its temperature and humidity, which is beneficial to the electrochemical reaction. A pressure-temperature sensor 28 is installed on the cooling water inlet line and is located between the water pump 27 and the cooling water inlet of the hydrogen fuel cell stack 1. The pressure-temperature sensor 28 is used to monitor the pressure and temperature of the cooling water before it enters the stack, so as to adjust the operation of the water pump 27 and ensure that the cooling water enters the hydrogen fuel cell stack 1 in a suitable state. The intercooler 5 is connected to the cooling water inlet line through the twelfth line, which is connected between the water pump 27 and the pressure-temperature sensor 28. The intercooler 5 can transfer cooling water to the intercooler 5, mix the cooling water with the air entering the stack, increase the humidity of the air entering the stack, and improve the power generation efficiency and stability of the fuel cell system.

[0036] The air and hydrogen subsystems of this invention can precisely control the flow rate and humidity of hydrogen and air entering the hydrogen fuel cell stack 1. By introducing intelligent regulating valves into the gas channels, the humidity and flow rate of the gas are dynamically adjusted according to the real-time operating status of the hydrogen fuel cell stack 1, ensuring that the humidity conditions required for the electrochemical reaction are met even without a humidifier. For example, during the start-up phase, the initial gas flow rate is appropriately reduced; during normal operation, the gas flow rate and humidity ratio are precisely adjusted according to load changes. An efficient thermal management system is crucial for a humidifier-free fuel cell system. The cooling subsystem of this invention employs advanced cooling technology and sensors to monitor the temperature of the hydrogen fuel cell stack 1 in real time. Through the circulation of the cooling medium and the optimization of the heat dissipation structure, the temperature of the hydrogen fuel cell stack 1 is controlled within a suitable range, avoiding the impact of excessively high or low temperatures on water management and the electrochemical reaction.

[0037] Furthermore, the humidifier-free fuel cell system for a passenger vehicle in this embodiment can also integrate an intelligent control system. Sensors collect various operating parameters of the hydrogen fuel cell stack 1 in real time, such as voltage, current, temperature, and gas flow rate, and comprehensively control the system according to preset algorithms and strategies. Without a humidifier, the control system can quickly respond and adjust the operating status of each subsystem to ensure that the hydrogen fuel cell stack 1 system is always in optimal performance. For example, when insufficient gas humidity is detected, the control system automatically adjusts the parameters of the gas supply system, reducing the frequency of hydrogen and water discharge and increasing gas humidity; when the load on the hydrogen fuel cell stack 1 changes, the output power and gas flow rate of the fuel cell system are adjusted in a timely manner to ensure the stability and reliability of the system.

[0038] This embodiment tested the output power of the fuel cell system, and the test results are as follows: Figure 2 As shown in the figure, the electrical density of the fuel cell system in this test is 1400, the stack power is 59.9kW, the fuel cell system power is 50.8kW, and the average voltage of a single cell is 660mV. As shown in the figure, the output power of the system can be continuously and stably output at each electrical density point, and the average voltage and system power have a linear relationship.

[0039] This embodiment conducted a stability test on the fuel cell system, and the test results are as follows: Figure 3 As shown, the amount of hydrogen used in this test was 8 kg, the average power was 30 kW, the maximum power was 30.4 kW, and the minimum power was 29.6 kW. The output power of the fuel cell system remained at 97% to 103% of the average power throughout the effective measurement period. The test results are valid and the system performance is good.

[0040] This embodiment included performance testing of the fuel cell system.

[0041] A comprehensive performance test of a 50kW fuel cell system was conducted on a professional fuel cell system test bench. Upon startup, the fuel cell system operates at idle speed. Air supply is directly discharged to the exhaust via a bypass throttle valve 7 to reduce dry air flow and ensure adequate air humidity at low power levels. As power increases, the cathode water production increases, causing the bypass throttle valve 7 to decrease in size until it closes completely, relying entirely on the main air throttle valve 6 for air humidity balance. Hydrogen is preheated (12) for temperature control, achieving efficient heat matching and energy recovery. Flow is controlled by the hydrogen circulation pump 17, and pressure is controlled by the proportional valve 15, with automatic opening adjustment based on power changes to ensure sufficient hydrogen supply. Anode humidity is regulated by intelligently adjusting the switching frequency and time of the drain solenoid valve 20. Using the voltage difference between individual stack cells as a benchmark (less than 30mV), the hydrogen and air subsystems intelligently regulate the humidity of both the anode and cathode.

[0042] The coolant temperature also has a crucial impact on the humidity of the fuel cell system. Real-time data is measured by the infeed pressure-temperature sensor 28 and the outfeed pressure-temperature sensor 29. By controlling the speed of the water pump 27, the temperature difference between the infeed and outfeed is kept within 10°C. Target temperature calibration is performed for each power point, with the voltage range of a single cell in the hydrogen fuel cell stack 1 as a benchmark, and the range is less than 30mV. The main cooling fan 21 is used for precise control based on the target temperature and humidity, thereby achieving the purpose of temperature and humidity control and regulation.

[0043] The FCU collects operating parameters in real time, including voltage, current, temperature, gas flow rate, and coolant flow rate, through air pressure sensor 10, first hydrogen pressure sensor 13, second hydrogen pressure sensor 16, infeed pressure-temperature sensor, and outfeed pressure-temperature sensor. Pre-set algorithms and strategies are used for each power point to comprehensively control the system. When the CVM range is detected to be greater than 30mV, indicating insufficient gas humidity, the control system automatically adjusts the parameters of the gas hydrogen subsystem, air subsystem, and cooling subsystem to ensure adequate gas humidity. When the fuel cell system load changes, the output power of the fuel cell system is adjusted promptly to ensure the stability and reliability of the fuel cell system.

[0044] The test bench measured parameters such as power output, efficiency, and hydrogen consumption rate under different load conditions. The experimental data are shown in Table 1. Without a humidifier, the fuel cell system demonstrated stable power output, continuously delivering 50kW of power under rated load. The system efficiency exceeded 46%, and the hydrogen consumption rate was at a reasonable level, indicating good performance.

[0045] Table 1. Experimental data on fuel cell system performance testing

[0046]

[0047] This embodiment included NVH testing: an MPV equipped with the humidifier-free fuel cell system for passenger vehicles was placed in a professional NVH testing laboratory. High-precision noise and vibration sensors were used to measure the noise and vibration levels generated by the fuel cell system under different operating conditions, such as idling, low-speed driving, high-speed driving, and acceleration. Test results showed that the system operated smoothly, and both noise and vibration values ​​were below industry standards.

[0048] This embodiment included start-stop testing of the fuel cell system: Multiple start-stop tests were conducted on the fuel cell system in a real-world application scenario, including temporary stops, waiting at traffic lights, and parking and locking tests. The time required for each start-up, voltage and current changes during start-up, and response speed during shutdown were recorded. Extensive testing was conducted, including tests on temporary stops and waiting at traffic lights (vehicle speed not exceeding 3 km / h). The fuel cell system automatically and rapidly shut down after 5 seconds (without purging). After passing a traffic light, the system automatically restarted after maintaining a speed of 10 km / h for 10 seconds. In standby mode, when the vehicle speed exceeded 50 km / h and the battery level was below 38%, the fuel cell system automatically started charging. In standby mode, when the battery level was below 40%, the fuel cell system automatically started charging again. When the battery level was above 43%, the fuel cell system automatically shut down for purging. When the hydrogen tank pressure was below 3 MPa, the system automatically shut down, purged for 2 minutes, and then powered off. Upon receiving a power-off signal from the vehicle key, the fuel cell system started and ran for 10 seconds before shutting down and purging for 2 minutes. After purging, it returned to standby mode, and the ECU went into hibernation. The fuel cell system started rapidly, with an average start time of less than 2 seconds, and the shutdown process was smooth without abnormal fluctuations, meeting the frequent start-stop requirements of passenger vehicles.

[0049] The humidifier-free fuel cell system of this invention is suitable for use in new energy vehicles, and can demonstrate its advantages in various practical application scenarios such as urban commuting and long-distance travel. In congested urban traffic, the system's rapid start-stop performance and low noise characteristics can enhance the driving experience; during long-distance travel, efficient energy utilization and stable power output ensure the vehicle's range and power performance.

[0050] The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and to design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A humidifier-free fuel cell system for passenger vehicles, characterized in that, include A hydrogen fuel cell stack (1) is used to generate electrical energy through electrochemical reactions; An air subsystem, which is connected to the hydrogen fuel cell stack (1), is used to supply air to the hydrogen fuel cell stack (1); A hydrogen subsystem, which is connected to the hydrogen fuel cell stack (1) and is used to supply hydrogen to the hydrogen fuel cell stack (1); A cooling subsystem, which is connected to the hydrogen fuel cell stack (1), is used to cool the hydrogen fuel cell. The air subsystem includes an intercooler (5), the hydrogen subsystem includes a preheater (12), and the cooling subsystem includes a cooling water inlet pipeline, a cooling water outlet pipeline, a water pump (27), and a deionizer (26). The air subsystem also includes an air filter (2), an air compressor (4), a silencer (9), and an expansion tank (25). The air filter (2) is connected to the air compressor (4) via a first pipeline. The air compressor (4) is connected to the intercooler (5) via a second pipeline. The intercooler (5) is connected to the silencer (9) via a third pipeline. The intercooler (5) is connected to the air inlet of the hydrogen fuel cell stack (1) via an air delivery pipeline, and the air delivery pipeline is connected to the third pipeline. The silencer (9) is connected to the air outlet of the hydrogen fuel cell stack (1) via an air exhaust pipeline, and the air exhaust pipeline is connected to the third pipeline. The outlet of the expansion tank (25) is connected to the cooling water inlet pipeline via an eighth pipeline. A bypass pipe is provided between the air supply pipe and the air exhaust pipe, and a bypass throttle valve (7) is provided on the bypass pipe. The third pipeline is provided with an air main throttle valve (6) and a back pressure throttle valve (8). The air main throttle valve (6) is located between the intercooler (5) and the air supply pipeline, and the back pressure throttle valve (8) is located between the air exhaust pipeline and the muffler (9). The cooling water outlet pipeline is equipped with an outlet pressure-temperature sensor (29), and the outlet pressure-temperature sensor (29) is located between the cooling water outlet of the hydrogen fuel cell stack (1) and the deionizer (26). The preheater (12) is connected to the cooling water outlet pipeline through an eleventh pipeline, and the eleventh pipeline is connected between the outlet pressure-temperature sensor (29) and the deionizer (26). The cooling subsystem includes a main cooling fan (21) and a PTC heater (23). The inlet of the main cooling fan (21) is connected to the cooling water outlet of the hydrogen fuel cell stack (1) through a cooling water outlet pipeline. The outlet of the main cooling fan (21) is connected to the cooling water inlet of the hydrogen fuel cell stack (1) through a cooling water inlet pipeline. The inlet of the PTC heater (23) is connected to the cooling water outlet pipeline through a ninth pipeline, and the ninth pipeline is connected between the eighth pipeline and the main cooling fan (21). The outlet of the PTC heater (23) is connected to the cooling water inlet pipeline through a tenth pipeline, and a three-way valve (24) is provided at the connection between the tenth pipeline and the cooling water inlet pipeline.

2. The humidifier-free fuel cell system for a passenger vehicle according to claim 1, characterized in that, The hydrogen subsystem also includes a hydrogen inlet (11), a water distributor (18), and a hydrogen circulation pump (17). The hydrogen inlet (11) is connected to the preheater (12) via a fourth pipeline. The preheater (12) is connected to the hydrogen inlet of the hydrogen fuel cell stack (1) via a hydrogen delivery pipeline. The water distributor (18) is connected to the hydrogen outlet of the hydrogen fuel cell stack (1) via a hydrogen discharge pipeline. The hydrogen discharge port of the water distributor (18) is connected to the silencer (9) via a hydrogen discharge pipeline. The drain port of the water distributor (18) is connected to the silencer (9) via a drain pipeline. The water distributor (18) is connected to the hydrogen circulation pump (17) via the fifth pipeline, and the hydrogen circulation pump (17) is connected to the hydrogen delivery pipeline via the hydrogen circulation pipeline. The cooling water inlet pipeline is equipped with an inlet pressure-temperature sensor (28), and the inlet pressure-temperature sensor (28) is located between the water pump (27) and the cooling water inlet of the hydrogen fuel cell stack (1). The intercooler (5) is connected to the cooling water inlet pipeline via the twelfth pipeline, and the twelfth pipeline is connected between the water pump (27) and the inlet pressure-temperature sensor (28).

3. A humidifier-free fuel cell system for a passenger vehicle according to claim 1, characterized in that, A flow meter (3) is installed on the first pipeline, and an air pressure sensor (10) is installed on the air delivery pipeline.

4. A humidifier-free fuel cell system for a passenger vehicle according to claim 1, characterized in that, The third pipeline is also connected to the housing of the hydrogen fuel cell stack (1) via a purge pipeline. The purge pipeline is connected between the intercooler (5) and the main air throttle valve (6). The housing of the hydrogen fuel cell stack (1) is connected to the third pipeline via an exhaust pipeline. The exhaust pipeline is connected between the back pressure throttle valve (8) and the muffler (9).

5. A humidifier-free fuel cell system for a passenger vehicle according to claim 2, characterized in that, The hydrogen delivery pipeline is provided with a first hydrogen pressure sensor (13), a hydrogen high-pressure solenoid valve (14), a proportional valve (15), and a second hydrogen pressure sensor (16) in sequence. The hydrogen circulation pipeline is connected between the second hydrogen pressure sensor (16) and the hydrogen fuel cell stack (1). The hydrogen discharge pipeline is provided with a hydrogen discharge solenoid valve (19), and the drainage pipeline is provided with a drainage solenoid valve (20).

6. A humidifier-free fuel cell system for a passenger vehicle according to claim 5, characterized in that, The inlet of the deion tank (26) is connected to the cooling water outlet pipeline via the sixth pipeline, the outlet of the deion tank (26) is connected to the inlet of the expansion tank (25) via the seventh pipeline, and the eighth pipeline is connected between the water pump (27) and the main cooling fan (21).

7. A humidifier-free fuel cell system for a passenger vehicle according to claim 1, characterized in that, A conductivity meter (22) is provided on the cooling water inlet pipeline, and the conductivity meter (22) is located between the three-way valve (24) and the main cooling fan (21).

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