Fuel cell system and vehicle

Abstract

The present disclosure relates to a fuel cell system and a vehicle, the fuel cell system comprising a stack body, a humidifying device for increasing humidity of air entering the stack body, a first liquid supply and a second liquid supply, wherein the first liquid supply and the second liquid supply are configured to selectively supply liquid to the humidifying device, and the liquid in the first liquid supply and the second liquid supply is at different temperatures. In this way, during use of the fuel cell system, the temperature of the liquid supplied to the humidifying device can be flexibly switched or combined according to real-time working conditions, so that the humidifying device can adapt to different requirements for humidity in different stages of the fuel cell system, such as cold start, low temperature operation and high power operation, and the problem of insufficient coverage of a single humidification mode can be improved. In addition, the first liquid supply and the second liquid supply can also back up each other, which is beneficial to improve the stability and reliability of the fuel cell system during use.

Description

Technical Field

[0001] This disclosure relates to the field of fuel cell technology, and more specifically, to a fuel cell system and vehicle. Background Technology

[0002] The performance, efficiency, and lifespan of proton exchange membrane fuel cells are highly dependent on the humidity state of the membrane electrode assembly. In related technologies, humidity control of fuel cell systems typically employs a single humidification mode, which is insufficient to cover the wide range of humidity regulation requirements from cold start to high-power operation. Summary of the Invention

[0003] The purpose of this disclosure is to provide a fuel cell system and vehicle that at least partially solves the aforementioned technical problems.

[0004] To achieve the above objectives, a first aspect of this disclosure provides a fuel cell system, comprising: The stack body; A humidification device is used to increase the humidity of the air entering the fuel cell stack body; A first liquid supply component and a second liquid supply component, both of which are used to supply liquid to the humidification device; The liquid temperatures in the first liquid supply component and the second liquid supply component are different, and both the first liquid supply component and the second liquid supply component are configured to selectively supply liquid to the humidification device.

[0005] In some possible implementations, the fuel cell system further includes a thermostat, through which both the first liquid supply unit and the second liquid supply unit are connected to the humidification device.

[0006] In some possible implementations, a heater is provided within the first liquid supply element, the heater being used to maintain the temperature of the liquid within the first liquid supply element at a temperature greater than or equal to a first temperature threshold; and / or, The second liquid supply unit is equipped with a cooler, which is used to keep the temperature of the liquid in the second liquid supply unit below or equal to a second temperature threshold.

[0007] In some possible implementations, the humidification device includes a membrane humidifier and a steam generator, the membrane humidifier and the steam generator being used to contact the air flowing through the humidification device to increase the humidity of the air entering the fuel cell stack body; Both the first liquid supply component and the second liquid supply component are configured to selectively supply liquid to the membrane humidifier and the steam generator.

[0008] In some possible implementations, the fuel cell system further includes a heat exchanger and a radiator, one end of the heat exchanger being connected to the outlet of the fuel cell stack body, and the other end of the heat exchanger being connected to the inlet of the fuel cell stack body through the radiator, the radiator being used for heat exchange with the external environment. The heat exchanger is in thermal contact with the steam generator.

[0009] In some possible implementations, the fuel cell system further includes a thermostat and a first three-way valve having ports A, B, and C. The first liquid supply component and the second liquid supply component are connected to port A of the first three-way valve through the thermostat. Port B and port C of the first three-way valve are respectively connected to the heat exchanger and the steam generator.

[0010] In some possible implementations, the fuel cell system further includes a water-gas separator, which includes an inlet, an air outlet, and a liquid outlet. The inlet of the water-gas separator is connected to the exhaust port of the fuel cell stack body, the air outlet is in communication with the external environment, and the liquid outlet is optionally connected to the first liquid supply unit and the second liquid supply unit.

[0011] In some possible implementations, the fuel cell system further includes a second three-way valve having a D port, an E port, and an F port; The D port of the second three-way valve is connected to the liquid outlet, and the E port and F port of the second three-way valve are respectively connected to the first liquid supply component and the second liquid supply component.

[0012] In some possible implementations, the fuel cell system has a first liquid supply mode, in which the ambient temperature of the fuel cell stack is less than a third temperature threshold, and the temperature of the liquid flowing to the humidification device via the first and second liquid supply components is greater than or equal to a fourth temperature threshold, the fourth temperature threshold being greater than the third temperature threshold; and / or, The fuel cell system has a second liquid supply mode. The humidification device includes a membrane humidifier and a steam generator. The membrane humidifier and the steam generator are used to contact the air flowing through the humidification device. In the second liquid supply mode, the rate of change of current in the fuel cell stack is greater than the rate of change of current in the first current, and the flow rate of liquid flowing through the steam generator is greater than the flow rate of liquid flowing through the membrane humidifier; and / or, The fuel cell system has a third liquid supply mode. The humidification device includes a membrane humidifier and a steam generator. The membrane humidifier and the steam generator are used to contact the air flowing through the humidification device. In the third liquid supply mode, the current change of the stack body is less than or equal to the first current change, and the flow rate of the liquid flowing through the steam generator is less than the flow rate of the liquid flowing through the membrane humidifier.

[0013] In some possible implementations, the humidification device includes a membrane humidifier and a steam generator, the membrane humidifier and the steam generator being used to contact the air flowing through the humidification device; The fuel cell system has a first humidification mode. In the first humidification mode, the difference between the target humidity of the air and the actual humidity of the air is greater than a first humidity threshold. The liquid from the first liquid supply unit and the second liquid supply unit both flow to the steam generator. The fuel cell system has a second humidification mode. In the second humidification mode, the difference between the target humidity of the air and the actual humidity of the air is less than or equal to a first humidity threshold and greater than a second humidity threshold. The ratio of the flow rate of the liquid flowing through the steam generator to the flow rate of the liquid flowing through the membrane humidifier is 7:3. The fuel cell system has a third humidification mode, in which the difference between the target humidity and the actual humidity of the air is less than or equal to a second humidity threshold, and the liquid from the first liquid supply unit and the second liquid supply unit flows to the membrane humidifier.

[0014] According to a second aspect of this disclosure, a vehicle is provided, including the fuel cell system described above.

[0015] Through the above technical solution, since both the first liquid supply unit and the second liquid supply unit are configured to selectively supply liquid to the humidification device, and the liquid temperatures in the first liquid supply unit and the second liquid supply unit are different, the liquid supply can be flexibly switched or combined according to real-time operating conditions during the use of the fuel cell system. This allows the temperature of the liquid entering the humidification device to be adjusted, enabling the humidification device to adapt to the differentiated humidity requirements of different stages of the fuel cell system, such as cold start, low temperature operation, and high power operation. This improves the problem of insufficient coverage of a single humidification mode and helps to meet the wide range of humidity regulation requirements of the fuel cell system from cold start to high power operation.

[0016] Furthermore, during the use of the fuel cell system, the first liquid supply unit and the second liquid supply unit can also serve as backups for each other. Even if one of the first liquid supply unit and the second liquid supply unit fails, the other of the first liquid supply unit and the second liquid supply unit can still supply liquid to the humidification device normally, which helps to improve the stability and reliability of the fuel cell system during use.

[0017] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0018] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the structure of a fuel cell system provided by an exemplary embodiment of the present invention.

[0019] Explanation of reference numerals in the attached figures 100-Fuel cell system; 1-Stack body; 11-Air inlet; 12-Exhaust outlet; 13-Hydrogen inlet; 14-Hydrogen outlet; 15-Water inlet; 16-Water outlet; 2-Humidification device; 21-Membrane humidifier; 22-Steam generator; 23-Air flow path; 3-First liquid supply unit; 4-Second liquid supply unit; 5-Thermostat; 6-Heat exchanger; 7-Radiator; 8-Drive pump; 9-First three-way valve; 10-Second three-way valve; 20-Water-air separator; 201-Inlet; 202-Air outlet; 203-Liquid outlet. Detailed Implementation

[0020] Embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings. While some embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this disclosure. It should be understood that the accompanying drawings and embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of protection of this disclosure.

[0021] Furthermore, "comprising" and its variations are open-ended, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment". Definitions of other terms will be given in the following description.

[0022] The concepts of "first" and "second" mentioned in this disclosure are used only to distinguish different devices, modules or units, and are not used to define the order of functions performed by these devices, modules or units or their interdependencies.

[0023] The terms “a” and “a plurality” used in this disclosure are illustrative and not restrictive, and those skilled in the art should understand that they should be understood as “one or more” unless otherwise expressly indicated in the context.

[0024] In the description of this disclosure, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "connect," "link," and "install" should be interpreted broadly. For example, they can refer to a fixed connection (e.g., welding, bonding, or any suitable fixed connection method), a detachable connection (e.g., threaded connection, snap-fit, or any suitable fixed connection method), or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0025] As mentioned above, a single humidification mode is insufficient to cover the wide range of humidity regulation requirements of a fuel cell system from cold start to high-power operation.

[0026] In view of this, such as Figure 1 As shown, a first aspect of this disclosure provides a fuel cell system 100, including a stack body 1, a humidification device 2, a first liquid supply unit 3, and a second liquid supply unit 4. The humidification device 2 is used to increase the humidity of the air entering the stack body 1. The first liquid supply unit 3 and the second liquid supply unit 4 are both used to supply liquid to the humidification device 2. The liquid temperatures in the first liquid supply unit 3 and the second liquid supply unit 4 are different, and the first liquid supply unit 3 and the second liquid supply unit 4 are both configured to selectively supply liquid to the humidification device 2.

[0027] In the fuel cell system 100 provided in this disclosure, the humidification device 2 can be used to increase the humidity of the air entering the stack body 1. For example, the humidification device 2 can be located upstream of the air inlet of the stack body 1, and its internal flow channel is connected to the reaction gas path. It converts liquid water into water vapor or directly transfers it to the air in the form of a liquid film through gas-liquid contact, thereby maintaining the water content required by the proton exchange membrane.

[0028] Through the above technical solution, since both the first liquid supply component 3 and the second liquid supply component 4 are configured to selectively supply liquid to the humidification device 2, and the liquid temperatures in the first liquid supply component 3 and the second liquid supply component 4 are different, the liquid supply can be flexibly switched or combined according to the real-time operating conditions during the use of the fuel cell system 100. This allows the temperature of the liquid entering the humidification device 2 to be adjusted, enabling the humidification device 2 to adapt to the differentiated humidity requirements of the fuel cell system 100 at different stages such as cold start, low temperature operation, and high power operation. This improves the problem of insufficient coverage of a single humidification mode and helps to meet the wide range of humidity regulation requirements of the fuel cell system 100 from cold start to high power operation.

[0029] For example, by selecting a higher temperature liquid supply path during the low temperature or cold start phase, it is possible to avoid local condensation and freezing caused by a single low temperature humidification method.

[0030] Furthermore, during the use of the fuel cell system 100, the first liquid supply component 3 and the second liquid supply component 4 can serve as backups for each other. Even if one of the first liquid supply component 3 and the second liquid supply component 4 fails, the other of the first liquid supply component 3 and the second liquid supply component 4 can still supply liquid to the humidification device 2 normally, which helps to improve the stability and reliability of the fuel cell system 100 during use.

[0031] In order to achieve temperature regulation of the liquid flowing to the humidification device 2 via the first liquid supply element 3 and the second liquid supply element 4, in some possible embodiments, such as Figure 1 As shown, the fuel cell system 100 may further include a thermostat 5, and the first liquid supply unit 3 and the second liquid supply unit 4 are both connected to the humidification device 2 through the thermostat 5. Thus, during operation, the thermostat 5 can mix and regulate the liquid from the liquid supply units (i.e., the first liquid supply unit 3 and the second liquid supply unit 4) at different temperatures according to actual needs and environmental conditions, precisely controlling the temperature of the liquid entering the humidification device 2 within the optimal operating range, thereby meeting the humidification requirements of the fuel cell system 100 under different operating conditions.

[0032] Furthermore, since the thermostat 5 can achieve adaptive adjustment of humidification water temperature without the need for frequent intervention from complex electronic sensors and electronic control units (ECUs), it is beneficial to reduce the situation where the overall structure of the fuel cell system 100 is complex and the cost is high due to the setting of multiple sensors and electronic control units. It is also beneficial to simplify the electronic control logic of humidification water temperature and improve the reliability and stability of the humidification water temperature adjustment process.

[0033] In order to make the liquid temperature in the first liquid supply component 3 different from the liquid temperature in the second liquid supply component 4, in some possible embodiments, a heater may be provided in the first liquid supply component 3. The heater is used to maintain the temperature of the liquid in the first liquid supply component 3 at a level greater than or equal to a first temperature threshold.

[0034] It is understood that in the fuel cell system 100 provided in this disclosure, the first temperature threshold can be any suitable temperature, as long as it can meet the usage requirements of the fuel cell system 100. This disclosure does not limit it. As an exemplary embodiment, the first temperature threshold can be 70°C.

[0035] By maintaining the temperature of the liquid in the first liquid supply component 3 at a level greater than or equal to a first temperature threshold (e.g., 70°C), the liquid in the first liquid supply component 3 can have a high saturated vapor pressure. In this way, when the liquid in the first liquid supply component 3 flows to the humidification device 2, the humidification device 2 can quickly generate a large amount of steam per unit time, thereby meeting the humidity requirements of the fuel cell stack 1 under high load operation.

[0036] Furthermore, the liquid in the first liquid supply unit 3, whose temperature is maintained at or above the first temperature threshold (e.g., 70°C), can also be mixed with the liquid in the second liquid supply unit 4 to any other suitable temperature and flow to the humidification device 2, thus meeting the usage requirements of the fuel cell system 100 under different operating conditions.

[0037] In addition, the heater can also achieve a relatively constant liquid temperature in the first liquid supply component 3, which can prevent large fluctuations in the liquid temperature in the first liquid supply component 3.

[0038] In some possible implementations, a cooler is provided inside the second liquid supply component 4, which is used to keep the temperature of the liquid inside the second liquid supply component 4 below or equal to a second temperature threshold.

[0039] It is understood that in the fuel cell system 100 provided in this disclosure, the aforementioned second temperature threshold can be any suitable temperature, as long as it can meet the usage requirements of the fuel cell system 100. This disclosure does not limit it. As an exemplary embodiment, the second temperature threshold can be 10°C.

[0040] By maintaining the temperature of the liquid in the second liquid supply unit 4 at less than or equal to a second temperature threshold (e.g., 10°C), the liquid in the second liquid supply unit 4 can have a lower temperature. In this way, when the liquid in the second liquid supply unit 4 flows to the humidification device 2, the inlet water temperature of the humidification device 2 can be rapidly reduced, thereby reducing the temperature of the reaction air entering the fuel cell stack 1. This helps to prevent the membrane electrode from dehydrating or degrading due to overheating of the fuel cell stack 1. Furthermore, by mixing hot and cold water, a wide range and high precision adjustment of the humidifier inlet water temperature can be achieved, ensuring that the humidity control is always within the optimal range.

[0041] Furthermore, the liquid in the second liquid supply unit 4, whose temperature is maintained at less than or equal to the second temperature threshold (10°C), can also mix with the liquid in the first liquid supply unit 3 to any other suitable temperature and flow to the humidification device 2, thus meeting the usage requirements of the fuel cell system 100 under different operating conditions.

[0042] In addition, the cooler can also achieve a relatively constant liquid temperature in the second liquid supply component 4, which can avoid large fluctuations in the liquid temperature in the second liquid supply component 4.

[0043] In the fuel cell system 100 provided in this disclosure, the humidification device 2 can have any suitable structure, and this disclosure does not limit it. In some possible embodiments, the humidification device 2 may include a membrane humidifier 21 and a steam generator 22, which are used to contact the air flowing through the humidification device 2 to increase the humidity of the air entering the stack body 1, wherein the first liquid supply member 3 and the second liquid supply member 4 are both configured to selectively supply liquid to the membrane humidifier 21 and the steam generator 22.

[0044] By arranging a membrane humidifier 21 and a steam generator 22 in the humidification device 2, when air flows through the humidification device 2, it can flow through these two humidifiers (membrane humidifier 21 and steam generator 22) separately or simultaneously. This allows the humidification device 2 to flexibly switch humidification strategies according to different operating conditions of the fuel cell system 100. For example, in the initial stage of the fuel cell system 100 startup or when the environment is dry, the membrane humidifier 21 may be inefficient. In this case, the steam generator 22 can be used to quickly increase the humidity of the air. During the steady-state operation phase, the membrane humidifier 21 can be switched to reduce energy consumption.

[0045] Furthermore, since both the first liquid supply component 3 and the second liquid supply component 4 are configured to selectively supply liquid to the membrane humidifier 21 and the steam generator 22, the humidification strategy can be adjusted by controlling the liquid supply of the first liquid supply component 3 and the second liquid supply component 4, which helps to reduce the difficulty of adjusting the humidification strategy.

[0046] In addition, the membrane humidifier 21 and the steam generator 22 can also serve as backups for each other. Even if one of the membrane humidifier 21 and the steam generator 22 fails, the other of the membrane humidifier 21 and the steam generator 22 can still humidify the air, which helps to improve the stability and reliability of the entire fuel cell system 100.

[0047] To achieve air humidification, in some possible implementations, such as Figure 1 As shown, the humidification device 2 may include an airflow path 23. One end of the airflow path 23 is connected to the external environment, and the other end is connected to the air inlet 11 of the fuel cell stack body 1. The air flowing through the airflow path 23 is configured to contact the membrane humidifier 21 and / or the steam generator 22. By bringing the air flowing through the humidification device 2 into contact with the membrane humidifier 21 and / or the steam generator 22, the humidity of the air can be increased, thereby meeting the usage requirements of the fuel cell stack body 1.

[0048] To improve the waste heat recovery capability of the fuel cell system 100, in some possible implementations, such as Figure 1As shown, the fuel cell system 100 may also include a heat exchanger 6 and a radiator 7. One end of the heat exchanger 6 is connected to the water outlet 16 of the fuel cell stack body 1, and the other end of the heat exchanger 6 is connected to the water inlet 15 of the fuel cell stack body 1 through the radiator 7. The radiator 7 is used for heat exchange with the external environment. The heat exchanger 6 is in thermal contact with the steam generator 22.

[0049] In other words, the heat exchanger 6 is connected in series between the outlet side of the cooling circuit of the fuel cell stack 1 and the inlet side of the radiator 7. At this position, the coolant flowing through the heat exchanger 6 carries a large amount of waste heat generated by the fuel cell stack 1 during operation. By making thermal contact between the heat exchanger 6 and the steam generator 22, the steam generator 22 can use the waste heat generated by the fuel cell stack 1 during operation to generate steam. This helps to reduce the energy consumption of the steam generator 22 when generating steam, improve the waste heat recovery capability of the fuel cell system 100, and improve the energy utilization efficiency of the entire fuel cell system 100.

[0050] The aforementioned heat exchanger 6 and steam generator 22 thermal contact means that heat exchange can occur between the heat exchanger 6 and the steam generator 22. This can be a direct contact between the physical surfaces of the heat exchanger 6 and the steam generator 22, or an indirect heat transfer between the heat exchanger 6 and the steam generator 22 through thermally conductive silicone grease, metal fins or an intermediate circulating medium. This disclosure does not limit this.

[0051] In some possible implementations, the fuel cell system 100 may further include a drive pump 8 for driving the flow of liquid within the cooling circuit of the fuel cell stack 1. This allows for continuous flow and heat exchange of the liquid within the cooling circuit of the fuel cell stack 1, thereby enabling heat recovery from the cooling circuit and continuous heat dissipation from the fuel cell stack 1.

[0052] To enable the first liquid supply element 3 and the second liquid supply element 4 to selectively supply liquid to the membrane humidifier 21 and the steam generator 22, in some possible embodiments, such as... Figure 1 As shown, the fuel cell system 100 also includes a thermostat 5 and a first three-way valve 9. The first three-way valve 9 has an A port, a B port and a C port. The first liquid supply component 3 and the second liquid supply component 4 are connected to the A port of the first three-way valve 9 through the thermostat 5. The B port and the C port of the first three-way valve 9 are respectively connected to the heat exchanger 6 and the steam generator 22.

[0053] In other words, port A of the first three-way valve 9 can serve as the main liquid inlet of the humidification device 2 to receive liquid at the temperature adjusted by the thermostat 5400. Ports B and C serve as two independent diversion outlets, which can respectively adjust the liquid flow to the membrane humidifier 21 and the steam generator 22, thereby flexibly adjusting the air humidification strategy.

[0054] To further improve the waste heat recovery capability of the fuel cell system 100, in some possible implementations, such as Figure 1 As shown, the fuel cell system 100 also includes a water-gas separator 20, which includes an inlet 201, an air outlet 202, and a liquid outlet 203. The inlet 201 of the water-gas separator 20 is connected to the exhaust port 12 of the fuel cell stack body 1, the air outlet 202 is connected to the external environment, and the liquid outlet 203 can be selectively connected to the first liquid supply component 3 and the second liquid supply component 4.

[0055] In other words, the water-gas separator 20 is connected in series between the exhaust side of the fuel cell stack 1 and the water inlet side of the first liquid supply unit 3 and / or the second liquid supply unit 4. At this location, the gas-liquid mixture discharged from the exhaust side of the fuel cell stack 1 and flowing through the water-gas separator 20 can be separated by the water-gas separator 20. The separated liquid with heat can flow to the first liquid supply unit 3 and / or the second liquid supply unit 4, which can realize the replenishment of the first liquid supply unit 3 and the second liquid supply unit 4. It also helps to reduce the energy consumption of the first liquid supply unit 3 and the second liquid supply unit 4 in maintaining the temperature, which is conducive to further improving the waste heat recovery capacity of the fuel cell system 100, thereby further improving the energy utilization efficiency of the entire fuel cell system 100.

[0056] In addition, during the waste heat recovery process, the water-gas separator 20 can also discharge the air in the exhaust gas mixture discharged by the fuel cell system 100 to the atmospheric environment, which can prevent air from flowing into the first liquid supply component 3 and / or the second liquid supply component 4, affecting the internal pressure of the first liquid supply component 3 and / or the second liquid supply component 4, and thus affecting the normal liquid supply of the first liquid supply component 3 and / or the second liquid supply component 4.

[0057] To enable the liquid outlet 203 of the water-gas separator 20 to be selectively connected to the first liquid supply unit 3 and the second liquid supply unit 4, in some possible embodiments, the fuel cell system 100 further includes a second three-way valve 10 having a D port, an E port, and an F port. The D port of the second three-way valve 10 is connected to the liquid outlet 203, and the E port and the F port of the second three-way valve 10 are respectively connected to the first liquid supply unit 3 and the second liquid supply unit 4.

[0058] In other words, port D of the second three-way valve 10 can serve as the main inlet of the first liquid supply component 3 and the second liquid supply component 4 to receive the liquid recovered from the water-air separator 20. Ports E and F can serve as two independent diversion outlets to adjust the flow rate of the liquid flowing to the first liquid supply component 3 and the second liquid supply component 4 respectively. Thus, the specific flow direction of the recovered liquid can be flexibly adjusted according to the temperature of the liquid recovered through the water-air separator 20.

[0059] For example, the liquid can flow to either the first liquid supply unit 3 or the second liquid supply unit 4 individually, or it can flow to both the first liquid supply unit 3 and the second liquid supply unit 4 simultaneously.

[0060] The fuel cell system 100 provided in this disclosure may have multiple liquid supply modes, and this disclosure does not limit them. In some possible embodiments, the fuel cell system 100 may have a first liquid supply mode, in which the ambient temperature of the stack body 1 is less than a third temperature threshold, and the temperature of the liquid flowing to the humidification device 2 via the first liquid supply component 3 and the second liquid supply component 4 is greater than or equal to a fourth temperature threshold, and the fourth temperature threshold is greater than the third temperature threshold.

[0061] It is understood that in the fuel cell system 100 provided in this disclosure, the aforementioned third temperature threshold and fourth temperature threshold can be any suitable temperature, as long as it can meet the usage requirements of the fuel cell system 100. This disclosure does not limit this. As an exemplary embodiment, the third temperature threshold can be 5°C and the fourth temperature threshold can be 30°C.

[0062] By supplying liquid with a temperature greater than or equal to a fourth temperature threshold (30°C) to the humidification device 2 when the ambient temperature of the fuel cell stack 1 is less than the third temperature threshold (e.g., 5°C), that is, supplying liquid with a temperature greater than the ambient temperature to the fuel cell stack 1, it is possible to effectively prevent the condensation of water on the electrode surfaces of the humidification device 2 and the fuel cell stack 1 from freezing, and also to increase the temperature of the humid air entering the fuel cell stack 1, which is beneficial to the rapid start-up and stable operation of the fuel cell system 100 in low-temperature environments.

[0063] In some possible implementations, in the first liquid supply mode, the ambient temperature of the fuel cell stack 1 is less than 5°C, and the humidification rate of the air by the humidification device 2 is ≤3% / s. That is, in the first liquid supply mode, the humidity rise rate of the air flowing through the humidification device 2 is ≤3% / s. By limiting the humidity rise rate of the air flowing through the humidification device 2, it is possible to further prevent the condensation and freezing of water on the electrode surfaces of the humidification device 2 and the fuel cell stack 1.

[0064] It is understood that in the fuel cell system 100 provided in this disclosure, the humidity rise rate of the air flowing through the humidification device 2 can be limited by adjusting the liquid supply amount and liquid supply speed of the first liquid supply component 3 and / or the second liquid supply component 4. The humidity rise rate of the air flowing through the humidification device 2 can also be limited by any other appropriate means. This disclosure does not limit this.

[0065] In some possible implementations, the fuel cell system 100 may also have a second liquid supply mode, wherein the humidification device 2 includes a membrane humidifier 21 and a steam generator 22, which are used to contact the air flowing through the humidification device 2. In the second liquid supply mode, the rate of change of current of the stack body 1 is greater than the rate of change of current of the first current (i.e., the stack body 1 is in a high dynamic load mode), and the flow rate of liquid flowing through the steam generator 22 is greater than the flow rate of liquid flowing through the membrane humidifier 21.

[0066] It is understood that in the fuel cell system 100 provided in this disclosure, the first current change rate can have any appropriate value, as long as it can meet the usage requirements of the fuel cell system 100. This disclosure does not limit it. As an exemplary implementation, the first current change rate can be 50A / s (i.e., the stack body 1 is in a high dynamic load mode).

[0067] In other words, when the fuel cell stack 1 has a large current change rate (e.g., when the fuel cell stack 1 is in a high dynamic load mode), the flow rate of the liquid flowing through the steam generator 22 is greater than the flow rate of the liquid flowing through the membrane humidifier 21. At this time, the steam generator 22 can generate a large amount of steam and, with the assistance of the membrane humidifier 21, can meet the demand for a large amount of humid air in the fuel cell stack 1 when it has a large current change rate (high dynamic load mode).

[0068] It is understandable that when the fuel cell stack 1 has a large current change rate (high dynamic load mode), the steam generator 22 can also recover the waste heat of the fuel cell stack 1 through the heat exchanger 6 mentioned above.

[0069] In some possible implementations, the fuel cell system 100 may also have a third liquid supply mode, wherein the humidification device 2 includes a membrane humidifier 21 and a steam generator 22, the membrane humidifier 21 and the steam generator 22 being used to contact the air flowing through the humidification device 2, and in the third liquid supply mode, the current change of the stack body 1 is less than or equal to the first current change, and the flow rate of the liquid flowing through the steam generator 22 is less than the flow rate of the liquid flowing through the membrane humidifier 21.

[0070] It is understood that in the fuel cell system 100 provided in this disclosure, the aforementioned first current change can have any appropriate value, as long as it can meet the usage requirements of the fuel cell system 100. This disclosure does not limit this value. As an exemplary implementation, the first current change can be 1% (i.e., the fuel cell stack 1 is in a steady-state operating mode). In other words, when the current change of the fuel cell stack 1 is small (e.g., in a steady-state operating mode), the flow rate of the liquid flowing through the membrane humidifier 21 is greater than the flow rate of the liquid flowing through the steam generator 22. At this time, the humidification device 2 as a whole can meet the gas demand of the fuel cell stack 1 while having lower overall energy consumption, which is beneficial to improving the overall energy consumption performance of the fuel cell stack 1.

[0071] The fuel cell system 100 provided in this disclosure may have multiple humidification modes, and this disclosure does not limit the specific humidification modes. In some possible embodiments, the humidification device 2 may include a membrane humidifier 21 and a steam generator 22, which are used to contact the air flowing through the humidification device 2. The fuel cell system 100 may have a first humidification mode in which the difference between the target humidity of the air and the actual humidity of the air is greater than a first humidity threshold, and the liquid from the first liquid supply device 3 and the second liquid supply device 4 flows to the steam generator 22.

[0072] It is understood that in the fuel cell system 100 provided in this disclosure, the first humidity threshold can have any appropriate value, as long as it can meet the usage requirements of the fuel cell system 100. This disclosure does not limit it. As an exemplary implementation, the first humidity threshold can be 15% (that is, the difference between the target humidity of the air and the actual humidity of the air is large).

[0073] When the difference between the target humidity and the actual humidity of the air is large (e.g., greater than 15%), the liquid in the first liquid supply component 3 and the second liquid supply component 4 flows to the steam generator 22. This allows the liquid in the first liquid supply component 3 and the second liquid supply component 4 to be converted into water vapor by the steam generator 22. The humidification device 2 as a whole can be in the maximum humidification state and mix with the air flowing through the humidification device 2 to humidify the air, thereby meeting the demand for rapid air humidification.

[0074] Understandably, when the fuel cell system 100 is in the first humidification mode, the opening degree of port B of the first three-way valve 9 can be 0%, and the opening degree of port C of the first three-way valve 9 can be 100%. In this way, the liquid from the first liquid supply component 3 and the second liquid supply component 4 can both flow to the steam generator 22.

[0075] In some possible implementations, the fuel cell system 100 may also have a second humidification mode in which the difference between the target humidity of the air and the actual humidity of the air is less than or equal to a first humidity threshold and greater than a second humidity threshold, and the ratio of the flow rate of liquid flowing through the steam generator 22 to the flow rate of liquid flowing through the membrane humidifier 21 is greater than that of liquid flowing through the membrane humidifier 21.

[0076] It is understood that in the fuel cell system 100 provided in this disclosure, the second humidity threshold can have any appropriate value, as long as it can meet the usage requirements of the fuel cell system 100. This disclosure does not limit it. As an exemplary implementation, the second humidity threshold can be 5% (that is, the air in the external environment has a certain humidity, but the humidity is insufficient).

[0077] When the difference between the target humidity and the actual humidity of the air is less than or equal to 15% and greater than 5%, the flow rate of liquid flowing through the steam generator 22 is greater than that of liquid flowing through the membrane humidifier 21. This can reduce the overall energy consumption of the humidification device 2 while meeting the air humidification requirements, thereby improving the energy consumption performance of the entire fuel cell stack 1.

[0078] For example, the ratio of the liquid flow rate through the steam generator 22 to the liquid flow rate through the membrane humidifier 21 can be 7:3. In this case, the amount of liquid flowing through the steam generator 22 is larger.

[0079] In some possible implementations, when the fuel cell system 100 is in the second humidification mode, the opening degree of port B of the first three-way valve 9 can be 30%, and the opening degree of port C of the first three-way valve 9 can be 70%. In this way, the liquid from the first liquid supply component 3 and the second liquid supply component 4 can flow to the steam generator 22 and the membrane humidifier 21 respectively according to a preset ratio.

[0080] In some possible implementations, the fuel cell system 100 may also have a third humidification mode in which the difference between the target humidity of the air and the actual humidity of the air is less than or equal to a second humidity threshold, that is, the difference between the target humidity of the air and the actual humidity of the air is small, the air in the external environment has a large humidity, and the liquids from the first liquid supply unit 3 and the second liquid supply unit 4 flow to the membrane humidifier 21.

[0081] When the difference between the target humidity and the actual humidity of the air is less than or equal to the second temperature threshold, the liquid in the first liquid supply unit 3 and the second liquid supply unit 4 flows to the membrane humidifier 21. This allows the liquid in the first liquid supply unit 3 and the second liquid supply unit 4 to humidify the air through the membrane humidifier 21. The humidification device 2 as a whole can be in a humidification state with the lowest energy consumption and mix with the air flowing through the humidification device 2 to achieve air humidification. The overall energy consumption of the humidification device 2 is low, which is beneficial to improving the energy consumption performance of the entire fuel cell stack 1.

[0082] It is understandable that when the fuel cell system 100 is in the third humidification mode, the opening degree of port B of the first three-way valve 9 can be 100%, and the opening degree of port C of the first three-way valve 9 can be 0%. In this way, the liquid from the first liquid supply component 3 and the second liquid supply component 4 can both flow to the membrane humidifier 21.

[0083] In some possible implementations, such as Figure 1 As shown, temperature sensors are installed at the inlet 201 of the water-air separator 20, the inlet 201 of the first liquid supply component 3, the inlet 201 of the second liquid supply component 4, the inlet 201 of the membrane humidifier 21, the inlet 201 of the steam generator 22, the air inlet of the fuel cell stack 1, the water outlet 16 of the fuel cell stack 1, and the water inlet 15 of the fuel cell stack 1. Flow sensors are installed at the outlet of the first liquid supply component 3, the outlet of the second liquid supply component 4, and the air inlet of the fuel cell stack 1. A humidity sensor is also installed at the air inlet of the fuel cell stack 1.

[0084] Through the aforementioned multiple temperature sensors, flow sensors, and humidity sensors, information such as the temperature, flow rate, and humidity of each component can be obtained in real time, thereby enabling control of components such as thermostat 5, first three-way valve 9, and second three-way valve 10.

[0085] In some possible implementations, the fuel cell stack body 1 may also include a hydrogen inlet 13 and a hydrogen outlet 14, wherein the hydrogen inlet 13 is used to supply hydrogen into the fuel cell stack body 1 and the hydrogen outlet 14 is used to supply hydrogen out of the fuel cell stack body 1.

[0086] In this way, hydrogen can enter the fuel cell stack 1 through the hydrogen inlet and be discharged from the hydrogen outlet 14 after reacting with the humid air, thereby realizing the power generation of the fuel cell stack 1.

[0087] According to a second aspect of this disclosure, a vehicle is provided, including the fuel cell system 100 as described above.

[0088] The vehicle has all the beneficial effects of the aforementioned fuel cell system 100, which will not be elaborated here.

[0089] It should be noted that this disclosure does not limit the specific type of vehicle mentioned above. The vehicle can be any vehicle suitable for using the fuel cell system 100 provided by this disclosure. For example, the vehicle can be a passenger car, such as a sedan or SUV, or a commercial vehicle, such as a truck, lorry, or special vehicle (such as a water tanker or garbage truck). The vehicle can be a traditional energy vehicle, such as a fuel vehicle, or a new energy vehicle. This disclosure does not limit the specific details. The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solution of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0090] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0091] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A fuel cell system, characterized in that, include: Stack body (1); A humidification device (2) is used to increase the humidity of the air entering the fuel cell stack body (1); The first liquid supply component (3) and the second liquid supply component (4) are both used to supply liquid to the humidification device (2); The liquid temperatures in the first liquid supply unit (3) and the second liquid supply unit (4) are different, and both the first liquid supply unit (3) and the second liquid supply unit (4) are configured to selectively supply liquid to the humidification device (2).

2. The fuel cell system according to claim 1, characterized in that, The first liquid supply component (3) is provided with a heater, which is used to maintain the temperature of the liquid in the first liquid supply component (3) at a temperature greater than or equal to a first temperature threshold; and / or, The second liquid supply component (4) is provided with a cooler, which is used to keep the temperature of the liquid in the second liquid supply component (4) less than or equal to a second temperature threshold.

3. The fuel cell system according to claim 1, characterized in that, The humidification device (2) includes a membrane humidifier (21) and a steam generator (22), which are used to contact the air flowing through the humidification device (2) to increase the humidity of the air entering the fuel cell stack body (1); The first liquid supply unit (3) and the second liquid supply unit (4) are both configured to selectively supply liquid to the membrane humidifier (21) and the steam generator (22).

4. The fuel cell system according to claim 3, characterized in that, The fuel cell system (100) also includes a heat exchanger (6) and a radiator (7). One end of the heat exchanger (6) is connected to the outlet (16) of the fuel cell stack body (1), and the other end of the heat exchanger (6) is connected to the inlet (15) of the fuel cell stack body (1) through the radiator (7). The radiator (7) is used for heat exchange with the external environment. The heat exchanger (6) is in thermal contact with the steam generator (22).

5. The fuel cell system according to claim 3, characterized in that, The fuel cell system (100) also includes a thermostat (5) and a first three-way valve (9), the first three-way valve (9) having an A port, a B port and a C port; The first liquid supply component (3) and the second liquid supply component (4) are connected to the A port of the first three-way valve (9) through the thermostat (5). The B port and the C port of the first three-way valve (9) are respectively connected to the heat exchanger (6) and the steam generator (22).

6. The fuel cell system according to any one of claims 1-5, characterized in that, The fuel cell system (100) further includes a water-gas separator (20), which includes an inlet (201), an air outlet (202), and a liquid outlet (203). The inlet (201) of the water-gas separator (20) is connected to the exhaust port (12) of the stack body (1), the air outlet (202) is connected to the external environment, and the liquid outlet (203) is optionally connected to the first liquid supply unit (3) and the second liquid supply unit (4).

7. The fuel cell system according to claim 6, characterized in that, The fuel cell system (100) further includes a second three-way valve (10), which has a D port, an E port and an F port; The D port of the second three-way valve (10) is connected to the liquid outlet (203), and the E port and F port of the second three-way valve (10) are respectively connected to the first liquid supply component (3) and the second liquid supply component (4).

8. The fuel cell system according to any one of claims 1-5, characterized in that, The fuel cell system (100) has a first liquid supply mode in which the ambient temperature of the stack body (1) is less than a third temperature threshold, and the temperature of the liquid flowing to the humidification device (2) via the first liquid supply component (3) and the second liquid supply component (4) is greater than or equal to a fourth temperature threshold, which is greater than the third temperature threshold; and / or, The fuel cell system (100) has a second liquid supply mode. The humidification device (2) includes a membrane humidifier (21) and a steam generator (22). The membrane humidifier (21) and the steam generator (22) are used to contact the air flowing through the humidification device (2). In the second liquid supply mode, the rate of change of current in the stack body (1) is greater than the rate of change of current in the first current, and the flow rate of liquid flowing through the steam generator (22) is greater than the flow rate of liquid flowing through the membrane humidifier (21); and / or, The fuel cell system (100) has a third liquid supply mode. The humidification device (2) includes a membrane humidifier (21) and a steam generator (22). The membrane humidifier (21) and the steam generator (22) are used to contact the air flowing through the humidification device (2). In the third liquid supply mode, the current change of the stack body (1) is less than or equal to the first current change, and the flow rate of the liquid flowing through the steam generator (22) is less than the flow rate of the liquid flowing through the membrane humidifier (21).

9. The fuel cell system according to any one of claims 1-5, characterized in that, The humidification device (2) includes a membrane humidifier (21) and a steam generator (22), the membrane humidifier (21) and the steam generator (22) being used to contact the air flowing through the humidification device (2); The fuel cell system (100) has a first humidification mode. In the first humidification mode, the difference between the target humidity of the air and the actual humidity of the air is greater than a first humidity threshold. The liquid from the first liquid supply unit (3) and the second liquid supply unit (4) both flow to the steam generator (22). The fuel cell system (100) has a second humidification mode, in which the difference between the target humidity of the air and the actual humidity of the air is less than or equal to a first humidity threshold and greater than a second humidity threshold, and the flow rate of liquid flowing through the steam generator (22) is greater than the flow rate of liquid flowing through the membrane humidifier (21). The fuel cell system (100) has a third humidification mode in which the difference between the target humidity of the air and the actual humidity of the air is less than or equal to a second humidity threshold, and the liquid from the first liquid supply unit (3) and the second liquid supply unit (4) flows to the membrane humidifier (21).

10. A vehicle, characterized in that, Includes the fuel cell system (100) according to any one of claims 1-9.

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