An air system for fuel cell turbine energy recovery and control method thereof

Abstract

The present invention discloses an air system for fuel cell turbine energy recovery and a control method thereof, aiming to solve the problems of liquid water damaging the impeller at the turbine end and low energy recovery efficiency during turbine energy recovery. The air system includes a turbo compressor, an integrated water separation evaporator, an intercooler, a humidifier and a fuel cell stack. The integrated water separation evaporator is provided, and its evaporation chamber is used to cool and absorb the high-temperature and high-pressure gas at the supercharging end, and the tail gas and liquid water entering the water separation chamber are heated and evaporated. At the same time, a tail gas direct discharge channel connected in parallel with the integrated water separation evaporator is provided, and a tail gas bypass valve is provided on the tail gas direct discharge channel, so as to determine the release mode of the tail gas according to the actual operation state of the system.

Description

Technical Field

[0001] The invention relates to the technical field of fuel cells, and in particular to an air system for recovering energy from a fuel cell turbine and a control method thereof. Background Art

[0002] As the power of fuel cell systems continues to increase, the requirements for the comprehensive efficiency of fuel cells are gradually increasing. Fuel cell technology solutions are gradually adopting turbine energy recovery solutions to recycle tail exhaust energy and improve the comprehensive efficiency of fuel cell systems. However, most turbine energy recovery currently configures a steam-water separator at the front end of the turbine inlet to reduce the liquid water entering the turbine airflow and prevent liquid water from impacting the impeller.

[0003] The existing tail exhaust energy recovery structure design and function are single, the utilization rate of the comprehensive energy of the fuel cell is low, the structure size of the water separator is large, which is not conducive to the integration of the fuel cell system, and the existing solution cannot effectively control the heat of the air system. Summary of the invention

[0004] (I) Purpose of the invention

[0005] The purpose of the present invention is to provide an air system for fuel cell turbine energy recovery and a control method thereof. By setting an integrated water separation evaporator and an exhaust gas direct discharge channel connected in parallel therewith, an appropriate exhaust gas discharge mode is selected according to the actual power of the fuel cell stack to reduce liquid water in the exhaust gas and improve the energy recovery rate.

[0006] (II) Technical solution

[0007] To solve the above problems, the first aspect of the present invention provides an air system for fuel cell turbine energy recovery, comprising a turbo air compressor, an integrated water separation evaporator, an intercooler, a humidifier and a fuel cell stack;

[0008] The turbo air compressor includes a boost end and a turbine end, and the integrated water separation evaporator includes an evaporation chamber and a water separation chamber;

[0009] The outlet of the boost end is connected to the inlet of the evaporation chamber, the outlet of the evaporation chamber is connected to the inlet of the intercooler, the outlet of the intercooler is connected to the first inlet of the humidifier, the first outlet of the humidifier is connected to the inlet of the battery stack, the outlet of the battery stack is connected to the second inlet of the humidifier, the second outlet of the humidifier is connected to the inlet of the water separation chamber, and the outlet of the water separation chamber is connected to the inlet of the turbine end;

[0010] An exhaust gas direct discharge channel connected in parallel with the integrated water separation evaporator is arranged between the second outlet of the humidifier and the inlet of the turbine end, and a tail gas bypass valve is arranged on the exhaust gas direct discharge channel.

[0011] Through such a setting, the supercharged end passes the high-pressure and high-temperature air through the evaporation chamber, intercooler and humidifier in sequence, and enters the stack along the stack air inlet. The stack discharges the high-humidity exhaust gas from the stack air outlet, passes through the humidifier, enters the water separation chamber or passes through the exhaust gas direct discharge channel, and is discharged along the turbine end. The evaporation chamber absorbs the heat of the high-pressure and high-temperature air released from the supercharged end. On the one hand, it effectively reduces the load of the intercooler, reduces its performance requirements, and can be configured with a smaller intercooler, making the overall structure more compact; at the same time, the heat absorbed by the evaporation chamber is used to heat the exhaust gas entering the water separation chamber to promote energy recovery, and heat and evaporate the liquid water in the exhaust gas body or deposited to avoid the impact of liquid water on the impeller at the turbine end. By setting the integrated water separation evaporator and the exhaust gas direct discharge channel in parallel, the exhaust gas emission method can be determined according to the actual working conditions of the system, and the efficiency of exhaust gas emission and energy recovery can be improved.

[0012] Preferably, a liquid level sensor and a drain valve are provided in the integrated water-separation evaporator, wherein the liquid level sensor is used to collect the liquid level in the integrated water-separation evaporator, and the drain valve is used to discharge the condensed liquid in the integrated water-separation evaporator.

[0013] Through such a setting, the liquid level sensor can collect the real-time liquid level in the integrated water separation evaporator to prevent the liquid level from being too high and affecting the normal discharge of exhaust gas. At the same time, a drain valve is set to discharge liquid water under extreme conditions or after the system operation ends, thereby reducing the system load.

[0014] Preferably, the air system further comprises a back pressure valve arranged between the turbine end and the integrated water separation evaporator, and the back pressure valve and the tail exhaust bypass valve are arranged in series.

[0015] Through such an arrangement, a back pressure valve is provided on the exhaust gas passage entering the turbine end to prevent the exhaust gas from flowing back, and at the same time prevent impurities in the turbine end from entering the exhaust pipe and polluting the system.

[0016] Preferably, the air system further comprises an air filter arranged at the upstream side of the supercharging end, and the air filter is connected to the inlet of the supercharging section.

[0017] Through such a setting, when the atmosphere enters the boost end, it first passes through the air filter to filter out dust and solid impurities in the air, preventing the high-pressure and high-temperature gas released through the boost end from damaging the system structure. At the same time, after the filtered high-temperature and high-pressure gas enters the fuel cell stack, the fuel cell stack provides stable energy to the system.

[0018] According to another aspect of the present invention, a control method for an air system of a fuel cell turbine energy recovery is provided, the control method comprising:

[0019] During the operation of the air system, the actual power P of the fuel cell stack is obtained. act ;

[0020] According to the actual power P of the battery stack act The range controls the opening and closing of the tail exhaust bypass valve.

[0021] Preferably, the actual power P of the battery stack act The range in which the tail exhaust bypass valve is controlled to open and close includes:

[0022] If P act <P low , so that the tail exhaust bypass valve is opened;

[0023] If P low ≤P act <P middle , closing the tail exhaust bypass valve;

[0024] If P middle ≤P act <P high , first close the tail bypass valve, and then determine whether the liquid level H in the water diversion chamber is greater than H max , controlling the tail exhaust bypass valve according to the judgment result;

[0025] If P high ≤P act First, close the tail drain bypass valve, then determine whether the liquid level H in the water diversion chamber is greater than H1, and control the drain valve according to the determination result.

[0026] Preferably, controlling the tail exhaust bypass valve according to the judgment result includes:

[0027] If H>H max , so that the tail bypass valve is partially opened, the liquid level in the water diversion chamber begins to drop, and when the liquid level drops to H<H min When the tail exhaust bypass valve is closed;

[0028] If H≤H max , so that the tail exhaust bypass valve maintains the current state.

[0029] Preferably, controlling the drain valve according to the judgment result includes:

[0030] If H>H1, open the drain valve;

[0031] If H≤H1, close the drain valve.

[0032] Preferably, the control method further includes:

[0033] During the start-up of the air system, the tail exhaust bypass valve is closed to preheat the water separation chamber, and the temperature of the evaporation chamber is maintained by heat conduction.

[0034] Preferably, the control method further includes:

[0035] When the air system ends its operation, the tail drain bypass valve is closed and the drain valve is opened to drain the liquid water in the water separation chamber and dry the water separation chamber.

[0036] An integrated water-separation evaporator is provided, and its evaporation chamber is used to cool down and absorb heat from the high-temperature and high-pressure gas at the boost end, and to heat and evaporate the exhaust gas and liquid water entering the water-separation chamber. At the same time, an exhaust gas direct discharge channel is provided in parallel with the integrated water-separation evaporator, and a tail exhaust bypass valve is provided on the exhaust gas direct discharge channel, so as to determine the release method of the exhaust gas according to the actual operating status of the system.

[0037] (III) Beneficial effects

[0038] The above technical solution of the present invention has the following beneficial technical effects:

[0039] 1. An integrated water separation evaporator is set up to cool down the high-temperature and high-pressure gas, effectively reduce the load of the intercooler, reduce the demand for the intercooler, and configure a smaller intercooler. At the same time, the heat absorbed by the evaporation chamber can conduct heat to the tail gas of the tail water separation chamber and evaporate the liquid water in the tail gas body or in the water separation chamber, thereby increasing the emission energy of the tail gas and being more conducive to energy recovery at the turbine end.

[0040] 2. Set up an exhaust gas direct discharge channel in parallel with the integrated water separation evaporator, and provide a tail gas bypass valve on the exhaust gas direct discharge channel to control the opening and closing of the exhaust gas direct discharge channel, so as to enable the system to select the appropriate exhaust gas emission mode under different power operating environments, thereby improving the efficiency of exhaust gas emission without affecting energy recovery.

[0041] 3. By installing a liquid level sensor and a drain valve in the integrated water separation evaporator, the liquid water generated during the operation of the system can be monitored and discharged. According to the system operating power, the liquid water in the integrated water separation evaporator can be evaporated or directly discharged, which is beneficial to the efficient operation of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a schematic structural diagram of an air system for fuel cell energy recovery according to an embodiment of the present invention;

[0043] Figure 2 4 is a flow chart of an air system control method for fuel cell energy recovery according to an embodiment of the present invention. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0045] The accompanying drawings show schematic diagrams of layer structures according to embodiments of the present invention. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clarity. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0046] Obviously, the described embodiments are only some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] The technical solution of the present invention is described in detail below with reference to the accompanying drawings. According to one embodiment of the present invention, an air system for fuel cell energy recovery is provided, such as Figure 1 As shown, the air system includes a turbo compressor, an integrated water-separating evaporator, an intercooler, a humidifier and a fuel cell stack; the turbo compressor includes a boost end and a turbine end, and the integrated water-separating evaporator includes an evaporation chamber and a water-separating chamber; the outlet of the boost end is connected to the inlet of the evaporation chamber, the outlet of the evaporation chamber is connected to the inlet of the intercooler, the outlet of the intercooler is connected to the first inlet of the humidifier, the first outlet of the humidifier is connected to the inlet of the fuel cell stack, the outlet of the fuel cell stack is connected to the second inlet of the humidifier, the second outlet of the humidifier is connected to the inlet of the water-separating chamber, and the outlet of the water-separating chamber is connected to the inlet of the turbine end; an exhaust gas direct discharge channel connected in parallel with the integrated water-separating evaporator is provided between the second outlet of the humidifier and the inlet of the turbine end, and a tail exhaust bypass valve is provided on the exhaust gas direct discharge channel.

[0048] Through such a setting, the supercharged end passes the high-pressure and high-temperature air through the evaporation chamber, intercooler and humidifier in sequence, and enters the stack along the stack air inlet. The stack discharges the high-humidity exhaust gas from the stack air outlet, passes through the humidifier, enters the water separation chamber or passes through the exhaust gas direct discharge channel, and is discharged along the turbine end. The evaporation chamber absorbs the heat of the high-pressure and high-temperature air released from the supercharged end. On the one hand, it effectively reduces the load of the intercooler, reduces its performance requirements, and can be configured with a smaller intercooler, making the overall structure more compact; at the same time, the heat absorbed by the evaporation chamber is used to heat the exhaust gas entering the water separation chamber to promote energy recovery, and heat and evaporate the liquid water in the exhaust gas body or deposited to avoid the impact of liquid water on the impeller at the turbine end. By setting the integrated water separation evaporator and the exhaust gas direct discharge channel in parallel, the exhaust gas emission method can be determined according to the actual working conditions of the system, and the efficiency of exhaust gas emission and energy recovery can be improved.

[0049] It should be noted that the boost end of the turbo compressor pressurizes the air, and the outlet of the boost end is high-pressure and high-temperature air. The high-temperature and high-pressure air passes through the integrated water-separating evaporator, transfers part of the heat to the evaporation chamber, and then passes through the intercooler for cooling to reach the air temperature required for the stack reaction to generate electricity; further, the humidifier has a first inlet and a first outlet, which are used to humidify the high-pressure air discharged from the outlet of the intercooler to achieve the air humidity required for the stack reaction to generate electricity. At the same time, the humidifier is also provided with a second inlet and a second outlet for the tail gas to pass through the humidifier. In a preferred case, the tail gas channel in the humidifier is provided with a membrane tube or a water exchange structure, which absorbs part of the moisture in the tail gas into the humidifier, which is used to humidify the high-pressure gas, reduce the liquid water in the tail gas, reduce the load of the water-separating chamber and the turbine end, and provide a source of moisture for the humidifier, so that the structure of the humidifier is more compact and the humidification effect is better. Furthermore, the exhaust gas discharged from the second outlet of the humidifier is led to the turbine end through an integrated water separation evaporator or an exhaust gas direct discharge channel. The turbine end drives the turbine to recover rotational energy through the exhaust gas. The integrated water separation evaporator uses the air at the high-pressure and high-temperature outlet of the air compressor to transfer heat between the evaporation chamber and the wall of the high-temperature air channel, and the exhaust gas flow is heated and evaporated by the heat conduction material in the evaporation chamber. The water separation chamber separates the exhaust gas flow entering the water separation chamber of the integrated water separator into gas and liquid, discharges condensed liquid water, and reduces the amount of liquid water entering the turbine end of the air compressor. The specific structure of the water separation chamber and the evaporation chamber in the integrated water separation evaporator is not limited here, as long as the water separation chamber has the function of a water separator and the evaporation chamber has the function of evaporation heat transfer.

[0050] Further, a liquid level sensor and a drain valve are provided in the integrated water-dividing evaporator, the liquid level sensor is used to collect the liquid level in the integrated water-dividing evaporator, and the drain valve is used to discharge the condensed liquid in the integrated water-dividing evaporator. The specific positions of the liquid level sensor and the drain valve are not limited here, and the liquid level in the integrated water-dividing evaporator can be monitored, and the liquid water can be discharged by opening and closing the drain valve. Through such a setting, the liquid level sensor can collect the real-time liquid level in the integrated water-dividing evaporator to prevent the liquid level from being too high and affecting the normal discharge of the tail gas. At the same time, a drain valve is set to discharge the liquid water under extreme conditions or after the system operation is completed to reduce the system load. Preferably, the air system also includes a back pressure valve arranged between the turbine end and the integrated water-dividing evaporator, and the back pressure valve and the tail exhaust bypass valve are arranged in series. The tail exhaust gas passes through the integrated water-dividing evaporator or the tail gas direct discharge channel, and enters the inlet of the turbine end through the back pressure valve. Through such a setting, the back pressure valve can prevent the tail exhaust gas from flowing back, and at the same time prevent the impurities in the turbine end from entering the tail exhaust pipeline and polluting the system. Preferably, the air system also includes an air filter disposed on the upstream side of the supercharging end, and the air filter is connected to the inlet of the supercharging section. When the atmosphere enters the supercharging end, it first passes through the air filter to filter out dust and solid impurities in the air, thereby preventing the high-pressure and high-temperature gas released through the supercharging end from damaging the structure of the system. At the same time, after the filtered high-temperature and high-pressure gas enters the fuel cell stack, the fuel cell stack provides stable energy to the system.

[0051] The embodiment of the present invention also provides a control method for an air system of a fuel cell turbine energy recovery, the control method comprising: obtaining the actual power P of the fuel cell stack during the operation of the air system act ; According to the actual power P of the battery stack act The range controls the opening and closing of the tail exhaust bypass valve. According to the actual power of the battery stack, the liquid water content in the tail exhaust body is inferred. Generally, the higher the actual power of the battery stack, the higher the liquid water content in the tail exhaust body, so different tail exhaust gas discharge methods are adopted.

[0052] like Figure 2 As shown, Figure 2 is a flow chart of a method for controlling an air system for fuel cell energy recovery in one embodiment of the present invention. During the operation of the air system, according to the actual power P of the fuel cell stack, act The scope controls the opening and closing of the tail exhaust bypass valve, including:

[0053] If P act <P low At this time, the liquid water content in the exhaust gas body is relatively small, the damage to the blades at the turbine end is negligible, and it does not affect energy recovery. The controller in the system opens the tail exhaust bypass valve, and the tail exhaust gas enters the turbine end through the exhaust gas direct discharge channel, completing the tail exhaust gas discharge and energy recovery;

[0054] If P low ≤P act <P middle At this time, the liquid water content in the tail gas is relatively high and cannot be discharged directly from the tail gas direct discharge channel. The tail gas bypass valve is closed through the controller, and the tail gas enters the integrated water separation evaporator. The tail gas passing through the water separation chamber is heated by the evaporation chamber. After the liquid water evaporates, it enters the turbine end along with the tail gas. It should be noted that at this time, the evaporation capacity of the evaporation chamber can meet the evaporation demand of the liquid water in the tail gas, that is, it can prevent the liquid water from condensing in the integrated water separation evaporator. At the same time, the evaporated water is mixed with the tail gas and discharged to the turbine end together, which increases the kinetic energy of the tail gas, improves the efficiency of turbine energy recovery, and also prevents the direct discharge of liquid water from causing damage to the turbine end.

[0055] If P middle ≤P act <P high At this time, the liquid water content in the tail gas is high. When the tail gas is separated and discharged from the integrated water separation rectifier alone, the evaporation capacity of the evaporation chamber cannot organize the liquid water evaporation demand, and liquid water condensation will form in the integrated water separation rectifier. The system controller first closes the tail gas bypass valve, and the tail gas passes through the integrated water separation evaporator into the water separation chamber. During this process, the liquid level in the integrated water separation evaporator continues to rise, and then it is judged whether the liquid level H in the water separation chamber is greater than H max , the tail gas bypass valve is controlled according to the judgment result, and the load of the integrated fractional evaporator is reduced through the tail gas direct discharge channel, so that the system can operate normally;

[0056] If P high ≤P act At this time, the liquid water content in the tail gas body is too high and cannot be discharged through the tail gas direct discharge channel. The controller in the system first closes the tail gas bypass valve, and then determines whether the liquid level H in the water distribution chamber is greater than H1. According to the judgment result, the drain valve is controlled to realize the discharge of liquid water and make the system operate normally.

[0057] Furthermore, when P middle ≤P act <P high When the water level H in the water distribution chamber is used for judgment, the tail bypass valve is then controlled, including:

[0058] If H>H max , so that the tail bypass valve is partially opened, the liquid level in the water distribution chamber begins to drop. When the liquid level drops to H<H min When the tail bypass valve is closed, the liquid level in the water distribution chamber reaches H maxWhen the water content in the tail gas body is 100%, the controller partially opens the tail gas bypass valve, and the exhaust is discharged through the tail gas direct discharge channel and the integrated water separation evaporator to reduce the load in the water separation chamber. Part of the tail gas is discharged from the tail gas direct discharge channel, so that the evaporation capacity of the evaporation chamber can meet the evaporation demand of the liquid water in the water separation chamber, so that the liquid water level in the water separation chamber begins to drop. When the liquid water level drops to H min When the integrated water separation evaporator meets the capacity of separate exhaust, the tail exhaust bypass valve is closed to achieve normal operation of the system;

[0059] If H≤H max , so that the tail drain bypass valve maintains the current state. Through such a control method, when the tail drain bypass valve is closed, the liquid level in the water diversion chamber continues to rise. When the tail drain bypass valve is opened, the liquid level in the water diversion chamber begins to drop, avoiding the liquid level being too high to affect the operation of the system.

[0060] Furthermore, when P high ≤P act When the water level H in the water distribution chamber is greater than H1, the drain valve is controlled according to the judgment result, including:

[0061] If H>H1, open the drain valve;

[0062] If H≤H1, the drain valve is closed. Through this control method, the liquid level in the water diversion chamber is always kept below H1, so that the water diversion chamber operates normally.

[0063] It should be noted that when judging the actual power range of the battery stack, P low , P middle and P high According to the actual parameters of the system, the operating power area of ​​the stack is preset in advance before the system is operated, and the operating power area of ​​the stack is divided into a low power area, namely P act <P low , medium power area, namely P low ≤P act <P high , high power area, namely P high ≤P act , where P low <P middle <P high Furthermore, the liquid level H in the water diversion chamber min and H max Determined according to the operating capacity of the water distribution chamber, the system judgment threshold is preset, where H min <H max It should be noted that H1 and H min and H max There is no direct relationship. The liquid level threshold is mainly to ensure the normal operation of the water diversion chamber.

[0064] In a preferred case, the control method further comprises: during the start-up of the air system, the tail exhaust bypass valve is closed, the water separation chamber is preheated, and the temperature of the evaporation chamber is maintained by heat conduction. At this time, the tail exhaust bypass valve is closed, the tail exhaust gas enters the water separation chamber for preheating, and the temperature is maintained by heat conduction of the evaporation chamber of the integrated water separator. Through such a setting, the evaporation chamber and the water separation chamber are always in the optimal working state during the operation of the system, so that the system runs more smoothly.

[0065] In a preferred case, the control method further includes: when the air system ends operation, closing the tail drain bypass valve, opening the drain valve to drain the liquid water in the water separation chamber, drying the water separation chamber, closing the drain valve after drying, and ending operation. Through such a setting, it is ensured that the liquid water in the water separation chamber is completely drained after the system ends operation, and the dry state is maintained, so that the system is in the best state when it is used next time, and the service life of the system is extended, and the cost is reduced.

[0066] In summary, the present invention sets up an integrated water-separation evaporator, utilizes its evaporation chamber to cool down and absorb heat of the high-temperature and high-pressure gas at the boost end, and heats and evaporates the exhaust gas and liquid water entering the water-separation chamber. At the same time, an exhaust gas direct discharge channel connected in parallel with the integrated water-separation evaporator is set, and a tail exhaust bypass valve is set on the exhaust gas direct discharge channel, so as to determine the release method of the exhaust gas according to the actual operating state of the system.

[0067] By setting up an integrated water-separation evaporator, the high-temperature and high-pressure gas can be cooled, the load of the intercooler can be effectively reduced, the demand for the intercooler can be reduced, and a smaller intercooler can be configured. At the same time, the heat absorbed by the evaporation chamber can conduct heat to the tail gas of the tail water-separation chamber, and evaporate the liquid water in the tail gas body or in the water-separation chamber, thereby increasing the emission energy of the tail gas and being more conducive to energy recovery at the turbine end; an exhaust gas direct discharge channel is set in parallel with the integrated water-separation evaporator, and a tail gas bypass valve is provided on the exhaust gas direct discharge channel to control the opening and closing of the exhaust gas direct discharge channel, so that the system can select a suitable exhaust gas emission mode under different power operating environments, and improve the efficiency of exhaust gas emission without affecting energy recovery; by setting a liquid level sensor and a drain valve in the integrated water-separation evaporator, the liquid water generated during the operation of the system can be monitored and discharged, and according to the system operating power, the liquid water in the integrated water-separation evaporator can be evaporated or directly discharged, which is conducive to the efficient operation of the system.

[0068] It should be understood that the above specific embodiments of the present invention are only used to illustrate or explain the principles of the present invention, and do not constitute a limitation of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention. In addition, the appended claims of the present invention are intended to cover all changes and modifications that fall within the scope and boundaries of the appended claims, or the equivalent forms of such scope and boundaries.

Claims

1. A control method for an air system of a fuel cell turbine energy recovery, characterized in that: The air system includes a turbo compressor, an integrated water separation evaporator, an intercooler, a humidifier and a fuel cell stack. The turbo compressor includes a boost end and a turbine end. The integrated water separation evaporator includes an evaporation chamber and a water separation chamber. The outlet of the boost end is connected to the inlet of the evaporation chamber, the outlet of the evaporation chamber is connected to the inlet of the intercooler, the outlet of the intercooler is connected to the first inlet of the humidifier, the first outlet of the humidifier is connected to the inlet of the fuel cell stack, the outlet of the fuel cell stack is connected to the second inlet of the humidifier, and the humidifier The second outlet of the humidifier is connected to the inlet of the water separation chamber, the outlet of the water separation chamber is connected to the inlet of the turbine end, an exhaust gas direct discharge channel connected in parallel with the integrated water separation evaporator is provided between the second outlet of the humidifier and the inlet of the turbine end, a tail gas direct discharge channel is provided with a tail discharge bypass valve, a liquid level sensor and a drain valve are provided in the integrated water separation evaporator, the liquid level sensor is used to collect the liquid level in the integrated water separation evaporator, and the drain valve is used to discharge the condensed liquid in the integrated water separation evaporator; The control method comprises: During the operation of the air system, the actual power P of the fuel cell stack is obtained. act ; If P act <P low , so that the tail exhaust bypass valve is opened; If P low ≤P act <P middle , closing the tail exhaust bypass valve; If P middle ≤P act <P high , first close the tail bypass valve, and then determine whether the liquid level H in the water diversion chamber is greater than H max , controlling the tail exhaust bypass valve according to the judgment result; If P high ≤P act , first close the tail drain bypass valve, then determine whether the liquid level H in the water diversion chamber is greater than H1, and control the drain valve according to the determination result. When the liquid level in the water diversion chamber is below H1, the water diversion chamber operates normally; If H>H max , so that the tail bypass valve is partially opened, the liquid level in the water diversion chamber begins to drop, and when the liquid level drops to H<H min When the tail exhaust bypass valve is closed; If H≤H max , so that the tail exhaust bypass valve maintains the current state; If H>H1, open the drain valve; If H≤H1, close the drain valve.

2. The control method according to claim 1, characterized in that: The control method further comprises: During the start-up of the air system, the tail exhaust bypass valve is closed to preheat the water separation chamber, and the temperature of the evaporation chamber is maintained by heat conduction.

3. The control method according to claim 1, characterized in that: The control method further comprises: When the air system ends its operation, the tail drain bypass valve is closed and the drain valve is opened to drain the liquid water in the water separation chamber and dry the water separation chamber.

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