Hydrogen fuel cell system and preheating accelerating method thereof

Abstract

The invention discloses a hydrogen fuel cell system and an accelerated preheating method thereof, which are characterized in that a bypass pipeline and a throttle valve are additionally arranged between a cathode loop and an anode loop, when the system is in cold start, the throttle valve is opened, and the cathode loop and the anode loop are conducted; high-temperature gas compressed by the air compressor enters the intercooler and exchanges heat with cooling liquid of the intercooler, and the cooling liquid after heat exchange circulates in the electric pile and a cooling loop thereof through the water pump; one part of the gas subjected to heat exchange by the intercooler sequentially enters a humidifier dry side, a stack cathode, a humidifier wet side and a collecting pipe along a cathode loop for purging, and the other part of the gas enters an anode loop through a throttle valve and flows through a stack anode, a hydrogen pump, a Venturi tube, a proportional valve, a water-vapor separator and a drain valve, so that the stack and key parts of the loop of the stack are preheated; meanwhile, the heat exchanger is additionally arranged at the outlet end of the collecting pipe, so that waste heat discharged by the system is recycled, and the preheating efficiency of cooling liquid outside the system is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and in particular to a hydrogen fuel cell system and a method for accelerating preheating thereof. Background Art

[0002] When a fuel cell engine is started and operated at low temperatures, ice or an ice-water mixture may exist in the tail valve, hydrogen pump, proportional valve and other areas. It may require a long time to preheat or fail to start when running at low temperatures. Most fuel cell integrated systems use proportional valves for heating or rely on the components' own ice-breaking capabilities, or use heating devices such as PTC to heat the stack coolant, or use a heat exchanger to heat the coolant by gas-liquid heat exchange, and preheat the stack by transferring the heat of the coolant to the stack.

[0003] In the existing technical solutions, when the fuel cell system is in a cold start or cold state, most systems only heat the coolant to preheat the fuel cell stack, and do not consider multiple ways to preheat the fuel cell stack, key system components and the peripheral coolant of the fuel cell system to shorten the cold start and warm-up time of the system; at the same time, do not consider recovering the heat lost by the exhaust gas and liquid of the system to shorten the heating time of the peripheral coolant of the fuel cell system when the system is cold. Summary of the invention

[0004] The purpose of the present invention is to provide a hydrogen fuel cell system and a method for accelerating preheating thereof, which can shorten the preheating and cold start time of the fuel cell stack, eliminate the use of a PTC heater to heat the fuel cell stack coolant, reduce the system integration cost, and recover the tail exhaust waste heat during cold start or cold machine state, thereby improving the preheating efficiency of the system's external coolant.

[0005] In order to achieve the above-mentioned purpose, the present invention provides a hydrogen fuel cell system, which includes a fuel cell stack, wherein the fuel cell stack is provided with a fuel cell stack cathode, a fuel cell stack anode and a fuel cell stack cooling channel, the fuel cell stack cathode is provided with an air inlet and an air outlet, the fuel cell stack anode is provided with a hydrogen inlet and a hydrogen outlet, and the fuel cell stack cooling channel is provided with a coolant inlet and a coolant outlet; the air inlet is connected to an air compressor, an intercooler, a dry side of a humidifier and a first throttle valve in sequence according to its inlet direction; the coolant inlet is connected to a water pump and a filter in sequence according to its inlet direction; the hydrogen inlet is connected to a proportional valve and a venturi tube in sequence according to its inlet direction; the air outlet is connected to a second throttle valve, a wet side of a humidifier and a confluence valve in sequence according to its outlet direction pipe; the coolant outlet is connected to the water pump according to its outlet direction to form a first coolant circulation loop; the hydrogen outlet is connected to a water vapor separator, and the water outlet of the water vapor separator is connected to a drain valve and a manifold in sequence according to its outlet direction; the gas outlet of the water vapor separator is connected to the hydrogen pump and the venturi tube respectively according to the outlet direction, and the outlet end of the hydrogen pump is connected to the outlet end of the venturi tube; the outlet side of the intercooler is respectively connected to a first bypass pipeline, and one end of the first bypass pipeline away from the intercooler is respectively connected to the outlet end of the hydrogen pump and the outlet end of the venturi tube, and a third throttle is provided on the first bypass pipeline; the outlet end of the manifold is connected to a heat exchanger or the outside through a three-way valve.

[0006] As a preferred solution of the above hydrogen fuel cell system, a first temperature sensor and a first pressure sensor are provided at the air inlet.

[0007] As a preferred solution of the above hydrogen fuel cell system, a second temperature sensor and a second pressure sensor are provided at the coolant inlet.

[0008] As a preferred solution of the above hydrogen fuel cell system, a third temperature sensor and a third pressure sensor are provided at the hydrogen inlet.

[0009] As a preferred solution of the above hydrogen fuel cell system, a second bypass line is connected to the outlet side of the intercooler, one end of the second bypass line away from the intercooler is connected to the manifold, and a fourth throttle valve is provided on the second bypass line.

[0010] As a preferred embodiment of the above-mentioned hydrogen fuel cell system, the coolant outlet is connected to the fifth throttle, the external cooling system, the first heat exchange side of the heat exchanger, the fourth temperature sensor, the sixth throttle and the water pump in sequence according to its outlet direction to form a second coolant circulation loop; the outlet end of the manifold is connected to the fifth temperature sensor, the three-way valve and the second heat exchange side of the heat exchanger in sequence according to its outlet direction.

[0011] In addition, the present invention also provides a method for accelerating preheating of a hydrogen fuel cell system using the above items, which comprises the following steps:

[0012] Detect the temperature at the coolant inlet;

[0013] When the temperature at the coolant inlet is lower than the set temperature value, the hydrogen fuel cell system performs a preheating purge mode before starting. The working process of the preheating purge mode is as follows:

[0014] Open the first throttle, the second throttle, the third throttle, the three-way valve and the drain valve, close the proportional valve, start the air compressor, and the high-temperature gas compressed by the air compressor enters the intercooler to exchange heat with the coolant sent to the intercooler by the water pump; the gas after heat exchange in the intercooler enters the cathode loop and the anode loop respectively, and the waste heat of the gas is used to preheat the cathode of the fuel cell stack, the humidifier, the anode of the fuel cell stack, the hydrogen pump, the venturi tube, the proportional valve, the water vapor separator and the drain valve; the coolant after heat exchange in the intercooler and the coolant in the cooling channel of the fuel cell stack circulate in the first coolant circulation loop under the action of the water pump, and the coolant is heated to preheat the fuel cell stack.

[0015] As a preferred solution of the above-mentioned accelerated preheating method, a second bypass pipe is connected to the outlet side of the intercooler, an end of the second bypass pipe away from the intercooler is connected to the manifold, and a fourth throttle valve is provided on the second bypass pipe; during the operation of the preheating purge mode, the fourth throttle valve is opened at the same time, and the three-way valve only opens the passage from the manifold to the heat exchanger, and part of the gas after heat exchange in the intercooler, the exhaust gas of the cathode circuit and the tail liquid of the anode circuit respectively enter the heat exchanger through the manifold and are discharged to the outside after heat exchange in the heat exchanger.

[0016] As a preferred embodiment of the above-mentioned accelerated preheating method, during the process of preheating and purging the cathode and anode of the fuel cell stack by the gas after heat exchange in the intercooler, if the cathode or anode of the fuel cell stack is completely blocked by ice, when it is detected that the pressure value fed back by the pressure sensor at the inlet of the cathode or anode of the fuel cell stack exceeds the set pressure value, the first throttle valve or the third throttle valve is closed until the internal air pressure of the fuel cell stack is released and the pressure is within the pressure resistance range of the fuel cell stack assembly, and then the first throttle valve or the third throttle valve is reopened to continue preheating and purging the cathode or anode of the fuel cell stack.

[0017] As a preferred solution of the above-mentioned accelerated preheating method, the coolant outlet is connected to the fifth throttle, the external cooling system, the first heat exchange side of the heat exchanger, the fourth temperature sensor, the sixth throttle and the water pump in sequence according to its outlet direction to form a second coolant circulation loop; the outlet end of the manifold is connected to the fifth temperature sensor, the three-way valve and the second heat exchange side of the heat exchanger in sequence according to its outlet direction; the coolant in the hydrogen fuel cell system comes from the external cooling system. During the operation of the preheating purge mode, when the coolant temperature in the hydrogen fuel cell system rises and exceeds the set temperature value, the fifth throttle and At the sixth throttle, the coolant of the external cooling system passes through the heat exchanger and the water pump in turn into the intercooler and the stack cooling channel respectively; part of the coolant after heat exchange in the intercooler and part of the coolant flowing through the stack cooling channel flow back to the external cooling system, and re-enters the heat exchanger for the next cycle; and, during the circulation of the coolant, the opening of the three-way valve is controlled according to the feedback value of the temperature sensor at the outlet end of the manifold and the feedback value of the temperature sensor at the coolant outlet of the heat exchanger, so as to change the flow rate of the exhaust gas discharged by the system through the heat exchanger, thereby changing the heat exchange with the coolant, and realizing the function of controlling the degree of preheating of the coolant in the periphery of the system.

[0018] The hydrogen fuel cell system and the accelerated preheating method provided by the present invention have the following beneficial effects compared with the prior art:

[0019] The present invention adds a first bypass pipeline and a third throttle valve between the cathode loop and the anode loop of the fuel cell system. When the system is cold started, the third throttle valve is opened, the cathode loop and the anode loop are connected through the first bypass pipeline, and the air compressor is started. The high-temperature gas compressed by the air compressor enters the intercooler and exchanges heat with the coolant of the intercooler. The coolant after heat exchange circulates in the stack and its first coolant circulation loop through a water pump to achieve the effect of heating the coolant inside the system and preheating the stack. A part of the gas after heat exchange in the intercooler enters the dry side of the humidifier, the cathode of the stack, the wet side of the humidifier and the manifold in sequence along the cathode loop, and the other part enters the anode loop through the first bypass pipeline, flows through the anode of the stack, the hydrogen pump, the venturi tube, the proportional valve, the water vapor separator and the drain valve, thereby realizing preheating of the key components of the stack and its loop. At the same time, a heat exchanger is added at the outlet end of the manifold, and the heat exchange heat source of the heat exchanger mainly comes from the exhaust gas discharged from the system, so as to realize the recovery of the waste heat discharged from the system. It can be seen that the hydrogen fuel cell system and its accelerated preheating method of the present invention can shorten the preheating and cold start time of the fuel cell stack, and eliminate the use of a PTC heater to heat the fuel cell stack coolant, thereby reducing the system integration cost. At the same time, it can recover the tail exhaust waste heat during cold start or cold machine status, thereby improving the system external coolant preheating efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1It is a schematic diagram of the structure of a hydrogen fuel cell system provided by an embodiment of the present invention.

[0021] Reference numerals:

[0022] Fuel cell stack 1; fuel cell stack cathode 1a; fuel cell stack anode 1b; fuel cell stack cooling channel 1c; air compressor 2; intercooler 3; humidifier 4; first throttle valve 5; water pump 6; filter 7; proportional valve 8; venturi tube 9; second throttle valve 10; manifold 11; water vapor separator 12; drain valve 13; hydrogen pump 14; first bypass line 15; third throttle valve 16; three-way valve 17; heat exchanger 18; first temperature sensor 19; first pressure sensor 20; second temperature sensor 21; second pressure sensor 22; third temperature sensor 23; third pressure sensor 24; second bypass line 25; fourth throttle valve 26; fifth throttle valve 27; external cooling system 28; fourth temperature sensor 29; sixth throttle valve 30; fifth temperature sensor 31. DETAILED DESCRIPTION

[0023] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0024] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0025] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0026] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0027] like Figure 1As shown, a hydrogen fuel cell system provided by an embodiment of the present invention includes a fuel cell stack 1, wherein the fuel cell stack 1 is provided with a fuel cell cathode 1a, a fuel cell anode 1b and a fuel cell stack cooling channel 1c, wherein the fuel cell cathode 1a is provided with an air inlet and an air outlet, the fuel cell anode 1b is provided with a hydrogen inlet and a hydrogen outlet, and the fuel cell stack cooling channel 1c is provided with a coolant inlet and a coolant outlet; the air inlet is connected to an air compressor 2, an intercooler 3, a dry side of a humidifier 4 and a first throttle valve 5 in sequence according to its inlet direction; the coolant inlet is connected to a water pump 6 and a filter 7 in sequence according to its inlet direction; the hydrogen inlet is connected to a proportional valve 8 and a venturi tube 9 in sequence according to its inlet direction; the air outlet is connected to a second throttle valve 10, a wet side of a humidifier 4 and a manifold 11 in sequence according to its outlet direction; The liquid outlet is connected to the water pump 6 in its outlet direction to form a first coolant circulation loop; the hydrogen outlet is connected to the water vapor separator 12, and the water outlet of the water vapor separator 12 is connected to the drain valve 13 and the manifold 11 in sequence in its outlet direction; the gas outlet of the water vapor separator 12 is connected to the hydrogen pump 14 and the venturi tube 9 in the outlet direction, and the outlet end of the hydrogen pump 14 is connected to the outlet end of the venturi tube 9; the outlet side of the intercooler 3 is connected to the first bypass pipeline 15, and one end of the first bypass pipeline 15 away from the intercooler 3 is respectively connected to the outlet end of the hydrogen pump 14 and the outlet end of the venturi tube 9, and the first bypass pipeline 15 is provided with a third throttle valve 16; the outlet end of the manifold 11 is connected to the heat exchanger 18 or the outside through a three-way valve 17.

[0028] Therefore, according to a hydrogen fuel cell system provided by an embodiment of the present invention, a first bypass pipeline 15 and a third throttle valve are added between the cathode loop and the anode loop of the fuel cell system. When the system is cold started, the third throttle valve is opened, the cathode loop and the anode loop are connected through the first bypass pipeline 15, and the air compressor 2 is started. The high-temperature gas compressed by the air compressor 2 enters the intercooler 3 and exchanges heat with the coolant of the intercooler 3. The coolant after heat exchange circulates in the fuel cell stack and its first coolant circulation loop through a water pump, so as to achieve the purpose of heating the coolant inside the system and preheating the fuel cell stack. Effect; and after the heat exchange in the intercooler 3, a part of the gas enters the dry side of the humidifier 4, the cathode 1a of the fuel cell stack, the wet side of the humidifier 4 and the manifold 11 in sequence along the cathode loop, and the other part enters the anode loop through the first bypass line 15, flows through the anode 1b of the fuel cell stack, the hydrogen pump 14, the venturi tube 9, the proportional valve 8, the water vapor separator 12 and the drain valve 13, thereby realizing the preheating of the key components of the fuel cell stack and its loop; at the same time, a heat exchanger 18 is added at the outlet end of the manifold 11, and the heat source of the heat exchanger 18 is mainly derived from the exhaust gas of the system, so as to realize the recovery of the waste heat discharged from the system.

[0029] Exemplarily, in order to ensure the thermal balance and stable operation inside the fuel cell stack, the air inlet is provided with a first temperature sensor 19 for monitoring the air temperature of the fuel cell stack cathode 1a and a first pressure sensor 20 for monitoring the air pressure of the fuel cell stack cathode 1a; the coolant inlet is provided with a second temperature sensor 21 for monitoring the coolant temperature of the fuel cell stack cooling channel 1c and a second pressure sensor 22 for monitoring the coolant pressure of the fuel cell stack cooling channel 1c; the hydrogen inlet is provided with a third temperature sensor 23 for monitoring the hydrogen temperature of the fuel cell stack anode 1b and a third pressure sensor 24 for monitoring the hydrogen pressure of the fuel cell stack anode 1b.

[0030] Exemplarily, the outlet side of the intercooler 3 is connected to a second bypass line 25, and the end of the second bypass line 25 away from the intercooler 3 is connected to the manifold 11, and the fourth throttle valve 26 is provided on the second bypass line 25. Such a design can allow the gas after heat exchange in the intercooler 3 to directly enter the manifold 11, and according to the system operation status, the three-way valve 17 can be controlled to switch to the channel flowing to the heat exchanger 18, so that this part of the gas is sent to the heat exchanger 18 for gas waste heat recovery and then discharged to the outside, or the three-way valve 17 can be controlled to switch to the channel flowing to the outside, so that this part of the gas is directly discharged. It should be noted that during the normal operation of the system, the second bypass line 25 can divert the air entering the cathode 1a of the stack, that is, by adjusting the opening degree of the fourth throttle valve 26, the air flow entering the cathode 1a of the stack can be controlled.

[0031] Exemplarily, the coolant outlet is connected to the fifth throttle 27, the external cooling system 28, the first heat exchange side of the heat exchanger 18, the fourth temperature sensor 29, the sixth throttle 30 and the water pump 6 in sequence according to its outlet direction, forming a second coolant circulation loop; the outlet end of the manifold 11 is connected to the fifth temperature sensor 31, the three-way valve 17 and the second heat exchange side of the heat exchanger 18 in sequence according to its outlet direction. Thus, the coolant in the hydrogen fuel cell system comes from the external cooling system 28. When the coolant temperature in the hydrogen fuel cell system exceeds the set temperature value, the fifth throttle 27 and the sixth throttle 30 are opened, and the external cooling system 28 can replenish the low-temperature coolant to the hydrogen fuel cell system in time. Especially in the cold start or cold machine state, the heat exchanger 18 can recover the waste heat of the tail exhaust and the waste heat of the gas output through the second bypass pipeline 25, thereby preheating the external coolant of the system.

[0032] In addition, the present invention also provides a method for accelerating preheating of a hydrogen fuel cell system using the above items, which comprises the following steps:

[0033] Detect the temperature at the coolant inlet;

[0034] When the temperature at the coolant inlet is lower than the set temperature value, the hydrogen fuel cell system performs a preheating purge mode before starting. The working process of the preheating purge mode is as follows:

[0035] The first throttle valve 5, the second throttle valve 10, the third throttle valve 16, the three-way valve 17 and the drain valve 13 are opened, the fifth throttle valve 27, the sixth throttle valve 30 and the proportional valve 8 are closed, and the air compressor 2 is started. The high-temperature gas compressed by the air compressor 2 enters the intercooler 3 and exchanges heat with the coolant sent to the intercooler 3 by the water pump 6; the gas after heat exchange in the intercooler 3 enters the cathode loop and the anode loop respectively, and the waste heat of the gas is used to preheat and purge the cathode 1a of the stack, the humidifier 4, the anode 1b of the stack, the hydrogen pump 14, the venturi tube 9, the proportional valve 8, the water vapor separator 12 and the drain valve 13; the coolant after heat exchange in the intercooler 3 and the coolant in the stack cooling channel 1c are merged under the action of the water pump 6 and re-enter the intercooler 3 and the stack cooling channel 1c, circulate in the first coolant circulation loop, the coolant is heated, and the stack is preheated.

[0036] Furthermore, during the operation of the preheating and purging mode, the fourth throttle valve 26 is opened at the same time, and the three-way valve 17 only opens the channel from the manifold 11 to the heat exchanger 18, and part of the gas after heat exchange in the intercooler 3, the exhaust gas of the cathode circuit and the tail liquid of the anode circuit enter the heat exchanger 18 through the manifold 11 respectively, and are discharged to the outside after heat exchange in the heat exchanger 18.

[0037] Furthermore, during the process of preheating and purging the stack cathode 1a and the stack anode 1b with the gas after heat exchange in the intercooler 3, if the stack cathode 1a or the stack anode 1b is completely blocked by ice, when it is detected that the pressure value fed back by the pressure sensor at the inlet of the stack cathode 1a or the stack anode 1b exceeds the set pressure value, the first throttle valve 5 or the third throttle valve 16 is closed until the internal air pressure of the stack is released and the pressure is within the pressure resistance range of the stack assembly, and then the first throttle valve 5 or the third throttle valve 16 is reopened to continue preheating and purging the stack cathode 1a or the stack anode 1b.

[0038] Furthermore, during the operation of the preheating and purging mode, when the coolant temperature in the hydrogen fuel cell system rises and exceeds the set temperature value, the fifth throttle valve 27 and the sixth throttle valve 30 are opened, and the coolant of the external cooling system 28 enters the intercooler 3 and the stack cooling channel 1c respectively through the heat exchanger 18 and the water pump 6 in turn; part of the coolant after heat exchange in the intercooler 3 and part of the coolant flowing through the stack cooling channel 1c are returned to the external cooling system 28, and re-enter the heat exchanger 18 for the next cycle; and, during the circulation of the coolant, according to the feedback value of the temperature sensor at the outlet end of the manifold 11 (i.e., the fifth temperature sensor 31) and the feedback value of the temperature sensor at the coolant outlet of the heat exchanger 18 (i.e., the fourth temperature sensor 29), the opening of the three-way valve 17 is controlled to change the flow rate of the exhaust gas discharged by the system through the heat exchanger 18, thereby changing the heat exchange with the coolant, and realizing the function of controlling the degree of preheating of the coolant in the periphery of the system.

[0039] In summary, the implementation of the hydrogen fuel cell system and the accelerated preheating method thereof of the embodiments of the present invention can shorten the preheating and cold start time of the fuel cell stack, and eliminate the use of a PTC heater to heat the fuel cell stack coolant, thereby reducing the system integration cost. At the same time, it can recover the tail exhaust waste heat during cold start or cold machine status, thereby improving the preheating efficiency of the system's external coolant.

[0040] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0041] Although embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A hydrogen fuel cell system, characterized in that: The stack comprises a stack, wherein the stack is provided with a stack cathode, a stack anode and a stack cooling channel, the stack cathode is provided with an air inlet and an air outlet, the stack anode is provided with a hydrogen inlet and a hydrogen outlet, and the stack cooling channel is provided with a coolant inlet and a coolant outlet; The air inlet is connected to the air compressor, the intercooler, the dry side of the humidifier and the first throttle valve in sequence according to its inlet direction; The coolant inlet is connected to a water pump and a filter in sequence according to its inlet direction; The hydrogen inlet is connected to a proportional valve and a venturi tube in sequence according to its inlet direction; The air outlet is connected to the second throttle valve, the wet side of the humidifier and the manifold in sequence according to its outlet direction; The coolant outlet is connected to the water pump in its outlet direction to form a first coolant circulation loop; The hydrogen outlet is connected to a water vapor separator, and the water outlet of the water vapor separator is connected to a drain valve and a manifold in sequence according to its outlet direction; the gas outlet of the water vapor separator is connected to a hydrogen pump and the venturi tube in the outlet direction, respectively, and the outlet end of the hydrogen pump is connected to the outlet end of the venturi tube; The outlet sides of the intercoolers are respectively connected to first bypass pipelines, one end of the first bypass pipelines away from the intercoolers is respectively connected to the outlet end of the hydrogen pump and the outlet end of the venturi tube, and a third throttle valve is provided on the first bypass pipelines; The outlet end of the manifold is connected to the heat exchanger or the outside through a three-way valve.

2. A hydrogen fuel cell system according to claim 1, characterized in that: The air inlet is provided with a first temperature sensor and a first pressure sensor.

3. A hydrogen fuel cell system according to claim 1, characterized in that: A second temperature sensor and a second pressure sensor are provided at the coolant inlet.

4. A hydrogen fuel cell system according to claim 1, characterized in that: A third temperature sensor and a third pressure sensor are provided at the hydrogen inlet.

5. A hydrogen fuel cell system according to any one of claims 1 to 4, characterized in that: The outlet side of the intercooler is connected with a second bypass pipeline, one end of the second bypass pipeline away from the intercooler is connected with the manifold, and a fourth throttle valve is arranged on the second bypass pipeline.

6. A hydrogen fuel cell system according to claim 5, characterized in that: The coolant outlet is connected to the fifth throttle, the external cooling system, the first heat exchange side of the heat exchanger, the fourth temperature sensor, the sixth throttle and the water pump in sequence according to its outlet direction to form a second coolant circulation loop; the outlet end of the manifold is connected to the fifth temperature sensor, the three-way valve and the second heat exchange side of the heat exchanger in sequence according to its outlet direction.

7. A method for accelerating preheating of a hydrogen fuel cell system using any one of claims 1 to 6, characterized in that: The following steps are involved: Detect the temperature at the coolant inlet; When the temperature at the coolant inlet is lower than the set temperature value, the hydrogen fuel cell system performs a preheating purge mode before starting. The working process of the preheating purge mode is as follows: Open the first throttle, the second throttle, the third throttle, the three-way valve and the drain valve, close the proportional valve, start the air compressor, and the high-temperature gas compressed by the air compressor enters the intercooler to exchange heat with the coolant sent to the intercooler by the water pump; the gas after heat exchange in the intercooler enters the cathode loop and the anode loop respectively, and the waste heat of the gas is used to preheat the stack cathode, humidifier, stack anode, hydrogen pump, venturi tube, proportional valve, water vapor separator and drain valve; The coolant after heat exchange in the intercooler and the coolant in the cooling channel of the fuel cell stack circulate in the first coolant circulation loop under the action of the water pump, and the coolant is heated to preheat the fuel cell stack.

8. The method for accelerating preheating of a hydrogen fuel cell system according to claim 7, characterized in that: The outlet side of the intercooler is connected to a second bypass pipeline, one end of the second bypass pipeline away from the intercooler is connected to the manifold, and a fourth throttle valve is arranged on the second bypass pipeline; During the operation of the preheating and purge mode, the fourth throttle valve is opened at the same time, and the three-way valve only opens the channel from the manifold to the heat exchanger, and part of the gas after heat exchange in the intercooler, the exhaust gas of the cathode circuit and the tail liquid of the anode circuit enter the heat exchanger through the manifold respectively, and are discharged to the outside after heat exchange in the heat exchanger.

9. The method for accelerating preheating of a hydrogen fuel cell system according to claim 7, characterized in that: During the process of preheating and purging the cathode and anode of the fuel cell stack with the gas after heat exchange in the intercooler, if the cathode or anode of the fuel cell stack is completely blocked by ice, when it is detected that the pressure value fed back by the pressure sensor at the inlet of the cathode or anode of the fuel cell stack exceeds the set pressure value, the first throttle valve or the third throttle valve is closed until the internal air pressure of the fuel cell stack is released and the pressure is within the pressure resistance range of the fuel cell stack assembly, the first throttle valve or the third throttle valve is reopened to continue preheating and purging the cathode or anode of the fuel cell stack.

10. The method for accelerating preheating of a hydrogen fuel cell system according to claim 7, characterized in that: The coolant outlet is connected to the fifth throttle, the external cooling system, the first heat exchange side of the heat exchanger, the fourth temperature sensor, the sixth throttle and the water pump in sequence according to its outlet direction to form a second coolant circulation loop; the outlet end of the manifold is connected to the fifth temperature sensor, the three-way valve and the second heat exchange side of the heat exchanger in sequence according to its outlet direction; The coolant in the hydrogen fuel cell system comes from the external cooling system. During the operation of the preheating and purging mode, when the coolant temperature in the hydrogen fuel cell system rises and exceeds the set temperature value, the fifth throttle valve and the sixth throttle valve are opened, and the coolant in the external cooling system passes through the heat exchanger and the water pump in turn into the intercooler and the stack cooling channel; Part of the coolant after heat exchange in the intercooler and part of the coolant flowing through the stack cooling channel flows back to the external cooling system and re-enters the heat exchanger for the next cycle; Moreover, during the circulation of the coolant, the opening of the three-way valve is controlled according to the feedback value of the temperature sensor at the outlet end of the manifold and the feedback value of the temperature sensor at the coolant outlet of the heat exchanger, thereby changing the flow rate of the exhaust gas discharged by the system through the heat exchanger, thereby changing the heat exchange with the coolant, thereby realizing the function of controlling the degree of preheating of the coolant around the system.

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