Forklift fuel cell system based on solid hydrogen storage

Abstract

The forklift fuel cell system based on solid hydrogen storage comprises a fuel cell stack, an air inlet and outlet structure, a hydrogen inlet and outlet structure and a hydrothermal management structure, the air inlet and outlet structure is connected with the fuel cell stack, the hydrogen inlet and outlet structure is connected with the fuel cell stack, the hydrogen inlet and outlet structure adopts a solid hydrogen storage mode, and the hydrothermal management structure is connected with the air inlet and outlet structure. Hydrogenation of the forklift fuel cell is facilitated, the hydrothermal management structure is connected with the fuel cell stack, the air inlet and outlet structure and the hydrogen inlet and outlet structure, the hydrothermal management structure can prevent water generated by the fuel cell system from freezing in a low-temperature environment, power consumption loss of the fuel cell system can be avoided, the efficiency of the fuel cell is improved, and the service life of the fuel cell system is prolonged. The forklift fuel cell system based on solid hydrogen storage provided by the invention can prevent water generated by the fuel cell system from freezing in a low-temperature environment, and can heat water generated by hydrogen reaction by using a self heat source, thereby avoiding power consumption loss of the fuel cell system, and being beneficial to improving the efficiency of a fuel cell.

Description

Technical Field

[0001] The present invention belongs to the field of fuel cells. Specifically, the present invention relates to a forklift fuel cell system based on solid-state hydrogen storage. Background Art

[0002] With the increasingly prominent environmental problems, hydrogen energy with no pollution and zero emissions has received more and more attention in recent years. As a device for converting hydrogen energy into electrical energy, fuel cells have been mass-applied in fields such as passenger cars, buses, and logistics vehicles in recent years. In the application fields of forklifts and logistics vehicles, the operating range of forklifts is relatively fixed, which well fits the application scenarios of fuel cells.

[0003] The construction layout of domestic hydrogen refueling stations is not very perfect. Forklifts are generally used in fixed scenarios such as warehousing logistics or in-station operation, and hydrogen refueling is not very convenient. Therefore, a solid-state hydrogen storage solution is usually adopted. Solid-state hydrogen storage is a technology that stores hydrogen by using solid materials as an intermediate medium. It mainly utilizes the high specific surface area of porous materials to adsorb hydrogen molecules on the surface through van der Waals forces, and has the advantages of high hydrogen storage density and good safety. It can quickly replace the gas source and save the time cost of the hydrogen refueling process in hydrogen refueling stations. The application environment of forklifts is indoor or outdoor. When the fuel cell works in a forklift, water will be generated. Under normal circumstances, the water will directly drain out of the fuel cell stack. However, when the forklift runs indoors, the directly drained water will cause indoor water accumulation and affect indoor work safety. When running outdoors, especially when the temperature is relatively low, the generated water may freeze after direct discharge, thus causing safety accidents.

[0004] Therefore, in order to improve or solve at least one of the above problems, a forklift fuel cell system based on solid-state hydrogen storage is provided, which can solve the problem of inconvenient hydrogen refueling of forklift fuel cells, adopts solid-state hydrogen storage, can prevent the water generated by the fuel cell system from freezing in a low-temperature environment, can use its own heat source to heat the water generated by the hydrogen reaction, avoid causing power consumption loss of the fuel cell system, and is beneficial to improving the efficiency of the fuel cell. Summary of the Invention

[0005] The present invention is made to solve the above problems, and the purpose is to provide a forklift fuel cell system based on solid-state hydrogen storage, which can solve the problem of inconvenient hydrogen refueling of forklift fuel cells, adopts solid-state hydrogen storage, can prevent the water generated by the fuel cell system from freezing in a low-temperature environment, can use its own heat source to heat the water generated by the hydrogen reaction, avoid causing power consumption loss of the fuel cell system, and is beneficial to improving the efficiency of the fuel cell. To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] The present invention provides a forklift fuel cell system based on solid-state hydrogen storage, having the following characteristics: it includes a fuel cell stack, an air inlet and outlet structure, a hydrogen inlet and outlet structure, and a water and heat management structure. The air inlet and outlet structure is connected to the fuel cell stack, the hydrogen inlet and outlet structure is connected to the fuel cell stack, and the water and heat management structure is connected to the fuel cell stack, the air inlet and outlet structure, and the hydrogen inlet and outlet structure.

[0007] In the forklift fuel cell system based on solid-state hydrogen storage provided by the present invention, it may further have the following characteristics: the air inlet and outlet structure includes an air main pipe, a first air branch pipe, and a second air branch pipe. One end of the first air branch pipe is connected to the air main pipe, the other end of the first air branch pipe is connected to the fuel cell stack, and a first throttle valve is provided on the first air branch pipe; one end of the second air branch pipe is connected to the air main pipe, the other end of the second air branch pipe is connected to the fuel cell stack, and a second throttle valve is provided on the second air branch pipe.

[0008] In the forklift fuel cell system based on solid-state hydrogen storage provided by the present invention, it may further have the following characteristics: a first temperature sensor and a first pressure sensor are provided on the first air branch pipe; a second temperature sensor and a second pressure sensor are provided on the second air branch pipe.

[0009] In the forklift fuel cell system based on solid-state hydrogen storage provided by the present invention, it may further have the following characteristics: an air filter, a mass flow meter, an air compressor, and an intercooler are sequentially provided on the air main pipe. An air temperature sensor is provided between the air filter and the mass flow meter, and a bypass valve and a third throttle valve are also provided on the air main pipe.

[0010] In the forklift fuel cell system based on solid-state hydrogen storage provided by the present invention, it may further have the following characteristics: the hydrogen inlet and outlet structure includes a solid-state hydrogen storage unit, a hydrogen main pipe, a first hydrogen branch pipe, and a second hydrogen branch pipe. One end of the hydrogen main pipe is connected to the solid-state hydrogen storage unit, one end of the first hydrogen branch pipe is connected to the hydrogen main pipe, and the other end of the first hydrogen branch pipe is connected to the fuel cell stack; one end of the second hydrogen branch pipe is connected to the hydrogen main pipe, and the other end of the second hydrogen branch pipe is connected to the fuel cell stack.

[0011] In the forklift fuel cell system based on solid-state hydrogen storage provided by the present invention, it may further have the following characteristics: a third temperature sensor and a third pressure sensor are provided on the first hydrogen branch pipe; a fourth temperature sensor and a fourth pressure sensor are provided on the second hydrogen branch pipe.

[0012] In the forklift fuel cell system based on solid-state hydrogen storage provided by the present invention, it may further have the following features: a pressure reducing valve, a proportional valve, and a hydrogen circulation pump are sequentially arranged on the hydrogen main pipe. The hydrogen inlet and outlet structure further includes a drain pipe, on which a gas-water separator and a heating drain solenoid valve are arranged. The hydrogen circulation pump is located between the first hydrogen branch pipe and the second hydrogen branch pipe. The gas-water separator is connected to one end of the second hydrogen branch pipe far from the fuel cell stack.

[0013] In the forklift fuel cell system based on solid-state hydrogen storage provided by the present invention, it may further have the following features: the water thermal management structure includes a water circulation pipe, a water pump, a radiator, a particle filter, a first electronic three-way valve, a heating branch pipe, and a PTC heating element. The end of the water circulation pipe is connected to the fuel cell stack. The water pump is arranged on the water circulation pipe. The radiator is arranged on the water circulation pipe. The particle filter is arranged on the water circulation pipe. The first electronic three-way valve is arranged on the water circulation pipe. One end of the heating branch pipe is connected to the first electronic three-way valve, and the other end of the heating branch pipe is connected to the water circulation pipe. The PTC heating element is arranged on the heating branch pipe.

[0014] In the forklift fuel cell system based on solid-state hydrogen storage provided by the present invention, it may further have the following features: the water thermal management structure further includes an intercooler cooling pipeline, the end of which is connected to the water circulation pipe, and a deionizer is arranged on the intercooler cooling pipeline; the water thermal management structure further includes a hydrogen heating pipeline, the end of which is connected to the water circulation pipe, and a second electronic three-way valve is arranged on the hydrogen heating pipeline.

[0015] In the forklift fuel cell system based on solid-state hydrogen storage provided by the present invention, it may further have the following features: it further includes an exhaust tail assembly, which includes an exhaust tail body and a water flow channel arranged in the exhaust tail body. The exhaust tail body is provided with a first inlet, a second inlet, a first outlet, a second outlet, and a liquid level sensor. The first inlet is connected to the air main pipe; the second inlet is connected to the drain pipe.

[0016] The technical effect of the present invention is as follows: The forklift fuel cell system based on solid-state hydrogen storage provided by the present invention includes a fuel cell stack, an air inlet and outlet structure, a hydrogen inlet and outlet structure, and a water thermal management structure. The air inlet and outlet structure is connected to the fuel cell stack, and the hydrogen inlet and outlet structure is connected to the fuel cell stack. The hydrogen inlet and outlet structure adopts the solid-state hydrogen storage method, which is convenient for hydrogen refueling of the forklift fuel cell. The water thermal management structure is connected to the fuel cell stack, the air inlet and outlet structure, and the hydrogen inlet and outlet structure. The water thermal management structure can prevent the water generated by the fuel cell system from freezing in a low-temperature environment, avoid power consumption loss of the fuel cell system, and is beneficial to improving the fuel cell efficiency.

[0017] Therefore, the forklift fuel cell system based on solid-state hydrogen storage provided by the present invention can solve the problem of inconvenient hydrogen refueling for forklift fuel cells, prevent the water generated by the fuel cell system from freezing in a low-temperature environment, and can use its own heat source to heat the water generated by the hydrogen reaction, avoiding power consumption loss of the fuel cell system and being beneficial to improving the fuel cell efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] This specification includes the following drawings, and the shown contents are respectively:

[0019] Figure 1 is a schematic structural diagram of a forklift fuel cell system based on solid-state hydrogen storage in an embodiment of the present invention;

[0020] Figure 2 is a schematic structural diagram of an exhaust tail assembly in an embodiment of the present invention.

[0021] In the figure, the markings are: fuel cell stack - 10, air inlet and outlet structure - 20, air main pipe - 21, first air branch pipe - 22, first throttle valve - 221, first temperature sensor - 222, first pressure sensor - 223, second air branch pipe - 23, second throttle valve - 231, second temperature sensor - 232, second pressure sensor - 233, air filter - 24, air temperature sensor - 241, mass flow meter - 25, air compressor - 26, intercooler - 27, bypass valve - 28, third throttle valve - 29, hydrogen inlet and outlet structure - 30, solid-state hydrogen storage unit - 31, hydrogen main pipe - 32, first hydrogen branch pipe - 33, third temperature sensor - 331, third pressure sensor - 332, second hydrogen branch pipe - 34, fourth temperature sensor - 341, fourth pressure sensor - 342, pressure reducing valve - 35, proportional valve - 36, hydrogen circulation pump - 37, drain pipe - 38, gas-water separator - 381, heating drain solenoid valve - 382, water heat management structure - 40, water circulation pipe - 41, water pump - 42, radiator - 43, particle filter - 44, first electronic three-way valve - 45, heating branch pipe - 46, PTC heating element - 47, intercooler cooling pipeline - 48, deionizer - 481, hydrogen heating pipeline - 49, second electronic three-way valve - 491, exhaust tail assembly - 50, exhaust tail body - 51, first inlet - 511, second inlet - 512, first outlet - 513, second outlet - 514, liquid level sensor - 515, water flow channel - 52, exhaust tail branch pipe - 53. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The following will, with reference to the drawings, further elaborate on the specific embodiments of the present invention through the description of the embodiments, aiming to help those skilled in the art have a more complete, accurate, and in-depth understanding of the inventive concept and technical solutions of the present invention and facilitate its implementation.

[0023] Figure 1 It is a schematic structural diagram of a forklift fuel cell system based on solid-state hydrogen storage in an embodiment of the present invention.

[0024] As Figure 1 shown, the forklift fuel cell system based on solid-state hydrogen storage provided by the present invention includes a fuel cell stack 10, an air inlet and outlet structure 20, a hydrogen inlet and outlet structure 30, and a water and heat management structure 40. The air inlet and outlet structure 20 is connected to the fuel cell stack 10, the hydrogen inlet and outlet structure 30 is connected to the fuel cell stack 10, and the hydrogen inlet and outlet structure 30 adopts a solid-state hydrogen storage method, which is convenient for hydrogen refueling of the forklift fuel cell. The water and heat management structure 40 is connected to the fuel cell stack 10, the air inlet and outlet structure 20, and the hydrogen inlet and outlet structure 30. The water and heat management structure 40 can prevent the water generated by the fuel cell stack 10 from freezing in a low-temperature environment, avoid power consumption loss of the fuel cell system, is beneficial to improving the fuel cell efficiency, enables the forklift fuel cell system based on solid-state hydrogen storage provided by the present invention to solve the problem of inconvenient hydrogen refueling of the forklift fuel cell, can prevent the water generated by the fuel cell system from freezing in a low-temperature environment, can heat the water generated by the hydrogen reaction by using its own heat source, avoid power consumption loss of the fuel cell system, and is beneficial to improving the fuel cell efficiency.

[0025] As Figure 1 shown, the air inlet and outlet structure 20 includes an air main pipe 21, a first air branch pipe 22, and a second air branch pipe 23. The air main pipe 21 is used for air circulation. One end of the first air branch pipe 22 is connected to the air main pipe 21, and the other end of the first air branch pipe 22 is connected to the fuel cell stack 10. The first air branch pipe 22 is used to introduce air into the fuel cell stack 10, and a first throttle valve 221 is provided on the first air branch pipe 22. The first throttle valve 221 can control the gas flow rate in the first air branch pipe 22. One end of the second air branch pipe 23 is connected to the air main pipe 21, and the other end of the second air branch pipe 23 is connected to the fuel cell stack 10. The second air branch pipe 23 is used to export the air after reaction in the fuel cell stack 10, and a second throttle valve 231 is provided on the second air branch pipe 23. The second throttle valve 231 can control the gas flow rate in the second air branch pipe 23.

[0026] A first temperature sensor 222 and a first pressure sensor 223 are also provided on the first air branch pipe 22. The first temperature sensor 222 can monitor the temperature of the gas in the first air branch pipe 22, and the first pressure sensor 223 can monitor the pressure of the gas in the first air branch pipe 22, which is convenient for ensuring that the temperature and pressure of the air entering the fuel cell stack 10 meet the working requirements of the fuel cell stack 10. A second temperature sensor 232 and a second pressure sensor 233 are also provided on the second air branch pipe 23. The second temperature sensor 232 can monitor the temperature of the gas in the second air branch pipe 23, and the second pressure sensor 233 can monitor the pressure of the gas in the second air branch pipe 23, which is convenient for monitoring the temperature and pressure of the air discharged from the fuel cell stack 10 after the reaction.

[0027] An air filter 24, a mass flow meter 25, an air compressor 26 and an intercooler 27 are sequentially provided on the air main pipe 21. An air temperature sensor 241 is provided between the air filter and the mass flow meter. A bypass valve 28 and a third throttle valve 29 are also provided on the air main pipe. The bypass valve 28 is located between the first air branch pipe 22 and the second air branch pipe 23, and the third throttle valve 29 is located on the side of the second air branch pipe 23 away from the bypass valve 28.

[0028] The air filter 24 can perform physical filtration and chemical adsorption. Physical filtration can filter out impurities and dust in the air, and chemical adsorption can filter out harmful gases such as nitrogen compounds and sulfur compounds in the air that are harmful to the membrane electrode. The air temperature sensor 241 is used to detect the ambient temperature of the external air; the clean air filtered by the air filter 24 enters the mass flow meter 25, and the mass flow meter 25 can monitor whether the intake air flow meets the requirements of the fuel cell stack 10; the air compressor 26 can compress the air to meet the air pressure requirements of the fuel cell stack 10; the intercooler 27 can cool the air pressurized by the air compressor 26 to reach the air temperature required for the optimal operation of the fuel cell stack 10, which is between 70 °C and 80 °C.

[0029] When the fuel cell stack 10 stops working, the first throttle valve 221 and the second throttle valve 231 are closed to play a sealing role; when the fuel cell stack 10 is working, the first throttle valve 221 and the second throttle valve 231 are in a fully open state (100% opening), reducing the flow resistance. The bypass valve 28 can discharge the excess air through the bypass valve 28 and the air main pipe 21 while meeting the needs of the fuel cell stack 10 for the gas compressed by the air compressor 26, avoiding surging of the air compressor 26.

[0030] The hydrogen inlet and outlet structure 30 includes a solid-state hydrogen storage unit 31, a hydrogen main pipe 32, a first hydrogen branch pipe 33, and a second hydrogen branch pipe 34. One end of the hydrogen main pipe 32 is connected to the solid-state hydrogen storage unit 31. One end of the first hydrogen branch pipe 33 is connected to the hydrogen main pipe 32, and the other end of the first hydrogen branch pipe 33 is connected to the fuel cell stack 10, capable of introducing the hydrogen stored in the solid-state hydrogen storage unit 31 into the fuel cell stack 10. One end of the second hydrogen branch pipe 34 is connected to the end of the hydrogen main pipe 32 far from the solid-state hydrogen storage unit 31, and the other end of the second hydrogen branch pipe 34 is connected to the fuel cell stack 10, capable of discharging the reacted hydrogen from the fuel cell stack 10.

[0031] A third temperature sensor 331 and a third pressure sensor 332 are provided on the first hydrogen branch pipe 33. The third temperature sensor 331 can monitor the temperature of the hydrogen entering the fuel cell stack 10 in the first hydrogen branch pipe 33, and the third pressure sensor 332 can monitor the pressure of the hydrogen entering the fuel cell stack 10 in the first hydrogen branch pipe 33. A fourth temperature sensor 341 and a fourth pressure sensor 342 are provided on the second hydrogen branch pipe 34. The fourth temperature sensor 341 can monitor the temperature of the hydrogen leaving the fuel cell stack 10 in the second hydrogen branch pipe 34, and the fourth pressure sensor 342 can monitor the pressure of the hydrogen leaving the fuel cell stack 10 in the second hydrogen branch pipe 34.

[0032] A pressure reducing valve 35, a proportional valve 36, and a hydrogen circulation pump 37 are sequentially provided on the hydrogen main pipe 32. The temperature required for the solid-state hydrogen storage unit 31 to release hydrogen is 50°C to 80°C, and the pressure of the released hydrogen is 1.0 MPa to 1.5 MPa. The pressure reducing valve 35 can reduce the pressure of the hydrogen released by the solid-state hydrogen storage unit 31 to 200 kPa. The proportional valve 36 can inject the hydrogen depressurized by the pressure reducing valve 35 into the fuel cell stack 10 according to the pressure required during the operation of the fuel cell stack 10. The hydrogen circulation pump 37 is located between the first hydrogen branch pipe 33 and the second hydrogen branch pipe 34.

[0033] The hydrogen inlet and outlet structure 30 further includes a drain pipe 38. An air-water separator 381 and a heating drain solenoid valve 382 are provided on the drain pipe 38. The air-water separator 381 is connected to one end of the second hydrogen branch pipe 34 away from the fuel cell stack 10, and the air-water separator 381 is connected to one end of the hydrogen main pipe 32 away from the solid hydrogen storage unit 31. By connecting to the hydrogen main pipe 32, it can separate the mixture formed by the unreacted hydrogen discharged from the second hydrogen branch pipe 34 and the water generated by the reaction. After separation, the hydrogen is mixed with the newly injected hydrogen by the hydrogen circulation pump 37 and the proportional valve 36 and then enters the fuel cell stack 10 again for reaction to achieve the purpose of hydrogen recycling, improving the utilization rate of hydrogen and the efficiency of the fuel cell system. The water separated by the air-water separator 381 is discharged through the heating drain solenoid valve 382. The heating drain solenoid valve 382 performs pulsed discharge, with a pulsed discharge of 1 s to 2 s within 20 s to 30 s, to timely discharge the water in the air-water separator 381, avoiding affecting the operation of the air-water separator 381 and improving the reliability of the structure.

[0034] The water thermal management structure 40 is used to maintain the fuel cell stack 10 within the operating range of 70°C to 80°C, and at the same time ensure the fast cold start ability of the fuel cell stack 10. The water thermal management structure 40 includes a water circulation pipe 41, a water pump 42, a radiator 43, a particle filter 44, a first electronic three-way valve 45, a heating branch pipe 46, and a PTC heating element 47. The inlet and outlet at both ends of the water circulation pipe 41 are respectively connected to the inlet and outlet of the coolant on the fuel cell stack 10, so as to realize the circulating flow of the coolant within the fuel cell system. Temperature sensors and pressure sensors are provided at both ends of the water circulation pipe 41 to detect the temperature and pressure of the coolant entering and leaving the fuel cell stack 10.

[0035] The water pump 42 is arranged on the water circulation pipe 41 to provide power for the circulating flow of the coolant; the radiator 43 is arranged on the water circulation pipe 41, and the radiator 43 exchanges heat between the air temperature of the external environment and the coolant to dissipate heat from the coolant; the particle filter 44 is arranged on the water circulation pipe 41, and the particle filter 44 can filter the coolant to filter out the particulate matter in the coolant; the first electronic three-way valve 45 is arranged on the water circulation pipe 41 to realize the diversion of the coolant between the water circulation pipe 41 and the heating branch pipe 46. One end of the heating branch pipe 46 is connected to the first electronic three-way valve 45, and the other end of the heating branch pipe 46 is connected to the water circulation pipe 41. The PTC heating element is arranged on the heating branch pipe 46.

[0036] When the fuel cell stack 10 is operating, heat is continuously generated. The water pump 42 provides power for the coolant, causing the coolant to circulate within the fuel cell system to ensure the temperature of the fuel cell stack 10. Based on the temperature monitored by the air temperature sensor 241, it is determined whether it is in a low-temperature environment. In a low-temperature environment, the small water-heat management circulation mode is activated. By controlling the opening degree of the first electronic three-way valve 45, the coolant is heated by the PTC heating element 47 under the action of the water pump 42. The heated water directly enters the fuel cell stack 10. Combining with the heat generated by the operation of the fuel cell stack 10, the temperature of the fuel cell stack 10 can be rapidly increased to reach the operating range of 70°C to 80°C for the fuel cell stack 10. In a non-low-temperature environment or during normal operation, the large water-heat management circulation mode is activated. By controlling the opening degree of the first electronic three-way valve 45, under the action of the water pump 42, after the coolant passes through the radiator 43, it enters the particulate filter 44 and then enters the fuel cell stack 10 through the first electronic three-way valve 45.

[0037] The water-heat management structure 40 further includes an intercooler cooling pipeline 48. One end of the intercooler cooling pipeline 48 is connected to the outlet of the water circulation pipe 41, and the other end of the intercooler cooling pipeline 48 is connected to the inlet of the water circulation pipe 41. A deionizer 481 is provided on the intercooler cooling pipeline 48. The deionizer 481 can filter out metal ions precipitated from metal components in the fuel cell system, reduce the conductivity of the coolant, and improve the insulation of the fuel cell system. And the intercooler cooling pipeline 48 passes through the intercooler 27. After the coolant flows through the deionizer 481, it is in series with the intercooler 27. The coolant exchanges heat with the high-temperature air compressed by the air compressor 26 in the intercooler 27 to cool the high-temperature air, so that the air reaches the air temperature required for the optimal operation of the fuel cell stack 10, that is, 70°C to 80°C.

[0038] The water-heat management structure 40 further includes a hydrogen heating pipeline 49. One end of the hydrogen heating pipeline 49 is connected to the outlet of the water circulation pipe 41, and the other end of the hydrogen heating pipeline 49 is connected to the inlet of the water circulation pipe 41. And the hydrogen heating pipeline 49 passes through the solid-state hydrogen storage unit 31. A second electronic three-way valve 491 is provided on the hydrogen heating pipeline 49. The coolant heats the solid-state hydrogen storage unit 31 through the hydrogen heating pipeline 49, enabling the solid-state hydrogen storage unit 31 to continuously release hydrogen to provide a gas source for the operation of the fuel cell stack 10.

[0039] The forklift fuel cell system based on solid-state hydrogen storage provided by the present invention further includes an exhaust gas assembly 50. The exhaust gas assembly includes an exhaust gas main body 51 and a water flow channel 52 provided in the exhaust gas main body 51. The exhaust gas main body 51 is connected to an exhaust gas branch pipe 53 communicating with the water flow channel 52. One end of the exhaust gas branch pipe 53 is connected to the second electronic three-way valve 491, and the other end of the exhaust gas branch pipe 53 is connected to the hydrogen heating pipeline 49, thereby connecting the water flow channel 52 with the hydrogen heating pipeline 49. The exhaust gas main body 51 is provided with a first inlet 511, a second inlet 512, a first outlet 513, a second outlet 514 and a liquid level sensor 515. The first inlet 511 is connected to the air main pipe 21, and the excess air in the air main pipe 21 is discharged through the first outlet 513. The second inlet 512 is connected to the drain pipe 38. The water generated by the fuel cell stack 10 is discharged into the exhaust gas main body 51 through the drain pipe 38 and then discharged through the second outlet 514. The liquid level sensor 515 monitors the liquid level height in the exhaust gas main body 51 and is discharged through the second outlet 514 after reaching the set value. A manual drain valve and an electronic drain valve may be provided at the second outlet 514 to facilitate the discharge of waste water in the exhaust gas main body 51.

[0040] In a low-temperature environment, there is a risk of icing for the water generated by the operation of the fuel cell system and discharged into the exhaust gas main body 51 through the drain pipe 38. The exhaust gas main body 51 is heated by the coolant in the thermal management system. Through the control of the second electronic three-way valve 491, the coolant in the hydrogen heating pipeline 49 flows through the water flow channel 52 and the exhaust gas main body 51 to heat the waste water in the exhaust gas main body 51, which can avoid the icing of the water generated by the fuel cell system in a low-temperature environment without the need for an external heat source to heat it, thus avoiding power consumption loss of the fuel cell system and reducing the fuel cell efficiency.

[0041] Functions and effects of the embodiment

[0042] The forklift fuel cell system based on solid-state hydrogen storage provided by the present invention includes a fuel cell stack 10, an air inlet and outlet structure 20, a hydrogen inlet and outlet structure 30 and a water and heat management structure 40. The air inlet and outlet structure 20 is connected to the fuel cell stack 10, and the hydrogen inlet and outlet structure 30 is connected to the fuel cell stack 10. The hydrogen inlet and outlet structure 30 adopts a solid-state hydrogen storage method, which is convenient for hydrogen refueling of the forklift fuel cell. The water and heat management structure 40 is connected to the fuel cell stack 10, the air inlet and outlet structure 20 and the hydrogen inlet and outlet structure 30. The water and heat management structure 40 can avoid the icing of the water generated by the fuel cell stack 10 in a low-temperature environment, can avoid power consumption loss of the fuel cell system, is beneficial to improving the fuel cell efficiency, enables the forklift fuel cell system provided by the present invention to solve the problem of inconvenient hydrogen refueling of the forklift fuel cell, can prevent the water generated by the fuel cell system from icing in a low-temperature environment, can heat the water generated by the hydrogen reaction by using its own heat source, avoid power consumption loss of the fuel cell system, and is beneficial to improving the fuel cell efficiency.

[0043] The present invention has been described by way of example in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited by the above methods. As long as various non-substantive improvements are made by adopting the method concept and technical solution of the present invention; or without improvement, the above concept and technical solution of the present invention are directly applied to other occasions, they are all within the protection scope of the present invention.

Claims

1. A forklift fuel cell system based on solid-state hydrogen storage, characterized in that: The invention comprises a fuel cell stack (10), an air inlet and outlet structure (20), a hydrogen inlet and outlet structure (30) and a water heat management structure (40), wherein the air inlet and outlet structure (20) is connected to the fuel cell stack (10), the hydrogen inlet and outlet structure (30) is connected to the fuel cell stack (10), and the water heat management structure (40) is connected to the fuel cell stack (10), the air inlet and outlet structure (20) and the hydrogen inlet and outlet structure (30).

2. The forklift fuel cell system based on solid-state hydrogen storage according to claim 1 is characterized in that: The air inlet and outlet structure (20) comprises an air main pipe (21), a first air branch pipe (22) and a second air branch pipe (23); one end of the first air branch pipe (22) is connected to the air main pipe (21), the other end of the first air branch pipe (22) is connected to the fuel cell stack (10), and a first throttle valve (221) is provided on the first air branch pipe (22); one end of the second air branch pipe (23) is connected to the air main pipe (21), the other end of the second air branch pipe (23) is connected to the fuel cell stack (10), and a second throttle valve (231) is provided on the second air branch pipe (23).

3. The forklift fuel cell system based on solid-state hydrogen storage according to claim 2 is characterized in that: The first air branch pipe (22) is provided with a first temperature sensor (222) and a first pressure sensor (223); the second air branch pipe (23) is provided with a second temperature sensor (232) and a second pressure sensor (233).

4. The forklift fuel cell system based on solid-state hydrogen storage according to claim 3 is characterized in that: The air main pipe (21) is provided with an air filter (24), a mass flow meter (25), an air compressor (26) and an intercooler (27) in sequence; an air temperature sensor (241) is provided between the air filter (24) and the mass flow meter (25); and the air main pipe (21) is also provided with a bypass valve (28) and a third throttle valve (29).

5. The forklift fuel cell system based on solid-state hydrogen storage according to claim 4 is characterized in that: The hydrogen inlet and outlet structure (30) comprises a solid hydrogen storage unit (31), a hydrogen main pipe (32), a first hydrogen branch pipe (33) and a second hydrogen branch pipe (34); one end of the hydrogen main pipe (32) is connected to the solid hydrogen storage unit (31), one end of the first hydrogen branch pipe (33) is connected to the hydrogen main pipe (32), and the other end of the first hydrogen branch pipe (33) is connected to the fuel cell stack (10); one end of the second hydrogen branch pipe (34) is connected to the hydrogen main pipe (32), and the other end of the second hydrogen branch pipe (34) is connected to the fuel cell stack (10).

6. The forklift fuel cell system based on solid-state hydrogen storage according to claim 5 is characterized in that: The first hydrogen branch pipe (33) is provided with a third temperature sensor (331) and a third pressure sensor (332); the second hydrogen branch pipe (34) is provided with a fourth temperature sensor (341) and a fourth pressure sensor (342).

7. The forklift fuel cell system based on solid-state hydrogen storage according to claim 6 is characterized in that: The hydrogen main pipe (32) is provided with a pressure reducing valve (35), a proportional valve (36) and a hydrogen circulation pump (37) in sequence. The hydrogen inlet and outlet structure (30) also includes a drain pipe (38). The drain pipe (38) is provided with a gas-water separator (381) and a heating drain solenoid valve (382). The hydrogen circulation pump (37) is located between the first hydrogen branch pipe (33) and the second hydrogen branch pipe (34). The gas-water separator (381) is connected to an end of the second hydrogen branch pipe (34) away from the fuel cell stack (10).

8. The forklift fuel cell system based on solid-state hydrogen storage according to claim 7 is characterized in that: The water heat management structure (40) comprises a water circulation pipe (41), a water pump (42), a radiator (43), a particle filter (44), a first electronic three-way valve (45), a heating branch pipe (46) and a PTC heating element (47); the end of the water circulation pipe (41) is connected to the fuel cell stack (10); the water pump (42) is arranged on the water circulation pipe (41); the radiator (43) is arranged on the water circulation pipe (41); the particle filter (44) is arranged on the water circulation pipe (41); the first electronic three-way valve (45) is arranged on the water circulation pipe (41); one end of the heating branch pipe (46) is connected to the first electronic three-way valve (45); the other end of the heating branch pipe (46) is connected to the water circulation pipe (41); and the PTC heating element (47) is arranged on the heating branch pipe (46).

9. The forklift fuel cell system based on solid-state hydrogen storage according to claim 8, characterized in that: The water heat management structure (40) further comprises an intercooler cooling pipeline (48), the end of which is connected to the water circulation pipe (41), and a deionizer (481) is provided on the intercooler cooling pipeline (48); the water heat management structure (40) further comprises a hydrogen heating pipeline (49), the end of which is connected to the water circulation pipe (41), and a second electronic three-way valve (491) is provided on the hydrogen heating pipeline (49).

10. The forklift fuel cell system based on solid-state hydrogen storage according to claim 9, characterized in that: The invention also comprises a tail drain assembly (50), wherein the tail drain assembly (50) comprises a tail drain body (51) and a water flow channel (52) arranged in the tail drain body (51); the tail drain body (51) is provided with a first inlet (511), a second inlet (512), a first outlet (513), a second outlet (514) and a liquid level sensor (515); the first inlet (511) is connected to the air main pipe (21); and the second inlet (512) is connected to the drain pipe (38).

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