Thermal management method for metal solid-state hydrogen storage, hydrogen fuel cell system thereof and rail transit vehicle

Abstract

A thermal management method for metal solid-state hydrogen storage, a hydrogen fuel cell system thereof and a rail transit vehicle. The hydrogen fuel cell system comprises a hydrogen fuel cell module and solid-state hydrogen storage modules, which are communicated via a hydrogen pipe; a first branch is provided on the periphery of the hydrogen fuel cell module; a diverter valve is provided at a liquid outlet end of the first branch, one branch of the diverter valve being communicated with a heat dissipation system, and another branch of the diverter valve being communicated with a second branch. Using heat generated during power generation of a hydrogen fuel cell to successively start the solid-state hydrogen storage modules helps to increase the system starting speed, thus improving the efficiency of hydrogen fuel cell systems.

Description

A thermal management method for metal solid-state hydrogen storage, a hydrogen fuel cell system, and a rail transit vehicle Technical Field

[0001] The present invention relates to the technical field of rail transit vehicles, and in particular to a thermal management method for metal solid-state hydrogen storage, a hydrogen fuel cell system thereof, and a rail transit vehicle. Background Art

[0002] Hydrogen fuel cells are energy devices that generate electricity through the electrochemical reaction between hydrogen and oxygen. They offer advantages such as zero pollution, high efficiency, and low noise, and have broad application prospects in the field of traction power supply systems for rail transit vehicles. Currently, hydrogen fuel cell systems are already being used in the traction power supply systems of rail transit vehicles, including locomotives, EMUs, trams, and engineering vehicles.

[0003] A hydrogen fuel cell system is usually composed of a hydrogen fuel cell module, a hydrogen storage module, and a heat dissipation module. The function of the hydrogen storage module is to store hydrogen and provide a hydrogen flow with pressure, temperature, and flow that meet the requirements to the hydrogen fuel cell module. Depending on the mechanism of hydrogen storage, hydrogen storage methods include high-pressure gaseous hydrogen storage, low-temperature liquid hydrogen storage, solid-state hydrogen storage, and organic hydrogen storage. Among them, high-pressure gaseous hydrogen storage compresses H2 to a pressure of 35MPa or 70MPa and stores it in a high-pressure hydrogen storage bottle. Solid-state hydrogen storage utilizes the reversible catalytic dissociation and adsorption effect of hydrogen storage alloys (including Mg-based, TiMn-based, rare earth metal-based materials) on H2 to store hydrogen in the hydrogen storage alloy in atomic form.

[0004] High-pressure gaseous hydrogen storage, with its mature technology, simple structure, and easy hydrogen absorption and desorption conditions, is currently the most widely used hydrogen storage method. However, its application in rail transit vehicles suffers from its low volumetric hydrogen storage density of only 24g / L at 35MPa or 40g / L at 70MPa, which makes it difficult to meet the rail transit vehicle's requirements for large hydrogen storage capacities and long driving ranges. Solid-state hydrogen storage, on the other hand, offers advantages such as high volumetric hydrogen storage density exceeding 50g / L, high safety, and hydrogen absorption and desorption pressures typically no higher than 5MPa. It is suitable for rail transit vehicles, particularly locomotives and engineering vehicles, where equipment installation space is limited but weight is not a concern. Therefore, solid-state hydrogen storage holds great promise for application in rail transit vehicles.

[0005] A Chinese patent with publication number CN214093991U discloses an on-vehicle solid-state hydrogen storage and supply system, which relates to the field of hydrogen energy storage and supply technology. It includes a hydrogen storage container, a hydrogen filling system, a hydrogen supply system, a cooling system, and a heating system. The hydrogen storage container is provided with a solid material capable of absorbing hydrogen. When hydrogen supply is required, the heating system is used to heat the hydrogen storage container, causing the solid material in the hydrogen storage container to release hydrogen, which is then supplied to the vehicle fuel cell system through the hydrogen supply system. This patent uses the entire hydrogen storage container, and the heating system is required to heat the hydrogen storage container throughout the entire process, which consumes a large amount of energy, is costly, and has a slow startup speed.

[0006] Chinese patent publication number CN113422087A discloses an on-vehicle low-temperature liquid hydrogen fuel cell system and fuel cell heat exchange method. The on-vehicle low-temperature liquid hydrogen fuel cell system includes a fuel cell, an on-vehicle hydrogen storage system, a waste heat utilization system, and a controller. The on-vehicle hydrogen storage system includes a liquid hydrogen storage tank and a liquid hydrogen vaporization unit, which includes a liquid hydrogen vaporizer. The liquid hydrogen storage tank is connected to the fuel cell via the liquid hydrogen vaporizer. The waste heat utilization system includes a heat exchange pipe for exchanging heat between the liquid hydrogen vaporizer and the fuel cell and / or heating unit. The heat exchange pipe is equipped with a control valve. The controller controls the opening or closing of the control valve based on the response power of the fuel cell. This patent includes a dedicated waste heat utilization system.

[0007] In solid-state hydrogen storage, the reversible adsorption and desorption of H2 by hydrogen storage alloys is accompanied by significant thermal effects. The release of hydrogen from the hydrogen storage alloy, i.e., the supply of hydrogen to the hydrogen fuel cell module, is an endothermic reaction. Therefore, a specialized thermal management system (i.e., the waste heat utilization system described in Chinese patent publication number CN113422087A) is required to regulate the temperature of the hydrogen storage alloy. This technology faces the following challenges:

[0008] (1) The dehydrogenation process of the hydrogen storage alloy, i.e., the hydrogen supply process for the hydrogen fuel cell, is an endothermic reaction. The solid-state hydrogen storage module must be continuously heated to maintain the dehydrogenation process. The required heating power is relatively large, such as more than 12MJ / kg H2 for TiMn-based hydrogen storage alloys. The power consumed by heating reduces the net output power of the hydrogen fuel cell system, thereby reducing the power generation efficiency of the hydrogen fuel cell system.

[0009] (2) The hydrogen release process of the hydrogen storage alloy, that is, the hydrogen supply process for the hydrogen fuel cell, is an endothermic reaction. During the startup phase of the hydrogen fuel cell system, the hydrogen storage alloy must first be heated to the initial hydrogen release temperature. For example, the TiMn hydrogen storage alloy must be heated to 60°C, which consumes a lot of energy and limits the startup speed of the hydrogen fuel cell system.

[0010] (3) The above-mentioned heating system required for controlling the hydrogen release process of the hydrogen storage alloy, i.e., the thermal management system of solid-state hydrogen storage, increases the volume and weight of the solid-state hydrogen storage module, reduces the volumetric hydrogen storage density and weight hydrogen storage density of the solid-state hydrogen storage module; consumes power, and reduces the power generation efficiency of the hydrogen fuel cell system; the required compressors, fans and other equipment increase the noise emission of the hydrogen fuel cell system and its hydrogen-powered rail transit vehicles, and reduce the vehicle comfort.

[0011] Summary of the Invention

[0012] The technical problem to be solved by the present invention is to provide a thermal management method for metal solid-state hydrogen storage and its hydrogen fuel cell system and rail transit vehicle to improve the startup speed of the hydrogen fuel cell system in view of the shortcomings of the existing technology.

[0013] In addition, the thermal management method of metal solid-state hydrogen storage and its hydrogen fuel cell system and rail transit vehicle of the present invention also help to simplify the heating system, improve vehicle comfort, and improve the efficiency of the hydrogen fuel cell system.

[0014] To solve the above technical problems, the technical solution adopted by the present invention is: a hydrogen fuel cell system, comprising a hydrogen fuel cell module and a solid-state hydrogen storage module connected by a hydrogen pipeline, a first branch being provided on the periphery of the hydrogen fuel cell module, a diverter valve being provided at the liquid outlet of the first branch, wherein one of the branches of the diverter valve is connected to the heat dissipation system, and the other branch of the diverter valve is connected to the second branch, and a heater is provided at the liquid inlet of the second branch, the solid-state hydrogen storage module comprises two or more, the second branch is respectively provided on the periphery of multiple solid-state hydrogen storage modules through multiple branch pipes, the liquid inlets of the branch pipes are all provided with coolant shut-off valves, the liquid outlet of the second branch is connected to the heat dissipation system or the first branch, the liquid outlet of the heat dissipation system is connected to the liquid inlet of the first branch, and the first branch and the second branch contain coolant.

[0015] A hydrogen fuel cell system includes a hydrogen fuel cell module and a solid-state hydrogen storage module connected through a hydrogen pipeline, wherein a first branch is provided on the periphery of the hydrogen fuel cell module, and a diverter valve is provided at the liquid outlet of the first branch, the diverter valve having a first outlet and a second outlet, wherein the first outlet of the diverter valve is connected to a heat dissipation system, and the second outlet of the diverter valve is connected to a second branch, and a heater is provided on the second branch. There are two or more solid-state hydrogen storage modules, and the second branch is respectively provided on the periphery of multiple solid-state hydrogen storage modules through multiple branch pipes, and the liquid inlets of the branch pipes are all provided with coolant shut-off valves, the liquid outlet of the second branch is connected to the heat dissipation system or the first branch, the liquid outlet of the heat dissipation system is connected to the liquid inlet of the first branch, and the first branch and the second branch are both filled with coolant.

[0016] Furthermore, the hydrogen fuel cell module has a coolant inlet and a coolant outlet, the coolant inlet is connected to the liquid outlet of the heat dissipation system, and the coolant outlet is connected to the liquid outlet of the first branch.

[0017] Furthermore, a coolant circulation pump is provided between the coolant inlet and the liquid outlet of the heat dissipation system.

[0018] Furthermore, the liquid outlet of the second branch is connected to the first branch located between the liquid outlet of the heat dissipation system and the coolant circulation pump. In this way, by providing a single coolant circulation pump, the coolant can circulate and flow through the first branch and the second branch, which helps to further simplify the structure.

[0019] Furthermore, the liquid inlet of each coolant stop valve is connected to the second branch.

[0020] Furthermore, the heater is located between the second outlet of the diverter valve and the coolant shut-off valve, which helps to fully utilize the function of the heater and start the hydrogen fuel cell system more quickly.

[0021] The solid-state hydrogen storage thermal management system, hydrogen fuel cell system, and rail transit vehicle provided by the present invention can achieve the following functions, thereby solving the problems existing in the background technology.

[0022] (1) The present invention uses a solid-state hydrogen storage module to provide hydrogen for a hydrogen fuel cell module, including a plurality of solid-state hydrogen storage modules;

[0023] (2) During the startup phase of the hydrogen fuel cell system, the present invention utilizes a startup heater to heat a solid-state hydrogen storage module and a hydrogen fuel cell module to a starting hydrogen release temperature, and the released H2 is used to generate electricity for the hydrogen fuel cell module; the heat generated by the hydrogen fuel cell module is used to sequentially heat other solid-state hydrogen storage modules, thereby increasing the startup speed of the hydrogen fuel cell system;

[0024] (3) In the solid-state hydrogen storage thermal management system provided by the present invention, the hydrogen fuel cell module, the solid-state hydrogen storage module, and the liquid heat transfer medium of the heat dissipation system circulate among each other without the need to exchange heat through a heat exchanger.

[0025] (4) The present invention utilizes the waste heat generated by the hydrogen fuel cell module to heat the solid-state hydrogen storage module, thereby maintaining the hydrogen release process of the solid-state hydrogen storage module without consuming additional electrical energy to heat the solid-state hydrogen storage module; at the same time, the heat dissipation power of the hydrogen fuel cell module is reduced, thereby reducing the power consumption of the heat dissipation cooling module and improving the efficiency of the hydrogen fuel cell system;

[0026] The coolant is the thermal management medium of the solid-state hydrogen storage module, which flows through the interior of the solid-state hydrogen storage module and transfers heat to the solid-state hydrogen storage material.

[0027] In a preferred embodiment of the present invention, the heat dissipation system includes a radiator and a pipeline arranged around the radiator, and a heat dissipation fan is installed on the outside of the radiator.

[0028] The present invention also discloses a thermal management method for metal solid-state hydrogen storage, comprising the following steps:

[0029] S1. Open the coolant shut-off valve of the first solid-state hydrogen storage module, start the heater to heat the coolant, and start circulating the coolant;

[0030] S2. When the temperature of the first solid-state hydrogen storage module T> T0, start the hydrogen fuel cell module;

[0031] S3. When the temperature T of the hydrogen fuel cell module is greater than T1, turn off the heater and open the coolant shut-off valve of the second solid-state hydrogen storage module;

[0032] S4. When the temperature of the second solid-state hydrogen storage module T> T0, open the coolant shut-off valve of the third solid-state hydrogen storage module;

[0033] S5. When the temperature T>T0 of the n-1 solid-state hydrogen storage module, open the coolant shut-off valve of the n-th solid-state hydrogen storage module;

[0034] S6. When the temperatures of all solid-state hydrogen storage modules satisfy T>T0, turn on the heat dissipation system.

[0035] During the startup phase of the hydrogen fuel cell system, the present invention utilizes a startup heater to heat a solid-state hydrogen storage module and a hydrogen fuel cell module to a starting hydrogen release temperature, and the released H2 is used to generate electricity for the hydrogen fuel cell module; the heat generated by the hydrogen fuel cell module is used to heat other solid-state hydrogen storage modules in sequence, thereby increasing the startup speed of the hydrogen fuel cell system, reducing the heating system, improving vehicle comfort, and improving the efficiency of the hydrogen fuel cell system.

[0036] Furthermore, after the heat dissipation system is turned on (ie, after the hydrogen fuel cell system operates normally), the flow ratio of the first branch and the second branch is controlled to be:

[0037] Where f1 is the coolant flow rate of the first branch, f2 is the coolant flow rate of the second branch, both in g / s; ΔG(H2) is the heat released by the hydrogen fuel cell module when it consumes unit mass of hydrogen to generate electricity, and ΔG(M) is the heat that the solid-state hydrogen storage module must absorb when it releases unit mass of hydrogen, both in kJ / g; T 2,in and T 2,out are the temperatures of the coolant inlet and outlet of the second branch, T 1,in and T 1,out are the temperatures of the coolant inlet and outlet of the first branch, both in ℃.

[0038] In a preferred embodiment of the present invention, the flow ratio between the first branch and the second branch is:

[0039] Where f1 is the coolant flow rate of the first branch, f2 is the coolant flow rate of the second branch, both in g / s; ΔG(H2) is the heat released by the hydrogen fuel cell module when it consumes unit mass of hydrogen to generate electricity, and ΔG(TiMn) is the heat that the solid-state hydrogen storage module (TiMn-based hydrogen storage alloy material) must absorb when it releases unit mass of hydrogen, both in kJ / g; T 2,in and T 2,out are the temperatures of the coolant inlet and outlet of the second branch, T 1,in and T 1,out The temperatures of the coolant inlet and outlet of the first branch are both in °C. ΔG(H2)=HHV(H2)-LHV(H2)·η

[0040] Where HHV(H2) is the higher heating value of hydrogen; LHV(H2) is the lower heating value of hydrogen, and η is the efficiency of hydrogen fuel cell power generation.

[0041] Wherein, U is the output voltage of the hydrogen fuel cell stack, which is measured by the current sensor at the output end of the hydrogen fuel cell stack; U OCV is the open circuit voltage of the hydrogen fuel cell stack, in V. OCV =1.185×n

[0042] Where n is the number of single cells contained in the hydrogen fuel cell stack.

[0043] Furthermore, the opening of the diverter valve is:

[0044] Where δ is the opening of the diverter valve, and f(sv) is the transfer function of the diverter valve (generally determined by the structure and characteristics of the diverter valve itself).

[0045] The hydrogen fuel cell module is a proton exchange membrane hydrogen fuel cell, and the solid-state hydrogen storage module is made of a TiMn series hydrogen storage alloy material, with T0 being 15-25°C and T1 being 60-80°C.

[0046] The present invention also discloses a rail transit vehicle, the technical feature of which is that it is equipped with the hydrogen fuel cell system.

[0047] When the hydrogen fuel cell system is operating stably, the heat dissipated by the first branch accounts for about 80% of the total heat generated by the hydrogen fuel cell.

[0048] A coolant circulation pump is installed on the first branch.

[0049] The hydrogen pipeline is connected to the plurality of solid-state hydrogen storage modules through a plurality of hydrogen branch pipes, and hydrogen shut-off valves are installed on the plurality of hydrogen branch pipes.

[0050] The hydrogen supplied by the multiple solid-state hydrogen storage modules is converged to provide H2 to the hydrogen fuel cell module.

[0051] The radiator may be a tube-fin radiator or a plate-fin radiator;

[0052] The heat dissipation fan can be an axial flow fan or a centrifugal fan.

[0053] The second branch provides heat for the solid-state hydrogen storage module. A coolant control valve and a start-up heating device are provided on the second branch. The coolant of the hydrogen fuel cell is used to heat the solid-state hydrogen storage module to maintain the temperature of the solid-state hydrogen storage module. When the hydrogen fuel cell system is operating stably, the heat used by the second branch accounts for approximately 20% of the total heat generated by the hydrogen fuel cell.

[0054] The second branch pipeline flows through the interior of the solid-state hydrogen storage module to transfer coolant and heat to the solid-state hydrogen storage material;

[0055] The heater adopts a low-temperature starting heating device, which is powered by the rail transit vehicle and can be a heating rod, a heating plate or a PTC heating film.

[0056] The first branch and the second branch are connected to the coolant outlet of the hydrogen fuel cell module through a coolant distribution valve, and the coolant flow rate of the first branch and the second branch is distributed by the coolant distribution valve.

[0057] The coolant of the first branch flows through the radiator, and then flows through the solid hydrogen storage module with the coolant of the second branch, and then mixes and flows into the hydrogen fuel cell module, with a temperature range of 60 to 80°C.

[0058] During the startup phase of the hydrogen fuel cell system, a startup heating device is used to heat a solid-state hydrogen storage module and a hydrogen fuel cell module to a starting hydrogen release temperature, and the released H2 is used to generate electricity for the hydrogen fuel cell module; the heat generated by the hydrogen fuel cell module is used to heat other solid-state hydrogen storage modules in turn.

[0059] The hydrogen fuel cell module is a proton exchange membrane hydrogen fuel cell, and when the solid-state hydrogen storage module is made of a TiMn-based hydrogen storage alloy material, HHV(H2) is the higher calorific value of hydrogen and is 141.8 MJ / kg, and LHV(H2) is the lower calorific value of hydrogen and is 120.7 MJ / kg.

[0060] The metal solid-state hydrogen storage thermal management system, hydrogen fuel cell system, and rail transit vehicle provided by the present invention have the following characteristics:

[0061] (1) The heat generation rate of the hydrogen fuel cell power generation (the heat generated by consuming 1 kg of H2) is greater than the heat absorption rate of the solid-state hydrogen storage module for hydrogen release (the heat absorbed by releasing 1 kg of H2), and the waste heat of the hydrogen fuel cell power generation is sufficient to maintain the hydrogen release of the solid-state hydrogen storage module;

[0062] (2) Diverting the coolant from the hydrogen fuel cell module into the solid-state hydrogen storage module, and utilizing the waste heat from the hydrogen fuel cell to provide the solid-state hydrogen storage module with the heat required for hydrogen release;

[0063] (3) The hydrogen storage material—the dehydrogenation temperature of the TiMn-based hydrogen storage alloy—matches the outlet temperature range of the hydrogen fuel cell coolant;

[0064] (4) Use hydrogen fuel cell systems to generate electricity and provide the electricity required for the operation of rail transit vehicles.

[0065] Compared with the prior art, the present invention has the following beneficial effects:

[0066] (1) The present invention uses the heat generated by hydrogen fuel cells to start the solid-state hydrogen storage modules in sequence, which is beneficial to improving the startup speed of the system;

[0067] (2) The coolants of the hydrogen fuel cell module, solid-state hydrogen storage module, and thermal management module of the present invention are directly connected to each other, which simplifies the system structure;

[0068] (3) The TiMn-based hydrogen storage alloy used in the present invention has a high volume hydrogen storage density, which is beneficial for increasing the hydrogen storage capacity of rail transit vehicles, especially high-power locomotives;

[0069] (4) The present invention utilizes the waste heat from hydrogen fuel cell power generation to supply heat to the solid-state hydrogen storage module, without consuming additional electricity. This reduces the heat dissipation power and power consumption of the radiator, improves the efficiency of the hydrogen fuel cell system, and helps reduce the volume and weight of the radiator. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] FIG1 is a simplified structural diagram of a solid-state hydrogen storage thermal management system and a hydrogen fuel cell system thereof according to the present invention.

[0071] FIG2 is a schematic structural diagram of a solid-state hydrogen storage module according to the present invention.

[0072] FIG3 is a diagram of a thermal management system for solid-state hydrogen storage and its low-temperature startup control logic for a hydrogen fuel cell system according to the present invention.

[0073] FIG4 is a simplified structural diagram of a solid-state hydrogen storage thermal management system and its hydrogen fuel cell system and rail transit vehicle according to the present invention.

[0074] FIG5 is a simplified structural diagram of a solid-state hydrogen storage thermal management system and a hydrogen fuel cell system thereof according to the present invention. DETAILED DESCRIPTION

[0075] In order to more clearly illustrate the technical solution and implementation method of the present invention, the implementation method of the technical solution of the present invention is described below with reference to the accompanying drawings.

[0076] Figures 1 and 5 show the structural diagrams of the solid-state hydrogen storage thermal management system and its hydrogen fuel cell system according to the present invention. A hydrogen fuel cell system includes a hydrogen fuel cell module 1 and a solid-state hydrogen storage module 2 connected by a hydrogen pipeline 5. A first branch 3 is provided on the periphery of the hydrogen fuel cell module 1, and a diverter valve 4 is provided at the liquid outlet end of the first branch 3. The diverter valve 4 has a first outlet and a second outlet, wherein the first outlet of the diverter valve 4 is connected to the heat dissipation system, and the second outlet of the diverter valve 4 is connected to the second branch 6. A heater 7 is provided on the second branch 6. The number of the solid-state hydrogen storage modules 2 is two or more, and the solid-state hydrogen storage modules 2 include a first solid-state hydrogen storage module 21, a second solid-state hydrogen storage module 22, a third solid-state hydrogen storage module 23, and an nth solid-state hydrogen storage module 2n.

[0077] The second branch 6 is provided through multiple branch pipes on the periphery of the first solid-state hydrogen storage module 21, the second solid-state hydrogen storage module 22, the third solid-state hydrogen storage module 23, and the nth solid-state hydrogen storage module 2n. The liquid inlets of the branch pipes are each provided with a coolant shut-off valve 11. The liquid outlet of the second branch 6 is connected to the first branch 3. The liquid outlet of the heat dissipation system is connected to the liquid inlet of the first branch 3. The first branch 3 and the second branch 6 are filled with coolant. The heat dissipation system includes a radiator 8, a pipeline 9 arranged around the radiator 8, and a heat dissipation fan 10 installed on the outside of the radiator 8. A coolant circulation pump 19 is installed on the first branch 3. The hydrogen pipeline 5 is connected to the multiple solid-state hydrogen storage modules 2 through multiple hydrogen branch pipes, and the multiple hydrogen branch pipes are provided with a hydrogen shut-off valve 14.

[0078] The hydrogen fuel cell module 1 has a coolant inlet and a coolant outlet. The coolant inlet is connected to the liquid outlet of the heat dissipation system, and the coolant outlet is connected to the liquid outlet of the first branch 3. The coolant circulation pump 19 is disposed between the coolant inlet and the liquid outlet of the heat dissipation system. The liquid outlet of the second branch 6 is connected to the first branch 3 located between the liquid outlet of the heat dissipation system 5 and the coolant circulation pump 19. The liquid inlet of each coolant shut-off valve 11 is connected in parallel to the liquid inlet section 601 of the second branch 6. The heater 7 is located on the first branch 3 between the second outlet of the diverter valve and the coolant shut-off valve 11.

[0079] The solid-state hydrogen storage module has a coolant inlet A and a coolant outlet A. The outlet of each branch pipe is connected to the corresponding coolant inlet A, and each coolant outlet A is connected in parallel to the liquid outlet section 602 of the second branch 6.

[0080] The hydrogen fuel cell module is a proton exchange membrane fuel cell (PEMFC), which generates electricity through the electrochemical reaction between H2 and O2, with a power generation efficiency of approximately 40% to 60%, that is, 13.4 to 20.2 kWh / kg H2. The remaining energy is converted into heat energy, generating a heat output of approximately 48.4 to 72.6 MJ / kg H2. The hydrogen fuel cell module is cooled by a coolant, and the coolant outlet temperature range is 60 to 80°C.

[0081] The hydrogen fuel cell module adopts liquid cooling for heat dissipation, with the coolant inlet temperature not lower than 60°C and the coolant outlet temperature generally not higher than 80°C.

[0082] The solid-state hydrogen storage module is made of a TiMn-based hydrogen storage alloy material, and adsorbs and stores H2 through the reaction between the hydrogen storage alloy and H2; the hydrogen desorption process, that is, the hydrogen supply process to the hydrogen fuel cell, is an endothermic reaction; the stable hydrogen desorption temperature is above approximately 60°C, and the solid-state hydrogen storage module must be continuously heated to maintain the hydrogen desorption process, with a heating amount of not less than 12MJ / kg H2.

[0083] The coolant is driven by the coolant circulation pump 19, flows into the interior of the hydrogen fuel cell module, takes away the heat generated by the hydrogen fuel cell module, and then flows out, and is divided into a first branch and a second branch through a diverter valve.

[0084] The first branch is the fuel cell radiator branch, which includes a radiator and a cooling fan, and dissipates heat for the hydrogen fuel cell through forced air cooling. When the hydrogen fuel cell system is working stably, the heat dissipation of the first branch accounts for about 80% of the total heat generated by the hydrogen fuel cell.

[0085] The radiator may be a tube-fin radiator or a plate-fin radiator.

[0086] The heat dissipation fan can be an axial flow fan or a centrifugal fan.

[0087] The second branch provides heat for the solid-state hydrogen storage module, including a heater and a coolant shut-off valve, and uses the heat of the hydrogen fuel cell coolant to heat the solid-state hydrogen storage module to maintain the temperature of the solid-state hydrogen storage module; when the hydrogen fuel cell system is operating stably, the heat utilized by the second branch accounts for approximately 20% of the total heat generated by the hydrogen fuel cell.

[0088] Figure 2 shows a schematic structural diagram of the solid-state hydrogen storage module of the present invention, which includes a metal solid-state hydrogen storage tube 12, a tube fixing frame 13, an end plate 14, a hydrogen bus 15, a hydrogen shut-off valve 16, a thermal management medium outlet 17, a thermal management medium flow channel 18, and a side plate (not shown in the figure).

[0089] The metal solid-state hydrogen storage tubes 12 are long cylindrical tubes containing TiMn series hydrogen storage alloy material. The tail end of the tubes is a closed structure, and the head end is an interface for hydrogen inflow and outflow.

[0090] The solid-state hydrogen storage module comprises a plurality of metal solid-state hydrogen storage tubes 12 , which are stacked in parallel and fixed by tube fixing frames, with a spacing between adjacent frames being 200 to 500 mm.

[0091] The end plates 14 are located at both ends of the metal solid hydrogen storage tubes 12 , and the hydrogen inlet and outlet interfaces protrude from the surfaces of the side end plates 14 . The end plates 14 and the metal solid hydrogen storage tubes 12 are sealed and connected with sealing rings.

[0092] The side plates are located on the upper, lower, left and right sides of the solid-state hydrogen storage module. The side plates and the side plates and the end plates 14 are welded together. The side plates and the end plates 14 form a sealed space surrounding the metal solid-state hydrogen storage tubes 12.

[0093] The hydrogen bus 15 is connected to the hydrogen inlet and outlet interfaces at the ends of the metal solid-state hydrogen storage tubes, and all the inlet and outlet interfaces are combined into one interface.

[0094] The hydrogen shut-off valve 16 is located at the end of the hydrogen busbar.

[0095] The heat management medium outlet 17 is installed on the surface of the end plate at the tail end of the metal solid hydrogen storage tube array, and the heat management medium inlet is installed on the surface of the end plate at the head end of the metal solid hydrogen storage tube array.

[0096] The thermal management medium is deionized water or a low ion conductivity ethylene glycol solution with a conductivity of ≤5 μS / cm.

[0097] The heat management medium flows in from the heat management medium inlet, flows through the gaps between the metal solid hydrogen storage tubes (constituting the heat management medium flow channel), and flows out from the heat management medium outlet, exchanging heat with the metal solid hydrogen storage tubes.

[0098] The hydrogen fuel cell system includes one or more solid-state hydrogen storage modules.

[0099] The hydrogen supplied by the one or more solid-state hydrogen storage modules is converged to provide H2 to the hydrogen fuel cell module through a hydrogen pipeline, and the hydrogen pipeline includes a hydrogen main shut-off valve.

[0100] The flow distribution control method of the first branch and the second branch is:

[0101] When the hydrogen fuel cell system is started and operates normally, the flow ratio between the first branch and the second branch is controlled to be:

[0102] Where f1 is the coolant flow rate of the first branch, f2 is the coolant flow rate of the second branch, both in g / s; ΔG(H2) is the heat released by the hydrogen fuel cell when consuming unit mass of hydrogen to generate electricity, and ΔG(TiMn) is the heat that the solid hydrogen storage material must absorb to release unit mass of hydrogen, both in kJ / g; T 2,in and T 2,out are the temperatures of the coolant inlet (located on the second branch between the second outlet of the diverter valve and the coolant shut-off valve 11) and outlet (located on the liquid outlet section) of the second branch, T 1,in and T 1,out The temperatures of the coolant inlet (located on the first branch between the first outlet of the diverter valve and the liquid inlet of the heat dissipation system) and outlet (located on the first branch between the liquid outlet of the heat dissipation system and the connection point between the liquid outlet of the second branch 6 and the first branch 3) are respectively expressed in °C. ΔG(H2)=HHV(H2)-LHV(H2)·η

[0103] Here, HHV(H2) is the higher heating value of hydrogen, 141.8 MJ / kg; LHV(H2) is the lower heating value of hydrogen, 120.7 MJ / kg; and η is the efficiency of hydrogen fuel cell power generation.

[0104] Wherein, U is the output voltage of the hydrogen fuel cell stack, which is measured by the current sensor at the output end of the hydrogen fuel cell stack; U OCV is the open circuit voltage of the hydrogen fuel cell stack, in V. OCV =1.185×n

[0105] Where n is the number of single cells contained in the hydrogen fuel cell stack.

[0106] The opening of the diverter valve is:

[0107] Where δ is the opening of the diverter valve, and f(sv) is the transfer function of the diverter valve.

[0108] The low-temperature starting heating device is powered by the rail transit vehicle and can be a heating rod, a heating plate or a PTC heating film.

[0109] After flowing through the heater, the coolant is divided into n routes (n is the number of solid-state hydrogen storage modules configured in the system), each route is controlled by one of the coolant shut-off valves, flows into a solid-state hydrogen storage module through the thermal management medium inlet, and flows out of the solid-state hydrogen storage module through the thermal management medium outlet.

[0110] The coolant of the first branch flows through the radiator and then flows through the solid hydrogen storage module with the coolant of the second branch. After mixing, it is driven by the coolant circulation pump and flows into the hydrogen fuel cell module, with the inlet temperature not lower than 60°C.

[0111] FIG3 shows the thermal management system of the solid-state hydrogen storage and the low-temperature startup control logic of the hydrogen fuel cell system thereof according to the present invention.

[0112] When the hydrogen fuel cell system is started at a low temperature, the heater is used to heat one of the solid-state hydrogen storage modules and the hydrogen fuel cell module to a starting hydrogen release temperature, and the released H2 is used to generate electricity for the hydrogen fuel cell module; and the heat generated by the power generation is used to heat the other solid-state hydrogen storage modules in sequence. The specific steps are as follows:

[0113] Open the coolant shut-off valve of the first solid-state hydrogen storage module 21;

[0114] Starting the heater and the coolant circulation pump;

[0115] Detecting the temperature T of the first solid-state hydrogen storage module 21, and when T>T0 (T0 is the hydrogen release starting temperature of the solid-state hydrogen storage module, usually set to 20°C), opening the hydrogen shut-off valve of the first solid-state hydrogen storage module 21 and the hydrogen main shut-off valve;

[0116] starting the hydrogen fuel cell module;

[0117] detecting the temperature T of the hydrogen fuel cell module, and turning off the heater when T>T1 (T1 is the temperature of the hydrogen fuel cell module, usually set to 60° C.);

[0118] Open the coolant shut-off valve and hydrogen shut-off valve of the second solid-state hydrogen storage module 22;

[0119] Detect the temperature T of the second solid-state hydrogen storage module 22. When T>T0 (T0 is the hydrogen release starting temperature of the solid-state hydrogen storage module, usually set to 20°C), open the coolant shut-off valve and hydrogen shut-off valve of the third solid-state hydrogen storage module 23.

[0120] The solid-state hydrogen storage modules are started in sequence according to the above startup procedure until the temperature T of the nth solid-state hydrogen storage module 2n satisfies T>T0, the diverter valve is opened to divert the coolant to the radiator, and then the cooling fan is started. The radiator is controlled by the hydrogen fuel cell heat dissipation cooling system, and the low-temperature startup control procedure ends.

[0121] FIG4 is a simplified structural diagram of the solid-state hydrogen storage thermal management system and its hydrogen fuel cell system and rail transit vehicle according to the present invention.

[0122] The technical feature of the rail transit vehicle is that, as a rail transit vehicle platform 24 , it is equipped with the hydrogen fuel cell system, including a hydrogen fuel cell module 1 , a metal solid-state hydrogen storage module 2 and a heat dissipation system 25 .

[0123] The technical features of the rail transit vehicle also include being equipped with an energy storage power supply 26, which can be one or more of a lithium iron phosphate battery, a lithium titanate battery, a double-layer supercapacitor, and a battery capacitor.

[0124] The hydrogen fuel cell system and the energy storage power supply constitute a hydrogen energy hybrid power system that provides traction power to the rail transit vehicle. The hydrogen fuel cell system consumes fuel (H2) to generate electricity, which is used to power the vehicle's traction and auxiliary loads, and also to supply power to the energy storage power supply. The energy storage power supply stores the electricity generated by the hydrogen fuel cell system, which is used to power the vehicle's traction and auxiliary loads, and absorbs regenerative braking energy from the vehicle.

[0125] The energy storage power supply supplies power to the heater of the thermal management system of the metal solid-state hydrogen storage during the low-temperature startup phase of the hydrogen fuel cell system.

Claims

1. A hydrogen fuel cell system, comprising a hydrogen fuel cell module (1) and a solid hydrogen storage module (2) connected via a hydrogen pipeline (5), characterized in that: The hydrogen fuel cell module (1) is provided with a first branch (3) at its periphery, a diverter valve (4) is provided at a liquid outlet of the first branch (3), the diverter valve (4) having a first outlet and a second outlet, wherein the first outlet of the diverter valve (4) is connected to a heat dissipation system, the second outlet of the diverter valve (4) is connected to a second branch (6), a heater (7) is provided on the second branch (6), the number of the solid-state hydrogen storage modules (2) is two or more, the second branch (6) is respectively provided at the periphery of a plurality of the solid-state hydrogen storage modules (2) through a plurality of branch pipes, the liquid inlets of the branch pipes are provided with a coolant stop valve (11), the liquid outlet of the second branch (6) is connected to the heat dissipation system (5) or the first branch (3), the liquid outlet of the heat dissipation system is connected to the liquid inlet of the first branch (3), and the first branch (3) and the second branch (6) are both filled with coolant.

2. The hydrogen fuel cell system according to claim 1, characterized in that: The heat dissipation system comprises a radiator (8), a pipeline (9) arranged around the radiator (8), and a heat dissipation fan (10) is installed outside the radiator (8).

3. The hydrogen fuel cell system according to claim 1, characterized in that: The hydrogen fuel cell module (1) has a coolant inlet and a coolant outlet, the coolant inlet is connected to the liquid outlet of the heat dissipation system, and the coolant outlet is connected to the liquid outlet of the first branch (3).

4. The hydrogen fuel cell system according to claim 3, characterized in that: A coolant circulation pump (19) is provided between the coolant inlet and the liquid outlet of the heat dissipation system.

5. The hydrogen fuel cell system according to claim 4, characterized in that: The liquid outlet of the second branch (6) is connected to the first branch (3) located between the liquid outlet of the heat dissipation system (5) and the coolant circulation pump (19).

6. The hydrogen fuel cell system according to any one of claims 1 to 5, characterized in that: The liquid inlet of each coolant stop valve (11) is connected to the second branch (6).

7. The hydrogen fuel cell system according to any one of claims 1 to 5, characterized in that: The heater (7) is located between the second outlet of the diverter valve and the coolant stop valve (11).

8. A thermal management method for metal solid hydrogen storage in a hydrogen fuel cell system according to any one of claims 1 to 7, characterized in that The following steps are involved: S1. Open the coolant shut-off valve of the first solid hydrogen storage module, start the heater to heat the coolant, and start circulating the coolant; S2. When the temperature of the first solid-state hydrogen storage module T>T0, start the hydrogen fuel cell module; S3. The temperature T of the hydrogen fuel cell module is greater than T1, the heater is turned off, and the cooling of the second solid-state hydrogen storage module is turned on. Liquid stop valve; S4. When the temperature of the second solid-state hydrogen storage module T>T0, open the coolant shut-off valve of the third solid-state hydrogen storage module; S5. When the temperature T of the n-1th solid-state hydrogen storage module is greater than T0, the coolant shut-off valve of the nth solid-state hydrogen storage module is opened; S6. When the temperatures of all solid-state hydrogen storage modules satisfy T>T0, turn on the heat dissipation system.

9. The thermal management method of metal solid hydrogen storage according to claim 8, characterized in that: After the cooling system is turned on, the flow ratio between the first branch and the second branch is controlled to be: Wherein, f1 is the coolant flow rate of the first branch, f2 is the coolant flow rate of the second branch, both in g / s; ΔG(H2) is the heat released by the hydrogen fuel cell module consuming unit mass of hydrogen to generate electricity, ΔG(M) is the heat that the solid hydrogen storage module must absorb to release unit mass of hydrogen, both in kJ / g; T 2,in and T 2,out are the temperatures of the coolant inlet and outlet of the second branch, T 1,in and T 1,out They are the temperatures of the coolant inlet and outlet of the first branch, both in ℃.

10. The thermal management method of metal solid hydrogen storage according to claim 9, characterized in that: △G(H2)=HHV(H2)-LHV(H2)·η Among them, HHV(H2) is the high heating value of hydrogen; LHV(H2) is the low heating value of hydrogen, and η is the efficiency of hydrogen fuel cell power generation.

11. The thermal management method of metal solid hydrogen storage according to claim 10, characterized in that: Wherein, U is the output voltage of the hydrogen fuel cell stack, which is measured by the current sensor at the output end of the hydrogen fuel cell stack; U OCV It is the open circuit voltage of the hydrogen fuel cell stack, and the unit is V.

12. The thermal management method of metal solid hydrogen storage according to claim 11, characterized in that: IN OCV =1.185×n Wherein, n is the number of single cells contained in the hydrogen fuel cell stack.

13. The thermal management method of metal solid hydrogen storage according to claim 12, characterized in that: The opening of the diverter valve is: Where δ is the opening of the diverter valve, and f(sv) is the transfer function of the diverter valve.

14. The thermal management method of metal solid hydrogen storage according to claim 13, characterized in that: The hydrogen fuel cell module is a proton exchange membrane hydrogen fuel cell, and the metal solid-state hydrogen storage module is a TiMn series hydrogen storage alloy material, with T0 being 15-25°C and T1 being 60-80°C.

15. A rail transit vehicle, characterized in that A hydrogen fuel cell system comprising any one of claims 1-7.

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