Liquid hydrogen storage device for locomotive and hydrogen supply method

Abstract

The invention discloses a liquid hydrogen storage device for a locomotive and a hydrogen supply method. The device comprises a liquid hydrogen storage tank, a liquid hydrogen primary heat exchanger and a liquid hydrogen secondary heat exchanger, a liquid phase and a gas phase of the liquid hydrogen storage tank are respectively connected with a liquid hydrogen storage tank liquid discharge control valve and a liquid hydrogen storage tank BOG (Boil Off Gas) recovery control valve, are combined and are sequentially connected with the liquid hydrogen primary heat exchanger and the liquid hydrogen secondary heat exchanger in series, and a secondary heat exchanger inlet stop valve is also arranged between connecting lines of the liquid hydrogen primary heat exchanger and the liquid hydrogen secondary heat exchanger. According to the scheme, two stages of liquid hydrogen heat exchangers are arranged, environment heat and waste heat are used for gasifying liquid hydrogen, the hydrogen temperature is maintained, the hydrogen pressure is increased through a pump, and the volume energy density of hydrogen is improved. The exhaust denitration device is arranged for the diesel locomotive, so that the safety, the economical efficiency and the environment-friendly characteristic of the diesel locomotive are ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen-powered locomotives, and in particular to a liquid hydrogen storage device for locomotives and a hydrogen supply method. Background Art

[0002] Hydrogen energy has the triple characteristics of "efficient and clean secondary energy, flexible and intelligent energy carrier, and green and low-carbon industrial raw material". It has gradually built diversified application scenarios in the fields of transportation, energy storage, power generation, industry, etc., and is considered to be a technical means to achieve carbon neutrality. Under the background of the country's "dual carbon", the clean and low-carbon transformation of old diesel-powered internal combustion locomotives is imminent. Hydrogen locomotives are free from the constraints of overhead line operating conditions and are very suitable for existing non-electrified line sections, avoiding the huge infrastructure investment and maintenance costs brought about by electrification transformation.

[0003] The hydrogen storage routes for hydrogen locomotives include 35MPa (density 25kg / m3) and 70MPa density 41kg / m3) high-pressure hydrogen cylinder groups, and liquid hydrogen (standard density 70kg / m3) gasification supply solutions. Taking into account the residual pressure of the hydrogen storage bottle and the endurance requirements to avoid the locomotive breaking down, the lower limit pressure of the high-pressure hydrogen bottle should usually be controlled at around 5MPa (4.3kg / m3). Therefore, the net density of a 35MPa hydrogen bottle is about 20.7kg / m3, and that of a 70MPa is about 36.7kg / m3, both of which are much lower than the density of liquid hydrogen. For locomotive application scenarios, the liquid hydrogen route will be the best choice for hydrogen fuel locomotives. Hydrogen fuel cell locomotives and hydrogen internal combustion engines are two application directions of hydrogen energy in locomotives. They will be a revolutionary breakthrough in the locomotive industry and can ultimately achieve zero emissions for locomotives.

[0004] Chinese invention patent CN116691376A "A method for configuring a hydrogen train": This patent discloses a method for configuring a hydrogen train, including a set of electric traction motors, a fuel cell to provide the power required for traction through the reaction of hydrogen and air, a heat exchange system, an air system to provide air for the fuel cell, a cooling system to cool the fuel cell generator, a set of batteries for storing the electricity generated by the fuel cell generator, an electronic process system, and a tank truck for storing a large amount of liquid hydrogen and a corresponding hydrogen transport device. The evaporation rate of the liquid hydrogen storage tank in this patent is difficult to control and has poor economic efficiency.

[0005] Chinese invention patent CN219790149U "A hydrogen-electric hybrid locomotive": This patent discloses a hydrogen-electric hybrid locomotive, including: a hydrogen storage unit, a hydrogen transmission unit, a heating unit, a waste heat utilization unit, a hydrogen internal combustion engine, a power battery and a traction motor. This patent is for a hybrid locomotive, and the charging and replacement of the power battery is relatively cumbersome. Summary of the invention

[0006] In view of the above technical problems, the present invention provides a liquid hydrogen storage device and a hydrogen supply method for a locomotive.

[0007] The present invention is achieved by adopting the following technical solutions: In a first aspect, a liquid hydrogen storage device for a locomotive includes a liquid hydrogen storage tank, a liquid hydrogen primary heat exchanger, and a liquid hydrogen secondary heat exchanger; the liquid phase and the gas phase of the liquid hydrogen storage tank are respectively connected to a liquid hydrogen storage tank discharge control valve and a liquid hydrogen storage tank BOG recovery control valve and then merged, and the liquid hydrogen primary heat exchanger and the liquid hydrogen secondary heat exchanger are connected in series in sequence, and a secondary heat exchanger inlet shut-off valve is also provided between the connecting lines of the liquid hydrogen primary heat exchanger and the liquid hydrogen secondary heat exchanger.

[0008] Specifically, the outlet end of the liquid hydrogen secondary heat exchanger is sequentially connected to a hydrogen booster pump, a circulation ejector, a hydrogen fuel cell / internal combustion engine, an internal combustion engine exhaust denitration device and an emission control valve and then returns to the liquid hydrogen secondary heat exchanger.

[0009] Specifically, two ends of the liquid hydrogen secondary heat exchanger are connected in parallel with a liquid hydrogen secondary heat exchanger bypass cut-off valve.

[0010] Specifically, the circulation ejector is also connected to a waste heat recovery control valve, and the other end of the waste heat recovery control valve is connected to a connection line between the internal combustion engine exhaust denitration device and the emission control valve.

[0011] Specifically, the liquid hydrogen storage tank adopts a horizontal structure, the inner container of the liquid hydrogen storage tank is made of 316 series liquid hydrogen-specific stainless steel, and the outer container is made of 304 series stainless steel. Both the inner container and the outer container are mirror-polished and are provided with multiple layers of variable-density insulation materials.

[0012] Specifically, the liquid hydrogen primary heat exchanger adopts an air-temperature structure and utilizes the ambient temperature to heat the gasified liquid hydrogen; the liquid hydrogen secondary heat exchanger adopts a coiled tube structure or a plate-fin structure and utilizes the exhaust waste heat of the hydrogen fuel cell / internal combustion engine to heat the hydrogen.

[0013] In another aspect, a method for supplying hydrogen to a liquid hydrogen storage device for a locomotive comprises: Under normal operation, the liquid hydrogen tank discharge is used as the locomotive energy source; When the pressure of the liquid hydrogen storage tank exceeds the set value, the BOG recovery control valve of the liquid hydrogen storage tank is opened, and the liquid hydrogen storage tank discharge control valve is closed. The gas phase of the liquid hydrogen storage tank is used as the energy source of the locomotive, and the gas of the liquid hydrogen storage tank is used to quickly reduce the tank pressure to ensure the safe operation of the liquid hydrogen storage tank; After being heated and gasified by the first and second liquid hydrogen heat exchangers, the hydrogen pressure entering the hydrogen fuel cell / internal combustion engine is increased by a hydrogen booster pump to increase the volume energy density of hydrogen; the waste heat of the hydrogen fuel cell / internal combustion engine is used as the heat source of the second liquid hydrogen heat exchanger.

[0014] Specifically, the liquid hydrogen storage tank has a design pressure of 1.6-2.0 MPa and uses supercooled liquid hydrogen for storage, thereby reducing the tripping frequency of the safety valve of the liquid hydrogen storage system and reducing liquid hydrogen loss.

[0015] The beneficial effects of the present invention are as follows: the present invention uses liquid hydrogen as an energy carrier and has no CO2 emissions. A high-vacuum multi-layer winding liquid hydrogen storage tank with a low evaporation rate is provided, and a BOG recovery control valve is provided to control the pressure of the liquid hydrogen storage tank to be within a safe operating range. A two-stage liquid hydrogen heat exchanger is provided to respectively utilize ambient heat and waste heat to gasify liquid hydrogen and maintain the hydrogen temperature, and a pump is used to increase the hydrogen pressure and improve the volume energy density of hydrogen. An exhaust denitration device is provided for the diesel locomotive to ensure the safety, economy and environmental protection characteristics of the hydrogen diesel locomotive. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0017] Figure 1 This is a structural diagram of a liquid hydrogen storage device for a locomotive in an embodiment of the present invention; Among them, 1-liquid hydrogen storage tank, 2-liquid hydrogen storage tank discharge control valve, 3-liquid hydrogen storage tank BOG recovery control valve, 4-liquid hydrogen primary heat exchanger, 5-secondary heat exchanger inlet shut-off valve, 6-liquid hydrogen secondary heat exchanger, 7-hydrogen booster pump, 8-circulation ejector, 9-hydrogen fuel cell / internal combustion engine, 10-internal combustion engine exhaust denitrification device, 11-waste heat recovery control valve, 12-emission control valve, 13-liquid hydrogen secondary heat exchanger bypass shut-off valve. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0019] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0020] The following is combined with Figure 1, some embodiments of the present invention are described in detail. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0021] The present invention proposes a liquid hydrogen storage device for locomotives and a hydrogen supply method. In this embodiment, a liquid hydrogen storage device for locomotives is as follows: Figure 1 As shown, it includes a liquid hydrogen storage tank 1, a liquid hydrogen primary heat exchanger 4 and a liquid hydrogen secondary heat exchanger 6; the liquid phase and the gas phase of the liquid hydrogen storage tank 1 are respectively connected to the liquid hydrogen storage tank discharge control valve 2 and the liquid hydrogen storage tank BOG recovery control valve 3 and then merged, and the liquid hydrogen primary heat exchanger 4 and the liquid hydrogen secondary heat exchanger 6 are connected in series in sequence, and a secondary heat exchanger inlet cut-off valve 5 is also provided between the connecting lines of the liquid hydrogen primary heat exchanger 4 and the liquid hydrogen secondary heat exchanger 6.

[0022] In this embodiment, the outlet end of the liquid hydrogen secondary heat exchanger 6 is connected in sequence to the hydrogen booster pump 7, the circulation ejector 8, the hydrogen fuel cell / internal combustion engine 9, the internal combustion engine exhaust denitrification device 10 and the emission control valve 12, and then returns to the liquid hydrogen secondary heat exchanger 6.

[0023] In this embodiment, two ends of the liquid hydrogen secondary heat exchanger 6 are connected in parallel with a liquid hydrogen secondary heat exchanger bypass cut-off valve 13 .

[0024] In this embodiment, the circulating ejector 8 is also connected to a waste heat recovery control valve 11 , and the other end of the waste heat recovery control valve 11 is connected to a connection line between the internal combustion engine exhaust denitration device 10 and the emission control valve 12 .

[0025] In this embodiment, the liquid hydrogen storage tank 1 adopts a horizontal structure. The inner container of the liquid hydrogen storage tank 1 is made of 316 series liquid hydrogen-specific stainless steel, and the outer container is made of 304 series stainless steel. The inner container and the outer container are both mirror-polished and are also provided with multiple layers of variable-density insulation materials.

[0026] In this embodiment, the liquid hydrogen primary heat exchanger 4 adopts an air-temperature structure, using the ambient temperature to heat the gasified liquid hydrogen; the liquid hydrogen secondary heat exchanger 6 adopts a coiled tube structure or a plate-fin structure, using the exhaust waste heat of the hydrogen fuel cell / internal combustion engine to heat the hydrogen.

[0027] The present invention also accordingly proposes a method for supplying hydrogen to a liquid hydrogen storage device for a locomotive, comprising: In normal operation, the liquid hydrogen storage tank 1 is drained as the energy source for the locomotive; When the pressure of liquid hydrogen storage tank 1 exceeds the set value, open the liquid hydrogen storage tank BOG recovery control valve 3, close the liquid hydrogen storage tank discharge control valve 2, use the gas phase of liquid hydrogen storage tank 1 as the locomotive energy source, and use the gas of liquid hydrogen storage tank 1 to quickly reduce the tank pressure to ensure the safe operation of the liquid hydrogen storage tank; After being heated and gasified by the liquid hydrogen primary heat exchanger 4 and the liquid hydrogen secondary heat exchanger 6, the pressure of the hydrogen entering the hydrogen fuel cell / internal combustion engine 9 is increased by the hydrogen booster pump 7 to increase the volume energy density of the hydrogen; the waste heat of the hydrogen fuel cell / internal combustion engine 9 is used as the heat source of the secondary liquid hydrogen heat exchanger.

[0028] In this embodiment, the design pressure of the liquid hydrogen storage tank 1 is 1.6-2.0 MPa, and supercooled liquid hydrogen is used for storage, which reduces the tripping frequency of the safety valve of the liquid hydrogen storage system and reduces the loss of liquid hydrogen.

[0029] In another embodiment, a liquid hydrogen storage device for a locomotive includes a liquid hydrogen storage tank 1, a liquid hydrogen storage tank discharge control valve 2, a liquid hydrogen storage tank BOG recovery control valve 3, a liquid hydrogen primary heat exchanger 4, a secondary heat exchanger inlet shut-off valve 5, a liquid hydrogen secondary heat exchanger 6, a hydrogen booster pump 7, a circulation ejector 8, a hydrogen fuel cell / internal combustion engine 9, an internal combustion engine exhaust denitrification device 10, a waste heat recovery control valve 11, an emission control valve 12, and a liquid hydrogen secondary heat exchanger bypass shut-off valve 13.

[0030] The liquid phase and gas phase of the liquid hydrogen storage tank 1 are connected to the liquid hydrogen storage tank discharge control valve 2 and the liquid hydrogen storage tank BOG recovery control valve 3 respectively, and the first and second stage heat exchangers of liquid hydrogen are arranged in series at the control valve outlet. After the two-stage heat exchanger, a hydrogen booster pump 7 is set to increase the hydrogen pressure entering the hydrogen fuel cell / internal combustion engine. When used for a hydrogen internal combustion engine, a denitrification device 10 is set at the outlet of the internal combustion engine. Finally, the waste heat is used to gasify the liquid hydrogen in the second stage heat exchanger and then discharged.

[0031] The locomotive is equipped with a liquid hydrogen storage tank 1 with a high vacuum multi-layer winding structure. Liquid hydrogen is used as the energy supply carrier of the locomotive. It has a high energy density per unit mass and no CO2 emissions. The liquid hydrogen storage tank 1 adopts a horizontal structure to facilitate the layout of the locomotive. The inner container is made of 316 series liquid hydrogen special stainless steel, and the outer container is made of 304 series stainless steel. Multiple layers of variable density insulation materials are set between the inner and outer containers, and high vacuum is drawn to reduce the evaporation rate of liquid hydrogen. The inner and outer containers are mirror polished to reduce the radiation heat transfer of the storage tank and further reduce the evaporation rate of liquid hydrogen.

[0032] The locomotive system is equipped with a liquid hydrogen tank discharge control valve 2 and a liquid hydrogen tank BOG recovery control valve 3. Under normal circumstances, the tank discharge is used as the locomotive energy source. When the liquid hydrogen tank pressure exceeds the set value, the liquid hydrogen tank BOG recovery control valve is opened, the discharge control valve is closed, and the gas phase of the liquid hydrogen tank is used as the locomotive energy source to quickly reduce the tank pressure and ensure the safe operation of the liquid hydrogen tank.

[0033] The locomotive system is equipped with a liquid hydrogen primary heat exchanger 4 and a liquid hydrogen secondary heat exchanger 6 as heat exchange equipment for liquid hydrogen gasification to ensure that the hydrogen temperature meets the use requirements of the hydrogen internal combustion engine. The primary heat exchanger adopts an air temperature structure, using the ambient temperature to heat the gasified liquid hydrogen, to avoid the liquid hydrogen temperature in the secondary heat exchanger being too low to cause water to freeze and affect the normal operation of the equipment. The secondary heat exchanger adopts a coiled tube structure or a plate-fin structure, using the exhaust heat of the hydrogen internal combustion engine to heat the hydrogen without additional energy consumption.

[0034] The locomotive system is equipped with a hydrogen booster pump 7 to increase the pressure of hydrogen to increase the volume energy density of hydrogen. When a hydrogen-powered internal combustion locomotive is used, a denitration device is installed at the exhaust outlet of the internal combustion engine of the system, and a denitration catalyst is installed inside to catalytically oxidize nitrogen oxides produced in the internal combustion engine into nitrogen to ensure the environmental performance of the locomotive. A waste heat recovery control valve and an emission control valve are set to adjust the recycling amount through the combined action of the two control valves.

[0035] A method for supplying hydrogen to a liquid hydrogen storage type hydrogen energy locomotive comprises the following steps: Under normal circumstances, the tank discharge is used as the locomotive energy source. When the liquid hydrogen tank pressure exceeds the set value, the liquid hydrogen tank BOG recovery control valve is opened, the discharge control valve is closed, and the liquid hydrogen tank gas phase is used as the locomotive energy source. The tank gas is used to quickly reduce the tank pressure to ensure the safe operation of the liquid hydrogen tank.

[0036] After the liquid hydrogen or BOG is heated and gasified by the primary and secondary heat exchangers, the hydrogen booster pump increases the pressure of the hydrogen entering the hydrogen internal combustion engine to increase the volume energy density of the hydrogen. The waste heat of the hydrogen fuel cell / internal combustion engine is used as the heat source of the secondary liquid hydrogen heat exchanger.

[0037] Working principle: A liquid hydrogen storage device for locomotives is equipped with a high-vacuum multi-layer wound liquid hydrogen storage tank with mirror-polished inner and outer containers to reduce the evaporation loss of liquid hydrogen. When the tank pressure exceeds the set value, the tank BOG recovery control valve is opened to ensure that the liquid hydrogen storage tank operates within a safe pressure range. A liquid hydrogen primary heater and a secondary heater are configured to heat and vaporize the liquid hydrogen using ambient heat and waste heat, respectively, to ensure that the hydrogen meets the operating temperature requirements. A hydrogen booster pump is configured to increase the hydrogen pressure and hydrogen volume energy density to improve work efficiency. A hydrogen internal combustion engine exhaust denitrification device is configured to reduce the concentration of nitrogen oxides in the exhaust of the internal combustion engine by combining exhaust circulation with catalytic denitrification to ensure that the locomotive meets environmental protection requirements.

[0038] For the aforementioned embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the order of the actions described, because according to the present application, some steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are preferred embodiments, and the actions involved are not necessarily required by the present application.

[0039] The above embodiments describe the basic principles and main features of the present invention and the advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the changes and modifications made by those skilled in the art shall be within the scope of protection of the appended claims of the present invention without departing from the spirit and scope of the present invention.

Claims

1. A liquid hydrogen storage device for locomotive, characterized in that: The invention comprises a liquid hydrogen storage tank (1), a liquid hydrogen primary heat exchanger (4) and a liquid hydrogen secondary heat exchanger (6); the liquid phase and the gas phase of the liquid hydrogen storage tank (1) are respectively connected to a liquid hydrogen storage tank discharge control valve (2) and a liquid hydrogen storage tank BOG recovery control valve (3) and then merged, and the liquid hydrogen primary heat exchanger (4) and the liquid hydrogen secondary heat exchanger (6) are sequentially connected in series, and a secondary heat exchanger inlet cut-off valve (5) is also provided between the connection line of the liquid hydrogen primary heat exchanger (4) and the liquid hydrogen secondary heat exchanger (6).

2. A liquid hydrogen storage device for locomotives as claimed in claim 1, characterized in that: The outlet end of the liquid hydrogen secondary heat exchanger (6) is sequentially connected to a hydrogen booster pump (7), a circulation ejector (8), a hydrogen fuel cell / internal combustion engine (9), an internal combustion engine exhaust denitration device (10) and an emission control valve (12) and then returns to the liquid hydrogen secondary heat exchanger (6).

3. A liquid hydrogen storage device for locomotives as claimed in claim 2, characterized in that: The two ends of the liquid hydrogen secondary heat exchanger (6) are connected in parallel with a liquid hydrogen secondary heat exchanger bypass cut-off valve (13).

4. A locomotive liquid hydrogen storage device as claimed in claim 3, characterized in that: The circulating ejector (8) is also connected to a waste heat recovery control valve (11), and the other end of the waste heat recovery control valve (11) is connected to a connection line between an internal combustion engine exhaust denitration device (10) and an emission control valve (12).

5. The locomotive liquid hydrogen storage device according to claim 1, characterized in that: The liquid hydrogen storage tank (1) adopts a horizontal structure. The inner container of the liquid hydrogen storage tank (1) is made of 316 series liquid hydrogen special stainless steel, and the outer container is made of 304 series stainless steel. The inner container and the outer container are both mirror-polished and are also provided with multiple layers of variable density thermal insulation material.

6. A locomotive liquid hydrogen storage device as claimed in claim 4, characterized in that: The liquid hydrogen primary heat exchanger (4) adopts an air temperature structure and utilizes the ambient temperature to heat and gasify the liquid hydrogen; the liquid hydrogen secondary heat exchanger (6) adopts a coiled tube structure or a plate-fin structure and utilizes the exhaust waste heat of the hydrogen fuel cell / internal combustion engine to heat the hydrogen.

7. A method for supplying hydrogen to a liquid hydrogen storage device for a locomotive, implemented based on a liquid hydrogen storage device for a locomotive according to any one of claims 1 to 6, characterized in that: include: In normal operation, the liquid hydrogen storage tank (1) is drained as the energy source for the locomotive; When the pressure of the liquid hydrogen storage tank (1) exceeds the set value, the BOG recovery control valve (3) of the liquid hydrogen storage tank is opened, and the liquid hydrogen storage tank discharge control valve (2) is closed, and the gas phase of the liquid hydrogen storage tank (1) is used as the energy source of the locomotive, and the gas in the liquid hydrogen storage tank (1) is used to quickly reduce the tank pressure to ensure the safe operation of the liquid hydrogen storage tank; After being heated and gasified by the first liquid hydrogen heat exchanger (4) and the second liquid hydrogen heat exchanger (6), the pressure of the hydrogen entering the hydrogen fuel cell / internal combustion engine (9) is increased by a hydrogen booster pump (7) to increase the volume energy density of the hydrogen; the waste heat of the hydrogen fuel cell / internal combustion engine (9) is used as a heat source for the second liquid hydrogen heat exchanger.

8. A method for supplying hydrogen to a liquid hydrogen storage device for a locomotive as claimed in claim 7, characterized in that: The liquid hydrogen storage tank (1) has a design pressure of 1.6-2.0 MPa and uses supercooled liquid hydrogen for storage, thereby reducing the tripping frequency of the safety valve of the liquid hydrogen storage system and reducing the loss of liquid hydrogen.

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