Hydrogen engine vehicle

Abstract

The present disclosure provides a hydrogen engine vehicle that achieves an improvement in fuel consumption of the hydrogen engine vehicle. A hydrogen engine vehicle (100) is provided with: a hydrogen engine (10); a hydrogen tank (41) for storing liquid hydrogen; a vaporizer (30) that generates hydrogen gas to be supplied to the hydrogen engine (10) by vaporizing the liquid hydrogen gas by the exhaust heat of the hydrogen engine (10); and an evaporation line (60) that is connected to the hydrogen tank (41) and that discharges the boil-off gas vaporized in the hydrogen tank (41) to the outside of the vehicle, the evaporation line (60) being provided with: a second pipe (33) that is disposed in the vaporizer (30) and heats the circulating boil-off gas; and a catalyst (65) that generates water by reacting air with the boil-off gas.

Description

Technical Field

[0001] This disclosure relates to the structure of a hydrogen engine vehicle. Background Technology

[0002] Patent document 1 discloses a hydrogen engine vehicle that pressurizes liquid hydrogen stored in a hydrogen tank by a pump, vaporizes it by a vaporizer, stores the hydrogen in a pressure chamber, and supplies the hydrogen stored in the pressure chamber to the hydrogen engine.

[0003] Patent document 2 discloses a vaporizer having a housing for the flow of a heating medium and a finned tube for the flow of liquid hydrogen, which exchanges heat between the liquid hydrogen and the heating medium to vaporize the liquid hydrogen.

[0004] Patent document 3 discloses a liquid hydrogen storage system having an evaporation line that releases evaporated gas generated inside a hydrogen tank to the outside of the vehicle. A catalyst is disposed on this evaporation line to react the evaporated gas with oxygen in the air to convert it into water.

[0005] Prior art literature

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2024-6546

[0008] Patent Document 2: Japanese Patent Application Publication No. 2024-5617

[0009] Patent Document 3: Japanese Patent Application Publication No. 2024-6562 Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] However, liquid hydrogen is stored in hydrogen tanks at extremely low temperatures, and the evaporated gas is also at extremely low temperatures. On the other hand, the catalyst that reacts the evaporated gas with oxygen in the air to convert it into water is not activated at low temperatures, resulting in incomplete reaction. Therefore, the evaporated gas or air is heated by a heater or the like and then fed to the catalyst to allow the catalyst to react fully. However, when using a heater to heat the evaporated gas or air, there is a problem of decreased fuel consumption.

[0012] Therefore, the purpose of this disclosure is to improve the fuel efficiency of hydrogen engine vehicles.

[0013] Methods for solving problems

[0014] The hydrogen engine vehicle disclosed herein is characterized by comprising: a hydrogen engine; a hydrogen tank for storing liquid hydrogen; a vaporizer for vaporizing the liquid hydrogen by means of the exhaust heat from the hydrogen engine, thereby generating hydrogen gas to be supplied to the hydrogen engine; and an evaporation line connected to the hydrogen tank for releasing the vaporized gas vaporized in the hydrogen tank to the outside of the vehicle, the evaporation line comprising: a heating channel disposed in the vaporizer for heating the flowing vaporized gas; and a catalyst for reacting air with the vaporized gas to generate water.

[0015] This structure utilizes the exhaust heat from the hydrogen engine to heat the evaporating gas, thus improving fuel efficiency compared to existing technologies that use heaters or similar methods to heat the evaporating gas.

[0016] Invention Effects

[0017] This disclosure enables improvements in the fuel efficiency of hydrogen engine vehicles. Attached Figure Description

[0018] Figure 1 This is a system diagram illustrating the structure of a hydrogen engine vehicle according to an embodiment.

[0019] Figure 2 for Figure 1 The diagram shows the control module of the control unit.

[0020] Figure 3 for Figure 1 The side cross-section of the vaporizer is shown.

[0021] Figure 4 This is a cross-sectional view of the vaporizer, and it is... Figure 3 The AA section is shown. Detailed Implementation

[0022] The structure of the hydrogen engine vehicle 100 according to the embodiment will be described below with reference to the accompanying drawings. Figure 1 As shown, the hydrogen engine vehicle 100 includes a hydrogen engine 10, a cooling water flow channel 15, a heat transfer medium flow channel 20, a carburetor 30, a radiator 50, a hydrogen flow channel 40, an evaporation line 60, and a control unit 80. Additionally, in each figure, LH2 represents liquid hydrogen, and H2 represents hydrogen gas.

[0023] The hydrogen engine 10 has an air intake port 11 for drawing in external gas, a hydrogen nozzle 12 for supplying hydrogen, and an exhaust port 13 for discharging exhaust gas produced by hydrogen combustion. The hydrogen engine 10 also has an internal cooling channel 14 for cooling water to flow through.

[0024] The cooling water flow channel 15 is connected to the internal cooling flow channel 14 and is a channel for the flow of cooling water to cool the hydrogen engine 10. A radiator 50 is connected to the cooling water flow channel 15, and the radiator 50 releases the heat from the cooling water that has increased in temperature while flowing through the internal cooling flow channel 14 of the hydrogen engine 10 to the outside. The cooling water flow channel 15 consists of a cooling water pump 19, a cooling water supply pipe 16, the internal cooling flow channel 14, a cooling water outlet pipe 17, a radiator cooling water flow channel 51, and a cooling water return pipe 18. The cooling water supply pipe 16 connects to the outlet of the cooling water pump 19 and the inlet of the internal cooling flow channel 14 of the hydrogen engine 10. The cooling water outlet pipe 17 connects to the outlet of the internal cooling flow channel 14 and the inlet of the radiator cooling water flow channel 51. The cooling water return pipe 18 connects to the outlet of the radiator cooling water flow channel 51 and the inlet of the cooling water pump 19.

[0025] In the vaporizer 30, a heat medium heated by the exhaust heat of the hydrogen engine 10 flows with extremely low-temperature liquid hydrogen, causing the liquid hydrogen to vaporize through the heat medium, thereby forming hydrogen gas. Furthermore, the vaporizer 30 heats the vaporized gas inside the hydrogen tank 41 through the heat medium. The vaporizer 30 consists of a housing 31, a first pipe 32 installed inside the housing 31, and a second pipe 33. The housing 31 has a heat medium inlet 31a for the heat medium to flow into and a heat medium outlet 31b for the heat medium to flow out. The first pipe 32 is a pipe member formed by shaping a thin tube into a spiral shape. Liquid hydrogen flows into the first pipe 32 through the first pipe inlet 32a and hydrogen gas flows out through the first pipe outlet 32b. Inside the first pipe 32, liquid hydrogen and hydrogen gas flow together and exchange heat with the heat medium flowing on the outer surface. The second pipe 33 is a pipe member formed by shaping a thin tube into a spiral shape. The second pipe 33 allows low-temperature evaporating gas to flow into it through the inlet 33a and exits it through the outlet 33b. The second pipe 33 forms a heating channel for heating the evaporating gas by facilitating heat exchange between the evaporating gas flowing inside and the hot medium flowing on its outer surface. Further details regarding the structure of the vaporizer 30 will be provided later. Figure 3 and Figure 4 Please provide an explanation.

[0026] The heat medium flow channel 20 is a flow channel for the circulation of liquid heat medium. The heat medium flow channel 20 consists of a heat medium pump 25, a heat medium supply pipe 21, a radiator heat medium flow channel 52, a heat medium outlet pipe 22, a vaporizer housing 31, a heat medium return pipe 23, a bypass pipe 26, a radiator shut-off valve 27, and a bypass valve 28. The bypass pipe 26 constitutes a bypass flow channel.

[0027] The heat exchanger channel 52 is disposed inside the radiator 50, and heats the low-temperature heat exchanger by exchanging heat with the high-temperature cooling water flowing in the radiator cooling water channel 51. Thus, the radiator 50 is a heat exchanger configured to span the cooling water channel 15 and the heat exchanger channel 20, allowing the cooling water and heat exchanger to flow and heating the heat exchanger through the cooling water.

[0028] A heat medium supply pipe 21 connects to the outlet of the heat medium pump 25 and the inlet of the heat medium flow channel 52 of the radiator. A heat medium temperature sensor 74 is installed on the heat medium supply pipe 21 to detect the heat medium temperature T2 at the outlet of the heat medium pump 25. A heat medium outlet pipe 22 connects to the outlet of the heat medium flow channel 52 of the radiator and the heat medium inlet 31a of the housing 31 of the vaporizer 30. A heat medium return pipe 23 connects to the heat medium outlet 31b of the housing 31 of the vaporizer 30 and the inlet of the heat medium pump 25.

[0029] A bypass pipe 26 connects the heat medium supply pipe 21 and the heat medium outlet pipe 22 in a manner that bypasses the radiator heat medium flow channel 52. A bypass valve 28 is installed on the bypass pipe 26. A radiator shut-off valve 27 is installed at the outlet of the radiator heat medium flow channel 52, between the junction of the heat medium outlet pipe 22 and the bypass pipe 26. The bypass valve 28 and the radiator shut-off valve 27 can be electromagnetic shut-off valves.

[0030] The hydrogen flow channel 40 consists of a hydrogen tank 41, a liquid hydrogen pump 42, a liquid hydrogen supply pipe 43, a first pipe 32 of the vaporizer 30, a hydrogen outlet pipe 44, a chamber 45, a hydrogen supply pipe 46, and a pressure reducing valve 47.

[0031] Hydrogen tank 41 is a tank for storing liquid hydrogen at extremely low temperatures. A liquid hydrogen supply pipe 43 connects hydrogen tank 41 and the first pipe inlet 32a. A liquid hydrogen pump 42 for pressurizing liquid hydrogen is installed on the liquid hydrogen supply pipe 43. A hydrogen outlet pipe 44 connects the first pipe outlet 32b of the vaporizer 30 and the chamber 45. A hydrogen temperature sensor 71 for detecting the hydrogen temperature T1 at the outlet of the vaporizer 30 is installed on the hydrogen outlet pipe 44. The chamber 45 stores high-pressure hydrogen. A hydrogen supply pipe 46 connects chamber 45 and the hydrogen nozzle 12 of the hydrogen engine 10. A pressure reducing valve 47 for reducing hydrogen pressure is installed on the hydrogen supply pipe 46. Furthermore, a pressure sensor 72 and a flow sensor 73 are installed on the hydrogen supply pipe 46.

[0032] Evaporation line 60 is a flow path for releasing the vaporized gas inside the hydrogen tank 41 to the outside of the hydrogen engine vehicle 100. Evaporation line 60 consists of an evaporation gas port connection pipe 61, a second pipe 33 of the vaporizer 30, a reactor connection pipe 62, a reactor 63, and an atmospheric vent pipe 64. The second pipe 33 of the vaporizer 30 is disposed within the vaporizer 30 and forms a heating flow path for heating the evaporation gas by exchanging heat between the evaporation gas flowing inside and the heat medium flowing on the outer surface. The evaporation gas port connection pipe 61 connects to the evaporation gas port 41A and the second pipe inlet 33a of the hydrogen tank 41. The reactor connection pipe 62 connects to the second pipe outlet 33b and the inlet of the reactor 63. An evaporation gas temperature sensor 75 is installed on the reactor connection pipe 62 to detect the temperature of the evaporation gas heated by the vaporizer 30. The atmospheric vent pipe 64 releases the evaporation gas that has passed through the reactor 63 to the atmosphere. The reactor 63 introduces evaporating gas and air into its interior and contains a catalyst 65 that allows the evaporating gas to react with oxygen in the air to produce water.

[0033] The control unit 80 is a computer internally equipped with a CPU 81 for information processing and a memory 82 for storing control programs and control data. Data detected by the hydrogen temperature sensor 71, the thermal medium temperature sensor 74, the evaporating gas temperature sensor 75, the pressure sensor 72, and the flow sensor 73 are input into the control unit 80. Based on the flow data detected by the flow sensor 73, the control unit 80 adjusts the operation of the liquid hydrogen pump 42. Furthermore, based on the pressure data detected by the pressure sensor 72, the control unit adjusts the operation of the pressure reducing valve 47.

[0034] Furthermore, the control unit 80 adjusts the operation of the heat transfer pump 25 based on the hydrogen temperature T1 detected by the hydrogen temperature sensor 71 and the evaporating gas temperature T3 detected by the evaporating gas temperature sensor 75. Details of this operation will be provided later. Figure 2 Please provide an explanation.

[0035] Furthermore, the control unit 80 adjusts the operation of the radiator shut-off valve 27 and the bypass valve 28 based on the heat medium temperature T2 detected by the heat medium temperature sensor 74. For example, if the heat medium temperature T2 detected by the heat medium temperature sensor 74 exceeds a predetermined temperature, the control unit 80 closes the radiator shut-off valve 27 and opens the bypass valve 28, thereby preventing the heat medium from flowing into the radiator heat medium flow channel 52 and lowering the temperature of the heat medium. Conversely, if the heat medium temperature T2 detected by the heat medium temperature sensor 74 is lower than the predetermined temperature, the control unit 80 opens the radiator shut-off valve 27 and closes the bypass valve 28, allowing the heat medium to flow into the radiator heat medium flow channel 52 and raising the temperature of the heat medium. In this way, the control unit 80 adjusts the heat medium temperature T2 to a predetermined range by adjusting the flow rate of the bypass pipe 26.

[0036] In addition, the hydrogen engine 10 and the cooling water pump 19 are controlled by an engine control unit (not shown).

[0037] Next, refer to Figure 2 The control of the heat medium pump 25 in the control unit 80 will be explained. For example... Figure 2 As shown, the control unit 80 includes three control modules: a temperature feedback control unit 85, a temperature correction value calculation unit 86, and an adder 87. The operation of each control module can be realized by the CPU 81 executing the control program stored in the memory 82.

[0038] The temperature feedback control unit 85 implements feedback control to make the hydrogen temperature T1 (actual temperature of hydrogen) input from the hydrogen temperature sensor 71 the target temperature, and adjusts the duty cycle of the heat transfer pump 25. The temperature correction value calculation unit 86 calculates a temperature correction value to correct the hydrogen control target temperature, i.e., the first target temperature, based on the difference between the evaporating gas temperature T3 (actual temperature of the evaporating gas) detected by the evaporating gas temperature sensor 75 and the control target temperature of the evaporating gas, i.e., the second target temperature. The adder 87 adds the temperature correction value to the first target temperature to calculate the target temperature input to the temperature feedback control unit 85.

[0039] The flow rate of the vaporized gas flowing through the vaporizer 30 is negligible compared to the flow rate of the hydrogen flowing through the vaporizer 30. Therefore, normally, as long as the heat transfer pump 25 performs feedback control such that the hydrogen temperature T1 is within a predetermined temperature range, the vaporized gas temperature T3 will also be within a predetermined temperature range. However, depending on the situation, the difference between the vaporized gas temperature T3 and the second target temperature may become larger. In such cases, the temperature correction value calculation unit 86 calculates a temperature correction value based on this difference and corrects the first target temperature. As a result, the vaporized gas temperature T3 can be set to the temperature at which the catalyst 65 can react sufficiently. Furthermore, since the heating of this vaporized gas utilizes the exhaust heat of the hydrogen engine 10, the fuel consumption rate can be improved compared to the case where the vaporized gas is heated by a heater or the like in the prior art.

[0040] Next, refer to Figure 3 , Figure 4 The detailed structure of the vaporizer 30 will be explained below. For example... Figure 3 As shown, the vaporizer 30 includes a housing 31, a first tube 32, a second tube 33, a hollow slender member 34, an outer tube support 35, a middle tube support 36, an inner tube support 37, and a bracket 38.

[0041] The housing 31 is a slender, bag-shaped component with a diameter of D1, and has a heat medium inlet 31a and a heat medium outlet 31b at both ends. For example... Figure 4 As shown, an outer tube support 35 composed of multiple round bars is provided on the inner surface of the housing 31.

[0042] The first tube 32 is composed of a first inner tube 32i and a first outer tube 32j. The first inner tube 32i is a tube with a diameter of d1 wound into a spiral shape with a first outer winding inner diameter of E1 and a first outer winding outer diameter of E2. The first outer tube 32j is a tube with a diameter of d1 wound into a spiral shape with a first outer winding outer diameter of F2 and a first outer winding inner diameter of F1. The first inner tube 32i is nested inside the first outer winding inner diameter F1 of the first outer tube 32j. One end of the first inner tube 32i is connected to one end of the first outer tube 32j, and the first inner tube 32i and the first outer tube 32j constitute a first tube 32. The other end of the first inner tube 32i constitutes a first tube inlet 32a for liquid hydrogen to flow in. In addition, the other end of the first outer tube 32j constitutes a first tube outlet 32b for vaporized hydrogen to flow out.

[0043] A hollow, slender member 34 is coaxially arranged with the housing 31 via a cylindrical slender member with an outer diameter of D2. Both ends of the hollow, slender member 34 are connected to both ends of the housing 31. An evaporation gas inlet 34a for the inflow of evaporating gas is provided at one end of the hollow, slender member 34. Figure 4As shown, an inner tube support 37 composed of multiple round bars is provided on the outer surface of the hollow slender member 34.

[0044] The second tube 33 is a tube with a diameter of d2 wound into a spiral shape with a second inner diameter of G1 and a second outer diameter of G2. One end of the second tube 33 is connected to a hollow elongated member 34. The other end of the second tube 33 forms a second tube outlet 33b for the heated evaporating gas to flow out.

[0045] The second inner diameter G1 of the second tube 33 is larger than the outer diameter D2 of the hollow elongated member 34. The inner surface of the second tube 33 is supported by the outer diameter surface of the inner tube support 37 provided on the outer surface of the hollow elongated member 34. Therefore, the hollow elongated member 34 is disposed inside the second inner diameter G1 of the second tube 33.

[0046] Furthermore, multiple brackets 38 extending radially from the hollow elongated member 34 are provided at both ends of the hollow elongated member 34. Between each bracket 38, a central tube support 36, composed of round bars extending in the longitudinal direction, is installed. The wound inner surface of the first inner tube 32i is supported by the outer diameter surface of the central tube support 36. Furthermore, the wound outer surface of the first outer tube 32j is supported by the inner diameter surface of the outer tube support 35 provided on the housing 31. Thus, the first tube 32 and the second tube 33 are arranged in a nested configuration.

[0047] Liquid hydrogen flows in from the first inlet 32a of the first inner tube 32i, and vaporized hydrogen flows out from the first outlet 32b of the first outer tube 32j. Furthermore, evaporated gas flows into the interior of the hollow elongated member 34 from the evaporated gas inlet 34a, and flows from one end of the hollow elongated member 34 into one end of the second tube 33. It then flows out from the second outlet 33b at the other end of the second tube 33. Therefore, the evaporated gas inlet 34a of the hollow elongated member 34 constitutes the second tube inlet 33a. A heat medium flows in from the heat medium inlet 31a of the housing 31 and flows in an annular channel of width W between the inner surface of the housing 31 and the outer surface of the hollow elongated member 34. It then exchanges heat with the liquid hydrogen or hydrogen flowing in the first tube 32 in this annular channel, and with the evaporated gas flowing in the second tube 33, and flows out from the heat medium outlet 31b.

[0048] As explained above, since the vaporizer 30 has the first tube 32 and the second tube 33 nested inside the housing 31, it is possible to perform the vaporization of liquid hydrogen and the heating of the evaporated gas through a compact structure.

[0049] Furthermore, since the heat medium flows in an annular channel of width W between the inner surface of the housing 31 and the outer surface of the hollow elongated member 34, it can become a vaporizer 30 that accelerates the flow rate of the heat medium and has high heat exchange efficiency.

[0050] Symbol Explanation

[0051] 10…Hydrogen engine; 11…Intake port; 12…Hydrogen nozzle; 13…Exhaust port; 14…Internal cooling channel; 15…Cooling water channel; 16…Cooling water supply pipe; 17…Cooling water outlet pipe; 18…Cooling water return pipe; 19…Cooling water pump; 20…Heat medium channel; 21…Heat medium supply pipe; 22…Heat medium outlet pipe; 23…Heat medium return pipe; 25…Heat medium pump; 26…Bypass pipe; 27…Radiator 28…Bypass valve; 30…Vaporizer; 31…Casing; 31a…Heat medium inlet; 31b…Heat medium outlet; 32…First pipe; 32a…First pipe inlet; 32b…First pipe outlet; 32i…First inner pipe; 32j…First outer pipe; 33…Second pipe; 33a…Second pipe inlet; 33b…Second pipe outlet; 34…Hollow slender member; 34a…Evaporated gas inlet; 35…Outer pipe support; 3 6…Intermediate tube support; 37…Inner tube support; 38…Bracket; 40…Hydrogen flow channel; 41…Hydrogen tank; 41A…Evaporation gas port; 42…Liquid hydrogen pump; 43…Liquid hydrogen supply pipe; 44…Hydrogen outlet pipe; 45…Cavity; 46…Hydrogen supply pipe; 47…Pressure reducing valve; 50…Radiator; 51…Radiator cooling water flow channel; 52…Radiator heat medium flow channel; 60…Evaporation circuit; 61…Evaporation gas port connection pipe; 62…Reactor connection pipe; 63…Reactor; 64…Atmospheric vent pipe; 65…Catalyst; 71…Hydrogen temperature sensor; 72…Pressure sensor; 73…Flow sensor; 74…Heat medium temperature sensor; 75…Evaporation gas temperature sensor; 80…Control unit; 81…CPU; 82…Memory; 85…Temperature feedback control unit; 86…Temperature correction value calculation unit; 87…Adder; 100…Hydrogen engine vehicle.

Claims

1. A hydrogen engine vehicle, characterized in that, have: Hydrogen engine; Hydrogen tanks are used to store liquid hydrogen. A vaporizer that vaporizes the liquid hydrogen by means of the exhaust heat from the hydrogen engine, thereby producing hydrogen that is supplied to the hydrogen engine. An evaporation circuit, connected to the hydrogen tank, releases the vaporized gas in the hydrogen tank to the outside of the vehicle. The evaporation line includes: A heating channel, which is disposed in the vaporizer, heats the flowing evaporated gas; A catalyst that causes air to react with the evaporated gas to produce water.

Images