Coupling hydrogen afterburning organic liquid hydrogen storage combined hydrogen engine power system and method

Abstract

The invention discloses a coupling hydrogen afterburning organic liquid hydrogen storage combined hydrogen engine power system and a working method thereof, and belongs to the technical field of new energy automobile power systems. The system comprises an organic liquid hydrogen storage (LOHC) preheating subsystem, an LOHC dehydrogenation subsystem, a hydrogen separation and purification subsystem, a hydrogen internal combustion engine subsystem, a catalytic combustion energy supplementing subsystem, a cooling liquid subsystem and an electric heating and electric auxiliary heating starting subsystem. According to the system, waste heat of cooling liquid of the hydrogen internal combustion engine, dehydrogenated mixed gas and energy-supplied tail gas is recycled in sequence through a multi-stage heat exchange network and used for preheating LOHC; and part of hydrogen is used for performing catalytic combustion energy supplement on engine tail gas, and high-temperature tail gas is used as a main heat source for dehydrogenation reaction, so that the contradiction between low temperature of high-efficiency engine tail gas and high heat required by dehydrogenation is solved. The system is integrated with a central control unit and can intelligently coordinate all subsystems according to working conditions. The energy comprehensive utilization efficiency is remarkably improved, and the cold start capacity of the system is ensured.

Description

Technical Field

[0001] This invention relates to the field of hydrogen energy technology, specifically to a combined organic liquid hydrogen storage and hydrogen engine power system and method coupled with hydrogen afterburning. Background Technology

[0002] In response to the requirements for carbon dioxide emission reduction, adopting carbon-free fuels in the automotive sector is an effective solution. Hydrogen, as an excellent renewable energy carrier, is the most promising zero-carbon energy source, possessing unique advantages such as wide availability and high energy density.

[0003] However, the application of hydrogen in vehicles has always faced severe safety challenges. Its small molecular size, low viscosity, wide flammability range, and low ignition energy make it more prone to leakage and combustion risks under high pressure or low temperature conditions in vehicles. This constitutes a primary safety challenge that must be addressed in the design and application of on-board hydrogen storage systems. Currently, the mainstream method for on-board hydrogen storage is high-pressure gas storage, with on-board high-pressure hydrogen storage cylinders storing approximately 39 grams of hydrogen per liter at 70 MPa pressure. The industry currently mainly uses 35 MPa hydrogen storage cylinders, which only store about 20-22 grams of hydrogen per liter and pose safety hazards such as hydrogen leakage and explosion. In contrast, organic liquid hydrogen storage (LOHC) technology provides a new path for on-board hydrogen energy systems with high safety, high volumetric hydrogen storage density, and strong engineering compatibility.

[0004] Organic liquid hydrogen storage technology mainly relies on the reversible hydrogenation and dehydrogenation reactions of specific unsaturated organic carriers to achieve stable storage and on-demand release of hydrogen at the chemical bond level. It is in a liquid state under normal conditions and can be safely stored and transported under normal pressure and temperature. Organic liquid hydrogen storage has the following characteristics: (1) The reaction process is reversible and the hydrogen storage density is high; (2) The organic liquid hydrogen storage carrier is in a liquid state, making storage and transportation safe and convenient, and suitable for long-distance transportation; (3) It can be perfectly compatible with existing gasoline pipelines, gas stations and other oil infrastructure.

[0005] Meanwhile, organic liquid hydrogen storage also presents challenges: the dehydrogenation reaction of LOHC (liquid organic hydrogen carrier) requires harsh conditions, including high-temperature catalysis and significant energy consumption. Stable heat is also essential to ensure product purity and yield. Relying entirely on external heat sources would lead to a decrease in system efficiency.

[0006] During operation, a hydrogen internal combustion engine involves the combustion reaction of hydrogen with oxygen in the air, resulting in exhaust temperatures reaching up to 500°C. Simultaneously, the engine typically relies on coolant for cooling, which dissipates heat through heat exchange with the outside air. The directly emitted high-temperature exhaust gases and the heat lost through the coolant account for approximately 50% of the total energy released by fuel combustion in a hydrogen internal combustion engine. Failure to recover and utilize this heat leads to significant energy waste. At the system integration level, there is significant potential for thermal synergy between a LOHC (Loose-of-Hybrid Engine) and a hydrogen internal combustion engine—the heat required for the dehydrogenation process can be partially provided by the waste heat from the hydrogen internal combustion engine, allowing for a good energy match and thus improving the overall vehicle energy efficiency. Building upon this, traditional engines prioritize high thermal efficiency and low exhaust temperatures. However, in a power system coupled with a hydrogen supply system, the engine must both output power and provide heat to the hydrogen supply unit. Therefore, the approach to adjusting the engine's thermodynamic cycle differs from traditional goals and requires design modifications.

[0007] In summary, mainstream high-pressure gaseous hydrogen storage poses significant safety risks. High-density, high-safety organic liquid hydrogen storage technology requires a stable heat source during operation. Existing LOHC combined internal combustion engine systems often suffer from unstable heat sources, leading to low dehydrogenation efficiency. Furthermore, existing systems do not adequately utilize waste heat from various parts of the internal combustion engine, resulting in low system efficiency. The contradiction between engine thermal efficiency and the energy supply of the dehydrogenation system in waste heat utilization also urgently needs to be addressed. Summary of the Invention

[0008] To overcome the above technical problems, the present invention aims to provide an organic liquid hydrogen storage combined with hydrogen engine power system and its working method, which features three-stage preheating of the coolant, reactant gas and exhaust gas of the organic carrier, catalytic combustion of exhaust gas to provide heat for dehydrogenation reaction and electric heating to assist start-up, thereby maximizing energy utilization and the efficiency of the coupled power system.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A combined organic liquid hydrogen storage and hydrogen engine power system coupled with hydrogen afterburning mainly includes an LOHC preheating subsystem, an LOHC dehydrogenation subsystem, a hydrogen purification and separation subsystem, a hydrogen internal combustion engine subsystem, a catalytic combustion energy supplementation subsystem, a coolant subsystem, and an electric heating and electric auxiliary heating start-up subsystem. The LOHC preheating subsystem is used to preheat LOHC. The LOHC dehydrogenation reaction subsystem includes a dehydrogenation reactor that receives the preheated LOHC and converts it into dehydrogenated organic gaseous working fluid and hydrogen through a dehydrogenation reaction. The hydrogen purification and separation subsystem separates the dehydrogenated organic working fluid and hydrogen through secondary pressurization. Most of the dehydrogenated organic gaseous working fluid is cooled to a liquid state for separation, and a small portion of the still gaseous organic working fluid is separated through a permeate membrane. The heat dissipated during the cooling process before separation is recovered. Part of the recovered heat enters the hydrogen internal combustion engine subsystem for combustion and work, and the other part enters the catalytic combustion energy replenishment subsystem to replenish the exhaust gas. The hydrogen internal combustion engine subsystem converts the energy from hydrogen combustion into output power, and at the same time generates high-temperature exhaust gas during operation, which exchanges heat with the hydrogen-rich organic liquid working fluid in the dehydrogenation reactor to supply energy for the dehydrogenation reaction; the catalytic combustion energy replenishment subsystem raises the exhaust gas temperature through hydrogen catalytic combustion and uses the exhaust gas to supply energy for the dehydrogenation reaction. The coolant subsystem is used to cool the hydrogen internal combustion engine and the mixture after the dehydrogenation reaction; the electric heating and electric auxiliary heating starter subsystem uses electrical energy to provide auxiliary power for the dehydrogenation reaction and uses electrical energy to output power when the car is cold-started.

[0010] In one embodiment, the LOHC preheating subsystem performs three-stage preheating of the LOHC to recover the following three parts of heat: ① heat of the hydrogen internal combustion engine coolant ② heat of the mixture of hydrogen and organic gaseous working fluid after dehydrogenation reaction ③ heat of the exhaust gas after power supply. Preferably, the LOHC preheating system includes an oil tank, an organic liquid pump, a heat exchanger 1, a heat exchanger 2, and a heat exchanger 3 connected in series. The cold flow inlet of heat exchanger 1 is connected to the outlet of the oil tank, the cold flow outlet of heat exchanger 1 is connected to the cold flow inlet of heat exchanger 2, the cold flow outlet of heat exchanger 2 is connected to the cold flow inlet of heat exchanger 3, and the cold flow outlet of heat exchanger 3 is directly or through a thermal oil electric heater connected to the dehydrogenation reactor. The hydrogen generated in the dehydrogenation reactor is mixed with the dehydrogenated organic gaseous working fluid through the dehydrogenation reactor outlet and connected to the heat inlet of heat exchanger two. The heat outlet of heat exchanger two is connected to the heat inlet of heat exchanger four. The internal combustion engine coolant recovered by the hydrogen purification and separation subsystem is connected to the heat inlet of heat exchanger one. The exhaust gas after powering the dehydrogenation reactor is connected to the heat inlet of heat exchanger three.

[0011] In one embodiment, the LOHC dehydrogenation reaction subsystem converts the LOHC preheated by the LOHC preheating subsystem into dehydrogenated organic gaseous working fluid and hydrogen through a dehydrogenation reaction. The energy for the dehydrogenation reaction is supplied by the tail gas. When the tail gas energy is insufficient to supply the dehydrogenation reaction or during a cold start, electric heating is used to supplement the energy.

[0012] In one embodiment, the hydrogen separation and purification subsystem is used to separate hydrogen from dehydrogenated organic working fluid through secondary pressurization, while recovering the heat dissipated during the cooling process before separation, purifying the hydrogen through a hydrogen permeation membrane to ensure purity, and dividing it into two streams: one stream enters the hydrogen internal combustion engine subsystem for combustion and power generation, and the other stream enters the catalytic combustion energy replenishment subsystem to replenish the exhaust gas.

[0013] Preferably, the hydrogen purification and separation subsystem includes heat exchanger four, heat exchanger five, cooler one, separator one, booster, heat exchanger six, cooler two, separator two, hydrogen permeation membrane, and distributor; the mixture of hydrogen and dehydrogenated organic gaseous working fluid enters the hot flow inlet of heat exchanger four, the hot flow outlet of heat exchanger four is connected to the hot flow inlet of heat exchanger five, the hot flow outlet of heat exchanger five is connected to the inlet of cooler one, the outlet of cooler one is connected to the inlet of separator one, the liquid phase outlet of separator one leads to an organic liquid storage tank, and the gas phase outlet of separator one... The liquid phase outlet is connected to the turbocharger inlet, the turbocharger outlet is connected to the heat exchanger six hot flow inlet, the heat exchanger six hot flow outlet is connected to the cooler two inlet, the cooler two outlet is connected to the separator two inlet, the separator two liquid phase outlet leads to the organic liquid storage tank, the separator two gas phase outlet is connected to the hydrogen permeation membrane inlet, the hydrogen permeation membrane outlet is connected to the splitter, one of the splitter outlets is connected to one of the inlets of the mixer at the intake end of the hydrogen internal combustion engine subsystem, and the other outlet is connected to one of the inlets of the catalytic combustion exhaust gas recharger.

[0014] In one embodiment, to address excess hydrogen generated after system shutdown, the hydrogen purification and separation subsystem further includes a hydrogen buffer tank disposed between the hydrogen permeation membrane and the splitter for storing excess hydrogen after the vehicle stops.

[0015] In one embodiment, the hydrogen internal combustion engine subsystem converts the energy from hydrogen combustion into output power, while generating high-temperature exhaust gas during operation. This exhaust gas exchanges heat with the hydrogen-rich organic working fluid in the dehydrogenation reactor via heat transfer oil, thereby supplying energy to the dehydrogenation reactor.

[0016] Preferably, the hydrogen internal combustion engine subsystem includes a turbocharger, a third cooler, a mixer, a compressor, a combustion chamber, an expander, and a compression turbine. Air enters the turbocharger, and the outlet of the turbocharger is connected to the inlet of the third cooler. The third cooler is connected to one inlet of the mixer. The hydrogen-air premixed gas is connected to the compressor through the outlet of the mixer. The outlet of the compressor is connected to the inlet of the combustion chamber. The exhaust gas generated by hydrogen combustion is connected to the expander through the outlet of the combustion chamber. The outlet of the expander is connected to the inlet of the compression turbine. The outlet of the compression turbine is connected to a catalytic combustion exhaust gas booster.

[0017] In one embodiment, the catalytic combustion energy replenishment subsystem is used to increase the exhaust gas temperature through the catalytic combustion of hydrogen, and use the exhaust gas to power the dehydrogenation reaction. This resolves the contradiction between the engine's need for high-efficiency power output and the need to power the dehydrogenation device, replacing the electric heating process, reducing external energy consumption, and improving system efficiency.

[0018] Preferably, the catalytic combustion energy replenishment subsystem includes a catalytic combustion tail gas replenishment device. Hydrogen and tail gas enter the catalytic combustion tail gas replenishment device through two inlets for combustion. The outlet of the catalytic combustion tail gas replenishment device is connected to the dehydrogenation reactor. The tail gas replenished by the catalytic combustion tail gas replenishment device is fed into the dehydrogenation reactor to provide energy for the dehydrogenation reaction.

[0019] In one embodiment, the cooling water subsystem is used to cool the hydrogen internal combustion engine, simultaneously to cool the mixture after the dehydrogenation reaction, and finally to preheat the LOHC.

[0020] Preferably, the cooling water subsystem includes a cooling water pump, a cooler four, a heat exchanger six, a heat exchanger four, and a heat exchanger one connected in series. The cooler four is used to cool the hydrogen internal combustion engine, and the heat exchanger six is ​​used to cool the mixture after the dehydrogenation reaction. The heat absorbed during the cooling process is used to preheat the LOHC through the heat exchanger four and the heat exchanger one.

[0021] In one embodiment, the electric heating and electric auxiliary heating starter subsystem is used to supplement the energy of the vehicle when it is cold-started or when the exhaust gas energy is insufficient to power the dehydrogenation reaction. At the same time, it uses electric energy to output power when the vehicle is cold-started, thus solving the problem of cold-starting the vehicle.

[0022] Preferably, the electric heating and electric auxiliary heating start-up subsystem includes a power battery and an electric auxiliary heating cold start device. One power outlet of the power battery directly outputs kinetic energy, and the other power outlet is connected to the electric auxiliary heating cold start device. During cold start, the electric auxiliary heating cold start device provides electric heating to replenish energy to the dehydrogenation reactor.

[0023] In one embodiment, the system further includes a central control unit and an ECU engine control unit, used to interact with various components of the system and perform operating condition control so that the system operates under optimal conditions. The central control unit is connected to the ECU engine control unit, organic liquid pump, cooling water pump, power battery, electric auxiliary heating cold start device, dehydrogenation reactor, heat transfer oil electric heater, distributor and catalytic combustion exhaust gas booster, and monitors and controls various parameters; the ECU engine control unit is connected to the turbocharger, compressor, combustion chamber and expander, and monitors and controls various engine parameters.

[0024] This invention also discloses a method for operating the aforementioned organic liquid hydrogen storage combined with hydrogen engine power system coupled with hydrogen afterburning: When the engine starts, the LOHC is preheated to its rated operating temperature. At the same time, the electric heating and electric auxiliary heating start-up subsystems supply heat to the dehydrogenation reactor. The preheated LOHC reacts in the dehydrogenation reactor to generate a mixture of hydrogen and hydrogen-lean organic working fluid. The mixture is fed into the LOHC preheating subsystem to preheat the incoming LOHC. After being cooled by the engine coolant and hydrogen in sequence, it undergoes secondary pressurization and separation through the hydrogen purification and separation subsystem. The separated hydrogen-lean organic working fluid enters the storage tank for reuse. Part of the hydrogen enters the hydrogen internal combustion engine subsystem for combustion and power generation. The combustion exhaust gas is sent to the catalytic combustion energy replenishment subsystem. The other part of the hydrogen is directly fed into the catalytic combustion energy replenishment subsystem. The mixed combustion raises the exhaust gas temperature. The exhaust gas is sent to the dehydrogenation reactor to supply energy. The energy-supplied exhaust gas is then fed into the LOHC preheating subsystem to preheat the LOHC before being discharged. After the engine starts, the required hydrogen flow rate is calculated based on the required output power. The air flow rate, compression ratio and exhaust pressure at the current power are controlled to achieve the optimal efficiency. Based on the required hydrogen flow rate, the LOHC flow rate at the optimal efficiency is calculated so that the hydrogen flow rate entering the hydrogen internal combustion engine subsystem and the catalytic combustion energy replenishment subsystem meets the optimal efficiency conditions. When energy is insufficient, the preheating and dehydrogenation processes are replenished. At the same time, the coolant subsystem is used to cool the incoming flow to the required separation temperature. The coolant flow rate is controlled to cool the engine to a suitable temperature so that the entire power system operates under the best efficiency conditions. When the engine stops running, the pumping of LOHC stops and the generated hydrogen is temporarily stored.

[0025] In this invention, there are multiple output strategies when outputting power. The engine and the power battery can output power separately, or they can run simultaneously. The engine can also output electrical energy to the power battery when it is running.

[0026] The beneficial effects of this invention are: This invention deeply couples organic liquid hydrogen storage technology with hydrogen engine technology, enabling better energy synergy between the two. It innovatively constructs a three-stage waste heat utilization network, which utilizes the waste heat of hydrogen internal combustion engine coolant, dehydrogenated mixture and exhaust gas in a cascade manner for LOHC preheating and LOHC dehydrogenation process, greatly reducing the net energy consumption of the dehydrogenation process.

[0027] This invention uses a catalytic combustion energy replenishment subsystem to use a portion of the hydrogen to increase the exhaust gas temperature, thus resolving the contradiction between the low exhaust gas temperature under high-efficiency operating conditions of hydrogen internal combustion engines and the need for a high-temperature heat source for the dehydrogenation reaction, thereby improving system efficiency.

[0028] This invention features an integrated electric heating and electric auxiliary heating start-up subsystem, ensuring rapid system start-up capability in the absence of a heat source, thereby improving vehicle practicality and user experience.

[0029] This invention employs a central control unit and an engine ECU for coordinated control, which can optimize the LOHC dehydrogenation amount, hydrogen split ratio, cooling intensity, and refueling strategy in real time according to power requirements, so that the complex system always operates at its optimal efficiency point.

[0030] This invention organically integrates LOHC hydrogen storage, efficient hydrogen dehydrogenation, hydrogen internal combustion engine power, and hybrid power control to form a complete, efficient, and controllable vehicle power solution, which has significant engineering application value. Attached image description: Figure 1 This is a schematic diagram of the system flow of the present invention. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to the embodiments.

[0032] like Figure 1 As shown, the LOHC preheating system achieves LOHC preheating through a series of interconnected components: oil tank 1, organic liquid pump 2, heat exchanger 1 3, heat exchanger 2 4, and heat exchanger 3 5.

[0033] The oil tank 1 stores hydrogen-rich LOHC. The cold inlet of heat exchanger 3 is connected to the outlet of oil tank 1. The cold outlet of heat exchanger 3 is connected to the cold inlet of heat exchanger 4. The cold outlet of heat exchanger 4 is connected to the cold inlet of heat exchanger 5. The cold outlet of heat exchanger 5 is connected to the heat transfer oil electric heater 6. The hydrogen generated in the dehydrogenation reactor 7 and the dehydrogenated working fluid mixture are connected to the hot inlet of heat exchanger 4 through the outlet of dehydrogenation reactor 7. The hot outlet of heat exchanger 4 is connected to the hot inlet of heat exchanger 8. The internal combustion engine coolant recovered by the waste heat of the hydrogen purification and separation subsystem is connected to the hot inlet of heat exchanger 3. The exhaust gas after powering dehydrogenation reactor 7 is connected to the hot inlet of heat exchanger 5, forming the LOHC feeding process.

[0034] This step completes the LOHC feeding process and enables LOHC preheating. The LOHC preheating system includes three stages of preheating: The first stage of preheating of the LOHC is completed in heat exchanger 3, where the hydrogen internal combustion engine coolant exchanges heat with the hydrogen-rich LOHC at room temperature, increasing the temperature of the LOHC when it enters heat exchanger 4. Subsequently, the LOHC enters heat exchanger 4, where the mixture of hydrogen generated in dehydrogenation reactor 7 and the hydrogen-lean organic working fluid is connected to the heat inlet of heat exchanger 4 through the outlet of dehydrogenation reactor 7. This process completes the preheating of the hydrogen-rich LOHC by the dehydrogenation product mixture. The exhaust gas after powering dehydrogenation reactor 7 is connected to the heat inlet of heat exchanger 5, allowing for further heat exchange between the powered exhaust gas and the hydrogen-rich LOHC. This step performs two stages of preheating of the LOHC, bringing it closer to the temperature required for the dehydrogenation reaction. This enables the cascade utilization of waste heat from the hydrogen internal combustion engine coolant, the dehydrogenated LOHC and hydrogen mixture, and the exhaust gas, improving energy efficiency.

[0035] The preheated LOHC then enters the LOHC dehydrogenation reaction subsystem, where the dehydrogenation reaction is achieved through a series of connected thermal oil electric heaters 6 and dehydrogenation reactors 7. The LOHC preheated by the LOHC preheating subsystem is converted into dehydrogenated organic liquid and hydrogen through the dehydrogenation reaction. The cold outlet corresponding to heat exchanger 35 is connected to the thermal oil electric heater 6. The central control unit 28 monitors the temperature of the LOHC entering the thermal oil electric heater 6 in real time. If the LOHC temperature is lower than the dehydrogenation reaction temperature, the central control unit 28 will control the thermal oil electric heater 6 to heat the LOHC until it reaches the dehydrogenation reaction temperature. The LOHC that has reached the reaction temperature after passing through the thermal oil electric heater 6 enters the dehydrogenation reactor 7 for reaction. The dehydrogenation reaction is a strongly endothermic reaction that requires a large amount of energy. This energy is supplied by the exhaust gas passing through the catalytic combustion exhaust gas supplementer 25. The central control unit 28 monitors the hydrogen yield in real time. If the hydrogen yield decreases, the central control unit 28 controls the power battery 31 to start supplying electrical energy to the electric auxiliary heating cold start device 32. The electric auxiliary heating cold start device 32 provides energy for the dehydrogenation reaction. During cold start, the heat is also mainly provided by the electric auxiliary heating cold start device 32.

[0036] Subsequently, the mixture of hydrogen and hydrogen-poor organic working fluid enters the separation and purification system, where it undergoes a secondary pressurization, separation, and purification process through heat exchanger 48, heat exchanger 59, cooler 10, separator 11, turbocharger 12, heat exchanger 613, cooler 214, separator 215, hydrogen permeation membrane 16, and distributor 17, resulting in high-purity hydrogen that finally enters the engine subsystem.

[0037] The mixture of hydrogen and dehydrogenated organic working fluid enters the hot inlet of heat exchanger 48. The hot outlet of heat exchanger 48 is connected to the hot inlet of heat exchanger 59, and the hot outlet of heat exchanger 59 is connected to the inlet of cooler 10. This process achieves the liquefaction of the hydrogen-deficient gaseous organic working fluid. The outlet of cooler 10 is connected to the inlet of separator 11. The liquid phase outlet of separator 11 leads to an organic liquid storage tank, and the gas phase outlet of separator 11 is connected to the inlet of booster 12. This part achieves the first cooling and separation of hydrogen. The outlet of booster 12 is connected to the hot inlet of heat exchanger 613, the hot outlet of heat exchanger 613 is connected to the inlet of cooler 214, and the outlet of cooler 214 is connected to the inlet of separator 215. The liquid phase outlet of separator 2 15 leads to an organic liquid storage tank, and the gas phase outlet of separator 2 15 is connected to the inlet of hydrogen permeation membrane 16. This part realizes secondary pressurization and cooling separation of hydrogen, cooling most of the dehydrogenated organic gaseous working fluid to liquid state for separation, further improving the purity of hydrogen. The outlet of hydrogen permeation membrane 16 is connected to splitter 17, which separates a small portion of the still gaseous organic working fluid through the permeation membrane. One outlet of splitter 17 is connected to one inlet of mixer 20, and the other outlet is connected to one inlet of catalytic combustion exhaust gas recharger 25. Finally, the hydrogen is divided into two streams. One stream enters the hydrogen internal combustion engine subsystem for combustion and power, and the other stream enters the catalytic combustion recharge subsystem to recharge the exhaust gas.

[0038] The hydrogen stream entering the hydrogen internal combustion engine subsystem passes through turbocharger 18, cooler 19, mixer 20, compressor 21, combustion chamber 22, expander 23, and compression turbine 24, converting the energy of hydrogen combustion into output power. Air enters turbocharger 18 and is turbocharged there. The outlet of turbocharger 18 is connected to the inlet of cooler 19, which is connected to one inlet of mixer 20. The hydrogen-air premixed gas passes through the outlet of mixer 20 and is connected to compressor 21. The outlet of compressor 21 is connected to the inlet of combustion chamber 22. The exhaust gas produced by hydrogen combustion passes through the outlet of combustion chamber 22 and is connected to expander 23. The outlet of expander 23 is connected to the inlet of compression turbine 24, completing the conversion of hydrogen combustion energy into output power. The ECU engine control unit 30 monitors the operating status of each component in real time, adjusts the operating parameters in real time, and calculates the required hydrogen flow rate according to the output power demand, interacting with the central control unit 28. The outlet of compression turbine 24 is connected to catalytic combustion exhaust gas recharger 25.

[0039] The catalytic combustion energy replenishment subsystem heats the exhaust gas through the catalytic combustion exhaust gas replenishment device 25. When the central control unit 28 detects that the exhaust gas temperature is insufficient to provide energy for the dehydrogenation reaction, it increases the hydrogen flow rate entering the catalytic combustion exhaust gas replenishment device 25. The hydrogen and exhaust gas enter the catalytic combustion exhaust gas replenishment device 25 through two inlets for combustion. The outlet of the catalytic combustion exhaust gas replenishment device 25 is connected to the dehydrogenation reactor 7 to supply energy for the dehydrogenation reaction.

[0040] The cooling water subsystem cools the engine by connecting the cooling water pump 26, cooler 4 27, heat exchanger 6 13, heat exchanger 4 8, and heat exchanger 1 3 in series. At the same time, it recovers the heat from the dehydrogenation process and uses it for preheating of LOHC.

[0041] Based on the above structure, the working method of the power system of the present invention is as follows: When the engine starts, LOHC is pumped from fuel tank 1 by organic liquid pump 2, preheated to rated operating temperature by heat transfer oil electric heater 6, and simultaneously the power battery 31 provides electrical energy to the electric auxiliary heating cold start device 32 to supply heat to the dehydrogenation reactor. The preheated LOHC reacts in dehydrogenation reactor 7 to generate a mixture of hydrogen and hydrogen-lean organic working fluid. The mixture is passed into heat exchanger 4 to preheat the incoming LOHC, and then sequentially enters heat exchanger 8 and heat exchanger 9 to be cooled by engine coolant and hydrogen respectively, and then undergoes secondary pressurization and separation to obtain a higher purity LOHC. Hydrogen is separated from the hydrogen-poor organic working fluid and stored in a tank for reuse. The hydrogen with higher purity enters the distributor 17. Part of it flows to the engine and mixes with the control gas after turbocharging. After being compressed by the compressor 21, it enters the combustion chamber 22 for combustion. The combustion exhaust gas is sent to the catalytic combustion exhaust gas recharger 25. The other part of the hydrogen is directly sent to the catalytic combustion exhaust gas recharger 25. The two are mixed and then burned to increase the exhaust gas temperature. The exhaust gas is sent to the dehydrogenation reactor 7 to supply energy. The exhaust gas after energy supply is sent to the heat exchanger 3 5 to preheat the LOHC before being discharged. When the engine starts, the ECU engine control unit 30 receives the required output power command, calculates the required hydrogen flow rate of the engine and feeds it back to the central control unit 28, and controls the air flow rate, compression ratio and exhaust pressure at the optimal efficiency under the current power. According to the required hydrogen flow rate, the central control unit 28 calculates the LOHC flow rate at the optimal efficiency, so that the hydrogen flow rate entering the engine subsystem and the catalytic combustion exhaust gas supplementer 25 meets the optimal efficiency conditions. When the energy is insufficient, the heat transfer oil electric heater 6 and the electric auxiliary heating cold start device 32 are controlled to provide necessary supplementary energy for the preheating and dehydrogenation process. At the same time, the cooler 10 and cooler 2 14 are controlled to cool the incoming flow to the required separation temperature, and the cooling water flow rate is controlled to cool the engine to a suitable temperature, so that the entire power system operates under the best efficiency conditions. When the engine stops running, the ECU engine control unit 30 outputs a signal to the central control unit 28, which controls the organic liquid pump 2 to stop pumping out the organic working fluid and at the same time closes the outlet of the hydrogen buffer tank 29, allowing the hydrogen already generated in the system to be temporarily stored in the hydrogen buffer tank.

[0042] When outputting power, there are multiple output strategies. The engine and the power battery can output power separately, or both can run simultaneously. The engine can also output electrical energy to the power battery when it is running.

[0043] In summary, this invention utilizes a multi-stage heat exchange network to sequentially recover waste heat from the hydrogen internal combustion engine coolant, the dehydrogenated mixture, and the exhaust gas after power supply, for preheating the LOHC (Lower Open Hybrid Heat Storage Unit). Furthermore, a portion of the hydrogen is used for catalytic combustion of the engine exhaust gas to supplement its energy supply. By using the high-temperature exhaust gas as the primary heat source for the dehydrogenation reaction, this invention resolves the contradiction between the low exhaust gas temperature of high-efficiency engines and the high heat required for dehydrogenation. The system integrates a central control unit, which can intelligently coordinate the various subsystems according to operating conditions. This invention significantly improves overall energy utilization efficiency, ensures the system's cold-start capability, and achieves efficient, stable, and intelligent operation of the onboard organic liquid hydrogen storage power system.

[0044] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope disclosed in the present invention, based on the technical solution and inventive concept of the present invention, shall fall within the scope of protection of the present invention.

Claims

1. A combined organic liquid hydrogen storage and hydrogen engine power system with coupled hydrogen afterburning, characterized in that, It includes a LOHC preheating subsystem, a LOHC dehydrogenation subsystem, a hydrogen purification and separation subsystem, a hydrogen internal combustion engine subsystem, a catalytic combustion energy replenishment subsystem, a coolant subsystem, and an electric heating and electric auxiliary heating start-up subsystem; The LOHC preheating subsystem is used to preheat LOHC. The LOHC dehydrogenation reaction subsystem includes a dehydrogenation reactor (7), which receives the preheated LOHC and converts it into dehydrogenated organic gaseous working fluid and hydrogen through a dehydrogenation reaction. The hydrogen purification and separation subsystem separates the dehydrogenated organic liquid and hydrogen through secondary pressurization and recovers the heat dissipated during the cooling process before separation. Part of the recovered heat enters the hydrogen internal combustion engine subsystem to burn and do work, and the other part enters the catalytic combustion energy replenishment subsystem to replenish the tail gas. The hydrogen internal combustion engine subsystem converts the energy from hydrogen combustion into output power, and at the same time generates high-temperature exhaust gas during operation, which exchanges heat with the hydrogen-rich organic liquid working medium in the dehydrogenation reactor (7) to provide energy for the dehydrogenation reaction; the catalytic combustion energy replenishment subsystem raises the exhaust gas temperature through hydrogen catalytic combustion and uses the exhaust gas to provide energy for the dehydrogenation reaction. The coolant subsystem is used to cool the hydrogen internal combustion engine and the mixture after the dehydrogenation reaction; the electric heating and electric auxiliary heating starter subsystem uses electrical energy to provide auxiliary power for the dehydrogenation reaction and uses electrical energy to output power when the car is cold-started.

2. The organic liquid hydrogen storage combined with hydrogen engine power system coupled with hydrogen afterburning as described in claim 1, characterized in that, The LOHC preheating subsystem performs three-stage preheating of the LOHC, recovering the following three parts of heat: the heat of the hydrogen internal combustion engine coolant, the heat of the mixture of hydrogen and organic gaseous working fluid after the dehydrogenation reaction, and the heat of the exhaust gas after power supply. The LOHC preheating system includes an oil tank (1), an organic liquid pump (2), a heat exchanger one (3), a heat exchanger two (4), and a heat exchanger three (5) connected in series. The cold flow inlet of heat exchanger one (3) is connected to the outlet of oil tank (1), the cold flow outlet of heat exchanger one (3) is connected to the cold flow inlet of heat exchanger two (4), the cold flow outlet corresponding to heat exchanger two (4) is connected to the cold flow inlet of heat exchanger three (5), and the cold flow outlet corresponding to heat exchanger three (5) is directly or through a thermal oil electric heater (6) connected to the dehydrogenation reactor (7). The hydrogen generated in the dehydrogenation reactor (7) and the dehydrogenated organic gaseous working fluid are mixed and connected to the heat inlet of heat exchanger 2 (4) through the outlet of the dehydrogenation reactor (7). The heat outlet of heat exchanger 2 (4) is connected to the heat inlet of heat exchanger 4 (8). The internal combustion engine coolant recovered by the waste heat of the hydrogen purification and separation subsystem is connected to the heat inlet of heat exchanger 1 (3). The exhaust gas after powering the dehydrogenation reactor (7) is connected to the heat inlet of heat exchanger 3 (5).

3. The organic liquid hydrogen storage combined with hydrogen engine power system coupled with hydrogen afterburning as described in claim 1, characterized in that, The hydrogen purification and separation subsystem includes heat exchanger four (8), heat exchanger five (9), cooler one (10), separator one (11), booster (12), heat exchanger six (13), cooler two (14), separator two (15), hydrogen permeation membrane (16), and splitter (17). The mixture of hydrogen and dehydrogenated organic gaseous working fluid enters the heat inlet of heat exchanger four (8). The heat outlet of heat exchanger four (8) is connected to the heat inlet of heat exchanger five (9). The heat outlet of heat exchanger five (9) is connected to the inlet of cooler one (10). The outlet of cooler one (10) is connected to the inlet of separator one (11). The liquid phase outlet of separator one (11) leads to an organic liquid storage tank. The gas phase outlet of separator one (11) is connected to the inlet of booster (12). The outlet of booster (12) is connected to the heat inlet of heat exchanger six (13). The hot flow outlet of 13) is connected to the inlet of cooler 2 (14), the outlet of cooler 2 (14) is connected to the inlet of separator 2 (15), the liquid phase outlet of separator 2 (15) leads to the organic liquid storage tank, the gas phase outlet of separator 2 (15) is connected to the inlet of hydrogen permeation membrane (16), the outlet of hydrogen permeation membrane (16) is connected to the splitter (17), one of the outlets of the splitter (17) is connected to one of the inlets of the mixer (20) at the intake end of the hydrogen internal combustion engine subsystem, and the other outlet is connected to one of the inlets of the catalytic combustion exhaust gas booster (25).

4. The organic liquid hydrogen storage combined with hydrogen engine power system coupled with hydrogen afterburning as described in claim 3, characterized in that, The hydrogen purification and separation subsystem also includes a hydrogen buffer tank (29), which is arranged between the hydrogen permeation membrane (16) and the splitter (17) for storing excess hydrogen after the vehicle stops.

5. The organic liquid hydrogen storage combined with hydrogen engine power system coupled with hydrogen afterburning as described in claim 1, characterized in that, The hydrogen internal combustion engine subsystem includes a turbocharger (18), a third cooler (19), a mixer (20), a compressor (21), a combustion chamber (22), an expander (23), and a compression turbine (24). Air enters the turbocharger (18), and the outlet of the turbocharger (18) is connected to the inlet of the third cooler (19). The third cooler (19) is connected to one inlet of the mixer (20). The hydrogen and air premixed gas is connected to the compressor (21) through the outlet of the mixer (20). The outlet of the compressor (21) is connected to the inlet of the combustion chamber (22). The exhaust gas generated by the hydrogen combustion is connected to the expander (23) through the outlet of the combustion chamber (22). The outlet of the expander (23) is connected to the inlet of the compression turbine (24). The outlet of the compression turbine (24) is connected to the catalytic combustion exhaust gas booster (25).

6. The organic liquid hydrogen storage combined with hydrogen engine power system coupled with hydrogen afterburning as described in claim 1, characterized in that, The catalytic combustion energy replenishment subsystem includes a catalytic combustion tail gas replenishment device (25). Hydrogen and tail gas enter the catalytic combustion tail gas replenishment device (25) through two inlets for combustion. The outlet of the catalytic combustion tail gas replenishment device (25) is connected to the dehydrogenation reactor (7). The tail gas replenished by the catalytic combustion tail gas replenishment device (25) is fed into the dehydrogenation reactor (7) to provide energy for the dehydrogenation reaction.

7. The organic liquid hydrogen storage combined with hydrogen engine power system coupled with hydrogen afterburning as described in claim 1, characterized in that, The cooling water subsystem includes a cooling water pump (26), a cooler four (27), a heat exchanger six (13), a heat exchanger four (8), and a heat exchanger one (3) connected in series. The cooler four (27) is used to cool the hydrogen internal combustion engine, and the heat exchanger six (13) is used to cool the mixed gas after the dehydrogenation reaction. The heat absorbed during the cooling process is used to preheat the LOHC through the heat exchanger four (8) and the heat exchanger one (3).

8. The organic liquid hydrogen storage combined with hydrogen engine power system coupled with hydrogen afterburning as described in claim 1, characterized in that, The electric heating and electric auxiliary heating start-up subsystem includes a power battery (31) and an electric auxiliary heating cold start device (32). One power outlet of the power battery (31) directly outputs kinetic energy, and the other power outlet is connected to the electric auxiliary heating cold start device (32). During cold start, the electric auxiliary heating cold start device (32) provides electric heating to replenish the energy of the dehydrogenation reactor (7).

9. The organic liquid hydrogen storage combined with hydrogen engine power system coupled with hydrogen afterburning as described in claim 1, characterized in that, The system also includes a central control unit (28) and an ECU engine control unit (30), which are used to interact with various components of the system and perform operating condition control so that the system operates under optimal conditions; The central control unit (28) is connected to the ECU engine control unit (30), organic liquid pump (2), cooling water pump (26), power battery (31), electric auxiliary heating cold start device (32), dehydrogenation reactor (7), heat transfer oil electric heater (6), splitter (17) and catalytic combustion exhaust gas supplementer (25), and monitors and controls various parameters; the ECU engine control unit (30) is connected to the turbocharger (18), compressor (21), combustion chamber (22) and expander (23), and monitors and controls various engine parameters.

10. A method for operating the organic liquid hydrogen storage combined with hydrogen engine power system coupled with hydrogen afterburning as described in claim 1, characterized in that: When the engine starts, the LOHC is preheated to the rated operating temperature. At the same time, the electric heating and electric auxiliary heating start-up subsystems supply heat to the dehydrogenation reactor (7). The preheated LOHC reacts in the dehydrogenation reactor (7) to generate a mixture of hydrogen and hydrogen-poor organic working fluid. The mixture is fed into the LOHC preheating subsystem to preheat the incoming LOHC. After being cooled by the engine coolant and hydrogen in sequence, it is subjected to secondary pressurization and separation by the hydrogen purification and separation subsystem. The separated hydrogen-poor organic working fluid enters the storage tank for reuse. Part of the hydrogen enters the hydrogen internal combustion engine subsystem to burn and do work. The combustion exhaust gas is fed to the catalytic combustion energy replenishment subsystem. The other part of the hydrogen is directly fed into the catalytic combustion energy replenishment subsystem. The mixed combustion raises the exhaust gas temperature. The exhaust gas is fed to the dehydrogenation reactor (7) to supply energy. The exhaust gas after energy supply is fed into the LOHC preheating subsystem to preheat the LOHC before being discharged. After the engine starts, the required hydrogen flow rate is calculated based on the required output power. The air flow rate, compression ratio and exhaust pressure at the current power are controlled to achieve the optimal efficiency. Based on the required hydrogen flow rate, the LOHC flow rate at the optimal efficiency is calculated so that the hydrogen flow rate entering the hydrogen internal combustion engine subsystem and the catalytic combustion energy replenishment subsystem meets the optimal efficiency conditions. When energy is insufficient, the preheating and dehydrogenation processes are replenished. At the same time, the coolant subsystem is used to cool the incoming flow to the required separation temperature. The coolant flow rate is controlled to cool the engine to a suitable temperature so that the entire power system operates under the best efficiency conditions. When the engine stops running, the pumping of LOHC stops and the generated hydrogen is temporarily stored.

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