A secondary combustion system coupling an organic liquid hydrogen supply system with a heat engine system

Abstract

The present invention discloses a secondary combustion system in which an organic liquid hydrogen supply system is coupled with a heat engine system, comprising: a dehydrogenation system, a heat engine system, a heat stabilization system, and a control unit; the dehydrogenation system performs a dehydrogenation reaction on liquid hydrogen oil to generate hydrogen, and the hydrogen is respectively sent to the heat engine system and the heat stabilization system through the control unit, and the hydrogen performs work or generates electricity in the heat engine system, and the high-temperature tail gas of the heat engine system and part of the hydrogen enter the heat stabilization system, and a catalyst is arranged in the heat stabilization system, and the hydrogen and the high-temperature tail gas react after contacting the catalyst in the heat stabilization system to further increase the temperature of the heated tail gas, and the heated tail gas enters the dehydrogenation system to provide heat for the dehydrogenation reaction. The secondary combustion system of the present application can efficiently utilize the heat energy discharged by the heat engine system, and at the same time ensure the temperature stability of the dehydrogenation system, so that the dehydrogenation reaction can be carried out continuously and stably.

Description

Technical Field

[0001] The invention belongs to the field of chemical equipment and control, and in particular relates to a secondary combustion system in which an organic liquid hydrogen supply system is coupled with a thermal engine system. Background Art

[0002] Hydrogen energy utilization technology, such as hydrogen fuel cells and hydrogen internal combustion engines, can provide stable, efficient and pollution-free power, and has broad application prospects in the fields of electric vehicles and mobile devices. In the past 10 years, developed countries such as the United States, Europe, and Japan, as well as Chinese government departments and enterprises have invested huge amounts of money to develop the "hydrogen energy economy", and have made breakthroughs in large-scale hydrogen preparation, hydrogen fuel cells and other fields. In 2015, major automobile manufacturers in the world (including SAIC) will mass-produce hydrogen fuel cell vehicles. According to the forecast of the U.S. Department of Energy and the U.S. Academy of Engineering, hydrogen fuel cell vehicles will replace existing fuel vehicles and hybrid vehicles within 15 to 20 years and dominate the global automobile market. In addition, hydrogen energy technology can also be used in backup power supply, energy storage, peak-shaving and valley-filling grid-connected power generation and distributed energy supply, combustion support and environmental protection. It can be foreseen that when hydrogen energy technology quickly completes the marketization process and integrates into people's lives, the country's energy crisis and environmental pressure will be greatly alleviated.

[0003] Hydrogen energy technology includes the large-scale preparation, storage and transportation of hydrogen, efficient use, and the construction of supporting infrastructure. Storage and transportation are one of the most critical technologies for the safe and effective use of hydrogen energy. At present, the industry mainly uses storage and transportation technologies such as liquefied hydrogen at -253°C or high-pressure hydrogen at 350 to 700 atmospheres. The energy consumption required for high-pressure hydrogen or liquefied hydrogen technology and its application is more than 20 times the cost of hydrogen production, and there are safety hazards such as leakage or excessive pressure in hydrogen storage tanks. If hydrogen molecules can be adsorbed on a certain carrier to achieve safe storage at room temperature and pressure, and when used, hydrogen can be released in a controllable manner under mild conditions, hydrogen energy can be used effectively and safely. Therefore, the world's major industrial countries are developing liquid organic hydrogen storage technology based on room temperature and pressure. Taking Germany as an example, the liquid organic hydrogen storage technology developed can achieve hydrogen absorption / release cycles under relatively mild conditions, but the released hydrogen contains byproduct gases that are poisonous to fuel cells, and has important defects such as low capacity and inconvenience in use. Japan is currently developing hydrogen storage technology based on traditional organic materials such as toluene, but the dehydrogenation temperature is too high (greater than 300°C), and there is also the problem of byproducts poisoning fuel cells. Therefore, the large-scale application of these two hydrogen storage technologies is restricted.

[0004] The research team of the Sustainable Energy Laboratory of China University of Geosciences (Wuhan), led by Professor Cheng Hansong, who is a member of the second batch of the "Thousand Talents Plan" of the Organization Department of the CPC Central Committee, has discovered a type of liquid organic conjugated molecular hydrogen storage material through long-term exploration and research based on the original work in the United States. This type of material has low melting point (the technology currently developed has been as low as -20°C), high flash point (above 150°C), and under the action of self-made high-efficiency catalysts, the released gas purity is high (99.99%), the dehydrogenation temperature is low (about 150°C), and the cycle life is long (more than 2,000 times), reversible, and does not produce carbon monoxide and other gases that poison fuel cells. As a hydrogen carrier, this type of material always exists in liquid form during use, and can be stored and transported at room temperature and pressure like petroleum, and can fully utilize the existing gasoline transportation method and gas station structure. This project proposed for the first time the integration technology of hydrogen storage and fuel cell or internal combustion engine system, which directly enters the hydrogen released by dehydrogenation of liquid hydrogen storage materials at room temperature and pressure into the fuel cell or internal combustion engine system. Summary of the invention

[0005] The purpose of the present invention is to provide a secondary combustion system for liquid hydrogen storage materials, which couples an organic liquid hydrogen supply system with a heat engine system.

[0006] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a secondary combustion system in which an organic liquid hydrogen supply system is coupled with a heat engine system, comprising: a dehydrogenation system, a heat engine system, a heat stabilization system, and a control unit; the dehydrogenation system dehydrogenates liquid hydrogen oil to generate hydrogen, and the hydrogen is respectively sent to the heat engine system and the heat stabilization system through the control unit, and the hydrogen performs work or generates electricity in the heat engine system, and the high-temperature exhaust gas of the heat engine system and part of the hydrogen enter the heat stabilization system, and a catalyst is arranged in the heat stabilization system, and the hydrogen and the high-temperature exhaust gas react after contacting the catalyst in the heat stabilization system to further increase the temperature of the heated exhaust gas, and the heated exhaust gas enters the dehydrogenation system to provide heat for the dehydrogenation reaction.

[0007] Furthermore, the thermal stabilization system includes a three-way valve, a temperature sensor and a controller, wherein the three-way valve is respectively connected to the dehydrogenation system, the heat engine system and the thermal stabilization system; the temperature sensor is arranged in the dehydrogenation system for real-time monitoring of the temperature of the dehydrogenation system, and according to the temperature detected by the temperature sensor, the controller controls the ratio of hydrogen flow to the heat engine system and the thermal stabilization system.

[0008] Furthermore, the thermal engine system is a hydrogen internal combustion engine, a hydrogen fuel cell or a hydrogen gas turbine.

[0009] Furthermore, hydrogen is transported between the control system and the thermal stabilization system through a flexible pipeline.

[0010] Furthermore, a flame arrester is arranged on the flexible pipeline.

[0011] Furthermore, an injector is arranged on the flexible pipeline, and hydrogen enters the thermal stabilization system through the injector.

[0012] Furthermore, a mixer is provided on the flexible pipeline, and the mixer is connected to the thermal engine system at the same time. The high-temperature exhaust gas and hydrogen enter the thermal stabilization system after being mixed in the mixer.

[0013] The present application uses the high-temperature tail gas generated by the heat engine system as the heat source for the dehydrogenation reaction. The heat engine system can be a hydrogen internal combustion engine or a hydrogen gas turbine. The heat engine will produce high-temperature tail gas while doing work externally. For gas turbines or hydrogen internal combustion engines, improving their efficiency will inevitably reduce the quality of high-temperature tail gas, resulting in insufficient heat in the dehydrogenation system. At this time, a heat stabilization system is needed to supplement heat. The heat stabilization system is embedded with a high-efficiency hydrogen catalyst, which performs an efficient catalytic combustion exothermic reaction on the hydrogen flowing into it when the high-temperature tail gas passes through, thereby increasing the quality of the high-temperature tail gas.

[0014] The secondary combustion system of the present application can efficiently utilize the heat energy discharged by the heat engine system, while ensuring the temperature stability of the dehydrogenation system, so that the dehydrogenation reaction can be carried out continuously and stably. It not only ensures high heat engine efficiency, but also ensures sufficient dehydrogenation heat, so that the dehydrogenation reaction can be carried out continuously and stably. The hydrogen flow ratio is accurately adjusted by temperature to ensure the efficient operation of the dehydrogenation system. The heat-stabilizing system with high conversion efficiency ensures that there is no hydrogen release in the entire system. More efficiently, the heat-stabilizing system is integrated into the heat engine system to shorten the running distance of the tail gas and further improve the thermal efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of a secondary combustion system in which an organic liquid hydrogen supply system is coupled with a heat engine system in an embodiment. DETAILED DESCRIPTION

[0016] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0017] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of the present application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or apparatuses.

[0018] Liquid hydrogen storage carrier (i.e. liquid storage oil) is a hydrogen storage system that can be in liquid state at normal temperature and pressure, including at least two different hydrogen storage components, the hydrogen storage components are unsaturated aromatic hydrocarbons or heterocyclic unsaturated compounds, and at least one hydrogen storage component is a low melting point compound, and the melting point of the low melting point compound is lower than 80°C.

[0019] Furthermore, the hydrogen storage component is selected from heterocyclic unsaturated compounds, and the heteroatoms in the heterocyclic unsaturated compounds are one or more of N, S, O and P.

[0020] Furthermore, the total number of heterocyclic rings and aromatic rings in the heterocyclic unsaturated compound is 1-20, and the total number of heteroatoms is 1-20.

[0021] Furthermore, relative to the total mass of the liquid hydrogen storage system, the mass fraction of the low melting point compound is 5 to 95%.

[0022] Furthermore, the liquid hydrogen storage system also includes a hydrogenation additive, and the hydrogenation additive is a polar solvent and / or a non-polar solvent.

[0023] Furthermore, the amount of hydrogenation additive added is 0.1 to 10 mL per gram of hydrogen storage component.

[0024] Furthermore, different hydrogen storage components are selected from the group consisting of benzene, toluene, ethylbenzene, o-xylene, p-xylene, styrene, phenylacetylene, anthracene, naphthalene, fluorene, aniline, carbazole, N-methylcarbazole, N-ethylcarbazole, N-n-propylcarbazole, N-isopropylcarbazole, N-n-butylcarbazole, indole, N-methylindole, N-ethylindole, N-propylindole, quinoline, isoquinoline, pyridine, pyrrole, furan, benzofuran, thiophene, pyrimidine and imidazole and their derivatives.

[0025] Furthermore, the polar solvent is selected from one or more of ethanol, methanol, ethyl ether, methyl ether, acetonitrile, ethyl acetate, formamide, isopropanol, n-butanol, dioxane, n-butyl ether, isopropyl ether, dichloromethane, chloroform and dichloroethane.

[0026] Furthermore, the non-polar solvent is selected from one or more of n-hexane, n-pentane, cyclohexane, mesitylene, carbon disulfide, petroleum ether and carbon tetrachloride.

[0027] Furthermore, the hydrogen storage system also includes a dehydrogenation additive, and the dehydrogenation additive is selected from one or more of decalin, mesitylene, petroleum ether and phenyl ether.

[0028] Furthermore, the amount of the dehydrogenation additive added is 0.1 to 10 mL per gram of the hydrogen storage component.

[0029] The liquid hydrogen storage carrier (i.e., liquid storage oil) undergoes a hydrogenation chemical reaction under the action of a hydrogenation catalyst to generate a liquid hydrogen source material (i.e., liquid hydrogen oil), and the liquid hydrogen source material undergoes a dehydrogenation chemical reaction under the action of a dehydrogenation catalyst to be reduced to a liquid hydrogen storage carrier.

[0030] like Figure 1 The secondary combustion system shown in the figure, which is a coupling between an organic liquid hydrogen supply system and a heat engine system, comprises a dehydrogenation system 1, a heat engine system 2, a heat stabilization system 3, and a control unit.

[0031] The dehydrogenation system dehydrogenates liquid hydrogen oil to generate hydrogen and stored oil. The hydrogen is sent to the heat engine system and the thermal stabilization system respectively through the control unit. The hydrogen performs work or generates electricity in the heat engine system. The high-temperature exhaust gas of the heat engine system and part of the hydrogen enter the thermal stabilization system. The thermal stabilization system is provided with a catalyst. The hydrogen and the high-temperature exhaust gas react and heat the exhaust gas after contacting the catalyst in the thermal stabilization system. The heated exhaust gas enters the dehydrogenation system to provide heat for the dehydrogenation reaction.

[0032] The thermal stabilization system includes a three-way valve 4, a temperature sensor 5 and a controller 6. The three-way valve is connected to the dehydrogenation system, the thermal engine system and the thermal stabilization system respectively. The temperature sensor is arranged in the dehydrogenation system for real-time monitoring of the temperature of the dehydrogenation system. According to the temperature detected by the temperature sensor, the controller controls the ratio of hydrogen flow to the thermal engine system and the thermal stabilization system. The three-way valve is an automatic control valve, which is controlled by feedback from the temperature sensor arranged in the dehydrogenation system. If the temperature of the dehydrogenation system is too high, the controller adjusts the opening of the three-way valve to reduce the hydrogen flow to the thermal stabilization system. If the temperature is too low, the controller increases the hydrogen flow.

[0033] The heat engine system can be a hydrogen internal combustion engine or a hydrogen gas turbine. When the heat engine performs external work, it will produce high-temperature exhaust gas. For gas turbines or hydrogen internal combustion engines, improving their efficiency will inevitably reduce the quality of high-temperature exhaust gas, resulting in insufficient heat in the dehydrogenation system. At this time, a heat stabilization system is needed to supplement heat.

[0034] The heat stabilization system is embedded with a highly efficient hydrogen catalyst, which performs a highly efficient catalytic combustion exothermic reaction on the hydrogen flowing into it when the high-temperature exhaust gas passes through, thereby increasing the quality of the high-temperature exhaust gas.

[0035] The hydrogen is connected to the thermal stabilization system through the flexible pipeline 7, which reduces the impact caused by the hydrogen flow fluctuation in the pipeline, reduces the thermal stress of the system, and allows the flexible pipeline to be freely arranged to reduce the system volume.

[0036] Furthermore, a flame arrester 8 is provided on the flexible pipeline, and the flame arrester also has the function of a one-way valve to prevent backfire.

[0037] Furthermore, an injector 9 may be provided on the flexible pipeline, and hydrogen is injected into the thermal stabilization system, so that the hydrogen is more easily contacted and diffused with the high-temperature exhaust gas, as shown in line A.

[0038] Furthermore, a mixer 10 may be provided on the flexible pipeline, and the hydrogen is mixed with the high-temperature tail gas and then enters the heat stabilization system, as shown in line B in the figure. Line A or B may be selected for use.

[0039] The thermal stabilization system is fixed with a catalyst, which is a bulk particle catalyst or an integral catalyst. A large flow of high-temperature exhaust gas is mixed with hydrogen and then contacts the catalyst. The hydrogen reacts with the oxygen in the exhaust gas to generate heat, thereby heating the high-temperature exhaust gas.

[0040] For hydrogen internal combustion engines, the thermal stabilization system is installed behind the supercharger, and the flexible pipe hydrogen outlet is installed behind the supercharger.

[0041] For hydrogen gas turbines, the heat stabilization system is installed behind the recuperator, and the flexible pipe hydrogen outlet is installed behind the recuperator.

[0042] Hydrogen undergoes two combustions, most of which occur in the heat engine system. When the heat output of the heat engine system is insufficient, secondary combustion will be carried out in real time. The secondary combustion occurs in the heat stabilization system behind the heat engine system. Therefore, this technology is called a secondary combustion heat stabilization technology that couples an organic liquid hydrogen supply system with a heat engine system.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A secondary combustion system that couples an organic liquid hydrogen supply system with a heat engine system. Features include: Dehydrogenation system, heat engine system, heat stabilization system, control unit; the dehydrogenation system performs dehydrogenation reaction on liquid hydrogen oil to generate hydrogen, and the hydrogen is respectively sent to the heat engine system and the heat stabilization system through the control unit, and the hydrogen performs work or generates electricity in the heat engine system, and the high-temperature tail gas of the heat engine system and part of the hydrogen enter the heat stabilization system, and the heat stabilization system is provided with a catalyst, and the hydrogen and the high-temperature tail gas react after contacting the catalyst in the heat stabilization system to further increase the temperature of the heated tail gas, and the heated tail gas enters the dehydrogenation system to provide heat for the dehydrogenation reaction; The thermal stabilization system comprises a three-way valve, a temperature sensor and a controller, wherein the three-way valve is respectively connected to the dehydrogenation system, the heat engine system and the thermal stabilization system; the temperature sensor is arranged in the dehydrogenation system to monitor the temperature of the dehydrogenation system in real time, and the controller controls the ratio of hydrogen flow to the heat engine system and the thermal stabilization system according to the temperature detected by the temperature sensor; Hydrogen is transported between the control system and the thermal stability system through a flexible pipeline; The flexible pipeline is provided with a flame arrester; The flexible pipeline is provided with an injector, and the hydrogen enters the thermal stabilization system through the injector; The flexible pipeline is provided with a mixer, which is connected to the thermal engine system at the same time. The high-temperature tail gas and hydrogen enter the thermal stabilization system after being mixed in the mixer.

2. The secondary combustion system of the organic liquid hydrogen supply system coupled with the heat engine system according to claim 1, Features: The heat engine system is a hydrogen internal combustion engine, a hydrogen fuel cell or a hydrogen gas turbine.

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