Efficient adjustable energy supply system based on organic liquid and hydrogen combustion engine

Abstract

The invention discloses an efficient adjustable energy supply system based on organic liquid and a hydrogen combustion engine. The efficient adjustable energy supply system comprises a dehydrogenation system, a hydrogen energy conversion device, a heat exchange system and a control system. The dehydrogenation system is used for generating stored oil and hydrogen from the hydrogen oil; the hydrogen energy conversion device comprises a hydrogen-fired engine and more than one of a proton exchange membrane fuel cell and an SOFC (Solid Oxide Fuel Cell); the heat exchange system is used for conducting waste heat of the hydrogen energy conversion device to the dehydrogenation system through a heat-conducting medium or recycling the waste heat; and the control system is used for controlling the output proportion of different power generation devices in the hydrogen energy conversion device and the reaction rate of the dehydrogenation system so as to realize the output of heat and electric energy in different proportions. When the dehydrogenation system based on the organic liquid hydrogen storage technology is coupled with a hydrogen engine, a proton exchange membrane fuel cell or an SOFC, the defect that a single hydrogen energy conversion device is coupled with the dehydrogenation system is overcome, the whole system is controlled, electric energy and heat of different proportions are flexibly output, and the comprehensive efficiency of the system is improved.

Description

Technical Field

[0001] The invention belongs to the field of chemical equipment, and in particular relates to a high-efficiency adjustable energy supply system based on organic liquid and a hydrogen combustion engine. Background Art

[0002] A hydrogen combustion engine is a power generation device that converts hydrogen and oxygen directly into electrical energy through an electrochemical reaction. The process does not involve combustion, there is no mechanical loss, the energy conversion rate is high, the products are only electricity, heat and water, and it runs smoothly with low noise. It is called the "ultimate environmentally friendly engine." However, hydrogen combustion engines are not efficient, and this method has a low power output.

[0003] The operating temperature of proton exchange membrane fuel cells is below 100°C, generally between 60 and 80°C.

[0004] Solid oxide fuel cell (SOFC) is a fully solid-state fuel cell that does not contain any liquid and does not have the risk of liquid corrosion and leakage. It uses yttria-doped zirconium oxide Y2O3-ZrO2 (YSZ) as an electrolyte and has oxygen ion conductivity at high temperatures. Like MCFC, it is a high-temperature fuel cell with an operating range of 500 to 1000°C. SOFC has high energy conversion efficiency, and the required heat can be used as waste heat from industrial production to further reduce energy consumption; battery waste heat can be used for combined heat and power generation, making the energy efficiency of the entire system reach more than 85%. However, too high a temperature brings about problems such as slow startup and short life, and places high demands on the heat resistance of the material. Summary of the invention

[0005] The purpose of the present invention is to provide a fuel cell and hydrogen engine cogeneration system based on organic liquid to address the shortcomings of hydrogen engines, proton exchange membrane fuel cells and solid oxide fuel cells when coupled with dehydrogenation systems, as well as how to control the entire system to achieve flexible output of electricity and heat in different proportions, improve the overall efficiency of the system.

[0006] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: an efficient and adjustable energy supply system based on organic liquid and hydrogen combustion engine, comprising: a dehydrogenation system, a hydrogen energy conversion device, a heat exchange system and a control system;

[0007] The dehydrogenation system is used to generate storage oil and hydrogen from hydrogen oil;

[0008] The hydrogen energy conversion device includes a hydrogen combustion engine, and includes one or more of a proton exchange membrane fuel cell and a SOFC, and the power generation device is arranged in parallel, and the hydrogen produced by the dehydrogenation system is used as the energy source of the power generation device;

[0009] The heat exchange system is used to transfer the heat released by the hydrogen energy conversion device to the dehydrogenation system through a heat transfer medium or to recycle it;

[0010] The control system is used to control the output ratios of different power generation devices in the hydrogen energy conversion device and the reaction rate of the dehydrogenation system to achieve outputs of heat and electric energy in different ratios.

[0011] Furthermore, the dehydrogenation system includes a dehydrogenation reactor, a gas-liquid separator and a buffer tank; the dehydrogenation reactor is used to generate storage oil and hydrogen from hydrogen oil, the gas-liquid separator is used to separate storage oil and hydrogen, and the buffer tank is used to stabilize the output hydrogen flow.

[0012] Furthermore, when the heat exchange system uses water or water vapor as the heat transfer medium, the number of heat exchange devices is more than one, and the heat transfer medium recovers heat from the hydrogen combustion engine or / and SOFC through the heat exchange device, transfers the heat to the dehydrogenation system, and then directly supplies heat to the outside through water vapor or hot water;

[0013] When a substance other than water or water vapor is used as the heat transfer medium, there are two heat exchange devices: a first heat exchange device and a second heat exchange device; the first heat exchange device is used to recover heat from the hydrogen-fired engine or / and SOFC through the heat transfer medium, and transfer the heat to the dehydrogenation system; the second heat exchange device is used to continue to recover heat from the heat transfer medium passing through the first heat exchange device, and output hot water or steam to the outside.

[0014] Furthermore, when the hydrogen energy conversion device includes a proton exchange membrane fuel cell, the heat exchange system also includes a third heat exchange device for recovering heat from the proton exchange membrane fuel cell through a heat transfer medium and outputting hot water to the outside.

[0015] Further, the control system adopts the following steps:

[0016] (1) Starting the hydrogen-fired engine, the heat generated is provided to the dehydrogenation system for dehydrogenation reaction, and the generated hydrogen is supplied to the hydrogen-fired engine;

[0017] (2) After the dehydrogenation system is stabilized, the SOFC and / or the proton exchange membrane fuel cell are started, and the amount of hydrogen entering the hydrogen combustion engine, SOFC and / or the proton exchange membrane fuel cell is adjusted according to real-time demand to output corresponding electrical energy and thermal energy to the outside.

[0018] Hydrogen combustion engines, proton exchange membrane fuel cells, and SOFCs can all generate waste heat during their working process. In order to make full use of this waste heat, a dehydrogenation system based on organic liquid hydrogen storage technology is coupled with the above-mentioned hydrogen energy conversion device, and waste heat is used to provide heat for the dehydrogenation reaction. This is a good method to improve the thermal utilization efficiency of the system. However, when the above-mentioned single hydrogen energy device is coupled with the dehydrogenation system, there are some defects: when the dehydrogenation system is coupled with the hydrogen combustion engine, the power output is small and the power generation efficiency is low; when the dehydrogenation system is coupled with the proton exchange membrane fuel cell, the low-grade waste heat cannot provide heat for the dehydrogenation system, and the thermal utilization rate is low; when the dehydrogenation system is coupled with the SOFC, the startup time is long, temperature maintenance is required when shutting down, and peak regulation is not flexible. When the present invention couples the dehydrogenation system based on organic liquid hydrogen storage technology with the hydrogen combustion engine, the proton exchange membrane fuel cell, and the SOFC, it overcomes the defects of coupling a single hydrogen energy conversion device with the dehydrogenation system, controls the entire system, and realizes the problem of flexible output of different proportions of electric energy and heat, thereby improving the overall efficiency of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of Example 1, which is a high-efficiency adjustable energy supply system based on organic liquid and hydrogen combustion engine.

[0020] Figure 2 This is a schematic diagram of the structure of Example 2, a highly efficient and adjustable energy supply system based on organic liquid and a hydrogen combustion engine. DETAILED DESCRIPTION

[0021] 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.

[0022] 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.

[0023] Hydrogen oil enters the dehydrogenation system through the hydrogen oil pump, and the stored oil generated by the reaction returns to the oil storage tank; the generated hydrogen enters the hydrogen energy conversion device (two or more combinations: proton exchange membrane fuel cell 1, hydrogen combustion engine 2, SOFC3), and the generated electricity is collected to the power output module. The generated waste heat of different grades is given different functions through the heat exchange system: for high-grade heat, it enters the dehydrogenation system to provide heat for the dehydrogenation reaction of the dehydrogenation system; secondly, the high-grade heat becomes medium-grade heat after coming out of the dehydrogenation system, and steam can be produced for users; for low-grade heat, hot water and other heat can be provided to users. And through the control system, the output ratio of the heat engine can be freely adjusted to achieve different proportions of heat and electricity output.

[0024] Generally, the dehydrogenation system 4 includes a dehydrogenation reactor, a gas-liquid separator, and a buffer tank. The reactor is a place where hydrogen oil is generated and stored; the gas-liquid separator is a place where oil is stored and hydrogen is separated; and the buffer tank is a place where the hydrogen flow is stabilized. Generally, there are multiple dehydrogenation reactors to cope with extreme power generation conditions. Generally, a heat exchange system can also be set in the dehydrogenation system.

[0025] Generally, the centralized heat exchange system 5 includes three groups of heat exchange systems. The third heat exchange system 8 is to recover low-grade heat and output hot water to the outside. Generally, a shell and tube heat exchanger, a plate heat exchanger, etc. can be used to form a heat exchange unit. The first heat exchange system 6 is to recover high-grade heat to provide heat for the dehydrogenation reaction. Generally, a shell and tube heat exchanger, a plate heat exchanger, etc. can be used to form a heat exchange unit. The second heat exchange system 7 is to recover medium-grade heat and output steam to the outside. Generally, a waste heat boiler can be used. Generally, when there is no demand for steam from the outside, the medium-grade heat to low-grade heat valve is opened, and hot water is output together.

[0026] Generally, since the dehydrogenation system directly produces hydrogen, SOFC can directly use hydrogen as fuel without the need for a reformer. A hydrogen regulating valve is set at the inlet of the hydrogen-fired engine, and a high-grade hot outlet is set at the outlet.

[0027] Generally, a hydrogen regulating valve is provided at the inlet of a proton exchange membrane fuel cell, and a low-grade heat outlet is provided at the outlet.

[0028] Generally, a hydrogen regulating valve is provided at the inlet of a hydrogen-fired engine, and a high-grade hot outlet is provided at the outlet.

[0029] Generally, the control system 9 mainly controls: the amount of hydrogen oil inflow (adjusted when the system balance state needs to be changed); hydrogen inflow ratio (adjusting the ratio of heat and electricity in real time according to the user end); medium and low quality heat ratio (according to the hot water / steam demand of the user end). Other controls that need to ensure the stable operation of the system are not described here (such as system pressure, liquid level control, interlocking alarm, etc.)

[0030] Example 1

[0031] A proton exchange membrane fuel cell 1, a hydrogen combustion engine 2, a SOFC 3, and a dehydrogenation system 4 are combined, such as Figure 1 shown.

[0032] When the system is used for a long period of time, when it is turned on, the hydrogen regulating valve of the hydrogen combustion engine is opened first, and the regulating valves of the SOFC and the proton exchange membrane fuel cell are closed. The high-grade heat produced by the hydrogen combustion engine is converted into medium-grade heat through the first heat exchange system 6 in the centralized heat exchange system 5, and the reduced heat is transported to the dehydrogenation system. After reaching stability, the SOFC regulating valve is opened, and the regulating valve of the hydrogen combustion engine is lowered at the same time. The hydrogen regulating valves of the two heat engines are adjusted by controlling the internal temperature of the dehydrogenation system (to ensure heat balance), thereby controlling different hydrogen amounts until a balance is reached, and the power and heat are completely supplied by the SOFC. At this time, the hydrogen regulating valve of the hydrogen combustion engine is closed.

[0033] The medium-grade heat after the first heat exchange system enters the second heat exchange system 7 to produce steam externally. When there is no steam demand, the valve can be adjusted by the control system to allow the medium-grade heat to enter the third heat exchange system 8 and be combined with the low-grade heat to provide hot water.

[0034] In this embodiment, a hydrogen-fired engine is used in the startup phase to avoid the problem of long SOFC startup time; the hydrogen-fired engine is turned off in the stable phase and the SOFC is turned on to avoid the problem of low power generation efficiency of the hydrogen-fired engine. When the application scenario requires more heat, the SOFC hydrogen intake is reduced and the hydrogen intake regulating valve of the hydrogen-fired engine is opened.

[0035] When the proton exchange membrane fuel cell is not working, the state with the highest power generation efficiency is to turn off the hydrogen combustion engine and only start the SOFC state, which corresponds to the state with the minimum heat generation; the state with the maximum heat generation is to turn off the SOFC and only start the hydrogen combustion engine, which corresponds to the state with the minimum power generation.

[0036] Therefore, the hydrogen consumption of the hydrogen-fired engine (the opening degree of the hydrogen-fired engine regulating valve) is used as the horizontal axis, and the hydrogen consumption of the SOFC (the opening degree of the SOFC regulating valve) is used as the vertical axis to mark different power generation and heat generation. After being incorporated into the control system, the control system can automatically control according to real-time needs and output different electricity and heat to the outside.

[0037] In this state, the maximum power generation of the system is limited by the rated power generation power of SOFC.

[0038] Furthermore, when the system needs to output at full power, when the above equilibrium state is reached, the control system increases the liquid inlet of the hydrogen oil pump, and opens all dehydrogenation reactors in the dehydrogenation system to produce more hydrogen, and opens the proton exchange membrane fuel cell regulating valve, and finally reaches the thermal balance of the dehydrogenation system, and the full power output state of SOFC, proton exchange membrane fuel cell and hydrogen combustion engine. In this state, the maximum power generation of the system is limited by the sum of the rated power generation of the proton exchange membrane fuel cell, hydrogen combustion engine and SOFC.

[0039] Example 2

[0040] A proton exchange membrane fuel cell 1, a hydrogen combustion engine 2, and a dehydrogenation system 4 are combined, such as Figure 2 shown.

[0041] In this state, when starting up, first open the hydrogen regulating valve of the hydrogen combustion engine, and close the regulating valve of the proton exchange membrane fuel cell. The high-grade heat produced by the hydrogen combustion engine is converted into medium-grade heat through the first heat exchange system 6, and the reduced heat is transported to the dehydrogenation system. After reaching stability, the regulating valve of the proton exchange membrane fuel cell is opened, and the amount of hydrogen oil is increased at the same time to increase the hydrogen output. By detecting and controlling the internal temperature of the dehydrogenation system (to ensure heat balance), the regulating valve of the proton exchange membrane fuel cell is adjusted until equilibrium is reached. Since the waste heat of the proton exchange membrane fuel cell is always low-grade heat, the reaction heat of the dehydrogenation system is completely supplied by the hydrogen combustion engine. Therefore, the equilibrium state of this embodiment is that the hydrogen combustion engine and the proton exchange membrane fuel cell work in parallel, and the difference between the high-grade heat and the medium-grade heat of the hydrogen combustion engine determines the hydrogen production of the entire system.

[0042] This embodiment uses a hydrogen-fired engine to avoid the problem that the waste heat of the proton exchange membrane fuel cell is of low quality and cannot provide heat for the dehydrogenation system; in the stable stage, the hydrogen-fired engine and the proton exchange membrane fuel cell are turned on at the same time, avoiding the problem of low power generation efficiency of the hydrogen-fired engine and effectively improving the overall efficiency of the system. When the application scenario requires more heat, the hydrogen intake of the proton exchange membrane fuel cell is lowered, and the hydrogen intake regulating valve of the hydrogen-fired engine is increased. The state with the highest power generation efficiency is the full power operation state of the fuel cell, which corresponds to the minimum heat generation state; the state with the maximum heat generation is to start only the hydrogen-fired engine, which corresponds to the minimum power generation state.

[0043] Therefore, the hydrogen consumption of the hydrogen engine (the opening degree of the hydrogen engine regulating valve) is used as the horizontal axis, and the hydrogen consumption of the proton exchange membrane fuel cell (the opening degree of the proton exchange membrane fuel cell regulating valve) is used as the vertical axis to mark different power generation and heat generation. If they are incorporated into the control system, the control system can automatically control according to real-time needs and output different electricity and heat to the outside.

[0044] In this embodiment, the maximum power generation of the system is limited by the sum of the rated power generation of the proton exchange membrane fuel cell and the hydrogen combustion engine.

[0045] It should be understood that the present invention is described by way of example only and can be modified within the scope and spirit of the present invention. The preferred specific embodiments of the present invention are described in detail above. It should be understood that ordinary skills in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, all technical solutions that can be obtained by technicians in the technical field through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A highly efficient and adjustable energy supply system based on organic liquid and hydrogen combustion engine, characterized in that include: Dehydrogenation system, hydrogen energy conversion device, heat exchange system and control system; The dehydrogenation system is used to generate storage oil and hydrogen from hydrogen oil; The hydrogen energy conversion device includes a hydrogen combustion engine and includes one or more of a proton exchange membrane fuel cell or a SOFC, and the power generation device is arranged in parallel, and the hydrogen produced by the dehydrogenation system is used as the energy source of the power generation device; The heat exchange system is used to transfer the waste heat of the hydrogen energy conversion device to the dehydrogenation system or to recycle it through a heat transfer medium; The control system is used to control the output ratios of different power generation devices in the hydrogen energy conversion device and the reaction rate of the dehydrogenation system to achieve outputs of heat and electric energy in different ratios.

2. The high-efficiency adjustable energy supply system based on organic liquid and hydrogen combustion engine according to claim 1 is characterized in that: The dehydrogenation system includes a dehydrogenation reactor, a gas-liquid separator and a buffer tank; the dehydrogenation reactor is used to generate storage oil and hydrogen from hydrogen oil, the gas-liquid separator is used to separate storage oil and hydrogen, and the buffer tank is used to smooth the fluctuation of hydrogen.

3. The high-efficiency adjustable energy supply system based on organic liquid and hydrogen combustion engine according to claim 1 is characterized in that: When the heat exchange system uses water or water vapor as the heat transfer medium, the number of heat exchange devices is more than one, and the heat transfer medium recovers heat from the hydrogen combustion engine or / and SOFC through the heat exchange device, transfers the heat to the dehydrogenation system, and then directly supplies heat to the outside through water vapor or hot water; When a substance other than water and water vapor is used as the heat transfer medium, there are two heat exchange devices: a first heat exchange device and a second heat exchange device; the first heat exchange device is used to recover heat from the hydrogen-fired engine and / or SOFC through the heat transfer medium, and transfer the heat to the dehydrogenation system; the second heat exchange device is used to continue to recover heat from the heat transfer medium passing through the first heat exchange device, and output hot water or steam to the outside.

4. The high-efficiency adjustable energy supply system based on organic liquid and hydrogen combustion engine according to claim 3 is characterized in that: When the hydrogen energy conversion device includes a proton exchange membrane fuel cell, the heat exchange system also includes a third heat exchange device for recovering heat from the proton exchange membrane fuel cell through a heat-conducting medium and outputting hot water to the outside.

5. The high-efficiency adjustable energy supply system based on organic liquid and hydrogen combustion engine according to claim 1 is characterized in that: The control system adopts the following steps: (1) Starting the hydrogen-fired engine, the heat generated is provided to the dehydrogenation system for dehydrogenation reaction, and the generated hydrogen is supplied to the hydrogen-fired engine; (2) After the dehydrogenation system is stabilized, the SOFC and / or the proton exchange membrane fuel cell are started, and the amount of hydrogen entering the hydrogen combustion engine, SOFC and / or the proton exchange membrane fuel cell is adjusted according to real-time demand to output corresponding electrical energy and thermal energy to the outside.

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