A power generation system based on coupling of an electrochemical hydrogen pump with a liquid fuel reforming gas fuel cell

Abstract

The application belongs to the technical field of fuel cell, and relates to a power generation system of a fuel cell based on an electrochemical hydrogen pump coupling liquid fuel reforming gas, which realizes reforming gas purification and hydrogen pressurization simultaneously through the electrochemical hydrogen pump; while improving the power of the fuel cell stack, the energy efficiency is improved and the energy cost is reduced through a thermal coupling design; according to the power load demand of a user, a control unit is used to realize a one-key adjustment operation mode to stably output electric energy in a wide load range; the system proposed in the application fundamentally avoids problems such as low hydrogen partial pressure of an anode of a reforming gas fuel cell and partial poisoning of a fuel cell catalyst caused by reverse water gas shift; while meeting the power demand of a user, the swelling of a proton exchange membrane is avoided, the performance and service life of the fuel cell stack are improved, and the quality and efficiency of a distributed power generation system based on fuel cell utilization are promoted.

Description

Technical Field

[0001] This invention belongs to the field of fuel cell technology and relates to a power generation system based on an electrochemical hydrogen pump coupled with a liquid fuel reforming gas fuel cell. The system purifies the reforming gas and simultaneously pressurizes the hydrogen through the electrochemical hydrogen pump; while increasing the power of the fuel cell stack, it improves energy utilization efficiency and reduces energy costs through thermal integration design; according to the user's power load demand, the control unit has a "one-click adjustment" operation mode, ensuring stable power output over a wide load range; the system proposed in this invention fundamentally avoids problems such as low hydrogen partial pressure at the anode of reforming gas fuel cells and catalyst poisoning caused by reverse water-gas conversion; while meeting the user's power demand, it avoids proton exchange membrane swelling, improves the performance and lifespan of the fuel cell stack, and is conducive to promoting the quality and efficiency improvement of distributed power generation systems based on fuel cells. Background Technology

[0002] Distributed energy systems based on hydrogen fuel cells are key to achieving the decarbonization and "dual-carbon" goals of future energy systems. However, the unique properties of hydrogen (H2) make its storage and transportation particularly difficult. Currently, hydrogen needs to be stored or transported in liquid form (-253℃) or under high pressure (≥30MPa). On the one hand, the production of liquid hydrogen requires extreme environments such as high pressure and cryogenics, resulting in huge investment and operating costs, making it difficult to promote on a large scale. On the other hand, the harsh storage conditions for high-pressure or liquid hydrogen and the resulting poor transportation safety are major obstacles to the widespread adoption of hydrogen energy. Therefore, developing a new hydrogen energy supply method to overcome the current bottlenecks in hydrogen transportation and storage is crucial.

[0003] On-site hydrogen production based on liquid fuel reforming offers an engineering solution to the hydrogen source problem in distributed energy systems utilizing fuel cells. On the one hand, liquid fuels such as methanol, ethanol, glycerol, dimethyl ether, and biodiesel are liquids at room temperature and pressure, making them easy to transport and highly safe. On the other hand, liquid fuels are widely available; methanol and ethanol, for example, can be obtained through green processes such as carbon dioxide hydrogenation and biomass conversion. These processes have low carbon emissions, and liquid fuels possess high energy density, making them promising for application in the context of my country's "dual-carbon" goals. Based on these characteristics, hydrogen fuel cell systems integrating liquid fuel reforming units have emerged. In this system, liquid fuel enters the reforming unit after passing through a preheater, vaporizer, and superheater. The reforming method can be steam reforming or autothermal reforming, which completely converts the fuel. The reformer outlet yields reformed fuel gas, containing ≥50 mol% hydrogen (H2), ≥20 mol% carbon dioxide (CO2), and approximately 1.0 mol% carbon monoxide (CO). Further, the reformed gas / air mixture enters a selective oxidation reactor, converting the CO to CO2, resulting in an outlet gas CO content below 10 ppm. At this point, the reformed gas meets the requirements of the fuel cell. Then, the CO-free reformed gas, after heat exchange, enters the fuel cell anode, where some of the hydrogen (H2) is converted to protons (H+) under the action of a platinum catalyst. + ), H + The proton exchange membrane reaches the cathode catalyst layer and reacts with oxygen (O2) to produce water (H2O), which is discharged from the cathode side. Air is introduced into the cathode side of the fuel cell. Electrons are exported through the external circuit and output as electrical energy. The exhaust gas from the outlet of the fuel cell anode side enters the combustion furnace to power the entire fuel cell system. However, this process still has shortcomings. On the one hand, since the fuel cell is supplied with reformed gas, which contains impurities such as carbon dioxide, the high current density of the fuel cell results in a lower hydrogen partial pressure at the anode, leading to a higher concentration overpotential and consequently a decrease in stack voltage and power. Furthermore, CO2 and H2 undergo a reverse water-gas shift reaction under the conditions of an electric field and a platinum catalyst, generating adsorbed CO and causing partial catalyst poisoning, further reducing stack voltage and power. More importantly, due to the constraints of on-site reforming hydrogen production unit operation and site conditions, the reformed gas may contain unconverted fuel molecules (e.g., alcohols, ethers, etc.). Long-term operation of the battery under complex mixed gas feed conditions leads to swelling of the proton exchange membrane, reduced proton conductivity, and severely shortened fuel cell lifespan. Therefore, from an engineering perspective, fuel cells based on reformed gas are not suitable for long-term operation. Based on these problems, a highly efficient hydrogen purification device is urgently needed to improve fuel cell power generation systems based on reformed gas.

[0004] Electrochemical hydrogen pumps are a highly efficient hydrogen separation technology that combines hydrogen purification and compression, providing a new solution for process intensification in fuel cell systems utilizing reformed gas. Under DC power, hydrogen (H2) in the reformed gas at the anode dissociates into protons and electrons in the anode catalyst layer. Electrons are conducted to the cathode via an external circuit, while protons travel through a proton exchange membrane to the cathode catalyst layer and recombine with electrons to form hydrogen, outputting pressurized pure hydrogen at the cathode. This process is energy-efficient (hydrogen has the lowest dissociation voltage, approaching 0mV), the electrochemical hydrogen pump purification equipment has a small footprint and is easy to operate, allows for ambient temperature and pressure feeding, and can obtain pressurized pure hydrogen at the cathode. It not only solves the reformed gas purification problem but also increases the hydrogen partial pressure at the fuel cell anode, fundamentally addressing issues such as low hydrogen partial pressure at the anode and catalyst poisoning in fuel cells utilizing reformed gas. This improves fuel cell performance and lifespan, providing a new technical solution for process intensification in fuel cell power generation systems.

[0005] To address the problems of low hydrogen partial pressure at the anode and catalyst poisoning in existing fuel cell power generation systems based on reformed gas, the electrochemical hydrogen pump coupled with reformed gas fuel cell system proposed in this invention fundamentally avoids these issues. It addresses the problems caused by low hydrogen partial pressure at the anode and catalyst poisoning due to reverse water-gas conversion. While meeting user power demands, it improves the performance and lifespan of the fuel cell stack, thus promoting the improvement of efficiency and effectiveness of distributed power generation systems based on fuel cells. Summary of the Invention

[0006] The purpose of this invention is to provide a power generation system based on an electrochemical hydrogen pump coupled with a liquid fuel reformer fuel cell. This system fundamentally avoids problems such as low hydrogen partial pressure at the anode and catalyst poisoning caused by reverse water-gas shift in reformer fuel cells. While meeting user power demands, it improves the performance and lifespan of the fuel cell stack, thus promoting the improvement of efficiency and effectiveness of distributed power generation systems based on fuel cells. To achieve the above objectives, the technical solution of this invention is as follows:

[0007] A power generation system based on an electrochemical hydrogen pump coupled with a liquid fuel reforming gas fuel cell, the power generation system based on an electrochemical hydrogen pump coupled with a liquid fuel reforming gas fuel cell includes a preheating unit, a reforming unit, a hydrogen purification and power generation unit, and a system auxiliary unit;

[0008] The preheating unit includes a No. 1 mixer 1, a raw material transfer pump 2, a preheater 3, a vaporizer 4, and a superheater 5. The inlet of the No. 1 mixer 1 is connected to the raw material water and methanol fuel respectively, and the outlet of the No. 1 mixer 1 is connected to the inlet of the raw material transfer pump 2. The outlet of the raw material transfer pump 2 is connected to the cold end inlet of the preheater 3, the cold end outlet of the preheater 3 is connected to the cold end inlet of the vaporizer 4, the cold end outlet of the vaporizer 4 is connected to the cold end inlet of the superheater 5, and the cold end outlet of the superheater 5 is connected to the superheated steam inlet of the fuel reformer 6 of the reforming unit. The hot end inlet of the superheater 5 is connected to the outlet of the selective oxidation reactor 8, the hot end outlet of the superheater 5 is connected to the hot end inlet of the preheater 3, and the hot end outlet of the preheater 3 is connected to the anode side inlet of the electrochemical hydrogen pump 9 and the inlet of the No. 3 mixer 10 respectively.

[0009] The reforming unit includes a fuel reformer 6, a second mixer 7, and a selective oxidation reactor 8. The reformed gas outlet of the fuel reformer 6 is connected to the inlet of the second mixer 7 to achieve mixing with air from the air compressor 14. The outlet of the second mixer 7 is connected to the inlet of the selective oxidation reactor 8. The cooled flue gas outlet of the fuel reformer 6 is connected to the hot end inlet of the vaporizer 4. The high-temperature flue gas inlet of the fuel reformer 6 is connected to the high-temperature flue gas outlet of the combustion furnace 13.

[0010] The hydrogen purification and power generation unit includes an electrochemical hydrogen pump 9, a third mixer 10, a fuel cell 11, and a gas-liquid separator 12. The cathode-side outlet of the electrochemical hydrogen pump 9 is connected to the inlet of the third mixer 10, the outlet of the third mixer 10 is connected to the anode-side inlet of the fuel cell 11, and the cathode-side outlet of the fuel cell 11 is connected to the inlet of the gas-liquid separator 12. The anode-side outlet of the electrochemical hydrogen pump 9 is connected to the inlet of the combustion furnace 13. The anode-side outlet of the fuel cell 11 is connected to both the anode-side inlet of the electrochemical hydrogen pump 9 and the inlet of the third mixer 10.

[0011] The system auxiliary unit mainly includes a combustion furnace 13 and an air compressor 14; wherein, the air from the external environment is compressed by the compressor 14 and connected to the selective oxidation reactor 8, the fuel cell 11 and the combustion furnace 13 respectively; the inlet of the combustion furnace 13 is also connected to methanol fuel and the oxygen-deficient air outlet after water removal by the gas-liquid separator 12; the combustion furnace 13 provides heat for the reforming reaction and vaporization process in the fuel reformer 6 and the vaporizer 4 by burning hydrogen-containing gas and liquid fuel.

[0012] The method for generating electricity using the above-mentioned power generation system based on an electrochemical hydrogen pump coupled with a liquid fuel reforming gas fuel cell includes the following steps: The power generation system has two operating modes: (I) pre-purification mode and (II) post-purification mode.

[0013] (I) Pre-purification mode: When the user's power demand is high, methanol fuel is supplied to the combustion furnace 13 and the No. 1 mixer 1, respectively, to provide power to the system and to fully mix with the raw material water; the mixed liquid from the No. 1 mixer 1 is pressurized by the raw material transfer pump 2 and then enters the preheater 3 to be preheated to saturation; the saturated liquid at the cold end outlet of the preheater 3 enters the vaporizer 4 and is converted into saturated steam; the saturated steam at the cold end outlet of the vaporizer 4 enters the superheater 5 for further heating; the superheated steam at the cold end outlet of the superheater 5 enters the fuel reforming unit 6, where the superheated steam is further heated in the fuel reforming unit 6. The reformer 6, under the action of the internal catalyst, converts the gas into reformed gas, which includes hydrogen, carbon dioxide, and carbon monoxide. The reformed gas is mixed with pressurized air from air compressor 14 in mixer #2 to obtain a reformed gas / air mixture, which enters selective oxidation reactor 8 to oxidize CO into CO2. The outlet gas of selective oxidation reactor 8 passes through the hot end of heater 5 and preheater 3 for heat recovery to obtain cooled and purified reformed gas. The cooled and purified reformed gas enters the anode side of electrochemical hydrogen pump 9, where hydrogen on the anode side dissociates into protons and electrons on the surface of the anode catalyst layer. Electrons are conducted to the cathode via the external circuit, while protons pass through the proton exchange membrane to the catalyst layer on the cathode side, where they recombine with electrons to form hydrogen molecules, resulting in pressurized pure hydrogen gas being output from the cathode side. This pressurized pure hydrogen gas then enters the anode side of the fuel cell 11 after passing through mixer #3 10. The outlet gas from the anode side of the fuel cell 11 enters mixer #3 10 and mixes with the pressurized pure hydrogen gas before entering the anode side of the fuel cell 11 to participate in the hydrogen cycle. Air, after being pressurized by air compressor 14, is also supplied to the cathode side of the fuel cell 11 and the combustion furnace 13. The pressurized air supplied to the cathode side of the fuel cell 11 is used in the fuel cell combustion process. After consuming some oxygen at the cathode side of battery 11, it is converted into oxygen-deficient air and discharged from the cathode. The oxygen-deficient air enters the gas-liquid separator 12 to remove free water. The oxygen-deficient air after water removal enters the combustion furnace 13 to provide oxygen for the fuel combustion process. The high-temperature flue gas at the outlet of the combustion furnace 13 passes through the reformer 6 to provide heat for the reforming process. The cooled flue gas from the reformer 6 passes through the vaporizer 4 to provide heat for the vaporization process of the liquid raw materials. After the temperature decreases, it is converted into exhaust gas and discharged. The hydrogen-containing gas from the anode side of the electrochemical hydrogen pump 9 enters the combustion furnace 13 for combustion. The high-temperature flue gas produced provides energy for the entire system.

[0014] (II) Post-purification mode: When the user's power demand is low, the difference from (I) pre-purification mode is that the cooled and purified reformed gas obtained after the selective oxidation reactor 8 outlet gas recovers heat from the hot end of the heater 5 and preheater 3 does not enter the anode side of the electrochemical hydrogen pump 9, but enters the No. 3 mixer 10. After mixing with the pure hydrogen from the cathode side of the electrochemical hydrogen pump 9, it enters the anode side of the fuel cell 11; the outlet gas from the anode side of the fuel cell 11 enters the anode side of the electrochemical hydrogen pump 9; the pressurized pure hydrogen output from the cathode side of the electrochemical hydrogen pump 9 enters the mixer 10 and enters the anode side of the fuel cell 11 to provide hydrogen for the fuel cell.

[0015] The beneficial effects of this invention are as follows: This system achieves efficient purification of reformed gas and simultaneous hydrogen pressurization through an electrochemical hydrogen pump; while increasing the power of the fuel cell stack, it improves system energy efficiency and reduces power generation costs through process thermal coupling design. The system proposed in this invention fundamentally avoids problems such as low hydrogen partial pressure at the anode of liquid fuel reformed gas fuel cells and catalyst poisoning caused by reverse water-gas conversion. While meeting user electricity demands, it improves the performance and lifespan of the fuel cell stack, which is conducive to promoting the quality and efficiency improvement of distributed power generation systems based on fuel cells. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the system of the present invention.

[0017] 1. Mixer #1; 2. Feed pump; 3. Preheater; 4. Vaporizer; 5. Superheater; 6. Fuel reformer; 7. Mixer #2; 8. Selective oxidation reactor; 9. Electrochemical hydrogen pump; 10. Mixer #3; 11. Fuel cell; 12. Gas-liquid separator; 13. Combustion furnace; 14. Air compressor.

[0018] 1-1 Methanol fuel; 1-2 Feed water; 1-3 First stage methanol fuel; 1-4 Second stage methanol fuel; 1-5 Mixed liquid; 1-6 Pressurized liquid; 1-7 Saturated liquid; 1-8 Saturated steam; 1-9 Superheated steam;

[0019] 2-1 Reformer gas; 2-2 Reformer gas / air mixture; 2-3 Selective oxidation reactor outlet gas; 2-4 First-stage cooling and purification reformer gas; 2-5 Second-stage cooling and purification reformer gas; 2-6 First-stage outlet gas of No. 1 tee (S-1); 2-7 Electrochemical hydrogen pump anode side inlet gas; 2-8 Pressurized pure hydrogen; 2-9 Fuel cell anode side inlet gas; 2-10 Fuel cell anode side outlet gas; 2-11 First-stage outlet gas of No. 3 tee (S-3); 2-12 First-stage outlet gas of No. 4 tee (S-4); 2-13 Second-stage outlet gas of No. 3 tee (S-3); 2-14 Second-stage outlet gas of No. 4 tee (S-4); 2-15 Electrochemical hydrogen pump anode side outlet gas.

[0020] 3-1 Air; 3-2 First stage pressurized air; 3-3 Second stage pressurized air; 3-4 Third stage pressurized air; 3-5 Oxygen-deficient air; 3-6 Oxygen-deficient air after water removal;

[0021] 4-1 High-temperature flue gas; 4-2 Cooled flue gas; 4-3 Emission flue gas;

[0022] 5-1 Free water;

[0023] V-1 First system control valve; V-2 Second system control valve; V-3 Third system control valve; V-4 Fourth system control valve; V-5 Fifth system control valve; S-1 No. 1 tee; S-2 No. 2 tee; S-3 No. 3 tee; S-4 No. 4 tee. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the invention.

[0025] See Figure 1 The system of the present invention includes a first mixer 1, a raw material delivery pump 2, a preheater 3, a vaporizer 4, a superheater 5, a fuel reformer 6, a second mixer 7, a selective oxidation reactor 8, an electrochemical hydrogen pump 9, a third mixer 10, a fuel cell 11, a gas-liquid separator 12, a combustion furnace 13, and an air compressor 14.

[0026] This system achieves efficient purification of reformed gas and simultaneous hydrogen pressurization through an electrochemical hydrogen pump. While increasing the power of the fuel cell stack, it also improves system energy efficiency and reduces power generation costs through process thermal coupling design. The system proposed in this invention fundamentally avoids problems such as low hydrogen partial pressure at the anode of reformed gas fuel cells and partial catalyst poisoning caused by reverse water-gas conversion. It meets users' electricity needs while improving the performance and lifespan of the fuel cell stack, which is conducive to promoting the quality and efficiency improvement of distributed power generation systems based on fuel cells.

[0027] Example 1 (Liquid fuel: methanol fuel, pre-purification mode)

[0028] When user power demand is high, the pre-purification mode is activated, where the reformed gas is purified by an electrochemical hydrogen pump and supplied to the fuel cell as pure hydrogen to maximize power output. Through the "one-button adjustment" operation mode of the control unit, the first system regulating valve V-1, the fourth system regulating valve V-4, and the fifth system regulating valve V-5 are opened; the second system regulating valve V-2 and the third system regulating valve V-3 are closed. The liquid fuel used in the power generation system is methanol. The fuel cell in the power generation system is a low-temperature proton exchange membrane fuel cell, and the catalyst is specifically limited to a platinum-carbon noble metal catalyst with a platinum content >20%. The electrochemical hydrogen pump in the power generation system is a low-temperature electrochemical hydrogen pump, and the proton exchange membrane type is a perfluorosulfonic acid proton exchange membrane. Methanol fuel 1-1 is split into two streams. The second-stage methanol fuel 1-4 supplies power to the combustion furnace 13. The first-stage methanol fuel 1-3 and raw material water 1-2 are fully mixed in mixer #1, with a volume ratio of 1.5:1 between raw material water 1-2 and first-stage methanol fuel 1-3. The mixed liquid 1-5 is pressurized by the raw material transfer pump 2 and transformed into pressurized liquid 1-6 at a pressure of 300 kPa and a temperature of 40°C. The pressurized liquid 1-6 then enters the preheater 3 for preheating to saturation. The saturated liquid 1-7 from the cold end outlet of preheater 3 enters vaporizer 4 and is converted into saturated steam 1-8 at a temperature of 125℃. The saturated steam 1-8 from the cold end outlet of evaporator 4 enters superheater 5 and is further heated to 255℃. The superheated steam 1-9 from the cold end outlet of superheater 5 enters fuel reformer 6. Under the action of the catalyst inside fuel reformer 6, the superheated steam 1-9 is converted into reformed gas 2-1, in which the hydrogen (H2) content is 65.6 mol% and carbon dioxide is 1-9. The CO2 content is 21.0 mol%, and the carbon monoxide (CO) content is 1.2 mol%. The temperature of the reformed gas 2-1 is 255℃, and the pressure is 300 kPa. To remove the CO poison from the fuel cell catalyst, the reformed gas 2-1 and the first-stage pressurized air 3-2 are mixed in mixer #2 7 to obtain the reformed gas / air mixture 2-2, which enters the selective oxidation reactor 8 to oxidize the CO to CO2. The CO content in the selective oxidation reactor outlet gas 2-3 is less than 10 ppm, and the temperature is 346℃. Since the selective oxidation reactor outlet gas 2-3 has a high temperature, heat recovery is required. After heat recovery at the hot end of the heater 5 and preheater 3, the outlet gas 2-3 is cooled to 80℃. The second-stage cooled and purified reformed gas 2-5 enters the anode side of the electrochemical hydrogen pump 9 through the first three-way valve S-1, the first system regulating valve V-1, and the second three-way valve S-2. The hydrogen (H2) on the anode side dissociates into protons (H2O) on the surface of the anode catalyst layer. + ) and electrons (e -Electrons are conducted to the cathode via the external circuit, and protons reach the catalyst layer on the cathode side through the proton exchange membrane, where they recombine with electrons to form hydrogen molecules, outputting pressurized pure hydrogen gas 2-8 at a pressure of 300 kPa on the cathode side. The electrochemical hydrogen pump 9 applies a potential of 100 mV. After passing through mixer 10, the gas enters the anode side of fuel cell 11. The outlet gas 2-15 on the anode side of the electrochemical hydrogen pump contains some hydrogen and enters the combustion furnace 13 to provide energy for the system. The outlet gas 2-10 on the anode side of fuel cell 11 passes through three-way valve S-3, fifth system regulating valve V-5, four-way valve S-4, and fourth system regulating valve V-4 before entering mixer 10 and mixing with pressurized pure hydrogen gas 2-8. After mixing, the gas enters the anode side of fuel cell 11 to participate in the hydrogen cycle.

[0029] Air 3-1, after being pressurized by air compressor 14, is divided into three streams: first-stage pressurized air 3-2, second-stage pressurized air 3-3, and third-stage pressurized air 3-4, which are supplied to selective oxidation reactor 8, fuel cell 11, and combustion furnace 13, respectively. The third-stage pressurized air 3-4 supplied to fuel cell 11, after some oxygen is consumed at the cathode of fuel cell 11, is converted into oxygen-deficient air 3-5 and discharged from the cathode, containing approximately 5.0 mol% oxygen. The oxygen-deficient air 3-5 then enters gas-liquid separator 12 to remove impurities. After water removal (5-1), the oxygen-deficient air (3-6) enters the combustion furnace (13) to provide oxygen for the fuel combustion process, thereby maximizing the oxygen utilization rate of the system and reducing the compression power consumption of the air compressor (14). The high-temperature flue gas (4-1) at the outlet of the combustion furnace (13) has a temperature of 880°C. The high-temperature flue gas (4-1) passes through the reformer (6) to provide heat for the reforming process, and the temperature is reduced to 260°C. Further, the cooled flue gas (4-2) passes through the vaporizer (4) to provide heat for the raw material vaporization process. After the temperature is reduced to 135°C, it becomes the emission flue gas (4-3) and is emitted.

[0030] Example II (Liquid fuel: methanol fuel, post-purification mode)

[0031] When power demand is low, users can activate the post-purification mode, where a mixture of reformed gas and pure hydrogen supplies hydrogen to the fuel cell. The gas exiting from the anode side of the fuel cell enters the cathode side of the electrochemical hydrogen pump, where some hydrogen is separated and mixed with the reformed gas. This appropriately increases the hydrogen partial pressure, reduces the parasitic power consumption of the electrochemical hydrogen pump, and ensures the system's output power is at an appropriate level. Through the "one-click adjustment" operation mode of the control unit, the second system regulating valve V-2, the third system regulating valve V-3, and the fourth system regulating valve V-4 are open; the first system regulating valve V-1 and the fifth system regulating valve V-5 are closed. The liquid fuel used in the power generation system is methanol. The fuel cell in the power generation system is a low-temperature proton exchange membrane fuel cell, and the catalyst is specifically limited to a platinum-carbon noble metal catalyst with a platinum content >20%. The electrochemical hydrogen pump in the power generation system is a low-temperature electrochemical hydrogen pump, and the proton exchange membrane type is a perfluorosulfonic acid proton exchange membrane.Methanol fuel 1-1 is split into two streams. The second-stage methanol fuel 1-4 supplies power to the combustion furnace 13. The first-stage methanol fuel 1-3 and raw material water 1-2 are fully mixed in mixer #1, with a mixing ratio of 1.5:1. The mixed liquid 1-5 is pressurized by the raw material pump 2 to become pressurized liquid 1-5 at a pressure of 300 kPa and a temperature of 40°C. The pressurized liquid 1-6 enters the preheater 3 and is preheated to saturation at a temperature of 118°C. The saturated liquid 1-7 from the cold end outlet of the preheater 3 enters the vaporization chamber. Vaporizer 4 converts the vaporized steam into saturated steam 1-8 at a temperature of 125℃. The saturated steam 1-8 from the cold end outlet of vaporizer 4 enters superheater 5 and is further heated to 255℃. The superheated steam 1-9 from the cold end outlet of superheater 5 enters fuel reformer 6. Under the action of a catalyst inside the reformer, the superheated steam 1-9 is converted into reformed gas 2-1, containing 65.6 mol% hydrogen (H2), 21.0 mol% carbon dioxide (CO2), and 1.2 mol% carbon monoxide (CO). Reformed gas 2-1 has a temperature of 255℃ and a pressure of 300 kPa. After removing the CO poison from the fuel cell catalyst, the reformed gas 2-1 is mixed with the first-stage pressurized air 3-2 in mixer #2 7. The reformed gas / air mixture 2-2 then enters the selective oxidation reactor 8. The CO content in the outlet gas 2-3 of the selective oxidation reactor is less than 10 ppm, and the temperature is 346℃. Due to the high temperature of the outlet gas 2-3, heat recovery is required. After heat recovery at the hot end of the heater 5 and preheater 3, the outlet gas 2-3 is cooled to 80℃. The second stage of cooling and purification reforming... Gas 2-5 enters mixer 10 after passing through three-way valve S-1, third system regulating valve V-3, four-way valve S-4, and fourth system regulating valve V-4. Pressurized pure hydrogen 2-8 and fuel cell anode side inlet gas 2-9 enter the anode side of fuel cell 11. After consuming some hydrogen, fuel cell anode side outlet gas 2-10 has a hydrogen content of 55.0 mol%. It enters the anode side of electrochemical hydrogen pump 9 after passing through three-way valve S-3, second system regulating valve V-2, and two-way valve S-2. The hydrogen (H2) on the anode side dissociates into protons (H) on the surface of the anode catalyst layer. + ) and electrons (e - Electrons are conducted to the cathode side via the external circuit, and protons reach the catalyst layer on the cathode side via the proton exchange membrane, where they recombine with electrons to form hydrogen molecules. Pressurized pure hydrogen gas 2-8 is output on the cathode side at a pressure of 300 kPa, and the applied potential of the electrochemical hydrogen pump 9 is 100 mV. The outlet gas 2-15 on the anode side of the electrochemical hydrogen pump contains some hydrogen and enters the combustion furnace 13 to provide energy for the system. The pressurized pure hydrogen gas 2-8 is mixed with the outlet gas of the first stage of the No. 4 three-way S-4 of 2-12 to supply hydrogen to the fuel cell 11.

[0032] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A power generation system based on an electrochemical hydrogen pump coupled with a liquid fuel reforming gas fuel cell, characterized in that: The power generation system based on an electrochemical hydrogen pump coupled with a liquid fuel reforming gas fuel cell includes a preheating unit, a reforming unit, a hydrogen purification and power generation unit, and a system auxiliary unit. The preheating unit includes a No. 1 mixer (1), a raw material conveying pump (2), a preheater (3), a vaporizer (4), and a superheater (5). The inlet of the No. 1 mixer (1) is connected to the raw material water and methanol fuel respectively, and the outlet of the No. 1 mixer (1) is connected to the inlet of the raw material conveying pump (2). The outlet of the raw material conveying pump (2) is connected to the cold end inlet of the preheater (3), and the cold end outlet of the preheater (3) is connected to the cold end inlet of the vaporizer (4). (4) The cold end outlet is connected to the cold end inlet of the superheater (5), and the cold end outlet of the superheater (5) is connected to the superheated steam inlet of the fuel reformer (6) of the reforming unit; the hot end inlet of the superheater (5) is connected to the outlet of the selective oxidation reactor (8), and the hot end outlet of the superheater (5) is connected to the hot end inlet of the preheater (3). The hot end outlet of the preheater (3) is connected to the anode side inlet of the electrochemical hydrogen pump (9) and the inlet of the No. 3 mixer (10), respectively. The reforming unit includes a fuel reformer (6), a second mixer (7), and a selective oxidation reactor (8); the reformed gas outlet of the fuel reformer (6) is connected to the inlet of the second mixer (7) to achieve mixing with air from the air compressor (14); the outlet of the second mixer (7) is connected to the inlet of the selective oxidation reactor (8); the cooled flue gas outlet of the fuel reformer (6) is connected to the hot end inlet of the vaporizer (4); and the high-temperature flue gas inlet of the fuel reformer (6) is connected to the high-temperature flue gas outlet of the combustion furnace (13). The hydrogen purification and power generation unit includes an electrochemical hydrogen pump (9), a third mixer (10), a fuel cell (11), and a gas-liquid separator (12); the cathode outlet of the electrochemical hydrogen pump (9) is connected to the inlet of the third mixer (10), the outlet of the third mixer (10) is connected to the anode inlet of the fuel cell (11), and the cathode outlet of the fuel cell (11) is connected to the inlet of the gas-liquid separator (12); the anode outlet of the electrochemical hydrogen pump (9) is connected to the inlet of the combustion furnace (13); the anode outlet of the fuel cell (11) is connected to the anode inlet of the electrochemical hydrogen pump (9) and the inlet of the third mixer (10), respectively. The system auxiliary unit mainly includes a combustion furnace (13) and an air compressor (14); the air from the external environment is compressed by the compressor (14) and connected to the selective oxidation reactor (8), fuel cell (11) and combustion furnace (13) respectively; the inlet of the combustion furnace (13) is also connected to methanol fuel and the oxygen-deficient air outlet after water removal by the gas-liquid separator (12); the combustion furnace (13) provides heat for the reforming reaction and vaporization process in the fuel reformer (6) and vaporizer (4) by burning hydrogen-containing gas and liquid fuel; When the user's power demand is high, the hot end outlet of the preheater (3) is connected to the anode side inlet of the electrochemical hydrogen pump (9), and the anode side outlet of the fuel cell (11) is connected to the inlet of the third mixer (10); when the user's power demand is low, the hot end outlet of the preheater (3) is connected to the inlet of the third mixer (10), and the anode side outlet of the fuel cell (11) is connected to the anode side inlet of the electrochemical hydrogen pump (9).

2. A method for generating electricity using a power generation system based on an electrochemical hydrogen pump coupled with a liquid fuel reforming gas fuel cell as described in claim 1, characterized in that, The steps are as follows: The power generation system has two operating modes: (I) pre-purification mode and (II) post-purification mode; (I) Pre-purification mode: When the user's power demand is large, methanol fuel is supplied to the combustion furnace (13) and the No. 1 mixer (1) respectively, for powering the system and for fully mixing with the raw material water; the mixed liquid from the No. 1 mixer (1) is pressurized by the raw material conveying pump (2) and then enters the preheater (3) to be preheated to saturation; the saturated liquid at the cold end outlet of the preheater (3) enters the vaporizer (4) and is converted into saturated steam. The saturated steam at the cold end outlet of the vaporizer (4) enters the superheater (5) and is further heated. The superheated steam at the cold end outlet of the superheater (5) enters the fuel reformer (6). The superheated steam is converted into reformed gas under the action of the catalyst inside the fuel reformer (6). The reformed gas includes hydrogen, carbon dioxide and carbon monoxide. The reformed gas and pressurized air from the air compressor (14) are mixed in the No. 2 mixer (7) to obtain a reformed gas / air mixture, which enters the selective oxidation reactor (8) to oxidize CO into CO2. The gas from the outlet of the selective oxidation reactor (8) is cooled and purified after heat recovery at the hot end of the heater (5) and preheater (3). The cooled and purified reformed gas enters the anode side of the electrochemical hydrogen pump (9). The hydrogen on the anode side dissociates into protons and electrons on the surface of the anode catalyst layer. The electrons are conducted to the cathode through the external circuit, and the protons reach the cathode catalyst layer through the proton exchange membrane and recombine with the electrons to form hydrogen molecules. Pressurized pure hydrogen is output on the cathode side. The pressurized pure hydrogen enters the anode side of the fuel cell (11) after passing through the No. 3 mixer (10). The gas from the anode side of the fuel cell (11) enters the No. 3 mixer (10) and is mixed with the pressurized pure hydrogen before entering the fuel cell. The anode side of the fuel cell (11) participates in the hydrogen cycle; the air is pressurized by the air compressor (14) and then delivered to the cathode side of the fuel cell (11) and the combustion furnace (13) respectively; among them, the pressurized air supplied to the cathode side of the fuel cell (11) consumes part of the oxygen on the cathode side of the fuel cell (11) and is converted into oxygen-deficient air and discharged from the cathode; the oxygen-deficient air enters the gas-liquid separator (12) to remove free water, and the oxygen-deficient air after water removal enters the combustion furnace (13) to provide oxygen for the fuel combustion process; the high-temperature flue gas at the outlet of the combustion furnace (13) passes through the fuel reformer (6) to provide heat for the reforming process; the cooled flue gas from the fuel reformer (6) passes through the vaporizer (4) to provide heat for the vaporization process of liquid raw materials, and after the temperature decreases, it is converted into exhaust gas for emission; the hydrogen-containing gas from the anode side of the electrochemical hydrogen pump (9) enters the combustion furnace (13) for combustion, and the generated high-temperature flue gas provides energy for the entire system; (II) Post-purification mode: When the user's power demand is small, the difference from (I) pre-purification mode is that the cooled and purified reformed gas obtained after the selective oxidation reactor (8) outlet gas recovers heat from the hot end of the heater (5) and preheater (3) does not enter the anode side of the electrochemical hydrogen pump (9), but enters the No. 3 mixer (10), mixes with the pure hydrogen gas from the cathode side of the electrochemical hydrogen pump (9), and then enters the anode side of the fuel cell (11); the outlet gas from the anode side of the fuel cell (11) enters the anode side of the electrochemical hydrogen pump (9); the pressurized pure hydrogen gas output from the cathode side of the electrochemical hydrogen pump (9) enters the No. 3 mixer (10), enters the anode side of the fuel cell (11) to provide hydrogen gas for the fuel cell.

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