A solid oxide fuel cell and fluidized bed integrated power generation device and method

Abstract

The present invention provides a power generation device and method integrating a solid oxide fuel cell and a fluidized bed, including a fluidized bed gasifier, wherein a plurality of tubular solid oxide fuel cell monomers are coaxially arranged in the longitudinal direction in the fluidized bed gasifier; two adjacent tubular solid oxide fuel cell monomers are connected end to end through a connecting pipe to form a fuel cell group. The present invention utilizes a fluidized bed reactor to gasify solid carbon fuel, thereby solving the problems of feeding, limited contact between solid fuel and electrode, and low reaction activity of carbon fuel itself; and the direct integration of fuel cell and carbon gasification reaction enables CO2 generated by the electrochemical reaction of the fuel cell to directly gasify carbon particles, thereby promoting the progress of carbon gasification reaction; the heat generated by the operation of SOFC itself can be directly supplied to the endothermic process of carbon gasification itself, thereby reducing energy loss and achieving a higher energy conversion rate.

Description

Technical Field

[0001] The present invention relates to fuel cell technology, in particular to a power generation device and method integrating a solid oxide fuel cell and a fluidized bed. Background Art

[0002] Compared with traditional thermal power generation, fuel cell technology is a power generation method that can directly convert chemical energy in fuel into electrical energy. It is not limited by the Carnot cycle and has the advantages of high efficiency, cleanliness, and low noise. Solid oxide fuel cell (SOFC) is a typical high-temperature fuel cell (600-1000℃). Compared with other fuel cells, the high-temperature working environment has the advantages of low catalyst cost, strong fuel type compatibility, and high fuel energy conversion rate. Direct carbon solid oxide fuel cell (DC-SOFC) directly uses solid carbon-containing fuel, and the overall reaction is C(s)+O 2 (g) →CO 2 (g), its theoretical efficiency can reach 100%. Compared with gaseous fuels such as hydrogen and natural gas, solid carbon-containing fuels can use coal, biomass, solid waste, etc. as fuels, with a wider range of fuel sources, high energy density, greater safety, and easy storage and transportation.

[0003] However, for traditional direct carbon solid oxide fuel cells, the solid fuel needs to be in close enough contact with the anode for the electrochemical reaction to occur, and this contact is difficult to sustain as the carbon is consumed. The reactivity of the carbon fuel itself is also relatively low compared to that of the gas, and during continuous operation, the problem of feeding the solid fuel also needs to be solved urgently. Therefore, these factors limit the working performance of direct carbon solid oxide fuel cells. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a power generation device and method integrating a solid oxide fuel cell and a fluidized bed, which effectively solves the problems of limited contact between solid fuel and electrode and low reaction activity of carbon fuel itself.

[0005] The present invention is achieved through the following technical solutions:

[0006] A power generation device integrating a solid oxide fuel cell and a fluidized bed, comprising a fluidized bed gasifier, wherein a plurality of tubular solid oxide fuel cell monomers are coaxially arranged in the fluidized bed gasifier along the longitudinal direction;

[0007] Two adjacent tubular solid oxide fuel cell monomers are connected end to end through a connecting tube to form a fuel cell group; the tubular solid oxide fuel cell monomers are composed of a porous anode, a solid oxide electrolyte and a porous cathode from the outside to the inside;

[0008] The bottom opening of the tubular solid oxide fuel cell unit located at the bottom of the fluidized bed gasifier is a cathode air inlet, and the top opening of the tubular solid oxide fuel cell unit located at the top of the fluidized bed gasifier is a cathode air outlet;

[0009] The fluidized bed gasifier is provided with a gasifier air inlet at the bottom, a gasifier air outlet at the top, and an air distribution plate above the gasifier air inlet.

[0010] Preferably, a plurality of fuel cell groups are evenly arranged in the fluidized bed gasifier.

[0011] Preferably, an exhaust gas circulation device is further provided, and the gasifier gas outlet at the top of the fluidized bed gasifier is connected to the gasifier gas inlet at the bottom of the fluidized bed gasifier through the exhaust gas circulation device.

[0012] Preferably, two adjacent tubular solid oxide fuel cell monomers in each fuel cell group are connected in series via a current collecting wire.

[0013] Preferably, the bottom of the tubular solid oxide fuel cell unit located at the bottom of the fluidized bed gasifier is connected to a gas outlet pipe, and the gas outlet pipe extends out of the fluidized bed gasifier.

[0014] Furthermore, the gas outlet pipe passes through the fluidized bed gasifier through the air distribution plate.

[0015] Furthermore, the connection between the air outlet pipe and the air distribution plate is sealed with high temperature resistant glue.

[0016] Preferably, the top of the tubular solid oxide fuel cell unit located at the top of the fluidized bed gasifier is connected to an air inlet pipe, and the air inlet pipe extends out of the fluidized bed gasifier.

[0017] Furthermore, the connection between the air inlet pipe and the fluidized bed gasifier is sealed with high temperature resistant glue.

[0018] A power generation method, the power generation device adds solid carbon fuel into a fluidized bed gasifier, heats the fluidized bed gasifier, introduces air into the interior of a fuel cell group from a cathode air inlet, introduces fluidized fuel gas from the bottom of the fluidized bed gasifier, and collects current generated by the fuel cell group.

[0019] Compared with the prior art, the present invention has the following beneficial technical effects:

[0020] When the present invention is used, solid carbon fuel is added into the fluidized bed gasifier, and the fluidized bed gasifier is heated. Air is introduced into the cathode outlet, and the air undergoes an electrochemical reaction at the cathode. CO is introduced into the fluidized bed gasifier from the bottom. 2 Gas, CO 2The gas enters the fluidized bed gasifier through the air distribution plate, fluidizes the solid carbon fuel, and the CO generated by the gasification of the solid carbon fuel is used as the fuel gas to undergo an electrochemical reaction at the porous anode. Compared with CN201110217478.6, the main feature of this device is the difference in the arrangement direction of the fuel cell. The present invention arranges the tubular fuel cell parallel to the flow channel of the gas-solid two-phase flow. This improvement can bring many benefits: first, it is conducive to the improvement of battery performance. In the fluidized bed gasifier, the concentration of fuel gas CO gradually increases with the height of the bed. When placed longitudinally (parallel to the gas-solid two-phase flow), the arrangement height of the battery can be adjusted according to the gasification characteristics of different carbon-based fuels, so that the concentration of CO on the anode surface of the tubular fuel cell is close to the equilibrium concentration under the corresponding working conditions. By adjusting the battery spacing and the air flow velocity, the gasification rate of the carbon particles is matched with the consumption rate of CO by the battery, and the CO concentration on the anode surface is more balanced, thereby improving the battery performance. Secondly, it is conducive to the integration and assembly of the battery pack. When placed horizontally, the CO concentration at different heights is different. This difference will cause differences in battery performance, which is not conducive to the assembly and integration of battery packs; when placed vertically, the fuel atmospheres of each tubular fuel cell are very similar, and the battery performance is similar, which is conducive to the assembly and integration of batteries. Thirdly, it is conducive to the thermal coupling between the gasification process and the battery. Since the gasification of solid carbon is an endothermic process, and the fuel cell will release a certain amount of heat when it is running, the vertical placement of the fuel cell improves the degree of thermal coupling between the two, which is conducive to the temperature control of the system and reduces the probability of local overheating or overcooling. Finally, it is conducive to extending the battery life. The battery is placed vertically (parallel to the gas-solid two-phase flow) to reduce the impact and collision of solid particles on the electrode surface, thereby reducing the damage to the battery due to the gas-solid two-phase flow and extending the battery life. The present invention uses a fluidized bed reactor to gasify solid carbon fuel, which solves the problems of feeding, limited contact between solid fuel and electrode, and low reaction activity of carbon fuel itself; and the direct integration of fuel cell and carbon gasification reaction makes the CO generated by the electrochemical reaction of the fuel cell 2 , can directly gasify carbon particles, promoting the carbon gasification reaction; the heat generated by the SOFC itself can be directly supplied to the endothermic process of carbon gasification itself, reducing energy loss and achieving a higher energy conversion rate. Each group of tubular fuel cells adopts the connection method of SOFC monomers connected end to end through connecting tubes, which is easy to assemble and also conducive to the expansion and enlargement of fuel cell stacks.

[0021] Furthermore, each group of fuel cells is evenly distributed in the carbon fuel bed, making the performance of the entire fuel cell stack more balanced and stable.

[0022] Furthermore, the tail gas discharged from the fluidized bed gasifier passes through the tail gas circulation device and re-enters the fluidized bed gasifier to participate in the carbon gasification process, thereby improving material utilization and saving resources.

[0023] Furthermore, connecting through collecting wires can both meet the electronic collection needs and reduce costs.

[0024] Furthermore, sealing with high temperature resistant glue can prevent the cathode from being exposed to external CO 2 Gas influence. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is the overall device diagram of the present invention;

[0026] Figure 2 It is a cross-sectional view of a single body of a tubular solid oxide fuel cell;

[0027] Figure 3 and Figure 4 Schematic diagram of the wind distribution plate.

[0028] Figure 5 The CO concentration in the gasifier changes with height under different current densities.

[0029] In the figure: 1. connecting pipe; 2. tubular solid oxide fuel cell monomer; 3. fluidized bed gasifier; 4. solid carbon fuel; 5. cathode gas outlet; 6. fluidized fuel gas; 7. nut; 8. air distribution plate; 9. gas outlet pipe; 10. current collecting wire; 11. fluidized bed tail gas; 12. cathode gas inlet; 13. porous anode; 14. solid oxide electrolyte; 15. porous cathode; 16. gas inlet pipe. DETAILED DESCRIPTION

[0030] The present invention is further described in detail below in conjunction with specific embodiments, which are intended to explain the present invention rather than to limit it.

[0031] like Figure 1 As shown, the power generation device integrating tubular solid oxide fuel cells and fluidized bed of the present invention comprises a fluidized bed gasifier 3, in which a plurality of tubular solid oxide fuel cell monomers 2 are arranged in the longitudinal direction.

[0032] The tubular solid oxide fuel cell monomer 2 is open at both ends, each tubular solid oxide fuel cell monomer 2 is coaxially arranged, and two adjacent tubular solid oxide fuel cell monomers 2 are connected end to end through a connecting pipe 1 to form a fuel cell group. The inner diameter of the connecting pipe 1 is equal to the inner diameter of the tubular solid oxide fuel cell monomer 2, and the connecting pipe 1 and the tubular solid oxide fuel cell monomer 2 are fixed by welding. A plurality of fuel cell groups are arranged in the fluidized bed gasifier 3.

[0033] The bottom of the tubular solid oxide fuel cell unit 2 located at the bottom of the fluidized bed gasifier 3 is connected to the cathode outlet pipe 9, the cathode outlet pipe 9 extends out of the fluidized bed gasifier 3, and the bottom opening of the cathode outlet pipe 9 serves as the cathode outlet port 5; the top of the tubular solid oxide fuel cell unit 2 located at the top of the fluidized bed gasifier 3 is connected to the cathode inlet pipe 16, the cathode inlet pipe 16 extends out of the fluidized bed gasifier 3, and the top opening of the cathode inlet pipe 16 serves as the cathode inlet port 12. The inner diameters of the cathode outlet pipe 9 and the cathode inlet pipe 16 are equal to the inner diameter of the tubular solid oxide fuel cell unit 2. In order to install the fuel cell stack, the top of the fluidized bed gasifier and the air distribution plate 8 are perforated ( Figure 3 , Figure 4 ), the size of the hole matches the radial size of the cathode outlet pipe 9 and the cathode inlet pipe 16, and the top of the fluidized bed gasifier and the position of the air distribution plate hole correspond one to one.

[0034] The bottom plate of the fluidized bed gasifier 3 is an air distribution plate 8, and the cathode gas outlet pipe 9 is connected to the air distribution plate 8 through a metal gasket and a nut 7, and is sealed with a high temperature resistant glue.

[0035] The gasifier gas outlet at the top of the fluidized bed gasifier 3 is connected to the gasifier gas inlet at the bottom. When in use, the fluidized bed gasifier 3 contains solid carbon fuel 4.

[0036] The tubular solid oxide fuel cell unit 2 is composed of a porous anode 13, a solid oxide electrolyte 14 and a porous cathode 15 from the outside to the inside. Two adjacent tubular solid oxide fuel cell units 2 in each fuel cell group are connected in series via a current collecting wire 10.

[0037] The method of using the present invention is as follows: heat the fluidized bed gasifier 3 to maintain the operating temperature at 800-1000°C, introduce air into the cathode air inlet 12, and introduce fluidized fuel gas 6 (CO 2) into the gasifier air inlet at the bottom of the fluidized bed gasifier 3. 2 Gas), CO 2 The gas enters the fluidized bed gasifier 3 through the air distribution plate 8, fluidizes the solid carbon fuel 4, and the CO generated by the gasification of the solid carbon fuel 4 acts as a fuel gas to undergo an electrochemical reaction at the porous anode 13; by gradually increasing the CO 2 The gas flow rate can make the bed particles in a fixed bed, dispersed fluidized bed or bubbling bed state, and the heat and mass transfer in the fluidized bed is gradually enhanced. The fluidized bed tail gas 11 discharged from the gasifier outlet of the fluidized bed gasifier 3 is re-introduced into the fluidized bed gasifier 3 through the exhaust gas circulation device. The operating temperature and the inlet gas flow rate are adjusted to make the fluidized bed reactor reach different carbon gasification reaction rates, thereby controlling the actual working output power of the fuel cell, so as to make the device more flexible and applicable to different working conditions.

[0038] like Figure 5As shown in the figure, the CO concentration in the gasifier changes with height under different current densities. 2 Increased to 8000A / m 2 When the battery is placed at a certain height and the air intake rate is adjusted, the concentration distribution of CO in the gasifier can be controlled to optimize the battery performance.

[0039] Embodiment 1:

[0040] 1) The device includes 64 tubular solid oxide fuel cell monomers 2, solid carbon fuel, a fluidized bed gasifier, an air distribution plate, a number of connecting pipes, a current collecting wire, and an exhaust gas circulation device.

[0041] 2) The outer diameter of the tubular solid oxide fuel cell monomer 2 is 1.4 cm, the inner diameter is 1 cm, and the height is 10 cm; the outer diameter of the connecting pipe is 1.3 cm, and the inner diameter is 1 cm; coal powder with a particle size of 50-150 microns is used as solid carbon fuel.

[0042] 3) Each fuel cell group is composed of three tubular solid oxide fuel cell monomers 2, both ends of which are connected end to end through a connecting pipe ( Figure 2 ), the connecting pipe and the fluidized bed gasifier are fixed by welding. The monomers of each fuel cell group are connected in series by current collecting wires.

[0043] 4) Drill 4*4 holes with a diameter of 1.3 cm on the top and air distribution plate of the fluidized bed gasifier ( Figure 3 ), the size of the hole matches the radial size of the connecting pipe, and the top of the fluidized bed gasifier and the position of the air distribution plate hole correspond one to one.

[0044] 5) Arrange 4*4 groups of fuel cell groups in the fluidized bed gasifier according to the above-mentioned punching positions, the upper end of the topmost tubular solid oxide fuel cell monomer 2 in each group passes through the top of the fluidized bed gasifier, and the lower end of the bottommost tubular solid oxide fuel cell monomer 2 passes through the air distribution plate. The air inlet pipe and the gasifier, the air outlet pipe and the air distribution plate are fixed by nuts and metal gaskets, and sealed with high temperature resistant glue.

[0045] 6) Place coal powder at a certain height in the fluidized bed gasifier. Heat the fluidized bed gasifier to maintain the operating temperature at 850°C, and introduce CO from the bottom of the fluidized bed reactor. 2 Gas, air is introduced into the cathode air inlet.

[0046] 7) Control the flow rate so that the bed particles are in a fixed bed, dispersed fluidized bed or bubbling bed state, and adjust the actual working output power range of the fuel cell.

[0047] 8) The tail gas discharged from the fluidized bed gasifier passes through the tail gas circulation device and re-enters the fluidized bed gasifier to participate in the carbon gasification process.

[0048] Embodiment 2:

[0049] 1) The device includes 105 tubular solid oxide fuel cell monomers 2, solid carbon fuel, a fluidized bed gasifier, an air distribution plate, a number of connecting pipes, a current collecting conductor, and an exhaust gas circulation device.

[0050] 2) The outer diameter of the tubular solid oxide fuel cell monomer 2 is 1.4 cm, the inner diameter is 1 cm, and the height is 10 cm; the outer diameter of the connecting tube is 1.3 cm, and the inner diameter is 1 cm; coconut shell with a particle size of 75-300 microns is used as the solid carbon fuel.

[0051] 3) Each fuel cell group is composed of three tubular solid oxide fuel cell monomers 2, both ends of which are connected end to end through a connecting pipe ( Figure 2 ), the connecting tube and the tubular solid oxide fuel cell monomer 2 are fixed by welding. The monomers of each group of fuel cell groups are connected in series by current collecting wires.

[0052] 4) Punch 5*7 holes with a diameter of 1.3 cm on the top and air distribution plate of the fluidized bed gasifier ( Figure 4 ), the size of the hole matches the radial size of the connecting pipe, and the top of the fluidized bed gasifier and the position of the air distribution plate hole correspond one to one.

[0053] 5) Arrange 5*7 groups of fuel cell groups in the fluidized bed gasifier according to the above-mentioned punching positions, the upper end of the topmost tubular solid oxide fuel cell monomer 2 in each group passes through the top of the fluidized bed gasifier, and the lower end of the bottommost tubular solid oxide fuel cell monomer 2 passes through the air distribution plate. The air inlet pipe and the gasifier, the air outlet pipe and the air distribution plate are fixed by nuts and metal gaskets, and sealed with high temperature resistant glue.

[0054] 6) Place coconut shells at a certain height in the fluidized bed gasifier. Heat the fluidized bed gasifier to maintain the operating temperature at 900°C, and introduce CO from the bottom of the fluidized bed gasifier. 2 Gas, air is introduced into the cathode air inlet.

[0055] 7) Control the flow rate so that the bed particles are in a fixed bed, dispersed fluidized bed or bubbling bed state, and adjust the actual working output power range of the fuel cell.

[0056] 8) The tail gas discharged from the fluidized bed gasifier passes through the tail gas circulation device and re-enters the fluidized bed gasifier to participate in the carbon gasification process.

[0057] The present invention utilizes the advantages of a gas-solid fluidized bed reactor that can fully mix and react gas and particles and has high heat and mass transfer efficiencies. Through direct coupling of a solid oxide fuel cell and a fluidized bed, carbon fuel is converted into CO through a gasification reaction in the fluidized bed. CO directly enters the electrode as a fuel to participate in the electrochemical reaction to generate electricity, thereby solving the problems of limited contact between the solid fuel and the electrode and low reaction activity of the carbon fuel itself.

Claims

1. A power generation device integrating a solid oxide fuel cell and a fluidized bed, characterized in that: It comprises a fluidized bed gasification furnace (3), wherein a plurality of tubular solid oxide fuel cell monomers (2) are coaxially arranged in the longitudinal direction in the fluidized bed gasification furnace (3); Two adjacent tubular solid oxide fuel cell monomers (2) are connected end to end via a connecting tube (1) to form a fuel cell group; the tubular solid oxide fuel cell monomers (2) are provided with a porous anode (13), a solid oxide electrolyte (14) and a porous cathode (15) from the outside to the inside; The bottom opening of the tubular solid oxide fuel cell unit (2) located at the bottom of the fluidized bed gasification furnace (3) serves as a cathode gas outlet (5), and the top opening of the tubular solid oxide fuel cell unit (2) located at the top of the fluidized bed gasification furnace (3) serves as a cathode gas inlet (12); The fluidized bed gasifier (3) is provided with a gasifier air inlet at the bottom, a gasifier air outlet at the top, and an air distribution plate (8) is provided above the gasifier air inlet.

2. The power generation device integrating a solid oxide fuel cell and a fluidized bed according to claim 1, characterized in that: A plurality of fuel cell groups are evenly arranged in the fluidized bed gasification furnace (3).

3. The power generation device integrating a solid oxide fuel cell and a fluidized bed according to claim 1, characterized in that: An exhaust gas circulation device is also provided, and a gasifier gas outlet at the top of the fluidized bed gasifier (3) and a gasifier gas inlet at the bottom of the fluidized bed gasifier (3) are connected via the exhaust gas circulation device.

4. The power generation device integrating a solid oxide fuel cell and a fluidized bed according to claim 1, characterized in that: Two adjacent tubular solid oxide fuel cell monomers (2) in each fuel cell group are connected in series via a current collecting wire (10).

5. The power generation device integrating a solid oxide fuel cell and a fluidized bed according to claim 1, characterized in that: The bottom of the tubular solid oxide fuel cell unit (2) located at the bottom of the fluidized bed gasifier (3) is connected to a gas outlet pipe (9), and the gas outlet pipe (9) extends out of the fluidized bed gasifier (3).

6. The power generation device integrating a solid oxide fuel cell and a fluidized bed according to claim 5, characterized in that: The gas outlet pipe (9) passes through the air distribution plate (8) and passes out of the fluidized bed gasification furnace (3).

7. The power generation device integrating a solid oxide fuel cell and a fluidized bed according to claim 6, characterized in that: The connection between the air outlet pipe (9) and the air distribution plate (8) is sealed with high temperature resistant glue.

8. The power generation device integrating a solid oxide fuel cell and a fluidized bed according to claim 1, characterized in that: The top of the tubular solid oxide fuel cell unit (2) located at the top of the fluidized bed gasifier (3) is connected to an air intake pipe (16), and the air intake pipe (16) extends out of the fluidized bed gasifier (3).

9. The power generation device integrating a solid oxide fuel cell and a fluidized bed according to claim 8, characterized in that: The connection between the air inlet pipe (16) and the fluidized bed gasifier (3) is sealed with high temperature resistant glue.

10. A method for generating electricity, characterized in that: Based on the power generation device described in any one of claims 1 to 9, solid carbon fuel is added to a fluidized bed gasifier, and the fluidized bed gasifier is heated, air is introduced into the interior of the fuel cell stack from the cathode air inlet, fluidized fuel gas is introduced from the bottom of the fluidized bed gasifier, and the current generated by the fuel cell stack is collected.

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