CN114649548A - Multi-stage fuel cell system and energy conversion method thereof - Google Patents
Multi-stage fuel cell system and energy conversion method thereof Download PDFInfo
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- 239000000446 fuel Substances 0.000 title claims abstract description 488
- 238000006243 chemical reaction Methods 0.000 title claims abstract description 48
- 238000000034 method Methods 0.000 title claims abstract description 12
- 239000003546 flue gas Substances 0.000 claims abstract description 57
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims abstract description 52
- 239000007789 gas Substances 0.000 claims description 70
- 239000002912 waste gas Substances 0.000 claims description 54
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 36
- 238000001816 cooling Methods 0.000 claims description 13
- 238000003303 reheating Methods 0.000 claims description 6
- 239000004215 Carbon black (E152) Substances 0.000 claims description 4
- 229930195733 hydrocarbon Natural products 0.000 claims description 4
- 150000002430 hydrocarbons Chemical class 0.000 claims description 4
- 210000004027 cell Anatomy 0.000 description 226
- 239000000203 mixture Substances 0.000 description 5
- 239000000779 smoke Substances 0.000 description 4
- 239000002918 waste heat Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 239000000376 reactant Substances 0.000 description 3
- 239000002737 fuel gas Substances 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000010763 heavy fuel oil Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000002035 prolonged effect Effects 0.000 description 2
- 230000036647 reaction Effects 0.000 description 2
- 238000002407 reforming Methods 0.000 description 2
- 238000006467 substitution reaction Methods 0.000 description 2
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 210000003850 cellular structure Anatomy 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000013589 supplement Substances 0.000 description 1
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04007—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids related to heat exchange
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04007—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids related to heat exchange
- H01M8/04014—Heat exchange using gaseous fluids; Heat exchange by combustion of reactants
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04007—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids related to heat exchange
- H01M8/04029—Heat exchange using liquids
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04082—Arrangements for control of reactant parameters, e.g. pressure or concentration
- H01M8/04089—Arrangements for control of reactant parameters, e.g. pressure or concentration of gaseous reactants
- H01M8/04097—Arrangements for control of reactant parameters, e.g. pressure or concentration of gaseous reactants with recycling of the reactants
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04298—Processes for controlling fuel cells or fuel cell systems
- H01M8/04694—Processes for controlling fuel cells or fuel cell systems characterised by variables to be controlled
- H01M8/04701—Temperature
- H01M8/04708—Temperature of fuel cell reactants
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04298—Processes for controlling fuel cells or fuel cell systems
- H01M8/04694—Processes for controlling fuel cells or fuel cell systems characterised by variables to be controlled
- H01M8/04701—Temperature
- H01M8/04716—Temperature of fuel cell exhausts
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/06—Combination of fuel cells with means for production of reactants or for treatment of residues
- H01M8/0662—Treatment of gaseous reactants or gaseous residues, e.g. cleaning
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/14—Fuel cells with fused electrolytes
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/24—Grouping of fuel cells, e.g. stacking of fuel cells
- H01M8/249—Grouping of fuel cells, e.g. stacking of fuel cells comprising two or more groupings of fuel cells, e.g. modular assemblies
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/14—Fuel cells with fused electrolytes
- H01M2008/147—Fuel cells with molten carbonates
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/50—Fuel cells
Abstract
The invention discloses a multi-stage fuel cell system, which comprises a top fuel cell, a bottom fuel cell, a flue gas preheater, an intermediate reheater, a fuel pre-converter, a fuel preheater, an intermediate cooler, a cooler and CO2A trapping device;the flue gas preheater, the top fuel cell cathode, the middle reheater and the bottom fuel cell cathode are sequentially connected through pipelines; the flue gas preheater is respectively connected with the fuel pre-converter and the cathode of the bottom fuel cell through pipelines; the fuel pre-converter, the anode inlet of the top fuel cell and the anode outlet of the top fuel cell are respectively connected with the fuel preheater; fuel preheater, intercooler, intermediate reheater, bottom fuel cell anode, cooler, CO2The trapping devices are connected in sequence through pipelines. The invention also discloses an energy conversion method of the system. The invention improves the overall fuel utilization rate and energy conversion efficiency of the multi-stage fuel cell system and prolongs the overall service life of the system.
Description
Technical Field
The present invention relates to fuel cells, and more particularly, to a multi-stage fuel cell system and a method for converting energy thereof.
Background
The fuel cell can directly convert chemical energy stored in fuel into electric energy, so that the fuel cell is not limited by Carnot cycle, avoids energy loss of intermediate links, and has the advantages of high energy conversion efficiency, cleanness, low noise, fuel diversity and the like.
Currently, fuel cell technologies include proton exchange membrane fuel cells, high-temperature solid oxide fuel cells, molten salt fuel cells, and the like. Among them, molten carbonate fuel cell technology can not only efficiently generate electricity, but also serve as CO compared to other fuel cell technologies2One way of trapping.
CN107690722A discloses a high efficiency fuel cell system comprising a top fuel cell assembly and a bottom fuel cell assembly, wherein the top fuel cell assembly has a larger number of fuel cells. The system mixes the anode exhaust of the top fuel cell and then leads the mixed anode exhaust to the bottom fuel cell component,thereby separating high-concentration CO while fully utilizing oxygen in the flue gas to generate electric power2. The technical defects are as follows: the top fuel cell assembly has a greater number of fuel cells and the mixing of the top fuel cell anode exhaust into the bottom fuel cell assembly results in:
(1) the flow through the bottom fuel cell anode is significantly increased;
(2) in the fuel mixed gas flowing through the anode of the bottom fuel cell, the fuel content is too low, so that the fuel utilization rate of the bottom fuel cell is obviously reduced, and the overall efficiency of the fuel cell system is reduced;
(3) the inlet temperature of the anode mixture flowing through the bottom fuel cell increases significantly (due to the absorption of process heat from the top fuel cell), which can cause the bottom fuel cell to operate at a higher temperature than the top fuel cell, and the bottom fuel cell or the top fuel cell deviates from the optimal operating temperature of the fuel cell system, resulting in 1) uneven temperature distribution between different fuel cells (i.e., the top fuel cell and the bottom fuel cell) within the fuel cell system; 2) the temperature difference between the inlet and the outlet of the bottom fuel cell is increased, the durability of the galvanic pile is reduced, the performance attenuation of the galvanic pile is accelerated, and the service life of a fuel cell system is further shortened.
Disclosure of Invention
In order to overcome the above drawbacks and deficiencies of the prior art, an object of the present invention is to provide a multi-stage fuel cell system, which improves the overall fuel utilization and energy conversion efficiency of the multi-stage fuel cell system, and improves the overall life of the multi-stage fuel cell system.
Another object of the present invention is to provide an energy conversion method of the multi-stage fuel cell system.
The purpose of the invention is realized by the following technical scheme:
a multi-stage fuel cell system includes a top fuel cell, a bottom fuel cell, a flue gas preheater, an intermediate reheater, a fuel pre-converter, a fuel preheater, an intermediate cooler, a cooler, and CO2A trapping device;
the topping fuel cell comprises a topping fuel cell anode and a topping fuel cell cathode;
the bottom fuel cell comprises a bottom fuel cell anode and a bottom fuel cell cathode;
the flue gas preheater, the top fuel cell cathode, the middle reheater and the bottom fuel cell cathode are sequentially connected through pipelines;
the flue gas preheater is respectively connected with the fuel pre-converter and the cathode of the bottom fuel cell through pipelines;
the fuel pre-converter, the anode inlet of the top fuel cell and the anode outlet of the top fuel cell are respectively connected with the fuel preheater;
the fuel preheater, the intercooler, the intermediate reheater, the bottom fuel cell anode, the cooler, and CO2The trapping devices are connected in sequence through pipelines.
Preferably, the CO is2The trapping device is connected with the fuel preheater through a pipeline.
Preferably, the condensed water pipelines of the cooler and the intercooler are both connected with the fuel pre-converter.
Preferably, the CO is2The trapping device is connected with the cathode of the bottom fuel cell through a pipeline.
Preferably, the fuel preheater is connected to the bottom fuel cell anode via a conduit.
Preferably, the fuel preheater is connected with an external cold water supplement pipeline.
Preferably, the topping fuel cell comprises a plurality of topping fuel cell units; the cathode of each top fuel cell unit is respectively connected with the flue gas preheater and the intermediate reheater through pipelines;
the anode inlet and the anode outlet of each top fuel cell unit are connected to the fuel preheater, respectively.
Preferably, the bottoming fuel cell comprises a plurality of bottoming fuel cell units;
the flue gas preheater and the intermediate reheater are respectively connected with the cathode of each bottom fuel cell unit through pipelines;
the intermediate reheater and the cooler are respectively connected to the anode of each bottom fuel cell unit.
Preferably, the cathode of each bottom fuel cell unit is connected to the CO2The trapping devices are connected through a pipeline;
the anode of each bottom fuel cell unit is connected to the fuel preheater by a conduit.
The energy conversion method of the multi-stage fuel cell system includes:
introducing the primary flue waste gas into a flue gas preheater, and introducing primary fuel into a fuel pre-converter;
preheating primary flue waste gas in a flue gas preheater, then entering a top fuel cell anode for reaction, introducing secondary flue waste gas obtained by the reaction into an intermediate reheater for cooling, and reheating fuel mixed gas flowing out of the intermediate reheater;
the temperature of the secondary flue waste gas flowing out of the intermediate reheater is reduced to meet the inlet temperature of the bottom fuel cell, and the secondary flue waste gas is further introduced into the cathode of the bottom fuel cell to react;
after the secondary flue waste gas passes through the cathode of the bottom fuel cell, the secondary flue waste gas is introduced into a flue gas preheater to preheat the primary flue waste gas; then further introducing the fuel into a fuel pre-converter to provide a heat source for the pre-conversion of the hydrocarbon fuel; exhausting the tail gas from the fuel pre-converter into the atmosphere;
the primary fuel is pre-converted in a fuel pre-converter, then enters a fuel preheater for preheating, and the primary fuel from the fuel preheater is introduced into the anode of the top fuel cell for reaction; introducing secondary fuel mixed gas from the anode of the top fuel cell into a fuel preheater for preheating, and then introducing the secondary fuel mixed gas into an intercooler for cooling;
after passing through an intermediate cooler, the secondary fuel mixed gas enters an intermediate reheater and is heated by using secondary flue waste gas of a cathode of the top fuel cell;
introducing the secondary fuel mixed gas into the anode of the bottom fuel cell for reaction after the secondary fuel mixed gas passes through the intermediate reheater; tertiary fuel gas mixture from bottom fuel cell anodeCooling in a cooler; introducing CO into the tertiary fuel mixed gas from the cooler2A trap device for separating CO2(ii) a From CO2And the tertiary fuel mixed gas from the trapping device enters the fuel pre-converter through the recirculation loop and is mixed with the pre-converted primary fuel.
Compared with the prior art, the invention has the following advantages and beneficial effects:
(1) the multi-stage fuel cell system adopts the intercooler to remove water vapor before the secondary fuel enters the bottom fuel cell, thereby avoiding the obvious increase of the flow passing through the anode of the bottom fuel cell, simultaneously improving the fuel content (percentage) in the secondary fuel, further improving the utilization rate of the secondary fuel (namely improving the fuel utilization rate and the energy conversion efficiency of the bottom fuel cell), and further improving the overall fuel utilization rate and the energy conversion efficiency of the multi-stage fuel cell system.
(2) The multi-stage fuel cell system adopts the middle reheater, the heat source of the middle reheater is the secondary flue waste gas discharged by the cathode of the top fuel cell, the middle reheater can provide reheating heat for the secondary fuel mixed gas discharged by the anode of the top fuel cell, and simultaneously, the temperature of the middle reheater is reduced, so that the temperature of the secondary flue waste gas entering the cathode of the bottom fuel cell is not too high, the temperature difference between the inlet and the outlet of the bottom fuel cell is not enlarged, the bottom fuel cell is kept to operate within the optimal operation temperature range of the system, and the operation efficiency and the durability of the bottom fuel cell are further improved; in addition, the uneven temperature distribution between different fuel cells (namely, a top fuel cell and a bottom fuel cell) in the multi-stage fuel cell system is avoided, and the overall service life of the multi-stage fuel cell system is prolonged.
(3) In the multi-stage fuel cell system, the anodes of the top fuel cell and the bottom fuel cell are connected in series in a cascade mode, so that the fuel is fully utilized, the fuel utilization rate of the multi-stage fuel cell system is improved, and the CO in the fuel mixed gas is gradually improved2Concentration of CO so that CO of high purity can be separated from the final tertiary fuel mixed gas2Concentration, realizing high-efficiency output of electricitySimultaneous CO capture from flue gas2。
(4) In the multi-stage fuel cell system, the cathodes of the top fuel cell and the bottom fuel cell adopt a cascade connection mode in series, and the O in the primary flue waste gas is fully utilized2As reactant, CO in flue gas is collected as much as possible2So that the CO of the final tail gas at the smoke side2The concentration reaches the lowest; in addition, the cascade mode of the cathode also fully utilizes the waste heat in the secondary flue waste gas, so that the heating link is not needed before the secondary flue waste gas enters the bottom fuel cell, and the energy is recycled.
(5) The multi-stage fuel cell system recycles the condensed water, recovers the water removed from the cooler and the water removed from the intercooler, and utilizes the water (used for reforming) in the fuel pre-converter, thereby reducing the required amount of external make-up water and improving the overall water utilization rate of the multi-stage fuel cell system.
(6) The multi-stage fuel cell system is provided with the recirculation loop, so that the residual fuel in the tertiary fuel mixed gas is fully utilized, and the overall fuel utilization rate of the multi-stage fuel cell system is improved.
(7) The fuel pre-converter, the flue gas preheater, the fuel preheater and the intermediate reheater of the multi-stage fuel cell system all follow the reasonable utilization of energy grade/quality, so that the energy cascade utilization of the multi-stage fuel cell system is realized, and the overall energy conversion efficiency of the multi-stage fuel cell system is improved.
Drawings
Fig. 1 is a schematic configuration diagram of a flue gas side operation circuit of a multi-stage fuel cell system according to an embodiment of the present invention.
Fig. 2 is a schematic structural view of a fuel-side operation circuit of a multi-stage fuel cell system according to an embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to examples, but the embodiments of the present invention are not limited thereto.
Hair brushA multi-stage fuel cell system of an illustrative embodiment includes a topping fuel cell, a bottoming fuel cell, a flue gas preheater, an intermediate reheater, a fuel pre-converter, a fuel preheater, an intercooler, a cooler, and CO2A trapping device;
the topping fuel cell comprises a topping fuel cell anode and a topping fuel cell cathode;
the bottom fuel cell comprises a bottom fuel cell anode and a bottom fuel cell cathode;
the flue gas preheater, the top fuel cell cathode, the middle reheater and the bottom fuel cell cathode are sequentially connected through pipelines;
the flue gas preheater is respectively connected with the fuel pre-converter and the cathode of the bottom fuel cell through pipelines;
the fuel pre-converter, the anode inlet of the top fuel cell and the anode outlet of the top fuel cell are respectively connected with the fuel preheater;
the fuel preheater, the intercooler, the intermediate reheater, the bottom fuel cell anode, the cooler, and CO2The trapping devices are connected in sequence through pipelines.
In this example, the CO2The trapping device is connected with the fuel preheater through a pipeline.
In this embodiment, the condensed water pipes of the cooler and the intercooler are both connected to the fuel pre-converter.
In this example, the CO2The trapping device is connected with the cathode of the bottom fuel cell through a pipeline.
In this embodiment, the fuel preheater is connected to the bottom fuel cell anode via a conduit.
In this embodiment, the fuel preheater is connected to an external cold water supply line.
In this embodiment, the topping fuel cell includes a plurality of topping fuel cell units; the cathode of each top fuel cell unit is respectively connected with the flue gas preheater and the intermediate reheater through pipelines;
the anode inlet and the anode outlet of each top fuel cell unit are connected to the fuel preheater, respectively.
In this embodiment, the bottoming fuel cell may include a plurality of bottoming fuel cell units;
the flue gas preheater and the intermediate reheater are respectively connected with the cathode of each bottom fuel cell unit through pipelines;
the intermediate reheater and the cooler are respectively connected to the anode of each bottom fuel cell unit.
In this embodiment, the cathode of each bottom fuel cell unit is coupled to the CO2The trapping devices are connected through a pipeline;
the anode of each bottom fuel cell unit is connected to the fuel preheater by a conduit.
The energy conversion method of the multi-stage fuel cell system in the embodiment includes:
introducing the primary flue waste gas into a flue gas preheater, and introducing primary fuel into a fuel pre-converter;
preheating primary flue waste gas in a flue gas preheater, then entering a top fuel cell anode for reaction, introducing secondary flue waste gas obtained by the reaction into an intermediate reheater for cooling, and reheating fuel mixed gas flowing out of the intermediate reheater;
the temperature of the secondary flue waste gas flowing out of the intermediate reheater is reduced to meet the inlet temperature of the bottom fuel cell, and the secondary flue waste gas is further introduced into the cathode of the bottom fuel cell to react;
after the secondary flue waste gas passes through the cathode of the bottom fuel cell, introducing the secondary flue waste gas into a flue gas preheater to preheat the primary flue waste gas; then further introducing the fuel into a fuel pre-converter to provide a heat source for the pre-conversion of the hydrocarbon fuel; exhausting the tail gas from the fuel pre-converter into the atmosphere;
the primary fuel is pre-converted in a fuel pre-converter, then enters a fuel preheater for preheating, and the primary fuel from the fuel preheater is introduced into the anode of the top fuel cell for reaction; introducing secondary fuel mixed gas from the anode of the top fuel cell into a fuel preheater for preheating, and then introducing the secondary fuel mixed gas into an intercooler for cooling;
after passing through an intermediate cooler, the secondary fuel mixed gas enters an intermediate reheater and is heated by using secondary flue waste gas of a cathode of the top fuel cell;
introducing secondary fuel mixed gas into the anode of the bottom fuel cell for reaction after the secondary fuel mixed gas passes through the intermediate reheater; introducing the tertiary fuel mixed gas from the anode of the bottom fuel cell into a cooler for cooling; introducing CO into the tertiary fuel mixed gas from the cooler2A trap device for separating CO2(ii) a From CO2And the tertiary fuel mixed gas from the trapping device enters the fuel pre-converter through the recirculation loop and is mixed with the pre-converted primary fuel.
The multi-stage fuel cell system of the present embodiment will be described more specifically in terms of the flue gas side (cathode) of the multi-stage fuel cell system, the fuel side (anode) of the multi-stage fuel cell system, and the condensed water circulation:
1. flue gas side of a multi-stage fuel cell system
Fig. 1 is a schematic diagram showing the configuration of the operation circuit on the flue gas side of the multi-stage fuel cell system of the present embodiment. The flue gas side gas may be a primary flue gas (not subjected to CO) from a power plant or a plant2Trapped flue gas containing a concentration of CO2) Using O in flue gas2Performing reaction to generate power and trapping CO in the primary flue gas2。
Primary flue exhaust from a power plant or plant is first preheated by a flue gas preheater and then enters the top fuel cell flue gas side (cathode) for reaction. With H2For fuel as an example, the cathode reaction equation is shown in equation (1). Wherein the primary flue gas mainly provides O2And CO2Participate in the reaction and secondly carry away the process heat generated by the top fuel cell reaction.
CO2+1/2O2+2e-＝＝＝＝CO3 2- (1)
The primary flue waste gas after passing through the top fuel cell is changed into secondary flue waste gas, the temperature of the secondary flue waste gas is increased by about 100 ℃, and if the secondary flue waste gas is directly introduced into the bottom fuel cell for reutilization without cooling, the problems of overhigh operation temperature, increased temperature difference between an inlet and an outlet and the like of the bottom fuel cell can be caused. In order to ensure that the inlet temperature of the bottom fuel cell is maintained in a required temperature range, the secondary flue waste gas is introduced into an intermediate reheater for cooling, and meanwhile, the fuel mixed gas flowing out of the intermediate reheater is reheated, so that the process heat of the reaction of the top fuel cell is fully utilized.
The temperature of the secondary flue waste gas flowing out of the intermediate reheater is reduced to meet the inlet temperature of the bottom fuel cell, the secondary flue waste gas is further introduced into the cathode of the bottom fuel cell to react, the waste heat of the secondary flue waste gas is fully utilized, and meanwhile O in the secondary flue waste gas is further utilized2And capturing CO therein2。
The primary flue gas passes through the top fuel cell and then becomes secondary flue gas, CO2The concentration is reduced and therefore the bottom fuel cell is not efficient. If it is desired to further improve the bottoming fuel cell efficiency, a CO stream may be added2Make-up circuit (optional) from CO2Extracting a very small portion of the collected high concentration CO in a capture device2Mixing with the secondary flue gas, and introducing into the bottom fuel cell to improve the efficiency of the bottom fuel cell and make full use of O in the flue gas2。
After the secondary flue waste gas passes through the bottom fuel cell, further separating CO2So that CO in the tail gas of the system is finally discharged2The content reaches the lowest. In addition, after the secondary flue waste gas passes through the bottom fuel cell, the temperature rises due to taking away the reaction process heat of the bottom fuel cell, and in order to fully utilize the waste heat of the secondary flue waste gas, the flue gas side tail gas is introduced into a flue gas preheater so as to preheat the primary flue waste gas at the flue gas side inlet of the fuel cell system. After passing through the flue gas preheater, the tail gas at the flue gas side also has residual heat of about 200 ℃, and can be further introduced into a fuel pre-converter to provide a heat source for the pre-conversion of hydrocarbon fuel. And the tail gas on the smoke side in the fuel pre-converter forms the final tail gas on the smoke side. As it passes through the multi-stage fuel cell, O therein2Has been fully utilized, and CO2The concentration is also minimized and can therefore be vented directly to the atmosphere.
2. Fuel side of multi-stage fuel cell system
Fig. 2 is a schematic structural diagram of the fuel-side operation circuit of the multi-stage fuel cell system of the present embodiment. After the primary fuel at the fuel side enters the multi-stage fuel cell system, the primary fuel is firstly pre-converted in the fuel pre-converter and then enters the fuel preheater for preheating, and the temperature is further increased. The primary fuel from the fuel preheater is passed to the fuel side (anode) of the topping fuel cell for reaction with H2For fuel as an example, the anode reaction equation and the overall reaction equation are shown in equations (2) and (3). Wherein H2Reaction to produce steam H2O and release CO2。
H2+CO3 2-＝＝＝＝H2O+CO2+2e- (2)
H2+1/2O2+CO2(cathode) ═ H2O+CO2(Anode) (3)
The secondary fuel mixed gas from the anode of the topping fuel cell contains a large amount of the reactant H2O and CO2Meanwhile, as part of the process heat generated by the reaction of the top fuel cell is taken away, the temperature of the secondary fuel mixed gas is increased. For removing H from the secondary fuel gas mixture2And O, fully utilizing the residual heat, introducing the secondary fuel mixed gas into a fuel preheater to preheat the pre-converted fuel before the secondary fuel mixed gas is introduced into the bottom fuel cell, and then introducing the secondary fuel mixed gas into an intercooler to further cool the secondary fuel mixed gas so as to separate the moisture in the secondary fuel mixed gas, reduce the flow of the secondary fuel mixed gas entering the anode of the bottom fuel cell, and provide the percentage of the fuel content in the secondary fuel mixed gas.
After passing through the intercooler, the secondary fuel mixture is heated by the secondary flue gas from the cathode of the topping fuel cell (intermediate reheater). Because the flow rate of the secondary flue waste gas is far greater than that of the secondary fuel mixed gas, and the temperature of the secondary flue waste gas is increased compared with that of the primary flue waste gas after passing through the top fuel cell, the temperature of the secondary flue waste gas can be reduced to be about the temperature of the primary flue waste gas inlet after passing through the intermediate reheater; at the same time, the secondary fuel mixed gas is heated to the inlet temperature required for operation of the bottom fuel cell.
The secondary fuel mixed gas still contains the reaction product CO of the top fuel cell2If it is desired to further increase the fuel content in the secondary fuel mixed gas to further increase the utilization rate and the energy conversion efficiency of the bottom fuel cell, a fuel supply line (optional) may be added, that is, the reheated secondary fuel mixed gas is appropriately supplemented with the primary fuel to increase the fuel content in the mixed gas, thereby increasing the fuel utilization rate and the energy conversion efficiency of the bottom fuel cell.
And introducing the secondary fuel mixed gas into the bottom fuel cell for reaction after intermediate cooling and intermediate reheating. The tertiary fuel mixed gas from the anode of the bottom fuel cell contains a large amount of CO2、H2O and a small amount of fuel. And introducing the tertiary fuel mixed gas into a cooler for cooling so as to separate moisture in the tertiary fuel mixed gas. Introducing CO into the tertiary fuel mixed gas from the cooler2The trapping device can separate high-concentration CO because the tertiary fuel mixed gas passes through the multi-stage fuel cell reaction and the cooler2. From CO2Removing moisture and CO from the tertiary fuel mixed gas from the trapping device2After separation, the fuel is mixed with the pre-converted primary fuel through a recirculation loop so as to further improve the overall fuel utilization rate of the multi-stage fuel cell system.
3. Circulation of condensed water
In a multi-stage fuel cell system, most of condensed water is separated from fuel mixture gas during the cooling of an intercooler and a cooler, and in order to make full use of the most of the condensed water and improve the overall water utilization rate of the multi-stage fuel cell system, as shown in fig. 2, condensed water 1 of the cooler and condensed water 2 of the intercooler are collected into condensed water 3 and sent to a fuel pre-converter for reaction, thereby improving the utilization rate of system water. If the water flow rate of the condensed water 3 does not meet the demand of the fuel pre-converter, it is supplemented externally by the multi-stage fuel cell system.
The multi-stage fuel cell system adopts the intercooler to remove water vapor before the secondary fuel enters the bottom fuel cell, thereby avoiding the obvious increase of the flow passing through the anode of the bottom fuel cell, simultaneously improving the fuel content (percentage) in the secondary fuel, further improving the utilization rate of the secondary fuel (namely improving the fuel utilization rate and the energy conversion efficiency of the bottom fuel cell), and further improving the overall fuel utilization rate and the energy conversion efficiency of the multi-stage fuel cell system.
The multi-stage fuel cell system adopts the intermediate reheater, the heat source of the intermediate reheater is the secondary flue waste gas discharged by the cathode of the top fuel cell, the intermediate reheater can provide reheating heat for the secondary fuel mixed gas discharged by the anode of the top fuel cell, and simultaneously, the temperature of the intermediate reheater can be reduced, so that the temperature of the secondary flue waste gas entering the cathode of the bottom fuel cell can be ensured not to be too high, the temperature difference of the inlet and the outlet of the bottom fuel cell can not be enlarged, the bottom fuel cell can be kept to operate within the optimal operation temperature range of the system, and the operation efficiency and the durability of the bottom fuel cell can be further improved; in addition, the uneven temperature distribution between different fuel cells (namely, a top fuel cell and a bottom fuel cell) in the multi-stage fuel cell system is avoided, and the overall service life of the multi-stage fuel cell system is prolonged.
In the multi-stage fuel cell system of the embodiment, the anodes of the top fuel cell and the bottom fuel cell are connected in series in a cascade mode, so that the fuel is fully utilized, the fuel utilization rate of the multi-stage fuel cell system is improved, and simultaneously, the CO in the fuel mixed gas is gradually improved2Concentration so that CO of high purity can be separated from the final tertiary fuel mixed gas2Concentration, realizing high-efficiency output of electric energy and simultaneously trapping CO from flue gas2。
In the multi-stage fuel cell system of the present embodiment, the cathodes of the top fuel cell and the bottom fuel cell are cascaded in series, and O in the primary flue gas is fully utilized2As reactant, CO in flue gas is collected as much as possible2So that the CO of the final tail gas at the smoke side is obtained2The concentration reaches the lowest; in addition, the cascade mode of the cathode also fully utilizes the waste heat in the secondary flue waste gas, so that the heating link is not needed before the secondary flue waste gas enters the bottom fuel cell, and the energy recycling is realized.
The multi-stage fuel cell system of the present embodiment recycles the condensed water, recovers the moisture removed in the cooler (condensed water 1) and the moisture removed in the intercooler (condensed water 2), and uses the recovered moisture (condensed water) in the fuel pre-converter (for reforming), thereby reducing the amount of water required for external makeup, and improving the overall water utilization rate of the multi-stage fuel cell system.
The multi-stage fuel cell system of the embodiment is provided with the recirculation loop, so that the residual fuel in the tertiary fuel mixed gas is fully utilized, and the overall fuel utilization rate of the multi-stage fuel cell system is improved.
The multi-stage fuel cell system of the embodiment, the fuel pre-converter, the flue gas preheater, the fuel preheater and the intermediate reheater all follow the reasonable utilization of energy grade/quality, so that the energy cascade utilization of the multi-stage fuel cell system is realized, and the overall energy conversion efficiency of the multi-stage fuel cell system is further improved.
The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.
Claims (10)
1. A multi-stage fuel cell system comprising a top fuel cell, a bottom fuel cell, a flue gas preheater, an intermediate reheater, a fuel pre-converter, a fuel preheater, an intermediate cooler, a cooler and CO2A trapping device;
the topping fuel cell comprises a topping fuel cell anode and a topping fuel cell cathode;
the bottom fuel cell comprises a bottom fuel cell anode and a bottom fuel cell cathode;
the flue gas preheater, the top fuel cell cathode, the middle reheater and the bottom fuel cell cathode are sequentially connected through pipelines;
the flue gas preheater is respectively connected with the fuel pre-converter and the cathode of the bottom fuel cell through pipelines;
the fuel pre-converter, the anode inlet of the top fuel cell and the anode outlet of the top fuel cell are respectively connected with the fuel preheater;
the fuel preheater, the intercooler, the intermediate reheater, the bottom fuel cell anode, the cooler, and CO2The trapping devices are connected in sequence through pipelines.
2. The multi-stage fuel cell system of claim 1, wherein the CO is present in the fuel cell system2The trapping device is connected with the fuel preheater through a pipeline.
3. The multi-stage fuel cell system according to claim 1, wherein the condensed water pipes of the coolers and the intercooler are connected to a fuel pre-converter.
4. The multi-stage fuel cell system of claim 1, wherein the CO is present in the fuel cell system2The trapping device is connected with the cathode of the bottom fuel cell through a pipeline.
5. The multi-stage fuel cell system of claim 1, wherein the fuel preheater is connected to the bottom fuel cell anode by a conduit.
6. The multi-stage fuel cell system of claim 1, wherein an external cold water make-up conduit is connected to the fuel preheater.
7. The multi-stage fuel cell system of claim 1, wherein the topping fuel cell comprises a plurality of topping fuel cell units; the cathode of each top fuel cell unit is respectively connected with the flue gas preheater and the intermediate reheater through pipelines;
the anode inlet and the anode outlet of each top fuel cell unit are connected to the fuel preheater, respectively.
8. The multi-stage fuel cell system of claim 1 or 7, wherein the bottoming fuel cell comprises a plurality of bottoming fuel cell units;
the flue gas preheater and the intermediate reheater are respectively connected with the cathode of each bottom fuel cell unit through pipelines;
the intermediate reheater and the cooler are respectively connected to the anode of each bottom fuel cell unit.
9. The multi-stage fuel cell system of claim 8, wherein the cathode of each bottom fuel cell unit is coupled to the CO2The trapping devices are connected through a pipeline;
the anode of each bottom fuel cell unit is connected to the fuel preheater by a conduit.
10. The method for converting energy of a multi-stage fuel cell system according to any one of claims 1 to 9, comprising:
introducing the primary flue waste gas into a flue gas preheater, and introducing primary fuel into a fuel pre-converter;
preheating primary flue waste gas in a flue gas preheater, then entering a top fuel cell anode for reaction, introducing secondary flue waste gas obtained by the reaction into an intermediate reheater for cooling, and reheating fuel mixed gas flowing out of the intermediate reheater;
the temperature of the secondary flue waste gas flowing out of the intermediate reheater is reduced to meet the inlet temperature of the bottom fuel cell, and the secondary flue waste gas is further introduced into the cathode of the bottom fuel cell to react;
after the secondary flue waste gas passes through the cathode of the bottom fuel cell, introducing the secondary flue waste gas into a flue gas preheater to preheat the primary flue waste gas; then further introducing the fuel into a fuel pre-converter to provide a heat source for the pre-conversion of the hydrocarbon fuel; exhausting the tail gas from the fuel pre-converter into the atmosphere;
the primary fuel is pre-converted in a fuel pre-converter, then enters a fuel preheater for preheating, and the primary fuel from the fuel preheater is introduced into the anode of the top fuel cell for reaction; introducing secondary fuel mixed gas from the anode of the top fuel cell into a fuel preheater for preheating, and then introducing the secondary fuel mixed gas into an intercooler for cooling;
after passing through an intercooler, the secondary fuel mixed gas enters an intermediate reheater and is heated by using secondary flue waste gas of the cathode of the top fuel cell;
introducing secondary fuel mixed gas into the anode of the bottom fuel cell for reaction after the secondary fuel mixed gas passes through the intermediate reheater; introducing the tertiary fuel mixed gas from the anode of the bottom fuel cell into a cooler for cooling; introducing CO into the tertiary fuel mixed gas from the cooler2A trap device for separating CO2(ii) a From CO2And the tertiary fuel mixed gas from the trapping device enters the fuel pre-converter through the recirculation loop and is mixed with the pre-converted primary fuel.
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101964426A (en) * | 2010-09-28 | 2011-02-02 | 吉林大学 | Solid oxide fuel cell comprehensive experiment apparatus |
| US20140272616A1 (en) * | 2013-03-15 | 2014-09-18 | Exxonmobil Research And Engineering Company | Integrated power generation and carbon capture using fuel cells |
| US9502728B1 (en) * | 2015-06-05 | 2016-11-22 | Fuelcell Energy, Inc. | High-efficiency molten carbonate fuel cell system with carbon dioxide capture assembly and method |
| WO2017184818A1 (en) * | 2016-04-21 | 2017-10-26 | Fuelcell Energy, Inc. | High efficiency fuel cell system with intermediate co2 recovery system |
| JP2019102283A (en) * | 2017-12-04 | 2019-06-24 | 株式会社豊田中央研究所 | Fuel cell system |
| DE102018210173A1 (en) * | 2018-06-22 | 2019-12-24 | Audi Ag | Fuel cell system and method for operating a fuel cell system |
| US20200313205A1 (en) * | 2016-06-23 | 2020-10-01 | Kyungdong Navien Co., Ltd. | Fuel cell system including heat exchanger using anode gas or anode off-gas |
| GB202102985D0 (en) * | 2021-03-03 | 2021-04-14 | Ceres Ip Co Ltd | Fuel cell system |
| CN113314755A (en) * | 2021-05-26 | 2021-08-27 | 广东电网有限责任公司广州供电局 | Cascade high temperature fuel cell system |
-
2022
- 2022-03-11 CN CN202210245066.1A patent/CN114649548B/en active Active
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101964426A (en) * | 2010-09-28 | 2011-02-02 | 吉林大学 | Solid oxide fuel cell comprehensive experiment apparatus |
| US20140272616A1 (en) * | 2013-03-15 | 2014-09-18 | Exxonmobil Research And Engineering Company | Integrated power generation and carbon capture using fuel cells |
| US9502728B1 (en) * | 2015-06-05 | 2016-11-22 | Fuelcell Energy, Inc. | High-efficiency molten carbonate fuel cell system with carbon dioxide capture assembly and method |
| US20160359182A1 (en) * | 2015-06-05 | 2016-12-08 | Fuelcell Energy, Inc. | High-efficiency molten carbonate fuel cell system with carbon dioxide capture assembly and method |
| CN107690722A (en) * | 2015-06-05 | 2018-02-13 | 燃料电池能有限公司 | High-efficiency fuel cell system and its method with collecting carbonic anhydride component |
| WO2017184818A1 (en) * | 2016-04-21 | 2017-10-26 | Fuelcell Energy, Inc. | High efficiency fuel cell system with intermediate co2 recovery system |
| US20200313205A1 (en) * | 2016-06-23 | 2020-10-01 | Kyungdong Navien Co., Ltd. | Fuel cell system including heat exchanger using anode gas or anode off-gas |
| JP2019102283A (en) * | 2017-12-04 | 2019-06-24 | 株式会社豊田中央研究所 | Fuel cell system |
| DE102018210173A1 (en) * | 2018-06-22 | 2019-12-24 | Audi Ag | Fuel cell system and method for operating a fuel cell system |
| GB202102985D0 (en) * | 2021-03-03 | 2021-04-14 | Ceres Ip Co Ltd | Fuel cell system |
| CN113314755A (en) * | 2021-05-26 | 2021-08-27 | 广东电网有限责任公司广州供电局 | Cascade high temperature fuel cell system |
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