CN117594826A - Waste heat recovery system of fuel cell and control method - Google Patents
Waste heat recovery system of fuel cell and control method Download PDFInfo
- Publication number
- CN117594826A CN117594826A CN202311802867.4A CN202311802867A CN117594826A CN 117594826 A CN117594826 A CN 117594826A CN 202311802867 A CN202311802867 A CN 202311802867A CN 117594826 A CN117594826 A CN 117594826A
- Authority
- CN
- China
- Prior art keywords
- water
- water tank
- heat
- heat exchange
- fuel cell
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000000446 fuel Substances 0.000 title claims abstract description 84
- 239000002918 waste heat Substances 0.000 title claims abstract description 50
- 238000011084 recovery Methods 0.000 title claims abstract description 47
- 238000000034 method Methods 0.000 title claims abstract description 12
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 604
- 239000007788 liquid Substances 0.000 claims abstract description 133
- 239000007789 gas Substances 0.000 claims abstract description 36
- 238000006243 chemical reaction Methods 0.000 claims description 43
- 238000012806 monitoring device Methods 0.000 claims description 10
- 238000001816 cooling Methods 0.000 abstract description 2
- 238000012546 transfer Methods 0.000 description 8
- 239000012535 impurity Substances 0.000 description 7
- 239000002699 waste material Substances 0.000 description 7
- 238000010438 heat treatment Methods 0.000 description 6
- 238000004064 recycling Methods 0.000 description 4
- 239000007787 solid Substances 0.000 description 4
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- 238000009833 condensation Methods 0.000 description 3
- 230000005494 condensation Effects 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 230000036647 reaction Effects 0.000 description 3
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 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
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000002309 gasification Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000007800 oxidant agent Substances 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 230000010349 pulsation Effects 0.000 description 1
- 239000008213 purified water Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000013589 supplement Substances 0.000 description 1
Classifications
-
- 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
- H01M8/04007—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
- H01M8/04067—Heat exchange or temperature measuring elements, thermal insulation, e.g. heat pipes, heat pumps, fins
-
- 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
-
- 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
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Sustainable Development (AREA)
- Sustainable Energy (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Fuel Cell (AREA)
Abstract
The invention relates to the technical field of fuel cells and discloses a waste heat recovery system and a control method of a fuel cell, wherein the waste heat recovery system comprises a waste heat recovery module, the waste heat recovery module comprises a heat exchange unit and a first water tank, the heat exchange unit is connected with the fuel cell module, and the heat exchange unit exchanges heat between tail gas conveyed by the fuel cell module and liquid water conveyed by the first water tank; the output end of the first water tank conveys liquid water in the tank to the heat exchange unit for heat exchange and temperature rise, and the receiving end of the first water tank receives the temperature-rising liquid water output by the heat exchange unit; the water outlet end of the first water tank is connected with the heat utilization module and conveys liquid water in the tank to the heat utilization module; according to the invention, the temperature-rising liquid water output by the heat exchange unit and the low-temperature liquid water input by the first water source are mixed in the first water tank for cooling and then are input into the heat utilization module, so that the temperature of the liquid water in the first water tank is more suitable and stable, the larger heat utilization requirement of the heat utilization module is met, the heat energy white loss is avoided, and the waste heat recovery utilization rate of the fuel cell is improved.
Description
Technical Field
The invention relates to the technical field of fuel cells, in particular to a waste heat recovery system of a fuel cell and a control method.
Background
A fuel cell is an electrochemical device that can directly convert chemical energy stored in a fuel and an oxidant into electric energy. Since the 40 s of the 20 th century, four generations of fuel cells have been developed so far, the first generation being Alkaline Fuel Cells (AFC) and Phosphoric Acid Fuel Cells (PAFC), the second generation being Molten Carbonate Fuel Cells (MCFC), the third generation being Solid Oxide Fuel Cells (SOFC), the fourth generation being Proton Exchange Membrane Fuel Cells (PEMFC) and direct methanol fuel cells. The solid oxide fuel cell has higher working temperature, usually in the range of 800-1000 ℃, so that the waste heat of the solid oxide fuel cell can be utilized to realize cogeneration while generating electricity, and the energy utilization efficiency can reach 90%.
The solid oxide fuel cell has high working temperature, can generate tail gas with higher temperature and simultaneously contains a large amount of water vapor, the temperature of the tail gas is usually in the range of 150-200 ℃, the energy utilization efficiency of a fuel cell system can be effectively improved by recycling waste heat in the tail gas, and the power generation cost of the fuel cell system can be reduced by recycling a large amount of water vapor contained in the tail gas.
At present, the field of fuel cells has widely adopted waste heat recovery technology, but the existing waste heat recovery technology lacks a stable control link of temperature, heat energy generated after tail gas recovery treatment is directly conveyed to a heat utilization facility, the output temperature is too high and unstable, the direct use of the heat utilization facility is not facilitated, more heat utilization facilities cannot be met, the heat utilization facility always needs to wait for the temperature to dissipate to a proper temperature for direct use, and the heat energy is wasted, so that the waste heat recovery utilization rate of the fuel cells is not high.
Disclosure of Invention
The invention aims to solve the technical problems that: in order to solve the technical problems, the invention provides a waste heat recovery system of a fuel cell, which comprises a fuel cell module, a waste heat recovery module and a heat utilization module which are sequentially connected, wherein the waste heat recovery module comprises a heat exchange unit and a first water tank which are connected, the heat exchange unit is connected with the fuel cell module, and the heat exchange unit is used for carrying out heat exchange on tail gas of water-containing steam conveyed by the fuel cell module and liquid water conveyed by the first water tank;
the first water tank is provided with a water inlet end, an output end, a receiving end and a water outlet end, a temperature sensor is arranged in the first water tank, the water inlet end is connected with a first water source, the first water source is used for conveying liquid water to the first water tank, the output end is communicated with the heat exchange unit and is used for conveying the liquid water in the tank to the heat exchange unit for heat exchange and temperature rise, and the receiving end is communicated with the heat exchange unit and is used for receiving the heated liquid water output by the heat exchange unit; the water outlet end is connected with the heat utilization module and conveys liquid water reaching a preset temperature range in the first water tank to the heat utilization module.
Preferably, the heat utilization module comprises a plurality of heat utilization facilities connected in parallel, wherein an inlet end of the heat utilization facilities is connected with the water outlet end to receive and use liquid water reaching a preset temperature range, an outlet end of the heat utilization facilities is connected with a second water pump, and an output end of the second water pump is connected with the water inlet end to return the liquid water after the heat utilization facilities are used to the first water tank.
Preferably, a filter, a first flowmeter and a first water pump are sequentially arranged between the output end and the heat exchange unit.
Preferably, a buffer part is arranged between the receiving end of the first water tank and the heat exchange unit.
Preferably, the fuel cell module comprises a water treatment unit and a heat box unit which are connected, wherein the water treatment unit is connected with a second water source, the water treatment unit is used for purifying and treating reaction water of the second water source and then conveying the reaction water to the heat box unit to participate in the reaction, and the heat box unit is used for generating tail gas by the reaction and conveying the tail gas to the heat exchange unit.
Preferably, the heat exchange unit is further connected with the water treatment unit, a second flowmeter, a third water tank and a third water pump are further arranged between the heat exchange unit and the water treatment unit in sequence, and the third water pump is used for conveying condensate water generated after tail gas heat exchange to the water treatment unit.
Preferably, the water treatment unit comprises a second water tank, a liquid level monitoring device is arranged in the second water tank, and the reaction water of the second water source flows through the second water tank and is then conveyed to the hot box unit; the heat exchange unit is communicated with the second water tank and used for conveying condensate water generated after tail gas heat exchange to the second water tank.
The invention also provides a control method of the waste heat recovery system of the fuel cell, which comprises the following steps:
the method comprises the steps of controlling a first water source to input liquid water into a first water tank, controlling the liquid water in the first water tank to circularly flow between the first water tank and a heat exchange unit, enabling the liquid water in the first water tank to flow through the heat exchange unit for heat exchange and then flow back to the first water tank, and enabling the temperature of the liquid water output to a heat utilization module by the first water tank to be stable within a preset temperature range.
Preferably, when the second flowmeter detects that the water flow of the condensed water is smaller than the water required by the fuel cell module, the reaction water output by the second water source and the condensed water output by the third water pump are treated by the water treatment unit together, and then the water is supplied to the hot box unit to participate in the reaction; and when the second flowmeter detects that the water flow of the condensed water is not smaller than the water required by the fuel cell module, stopping the second water source from inputting the reaction water to the water treatment unit, and only the condensed water output by the third water pump is treated by the water treatment unit and then is supplied to the heat box unit to participate in the reaction.
Preferably, the water level in the second water tank is controlled to be between a first water level and a second water level, and the second water level is higher than the first water level;
when the liquid level monitoring device monitors that the water level in the second water tank is smaller than a first water level, the water amount of the reaction water and/or the condensed water input into the second water tank is increased; and when the liquid level monitoring device monitors that the water level in the second water tank is not smaller than a second water level, reducing the water amount of the reaction water and/or the condensed water input into the second water tank.
Preferably, when the water level in the second water tank is not less than the first water level, the second water source is controlled to stop inputting the reaction water into the second water tank, and only the heat exchange unit inputs condensed water into the second water tank.
Compared with the prior art, the waste heat recovery system of the fuel cell provided by the embodiment of the invention has the beneficial effects that:
the fuel cell module generates a large amount of high-temperature tail gas containing water vapor, the tail gas enters the heat exchange unit to exchange heat with liquid water to raise the temperature of the liquid water, the heated liquid water formed after heat exchange and temperature rise of the heat exchange unit is mixed with the liquid water reserved in the first water tank and low-temperature liquid water input by the first water source in the first water tank, so that the liquid water mixed to the equilibrium temperature is obtained in the first water tank, one part of the liquid water mixed to the equilibrium temperature in the first water tank is continuously circulated to the heat exchange unit to exchange heat, and the other part of the liquid water is sent to the heat utilization module to be utilized; through setting up temperature sensor, the temperature of liquid water in the real-time supervision first water tank, when the high temperature liquid water temperature of heat transfer unit output to first water tank is higher, can be through the quantity of the low temperature liquid water of control valve control first water source input to first water tank, the high temperature liquid water of heat transfer unit output and the low temperature liquid water of first water source new input are respectively input into in the heat module and the heat transfer unit after mixing in first water tank, make the temperature of liquid water in the first water tank more stable more be suitable for with the hot module direct use, unnecessary heat energy of high temperature liquid water also can not be wasted in the heat module, but be used for heating the low temperature liquid water of first water source input to suitable temperature, make the liquid water of the usable suitable temperature of heat module more, can satisfy the heat demand that uses the hot module bigger, the white loss of heat energy has been avoided, the waste heat recovery utilization ratio of fuel cell has been improved.
Drawings
FIG. 1 is a schematic diagram of the structure of one embodiment of the present invention;
FIG. 2 is a schematic diagram of another embodiment of the present invention;
fig. 3 is a schematic structural view of a further embodiment of the present invention.
In the figure: 1. a fuel cell module; 11. a water treatment unit; 111. a second water tank; 112. a liquid level monitoring device; 12. a thermal box unit; 13. a second water source; 14. a second flowmeter; 15. a third water tank; 16. a third water pump;
2. a waste heat recovery module; 21. a heat exchange unit; 22. a first water tank; 221. a temperature sensor; 23. a first water source; 231. a control valve; 232. a third flowmeter; 24. a filter; 25. a first flowmeter; 26. a first water pump; 27. a buffer member; 28. a pressure release valve; 29. a blow-down valve;
3. using a thermal module; 31. a heat utilization facility; 32. a second water pump;
4. tail gas.
Detailed Description
The following describes in further detail the embodiments of the present invention with reference to the drawings and examples. The following examples are illustrative of the invention and are not intended to limit the scope of the invention.
As shown in fig. 1, a preferred embodiment of the present invention provides a waste heat recovery system of a fuel cell, which includes a fuel cell module 1, a waste heat recovery module 2 and a heat utilization module 3 connected in sequence, wherein the waste heat recovery module 2 includes a heat exchange unit 21 and a first water tank 22 connected, the heat exchange unit 21 is connected to the fuel cell module 1, and the heat exchange unit 21 is used for exchanging heat between an exhaust gas 4 containing water vapor conveyed by the fuel cell module 1 and liquid water conveyed by the first water tank 22;
the first water tank 22 is provided with a water inlet end, an output end, a receiving end and a water outlet end, a temperature sensor 221 is arranged in the first water tank 22, the water inlet end is sequentially connected with a control valve 231 and a first water source 23, the first water source 23 is used for conveying liquid water to the first water tank 22, the output end is communicated with the heat exchange unit 21 so as to be used for conveying the liquid water in the tank to the heat exchange unit 21 for heat exchange and temperature rise, and the receiving end is communicated with the heat exchange unit 21 so as to be used for receiving the heated liquid water output by the heat exchange unit 21; the water outlet end is connected with the heat module 3 and conveys the liquid water in the first water tank 22 to the heat module 3.
Specifically, the high-temperature tail gas 4 containing water vapor generated during the operation of the fuel cell module 1 is conveyed to the hot side in the heat exchange unit 21, the output end of the first water tank 22 conveys the liquid water in the tank to the cold side of the heat exchange unit 21, the hot side and the cold side in the heat exchange unit 21 exchange heat due to temperature difference, the temperature of the liquid water is increased, and the temperature of the tail gas 4 is reduced, but in the conventional technology, the temperature of the heated liquid water after heat exchange output by the heat exchange unit 21 is too high due to the too high temperature of the tail gas 4, so that the use is not only inconvenient, but also the waste heat of the recovered fuel cell is wasted due to the too high temperature of the liquid water, in the invention, the heated liquid water after heat exchange is conveyed back to the first water tank 22 instead of being directly conveyed to the heat exchange module 3, so that the heated liquid water is mixed with the low-temperature liquid water input by the first water source 23 in the first water tank 22, the temperature of the heated liquid water source 22 is controlled by the control valve 231, the temperature of the heated up liquid water is too high, and the heat energy is not directly conveyed to the first water tank 22 in the heat exchange module 22 due to the too high temperature is not only in the heat exchange module 3, and the heat loss is avoided in the water tank 22, and the temperature is not suitable for the heat loss is avoided in the heat exchange module.
Further, after the low-temperature liquid water input from the first water source 23 is mixed with the heating liquid water, the temperature is raised to a proper temperature, and then the mixture is conveyed to the heat module 3 for direct use or conveyed to the heat exchange unit 21 for continuing the heat exchange cycle, but the heat energy of the heating liquid water is not wasted, but is obtained by the low-temperature liquid water, then is heated to a proper temperature and conveyed to the heat module 3 for use, so that the problem that the heating liquid water cannot be directly used by the heat module 3 and the recovered heat energy is wasted is avoided.
Furthermore, the cold side and the hot side of the heat exchange unit 21 can be integrated into a heat exchange tube, and the length, the inner diameter and the outer diameter of the heat exchange tube are designed according to actual needs, so that the temperature of the tail gas 4 after heat exchange is finished is lower than the saturation temperature under the current atmospheric pressure, and the water vapor in the tail gas 4 can be fully condensed.
Furthermore, in some embodiments, the heat exchange unit 21 is integrated with the first water tank 22, the first water source 23 inputs low-temperature liquid water into the first water tank 22, the high-temperature tail gas passes through the heat exchange unit 21 integrated in the first water tank 22 to exchange heat with the liquid water in the first water tank 22 to heat the liquid water in the first water tank 22, the temperature sensor 221 in the first water tank 22 monitors the temperature of the liquid water in the first water tank 22 at any time, and the control valve 231 is used to control the amount of low-temperature liquid water input into the first water tank 22 by the first water source 23 to stably control the temperature of the liquid water in the first water tank 22, at this time, the integrated heat exchange unit 21 and first water tank 22 can store a large amount of liquid water suitable for direct use by heat facilities besides the function of heat exchange condensation, the structure is more exquisite, the space utilization is more reasonable, and the heat exchange efficiency is higher.
As shown in fig. 2, in some embodiments, the heat using module 3 includes a plurality of heat using facilities 31 connected in parallel, an inlet end of the heat using facilities 31 is connected to an outlet end of the first water tank 22 to receive and use liquid water reaching a preset temperature range, an outlet end of the heat using facilities 31 is connected to a second water pump 32, and an output end of the second water pump 32 is connected to an inlet end of the first water tank 22 to return water after the heat using facilities 31 to the first water tank 22.
Specifically, the liquid water in the first water tank 22 is conveyed to the heat utilization module 3 and is dispersed into each heat utilization facility 31 for use, the water after the use of the heat utilization facilities 31 is discharged through the waste discharge ports of the heat utilization facilities 31, according to different purposes of the heat utilization facilities 31 on the water, part of the water in the heat utilization facilities 31 cannot be recovered and is directly discharged through the waste discharge ports, and part of the water in the heat utilization facilities 31 can be recovered, the water discharged through the waste discharge ports of the heat utilization facilities 31 is pumped back to the first water tank 22 again through the second water pump 32 for continuous use, and water resources are saved; it can be understood that a filtering treatment device is required between the first water tank 22 and the second water pump 32 or between the second water pump 32 and the heat utilization facility 31 to filter the water used by the heat utilization facility 31 so as to be returned to the first water tank 22 for continuous use; further, the heat utilization facilities 31 include a shower room, a kitchen, a radiator, a floor heating, etc., and it is known that the radiator and the water used for the floor heating can be continuously used by being conveyed to the first water tank 22 through the second water pump 32 after being treated, while the kitchen water, etc., are not used, and are required to be directly discharged through the waste outlet.
Further, the water inlet end is further provided with a third flowmeter 232, the third flowmeter 232 can monitor the amount of low-temperature liquid water entering the first water tank 22, and determine by combining the amount of liquid water remaining in the first water tank 22, when the amount of liquid water remaining in the first water tank 22 is sufficient, the control valve 231 can be closed to limit the low-temperature liquid water input by the first water source 23, and further the low-temperature liquid water input by the second water pump 32 is fully utilized, and the third flowmeter 232 is matched with the control valve 231 to ensure the amount of low-temperature liquid water input into the first water tank 22 in unit time so as to stabilize the amount of liquid water remaining in the first water tank 22 to meet the water demand of the water outlet end of the first water tank 22.
As shown in fig. 3, in some embodiments, a filter 24, a first flowmeter 25, and a first water pump 26 are sequentially disposed between the output end and the heat exchange unit 21. The first water pump 26 can be quick be used for heat transfer with the liquid water pump in the first water tank 22 in the heat transfer unit 21, through the power of adjusting first water pump 26, can adjust the quantity of the liquid water of unit time in to the heat transfer unit 21 input, the more the liquid water of unit time in input, just can take away the heat energy in more tail gas 4, thereby control heat exchange efficiency and fuel cell's waste heat recovery efficiency, and the discharge of liquid water flow to the heat transfer unit 21 can be monitored to first flowmeter 25, thereby more accurate regulation and control waste heat recovery degree, filter 24 then can filter the impurity in the liquid water, avoid impurity in the liquid water too much, impurity pile up in the heat transfer unit 21 influences heat exchange efficiency.
Further, the filter 24, the first flowmeter 25 and the first water pump 26 are sequentially arranged, the filter 24 filters the liquid water in advance, so as to avoid the influence of impurities in the liquid water on the first flowmeter 25 and the first water pump 26, and the first flowmeter 25 is arranged at the front end of the first water pump 26, so that the problem of fluctuation of the indication of the first flowmeter 25 caused by pulsation of the first water pump 26 can be avoided, and the measurement of the first flowmeter 25 is more accurate.
In some embodiments, a buffer member 27 is provided between the receiving end and the heat exchange unit 21. Specifically, the buffer member 27 comprises one or a combination of more of a buffer tank, a capillary tube, a laminar flow element; in the starting stage of waste heat recovery, as liquid water is just introduced into the heat exchange unit 21, the water quantity is small, the liquid water is easy to change into water vapor in the heat exchange unit 21, so that the air pressure in the heat exchange unit 21 is unstable, and when the waste heat recovery is in the shutdown stage, a small amount of residual liquid water exists in the heat exchange unit 21, and the residual small amount of liquid water is easily evaporated at the moment, so that the air pressure in the heat exchange unit 21 is unstable, and the air pressure instability can cause deformation, cracking and abnormal sound of a pipeline, therefore, a buffer component 27 is arranged between the receiving end of the first water tank 22 and the heat exchange unit 21 to inhibit pressure fluctuation caused by severe evaporation and gasification of the liquid water in the starting stage and the shutdown stage of the waste heat recovery, and the problems of water pipeline cracking, deformation, abnormal sound and the like caused by the air pressure instability are solved.
In some embodiments, the first tank 22 is connected with a pressure relief valve 28. Since the first water tank directly receives the warmed liquid water heated by the heat exchange unit 21, the water temperature in the first water tank is relatively high, and the pressure release valve 28 can balance the air pressure in the first water tank 22, so that the first water tank 22 is prevented from being damaged due to excessive pressure.
In some embodiments, the first tank 22 is further provided with a drain end to which a drain valve 29 is connected. Although the filter 24 is provided between the first water tank 22 and the heat exchange unit 21, the first water tank 22 may generate impurities after a long period of operation, and the impurities in the first water tank 22 need to be discharged through the drain end.
In some embodiments, the fuel cell module 1 includes a water treatment unit 11 and a heat box unit 12 connected, the water treatment unit 11 is connected with a second water source 13, the water treatment unit 11 is used for purifying water of the second water source 13 and then delivering the purified water to the heat box unit 12 to participate in the reaction, and the heat box unit 12 is used for generating the tail gas 4 by the reaction and delivering the tail gas to the heat exchange unit 21. The water treatment unit 11 can provide power for water entering the hot box unit 12, remove impurities and ions, and ensure the purity of reaction water; wherein the cartridge unit 12 includes a fuel cell, a heat exchanger, a reformer, a burner, a water evaporator, and the like.
In some embodiments, the heat exchange unit 21 is further connected to the water treatment unit 11, and condensed water generated after the heat exchange of the tail gas 4 in the heat exchange unit 21 can be conveyed to the water treatment unit 11 for reuse. The water vapor in the tail gas 4 of the heat box unit 12 is condensed into liquid condensed water, and then flows back to the water treatment unit 11 for collection, treatment and reutilization, so that the waste of water resources is avoided, and the self-circulation of the fuel cell reaction water is realized.
In some embodiments, a second flowmeter 14, a third water tank 15, and a third water pump 16 are sequentially disposed between the heat exchange unit 21 and the water treatment unit 11. The third water pump 16 can quickly pump the condensed water into the second water tank 111 for recycling, so that the reaction water of the fuel cell can circulate, the second flowmeter 14 can monitor the recovery rate of the condensed water, the third water tank 15 can pre-store the condensed water, when the water amount in the second water tank 111 is enough, the condensed water can be temporarily stored in the third water tank 15, when the water amount in the second water tank 111 is insufficient, the condensed water in the third water tank 15 can be preferentially started, and when the condensed water in the third water tank 15 is also insufficient, the second water source 13 can be started to supplement water resources for the second water tank 111; wherein the third water tank 15 is further provided with an overflow valve, and the overflow valve can drain the condensed water in the third water tank 15 to the outside when the condensed water in the third water tank 15 is too much.
In yet other embodiments, the water treatment unit 11 includes a second water tank 111, with a liquid level monitoring device 112 disposed within the second water tank 111. The second water tank 111 is used for storing a certain amount of water and supplying reaction water to the reaction in the hot box unit 12, and also can cope with the risk of short-term outage of the second water source 13.
Further, the water treatment unit 11 includes an overflow valve, which is connected to the second water tank 111, and plays a role of constant pressure overflow, so that the overflow valve can discharge surplus water under the condition of meeting the water requirement of the fuel cell system, thereby controlling water balance and ensuring stable inlet pressure of the overflow valve.
The invention also provides a control method of the waste heat recovery system of the fuel cell, which comprises the following steps:
controlling a first water source 23 to input liquid water into the first water tank 22, controlling the liquid water in the first water tank 22 to circularly flow between the first water tank 22 and the heat exchange unit 21, enabling the liquid water in the first water tank 22 to flow through the heat exchange unit 21 for heat exchange and then flow back to the first water tank 22, and enabling the temperature of the liquid water output to the heat utilization module by the first water tank 22 to be stable within a preset temperature range;
when the temperature sensor 221 detects that the temperature in the first water tank 22 exceeds the first threshold value, the water quantity of the low-temperature liquid water input by the first water source 23 is increased and/or the water quantity of the temperature-rising liquid water output by the heat exchange unit is reduced; when the temperature sensor 221 detects that the temperature in the first water tank 22 is lower than the second threshold value, the amount of the low-temperature liquid water input by the first water source 23 is reduced and/or the amount of the temperature-raising liquid water output by the heat exchange unit is increased.
Further, in some embodiments, when the second flowmeter 14 detects that the water flow of the condensed water is smaller than the water required by the fuel cell module 1, the condensed water output by the second water source 13 and the condensed water output by the third water tank 15 are treated by the water treatment unit 11 together, and then water is supplied to the heat box unit 12 to participate in the reaction; when the second flowmeter 14 detects that the water flow of the condensed water is not smaller than the water required by the fuel cell module 1, the second water source 13 stops inputting the reaction water to the water treatment unit 11, and the condensed water is only output by the third water pump 16 and is treated by the water treatment unit 11 and then supplied to the heat box unit 12 to participate in the reaction.
In other embodiments, the water level in the second water tank 111 is controlled to be between the first water level and the second water level, and the second water level is higher than the first water level;
when the liquid level monitoring device 112 monitors that the water level in the second water tank 111 is smaller than the first water level, controlling to increase the amount of the reaction water input to the second water tank 111 from the second water source 13 and/or the condensed water input to the second water tank 111 from the heat exchange unit 21; when the liquid level monitoring device 112 monitors that the water level in the second water tank 111 is not less than the second water level, the amount of the reaction water and/or condensed water input to the second water tank 111 is reduced. Wherein the first water level and the second water level can be adjusted and set according to actual requirements, and an overflow valve can be arranged in the second water tank 111 to drain water in the second water tank 111.
Further, in some embodiments, when the water level in the second water tank 111 is not less than the first water level, the second water source 13 is controlled to stop the supply of the reaction water to the second water tank, and only the condensed water is supplied to the second water tank 111 by the heat exchange unit 21. The self-circulation of the fuel cell reaction water can be realized at this time, the water source can be better saved, and the waste of water resources is avoided.
Specifically, when the fuel cell module 1 is just started, the amount of the tail gas generated in the hot box unit 12 is not large enough, the temperature is also not high enough, at the moment, the recoverable waste heat and condensed water are limited, the recovered condensed water is difficult to completely meet the reaction requirement of the fuel cell module 1, so that the second water source 13 is required to continuously input reaction water into the water treatment unit 11 to meet the reaction requirement of the fuel cell module 1, and meanwhile, the first water source 23 also continuously inputs low-temperature liquid water into the first water tank 22, at the moment, the temperature of the liquid water in the first water tank 22 is lower, the direct use of the hot box 3 cannot be met, and the liquid water circulates in the first water tank 22 and the heat exchange unit 21 to stably increase the temperature of the liquid water in the first water tank 22;
when the fuel cell enters a stable operation stage, the amount of the tail gas is large, the heat content in the tail gas is high, the waste heat recovery efficiency and the condensation water amount are large, the condensation water amount can meet the water use requirement of the fuel cell, the second water source 13 can be closed at the moment, the self-circulation of the water used by the fuel cell is realized, and the consumption of the water source is reduced; likewise, when the temperature in the first water tank 22 exceeds the temperature suitable for the direct use of the thermal module 3, more low-temperature liquid water can be input into the first water tank 22 through the control valve 231 and the first water source 23 to reduce the temperature of the liquid water in the first water tank to be within a suitable temperature range and increase the amount of the liquid water in the usable temperature range, so that the greater water consumption requirement of the thermal module 3 can be met;
in the cooling stage of the fuel cell, the heat content and the water content of the tail gas output by the heat box unit 12 are also lower, the waste heat and the condensed water which can be recovered are lower, the condensed water cannot meet the water requirement of the fuel cell module 1, at the moment, the second water source 13 needs to be re-opened to input reaction water into the water treatment unit 11 so as to maintain the reaction of the fuel cell module 1, and the same waste heat which can be recovered is less, so that the temperature of the liquid water in the first water tank 22 is reduced, the heat requirement of the heat utilization module 3 is not met, and at the moment, the temperature of the liquid water in the first water tank 22 can be stably maintained in a proper range by reducing the amount of the low-temperature liquid water input by the first water source 23, and the heat requirement of the heat utilization module is met.
In summary, the embodiment of the invention provides a waste heat recovery system of a fuel cell, wherein a heat exchange unit 21 in a waste heat recovery module 2 can realize heat exchange between liquid water and tail gas 4 generated by the fuel cell module 1, so that waste heat recovery of the fuel cell is realized, condensed water generated after heat exchange of the tail gas 4 is purified by a water treatment unit 11 and then is input into a heat box unit 12 again to participate in reaction, and recycling of water for fuel cell reaction is realized; the warmed liquid water after heat exchange and temperature rise in the heat exchange unit 21 is returned to the first water tank 22 to be mixed with the liquid water in the first water tank 22 so as to stabilize the temperature of the liquid water in the first water tank 22, one part of the liquid water in the first water tank 22 enters the heat exchange unit 21 again to participate in heat exchange circulation, the other part of the liquid water goes to each heat utilization facility 31 of the heat utilization module 3 to be reused, and part of the water used in the heat utilization facility 31 is pumped into the first water tank 22 again through the second water pump 32 to participate in heat exchange circulation and heat utilization circulation, so that water resources are further saved, meanwhile, the circulation of the liquid water between the first water tank 22 and the heat exchange unit 21 can stabilize the temperature of the liquid water in the first water tank 22 in a proper temperature range, the heat utilization convenience of the heat utilization facility 31 is improved, the waste of the heat recovery of a fuel cell is avoided, the capacity of the liquid water with proper temperature output of the first water tank 22 is improved, and the heat utilization requirement of more heat utilization facilities 31 can be met.
The foregoing is merely a preferred embodiment of the present invention, and it should be noted that modifications and substitutions can be made by those skilled in the art without departing from the technical principles of the present invention, and these modifications and substitutions should also be considered as being within the scope of the present invention.
Claims (10)
1. The utility model provides a waste heat recovery system of fuel cell, includes fuel cell module, waste heat recovery module and the heat utilization module that connects gradually, its characterized in that:
the waste heat recovery module comprises a heat exchange unit and a first water tank which are connected, the heat exchange unit is connected with the fuel cell module and is used for carrying out heat exchange on tail gas of water vapor conveyed by the fuel cell module and liquid water conveyed by the first water tank;
the first water tank is provided with a water inlet end, an output end, a receiving end and a water outlet end, a temperature sensor is arranged in the first water tank, the water inlet end is connected with a first water source, the first water source is used for conveying liquid water to the first water tank, the output end is communicated with the heat exchange unit and is used for conveying the liquid water in the tank to the heat exchange unit for heat exchange and temperature rise, and the receiving end is communicated with the heat exchange unit and is used for receiving the heated liquid water output by the heat exchange unit; the water outlet end is connected with the heat utilization module and conveys liquid water reaching a preset temperature range in the first water tank to the heat utilization module.
2. The waste heat recovery system of a fuel cell according to claim 1, wherein the heat utilization module includes a heat utilization facility, an inlet end of the heat utilization facility is connected to the water outlet end to receive and use liquid water reaching a preset temperature range, an outlet end of the heat utilization facility is connected to a second water pump, and an output end of the second water pump is connected to the water inlet end to return the liquid water after the use of the heat utilization facility to the first water tank.
3. The waste heat recovery system of a fuel cell according to claim 1, wherein a buffer member is provided between the receiving end and the heat exchanging unit.
4. The waste heat recovery system of a fuel cell according to claim 1, wherein the fuel cell module comprises a water treatment unit and a heat box unit which are connected, the water treatment unit is connected with a second water source, the water treatment unit is used for purifying and then conveying reaction water of the second water source to the heat box unit to participate in reaction, and the heat box unit is communicated with the heat exchange unit and is used for conveying tail gas generated by the heat box unit to the heat exchange unit.
5. The waste heat recovery system of a fuel cell according to claim 4, wherein the heat exchange unit is further connected to the water treatment unit; and a second flowmeter, a third water tank and a third water pump are further arranged between the heat exchange unit and the water treatment unit in sequence, and the third water pump is used for conveying condensate water generated after tail gas heat exchange to the water treatment unit.
6. The waste heat recovery system of a fuel cell according to claim 4, wherein the water treatment unit comprises a second water tank, a liquid level monitoring device is arranged in the second water tank, and the reaction water of the second water source flows through the second water tank and is then conveyed to the hot box unit; the heat exchange unit is communicated with the second water tank and used for conveying condensate water generated after tail gas heat exchange to the second water tank.
7. A control method of a waste heat recovery system of a fuel cell, characterized by comprising the waste heat recovery system of a fuel cell according to any one of claims 1 to 6, comprising the steps of:
the method comprises the steps of controlling a first water source to input liquid water into a first water tank, controlling the liquid water in the first water tank to circularly flow between the first water tank and a heat exchange unit, enabling the liquid water in the first water tank to flow through the heat exchange unit for heat exchange and then flow back to the first water tank, and enabling the temperature of the liquid water output to a heat utilization module by the first water tank to be stable within a preset temperature range.
8. The control method of the waste heat recovery system of a fuel cell according to claim 7, comprising the steps of:
when the second flowmeter detects that the water flow of the condensed water is smaller than the water required by the fuel cell module, the reaction water output by the second water source and the condensed water output by the third water pump are processed together by the water processing unit and then supplied to the hot box unit to participate in reaction; and when the second flowmeter detects that the water flow of the condensed water is not smaller than the water required by the fuel cell module, stopping the second water source from inputting the reaction water to the water treatment unit, and only the condensed water output by the third water pump is treated by the water treatment unit and then is supplied to the heat box unit to participate in the reaction.
9. The control method of the waste heat recovery system of a fuel cell according to claim 7, comprising the steps of:
controlling a water level in the second water tank between a first water level and a second water level, the second water level being higher than the first water level;
when the liquid level monitoring device monitors that the water level in the second water tank is smaller than a first water level, the water amount of the reaction water and/or the condensed water input into the second water tank is increased; and when the liquid level monitoring device monitors that the water level in the second water tank is not smaller than a second water level, reducing the water amount of the reaction water and/or the condensed water input into the second water tank.
10. The control method of the waste heat recovery system of a fuel cell according to claim 9, characterized by further comprising the steps of:
when the water level in the second water tank is not less than the first water level, controlling the second water source to stop inputting the reaction water into the second water tank, and only inputting condensed water into the second water tank by the heat exchange unit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311802867.4A CN117594826A (en) | 2023-12-25 | 2023-12-25 | Waste heat recovery system of fuel cell and control method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311802867.4A CN117594826A (en) | 2023-12-25 | 2023-12-25 | Waste heat recovery system of fuel cell and control method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117594826A true CN117594826A (en) | 2024-02-23 |
Family
ID=89911665
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311802867.4A Pending CN117594826A (en) | 2023-12-25 | 2023-12-25 | Waste heat recovery system of fuel cell and control method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117594826A (en) |
-
2023
- 2023-12-25 CN CN202311802867.4A patent/CN117594826A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5160774B2 (en) | Control method of fuel cell system and fuel cell system | |
| US6699612B2 (en) | Fuel cell power plant having a reduced free water volume | |
| CN113278992B (en) | Water vapor turbocharged fuel cell electrolytic cell system and working method thereof | |
| RU2332753C2 (en) | Thermoregulation in electrochemical fuel elements | |
| CN113793947B (en) | Fuel cell waste heat utilization system and energy system | |
| CN115172800A (en) | Solid oxide fuel cell combined heat and power system | |
| CN213459815U (en) | Methanol reforming hydrogen production power generation system | |
| CN113851670A (en) | Combined cooling heating and power method based on proton exchange membrane fuel cell | |
| RU2443040C2 (en) | Fuel elements system | |
| CN115101781A (en) | Thermoelectric cogeneration system and method based on flat-tube SOFC | |
| JP2003105577A (en) | Gas generator and fuel cell hybrid system | |
| JP2889807B2 (en) | Fuel cell system | |
| JP2016515190A (en) | Heating equipment and method of operating heating equipment | |
| CN221687565U (en) | Waste heat recovery system of fuel cell | |
| CN112582642A (en) | Heat preservation heating device for hydrogen supply and hydrogen return of fuel cell | |
| CN220086095U (en) | Proton exchange membrane hydrogen fuel cell cogeneration system | |
| US9219283B2 (en) | Method for controlling fuel cell device during power generation start by controlling power conditioner | |
| CN117594826A (en) | Waste heat recovery system of fuel cell and control method | |
| JPH0249359A (en) | Fuel cell power generating system | |
| JP2007052981A (en) | Fuel cell power generation system and its operation method | |
| CN111933978B (en) | Fuel cell cogeneration system | |
| JP3263129B2 (en) | Fuel cell system | |
| CN213936265U (en) | Heat preservation heating device for hydrogen supply and hydrogen return of fuel cell | |
| CN212366006U (en) | Heating system in fuel cell cogeneration system | |
| JP3906677B2 (en) | Water treatment device for fuel cell |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |