A cooling and humidification integrated system for a fuel cell

Abstract

The application relates to a cooling and humidifying integrated system of a fuel cell, which comprises a fuel cell stack, a gas-liquid separator, a water tank, a radiator, a water pump, a middle-cooling humidifier and an air compressor, the middle-cooling humidifier comprises a water channel and an air channel, and the water channel and the air channel are communicated through a baffle humidifying structure; the air outlet of the fuel cell stack is connected with the inlet of the water tank through the gas-liquid separator, the outlet of the water tank and the inlet of the water channel are provided with the radiator and the water pump; the exhaust port of the air compressor is connected with the inlet of the air channel, and the outlet of the air channel is connected with the air inlet of the fuel cell stack. The humidifying system and the cooling system of the fuel cell system are integratedly designed, the air discharged by the air compressor is cooled and humidified by using the water generated by the fuel cell system, the system components and the running fault points are reduced, the complexity and the manufacturing cost of the system are greatly reduced, the space is saved, and good humidifying effect can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and in particular to a cooling and humidifying integrated system for fuel cells. Background Art

[0002] Fuel cell technology, as an environmentally friendly technology that provides a new generation of efficient, zero-pollution clean energy, is being increasingly used in industries such as power, power supply, and energy storage. Among fuel cells, the most widely used and developed cell structure is the proton exchange membrane fuel cell (PEMFC). A fuel cell power generation system is a power generation device that provides electricity based on fuel cells. A typical fuel cell power generation system mainly includes a main controller (control system), a fuel cell (stack), a cooling system (including stack cooling and air compressor outlet air cooling), an air supply system and its humidification system, and a fuel supply and recovery circulation system. Hydrogen fuel cell systems use hydrogen, a clean energy source, as fuel. They have advantages such as low-temperature start-up, high energy density, fast start-up, and good system performance, and have received widespread attention and practical application.

[0003] A fuel cell is a power generation device that converts the chemical energy of fuel and electrolyte directly into electrical energy. Figure 1 As shown, its working principle is: the hydrogen entering the anode side of the fuel cell is decomposed into H atoms under the action of the catalyst. + With e – , where H + It enters the anode side and passes through the proton exchange membrane to reach the cathode side under hydration. Since electrons cannot pass through the proton exchange membrane, they can only reach the cathode side through the outside (forming an external circuit for doing work); on the cathode side, protons, electrons and oxygen atoms react under the action of the catalyst to form water molecules and release a large amount of heat.

[0004] The electrode reaction equation of the proton exchange membrane fuel cell is as follows:

[0005] Positive electrode: O2+4e - +4H + =2H2O

[0006] Negative electrode: 2H2=4H + +4e -

[0007] Overall chemical reaction: 2H2+O2=2H2O

[0008] The water conductivity of the proton exchange membrane is an important parameter affecting the performance of the fuel cell for the operation of the fuel cell. According to the experimental data at home and abroad, the fuel cell works at 60℃, the gas humidity is between 80% and 100%, the reaction efficiency is the highest, if the reaction gas is too dry, the water molecules in the proton exchange membrane are too few, which leads to the decrease of the working efficiency of the fuel cell and may cause the damage of the exchange membrane; and if the reaction gas is too humid, the performance of the battery system will be deteriorated due to the "waterlogging" and other reasons, so the most important factor affecting the overall performance of the fuel cell during operation is the humidification system.

[0009] Due to the oxygen supply for the fuel cell system, at present, the air is provided by the air compressor with high speed and large flow, and the outlet air temperature of the air compressor is very high (usually up to 120-130℃) during operation, which requires that the air entering the fuel cell stack be cooled to a temperature of about 40-50℃ to meet the normal working temperature of the stack, and a necessary air cooling system is added, which is mainly composed of a intercooler, a water pump, a radiator, a radiator fan and a radiator water tank.

[0010] The humidification system of the fuel cell has various forms, which are mainly divided into external humidification and internal humidification. The internal humidification is to add a humidification section in the stack, which relies on the gas resistance characteristics of the membrane and the concentration diffusion of water in the membrane to realize; and the external humidification method mainly includes bubble humidification, liquid water injection humidification, wet membrane humidification, hollow fiber humidification and steam injection humidification.

[0011] The air compressor cooling system and the humidification system of the existing fuel cell system increase the complexity of the system and the fault points of the system to a certain extent: a complete cooling system is needed for the outlet air cooling of the air compressor; at the same time, for the fuel cell external humidification system, a complete humidification system with a supplementary water tank, a humidification pump and a humidification method of membrane humidification or liquid water injection humidification or steam injection humidification is also needed, which not only increases the complexity of the system, but also occupies a large space and increases the inherent cost of the system. Under the technical background of pursuing and improving the volume power ratio of the fuel cell and reducing the system manufacturing cost to increase the market competitiveness, the shortcomings are particularly prominent. SUMMARY

[0012] In order to solve the above problems, the present application provides a cooling and humidification integrated system of a fuel cell, which comprises a fuel cell stack, a gas-liquid separator, a radiator, a water pump, an intercooling humidifier and an air compressor, the intercooling humidifier comprises a water channel and an air channel, and the water channel and the air channel are communicated through a partition plate humidification structure.

[0013] The air outlet of the fuel cell stack is connected with the inlet of the water tank through the gas-liquid separator, and the outlet of the water tank is connected with the inlet of the water channel, and the radiator and the water pump are arranged between the outlet of the water tank and the inlet of the water channel.

[0014] The air outlet of the air compressor is connected with the inlet of the air channel, and the outlet of the air channel is connected with the air inlet of the fuel cell stack.

[0015] Preferably, the baffle humidification structure comprises a baffle, and a plurality of first openings are arranged on the baffle and communicated with the water channel and the air channel respectively.

[0016] Preferably, the water channel and the air channel are both formed by fins, and the fins forming the water channel and the fins forming the air channel are both parallel to the baffle.

[0017] Preferably, the fins are in linear contact or surface contact with the baffle, and when the fins are in surface contact with the baffle, a second opening is arranged on the fins overlapping the baffle and communicated with the first opening.

[0018] Preferably, the fin structure is flat, and when the cross section of the fin is rectangular, the second opening is arranged on the part of the fin overlapping the baffle.

[0019] Preferably, the baffle is a hollow cavity structure, and the hollow part of the baffle is provided with a microporous support wrapped by a water-permeable membrane, and a plurality of first openings are arranged on the baffle and communicated with the water channel and the air channel respectively.

[0020] Preferably, the microporous support is a foam metal structure.

[0021] Preferably, the outlet of the water channel is connected with the inlet of the water tank.

[0022] Preferably, a drain valve is further arranged between the outlet of the water channel and the inlet of the water tank.

[0023] Preferably, a vacuum pump is further arranged between the gas-liquid separator and the water tank.

[0024] Compared with the prior art, the present application has the following technical effects:

[0025] The application provides a cooling and humidifying integrated system of a fuel cell, which integrates a humidifying system and a cooling system of a fuel cell system, reduces the use of a intercooler / humidifier component and a humidifying water pump, and is an internal cooling and humidifying system, which uses water generated by the fuel cell system (recycles a large amount of water in air exhausted by the fuel cell system) to cool and humidify air discharged by an air compressor, so that the system components and failure points in operation are reduced, the complexity and manufacturing cost of the system are greatly reduced, space is saved, and good humidifying effect is achieved. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description only constitute some embodiments of the application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor. The drawings are as follows:

[0027] Figure 1 A working principle diagram of the fuel cell;

[0028] Figure 2 A structural block diagram of the fuel cell with the cooling and humidifying integrated system provided by the preferred embodiment of the application;

[0029] Figure 3 A structural schematic diagram of the intercooling humidifier provided by the preferred embodiment of the application;

[0030] Figure 4 A structural schematic diagram of the air passage fin or water passage fin provided by the preferred embodiment of the application;

[0031] Figure 5 A structural schematic diagram of the baffle humidifying structure in the membrane humidifying scheme provided by the preferred embodiment of the application. DETAILED DESCRIPTION

[0032] The following will combine Figures 2 to 5 The cooling and humidifying integrated system of the fuel cell provided by the application will be described in detail, the embodiment is implemented on the premise of the technical solution of the application, and detailed implementation manners and specific operation processes are given, but the protection scope of the application is not limited to the following embodiments, and those skilled in the art can modify and polish them without changing the spirit and content of the application.

[0033] Please refer to Figures 2 to 5The application discloses a cooling and humidifying integrated system 10 of a fuel cell, which is an internal cooling and humidifying system, and utilizes water generated by the fuel cell system to cool and humidify air discharged by an air compressor, and the system comprises a fuel cell stack 1, a gas-liquid separator 2, a water tank 3, a radiator 5, a water pump 6, a middle cooling and humidifying device 7 and the air compressor 4, wherein the middle cooling and humidifying device 7 comprises a water channel and an air channel, and the water channel and the air channel are communicated through a baffle humidifying structure.

[0034] The gas-liquid separator 2 is arranged at an air outlet of the fuel cell stack 1, and the purpose is to separate the air tail discharge of the fuel cell stack 1 containing a large amount of water through the gas-liquid separator 2, and to connect the separated water with a water inlet of the water tank 3 through a pipeline. The air outlet of the fuel cell stack 1 is connected with the water inlet of the water tank 3 through the gas-liquid separator 2, and the outlet of the water tank 3 is provided with the radiator 5 and the water pump 6 between the outlet and the inlet of the water channel.

[0035] The air outlet of the air compressor 4 is connected with the inlet of the air channel, and the outlet of the air channel is connected with the air inlet of the fuel cell stack 1.

[0036] In the middle cooling and humidifying device 7, the water in the air discharged by the fuel cell stack 1 is cooled and humidified through the middle cooling and humidifying device 7, and the air discharged by the air compressor 4 is cooled and humidified.

[0037] As an embodiment, the outlet of the water channel of the middle cooling and humidifying device 7 is connected with the water inlet of the water tank 3, and a water circulation is formed in the cooling and humidifying integrated system 10.

[0038] Further, the outlet of the water channel is further provided with a drain valve 8 between the outlet and the inlet of the water tank 3.

[0039] Of course, the outlet of the water channel of the middle cooling and humidifying device 7 is connected with the outside of the system through the drain valve 8, and when maintenance is needed, the water in the cooling and humidifying system is drained to the outside of the system through the drain valve 8.

[0040] The outlet of the water tank 3 is provided with the radiator 5 and the water pump 6 between the outlet and the inlet of the water channel, and the application does not make specific limitation on the arrangement order of the radiator 5 and the water pump 6. Figure 2 For example, the arrangement order of the water tank 3, the radiator 5 and the water pump 6 is sequentially arranged.

[0041] In the working of the cooling and humidifying integrated system 10, the air (containing a large amount of water) discharged by the fuel cell system is repeatedly utilized after steam-water separation, and tail discharge water is used to supplement the water amount of the water tank 3 of the cooling and humidifying system. The system is started through the circulation of the water pump 6, the radiator 5 firstly cools the water flowing out from the water tank 3, and then the water is input into the middle cooling and humidifying device 7 through the water pump 6, so as to cool and humidify the air in the middle cooling and humidifying device 7.

[0042] Further, a vacuum pump 9 is arranged between the gas-liquid separator 2 and the water tank 3.

[0043] In the present application, there are two humidification schemes, one is a membrane humidification scheme, and the other is a liquid water injection humidification scheme. The two humidification schemes will be described in detail below.

[0044] Liquid water injection humidification scheme

[0045] In the present scheme, the baffle humidification structure comprises a baffle 73, and a plurality of first holes are arranged on the baffle 73 and communicated with the water channel and the air channel respectively.

[0046] The water channel and the air channel are both formed by fins, and the water channel fin 71 forming the water channel and the air channel fin 72 forming the air channel are both parallel to the baffle 73.

[0047] The cross-sectional structure of the fin is not specifically limited in the present embodiment, and the fin can be in linear contact with the baffle 73 or in surface contact with the baffle 73. When the fin is in linear contact with the baffle 73, no hole needs to be opened on the fin. If the fin is in surface contact with the baffle 73, a second hole 721 needs to be opened on the water channel fin 71 and the air channel fin 72 overlapping the baffle 73, and the first hole and the second hole 721 are communicated at the overlapping position.

[0048] In the present embodiment, the water channel fin 71 and the air channel fin 72 are both flat, and the cross-sectional shape is not fixed. When the cross-section of the fin is rectangular, the second hole 721 is arranged on the part of the fin overlapping the baffle.

[0049] The present application does not limit the number of baffles 73, water channels and air channels in the intermediate cooling humidifier 7. In the present embodiment, two baffles 73, two water channel fins 71 and one air channel fin 72 are taken as an example. The air channel fin 72 is located between the two water channel fins 71, and baffles 73 are arranged on the upper and lower sides of the air channel fin 72 respectively. A plurality of second holes 721 are arranged on the part of the air channel fin 72 overlapping the baffle 73, a plurality of second holes 721 are arranged on the part of the water channel fin 71 above the air channel fin 72 overlapping the baffle 73, and a plurality of second holes 721 are arranged on the part of the water channel fin 71 below the air channel fin 72 overlapping the baffle 73. The upper end of the upper water channel fin 71 and the lower end of the lower water channel fin 71 are both provided with an end plate 74.

[0050] Preferably, the part of the baffle 73 not overlapping with the fin is communicated with the fin channel through the first opening on the baffle 73, the first opening of the part of the baffle 73 overlapping with the fin and the second opening 721 overlap, and the first opening and the second opening 721 are both micropores with a diameter less than 0.2 mm, which functions to form the communication between the water channel and the air channel, and ensure that the water channel sprays water mist to the air channel under a certain pressure to achieve the humidification purpose.

[0051] Further, the water channel and the air channel are perpendicular.

[0052] Membrane humidification scheme

[0053] The difference between the membrane humidification scheme and the liquid water injection humidification scheme lies in the structure of the baffle. In the present scheme, the baffle 73' is a hollow cavity structure, the hollow part of the baffle 73' is provided with a microporous support 75 wrapped by a water-permeable membrane 76 as a wet membrane structure for air humidification, and the baffle 73' is provided with a plurality of first openings respectively communicated with the water channel and the air channel.

[0054] Further, the microporous support 75 is a foamed metal structure, preferably a foamed metal nickel support.

[0055] In the intercooler humidifier 7 provided in the present scheme, the water in the water channel is humidified to the air in the air channel through the wet membrane structure in the baffle 73'.

[0056] The intercooler humidifier 7 provided in the present scheme can exhibit good humidification effect through the membrane humidification or water injection humidification scheme. Since the outlet exhaust temperature of the air compressor 4 is relatively high (usually up to about 120-130℃), in the scheme of membrane humidification, the water humidified through the water-permeable membrane 76 is atomized to a certain extent in the high-temperature air, thereby improving the humidification capacity of the fuel cell stack 1. Especially in the water injection humidification scheme, the humidification water itself is atomized through the 0.1-0.2 mm injection hole, and then heated by the high-temperature air to form a certain vaporization of the water mist, which will significantly improve the humidification effect.

Claims

1. A cooling and humidification integrated system for a fuel cell, characterized by, The system comprises a fuel cell stack, a gas-liquid separator, a water tank, a radiator, a water pump, a middle-cooling humidifier and an air compressor, the middle-cooling humidifier comprises a water channel and an air channel, and the water channel and the air channel are communicated through a baffle humidification structure; The baffle humidification structure comprises a baffle, and a plurality of first holes are arranged on the baffle and communicated with the water channel and the air channel respectively; The air outlet of the fuel cell stack is connected with the inlet of the water tank through the gas-liquid separator, and the outlet of the water tank and the inlet of the water channel are provided with the radiator and the water pump; The exhaust port of the air compressor is connected with the inlet of the air channel, and the outlet of the air channel is connected with the air inlet of the fuel cell stack; The outlet of the water channel of the middle-cooling humidifier is connected with the water inlet of the water tank, and a water circulation is formed in the cooling and humidifying integrated system; The water channel and the air channel are both formed by fins, the fins forming the water channel and the fins forming the air channel are both parallel to the baffle, the air channel fin is located between two water channel fins, and the upper and lower sides of the air channel fin are respectively provided with the baffle between the two water channel fins, a plurality of second holes are arranged on the overlapping part of the air channel fin and the baffle, a plurality of second holes are arranged on the overlapping part of the upper water channel fin and the baffle above the air channel fin, a plurality of second holes are arranged on the overlapping part of the lower water channel fin and the baffle below the air channel fin, and the upper end of the upper water channel fin and the lower end of the lower water channel fin are both provided with a sealing plate; The first holes and the second holes are both micropores with a diameter less than 0.2mm.

2. A cooling and humidification integrated system for a fuel cell as claimed in claim 1, wherein, A drain valve is further arranged between the outlet of the water channel and the inlet of the water tank.

3. The cooling and humidification integrated system of a fuel cell according to claim 1, wherein A vacuum pump is further arranged between the gas-liquid separator and the water tank.

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