Air humidifier for fuel cell and fuel cell system

Abstract

The invention discloses an air humidifier for a fuel cell, which comprises a front-section channel switching system, a rear-section channel switching system and a humidifying system for humidifying air flowing to an electric pile, the front-section channel switching system is connected with the humidifying system, an air source and a tail exhaust system, the rear-section channel switching system is connected with the electric pile and the humidifying system, and the rear-section channel switching system is connected with the rear-section channel switching system. And the rear-section channel switching system is arranged to be used for guiding water discharged by the electric pile to the humidifying system. According to the air humidifier for the fuel cell, the water storage action and the humidifying action are separated, so that the size and the cost of a humidifying system can be remarkably reduced, and the service life can be prolonged. The invention also discloses a fuel cell system.

Description

Technical Field

[0001] The present invention belongs to the technical field of fuel cells, and in particular, relates to an air humidifier for fuel cells and a fuel cell system. Background Art

[0002] Proton exchange membrane fuel cell (PEMFC) is one of the most promising and popular fuel cell technologies. It has many advantages such as no pollution, high energy conversion rate, short charging time, low operating temperature and low noise. It can be widely used in many fields such as transportation vehicles, cogeneration, fixed base stations, mobile portable devices, drones, military equipment, etc.

[0003] Hydrothermal management of fuel cells has always been a key concern in the field, and one of the most important factors in improving the performance of polymer electrolyte membrane fuel cells (PEMFC) is to maintain functional efficiency by supplying a certain amount of moisture to the polymer electrolyte membrane (PEM) or proton exchange membrane in the membrane electrode assembly (MEA). This is because when the polymer electrolyte membrane is dry, the power generation efficiency decreases rapidly.

[0004] The prior art mostly uses a membrane exchange air humidifier to achieve humidification inside the fuel cell. A Chinese patent with application number 202180087308.2 discloses a fuel cell humidification system for supplying humidified gas to a fuel cell, comprising: a plurality of humidification modules, the plurality of humidification modules being configured to humidify the cell gas supplied to the fuel cell stack by using moisture; a humidifier, the humidifier being configured to supply moisture to the humidification modules and discharge moisture discharged from the humidification modules; a supply cover, the supply cover being connected to one side of the humidification section to supply the cell gas to the humidification module; and a discharge cover, which is connected to the other side of the humidification part to discharge the battery gas discharged from the humidification module to the fuel cell stack, and each humidification module includes a filter element connected to a plurality of hollow fiber membranes, an intermediate shell connected to one or more filter elements, a supply hole formed to penetrate the intermediate shell so that moisture is supplied to the intermediate shell, and a discharge hole formed to penetrate the intermediate shell so that moisture is discharged from the intermediate shell, and the humidification part includes a humidification body in which the humidification module is accommodated, a supply member for supplying moisture to the humidification body, and a discharge member for discharging moisture from the humidification body. In this patent, the humidification system of the fuel cell directly humidifies the gas entering the stack with the moisture at the outlet of the stack through the hollow fiber membrane. Due to the requirements for the flow resistance and water exchange efficiency of the humidifier, the humidifier requires a large exchange area, resulting in a large volume and high cost of the humidifier, and the life of the humidifier is greatly affected by the membrane.

[0005] It would be desirable to provide an improved air humidifier for use with a fuel cell, particularly with respect to reducing cost. Summary of the invention

[0006] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides an air humidifier for a fuel cell, the purpose of which is to reduce the cost.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is: an air humidifier for a fuel cell, comprising a front-end channel switching system, a rear-end channel switching system and a humidification system for humidifying the air flowing to the fuel cell stack, the front-end channel switching system is connected to the humidification system, the air source and the tail exhaust system, the rear-end channel switching system is connected to the fuel cell stack and the humidification system, and the rear-end channel switching system is configured to guide water discharged from the fuel cell stack to the humidification system.

[0008] The humidification system is located between the front-end channel switching system and the rear-end channel switching system, and the rear-end channel switching system is located between the battery stack and the humidification system.

[0009] The humidification system includes a humidity storage tank, at least two of which are connected to the front-end channel switching system and the rear-end channel switching system. The humidity storage tank is configured to receive air from the front-end channel switching system and humidify the air, and can be used to receive water from the rear-end channel switching system.

[0010] In the humidification system, at least one of the humidification tanks is configured to receive air from the front-end channel switching system and humidify the air, and at least one of the humidification tanks is configured to receive water from the rear-end channel switching system.

[0011] A heating device is provided, and the heating device is configured to heat the humidification storage tank that is receiving air from the front-stage channel switching system.

[0012] A cooling device is provided, and the cooling device is configured to cool the humidification storage tank that is receiving water from the rear-stage channel switching system.

[0013] Two humidity storage tanks are provided.

[0014] The front-end channel switching system includes a first switching valve, and the first switching valve is connected to the air source and the humidification system.

[0015] The rear channel switching system includes a second switching valve, and the second switching valve is connected to the battery stack and the humidification system.

[0016] The present invention also provides a fuel cell system, comprising the air humidifier for the fuel cell.

[0017] The air humidifier for a fuel cell of the present invention can significantly reduce the volume and cost of the humidification system and increase the service life by separating water storage from humidification. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of a first working state of the air humidifier for a fuel cell of the present invention;

[0019] Figure 2 This is a schematic diagram of a second working state of the air humidifier for a fuel cell of the present invention;

[0020] The markings in the above figures are: 1. Front-end channel switching system; 2. Rear-end channel switching system; 3. First humidity storage tank; 4. Second humidity storage tank; 5. Fuel stack. DETAILED DESCRIPTION

[0021] The specific implementation methods of the present invention are further explained in detail below by describing the embodiments with reference to the accompanying drawings, with the aim of helping those skilled in the art to have a more complete, accurate and in-depth understanding of the concept and technical solution of the present invention and facilitating its implementation.

[0022] It should be noted that when an element is referred to as being "fixed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower" and similar expressions used in this article are for illustrative purposes only.

[0023] It should be noted that, in the following embodiments, the “first” and “second” mentioned do not represent an absolute distinction in structure and / or function, nor do they represent a sequential order of execution, but are merely for the convenience of description.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly connected by technicians in the technical field to which the present invention belongs. The terminology used in the specification of the present invention is for the purpose of describing specific embodiments and is not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0025] like Figure 1 and Figure 2As shown, the present invention provides an air humidifier for a fuel cell, comprising a front-end channel switching system 1, a rear-end channel switching system 2 and a humidifying system for humidifying the air flowing to the fuel cell stack 5, the front-end channel switching system 1 is connected to the humidifying system, the air source and the tail exhaust system, the rear-end channel switching system 2 is connected to the fuel cell stack 5 and the humidifying system, and the rear-end channel switching system 2 is configured to guide the water discharged from the fuel cell stack 5 to the humidifying system.

[0026] The humidification system is located between the front-end channel switching system 1 and the rear-end channel switching system 2, and the rear-end channel switching system 2 is located between the battery stack 5 and the humidification system.

[0027] The humidification system includes a humidity storage tank, at least two of which are connected to the front-end channel switching system 1 and the rear-end channel switching system 2. The humidity storage tank is configured to receive air from the front-end channel switching system 1 and humidify the air, and can be used to receive water from the rear-end channel switching system 2.

[0028] In the humidification system, at least one of the humidification tanks is configured to receive air from the front-end channel switching system 1 and humidify the air, and at least one of the humidification tanks is configured to receive water from the rear-end channel switching system 2.

[0029] A heating device is provided, and the heating device is configured to heat the humidification tank that is receiving air from the front-stage channel switching system 1.

[0030] A cooling device is provided, and the cooling device is configured to cool the humidification tank that is receiving water from the rear-stage channel switching system 2 .

[0031] Two humidity storage tanks are provided.

[0032] The front-end channel switching system 1 includes a first switching valve, and the first switching valve is connected to the air source and the humidification system.

[0033] The rear channel switching system 2 includes a second switching valve, and the second switching valve is connected to the battery stack 5 and the humidification system.

[0034] The present invention also provides a fuel cell system, comprising the air humidifier for the fuel cell.

[0035] Example

[0036] First, as Figure 1 and Figure 2As shown, an embodiment of the present invention provides an air humidifier for a fuel cell, comprising a front-end channel switching system 1, a rear-end channel switching system 2, and a humidifying system for humidifying air flowing to the fuel cell stack 5, wherein the front-end channel switching system 1 is connected to the humidifying system, the air source, and the tail exhaust system, and the rear-end channel switching system 2 is connected to the fuel cell stack 5 and the humidifying system. The humidifying system is located between the front-end channel switching system 1 and the rear-end channel switching system 2, the rear-end channel switching system 2 is located between the fuel cell stack 5 and the humidifying system, and the rear-end channel switching system 2 is configured to guide the water discharged from the fuel cell stack 5 to the humidifying system.

[0037] like Figure 1 and Figure 2 As shown, the humidification system includes two humidity storage tanks, which have the function of humidifying the air and storing water. The humidity storage tanks are connected to the front-end channel switching system 1 and the rear-end channel switching system 2. The humidity storage tanks are configured to receive air from the front-end channel switching system 1 and humidify the air, and can be used to receive water from the rear-end channel switching system 2. The water discharged from the battery stack 5 enters the humidity storage tank through the rear-end channel switching system 2, so as to realize the collection and utilization of tail water.

[0038] The gas source is used to provide air, and the tail exhaust system mainly includes a tail exhaust mixing pipe. The front channel switching system 1 can switch the direct connection pipes between the gas source inlet, the tail exhaust port and all the humidification tanks. The rear channel switching system 2 can switch the direct connection pipes between the cell stack 5 inlet, the cell stack 5 outlet and all the humidification tanks. The humidification tank can collect the water at the outlet of the cell stack 5, and can also use the collected water to humidify the air. The air humidified by the humidification tank enters the cell stack 5 through the rear channel switching system 2. The water discharged from the cell stack 5 enters the humidification tank through the rear channel switching system 2. The humidification tank can store water and collect tail exhaust water. The excess water in the humidification tank can be discharged to the tail exhaust system through the front channel switching system 1.

[0039] like Figure 1 and Figure 2 As shown, during the operation of the humidification system, one of the humidity storage tanks is configured to receive air from the front channel switching system 1 and humidify the air, and the other humidity storage tank is configured to receive water from the rear channel switching system 2.

[0040] Preferably, a heating device is provided in the air humidifier for a fuel cell in an embodiment of the present invention. The heating device is configured to heat a humidification tank that is receiving air from the front-end channel switching system 1, thereby controlling the humidification humidity of the air in the humidification tank, thereby ensuring that the humidity of the air entering the fuel cell stack 5 is maintained within an optimal range, providing better operating conditions for the fuel cell stack 5, effectively controlling the performance of the fuel cell stack 5, and improving the stability of the entire fuel cell system.

[0041] Preferably, a cooling device is provided in the air humidifier for a fuel cell in an embodiment of the present invention. The cooling device is configured to cool the humidification tank that is receiving water from the rear-stage channel switching system 2, so that the humidification tank can store more water, which helps to humidify the air subsequently, improve work efficiency and reduce costs.

[0042] like Figure 1 and Figure 2 As shown, two humidity storage tanks are provided, and the two humidity storage tanks are respectively located in the first humidity storage tank 3 and the second humidity storage tank 4. One end of the first humidity storage tank 3 is connected to the front channel switching system 1, and the other end of the first humidity storage tank 3 is connected to the rear channel switching system 2. One end of the second humidity storage tank 4 is connected to the front channel switching system 1, and the other end of the second humidity storage tank 4 is connected to the rear channel switching system 2.

[0043] like Figure 1 As shown, it is the first working state of the air humidifier of the embodiment of the present invention, the front-end channel switching system 1 and the rear-end channel switching system 2 are switched to the first working state, the first humidification storage tank 3 is configured to receive air from the front-end channel switching system 1 and humidify the air, and the second humidification storage tank 4 is configured to receive water from the rear-end channel switching system 2. At this time, the air of the air source enters the first humidification storage tank 3 through the front-end channel switching system 1, and the first humidification storage tank 3 humidifies the air. The humidified air enters the fuel cell 5 through the rear-end channel switching system 2. At the same time, the water discharged from the fuel cell 5 enters the second humidification storage tank 4 through the rear-end channel switching system 2. The second humidification storage tank 4 collects tail water. The second humidification storage tank 4 can humidify the air when the working state is switched next time.

[0044] When the air humidifier is in the first working state, the heating device can also be started to heat the first humidity storage tank 3 to effectively control the humidity of the air in the first humidity storage tank 3, and the cooling device can be started to cool the second humidity storage tank 4 so that the second humidity storage tank 4 can store more water.

[0045] like Figure 2As shown, it is the second working state of the air humidifier of the embodiment of the present invention, the front-end channel switching system 1 and the rear-end channel switching system 2 are switched to the second working state, the second humidification storage tank 4 is configured to receive the air from the front-end channel switching system 1 and humidify the air, the first humidification storage tank 3 is configured to receive water from the rear-end channel switching system 2, at this time, the air of the air source enters the second humidification storage tank 4 through the front-end channel switching system 1, the second humidification storage tank 4 humidifies the air, the humidified air enters the fuel cell 5 through the rear-end channel switching system 2, and the water discharged from the fuel cell 5 enters the first humidification storage tank 3 through the rear-end channel switching system 2, the first humidification storage tank 3 collects the tail water, and the first humidification storage tank 3 can humidify the air when the working state is switched next time.

[0046] When the air humidifier is in the first working state, the heating device can also be started to heat the second humidity storage tank 4 to effectively control the humidity of the air in the second humidity storage tank 4, and the cooling device can be started to cool the first humidity storage tank 3 so that the first humidity storage tank 3 can store more water.

[0047] The air humidifier of the embodiment of the present invention can humidify the air entering the battery stack 5 by switching the working states of the front channel switching system 1 and the rear channel switching system 2, and cooperate with the first humidity storage tank 3 and the second humidity storage tank 4, and can also collect the tail water of the battery stack 5. At the same time, the switching cycle can be adjusted by monitoring the humidity of the battery stack 5 entering the stack, and more water can be stored by cooling the humidity storage tank that is performing the humidity storage function, and the air humidification humidity can be controlled by heating the humidity storage tank that is performing the humidification function. Compared with traditional membrane humidifiers, air humidifiers with this structure have the advantages of low cost and small size.

[0048] like Figure 1 and Figure 2 As shown, the front-end channel switching system 1 includes a first switching valve, which is connected to the gas source and the humidification system, and is a two-position four-way reversing valve. The rear-end channel switching system 2 includes a second switching valve, which is connected to the battery stack 5 and the humidification system, and is a two-position four-way reversing valve.

[0049] In a second aspect, an embodiment of the present invention further provides a fuel cell system, comprising an air humidifier for a fuel cell of the above structure. The specific structure of the air humidifier for a fuel cell can be referred to Figure 1 to Figure 2 Since the fuel cell system of the present invention includes the air humidifier for fuel cells in the above embodiment, it has all the advantages of the above air humidifier for fuel cells.

[0050] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. An air humidifier for a fuel cell, characterized in that: It includes a front-end channel switching system, a rear-end channel switching system and a humidification system for humidifying the air flowing to the fuel cell stack. The front-end channel switching system is connected to the humidification system, the air source and the tail exhaust system, the rear-end channel switching system is connected to the fuel cell stack and the humidification system, and the rear-end channel switching system is configured to guide water discharged from the fuel cell stack to the humidification system.

2. The air humidifier for a fuel cell according to claim 1, characterized in that: The humidification system is located between the front-end channel switching system and the rear-end channel switching system, and the rear-end channel switching system is located between the battery stack and the humidification system.

3. The air humidifier for a fuel cell according to claim 1, characterized in that: The humidification system includes a humidity storage tank, at least two of which are connected to the front-end channel switching system and the rear-end channel switching system. The humidity storage tank is configured to receive air from the front-end channel switching system and humidify the air, and can be used to receive water from the rear-end channel switching system.

4. The air humidifier for a fuel cell according to claim 3, characterized in that: In the humidification system, at least one of the humidification tanks is configured to receive air from the front-end channel switching system and humidify the air, and at least one of the humidification tanks is configured to receive water from the rear-end channel switching system.

5. The air humidifier for a fuel cell according to claim 4, characterized in that: A heating device is provided, and the heating device is configured to heat the humidification storage tank that is receiving air from the front-stage channel switching system.

6. The air humidifier for a fuel cell according to claim 4, characterized in that: A cooling device is provided, and the cooling device is configured to cool the humidification storage tank that is receiving water from the rear-stage channel switching system.

7. The air humidifier for a fuel cell according to any one of claims 3 to 6, characterized in that: Two humidity storage tanks are provided.

8. The air humidifier for a fuel cell according to any one of claims 1 to 7, characterized in that: The front-end channel switching system includes a first switching valve, and the first switching valve is connected to the air source and the humidification system.

9. The air humidifier for a fuel cell according to any one of claims 1 to 7, characterized in that: The rear channel switching system includes a second switching valve, and the second switching valve is connected to the battery stack and the humidification system.

10. A fuel cell system, characterized in that: An air humidifier for a fuel cell comprising any one of claims 1 to 9.

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