CN114759221A - Fuel cell air supply device and method based on stack tail gas, fuel cell system and vehicle - Google Patents

Abstract

The invention relates to the field of fuel cell systems, in particular to a fuel cell air supply device and method based on stack exhaust gas, a fuel cell system, and a vehicle; the air supply device is communicated with the stack, and the air supply device includes a first A water separator and an air compressor, the inlet of the first water separator is communicated with the outlet of the stack through a pipeline, and the first outlet of the first water separator is communicated with the inlet of the air compressor, The outlet of the air compressor is communicated with the inlet of the air path of the stack; in the embodiment of the present invention, the exhaust gas of the stack is passed through the water separator, and the generated water is directly introduced into the inlet of the air compressor to improve the air intake of the stack air path. humidity, thereby reducing the gas temperature; it solves the problems of inefficiency of the existing single-use air compressor, high motor speed requirements, and the risk of surge blockage, improves the efficiency of the air compressor, simplifies the structure of the supporting equipment of the fuel cell system, reduces the The overall power consumption of the fuel cell system supporting equipment.

Description

Fuel cell air supply device, method, fuel cell system, and vehicle based on stack exhaust gas

technical field

The invention relates to the field of fuel cell systems, in particular to a fuel cell air supply device and method based on stack exhaust gas, a fuel cell system and a vehicle.

Background technique

The fuel cell converts the chemical energy of hydrogen and air (oxygen) into electrical energy through an electrochemical reaction through a proton exchange membrane, and then drives the vehicle to run through a motor. Among them, the air compressor is the core component of the fuel cell cathode air supply system. It increases the intake air volume and pressure of the air in the fuel cell by pressurizing the air entering the fuel cell, and provides the stack with a certain temperature. , pressure and flow of compressed air, thereby increasing the power density and efficiency of fuel cells.

In the prior art, the air supply system of the fuel cell system generally uses a centrifugal air compressor to compress the gas, and the compressed high-temperature and high-pressure gas is then passed through the intercooler and other devices to adjust the temperature and humidity, while the fuel cell stack is used for gas compression. The exhaust gas is directly discharged to the atmosphere. In particular, the gas supply system of a high-power fuel cell system (power>120kW) requires a high air pressure ratio and a large flow rate, which often needs to consume more power of the stack. In addition, the currently generally used centrifugal air compressors have disadvantages such as high rotational speed, high technical requirements for the motor, the risk of surge blockage, and low efficiency. therefore. How to reduce the power consumption of the fuel cell stack and supporting equipment is a technical problem to be solved urgently by those skilled in the art.

SUMMARY OF THE INVENTION

In view of the technical defects and technical drawbacks existing in the prior art, the embodiments of the present invention provide a stack exhaust-based fuel cell air supply device and method, a fuel cell system, and a vehicle that overcome the above problems or at least partially solve the above problems, It solves the problems of the current fuel cell air supply device with many accessories, high processing cost, low energy utilization rate, high speed requirement of the air compressor motor, the risk of surge blockage, and low efficiency.

As an aspect of the embodiments of the present invention, a fuel cell air supply device based on stack exhaust gas is provided, the air supply device is communicated with the stack, and the air supply device includes a first water separator and an air compressor , the inlet of the first water separator is communicated with the outlet of the stack through a pipeline, the first outlet of the first water separator is communicated with the inlet of the air compressor, and the outlet of the air compressor It communicates with the inlet of the stack air circuit.

Further, the first water separator is also provided with a second outlet, the second outlet is communicated with the inlet of the expander through a pipeline, and the outlet of the expander is communicated with the inlet of the air compressor through a pipeline .

Further, an expander is arranged between the first outlet of the first water separator and the inlet of the air compressor, and the first outlet of the first water separator is connected with the inlet of the expander through a pipeline, the said The outlet of the expander is communicated with the inlet of the air compressor through a pipeline.

Further, between the outlet of the expander and the inlet of the air compressor, a second water separator communicated through a pipeline is provided, and the second water separator is provided with an exhaust port.

Further, the inlet of the air compressor is connected to the air filter device through a pipeline, and the downstream of the air filter device is communicated with the outlet of the first water separator and/or the second water separator through a pipeline.

Further, the air compressor is a Roots blower, a single-screw air compressor or a twin-screw air compressor.

Further, the air compressor is coaxially connected to the expander through a motor.

Further, an intercooler is arranged between the outlet of the air compressor and the inlet of the stack.

As a further aspect of the embodiments of the present invention, a fuel cell air supply method based on stack exhaust gas is provided, and the fuel cell air supply method includes:

Collect the exhaust gas of the stack through a water separator, and separate the exhaust gas to generate liquid water;

Connect the outlet of the water separator and the inlet of the air compressor, and introduce the liquid water into the inlet of the air compressor;

Use an air compressor to input the compressed gas into the air path of the stack.

As yet another aspect of the embodiments of the present invention, a fuel cell system is provided, and the fuel cell system includes the fuel cell air supply device based on stack exhaust gas in any one of the foregoing embodiments.

As another aspect of the embodiments of the present invention, a vehicle is provided, and the vehicle includes the fuel cell system described in the above embodiments.

The embodiments of the present invention achieve at least some of the following technical effects:

In the embodiment of the present invention, the exhaust gas of the stack is passed through a water separator, and water is directly introduced into the inlet of the air compressor to increase the humidity of the intake air of the stack air path, thereby reducing the gas temperature. Further, by connecting the air compressor with the expander, the energy of the stack exhaust is recovered, and the inefficiency of using the air compressor alone is overcome; the humidity of the stack exhaust is more effectively utilized through the connection of the pipeline, and the air is improved. Compressor efficiency and reduce air compressor power consumption.

The embodiment of the present invention not only solves the problems of high processing cost, high motor speed requirement, surge blockage risk, low efficiency, etc. of the air compressor in the current fuel cell system, but also can reduce the power consumption of the supporting equipment of the fuel cell system, simplify the The structure of the supporting equipment of the fuel cell system.

Other features and advantages of the present invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objects and other advantages of the present invention may be realized and attained by the structures described in the written description, the accompanying drawings, and the like.

The technical solutions of the present invention will be further described in detail below through the accompanying drawings and embodiments.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the specification, and are used to explain the present invention together with the embodiments of the present invention, and do not constitute a limitation to the present invention. In the attached image:

1 is a schematic diagram of a fuel cell air supply device and a fuel cell system based on stack exhaust gas according to Embodiment 1 of the present invention;

2 is a schematic diagram of a fuel cell air supply device and a fuel cell system based on stack exhaust gas according to Embodiment 2 of the present invention;

3 is a schematic diagram of a fuel cell air supply device and a fuel cell system based on stack exhaust gas according to Embodiment 3 of the present invention.

Description of drawings: 1. Electric stack; 2. First water separator; 3. Air compressor; 4. Motor; 5. Air filter device; 6. Expander; 7. Second water separator; 8. Intercooler device.

Detailed ways

In order to describe in detail the technical content, achieved objects and effects of the present invention, the following descriptions are given with reference to the embodiments and the accompanying drawings.

The drawings and the following description describe alternative embodiments of the invention to teach those skilled in the art how to practice and reproduce the invention. In order to teach the technical solutions of the present invention, some conventional aspects have been simplified or omitted. Those skilled in the art will appreciate that modifications or substitutions derived from these embodiments will fall within the scope of the present invention. Those skilled in the art will appreciate that the following features can be combined in various ways to form various variations of the invention. Thus, the present invention is not limited to the alternative embodiments described below, but only by the claims and their equivalents.

Example 1

With reference to FIG. 1 , the present embodiment provides a fuel cell air supply device and a fuel cell system based on stack exhaust gas, wherein the fuel cell system includes a stack 1 and a fuel cell air supply device, and the air supply device is connected to the stack. 1 is connected, the air supply device includes a first water separator 2 and an air compressor 3, the inlet of the first water separator 2 is connected with the outlet of the stack 1 through a pipeline, and the first water separator The first outlet of the device 2 is communicated with the inlet of the air compressor 3 , and the outlet of the air compressor 3 is communicated with the inlet of the air path of the stack 1 . The supply method provided for the stack by the fuel cell air supply device of this embodiment includes collecting the exhaust gas of the stack through a water separator, separating the exhaust gas to generate liquid water; connecting the outlet of the water separator and the inlet of the air compressor, Introduce liquid water into the inlet of the air compressor; use the air compressor to input the compressed gas into the air path of the stack. Among them, the exhaust gas of the stack passes through the water separator to generate liquid water and then directly leads to the air compressor inlet, and the water is introduced into the air compressor inlet to increase the humidity of the intake air of the stack air path, thereby reducing the gas temperature; at the same time, it can be reduced or removed. Humidifier, intercooler.

Preferably, the inlet of the air compressor 3 is connected to the air filter device 5 through a pipeline, and the downstream of the air filter device 5 is communicated with the outlet of the first water separator through a pipeline.

Preferably, the air compressor can be a Roots blower, a single-screw air compressor or a twin-screw air compressor, which overcomes the problems of high rotational speed and low efficiency of the existing centrifugal air compressors, which can be further efficient. The water vapor of the stack is used more effectively, the water generated by the stack is more effectively used, and the energy utilization efficiency is higher.

The implementation of the present invention does not limit the type of air compressor, preferably, a Roots-type, twin-screw, and single-screw air compressor; wherein the air compressor can also be integrated with the expander, or can be separated.

Preferably, the air compressor is connected with the motor through gears, and connected with the air compressor by means of gear transmission, which can fully utilize the moisture in the stack exhaust gas and effectively improve the efficiency of the air compressor.

Preferably, an intercooler is arranged between the outlet of the air compressor and the inlet of the stack. The intercooler in this embodiment is not necessary, and parameters such as temperature and pressure of the stack air path can be further optimized and controlled according to the setting of the working conditions.

Embodiment 2

Referring to FIG. 2 , on the basis of Embodiment 1, the same parts will not be repeated. In the fuel cell air supply device and fuel cell system based on stack exhaust gas provided in this embodiment, the first water separator 2 An expander 6 is arranged between the outlet and the inlet of the air compressor 3. The first outlet of the first water separator 2 is connected with the inlet of the expander 6 through a pipeline, and the outlet of the expander 6 is connected to the air compressor. The inlets of 3 are connected through pipelines. In this embodiment, the fuel cell air supply device includes both an air compressor and an expander, wherein the compressor and the expander can be integrated or separated, and the operation of the air compressor and the expander can be performed through a The motors are driven at the same time. When one motor is used to drive the air compressor and the expander at the same time, the air compressor can be coaxially connected to the expander through the motor, which can make the structure of the fuel cell air supply device more compact and reduce the size of the fuel cell. It can also be driven by two motors; and, in this embodiment, the inlet of the liquid water of the air compressor includes at least two branches, one of which is obtained directly from the water separator, and the other is obtained through expansion. For the liquid water obtained from the machine, the flowmeter power of both can be adjusted, which is more convenient for humidity control and provides efficiency; of course, it is not limited to only two branches, and can also be set to multiple, such as 3, 4, etc.

Preferably, between the outlet of the expander 6 and the inlet of the air compressor 3, a second water separator 7 communicated through a pipeline is provided, and the second water separator 7 is provided with an exhaust port; The moisture in the air compressor is collected, part of the exhaust gas is discharged, and the part condensed into liquid water is introduced into the air compressor 3 to better improve the humidity of the gas in the air compressor, thereby further improving the inlet humidity of the air path of the fuel cell system. The first water separator and the second water separator can exist independently or at the same time. The liquid water after passing through the first water separator and the second water separator is introduced into the inlet of the air compressor to improve the humidity of the stack air path and increase the The outlet pressure decreases, reducing the air temperature.

Preferably, the inlet of the air compressor 3 is connected to the air filter device 5 through a pipeline, and the downstream of the air filter device 5 is communicated with the outlet of the first water separator 2 and the second water separator 7 through a pipeline.

Preferably, this embodiment provides a fuel cell Roots-type (single-screw, twin-screw) air compressor with an energy recovery function. The air compressor is used as the air compression component, and the motor is connected to the air compressor by means of gear transmission. Connected together with Roots (single-screw, twin-screw) expander, it can recover the energy of stack exhaust, further improve efficiency, and overcome the inefficiency of using Roots-type air compressor alone. Moreover, the humidity of the stack exhaust gas is further utilized to improve the efficiency of the air compressor and reduce the power consumption of the air compressor.

Embodiment 3

Referring to FIG. 3 , on the basis of Embodiment 1, the same parts will not be repeated. In the fuel cell air supply device and fuel cell system based on stack exhaust gas provided in this embodiment, the first water separator 2 is also provided with There is a second outlet, the second outlet is communicated with the inlet of the expander 6 through a pipeline, and the outlet of the expander 6 is communicated with the inlet of the air compressor through a pipeline. In this embodiment, the water vapor is introduced into the inlet of the air compressor after passing through the first water separator and the expander, which improves the recovery efficiency and facilitates further optimization and control of parameters such as air temperature and humidity compressed by the air compressor.

Preferably, the inlet of the air compressor 3 is connected to the air filter device 5 through a pipeline, and the downstream of the air filter device 5 is communicated with the outlet of the second water separator 7 through a pipeline.

Embodiment 4

Based on the same technical concept as the above-mentioned embodiments, this embodiment applies the above-mentioned fuel cell system to a vehicle to provide a vehicle including the fuel cell system in any of the above-mentioned embodiments. The air compressor of the air supply device has high power and low connection cost, and the air supply device has a simple and compact structure, and the humidifier can be reduced or eliminated, thereby saving vehicle space and improving vehicle performance.

Words such as "first", "second", etc. used in the description and the claims are used to modify the corresponding element, which does not mean that the element has any ordinal number, nor does it mean that a certain element is related to the corresponding element. The order of another element, the use of the ordinal numbers is only used to clearly distinguish one element with a certain designation from another element with the same designation.

Similarly, it is to be understood that in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together into a single embodiment, figure, or its description. However, this method of the invention should not be construed to reflect the intention that the invention as claimed requires more features than are expressly recited in each claim. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this invention.

The embodiments of the present invention have been described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific embodiments, which are merely illustrative rather than restrictive. Under the inspiration of the present invention, without departing from the scope of protection of the present invention and the claims, many forms can be made, which all belong to the protection of the present invention.

Claims (10)

1. The fuel cell air supply device is characterized by comprising a first water separator and an air compressor, wherein the inlet of the first water separator is communicated with the outlet of the electric pile through a pipeline, the first outlet of the first water separator is communicated with the inlet of the air compressor, and the outlet of the air compressor is communicated with the inlet of an air path of the electric pile.

2. The stack tail gas-based fuel cell air supply device according to claim 1, wherein the first water separator is further provided with a second outlet, the second outlet is communicated with an inlet of an expander through a pipeline, and an outlet of the expander is communicated with an inlet of an air compressor through a pipeline.

3. The stack tail gas-based fuel cell air supply device according to claim 1, wherein an expander is disposed between the first outlet of the first water separator and the inlet of the air compressor, the first outlet of the first water separator is communicated with the inlet of the expander through a pipeline, and the outlet of the expander is communicated with the inlet of the air compressor through a pipeline.

4. The stack tail gas-based fuel cell air supply device according to claim 2 or 3, wherein a second water separator communicated with the inlet of the air compressor through a pipeline is arranged between the outlet of the expander and the inlet of the air compressor, and the second water separator is provided with an exhaust port; and/or

The air compressor is coaxially connected with the expansion machine through a motor.

5. The stack tail gas-based fuel cell air supply device according to claim 4, wherein an inlet of the air compressor is connected with an air filter device through a pipeline, and a downstream of the air filter device is communicated with an outlet of the first water divider and/or the second water divider through a pipeline.

6. The stack tail gas-based fuel cell air supply device according to claim 1, wherein the air compressor is a roots blower, a single screw air compressor, or a twin screw air compressor.

7. The stack tail gas-based fuel cell air supply device according to claim 1, wherein an intercooler is provided between an outlet of the air compressor and an inlet of the stack.

8. A fuel cell air supply method based on stack tail gas is characterized by comprising the following steps:

collecting tail gas of the galvanic pile through a water separator, and separating the tail gas to generate liquid water;

the outlet of the water separator is communicated with the inlet of the air compressor, and liquid water is introduced into the inlet of the air compressor;

and the compressed gas is input into an air path of the electric pile by using an air compressor.

9. A fuel cell system comprising a stack tail gas-based fuel cell air supply apparatus according to any one of claims 1 to 7.

10. A vehicle characterized by comprising the fuel cell system according to claim 9.

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