Hydrogen fuel cell air control system and control method

Abstract

The invention relates to the technical field of new energy automobiles, and discloses a hydrogen fuel cell air control system and method.The hydrogen fuel cell air control system comprises an air compressor used for compressing air, the air compressor is connected with an expansion machine, the expansion machine is connected with a three-way valve used for controlling the air flow and direction, and the three-way valve is connected with the air compressor; the three-way valve is respectively connected with an intercooler and a hydrogen heat exchanger, the intercooler and the hydrogen heat exchanger are both connected with a humidifier for controlling air humidity, the humidifier is connected with a fuel cell stack, and the exhaust end of the fuel cell stack is respectively connected with the three-way valve and the expansion machine; the system is high in energy utilization rate, low in power consumption and small in energy loss, and effectively improves the system operation efficiency.

Description

Technical Field

[0001] The present application relates to the field of new energy vehicle technology, and specifically to a hydrogen fuel cell air control system and control method. Background Art

[0002] The air supply system includes air filters, air compressors, expanders, tail exhaust structures, bypass valves, intercoolers, humidifiers and other components. The air compressor can pressurize the outside air and drive the air supply system to operate, so that the air flows through the intercooler and humidifier and enters the fuel cell stack to provide oxygen and hydrogen in the air for reaction. In the process of pressurizing the air, the air compressor will also cause the gas temperature at the air compressor outlet to rise due to the work done on the air, in order to ensure the normal operation of the system.

[0003] The existing hydrogen fuel cell air control system needs to cool down the high-temperature gas generated by the air compressor through an intercooler with a cooling function. After cooling, the high-temperature gas enters the humidifier for humidification, and then enters the fuel cell stack to participate in the reaction. When the whole vehicle is cold-started, the coolant needs to be heated to heat the hydrogen. The energy utilization rate of the whole process is low. When the hydrogen fuel cell system is idling and running at low power, in order to prevent the air compressor from surging, it is often necessary to increase the speed of the air compressor, and it is necessary to divert excess air flow, resulting in an increase in the power consumption of the air compressor. At the same time, when the air is diverted, the excess air needs to be cooled by the intercooler and controlled by the rear bypass valve, which increases the energy loss of the system and increases the heat dissipation burden of the system. This leads to low energy utilization, high power consumption, large energy loss and low operating efficiency of the existing hydrogen fuel cell air control system.

[0004] Application Contents

[0005] The purpose of this application is to provide a hydrogen fuel cell air control system and control method with high energy utilization, low power consumption, small energy loss, and effective improvement of system operation efficiency.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A hydrogen fuel cell air control system of the present invention comprises an air compressor for compressing air, wherein the air compressor is connected to an expander, wherein the expander is connected to a three-way valve for controlling air flow and direction, wherein the three-way valve is connected to the air compressor, wherein the three-way valve is respectively connected to an intercooler and a hydrogen heat exchanger, wherein the intercooler and the hydrogen heat exchanger are both connected to a humidifier for controlling air humidity, wherein the humidifier is connected to a fuel cell stack, and wherein the exhaust end of the fuel cell stack is respectively connected to the three-way valve and the expander.

[0008] Furthermore, an air filter for cleaning and filtering air is connected to the input end of the air compressor.

[0009] Furthermore, the expander is connected to a tail exhaust structure, and the tail exhaust structure is connected to a muffler for noise reduction.

[0010] A hydrogen fuel cell air control method used in a hydrogen fuel cell air control system includes: outside air entering an air compressor and being output as high-temperature and high-pressure gas through the air compressor; the high-temperature and high-pressure gas output by the air compressor is diverted to a hydrogen heat exchanger through a three-way valve; and the high-temperature gas output by the air compressor is heat-exchanged with hydrogen through the hydrogen heat exchanger to heat the hydrogen and accelerate the cold start of the entire vehicle.

[0011] A hydrogen fuel cell air control method used in a hydrogen fuel cell air control system includes diverting the gas exhausted by a fuel cell stack to a three-way valve through an exhaust pipeline of the fuel cell stack; and supplying the gas exhausted by the fuel cell stack to an air compressor through the three-way valve to avoid surging of the air compressor.

[0012] A hydrogen fuel cell air control method used in a hydrogen fuel cell air control system includes diverting gas exceeding a limit value to an expander for recovery through a three-way valve.

[0013] Compared with the prior art, the beneficial effects of this application are:

[0014] In actual applications, the outside air is compressed by the air compressor and then enters the three-way valve. The three-way valve controls the gas to enter the intercooler for cooling according to the gas flow and pressure required by the fuel cell stack. The gas cooled to the required temperature enters the humidifier for humidification to meet the gas humidity requirements of the internal reaction of the fuel cell stack. The gas humidified by the humidifier enters the fuel cell stack to participate in the reaction at a certain flow rate, pressure and temperature. The reacted gas is discharged to the expander through the exhaust flow channel of the fuel cell stack for energy recovery, reducing the system power consumption, and the gas is discharged from the expander; the hydrogen heat exchanger is connected to the three-way valve and the humidifier respectively. The hydrogen heat exchanger is used to convert the high temperature generated by the air compressor into The high-pressure gas and hydrogen are heat-exchanged to accelerate the heating of the hydrogen, efficiently utilize the system energy, and improve the cold start efficiency; to prevent the air compressor from surging, the exhaust end of the fuel cell stack is connected to the three-way valve, and the exhaust of the fuel cell stack is used to counter-compensate the air compressor through the three-way valve, thereby avoiding the increase in the power consumption of the air compressor and improving the efficiency of the hydrogen fuel cell system; the air compressor and the expander are both connected to the three-way valve, and when the air flow exceeds the limit, the three-way valve controls part of the high-temperature and high-pressure gas to be diverted to the expander to avoid excess gas from re-entering the intercooler for cooling, thereby reducing the energy loss of the system; the application has high energy utilization, low power consumption, and small energy loss, effectively improving the operating efficiency of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the implementation methods of the present application, the drawings required for use in the implementation methods will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 It is a schematic diagram of the electrical structure of this application.

[0017] Figure numerals: air filter 1; air compressor 2; expander 3; three-way valve 4; intercooler 5; hydrogen heat exchanger 6; humidifier 7; fuel cell stack 8; tail exhaust structure 9. DETAILED DESCRIPTION

[0018] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0019] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show the layers related to the present invention rather than being drawn according to the number, shape and size of the layers in actual implementation. In actual implementation, the type, quantity and proportion of each layer may be changed arbitrarily, and the layer layout may also be more complicated.

[0020] In the following description, numerous details are discussed to provide a more thorough explanation of embodiments of the present invention; however, it is apparent to one skilled in the art that embodiments of the present invention may be practiced without these specific details.

[0021] See also Figure 1 , a hydrogen fuel cell air control system, comprising an air compressor 2 for compressing air, the air compressor 2 is connected to an expander 3, the expander 3 is connected to a three-way valve 4 for controlling air flow and direction, the three-way valve 4 is connected to the air compressor 2, the three-way valve 4 is respectively connected to an intercooler 5 and a hydrogen heat exchanger 6, the intercooler 5 and the hydrogen heat exchanger 6 are both connected to a humidifier 7 for controlling air humidity, the humidifier 7 is connected to a fuel cell stack 8, and the exhaust end of the fuel cell stack 8 is respectively connected to the three-way valve 4 and the expander 3.

[0022] In practical applications, the outside air is compressed by the air compressor 2 and then enters the three-way valve 4. The three-way valve 4 controls the gas to enter the intercooler 5 for cooling according to the gas flow and pressure required by the fuel cell stack 8. The gas cooled to the required temperature enters the humidifier 7 for humidification to meet the gas humidity requirement of the internal reaction of the fuel cell stack 8. The gas humidified by the humidifier 7 enters the fuel cell stack 8 at a certain flow rate, pressure and temperature to participate in the reaction. The reacted gas is discharged to the expander 3 through the exhaust flow channel of the fuel cell stack 8 for energy recovery, thereby reducing the system power consumption, and the gas is discharged from the expander 3; the hydrogen heat exchanger 6 is respectively connected to the three-way valve 4 and the humidifier 7, and the hydrogen heat exchanger 6 is used to convert the hydrogen generated by the air compressor 2 into hydrogen. The high-temperature and high-pressure gas is heat-exchanged with the hydrogen to accelerate the heating of the hydrogen, efficiently utilize the system energy, and improve the cold start efficiency; to prevent the air compressor 2 from surging, the exhaust end of the fuel cell stack 8 is connected to the three-way valve 4, and the exhaust of the fuel cell stack 8 is used to counter-compensate the air compressor 2 through the three-way valve 4, so as to avoid the increase of the power consumption of the air compressor 2 and improve the efficiency of the hydrogen fuel cell system; the air compressor 2 and the expander 3 are both connected to the three-way valve 4, and when the air flow exceeds the limit, the three-way valve 4 controls part of the high-temperature and high-pressure gas to be diverted to the expander 3 to avoid excess gas from re-entering the intercooler 5 for cooling, thereby reducing the energy loss of the system; the present application has high energy utilization, low power consumption, and small energy loss, and effectively improves the operation efficiency of the system.

[0023] See also Figure 1 The input end of the air compressor 2 is connected to an air filter 1 for cleaning and filtering air.

[0024] In this embodiment, an air filter 1 is connected to the air inlet end of the air compressor 2, and the air is cleaned and filtered by the air filter 1 to ensure the cleanliness of the air entering the air compressor 2 and the back-end system, avoid contamination or blockage of the system, and ensure the service life of the system.

[0025] See also Figure 1 The expander 3 is connected to a tail exhaust structure 9, and the tail exhaust structure 9 is connected to a silencer for noise reduction.

[0026] In this embodiment, the gas in the expander 3 is discharged to the atmosphere through the tail exhaust structure 9, and is silenced and reduced in noise by a muffler to reduce noise pollution.

[0027] See also Figure 1 A hydrogen fuel cell air control method used in a hydrogen fuel cell air control system is characterized in that outside air enters an air compressor 2 and is output as high-temperature and high-pressure gas through the air compressor 2; the high-temperature and high-pressure gas output by the air compressor 2 is diverted to a hydrogen heat exchanger 6 through a three-way valve 4; the high-temperature gas output by the air compressor 2 is heat exchanged with hydrogen through the hydrogen heat exchanger 6 to heat the hydrogen and accelerate the cold start of the entire vehicle.

[0028] In this embodiment, when the whole vehicle needs to be cold-started, the hydrogen heat exchanger 6 uses the high-temperature gas output by the air compressor 2 to quickly heat up the hydrogen. Compared with the existing method of relying on coolant to heat up the hydrogen, the method of the present application is faster and more efficient, and can effectively shorten the time taken to cold-start the whole vehicle. The air that has completed the heat exchange is collected to the front end of the humidifier 7 through a pipeline. After being humidified by the humidifier 7, it enters the fuel cell stack 8 at a certain flow rate, pressure and temperature to participate in the reaction.

[0029] See also Figure 1 A hydrogen fuel cell air control method used in a hydrogen fuel cell air control system includes diverting the gas exhausted by the fuel cell stack 8 to the three-way valve 4 through the exhaust pipeline of the fuel cell stack 8; and supplying the gas exhausted by the fuel cell stack 8 to the air compressor 2 through the three-way valve 4 to avoid surging of the air compressor 2.

[0030] In the present embodiment, when the fuel cell system is idling and operating at low power, the air compressor 2 operates at a low speed. The air compressor 2 is prone to surge in the small flow and high pressure ratio area. The gas discharged from the fuel cell stack 8 is fed back to the air compressor 2 through the three-way valve 4 to avoid surge of the air compressor 2. Compared with the prior art that avoids surge of the air compressor 2 at the cost of increasing the power consumption of the air compressor 2, the present application has low power consumption, efficient use of system resources, good effect, and effectively improves the system operation efficiency.

[0031] See also Figure 1 A hydrogen fuel cell air control method used in a hydrogen fuel cell air control system includes diverting gas exceeding a limit value to an expander 3 for recovery through a three-way valve 4.

[0032] In this embodiment, when the fuel cell system is running, if it is monitored that the system air flow exceeds the limit, the gas exceeding the limit is recovered through the expander 3 under the diversion effect of the three-way valve 4, and the gas exceeding the limit does not need to enter the intercooler 5 and the back-end system, which effectively reduces the heat dissipation burden of the system, reduces the energy loss of the system, and improves the operation efficiency of the system.

[0033] In the above-mentioned embodiments, although the present invention has been described in conjunction with the specific embodiments of the present invention, many replacements, modifications and variations of these embodiments will be apparent to those of ordinary skill in the art based on the foregoing description. The embodiments of the present invention are intended to cover all such replacements, modifications and variations falling within the broad scope of the appended claims.

[0034] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A hydrogen fuel cell air control system, characterized in that: The invention comprises an air compressor (2) for compressing air, wherein the air compressor (2) is connected to an expander (3), wherein the expander (3) is connected to a three-way valve (4) for controlling the air flow and direction, wherein the three-way valve (4) is connected to the air compressor (2), wherein the three-way valve (4) is respectively connected to an intercooler (5) and a hydrogen heat exchanger (6), wherein the intercooler (5) and the hydrogen heat exchanger (6) are both connected to a humidifier (7) for controlling the air humidity, wherein the humidifier (7) is connected to a fuel cell stack (8), wherein the exhaust end of the fuel cell stack (8) is respectively connected to the three-way valve (4) and the expander (3).

2. A hydrogen fuel cell air control system according to claim 1, characterized in that: The input end of the air compressor (2) is connected to an air filter (1) for cleaning and filtering air.

3. A hydrogen fuel cell air control system according to claim 1, characterized in that: The expander (3) is connected to a tail exhaust structure (9), and the tail exhaust structure (9) is connected to a silencer for noise reduction.

4. A hydrogen fuel cell air control method used in a hydrogen fuel cell air control system as claimed in claim 1, characterized in that: The method comprises: outside air enters an air compressor (2), and is output as high-temperature and high-pressure gas through the air compressor (2); the high-temperature and high-pressure gas output by the air compressor (2) is diverted to a hydrogen heat exchanger (6) through a three-way valve (4); and the high-temperature gas output by the air compressor (2) is heat-exchanged with hydrogen through the hydrogen heat exchanger (6), thereby heating the hydrogen and accelerating the cold start of the entire vehicle.

5. A hydrogen fuel cell air control method used in a hydrogen fuel cell air control system as claimed in claim 1, characterized in that: The method comprises: diverting the gas exhausted from the fuel cell stack (8) to a three-way valve (4) through an exhaust pipeline of the fuel cell stack (8); and supplying the gas exhausted from the fuel cell stack (8) to an air compressor (2) through the three-way valve (4) to avoid surging of the air compressor (2).

6. A hydrogen fuel cell air control method used in a hydrogen fuel cell air control system as claimed in claim 1, characterized in that: The method comprises diverting the gas exceeding the limit value to the expander (3) for recovery through a three-way valve (4).

Images