CN218299836U

CN218299836U - System for regulating stack inlet humidity and outlet back pressure of fuel cell

Info

Publication number: CN218299836U
Application number: CN202222221319.XU
Authority: CN
Inventors: 赵海柱; 刘坚; 陈志星
Original assignee: Shenzhen Nanke Power Technology Co ltd
Current assignee: Shenzhen Nanke Power Technology Co ltd
Priority date: 2022-08-23
Filing date: 2022-08-23
Publication date: 2023-01-13
Anticipated expiration: 2032-08-23

Abstract

The utility model provides a system for be used for adjusting fuel cell's galvanic pile entry humidity and export backpressure, with fuel cell galvanic pile intercommunication, include: the gas input main line is communicated with the inlet of the fuel cell stack and is used for conveying air to the fuel cell stack; the gas output main line is communicated with the outlet of the electric pile and is used for discharging water and tail gas generated by the reaction of the fuel cell electric pile; the humidifier component is arranged on the gas input main line and the gas output main line simultaneously; the humidifier component is formed by connecting at least two humidifiers in parallel; one of the humidifier components comprises a tail gas inlet, a bypass adjusting valve is arranged on a pipeline between the tail gas inlet and the outlet of the galvanic pile, and the bypass adjusting valve is used for adjusting and controlling back pressure at the outlet of the galvanic pile. The system can realize the purpose of regulating the humidity at the inlet and the back pressure at the outlet of the fuel cell stack.

Description

System for regulating stack inlet humidity and outlet backpressure of fuel cell

Technical Field

The utility model relates to a fuel cell system technical field, in particular to a system for be used for adjusting fuel cell's galvanic pile entry humidity and export backpressure.

Background

With the increase of the use amount of non-renewable energy sources such as fossil fuel and the like and the serious pollution to the environment, people are urgently required to develop new energy sources such as hydrogen energy, solar energy and the like to deal with the problems of energy crisis, environmental pollution and the like. The hydrogen energy has rich sources, can be efficiently converted, has no emission pollution in the using process, is used as a carrier of secondary energy, and has important application prospects in the fields of industry, traffic and the like.

Fuel cells are energy conversion devices that provide electrochemical reaction sites for hydrogen and oxygen. Unlike chemical energy storage cells, the storage of the reaction media (hydrogen and air/oxygen) in fuel cells is independent of the reaction site, such as the stack, and requires special delivery equipment to continuously deliver the reaction media to the stack during operation of the hydrogen fuel cell.

Taking a proton exchange membrane fuel cell as an example, gas enters from the anode side, hydrogen atoms lose electrons at the anode to become protons, the protons pass through the proton exchange membrane to reach the cathode, the electrons also reach the cathode through an external loop, and the protons, the electrons and oxygen combine at the cathode to generate water. The fuel cell converts chemical energy into electric energy in a non-combustion mode, and the direct power generation efficiency can reach 45% because the fuel cell is not limited by Carnot cycle. The fuel cell system integrates modules such as power management and thermal management, and has the characteristics of thermal, electric, water and gas overall management. Fuel cell system products range from stationary power stations, to mobile power supplies; from electric automobiles, to space shuttles; from military equipment to civilian products, it is widely used.

During the operation of the pem fuel cell, the pem needs to maintain a certain degree of wettability to maintain high proton conductivity and good operating characteristics. The water content of the membrane of a proton exchange membrane fuel cell directly affects the electrical conductivity of the proton exchange membrane.

When the humidity of air introduced into the fuel cell is too low, the proton exchange membrane is dried, the internal resistance of the dried proton exchange membrane is increased, so that the membrane loses the capability of conducting protons, and the membrane is dehydrated, shrunk or even cracked when the internal resistance is serious; when the humidity of air introduced into the fuel cell is too high, the water content in the proton exchange membrane is too high, so that the problems of flooding, blocking a gas flow passage and increasing concentration polarization are caused, and the performance of the cell is greatly reduced.

Therefore, adjusting the air humidity at the inlet of the stack to maintain water balance inside the fuel cell is a key issue to improve the performance and life of the fuel cell. At present, a typical fuel cell air humidification system is that, as shown in fig. 1, a humidifier is arranged at an inlet of a stack, and dry air sequentially passes through an air compressor, an intercooler, and the humidifier and then enters the fuel cell stack for reaction. In order to save energy, the water generated by the reaction enters the humidifier again along with the tail gas for utilization, and then the tail gas is discharged through the backpressure valve. The fluid resistance inside this in-process humidifier increases, has improved the power consumption of air compressor machine greatly, and simultaneously, the humidity control degree of difficulty increase of galvanic pile entrance.

Disclosure of Invention

The main objective of the present invention is to provide a system for adjusting fuel cell's galvanic pile inlet humidity and outlet backpressure, the system is through the mode of parallelly connected humidifier, need not set up the backpressure valve simultaneously, can realize adjusting fuel cell's galvanic pile inlet humidity and outlet backpressure's purpose.

Based on this, the utility model provides a system for be used for adjusting fuel cell's galvanic pile entry humidity and export backpressure, with fuel cell galvanic pile intercommunication, include: the gas input main line is communicated with the inlet of the fuel cell stack and is used for conveying air to the fuel cell stack; the gas output main line is communicated with the outlet of the electric pile and is used for discharging water and tail gas generated by the reaction of the fuel cell electric pile; the humidifier component is arranged on the gas input main line and the gas output main line simultaneously; the humidifier component is formed by connecting at least two humidifiers in parallel; one of the humidifier in the humidifier component includes the tail gas entry, be provided with the bypass governing valve on the pipeline between the export of tail gas entry and galvanic pile, the back pressure of the export of bypass governing valve is used for regulating and control galvanic pile.

Further, the air flow rate of each humidifier in the humidifier assembly is the total flow rate input to the humidifier assembly divided by the number of humidifiers.

Further, the resistance inside the humidifier is approximately proportional to the square of the input air flow rate.

Further, the exhaust flow of each humidifier in the humidifier assembly is the total flow input to the humidifier assembly divided by the number of humidifiers.

Further, the resistance inside the humidifier is approximately proportional to the square of the input tail gas flow rate.

Furthermore, according to the circulation direction of air, still set gradually air compressor machine, intercooler on the gas input main line.

Further, a back pressure valve is omitted from the gas output main line.

Further, the humidifier assembly is composed of two humidifiers connected in parallel.

Through the technical scheme, when the humidifier component selects two parallel connection, the purpose of adjusting the humidity at the inlet of the fuel cell stack can be achieved, and cost cannot be increased due to too many humidifiers.

To sum up, the utility model discloses there is following beneficial effect:

1. the technical scheme can adjust the humidity at the inlet of the fuel cell stack, thereby optimizing the operation condition of the stack and improving the efficiency of the stack.

2. The fluid resistance of a humidifier in the fuel cell engine is reduced, so that the power consumption of the air compressor is reduced, the pressure ratio of the air compressor is reduced, the burden of an intercooler is reduced, and the overall efficiency of the fuel cell system is improved.

3. The system control strategy is greatly simplified due to the elimination of the back pressure valve.

4. The back pressure valve is a movable mechanical part, so that the situation of serious abrasion is easy to occur in the using process, the back pressure valve is eliminated, the system cost can be reduced, and the maintenance cost can be reduced. Meanwhile, the back pressure valve is eliminated, so that the risk of stack gas overpressure caused by the failure of the back pressure valve can be avoided, and the service life of the fuel cell stack is protected.

5. When the load of air compressor machine alleviates greatly, the outlet pressure ratio of air compressor machine reduces, and the gas outlet temperature of air compressor machine reduces, and the load of intercooler also reduces thereupon, helps alleviateing system's energy consumption, reduces the cooling water quantity, and reduces air compressor machine noise.

Drawings

In order to illustrate the embodiments of the present invention or the technical solutions in the prior art more clearly, the drawings used in the description of the embodiments or the prior art will be briefly introduced, it is obvious that the drawings in the description below are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the devices shown in the drawings without creative efforts.

FIG. 1 is a prior art fuel cell air humidification system;

FIG. 2 is a system for regulating stack inlet humidity and outlet back pressure of a fuel cell in one embodiment.

Wherein, 1, an air compressor; 2. an intercooler; 3. a humidifier component; 31. a first humidifier; 311. a first air inlet; 312. a first air outlet; 313; a first tail gas inlet; 314. a first tail gas outlet; 32. a second humidifier; 321. a second air inlet; 322. a second air outlet; 323. a second tail gas inlet; 324. a second tail gas outlet; 4. a fuel cell stack; 41. a cell stack inlet; 42. an outlet of the electric pile; 5. a back pressure valve; 6. a bypass regulating valve.

The realization, the functional characteristics and the advantages of the utility model are further explained by combining the embodiment and referring to the attached drawings.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that all the directional indicators (such as up, down, left, right, front, back \8230;) in the embodiments of the present invention are only used to explain the relative position relationship between the components, the motion situation, etc. in a specific posture (as shown in the attached drawings), and if the specific posture is changed, the directional indicator is changed accordingly. In addition, the descriptions related to "first", "second", etc. in the present invention are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicit ly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, "and/or" in the whole text includes three schemes, taking a and/or B as an example, and includes a technical scheme a, a technical scheme B, and a technical scheme that a and B meet simultaneously; in addition, the technical solutions in the embodiments may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory to each other or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

The above is only the preferred embodiment of the present invention, not so limiting the patent scope of the present invention, all of which are in the utility model discloses a conceive, utilize the equivalent device transform that the content of the specification and the attached drawings was done, or directly/indirectly use all to include in other relevant technical fields the patent protection scope of the present invention.

The system for adjusting the humidity and outlet back pressure of the stack inlet 41 of the fuel cell according to a preferred embodiment of the present invention is connected to the fuel cell stack 4, as shown in fig. 2, the fuel cell stack 4 includes a stack inlet 41 and a stack outlet 42.

The system includes a gas input main line and a gas output main line.

A gas input main line communicating with the stack inlet 41 for supplying air to the fuel cell stack 4; and a gas output main line which is communicated with the electric pile outlet 42 and is used for discharging water and tail gas generated by the reaction of the fuel cell electric pile 4.

According to the circulation direction of air, an air compressor 1, an intercooler 2 and a humidifier component 3 are sequentially arranged on the air input main line. Wherein, humidifier subassembly 3 is connected in parallel by at least two humidifiers and is constituteed.

The exhaust gas exits the system through the humidifier assembly 3, depending on the direction of exhaust of the exhaust gas.

In one embodiment, as shown in fig. 2, the humidifier assembly 3 is composed of two humidifiers connected in parallel, including a first humidifier 31 and a second humidifier 32.

The first humidifier 31 includes a first air inlet 311 and a first air outlet 312, and the first air inlet 311 and the first air outlet 312 are connected to the gas input main line.

The first humidifier 31 further includes a first off-gas inlet 313 and a first off-gas outlet 314, and the first off-gas inlet 313 and the first off-gas outlet 314 are connected to the gas output main line.

The second humidifier 32 includes a second air inlet 321 and a second air outlet 322, and the second air inlet 321 and the second air outlet 322 are connected to the gas input main line.

The second humidifier 32 further comprises a second off-gas inlet 323 and a second off-gas outlet 324, and the second off-gas inlet 323 and the second off-gas outlet 324 are connected to the gas output main line.

A bypass regulating valve 6 is arranged on a pipeline between the first tail gas inlet 313 and the cell stack outlet 42 of the first humidifier 31, and the bypass regulating valve 6 is used for regulating and controlling the back pressure at the cell stack outlet 42.

In the present embodiment, the first humidifier 31 and the second humidifier 32 are used to divide the flow of the air, that is, the flow of the drying air entering each humidifier is half of the output flow of the air compressor 1. Since the resistance inside the humidifier is approximately proportional to the square of the gas flow rate, the delivery resistance of the air in each humidifier can be reduced by 75%. Correspondingly, due to the flow dividing effect of the two humidifiers, namely, the flow of the wet tail gas entering each humidifier is half of the output flow of the cell stack outlet 42, the delivery resistance of the tail gas in each humidifier can be reduced by 75%. So set up, air compressor machine 1's load greatly reduced, simultaneously, air compressor machine 1's consumption reduces, has improved fuel cell system's efficiency.

Therefore, when the load of the air compressor 1 is greatly reduced, the outlet pressure ratio of the air compressor 1 is reduced, the temperature of the gas outlet of the air compressor 1 is reduced, and the load of the intercooler 2 is reduced, so that the system energy consumption is reduced, the cooling water consumption is reduced, and the noise of the air compressor 1 is reduced.

The utility model provides a pair of a working process that is used for adjusting 41 humidity of fuel cell's galvanic pile entry and the system of export backpressure does:

when the humidity at the stack inlet 41 of the fuel cell is excessively high, the flow rate at the first air outlet 312 of the first humidifier 31 is continuously maintained. Meanwhile, the second air inlet 321 of the second humidifier 32 is kept smooth, and the burden of the air compressor 1 is not increased; the second air outlet 322 of the second humidifier 32 is partially or completely closed, and at this time, the humidity at the stack inlet 41 is reduced, so as to achieve the purpose of adjusting the humidity at the stack inlet 41.

In addition, when the back pressure is needed to be high, the bypass regulating valve 6 can be partially closed or completely closed, the regulating range can meet the operating pressure of the fuel cell stack 4, regulation and control of the back pressure valve 5 are not needed, the complexity of control of the back pressure valve 5 can be avoided, and the operation is safe because the back pressure valve 5 is not used, so that the maintenance cost is reduced.

Claims

1. A system for regulating stack inlet humidity and outlet backpressure of a fuel cell in communication with a fuel cell stack, comprising:

the gas input main line is communicated with the inlet of the electric pile and is used for conveying air to the fuel cell electric pile; the gas output main line is communicated with the outlet of the electric pile and is used for discharging water and tail gas generated by the reaction of the fuel cell electric pile;

the humidifier component is arranged on the gas input main line and the gas output main line simultaneously;

the humidifier component is formed by connecting at least two humidifiers in parallel;

one of the humidifier in the humidifier component includes the tail gas entry, be provided with the bypass governing valve on the pipeline between the export of tail gas entry and galvanic pile, the back pressure of the export of bypass governing valve is used for regulating and control galvanic pile.

2. The system for regulating stack inlet humidity and outlet backpressure of a fuel cell of claim 1, wherein the air flow to each humidifier in the humidifier assembly is the total flow input to the humidifier assembly divided by the number of humidifiers.

3. The system for regulating stack inlet humidity and outlet backpressure of a fuel cell of claim 2, wherein the resistance inside the humidifier is approximately proportional to the square of the input air flow rate.

4. The system for regulating stack inlet humidity and outlet backpressure of a fuel cell of claim 1, wherein the exhaust flow rate of each humidifier in the humidifier assembly is the total flow rate input to the humidifier assembly divided by the number of humidifiers.

5. The system for regulating stack inlet humidity and outlet backpressure of a fuel cell of claim 4, wherein the resistance inside the humidifier is approximately proportional to the square of the input exhaust gas flow rate.

6. The system for regulating stack inlet humidity and outlet back pressure of a fuel cell according to claim 1, wherein an air compressor and an intercooler are further provided in sequence on the gas input main line depending on the direction of air circulation.

7. The system for regulating stack inlet humidity and outlet backpressure of a fuel cell of claim 1, in which a backpressure valve is eliminated from the gas output main line.

8. The system for regulating stack inlet humidity and outlet backpressure of a fuel cell of claim 1, wherein the humidifier assembly is comprised of two humidifiers in parallel.