CN111092245A

CN111092245A - Fuel cell stack and system, fuel cell vehicle and water management method thereof

Info

Publication number: CN111092245A
Application number: CN201911422703.2A
Authority: CN
Inventors: 李骏; 汤千秋; 徐鑫; 甘全全
Original assignee: Shanghai Shen Li High Tech Co Ltd
Current assignee: Shanghai Shenli Technology Co Ltd
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2020-05-01
Anticipated expiration: 2039-12-31
Also published as: CN111092245B

Abstract

The invention relates to a fuel cell stack and a system thereof, a fuel cell automobile and a water management method thereof, wherein a first end plate of the fuel cell stack is provided with a hydrogen inlet, an air inlet, a first hydrogen outlet and a first air outlet; the fuel cell electric pile and the gyroscope are arranged on the fuel cell automobile; the invention utilizes the gyroscope to monitor the running condition of the vehicle in real time, if the gyroscope monitors that the galvanic pile turns, climbs or descends, the electromagnetic valve is opened through the control system, and the hydrogen and/or air outlet on the other side end plate is opened, so that the drainage is increased, and the end part of the galvanic pile is prevented from flooding. Compared with the prior art, the method has the advantages of simple and easy operation, low cost and the like.

Description

Fuel cell stack and system, fuel cell vehicle and water management method thereof

Technical Field

The invention relates to the technical field of fuel cell stacks, in particular to a fuel cell stack and a system, a fuel cell automobile and a water management method thereof.

Background

Although the industrialization of fuel cell system components has been small and scalable, water management remains a very critical issue and has not been fully addressed to date. The high quality water management should achieve the balance of water content in the membrane, anode proton-electric drag (EOD) with water and cathode reverse osmosis water, and at least ensure that the performance does not fluctuate greatly due to the obstruction of liquid water in the process of transmitting reaction gas to a reaction interface, and simultaneously ensure that the performance does not decrease obviously due to water shortage and the like in the process of proton conduction. However, in actual practice, it is difficult to achieve both of the above two points, and therefore, a problem of flooding or water shortage occurs in the fuel cell stack.

Flooding may occur in a Catalyst Layer (CL), a Gas Diffusion Layer (GDL), and a gas flow channel (GC) of a fuel cell stack. Slight flooding for a short time may cause a slight decrease in output power, but once severe flooding occurs in the gas diffusion layer or the gas flow channel, intermittent large fluctuations in voltage may be caused, and even a malfunction may be caused. This not only results in unstable output, but also results in degradation of the catalyst and corrosion of the diffusion layer due to local gas starvation, which affects the service life of the fuel cell stack.

The lack of water in the membrane directly causes the reduction of the conductivity of the proton exchange membrane, the increase of the ohmic resistance and the reduction of the output power. In addition, the water shortage of the membrane causes the pores on the membrane to begin to shrink, and the reverse osmosis effect is slowed down. Thus, if water shortage is caused by low humidity of the anode intake air, such a vicious cycle of water shortage will be unavoidable. Once sustained for a longer period, the membrane can become brittle and even crack, greatly affecting fuel cell durability. Therefore, in order to ensure smooth operation of the fuel cell system and to extend the service life of the fuel cell stack, water management is required during the design process and subsequent use of the stack.

In the design of the stack, the GDL is usually subjected to hydrophobic treatment, such as polytetrafluoroethylene. In addition, the discharge of liquid water is facilitated by adding an extremely thin microporous layer (MPL) between CL and GDL, by using a serpentine corrugated flow channel as much as possible, and by appropriate hydrophilic treatment of the flow channel surface. In the aspect of adjusting working condition parameters, management is mainly carried out through the ideas of reducing water production and increasing water drainage. For example, adjusting stack temperature to change the water carrying capacity of the air flow, adjusting inlet air humidity, adjusting flow, controlling cathode and anode pressure difference, etc. The two parameters of the stack temperature and the humidity are often coupled with each other, and under the condition that the dew point temperature is not changed, the change of the stack temperature also means the change of the relative humidity.

Although there are many documents and patents on water management of fuel cell stacks, the prior art is mainly concerned with fuel cell stacks having less than 50 individual cells. However, to meet the power density requirements for commercial applications, the number of fuel cells for commercial vehicles is currently greater than 50, and even greater than 200, and as the number of cells increases, the water management problems of the stack become more complex. In addition, the operating condition of the commercial vehicle is also increasingly complex at present, and the conditions of climbing, descending, turning, accelerating, decelerating and the like need to be met, under the conditions, for example, when the vehicle meets the conditions of climbing and descending, the fuel cell stack and the horizontal plane form a certain inclination angle, and when the vehicle meets the conditions of turning, the fuel cell stack can also be influenced by centripetal force, namely, the fuel cell stack and the horizontal plane form a certain inclination angle. In this state, the water management of the fuel cell stack is more complicated, and the flooding problem is more likely to occur. As shown in fig. 1 and 2, a fuel cell stack of a fuel cell engine system includes a single cell, and a first end plate and a second end plate provided at both ends of the fuel cell stack. The first end plate or the second end plate can be provided with a hydrogen inlet, an air inlet, a cooling water inlet, a hydrogen outlet and an air outlet. Taking the second end plate arranged in the direction of the vehicle head, the first end plate as the anode end plate, and the hydrogen inlet, the air inlet and the cooling water inlet arranged on the first end plate as an example, when the vehicle runs down a slope, the anode end plate of the fuel cell stack is lifted, and the lowest single cell voltage (the single sheet with the lowest voltage is located at a position close to the second end plate in fig. 2 and 9) in the stack is rapidly reduced along with the accumulation of time, which finally causes the fault shutdown of the stack.

In order to solve the problem of flooding, patent CN 201810515895.0 adopts a scheme of setting special hydrogen side and air side drainage channels, which makes the drainage channels parallel to and set below the hydrogen channel and the air channel respectively, when the stack is inclined, the generated water will not gather at the end, but enters the drainage channels and then is discharged out of the stack, however, the addition of the drainage channels has a large change to the stack structure, the operation is complex and the cost is high, and the problem of rapid decrease of the cell voltage when the stack is inclined cannot be solved at the same time. Patent CN 200680048003.6 estimates the amount of water discharged from the fuel cell based on the state of the fuel cell (the remaining water amount or the inclination angle), so as to determine the strength of the subsequent purging, and solve the water discharge problem through purging, thereby enabling the stack to start normally.

Disclosure of Invention

The present invention is directed to overcoming the above-mentioned shortcomings of the prior art and providing a fuel cell stack and system, a fuel cell vehicle and a water management method thereof.

The purpose of the invention can be realized by the following technical scheme:

the utility model provides a fuel cell pile, includes the monocell and locates first end plate and the second end plate at fuel cell pile both ends, is equipped with hydrogen import, air intlet, first hydrogen export, first air outlet on the first end plate, is equipped with second hydrogen export and/or second air outlet on the second end plate, second hydrogen export and/or second air outlet are equipped with the solenoid valve, the control system of fuel cell pile be connected to the solenoid valve.

Furthermore, the electromagnetic valve adopts a stop valve, a throttle valve or an adjustable one-way throttle valve.

A fuel cell engine system comprises the fuel cell stack, a hydrogen system, an air system, a cooling system, a humidifying system, a power output system and a control system.

A fuel cell automobile comprises the fuel cell engine system and a gyroscope used for monitoring the running stability of the automobile. The gyroscope is fixed at any position of the vehicle. The fuel cell engine system is arranged at the position of the vehicle close to the head of the vehicle, the tail of the vehicle or the upper cover of the vehicle.

Furthermore, the gyroscope is a piezoelectric gyroscope, a micromechanical gyroscope, an optical fiber gyroscope or a laser gyroscope.

The water management method of the fuel cell automobile comprises the following working processes:

and the gyroscope is utilized to feed back the monitoring result of the running condition of the vehicle to the control system, and the control system controls the intermittent opening and closing of the second hydrogen outlet and/or the second air outlet by controlling the opening and closing of the electromagnetic valve so as to control the drainage of the fuel cell stack.

When the monitoring result of the gyroscope is that the fuel cell automobile carrying the fuel cell stack runs stably, the first hydrogen outlet and the first air outlet are opened or intermittently opened and closed, and the second hydrogen outlet and/or the second air outlet electromagnetic valve are controlled to be in a closed state; when the gyroscope monitors that the vehicle climbs, descends or turns, the control system controls the electromagnetic valve to be opened and closed intermittently, the opening time of the electromagnetic valve lasts for 0.1-60 s each time, then the electromagnetic valve is closed for a period of time, and the closing time of the electromagnetic valve lasts for 0.1-500 s; when the gyroscope monitors that the vehicle stops climbing, descending or turning and starts to run stably, the control system controls the electromagnetic valve to be closed.

Further, the solenoid valve is opened for 0.1s to 30s each time and then closed for a period of time, and the solenoid valve is closed for 0.1s to 100 s.

Compared with the prior art, the invention has the following advantages:

1) the invention designs a new fuel cell water management technical scheme, which utilizes a gyroscope to monitor the running condition of a fuel cell automobile in real time, and adopts the design of a fuel cell stack that additional hydrogen and/or air outlets are arranged on end plates at two sides, when the fuel cell stack does not turn, climb or descend, the hydrogen and air outlets on the end plate at one side are opened or are in an intermittent opening and closing state, and the hydrogen and/or air outlets on the end plate at the other side are closed through a normally closed electromagnetic valve; if the gyroscope monitors that the galvanic pile turns, climbs or descends, the electromagnetic valve is opened through the control system, the hydrogen and/or air outlet on the end plate on the other side is opened, water drainage is increased to avoid flooding at the end part of the galvanic pile, and further, the shutdown fault caused by too low lowest single-chip voltage is effectively prevented, and the operation is simple and easy to implement;

2) according to the invention, effective water management can be realized only by adding extra hydrogen and/or air outlets on the fuel cell stack and controlling by using the electromagnetic valve, and a drainage channel is not required to be additionally arranged or the structure of the stack is not required to be greatly changed, so that the operation is convenient and fast, the control cost is low, and the control is fast;

3) the invention can be suitable for optimizing the water management of various fuel cell stacks including single cells with the number more than 50, and has stronger applicability.

Drawings

FIG. 1 is a schematic top view of a prior art fuel cell engine system;

FIG. 2 is a schematic diagram of a prior art fuel cell stack;

FIG. 3 is a schematic illustration of the inlet and outlet of a prior art fuel cell stack;

FIG. 4 is a schematic diagram of the inlet and outlet of a fuel cell stack with a second outlet for hydrogen and a second outlet for air added in accordance with an embodiment of the present invention;

FIG. 5 is a schematic illustration of the inlet and outlet of a fuel cell stack with a second outlet for hydrogen added in accordance with an embodiment of the present invention;

FIG. 6 is a schematic front view of a fuel cell vehicle according to an embodiment of the present invention;

FIG. 7 is a schematic top view of a fuel cell vehicle according to an embodiment of the present invention;

FIG. 8 is a flowchart illustrating a water management method for a fuel cell vehicle according to an embodiment of the present invention;

fig. 9 is a diagram showing a hydrogen gas distribution state of the fuel cell stack when the second hydrogen outlet is kept closed or not provided while the vehicle is climbing a slope, descending a slope, or turning a corner;

FIG. 10 is a graph of the lowest monolithic voltage over time when the second hydrogen outlet remains closed, or is not provided, when the vehicle is climbing a hill, descending a slope, or turning a corner;

FIG. 11 shows a hydrogen distribution state of a fuel cell stack when a solenoid valve controls a second hydrogen outlet to be opened when a vehicle climbs a slope, goes downhill or turns a corner according to an embodiment of the present invention;

FIG. 12 is a graph showing the time variation of the lowest single-chip voltage when the solenoid valve controls the second hydrogen outlet to open or close according to a certain frequency when the vehicle climbs a slope, goes downhill or turns in the embodiment of the present invention;

FIG. 13 shows the hydrogen distribution status of the fuel cell stack when the solenoid valve controls the second hydrogen outlet to open when the vehicle climbs a slope, goes downhill or turns a corner according to the embodiment of the present invention;

fig. 14 shows a hydrogen distribution state of the fuel cell stack when the first hydrogen outlet is closed and the second hydrogen outlet is kept open while the vehicle is climbing a slope, descending a slope, or turning a corner.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, shall fall within the scope of protection of the present invention.

Examples

The invention relates to a fuel cell stack and a system thereof, a fuel cell automobile and a water management method thereof.

And a hydrogen inlet, an air inlet, a cooling water inlet, a first hydrogen outlet, a second hydrogen outlet, a first air outlet and/or a second air outlet are/is arranged on the first end plate or the second end plate of the fuel cell stack. Wherein, first hydrogen export and second hydrogen export can not set up simultaneously on first end plate, and first hydrogen export and second hydrogen export also can not set up simultaneously on the second end plate. When the first hydrogen outlet is disposed on the first end plate, the second hydrogen outlet is disposed on the second end plate. Wherein the first air outlet and the second air outlet likewise cannot be provided simultaneously on the first end plate, nor can the first air outlet and the second air outlet likewise be provided simultaneously on the second end plate. When the first air outlet is provided on the first end plate, the second air outlet is provided on the second end plate.

For example, the hydrogen inlet, the air outlet, the cooling water inlet and the second hydrogen outlet are arranged on the first end plate, and the first hydrogen outlet, the air inlet and the cooling water outlet are arranged on the second end plate; the hydrogen inlet, the air inlet, the cooling water inlet and the second hydrogen outlet are arranged on the first end plate, and the first hydrogen outlet, the air outlet and the cooling water outlet are arranged on the second end plate; the hydrogen inlet, the air inlet, the cooling water inlet, the first hydrogen outlet, the air outlet and the cooling water outlet are all arranged on the first end plate, and the second hydrogen outlet is arranged on the second end plate.

As shown in fig. 4, the fuel cell stack is provided with a hydrogen inlet, a cooling water inlet, an air inlet, a first hydrogen outlet, a cooling water outlet, and a first air outlet on the first end plate, and the second end plate is provided with an additional second hydrogen outlet and/or a second air outlet in this embodiment (or the first end plate is provided with a hydrogen inlet, a cooling water inlet, an air inlet, a second hydrogen outlet, and a cooling water outlet, and the second end plate is provided with a first air outlet and a first hydrogen outlet, as shown in fig. 5). When the fuel cell stack does not turn, climb or descend, the first hydrogen outlet and the first air outlet on the first end plate are opened, and the second hydrogen outlet and/or the second air outlet on the second end plate are closed through the normally closed electromagnetic valve.

The solenoid valve used is a normally closed solenoid valve, and the opening of the solenoid valve is controlled by the operating conditions of the vehicle, i.e., by the operating conditions of the vehicle detected by the gyroscope. The electromagnetic valve can be a stop valve, a throttle valve, an adjustable one-way throttle valve and the like. Note that the designations of the cooling water inlet and outlet, etc., are omitted in fig. 4 and 5. When the vehicle runs up a slope, runs down a slope or turns, the state change of the vehicle is monitored, and the electromagnetic valve is controlled to be opened and closed intermittently, so that the opening and closing of the second hydrogen outlet and/or the second air outlet are controlled, and the water is drained conveniently.

The invention also discloses a fuel cell engine system of the fuel cell stack, which further comprises a hydrogen system, an air system, a cooling system, a humidifying system, a power output system and a control system.

The invention also discloses a fuel cell automobile which comprises the fuel cell engine system and a gyroscope. As shown in fig. 6 and 7, the gyroscope functions to sense the operating conditions of the vehicle, such as turning, climbing, descending, accelerating, decelerating, etc., and feed the sensing results back to the control system of the fuel cell stack. The gyroscopes may be piezoelectric gyroscopes, micromechanical gyroscopes, fiber optic gyroscopes, and laser gyroscopes. The gyroscope may be fixedly positioned anywhere within the fuel cell vehicle. The fuel cell engine system may be placed near the head, tail, or upper hood of the vehicle, etc. The fuel cell engine system also includes a fuel cell stack, a hydrogen system, an air system, a cooling system, a humidification system, a power output system, and a control system.

Fig. 8 shows a flowchart of a water management method for a fuel cell vehicle according to the present invention, in which a gyroscope detects a steady state of the fuel cell vehicle on which a fuel cell stack is mounted. When the fuel cell vehicle on which the fuel cell stack is mounted is operating smoothly, only the first hydrogen outlet and the first air outlet are open, and the electromagnetic valve is in a closed state. When the gyroscope of the vehicle fuel cell system detects that the running condition of the vehicle changes, such as the vehicle runs on a climbing slope, a descending slope or a turning curve, the control system enables the electromagnetic valve to be opened, so that the second hydrogen outlet and/or the second air outlet are/is opened, the opening time of the electromagnetic valve lasts for 0.1-60 s each time and then is closed for 0.1-500 s, and if the gyroscope detects that the vehicle continuously climbs the slope, descends the slope or turns the curve, the electromagnetic valve continues to be opened for 0.1-60 s and then is closed for 0.1-500 s. When the gyroscope monitors that the vehicle stops climbing, descending or turning, the control system controls the electromagnetic valve to be closed. In some embodiments, the solenoid valve is opened for a period of time ranging from 0.1s to 30s each time, and then closed for a period of time, and the solenoid valve is closed for a period of time ranging from 0.1s to 100s each time.

When the second hydrogen outlet is opened, the distribution of hydrogen inside the fuel cell stack is as shown in fig. 11 and 13, and the direction shown by the dotted line in fig. 13 is the flow direction of hydrogen. As shown in fig. 12, the lowest cell voltage of the stack (the cell with the lowest voltage is located near the second end plate in fig. 1) gradually decreases with the accumulation of time, and when the solenoid valve is opened, the lowest cell voltage rapidly increases and stably operates for a while, and when the solenoid valve is opened again, the lowest cell voltage rapidly increases as the lowest cell voltage continues to decrease with the accumulation of time. Therefore, the electromagnetic valve controls the opening and closing of the second hydrogen outlet, and the shutdown fault caused by the excessively low lowest single-chip voltage can be effectively prevented.

In some embodiments, when the vehicle runs up a slope, runs down a slope or turns, the first hydrogen outlet is controlled to be closed by using a solenoid valve, and the second hydrogen outlet is kept in an open state, in this case, the hydrogen distribution mode in the electric pile is as shown in fig. 14; in this way, the rapid drop of the monolith can also be mitigated.

The invention monitors the running condition of the vehicle by utilizing the gyroscope, and respectively arranges additional hydrogen and/or air outlets on the end plates at the two sides of the fuel cell stack, controls the opening and closing of the second hydrogen outlet by the electromagnetic valve, increases the drainage to avoid the end part flooding of the stack, further effectively prevents the shutdown fault caused by the over-low lowest single-chip voltage, does not need to additionally arrange a drainage channel or a stack structure, and has simple and easy operation.

While the invention has been described with reference to specific embodiments, the invention is not limited thereto, and those skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope of the invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. The utility model provides a fuel cell pile, includes the monocell and locates first end plate and the second end plate at fuel cell pile both ends, is equipped with hydrogen import, air intlet, first hydrogen export, first air outlet on the first end plate, its characterized in that, is equipped with second hydrogen export and/or second air outlet on the second end plate, second hydrogen export and/or second air outlet are equipped with the solenoid valve, the control system of fuel cell pile be connected to the solenoid valve.

2. The fuel cell stack of claim 1 wherein the solenoid valve is a shut-off valve, a throttle valve or a variable one-way throttle valve.

3. A fuel cell engine system comprising the fuel cell stack according to any one of claims 1 to 2, the fuel cell engine system further comprising a hydrogen system, an air system, a cooling system, a humidification system, a power output system, and a control system.

4. A fuel cell vehicle comprising a fuel cell engine system as claimed in claim 3 and a gyroscope for monitoring the ride of the vehicle.

5. The fuel cell vehicle according to claim 4, wherein the gyroscope is fixed at an arbitrary position of the vehicle.

6. The fuel cell vehicle of claim 4, wherein the fuel cell engine system is disposed near a head of the vehicle, a tail of the vehicle, or a hood of the vehicle.

7. The fuel cell vehicle according to claim 4, wherein the gyroscope is a piezoelectric gyroscope, a micromechanical gyroscope, a fiber optic gyroscope, or a laser gyroscope.

8. The water management method for a fuel cell vehicle according to any one of claims 4 to 7, wherein the gyroscope feeds back the monitoring result of the operating condition of the fuel cell vehicle to the control system, and the control system controls the intermittent opening and closing of the second hydrogen outlet and/or the second air outlet by controlling the opening and closing of the electromagnetic valve, thereby controlling the water discharge of the fuel cell stack.

9. The water management method for a fuel cell vehicle according to claim 8, wherein when the monitoring result of the gyroscope is that the fuel cell vehicle on which the fuel cell stack is mounted is operating smoothly, the first hydrogen outlet and the first air outlet are opened or intermittently opened and closed, and the second hydrogen outlet and/or the second air outlet solenoid valve is controlled to be closed; when the gyroscope monitors that a fuel cell automobile carrying the fuel cell stack climbs, descends or turns, the control system controls the electromagnetic valve to be opened and closed intermittently, the opening time of the electromagnetic valve lasts for 0.1-60 s each time, then the electromagnetic valve is closed for a period of time, and the closing time of the electromagnetic valve lasts for 0.1-500 s; when the gyroscope monitors that the vehicle stops climbing, descending or turning and starts to run stably, the control system controls the electromagnetic valve to be closed.

10. The water management method of a fuel cell vehicle according to claim 9, wherein the solenoid valve is opened for 0.1s to 30s each time and then closed for a period of time, and the solenoid valve is closed for 0.1s to 100s each time.