CN223566636U

CN223566636U - Underwater equipment and fuel cell systems

Info

Publication number: CN223566636U
Application number: CN202423001415.9U
Authority: CN
Inventors: 彭晓盟; 苏俊龙; 赵阳; 张东山
Original assignee: Blue Ocean Easy Hydrogen Power Qingdao Co ltd
Current assignee: Blue Ocean Easy Hydrogen Power Qingdao Co ltd
Priority date: 2024-12-05
Filing date: 2024-12-05
Publication date: 2025-11-18
Anticipated expiration: 2034-12-05

Abstract

The present application relates to an underwater device and a fuel cell system. The fuel cell system comprises a blind-end oxyhydrogen fuel cell stack, a hydrogen conveying structure, an oxygen conveying structure, a purging structure and a purging structure, wherein a first gas passage and a first discharge pipeline are respectively arranged at two ends of the blind-end oxyhydrogen fuel cell stack, a first on-off valve is arranged at the first gas passage, a second gas passage and a second discharge pipeline are respectively arranged at two ends of the blind-end oxyhydrogen fuel cell stack, a second on-off valve is arranged at the second gas passage, and the purging structure can supply purging gas to the first gas passage and the second gas passage when the fuel cell system is stopped, and the purging gas is stored in an installation space of the fuel cell system in advance. Therefore, residual hydrogen and oxygen can not exist in the blind-end hydrogen-oxygen fuel cell stack after purging, the blind-end hydrogen-oxygen fuel cell stack is prevented from being in an open-circuit state with high voltage for a long time, and a nitrogen bottle for providing purging gas does not need to be specially carried.

Description

Underwater device and fuel cell system

Technical Field

The application relates to the technical field of underwater fuel cell safety management, in particular to an underwater device and a fuel cell system.

Background

At present, hydrogen is used as fuel and oxygen is used as oxidant in the hydrogen-oxygen fuel cell, chemical energy of the fuel is directly converted into electric energy through electrochemical reaction, the electric energy is not limited by Carnot circulation, the power generation efficiency is as high as 50% -60%, and a reaction product is only water, so that the hydrogen-oxygen fuel cell has the characteristics of being green and efficient, and is an energy conversion system with wide prospects.

In general, the application of oxyhydrogen fuel cells is mainly based on road vehicles and cogeneration stationary power generation. However, in the special subdivision field, the oxyhydrogen fuel cell is more suitable for being used as a power system of UUV (unmanned underwater vehicle), has the advantages of high power density, long endurance mileage, light weight and the like compared with a lithium-ion power system, and has the advantages of low vibration noise, almost no tail gas exhaust and the like compared with a gas engine power system.

In an underwater closed scene, the underwater closed scene is limited by a small volume and a small internal space of the unmanned underwater vehicle, and high requirements are put forward on the space layout and the power generation efficiency of the fuel cell system.

In order to improve the power generation efficiency, the power consumption of accessories is required to be reduced as far as possible by the fuel cell system, a Dead-end hydrogen oxygen fuel cell (Dead-end PEMFC) configuration is suitable for the fuel cell system with smaller output power, and the technical routes of reduced pressure supply of a high-pressure hydrogen bottle and a high-pressure oxygen bottle, no gas circulation and gravity discharge of reaction water are directly adopted, so that the use of a gas circulation pump is eliminated, and the energy consumption of the system is greatly reduced.

However, there is a disadvantage in that the gas purging cannot be performed by the gas circulation pump when the fuel cell system is stopped, so that the fuel cell stack is in an open circuit state with high voltage for a long time, and irreversible damage such as carbon corrosion, platinum oxidation and the like can be caused to the membrane electrode. In addition, in order to improve the utilization rate of the internal space of the unmanned submersible vehicle of the oxyhydrogen fuel cell, the endurance mileage is improved as much as possible, and enough space is usually reserved as the fuel carrying space of the high-pressure hydrogen bottle and the high-pressure oxygen bottle, and the nitrogen bottle used for stopping and purging air supply is not carried, so that the stopping and purging of the fuel cell system are affected.

Disclosure of utility model

Based on the above, it is necessary to provide an underwater device and a fuel cell system, which can avoid the problem that the hydrogen oxygen fuel cell applied to the underwater device cannot be shut down and purged, and the like, and can avoid the open circuit state of the blind hydrogen oxygen fuel cell stack at high voltage for a long time, ensure the service performance and service life of the blind hydrogen oxygen fuel cell stack, and simultaneously, do not need to specially carry a nitrogen cylinder for providing purge gas, thereby reducing the volume and the structural complexity of the fuel cell system.

A fuel cell system comprising:

A blind-end hydrogen-oxygen fuel cell stack;

The hydrogen conveying structure comprises a first gas passage, a first on-off valve and a first exhaust pipeline, wherein the first gas passage and the first exhaust pipeline are respectively arranged at two ends of the blind-end hydrogen-oxygen fuel cell stack, and the first on-off valve is arranged in the first gas passage;

The oxygen conveying structure comprises a second gas passage, a second on-off valve and a second exhaust pipeline, wherein the second gas passage and the second exhaust pipeline are respectively arranged at two ends of the blind-end hydrogen-oxygen fuel cell stack, and the second on-off valve is arranged in the second gas passage;

and the purging structure is communicated with at least the first gas passage and the second gas passage, and can supply purging gas to the first gas passage and the second gas passage when the fuel cell system is stopped, and the purging gas is stored in the installation space of the fuel cell system in advance.

In one embodiment of the present application, the purge structure includes a purge pump, a first purge assembly, and a second purge assembly;

the first purging component is communicated with the first gas passage and the second gas passage and is positioned between the first on-off valve and the blind end hydrogen-oxygen fuel cell stack;

the second purge assembly communicates the first discharge line with the second discharge line;

The purge pump is in communication with the first purge assembly and controls the first purge assembly and the second purge assembly to purge at least one of the first gas passageway and the second gas passageway.

In an embodiment of the present application, the first purge component includes a first connection pipe, a first control valve and a second control valve, the first connection pipe communicates the first gas passage and the second gas passage, the first control valve and the second control valve are disposed in the first connection pipe at intervals, and the purge pump communicates between the first control valve and the second control valve;

The second purging component comprises a second connecting pipeline, a third control valve, a fourth control valve and a third discharging pipeline, the second connecting pipeline is communicated with the first discharging pipeline and the second discharging pipeline, the third control valve and the fourth control valve are arranged on the second connecting pipeline at intervals, and the third discharging pipeline is communicated with the second connecting pipeline.

In an embodiment of the present application, the purge structure uses air as a purge gas, and the purge pump purges the second gas passage through the first purge component and the second purge component, and purges the first gas passage and the second gas passage at the same time;

Or the purging structure adopts nitrogen as purging gas, and the purging pump simultaneously purges the first gas passage and the second gas passage through the first purging component and the second purging component.

In an embodiment of the present application, the hydrogen delivery structure further includes two first temperature and pressure detecting members, and the two first temperature and pressure detecting members are respectively disposed on the first gas passage and the first exhaust pipeline and are disposed near the blind-end oxy-hydrogen fuel cell stack;

the oxygen conveying structure further comprises two second temperature and pressure detection pieces, wherein the two second temperature and pressure detection pieces are respectively arranged on the second gas passage and the second discharge pipeline and are close to the blind-end oxyhydrogen fuel cell stack.

In an embodiment of the present application, the hydrogen delivery structure further includes a first pressure detecting member, where the first pressure detecting member is disposed in the first gas passage and located between the first on-off valve and the first purge component;

The oxygen delivery structure further includes a second pressure sensing member disposed in the second gas passageway and positioned between the second on/off valve and the first purge assembly.

In an embodiment of the present application, the hydrogen delivery structure further includes a first separator and a first drain valve, where the first drain valve is disposed on the first drain pipe and is located on a side of the second purge component away from the blind end oxy-hydrogen fuel cell stack, and the first separator is disposed on the first drain pipe and is located between the second purge component and the first drain valve;

The oxygen conveying structure further comprises a second separator and a second drain valve, the second drain valve is arranged on the second drain pipeline and is positioned on one side, far away from the blind end hydrogen-oxygen fuel cell stack, of the second purging component, and the second separator is arranged on the second drain pipeline and is positioned between the second purging component and the second drain valve.

In one embodiment of the application, the fuel cell system further comprises a hydrogen elimination structure in communication with the third vent line of the second purge assembly.

In an embodiment of the application, the first purge component further comprises a first regulating valve and a second regulating valve, wherein the first regulating valve is arranged in the first gas passage and is positioned between the first purge component and the blind-end oxyhydrogen fuel cell stack;

the second regulating valve is arranged in the second gas passage and is positioned between the first purging component and the blind end hydrogen-oxygen fuel cell stack.

A purging method of a fuel cell system, applied to the fuel cell system according to any of the above technical features, the purging method at least comprising the steps of:

acquiring a shutdown instruction of the fuel cell system;

controlling the hydrogen conveying structure and the oxygen conveying structure to be closed, and stopping conveying hydrogen and oxygen;

judging whether purge gas in an installation space where the fuel cell system is located is air or not;

If yes, the purging structure is controlled to purge the oxygen conveying structure, and then the hydrogen conveying structure and the oxygen conveying structure are purged at the same time;

if not, controlling the purging structure to purge the hydrogen conveying structure and the oxygen conveying structure at the same time;

Performing cyclic purging on the hydrogen conveying structure and the oxygen conveying structure;

Obtaining single-chip voltage of a blind-end hydrogen-oxygen fuel cell stack, and judging whether the single-chip voltage is within a preset range;

If yes, controlling the purging structure to stop purging;

if not, continuously and circularly purging the hydrogen conveying structure and the oxygen conveying structure;

Wherein the monolithic voltage is an average monolithic voltage and/or a highest monolithic voltage.

In one embodiment of the present application, the control purge structure first purges the oxygen delivery structure and then purges the hydrogen delivery structure and the oxygen delivery structure simultaneously, comprising the steps of:

closing the first control valve and the third control valve, and opening the second control valve and the fourth control valve;

Starting a purging pump, adjusting the rotating speed of the purging pump and the duty ratio of a second adjusting valve, and purging the oxygen conveying structure;

acquiring a first pressure of gas in a hydrogen conveying structure, and judging whether the first pressure is smaller than or equal to a first set threshold value;

If yes, opening the first control valve and the third control valve;

If not, continuing to regulate and control the rotating speed of the purging pump and the duty ratio of the second regulating valve, and purging the oxygen conveying structure.

In one embodiment of the present application, the purging structure is controlled to purge the hydrogen delivery structure and the oxygen delivery structure simultaneously, comprising the steps of:

Opening the first control valve, the third control valve, the second control valve and the fourth control valve;

And starting a purging pump, and regulating and controlling the rotating speed of the purging pump.

In one embodiment of the present application, the cyclic purging of the hydrogen delivery structure and the oxygen delivery structure comprises the steps of:

regulating and controlling the duty ratio of the first regulating valve and the second regulating valve;

Controlling the pressure in the oxygen delivery structure and the hydrogen delivery structure to be equal and smaller than a second set threshold;

Controlling a purge pump to purge for a first preset time at a first rotating speed, purging for a second preset time at a second rotating speed, and sequentially and circularly purging for the first preset time at the first rotating speed;

wherein the first rotational speed is different from the second rotational speed.

An underwater device comprising an underwater host and a fuel cell system as claimed in any one of the above technical features;

the fuel cell system is arranged on the underwater host and supplies power for the underwater host.

After the technical scheme is adopted, the application has at least the following technical effects:

In the underwater equipment and the fuel cell system, a first gas passage in a hydrogen conveying structure is communicated with two ends of a blind-end hydrogen-oxygen fuel cell stack through a first discharge pipeline, and a first on-off valve controls on-off of the first gas passage. In the oxygen conveying structure, a second gas passage is communicated with two ends of the blind end hydrogen-oxygen fuel cell stack through a second exhaust pipeline, and a second on-off valve controls on-off of the second gas passage. The purge structure is capable of communicating at least the first gas passage and the second gas passage to supply purge gas to the first gas passage and the second gas passage, the purge gas being stored in advance in an installation space of the fuel cell system.

When the fuel cell system is shut down, the purging structure can lead the purging gas into the first gas passage and the second gas passage, so that the purging gas can enable hydrogen to be discharged from the first gas passage, the blind-end hydrogen-oxygen fuel cell stack, the first discharge pipeline and the purging structure, and oxygen to be discharged from the second gas passage, the blind-end hydrogen-oxygen fuel cell stack, the second discharge pipeline and the purging structure. After the dead-end hydrogen-oxygen fuel cell stack after shutdown is purged, residual hydrogen and oxygen cannot exist in the dead-end hydrogen-oxygen fuel cell stack, irreversible damage such as carbon corrosion and platinum oxidation to a membrane electrode is avoided, the dead-end hydrogen-oxygen fuel cell stack is further prevented from being in a high-voltage open-circuit state for a long time, and the service performance and the service life of the dead-end hydrogen-oxygen fuel cell stack are ensured. Meanwhile, the purging structure adopts the gas which is stored in the installation space of the fuel cell system in advance as the purging gas, so that a nitrogen bottle for providing the purging gas does not need to be specially carried, and the volume and the structural complexity of the fuel cell system are reduced.

Drawings

Fig. 1 is a schematic diagram of a fuel cell system according to an embodiment of the present application.

Fig. 2 is a schematic view of the fuel cell system shown in fig. 1 illustrating a purge structure.

Fig. 3 is a partial schematic view of the fuel cell system shown in fig. 1 at a.

Fig. 4 is a partial schematic view of the fuel cell system shown in fig. 1 at B.

Fig. 5 is a schematic flow diagram of purge gas in the fuel cell system shown in fig. 1.

Fig. 6 is a purge flow chart of the fuel cell system shown in fig. 5.

The hydrogen-oxygen separator comprises a 100-fuel cell system, a 110-dead-end hydrogen-oxygen fuel cell stack, a 120-hydrogen conveying structure, 102-hydrogen paths, 121-first gas paths, 122-first on-off valves, 123-first discharge pipelines, 124-high-pressure hydrogen bottles, 125-first temperature-pressure detection parts, 126-first pressure detection parts, 127-first separators, 128-first drain valves, 130-oxygen conveying structure, 103-oxygen paths, 131-second gas paths, 132-second on-off valves, 133-second discharge pipelines, 134-high-pressure oxygen bottles, 135-second temperature-pressure detection parts, 136-second pressure detection parts, 137-second separators, 138-second drain valves, 140-purge structures, 141-purge pumps, 142-first purge components, 1421-first connecting pipelines, 1422-first control valves, 1423-second control valves, 1424-first regulating valves, 1425-second regulating valves, 143-second components, 1-second connecting pipelines, 2-third control valves, 1424-third control valves, 1434-fourth purge structures, 150-second hydrogen-eliminating structures.

Detailed Description

In order that the above objects, features and advantages of the application will be readily understood, a more particular description of the application will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. The present application may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the application, whereby the application is not limited to the specific embodiments disclosed below.

In the description of the present application, it should be understood that, if any, these terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., are used herein with respect to the orientation or positional relationship shown in the drawings, these terms refer to the orientation or positional relationship for convenience of description and simplicity of description only, and do not indicate or imply that the apparatus or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the application.

Furthermore, the terms "first," "second," and the like, if any, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, the terms "plurality" and "a plurality" if any, mean at least two, such as two, three, etc., unless specifically defined otherwise.

In the present application, unless explicitly stated and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly. For example, they may be fixedly connected, detachably connected or integrally formed, mechanically connected, electrically connected, directly connected or indirectly connected through an intermediate medium, and communicated between two elements or the interaction relationship between two elements unless clearly defined otherwise. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present application, unless expressly stated or limited otherwise, the meaning of a first feature being "on" or "off" a second feature, and the like, is that the first and second features are either in direct contact or in indirect contact through an intervening medium. Moreover, a first feature "above," "over" and "on" a second feature may be a first feature directly above or obliquely above the second feature, or simply indicate that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

It will be understood that if an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. If an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein, if any, are for descriptive purposes only and do not represent a unique embodiment.

It can be appreciated that in an underwater closed scenario, the fuel cell system is applied to an unmanned submersible vehicle to power the unmanned submersible vehicle. In order to improve the power generation efficiency, a Dead-end hydrogen oxygen fuel cell (Dead-end PEMFC) configuration is generally suitable for a fuel cell system having a smaller output power. However, when the fuel cell system is shut down, the gas cannot be purged through the gas circulating pump, so that the fuel cell stack is in an open circuit state with high voltage for a long time, and irreversible damage can be caused to the membrane electrode. In addition, in order to improve the utilization rate of the internal space of the unmanned submersible vehicle of the hydrogen-oxygen fuel cell, a nitrogen cylinder used as a shutdown purge gas supply is not generally carried, which affects the realization of the shutdown purge of the fuel cell system.

To this end, referring to fig. 1, the present application provides a novel fuel cell system 100. Fig. 1 is a schematic diagram of a fuel cell system 100 according to an embodiment of the application. The fuel cell system 100 is mainly applied to underwater equipment and is used for supplying power to an underwater main body of the underwater equipment so as to ensure that the underwater equipment operates in a water environment. Alternatively, the subsea equipment includes, but is not limited to, unmanned submarines, but may be other equipment that requires use of the fuel cell system 100 under water.

The fuel cell system 100 can purge the dead-end hydrogen-oxygen fuel cell stack 110 after shutdown, avoid the dead-end hydrogen-oxygen fuel cell stack 110 to be in an open circuit state of high voltage for a long time, ensure the service performance and service life of the dead-end hydrogen-oxygen fuel cell stack 110, simultaneously, do not need to specially carry a nitrogen cylinder for providing purge gas, and reduce the volume and the structural complexity of the fuel cell system 100.

The specific structure of the fuel cell system 100 of one embodiment is described below.

Referring to fig. 1-4, in one embodiment, a fuel cell system 100 includes a dead-end hydrogen-oxygen fuel cell stack 110, a hydrogen delivery structure 120, an oxygen delivery structure 130, and a purge structure 140. The hydrogen delivery structure 120 includes a first gas passage 121, a first on-off valve 122, and a first discharge pipe 123, where the first gas passage 121 and the first discharge pipe 123 are disposed at two ends of the blind end oxy-hydrogen fuel cell stack 110, and the first on-off valve 122 is disposed in the first gas passage 121. The oxygen delivery structure 130 includes a second gas passage 131, a second on-off valve 132, and a second exhaust pipe 133, where the second gas passage 131 and the second exhaust pipe 133 are disposed at two ends of the blind end oxy-hydrogen fuel cell stack 110, and the second on-off valve 132 is disposed in the second gas passage 131.

The purge structure 140 is in communication with at least the first gas passage 121 and the second gas passage 131, and when the fuel cell system 100 is stopped, the purge structure 140 can supply purge gas to the first gas passage 121 and the second gas passage 131, and the purge gas can be stored in the installation space of the fuel cell system 100 in advance. Fig. 2 is a schematic diagram of the fuel cell system 100 shown in fig. 1 illustrating the purge structure 140, fig. 3 is a partial schematic diagram of the fuel cell system 100 shown in fig. 1 at a, and fig. 4 is a partial schematic diagram of the fuel cell system 100 shown in fig. 1 at B.

The dead-end hydrogen-oxygen fuel cell stack 110 is the main body component of the fuel cell system 100 where the electrochemical reaction occurs. The blind-end hydrogen-oxygen fuel cell stack 110 is formed as a unit by stacking a plurality of single cells in series. The blind end hydrogen-oxygen fuel cell stack 110 uses hydrogen as fuel and oxygen as oxidant. Hydrogen enters the inside of the blind-end hydrogen-oxygen fuel cell stack 110 through the anode, hydrogen atoms are changed into protons after the anode loses electrons under the action of a catalyst, and the protons pass through a membrane electrode in the blind-end hydrogen-oxygen fuel cell stack 110 to reach the cathode.

At the same time, electrons pass through the external circuit of the dead-end hydrogen-oxygen fuel cell stack 110 to the cathode. On the cathode side, protons, electrons, and oxygen combine into liquid water, thereby generating an electric current. After the hydrogen and the oxygen undergo electrochemical reaction in the blind end hydrogen-oxygen fuel cell stack 110, liquid water can be generated, and the liquid water is discharged through a flow passage in the blind end hydrogen-oxygen fuel cell stack 110.

The dead-end hydrogen-oxygen fuel cell stack 110 is characterized in that the metering ratio of the amount of hydrogen introduced into the anode to the amount of oxygen introduced into the cathode is 1, and the pressure on the anode side is slightly higher than the pressure on the cathode side. In this way, the hydrogen and the oxygen are electrochemically reacted in the blind end hydrogen-oxygen fuel cell stack 110 according to the molar ratio of the hydrogen-oxygen chemical reaction, without circulation of the hydrogen and the oxygen and without power consumption of circulating components, so as to improve the system efficiency of the fuel cell system 100.

The inside of the blind end hydrogen-oxygen fuel cell stack 110 has a first channel for transporting hydrogen and produced liquid water and a second channel for transporting oxygen and produced liquid water. It should be noted that the present application focuses on the purging structure 140 to purge the blind-end oxy-hydrogen fuel cell stack 110, and the specific structure and the principle of the electrochemical reaction of the blind-end oxy-hydrogen fuel cell stack 110 are the prior art, which will not be described in detail.

The hydrogen gas delivery structure 120 is a structure for delivering hydrogen gas and discharging liquid water. Specifically, in the hydrogen delivery structure 120, the first gas passage 121 and the first exhaust pipe 123 are separately disposed at two ends of the blind end oxyhydrogen fuel cell stack 110, the first gas passage 121 is connected to the hydrogen inlet end of the blind end oxyhydrogen fuel cell stack 110, and the first exhaust pipe 123 is connected to the hydrogen outlet end of the blind end oxyhydrogen fuel cell stack 110. Namely, the first gas passage 121, the first channel of the dead-end hydrogen-oxygen fuel cell stack 110, and the first exhaust line 123, are communicated to form the hydrogen gas path 102. The first on-off valve 122 is disposed in the first gas passage 121 to control on-off of the first gas passage 121.

The oxygen delivery structure 130 is a structure for delivering oxygen and discharging liquid water. Specifically, in the oxygen delivery structure 130, the second gas passage 131 and the second exhaust pipe 133 are separately disposed at two ends of the blind end oxy-hydrogen fuel cell stack 110, the second gas passage 131 is connected to the oxygen inlet end of the blind end oxy-hydrogen fuel cell stack 110, and the second exhaust pipe 133 is connected to the oxygen outlet end of the blind end oxy-hydrogen fuel cell stack 110. Namely, the second gas passage 131, the second channel of the dead-end hydrogen-oxygen fuel cell stack 110, and the second exhaust line 133 are communicated to form the oxygen path 103. The second on-off valve 132 is disposed in the second gas passage 131 to control on-off of the second gas passage 131.

The first gas passage 121 delivers hydrogen to the blind hydrogen-oxygen fuel cell stack 110, and the second gas passage 131 delivers oxygen to the blind hydrogen-oxygen fuel cell stack 110, after which the hydrogen and oxygen react electrochemically within the blind hydrogen-oxygen fuel cell stack 110. The blind end hydrogen-oxygen fuel cell stack 110 discharges the mixture of hydrogen and liquid water through the first discharge pipeline 123, and discharges the mixture of oxygen and liquid water through the second discharge pipeline 133, so that the blind end hydrogen-oxygen fuel cell stack 110 can discharge water, and the damage of the blind end hydrogen-oxygen fuel cell stack 110 caused by liquid water accumulation is avoided.

Typically, the blind end oxy-hydrogen fuel cell stack 110 discharges liquid water generated by the electrochemical reaction through the first discharge line 123 and the second discharge line 133. The first discharge line 123 and the second discharge line 133 discharge hydrogen and oxygen, respectively, only when the average monolithic voltage or the lowest monolithic voltage of the dead-end hydrogen-oxygen fuel cell stack 110 is below a certain threshold.

When the fuel cell system 100 is shut down, the first on-off valve 122 is controlled to shut down the first gas passage 121, and the second on-off valve 132 is controlled to shut down the second gas passage 131. At this time, the first gas passage 121 is not transporting hydrogen, the second gas passage 131 is not transporting oxygen, and the blind end hydrogen-oxygen fuel cell stack 110 does not electrochemically react. However, residual hydrogen and oxygen are present in the blind-end oxyhydrogen fuel cell stack 110, and the hydrogen and the oxygen are pure hydrogen and pure oxygen (only hydrogen and oxygen are replaced later) react with the catalyst of the membrane electrode, so that a larger open-circuit voltage exists in the blind-end oxyhydrogen fuel cell stack 110, and the service life of the membrane electrode is affected.

To this end, the fuel cell system 100 of the present application is further provided with a purge structure 140, and the purge structure 140 communicates the first gas passage 121 with the second gas passage 131. The purge of the present application is actually a shutdown purge, and later only the purge is replaced, the purge structure 140 can be operated to purge gas when the fuel cell system 100 is shutdown, and the purge gas can be introduced into the blind-end oxy-hydrogen fuel cell stack 110 to allow hydrogen and oxygen to exit the blind-end oxy-hydrogen fuel cell stack 110. That is, the hydrogen and oxygen in the blind end hydrogen-oxygen fuel cell stack 110 are replaced with a purge gas.

After the blind end hydrogen oxygen fuel cell stack 110 is purged, only purge gas exists in the blind end hydrogen oxygen fuel cell stack 110, the purge gas can not react with a catalyst of a membrane electrode, the open-circuit voltage of the blind end fuel cell stack is reduced, the service life of the membrane electrode is ensured, and the service performance and the service life of the blind end fuel cell stack are further ensured.

Of course, the purge structure 140 also communicates the first exhaust line 123 with the second exhaust line 133. After the purge gas is introduced into the blind-end hydrogen-oxygen fuel cell stack 110, the purge gas can gradually discharge hydrogen and oxygen, at this time, the hydrogen can enter the purge structure 140 through the first discharge pipeline 123 and then be discharged, and the oxygen can enter the purge structure 140 through the second discharge pipeline 133 and then be discharged.

Meanwhile, after the fuel cell system 100 is applied to the underwater device, an installation space in which the fuel cell system 100 is located is a closed space, and purge gas is filled in the installation space in advance. When the fuel cell system 100 is stopped, the purge structure 140 can purge the blind-end oxyhydrogen fuel cell stack 110 by using purge gas in the installation space, and a nitrogen cylinder for carrying purge gas is not required, so that the overall volume of the fuel cell system 100 is reduced, and the complexity of the structure of the fuel cell system 100 is reduced.

When the fuel cell system 100 of the above embodiment is shut down, the purge structure 140 can introduce the purge gas into the first gas passage 121 and the second gas passage 131, and the purge gas can then discharge the hydrogen gas from the first gas passage 121, the blind end hydrogen-oxygen fuel cell stack 110, the first discharge pipe 123, and the purge structure 140, and the oxygen gas from the second gas passage 131, the blind end hydrogen-oxygen fuel cell stack 110, the second discharge pipe 133, and the purge structure 140.

In this way, residual hydrogen and oxygen cannot exist in the blind-end hydrogen-oxygen fuel cell stack 110, so that irreversible damage such as carbon corrosion and platinum oxidation to the membrane electrode is avoided, the blind-end hydrogen-oxygen fuel cell stack 110 is prevented from being in a high-voltage open-circuit state for a long time, and the service performance and the service life of the blind-end hydrogen-oxygen fuel cell stack 110 are ensured. Meanwhile, the purge structure 140 adopts the gas pre-stored in the installation space of the fuel cell system 100 as the purge gas, so that a nitrogen cylinder for providing the purge gas does not need to be specially carried, and the volume and the structural complexity of the fuel cell system 100 are reduced.

Referring to fig. 1-3, in one embodiment, the hydrogen delivery structure 120 further includes a high pressure hydrogen bottle 124, the high pressure hydrogen bottle 124 being in communication with the first gas passage 121. The high-pressure hydrogen bottle 124 is a bottle body storing high-pressure hydrogen gas. The high-pressure hydrogen bottle 124 is capable of delivering hydrogen gas through a first gas passage 121 into a first channel (not mentioned later) of the blind-end hydrogen-oxygen fuel cell stack 110.

Referring to fig. 1 to 3, in an embodiment, the oxygen delivery structure 130 further includes a high pressure oxygen bottle 134, and the high pressure oxygen bottle 134 communicates with the second gas passage 131. The high-pressure oxygen bottle 134 is a bottle body for storing high-pressure oxygen. The high-pressure oxygen bottle 134 is capable of delivering oxygen through the second gas passage 131 into a second channel (not mentioned later) of the blind end oxy-hydrogen fuel cell stack 110.

In one embodiment, the first on-off valve 122 and the second on-off valve 132 are both solenoid valves. Of course, in other embodiments of the present application, the first on-off valve 122 and the second on-off valve 132 may be other valves capable of achieving on-off control.

In an embodiment, the purge structure 140 uses air as the purge gas, the purge pump 141 purges the second gas passage 131 through the first purge component 142 and the second purge component 143, and purges the first gas passage 121 and the second gas passage 131 at the same time, or when the purge structure 140 uses nitrogen as the purge gas, the purge pump 141 purges the first gas passage 121 and the second gas passage 131 through the first purge component 142 and the second purge component 143 at the same time. The fuel cell system 100 of the present application may use air as the purge gas, or may use nitrogen as the purge gas.

When air is used as the purge gas, it is necessary to purge the second gas passage 131 (hereinafter, only the oxygen passage 103 is substituted). This is because, when oxygen is contained in the air and the air is purged by introducing the air into the first gas passage 121 (hereinafter, only the hydrogen passage 102 is used instead), the oxygen in the air reacts with the hydrogen in the hydrogen passage 102, and the purge of the blind-end oxy-hydrogen fuel cell stack 110 cannot be realized.

The purging structure 140 is disconnected from the hydrogen path 102, air is firstly introduced into the oxygen path 103, and the air flows in the oxygen path 103 under pressure, so that hydrogen in the blind-end hydrogen-oxygen fuel cell stack 110 can be consumed, and the hydrogen path 102 is in a micro negative pressure state. Subsequently, the purge structure 140 supplies air to the hydrogen path 102 and the oxygen path 103, respectively, to purge the hydrogen path 102 and the oxygen path 103. After purging is complete, the purge structure 140 stops working.

When nitrogen is used as the purge gas, the purge structure 140 can simultaneously supply nitrogen to the hydrogen path 102 and the oxygen path 103 because nitrogen does not react with hydrogen and oxygen. Specifically, the purge structure 140 supplies nitrogen to the hydrogen path 102 and the oxygen path 103, respectively, to purge the hydrogen path 102 and the oxygen path 103. After purging is complete, the purge structure 140 stops working.

In order to better illustrate the specific structure of the purge structure 140, only the purge structure 140 is illustrated herein while the hydrogen path 102 and the oxygen path 103 are delivering purge gas, and this is further illustrated in the description of the purge process and the purge method of the fuel cell system 100 as to whether the purge gas is air or nitrogen.

Referring to fig. 1-4, in one embodiment, the purge structure 140 includes a purge pump 141, a first purge assembly 142, and a second purge assembly 143. The first purge assembly 142 communicates the first gas passage 121 with the second gas passage 131 and is located between the first on-off valve 122 and the blind end oxy-hydrogen fuel cell stack 110. The second purge assembly 143 communicates the first exhaust line 123 with the second exhaust line 133. The purge pump 141 is in communication with the first purge assembly 142 and controls the first purge assembly 142 and the second purge assembly 143 to purge at least one of the first gas passage 121 and the second gas passage 131.

One end of the first purge component 142 is communicated with the first gas passage 121 and is positioned between the first on-off valve 122 and the blind end hydrogen-oxygen fuel cell stack 110, and the other end of the first purge component 142 is communicated with the second gas passage 131 and is positioned between the second on-off valve 132 and the blind end hydrogen-oxygen fuel cell stack 110. The purge pump 141 is a power source of the purge structure 140, and the purge pump 141 is communicated with the first purge assembly 142.

In this way, the purge pump 141 is able to deliver purge gas through the first purge assembly 142 into the hydrogen path 102 and the oxygen path 103. One end of the second purge component 143 is communicated with the first discharge pipeline 123, and the other end of the second purge component 143 is connected with the second discharge pipeline 133. In this way, the hydrogen or the purge gas output by the first exhaust pipe 123 can be exhausted through the second purge component 143, and the oxygen or the purge gas output by the second exhaust pipe 133 can be exhausted through the second purge component 143, so as to purge the blind-end hydrogen-oxygen fuel cell stack 110. Optionally, the purge pump 141 is an air pump.

Referring to fig. 1 to 4, in an embodiment, the first purge assembly 142 includes a first connection pipe 1421, a first control valve 1422, and a second control valve 1423, the first connection pipe 1421 communicates the first gas passage 121 and the second gas passage 131, the first control valve 1422 and the second control valve 1423 are disposed at a distance from the first connection pipe 1421, and the purge pump 141 communicates between the first control valve 1422 and the second control valve 1423. The second purge component 143 includes a second connection pipe 1431, a third control valve 1432, a fourth control valve 1433, and a third discharge pipe 1434, the second connection pipe 1431 communicates the first discharge pipe 123 with the second discharge pipe 133, the third control valve 1432 and the fourth control valve 1433 are disposed at intervals on the second connection pipe 1431, and the third discharge pipe 1434 communicates with the second connection pipe 1431.

One end of the first connection line 1421 is located between the first on-off valve 122 and the blind end hydrogen-oxygen fuel cell stack 110 and is communicated with the first gas passage 121, and the other end of the second connection line 1431 is located between the second on-off valve 132 and the blind end hydrogen-oxygen fuel cell stack 110 and is communicated with the second gas passage 131. In this way, the first connection line 1421 can communicate the first gas passage 121 with the second gas passage 131. The first control valve 1422 and the second control valve 1423 are disposed on the first connection pipeline 1421 at intervals, and the first control valve 1422 and the second control valve 1423 can control the on-off of the first connection pipeline 1421.

Further, the purge pump 141 is connected between the first control valve 1422 and the second control valve 1423. When the first control valve 1422 is opened and the second control valve 1423 is closed, the purge pump 141 is communicated with the first gas passage 121 through the first connecting pipe 1421, when the first control valve 1422 is closed and the second control valve 1423 is opened, the purge pump 141 is communicated with the second gas passage 131 through the first connecting pipe 1421, and when both the first control valve 1422 and the second control valve 1423 are opened, the purge pump 141 is simultaneously communicated with the first gas passage 121 and the second gas passage 131 through the first connecting pipe 1421. When the first control valve 1422 and the second control valve 1423 are both closed, the first connection line 1421 is disconnected from the first gas passage 121 and the second gas passage 131.

One end of the second connecting pipe 1431 communicates with the first discharge pipe 123, and the other end of the second connecting pipe 1431 communicates with the second discharge pipe 133. In this way, the second connecting line 1431 can communicate the first discharge line 123 with the second discharge line 133. The third discharge line 1434 is connected to the second connection line 1431. The hydrogen or purge gas outputted from the first discharge line 123 can be discharged through the second connection line 1431 and the third discharge line 1434, and the oxygen or purge gas outputted from the second discharge line 133 can be discharged through the second connection line 1431 and the third discharge line 1434. The third control valve 1432 and the fourth control valve 1433 are disposed on the second connection pipeline 1431 at intervals, and the third control valve 1432 and the fourth control valve 1433 can control on-off of the second connection pipeline 1431.

Further, a third exhaust line 1434 is connected between the third control valve 1432 and the fourth control valve 1433. When the third control valve 1432 is opened and the fourth control valve 1433 is closed, the first discharge pipeline 123 is communicated with the third discharge pipeline 1434 through the second connecting pipeline 1431, when the third control valve 1432 is closed and the fourth control valve 1433 is opened, the second discharge pipeline 133 is communicated with the third discharge pipeline 1434 through the second connecting pipeline 1431, when the third control valve 1432 and the fourth control valve 1433 are both opened, the first discharge pipeline 123 and the second discharge pipeline 133 are simultaneously communicated with the third discharge pipeline 1434 through the second connecting pipeline 1431, and when the third control valve 1432 and the fourth control valve 1433 are both closed, the second connecting pipeline 1431 is disconnected with the first discharge pipeline 123 and the second discharge pipeline 133.

When the purge structure 140 uses air as the purge gas, the first control valve 1422 is controlled to close and the third control valve 1432 is controlled to close, and the second control valve 1423 and the fourth control valve 1433 are controlled to open, at this time, the hydrogen path 102 is open, and the oxygen path 103 is closed. Subsequently, the first control valve 1422 and the third control valve 1432 are controlled to be opened again, so that the hydrogen path 102 and the oxygen path 103 are both paths. After the purge is completed, the first control valve 1422, the second control valve 1423, the third control valve 1432, and the fourth control valve 1433 are all closed.

When the purge structure 140 uses nitrogen as the purge gas, the first control valve 1422, the second control valve 1423, the third control valve 1432, and the fourth control valve 1433 are all opened, and the hydrogen path 102 and the oxygen path 103 are all paths. After the purge is completed, the first control valve 1422, the second control valve 1423, the third control valve 1432, and the fourth control valve 1433 are all closed.

In one embodiment, the first control valve 1422, the second control valve 1423, the third control valve 1432, and the fourth control valve 1433 are all solenoid valves. Of course, in other embodiments of the present application, the first control valve 1422, the second control valve 1423, the third control valve 1432, and the fourth control valve 1433 may be other valves capable of controlling the on-off of the pipeline.

Referring to fig. 1 to 4, in an embodiment, the first purge component 142 further includes a first adjusting valve 1424 and a second adjusting valve 1425, the first adjusting valve 1424 is disposed in the first gas passage 121 and located between the first purge component 142 and the blind end oxy-hydrogen fuel cell stack 110, and the second adjusting valve 1425 is disposed in the second gas passage 131 and located between the first purge component 142 and the blind end oxy-hydrogen fuel cell stack 110.

The first regulating valve 1424 is provided in the first gas passage 121. The flow rate of the purge gas in the first gas passage 121 can be adjusted by adjusting the duty (opening) of the first adjustment valve 1424. The second control valve 1425 is provided in the second gas passage 131, and controls the duty ratio of the second control valve 1425, so that the flow rate of the purge gas in the second gas passage 131 can be controlled.

In this way, the rotation speed of the purge pump 141 and the duty ratios of the first regulating valve 1424 and the second regulating valve 1425 can be adjusted to adjust the pressure of the purge gas in the first gas passage 121 and the second gas passage 131, so that the purge gas can be delivered to the blind-end oxy-hydrogen fuel cell stack 110 at a certain target pressure. Of course, the hydrogen delivery structure 120 may also include a first regulator valve 1424 and the oxygen delivery structure 130 may include a second regulator valve 1425.

In an embodiment, the first adjusting valve 1424 and the second adjusting valve 1425 are proportional valves, and the duty ratio of the proportional valves, i.e. the opening of the proportional valves, is adjusted to adjust the flow of the first gas passage 121 and the second gas passage 131. Of course, in other embodiments of the present application, the first adjusting valve 1424 and the second adjusting valve 1425 may be other valves capable of realizing opening adjustment.

Referring to fig. 1 to 4, in an embodiment, the hydrogen delivery structure 120 further includes two first temperature and pressure detecting members 125, where the two first temperature and pressure detecting members 125 are disposed on the first gas passage 121 and the first exhaust pipe 123, respectively, and are disposed near the blind end oxy-hydrogen fuel cell stack 110. The oxygen delivery structure 130 further includes two second temperature and pressure detecting members 135, where the two second temperature and pressure detecting members 135 are respectively disposed on the second gas passage 131 and the second exhaust pipe 133 and are disposed near the blind end oxy-hydrogen fuel cell stack 110.

One of the first temperature and pressure detecting members 125 is disposed at one end of the first gas passage 121 near the blind end oxy-hydrogen fuel cell stack 110, and the first temperature and pressure detecting member 125 can detect the temperature and pressure of the hydrogen inlet end. The other first temperature and pressure detecting member 125 is disposed at one end of the first exhaust pipe 123 near the blind end oxy-hydrogen fuel cell stack 110, and the first temperature and pressure detecting member 125 can detect the temperature and pressure of the hydrogen outlet end.

One of the second temperature and pressure detecting members 135 is disposed at one end of the second gas passage 131 near the blind end oxy-hydrogen fuel cell stack 110, and the second temperature and pressure detecting member 135 can detect the temperature and pressure of the oxygen inlet end. Another second temperature and pressure detecting member 135 is disposed at one end of the second exhaust pipe 133 near the blind end oxy-hydrogen fuel cell stack 110, and the second temperature and pressure detecting member 135 can detect the temperature and pressure of the oxygen outlet end.

The pressure value in the hydrogen gas path 102 can be detected by the first temperature-pressure detecting members 125 at both ends of the blind-end oxy-hydrogen fuel cell stack 110, and the pressure value in the oxygen gas path 103 can be detected by the second temperature-pressure detecting members 135 at both ends of the blind-end oxy-hydrogen fuel cell stack 110. In this way, when the purge structure 140 purges the blind end hydrogen-oxygen fuel cell stack 110, the purge mode can be adjusted according to the pressure values of the hydrogen gas path 102 and the oxygen gas path 103.

Referring to fig. 1 to 3, in an embodiment, the hydrogen delivery structure 120 further includes a first pressure detecting member 126, where the first pressure detecting member 126 is disposed in the first gas passage 121 and between the first on-off valve 122 and the first purge component 142. The oxygen delivery structure 130 further includes a second pressure detector 136, where the second pressure detector 136 is disposed in the second gas channel 131 and between the second on-off valve 132 and the first purge component 142.

The first pressure detecting member 126 is capable of detecting the pressure value of the first gas passage 121, and the second pressure detecting member 136 is capable of detecting the pressure value of the second gas passage 131. Thus, the pressure value in the hydrogen path 102 can be detected by the engagement of the first pressure detecting member 126, and the pressure value in the oxygen path 103 can be detected by the engagement of the second pressure detecting member 136. In this way, when the purge structure 140 purges the blind end hydrogen-oxygen fuel cell stack 110, the purge mode can be adjusted according to the pressure values of the hydrogen gas path 102 and the oxygen gas path 103.

In the present embodiment, the pressure value in the hydrogen path 102 can be detected by the cooperation of the first warm-pressure detecting member 125 and the first pressure detecting member 126, and the pressure value in the oxygen path 103 can be detected by the cooperation of the second warm-pressure detecting member 135 and the second pressure detecting member 136. In this way, when the purge structure 140 purges the blind end hydrogen-oxygen fuel cell stack 110, the purge mode can be adjusted according to the pressure values of the hydrogen gas path 102 and the oxygen gas path 103.

In one embodiment, the first temperature and pressure detecting member 125 and the second temperature and pressure detecting member 135 are temperature and pressure sensors. Of course, in other embodiments of the present application, the first temperature and pressure detecting member 125 and the second temperature and pressure detecting member 135 may be a thermometer, a manometer, or the like. In one embodiment, the first pressure detecting member 126 and the second pressure detecting member 136 are pressure sensors. Of course, in other embodiments of the present application, the first pressure detecting member 126 and the second pressure detecting member 136 may be pressure gauges.

Referring to fig. 1 and 4, in an embodiment, the hydrogen delivery structure 120 further includes a first separator 127 and a first drain valve 128, the first drain valve 128 is disposed on the first drain pipe 123 and located on a side of the second purge component 143 away from the blind end oxy-hydrogen fuel cell stack 110, and the first separator 127 is disposed on the first drain pipe 123 and located between the second purge component 143 and the first drain valve 128.

The first separator 127 is capable of separating hydrogen gas from liquid water. The first drain valve 128 can control the on-off of the first drain line 123. The liquid water generated by the electrochemical reaction of the blind-end hydrogen-oxygen fuel cell stack 110 contains hydrogen, and after being discharged, the liquid water enters the first separator 127 to be subjected to water-vapor separation through the first discharge pipeline 123, and the liquid water is discharged into a drainage container (not shown) through a drainage valve.

Referring to fig. 1 and 4, in an embodiment, the oxygen delivery structure 130 further includes a second separator 137 and a second drain valve 138, the second drain valve 138 is disposed on the second drain line 133 and located on a side of the second purge assembly 143 away from the blind end oxy-hydrogen fuel cell stack 110, and the second separator 137 is disposed on the second drain line 133 and located between the second purge assembly 143 and the second drain valve 138.

The second separator 137 is capable of separating oxygen from liquid water. The second drain valve 138 can control the on-off of the second drain line 133. The liquid water generated by the electrochemical reaction of the blind-end hydrogen-oxygen fuel cell stack 110 contains oxygen, and after being discharged, the liquid water enters the second separator 137 for water-steam separation through the second drainage pipeline, and the liquid water is discharged into the drainage container through the second drainage valve 138.

Optionally, the drain container is a water tank or the like. Optionally, the hydrogen delivery structure 120 and the oxygen delivery structure 130 respectively correspond to a drain container. Alternatively, the first drain valve 128 and the second drain valve 138 are solenoid valves or the like.

Referring to fig. 1, in one embodiment, the fuel cell system 100 further includes a hydrogen elimination structure 150, the hydrogen elimination structure 150 being in communication with the third exhaust 1434 of the second purge assembly 143. It will be appreciated that the blind end oxy-hydrogen fuel cell stack 110 still needs to improve performance by venting a portion of the accumulated impurity gases in the event of an excessively low average monolithic voltage or low minimum monolithic voltage.

For this purpose, a hydrogen elimination structure 150 is provided at the output of the third discharge line 1434 for the treatment of the discharged hydrogen and oxygen. In this way, the hydrogen gas exhausted from the dead-end hydrogen-oxygen fuel cell stack 110 can be removed by entering the hydrogen removal structure 150. It should be noted that, the hydrogen eliminating structure 150 may adopt a conventional scheme for implementing hydrogen elimination, and the specific structure thereof is not described herein.

Referring to fig. 1 and 5, fig. 5 is a schematic view of the flow of purge gas in the fuel cell system 100 shown in fig. 1, wherein the direction of the dotted arrow is the flow direction of the purge gas. Upon receipt of a shutdown command, the fuel cell system 100 of the present application will slowly bring the hydrogen delivery structure 120 (hydrogen path 102) and the oxygen delivery structure 130 (oxygen path 103) to normal pressure, e.g., 101kpa (absolute pressure, ABS).

Subsequently, the hydrogen gas line 102 is controlled to stop supplying hydrogen gas, the oxygen gas line 103 is controlled to stop supplying oxygen gas, and the first on-off valve 122, the first regulating valve 1424, the first drain valve 128, the second on-off valve 132, the second regulating valve 1425, and the second drain valve 138 are closed. At this time, hydrogen remains in the hydrogen path 102, and oxygen remains in the oxygen path 103, and the purge structure 140 is required to purge the hydrogen path 102 and the oxygen path 103 to replace the hydrogen in the hydrogen path 102 and the oxygen in the oxygen path 103 with purge gas.

When the purge gas is air, the first control valve 1422 and the third control valve 1432 are closed, and the second control valve 1423 and the fourth control valve 1433 are opened, and the oxygen passage 103 is a passage. The purge pump 141 is started, the rotating speed of the purge pump 141 and the duty ratio of the second regulating valve 1425 are regulated, and the purge pump 141 purges the oxygen gas path 103, namely, the purge pump 141 discharges air through the first connecting pipeline 1421, the second control valve 1423, the second gas path 131, the blind-end hydrogen-oxygen fuel cell stack 110, the second discharge pipeline 133, the fourth control valve 1433, the second connecting pipeline 1431 and the third discharge pipeline 1434 so as to replace oxygen in the oxygen gas path 103 with air.

In the process of purging the oxygen gas path 103 by the purge pump 141, since the hydrogen gas path 102 is at normal pressure, the purge pump 141 pressurizes the oxygen gas path 103, so that part of the hydrogen in the hydrogen gas path 102 can be consumed, and the hydrogen gas path 102 is in a micro negative pressure state. When the pressure of the hydrogen path 102 is not higher than the first set threshold P1, the first control valve 1422 and the third control valve 1432 are controlled to be opened, the duty ratio of the second control valve 1425 is regulated, the pressures of the hydrogen path 102 and the oxygen path 103 are controlled to be substantially equal, and the pressure is not higher than the second set threshold P2, so that the air in the hydrogen path 102 and the oxygen path 103 can be purged into the hydrogen elimination structure 150.

When the purge gas is nitrogen, the first control valve 1422, the second control valve 1423, the third control valve 1432, and the fourth control valve 1433 are controlled to be opened, and at this time, the hydrogen path 102 and the oxygen path 103 are both paths. The purge pump 141 is started, the rotation speed of the purge pump 141 and the duty ratio of the first regulating valve 1424 and the second regulating valve 1425 are regulated, the pressures of the hydrogen path 102 and the oxygen path 103 are controlled to be basically equal, and the pressure is not higher than a second set threshold value P2, so that nitrogen in the hydrogen path 102 and the oxygen path 103 can be purged into the hydrogen elimination structure 150.

After the purge gas in the hydrogen path 102 and the oxygen path 103 is purged to the hydrogen elimination structure 150, the rotation speed of the circulation regulating purge pump 141 is regulated, and the pressure disturbance is performed on the hydrogen path 102 and the oxygen path 103 through the change of the rotation speed, so as to rapidly purge the hydrogen and the oxygen in the blind-end hydrogen-oxygen fuel cell stack 110. When the single-chip voltage of the blind-end oxy-hydrogen fuel cell stack 110 is within the preset range, the first control valve 1422, the second control valve 1423, the third control valve 1432 and the fourth control valve 1433 are controlled to be closed, so that the purging of the blind-end oxy-hydrogen fuel cell stack 110 is completed.

The fuel cell system 100 of the application can realize the rapid purging of the underwater blind-end hydrogen-oxygen fuel cell stack 110 during the shutdown, avoid the long-time high-voltage open-circuit state of the blind-end hydrogen-oxygen fuel cell stack 110, reduce the open-circuit voltage of the blind-end hydrogen-oxygen fuel cell stack 110, and ensure the service performance and service life of the blind-end hydrogen-oxygen fuel cell stack 110. Moreover, the purge structure 140 adopts the purge pump 141 and a responsive valve as main power consumption devices, and only works when the blind-end hydrogen-oxygen fuel cell stack 110 is purged, so that the energy consumption of the fuel cell system 100 is reduced.

Meanwhile, the fuel cell system 100 does not carry a nitrogen gas bottle, and the blind-end hydrogen-oxygen fuel cell stack 110 is purged by using a purge gas prestored in an installation space of the underwater equipment. Different modes of purging can be performed according to different types of purging gases, so that the space in the underwater equipment is saved, more fuel and catalyst are carried, and the endurance mileage of the underwater equipment is improved.

Referring to fig. 5 and 6, fig. 6 is a flow chart of purging the fuel cell system 100 shown in fig. 5. The purging method of the fuel cell system 100 is applied to the fuel cell system 100 in any of the above embodiments, and the purging method at least includes the following steps:

Acquiring a shutdown instruction of the fuel cell system 100;

Controlling the hydrogen delivery structure 120 and the oxygen delivery structure 130 to be closed, and stopping delivering hydrogen and oxygen;

Judging whether the purge gas in the installation space where the fuel cell system 100 is located is air;

If yes, the control purge structure 140 first purges the oxygen delivery structure 130, and then purges the hydrogen delivery structure 120 and the oxygen delivery structure 130 at the same time;

If not, controlling the purging structure 140 to purge the hydrogen delivery structure 120 and the oxygen delivery structure 130 simultaneously;

performing cyclic purging on the hydrogen conveying structure 120 and the oxygen conveying structure 130;

Acquiring the single-chip voltage of the blind-end hydrogen-oxygen fuel cell stack 110, and judging whether the single-chip voltage is within a preset range;

If yes, controlling the purging structure to stop purging;

if not, the cyclic purging of the hydrogen delivery structure 120 and the oxygen delivery structure 130 is continued.

Upon receipt of a shutdown command by the fuel cell system 100, the hydrogen delivery structure 120 (hydrogen gas line 102) and the oxygen delivery structure 130 (oxygen gas line 103) will slowly be at a normal pressure, such as 101kpa (absolute, ABS). Subsequently, the hydrogen gas delivery structure 120 and the oxygen gas delivery structure 130 are closed, the hydrogen gas line 102 stops delivering hydrogen gas, and the oxygen gas line 103 stops delivering oxygen gas, i.e., the first on-off valve 122, the first regulating valve 1424, the first drain valve 128, the second on-off valve 132, the second regulating valve 1425, and the second drain valve 138 are closed.

At this time, hydrogen remains in the hydrogen path 102, and oxygen remains in the oxygen path 103, and the purge structure 140 is required to purge the hydrogen path 102 and the oxygen path 103 to replace the hydrogen in the hydrogen path 102 and the oxygen in the oxygen path 103 with purge gas. The installation space where the fuel cell system 100 is located stores a purge gas in advance, and the purge gas may be air or nitrogen. And judging whether the purge gas is air or not.

If the purge gas is air, the purge structure 140 needs to purge the second gas passage 131 (the oxygen passage 103) first. The purge structure 140 is disconnected from the first gas channel 121 (the hydrogen channel 102), air is firstly introduced into the oxygen channel 103, and the air flows in the oxygen channel 103 under pressure, so that hydrogen in the blind-end hydrogen-oxygen fuel cell stack 110 can be consumed, and the hydrogen channel 102 is in a micro-negative pressure state. Subsequently, the purge structure 140 supplies air to the hydrogen path 102 and the oxygen path 103, respectively, to purge the hydrogen path 102 and the oxygen path 103. If the purge gas is not air but nitrogen, the purge structure 140 may simultaneously supply nitrogen to the hydrogen path 102 and the oxygen path 103 to purge the hydrogen path 102 and the oxygen path 103.

Subsequently, the hydrogen path 102 and the oxygen path 103 are cyclically purged. During the cyclic purge, the average monolithic voltage of the dead-end hydrogen-oxygen fuel cell stack 110 is obtained. A preset range of the monolithic voltage is stored in the fuel system in advance, and it is determined whether the monolithic voltage of the blind-end hydrogen-oxygen fuel cell stack 110 is within the preset range. If the monolithic voltage is within the predetermined range, it indicates that the hydrogen and oxygen in the dead-end hydrogen-oxygen fuel cell stack 110 have displaced the purge gas.

If the monolithic voltage is outside the preset range, it indicates that the hydrogen and oxygen in the blind end hydrogen-oxygen fuel cell stack 110 are not completely replaced, and purging needs to be performed again. The continuous reciprocation is performed until the monolithic voltage is within a preset range, and the purging structure 140 is controlled to stop, namely, the first control valve 1422, the second control valve 1423, the third control valve 1432 and the fourth control valve 1433 are controlled to be closed, so that the purging of the blind-end oxyhydrogen fuel cell stack 110 is completed.

In this embodiment, the monolithic voltage is an average monolithic voltage and a highest monolithic voltage. The preset ranges of the average monolithic voltage and the highest monolithic voltage are stored in the fuel system in advance, and whether the average monolithic voltage and the highest monolithic voltage of the blind-end hydrogen-oxygen fuel cell stack 110 are within the preset ranges is judged.

If the average monolithic voltage and the highest monolithic voltage are within the predetermined ranges, it is indicated that the hydrogen and oxygen in the dead-end hydrogen-oxygen fuel cell stack 110 have displaced the purge gas. If the average monolithic voltage and the highest monolithic voltage are outside the preset range, it indicates that the hydrogen and oxygen in the blind end hydrogen-oxygen fuel cell stack 110 are not completely replaced, and purging needs to be performed again.

In this embodiment, the average monolithic voltage has a voltage value of less than 50mV and the highest monolithic voltage has a voltage value of not more than 80mV. Of course, in other embodiments of the present application, the average monolithic voltage and the highest monolithic voltage may be within other preset ranges, as long as the open circuit voltage of the blind end oxy-hydrogen fuel cell stack 110 can be reduced.

In other embodiments of the present application, the average monolithic voltage or the highest monolithic voltage may be used to determine whether the replacement of hydrogen and oxygen in the dead-end oxy-hydrogen fuel cell stack 110 is complete.

Referring to fig. 5 and 6, in one embodiment, the control purge structure 140 first purges the oxygen delivery structure 130 and then purges the hydrogen delivery structure 120 and the oxygen delivery structure 130 simultaneously, comprising the steps of:

The first control valve 1422 and the third control valve 1432 are closed, and the second control valve 1423 and the fourth control valve 1433 are opened;

Turning on the purge pump 141, adjusting the rotation speed of the purge pump 141 and the duty ratio of the second adjusting valve 1425, and purging the oxygen delivery structure 130;

Acquiring a first pressure of the gas in the hydrogen conveying structure 120, and judging whether the first pressure is smaller than or equal to a first set threshold value;

If yes, the first control valve 1422, the third control valve 1432 are opened;

if not, continuing to regulate the rotation speed of the purge pump 141 and the duty ratio of the second regulating valve 1425 to purge the oxygen delivery structure 130.

In the process of purging the oxygen path 103 by the purge pump 141, since the hydrogen path 102 is at normal pressure, the pressure difference between the oxygen path 103 and the hydrogen path 102 is a preset threshold Δp. The purge pump 141 pressurizes the oxygen line 103, and can consume part of the hydrogen in the hydrogen line 102, so that the hydrogen line 102 is in a state of micro negative pressure. When the pressure of the hydrogen path 102 is not higher than the first set threshold P1, the first control valve 1422 and the third control valve 1432 are controlled to be opened, the duty ratio of the second control valve 1425 is regulated, the pressures of the hydrogen path 102 and the oxygen path 103 are controlled to be substantially equal, and the pressure is not higher than the second set threshold P2, so that the air in the hydrogen path 102 and the oxygen path 103 can be purged into the hydrogen elimination structure 150.

In this embodiment, the preset threshold Δp is 30kpa (ABS), the first set threshold P1 is 30kpa (ABS), and the second set threshold P2 is 130kpa (ABS). Of course, in other embodiments of the present application, the preset threshold Δp, the first set threshold P1, and the second set threshold P2 may be other as long as purging of the blind-end hydrogen-oxygen fuel cell stack 110 can be achieved.

Referring to fig. 5 and 6, in one embodiment, controlling the purge structure 140 to purge the hydrogen delivery structure 120 and the oxygen delivery structure 130 simultaneously includes the steps of:

Opening the first control valve 1422, the third control valve 1432, the second control valve 1423, and the fourth control valve 1433;

the purge pump 141 is turned on, and the rotation speed of the purge pump 141 is regulated.

Subsequently, the hydrogen path 102 and the oxygen path 103 are cyclically purged.

Referring to fig. 5 and 6, in one embodiment, the cyclic purging of the hydrogen delivery structure 120 and the oxygen delivery structure 130 includes the steps of:

The duty ratio of the first regulating valve 1424 and the second regulating valve 1425 is regulated;

Controlling the pressure in the oxygen delivery structure 130 and the hydrogen delivery structure 120 to be equal and less than a second set threshold;

The purge pump 141 is controlled to purge for a first preset time at a first rotational speed, purge for a second preset time at a second rotational speed, and then purge for the first preset time at the first rotational speed, and sequentially circulate the purge;

After the purge gas of the hydrogen path 102 and the oxygen path 103 is blown to the hydrogen elimination structure 150, the pressure in the oxygen conveying structure 130 and the pressure in the hydrogen conveying structure 120 are equal and smaller than the second set threshold, at this time, the pressure disturbance is performed on the hydrogen path 102 and the oxygen path 103, so as to discharge the residual hydrogen and oxygen in the blind-end hydrogen-oxygen fuel cell stack 110, and realize rapid purging of the hydrogen and the oxygen in the blind-end hydrogen-oxygen fuel cell stack 110.

Specifically, the purge pump 141 purges the hydrogen path 102 and the oxygen path 103 for a first preset time at a first rotation speed, purges the hydrogen path 102 and the oxygen path 103 for a second preset time at a second rotation speed, purges the hydrogen path 102 and the oxygen path 103 for the first preset time at the first rotation speed, and sequentially and circularly purges. The pressure disturbance is performed on the hydrogen path 102 and the oxygen path 103 by varying the rotational speed. Optionally, the first preset time and the second preset time are both 5s or other times.

During the cyclic purge, the monolithic voltage of the dead-end hydrogen-oxygen fuel cell stack 110 is obtained. A preset range of the monolithic voltage is stored in the fuel system in advance, and it is determined whether the monolithic voltage of the blind-end hydrogen-oxygen fuel cell stack 110 is within the preset range. When the single-chip voltage of the blind-end oxy-hydrogen fuel cell stack 110 is within the preset range, the first control valve 1422, the second control valve 1423, the third control valve 1432 and the fourth control valve 1433 are controlled to be closed, so that the purging of the blind-end oxy-hydrogen fuel cell stack 110 is completed. If the monolithic voltage is outside the preset range, it indicates that the hydrogen and oxygen in the blind end hydrogen-oxygen fuel cell stack 110 are not completely replaced, and purging needs to be performed again.

The purging method of the fuel cell system 100 can realize that the underwater equipment with the fuel cell system 100 does not carry inert purging gas cylinders such as nitrogen and the like, saves the space of the fuel cell system 100, is used for carrying more fuel and catalyst, and improves the endurance mileage of the underwater equipment.

Moreover, the fast purging of the blind-end hydrogen-oxygen fuel cell stack 110 after receiving the shutdown instruction can be realized, so that the average single-chip voltage and the highest single-chip voltage of the blind-end hydrogen-oxygen fuel cell stack 110 are reduced to reasonable thresholds in a short time, the performance of the blind-end hydrogen-oxygen fuel cell stack 110 is protected, and the service life is prolonged.

Meanwhile, through the cooperation of the hydrogen elimination equipment in the underwater equipment, the too high concentration of hydrogen in the underwater equipment is avoided, so that the concentration of hydrogen in the underwater equipment is far lower than the lower limit of the hydrogen explosion value, and the safety of the operation of the underwater equipment is realized.

The present application also provides an underwater apparatus including an underwater host and the fuel cell system 100 in any of the above embodiments. The fuel cell system 100 is disposed on and powers an underwater host. After the fuel cell system 100 of the embodiment is adopted by the underwater equipment, the service performance and the service life of the blind-end hydrogen-oxygen fuel cell stack 110 can be ensured while the power is supplied to the underwater host, the space in the underwater equipment is saved, more fuel and catalyst are carried, and the endurance mileage of the underwater equipment is improved.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the application, which are described in detail and are not to be construed as limiting the scope of the claims. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of protection of the present application is to be determined by the appended claims.

Claims

1. A fuel cell system, characterized in that it comprises:

Blind-end hydrogen-oxygen fuel cell stack;

The hydrogen delivery structure includes a first gas passage, a first on/off valve, and a first discharge pipeline. The first gas passage and the first discharge pipeline are respectively located at both ends of the blind-end hydrogen-oxygen fuel cell stack, and the first on/off valve is located in the first gas passage.

An oxygen delivery structure includes a second gas passage, a second on/off valve, and a second discharge pipeline. The second gas passage and the second discharge pipeline are respectively located at both ends of the blind-end hydrogen-oxygen fuel cell stack, and the second on/off valve is located in the second gas passage.

The purging structure is at least connected to the first gas passage and the second gas passage. When the fuel cell system is shut down, the purging structure can supply purging gas to the first gas passage and the second gas passage. The purging gas is pre-stored in the installation space of the fuel cell system.

2. The fuel cell system according to claim 1, wherein the purging structure comprises a purging pump, a first purging assembly, and a second purging assembly;

The first purging assembly connects the first gas passage and the second gas passage, and is located between the first on/off valve and the blind-end hydrogen-oxygen fuel cell stack;

The second purging assembly connects the first discharge pipe and the second discharge pipe;

The purge pump is connected to the first purge assembly and controls the first purge assembly and the second purge assembly to purge at least one of the first gas passage and the second gas passage.

3. The fuel cell system according to claim 2, wherein the first purging assembly includes a first connecting pipe, a first control valve and a second control valve, the first connecting pipe connects the first gas passage and the second gas passage, the first control valve and the second control valve are spaced apart in the first connecting pipe, and the purging pump is connected between the first control valve and the second control valve;

The second purging assembly includes a second connecting pipe, a third control valve, a fourth control valve, and a third discharge pipe. The second connecting pipe connects the first discharge pipe and the second discharge pipe. The third control valve and the fourth control valve are spaced apart in the second connecting pipe. The third discharge pipe is connected to the second connecting pipe.

4. The fuel cell system according to claim 2, wherein the purging structure uses air as the purging gas, and the purging pump first purifies the second gas passage through the first purging component and the second purging component, and then simultaneously purifies the first gas passage and the second gas passage;

Alternatively, the purging structure uses nitrogen as the purging gas, and the purging pump simultaneously purifies the first gas passage and the second gas passage through the first purging component and the second purging component.

5. The fuel cell system according to claim 2, wherein the hydrogen delivery structure further includes two first temperature and pressure detection devices, the two first temperature and pressure detection devices being respectively disposed in the first gas passage and the first discharge pipeline, and disposed close to the blind end hydrogen-oxygen fuel cell stack;

The oxygen delivery structure also includes two second temperature and pressure detection devices, which are respectively disposed in the second gas passage and the second discharge pipeline, and are located near the blind end hydrogen-oxygen fuel cell stack.

6. The fuel cell system according to claim 2, wherein the hydrogen delivery structure further includes a first pressure detection element, the first pressure detection element being disposed in the first gas passage and located between the first on/off valve and the first purging assembly;

The oxygen delivery structure further includes a second pressure detection element, which is disposed in the second gas passage and located between the second on/off valve and the first purging assembly.

7. The fuel cell system according to claim 2, wherein the hydrogen delivery structure further comprises a first separator and a first drain valve, the first drain valve being disposed in the first discharge pipeline and located on the side of the second purging assembly away from the blind end hydrogen-oxygen fuel cell stack, and the first separator being disposed in the first discharge pipeline and located between the second purging assembly and the first drain valve;

The oxygen delivery structure further includes a second separator and a second drain valve. The second drain valve is disposed in the second discharge pipeline and located on the side of the second purging assembly away from the blind end hydrogen-oxygen fuel cell stack. The second separator is disposed in the second discharge pipeline and located between the second purging assembly and the second drain valve.

8. The fuel cell system according to claim 2, wherein the fuel cell system further comprises a hydrogen elimination structure, the hydrogen elimination structure being connected to the third discharge pipeline of the second purging assembly.

9. The fuel cell system according to any one of claims 2 to 8, wherein the first purging assembly further comprises a first regulating valve and a second regulating valve, the first regulating valve being disposed in the first gas passage and located between the first purging assembly and the blind-end hydrogen-oxygen fuel cell stack;

The second regulating valve is disposed in the second gas passage and located between the first purging assembly and the blind-end hydrogen-oxygen fuel cell stack.

10. An underwater device, characterized in that it comprises an underwater main unit and a fuel cell system as described in any one of claims 1 to 9;

The fuel cell system is installed on the underwater host and supplies power to the underwater host.