Underwater equipment and fuel cell system

Abstract

The utility model relates to underwater equipment and a fuel cell system. The fuel cell system comprises: a blind-end hydrogen-oxygen fuel cell stack; the hydrogen conveying structure, the first gas passage and the first discharge pipeline are respectively arranged at two ends of the blind-end hydrogen-oxygen fuel cell stack, and the first on-off valve is arranged on the first gas passage; the oxygen conveying structure, the second gas passage and the second discharge pipeline are respectively arranged at two ends of the blind-end hydrogen-oxygen fuel cell stack; the second on-off valve is arranged on the second gas passage; and 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, and the purging gas is stored in the mounting space of the fuel cell system in advance. Therefore, no residual hydrogen and oxygen 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 a high-voltage open-circuit state for a long time, and a nitrogen cylinder for providing purging gas does not need to be specially carried.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of underwater fuel cell safety management, in particular to an underwater device and a fuel cell system. BACKGROUND

[0002] At present, the hydrogen-oxygen fuel cell uses hydrogen as fuel and oxygen as oxidant, and directly converts the chemical energy of fuel into electrical energy through an electrochemical reaction, which is not limited by the Carnot cycle, and the power generation efficiency is as high as 50%-60%. Moreover, the reaction product is only water, which has the characteristics of green and high efficiency, and is a promising energy conversion system.

[0003] Generally, the application scenarios of the hydrogen-oxygen fuel cell are mainly road vehicles and combined heat and power fixed power generation. However, in special subfields, the hydrogen-oxygen fuel cell is more suitable as a power system of an UUV (underwater unmanned underwater vehicle), which has the advantages of high power density, long cruising range, light weight, etc. compared with a lithium electric power system; and has the advantages of small vibration noise and almost no tail exhaust, etc. compared with a gas engine power system.

[0004] In a closed underwater scene, due to the small volume and narrow internal space of the unmanned underwater vehicle, higher requirements are put forward for the spatial layout and power generation efficiency of the fuel cell system.

[0005] In order to improve the power generation efficiency, the fuel cell system needs to reduce the accessory power consumption as much as possible. The dead-end hydrogen-oxygen fuel cell (Dead-end PEMFC) configuration is suitable for a fuel cell system with small output power, which directly uses high-pressure hydrogen bottles and high-pressure oxygen bottles for pressure reduction supply, without gas circulation, and the reaction water is discharged through gravity, which cancels the use of a gas circulation pump and greatly reduces the system energy consumption.

[0006] However, there is also a disadvantage that the fuel cell system cannot be blown by the gas circulation pump when it is stopped, so that the fuel cell stack is in a high-voltage open circuit state for a long time, which will cause irreversible damage to the membrane electrode, such as carbon corrosion and platinum oxidation. In addition, in order to improve the internal space utilization rate of the hydrogen-oxygen fuel cell unmanned underwater vehicle and improve the cruising range as much as possible, enough space is usually left for the fuel carrying space of the high-pressure hydrogen bottle and the high-pressure oxygen bottle, and a nitrogen bottle for stoppage blowing is not carried, which affects the realization of stoppage blowing of the fuel cell system. Practical new type content

[0007] Therefore, it is necessary to provide an underwater equipment and fuel cell system to avoid the blind end hydrogen-oxygen fuel cell stack from being in a high voltage open circuit state for a long time, ensure the use performance and service life of the blind end hydrogen-oxygen fuel cell stack, and reduce the volume and structural complexity of the fuel cell system without carrying a nitrogen cylinder for providing a purge gas.

[0008] A fuel cell system comprises:

[0009] a blind end hydrogen-oxygen fuel cell stack;

[0010] a hydrogen gas delivery structure comprising a first gas passage, a first on-off valve and a first exhaust pipeline, the first gas passage and the first exhaust pipeline being arranged at two ends of the blind end hydrogen-oxygen fuel cell stack, and the first on-off valve being arranged in the first gas passage;

[0011] an oxygen gas delivery structure comprising a second gas passage, a second on-off valve and a second exhaust pipeline, the second gas passage and the second exhaust pipeline being arranged at the two ends of the blind end hydrogen-oxygen fuel cell stack, and the second on-off valve being arranged in the second gas passage;

[0012] a purge structure being communicated with at least the first gas passage and the second gas passage, and capable of supplying a purge gas to the first gas passage and the second gas passage when the fuel cell system is shut down, the purge gas being stored in advance in a mounting space of the fuel cell system.

[0013] In an embodiment of the present application, the purge structure comprises a purge pump, a first purge assembly and a second purge assembly.

[0014] The first purge assembly is communicated with 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.

[0015] The second purge assembly is communicated with the first exhaust pipeline and the second exhaust pipeline.

[0016] The purge pump is communicated 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 passage and the second gas passage.

[0017] In an embodiment of the present application, the first purge assembly comprises a first connecting pipeline, a first control valve and a second control valve, the first connecting pipeline is communicated with the first gas passage and the second gas passage, the first control valve and the second control valve are arranged in the first connecting pipeline, and the purge pump is communicated between the first control valve and the second control valve.

[0018] The second purge assembly comprises a second connecting pipeline, a third control valve, a fourth control valve and a third discharge pipeline, the second connecting pipeline is connected with the first discharge pipeline and the second discharge pipeline, the third control valve and the fourth control valve are arranged in the second connecting pipeline, and the third discharge pipeline is connected with the second connecting pipeline.

[0019] In an embodiment of the present application, air is used as the purge gas in the purge structure, and the purge pump first purges the second gas passage through the first purge assembly and the second purge assembly, and then simultaneously purges the first gas passage and the second gas passage through the first purge assembly and the second purge assembly.

[0020] Alternatively, nitrogen is used as the purge gas in the purge structure, and the purge pump simultaneously purges the first gas passage and the second gas passage through the first purge assembly and the second purge assembly.

[0021] In an embodiment of the present application, the hydrogen delivery structure further comprises two first temperature and pressure detection members, and the two first temperature and pressure detection members are arranged in the first gas passage and the first discharge pipeline respectively and close to the blind-end hydrogen-oxygen fuel cell stack.

[0022] The oxygen delivery structure further comprises two second temperature and pressure detection members, and the two second temperature and pressure detection members are arranged in the second gas passage and the second discharge pipeline respectively and close to the blind-end hydrogen-oxygen fuel cell stack.

[0023] In an embodiment of the present application, the hydrogen delivery structure further comprises a first pressure detection member, and the first pressure detection member is arranged in the first gas passage and between the first on-off valve and the first purge assembly.

[0024] The oxygen delivery structure further comprises a second pressure detection member, and the second pressure detection member is arranged in the second gas passage and between the second on-off valve and the first purge assembly.

[0025] In an embodiment of the present application, the hydrogen delivery structure further comprises a first separator and a first drain valve, the first drain valve is arranged in the first discharge pipeline and on the side of the second purge assembly away from the blind-end hydrogen-oxygen fuel cell stack, and the first separator is arranged in the first discharge pipeline and between the second purge assembly and the first drain valve.

[0026] The oxygen delivery structure further comprises a second separator and a second drain valve, the second drain valve is arranged in the second exhaust pipeline and is located on the side of the second purge assembly away from the blind-end hydrogen-oxygen fuel cell stack, and the second separator is arranged in the second exhaust pipeline and is located between the second purge assembly and the second drain valve.

[0027] In an embodiment of the present application, the fuel cell system further comprises a hydrogen removal structure, which communicates with a third exhaust pipeline of the second purge assembly.

[0028] In an embodiment of the present application, the first purge assembly further comprises a first regulating valve and a second regulating valve, the first regulating valve is arranged in the first gas passage and is located between the first purge assembly and the blind-end hydrogen-oxygen fuel cell stack;

[0029] The second regulating valve is arranged in the second gas passage and is located between the first purge assembly and the blind-end hydrogen-oxygen fuel cell stack.

[0030] A purging method of a fuel cell system, applied to the fuel cell system as described in any of the above technical features, the purging method at least comprises the following steps:

[0031] Obtaining a shutdown instruction of the fuel cell system;

[0032] Controlling a hydrogen delivery structure and an oxygen delivery structure to be closed and stop delivering hydrogen and oxygen;

[0033] Determining whether the purging gas in the installation space where the fuel cell system is located is air;

[0034] If yes, controlling the purging structure to first purge the oxygen delivery structure and then simultaneously purge the hydrogen delivery structure and the oxygen delivery structure;

[0035] If no, controlling the purging structure to simultaneously purge the hydrogen delivery structure and the oxygen delivery structure;

[0036] Circulating purging the hydrogen delivery structure and the oxygen delivery structure;

[0037] Obtaining a single-piece voltage of a blind-end hydrogen-oxygen fuel cell stack and determining whether the single-piece voltage is within a preset range;

[0038] If yes, controlling the purging structure to stop purging;

[0039] If no, continuing to circulate purging the hydrogen delivery structure and the oxygen delivery structure;

[0040] The single-piece voltage is an average single-piece voltage and / or a highest single-piece voltage.

[0041] In an embodiment of the present application, the control of the purging structure purging the oxygen gas delivery structure first, and then purging the hydrogen gas delivery structure and the oxygen gas delivery structure simultaneously, comprises the following steps:

[0042] closing the first control valve and the third control valve, and opening the second control valve and the fourth control valve;

[0043] starting the purging pump, adjusting the rotating speed of the purging pump and the duty cycle of the second adjusting valve, and purging the oxygen gas delivery structure;

[0044] acquiring the first pressure of the gas in the hydrogen gas delivery structure, and determining whether the first pressure is less than or equal to a first set threshold value;

[0045] if yes, opening the first control valve and the third control valve;

[0046] if no, continuing to adjust the rotating speed of the purging pump and the duty cycle of the second adjusting valve, and purging the oxygen gas delivery structure.

[0047] In an embodiment of the present application, the control of the purging structure purging the hydrogen gas delivery structure and the oxygen gas delivery structure simultaneously, comprises the following steps:

[0048] opening the first control valve, the third control valve, the second control valve and the fourth control valve;

[0049] starting the purging pump, and adjusting the rotating speed of the purging pump.

[0050] In an embodiment of the present application, the purging of the hydrogen gas delivery structure and the oxygen gas delivery structure is cyclic, comprising the following steps:

[0051] adjusting the duty cycle of the first adjusting valve and the second adjusting valve;

[0052] controlling the pressure in the oxygen gas delivery structure and the hydrogen gas delivery structure to be equal and less than a second set threshold value;

[0053] controlling the purging pump to rotate at a first rotating speed for a first preset time, at a second rotating speed for a second preset time, and then at the first rotating speed for the first preset time, and cyclically purging in turn;

[0054] wherein the first rotating speed is different from the second rotating speed.

[0055] An underwater device comprising an underwater main machine and a fuel cell system as claimed in any one of the preceding technical features;

[0056] The fuel cell system is arranged in the underwater main machine and supplies power to the underwater main machine.

[0057] By adopting the above technical solution, this application has at least the following technical effects:

[0058] The underwater equipment and fuel cell system of this application include a hydrogen delivery structure in which a first gas passage and a first discharge pipe connect to both ends of a blind-end hydrogen-oxygen fuel cell stack, and a first on / off valve controls the opening and closing of the first gas passage. Similarly, an oxygen delivery structure in which a second gas passage and a second discharge pipe connect to both ends of a blind-end hydrogen-oxygen fuel cell stack, and a second on / off valve controls the opening and closing of the second gas passage. A purging structure is designed to connect at least the first and second gas passages to supply purging gas to both passages, and the purging gas is pre-stored in the installation space of the fuel cell system.

[0059] When the fuel cell system is shut down, the purging structure introduces purge gas into the first and second gas passages. This purge gas allows hydrogen to exit through the first gas passage, the blind-end hydrogen-oxygen fuel cell stack, the first discharge line, and the purging structure, while oxygen exits through the second gas passage, the blind-end hydrogen-oxygen fuel cell stack, the second discharge line, and the purging structure. After purging the blind-end hydrogen-oxygen fuel cell stack following shutdown, no residual hydrogen or oxygen remains, preventing irreversible damage such as carbon corrosion and platinum oxidation to the membrane electrode assembly. This also prevents the blind-end hydrogen-oxygen fuel cell stack from being in a high-voltage open-circuit state for extended periods, ensuring its performance and lifespan. Furthermore, the purging structure uses gas pre-stored in the fuel cell system's built-in installation space as the purge gas, eliminating the need for a dedicated nitrogen cylinder for providing purge gas and reducing the size and structural complexity of the fuel cell system. Attached Figure Description

[0060] Figure 1 This is a schematic diagram of a fuel cell system according to an embodiment of this application.

[0061] Figure 2 for Figure 1 The diagram shown illustrates the purging structure of the fuel cell system.

[0062] Figure 3 for Figure 1 The diagram shows a partial schematic of the fuel cell system at point A.

[0063] Figure 4 for Figure 1 The diagram shows a partial view of the fuel cell system at point B.

[0064] Figure 5 for Figure 1 The diagram shows the flow of purge gas in the fuel cell system.

[0065] Figure 6 for Figure 5A purge flow chart of the fuel cell system.

[0066] Wherein: 100, fuel cell system; 110, blind end hydrogen-oxygen fuel cell stack; 120, hydrogen delivery structure; 102, hydrogen path; 121, first gas passage; 122, first on-off valve; 123, first discharge pipeline; 124, high-pressure hydrogen cylinder; 125, first temperature and pressure detection element; 126, first pressure detection element; 127, first separator; 128, first drain valve; 130, oxygen delivery structure; 103, oxygen path; 131, second gas passage; 132, second on-off valve; 133, second discharge pipeline; 134, high-pressure oxygen cylinder; 135, second temperature and pressure detection element; 136, second pressure detection element; 137, second separator; 138, second drain valve; 140, purge structure; 141, purge pump; 142, first purge assembly; 1421, first connecting pipeline; 1422, first control valve; 1423, second control valve; 1424, first regulating valve; 1425, second regulating valve; 143, second purge assembly; 1431, second connecting pipeline; 1432, third control valve; 1433, fourth control valve; 1434, third discharge pipeline; 150, hydrogen removal structure. DETAILED DESCRIPTION

[0067] In order to make the above objectives, features and advantages of the present application more apparent, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in a number of different ways beyond the specific embodiments described and it is therefore contemplated that the present application not be limited to the embodiments set forth in the following description.

[0068] In the description of the present application, it should be understood that if there are terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0069] In addition, the terms "first", "second", and the like, if any, are used herein for descriptive purposes only and should not be construed as indicating or implying relative importance or implicating the number of indicated technical features. Thus, a feature defined with "first", "second" may include at least one of the features explicitly or implicitly. In the description of the present application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise explicitly specified and limited.

[0070] In the present application, unless otherwise explicitly specified and limited, if the terms "mounting", "connecting", "connecting", "fixing" and the like appear, these terms should be interpreted broadly. For example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0071] In the present application, unless otherwise explicitly specified and limited, if the first feature is described as "on" or "under" the second feature, etc., it can mean that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be directly above or obliquely above the second feature, or simply indicate that the first feature is higher than the second feature in horizontal height. The first feature "below", "below" and "below" the second feature can be directly below or obliquely below the second feature, or simply indicate that the first feature is lower than the second feature in horizontal height.

[0072] It should be noted that if an element is referred to as "fixed to" or "disposed on" another element, it can be directly on another element or there can be a middle element. If an element is considered to be "connected" to another element, it can be directly connected to another element or there can be a middle element. If present, the terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used in the present application are only for illustrative purposes and do not represent the only implementation.

[0073] It can be understood that, in the underwater sealed scene, the fuel cell system is applied to the unmanned underwater vehicle to supply power for the unmanned underwater vehicle. In order to improve the power generation efficiency, the dead-end hydrogen-oxygen fuel cell (Dead-end PEMFC) configuration is usually suitable for the fuel cell system with small output power. However, the fuel cell system cannot be purged by the gas circulating pump when it is stopped, so that the fuel cell stack is in the open circuit state of high voltage for a long time, which can cause irreversible damage to the membrane electrode. In addition, in order to improve the internal space utilization rate of the hydrogen-oxygen fuel cell unmanned underwater vehicle, a nitrogen cylinder for supplying gas for shutdown purge is usually not carried, which affects the realization of shutdown purge of the fuel cell system.

[0074] For this purpose, referring to Figure 1 The present application provides a new type of fuel cell system 100. Figure 1 The schematic diagram of the fuel cell system 100 of an embodiment of the present application. The fuel cell system 100 is mainly applied to underwater equipment to supply power for the underwater main body of the underwater equipment to ensure that the underwater equipment operates in the water environment. Optionally, the underwater equipment includes but is not limited to unmanned underwater vehicles, and can also be other equipment that needs to use the fuel cell system 100 under water.

[0075] 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 being in the open circuit state of high voltage for a long time, ensure the use performance and service life of the dead-end hydrogen-oxygen fuel cell stack 110, and at the same time, without the need to specially carry a nitrogen cylinder for providing purge gas, reduce the volume and structural complexity of the fuel cell system 100.

[0076] The specific structure of the fuel cell system 100 of an embodiment is introduced below.

[0077] Referring to Figures 1 to 4 In an embodiment, the fuel cell system 100 includes a dead-end hydrogen-oxygen fuel cell stack 110, a hydrogen gas delivery structure 120, an oxygen gas delivery structure 130, and a purge structure 140. The hydrogen gas delivery structure 120 includes a first gas passage 121, a first on-off valve 122, and a first exhaust pipeline 123, the first gas passage 121 and the first exhaust pipeline 123 are arranged at two ends of the dead-end hydrogen-oxygen fuel cell stack 110, and the first on-off valve 122 is arranged in the first gas passage 121. The oxygen gas delivery structure 130 includes a second gas passage 131, a second on-off valve 132, and a second exhaust pipeline 133, the second gas passage 131 and the second exhaust pipeline 133 are arranged at two ends of the dead-end hydrogen-oxygen fuel cell stack 110, and the second on-off valve 132 is arranged in the second gas passage 131.

[0078] The purge structure 140 is connected to at least the first gas passage 121 and the second gas passage 131, and is capable of supplying purge gas to the first gas passage 121 and the second gas passage 131 when the fuel cell system 100 is stopped, the purge gas being stored in advance in the installation space of the fuel cell system 100. Figure 2 As shown in FIG. 1, the fuel cell system 100 includes a blind-end hydrogen-oxygen fuel cell stack 110, a fuel gas supply device 120, a purge structure 140, an air supply device 130, a water discharge device 150, a control device 160, and a power management device 170. Figure 1 As shown in FIG. 1, the fuel cell system 100 includes a blind-end hydrogen-oxygen fuel cell stack 110, a fuel gas supply device 120, a purge structure 140, an air supply device 130, a water discharge device 150, a control device 160, and a power management device 170. Figure 3 As shown in FIG. 1, the fuel cell system 100 includes a blind-end hydrogen-oxygen fuel cell stack 110, a fuel gas supply device 120, a purge structure 140, an air supply device 130, a water discharge device 150, a control device 160, and a power management device 170. Figure 1 As shown in FIG. 1, the fuel cell system 100 includes a blind-end hydrogen-oxygen fuel cell stack 110, a fuel gas supply device 120, a purge structure 140, an air supply device 130, a water discharge device 150, a control device 160, and a power management device 170. Figure 4 As shown in FIG. 1, the fuel cell system 100 includes a blind-end hydrogen-oxygen fuel cell stack 110, a fuel gas supply device 120, a purge structure 140, an air supply device 130, a water discharge device 150, a control device 160, and a power management device 170. Figure 1 As shown in FIG. 1, the fuel cell system 100 includes a blind-end hydrogen-oxygen fuel cell stack 110, a fuel gas supply device 120, a purge structure 140, an air supply device 130, a water discharge device 150, a control device 160, and a power management device 170.

[0079] The blind-end hydrogen-oxygen fuel cell stack 110 is the main component of the fuel cell system 100 in which electrochemical reactions occur. The blind-end hydrogen-oxygen fuel cell stack 110 is formed 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 blind-end hydrogen-oxygen fuel cell stack 110 through the anode and reaches the inside of the stack, where hydrogen atoms lose electrons to become protons under the action of a catalyst, and the protons pass through a membrane electrode inside the blind-end hydrogen-oxygen fuel cell stack 110 to reach the cathode.

[0080] Meanwhile, electrons reach the cathode through an external circuit of the blind-end hydrogen-oxygen fuel cell stack 110. At the cathode, the protons, electrons, and oxygen combine to form liquid water, thereby generating an electric current. Hydrogen and oxygen undergo electrochemical reactions in the blind-end hydrogen-oxygen fuel cell stack 110 to produce liquid water, which is discharged through a flow channel inside the blind-end hydrogen-oxygen fuel cell stack 110.

[0081] Furthermore, the blind-end hydrogen-oxygen fuel cell stack 110 refers to a ratio of the amount of hydrogen entering the anode to the amount of oxygen entering the cathode being 1, and the pressure at the anode being slightly higher than the pressure at the cathode. In this way, hydrogen and oxygen undergo electrochemical reactions in the blind-end hydrogen-oxygen fuel cell stack 110 according to the molar ratio of the hydrogen-oxygen chemical reaction, without circulation of hydrogen and oxygen, and without power consumption of circulation components, thereby improving the system efficiency of the fuel cell system 100.

[0082] The blind-end hydrogen-oxygen fuel cell stack 110 has a first channel for transporting hydrogen and generated liquid water, and a second channel for transporting oxygen and generated liquid water. It is worth noting that the focus of the present application is on purging the blind-end hydrogen-oxygen fuel cell stack 110 using the purge structure 140, and the specific structure of the blind-end hydrogen-oxygen fuel cell stack 110 and the principle of electrochemical reactions are prior art, which will not be described in detail hereinafter.

[0083] The hydrogen delivery structure 120 is a structure for delivering hydrogen and discharging liquid water. Specifically, in the hydrogen delivery structure 120, the first gas passage 121 and the first discharge pipeline 123 are arranged at two ends of the blind end hydrogen-oxygen fuel cell stack 110, the first gas passage 121 is connected to the hydrogen inlet end of the blind end hydrogen-oxygen fuel cell stack 110, and the first discharge pipeline 123 is connected to the hydrogen outlet end of the blind end hydrogen-oxygen fuel cell stack 110. That is, the first gas passage 121, the first channel of the blind end hydrogen-oxygen fuel cell stack 110, and the first discharge pipeline 123 are communicated to form the hydrogen path 102. The first on-off valve 122 is arranged in the first gas passage 121 to control the opening and closing of the first gas passage 121.

[0084] 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 discharge pipeline 133 are arranged at two ends of the blind end hydrogen-oxygen fuel cell stack 110, the second gas passage 131 is connected to the oxygen inlet end of the blind end hydrogen-oxygen fuel cell stack 110, and the second discharge pipeline 133 is connected to the oxygen outlet end of the blind end hydrogen-oxygen fuel cell stack 110. That is, the second gas passage 131, the second channel of the blind end hydrogen-oxygen fuel cell stack 110, and the second discharge pipeline 133 are communicated to form the oxygen path 103. The second on-off valve 132 is arranged in the second gas passage 131 to control the opening and closing of the second gas passage 131.

[0085] After the hydrogen is delivered to the blind end hydrogen-oxygen fuel cell stack 110 by the first gas passage 121 and the oxygen is delivered to the blind end hydrogen-oxygen fuel cell stack 110 by the second gas passage 131, the hydrogen and the oxygen undergo an electrochemical reaction in the blind end 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 to avoid damage caused by the accumulation of liquid water.

[0086] Generally, the blind end hydrogen-oxygen fuel cell stack 110 discharges the liquid water generated by the electrochemical reaction through the first discharge pipeline 123 and the second discharge pipeline 133. Only when the average single piece voltage or the lowest single piece voltage of the blind end hydrogen-oxygen fuel cell stack 110 is lower than a certain threshold value, the first discharge pipeline 123 and the second discharge pipeline 133 discharge hydrogen and oxygen, respectively.

[0087] When the fuel cell system 100 is shut down, the first on-off valve 122 is controlled to shut off the first gas passage 121, and the second on-off valve 132 is controlled to shut off the second gas passage 131. At this time, the first gas passage 121 does not transport hydrogen, the second gas passage 131 does not transport oxygen, and the blind end hydrogen-oxygen fuel cell stack 110 does not have electrochemical reaction. However, there are residual hydrogen and oxygen in the blind end hydrogen-oxygen fuel cell stack 110. The hydrogen and oxygen are pure hydrogen and pure oxygen, which react with the catalyst of the membrane electrode, resulting in a large open circuit voltage of the pure hydrogen and pure oxygen in the blind end hydrogen-oxygen fuel cell stack 110, affecting the service life of the membrane electrode.

[0088] Therefore, the fuel cell system 100 of the present application further has a purge structure 140, which is connected to the first gas passage 121 and the second gas passage 131. The purge of the present application is actually a shutdown purge. Hereinafter, the purge is replaced by the shutdown purge. When the fuel cell system 100 is shut down, the purge structure 140 can work to output purge gas, which can enter the blind end hydrogen-oxygen fuel cell stack 110 to discharge hydrogen and oxygen from the blind end hydrogen-oxygen fuel cell stack 110. That is, the purge gas is used to replace the hydrogen and oxygen in the blind end hydrogen-oxygen fuel cell stack 110.

[0089] After the blind end hydrogen-oxygen fuel cell stack 110 is purged, only the purge gas exists in the blind end hydrogen-oxygen fuel cell stack 110, which does not react with the catalyst of the membrane electrode, reduces the open circuit voltage of the blind end fuel cell stack, ensures the service life of the membrane electrode, and further ensures the service performance and life of the blind end fuel cell stack.

[0090] Of course, the purge structure 140 is also connected to the first discharge pipeline 123 and the second discharge pipeline 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.

[0091] Meanwhile, when the fuel cell system 100 is applied to underwater equipment, the installation space of the fuel cell system 100 is a closed space, and the purge gas is pre-charged in the installation space. When the fuel cell system 100 is shut down, the purge structure 140 can use the purge gas in the installation space to purge the blind end hydrogen-oxygen fuel cell stack 110, without the need to carry a nitrogen cylinder for supplying purge gas, thereby reducing the overall volume of the fuel cell system 100 and the complexity of the structure of the fuel cell system 100.

[0092] When the fuel cell system 100 of the above embodiment is shut down, the purge structure 140 is capable of passing purge gas into the first gas passage 121 and the second gas passage 131, and the purge gas is capable of expelling hydrogen from the first gas passage 121, the blind end hydrogen-oxygen fuel cell stack 110, the first exhaust pipeline 123 and the purge structure 140, and expelling oxygen from the second gas passage 131, the blind end hydrogen-oxygen fuel cell stack 110, the second exhaust pipeline 133 and the purge structure 140.

[0093] In this way, there is no residual hydrogen and oxygen in the blind end hydrogen-oxygen fuel cell stack 110, which avoids irreversible damage to the membrane electrode, such as carbon corrosion and platinum oxidation, and further avoids the blind end hydrogen-oxygen fuel cell stack 110 being in a high-voltage open circuit state for a long time, thereby ensuring the use performance and service life of the blind end hydrogen-oxygen fuel cell stack 110. At the same time, the purge structure 140 uses the gas stored in advance in the installation space of the fuel cell system 100 as the purge gas, without the need to specially carry a nitrogen cylinder for providing the purge gas, thereby reducing the volume and structural complexity of the fuel cell system 100.

[0094] Referring to Figures 1 to 3 In an embodiment, the hydrogen delivery structure 120 further includes a high-pressure hydrogen cylinder 124, which is connected to the first gas passage 121. The high-pressure hydrogen cylinder 124 is a cylinder body for storing high-pressure hydrogen. The high-pressure hydrogen cylinder 124 is capable of delivering hydrogen to the first channel (not mentioned hereinafter) of the blind end hydrogen-oxygen fuel cell stack 110 through the first gas passage 121.

[0095] Referring to Figures 1 to 3 In an embodiment, the oxygen delivery structure 130 further includes a high-pressure oxygen cylinder 134, which is connected to the second gas passage 131. The high-pressure oxygen cylinder 134 is a cylinder body for storing high-pressure oxygen. The high-pressure oxygen cylinder 134 is capable of delivering oxygen to the second channel (not mentioned hereinafter) of the blind end hydrogen-oxygen fuel cell stack 110 through the second gas passage 131.

[0096] In an 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 can also be other valves capable of realizing on-off control.

[0097] In one embodiment, the purging structure 140 uses air as the purging gas, and the purging pump 141 purges the second gas passage 131 first, and then purges the first gas passage 121 and the second gas passage 131 simultaneously through the first purging assembly 142 and the second purging assembly 143. Alternatively, when the purging structure 140 uses nitrogen as the purging gas, the purging pump 141 purges the first gas passage 121 and the second gas passage 131 simultaneously through the first purging assembly 142 and the second purging assembly 143. The fuel cell system 100 of the present application can use air as the purging gas, or can use nitrogen as the purging gas.

[0098] When air is used as the purging gas, the second gas passage 131 (hereinafter, only the oxygen path 103 is used as an example) needs to be purged first. This is because air contains oxygen, and if air is first introduced into the first gas passage 121 (hereinafter, only the hydrogen path 102 is used as an example) for purging, the oxygen in the air will react with the hydrogen in the hydrogen path 102, and purging of the blind end hydrogen-oxygen fuel cell stack 110 cannot be achieved.

[0099] The purging structure 140 is disconnected from the hydrogen path 102, air is first introduced into the oxygen path 103, and the air flows in the oxygen path 103 under pressure, which can consume the hydrogen in the blind end hydrogen-oxygen fuel cell stack 110, so that the hydrogen path 102 is in a state of micro-negative pressure. Subsequently, the purging structure 140 delivers air to the hydrogen path 102 and the oxygen path 103 respectively, so as to purge the hydrogen path 102 and the oxygen path 103. After purging is completed, the purging structure 140 stops working.

[0100] When nitrogen is used as the purging gas, since nitrogen does not react with hydrogen and oxygen, the purging structure 140 can deliver nitrogen to the hydrogen path 102 and the oxygen path 103 simultaneously. Specifically, the purging structure 140 delivers nitrogen to the hydrogen path 102 and the oxygen path 103 respectively, so as to purge the hydrogen path 102 and the oxygen path 103. After purging is completed, the purging structure 140 stops working.

[0101] In order to better illustrate the specific structure of the purging structure 140, only the case where the purging structure 140 simultaneously delivers purging gas to the hydrogen path 102 and the oxygen path 103 is described here. Whether the purging gas is air or nitrogen will be described in detail when the purging process and the purging method of the fuel cell system 100 are described.

[0102] Referring to Figures 1 to 4In an 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 is connected between the first gas passage 121 and the second gas passage 131 and between the first on-off valve 122 and the blind end hydrogen-oxygen fuel cell stack 110. The second purge assembly 143 is connected between the first exhaust pipeline 123 and the second exhaust pipeline 133. The purge pump 141 is connected to 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.

[0103] One end of the first purge assembly 142 is connected to the first gas passage 121 and 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 assembly 142 is connected to the second gas passage 131 and 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 connected to the first purge assembly 142.

[0104] In this way, the purge pump 141 can deliver the purge gas to the hydrogen path 102 and the oxygen path 103 through the first purge assembly 142. One end of the second purge assembly 143 is connected to the first exhaust pipeline 123, and the other end of the second purge assembly 143 is connected to the second exhaust pipeline 133. In this way, the hydrogen or the purge gas output by the first exhaust pipeline 123 can be discharged through the second purge assembly 143, and the oxygen or the purge gas output by the second exhaust pipeline 133 can be discharged through the second purge assembly 143, thereby achieving the purge of the blind end hydrogen-oxygen fuel cell stack 110. Alternatively, the purge pump 141 is a suction pump.

[0105] Referring to Figures 1 to 4 In an embodiment, the first purge assembly 142 includes a first connecting pipeline 1421, a first control valve 1422, and a second control valve 1423. The first connecting pipeline 1421 is connected between the first gas passage 121 and the second gas passage 131. The first control valve 1422 and the second control valve 1423 are arranged at intervals in the first connecting pipeline 1421. The purge pump 141 is connected between the first control valve 1422 and the second control valve 1423. The second purge assembly 143 includes a second connecting pipeline 1431, a third control valve 1432, a fourth control valve 1433, and a third exhaust pipeline 1434. The second connecting pipeline 1431 is connected between the first exhaust pipeline 123 and the second exhaust pipeline 133. The third control valve 1432 and the fourth control valve 1433 are arranged at intervals in the second connecting pipeline 1431. The third exhaust pipeline 1434 is connected to the second connecting pipeline 1431.

[0106] One end of the first connecting pipeline 1421 is located between the first on-off valve 122 and the blind end hydrogen-oxygen fuel cell stack 110, and communicates with the first gas passage 121, and the other end of the second connecting pipeline 1431 is located between the second on-off valve 132 and the blind end hydrogen-oxygen fuel cell stack 110, and communicates with the second gas passage 131. In this way, the first connecting pipeline 1421 can communicate the first gas passage 121 and the second gas passage 131. The first control valve 1422 and the second control valve 1423 are arranged on the first connecting pipeline 1421 in an interval, and the first control valve 1422 and the second control valve 1423 can control the on-off of the first connecting pipeline 1421.

[0107] Moreover, 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 communicates the first gas passage 121 through the first connecting pipeline 1421; when the first control valve 1422 is closed and the second control valve 1423 is opened, the purge pump 141 communicates the second gas passage 131 through the first connecting pipeline 1421; when the first control valve 1422 and the second control valve 1423 are both opened, the purge pump 141 simultaneously communicates the first gas passage 121 and the second gas passage 131 through the first connecting pipeline 1421. When the first control valve 1422 and the second control valve 1423 are both closed, the first connecting pipeline 1421 is disconnected from the first gas passage 121 and the second gas passage 131.

[0108] One end of the second connecting pipeline 1431 communicates with the first exhaust pipeline 123, and the other end of the second connecting pipeline 1431 communicates with the second exhaust pipeline 133. In this way, the second connecting pipeline 1431 can communicate the first exhaust pipeline 123 and the second exhaust pipeline 133. The third exhaust pipeline 1434 is connected to the second connecting pipeline 1431. The hydrogen or purge gas output by the first exhaust pipeline 123 can be exhausted through the second connecting pipeline 1431 and the third exhaust pipeline 1434, and the oxygen or purge gas output by the second exhaust pipeline 133 can be exhausted through the second connecting pipeline 1431 and the third exhaust pipeline 1434. The third control valve 1432 and the fourth control valve 1433 are arranged on the second connecting pipeline 1431 in an interval, and the third control valve 1432 and the fourth control valve 1433 can control the on-off of the second connecting pipeline 1431.

[0109] Further, the third discharge pipeline 1434 is connected between the third control valve 1432 and the fourth control valve 1433. When the third control valve 1432 is open 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 open, 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 open, 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 from the first discharge pipeline 123 and the second discharge pipeline 133.

[0110] When the purge structure 140 uses air as the purge gas, the first control valve 1422 and the third control valve 1432 are first controlled to be closed, and the second control valve 1423 and the fourth control valve 1433 are controlled to be open, at this time, the hydrogen path 102 is disconnected, and the oxygen path 103 is connected. Subsequently, the first control valve 1422 and the third control valve 1432 are controlled to be open, and the hydrogen path 102 and the oxygen path 103 are both connected. 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.

[0111] 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 open, and the hydrogen path 102 and the oxygen path 103 are both connected. 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.

[0112] In an 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 can also be other valves capable of controlling the connection and disconnection of the pipeline.

[0113] Referring to Figures 1 to 4 In an embodiment, the first purge assembly 142 further comprises a first regulating valve 1424 and a second regulating valve 1425, the first regulating valve 1424 is arranged in the first gas path 121 and located between the first purge assembly 142 and the blind end hydrogen-oxygen fuel cell stack 110, and the second regulating valve 1425 is arranged in the second gas path 131 and located between the first purge assembly 142 and the blind end hydrogen-oxygen fuel cell stack 110.

[0114] The first regulating valve 1424 is arranged in the first gas passage 121. By regulating the duty ratio (opening degree) of the first regulating valve 1424, the flow rate of the purge gas in the first gas passage 121 can be regulated. The second regulating valve 1425 is arranged in the second gas passage 131. By regulating the duty ratio of the second regulating valve 1425, the flow rate of the purge gas in the second gas passage 131 can be regulated.

[0115] In this way, by regulating the rotating speed of the purge pump 141 and the duty ratios of the first regulating valve 1424 and the second regulating valve 1425, the pressure of the purge gas in the first gas passage 121 and the second gas passage 131 can be regulated, so that the purge gas can be delivered to the blind-end hydrogen-oxygen fuel cell stack 110 at a certain target pressure. Of course, the hydrogen delivery structure 120 can include the first regulating valve 1424, and the oxygen delivery structure 130 can include the second regulating valve 1425.

[0116] In an embodiment, the first regulating valve 1424 and the second regulating valve 1425 are proportional valves. By regulating the duty ratios of the proportional valves, i.e., by regulating the opening degrees of the proportional valves, the flow rates of the first gas passage 121 and the second gas passage 131 can be regulated. Of course, in other embodiments of the present application, the first regulating valve 1424 and the second regulating valve 1425 can also be other valves capable of realizing opening degree regulation.

[0117] Referring to Figures 1 to 4 In an embodiment, the hydrogen delivery structure 120 further includes two first temperature-pressure detection members 125, which are arranged in the first gas passage 121 and the first discharge pipeline 123, respectively, and close to the blind-end hydrogen-oxygen fuel cell stack 110. The oxygen delivery structure 130 further includes two second temperature-pressure detection members 135, which are arranged in the second gas passage 131 and the second discharge pipeline 133, respectively, and close to the blind-end hydrogen-oxygen fuel cell stack 110.

[0118] One of the first temperature-pressure detection members 125 is arranged in the first gas passage 121 close to one end of the blind-end hydrogen-oxygen fuel cell stack 110. This first temperature-pressure detection member 125 can detect the temperature and pressure of the hydrogen inlet end. The other first temperature-pressure detection member 125 is arranged in the first discharge pipeline 123 close to one end of the blind-end hydrogen-oxygen fuel cell stack 110. This first temperature-pressure detection member 125 can detect the temperature and pressure of the hydrogen outlet end.

[0119] A second temperature and pressure detection member 135 is arranged on the second gas passage 131 near one end of the blind end hydrogen-oxygen fuel cell stack 110, and can detect the temperature and pressure of the oxygen inlet end. Another second temperature and pressure detection member 135 is arranged on the second exhaust passage 133 near one end of the blind end hydrogen-oxygen fuel cell stack 110, and can detect the temperature and pressure of the oxygen outlet end.

[0120] The first temperature and pressure detection member 125 arranged on both ends of the blind end hydrogen-oxygen fuel cell stack 110 can detect the pressure value in the hydrogen path 102, and the second temperature and pressure detection member 135 arranged on both ends of the blind end hydrogen-oxygen fuel cell stack 110 can detect the pressure value in the oxygen path 103. 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 path 102 and the oxygen path 103.

[0121] Referring to Figures 1 to 3 In an embodiment, the hydrogen delivery structure 120 further includes a first pressure detection member 126 arranged on the first gas passage 121 between the first on-off valve 122 and the first purge assembly 142. The oxygen delivery structure 130 further includes a second pressure detection member 136 arranged on the second gas passage 131 between the second on-off valve 132 and the first purge assembly 142.

[0122] The first pressure detection member 126 can detect the pressure value of the first gas passage 121, and the second pressure detection member 136 can detect the pressure value of the second gas passage 131. In this way, the pressure value in the hydrogen path 102 can be detected by the cooperation of the first pressure detection member 126, and the pressure value in the oxygen path 103 can be detected by the cooperation of the second pressure detection 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 path 102 and the oxygen path 103.

[0123] In this embodiment, the pressure value in the hydrogen path 102 can be detected by the cooperation of the first temperature and pressure detection member 125 and the first pressure detection member 126, and the pressure value in the oxygen path 103 can be detected by the cooperation of the second temperature and pressure detection member 135 and the second pressure detection 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 path 102 and the oxygen path 103.

[0124] In an 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 can also be thermometers and pressure gauges, etc. In an 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 can also be pressure gauges, etc.

[0125] Referring to Figure 1 and Figure 4 In an embodiment, the hydrogen delivery structure 120 further comprises a first separator 127 and a first drain valve 128, the first drain valve 128 is arranged in the first discharge pipeline 123 and is located at a side of the second purge assembly 143 away from the blind end hydrogen-oxygen fuel cell stack 110, and the first separator 127 is arranged in the first discharge pipeline 123 and is located between the second purge assembly 143 and the first drain valve 128.

[0126] The first separator 127 can separate hydrogen and liquid water. The first drain valve 128 can control the opening and closing of the first discharge pipeline 123. The liquid water generated by the electrochemical reaction of the blind end hydrogen-oxygen fuel cell stack 110 contains hydrogen, and after the liquid water is discharged, it enters the first separator 127 for water vapor separation through the first discharge pipeline 123, and the liquid water is discharged to a drain container (not shown) through the drain valve.

[0127] Referring to Figure 1 and Figure 4 In an embodiment, the oxygen delivery structure 130 further comprises a second separator 137 and a second drain valve 138, the second drain valve 138 is arranged in the second discharge pipeline 133 and is located at a side of the second purge assembly 143 away from the blind end hydrogen-oxygen fuel cell stack 110, and the second separator 137 is arranged in the second discharge pipeline 133 and is located between the second purge assembly 143 and the second drain valve 138.

[0128] The second separator 137 can separate oxygen and liquid water. The second drain valve 138 can control the opening and closing of the second discharge pipeline 133. The liquid water generated by the electrochemical reaction of the blind end hydrogen-oxygen fuel cell stack 110 contains oxygen, and after the liquid water is discharged, it enters the second separator 137 for water vapor separation through the second discharge pipeline, and the liquid water is discharged to a drain container through the second drain valve 138.

[0129] Optionally, the drain container is a water tank, etc. Optionally, the hydrogen delivery structure 120 and the oxygen delivery structure 130 correspond to a drain container respectively. Optionally, the first drain valve 128 and the second drain valve 138 are solenoid valves, etc.

[0130] Referring to Figure 1In one embodiment, the fuel cell system 100 further comprises a hydrogen-eliminating structure 150, which is connected to the third exhaust pipeline 1434 of the second purge assembly 143. It can be understood that the blind-end hydrogen-oxygen fuel cell stack 110 still needs to discharge a part of the accumulated impurity gas to improve performance when the average single-cell voltage is too low or the lowest single-cell voltage is low.

[0131] To this end, the hydrogen-eliminating structure 150 is arranged at the output end of the third exhaust pipeline 1434 to process the discharged hydrogen and oxygen. In this way, the hydrogen discharged by the purge blind-end hydrogen-oxygen fuel cell stack 110 can enter the hydrogen-eliminating structure 150 for elimination. It should be noted that the hydrogen-eliminating structure 150 can adopt an existing hydrogen-eliminating scheme, and the specific structure is not described here.

[0132] Referring to Figure 1 and Figure 5 , Figure 5 for Figure 1 The fuel cell system 100 is shown in the flow diagram of the purge gas, wherein the dashed arrow direction is the flow direction of the purge gas. After receiving the shutdown instruction, the hydrogen delivery structure 120 (hydrogen path 102) and the oxygen delivery structure 130 (oxygen path 103) slowly deliver hydrogen and oxygen to normal pressure, such as 101 kpa (absolute pressure, ABS).

[0133] Subsequently, the hydrogen path 102 is controlled to stop delivering hydrogen, the oxygen path 103 is controlled to stop delivering oxygen, 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 residual oxygen remains in the oxygen path 103, and the purge structure 140 needs to be purged to replace the hydrogen in the hydrogen path 102 and the oxygen in the oxygen path 103 with purge gas.

[0134] 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, at this time, the oxygen path 103 is a passage. Turn on the purge pump 141, control the speed of the purge pump 141 and the duty cycle of the second regulating valve 1425, and the purge pump 141 purges the oxygen path 103: the purge pump 141 discharges air through the first connecting pipeline 1421, the second control valve 1423, the second gas passage 131, the blind-end hydrogen-oxygen fuel cell stack 110, the second exhaust pipeline 133, the fourth control valve 1433, the second connecting pipeline 1431, and the third exhaust pipeline 1434, to replace the oxygen in the oxygen path 103 with air.

[0135] In the process of purging pump 141 purging oxygen path 103, because the hydrogen path 102 is at normal pressure, the purging pump 141 pressurizes the oxygen path 103, which can consume part of the hydrogen in the hydrogen path 102, so that the hydrogen path 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, control the first control valve 1422 and the third control valve 1432 to open, control the duty cycle of the second regulating valve 1425, control the pressure of the hydrogen path 102 and the oxygen path 103 to be substantially equal, and not higher than the second set threshold P2, which can purge the air in the hydrogen path 102 and the oxygen path 103 to the hydrogen elimination structure 150.

[0136] When the purge gas is nitrogen, control the first control valve 1422, the second control valve 1423, the third control valve 1432 and the fourth control valve 1433 to open, at this time, the hydrogen path 102 and the oxygen path 103 are both passages. Start the purge pump 141, control the speed of the purge pump 141 and the duty cycle of the first regulating valve 1424 and the second regulating valve 1425, control the pressure of the hydrogen path 102 and the oxygen path 103 to be substantially equal, and not higher than the second set threshold P2, which can purge the nitrogen in the hydrogen path 102 and the oxygen path 103 to the hydrogen elimination structure 150.

[0137] After the purge gas in the hydrogen path 102 and the oxygen path 103 is purged to the hydrogen elimination structure 150, adjust the speed of the circulating regulation purge pump 141, and disturb the pressure of the hydrogen path 102 and the oxygen path 103 by changing the speed, to quickly purge the hydrogen and oxygen in the blind end hydrogen-oxygen fuel cell stack 110. When the single piece voltage of the blind end hydrogen-oxygen fuel cell stack 110 is in the preset range, control the first control valve 1422, the second control valve 1423, the third control valve 1432 and the fourth control valve 1433 to close, complete the purge of the blind end hydrogen-oxygen fuel cell stack 110.

[0138] The fuel cell system 100 of the present application can realize the quick purge of the blind end hydrogen-oxygen fuel cell stack 110 under water when it is stopped, avoid the blind end hydrogen-oxygen fuel cell stack 110 in the open circuit state for a long time, reduce the open circuit voltage of the blind end hydrogen-oxygen fuel cell stack 110, and ensure the use performance and life of the blind end hydrogen-oxygen fuel cell stack 110. Moreover, the purge structure 140 uses the purge pump 141 and the responding valves as the main power consumption devices, which only work when the blind end hydrogen-oxygen fuel cell stack 110 is purged, so as to reduce the energy consumption of the fuel cell system 100.

[0139] Meanwhile, the fuel cell system 100 does not need to carry a nitrogen cylinder, and uses the pre-stored purge gas in the installation space of the underwater equipment to purge the blind-end hydrogen-oxygen fuel cell stack 110. Different modes of purging can be performed according to different types of purge gas, saving space in the underwater equipment for carrying more fuel and catalyst, and improving the endurance of the underwater equipment.

[0140] The present application discloses a purging method of a fuel cell system 100, as shown in Figure 5 and Figure 6 , Figure 6 for Figure 5 purging the fuel cell system 100. 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:

[0141] Obtaining a shutdown instruction of the fuel cell system 100;

[0142] Controlling the hydrogen delivery structure 120 and the oxygen delivery structure 130 to be closed and stop delivering hydrogen and oxygen;

[0143] Judging whether the purge gas in the installation space of the fuel cell system 100 is air;

[0144] If yes, controlling the purge structure 140 to first purge the oxygen delivery structure 130, and then simultaneously purge the hydrogen delivery structure 120 and the oxygen delivery structure 130;

[0145] If no, controlling the purge structure 140 to simultaneously purge the hydrogen delivery structure 120 and the oxygen delivery structure 130;

[0146] Cyclically purging the hydrogen delivery structure 120 and the oxygen delivery structure 130;

[0147] Obtaining the single-plate voltage of the blind-end hydrogen-oxygen fuel cell stack 110, and judging whether the single-plate voltage is within a preset range;

[0148] If yes, controlling the purge structure to stop purging;

[0149] If no, continuing to cyclically purge the hydrogen delivery structure 120 and the oxygen delivery structure 130.

[0150] After the fuel cell system 100 receives the shutdown instruction, the hydrogen delivery structure 120 (hydrogen path 102) and the oxygen delivery structure 130 (oxygen path 103) slowly bring the pressure in the hydrogen path 102 and the oxygen path 103 to the atmospheric pressure, such as 101 kPa (absolute pressure, ABS). Then, the hydrogen delivery structure 120 and the oxygen delivery structure 130 are closed, the hydrogen path 102 stops delivering hydrogen, and the oxygen path 103 stops delivering oxygen, 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.

[0151] At this time, hydrogen remains in the hydrogen path 102, and oxygen remains in the oxygen path 103. The purge structure 140 needs 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 the purge gas. The purge gas is pre-stored in the installation space of the fuel cell system 100, and the purge gas can be air or nitrogen. It is determined whether the purge gas is air.

[0152] If the purge gas is air, the purge structure 140 needs to first purge the second gas path 131 (oxygen path 103). The purge structure 140 is disconnected from the first gas path 121 (hydrogen path 102), and air is first introduced into the oxygen path 103. The air flows in the oxygen path 103 under pressure and can consume the hydrogen in the blind end hydrogen-oxygen fuel cell stack 110, so that the hydrogen path 102 is in a state of micro-negative pressure. Then, the purge structure 140 delivers air to the hydrogen path 102 and the oxygen path 103 to purge the hydrogen path 102 and the oxygen path 103. If the purge gas is not air but nitrogen, the purge structure 140 can simultaneously deliver nitrogen to the hydrogen path 102 and the oxygen path 103 to purge the hydrogen path 102 and the oxygen path 103.

[0153] Then, the hydrogen path 102 and the oxygen path 103 are subjected to cyclic purging. During the cyclic purging, the average single-cell voltage of the blind end hydrogen-oxygen fuel cell stack 110 is obtained. A preset range of the single-cell voltage is pre-stored in the fuel system, and it is determined whether the single-cell voltage of the blind end hydrogen-oxygen fuel cell stack 110 is within the preset range. If the single-cell voltage is within the preset range, it indicates that the hydrogen and the oxygen in the blind end hydrogen-oxygen fuel cell stack 110 have been replaced by the purge gas.

[0154] If the single-cell voltage is outside the preset range, it indicates that the hydrogen and the oxygen in the blind end hydrogen-oxygen fuel cell stack 110 have not been completely replaced, and purging needs to be performed again. This continuous reciprocation continues until the single-cell voltage is within the preset range, and the control of the purge structure 140 is stopped, i.e., the first control valve 1422, the second control valve 1423, the third control valve 1432, and the fourth control valve 1433 are closed, and the purging of the blind end hydrogen-oxygen fuel cell stack 110 is completed.

[0155] In the embodiment, the single-chip voltage is the average single-chip voltage and the highest single-chip voltage. The preset range of the average single-chip voltage and the highest single-chip voltage is stored in the fuel system, and it is determined whether the average single-chip voltage and the highest single-chip voltage of the blind-end hydrogen-oxygen fuel cell stack 110 are within the preset range.

[0156] If the average single-chip voltage and the highest single-chip voltage are within the preset range, it indicates that the hydrogen and the oxygen in the blind-end hydrogen-oxygen fuel cell stack 110 have replaced the purge gas. If the average single-chip voltage and the highest single-chip voltage are outside the preset range, it indicates that the hydrogen and the oxygen in the blind-end hydrogen-oxygen fuel cell stack 110 have not completely replaced, and the purge needs to be performed again.

[0157] In the embodiment, the voltage value of the average single-chip voltage is lower than 50 mV, and the voltage value of the highest single-chip voltage is not higher than 80 mV. Of course, in other embodiments of the present application, the average single-chip voltage and the highest single-chip voltage can also be other preset ranges, as long as the open-circuit voltage of the blind-end hydrogen-oxygen fuel cell stack 110 can be reduced.

[0158] In other embodiments of the present application, the average single-chip voltage or the highest single-chip voltage can also be used to determine whether the hydrogen and the oxygen in the blind-end hydrogen-oxygen fuel cell stack 110 have completed replacement.

[0159] Referring to Figure 5 and Figure 6 In an embodiment, the control purge structure 140 first purges the oxygen delivery structure 130, and then simultaneously purges the hydrogen delivery structure 120 and the oxygen delivery structure 130, including the following steps:

[0160] 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;

[0161] The purge pump 141 is started, and the rotation speed of the purge pump 141 and the duty cycle of the second adjusting valve 1425 are adjusted to purge the oxygen delivery structure 130;

[0162] The first pressure of the gas in the hydrogen delivery structure 120 is obtained, and it is determined whether the first pressure is less than or equal to the first set threshold value;

[0163] If yes, the first control valve 1422 and the third control valve 1432 are opened;

[0164] If no, the rotation speed of the purge pump 141 and the duty cycle of the second adjusting valve 1425 are continuously adjusted to purge the oxygen delivery structure 130.

[0165] When the purge gas is air, the first control valve 1422 and the third control valve 1432 are closed, the second control valve 1423 and the fourth control valve 1433 are opened, at this time, the oxygen path 103 is a passage. The purge pump 141 is started, the rotation speed of the purge pump 141 and the duty ratio of the second adjusting valve 1425 are regulated, and the purge pump 141 purges the oxygen path 103: the purge pump 141 discharges air through the first connecting pipeline 1421, the second control valve 1423, the second gas passage 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 the oxygen in the oxygen path 103 with air.

[0166] During the purging of the oxygen path 103 by the purge pump 141, the pressure difference between the oxygen path 103 and the hydrogen path 102 is the preset threshold value ΔP because the hydrogen path 102 is at atmospheric pressure. The pressurization of the oxygen path 103 by the purge pump 141 can consume part of the hydrogen in the hydrogen path 102, so that the hydrogen path 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 value P1, the first control valve 1422 and the third control valve 1432 are controlled to be opened, the duty ratio of the second adjusting valve 1425 is regulated, and the pressure of the hydrogen path 102 and the oxygen path 103 is controlled to be substantially equal and not higher than the second set threshold value P2, so that the air in the hydrogen path 102 and the oxygen path 103 can be purged into the hydrogen removal structure 150.

[0167] In this embodiment, the preset threshold value ΔP is 30 kpa (ABS), the first set threshold value P1 is 30 kpa (ABS), and the second set threshold value P2 is 130 kpa (ABS). Of course, in other embodiments of the present application, the preset threshold value ΔP, the first set threshold value P1 and the second set threshold value P2 can also be other values, as long as they can achieve the purging of the blind end hydrogen-oxygen fuel cell stack 110.

[0168] Referring to Figure 5 and Figure 6 In an embodiment, the purge structure 140 simultaneously purges the hydrogen delivery structure 120 and the oxygen delivery structure 130, including the following steps:

[0169] The first control valve 1422, the third control valve 1432, the second control valve 1423 and the fourth control valve 1433 are opened.

[0170] The purge pump 141 is started, and the rotation speed of the purge pump 141 is regulated.

[0171] 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, at this time, the hydrogen path 102 and the oxygen path 103 are both open. The purge pump 141 is started, and the rotation speed of the purge pump 141 and the duty cycle of the first regulating valve 1424 and the second regulating valve 1425 are controlled to control the pressure of the hydrogen path 102 and the oxygen path 103 to be substantially equal and not higher than the second set threshold P2, so that the nitrogen in the hydrogen path 102 and the oxygen path 103 can be purged into the hydrogen elimination structure 150.

[0172] Subsequently, the hydrogen path 102 and the oxygen path 103 are cyclically purged.

[0173] Referring to Figure 5 and Figure 6 In an embodiment, the hydrogen delivery structure 120 and the oxygen delivery structure 130 are cyclically purged, including the following steps:

[0174] The duty cycle of the first regulating valve 1424 and the second regulating valve 1425 is controlled;

[0175] The pressure in the oxygen delivery structure 130 and the hydrogen delivery structure 120 is controlled to be equal and less than the second set threshold;

[0176] The purge pump 141 is controlled to purge at a first rotation speed for a first preset time, at a second rotation speed for a second preset time, and at the first rotation speed for the first preset time, and the purging is cyclically performed;

[0177] Wherein, the first rotation speed and the second rotation speed are different.

[0178] After the purge gas in the hydrogen path 102 and the oxygen path 103 is blown into the hydrogen elimination structure 150, the pressure in the oxygen delivery structure 130 and the hydrogen delivery structure 120 is equal and less than the second set threshold, at this time, the pressure in the hydrogen path 102 and the oxygen path 103 is disturbed to discharge the residual hydrogen and oxygen in the blind end hydrogen-oxygen fuel cell stack 110, and the hydrogen and oxygen in the blind end hydrogen-oxygen fuel cell stack 110 is rapidly purged.

[0179] Specifically, the purge pump 141 first purges the hydrogen path 102 and the oxygen path 103 at a first rotation speed for a first preset time, then purges the hydrogen path 102 and the oxygen path 103 at a second rotation speed for a second preset time, and then purges the hydrogen path 102 and the oxygen path 103 at the first rotation speed for the first preset time, and the purging is cyclically performed. The pressure in the hydrogen path 102 and the oxygen path 103 is disturbed by changing the rotation speed. Alternatively, the first preset time and the second preset time are both 5s or other times.

[0180] In the cycle purging process, the single cell voltage of the blind end hydrogen-oxygen fuel cell stack 110 is obtained. A preset range of the single cell voltage is stored in the fuel system in advance, and it is judged whether the single cell voltage of the blind end hydrogen-oxygen fuel cell stack 110 is within the preset range. When the single cell voltage of the blind end hydrogen-oxygen 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, and the purging of the blind end hydrogen-oxygen fuel cell stack 110 is completed. If the single cell 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 the purging needs to be performed again.

[0181] The purging method of the fuel cell system 100 of the present application can realize that the underwater equipment with the fuel cell system 100 does not carry inert purging gas bottles such as nitrogen, saves the space of the fuel cell system 100, and is used to carry more fuel and catalyst, thereby improving the endurance mileage of the underwater equipment.

[0182] 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 cell voltage and the highest single cell voltage of the blind end hydrogen-oxygen fuel cell stack 110 are reduced to a reasonable threshold value in a short time, and the performance of the blind end hydrogen-oxygen fuel cell stack 110 is protected and the service life is prolonged.

[0183] Meanwhile, by cooperating with the hydrogen removal equipment inside the underwater equipment, the concentration of hydrogen in the underwater equipment is avoided to be too high, 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 underwater equipment is realized.

[0184] The present application also provides an underwater equipment, which comprises an underwater main machine and the fuel cell system 100 in any of the above embodiments. The fuel cell system 100 is arranged in the underwater main machine and supplies power to the underwater main machine. After the underwater equipment adopts the fuel cell system 100 of the above embodiments, the use performance and the service life of the blind end hydrogen-oxygen fuel cell stack 110 can be ensured while supplying power to the underwater main machine, the space in the underwater equipment is saved to carry more fuel and catalyst, and the endurance mileage of the underwater equipment is improved.

[0185] The technical features of the above embodiments can be combined arbitrarily. In order to make the description simple, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combinations of the technical features do not exist contradictory, they should be considered as the scope of the present application.

[0186] The above embodiments only express several implementation ways of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation to the patent scope of the application. It should be pointed out that for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, which all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A fuel cell system characterized by comprising: The application relates to a hydrogen-oxygen fuel cell system, which comprises: a blind-end hydrogen-oxygen fuel cell stack; a hydrogen gas delivery structure, which comprises a first gas passage, a first on-off valve and a first exhaust pipeline, the first gas passage and the first exhaust pipeline being arranged at two ends of the blind-end hydrogen-oxygen fuel cell stack, and the first on-off valve being arranged in the first gas passage; an oxygen gas delivery structure, which comprises a second gas passage, a second on-off valve and a second exhaust pipeline, the second gas passage and the second exhaust pipeline being arranged at two ends of the blind-end hydrogen-oxygen fuel cell stack, and the second on-off valve being arranged in the second gas passage; a purging structure, which is connected to 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, the purging gas being stored in advance in an installation space of the fuel cell system.

2. The fuel cell system according to claim 1, characterized by, The purging structure comprises a purging pump, a first purging assembly and a second purging assembly. The first purging assembly is connected to the first gas passage and the second gas passage, and is arranged between the first on-off valve and the blind-end hydrogen-oxygen fuel cell stack. The second purging assembly is connected to the first exhaust pipeline and the second exhaust pipeline. The purging pump is connected to the first purging assembly, and controls the first purging assembly and the second purging assembly to purge at least one of the first gas passage and the second gas passage.

3. The fuel cell system of claim 2, wherein The first purging assembly comprises a first connecting pipeline, a first control valve and a second control valve, the first connecting pipeline is connected to the first gas passage and the second gas passage, the first control valve and the second control valve are arranged in the first connecting pipeline, and the purging pump is connected to the first control valve and the second control valve. The second purging assembly comprises a second connecting pipeline, a third control valve, a fourth control valve and a third exhaust pipeline, the second connecting pipeline is connected to the first exhaust pipeline and the second exhaust pipeline, the third control valve and the fourth control valve are arranged in the second connecting pipeline, and the third exhaust pipeline is connected to the second connecting pipeline.

4. The fuel cell system of claim 2, wherein The purging structure uses air as the purging gas, and the purging pump purges the second gas passage first, and then purges the first gas passage and the second gas passage simultaneously through the first purging assembly and the second purging assembly. Alternatively, the purging structure uses nitrogen as the purging gas, and the purging pump purges the first gas passage and the second gas passage simultaneously through the first purging assembly and the second purging assembly.

5. The fuel cell system of claim 2, wherein The hydrogen gas delivery structure further comprises two first temperature and pressure detection members, and the two first temperature and pressure detection members are arranged in the first gas passage and the first exhaust pipeline respectively and close to the blind-end hydrogen-oxygen fuel cell stack. The oxygen gas delivery structure further comprises two second temperature and pressure detection members, and the two second temperature and pressure detection members are arranged in the second gas passage and the second exhaust pipeline respectively and close to the blind-end hydrogen-oxygen fuel cell stack.

6. The fuel cell system of claim 2, wherein The hydrogen delivery structure further comprises a first pressure detecting member disposed in the first gas passage and located between the first on-off valve and the first purge assembly; The oxygen delivery structure further comprises a second pressure detecting member disposed in the second gas passage and located between the second on-off valve and the first purge assembly.

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

8. The fuel cell system of claim 2, wherein The fuel cell system further comprises a hydrogen removal structure, the hydrogen removal structure is communicated with the third exhaust pipeline of the second purge assembly.

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

10. An underwater apparatus, characterized by The fuel cell system is disposed in the underwater main engine and supplies power for the underwater main engine. The fuel cell system is disposed in the underwater main engine and supplies power for the underwater main engine.

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