A fuel cell cathode gas supply system

Abstract

The application provides a fuel cell cathode gas supply system, comprising an oxygen source, an injection assembly, an air compressor, a humidifier and a stack, a first inlet of the injection assembly being communicated with the oxygen source, a second inlet of the injection assembly being communicated with the atmosphere, an outlet of the injection assembly being communicated with an inlet of the air compressor, an outlet of the air compressor being communicated with an inlet of the humidifier, and an outlet of the humidifier being communicated with a cathode inlet of the stack, air in the atmosphere and oxygen provided by the oxygen source being compressed by the air compressor and the injection assembly and then being introduced into the stack. Since the injection assembly and the air compressor are connected in series, the injection assembly can cool the gas, the low-temperature oxygen introduced into the air compressor can cool the air compressor, the high-temperature alarm of the air compressor is avoided, and even the air compressor is prevented from malfunctioning due to the excessively high temperature. In addition, the low air temperature in the air compressor can reduce the cooling difficulty of the cooling system of the air compressor, and further reduce the power consumption.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fuel cell, in particular, to a fuel cell cathode gas supply system. BACKGROUND

[0002] Due to the increasing depletion of non-renewable energy sources such as oil and coal, hydrogen energy as a renewable energy source has gradually entered people's field of vision. In recent years, China has vigorously developed new energy, and the importance of fuel cells has become increasingly apparent. The existing fuel cell uses hydrogen as fuel and utilizes the electrochemical reaction of hydrogen and oxygen to generate electric energy, heat energy and water, and outputs energy externally. Compared with internal combustion engines, fuel cells have higher efficiency and power density, and are widely used in the field of new energy vehicles. The cathode gas supply system of the fuel cell provides air with a certain pressure and flow rate to the fuel cell system to ensure the normal progress of the electrochemical reaction in the fuel cell stack. The cathode gas supply system generally includes air compressors, coolers, humidifiers and other components. At present, air compressors of hydrogen fuel cell systems at home and abroad generally directly suck air from the atmosphere, and the oxygen content provided by the cathode gas supply system is low. Studies have shown that increasing the oxygen concentration in the cathode inlet gas of a proton exchange membrane fuel cell can improve its efficiency, and an oxygen content of 45% is the recommended optimal oxygen-rich concentration.

[0003] Chinese patent CN202223170112.0 discloses a fuel cell cathode gas supply system, which supplements oxygen to the air pipeline through the ejector connected to the air pipeline by setting an oxygen supplement pipeline, which can effectively improve the oxygen concentration in the gas supply system and meet the optimal working conditions of the fuel cell. However, one problem of this system is that the air compression power consumption is high.

[0004] In order to solve the problem of high air compression power consumption of the fuel cell cathode gas supply system, Chinese patent CN202222870090.2 provides another cathode gas supply system, which introduces the air discharged from the cathode outlet of the fuel cell into the cathode inlet after being compressed by the air compressor and being injected by the ejector with oxygen provided by the oxygen source. Since the air discharged from the cathode outlet has a certain pressure, it can reduce the power consumption of the air compressor. However, in this scheme, the air temperature at the cathode outlet is high, which can easily cause air compressor failure or even shutdown when directly introduced into the air compressor. Therefore, there is an urgent need to provide a reliable and low-power fuel cell cathode gas supply system. SUMMARY

[0005] In order to solve the problem of high power consumption and high temperature failure of the fuel cell cathode gas supply system in the prior art, the present application provides a new fuel cell cathode gas supply system, which connects the oxygen source with the air compressor in series through the ejector assembly, and uses low-temperature oxygen to cool the air compressor, which can effectively avoid the occurrence of high-temperature failure of the air compressor.

[0006] The application realizes the following: a fuel cell cathode gas supply system, comprising an oxygen source, an injection assembly, an air compressor, a humidifier and a stack, a first inlet of the injection assembly being in communication with the oxygen source, a second inlet of the injection assembly being in communication with the atmosphere, an outlet of the injection assembly being in communication with an inlet of the air compressor, an outlet of the air compressor being in communication with an inlet of the humidifier, an outlet of the humidifier being in communication with a cathode inlet of the stack, air in the atmosphere and oxygen provided by the oxygen source being compressed by the air compressor and the injection assembly and then being supplied to the stack.

[0007] Preferably, the injection assembly comprises a first injector and a second injector.

[0008] Preferably, the first inlet of the first injector and the first inlet of the second injector are both in communication with the oxygen source, the second inlet of the first injector and the second inlet of the second injector are both in communication with the atmosphere, and the outlet of the first injector and the outlet of the second injector are both in communication with the inlet of the air compressor.

[0009] Preferably, the first inlet of the first injector and the first inlet of the second injector are both in communication with the oxygen source, the second inlet of the first injector is in communication with the atmosphere, the outlet of the first injector is in communication with the second inlet of the second injector, and the outlet of the second injector is in communication with the inlet of the air compressor.

[0010] Preferably, a third flow regulating valve is connected in parallel between the upstream and the downstream of the air compressor.

[0011] Preferably, a first flow control valve and a first flow meter are arranged between the first inlet of the injection assembly and the oxygen source.

[0012] Preferably, an intercooler is arranged between the air compressor and the humidifier.

[0013] Preferably, an air filter, a second flow control valve and a second flow meter are arranged at the second inlet of the injection assembly.

[0014] Compared with the prior art, the application has at least the following technical effects:

[0015] 1. The fuel cell cathode system of the application is provided with an oxygen source, which can provide sufficient oxygen for the gas supply system to meet the optimal working concentration requirement of the fuel cell; since the injection assembly is connected in series with the air compressor, that is, the air injected by the injection assembly is compressed twice by the injection assembly and the air compressor, which can greatly reduce the power consumption of the air compressor and save energy; in addition, since the injection assembly is connected in series with the air compressor, the injection assembly can reduce the temperature of the oxygen, and the low-temperature oxygen entering the air compressor can cool the air compressor, avoiding high-temperature alarm of the air compressor, or even failure due to excessively high temperature; in addition, excessively low air temperature in the air compressor can reduce the cooling difficulty of the air compressor cooling system, further reducing power consumption.

[0016] 2. The injection assembly of the application includes a first injector and a second injector, and the oxygen provided by the oxygen source is injected by the first injector and the second injector, which can reasonably distribute the operating conditions of the air compressor according to the operating conditions of the fuel cell, thereby reducing the power consumption.

[0017] 3. The first injector and the second injector are connected in parallel, the first injector and the second injector are connected with the oxygen source through a first inlet, connected with the atmosphere through a second inlet, and connected with the inlet of the air compressor through an outlet, that is, the first injector and the second injector can work completely independently, and the opening of the first injector and the second injector can be selectively controlled; further, the entire system can still work normally when the first injector and the second injector fail, improving the reliability of the gas supply system.

[0018] 4. The first injector and the second injector are connected in series, that is, the outlet of the first injector is connected with the inlet of the second injector; in this way, more accurate oxygen concentration can be obtained through double injection, avoiding excessively high or low oxygen concentration; at the same time, the gas is compressed step by step through the first injector and the second injector, further reducing the compression difficulty of the air compressor, which is beneficial to reducing the system power consumption.

[0019] 5. By arranging a parallel pipeline between the upstream and downstream of the air compressor and arranging a third flow regulating valve on the parallel pipeline, when the fuel cell system is in a low load state, the air can be completely compressed by the air compressor and then introduced into the cathode by closing the flow regulating valve; when the fuel system is in a high load state, the third flow regulating valve is opened and the air compressor is closed, and the gas injected by the injection assembly is directly introduced into the parallel pipeline to the fuel cell cathode system.

[0020] 6. A first flow control valve and a first flow meter are arranged between the injector assembly and the oxygen source, which can accurately control the high-pressure oxygen flow according to the target oxygen concentration, ensuring the accuracy of the oxygen introduced into the fuel cell cathode system.

[0021] 7. The intercooler is arranged between the air compressor and the humidifier, and the intercooler can cool the gas discharged from the outlet of the air compressor, so as to avoid the fuel cell failure caused by the high temperature of the gas.

[0022] 8. The second inlet of the injection assembly is provided with an air filter, a second flow control valve and a second flow meter, the air filter is arranged to filter the impurities in the air, and the second flow control valve and the second flow meter are arranged to control the air flow of the injection assembly, so as to ensure that the oxygen concentration at the outlet of the injection assembly reaches the target concentration, and the precise control of the oxygen concentration of the gas supply system is realized. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0024] Figure 1 It is a schematic diagram of the fuel cell cathode gas supply system of the first embodiment of the present application.

[0025] Figure 2 It is a schematic diagram of the fuel cell cathode gas supply system of the second embodiment of the present application.

[0026] Figure 3 It is a schematic diagram of the fuel cell cathode gas supply system of the third embodiment of the present application.

[0027] Figure 4 It is a schematic diagram of the fuel cell cathode gas supply system of the fourth embodiment of the present application.

[0028] The drawings show that: 1, oxygen source; 2, on-off valve; 3, first flow control valve; 31, first sub-flow control valve; 32, second sub-flow control valve; 4, first flow meter; 41, first sub-flow meter; 42, second sub-flow meter; 5, injection assembly; 51, first injector; 52, second injector; 53, third injector; 6, pressure sensor; 7, air compressor; 8, intercooler; 9, temperature and pressure integrated sensor; 10, humidifier; 11, first flow regulating valve; 12, electric pile; 13, second flow regulating valve; 14, fourth flow regulating valve; 15, second flow meter; 151, third sub-flow meter; 152, fourth sub-flow meter; 16, second flow control valve; 161, third sub-flow control valve; 162, fourth sub-flow control valve; 17, air filter; 18, third flow regulating valve. DETAILED DESCRIPTION

[0029] In order to more clearly illustrate the overall concepts of the present application, the following will be described in detail with reference to the accompanying drawings.

[0030] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, it will be apparent to one skilled in the art that the present application can be practiced without the specific details and other implementations can be employed. Therefore, the scope of the present application is defined not by the detailed description, but by the appended claims, therefore it is not limited to the specific embodiments disclosed herein.

[0031] In addition, in the description of the present application, it should be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply 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 a limitation to the present application. As for the positional relationship of "upstream" and "downstream", it is based on the positional relationship when the fluid flows normally.

[0032] In addition, the terms "first", "second", and the like are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0033] In the present application, unless otherwise specifically defined and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be broadly understood, 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, or it can be communicated; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication or interaction relationship of two elements. 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.

[0034] In this application, unless specifically stated and limited otherwise, a first feature being "on" or "under" a second feature can mean that the first and second features are directly in contact, or that the first and second features are indirectly in contact through an intermediate medium. In the description of the specification, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any suitable manner in any one or more embodiments or examples.

[0035] As shown in Figure 1 The present application provides a fuel cell cathode gas supply system, specifically, the fuel cell cathode gas supply system comprises an oxygen source 1, an ejector assembly 5, an air compressor 7, a humidifier 10 and a stack arranged in series, wherein the oxygen source 1 is in communication with the first inlet of the ejector assembly 5, the second inlet of the ejector assembly 5 is in communication with the atmosphere, the outlet of the ejector assembly 5 is in communication with the inlet of the air compressor 7, the outlet of the air compressor 7 is in communication with the inlet of the humidifier 10, and the outlet of the humidifier 10 is in communication with the cathode inlet of the stack.

[0036] The air compressor 7 in the prior art fuel cell cathode gas supply system is usually arranged in parallel with the ejector, and the power consumption of the entire system is high. In order to solve the problem of high power consumption of the cathode gas supply system, the prior art provides another cathode gas supply system, which can reduce the power consumption of the entire system by compressing the air at the cathode outlet through the air compressor 7 and then introducing it into the inlet of the ejector to reuse the tail gas at the cathode outlet. However, the air at the cathode outlet is at a high temperature, and direct introduction into the air compressor 7 can easily cause high-temperature failure of the air compressor 7. The present application arranges the ejector assembly 5 and the air compressor 7 in series, and the oxygen discharged from the oxygen source 1 is introduced into the air compressor 7 after being ejected by the ejector assembly 5 and the air, and then compressed by the air compressor 7, humidified in the humidifier 10, and introduced into the cathode inlet of the stack to participate in the chemical reaction. Since the air introduced into the air compressor 7 is ejected by the ejector, the power consumption of the air compressor 7 can be reduced to a first extent. In addition, since the oxygen provided by the oxygen source 1 is at a low temperature, the temperature of the air compressor 7 can be effectively reduced to avoid high-temperature failure of the air compressor 7 causing the entire gas supply system to be paralyzed, and the reliability of the cathode gas supply system is greatly improved.

[0037] In the application, the tail gas discharged from the cathode outlet of the stack can be directly introduced into the second inlet of the ejector assembly 5 or the inlet of the air compressor 7. When the tail gas discharged from the cathode outlet is introduced into the second inlet of the ejector assembly 5, the high-temperature and high-pressure tail gas can be slowly mixed with the oxygen provided by the oxygen source 1 in the ejector, so that the temperature is reduced to avoid failure of the air compressor 7. When the tail gas discharged from the cathode outlet is directly introduced into the inlet of the air compressor 7, the low-temperature gas discharged from the ejector assembly 5 is mixed with the high-temperature tail gas in the air compressor 7, so that the failure of the air compressor 7 due to high temperature can also be avoided.

[0038] In the application, the oxygen source 1 is an oxygen tank or an oxygen cylinder, and the oxygen is stored in the oxygen source 1 by being compressed and liquefied. When the oxygen is introduced into the gas supply system, the oxygen is vaporized, and the vaporized oxygen has a relatively low temperature, which can cool the entire gas supply system.

[0039] In the application, the oxygen source 1 and the ejector assembly 5 are provided with a switch valve 2, which can control the on-off of the oxygen source 1 and the ejector assembly 5. Further, a first regulating valve and a first flowmeter 4 are arranged between the switch valve 2 and the first inlet of the ejector assembly 5, an air filter 17, a second flow control valve 16 and a second flowmeter 15 are arranged at the second inlet of the ejector assembly 5. The oxygen content in the ejector assembly 5 can be controlled by the interlocking control of the first flow control valve 3 and the first flowmeter 4, and the air content in the ejector assembly 5 can be controlled by the interlocking control of the second flow control valve 16 and the second flowmeter 15. The oxygen content in the gas supply pipeline can be ensured to be the target content by the joint action of the first flow control valve 3, the first flowmeter 4, the second flow control valve 16 and the second flowmeter 15, so as to realize accurate control of the oxygen concentration. In addition, the impurities in the air can be filtered by arranging the air filter 17 at the second inlet of the ejector assembly 5.

[0040] In the application, a intercooler 8 is further arranged between the air compressor 7 and the humidifier 10, which can cool the air discharged from the outlet of the air compressor 7 to avoid damage to the stack caused by overheating of the air introduced into the cathode of the stack. It can be understood that, since the air is compressed twice by the ejector assembly 5 and the air compressor 7, the power consumption of the air compressor 7 is low, and the temperature of the air discharged from the air compressor 7 is relatively low, so the intercooler 8 can not be arranged. However, in order to avoid high-temperature failure, the gas supply system of the application is preferably provided with the intercooler 8. In addition, in order to detect the temperature and pressure of the entire gas supply system, a pressure sensor 6 is further arranged between the ejector assembly 5 and the air compressor 7, and a temperature and pressure integrated sensor 9 is further arranged between the intercooler 8 and the humidifier 10.

[0041] In the present application, the humidifier 10 is provided with a first flow regulating valve 11 and a second flow regulating valve 13 between the cathode inlet and the cathode outlet of the stack, respectively. By closing the first flow regulating valve 11 and the second flow regulating valve 13 when the stack is not working, the air pipeline of the stack can be sealed. In addition, in order to avoid surge of the air compressor 7, the outlet of the air compressor 7 is provided with a fourth flow regulating valve 14.

[0042] It can be understood that the injection assembly 5 can be composed of one injector, or a plurality of injectors connected in series or in parallel. When the injection assembly 5 includes a plurality of injectors, the first inlet of the injection assembly 5 being communicated with the oxygen source 1 means that the first inlet of at least one of the injectors is communicated with the oxygen source 1, the second inlet of the injection assembly 5 being communicated with the atmosphere means that the second inlet of at least one of the injectors is communicated with the atmosphere, and the outlet of the injection assembly 5 being communicated with the inlet of the air compressor 7 means that the outlet of at least one of the injectors is communicated with the inlet of the air compressor 7.

[0043] Embodiment two.

[0044] Different from embodiment one, the present embodiment provides another fuel cell cathode gas supply system.

[0045] As shown in Figure 2 In the present embodiment, a parallel pipeline is connected between the upstream and the downstream of the air compressor 7, and a third flow regulating valve 18 is arranged on the parallel pipeline. By arranging the parallel pipeline between the upstream and the downstream of the air compressor 7 and arranging the third flow regulating valve 18 on the parallel pipeline, when the fuel cell system is in a low load state, the air can be compressed by the air compressor 7 and then introduced into the cathode by closing the third flow regulating valve 18, and when the fuel system is in a high load state, the third flow regulating valve 18 is opened and the air compressor 7 is closed, and the gas introduced by the injection assembly 5 is directly introduced into the parallel pipeline to the fuel cell cathode system.

[0046] The other structure and effect of the fuel cell cathode gas supply system of the present embodiment are the same as those of embodiment one, and will not be described herein.

[0047] Embodiment three.

[0048] Different from embodiment one, the present embodiment provides another fuel cell cathode gas supply system.

[0049] As shown in Figure 3As shown, in the present embodiment, the injection assembly 5 comprises a first injector 51 and a second injector 52, wherein the first inlet of the first injector 51 and the second injector 52 is communicated with the oxygen source 1, the second inlet of the first injector 51 and the second injector 52 is communicated with the atmosphere, and the outlet of the first injector 51 and the second injector 52 is communicated with the inlet of the air compressor 7. In this way, the first injector 51 and the second injector 52 are connected with the oxygen source 1 through the first inlet, communicated with the atmosphere through the second inlet, and communicated with the inlet of the air compressor 7 through the outlet, that is, the first injector 51 and the second injector 52 are connected in parallel, the first injector 51 and the second injector 52 can work completely independently, the opening of the first injector 51 and the second injector 52 can be selectively controlled, further, the entire system can still work normally when the first injector 51 and the second injector 52 fail, and the reliability of the gas supply system is improved.

[0050] In the present embodiment, the first flow control valve 3 comprises a first sub-flow control valve 31 and a second sub-flow control valve 32, the first flow meter 4 comprises a first sub-flow meter 41 and a second sub-flow meter 42, the first sub-flow control valve 31 and the first sub-flow meter 41 can be linked to control the oxygen flow rate sucked by the first injector 51, and the second sub-flow control valve 32 and the second sub-flow meter 42 are linked to control the oxygen content sucked by the second injector 52.

[0051] In the present embodiment, the second flow control valve 16 comprises a third sub-flow control valve 161 and a fourth sub-flow control valve 162, the second flow meter 15 comprises a third sub-flow meter 151 and a fourth sub-flow meter 152, the third sub-flow control valve 161 and the third sub-flow meter 151 can be linked to control the air flow rate sucked by the first injector 51, and the fourth sub-flow control valve 162 and the fourth sub-flow meter 152 are linked to control the air content sucked by the second injector 52.

[0052] The other structures and effects of the fuel cell cathode gas supply system of the present embodiment are the same as those of Embodiment One, and will not be described again.

[0053] Embodiment Four.

[0054] Different from Embodiment One, the present embodiment provides another fuel cell cathode gas supply system.

[0055] As Figure 4As shown, in the embodiment, the injection assembly 5 comprises a first injector 51 and a second injector 52, wherein the first inlets of the first injector 51 and the second injector 52 are communicated with the oxygen source 1, the second inlet of the first injector 51 is communicated with the atmosphere, the outlet of the first injector 51 is communicated with the second inlet of the second injector 52, and the outlet of the second injector 52 is communicated with the inlet of the air compressor 7. In this way, the double injection of the first injector 51 and the second injector 52 can obtain more accurate oxygen concentration, so as to avoid the situation that the oxygen concentration is too high or too low. Meanwhile, the step-by-step compression of the gas through the first injector 51 and the second injector 52 can further reduce the compression difficulty of the air compressor 7, so as to be beneficial to reducing the system power consumption.

[0056] In the embodiment, the first flow control valve 3 comprises a first sub-flow control valve 31 and a second sub-flow control valve 32, the first flow meter 4 comprises a first sub-flow meter 41 and a second sub-flow meter 42, the first sub-flow control valve 31 and the first sub-flow meter 41 can be linked to control the oxygen flow rate sucked by the first injector 51, and the second sub-flow control valve 32 and the second sub-flow meter 42 are linked to control the oxygen content sucked by the second injector 52.

[0057] The other structures and effects of the fuel cell cathode gas supply system in the embodiment are the same as those in the first embodiment, and will not be described here.

[0058] The above description is only the preferred embodiment of the present application, and is not intended to limit the scope of the present application. Any equivalent changes and modifications made according to the present application are included in the scope of the present application, and will not be described here.

Claims

1. A fuel cell cathode gas supply system comprising an oxygen source, an ejector assembly, an air compressor, a humidifier and a stack, characterized in that, The first inlet of the ejector assembly is communicated with the oxygen source, the second inlet of the ejector assembly is communicated with the atmosphere, the outlet of the ejector assembly is communicated with the inlet of the air compressor, the outlet of the air compressor is communicated with the inlet of the humidifier, the outlet of the humidifier is communicated with the cathode inlet of the stack, and air in the atmosphere and oxygen provided by the oxygen source are compressed by the air compressor and then enter the stack through the ejector assembly. The ejector assembly comprises a first ejector and a second ejector, the first inlet of the first ejector and the first inlet of the second ejector are communicated with the oxygen source, the second inlet of the first ejector is communicated with the atmosphere, the outlet of the first ejector is communicated with the second inlet of the second ejector, and the outlet of the second ejector is communicated with the inlet of the air compressor.

2. A fuel cell cathode gas supply system according to claim 1, wherein A third flow regulating valve is connected in parallel between the upstream and the downstream of the air compressor.

3. A fuel cell cathode gas supply system according to claim 1 or 2, wherein A first flow control valve and a first flow meter are arranged between the first inlet of the ejector assembly and the oxygen source.

4. A fuel cell cathode gas supply system according to claim 3, wherein A intercooler is arranged between the air compressor and the humidifier.

5. A fuel cell cathode gas supply system according to claim 4, wherein The second inlet of the ejector assembly is provided with an air filter, a second flow control valve and a second flow meter.

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