Megawatt fuel cell system

Abstract

The utility model discloses a megawatt fuel cell system, and particularly relates to the technical field of hydrogen fuel cells. A gas outlet of the hydrogen supply pipeline is connected with the electric pile, and the hydrogen supply pipeline is used for supplying hydrogen to the electric pile; the air supply pipeline comprises an air compressor, a freezing dryer, an air storage tank, a pressure reduction regulating valve and an air heater which are connected in sequence, and an air outlet of the air heater is connected with an air inlet of the electric pile; the humidity adjusting pipeline comprises a water supplementing tank, a water supplementing valve, a water storage tank, a high-pressure water suction pump and an atomizing nozzle which are sequentially connected, and an air outlet of the atomizing nozzle is connected with an air inlet of the air heater. According to the invention, an air supply mode adaptive to the megawatt high-power fuel cell can be provided, and the application range of the fuel cell system is enlarged.

Description

Technical Field

[0001] The present application relates to the field of hydrogen fuel cell technology, and in particular to a megawatt-class fuel cell system. Background Art

[0002] A hydrogen fuel cell is a power generation device that directly converts the chemical energy of hydrogen and oxygen into electrical energy. Its basic principle is to use the reverse reaction of water electrolysis to supply hydrogen and oxygen to the anode and cathode respectively. After hydrogen diffuses outward through the anode and reacts with the electrolyte, it releases electrons and reaches the cathode through an external load. Currently, hydrogen fuel cells have been widely used in many fields such as automotive energy and aerospace energy.

[0003] In the related technology, the fuel cell system mainly obtains oxygen by directly extracting air from the environment through an air compressor. The existing air compressor dedicated to the fuel cell system is limited by technology and the spatial layout of the fuel cell, and can only be adapted to fuel cell systems of 250kw and below, but cannot be adapted to megawatt-level high-power fuel cell systems. Therefore, the current megawatt-level high-power fuel cell system urgently needs an adapted air supply method. How to provide an air supply method that can be adapted to megawatt-level high-power fuel cells and increase the scope of application of the fuel cell system is an issue that urgently needs to be discussed and resolved. Utility Model Content

[0004] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a megawatt-class fuel cell system, which can provide an air supply method that can be adapted to megawatt-class high-power fuel cells, thereby increasing the scope of application of the fuel cell system.

[0005] A megawatt-class fuel cell system according to an embodiment of the present application includes:

[0006] Battery stack;

[0007] a hydrogen supply pipeline, the gas outlet of which is connected to the fuel cell stack and is used to supply hydrogen to the fuel cell stack;

[0008] An air supply pipeline, the air supply pipeline comprising an air compressor, a cold dryer, an air storage tank, a pressure reducing regulating valve and an air heater connected in sequence, the air outlet of the air heater being connected to the air inlet of the fuel cell stack, wherein the air compressor is used to compress the air, the cold dryer is used to cool and dry the compressed air, the air storage tank is used to store the compressed air, the pressure reducing regulating valve is used to adjust the flow rate and pressure of the output air, and the air heater is used to heat the air so that the air input to the fuel cell stack reaches a preset temperature;

[0009] A humidity regulating pipeline, the humidity regulating pipeline includes a water replenishment tank, a water replenishment valve, a water storage tank, a high-pressure water pump and an atomizing nozzle which are connected in sequence, the air outlet of the atomizing nozzle is connected to the air inlet of the air heater, wherein the water replenishment tank is used to replenish the water storage tank with water, the water replenishment valve is used to control whether the water replenishment tank replenishes the water storage tank with water, the water storage tank is used to store water, the high-pressure water pump is used to extract water from the water storage tank into the atomizing nozzle, and the atomizing nozzle is used to humidify the air input to the air heater so that the air input to the fuel cell stack reaches a preset humidity.

[0010] The megawatt-class fuel cell system according to the embodiment of the present application has at least the following beneficial effects: the present application compresses air through an air compressor, and transmits the compressed air to a gas tank after cooling and drying, and the gas tank stores the compressed air. When the power consumption of the power station is low, the air supply pipeline of the present application can store a large amount of compressed air through the gas tank, and stably supply air to the fuel cell stack when a large amount of air is needed for subsequent power generation, so that the power of the fuel cell system reaches the megawatt level, increasing the scope of application of the fuel cell system.

[0011] According to some embodiments of the present application, an air outlet pipeline is also included, and the air outlet pipeline includes a back pressure valve, a first air-water separator and a muffler connected in sequence, the air inlet of the back pressure valve is connected to the air outlet of the battery stack, the water outlet of the first air-water separator is connected to the water inlet of the water storage tank, the air outlet of the first air-water separator is connected to the air inlet of the muffler, and the air outlet of the muffler is connected to the outside, wherein the back pressure valve is used to adjust the air pressure in the battery stack, the first air-water separator is used to separate water from the gas discharged from the battery stack and transmit the separated water to the water storage tank, and the muffler is used to discharge the gas transmitted by the first air-water separator to the outside.

[0012] According to some embodiments of the present application, the hydrogen supply pipeline includes a hydrogen filter, a switch valve and a proportional valve connected in sequence, the hydrogen filter is connected to an external high-pressure hydrogen cylinder, and the outlet of the proportional valve is connected to the hydrogen inlet of the fuel cell stack, wherein the hydrogen filter is used to filter impurities in the input hydrogen, and the switch valve and the proportional valve are both used to adjust the pressure of the hydrogen input to the fuel cell stack.

[0013] According to some embodiments of the present application, a circulation pipeline is also included, which includes a gas-liquid separator and an ejector connected in sequence, the air inlet of the gas-liquid separator is connected to the air outlet of the fuel cell stack, the air outlet of the ejector is connected to the hydrogen inlet of the fuel cell stack, and the air inlet of the ejector is also connected to the air outlet of the proportional valve, wherein the gas-liquid separator is used to separate water from the gas discharged from the fuel cell stack, and the ejector is used to adsorb hydrogen in the gas-liquid separator and transmit the hydrogen to the fuel cell stack.

[0014] According to some embodiments of the present application, the air outlet pipeline also includes a mixing chamber, the air inlet of the mixing chamber is connected to the air outlet of the back pressure valve, and the air outlet of the mixing chamber is connected to the air inlet of the first gas-water separator; the circulation pipeline also includes a drain valve and an exhaust valve, the water inlet of the drain valve is connected to the water outlet of the gas-liquid separator, the water outlet of the drain valve is connected to the water inlet of the mixing chamber, the air inlet of the exhaust valve is connected to the air outlet of the gas-liquid separator, and the air outlet of the exhaust valve is connected to the air inlet of the mixing chamber, wherein the drain valve is used to discharge the water separated by the gas-liquid separator, and the exhaust valve is used to discharge the hydrogen in the gas-liquid separator when the battery stack fails, and the mixing chamber is used to mix the water discharged by the drain valve, the hydrogen discharged by the exhaust valve and the gas transmitted by the back pressure valve, and transmit them to the first gas-water separator.

[0015] According to some embodiments of the present application, a temperature regulating pipeline is also included, which includes a water pump, a thermostat, a heat dissipation branch, a heating branch and a particulate filter. The water inlet of the water pump is connected to the water outlet of the battery stack, the water outlet of the water pump is connected to the first end of the thermostat, the second end of the thermostat is connected to the water inlet of the heat dissipation branch, the third end of the thermostat is connected to the water inlet of the heating branch, the water outlet of the heat dissipation branch and the water outlet of the heating branch are both connected to the water inlet of the particulate filter, and the water outlet of the particulate filter is connected to the water inlet of the battery stack, wherein the thermostat is used to control the opening of the heat dissipation branch and the heating branch, the heat dissipation branch is used to dissipate the heat of the circulating water transmitted by the thermostat, the heating branch is used to heat the circulating water transmitted by the thermostat, and the particulate filter is used to filter impurities in the circulating water.

[0016] According to some embodiments of the present application, the heat dissipation branch includes a first heat exchanger, a second heat exchanger, a cooling tower and a plurality of stop valves, the water inlet of the first heat exchanger is connected to the second end of the thermostat, the water outlet of the first heat exchanger is connected to the water inlet of the second heat exchanger, the first heat exchanger is also connected to an external heating system, the water outlet of the second heat exchanger is connected to the water inlet of the particulate filter, the second heat exchanger is also connected to the cooling tower, and the plurality of stop valves are respectively arranged on the pipeline from the thermostat to the first heat exchanger, the pipeline from the first heat exchanger to the second heat exchanger, and the pipeline from the second heat exchanger to the particulate filter, wherein the first heat exchanger and the second heat exchanger are both used to dissipate heat for circulating water, and the stop valves are used to cut off or conduct the circulating water in the heat dissipation branch.

[0017] According to some embodiments of the present application, the heating branch includes a water heater, a water inlet of the water heater is connected to the third end of the thermostat, a water outlet of the water heater is connected to the water inlet of the particulate filter, and the water heater is used to heat the circulating water transmitted by the thermostat.

[0018] According to some embodiments of the present application, the temperature regulating pipeline also includes an expansion water tank and a deionizer, the water inlet of the deionizer is connected to the second end of the thermostat, the water outlet of the deionizer is connected to the water inlet of the expansion water tank, the water inlet of the expansion water tank is also connected to the water outlet of the particulate filter, and the water outlet of the expansion water tank is connected to the water inlet of a water pump, wherein the deionizer is used to remove ions in the circulating water, the expansion water tank is used to receive excess circulating water in the heat dissipation branch, and the expansion water tank is also used to supply circulating water to the heat dissipation branch and the heating branch.

[0019] According to some embodiments of the present application, the air supply pipeline also includes a second air-water separator, an air filter, a flow meter and a humidity sensor, the air inlet of the second air-water separator is connected to the air outlet of the air compressor, the air outlet of the second air-water separator is connected to the air inlet of the cold dryer, the air inlet of the air filter is connected to the air outlet of the pressure reducing regulating valve, the air outlet of the air filter is connected to the air inlet of the flow meter, the air outlet of the flow meter is connected to the air inlet of the air heater, and the humidity sensor is arranged at the air inlet of the fuel cell stack, wherein the second air-water separator is used to separate water from compressed air, the air filter is used to filter impurities in the air, the flow meter is used to measure the flow rate of air input into the fuel cell stack, and the humidity sensor is used to measure the humidity of air input into the fuel cell stack.

[0020] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0022] Figure 1 Schematic diagram of a megawatt-class fuel cell system according to an embodiment of the present application.

[0023] Figures: fuel cell stack 100; hydrogen supply pipeline 200; hydrogen filter 210; switch valve 220; proportional valve 230; air supply pipeline 300; air compressor 310; cold dryer 320; air storage tank 330; pressure reducing regulating valve 340; air heater 350; second air-water separator 360; air filter 370; flow meter 380; humidity sensor 390; humidity regulating pipeline 400; water supply tank 410; water supply valve 420; water storage tank 430; liquid level sensor 431; high-pressure water pump 440; atomizing nozzle 45 0; air outlet pipeline 500; back pressure valve 510; first gas-water separator 520; muffler 530; mixing chamber 540; circulation pipeline 600; gas-liquid separator 610; ejector 620; drain valve 630; exhaust valve 640; temperature regulating pipeline 700; water pump 710; thermostat 720; heat dissipation branch 730; first heat exchanger 731; second heat exchanger 732; cooling tower 733; stop valve 734; heating branch 740; water heater 741; particle filter 750; expansion water tank 760; deionizer 770. DETAILED DESCRIPTION

[0024] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0025] In the description of the present application, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0026] In the description of this application, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, and "above", "below", "within", etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0027] In the description of this application, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in this application based on the specific content of the technical solution.

[0028] A hydrogen fuel cell is a power generation device that directly converts the chemical energy of hydrogen and oxygen into electrical energy. Its basic principle is to use the reverse reaction of water electrolysis to supply hydrogen and oxygen to the anode and cathode respectively. After hydrogen diffuses outward through the anode and reacts with the electrolyte, it releases electrons and reaches the cathode through an external load. Currently, hydrogen fuel cells have been widely used in many fields such as automotive energy and aerospace energy. In related technologies, fuel cell systems mainly obtain oxygen by directly extracting air from the environment through air compressors. The existing air compressors dedicated to fuel cell systems are limited by technology and the spatial layout of fuel cells. They can only be adapted to fuel cell systems of 250kw and below, and cannot be adapted to megawatt-level high-power fuel cell systems. Therefore, the current megawatt-level high-power fuel cell system urgently needs an adapted air supply method. How to provide an air supply method that can be adapted to megawatt-level high-power fuel cells and increase the scope of application of fuel cell systems is an issue that needs to be discussed and solved urgently.

[0029] Based on this, the megawatt-class fuel cell system of the present application can provide an air supply method that can be adapted to megawatt-class high-power fuel cells, thereby increasing the scope of application of the fuel cell system.

[0030] Reference Figure 1 , Figure 1Schematic diagram of a megawatt-class fuel cell system of an embodiment of the present application. It can be understood that the megawatt-class fuel cell system of the present application includes: a fuel cell stack 100; a hydrogen supply pipeline 200, the gas outlet of the hydrogen supply pipeline 200 is connected to the fuel cell stack 100, and is used to supply hydrogen to the fuel cell stack 100; an air supply pipeline 300, the air supply pipeline 300 includes an air compressor 310, a cold dryer 320, an air storage tank 330, a pressure reducing regulating valve 340 and an air heater 350 connected in sequence, the gas outlet of the air heater 350 is connected to the air inlet of the fuel cell stack 100, wherein the air compressor 310 is used to compress the air, the cold dryer 320 is used to cool and dry the compressed air, the air storage tank 330 is used to store the compressed air, the pressure reducing regulating valve 340 is used to adjust the flow rate and pressure of the output air, and the air The air heater 350 is used to heat the air so that the air input to the fuel cell stack 100 reaches a preset temperature; the humidity regulating pipeline 400, the humidity regulating pipeline 400 includes a water replenishment tank 410, a water replenishment valve 420, a water storage tank 430, a high-pressure water pump 440 and an atomizing nozzle 450 connected in sequence, the air outlet of the atomizing nozzle 450 is connected to the air inlet of the air heater 350, wherein the water replenishment tank 410 is used to replenish water to the water storage tank 430, the water replenishment valve 420 is used to control whether the water replenishment tank 410 replenishes water to the water storage tank 430, the water storage tank 430 is used to store water, the high-pressure water pump 440 is used to extract water from the water storage tank 430 into the atomizing nozzle 450, and the atomizing nozzle 450 is used to humidify the air input to the air heater 350 so that the air input to the fuel cell stack 100 reaches a preset humidity.

[0031] It should be noted that the present application compresses air through the air compressor 310, and transmits the compressed air to the gas tank 330 after cooling and drying, and the gas tank 330 stores the compressed air. When the power consumption of the power station is off-peak, the air supply pipeline 300 of the present application can store a large amount of compressed air through the gas tank 330, and stably supply air to the fuel cell stack 100 when a large amount of air is needed for subsequent power generation, so that the power of the fuel cell system reaches the megawatt level, increasing the scope of application of the fuel cell system.

[0032] It can be understood that the air supply pipeline 300 also includes a second air-water separator 360, an air filter 370, a flow meter 380 and a humidity sensor 390, the air inlet of the second air-water separator 360 is connected to the air outlet of the air compressor 310, the air outlet of the second air-water separator 360 is connected to the air inlet of the cold dryer 320, the air inlet of the air filter 370 is connected to the air outlet of the pressure reducing regulating valve 340, the air outlet of the air filter 370 is connected to the air inlet of the flow meter 380, the air outlet of the flow meter 380 is connected to the air inlet of the air heater 350, and the humidity sensor 390 is arranged at the air inlet of the fuel cell stack 100, wherein the second air-water separator 360 is used to separate water in the compressed air, the air filter 370 is used to filter impurities in the air, the flow meter 380 is used to measure the flow rate of the air input to the fuel cell stack 100, and the humidity sensor 390 is used to measure the humidity of the air input to the fuel cell stack 100.

[0033] It should be noted that the air compressor 310 of the present application is an industrial oil-free air compressor that stores energy through air. The air from the oil-free air compressor will not cause harm to the fragile bipolar plates.

[0034] Exemplarily, the structure of the air supply pipeline 300 of the present application is explained here around the air supply process of the fuel cell system: first, the external air is compressed by the oil-free air compressor 310 to provide compressed air for the stack 100. Because the compressed air absorbs heat, which causes the air temperature to rise, it is also necessary to first separate the moisture in the compressed air through the second gas-water separator 360, and preliminarily dry the compressed air. After that, the air transmitted by the second gas-water separator 360 is cooled and dried by the cold dryer 320, and then the cooled and dried air is stored by the gas tank 330. Furthermore, when the power consumption of the power station is low, there is no need to supply a large amount of air to the stack 100. At this time, a large amount of compressed air can be stored by the gas tank 330, so that the air supply pipeline 300 of the present application is suitable for fuel cell systems of various powers.

[0035] When the fuel cell system is working, the pressure and flow of the air required by the fuel cell stack 100 can be adjusted by the pressure reducing regulating valve 340, so that the pressure and flow of the air output by the gas tank 330 match the pressure and flow of the air required by the fuel cell stack 100. After that, the air filter 370 filters the air to filter out impurities in the air, and then transmits the filtered air to the flow meter 380, which measures the flow of the air input to the fuel cell stack 100 to ensure that the flow of the air input to the fuel cell stack 100 meets the preset standard. Furthermore, after the air input into the fuel cell stack 100 comes out from the air outlet of the flow meter 380, one path of air flows to the atomizing nozzle 450, which humidifies the air and transmits the humidified air to the air heater 350; the other path of air flows to the air heater 350, the air and the humidified air are mixed, and the air is heated by the air heater 350 so that the air at the air inlet of the fuel cell stack 100 reaches a suitable temperature and humidity; finally, the humidity sensor 390 measures the humidity of the air flowing into the fuel cell stack 100 to ensure that the humidity of the air input into the fuel cell stack 100 meets the preset standard.

[0036] The structure of the humidity regulating pipeline 400 is explained here in conjunction with the scenario in which the atomizing nozzle 450 humidifies the air. When the air transmitted by the flow meter 380 needs to be humidified, the high-pressure water pump 440 draws water from the water tank 430 to the atomizing nozzle 450, and the atomizing nozzle 450 humidifies the air transmitted by the flow meter 380, so that the air at the air inlet of the fuel cell stack 100 reaches a suitable humidity.

[0037] Specifically, a liquid level sensor 431 is also provided inside the water tank 430, and the water tank 430 is also connected to the water replenishment tank 410 through a water replenishment valve 420. When the liquid level sensor 431 senses that the water inside the water tank 430 is lower than a preset height, the water replenishment valve 420 will open to replenish water to the water tank 430; when the liquid level sensor 431 senses that the water inside the water tank 430 is higher than a preset height, the water replenishment valve 420 will be closed to stop replenishing water to the water tank 430.

[0038] It can be understood that it also includes an air outlet pipeline 500, which includes a back pressure valve 510, a first gas-water separator 520 and a muffler 530 connected in sequence, the air inlet of the back pressure valve 510 is connected to the air outlet of the battery stack 100, the water outlet of the first gas-water separator 520 is connected to the water inlet of the water storage tank 430, the air outlet of the first gas-water separator 520 is connected to the air inlet of the muffler 530, and the air outlet of the muffler 530 is connected to the outside world, wherein the back pressure valve 510 is used to adjust the air pressure in the battery stack 100, the first gas-water separator 520 is used to separate water from the gas discharged from the battery stack 100 and transmit the separated water to the water storage tank 430, and the muffler 530 is used to discharge the gas transmitted by the first gas-water separator 520 to the outside world.

[0039] Exemplarily, the back pressure valve 510 is disposed at the gas outlet of the battery stack 100, and is used to adjust the gas pressure in the battery stack 100 so that the gas pressure at the cathode and anode inside the battery stack 100 can be balanced. After that, the air output by the battery stack 100 is transmitted to the mixing chamber 540, and the mixing chamber 540 mixes the hydrogen and water transmitted by the hydrogen circulation pipeline 600 with the air output by the battery stack 100, and transmits the mixed gas and water to the first gas-water separator 520, which separates them into gas and water. Since the water outlet of the first gas-water separator 520 is connected to the water storage tank 430, the first gas-water separator 520 transmits the separated water to the water storage tank 430, which stores it, and the first gas-water separator 520 transmits the separated gas to the muffler 530, and the muffler 530 discharges the gas to the outdoors.

[0040] It can be understood that the hydrogen supply pipeline 200 includes a hydrogen filter 210, a switch valve 220 and a proportional valve 230 which are connected in sequence, the hydrogen filter 210 is connected to an external high-pressure hydrogen cylinder, and the outlet of the proportional valve 230 is connected to the hydrogen inlet of the fuel cell stack 100, wherein the hydrogen filter 210 is used to filter impurities in the input hydrogen, and the switch valve 220 and the proportional valve 230 are both used to adjust the pressure of the hydrogen input to the fuel cell stack 100.

[0041] It can be understood that it also includes a circulation pipeline 600, which includes a gas-liquid separator 610 and an ejector 620 connected in sequence, the air inlet of the gas-liquid separator 610 is connected to the air outlet of the fuel cell stack 100, the air outlet of the ejector 620 is connected to the hydrogen inlet of the fuel cell stack 100, and the air inlet of the ejector 620 is also connected to the air outlet of the proportional valve 230, wherein the gas-liquid separator 610 is used to separate water from the gas discharged from the fuel cell stack 100, and the ejector 620 is used to adsorb hydrogen in the gas-liquid separator 610 and transmit the hydrogen to the fuel cell stack 100.

[0042] Reference Figure 1, exemplarily, after the external high-pressure hydrogen cylinder decompresses the hydrogen, the hydrogen is transmitted to the filter, and the filter filters the impurities in the hydrogen to prevent the impurities from damaging the bipolar plates in the stack 100. After that, the switch valve 220 and the proportional valve 230 adjust the pressure of the hydrogen input to the stack 100, and the pressure of the hydrogen is generally PID (a control algorithm, including: proportional, integral, differential) regulated according to the working power of the fuel cell and the air intake pressure. Further, in order to allow the fuel cell to work fully, it is necessary to provide excess hydrogen to the stack 100. The remaining hydrogen after the electrochemical reaction can be adsorbed back by the ejector 620 for reuse, that is, the gas-liquid separator 610 provided at the air inlet of the ejector 620 separates the water vapor refluxed in the stack 100, and the ejector 620 adsorbs the separated hydrogen back and retransmits it to the stack 100. On the other hand, since water vapor is generated after the electrochemical reaction of the battery stack 100, the condensation of water vapor will affect the supply of hydrogen. The present application can also separate the water vapor refluxed from the battery stack 100 through the gas-liquid separator 610, and the water vapor separated by the gas-liquid separator 610 is transmitted to the mixing chamber 540 by the drain valve 630.

[0043] It can be understood that the air outlet pipeline 500 also includes a mixing chamber 540, the air inlet of the mixing chamber 540 is connected to the air outlet of the back pressure valve 510, and the air outlet of the mixing chamber 540 is connected to the air inlet of the first gas-water separator 520; the circulation pipeline 600 also includes a drain valve 630 and an exhaust valve 640, the water inlet of the drain valve 630 is connected to the water outlet of the gas-liquid separator 610, the water outlet of the drain valve 630 is connected to the water inlet of the mixing chamber 540, and the air inlet of the exhaust valve 640 is connected to the air outlet of the gas-liquid separator 610. The outlet of the gas-liquid separator 610 is connected, and the outlet of the exhaust valve 640 is connected to the air inlet of the mixing chamber 540, wherein the drain valve 630 is used to discharge the water separated by the gas-liquid separator 610, and the exhaust valve 640 is used to discharge the hydrogen in the gas-liquid separator 610 when the fuel cell stack 100 fails, and the mixing chamber 540 is used to mix the water discharged by the drain valve 630, the hydrogen discharged by the exhaust valve 640 and the gas transmitted by the back pressure valve 510, and transmit them to the first gas-water separator 520.

[0044] Illustratively, when the fuel cell system is operating normally, the gas-liquid separator 610 separates the water vapor refluxed from the fuel cell stack 100, the ejector 620 adsorbs the hydrogen separated by the gas-liquid separator 610 and transmits it to the fuel cell stack 100, and the drain valve 630 transmits the water separated by the gas-liquid separator 610 to the mixing chamber 540; when the fuel cell system fails, in order to avoid the condensation of water vapor and the impact on the fuel cell stack 100, the drain valve 630 transmits the water separated by the gas-liquid separator 610 to the mixing chamber 540, and the exhaust valve 640 also transmits the hydrogen separated by the gas-liquid separator 610 to the mixing chamber 540, and they are discharged together by the muffler 530.

[0045] It can be understood that the temperature regulating pipeline 700 is also included, and the temperature regulating pipeline 700 includes a water pump 710, a thermostat 720, a heat dissipation branch 730, a heating branch 740 and a particle filter 750. The water inlet of the water pump 710 is connected to the water outlet of the fuel cell stack 100, the water outlet of the water pump 710 is connected to the first end of the thermostat 720, the second end of the thermostat 720 is connected to the water inlet of the heat dissipation branch 730, the third end of the thermostat 720 is connected to the water inlet of the heating branch 740, and the heat dissipation branch 730 is connected to the heating branch 740. The water outlet of the cooling branch 730 and the water outlet of the heating branch 740 are both connected to the water inlet of the particulate filter 750, and the water outlet of the particulate filter 750 is connected to the water inlet of the fuel cell stack 100, wherein the thermostat 720 is used to control the opening of the heat dissipation branch 730 and the heating branch 740, the heat dissipation branch 730 is used to dissipate the heat of the circulating water transmitted by the thermostat 720, the heating branch 740 is used to heat the circulating water transmitted by the thermostat 720, and the particulate filter 750 is used to filter impurities in the circulating water.

[0046] For example, with the development of fuel cell technology, the thermal management of fuel cells has also received much attention. The fuel cell power generation system continuously generates heat during the power generation process. If the heat is not dissipated in time, the temperature of the stack 100 will continue to rise. When the temperature of the stack 100 is too high, the proton exchange membrane will be dehydrated, resulting in a decrease in conductivity and poor performance of the stack 100. Therefore, it is necessary to dissipate heat from the fuel cell system in time to maintain the working temperature range of the normal electrochemical reaction inside the stack 100. Therefore, the present application also provides a heat dissipation branch 730 to dissipate heat from the circulating water flowing through the stack 100 to reduce the temperature of the stack 100.

[0047] On the other hand, in a low temperature environment below zero degrees, when the fuel cell system is started, the circulating water needs to be heated to keep the stack 100 within the operating temperature range so that the fuel cell can be started quickly. Therefore, the present application also provides a heating branch 740 to heat the circulating water flowing through the stack 100 to increase the temperature of the stack 100 in a low temperature environment.

[0048] It should be noted that in the present application, the second end of the thermostat 720 is connected to the water inlet of the heat dissipation branch 730, and the third end of the thermostat 720 is connected to the water inlet of the heating branch 740. In the fuel cell operating condition, the circulating water flow input to the heating branch 740 and the circulating water flow input to the heat dissipation branch 730 can be further controlled by controlling the opening of the thermostat 720.

[0049] Furthermore, the present application also provides a particle filter 750 at the water outlet of the heating branch 740 and the water outlet of the heat dissipation branch 730 to filter impurities in the circulating water to prevent the impurities in the circulating water from damaging the bipolar plates in the fuel cell stack 100.

[0050] It can be understood that the heat dissipation branch 730 includes a first heat exchanger 731, a second heat exchanger 732, a cooling tower 733 and a plurality of stop valves 734. The water inlet of the first heat exchanger 731 is connected to the second end of the thermostat 720, the water outlet of the first heat exchanger 731 is connected to the water inlet of the second heat exchanger 732, the first heat exchanger 731 is also connected to the external heating system, and the water outlet of the second heat exchanger 732 is connected to the water inlet of the particle filter 750. The second heat exchanger 732 is also connected to the cooling tower 733, and multiple stop valves 734 are respectively arranged on the pipeline from the thermostat 720 to the first heat exchanger 731, the pipeline from the first heat exchanger 731 to the second heat exchanger 732, and the pipeline from the second heat exchanger 732 to the particulate filter 750, wherein the first heat exchanger 731 and the second heat exchanger 732 are both used to dissipate heat for the circulating water, and the stop valve 734 is used to cut off or conduct the circulating water in the heat dissipation branch 730.

[0051] Exemplarily, the circulating water is first heat exchanged with an external heating system through the first heat exchanger 731 to cool the high-temperature circulating water and reduce the temperature of the circulating water. While initially cooling the circulating water, the purpose of heating the external heating system by the high-temperature circulating water is achieved. Then, the preliminarily cooled circulating water is heat exchanged with the cooling tower 733 through the second heat exchanger 732, and the circulating water is cooled again to reduce the temperature of the circulating water, thereby achieving the purpose of reducing the temperature of the fuel cell stack 100.

[0052] It can be understood that the heating branch 740 includes a water heater 741, the water inlet of the water heater 741 is connected to the third end of the thermostat 720, the water outlet of the water heater 741 is connected to the water inlet of the particulate filter 750, and the water heater 741 is used to heat the circulating water transmitted by the thermostat 720.

[0053] For example, in a low temperature environment below zero degrees, when the fuel cell system is started, the circulating water needs to be heated to keep the stack 100 within the operating temperature range so that the fuel cell can be started quickly. At this time, the opening of the thermostat 720 is adjusted so that the circulating water flows through the heating branch 740, and the circulating water transmitted from the third end of the thermostat 720 is heated by the water heater 741, and the heated circulating water is transmitted to the stack 100, and the stack 100 is heated to keep the stack 100 within the operating temperature range.

[0054] It can be understood that the temperature regulating pipeline 700 also includes an expansion water tank 760 and a deionizer 770, the water inlet of the deionizer 770 is connected to the second end of the thermostat 720, the water outlet of the deionizer 770 is connected to the water inlet of the expansion water tank 760, the water inlet of the expansion water tank 760 is also connected to the water outlet of the particle filter 750, and the water outlet of the expansion water tank 760 is connected to the water inlet of the water pump 710, wherein the deionizer 770 is used to remove ions in the circulating water, the expansion water tank 760 is used to receive excess circulating water in the heat dissipation branch 730, and the expansion water tank 760 is also used to supply circulating water to the heat dissipation branch 730 and the heating branch 740.

[0055] Exemplarily, in order to ensure the quality of circulating water, the present application is also provided with an expansion water tank 760 and a deionizer 770. The deionizer 770 is used to absorb the anions and cations released by the battery stack 100 and the temperature regulating pipeline 700 related parts, so that the conductivity of the temperature regulating pipeline 700 is maintained at a low value to prevent system leakage, and the expansion water tank 760 is used to store the excess circulating water in the temperature regulating pipeline 700 when the fuel cell system is just started, so as to balance the circulating water in the fuel cell system. On the other hand, the expansion water tank 760 can adjust the output water according to the actual operating conditions of the fuel cell system. When the amount of circulating water in the temperature regulating pipeline 700 is reduced, the water level of the expansion water tank 760 drops to replenish water for the temperature regulating pipeline 700, and the specific amount of replenishment needs to be determined in combination with the amount of circulating water reduced in the temperature regulating pipeline 700.

[0056] The embodiments of the present application are described in detail above in conjunction with the accompanying drawings, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present application.

Claims

1. A megawatt fuel cell system, characterized in that: include: Battery stack; a hydrogen supply pipeline, the gas outlet of which is connected to the fuel cell stack and is used to supply hydrogen to the fuel cell stack; An air supply pipeline, the air supply pipeline comprising an air compressor, a cold dryer, an air storage tank, a pressure reducing regulating valve and an air heater connected in sequence, the air outlet of the air heater being connected to the air inlet of the fuel cell stack, wherein the air compressor is used to compress the air, the cold dryer is used to cool and dry the compressed air, the air storage tank is used to store the compressed air, the pressure reducing regulating valve is used to adjust the flow rate and pressure of the output air, and the air heater is used to heat the air so that the air input to the fuel cell stack reaches a preset temperature; A humidity regulating pipeline, the humidity regulating pipeline includes a water replenishment tank, a water replenishment valve, a water storage tank, a high-pressure water pump and an atomizing nozzle which are connected in sequence, the air outlet of the atomizing nozzle is connected to the air inlet of the air heater, wherein the water replenishment tank is used to replenish the water storage tank with water, the water replenishment valve is used to control whether the water replenishment tank replenishes the water storage tank with water, the water storage tank is used to store water, the high-pressure water pump is used to extract water from the water storage tank into the atomizing nozzle, and the atomizing nozzle is used to humidify the air input to the air heater so that the air input to the fuel cell stack reaches a preset humidity.

2. The megawatt fuel cell system according to claim 1, characterized in that: It also includes an air outlet pipeline, which includes a back pressure valve, a first air-water separator and a muffler connected in sequence, the air inlet of the back pressure valve is connected to the air outlet of the battery stack, the water outlet of the first air-water separator is connected to the water inlet of the water storage tank, the air outlet of the first air-water separator is connected to the air inlet of the muffler, and the air outlet of the muffler is connected to the outside, wherein the back pressure valve is used to adjust the air pressure in the battery stack, the first air-water separator is used to separate water from the gas discharged from the battery stack and transmit the separated water to the water storage tank, and the muffler is used to discharge the gas transmitted by the first air-water separator to the outside.

3. The megawatt fuel cell system according to claim 2, characterized in that: The hydrogen supply pipeline includes a hydrogen filter, a switch valve and a proportional valve connected in sequence, the hydrogen filter is connected to an external high-pressure hydrogen cylinder, the outlet of the proportional valve is connected to the hydrogen inlet of the fuel cell stack, wherein the hydrogen filter is used to filter impurities in the input hydrogen, and the switch valve and the proportional valve are both used to adjust the pressure of the hydrogen input to the fuel cell stack.

4. The megawatt fuel cell system according to claim 3, characterized in that: It also includes a circulation pipeline, which includes a gas-liquid separator and an ejector connected in sequence, wherein the air inlet of the gas-liquid separator is connected to the air outlet of the fuel cell stack, the air outlet of the ejector is connected to the hydrogen inlet of the fuel cell stack, and the air inlet of the ejector is also connected to the air outlet of the proportional valve, wherein the gas-liquid separator is used to separate water from the gas discharged from the fuel cell stack, and the ejector is used to adsorb hydrogen in the gas-liquid separator and transmit the hydrogen to the fuel cell stack.

5. The megawatt fuel cell system according to claim 4, characterized in that: The air outlet pipeline also includes a mixing chamber, the air inlet of the mixing chamber is connected to the air outlet of the back pressure valve, and the air outlet of the mixing chamber is connected to the air inlet of the first gas-water separator; the circulation pipeline also includes a drain valve and an exhaust valve, the water inlet of the drain valve is connected to the water outlet of the gas-liquid separator, the water outlet of the drain valve is connected to the water inlet of the mixing chamber, the air inlet of the exhaust valve is connected to the air outlet of the gas-liquid separator, and the air outlet of the exhaust valve is connected to the air inlet of the mixing chamber, wherein the drain valve is used to discharge the water separated by the gas-liquid separator, and the exhaust valve is used to discharge the hydrogen in the gas-liquid separator when the battery stack fails, and the mixing chamber is used to mix the water discharged by the drain valve, the hydrogen discharged by the exhaust valve and the gas transmitted by the back pressure valve, and transmit them to the first gas-water separator.

6. The megawatt fuel cell system according to claim 1, characterized in that: It also includes a temperature regulating pipeline, which includes a water pump, a thermostat, a heat dissipation branch, a heating branch and a particle filter. The water inlet of the water pump is connected to the water outlet of the battery stack, the water outlet of the water pump is connected to the first end of the thermostat, the second end of the thermostat is connected to the water inlet of the heat dissipation branch, the third end of the thermostat is connected to the water inlet of the heating branch, the water outlet of the heat dissipation branch and the water outlet of the heating branch are both connected to the water inlet of the particle filter, and the water outlet of the particle filter is connected to the water inlet of the battery stack, wherein the thermostat is used to control the opening of the heat dissipation branch and the heating branch, the heat dissipation branch is used to dissipate the heat of the circulating water transmitted by the thermostat, the heating branch is used to heat the circulating water transmitted by the thermostat, and the particle filter is used to filter impurities in the circulating water.

7. The megawatt fuel cell system according to claim 6, characterized in that: The heat dissipation branch includes a first heat exchanger, a second heat exchanger, a cooling tower and a plurality of stop valves, wherein the water inlet of the first heat exchanger is connected to the second end of the thermostat, the water outlet of the first heat exchanger is connected to the water inlet of the second heat exchanger, the first heat exchanger is also connected to an external heating system, the water outlet of the second heat exchanger is connected to the water inlet of the particle filter, the second heat exchanger is also connected to the cooling tower, and the plurality of stop valves are respectively arranged on the pipeline from the thermostat to the first heat exchanger, the pipeline from the first heat exchanger to the second heat exchanger, and the pipeline from the second heat exchanger to the particle filter, wherein the first heat exchanger and the second heat exchanger are both used to dissipate heat for circulating water, and the stop valves are used to cut off or conduct the circulating water in the heat dissipation branch.

8. The megawatt fuel cell system according to claim 6, characterized in that: The heating branch includes a water heater, a water inlet of the water heater is connected to the third end of the thermostat, a water outlet of the water heater is connected to the water inlet of the particle filter, and the water heater is used to heat the circulating water transmitted by the thermostat.

9. The megawatt fuel cell system according to claim 6, characterized in that: The temperature regulating pipeline also includes an expansion water tank and a deionizer, the water inlet of the deionizer is connected to the second end of the thermostat, the water outlet of the deionizer is connected to the water inlet of the expansion water tank, the water inlet of the expansion water tank is also connected to the water outlet of the particle filter, and the water outlet of the expansion water tank is connected to the water inlet of the water pump, wherein the deionizer is used to remove ions in the circulating water, the expansion water tank is used to receive excess circulating water in the heat dissipation branch, and the expansion water tank is also used to supply circulating water to the heat dissipation branch and the heating branch.

10. The megawatt fuel cell system according to claim 1, characterized in that: The air supply pipeline also includes a second air-water separator, an air filter, a flow meter and a humidity sensor. The air inlet of the second air-water separator is connected to the air outlet of the air compressor, the air outlet of the second air-water separator is connected to the air inlet of the cold dryer, the air inlet of the air filter is connected to the air outlet of the pressure reducing regulating valve, the air outlet of the air filter is connected to the air inlet of the flow meter, the air outlet of the flow meter is connected to the air inlet of the air heater, and the humidity sensor is arranged at the air inlet of the fuel cell stack, wherein the second air-water separator is used to separate water from compressed air, the air filter is used to filter impurities in the air, the flow meter is used to measure the flow rate of air input to the fuel cell stack, and the humidity sensor is used to measure the humidity of air input to the fuel cell stack.

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