Fuel cell system and vehicle

Abstract

The utility model discloses a fuel cell system and a vehicle. The fuel cell system comprises an electric pile; the hydrogen storage bottle is used for supplying hydrogen to the electric pile; the mixing valve assembly comprises two ejectors and an ejector, the two ejectors are both communicated with the hydrogen storage bottle and are both provided with proportional valves, the diameters of nozzles of the two ejectors are different, the inlet end of the ejector is communicated with the outlet ends of the two ejectors, and the outlet end of the ejector is communicated with the outlet ends of the two ejectors. The outlet end of the ejector is communicated with the inlet end of the electric pile; and the diameters of the nozzles of the two ejectors are r1 and r2 respectively, and r1 and r2 respectively meet the relational expressions that r1 is more than or equal to 3.4 mm and less than or equal to 3.8 mm, and r1 is more than or equal to 4.7 mm and less than or equal to 5.0 mm. The injector nozzles with different calibers are arranged, and the two injectors correspond to one ejector, so that the hydrogen requirements of different hydrogen storage systems and the fuel cell system of the fuel cell system are met.

Description

Technical Field

[0001] The utility model relates to the technical field of fuel cell systems, in particular to a fuel cell system and a vehicle. Background Art

[0002] As current environmental regulations become more and more stringent, fuel cells are increasingly used as an energy supply unit, especially as a power unit in motor vehicles. However, high-power fuel cell systems are limited by the lag in on-board hydrogen storage, ejectors, circulation pumps and other technologies, which hinders the application of fuel cell systems on high-power, trunk roads. Therefore, in order to meet the needs of high-power and continuous high-power output, it is necessary to focus on improving the system's hydrogen supply assembly design capabilities.

[0003] In the relevant technologies, fuel cell systems are all used in urban or branch line operation scenarios below 200KW. In addition, the limitations of gas cylinder hydrogen storage capacity and circulating pump reflux volume make it impossible for high-power vehicles to operate stably and for a long time. If this problem cannot be solved, the fuel cell system will be limited to driving in specific scenarios and cannot meet the application scenarios of long-distance trunk lines. Utility Model Content

[0004] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model proposes a fuel cell system, which meets the hydrogen demand of different hydrogen storage systems and fuel cell systems of the fuel cell system by setting injector nozzles of different calibers and making two injectors and one ejector correspond to each other.

[0005] The utility model also provides a vehicle.

[0006] According to the first aspect of the present invention, the fuel cell system comprises: a hydrogen storage bottle; the mixing valve assembly comprises: two injectors and an ejector, the two injectors are connected to the hydrogen storage bottle and are provided with a proportional valve, the nozzles of the two injectors have different calibers, the inlet end of the ejector is connected to the outlet end of the two injectors; and a fuel cell stack, the outlet end of the ejector is connected to the inlet end of the fuel cell stack.

[0007] According to the fuel cell system of the embodiment of the utility model, injector nozzles with different calibers are provided to meet the hydrogen demand of different hydrogen storage systems and fuel cell systems of the fuel cell system.

[0008] According to some embodiments of the present invention, the mixing valve assembly further includes: a circulation pump, wherein an inlet end of the circulation pump is connected to an outlet end of the fuel cell stack, and a reflux end of the circulation pump is connected to an inlet end of the ejector.

[0009] According to some embodiments of the present invention, the fuel cell system further includes: a gas-liquid separator, which is arranged between the circulation pump and the outlet end of the fuel cell stack, and is used to separate hydrogen.

[0010] According to some embodiments of the present invention, the fuel cell system further includes: a water drain valve and a nitrogen exhaust valve, the water drain valve and the nitrogen exhaust valve are connected in parallel to each other, and the water drain valve and the nitrogen exhaust valve are both arranged on a side of the gas-liquid separator away from the fuel cell stack.

[0011] According to some embodiments of the utility model, a hollow cavity is defined in the ejector so that the outlet ends of the two ejectors and the reflux end of the circulation pump are in fluid communication with the hollow cavity, and the output end of the ejector is defined by an orifice formed in the ejector.

[0012] According to some embodiments of the present utility model, the fuel cell system further includes: a pressure reducing valve, which is arranged between the hydrogen storage bottle and the two injectors.

[0013] According to some embodiments of the present invention, the fuel cell system further includes: a first pressure sensor and a second pressure sensor, wherein the first pressure sensor is arranged between the pressure reducing valve and the two injectors, and the second pressure sensor is arranged between the ejector and the fuel cell stack.

[0014] According to some embodiments of the present invention, the fuel cell system further includes: a first temperature sensor and a second temperature sensor, wherein the first temperature sensor is arranged between the pressure reducing valve and the two injectors, and the second temperature sensor is arranged between the injector and the fuel cell stack.

[0015] According to some embodiments of the present invention, the fuel cell system further includes: a mixing channel, which is arranged between the two injectors and the ejector and is interconnected.

[0016] The vehicle according to the second embodiment of the utility model is characterized by comprising a fuel cell system.

[0017] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0019] Figure 1 It is a simplified structural diagram of a fuel cell system according to an embodiment of the utility model.

[0020] Reference numerals:

[0021] 100. Fuel cell system;

[0022] 10. Mixing valve assembly; 11. Ejector; 12. Mixing channel; 13. Ejector; 14. Circulation pump;

[0023] 20. Battery stack;

[0024] 30. Hydrogen storage bottle;

[0025] 41. Pressure reducing valve; 42. Gas-liquid separator; 43. Drain valve; 44. Nitrogen exhaust valve; 45. First pressure sensor; 46. Second pressure sensor; 47. First temperature sensor; 48. Second temperature sensor. DETAILED DESCRIPTION

[0026] The embodiments of the present utility model are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. The embodiments of the present utility model are described in detail below.

[0027] Reference below Figure 1 A fuel cell system 100 according to an embodiment of the present invention is described. The present invention also provides a vehicle.

[0028] The fuel cell system 100 of the embodiment of the present utility model includes: a hydrogen storage bottle 30 , a mixing valve assembly 10 and a fuel cell stack 20 .

[0029] The hydrogen storage bottle 30 stores hydrogen, and the hydrogen can be in liquid or gas phase. In addition, the hydrogen storage bottle 30 is divided into three hydrogen storage modes: high-pressure gas hydrogen bottle, low-pressure gas hydrogen bottle and liquid hydrogen bottle. The hydrogen demand has nothing to do with the output pressure of the on-board hydrogen storage system, and only changes positively with the power of the fuel cell stack 20.

[0030] Wherein, the mixing valve assembly 10 includes: two injectors 11 and an ejector 13. The inlet of the injector 11 is connected to the hydrogen storage bottle 30. For the fuel cell system 100, the inhaled fluid comes from the unreacted hydrogen in the anode chamber of the stack 20, and the high-pressure driving gas is the hydrogen with a higher pressure before the injector 11. After the high-pressure gas passes through the nozzle, due to adiabatic expansion, the pressure energy in the high-pressure moving fluid is converted into kinetic energy, which increases the flow rate but reduces the pressure. At this time, due to the pressure drop of the moving fluid, it will form a low-pressure area in the mixing chamber. Due to the existence of the low-pressure area, the mixing chamber will inhale the fluid and mix the inhaled fluid with the moving fluid in the mixing chamber. The mixed fluid then enters the diffuser of the ejector 13, where they are fully mixed and the kinetic energy is converted back into pressure energy. The final result will be a mixed fluid with a pressure higher than the low-pressure inhaled fluid but lower than the high-pressure moving fluid.

[0031] Both injectors 11 are connected to the hydrogen storage bottle 30 and are provided with a proportional valve. The nozzle diameters of the two injectors 11 are different. The inlet end of the ejector 13 is connected to the outlet ends of the two injectors 11; the outlet end of the ejector 13 is connected to the inlet end of the fuel cell stack 20.

[0032] That is, the ejector 11 has two types of nozzles, which are controlled by separate proportional valves and share a common mixing channel 12. Since the pressure regulation of variable load conditions is complex and the ejection performance is low, the embodiment of the utility model includes two nozzle coupling working conditions and a circulating pump 14 auxiliary working condition.

[0033] The gas hydrogen bottle can provide a stable pressure output, which is suitable for the small-sized ejector 13 nozzle. Under low-power conditions, the circulating pump 14 can be connected in series with the ejector 13 to provide part of the ejection pressure rise. After the liquid hydrogen undergoes phase change gasification, temperature and pressure adjustment, its hydrogen supply pressure fluctuates in the opposite direction with the flow rate. However, the high-power system's hydrogen demand pressure for the stack remains unchanged, and the ejector 13 nozzle size needs to be adjusted in real time to meet the hydrogen flow demand of the fuel cell system 100 at low pressure.

[0034] In this way, two types of injector 11 nozzles, large and small, are designed. The small-sized nozzle is suitable for the on-board hydrogen system with high-pressure output, and the large-sized nozzle is suitable for the on-board hydrogen system with low pressure or decreasing pressure. The opening and closing and coupling work are adjusted through the system closed-loop control, which can meet the two on-board hydrogen storage modes of liquid hydrogen and gaseous hydrogen, and meet the hydrogen demand of the fuel cell system under all working conditions.

[0035] Furthermore, the nozzle calibers of the two injectors 11 are r1 and r2, respectively, and r1 and r2 respectively satisfy the relationship: 3.4mm≤r1≤3.8mm, 4.7mm≤r1≤5.0mm. That is, the nozzle calibers of the two injectors 11 are different, and can be achieved by either one of the two injectors 11 being turned on or the two injectors 11 being coupled to work, so that different operating conditions of different fuel cell systems 100 can be achieved.

[0036] Preferably, the nozzle diameters of the two injectors 11 are 3.6 mm and 4.85 mm respectively, that is, under these sizes, they can correspond to different output pressures of the hydrogen storage bottles.

[0037] Therefore, by setting the injector 11 nozzles with different calibers and making the two injectors 11 correspond to one ejector 13, the hydrogen demand of different hydrogen storage systems of the fuel cell system 100 and the hydrogen demand of the fuel cell system 100 can be met.

[0038] In addition, the mixing valve assembly 10 also includes: a circulation pump 14 and a gas-liquid separator 42, the inlet end of the circulation pump 14 is connected to the outlet end of the fuel cell stack 20, the reflux end of the circulation pump 14 is connected to the inlet end of the ejector 13, and the gas-liquid separator 42 is arranged between the circulation pump 14 and the outlet end of the fuel cell stack 20, and the gas-liquid separator 42 is used to separate hydrogen.

[0039] That is, in addition to the reacted hydrogen, water and nitrogen (permeated from the cathode side) are also mixed in the outlet of the fuel cell stack 20. If the liquid water mixed in the hydrogen is not treated, a large amount of liquid water will re-enter the fuel cell stack 20 through the circulation pump 14, blocking the gas diffusion layer, causing flooding, and seriously affecting the normal operation of the fuel cell stack 20.

[0040] In the hydrogen reflux channel section from the gas-liquid separator 42 to the ejector 13, the excess gas can be discharged out of the system as needed. Figure 1 As shown, a hydrogen supply port is provided at one end of the hydrogen supply channel, and a hydrogen output end is provided at the other opposite end, so that the injector 11 and the ejector 13 are sequentially connected in series in the hydrogen supply channel between the hydrogen supply port and the hydrogen output end. The hydrogen supply port is used to be connected to the hydrogen storage bottle 30, and the hydrogen output end is used to be connected to the inlet of the fuel cell stack 20.

[0041] A hydrogen reflux port is provided at one end of the hydrogen reflux channel, so that the gas-liquid separator 42 is located downstream of the hydrogen reflux port in the hydrogen reflux channel. The hydrogen reflux channel is fluidly connected to the ejector 13 at one end opposite to the hydrogen reflux port.

[0042] In addition, the fuel cell system 100 also includes: a water drain valve 43 and a nitrogen exhaust valve 44, the water drain valve 43 and the nitrogen exhaust valve 44 are connected in parallel, and the water drain valve 43 and the nitrogen exhaust valve 44 are both arranged on the side of the gas-liquid separator 42 away from the stack 20. Hydrogen reacts electrochemically with oxygen on the cathode side in the stack 20 to generate electrical energy, and the unconsumed hydrogen carries the generated liquid water and water vapor and is discharged from the outlet of the stack 20 in the stack 20 to generate circulating gas that needs to be circulated. The circulating gas is a gas-liquid two-phase fluid containing liquid water droplets, hydrogen, etc. The liquid water is separated by a gas-water separator, and the remaining gas is re-entered into the ejector 13 and ejected. The water drain and nitrogen exhaust valve 44 will be opened and closed periodically to discharge the accumulated nitrogen and liquid water.

[0043] Furthermore, a hollow cavity is defined in the ejector 13, so that the outlet ends of the two ejectors 11 and the reflux end of the circulation pump 14 are in fluid communication with the hollow cavity, and the output end of the ejector 13 is defined by the orifice formed in the ejector 13. In other words, the hollow cavity is provided in the ejector 13, so that the hydrogen discharged from the ejector 11 and the hydrogen refluxed from the circulation pump 14 can be mixed in the hollow cavity and finally discharged through the orifice formed in the ejector 13.

[0044] In addition, if Figure 1As shown, the fuel cell system 100 also includes: a pressure reducing valve 41, which is arranged between the hydrogen storage bottle 30 and the two injectors 11. The pressure reducing valve 41 reduces the inlet pressure of the pressure reducing valve 41 to a certain required outlet pressure through adjustment, and automatically maintains a stable outlet pressure by relying on the energy of the hydrogen itself. That is, the pressure reducing valve 41 is a throttling element with variable local resistance, that is, by changing the throttling area, the flow rate and the kinetic energy of the fluid are changed, resulting in different pressure losses, thereby achieving the purpose of pressure reduction, and then relying on the adjustment of the control and regulation system, the pressure after the pressure reducing valve 41 is kept constant within a certain error range.

[0045] The fuel cell system 100 further includes: a first pressure sensor 45 and a second pressure sensor 46, wherein the first pressure sensor 45 is disposed between the pressure reducing valve 41 and the two injectors 11, and the second pressure sensor 46 is disposed between the ejector 13 and the fuel cell stack 20. In the fuel cell system 100, the pressure sensors can realize the supply of hydrogen and air to ensure the normal operation of the fuel cell.

[0046] Furthermore, a first pressure sensor 45 is provided between the pressure reducing valve 41 and the mixing valve assembly 10 so as to monitor the pressure of hydrogen at the inlet end of the mixing valve assembly 10; and a second pressure sensor 46 is provided between the mixing valve assembly 10 and the fuel cell stack 20 so as to monitor the pressure of hydrogen at the inlet end of the fuel cell stack 20.

[0047] In addition, the pressure sensor detects parameters such as hydrogen content and flow rate by measuring hydrogen pressure. Its working principle is that when hydrogen acts on the sensing material, the resistance of the sensing material changes. This change is proportional to the pressure of the hydrogen. In this way, the pressure sensor can convert the hydrogen pressure into an electrical signal output to achieve monitoring and control of hydrogen.

[0048] The fuel cell system 100 further includes: a first temperature sensor 47 and a second temperature sensor 48 . The first temperature sensor 47 is disposed between the pressure reducing valve 41 and the two injectors 11 , and the second temperature sensor 48 is disposed between the ejector 13 and the fuel cell stack 20 .

[0049] In the fuel cell system 100, there are several key points in the common operating temperature. The first is the minimum temperature, also known as the cold start temperature. At low temperatures, the active materials of the fuel cell system 100 are usually not active enough and the reaction rate is slow. In order to start the fuel cell system 100 at low temperatures, a preheating method can be used to heat the battery to an appropriate temperature. This can be achieved through an external heating device or a thermal management system.

[0050] Next is the optimal operating temperature, also known as the standard operating temperature. Within this temperature range, the efficiency of the fuel cell system 100 is the highest. At the standard operating temperature, the reaction rate of hydrogen and oxygen is faster, and the energy conversion efficiency is maximized. In addition, the corrosion and degradation of the material are relatively low. Therefore, selecting an appropriate operating temperature can improve the performance and life of the fuel cell system 100.

[0051] Finally, there is the maximum temperature, also known as the overheat temperature. At high temperatures, the reaction rate of the fuel cell system 100 will be accelerated, but it will also cause corrosion and degradation of materials. In order to prevent overheating, a cooling system can be used to control the temperature of the fuel cell system 100.

[0052] In addition to affecting the performance and efficiency of the fuel cell system 100, the operating temperature also has an important impact on the startup time and response time of the fuel cell system 100. At low temperatures, the startup time of the fuel cell system 100 is longer and it takes longer to reach the operating temperature. At high temperatures, the response time of the fuel cell system 100 is shorter and can respond quickly to load changes.

[0053] Furthermore, a first temperature sensor 47 is provided between the pressure reducing valve 41 and the mixing valve assembly 10 so that the temperature of the hydrogen at the inlet end of the mixing valve assembly 10 can be monitored; and a second temperature sensor 48 is provided between the mixing valve assembly 10 and the fuel cell stack 20 so that the temperature of the hydrogen at the inlet end of the fuel cell stack 20 can be monitored.

[0054] In addition, the fuel cell system 100 further includes: a mixing channel 12, which is disposed between the two injectors 11 and the ejector 13 and is in communication with each other. That is, the mixing channel 12 is disposed between the two injectors 11 and the ejector 13, so that the two injectors 11 and the ejector 13 can be connected through the mixing channel 12, that is, the two injectors 11 and the ejector 13 can be connected together, thereby effectively reducing the cost of the ejector 13.

[0055] The vehicle according to the second embodiment of the utility model is characterized by comprising a fuel cell system 100 .

[0056] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element 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 invention.

[0057] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example.

[0058] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A fuel cell system, characterized in that: include: Battery stack; A hydrogen storage bottle, which is used to supply hydrogen to the fuel cell stack; A mixing valve assembly, the mixing valve assembly comprising: two injectors and an ejector, the two injectors are both connected to the hydrogen storage bottle and are both provided with a proportional valve, the nozzles of the two injectors have different calibers, the inlet end of the ejector is connected to the outlet ends of the two injectors, and the outlet end of the ejector is connected to the inlet end of the fuel cell stack; and, The nozzle diameters of the two injectors are r1 and r2 respectively, and r1 and r2 respectively satisfy the relationship: 3.4mm≤r1≤3.8mm, 4.7mm≤r1≤5.0mm.

2. The fuel cell system according to claim 1, characterized in that: The mixing valve assembly further includes: a circulation pump, wherein an inlet end of the circulation pump is connected to an outlet end of the fuel cell stack, and a reflux end of the circulation pump is connected to an inlet end of the ejector.

3. The fuel cell system according to claim 2, characterized in that: Also includes: A gas-liquid separator is provided between the circulation pump and the outlet end of the fuel cell stack, and is used to separate hydrogen.

4. The fuel cell system according to claim 3, characterized in that: Also includes: A water drain valve and a nitrogen exhaust valve, wherein the water drain valve and the nitrogen exhaust valve are connected in parallel with each other, and both the water drain valve and the nitrogen exhaust valve are arranged on a side of the gas-liquid separator away from the fuel cell stack.

5. The fuel cell system according to claim 2, characterized in that: The ejector is defined in a hollow cavity so that the outlet ends of the two ejectors and the return end of the circulation pump are in fluid communication with the hollow cavity, and the output end of the ejector is defined by an orifice formed in the ejector.

6. The fuel cell system according to claim 1, characterized in that: Also includes: A pressure reducing valve is arranged between the hydrogen storage bottle and the two injectors.

7. The fuel cell system according to claim 6, characterized in that: Also includes: A first pressure sensor and a second pressure sensor, wherein the first pressure sensor is disposed between the pressure reducing valve and the two injectors, and the second pressure sensor is disposed between the ejector and the fuel cell stack.

8. The fuel cell system according to claim 6, characterized in that: Also includes: A first temperature sensor and a second temperature sensor, wherein the first temperature sensor is disposed between the pressure reducing valve and the two injectors, and the second temperature sensor is disposed between the ejector and the fuel cell stack.

9. The fuel cell system according to claim 1, characterized in that: Also includes: A mixing channel is provided between the two injectors and the ejector and is in communication with each other.

10. A vehicle, characterized in that: A fuel cell system comprising the fuel cell system as claimed in any one of claims 1 to 9.

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