Multifunctional gas humidifying system of fuel cell stack test bench and control method of multifunctional gas humidifying system

Abstract

The invention provides a multifunctional gas humidifying system of a fuel cell stack test bench and a control method thereof. The multifunctional gas humidifying system comprises a first three-way valve, a pressure reducing valve, a gas inlet pipeline, a first one-way valve, a first mass flow controller, a first gas diffuser, a second one-way valve, a second mass flow controller and a second gas diffuser which are connected in sequence, a bubbling humidifying tank is arranged on the lower layer of the main tank body, a spraying humidifying tank is arranged on the middle layer of the main tank body, and a gas mixing tank, a supplementing humidifying tank and a supplementing water tank are arranged on the upper layer of the main tank body. According to the multifunctional gas humidifying system for the fuel cell stack test bench and the control method thereof, the humidifying system which is more efficient and stronger than a traditional single humidifying mode is provided. According to the combination mode, the humidifying effect of the galvanic pile test board is remarkably improved, the functionality of the galvanic pile test board is enhanced, and the test board can cope with wider working conditions and requirements.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cell stack testing, and specifically to a multifunctional gas humidification system for a fuel cell stack test bench and its control method. Background Art

[0002] A fuel cell stack is a device that can directly convert the chemical energy of fuel and oxidant into electrical energy, and is widely used in the production and research and development processes of fuel cell stacks. In order to test the performance of a fuel cell stack, it is necessary to precisely control the flow rate, temperature, humidity, and pressure of the inlet gas of the fuel cell stack. The water content in the membrane inside the fuel cell will significantly affect the proton transfer efficiency, thereby affecting the power generation performance of the fuel cell. The humidity of the anode and cathode inlet gases is an important factor affecting the water content in the membrane. Over-dry gas will cause the proton exchange membrane of the fuel cell stack to dry out, while over-wet gas may cause flooding problems, thereby affecting the performance and lifespan of the fuel cell. Therefore, during the test process, it is usually necessary to pre-humidify the anode and cathode gases and precisely adjust the gas humidity to ensure the accuracy of the test and the optimal working state of the fuel cell stack.

[0003] Currently, the humidification methods for fuel cell stacks mainly include bubbling humidification, spray humidification, and membrane humidification. The membrane humidification method has a lag in adjusting humidity and cannot precisely adjust the humidity of the gas entering the fuel cell stack. Especially when the flow rate changes suddenly, its humidity adjustment effect is poor. Therefore, most test benches use bubbling humidification or spray humidification to improve the humidification effect. However, the humidification systems of existing fuel cell stack test benches still face the following problems: The adjustment of the humidification temperature usually relies on electrically heating deionized water, but the existing systems cannot effectively cool down or dehumidify. The cooling methods are usually natural cooling or water cooling, and both of these cooling methods require a long time; when humidifying high-power fuel cell stacks, a large flow rate of gas is required for humidification, and the existing test benches are prone to uneven humidity during large-flow humidification; the pipeline from the outlet of the humidification tank to the inlet of the fuel cell stack is relatively long, and the humidified gas may condense in the pipeline, resulting in a decrease in humidity. This condensed water will have an adverse impact on the test and cannot meet the process requirements of fuel cell testing. Summary of the Invention

[0004] Aiming at the deficiencies of the existing technology, the present invention provides a multifunctional gas humidification system for a fuel cell stack test bench and its control method, which solves the problems that the existing systems cannot effectively cool down or dehumidify; the humidity is prone to be uneven during large-flow humidification; and the humidity of the gas after humidification decreases due to condensation in the pipeline.

[0005] To achieve the above objectives, the present invention is realized through the following technical solutions: A multifunctional gas humidification system for a fuel cell stack test bench and its control method, including:

[0006] A first three-way valve, a pressure reducing valve, an inlet gas pipeline, a first one-way valve, a first mass flow controller, a first gas diffuser, a second one-way valve, a second mass flow controller, a second gas diffuser, a bubbling humidifying tank at the lower layer of the main tank body, a spray humidifying tank at the middle layer, a gas mixing tank at the upper layer, as well as a supplementary humidifying tank and a supplementary water tank, which are connected in sequence.

[0007] Preferably, the inlet gas pipeline is connected to the first gas diffuser and the second gas diffuser.

[0008] Preferably, a first water heating rod is arranged in the bubbling humidifying tank and is located in the water below the first gas diffuser. An air bubble removing baffle is arranged at the edge of the lower right corner of the bubbling humidifying tank. A first temperature sensor is arranged in the water of the bubbling humidifying tank, a second liquid level sensor is arranged below the normal water surface, and a third liquid level sensor is arranged above the normal water surface. A first humidity sensor is arranged at the outlet pipeline opening of the upper right of the bubbling humidifying tank.

[0009] Preferably, a first spray head is arranged in the center above the spray humidifying tank, an outlet pipeline of the spray tank is arranged at the upper left, a first liquid level sensor and a first switch valve are arranged at the lower left, and the first liquid level sensor is located below the second gas diffuser; the second three-way valve is responsible for the opening direction and can control the outlet gas of the bubbling humidifying tank to lead to the spray humidifying tank or the gas mixing tank in the pipeline.

[0010] Preferably, the gas mixing tank includes a pressure relief valve and a pressure sensor. At the same time, three parallel and staggered horizontal baffles are designed in the gas mixing tank to make the left and right wet gases convect after entering the gas mixing tank, so as to achieve the purpose of full mixing.

[0011] Preferably, an outlet gas pipeline is opened above the gas mixing tank, and the outlet gas pipeline is sequentially connected with a heat tracing band, a second humidity sensor, a supplementary humidifying tank, a heating tank for entering the pile, a second temperature sensor, a third humidity sensor, a gas-water separator, a back pressure valve, and a deionizer.

[0012] Preferably, the supplementary humidifying tank includes a second spray head and a sixth liquid level sensor. The second spray head supplements the humidity of the passing gas. When the sixth liquid level sensor detects a high liquid level, the second switch valve is opened to make the excess water enter the supplementary water tank.

[0013] Preferably, the makeup water tank includes two inlet pipelines and three outlet pipelines, and also includes a second water heating rod, a fourth liquid level sensor, and a fifth liquid level sensor. Among them, the middle outlet pipeline is connected to the second spray water pump and the second spray head. One of the two left outlet pipelines is connected to the first spray water pump and the first spray head, and the other pipeline is connected to the third switching valve. The bubbling humidification tank is connected to the circulating water pipeline through a circulating path three-way valve. The circulating water pipeline is connected to a circulating water pump, a circulating water heating tank, and a circulating water cooler. The inlet pipeline is divided into two paths through the connected third three-way valve. One path is connected to the upper right corner of the makeup water tank, and the other path is spirally wrapped around the circulating water cooler.

[0014] A control method for a multifunctional gas humidification system of a fuel cell stack test bench includes the following steps:

[0015] S1: Input the power of the fuel cell stack to be tested;

[0016] S2: Automatically select the humidification mode. After the humidification mode is selected, it enters three independent humidification modes of S3, S8, and S13 for operation;

[0017] S3: Low-power humidification mode;

[0018] S4: Open the first three-way valve, pressure reducing valve, second one-way valve, and second mass flow controller;

[0019] S5: The gas enters the intake pipeline and is dispersed to the spray humidification tank through the second gas diffuser;

[0020] S6: Open the first spray head to spray and humidify the gas;

[0021] S7: The humidified gas enters the gas mixing tank through the outlet pipeline of the spray tank. If S7 is completed in the low-power humidification mode, then it proceeds to step S23;

[0022] S8: Medium-power humidification mode;

[0023] S9: Open the first three-way valve, pressure reducing valve, first one-way valve, and first mass flow controller;

[0024] S10: The gas enters the intake pipeline and is dispersed to the bubbling humidification tank through the first gas diffuser;

[0025] S11: The gas undergoes bubbling humidification in the bubbling humidification tank;

[0026] S12: Open the second three-way valve, and the humidified gas enters the gas mixing tank. If S12 is completed in the medium-power humidification mode, then it proceeds to step S23;

[0027] S13: High-power humidification mode;

[0028] S14: Open the first three-way valve, pressure reducing valve, first one-way valve, second one-way valve, first mass flow controller, and second mass flow controller;

[0029] S15: The gas is divided into two paths. After S15 is executed, three steps of S16, S17, and S18, as well as three steps of S19, S20, and S21, are executed in parallel;

[0030] S16: Part of the gas enters the intake pipeline and is dispersed to the bubbling humidification tank via the first gas diffuser;

[0031] S17: The gas is bubbling humidified in the bubbling humidification tank 1;

[0032] S18: Open the second three-way valve, and the humidified gas enters the gas mixing tank;

[0033] S19: Part of the gas enters the intake pipeline and is dispersed to the spray humidification tank via the second gas diffuser;

[0034] S20: Open the first spray head to spray and humidify the gas;

[0035] S21: The humidified gas enters the gas mixing tank via the outlet pipeline of the spray tank;

[0036] S22: The two paths of gas converge in the gas mixing tank;

[0037] S23: The gas enters the supplementary humidification tank through the pipeline with a heating tape;

[0038] S24: Reach the target humidity value for entering the stack;

[0039] S25: Open the second spray head to supplement the humidification of the gas;

[0040] S26: The gas is heated to the target temperature in the stack heating tank;

[0041] S27: The gas enters the stack reaction.

[0042] The present invention provides a multifunctional gas humidification system for a fuel cell stack test bench and its control method. It has the following beneficial effects:

[0043] The multi-functional gas humidification system and its control method for the fuel cell stack test bench provide a more efficient and powerful humidification system than traditional single humidification methods. This combination not only significantly improves the humidification effect of the stack test bench but also enhances its functionality, enabling the test bench to handle a wider range of working conditions and requirements. In addition, real-time detection using multiple sensors can comprehensively monitor parameters such as the liquid level, humidity, temperature, and pressure of the humidification tank, thereby dynamically adjusting the supply of deionized humidification water to ensure the stability of humidity and temperature during the test process.

[0044] The present invention quickly realizes the temperature rise and fall of deionized water in the bubbling humidification tank through the circulating water pipeline, and combines the cooler of the external deionized water passing through the circulating water pipeline to maximize the utilization of existing resources and improve the efficiency and resource utilization rate of the system. In addition, the heating tape and supplementary humidification tank in the design can ensure that the humidified gas will not condense and cause a decrease in humidity, and can temporarily supplement the humidification function when the humidity is insufficient, thereby improving the reliability and flexibility of the humidification system and meeting the humidification requirements under different working conditions. Brief Description of the Drawings

[0045] Figure 1 It is a schematic structural diagram of a multi-functional humidification system for a fuel cell stack test bench in an embodiment of the present invention;

[0046] Figure 2 It is a top view of the first gas diffuser in an embodiment of the present invention;

[0047] Figure 3 It is a top view of the second gas diffuser in an embodiment of the present invention;

[0048] Figure 4 It is a bottom view of the spray head in an embodiment of the present invention;

[0049] Figure 5 It is a schematic diagram of the bubble removal baffle in an embodiment of the present invention;

[0050] Figure 6 It is a flowchart of the humidification control method in an embodiment of the present invention.

[0051] Among them, 1. Bubbling humidification tank; 100. Inlet gas pipeline; 101. First one-way valve; 102. First mass flow controller; 103. First gas diffuser; 2. Spray humidification tank; 200. Inlet gas pipeline; 201. Second one-way valve; 202. Second mass flow controller; 203. Second gas diffuser; 3. Gas mixing tank; 300. Circulating water pipeline; 301. Circulation path three-way valve; 302. Circulating water pump; 303. Circulating water heating tank; 304. Circulating water cooler; 4. First three-way valve; 400. Inlet water pipeline; 5. Pressure reducing valve; 500. Inlet water pipeline; 6. First water heating rod; 600. Make-up water pipeline; 601. Third switching valve; 7. Bubble removal baffle; 8. First temperature sensor; 9. First liquid level sensor; 10. Second liquid level sensor; 11. Third liquid level sensor; 12. First humidity sensor; 13. Second three-way valve; 14. First switching valve; 15. First spray head; 16. Spray tank outlet gas pipeline; 17. Pressure relief valve; 18. Pressure sensor; 19. Heat tracing tape; 20. Second humidity sensor; 21. Supplementary humidification tank; 22. In-pile heating tank; 23. Second temperature sensor; 24. Third humidity sensor; 25. Gas-liquid separator; 26. Back pressure valve; 27. Deionizer; 28. Third mass flow controller; 29. Third one-way valve; 30. Third three-way valve; 31. Supplementary water tank; 32. Second water heating rod; 33. Fourth liquid level sensor; 34. Fifth liquid level sensor; 35. First spray water pump; 36. Second spray water pump; 37. Second spray head; 38. Sixth liquid level sensor; 39. Second switching valve. Detailed implementation mode

[0052] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0053] See Figure 1 The figure shows a structural schematic diagram of a multi-functional gas humidification system for a fuel cell stack test bench in an embodiment of the present invention, including the main humidification tank part: bubbling humidification tank 1; spray humidification tank 2; gas mixing tank 3.

[0054] In the embodiment, the first three-way valve 4 has the function of respectively controlling nitrogen or hydrogen to enter the pipeline. When the test bench gas humidification working mode is running, the first three-way valve controls only hydrogen to enter the pipeline. And when purging at startup or shutdown, the first three-way valve controls only nitrogen to enter the pipeline.

[0055] Further, a pressure reducing valve 5 is provided after the first three-way valve 4 in the initial intake pipeline, which can reduce the pressure of the incoming gas so that the gas pressure meets the pressure value required for the humidification operation.

[0056] In the embodiment, when operating in the low-power humidification mode, the gas passes through the second one-way valve 201 and the second mass flow controller 202 and enters the intake pipeline 200, and then diffuses through the second gas diffuser 203 into the spray humidification tank 2 to wait for spray humidification.

[0057] In the embodiment, the second gas diffuser 203 can diffuse less gas than the first gas diffuser 103. Therefore, when humidifying at low power, the amount of gas required by the stack is less than that at medium and high power.

[0058] Further, the first spray head 15 humidifies the gas in the spray humidification tank 2, and the humidified gas rises and enters the gas mixing tank 3 through the spray tank outlet pipeline 16.

[0059] Further, after the gas in the spray humidification tank 2 is humidified for a period of time, excess condensed water will be generated and deposited in the spray humidification tank 2. Therefore, a first liquid level sensor 9 and a pipeline including a first switching valve 14 are provided. When the first liquid level sensor 9 detects that the height of the condensed water in the spray humidification tank 2 exceeds the set value, the system controls the first switching valve 14 to open, so that the condensed water flows through the pipeline into the bubbling humidification tank 1.

[0060] In the embodiment, when operating in the medium-power humidification mode, the gas passes through the first one-way valve 101 and the first mass flow controller 102 and enters the intake pipeline 100, and then diffuses through the first gas diffuser 103 into the bubbling humidification tank 1 to wait for bubbling humidification. The bubbling humidification tank 1 includes a first water heating rod 6 for heating the deionized water in the tank, a first temperature sensor 8, a bubble removal baffle 7, a second liquid level sensor 10, a third liquid level sensor 11, and a first humidity sensor 12.

[0061] Further, the first temperature sensor 8 is used to detect whether the deionized water in the bubbling humidification tank 1 meets the temperature required for bubbling humidification. If the temperature is low, the first water heating rod 6 is controlled to work to raise the temperature. If the temperature is high, the first water heating rod 6 is controlled to stop working to lower the temperature.

[0062] Further, the second liquid level sensor 10 and the third liquid level sensor 11 cooperate to detect the liquid level of the deionized water in the bubbling humidification tank 1, so as to control other components to keep the liquid level of the deionized water in the bubbling humidification tank 1 at a certain height. If the liquid level is lower than the height of the second liquid level sensor 10, the system controls the third switching valve 601 to open to supplement the deionized water. If the liquid level is higher than the height of the third liquid level sensor 11, the system controls the circulation path three-way valve 301 to open, so that the excess water flows into the water collection tank.

[0063] In some embodiments, the first humidity sensor 12 is used to detect the humidity value of the gas after bubbling humidification before it enters the pipeline here. If the humidity value meets the humidification target value, the system controls the second three-way valve 13 to open, allowing the gas to flow through the vertical pipeline and into the gas mixing tank 3. If the humidity value does not meet the humidification target value, the system controls the second three-way valve 13 to open, allowing the gas to flow through the horizontal pipeline and into the spray humidification tank 2. The first spray head 15 can humidify the gas here for the second time, and then the gas enters the gas mixing tank 3 through the spray tank outlet pipeline 16.

[0064] In an embodiment, when operating in the high-power humidification mode, the amount of humidified gas required by the fuel cell stack is large, so the humidified gas is supplied by a combination of spraying and bubbling. The gas is divided into two paths after passing through the first three-way valve 4 and the pressure reducing valve 5. One path of the gas passes through the first one-way valve 101 and the first mass flow controller 102 and enters the intake pipeline 100, and then diffuses through the first gas diffuser 103 into the bubbling humidification tank 1 to wait for bubbling humidification. The other path of the gas passes through the second one-way valve 201 and the second mass flow controller 202 and enters the intake pipeline 200, and then diffuses through the second gas diffuser 203 into the spray humidification tank 2 to wait for spray humidification.

[0065] Further, one path of the gas is humidified in the bubbling humidification tank 1 and then enters the gas mixing tank 3 through the second three-way valve 13. The other path of the gas is humidified in the spray humidification tank 2 and then enters the gas mixing tank 3 through the spray tank outlet pipeline 16. There are three parallel and staggered horizontal baffles designed in the gas mixing tank 3. After the two streams of wet gas from the bubbling humidification tank 1 and the spray humidification tank 2 enter the gas mixing tank 3 respectively, they form a convection, so that the wet gas can be fully mixed. The two paths of gas converge in the gas mixing tank 3 to form a new wet gas, and then flow out through the upper pipeline and enter the next link.

[0066] Further, the gas mixing tank 3 includes a pressure relief valve 17 and a pressure sensor 18. The pressure sensor 18 is used to detect the gas pressure in the gas mixing tank 3. If it is greater than the pressure threshold, the system controls the pressure relief valve 17 to open for pressure relief.

[0067] In an embodiment, the gas in the three modes will respectively pass through the gas mixing tank 3 and enter the next link.

[0068] Specifically, the humidified gas enters the pipeline through the top outlet of the gas mixing tank 3. The pipeline is provided with a heat tracing belt 19, which is used to keep the gas temperature at the target value, that is, to keep the humidity unchanged and prevent the humidified gas from condensing in the pipeline due to low temperature, resulting in a decrease in humidity.

[0069] Further, the wet gas enters the supplementary humidification tank 21 and the in-stack heating tank 22 in sequence through the pipeline, and then enters the fuel cell stack to participate in the reaction.

[0070] Further, the charging heating tank 22 is used to heat and raise the temperature of the gas to the optimal reaction temperature before charging. A second temperature sensor 23 and a third humidity sensor 24 are provided before the gas enters the fuel cell stack to detect the temperature and humidity of the gas before charging.

[0071] It should be noted that tracing tapes are provided for all pipelines from the top outlet of the gas mixing tank 3 to the gas entering the fuel cell stack.

[0072] In the embodiment, the gas is discharged after reacting in the fuel cell stack and enters the gas-water separator 25. The separated liquid water can be reused. However, considering the water discharged after the fuel cell stack reaction, a deionizer 27 is provided to perform deionization treatment on it. At the same time, a back pressure valve 26 is also provided after the gas-water separator 25 to regulate the reaction gas pressure in the fuel cell stack by back pressure.

[0073] Further, the deionized water after passing through the deionizer 27 flows into the makeup water tank 31, so that the deionized water can be recycled and the cost can be saved.

[0074] In the embodiment, the makeup water tank 31 has three water replenishing functions, that is, it can provide humidifying spray water for the supplementary humidifying tank 21, spray water for the spray humidifying tank 2, and deionized water for the bubbling humidifying tank 1.

[0075] Specifically, when the second humidity sensor 20 detects that the humidity of the gas in the pipeline does not meet the target humidity before charging, the gas will be supplemented with humidity in the supplementary humidifying tank 21. At this time, the system controls the second spray water pump 36 to work, and the deionized water in the makeup water tank 31 is sprayed out through the second spray head 37 to supplement the humidity of the gas. A sixth liquid level sensor 38 is provided in the supplementary humidifying tank 21 to detect the liquid level of the liquid condensate water in the supplementary humidifying tank. If the detected liquid level is higher than the sixth liquid level sensor 38, the system controls the second switching valve 39 to open, so that the excess water flows back to the makeup water tank 31.

[0076] Further, the makeup water tank 31 also provides deionized humidifying water for the spray humidifying tank 2. Specifically, the system controls the first spray water pump 35 to be turned on, so that the deionized water is pumped into the first spray head 15.

[0077] Further, the makeup water tank 31 also provides deionized water for the bubbling humidifying tank 1. Specifically, when the liquid level is detected to be low by the second liquid level sensor 10, the system controls the third switching valve 601 to open, so that the deionized water in the makeup water tank 31 flows through the makeup water pipeline 600 into the bubbling humidifying tank 1.

[0078] Further, the make-up water tank 31 contains a second water heating rod 32, a fourth liquid level sensor 33, and a fifth liquid level sensor 34. The second water heating rod 32 can heat up the deionized water in the make-up water tank 31. When the fifth liquid level sensor 34 detects that the liquid level is too high, the system controls the opening of the third switching valve 601 to discharge the excess deionized water into the bubbling humidification tank 1. When the fourth liquid level sensor 33 detects that the liquid level is too low, the system controls the third mass flow controller 28 and the third one-way valve 29 to work, and the deionized water enters the pipeline and replenishes the make-up water tank 31 through the water inlet pipeline 400 or the water inlet pipeline 500.

[0079] In the embodiment, a circulating water pipeline 300 is further provided, and a circulating path three-way valve 301, a circulating water pump 302, a circulating water heating tank 303, and a circulating water cooler 304 are sequentially connected to the pipeline. The circulating water pipeline 300 can provide the function of quickly cooling or heating up the bubbling humidification tank 1.

[0080] Specifically, when the first temperature sensor 8 detects whether the temperature of the deionized water in the bubbling humidification tank 1 meets the temperature required for bubbling humidification, the above-mentioned method is to control whether the first water heating rod 6 works to realize the temperature increase or decrease of the deionized water in the bubbling humidification tank 1. This method may not be able to quickly respond to the temperature requirement, so the function of quickly cooling or heating up can be realized through the circulating water pipeline 300.

[0081] More specifically, when the first temperature sensor 8 detects that the temperature of the deionized water in the bubbling humidification tank 1 is lower than the temperature required for bubbling humidification, the system controls the opening of the circulating path three-way valve 301, the circulating water pump 302, and the circulating water heating tank 303. The water in the bubbling humidification tank 1 passes through the circulating path three-way valve 301, enters the circulating water pipeline 300 through the circulating water pump 302, and is heated by the circulating water heating tank 303, and finally returns to the bubbling humidification tank 1, so as to realize the rapid heating of the water in the bubbling humidification tank 1.

[0082] More specifically, when the first temperature sensor 8 detects that the temperature of the deionized water in the bubbling humidification tank 1 is higher than the temperature required for bubbling humidification, the system controls the opening of the circulating path three-way valve 301, the circulating water pump 302, and the circulating water cooler 304. The water in the bubbling humidification tank 1 passes through the circulating path three-way valve 301, enters the circulating water pipeline 300 through the circulating water pump 302, and realizes air-cooled heat dissipation through the circulating water cooler 304, and finally returns to the bubbling humidification tank 1, so as to realize the rapid cooling of the water in the bubbling humidification tank 1.

[0083] In some embodiments, when the first temperature sensor 8 detects that the temperature of the deionized water in the bubbling humidification tank 1 is higher than the temperature required for bubbling humidification, the system controls the opening of the circulation path three-way valve 301 and the circulation water pump 302. The water in the bubbling humidification tank 1 enters the circulation water pipeline 300 via the circulation path three-way valve 301 and through the circulation water pump 302. Meanwhile, when the deionized water in the makeup water tank 31 is insufficient, the external deionized water enters the water inlet pipeline 400 through the third mass flow controller 28 and the third one-way valve 29. At this time, the water in the circulation water pipeline 300 can be cooled by water cooling in the circulation water cooler 304 and finally return to the bubbling humidification tank 1, thereby achieving rapid cooling of the water in the bubbling humidification tank 1 by this method.

[0084] The circulation water cooler 304 through which the water in the circulation water pipeline 300 passes is spirally wrapped with the water inlet pipeline 400. Since the water temperature of the water inlet pipeline 400 is low-temperature water, this low-temperature water can be used to cool the water in the circulation water pipeline 300 by water cooling to achieve the purpose of rapidly cooling the water in the bubbling humidification tank 1.

[0085] Among them, when replenishing water to the makeup water tank 31, it is replenished in two paths, that is, through the water inlet pipeline 400 or the water inlet pipeline 500. The specific method is judged according to the requirements of the circulation water pipeline: when the water in the circulation water pipeline 300 needs to be cooled, the third three-way valve 30 is opened to make the deionized water replenish the makeup water tank 31 through the water inlet pipeline 400; when the water in the circulation water pipeline 300 does not need to be cooled, the third three-way valve 30 is opened to make the deionized water replenish the makeup water tank 31 through the water inlet pipeline 500.

[0086] In the embodiment, before starting and after stopping the humidification operation of the test bench, the entire humidification system needs to be purged with nitrogen. At this time, the first three-way valve 4 is opened to allow nitrogen to enter the pipeline to purge all pipelines of the humidification system.

[0087] It should be noted that this invention's humidification structure has a control system. All the above-mentioned sensors and control valves are electrically connected to the control system, and the control system is used to realize the automatic operation of the humidification device. In addition, the mechanisms and components in the above-mentioned embodiments can also be electrically connected to the control system to realize control operation.

[0088] It should be noted that the gas in the above-mentioned embodiments is hydrogen supplied to the anode of the fuel cell stack reaction, and the humidification medium is deionized water. Of course, in other embodiments, it can also be air (oxygen) supplied to the cathode and a liquid that can be humidified, as long as the two do not react with each other and do not affect the various components in the invention embodiments.

[0089] See Figure 2The top view of the first gas diffuser 103 in the embodiment of the present invention is shown. The gas is diffused through the air outlet panels that are each at a 120° angle. The left end is the air inlet connected to the inlet pipeline 100.

[0090] See Figure 3 The top view of the second gas diffuser 203 in the embodiment of the present invention is shown. The gas is diffused through the linear air outlet panel. The left end is the air inlet connected to the inlet pipeline 200.

[0091] See Figure 4 The bottom view of the spray head 15 in the embodiment of the present invention is shown. The deionized water is atomized and sprayed through the designed three-ring panel. The middle is the water inlet connected to the deionized water pumped out by the makeup water tank 31.

[0092] See Figure 5 The schematic diagram of the bubble removal baffle 7 in the embodiment of the present invention is shown. It is designed as an arc-shaped metal plate with small holes of a certain size. Before the deionized water in the bubbling humidification tank 1 is discharged to the external water collection tank or enters the circulating water pipeline 300 through the circulating path three-way valve 301, it will first pass through the bubble removal baffle 7, which can break the bubbles here and prevent the bubbles from entering the circulating water pump 302 and causing cavitation to it.

[0093] See Figure 6 The flowchart of the control method of a multi-functional gas humidification system for a fuel cell stack test bench in the embodiment of the present invention is shown. This method includes steps in three modes: low, medium, and high.

[0094] Humidification control three power mode adjustment: Before the fuel cell stack test bench conducts an experiment, according to the rated power or peak power of the test stack, the stack is divided into three power levels, namely low power, medium power, and high power. The three power levels correspond to three power humidification modes of the test bench, namely low power humidification mode, medium power humidification mode, and high power humidification mode.

[0095] Steps of the low power humidification mode:

[0096] S1: By checking the power of the stack to be tested, input the power value of the stack to be tested.

[0097] S2: The system will automatically divide the power level according to the obtained power value of the stack to be tested. For example, if the power of this stack to be tested belongs to the low power level, the low power humidification mode will be selected.

[0098] S3: Enter the control process in the low power humidification mode.

[0099] S4: Control to open the first three-way valve 4, pressure reducing valve 5, second one-way valve 201, and second mass flow controller 202. The gas flows through the first three-way valve 4 in sequence, is decompressed by the pressure reducing valve 5, and the second one-way valve 201 can prevent the reverse flow of the gas. The second mass flow controller 202 can control the gas flow rate.

[0100] S5: The gas smoothly enters the intake pipe 200 and is diffused by the second gas diffuser 203. The gas is diffused into the spray humidification tank 2 and waits for the next step of spray humidification.

[0101] S6: Control to open the first spray head 15. The deionized water is atomized and sprayed out through the first spray head to humidify the gas in the spray humidification tank 2.

[0102] S7: After the gas is humidified in the previous step, it enters the gas mixing tank 3 through the gas outlet pipe 16 of the spray tank.

[0103] S23: The gas enters the pipe with the heat tracing belt 19 from the gas mixing tank 3. The heat tracing belt can keep the gas warm, prevent the wet gas from condensing in the pipe due to temperature reduction and thus reduce the humidity. The gas then enters the supplementary humidification tank 21 through the pipe.

[0104] S24: When the gas passes through the second humidity sensor 20, the humidity value fed back by the sensor is compared with the target humidity value for entering the stack. It is judged whether the humidity value reaches the target humidity value for entering the stack. If "no", it jumps to S25; if "yes", it jumps to S26.

[0105] S25: Open the second spray head 37. The deionized water is atomized and sprayed out through the second spray head to temporarily supplement the humidity of the gas in the supplementary humidification tank 21. After humidification, it enters S24 for judgment again.

[0106] S26: The gas is heated to the target temperature value for entering the stack by the stack inlet heating tank.

[0107] S27: The gas enters the stack reaction.

[0108] Steps of the medium power humidification mode:

[0109] S1: By checking the power of the stack to be tested, input the power value of the stack to be tested.

[0110] S2: The system automatically divides the power level according to the obtained power value of the stack to be tested. For example, if the power of this stack to be tested belongs to the medium power level, the medium power humidification mode will be selected.

[0111] S8: Enter the control process in the medium power humidification mode.

[0112] S8.1: Enter the automatic temperature and humidity adjustment mode. The system automatically adjusts the water temperature and humidity in the humidification tank according to the real-time detected temperature and humidity information to ensure the stable humidity of the wet gas under different power modes.

[0113] S8.2: Through the PID control algorithm, adjust the data of each sensor in the humidification system in real time and feedback it to the control system for dynamic adjustment.

[0114] S9: Control to open the first three-way valve 4, pressure reducing valve 5, first check valve 101, first mass flow controller 102. The gas flows through the first three-way valve 4 in sequence, is decompressed by the pressure reducing valve 5, and the first check valve 101 can prevent the reverse flow of the gas, and the first mass flow controller 102 can control the gas flow rate.

[0115] S10: The gas smoothly enters the intake pipe 100, and is diffused by the first gas diffuser 103. The gas is diffused into the bubbling humidification tank 1 and waits for the next step of bubbling humidification.

[0116] S11: The gas is bubbling humidified in the bubbling humidification tank 1.

[0117] S12: After the gas is humidified in the previous step, control to open the second three-way valve 13. The humidified gas enters the gas mixing tank 3 through this pipe.

[0118] The steps after step S12 in the medium power humidification mode are the same as steps S23, S24, S25, S26, S27 in the low power humidification mode.

[0119] High power humidification mode steps:

[0120] S1: By checking the power of the fuel cell stack to be tested, input the power value of the fuel cell stack to be tested.

[0121] S2: The system will automatically divide the power level according to the obtained power value of the fuel cell stack to be tested. For example, if the power of this fuel cell stack to be tested belongs to the high power level, the high power humidification mode will be selected.

[0122] S13: Enter the control process in the high power humidification mode.

[0123] S14: Control to open the first three-way valve 4, pressure reducing valve 5, first check valve 101, second check valve 201, first mass flow controller 102, second mass flow controller 202. The gas flows through the first three-way valve 4 in sequence, is decompressed by the pressure reducing valve 5, the first check valve 101 can prevent the reverse flow of the gas, the first mass flow controller 102 can control the gas flow rate, the second check valve 201 can prevent the reverse flow of the gas, and the second mass flow controller 202 can control the gas flow rate.

[0124] S15: The gas is divided into two paths. One path of the gas goes through steps S16, S17, and S18, and the other path of the gas goes through steps S19, S20, and S21. The two paths of gas converge at step S22.

[0125] S16: Part of the gas enters the intake pipeline 100, and gas diffusion is carried out via the first gas diffuser 103. The gas diffuses into the bubbling humidification tank 1 and waits for the next step of bubbling humidification.

[0126] S17: The gas undergoes bubbling humidification in the bubbling humidification tank 1.

[0127] S18: After the gas is humidified in the previous step, the second three-way valve 13 is controlled to open, and the humidified gas enters the gas mixing tank 3 through this pipeline.

[0128] S19: Part of the gas enters the intake pipeline 200, and gas diffusion is carried out via the second gas diffuser 203. The gas diffuses into the spray humidification tank 2 and waits for the next step of spray humidification.

[0129] S20: The first spray head 15 is controlled to open, and deionized water is atomized and sprayed out through the first spray head to humidify the gas in the spray humidification tank 2.

[0130] S21: After the gas is humidified in the previous step, it enters the gas mixing tank 3 through the gas outlet pipeline 16 of the spray tank.

[0131] S22: The two parts of gas converge in the gas mixing tank 3 and enter the next step.

[0132] The steps after step S22 in the high-power humidification mode are the same as steps S23, S24, S25, S26, and S27 in the low-power humidification mode.

[0133] The above embodiments are only for illustrating the technical concept and features of the present invention, and the purpose is to enable those skilled in the art to understand the content of the present invention and implement it. It cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the protection scope of the present invention.

[0134] Experimental example:

[0135] Experimental equipment and conditions:

[0136] Stack model: FC-120 (rated power 120KW)

[0137] Stack peak power: 150KW

[0138] Gas source: hydrogen, air (oxygen)

[0139] Test bench humidification system: including a bubbling humidification tank, a spray humidification tank, a gas mixing tank and a makeup water tank

[0140] Ambient temperature: 25°C ± 2°C

[0141] Experiment duration: 6 hours (2 hours for each power mode)

[0142] Humidification system working modes: low-power humidification mode, medium-power humidification mode, high-power humidification mode

[0143] Temperature and humidity sensors: Equipped with multiple temperature and humidity sensors to monitor the temperature and humidity of the intake pipeline, humidification tank and gas mixing tank in real time.

[0144] Experimental steps:

[0145] Preparation work:

[0146] Ensure that all equipment is properly connected and check whether the water level, temperature and humidity sensors are working properly.

[0147] Input the rated power of the stack (120KW), and the test bench automatically selects the appropriate humidification mode.

[0148] Low-power mode experiment:

[0149] Set the stack power to 40KW.

[0150] The system starts, and the gas diffuses into the spray humidification tank 2 through the second gas diffuser 203 and is spray humidified through the first spray head 15.

[0151] Measurement data:

[0152] Initial humidity: 20%RH

[0153] Target humidity: 45%RH

[0154] Humidity after humidification: 45%RH

[0155] Humidity stabilization time: 5 minutes

[0156] Temperature change: No significant change, remaining at 25°C ± 1°C

[0157] Medium-power mode experiment:

[0158] Set the stack power to 80KW.

[0159] The system starts, and the gas enters the bubbling humidification tank 1 through the first gas diffuser 103 for humidification.

[0160] Measurement data:

[0161] Initial humidity: 30%RH

[0162] Target humidity: 55% RH

[0163] Humidity after humidification: 55% RH

[0164] Humidity stabilization time: 8 minutes

[0165] Temperature change: The temperature rises to 28°C ± 2°C

[0166] High-power mode experiment:

[0167] Set the stack power to 120 KW.

[0168] The gas is divided into two paths. One part enters the bubbling humidification tank 1, and the other part enters the spray humidification tank 2, and is spray humidified through the first spray head 15.

[0169] Measurement data:

[0170] Initial humidity: 40% RH

[0171] Target humidity: 60% RH

[0172] Humidity after humidification: 60% RH

[0173] Humidity stabilization time: 10 minutes

[0174] Temperature change: The temperature rises to 33°C ± 2°C

[0175] Experimental results and analysis:

[0176] Humidity control:

[0177] In the low-power mode, the humidification system can increase the humidity from 20% RH to 45% RH within 5 minutes, reach the target humidity, and maintain stability.

[0178] In the medium-power mode, the humidification system increases the humidity from 30% RH to 55% RH within 8 minutes, and the system works stably.

[0179] In the high-power mode, the humidification system can increase the humidity from 40% RH to 60% RH within 10 minutes, and can effectively maintain the target humidity.

[0180] Temperature regulation:

[0181] In the low-power mode, the temperature remains at 25°C ± 1°C, and no significant change occurs.

[0182] In the medium-power mode, the temperature rises to 28°C ± 2°C, and the system successfully adjusts the temperature to meet the humidification requirements.

[0183] In the high-power mode, when the temperature rises to 33°C ± 2°C, the system conducts effective temperature control through the circulating water pipeline, avoiding the influence of excessive temperature on gas humidity.

[0184] System stability:

[0185] In the three power modes, the humidity and temperature control of the humidification system have reached the expected goals, the system operates stably, and no faults occur.

[0186] In the high-power mode, the humidification system can stably provide sufficient gas humidity to ensure the normal operation of the fuel cell stack under high load conditions.

[0187] Response time:

[0188] The response time in the low-power mode is relatively short, and the humidity adjustment time is 5 minutes.

[0189] The response times in the medium-power mode and the high-power mode are 8 minutes and 10 minutes respectively, showing the gradually improved response ability of the humidification system to adapt to the humidification requirements under different power conditions.

[0190] Summary:

[0191] This experiment verifies the high-efficiency humidification performance of the multifunctional gas humidification system of the present invention under different power modes. The experimental data shows that the system can quickly and accurately adjust the gas humidity to the target value and maintain a stable state under different power modes. The humidified gas humidity reaches the preset target value, and the temperature adjustment is also effectively controlled, ensuring the reliability and accuracy during the test process.

[0192] Table 1:

[0193]

[0194]

[0195] In addition, the humidification system of the present invention can operate stably in the high-power mode and meet the high-load test requirements of the fuel cell stack. During the entire test process, the humidification system responds quickly and can automatically adjust the humidification strategy according to real-time data under different working conditions, ensuring the accuracy and stability of the fuel cell stack test.

[0196] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A multi-functional gas humidification system for a fuel cell stack test bench, characterized in that, Including: A first three-way valve, a pressure reducing valve, an inlet gas pipeline, a first one-way valve, a first mass flow controller, a first gas diffuser, a second one-way valve, a second mass flow controller, a second gas diffuser, which are connected in sequence, a bubbling humidification tank at the lower layer of the main tank body, a spray humidification tank at the middle layer, a gas mixing tank at the upper layer, as well as a supplementary humidification tank and a supplementary water tank.

2. The multifunctional gas humidification system for a fuel cell stack test bench according to claim 1, wherein: The inlet gas pipeline is connected to the first gas diffuser, and the inlet gas pipeline is connected to the second gas diffuser.

3. The multifunctional gas humidification system for a fuel cell stack test bench according to claim 1, characterized in that: A first water heating rod is arranged in the bubbling humidification tank and is located in the water below the first gas diffuser. An air bubble removal baffle is arranged at the edge of the right bottom tank body of the bubbling humidification tank. A first temperature sensor is arranged in the water of the bubbling humidification tank, a second liquid level sensor is arranged below the normal water surface, a third liquid level sensor is arranged above the normal water surface, and a first humidity sensor is arranged at the outlet pipeline opening of the upper right of the bubbling humidification tank.

4. A multifunctional gas humidification system for a fuel cell stack test bench according to claim 1, characterized in that: A first spray head is arranged in the center above the spray humidification tank, a spray tank outlet pipeline is arranged at the upper left, a first liquid level sensor and a first switch valve are arranged at the lower left, and the first liquid level sensor is located below the second gas diffuser; the second three-way valve is responsible for the opening direction and can control the gas output from the bubbling humidification tank to lead to the spray humidification tank or the gas mixing tank in the pipeline.

5. A multifunctional gas humidification system for a fuel cell stack test bench according to claim 1, characterized in that: The gas mixing tank includes a pressure relief valve and a pressure sensor, and at the same time, three parallel and staggered horizontal baffles are designed in the gas mixing tank.

6. The multifunctional gas humidification system for a fuel cell stack test bench according to claim 1, wherein: An outlet gas pipeline is opened above the gas mixing tank, and the outlet gas pipeline is sequentially connected with a heat tracing belt, a second humidity sensor, a supplementary humidification tank, an in-pile heating tank, a second temperature sensor, a third humidity sensor, a gas-water separator, a back pressure valve, and a deionizer.

7. A multifunctional gas humidification system for a fuel cell stack test bench according to claim 1, characterized in that: The supplementary humidification tank includes a second spray head and a sixth liquid level sensor. The second spray head conducts supplementary humidification on the passing gas. When the sixth liquid level sensor detects a high liquid level, the second switch valve is opened to enable the excess water to enter the supplementary water tank.

8. A multifunctional gas humidification system for a fuel cell stack test bench according to claim 1, characterized in that: The supplementary water tank includes two inlet water pipelines and three outlet water pipelines, and also includes a second water heating rod, a fourth liquid level sensor, and a fifth liquid level sensor. Among them, the middle outlet water pipeline is connected to a second spray water pump and the second spray head. One of the two left outlet water pipelines is connected to the first spray water pump and the first spray head, and the other pipeline is connected to the third switch valve. The bubbling humidification tank is connected to the circulating water pipeline through a circulating path three-way valve. The circulating water pipeline is connected to a circulating water pump, a circulating water heating tank, and a circulating water cooler. The inlet water pipeline is divided into two paths through the connected third three-way valve.

9. A control method for a multi-functional gas humidification system of a fuel cell stack test bench, characterized in that, Including the following steps: S1: Input the power of the fuel cell stack to be measured; S2: Automatically select the humidification mode. After the humidification mode is selected, it transfers to three independent humidification modes of S3, S8, and S13 for operation; S3: Low-power humidification mode; S4: Open the first three-way valve, the pressure reducing valve, the second one-way valve, and the second mass flow controller; S5: The gas enters the inlet pipeline and is dispersed to the spray humidification tank through the second gas diffuser; S6: The first spray head is opened to conduct spray humidification on the gas; S7: The humidified gas enters the gas mixing tank through the spray tank outlet pipeline; If S7 is completed in the low-power humidification mode, then the process proceeds to step S23; S8: Medium-power humidification mode; S9: Open the first three-way valve, pressure reducing valve, first check valve, and first mass flow controller; S10: The gas enters the intake pipe and is dispersed through the first gas diffuser into the bubbling humidification tank; S11: The gas undergoes bubbling humidification in the bubbling humidification tank; S12: Open the second three-way valve, and the humidified gas enters the gas mixing tank. If S12 is completed in the medium-power humidification mode, then the process proceeds to step S23; S13: High-power humidification mode; S14: Open the first three-way valve, pressure reducing valve, first check valve, second check valve, first mass flow controller, and second mass flow controller; S15: The gas is divided into two paths; After S15 is completed, steps S16, S17, and S18, as well as steps S19, S20, and S21, are executed in parallel; S16: Part of the gas enters the intake pipe and is dispersed through the first gas diffuser into the bubbling humidification tank; S17: The gas undergoes bubbling humidification in the bubbling humidification tank 1; S18: Open the second three-way valve, and the humidified gas enters the gas mixing tank; S19: Part of the gas enters the intake pipe and is dispersed through the second gas diffuser into the spray humidification tank; S20: Open the first spray head to spray and humidify the gas; S21: The humidified gas enters the gas mixing tank through the spray tank outlet pipe; S22: The two paths of gas converge in the gas mixing tank; S23: The gas enters the supplementary humidification tank through the pipe with a heating tape; S24: Reach the target humidity value for entering the stack; S25: Open the second spray head to supplement the humidification of the gas; S26: Heat the gas to the target temperature in the stack inlet heating tank; S27: The gas enters the stack reaction.

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