Hydrogenation control method and system for hydrogen fuel cell vehicle

Abstract

The invention discloses a hydrogenation control method and system for a hydrogen fuel cell vehicle, and belongs to the technical field of hydrogen fuel cell vehicles. Comprising the following steps: S1, after the hydrogen fuel cell automobile is off line and before hydrogenation operation is carried out, carrying out vacuumizing operation on a hydrogen bottle in a fuel cell system; s2, judging whether the pressure of the hydrogen bottle reaches a preset absolute pressure value or not, and if not, continuing to vacuumize the hydrogen bottle; s3, when the pressure of the hydrogen bottle reaches a preset absolute pressure value, filling the hydrogen bottle with hydrogen of which the purity is greater than 99.97%; s4, detecting whether the purity of the hydrogen in the hydrogen cylinder is greater than 99.97% or not, if not, calculating the difference value between the purity at the moment and 99.97%, when the difference value is less than 0.02%, continuing to fill the hydrogen cylinder with the hydrogen with the purity greater than 99.97%, and when the difference value is greater than 0.02%, firstly emptying the hydrogen cylinder, and then carrying out the operations of the steps S1-S3; and S5, when the purity of the hydrogen in the hydrogen cylinder is greater than 99.97%, the vehicle supplemented with the hydrogen can enter a subsequent debugging link.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen fuel cell vehicles, and in particular to a hydrogen refueling control method and system for hydrogen fuel cell vehicles. Background Art

[0002] Hydrogen fuel cell vehicles, as efficient and clean new energy vehicles, have garnered widespread attention and development in recent years. They convert hydrogen's chemical energy directly into electrical energy through an electrochemical reaction to propel the vehicle, offering significant advantages such as zero emissions and high energy conversion efficiency. Hydrogen refueling is crucial to the operation of hydrogen fuel cell vehicles. Currently, hydrogen fuel cell vehicles commonly use high-pressure hydrogen cylinders for hydrogen storage. Due to hydrogen's flammability and explosiveness, as well as strict regulations governing the transportation of hazardous chemicals, hydrogen cylinders in hydrogen systems are not allowed to be filled with hydrogen at the factory. Typically, cylinders are filled with nitrogen at a slightly higher pressure than atmospheric pressure to maintain a positive pressure and effectively prevent air from entering the cylinders. However, according to the explicit requirements of GB / T37244-2018, "Hydrogen for Proton Exchange Membrane Fuel Cell Vehicles," the purity of hydrogen used in fuel cell operation must be at least 99.97%. Therefore, the nitrogen in the cylinders must be replaced with high-purity hydrogen before the vehicle is put into operation.

[0003] Existing conventional replacement methods have numerous drawbacks. Typically, the fuel cell hydrogen system is repeatedly filled with high-pressure hydrogen and then vented to expel nitrogen from the cylinder, ultimately achieving the hydrogen purity required for fuel cell operation. For example, for an 8×140L hydrogen system, three repetitive fillings and ventings at 2MPa are required to achieve the hydrogen purity required by national standards. However, this method suffers from low efficiency, long processing times, and significant hydrogen waste. A single filling and venting operation takes approximately 50 minutes, and the entire replacement process takes about 2.5 hours, wasting approximately 5kg of hydrogen. With the advancement of national fuel cell pilot demonstration policies, the focus of fuel cell vehicle applications is gradually shifting to medium- and heavy-duty vehicles. To meet the range requirements of these vehicles, the total capacity of hydrogen systems is increasing, with specifications such as 6×385L and 8×210L. For vehicles with these large-capacity hydrogen systems, the off-line replacement process is expected to take over 4 hours and consume over 7kg of hydrogen, significantly impacting production efficiency. Therefore, how to improve the hydrogen refueling efficiency of hydrogen fuel cell vehicles and reduce hydrogen loss has become a key technical issue that needs to be solved urgently. Summary of the Invention

[0004] The purpose of the present invention is to provide a hydrogen fuel cell vehicle hydrogenation control method and system to solve the current problems of low efficiency, long time and serious hydrogen waste in the hydrogen replacement process of hydrogen fuel cell vehicles, and to improve the overall performance and economy of the hydrogenation link of hydrogen fuel cell vehicles.

[0005] In view of the above problems, the technical solution proposed by the present invention is: A method for controlling hydrogen refueling of a hydrogen fuel cell vehicle comprises the following steps: S1. After the hydrogen fuel cell vehicle rolls off the production line and before the hydrogen refueling operation, the hydrogen cylinder in the fuel cell system is vacuumed; S2. Determine whether the pressure of the hydrogen bottle reaches a predetermined absolute pressure value. If not, continue to evacuate the hydrogen bottle; S3. When the pressure of the hydrogen bottle reaches a predetermined absolute pressure value, hydrogen with a purity greater than 99.97% is filled into the hydrogen bottle; S4. Check whether the purity of hydrogen in the hydrogen bottle is greater than 99.97%. If not, calculate the difference between the current purity and 99.97%. When the difference is less than 0.02%, continue to fill the hydrogen bottle with a purity greater than 99.97%. When the difference is greater than 0.02%, empty the hydrogen bottle first, and then perform the operations of steps S1-S3. S5. When the purity of hydrogen in the hydrogen bottle is greater than 99.97%, the vehicle that has been replenished with hydrogen can enter the subsequent debugging phase.

[0006] As a preferred technical solution of the present invention, the predetermined absolute pressure value in step S2 is determined based on, but not limited to, factors such as the material, design specifications, and safety standards for hydrogen filling of the hydrogen bottle. The predetermined absolute pressure value in step S2 is in the range of 10-50 Pa.

[0007] As a preferred technical solution of the present invention, during the hydrogen filling process in step S3, the hydrogen filling rate is determined based on but not limited to factors such as the volume of the hydrogen bottle, the pressure change rate that the material can withstand, and the pressure stability of the hydrogen supply source.

[0008] On the other hand, the present invention provides a system for hydrogen refueling control of a hydrogen fuel cell vehicle, comprising a hydrogen bottle, a pressure sensor installed on the side of the bottle valve of the hydrogen bottle, the pressure sensor being used to monitor the pressure of the hydrogen bottle, the bottle valve of the hydrogen bottle being connected to a first three-way valve, one port of the first three-way valve being connected to a vacuum pump, and the vacuum pump being used to evacuate the hydrogen bottle.

[0009] As a preferred technical solution of the present invention, the other port of the first three-way valve is connected to the second three-way valve, and one port of the second three-way valve is connected to a hydrogen source.

[0010] As a preferred technical solution of the present invention, the other port of the second three-way valve is connected to a pressure relief valve, the free end of the pressure relief valve is connected to an emptying valve, a hydrogen concentration sensor is connected between the pressure relief valve and the emptying valve, the pressure relief valve is used to adjust the pressure of the hydrogen bottle, the hydrogen concentration sensor is used to monitor the hydrogen concentration in the hydrogen bottle, and the emptying valve is used to empty the gas in the hydrogen bottle.

[0011] As a preferred technical solution of the present invention, it also includes a controller, which receives signals from the pressure sensor and the hydrogen concentration sensor, and controls the first three-way valve, the vacuum pump, the second three-way valve, and the hydrogen source, and the controller has a display screen.

[0012] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention performs a vacuum treatment on the hydrogen bottles in the fuel cell system after the vehicle rolls off the assembly line and before hydrogenation, which can discharge most of the nitrogen therein in advance. Compared with the traditional replacement method of multiple fillings with high-pressure hydrogen and then emptying, the number of hydrogenation replacements required to meet the hydrogen purity requirements is greatly reduced. Taking the common hydrogen system specifications as an example, the traditional method may require multiple repeated filling and emptying operations, which takes several hours. However, by adopting the method of the present invention, the hydrogen purity standard can be quickly achieved through one vacuuming and a fewer number of hydrogenation operations, which greatly shortens the replacement time and significantly improves the efficiency of hydrogen replacement during the vehicle roll-off process, which is of great significance for improving production efficiency.

[0013] Second, by reducing the number of hydrogenation and replacement, the present invention can avoid the large amount of hydrogen waste caused by multiple filling and emptying in the traditional method. In traditional operations, each time high-pressure hydrogen is filled and then emptied, a considerable amount of hydrogen will be discharged, resulting in a waste of resources and an increase in costs. However, the present invention optimizes the hydrogenation control process, performs hydrogenation operations only when necessary, and reduces the initial gas content in the hydrogen bottle by vacuuming before hydrogenation, so that each hydrogenation can more effectively improve the hydrogen purity, thereby greatly reducing hydrogen consumption and reducing the use cost and operating cost of hydrogen fuel cell vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a flow chart of a hydrogen fuel cell vehicle hydrogenation control method disclosed in an embodiment of the present invention; Figure 2 This is a block diagram of the hydrogen refueling control system for a hydrogen fuel cell vehicle disclosed in an embodiment of the present invention.

[0015] In the figure: 1. Hydrogen bottle; 2. Pressure sensor; 3. First three-way valve; 4. Vacuum pump; 5. Second three-way valve; 6. Hydrogen source; 7. Pressure relief valve; 8. Hydrogen concentration sensor; 9. Drain valve; 10. Controller. DETAILED DESCRIPTION

[0016] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0017] See also Figure 1 The present invention provides a technical solution: a hydrogen fuel cell vehicle hydrogenation control method, comprising the following steps: S1. After the hydrogen fuel cell vehicle rolls off the production line and before the hydrogen refueling operation, the hydrogen cylinder in the fuel cell system is vacuumed; S2. Determine whether the pressure of the hydrogen bottle reaches a predetermined absolute pressure value. If not, continue to evacuate the hydrogen bottle; S3. When the pressure of the hydrogen bottle reaches a predetermined absolute pressure value, hydrogen with a purity greater than 99.97% is filled into the hydrogen bottle; S4. Check whether the purity of hydrogen in the hydrogen bottle is greater than 99.97%. If it is not reached, calculate the difference between the current purity and 99.97%. When the difference is less than 0.02%, continue to fill the hydrogen bottle with a purity greater than 99.97%. When the difference is greater than 0.02%, empty the hydrogen bottle first, and then perform steps S1-S3. S5. When the purity of hydrogen in the hydrogen bottle is greater than 99.97%, the vehicle that has been replenished with hydrogen can enter the subsequent debugging phase.

[0018] As an embodiment of the present invention, further, the predetermined absolute pressure value in step S2 is determined based on, but not limited to, factors such as the material, design specifications, and safety standards for hydrogen filling of the hydrogen bottle. The predetermined absolute pressure value in step S2 is in the range of 10-50 Pa.

[0019] As an embodiment of the present invention, further, during the hydrogen filling process of step S3, the hydrogen filling rate is determined based on but not limited to factors such as the volume of the hydrogen bottle, the pressure change rate that the material can withstand, and the pressure stability of the hydrogen supply source.

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0021] See also Figure 2 The present invention provides a technical solution: a hydrogen fuel cell vehicle hydrogenation control system, comprising: a hydrogen bottle 1, a pressure sensor 2 installed on the side of the bottle valve of the hydrogen bottle 1, the pressure sensor 2 is used to monitor the pressure of the hydrogen bottle 1, the bottle valve of the hydrogen bottle 1 is connected to a first three-way valve 3, one port of the first three-way valve 3 is connected to a vacuum pump 4, and the vacuum pump 4 is used to evacuate the hydrogen bottle 1.

[0022] As an embodiment of the present invention, further, another port of the first three-way valve 3 is connected to the second three-way valve 5 , and one port of the second three-way valve 5 is connected to the hydrogen source 6 .

[0023] As an embodiment of the present invention, further, another port of the second three-way valve 5 is connected to a pressure relief valve 7, the free end of the pressure relief valve 7 is connected to an emptying valve 9, and a hydrogen concentration sensor 8 is connected between the pressure relief valve 7 and the emptying valve 9. The pressure relief valve 7 is used to adjust the pressure of the hydrogen bottle 1, the hydrogen concentration sensor 8 is used to monitor the hydrogen concentration in the hydrogen bottle 1, and the emptying valve 9 is used to empty the gas in the hydrogen bottle 1.

[0024] As an embodiment of the present invention, it further includes a controller 10, which receives signals from the pressure sensor 2 and the hydrogen concentration sensor 8, and controls the first three-way valve 3, the vacuum pump 4, the second three-way valve 5, and the hydrogen source 6, and the controller 10 has a display screen.

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] See also Figure 1-Figure 2 The present invention provides a technical solution: a hydrogen fuel cell vehicle hydrogenation control method and system, comprising the following steps: As an example of the present invention, a small hydrogen fuel cell vehicle equipped with a 4×80L hydrogen system was selected. After the vehicle was removed from the production line, it was moved to a dedicated hydrogen refueling area. The controller 10, pressure sensor 2, hydrogen concentration sensor 8, and other devices in the hydrogen refueling control system were initialized and operating normally. Operators used a sealing device to seal the hydrogen refueling port to ensure no gas leakage during the vacuum pumping and hydrogen refueling processes.

[0027] As an embodiment of the present invention, further, the controller 10 issues an instruction to start the vacuum pump 4 to perform a vacuum operation on the hydrogen bottle 1. The vacuum pump 4 is connected to the hydrogen bottle 1 through the first three-way valve 3 and starts to extract the gas in the hydrogen bottle. The pressure sensor 2 monitors the pressure in the hydrogen bottle 1 in real time and transmits the data to the controller 10. Since the hydrogen bottle is made of high-strength aluminum alloy, the design specifications require that the absolute pressure value after vacuuming is 30Pa. During the vacuuming process, the vacuum pump 4 continues to work and the pressure in the hydrogen bottle 1 gradually decreases. After about 15 minutes of vacuuming operation, the pressure sensor 2 detects that the pressure in the hydrogen bottle 1 reaches 30Pa. After receiving the signal, the controller 10 controls the vacuum pump 4 to stop working, and switches the passages of the first three-way valve 3 and the second three-way valve 5 to prepare for hydrogenation operation.

[0028] As an embodiment of the present invention, further, after switching the valve, the hydrogen source 6 is connected to the hydrogen bottle 1 through the second three-way valve 5, and hydrogen with a purity greater than 99.97% begins to be filled into the hydrogen bottle. During the hydrogenation process, taking into account the small volume of the hydrogen bottle of 80L per single, the ability of the material to withstand the rate of pressure change and the stable pressure of the hydrogen supply source, the hydrogen filling rate is set to make the pressure in the hydrogen bottle rise by 0.2MPa per minute. During the hydrogenation process, the pressure sensor 2 continuously monitors the pressure changes in the hydrogen bottle and feeds the data back to the controller 10. The controller 10 fine-tunes the hydrogen filling rate according to the pressure changes to ensure that the hydrogenation process is safe and stable. After about 20 minutes of hydrogenation operation, the hydrogenation is completed.

[0029] As an embodiment of the present invention, further, after hydrogenation is completed, the hydrogen concentration sensor 8 begins to detect the purity of the hydrogen in the hydrogen bottle 1. Upon detection, the hydrogen purity is 99.95%, which does not meet the standard requirement of 99.97%. The difference between the purity at this time and 99.97% is calculated to be 0.02%. According to the control method, the difference is equal to 0.02%, and the hydrogen bottle is selected to continue to be filled with hydrogen with a purity greater than 99.97%. After hydrogenation for another 5 minutes, the hydrogen concentration sensor 8 detects again, and the hydrogen purity reaches 99.98%, meeting the standard requirement.

[0030] As an embodiment of the present invention, after confirming that the hydrogen purity meets the standard, the vehicle enters the subsequent debugging stage. During the entire hydrogenation process, the operator can view key data such as the hydrogen bottle pressure and hydrogen purity in real time through the display screen of the controller 10, conveniently monitoring the hydrogenation process.

Claims

1. A hydrogen fuel cell vehicle hydrogenation control method, characterized in that: The following steps are involved: S1. After the hydrogen fuel cell vehicle rolls off the production line and before the hydrogen refueling operation, the hydrogen cylinder in the fuel cell system is vacuumed; S2. Determine whether the pressure of the hydrogen bottle reaches a predetermined absolute pressure value. If not, continue to evacuate the hydrogen bottle; S3. When the pressure of the hydrogen bottle reaches a predetermined absolute pressure value, hydrogen with a purity greater than 99.97% is filled into the hydrogen bottle; S4. Check whether the purity of hydrogen in the hydrogen bottle is greater than 99.97%. If not, calculate the difference between the current purity and 99.97%. When the difference is less than 0.02%, continue to fill the hydrogen bottle with a purity greater than 99.97%. When the difference is greater than 0.02%, empty the hydrogen bottle first, and then perform the operations of steps S1-S3. S5. When the purity of hydrogen in the hydrogen bottle is greater than 99.97%, the vehicle that has been replenished with hydrogen can enter the subsequent debugging phase.

2. A hydrogen fuel cell vehicle hydrogenation control method according to claim 1, characterized in that: The predetermined absolute pressure value in step S2 is determined based on, but not limited to, factors such as the material, design specifications, and safety standards for hydrogen filling of the hydrogen bottle. The predetermined absolute pressure value in step S2 is in the range of 10-50 Pa.

3. A hydrogen fuel cell vehicle hydrogenation control method according to claim 1, characterized in that: During the hydrogen filling process in step S3, the hydrogen filling rate is determined based on, but not limited to, factors such as the volume of the hydrogen bottle, the pressure change rate that the material can withstand, and the pressure stability of the hydrogen supply source.

4. A hydrogen fuel cell vehicle hydrogenation control system, as applied to a hydrogen fuel cell vehicle hydrogenation control method according to claims 1-3, characterized in that: The invention comprises a hydrogen bottle (1), wherein a pressure sensor (2) is installed on the side of a bottle valve of the hydrogen bottle (1), and the pressure sensor (2) is used to monitor the pressure of the hydrogen bottle (1); the bottle valve of the hydrogen bottle (1) is connected to a first three-way valve (3), and one port of the first three-way valve (3) is connected to a vacuum pump (4), and the vacuum pump (4) is used to evacuate the hydrogen bottle (1).

5. A hydrogen fuel cell vehicle hydrogenation control system according to claim 4, characterized in that: Another port of the first three-way valve (3) is connected to a second three-way valve (5), and one port of the second three-way valve (5) is connected to a hydrogen source (6).

6. A hydrogen fuel cell vehicle hydrogenation control system according to claim 5, characterized in that: The other port of the second three-way valve (5) is connected to a pressure relief valve (7), the free end of the pressure relief valve (7) is connected to an emptying valve (9), a hydrogen concentration sensor (8) is connected between the pressure relief valve (7) and the emptying valve (9), the pressure relief valve (7) is used to adjust the pressure of the hydrogen bottle (1), the hydrogen concentration sensor (8) is used to monitor the hydrogen concentration in the hydrogen bottle (1), and the emptying valve (9) is used to empty the gas in the hydrogen bottle (1).

7. A hydrogen fuel cell vehicle hydrogenation control system according to claim 6, characterized in that: The device further comprises a controller (10), wherein the controller (10) receives signals from the pressure sensor (2) and the hydrogen concentration sensor (8), and controls the first three-way valve (3), the vacuum pump (4), the second three-way valve (5), and the hydrogen source (6), and the controller (10) has a display screen.

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