Hydrogen filling station staged filling control method and system

Abstract

The present invention relates to the field of hydrogenation control, and provides a method and system for controlling graded filling of hydrogenation stations, including: S1: a control unit of a main station detects a replacement signal in real time, and if there is no replacement signal, it enters step S2, otherwise, a hydrogen storage bottle group replacement operation is performed; the hydrogen storage bottle group includes: a low-pressure hydrogen storage bottle, a medium-pressure hydrogen storage bottle, and a high-pressure hydrogen storage bottle; S2: the control unit of the main station detects a hydrogenation signal in real time, and if there is no hydrogenation signal, it enters step S3, otherwise, it enters step S4; S3: a long-tube trailer replenishes hydrogen to the hydrogen storage bottle group, and returns to step S1 after the replenishment is completed; S4: the hydrogen storage bottle group fills hydrogen to a hydrogen-powered vehicle, and returns to step S1 after the filling is completed. The present invention maintains the hydrogen filling rate at a high level of more than 2kg / min through the grading of hydrogen storage bottle groups and the graded filling of hydrogenation stations, thereby reducing the hydrogenation time of hydrogenation stations.

Description

Technical Field

[0001] The present invention relates to the field of hydrogenation control, and in particular to a staged filling control method and system for a hydrogenation station. Background Art

[0002] Hydrogen energy is recognized as one of the green energy sources that can replace fossil fuels. It has the advantages of light weight, abundant reserves, and good combustion performance. The European Commission describes hydrogen as an energy carrier with great potential as a clean and efficient power source in stationary, portable and transportation applications.

[0003] The use of hydrogen fuel vehicles began in the 20th century, when there were some remarkable technological breakthroughs, such as the use of hydrogen energy to power the Apollo 11 moon landing. Today, hydrogen fuel cell vehicles are gradually commercialized to solve the pollutant emissions (such as PM2.5, PM10, NO, NO2, CO and unburned hydrocarbons) and CO2 emissions of continuing fossil fuel vehicles. In practical applications, the efficiency of hydrogen fuel cells can be as high as 65%. In addition, water is the only byproduct produced during the operation of fuel cells, thus eliminating tailpipe emissions. Currently, heavy-duty fuel cell vehicles, such as trucks, are receiving increasing attention because in addition to the benefits of high efficiency and low emissions, there are also advantages of longer driving range and near-zero noise pollution.

[0004] However, in existing hydrogen refueling stations, the hydrogen storage bottle group of the hydrogen refueling station is often not optimized due to the staged filling, resulting in a problem of long hydrogen refueling time.

[0005] The above contents are only used to assist in understanding the technical solution of the present invention and do not constitute an admission that the above contents are prior art. Summary of the invention

[0006] The main purpose of the present invention is to solve the problem in the prior art that the staged filling of the hydrogen storage bottle group is not optimized, resulting in a long hydrogen filling time.

[0007] To achieve the above object, the present invention provides a method for controlling staged filling of a hydrogen filling station, comprising:

[0008] S1: The control unit of the main station detects the replacement signal in real time. If there is no replacement signal, it enters step S2, otherwise it performs a hydrogen storage bottle group replacement operation; the hydrogen storage bottle group includes: a low-pressure hydrogen storage bottle, a medium-pressure hydrogen storage bottle and a high-pressure hydrogen storage bottle;

[0009] S2: The control unit of the main station detects the hydrogenation signal in real time. If there is no hydrogenation signal, it goes to step S3, otherwise it goes to step S4;

[0010] S3: The long tube trailer replenishes hydrogen to the hydrogen storage bottle group, and after the replenishment is completed, returns to step S1;

[0011] S4: The hydrogen storage bottle group fills the hydrogen vehicle with hydrogen, and after the filling is completed, the process returns to step S1.

[0012] Preferably, the volume ratio among the low-pressure hydrogen storage bottle, the medium-pressure hydrogen storage bottle and the high-pressure hydrogen storage bottle is set to: 4:3:2.

[0013] Preferably, in step S1, the hydrogen storage bottle group replacement operation is specifically as follows:

[0014] S11: Open the vent valve of the hydrogen storage bottle group to perform a venting operation, and proceed to step S12 after confirming that there is no pressure in the hydrogen storage bottle group;

[0015] S12: Open the root valve of the hydrogen storage bottle group, and enter step S13 after confirming that the hydrogen storage bottle group is in an open state; the root valve of the hydrogen storage bottle group includes: a pressure gauge root valve, a safety valve root valve and a pressure transmitter root valve;

[0016] S13: Open the air inlet valve and close the vent valve;

[0017] S14: Open the nitrogen source and the displacement valve, and the nitrogen source purges nitrogen into the hydrogen storage bottle group;

[0018] S15: After the preset purging time T, the root valve is closed, hydrogen is added to the hydrogen storage bottle group to 3MPa, and then the vent valve is opened to discharge the hydrogen storage bottle group to a slight positive pressure;

[0019] S16: Repeat steps S11-S16 for n times, close the vent valve and the replacement valve, and open the hydrogen pipeline.

[0020] Preferably, step S3 specifically includes:

[0021] S31: The control unit of the main station detects the pressure inside the high-pressure hydrogen storage bottle. If the pressure inside the high-pressure hydrogen storage bottle is less than 42MPa, the long tube trailer replenishes hydrogen to the high-pressure hydrogen storage bottle, and the low-pressure hydrogen storage bottle and the medium-pressure hydrogen storage bottle stop replenishing hydrogen until the pressure inside the high-pressure hydrogen storage bottle reaches 45MPa, and then proceeds to step S32; otherwise, directly proceeds to step S32;

[0022] S32: The control unit of the main station detects the pressure inside the medium-pressure hydrogen storage bottle. If the pressure inside the medium-pressure hydrogen storage bottle is less than 42MPa, the long tube trailer replenishes hydrogen to the medium-pressure hydrogen storage bottle, and the low-pressure hydrogen storage bottle and the high-pressure hydrogen storage bottle stop replenishing hydrogen until the pressure inside the medium-pressure hydrogen storage bottle reaches 45MPa, and then proceeds to step S33; otherwise, directly proceeds to step S33;

[0023] S33: The control unit of the main station detects the pressure inside the low-pressure hydrogen storage bottle. If the pressure inside the low-pressure hydrogen storage bottle is less than 42MPa, the long tube trailer replenishes hydrogen to the low-pressure hydrogen storage bottle, and the medium-pressure hydrogen storage bottle and the high-pressure hydrogen storage bottle stop replenishing hydrogen until the pressure inside the low-pressure hydrogen storage bottle reaches 45MPa, and then proceeds to step S34; otherwise, directly proceeds to step S34;

[0024] S34: If the pressures in the low-pressure hydrogen storage bottle, the medium-pressure hydrogen storage bottle and the high-pressure hydrogen storage bottle all reach 45 MPa, the hydrogen compressor stops pressurizing, the hydrogen compressor performs self-circulation, and the process proceeds to step S35; otherwise, the process returns to step S31;

[0025] S35: If there is no boost command within the preset time t, the hydrogen compressor is shut down; otherwise, return to step S31.

[0026] Preferably, step S4 is specifically:

[0027] S41: Open the low-pressure hydrogen storage bottle to fill the hydrogen-powered vehicle with hydrogen, close the medium-pressure hydrogen storage bottle and the high-pressure hydrogen storage bottle, and the control unit of the main station detects the pressure inside the low-pressure hydrogen storage bottle; if the pressure difference between the pressure inside the low-pressure hydrogen storage bottle and the hydrogen pressure inside the onboard bottle of the hydrogen-powered vehicle is ≤2MPa, proceed to step S42; otherwise, repeat step S41;

[0028] S42: Open the medium-pressure hydrogen storage bottle to fill the hydrogen-powered vehicle with hydrogen, close the low-pressure hydrogen storage bottle and the high-pressure hydrogen storage bottle, and the control unit of the main station detects the pressure inside the medium-pressure hydrogen storage bottle; if the pressure difference between the pressure inside the medium-pressure hydrogen storage bottle and the hydrogen pressure inside the onboard bottle of the hydrogen-powered vehicle is ≤2MPa, proceed to step S43; otherwise, repeat step S42;

[0029] S43: Open the high-pressure hydrogen storage bottle to fill the hydrogen-powered vehicle with hydrogen, close the low-pressure hydrogen storage bottle and the medium-pressure hydrogen storage bottle, and the control unit of the main station detects the pressure inside the high-pressure hydrogen storage bottle; if the pressure difference between the pressure inside the high-pressure hydrogen storage bottle and the hydrogen pressure inside the onboard bottle of the hydrogen-powered vehicle is ≤2MPa, and the pressure inside the onboard bottle of the hydrogen-powered vehicle is less than 35MPa, then proceed to step S44; otherwise, repeat step S43;

[0030] S44: The hydrogen compressor directly pressurizes and adds hydrogen to the hydrogen-powered vehicle until the pressure in the onboard tank of the hydrogen-powered vehicle reaches 35 MPa, and the filling is completed.

[0031] A hydrogen refueling station staged refueling control system, used to implement the above-mentioned hydrogen refueling station staged refueling control method, comprising:

[0032] Long tube trailer, gas unloading cabinet, hydrogen compressor, sequence control cabinet, hydrogen storage bottle group, compressor chiller, hydrogenator, hydrogenator chiller, terminal control unit and hydrogen vehicle;

[0033] The long tube trailer is connected to the gas unloading cabinet, the gas unloading cabinet is connected to the hydrogen compressor, the hydrogen compressor is connected to the compressor chiller, the sequence control cabinet and the hydrogenator, the sequence control cabinet is connected to the hydrogen storage bottle group, the hydrogenator is connected to the hydrogenator chiller and the hydrogen vehicle,

[0034] The main station control unit is electrically connected to the gas unloading cabinet, the hydrogen compressor, the sequence control cabinet, the hydrogen storage bottle group and the hydrogenation machine.

[0035] The present invention has the following beneficial effects:

[0036] By grading hydrogen storage bottles and filling at hydrogen filling stations in stages, the hydrogen filling rate can be maintained at a high level of more than 2kg / min, reducing the hydrogen filling time at hydrogen filling stations. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a flow chart of a method according to an embodiment of the present invention;

[0038] Figure 2 The volume ratio of low, medium and high pressure hydrogen storage bottles is: the total hydrogen refueling time for ten vehicles when the volume ratio of low, medium and high pressure hydrogen storage bottles is 1:1:1;

[0039] Figure 3 The total hydrogen refueling time for ten vehicles when the volume ratio of low, medium and high pressure hydrogen storage bottles is 4:3:2;

[0040] Figure 4 This is a system structure diagram of an embodiment of the present invention;

[0041] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0042] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0043] Reference Figure 1 , the present invention provides a staged filling control method for a hydrogen filling station, which can maintain the hydrogen filling rate at a high level of more than 2kg / min;

[0044] Includes steps:

[0045] S1: The control unit of the main station detects the replacement signal in real time. If there is no replacement signal, it enters step S2, otherwise it performs a hydrogen storage bottle group replacement operation; the hydrogen storage bottle group includes: a low-pressure hydrogen storage bottle, a medium-pressure hydrogen storage bottle and a high-pressure hydrogen storage bottle;

[0046] S2: The control unit of the main station detects the hydrogenation signal in real time. If there is no hydrogenation signal, it goes to step S3, otherwise it goes to step S4;

[0047] S3: The long tube trailer replenishes hydrogen to the hydrogen storage bottle group, and after the replenishment is completed, returns to step S1;

[0048] S4: The hydrogen storage bottle group fills the hydrogen vehicle with hydrogen, and after the filling is completed, the process returns to step S1.

[0049] In this embodiment, the volume ratio between the low-pressure hydrogen storage bottle, the medium-pressure hydrogen storage bottle and the high-pressure hydrogen storage bottle is set to: 4:3:2;

[0050] Hydrogen storage in hydrogen refueling stations usually uses hydrogen storage bottle container groups. Hydrogen storage bottle container groups can store hydrogen to increase the refueling speed, and at the same time cope with the peak-shaving function of vehicle scheduling in hydrogen refueling stations. Hydrogen storage bottle groups are equipped with a series of safety facilities, such as full-opening safety valves, pressure gauges, pressure transmitters, and temperature transmitters. The hydrogen storage bottle group used in hydrogen refueling stations is the main component of the storage system, and the gas flow rate is proportional to the pressure difference. The increase in the working pressure of the hydrogen storage system will also reduce the frequency of compressor startup. The bottle group has a storage and buffering function. In order to avoid the frequent start and stop of the compressor and increase the vehicle hydrogenation rate, it is necessary to grade the bottle group.

[0051] The total water volume of a single set of hydrogen storage bottles commonly used in hydrogen refueling stations is 9m 3 , divided into three levels of low, medium and high pressure for external gas supply according to function; when using bottle groups to connect hydrogen, in order to ensure a certain flow rate and prevent the filling time from being too long, the pressure difference between the bottle group and the on-board gas cylinder (the pressure in the bottle is 5MPa when the vehicle arrives, and the pressure in the bottle is 35MPa when it is full) is generally set to be controlled above 2MPa; the main function of the low and medium pressure bottle group is to connect as much hydrogen as possible to the on-board gas cylinder under the premise of meeting the pressure difference; under the premise of meeting the pressure difference, the pressure of the low and medium pressure bottle group can continue to decrease; the main function of the high pressure bottle group is to ensure that the on-board gas cylinder is filled to the set pressure as much as possible under the premise of meeting the pressure difference, so the pressure of the high pressure bottle group should not be too low; in the filling of on-board gas cylinders, most of the hydrogen comes from the low and medium pressure bottle group, and only part of the hydrogen close to the set pressure of the on-board gas cylinder comes from the high pressure bottle group; therefore, the utilization rate of the bottle group at each pressure level is calculated as follows:

[0052] Utilization rate of high pressure bottle group: (Full filling pressure of fuel cell vehicle is 35Mpa)

[0053] Utilization rate of medium pressure bottle group: (Minimum pressure of fuel cell vehicle is 5Mpa)

[0054] Utilization rate of low-pressure bottle group: (Minimum pressure of fuel cell vehicle is 5Mpa)

[0055] It can be seen from the above calculation results that the utilization rate or gas extraction rate of the high-pressure bottle group is low, and the volume setting should not be too large. It should be smaller than the medium-pressure and low-pressure bottle groups. The utilization rate or gas extraction rate of the medium-pressure bottle group and the low-pressure bottle group is high, and the volume ratio setting should be large;

[0056] In addition, when there are vehicles coming to refuel with hydrogen, and the pressure of the low, medium and high pressure hydrogen storage bottle group is lower than the set value, the high pressure hydrogen storage bottle group will be pressurized first. If the design volume of the high pressure bottle group is small at this time, it can ensure that the high pressure hydrogen storage bottle group is filled with hydrogen higher than 35MPa (or reaches a higher pressure) in a shorter time, ensuring that the vehicle can be quickly filled to 35MPa (or can be filled to a higher pressure faster); on the contrary, if the volume of the high pressure bottle group is larger, the high pressure bottle group cannot be filled with hydrogen higher than 35MPa (or reach a higher pressure) in a shorter time; under the condition of hydrogen storage bottles in series, the filling time of the vehicle is proportional to the pressure difference between the hydrogen storage bottle and the on-board gas cylinder. A smaller pressure difference will result in too long a time for the vehicle to be filled; and it cannot be filled to the set pressure of the on-board gas cylinder;

[0057] refer to Figure 2 , when the volume ratio of low-pressure hydrogen storage bottle, medium-pressure hydrogen storage bottle and high-pressure hydrogen storage bottle is 1:1:1, the total hydrogen refueling time of ten vehicles is 267.6 minutes;

[0058] refer to Figure 3 When the volume ratio of low-pressure hydrogen storage bottle, medium-pressure hydrogen storage bottle and high-pressure hydrogen storage bottle is 4:3:2, the total hydrogen refueling time of ten vehicles is 252.6 minutes;

[0059] Based on the above reasons, taking into account the frequency of vehicle refueling and the quality of single vehicle refueling, and combined with long-term operating experience, it is more reasonable to grade the low: medium: high pressure bottle groups in 4:3:2; such graded refueling greatly improves the gas extraction rate or utilization rate of the hydrogen storage bottle group, avoids frequent start and stop of the compressor, and at the same time increases the vehicle hydrogen refueling rate, extends the service life of the compressor, and achieves the purpose of energy conservation and emission reduction.

[0060] In this embodiment, in step S1, the hydrogen storage bottle group replacement operation is specifically as follows:

[0061] S11: Open the vent valve of the hydrogen storage bottle group to perform a venting operation, and proceed to step S12 after confirming that there is no pressure in the hydrogen storage bottle group;

[0062] S12: Open the root valve of the hydrogen storage bottle group, and enter step S13 after confirming that the hydrogen storage bottle group is in an open state; the root valve of the hydrogen storage bottle group includes: a pressure gauge root valve, a safety valve root valve and a pressure transmitter root valve;

[0063] S13: Open the air inlet valve and close the vent valve;

[0064] S14: Open the nitrogen source and the displacement valve, and the nitrogen source purges nitrogen into the hydrogen storage bottle group;

[0065] S15: After the preset purging time T, the root valve is closed, hydrogen is added to the hydrogen storage bottle group to 3MPa, and then the vent valve is opened to discharge the hydrogen storage bottle group to a slight positive pressure;

[0066] S16: Repeat steps S11-S16 for n times, close the vent valve and the replacement valve, and open the hydrogen pipeline.

[0067] In this embodiment, step S3 is specifically as follows:

[0068] S31: The control unit of the main station detects the pressure inside the high-pressure hydrogen storage bottle. If the pressure inside the high-pressure hydrogen storage bottle is less than 42MPa, the long tube trailer replenishes hydrogen to the high-pressure hydrogen storage bottle, and the low-pressure hydrogen storage bottle and the medium-pressure hydrogen storage bottle stop replenishing hydrogen until the pressure inside the high-pressure hydrogen storage bottle reaches 45MPa, and then proceeds to step S32; otherwise, directly proceeds to step S32;

[0069] S32: The control unit of the main station detects the pressure inside the medium-pressure hydrogen storage bottle. If the pressure inside the medium-pressure hydrogen storage bottle is less than 42MPa, the long tube trailer replenishes hydrogen to the medium-pressure hydrogen storage bottle, and the low-pressure hydrogen storage bottle and the high-pressure hydrogen storage bottle stop replenishing hydrogen until the pressure inside the medium-pressure hydrogen storage bottle reaches 45MPa, and then proceeds to step S33; otherwise, directly proceeds to step S33;

[0070] S33: The control unit of the main station detects the pressure inside the low-pressure hydrogen storage bottle. If the pressure inside the low-pressure hydrogen storage bottle is less than 42MPa, the long tube trailer replenishes hydrogen to the low-pressure hydrogen storage bottle, and the medium-pressure hydrogen storage bottle and the high-pressure hydrogen storage bottle stop replenishing hydrogen until the pressure inside the low-pressure hydrogen storage bottle reaches 45MPa, and then proceeds to step S34; otherwise, directly proceeds to step S34;

[0071] S34: If the pressures in the low-pressure hydrogen storage bottle, the medium-pressure hydrogen storage bottle and the high-pressure hydrogen storage bottle all reach 45 MPa, the hydrogen compressor stops pressurizing, the hydrogen compressor performs self-circulation, and the process proceeds to step S35; otherwise, the process returns to step S31;

[0072] S35: If there is no boost command within the preset time t, the hydrogen compressor is shut down; otherwise, return to step S31.

[0073] In this embodiment, step S4 is specifically as follows:

[0074] S41: Open the low-pressure hydrogen storage bottle to fill the hydrogen-powered vehicle with hydrogen, close the medium-pressure hydrogen storage bottle and the high-pressure hydrogen storage bottle, and the control unit of the main station detects the pressure inside the low-pressure hydrogen storage bottle; if the pressure difference between the pressure inside the low-pressure hydrogen storage bottle and the hydrogen pressure inside the onboard bottle of the hydrogen-powered vehicle is ≤2MPa, proceed to step S42; otherwise, repeat step S41;

[0075] S42: Open the medium-pressure hydrogen storage bottle to fill the hydrogen-powered vehicle with hydrogen, close the low-pressure hydrogen storage bottle and the high-pressure hydrogen storage bottle, and the control unit of the main station detects the pressure inside the medium-pressure hydrogen storage bottle; if the pressure difference between the pressure inside the medium-pressure hydrogen storage bottle and the hydrogen pressure inside the onboard bottle of the hydrogen-powered vehicle is ≤2MPa, proceed to step S43; otherwise, repeat step S42;

[0076] S43: Open the high-pressure hydrogen storage bottle to fill the hydrogen-powered vehicle with hydrogen, close the low-pressure hydrogen storage bottle and the medium-pressure hydrogen storage bottle, and the control unit of the main station detects the pressure inside the high-pressure hydrogen storage bottle; if the pressure difference between the pressure inside the high-pressure hydrogen storage bottle and the hydrogen pressure inside the onboard bottle of the hydrogen-powered vehicle is ≤2MPa, and the pressure inside the onboard bottle of the hydrogen-powered vehicle is less than 35MPa, then proceed to step S44; otherwise, repeat step S43;

[0077] S44: The hydrogen compressor directly pressurizes and adds hydrogen to the hydrogen-powered vehicle until the pressure in the onboard tank of the hydrogen-powered vehicle reaches 35 MPa, and the filling is completed.

[0078] refer to Figure 4 The present invention provides a hydrogen refueling station staged filling control system, which is used to implement the above-mentioned hydrogen refueling station staged filling control method, including:

[0079] Long tube trailer, gas unloading cabinet, hydrogen compressor, sequence control cabinet, hydrogen storage bottle group, compressor chiller, hydrogenator, hydrogenator chiller, terminal control unit and hydrogen vehicle;

[0080] The long tube trailer is connected to the gas unloading cabinet, the gas unloading cabinet is connected to the hydrogen compressor, the hydrogen compressor is connected to the compressor chiller, the sequence control cabinet and the hydrogenator, the sequence control cabinet is connected to the hydrogen storage bottle group, the hydrogenator is connected to the hydrogenator chiller and the hydrogen vehicle,

[0081] The main station control unit is electrically connected to the gas unloading cabinet, the hydrogen compressor, the sequence control cabinet, the hydrogen storage bottle group and the hydrogenation machine.

[0082] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or system. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or system including the element.

[0083] The serial numbers of the embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments. In a unit claim that lists several means, several of these means may be embodied by the same hardware item. The use of the words first, second, and third, etc. does not indicate any order and these words may be interpreted as identifiers.

[0084] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for controlling the staged filling of a hydrogen filling station, characterized in that: include: S1: The control unit of the main station detects the replacement signal in real time. If there is no replacement signal, it enters step S2, otherwise it performs a hydrogen storage bottle group replacement operation; the hydrogen storage bottle group includes: a low-pressure hydrogen storage bottle, a medium-pressure hydrogen storage bottle and a high-pressure hydrogen storage bottle; S2: The control unit of the main station detects the hydrogenation signal in real time. If there is no hydrogenation signal, it goes to step S3, otherwise it goes to step S4; S3: The long tube trailer replenishes hydrogen to the hydrogen storage bottle group, and after the replenishment is completed, returns to step S1; S4: the hydrogen storage bottle group fills the hydrogen energy vehicle with hydrogen, and after the filling is completed, it returns to step S1; Step S3 is specifically as follows: S31: The control unit of the main station detects the pressure inside the high-pressure hydrogen storage bottle. If the pressure inside the high-pressure hydrogen storage bottle is less than 42MPa, the long tube trailer replenishes hydrogen to the high-pressure hydrogen storage bottle, and the low-pressure hydrogen storage bottle and the medium-pressure hydrogen storage bottle stop replenishing hydrogen until the pressure inside the high-pressure hydrogen storage bottle reaches 45MPa, and then proceeds to step S32; otherwise, directly proceeds to step S32; S32: The control unit of the main station detects the pressure inside the medium-pressure hydrogen storage bottle. If the pressure inside the medium-pressure hydrogen storage bottle is less than 42MPa, the long tube trailer replenishes hydrogen to the medium-pressure hydrogen storage bottle, and the low-pressure hydrogen storage bottle and the high-pressure hydrogen storage bottle stop replenishing hydrogen until the pressure inside the medium-pressure hydrogen storage bottle reaches 45MPa, and then proceeds to step S33; otherwise, directly proceeds to step S33; S33: The control unit of the main station detects the pressure inside the low-pressure hydrogen storage bottle. If the pressure inside the low-pressure hydrogen storage bottle is less than 42MPa, the long tube trailer replenishes hydrogen to the low-pressure hydrogen storage bottle, and the medium-pressure hydrogen storage bottle and the high-pressure hydrogen storage bottle stop replenishing hydrogen until the pressure inside the low-pressure hydrogen storage bottle reaches 45MPa, and then proceeds to step S34; otherwise, directly proceeds to step S34; S34: If the pressures in the low-pressure hydrogen storage bottle, the medium-pressure hydrogen storage bottle and the high-pressure hydrogen storage bottle all reach 45 MPa, the hydrogen compressor stops pressurizing, the hydrogen compressor performs self-circulation, and the process proceeds to step S35; otherwise, the process returns to step S31; S35: If there is no boost command within the preset time t, the hydrogen compressor is shut down; otherwise, return to step S31; The volume ratio between the low-pressure hydrogen storage bottle, the medium-pressure hydrogen storage bottle and the high-pressure hydrogen storage bottle is set to: 4:3:

2. In step S1, the hydrogen storage bottle group replacement operation is specifically as follows: S11: Open the vent valve of the hydrogen storage bottle group to perform a venting operation, and proceed to step S12 after confirming that there is no pressure in the hydrogen storage bottle group; S12: Open the root valve of the hydrogen storage bottle group, and enter step S13 after confirming that the hydrogen storage bottle group is in an open state; the root valve of the hydrogen storage bottle group includes: a pressure gauge root valve, a safety valve root valve and a pressure transmitter root valve; S13: Open the air inlet valve and close the vent valve; S14: Open the nitrogen source and the displacement valve, and the nitrogen source purges nitrogen into the hydrogen storage bottle group; S15: After the preset purging time T, the root valve is closed, hydrogen is added to the hydrogen storage bottle group to 3MPa, and then the vent valve is opened to discharge the hydrogen storage bottle group to a slight positive pressure; S16: repeat steps S11-S16 for n times, close the vent valve and the replacement valve, and open the hydrogen pipeline; Step S4 is specifically as follows: S41: Open the low-pressure hydrogen storage bottle to fill the hydrogen-powered vehicle with hydrogen, close the medium-pressure hydrogen storage bottle and the high-pressure hydrogen storage bottle, and the control unit of the main station detects the pressure inside the low-pressure hydrogen storage bottle; if the pressure difference between the pressure inside the low-pressure hydrogen storage bottle and the hydrogen pressure inside the onboard bottle of the hydrogen-powered vehicle is ≤2MPa, proceed to step S42; otherwise, repeat step S41; S42: Open the medium-pressure hydrogen storage bottle to fill the hydrogen-powered vehicle with hydrogen, close the low-pressure hydrogen storage bottle and the high-pressure hydrogen storage bottle, and the control unit of the main station detects the pressure inside the medium-pressure hydrogen storage bottle; if the pressure difference between the pressure inside the medium-pressure hydrogen storage bottle and the hydrogen pressure inside the onboard bottle of the hydrogen-powered vehicle is ≤2MPa, proceed to step S43; otherwise, repeat step S42; S43: Open the high-pressure hydrogen storage bottle to fill the hydrogen-powered vehicle with hydrogen, close the low-pressure hydrogen storage bottle and the medium-pressure hydrogen storage bottle, and the control unit of the main station detects the pressure inside the high-pressure hydrogen storage bottle; if the pressure difference between the pressure inside the high-pressure hydrogen storage bottle and the hydrogen pressure inside the onboard bottle of the hydrogen-powered vehicle is ≤2MPa, and the pressure inside the onboard bottle of the hydrogen-powered vehicle is less than 35MPa, then proceed to step S44; otherwise, repeat step S43; S44: The hydrogen compressor directly pressurizes and adds hydrogen to the hydrogen-powered vehicle until the pressure in the onboard tank of the hydrogen-powered vehicle reaches 35 MPa, and the filling is completed.

2. A hydrogen refueling station staged refueling control system, used to implement the hydrogen refueling station staged refueling control method as claimed in claim 1, characterized in that: include: Long tube trailer, gas unloading cabinet, hydrogen compressor, sequence control cabinet, hydrogen storage bottle group, compressor chiller, hydrogenator, hydrogenator chiller, terminal control unit and hydrogen vehicle; The long tube trailer is connected to the gas unloading cabinet, the gas unloading cabinet is connected to the hydrogen compressor, the hydrogen compressor is connected to the compressor chiller, the sequence control cabinet and the hydrogenator, the sequence control cabinet is connected to the hydrogen storage bottle group, the hydrogenator is connected to the hydrogenator chiller and the hydrogen vehicle, The main station control unit is electrically connected to the gas unloading cabinet, the hydrogen compressor, the sequence control cabinet, the hydrogen storage bottle group and the hydrogenation machine.

Images