Quick filling control method for hydrogen filling machine

Abstract

The invention discloses a rapid filling control method for a hydrogenation machine, and mainly solves the technical problem of low hydrogen filling efficiency corresponding to an existing hydrogenation control method. According to the control method, after connection between the hydrogen adding machine and the vehicle-mounted hydrogen storage bottle is established, high, medium and low gas source pressure data and vehicle-mounted hydrogen storage bottle pressure, gas source temperature, vehicle-mounted hydrogen storage bottle temperature and pipeline temperature data are obtained in real time; the low gas source, the medium gas source and the high gas source are sequentially and correspondingly connected with the hydrogen conveying pipeline in a communicating mode through the communicating control valves; the flow adjusting valve is correspondingly adjusted based on the gas source pressure data and the vehicle-mounted hydrogen storage cylinder pressure data, and the filling rate is controlled to be not larger than the preset maximum safe filling rate; and the cooling module is correspondingly regulated and controlled according to the gas source temperature, the vehicle-mounted hydrogen storage bottle temperature and the pipeline temperature, so that the gas source temperature and the vehicle-mounted hydrogen storage bottle temperature are not larger than the preset maximum safe filling temperature. The hydrogen filling efficiency can be effectively improved by accurately regulating and controlling the flow regulating valve and regulating and controlling the cooling module in advance.

Description

Technical Field

[0001] The present invention relates to the field of hydrogen energy technology, and in particular to a method for controlling rapid filling of a hydrogen filling machine. Background Art

[0002] As hydrogen energy as a green energy source has received more and more attention, the development of hydrogen-powered vehicles has also been rapid. As an important supporting facility for hydrogen-powered vehicles, the hydrogen filling speed of hydrogen refueling stations directly affects the endurance and user experience of hydrogen-powered vehicles. The hydrogen filling speed of hydrogen refueling stations determines the operating efficiency of hydrogen refueling stations and fuel cell vehicles. However, for safety reasons, the maximum filling speed of hydrogen refueling machines shall not exceed 7.2Kg / min, and the operating temperature of on-board hydrogen storage bottles shall not exceed 85°C. At the same time, the hydrogen filling rate must be between 95% and 100%.

[0003] The existing vehicle compressed hydrogen refueling machines known to the inventors are refueled in stages according to the pressure of the onboard hydrogen tank of the vehicle being refueled. However, in the process of implementing the technical solution in the embodiments of the present application, the inventors of the present application found that the above technology has at least the following technical problems: the hydrogen refueling speed during the refueling process is limited by the pressure and temperature of the hydrogen storage tank in the station; in addition, in order to reduce the warming effect during hydrogen refueling to increase the refueling rate, although a cooling device is built into the hydrogen refueling machine, the cooling effect cannot be adjusted with the actual refueling rate, and there is a problem of lag or asynchronism. For example, the existing refueling method often takes more than 15 minutes to refuel an onboard hydrogen storage tank with a nominal working pressure of 35MPa and a hydrogen mass of 25kg, and the hydrogen refueling efficiency is low.

[0004] The information disclosed in this background technology section is only used to deepen the understanding of the background technology of the present disclosure, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art known to those skilled in the art. Summary of the invention

[0005] In view of at least one of the above technical problems, the present disclosure provides a rapid filling control method for a hydrogenator, aiming to solve the technical problem of low hydrogen filling efficiency corresponding to the existing hydrogenation control method.

[0006] According to one aspect of the present disclosure, a method for controlling rapid filling of a hydrogen filling machine is provided, which is implemented based on a hydrogen filling system, wherein the hydrogen filling system includes a conductance control valve connected to high, medium and low gas sources respectively, a flow regulating valve for regulating the flow of hydrogen in a hydrogen transmission pipeline, and a cooling module for cooling hydrogen during the filling process. The method for controlling rapid filling of a hydrogen filling machine includes the following steps: (1) After establishing the connection between the hydrogen refueling machine and the on-board hydrogen storage bottle, obtain the high, medium and low gas source pressure data as well as the on-board hydrogen storage bottle pressure, gas source temperature, on-board hydrogen storage bottle temperature and pipeline temperature data in real time; (2) establishing a connection between the low, medium and high gas sources and the hydrogen transmission pipeline in sequence through the conduction control valve; and adjusting the flow control valve accordingly based on the gas source pressure data and the on-board hydrogen storage bottle pressure data to control the filling rate to be no greater than the preset maximum safe filling rate; (3) According to the gas source temperature, the vehicle-mounted hydrogen storage bottle temperature and the pipeline temperature, the cooling module is controlled so that the gas source temperature and the vehicle-mounted hydrogen storage bottle temperature are not greater than the preset maximum safe filling temperature; (4) Obtain the filling amount data of the on-board hydrogen storage bottle until the filling amount reaches the preset value, and then end the filling.

[0007] In some embodiments of the present disclosure, in the step (2), the opening of the flow control valve is adjusted based on a PID regulator.

[0008] In some embodiments of the present disclosure, in step (2), the maximum safe filling rate is used as the set value, the actual flow data at the flow control valve is used as the feedback value, the difference between the set value and the feedback value is used as the input of the PID regulator, and the opening of the flow control valve is correspondingly regulated according to the output of the PID regulator.

[0009] In some embodiments of the present disclosure, in step (3), based on historical data, a relationship between the filling rate and the ambient temperature, the gas source temperature, the vehicle-mounted hydrogen storage bottle temperature, and the pipeline temperature is established, and the cooling power of the cooling module is adjusted accordingly according to the changes in the gas source, vehicle-mounted hydrogen storage bottle and pipeline temperatures corresponding to different filling rates.

[0010] In some embodiments of the present disclosure, in step (3), the gas source temperature, the vehicle-mounted hydrogen storage bottle temperature and the pipeline temperature are predicted at different filling rates based on the neural network model, and the cooling power of the cooling module is adjusted in advance according to the cooling delay time of the cooling module and based on the predicted value.

[0011] In some embodiments of the present disclosure, in step (3), a portion of historical data including gas source pressure, on-board hydrogen storage bottle pressure, filling rate, ambient temperature, pipeline temperature, gas source temperature, and on-board hydrogen storage bottle temperature is randomly selected as a training set, and the remaining historical data is used as a test set; a BP neural network prediction model is established accordingly.

[0012] In some embodiments of the present disclosure, the cooling module includes a cold water spray unit arranged at the gas source, a heat exchange unit connected in series in the hydrogen delivery pipeline, and an air cooling or water cooling unit arranged at the vehicle-mounted hydrogen storage bottle.

[0013] One or more technical solutions provided in the embodiments of the present application have at least any of the following technical effects or advantages: 1. Based on PID feedback control, the opening of the flow control valve can be accurately regulated so that its opening matches the set filling rate, thereby avoiding the problem of excessive filling rate causing the filling temperature to rise and then reversely limiting the filling rate, ensuring the relative stability of the acceleration rate and filling safety, and reducing unnecessary energy consumption of the cooling module caused by excessive filling rate.

[0014] 2. By adaptively controlling the cooling efficiency of the cooling module, the problem of affecting the filling rate due to the cooling effect of the cooling module lagging behind the filling cooling demand can be avoided, which helps to improve the hydrogen filling rate.

[0015] 3. The BP neural network model can accurately predict the gas source temperature, pipeline temperature and on-board hydrogen storage bottle temperature under different gas source pressures, on-board hydrogen storage bottle pressures, filling rates and ambient temperatures, thereby facilitating the system to adjust the cooling power in advance to avoid the problem of excessive temperature affecting the hydrogen filling rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the control principle of the flow control valve opening in one embodiment of the present application. DETAILED DESCRIPTION

[0017] The programs involved or relied upon in the following embodiments are all conventional programs or simple programs in the technical field, and those skilled in the art can make conventional selections or adaptive adjustments according to specific application scenarios. The devices involved in the following embodiments, unless otherwise specified, are all conventional commercially available products.

[0018] In order to better understand the technical solution of the present application, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0019] In order to solve the technical problem of low filling efficiency during existing hydrogen filling, this example discloses a method for controlling rapid filling of a hydrogen filling machine. The hydrogen filling system based on the method includes a hydrogen gas source and a flow control valve connected to the hydrogen gas source for flow control.

[0020] Specifically, in this embodiment, the hydrogen gas source includes a high-pressure hydrogen storage bottle group, a medium-pressure hydrogen storage bottle group, and a low-pressure hydrogen storage bottle group corresponding to high, medium, and low gas sources, respectively; the high-pressure hydrogen storage bottle group, the medium-pressure hydrogen storage bottle group, and the low-pressure hydrogen storage bottle group are respectively connected to the hydrogen transmission pipeline through a conduction control valve, so that the gas source connected to the hydrogen transmission pipeline can be selected according to the filling demand through the conduction control valve. In addition, a flow control valve is connected in series in the hydrogen transmission pipeline to adjust the flow of the hydrogen transmission pipeline, so as to realize the control and regulation of the filling rate. Considering that the high-pressure hydrogen storage bottle group, the medium-pressure hydrogen storage bottle group, the low-pressure hydrogen storage bottle group and the pipeline will have the problem of temperature rise during the hydrogenation process, and for safety reasons, the hydrogen temperature needs to be controlled within a safe range during the filling process. For this reason, the hydrogen filling system of this example also includes a cooling module for reducing the hydrogen temperature, which helps to increase the hydrogen filling rate while ensuring safe filling, and avoids the problem of hydrogen filling rate being limited due to excessively high hydrogen temperature.

[0021] In this embodiment, the hydrogenation machine rapid filling control method mainly includes the following steps: (1) After establishing the connection between the hydrogen refueling machine and the on-board hydrogen storage bottle, the high, medium and low gas source pressure data as well as the on-board hydrogen storage bottle pressure, gas source temperature, on-board hydrogen storage bottle temperature and pipeline temperature data are obtained in real time.

[0022] Considering that the hydrogen filling rate is affected by the temperature and pressure of the hydrogen filling system, in this embodiment, temperature sensors and pressure sensors are respectively set at the high-pressure hydrogen storage bottle group, the medium-pressure hydrogen storage bottle group, the low-pressure hydrogen storage bottle group, the vehicle-mounted hydrogen storage bottle group, and the hydrogen transmission pipeline, so that during the hydrogen filling period, the real-time temperature and pressure of the high-pressure hydrogen storage bottle group, the medium-pressure hydrogen storage bottle group, the low-pressure hydrogen storage bottle group, the temperature and pressure of the vehicle-mounted hydrogen storage bottle group, the temperature in the hydrogen transmission pipeline, and the hydrogen pressure before and after the flow control valve are monitored in real time. In addition, considering that the hydrogen filling system is exposed to the hydrogen filling environment, in order to further achieve accurate and reliable control of the hydrogen filling rate, an ambient temperature sensor is set at the filling system to detect the ambient temperature, and the ambient temperature is taken into account in the factors affecting the hydrogen filling rate.

[0023] (2) Establishing corresponding connections between low, medium and high gas sources and the hydrogen transmission pipeline in sequence through the conduction control valve; and adjusting the flow control valve accordingly based on the gas source pressure data and the on-board hydrogen storage bottle pressure data to control the filling rate to be no greater than the preset maximum safe filling rate.

[0024] In order to reduce the power consumption of filling, in this embodiment, after establishing reliable connection between the hydrogen transmission pipeline and the on-board hydrogen storage bottle, the low-pressure hydrogen storage bottle group, the medium-pressure hydrogen storage bottle group, and the high-pressure hydrogen storage bottle group are connected to the hydrogen transmission pipeline in sequence by controlling the conduction control valve, and the hydrogen is automatically flowed from the gas source to the on-board hydrogen storage bottle group by relying on the pressure difference between each hydrogen storage bottle group at the upstream gas source and the downstream on-board hydrogen storage bottle. In this process, the hydrogen filling rate is affected by the pressure difference between the upstream gas source pressure and the downstream on-board hydrogen storage bottle and the degree of conduction of the flow control valve. In order to ensure the safe and rapid filling of hydrogen, the maximum safe filling rate is preset before filling. In this embodiment, the maximum safe filling rate is set to 7.2Kg / min. During the filling process, the flow meter at the pipeline is used for real-time monitoring, and the flow control valve is adjusted accordingly so that the hydrogen filling rate is not greater than the maximum safe filling rate.

[0025] In this embodiment, considering that the pressure of the gas source and the pressure of the on-board hydrogen storage bottle fluctuate with the progress of the filling process, that is, the filling rate fluctuates during the filling process, the filling pressure is relatively high in the initial filling stage, resulting in a hydrogen filling rate greater than the maximum safe filling rate, resulting in a high system temperature and limiting the filling rate; in the final stage of the filling process, the filling pressure is relatively reduced, resulting in a hydrogen acceleration rate far less than the maximum safe filling rate. Therefore, in order to ensure that the hydrogen filling rate is relatively stable during the filling process to ensure the efficiency and safety of the filling, in this embodiment, the opening of the flow control valve is adjusted based on the PID regulator.

[0026] For details, see Figure 1 In this example, the maximum safe filling rate is used as the control set value of the flow control valve, that is, the control input, and the actual hydrogen flow data at the flow control valve measured by the flow meter is used as the feedback value. A comparison is made between the set value and the feedback value, and the difference between the set value and the feedback value, that is, the control deviation, is used as the input of the PID regulator. The opening of the flow control valve is correspondingly regulated according to the output of the PID regulator, thereby constituting PID feedback control, thereby ensuring that the corresponding degree of opening of the flow control valve matches the set filling rate, thereby ensuring the smoothness of filling.

[0027] In some other embodiments, the average waiting time and queue length indicators of vehicles are set according to the peak and off-peak periods of the hydrogen station, and the refueling time that can be allocated to a single fuel vehicle is converted with the indicators, and the refueling rate corresponding to the refueling time is used as the input of the above-mentioned PID feedback control to control the opening of the flow control valve. In some other embodiments, the gas source pressure in the station before the current refueling operation is additionally considered, and the refueling rate is adjusted accordingly as the input of the PID feedback control to avoid the gas source in the station failing to meet the set refueling rate.

[0028] (3) The cooling module is regulated according to the gas source temperature, the vehicle-mounted hydrogen storage bottle temperature and the pipeline temperature so that the gas source temperature and the vehicle-mounted hydrogen storage bottle temperature are not greater than the preset maximum safe filling temperature.

[0029] During the hydrogen filling process, the temperature of the gas source bottle group, hydrogen transmission pipeline and on-board hydrogen storage bottle will increase. Therefore, it is necessary to cool down the gas source bottle group, hydrogen transmission pipeline and on-board hydrogen storage bottle through the cooling module to avoid high temperature limiting the filling rate and make the filling system within the preset maximum safe filling temperature range to avoid the safety hazards caused by excessively high hydrogen temperature. However, due to the hysteresis of the cooling effect of the cooling module, that is, there is a time delay, which leads to the refrigeration demand and the refrigeration effect being out of sync. The current refrigeration demand cannot be met at the beginning of the refrigeration demand, resulting in the filling rate being limited by the temperature during this time period. Therefore, in this embodiment, the temperature information of various parts of the hydrogen filling system is monitored in real time through the temperature sensors set at the high-pressure hydrogen storage bottle group, the medium-pressure hydrogen storage bottle group, the low-pressure hydrogen storage bottle group, the on-board hydrogen storage bottle group, the hydrogen transmission pipeline and the hydrogen filling environment, and the cooling power of the cooling module is adjusted accordingly to avoid the temperature exceeding the preset maximum safe filling temperature; wherein, in this example, the maximum safe filling temperature is preset to 85°C.

[0030] Specifically, since in this embodiment, the opening of the flow regulating valve is adjusted with the changes in the hydrogen filling process, and different flow regulating valve openings and different gas source pressures and on-board hydrogen storage bottle pressures correspond to different refrigeration requirements, for this reason, in this embodiment, based on historical data, the relationship between the hydrogen filling rate and the ambient temperature, gas source temperature, on-board hydrogen storage bottle temperature, and pipeline temperature is established. Therefore, according to the difference between the gas source, on-board hydrogen storage bottle and pipeline temperatures corresponding to different filling rates and the maximum safe filling temperature, that is, the refrigeration demand, the refrigeration power of the cooling module is adjusted accordingly.

[0031] In this example, by collecting the historical filling data of the hydrogen filling station, a neural network prediction model is established to predict the gas source temperature, on-board hydrogen storage bottle temperature and pipeline temperature at the filling rate corresponding to different gas sources and on-board hydrogen storage bottle pressures. According to the difference between the predicted value and the maximum safe filling temperature, the cooling power of the cooling module is adjusted in advance considering the cooling delay time of the cooling module. Specifically, in this example, the historical filling data of the hydrogen filling station includes gas source pressure, on-board hydrogen storage bottle pressure, filling rate, ambient temperature, pipeline temperature, gas source temperature, and on-board hydrogen storage bottle temperature. 80% of the data are randomly selected as the model training set, and the remaining 20% ​​of the data are used as the model test set. First, a corresponding BP neural network prediction model including a hidden layer is established, and then a simulation experiment is carried out based on the Matlab toolbox. The errors corresponding to different numbers of hidden nodes are counted, and the number of hidden nodes corresponding to the minimum error is selected. In this case, the number of hidden nodes is selected as 6, and ReLU is used as the activation function to enhance the nonlinear ability of the model. The gas source temperature, the temperature of the on-board hydrogen storage bottle, and the pipeline temperature are used as prediction values. The mean square error MSE is used to evaluate the quality of the model prediction results. The Adam optimization algorithm is used to train the model and update the weights and biases. Therefore, based on the current gas source pressure, on-board hydrogen storage bottle pressure, filling rate, and ambient temperature, the neural network model is used to predict the pipeline temperature, gas source temperature, and on-board hydrogen storage bottle temperature. According to the cooling efficiency of the cooling module, the cooling control command is output in advance to ensure that the filling rate matches the cooling effect, thereby improving the filling efficiency.

[0032] In addition, in this embodiment, the cooling module includes a cold water spray unit provided at the gas source, a heat exchange unit connected in series in the hydrogen delivery pipeline, and an air cooling or water cooling unit provided at the on-board hydrogen storage bottle. The cold water spray unit, the heat exchange unit, and the air cooling / water cooling unit are independent of each other. Before filling, the cooling efficiency of each unit, i.e., the cooling delay time, is measured in advance. Based on each delay time, each cooling unit is adjusted accordingly to ensure that its cooling effect matches the filling rate, so as to achieve the purpose of improving the filling efficiency.

[0033] (4) Obtain the filling amount data of the on-board hydrogen storage bottle until the filling amount reaches the preset value, and then end the filling.

[0034] Although some preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0035] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the inventive concept. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A method for controlling rapid filling of a hydrogenation machine, characterized in that: The method is implemented based on a hydrogen filling system, which includes a conduction control valve connected to high, medium and low gas sources respectively, a flow regulating valve for adjusting the flow of hydrogen in the hydrogen transmission pipeline, and a cooling module for cooling hydrogen during the filling process. The hydrogen filling machine rapid filling control method includes the following steps: (1) After establishing the connection between the hydrogen refueling machine and the on-board hydrogen storage bottle, obtain the high, medium and low gas source pressure data as well as the on-board hydrogen storage bottle pressure, gas source temperature, on-board hydrogen storage bottle temperature and pipeline temperature data in real time; (2) establishing a connection between the low, medium and high gas sources and the hydrogen transmission pipeline in sequence through the conduction control valve; and adjusting the flow control valve accordingly based on the gas source pressure data and the on-board hydrogen storage bottle pressure data to control the filling rate to be no greater than the preset maximum safe filling rate; (3) According to the gas source temperature, the vehicle-mounted hydrogen storage bottle temperature and the pipeline temperature, the cooling module is controlled so that the gas source temperature and the vehicle-mounted hydrogen storage bottle temperature are not greater than the preset maximum safe filling temperature; (4) Obtain the filling amount data of the on-board hydrogen storage bottle until the filling amount reaches the preset value, and then end the filling.

2. The hydrogenation machine rapid filling control method according to claim 1, characterized in that: In the step (2), the opening degree of the flow control valve is adjusted based on a PID regulator.

3. The hydrogenation machine rapid filling control method according to claim 2, characterized in that: In step (2), the maximum safe filling rate is used as the set value, the actual flow data at the flow control valve is used as the feedback value, and the difference between the set value and the feedback value is used as the input of the PID regulator. The opening of the flow control valve is correspondingly regulated according to the output of the PID regulator.

4. The hydrogenation machine rapid filling control method according to claim 2, characterized in that: In step (3), based on historical data, the relationship between the filling rate and the ambient temperature, the gas source temperature, the vehicle-mounted hydrogen storage bottle temperature, and the pipeline temperature is established, and the cooling power of the cooling module is adjusted accordingly according to the changes in the gas source, vehicle-mounted hydrogen storage bottle and pipeline temperatures corresponding to different filling rates.

5. The hydrogenation machine rapid filling control method according to claim 4, characterized in that: In step (3), the gas source temperature, the vehicle-mounted hydrogen storage bottle temperature and the pipeline temperature are predicted at different filling rates based on the neural network model, and the cooling power of the cooling module is adjusted in advance according to the cooling delay time of the cooling module and based on the predicted value.

6. The method for controlling rapid filling of a hydrogenation machine according to claim 5, characterized in that: In step (3), a portion of historical data including gas source pressure, on-board hydrogen storage bottle pressure, filling rate, ambient temperature, pipeline temperature, gas source temperature, and on-board hydrogen storage bottle temperature is randomly selected as a training set, and the remaining historical data is used as a test set; a BP neural network prediction model is established accordingly.

7. The method for controlling rapid filling of a hydrogenation machine according to claim 1, characterized in that: The cooling module includes a cold water spray unit arranged at the gas source, a heat exchange unit connected in series in the hydrogen delivery pipeline, and an air cooling or water cooling unit arranged at the vehicle-mounted hydrogen storage bottle.

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