Automatic metrological verification method for hydrogenation machine

Abstract

The invention discloses an automatic metrological verification method for a hydrogenation machine, and mainly solves the technical problems that the existing weighing verification is easily influenced by a test environment and verification errors cannot be found in time. The hydrogen output by the hydrogen adding machine is metered through the mass flow meter and the weighing device at the same time, so that the problem that the weighing device is influenced by the surrounding environment or the metering error of the mass flow meter is difficult to find is solved, and the metering reliability of the calibrating device is ensured. A mass flowmeter metering error curve is generated on the basis of historical data, the appropriate hydrogen flow is selected according to the actual hydrogen temperature in the verification process, a PID feedback closed-loop adjustment mode is adopted, the purpose of reducing the mass flowmeter adding error is achieved, and verification reliability is improved. The fuel cell is used for recycling diffused hydrogen at the weighing gas cylinder and can be used for providing electric power supply for the calibrating device, so that the diffusing pressure is reduced, and the calibrating economic benefit is improved at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogenation machine calibration, and in particular to an automatic metering calibration method for a hydrogenation machine. Background Art

[0002] Hydrogen is a clean and efficient energy source. Its combustion product is water, which does not produce any pollution. There are various ways to prepare and obtain hydrogen. Renewable energy such as solar energy, wind energy, and water potential energy can be converted into electrical energy. Hydrogen can be produced by electrolyzing water using electrolytic cells. As an important industrial raw material and energy carrier, hydrogen energy is also regarded as an ideal substitute for traditional fossil energy because of its high calorific value, environmental protection and renewable characteristics.

[0003] Hydrogen refueling machines are used to provide compressed hydrogen fuel filling services for hydrogen fuel cell vehicles, and have metering and pricing functions. They are generally composed of hydrogen flow meters, detection alarm devices, filters, solenoid valves, safety valves, hydrogenation guns, hydrogenation hoses, electronic controllers, auxiliary devices, etc. As an important measuring instrument and basis for hydrogen trade settlement, the long-term stability, safety and metering accuracy of hydrogen refueling machines are directly related to the economy and user experience of hydrogenation, so regular metering calibration of hydrogen refueling machines is required.

[0004] The inventors know of a hydrogenation machine measurement and calibration method that is based on electronic balance weighing to achieve measurement, and the measurement accuracy of the hydrogenation machine is determined by comparing the difference between the filling value measured by the hydrogenation machine display and the weighing value of the electronic balance. However, in the process of implementing the technical solution in the embodiment of the present application, the inventors of the present application found that the above technology has at least the following technical problems: the electronic balance is easily affected by the surrounding wind and vibration, etc., and due to the limitations of the calibration environment, there is an error between the measured indication and the actual weighing value, and when there is an error, it cannot be discovered in time, resulting in failure of measurement and calibration.

[0005] 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

[0006] In view of at least one of the above technical problems, the present disclosure provides an automatic metering and calibration method for a hydrogenation machine, aiming to solve the technical problems that the existing weighing calibration is easily affected by the test environment and the calibration error cannot be discovered in time.

[0007] According to one aspect of the present disclosure, a method for automatic metering and calibration of a hydrogenation machine is provided, which is implemented based on a calibration device, wherein the calibration device comprises an intake pipeline connected to an intake port and sequentially connected in series with a flow regulating valve, a pressure transmitter, a temperature transmitter and a mass flow meter, and a weighing and metering branch correspondingly connected to the downstream of the intake pipeline; the method for automatic metering and calibration of a hydrogenation machine comprises the following steps: (1) Connect the hydrogenation gun of the hydrogenation machine to be tested to the air inlet of the testing device; (2) Open the stop valve in the weighing and metering branch, start the hydrogen filling machine to fill hydrogen; the hydrogen in the weighing cylinder in the weighing and metering branch is measured by the weighing device, and the intake pressure and intake temperature in the intake pipeline are obtained in real time and recorded; (3) determining the hydrogen verification flow rate according to the error relationship curve between the flow rate and temperature generated based on the historical filling data and the measurement error of the mass flow meter in accordance with the set error range and the current intake temperature; (4) Using the hydrogen test flow rate as a set value and the measured value of the mass flow meter as a feedback value, PID control of the flow control valve opening is performed based on the deviation between the set value and the feedback value; (5) After the set mass hydrogen filling is completed, close the flow regulating valve and the stop valve in the weighing metering branch, obtain the metering indication of the hydrogen filling machine, the instrument measurement value of the mass flow meter and the weighing measurement value of the weighing device, and calculate the metering average value between the instrument measurement value and the weighing measurement value; (6) Release the hydrogen in the weighing gas cylinder and return the weighing device to zero accordingly; (7) Repeat steps (2) to (3) at least twice, calculate the measurement error between the measurement indication and the measurement average value, and complete the hydrogenation machine calibration.

[0008] In some embodiments of the present disclosure, the air inlet includes connection ports that are arranged in parallel and correspond to hydrogenation guns of different models.

[0009] In some embodiments of the present disclosure, in the step (2), the intake pressure and the intake temperature are correspondingly monitored at the inlet of the mass flow meter.

[0010] In some embodiments of the present disclosure, in step (3), the relationship curve has flow rate as the horizontal axis and measurement error as the vertical axis, including a measurement error curve of the mass flow meter at different hydrogen temperatures.

[0011] In some embodiments of the present disclosure, in the step (3), the maximum hydrogen flow rate within the error range is selected as the hydrogen verification flow rate.

[0012] In some embodiments of the present disclosure, in step (5), the metering indication of the hydrogen filling machine is obtained and recorded by corresponding photo identification through a camera terminal.

[0013] In some embodiments of the present disclosure, in the step (6), the discharge port of the weighing gas cylinder is connected to a fuel cell for supplying power to a calibration device for the discharge.

[0014] In some embodiments of the present disclosure, in the step (7), the metering error of the hydrogenation machine is adjusted according to the average value of the calculated error.

[0015] In some embodiments of the present disclosure, the calibration device further includes a filling branch disposed downstream of the mass flow meter and connected in parallel with the weighing and metering branch.

[0016] 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. The hydrogen output of the hydrogenation machine is measured by the mass flow meter and the weighing device at the same time, thus avoiding the problem that the weighing device is affected by the surrounding environment or the mass flow meter has a measurement error that is difficult to find, and ensuring the measurement reliability of the calibration device.

[0017] 2. Generate the measurement error curve of the mass flow meter based on historical data, select the appropriate hydrogen flow rate according to the actual hydrogen temperature during the calibration process, and adopt the PID feedback closed-loop adjustment method to reduce the mass flow meter addition error and improve the reliability of the calibration.

[0018] 3. The hydrogen released from the weighing gas cylinder is recycled by the fuel cell and can be used to provide power to the calibration device, thereby reducing the release pressure and improving the economic benefits of the calibration. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 1 is a schematic diagram of the principle structure of a testing device in one embodiment of the present application.

[0020] Figure 2 Graph showing the measurement error of the mass flow meter in one embodiment of the present application.

[0021] Figure 3 This is a schematic diagram of the opening control principle of the flow control valve in one embodiment of the present application.

[0022] In the above figures, 1 is a hydrogenator, 2 is an air inlet, 21 is an air inlet, 22 is a flow control valve, 23 is a pressure transmitter, 24 is a temperature transmitter, 25 is a mass flow meter, 3 is a filling branch, 31 is a filling stop valve, 32 is a gas outlet, 4 is a weighing and metering branch, 41 is a weighing and metering stop valve, 42 is a weighing device, 43 is a weighing gas cylinder, 5 is a venting pipeline, 51 is a venting stop valve, 52 is a fuel cell, 6 is a power supply for a calibration device, 71 is a camera terminal, 72 is a cloud, and 8 is a purge pipeline. DETAILED DESCRIPTION

[0023] 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.

[0024] Unless otherwise specified, the devices and the like involved in the following embodiments are conventional commercially available products.

[0025] 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.

[0026] In order to solve the technical problem that the reliability of the existing verification method is affected by the verification environment and when a verification error occurs, it is difficult to timely discover the verification error in the normal verification process unless the verification device is regularly calibrated, this example discloses an automatic metering verification method for a hydrogenation machine, which is implemented based on a verification device.

[0027] See also Figure 1The calibration device includes an air inlet 21. Considering that different hydrogenation machines or the same hydrogenation machine are equipped with different types of hydrogenation guns, in order to improve the wide applicability of the calibration operation and avoid affecting the calibration due to the universal interface problem, in this embodiment, the air inlet 21 includes connecting ports that match the commonly used TK17, TK16, and TK25 hydrogenation guns and are arranged in parallel. An air inlet pipeline 2 is provided downstream of the air inlet 21, and a flow control valve 22, a pressure transmitter 23, a temperature transmitter 24, and a mass flow meter 25 are connected in series in sequence from upstream to downstream in the air inlet pipeline. A filling branch 3 and a weighing and metering branch 4 are provided in parallel at the downstream of the air intake pipeline, and a filling stop valve 31 and a weighing and metering stop valve 41 are provided at the upstream of the filling branch 3 and the weighing and metering branch 4, respectively, thereby controlling the conduction between the filling branch and / or the weighing and metering branch 4 and the air intake pipeline 2, so as to realize the separate metering and calibration of the mass flow meter or the simultaneous metering and calibration of the mass flow meter and the weighing and metering as required. Among them, a gas delivery port 32 is provided at the downstream of the filling stop valve 31 of the filling branch 3, and several different types of hydrogenation gun connection ports are provided in parallel with the gas delivery port 32, so as to be suitable for different types of refueling vehicles, so that the vehicle fuel can be filled while metering. A weighing gas cylinder 43 is provided at the downstream of the weighing and metering stop valve 41 of the weighing and metering branch 4, and also includes a weighing device 42 for weighing the weighing gas cylinder 43.

[0028] The automatic metering and verification method of the hydrogenation machine in this example specifically includes the following steps: (1) Connect the hydrogenation gun of the hydrogenation machine to be tested to the air inlet of the testing device.

[0029] Before the calibration operation begins, first establish a reliable connection between the hydrogenation gun of the hydrogenator and the connection port corresponding to the air inlet of the calibration device, so that the hydrogen measured by the hydrogenator 1 can be transported to the calibration device for calibration, so as to determine whether the calibration value is the same as the metered value of the hydrogenator or is within the allowable error range, thereby determining the metering accuracy of the hydrogenator.

[0030] (2) Open the stop valve in the weighing and metering branch, start the hydrogen filling machine to fill hydrogen; the hydrogen in the weighing gas cylinder in the weighing and metering branch is measured by the weighing device, and the intake pressure and intake temperature in the intake pipeline are obtained in real time and recorded.

[0031] After the calibration operation begins, first open the flow regulating valve 22 in the air inlet pipeline to allow hydrogen to enter the calibration device. In order to avoid measurement errors in the mass flowmeter, in this embodiment, close the filling stop valve 31 in the filling branch 3 and correspondingly open the weighing and metering stop valve 41 in the weighing and metering branch 4 to achieve double calibration of the mass flowmeter 25 and weighing and metering, thereby ensuring the accuracy and reliability of the calibration. In addition, reset the scale indication to zero, then turn on the hydrogenator to set the filling amount and start the filling operation. The hydrogen output from the hydrogenator enters the weighing cylinder after being measured by the mass flowmeter, and the hydrogen mass is weighed and measured by the scale.

[0032] Among them, in order to ensure the measurement accuracy of the mass flowmeter 25, the hydrogen flow rate needs to be limited within its working range. Therefore, when the flow control valve 22 is started, the opening of the flow control valve 22 needs to be controlled according to the preset setting so that the hydrogen flow rate flowing through the mass flowmeter is within the rated range of the mass flowmeter. However, the inventor has found in long-term practice based on long-term practical experience that when measuring within the rated parameter working range of the flow control valve 22, the measurement accuracy is affected by factors such as medium pressure and temperature, and there are also non-negligible errors, thereby affecting the reliability of measurement. For this reason, in this embodiment, during the measurement process, the pressure transmitter and temperature transmitter in the intake pipeline are used to obtain the intake pressure and intake temperature information of the hydrogen at the intake port of the mass flowmeter in real time, which is used as the control basis for the opening of the flow control valve 22.

[0033] (3) According to the error relationship curve between the flow rate and temperature generated based on the historical filling data and the measurement error of the mass flow meter, the hydrogen verification flow rate is determined in accordance with the set error range and the current intake temperature.

[0034] Specifically, the flow control valve opening can be effectively regulated according to the real-time monitored intake pressure and intake temperature information, thereby ensuring the measurement accuracy of the mass flow meter. In this embodiment, based on historical filling data or test data, see Figure 2 , with the hydrogen flow rate flowing through the mass flow meter as the horizontal axis and the measurement error between the mass flow meter's measured value and the true value as the vertical axis, a measurement error curve of the mass flow meter at different hydrogen temperatures is established. From the curve, it can be seen that when the hydrogen flow rate is in the range of 2 to 8 kg / min, the measurement accuracy is relatively high, and due to different hydrogen temperatures, the error fluctuation is different. Therefore, by selecting the hydrogen flow value corresponding to a relatively small error, the hydrogen flow rate flowing through the mass flow meter is controlled, thereby ensuring the measurement accuracy of the mass flow meter.

[0035] Among them, since a certain degree of metering error is allowed during the calibration, the hydrogen flow value is selected within the allowable error range. The allowable error range is reflected in the metering error curve as two parallel lines parallel to the horizontal axis. The hydrogen flow value corresponding to the error curve within the range sandwiched by the two parallel lines is selected as the control basis. In this embodiment, in order to ensure the metering efficiency, the maximum value of the hydrogen flow value within the error range can be selected as the adjustment basis of the flow control valve, so as to improve the calibration efficiency as much as possible under the premise of ensuring the accurate measurement of the mass flowmeter. In addition, after the hydrogen flow in the hydrogen inlet pipeline is adjusted by the flow control valve, the hydrogen temperature in the pipe is bound to change. At this time, the temperature transmitter monitors the hydrogen temperature in the pipe in real time, and selects a new hydrogen flow value at the hydrogen temperature as the adjustment basis of the flow control valve, and repeats this cycle until the calibration and filling are completed.

[0036] (4) The hydrogen calibration flow rate is used as the set value and the measurement value of the mass flow meter is used as the feedback value. The PID control of the flow control valve opening is performed based on the deviation between the set value and the feedback value.

[0037] During the verification and filling process, after selecting the hydrogen verification flow value according to the error curve, in order to ensure that the flow control valve opening quickly matches the flow control value, the selected hydrogen verification flow value is used as the set value, and the flow information measured by the mass flow meter is used as the feedback value, thereby establishing feedback control. Figure 3 , the deviation between the set value and the feedback value is calculated accordingly, and the deviation is used as the input of the PID controller to adjust the opening of the flow control valve, thereby ensuring that the flow control valve follows the set value and that the flow rate of the mass flow meter is consistent with the hydrogen verification flow value selected according to the error curve.

[0038] (5) After the set mass hydrogen filling is completed, close the flow regulating valve and the stop valve, obtain the metering indication of the hydrogen filling machine, the instrument measurement value of the mass flow meter and the weighing measurement value of the weighing device, and calculate the metering average value between the instrument measurement value and the weighing measurement value.

[0039] After the hydrogen filling machine completes the filling according to the set filling value, the flow regulating valve and the weighing metering stop valve are controlled to close. In this embodiment, see Figure 1 , take a photo through the camera terminal 71 to obtain the filling indication interface of the hydrogen filling machine and identify the metering value, which can be used as a record for archiving to facilitate traceability; and in this example, the camera terminal 71 communicates wirelessly with the cloud to upload metering images and data. At the same time, obtain the instrument measurement value of the mass flow meter and the weighing measurement value of the weighing device to determine whether the instrument measurement value and the weighing measurement value are consistent. If there is a difference between the two, the corresponding measurement average between the instrument measurement value and the weighing measurement value is calculated, and the measurement average is used as the calibration value of the calibration device.

[0040] (6) Release the hydrogen in the weighing cylinder and return the weighing device to zero.

[0041] After the above-mentioned verification is completed, it is necessary to release the hydrogen in the weighing gas cylinder to ensure the safety of the verification device and facilitate the next verification. In the present embodiment, considering that the hydrogen is directly released through the release pipeline, due to the large amount of hydrogen in the weighing gas cylinder, the release speed is slow and the hydrogen concentration at the release port range is relatively high, which has potential safety hazards. For this reason, in the present embodiment, the release port of the weighing gas cylinder is connected to the fuel cell 52 through the release pipeline 5, and the power output end of the fuel cell 52 is electrically connected to the power supply 6 of the verification device, thus, after the release operation starts and the release stop valve is opened, the hydrogen in the weighing gas cylinder is used by the fuel cell 52, which can be used to supply power to the verification device, and the hydrogen exceeding the fuel cell demand is released through the release pipe, which can greatly reduce the release pressure on the one hand, and can also improve the efficiency of energy reuse on the other hand, and reduce economic losses.

[0042] (7) Repeat steps (2) to (3) at least twice, calculate the measurement error between the measurement indication and the measurement average value, and complete the hydrogenation machine calibration.

[0043] In order to avoid the measurement error caused by environmental factors in a single measurement, in this embodiment, a total of three calibration operations are performed. Before each calibration operation, after the gas in the corresponding gas cylinder to be weighed is released, the indication of the weighing device is reset to zero to ensure that the weighed value is the mass of hydrogen. In some other embodiments, the indication of the weighing device is recorded before the calibration operation. After the calibration is completed, the difference between the final indication of the weighing device and the initial recorded indication is used as the actual mass of hydrogen. After repeating steps (2) to (3) twice, three groups of metering values ​​including the hydrogenator metering indication and the metering average value of the mass flow meter and the weighing device can be obtained. In this example, the difference between the metering indication of each group of hydrogenators and the metering average value is calculated respectively, and the average is taken as the metering difference between the hydrogenator and the calibration device. The hydrogenator is calibrated accordingly to complete the calibration of the hydrogenator.

[0044] In addition, in this embodiment, after the calibration is completed, in order to remove the residual hydrogen inside the calibration device, the calibration device also includes a purge port, which is used to connect a nitrogen source through a purge pipeline to purge the pipelines and weighing gas cylinders inside the device to ensure the safe use of the calibration device.

[0045] 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.

[0046] 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 automatic metering and verification of a hydrogenation machine, characterized in that: The method is implemented based on a calibration device, which includes an intake pipeline connected to an air inlet and connected in series with a flow regulating valve, a pressure transmitter, a temperature transmitter and a mass flow meter, and a weighing and metering branch correspondingly connected to the downstream of the intake pipeline; the automatic metering calibration method of the hydrogenation machine includes the following steps: (1) Connect the hydrogenation gun of the hydrogenation machine to be tested to the air inlet of the testing device; (2) Open the stop valve in the weighing and metering branch, start the hydrogen filling machine to fill hydrogen; the hydrogen in the weighing cylinder in the weighing and metering branch is measured by the weighing device, and the intake pressure and intake temperature in the intake pipeline are obtained in real time and recorded; (3) determining the hydrogen verification flow rate according to the error relationship curve between the flow rate and temperature generated based on the historical filling data and the measurement error of the mass flow meter in accordance with the set error range and the current intake temperature; (4) Using the hydrogen test flow rate as a set value and the measured value of the mass flow meter as a feedback value, PID control of the flow control valve opening is performed based on the deviation between the set value and the feedback value; (5) After the set mass hydrogen filling is completed, close the flow regulating valve and the stop valve in the weighing metering branch, obtain the metering indication of the hydrogen filling machine, the instrument measurement value of the mass flow meter and the weighing measurement value of the weighing device, and calculate the metering average value between the instrument measurement value and the weighing measurement value; (6) Release the hydrogen in the weighing gas cylinder and return the weighing device to zero accordingly; (7) Repeat steps (2) to (3) at least twice, calculate the measurement error between the measurement indication and the measurement average value, and complete the hydrogenation machine calibration.

2. The automatic metering and verification method for a hydrogenation machine according to claim 1, characterized in that: The air inlet includes connection ports which are arranged in parallel and correspond to hydrogenation guns of different models.

3. The automatic metering and verification method for a hydrogenation machine according to claim 1, characterized in that: In the step (2), the intake pressure and intake temperature are monitored correspondingly at the inlet of the mass flow meter.

4. The automatic metering and verification method for a hydrogenation machine according to claim 1, characterized in that: In the step (3), the relationship curve has flow rate as the horizontal axis and measurement error as the vertical axis, and includes measurement error curves of the mass flow meter at different hydrogen temperatures.

5. The automatic metering and verification method for a hydrogenation machine according to claim 1, characterized in that: In the step (3), the maximum hydrogen flow rate within the error range is selected as the hydrogen verification flow rate.

6. The automatic metering and verification method for a hydrogenation machine according to claim 1, characterized in that: In step (5), the metering indication of the hydrogen filling machine is obtained and recorded by corresponding photo identification through the camera terminal.

7. The automatic metering and verification method for a hydrogenation machine according to claim 1, characterized in that: In the step (6), the discharge port of the weighing gas cylinder is connected to a fuel cell for supplying power to the calibration device for the discharge.

8. The automatic metering and verification method for a hydrogenation machine according to claim 1, characterized in that: In the step (7), the metering error of the hydrogenation machine is adjusted accordingly according to the average value of the calculated error.

9. The automatic metering and verification method for a hydrogenation machine according to claim 1, characterized in that: The verification device also includes a filling branch which is arranged downstream of the mass flow meter and connected in parallel with the weighing and metering branch.

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