Dynamic flow generation device control method based on fast switching array

Abstract

The invention relates to the field of valve electric control, in particular to a dynamic flow generation device control method based on a rapid switching array, which uses a high-speed switching three-way valve to replace a traditional two-way valve, so that a flow generation branch can rapidly correspond to a flow switching control instruction, the time for adjusting the flow of the device to a stable state is shortened, and the flow switching efficiency is improved. Flow fluctuation is reduced, and the overall stability of the system is improved; the dynamic flow generation device is composed of the dynamic flow generation branches controlled by multiple valves, and the flow of the flow generation branches is controlled through the throat area of the sonic nozzle, so that the dynamic flow detected by the flow meter can reflect the actual flow characteristic more accurately, and the detection authenticity of the flow meter to be detected is improved; after the reliability of the multiple flow generation branches is ranked, the flow generation branch combination with the highest reliability is selected to reach the set flow, namely the to-be-detected flow value, so that the flow control and test precision and accuracy can be improved.

Description

Technical Field

[0001] The present invention relates to the field of electric control of valves, and specifically to a control method for a dynamic flow generating device based on a fast-switching array. Background Art

[0002] In the field of flow measurement, a dynamic flow generating device is a key equipment for simulating and detecting the performance of flow meters. Traditional dynamic flow generating devices usually use two-way valves to control the switching and adjustment of flow rate. However, such devices have deficiencies in response speed and flow stability. Especially when performing high-frequency flow switching, the response time of the two-way valve is relatively long, resulting in an extended time for the flow rate to adjust to a stable state, an increase in flow rate fluctuations, thus affecting the overall stability of the system and the accuracy of flow meter detection.

[0003] In addition, traditional dynamic flow generating devices also have limitations in flow control. Due to the limited flow regulation range of two-way valves and the difficulty in achieving precise flow control, it is difficult to meet the requirements of modern flow meters for high-precision and high-stability flow sources. This has limited the development and application of flow meter detection technology to a certain extent.

[0004] To solve the above problems, a dynamic flow generating device based on a fast-switching valve and a sonic nozzle array proposed by the present invention has become a potential solution. By using a high-speed switching three-way valve to replace the traditional two-way valve and combining the precise flow control characteristics of sonic nozzles, the flow generating device is set as a multi-valve controlled flow generating device composed of multiple flow generating branches, realizing high-frequency response and precise control of dynamic flow. Summary of the Invention

[0005] To solve the above problems in the prior art, the first object of the present invention is to provide a control method for a dynamic flow generating device based on a fast-switching array. By using a fast-switching flow generating device composed of a three-way switching valve and a sonic nozzle, by calculating the reliability of the flow generating branches in each device, selecting the flow generating branch combination with the highest stability under the same total flow rate, and changing the detection state of the flow generating device through the valve switching of the three-way switching valve, the problem of long response time when the existing dynamic flow generating device for detecting the flow rate of a flow meter switches the detection state is solved, achieving the beneficial effects of improving the high-frequency response of dynamic flow and the response speed of the time when the flow meter reaches the set flow rate during multi-valve high-frequency collaborative control.

[0006] To achieve the above object, the solution provided by the present invention is: A control method for a dynamic flow generating device based on a fast-switching array, comprising: Initial parameter setting step: Measure the critical flow rate value of each flow generation branch, and calculate the start-up time for each flow generation branch to reach the critical flow rate value. Reliability ranking step: Calculate the reliability parameter of each flow generation branch according to the start-up time and the critical flow rate value, and rank the reliability of the flow generation branches according to the reliability parameter. Branch scheme selection step: Select the flow generation branches to be started according to the set flow rate value to be detected, and select the flow generation branches to be used according to the reliability ranking result of the selected flow generation branches. Branch scheme calibration step: Detect the overall flow rate fluctuation value when the valve state of the flow generation branch is switched. If the overall flow rate fluctuation value is higher than the set threshold, adjust the asynchronous switching time difference of the flow generation branch. If the detected overall flow rate fluctuation value is still higher than the threshold after adjustment, readjust the reliability parameter of the flow generation branch in the branch selection scheme and re-select the branches.

[0007] As a further improvement of the present invention, the flow generation branch is composed of a switching valve, a sonic nozzle and a high-speed switching three-way valve connected in series, and the critical flow rate value of the flow generation branch is in direct proportion to the throat area of the sonic nozzle.

[0008] As a further improvement of the present invention, the detection valve of the high-speed switching three-way valve is connected to the input end of the flowmeter to be detected, and the recovery valve of the high-speed switching three-way valve is connected to the output end of the flowmeter to be detected.

[0009] As a further improvement of the present invention, the reliability ranking step calculates the reliability parameter of each flow generation branch according to the start-up time of each flow generation branch and the degree of flow rate change of the flow generation branch when reaching the critical flow rate, and ranks the reliability of the flow generation branches through the reliability parameter.

[0010] As a further improvement of the present invention, the reliability parameter calculation is as follows: ; where R is the reliability parameter, F(t) is the function of the flow rate through the three-way valve at time t, F a is the average flow rate, Fmax is the maximum flow rate during detection; T is the total detection time, is the attenuation coefficient of the flow generation branch, used to represent its stability, Q 0 is the critical flow rate value that the sonic nozzle can reach, T s is the start-up time required to reach a stable flow rate after the three-way valve is opened, T d is the time required to reach a new stable state when the valve is switched.

[0011] As a further improvement of the present invention, in the branch selection step, the flow generation branches that can be optionally switched to the detection state are confirmed according to the set flow value to be detected, and the selection result of each flow generation branch that reaches the flow value to be detected is set as a set of branch selection schemes. The scheme reliability parameter is calculated according to the reliability parameter of the selected flow generation branch and the flow value to be detected, and the state of the flow generation branch is adjusted according to the branch selection result with the highest scheme reliability parameter.

[0012] As a further improvement of the present invention, the detection valve of the high-speed switching three-way valve is connected to the input end of the flowmeter to be detected, and the recovery valve of the high-speed switching three-way valve is connected to the output end of the flowmeter to be detected. The scheme reliability parameters are as follows: ; where W is the scheme reliability parameter, R i is the reliability parameter of the i-th flow generation branch, Q i is the critical flow value of the i-th flow generation branch, n is the number of flow generation branches, Q is the flow value to be detected, and Q = .

[0013] As a further improvement of the present invention, in the scheme calibration step, when the overall flow fluctuation value is higher than the set threshold, a reliability influence factor of the flow generation branch is generated. After the reliability parameter is recalculated by the reliability influence factor of the flow generation branch, the scheme reliability factor is calculated again, and the flow generation branch is selected again.

[0014] As a further improvement of the present invention, the dynamic flow generation device control method of the fast switching array further includes: by adding a control system, using a PLC to send an electrical signal to control the high-speed switching three-way valve.

[0015] The beneficial effects of the present invention are as follows: (1) By using a high-speed switching three-way valve to replace the traditional two-way valve, the flow generation branch can quickly respond to the flow switching control instruction, reduce the time for the device flow to adjust to the stable state, reduce the flow fluctuation, and improve the overall stability of the system.

[0016] (2) By using a dynamic flow generation device composed of dynamic flow generation branches controlled by multiple valves, and controlling the flow rate of the flow generation branch by the throat area of the sonic nozzle, the dynamic flow detected by the flowmeter can more accurately reflect the actual flow characteristics, and improve the authenticity of the detection of the flowmeter to be detected.

[0017] (3) By sorting the reliability of multiple flow generation branches and selecting the combination of flow generation branches with the highest reliability to reach the set flow rate, i.e., the flow value to be detected, the accuracy and accuracy of flow control and testing can be improved. Description of the Drawings

[0018] Figure 1 is a flowchart of a control method for a dynamic flow generating device based on a fast switching array according to the present invention; Figure 2 is a schematic diagram of a dynamic flow generating device in an embodiment of the present invention; Figure 3 is a schematic diagram of the flow direction of a high-speed switching three-way valve in an embodiment of the present invention; Figure 4 is the working flow curve of the dynamic flow generating device in an embodiment of the present invention. Detailed Description of the Invention

[0019] The specific embodiments of the present invention will be described in detail below. It should be noted that the embodiments described here are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the following embodiments, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0020] An embodiment of the present invention provides a control method for a dynamic flow generating device based on a fast switching array, as Figure 1 shown, including an initial parameter setting step, where the critical flow value of each flow generating branch is measured separately using a flowmeter on one side, and the critical flow value is converted into electrical signal data, and the start time for each flow generating branch to reach the critical flow value is calculated. The start time is the difference between the starting moment when the flow value starts from 0 and the moment when the electrical signal data reaches the critical flow value.

[0021] In the dynamic flow generating device of the present invention, there are several flow generating branches with different flow rates. The flow generating branches are composed of a switching valve, a sonic nozzle, and a high-speed switching three-way valve in cascade. The critical flow value of the flow generating branch is in a proportional relationship with the throat area of the sonic nozzle. By adjusting the throat area of the sonic nozzle, the flow rate of the overall flow generating branch can be adjusted, so that the flow rates of different flow generating branches are different, providing multiple flow generating branch combination schemes for the total flow rate value required by the flowmeter to be tested, and improving the stability and switching efficiency of the overall dynamic flow generating device under different flow conditions; by combining flow generating branches with different critical flow values, a flow generating device with controllable flow changes can be formed. Since the valves in the flow generating branch are composed of high-speed switching three-way valves, before the dynamic flow generating device starts to work, the switching valves of all flow generating branches are opened, and the high-speed switching three-way valves of all flow generating branches are opened to the state where the detection valve is closed and the recovery valve is opened. At this time, it can be ensured that the flow generating branch continuously maintains a flow output of the critical flow value, and the output flow is not connected to the flowmeter, providing a basis for the rapid switching of flows with different critical flow values in the subsequent flow generating device.

[0022] The detection valve of the high-speed switching three-way valve is connected to the input end of the flowmeter to be tested, and the recovery valve of the high-speed switching three-way valve is connected to the output end of the flowmeter to be tested. When the recovery valve of the high-speed switching three-way valve is opened, the flow generation branch is in a state of not being connected to the flowmeter to be tested; when the detection valve of the high-speed switching three-way valve is opened, the flow generation branch is in a state of being connected to the flowmeter to be tested. By using the high-speed switching three-way valve, the flow in the device can be kept stable when not being detected, and the time required for the gas source to pass through the front part of the pipeline is shortened. Furthermore, when the valve is switched, the flow through the flowmeter can quickly rise to the set flow value to be tested, that is, the set flow state.

[0023] Reliability ranking step: Calculate the reliability parameter of the flow generation branch according to the start time and the critical flow value, and rank the reliability of the flow generation branch according to the reliability parameter; Since different flow generation branches with different critical flow sizes can be selected to achieve the same flow value to be tested, therefore, it is necessary to calculate the size of the reliability parameter when each flow generation branch reaches a stable critical flow value, and judge the optimal flow generation branch selection scheme according to this parameter. The reliability parameter is calculated by detecting the various parameters of the flow value of the flow generation branch and the start time. According to the start time of each flow generation branch and the flow stability when the state changes, calculate the reliability parameter of each flow generation branch, and rank the flow generation branch by the reliability parameter. The flow stability includes the average flow value, the maximum flow value, the real-time monitored flow value, and the attenuation coefficient of the flow generation branch, etc. The calculation of the reliability parameter is as follows: ; wherein, R is the reliability parameter, F(t) is the function of the flow through the three-way valve at time t, F a is the average flow value, F max is the maximum flow value during detection; T is the total detection time, is the attenuation coefficient of the flow generation branch, which is used to represent its stability. The above data together represent the flow stability, Q 0 is the critical flow value that the sonic nozzle can reach, T s is the start time required to reach a stable flow after the three-way valve is opened, T d is the time required to reach a new stable state when the valve is switched. The higher the exponent of the reliability parameter, the stronger the reliability of the flow generation branch, and the more stable the flow generation branch is when generating a flow value with fixed parameters. By combining factors such as the flow change value, the branch start time, and the critical flow, the calculation of the reliability parameter of the flow generation branch can be made more accurate and comprehensive, improving the accuracy of the subsequent selection of the flow generation branch.

[0024] Branch scheme selection steps: Select the activated flow generation branch according to the set flow value to be detected, output a valve control signal according to the reliability sorting result of the selected flow generation branch, and control the detection valve of the selected flow generation branch to open according to the valve control signal. According to the reliability sorting result, output an electrical control signal to control the opening and closing of the valve of the high-speed switching three-way valve of the flow generation branch, which can achieve precise control and rapid control.

[0025] Branch scheme calibration steps: Detect the overall flow fluctuation value when the valve state of the flow generation branch is switched. If the overall flow fluctuation value is higher than the set threshold, adjust the asynchronous switching time difference of the flow generation branch. If the detected overall flow fluctuation value is still higher than the threshold after adjustment, readjust the reliability parameters of the flow generation branch in the branch selection scheme and re-perform branch selection. By monitoring and adjusting the flow fluctuation value in real time, the stability of the flow during the detection process is ensured. Through the optimization of the switching time difference and reliability parameters, the flow stability and flow response speed of the dynamic flow generation device are improved, and the accuracy and efficiency of the flowmeter detection are enhanced.

[0026] In this embodiment, referring to Figures 1 to 4 as shown, the branch selection steps are as follows: According to the set flow value to be detected, that is, the set flow, confirm the flow generation branch that can be switched to the detection state. Set the selection result of each flow generation branch that reaches the flow value to be detected, that is, the set flow, as a set of branch selection schemes. Calculate the reliability parameter of the scheme according to the reliability parameter of the selected flow generation branch and the flow value to be detected, that is, the set flow. Adjust the state of the flow generation branch according to the branch selection result with the highest scheme reliability parameter. By listing all the combinations of flow generation branches that can reach the flow value to be detected, that is, the set flow, and calculating the reliability parameter of the scheme according to the reliability parameter of the flow generation branch in each combination and the flow value to be detected, that is, the set flow magnitude, the flow generation branch startup scheme with the highest reliability can be selected, thereby improving the efficiency and flow stability of the dynamic flow generation device and providing a stable gas source for the subsequent flowmeter detection.

[0027] In this embodiment, referring to Figures 1 to 4 as shown, the detection valve of the high-speed switching three-way valve is connected to the input end of the flowmeter to be detected, and the recovery valve of the high-speed switching three-way valve is connected to the output end of the flowmeter to be detected. The reliability parameters of the scheme are as follows: ; where W is the reliability parameter of the scheme, R i is the reliability parameter of the i-th flow generation branch, Q i is the critical flow value of the i-th flow generation branch, n is the number of flow generation branches, Q is the flow value to be detected, that is, the set flow, and Q = By using the reliability parameter of the flow generation branch and the flow value to be detected, i.e., the set flow rate, to evaluate the reliability of the scheme, the flow stability of the dynamic flow generation device is improved.

[0028] In this embodiment, referring to Figures 1 to 4 As shown, when the overall flow fluctuation value is higher than the set threshold in the scheme calibration step, a reliability impact factor of the flow generation branch is generated. After recalculating the reliability parameter through the reliability impact factor of the flow generation branch, the scheme reliability factor is calculated again, and the flow generation branch is selected again. By detecting the sum of the overall flow fluctuation values during the switching between the recovery valve and the detection valve of the high-speed switching valve of the flow generation branch, the actual stability of the dynamic flow generation device in the actual application process can be obtained. When the overall flow fluctuation value is greater than the set threshold, it is determined at this time that the reliability of the branch selection scheme is reduced, and the reliability of the flow generation branch and the scheme reliability are recalculated.

[0029] In this embodiment, referring to Figures 1 to 4 As shown, the control method of the dynamic flow generation device with a fast switching array further includes: by adding a control system, using a PLC to send an electrical signal to control the high-speed switching three-way valve. By using the PLC to send an electrical signal to control the high-speed switching three-way valve, the valve can be switched at high speed to achieve a high-frequency response of the dynamic flow rate.

[0030] The basic features, principles, and advantages of the present invention have been shown and described above. It should be noted that the present invention is not limited by the above embodiments, but only some embodiments. Without departing from the spirit and scope of the present invention, several improvements and supplements made are regarded as the protection scope of the present invention.

Claims

1. A method for controlling a dynamic flow generating device based on a fast switching array, characterized in that: include: Initial parameter setting step, measuring the critical flow value of each flow generation branch, and calculating the start time for each flow generation branch to reach the critical flow value; A reliability sorting step, calculating the reliability parameters of the flow generation branches according to the start-up time and the critical flow value, and sorting the reliability of the flow generation branches according to the reliability parameters; The branch scheme selection step selects the flow generating branch to be started according to the set flow value to be tested, and outputs a valve control signal according to the reliability ranking result of the selected flow generating branch, and controls the detection valve of the selected flow generating branch to open according to the valve control signal. The branch scheme calibration step detects the overall flow fluctuation value when the flow generating branch switches the valve state. If the overall flow fluctuation value is higher than the set threshold, the asynchronous switching time difference of the flow generating branch is adjusted. If the overall flow fluctuation value detected after adjustment is higher than the threshold, the reliability parameter of the flow generating branch in the branch selection scheme is readjusted, and the branch selection is re-performed.

2. A method for controlling a dynamic flow generation device based on a fast switching array according to claim 1, characterized in that: The flow generation branch is composed of a switch valve, a sonic nozzle and a high-speed switching three-way valve in cascade, and the critical flow value of the flow generation branch is in direct proportion to the throat area of ​​the sonic nozzle.

3. A method for controlling a dynamic flow generation device based on a fast switching array according to claim 3, characterized in that: The detection valve of the high-speed switching three-way valve is connected to the input end of the flow meter to be tested, and the recovery valve of the high-speed switching three-way valve is connected to the output end of the flow meter to be tested.

4. A method for controlling a dynamic flow generation device based on a fast switching array according to claim 1, characterized in that: The reliability ranking step calculates the reliability parameter of each flow generation branch according to the start-up time of each flow generation branch and the flow change degree of the flow generation branch when the critical flow is reached, and ranks the reliability of the flow generation branches according to the reliability parameters.

5. A method for controlling a dynamic flow generation device based on a fast switching array according to claim 1, characterized in that: The reliability parameters are calculated as follows: ； Where R is the reliability parameter, F(t) is the function of the flow rate through the three-way valve at time t, and F a is the average flow rate, Fmax is the maximum flow rate during detection; T is the total detection time, is the attenuation coefficient of the flow branch, which is used to indicate its stability. Q0 is the critical flow value that the sonic nozzle can reach. T s is the start-up time required to reach a stable flow rate after the three-way valve is opened, T d It is the time required for the valve to reach a new stable state when switching.

6. A method for controlling a dynamic flow generation device based on a fast switching array according to claim 1, characterized in that: The branch selection step confirms the flow generating branch that can be selected to switch to the detection state according to the set flow value to be tested, sets each flow generating branch selection result that reaches the flow value to be tested as a group of branch selection schemes, and calculates the scheme reliability parameters according to the reliability parameters of the selected flow generating branch and the flow value to be tested, and adjusts the state of the flow generating branch according to the branch selection result with the highest scheme reliability parameter.

7. A method for controlling a dynamic flow generation device based on a fast switching array according to claim 1, characterized in that: The detection valve of the high-speed switching three-way valve is connected to the input end of the flow meter being tested, and the recovery valve of the high-speed switching three-way valve is connected to the output end of the flow meter being tested. The reliability parameters of the scheme are: ； Among them, W is the reliability parameter of the scheme, R i is the reliability parameter of the i-th traffic branch, Q i is the critical flow value of the i-th flow branch, n is the number of flow branches, Q is the flow value to be tested, Q= .

8. A method for controlling a dynamic flow generation device based on a fast switching array according to claim 1, characterized in that: In the scheme calibration step, when the overall flow fluctuation value is higher than the set threshold, a flow generation branch reliability impact factor is generated, the reliability parameter is recalculated using the flow generation branch reliability impact factor, the scheme reliability factor is calculated again, and the flow generation branch is reselected.

9. A method for controlling a dynamic flow generation device based on a fast switching array according to claim 1, characterized in that: The method for controlling the dynamic flow generating device of the fast switching array also includes: adding a control system and using a PLC to send an electrical signal to control the high-speed switching three-way valve.

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