CN-122015984-A - Fixed positive and negative pressure catheter flow testing method

CN122015984ACN 122015984 ACN122015984 ACN 122015984ACN-122015984-A

Abstract

The invention discloses a fixed positive and negative pressure catheter flow testing method. According to the invention, through the cooperation of accurate parameter setting and a staged pressure regulation strategy, the obvious improvement of pressure control performance is realized. The staged strategy firstly shortens the initial pressure gap by utilizing the maximum capability of hardware, and then breaks through the single logic limitation of conventional closed-loop control by finely calibrating the compression fluctuation range for multiple rounds, thereby ensuring the pressure to be stable within extremely high precision. The dynamic pre-stabilization mode shortens the pressure building time, provides a stable environment foundation for formal testing, directly improves the accuracy of flow measurement, enables the result to reflect the real performance of the catheter, adapts to the rapid response of different pressure requirements, reduces unnecessary waiting time, and improves the overall testing efficiency.

Inventors

YAN WEI
WANG JUE
XU HUAN
Liu Gaolie
ZHAO JIANG
KANG YONG
Liu Jiongcheng
ZHANG LULU
WU QIONG
WANG LIANGLIANG

Assignees

熠品(贵阳)质量科技有限公司

Dates

Publication Date: 20260512
Application Date: 20260106

Claims (10)

1. The fixed positive and negative pressure catheter flow testing method is characterized by comprising the following steps of: S1, switching on a 220V power supply and starting a system, waiting for the system to finish zero calibration of a pressure sensor and automatic zero setting of a weighing unit, ensuring that all basic modules are in a usable state, and providing accurate initial conditions for subsequent tests; S2, selecting a positive pressure or negative pressure test mode on a main interface of the touch screen, wherein the selection directly guides the specific operation direction of the subsequent sample installation; S3, completing sample installation according to the mode selected in the S2, wherein the positive pressure mode is to add not less than 500ml of purified water into the water storage container and connect the conduit to the test interface, and the negative pressure mode is to empty the water storage container and connect the conduit to an external water source container; S4, setting a target pressure value and a test duration, wherein the input parameters are used as core basis for subsequent adjustment of the pressure control system; S5, starting a dynamic pressure pre-stabilization process, wherein the system rapidly approximates the target pressure set in the step S4, and then carries out three small-amplitude pressure fine adjustments to ensure that the pressure is stabilized within the accuracy range of +/-0.3 kPa, so as to lay a stable pressure environment for formal test; S6, starting timing and executing testing, recording mass change data in a specified time period under stable pressure by the system, and automatically calculating a corresponding flow value by combining the sample type installed in the S3; And S7, automatically storing the data after the test is finished, generating a report containing a flow result and a pressure curve, and exporting the data through an interface for subsequent analysis.
2. The method for testing the flow of the fixed positive and negative pressure conduits according to claim 1, wherein in the step S1, zero calibration of the pressure sensor is completed first, the calibration process lasts for 3 seconds, the output value of the sensor is guaranteed to be completely matched with the zero pressure environment, then the weighing unit automatically executes zero-resetting operation, the zero-resetting precision is required to reach +/-0.1 g, and initial mass errors are eliminated.
3. The method of testing the flow rate of a stationary positive and negative pressure conduit according to claim 1, wherein in the step S2, the positive pressure mode corresponds to a test scenario in which the conduit is forward delivering fluid, the negative pressure mode corresponds to a scenario in which the conduit is reverse sucking fluid, and after the mode is selected, the system automatically switches the hardware configuration such that a water inlet control valve of the water storage container is opened in the positive pressure mode, and a pre-start program of the vacuum pump is started in the negative pressure mode.
4. The method for testing the flow rate of the fixed positive and negative pressure pipes according to claim 1, wherein in the step S3, in a positive pressure mode, not less than 500ml of purified water is required to be added into the water storage container, one end of each pipe is tightly connected to a positive pressure test interface of the system, the other end of each pipe is fixed at a water outlet of the water storage container, no leakage is guaranteed at all connecting positions, in a negative pressure mode, liquid in the water storage container is required to be completely emptied, one end of each pipe is connected to a negative pressure test interface of the system, the other end of each pipe is connected to a water inlet of an external water source container, tightness of the interface is checked, air is prevented from entering the system, after the installation is completed, the system automatically detects the connecting state, and the system enters the next step after confirming that no errors exist.
5. The method for testing the flow of the fixed positive and negative pressure conduit according to claim 1, wherein in the step S4, accurate setting of two key parameters, namely a target pressure value and a testing duration, is completed through a system interaction interface, and the two parameters directly guide a staged pressure regulation strategy of the step S5, and the method specifically comprises the following operations: Firstly, a user inputs a target pressure value through a parameter setting panel of a touch screen, wherein the settable range in a positive pressure mode is 0-50 kPa, the settable range in a negative pressure mode is-50 kPa-0, a system can check parameter rationality in real time during input, if the value exceeds the range of a pressure sensor or conflicts with the current mode, a red prompt can be popped up on an interface to lock the next operation, the operation is re-input after correction, and then test duration is set.
6. The method for testing the flow of the fixed positive and negative pressure conduits according to claim 1, wherein in the step S5, the initial pressure gap is shortened by utilizing the maximum capacity of hardware, the system firstly reads a target pressure value P target set by S4, calculates the pressure difference delta P=P target -P current by combining pressure sensor real-time data P current calibrated by S1, when the absolute value of delta P is larger than a preset threshold delta P threshold , the system skips the slow regulation of a conventional PID, directly drives a pressure pump to operate at rated power, and quickly reduces the pressure gap, and the key of the step is that the regulation inertia of the conventional PID is broken through an open-loop maximum output strategy, so that time is saved for subsequent fine adjustment, meanwhile, the system monitors the pressure change in real time, and immediately switches to a fine adjustment mode once the delta P enters the threshold range, so that excessive pressure fluctuation is avoided.
7. The method for testing the flow of the fixed positive and negative pressure conduits according to claim 1, wherein in the step S5, a system adopts a low-scale-coefficient adjusting logic in the first fine adjustment, a scale coefficient K p1 is set to be 1/3 of a conventional PID, preliminary convergence is conducted on the residual error after rapid approximation, the pressure is kept stable after adjustment for 0.5 seconds, a new current pressure P current1 is read, the scale coefficient is further reduced to K p2 in the second fine adjustment, the smaller error is finely adjusted, P current2 is obtained after the fine adjustment is conducted again, an integration link is introduced in the third fine adjustment, the small error is accumulated through an integration coefficient Ki, the static difference is thoroughly eliminated, and the pressure is ensured to be stable within a range of +/-0.3 kPa.
8. The method for testing the flow rate of the stationary positive and negative pressure conduit according to claim 1, wherein in the step S5, a control amount formula is output in a rapid approximation stage: ; wherein: The output power of the pressure pump in the rapid approximation stage; rated maximum output power of the pressure pump; a sign function, returning to 1 when x >0, and returning to-1 when x < 0; S4, setting a target pressure value; Reading a real-time pressure sensor; first fine tuning output control quantity formula: ; parameter definition: outputting power for the pressure pump subjected to the first fine adjustment; Fine tuning the scaling factor for the first time; the pressure is the real-time pressure after the rapid approximation stage is finished; the second fine tuning output control amount formula: ; parameter definition: Outputting power for the pressure pump of the second fine tuning; Fine tuning the scaling factor for the second time; the real-time pressure after the first fine tuning is finished; Third fine tuning output control amount formula: ; parameter definition: outputting power for the pressure pump subjected to the third fine adjustment; the integral adjustment coefficient; Duration for the third trim; is the real-time pressure at time t after the second fine tuning is finished.
9. The method for testing the flow of the fixed positive and negative pressure catheters according to claim 1, wherein in the step S6, the system automatically starts timing after finishing pressure stabilization in the step S5, the timing duration is consistent with the testing duration set in the step S4, in the testing process, the weighing unit records mass change data once per second, the pressure sensor collects pressure values 5 times per second and feeds the pressure values back to the control system in real time, the pressure is ensured to be always stabilized within the accuracy range of +/-0.3 kPa, the system automatically selects a flow calculation formula according to the sample mode installed in the step S3, the mass flowing out in unit time is divided by the liquid density to obtain the volume flow in the positive pressure mode, the mass sucked in unit time is divided by the liquid density in the negative pressure mode to obtain the volume flow, and in the testing process, all the data are stored in the temporary buffer area in real time.
10. The method of testing the flow rate of a stationary positive and negative pressure conduit according to claim 1, wherein in step S7, after the test is completed, the system automatically stops the pressure supply and closes the relevant valve, then stores all data of the current test in a local database in a CSV file, and then generates a detailed test report including the test date, test time, target pressure value, test duration, average flow value, and pressure fluctuation range.

Description

Fixed positive and negative pressure catheter flow testing method Technical Field The invention belongs to the technical field of conduit flow test, and particularly relates to a fixed positive and negative pressure conduit flow test method. Background The positive and negative pressure conduit flow measurement is a mature industrial metering technology based on the principle of hydrodynamic pressure difference. The core mechanism is that a throttling device (such as an orifice plate, a venturi tube and the like) is arranged in the pipeline, so that the pressure change is generated when the fluid flows through the pipeline. The positive pressure conduit is connected with the high-pressure taking port at the upstream of the throttling element, the negative pressure conduit is connected with the low-pressure taking port at the downstream, and pressure signals at two ends are introduced into the differential pressure transmitter for detection. The system accurately calculates and displays the instantaneous flow and the accumulated total amount of the medium according to the functional relation of the pressure difference and the fluid flow and by combining temperature and pressure compensation. The method is widely applied to complex industrial sites such as petroleum, chemical industry, metallurgy, electric power and the like by virtue of the characteristics of simple structure, high reliability, strong applicability and the like. However, in the prior art, a single closed-loop control logic is generally adopted, the pressure regulation precision is insufficient and the fluctuation is large, the stability in a high-precision range is difficult, the accuracy of a flow measurement result is limited, meanwhile, the pressure establishment time is long, the test efficiency is low, the flow automation degree is low, more human intervention is needed, the operation error is easy to introduce, and the requirements of two different test scenes of positive and negative pressure cannot be flexibly met due to the fact that the single pressure mode is mostly adapted. Disclosure of Invention The invention aims to solve the problems and provide a fixed positive and negative pressure catheter flow testing method. The invention adopts the technical scheme that the flow testing method of the fixed positive and negative pressure conduit comprises the following steps: And S1, switching on a 220V power supply and starting the system, waiting for the system to finish zero calibration of the pressure sensor and automatic zero setting of the weighing unit, ensuring that all basic modules are in a usable state, and providing accurate initial conditions for subsequent tests. S2, selecting a positive pressure or negative pressure test mode on a main interface of the touch screen, wherein the selection directly guides the specific operation direction of the subsequent sample installation. S3, completing sample installation according to the mode selected in the S2, wherein the positive pressure mode is to add at least 500ml of purified water into the water storage container and connect the conduit to the test interface, and the negative pressure mode is to empty the water storage container and connect the conduit to an external water source container. And S4, setting a target pressure value and a test duration, wherein the input parameters are used as core basis for subsequent adjustment of the pressure control system. And S5, starting a dynamic pressure pre-stabilization process, wherein the system rapidly approximates the target pressure set in the step S4, and then carries out three small-amplitude pressure fine adjustments, so that the pressure is ensured to be stabilized within the accuracy range of +/-0.3 kPa, and a stable pressure environment is laid for formal test. And S6, starting timing and executing testing, recording mass change data in a specified time period under stable pressure by the system, and automatically calculating a corresponding flow value by combining the sample type installed in the S3. And S7, automatically storing the data after the test is finished, generating a report containing a flow result and a pressure curve, and exporting the data through an interface for subsequent analysis. In a preferred embodiment, in the step S1, the zero calibration of the pressure sensor is completed first, the calibration process lasts for 3 seconds, so as to ensure that the output value of the sensor is completely matched with the zero pressure environment, then the weighing unit automatically performs the zeroing operation, the zeroing precision needs to reach +/-0.1 g, and the initial mass error is eliminated. After the self-checking is finished, the touch screen displays a prompt of 'system ready', and at the moment, all basic components such as the pressure pump, the water storage container valve, the data acquisition module and the like are in a normal working state, and no error information is generated, so that stable