CN115166010A - Flow self-adaptive intelligent gas calibration control method - Google Patents

Abstract

The invention discloses a flow self-adaptive intelligent gas calibration control method, which comprises the following steps: the PID controller controls the opening of an electronic valve of the air inlet numerical control flowmeter to enable the calibrated air flow to be lifted at a constant speed from 0 mL/min; when the gas inflow meets the calibration flow of an instrument to be calibrated, redundant gas flows out through an overflow pipeline and is measured by an overflow numerical control flow meter, and the overflow flow signal is fed back to the PID controller by the overflow numerical control flow meter; when the overflow flow reaches a certain proportion of the air inlet flow, the PID controller sends a current opening keeping instruction to the air inlet numerical control flowmeter, so that the flow in the air inlet pipeline stops rising and the current air flow is kept. The method can realize the functions of automatically determining the optimal calibration gas flow of the equipment to be tested and calibrating by the optimal calibration gas flow by the numerical control flowmeter under the condition of not defining the calibration gas flow required by the equipment to be tested.

Description

A flow adaptive intelligent gas calibration control method

technical field

The invention relates to an intelligent gas calibration control method, in particular to a flow adaptive intelligent gas calibration control method.

Background technique

In the basic scientific research and experimental research in the fields of energy chemical industry, material research and development, etc., it is inevitable to need various component detection equipment to accurately measure the gas components in the experiment, such as mass spectrometers, chromatographic analyzers, chemiluminescence detectors, etc. Wait. All precision testing equipment needs to go through the target gas calibration stage before running, that is to use a calibration gas with a known specific concentration to calibrate the instrument to determine the corresponding signal intensity at this concentration, so as to calibrate the testing accuracy of the testing equipment and realize the basic experimental process Accurate measurement of target gas concentration in However, due to different precision testing equipment and different types of testing equipment, the measuring range and air intake volume are different. Therefore, the intake flow requirements for the calibration gas are also different during calibration. Using too large or too small gas flow for calibration will interfere with the measurement accuracy of the testing equipment, and long-term incorrect calibration may even damage the equipment. In addition, the above situation also results in that when calibrating different precision testing equipment, it is necessary to adjust the calibration gas flow specifically for the instrument according to the characteristics of the equipment and refer to the equipment instruction manual, which greatly slows down the overall experimental efficiency. Therefore, in order to simplify the tedious calibration process and realize the optimization and improvement of the experimental detection process, especially the equipment calibration process, there is an urgent need for an intelligent calibration method that can automatically detect the required flow rate of calibration gases of different test equipment and achieve calibration with the optimal flow rate at the same time.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the difficulties of the prior art, and to provide a method that does not need to determine the required flow rate of the calibration gas of the detection equipment in advance, but adopts the overflow control strategy to intelligently adjust the flow rate of the calibration gas, so as to automatically find the best calibration gas flow and use This flow is calibrated with an intelligent gas calibration control method.

A flow adaptive intelligent gas calibration control method of the present invention includes the following steps:

Step 1. Connect the calibration control device. The calibration control device includes an intake pipeline, one end of the intake pipeline is connected to the calibration gas supply source and the other end is connected to the pressure reducing valve, the intake numerical control flowmeter, and the three-way connection in turn. A valve port of the three-way connector is connected to the overflow numerical control flowmeter and the exhaust pipe in turn through the overflow pipeline, the intake numerical control flowmeter and the overflow numerical control flowmeter. They are respectively connected with the PID controller through the data transmission line;

Step 2: Set the operation mode of the testing equipment to be calibrated as the calibration mode;

Step 3: Running the calibration control device, the specific steps are:

The first step is to adjust the intake pressure of the calibration gas entering the intake pipeline to be 1-2 bar through the pressure reducing valve, so that the gas pressure of 1-2 bar is maintained in the intake pipeline;

The second step, start the PID controller, the PID controller outputs a control signal to the intake numerical control flowmeter, and controls the electronic valve opening of the intake numerical control flowmeter so that the flow rate of the intake pipeline starts from 0mL/min, and reaches 50~100mL/s. When the intake flow does not meet the calibration flow of the testing equipment, the calibration gas is continuously sucked into the testing device to be calibrated through the three-way connector; with the increase of the intake flow, when the intake flow meets the calibration flow During the calibration flow of the instrument, the excess gas flows out through the overflow pipeline. During this process, the overflow flow is measured by the overflow numerical control flowmeter, and the overflow numerical control flowmeter feeds back the overflow flow signal to the PID controller; When the flow rate reaches 5% to 10% of the current value of the intake flow, the PID controller sends a command to maintain the current opening to the intake numerical control flowmeter through the data transmission line, so that the flow in the intake pipeline stops rising and maintains the current gas flow;

Step 4. Using the current gas flow, operate the calibration mode of the testing equipment to be calibrated and enter the calibration procedure;

Step 5. After completing the calibration procedure, close the calibration mode of the testing equipment to be calibrated and the calibration control device;

Step 6. Turn on the measurement mode of the detection equipment after calibration, and then the experimental measurement can be started.

Compared with the prior art, the present invention has the following beneficial technical effects:

For precision testing equipment, the calibration of the gas concentration to be measured is one of the most important steps in the gas concentration measurement process. During the calibration process of the testing equipment, the equipment will extract the calibration gas at a certain flow rate through its own vacuum pump for measurement. By comparing the amplitude of the measured signal of the device with the calibration gas value of known concentration, the conversion of the measured signal and the concentration is realized. In order to achieve accurate calibration of the gas concentration to be measured, the existing calibration method needs to determine the calibration gas flow required in the calibration process of the detection equipment in advance, so that a specific flow of calibration gas is manually passed through the flow meter for calibration. Compared with the prior art, the present invention can automatically determine the optimal calibration gas flow rate of the equipment to be tested by using the numerical control flowmeter combined with the overflow feedback control strategy without knowing the flow rate of the calibration gas required by the equipment to be tested. And the function of calibration with the best calibration gas flow.

Description of drawings

FIG. 1 is a schematic structural diagram of a device adopting a flow adaptive intelligent gas calibration control method of the present invention.

Detailed ways

The following examples further illustrate the content of the present invention, but should not be construed as limiting the present invention. Modifications and substitutions made to the methods, steps or conditions of the present invention without departing from the essence of the present invention all belong to the scope of the present invention.

As shown in Figure 1, a flow adaptive intelligent gas calibration control method of the present invention includes the following steps:

Step 1. Connect the calibration control device. The calibration control device includes an intake pipeline 3. One end of the intake pipeline 3 is connected to the calibration gas supply source and the other end is connected to the pressure reducing valve 2 and the intake numerical control flowmeter 4 in turn. , the three-way connector 5 and the testing equipment to be calibrated, a valve port of the three-way connector 5 is connected to the overflow numerical control flowmeter 8 and the exhaust pipeline in turn through the overflow pipeline 7, and the intake numerical control The flowmeter 4 and the overflow numerical control flowmeter 8 are respectively connected with the PID controller 10 through the data transmission line 11; the intake numerical control flowmeter 4 adopted in this step has its own electronic valve;

The pressure reducing valve 2 is used to adjust the outlet pressure of the calibration gas cylinder and stabilize the pressure of the intake line. The intake numerical control flow meter 4 is used to adjust the intake air flow in the intake pipeline. The three-way connector 5 is used to connect the intake pipeline, the equipment to be tested and the overflow pipeline. The overflow pipeline 7 is used to remove excess gas in the pipeline, and is connected to the exhaust pipeline through the overflow exhaust port 9 of the overflow pipeline 7 . The overflow numerical control flow meter 8 is used to measure and monitor the overflow flow in the overflow pipeline, and send a feedback signal to the PID controller 10 . The PID controller is used to feedback control the intake numerical control flowmeter according to the flow signal of the overflow flowmeter and display the current flow value of the intake numerical control flowmeter and the overflow numerical control flowmeter.

Step 2: Set the operation mode of the testing equipment to be calibrated as the calibration mode;

Step 3: Running the calibration control device, the specific steps are:

The first step is to adjust the inlet pressure of the calibration gas entering the inlet pipe 3 to be 1-2 bar through the pressure reducing valve 2, so that the gas pressure of 1-2 bar is maintained in the inlet pipe 3;

The second step is to start the PID controller, and the PID controller outputs a control signal to the intake numerical control flowmeter 4 to control the electronic valve opening of the intake numerical control flowmeter 4 so that the flow rate of the intake pipeline starts from 0mL/min, and reaches 50-100mL. The flow rate is increased at the speed of /s. When the intake air flow does not meet the calibration flow of the testing equipment, the calibration gas is continuously sucked into the testing equipment to be calibrated through the three-way connector; When the calibration flow of the instrument is to be calibrated, the excess gas flows out through the overflow pipeline 7. During this process, the overflow flow is measured by the overflow numerical control flowmeter 8, and the overflow numerical control flowmeter 8 feeds back the overflow flow signal to the PID. Controller 10; when the overflow flow reaches 5% to 10% of the current value of the intake flow, the PID controller 10 sends a command to maintain the current opening degree to the intake numerical control flowmeter 4 through the data transmission line 11, so that the flow in the intake pipeline is Stop the ascent and maintain the current gas flow; let the current gas flow be greater than the device calibration flow, and will not use the calibration flow that the device just needs for calibration. To prevent the calibration concentration fluctuation caused by the equipment inhaling ambient gas due to flow fluctuation, resulting in errors.

Step 4. Using the current gas flow, operate the calibration mode of the testing equipment to be calibrated and enter the calibration procedure;

Step 5. After completing the calibration procedure, close the calibration mode of the testing equipment to be calibrated and the calibration control device;

Step 6. Turn on the measurement mode of the detection equipment after calibration, and then the experimental measurement can be started.

Example

Before the experiment, the detection equipment-mass spectrometer is calibrated for the concentration of the gas to be measured, and the mass spectrometer, the calibration gas and the flow adaptive intelligent calibration system mentioned in the present invention are prepared.

1. Connect the calibration gas cylinder connection port 1 to the NO calibration gas cylinder of 5MPa with a concentration of 1000ppm, connect the to-be-calibrated instrument interface 6 to the to-be-calibrated mass spectrometer, and connect the overflow exhaust port 9 to the laboratory exhaust. Connect the pipes. The calibration gas refers to the gas of known concentration, which is used for calibration. Use the gas to calibrate the measurement signal of the device, and after calibration, the value of the device's measurement signal is considered to represent the concentration;

2. Open the pressure reducing valve and adjust the intake air flow to 1bar. Open the calibration program that comes with the mass spectrometer and run the calibration program for the mass spectrometer.

3. Power on and turn on the working switch of the PID controller, and start the flow rate increase program of the intake air flow through the PID controller 10.

4. The intake air flow and overflow flow can be monitored from the panel display of the PID controller. As the flow-up program runs, the flow rate of the intake pipeline is gradually increased from 0mL/min at a rising speed of 50mL/s.

5. Wait until the overflow flow meter shows flow, and the PID feedback control compares the intake flow with the overflow flow value.

6. When the overflow flow reaches 60mL/min, the intake flow rate is displayed as 600mL/min. The PID controller calculates that the overflow flow reaches 10% of the intake flow at this time, and then sends an instruction to the intake flowmeter to stop the intake flow and maintains continuous intake at 600mL/min.

7. At this time, the intake flow rate required for the calibration of the mass spectrometer can be obtained by subtracting the intake flow rate and the overflow flow rate displayed on the PID controller panel to be 540mL/min. Keep the current 600mL/min calibration gas inlet flow, so that the calibration system always has a calibration gas overflow flow of 60mL/min, and start the calibration. This step will not use the 540mL/min flow rate that the device just needs to be calibrated. To prevent the calibration concentration fluctuation caused by the equipment inhaling ambient gas due to flow fluctuation, resulting in errors.

8. Enter the known NO calibration gas concentration of 1000ppm in the mass spectrometer calibration program for calibration. At this time, the mass spectrometer automatically calibrates the corresponding relationship between the signal amplitude and the concentration according to the current NO measurement signal amplitude and the input NO concentration value. Calibration is complete.

9. After completing the calibration, close the equipment calibration procedure, close the pressure reducing valve, and close the calibration control device.

Claims (1)

1. A flow self-adaptive intelligent gas calibration control method is characterized by comprising the following steps:

step one, connecting a calibration control device, wherein the calibration control device comprises an air inlet pipeline, one end of the air inlet pipeline is connected with a calibration air supply source, the other end of the air inlet pipeline is sequentially connected with a pressure reducing valve, an air inlet numerical control flowmeter, a three-way connecting piece and a to-be-calibrated detection device, one valve port of the three-way connecting piece is sequentially connected with an overflow numerical control flowmeter and an exhaust pipeline through an overflow pipeline, and the air inlet numerical control flowmeter and the overflow numerical control flowmeter are respectively connected with a PID controller through data transmission lines;

setting the operation mode of the detection equipment to be calibrated as a calibration mode;

step three, operating the calibration control device, specifically comprising the following steps:

firstly, regulating the inlet pressure of the calibration gas entering the inlet pipeline to be 1-2 bar through the pressure reducing valve, so that the gas pressure of 1-2 bar is kept in the inlet pipeline;

secondly, starting a PID controller, wherein the PID controller outputs a control signal to the air inlet numerical control flowmeter, and the opening of an electronic valve of the air inlet numerical control flowmeter is controlled to ensure that the flow of an air inlet pipeline starts from 0mL/min, and the flow is increased at the speed of 50-100 mL/s, and when the air inlet flow does not meet the calibration flow of the detection equipment, the calibration gas is continuously sucked into the detection equipment to be calibrated through a three-way connecting piece; along with the increase of the air inlet flow, when the air inlet flow meets the calibration flow of an instrument to be calibrated, redundant gas flows out through an overflow pipeline, the overflow flow is measured through an overflow numerical control flow meter in the process, and the overflow flow signal is fed back to a PID controller by the overflow numerical control flow meter; when the overflow flow reaches 5% -10% of the current numerical value of the air inlet flow, the PID controller sends a current opening keeping instruction to the air inlet numerical control flow meter through a data transmission line, so that the flow in an air inlet pipeline stops rising and the current gas flow is kept;

step four, operating a calibration mode of the detection equipment to be calibrated to enter a calibration program by adopting the current gas flow;

step five, closing the calibration mode of the detection equipment to be calibrated and the calibration control device after the calibration program is completed;

and step six, starting a measurement mode of the calibrated detection equipment, and then starting experimental measurement.

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