Remote Calibration Device and Method for Tunnel Carbon Monoxide Content Detector

Abstract

The remote calibration device and method for a tunnel carbon monoxide content detector belong to the field of tunnel environment detection. In order to adapt to the installation scenarios of carbon monoxide sensors in narrow spaces and other places, and to simplify the working process of inflation and deflation, the present invention designs a flexible standard container with variable volume as the working space for calibrating the tunnel carbon monoxide content detector. The flexible container is made of plastic material, and an adapter bracket is provided on it for easy wall-mounted operation. Automated design of calibration site execution components. Calibration method or calibration process design based on remote calibration device. Since many automated execution components are involved in the remote calibration work, a reasonable calibration process is needed to standardize this working process. The inflation and exhaust work are mainly designed in a standardized manner for the purpose of creating a standard gas space with a specific concentration. The present invention overcomes the problems of low efficiency and high cost of conventional methods.

Description

Technical Field

[0001] The present invention belongs to the field of tunnel environment detection. Background Art

[0002] Tunnel carbon monoxide content detector: An instrument used to detect the carbon monoxide content or concentration in the tunnel environment.

[0003] Remote calibration: Remote calibration is a method that relies on network data transmission technology to connect the calibration site and the monitoring site to achieve the calibration of instrument equipment. Among them, the calibration site is mainly responsible for the implementation of calibration operations and the collection of calibration data, and the monitoring site is responsible for the supervision of calibration operations and the issuance of control instructions.

[0004] Carbon monoxide is a common gas that threatens human health. The concentration of carbon monoxide is generally controlled below the safety limit in most relatively enclosed environments. When the tunnel is too long to affect its normal natural ventilation, engineering generally sets up a tunnel carbon monoxide content detector to monitor the internal carbon monoxide concentration (most of which are based on electrochemical reaction formulas, and the present invention is only for the remote calibration of electro-chemical tunnel carbon monoxide content detectors), and turns on the ventilation device when its concentration approaches or exceeds the safety threshold to dilute its concentration. To form an effective safety response mechanism, the accurate and reliable detection value of the tunnel carbon monoxide content detector is an important prerequisite. The inside of the tunnel is generally cold and humid, and due to the continuous passing of vehicles, the concentration of suspended particles is also relatively high, which adds uncertain factors to the normal operation of the tunnel carbon monoxide content detector and easily causes inaccurate detection values. To avoid such phenomena, regular traceability is a relatively reliable solution, but due to the relatively scattered installation locations and mostly in mountainous areas with inconvenient transportation, it has set many obstacles to the regular traceability work. At present, the on-site calibration work of tunnel carbon monoxide content detectors has just started, but due to the travel problems of calibration personnel, the on-site calibration work is time-consuming and laborious, and as the installation volume of related instruments gradually increases, it becomes impossible to achieve large-scale value traceability, and only technical innovation can be relied on.

[0005] In recent years, remote calibration technology has developed rapidly in some industries, such as remote calibration of time frequency, remote calibration of intelligent water meters, etc. Different application fields have huge differences in the specific implementation technical solutions, and they are basically not applicable to the remote calibration of tunnel carbon monoxide content detectors. Therefore, it is of great significance to develop a device and method suitable for the remote calibration of tunnel carbon monoxide content detectors.

[0006] At present, the common solutions and steps for on-site calibration of gas content detectors in engineering are as follows:

[0007] (1) The calibration personnel carry the metrological standard instrument to the calibration site;

[0008] (2) Connect the standard gas cylinder, fixed volume calibration box and the instrument to be calibrated with gas pipelines and seals;

[0009] (3) Vacuuming the fixed volume calibration box;

[0010] (4) The fixed-volume calibration box is filled with standard gas of agreed concentration (in order to ensure the uniformity of standard gas distribution, some applications will also add gas stirring blades inside it);

[0011] (5) Record the data after the indication of the calibrated instrument stabilizes;

[0012] (6) Compare the standard value with the test value to obtain parameters such as the indication error of the calibrated instrument.

[0013] The current on-site calibration scheme has significant limitations in terms of calibration methods and approaches when applied to the calibration of tunnel carbon monoxide detectors, as reflected in the following aspects:

[0014] (1) On-site calibration work is highly dependent on calibration personnel, which will cause a huge waste of calibration resources due to travel and other factors.

[0015] (2) The installation location of the sensor of the tunnel carbon monoxide content detector is relatively narrow, which is not convenient for connecting the conventional fixed volume calibration box to the sensor;

[0016] (3) If the calibration site requires multiple concentrations of standard gases, multiple bottles of standard gases will be prepared according to the conventional method, which is extremely inconvenient to carry;

[0017] (4) Conventional calibration methods involve the vacuuming of a fixed-volume calibration box, which places strict demands on the airtightness of the device and increases the difficulty of manufacturing.

[0018] (5) Conventional methods are inefficient and costly, which is not conducive to the large-scale calibration of tunnel carbon monoxide content detectors.

[0019] 4.1 Flexible Standard Container Design. To accommodate carbon monoxide sensor installation scenarios in confined spaces and simplify the inflation and deflation processes, a flexible standard container with variable volume was designed as the workspace for calibrating the tunnel carbon monoxide content detector. The flexible container is made of plastic and equipped with an adapter bracket for easy wall mounting.

[0020] 4.2 Automated Design of Calibration Site Execution Components. To enable calibration personnel to remotely control calibration work at the site, the calibration site terminal components are automated. For example, an electric servo is installed on the knob. When powered on, the electric servo can rotate to a specific angle based on the input control signal, thereby driving the rotation of the knob.

[0021] 4.3 Calibration method or calibration process design based on the remote calibration device. Since many automated execution components are involved in the remote calibration work, a reasonable calibration process is required to standardize this working process. Mainly for the purpose of creating a specific concentration standard gas space, the design of inflation and exhaust work is standardized. Summary of the Invention

[0022] The remote calibration device for tunnel carbon monoxide content detector described in the present invention mainly consists of a flexible standard container, an electric execution component, a network communication module and a monitoring end system. Its framework diagram is as Figure 1 shown.

[0023] Among them, the flexible standard container 7 is used to create the working space for calibrating the tunnel carbon monoxide content detector, and mainly consists of a flexible container, a reference standard module, a gas distribution system module, an air inlet and outlet component, an elastic interface of the sensor to be calibrated, and a transfer bracket; the electric execution component makes corresponding action responses according to the control signal, such as rotation, sliding, pressing, including a servo motor, a linear motor, a solenoid valve / switch; the network communication module is used to convey the control instructions at the monitoring site to the calibration site, and is a wireless communication method; the monitoring end system monitors the calibration site according to the video feedback of the calibration site, including a monitoring display and an attitude perception panel. The overall connection diagram of the remote calibration device for tunnel carbon monoxide content detector is as Figure 2 shown, and the assembly of the flexible standard container is as Figure 3 shown.

[0024] Figure 2 In, the monitoring end system 1 can input calibration control instructions, including physical operation input or touch screen input, to control the entire calibration process and perform calibration correction according to the video feedback of the calibration site; the network communication module 2 is used to transmit the calibration control instructions at the monitoring site to the calibration site and transmit the video of the calibration site to the monitoring site; the PLC 3 is used to analyze the calibration control instructions transmitted by the network communication module and transfer them from the output port to the electric key 4, the electric servo motor 5, and the electromagnetic switch 6 in the form of digital signals or analog signals; the electric key 4, the electric servo motor 5, and the electromagnetic switch 6 perform corresponding actions according to digital signals or analog signals. For example, the electric key 4 presses or bounces according to the digital signals "0" or "1", and the output shaft of the electric servo motor 5 rotates a corresponding angle according to the pwm signal or voltage signal to control the knob directly connected to it; the flexible standard container creates a carbon monoxide standard gas with a specific concentration inside its flexible container through a series of operations of gas distribution, exhaust, and inflation to form a calibration working space.

[0025] Figure 3In it, standard air 17 and carbon monoxide standard gas 18 are jointly input into the gas distribution system 19. The gas distribution system can be started or the instrument operation can be confirmed through button 20. Different concentrations of carbon monoxide standard gas can be adjusted through knob 21, and the prepared carbon monoxide standard gas is transported to the flexible container 15. The solenoid valve 16 functions to open and close the gas path. The reference standard device 24 is used to measure the concentration of carbon monoxide gas in the flexible container 15 to provide the carbon monoxide concentration standard value. The connecting wire of the reference standard device 24 passes through the flexible container 15 without leakage through the aviation plug 23 and is connected to the display screen 22. The carbon monoxide concentration standard value is displayed through the display screen 22. The exhaust pump 11 is used to quickly exhaust the gas in the flexible container 15. A solenoid valve 12 is provided on the connecting pipeline between it and the flexible container to prevent gas backflow during the calibration working state, which may affect the concentration of carbon monoxide gas in the flexible container. The adapter bracket 13 is used to connect the flexible container 15 and the attached components to the tunnel side wall to facilitate the wall-hanging operation. One end of the elastic interface 14 of the sensor to be calibrated is hermetically connected to the flexible container, and the other end is used to connect the carbon monoxide sensor to be calibrated. The elastic setting is for one thing to adapt to different sizes of carbon monoxide sensors, and for another to play an auxiliary sealing role.

[0026] Innovations of the present invention:

[0027] (1) Monitoring end system - network remote communication - combination and adaptive design scheme of the remote control process of the electric actuator and the calibration of the tunnel carbon monoxide content detector;

[0028] (2) Working process and method for remote calibration of the tunnel carbon monoxide content detector;

[0029] (3) Application of the flexible standard container in the field of calibration of electro-chemical sensors;

[0030] (4) Overall design scheme of the flexible standard container, including but not limited to the design of the flexible container based on plastic materials, the application of the gas distribution system, the introduction of the reference standard device, the role of the solenoid valves at the air inlet and outlet in creating the working space for the standard gas, the design of the elastic interface of the sensor to be calibrated, etc. Description of the Drawings

[0031] Figure 1 Frame diagram of the remote calibration device for the tunnel carbon monoxide content detector

[0032] Figure 2 Overall connection diagram of the remote calibration device

[0033] Figure 3 Assembly schematic diagram of the flexible standard container

[0034] Figure 4 Flow chart of the remote calibration work DETAILED DESCRIPTION

[0035] Remote calibration work is mainly carried out according to the steps of connection or assembly - network configuration - remote control of monitoring end - remote operation and data recording - calculation of calibration results.

[0036] (1) Connect or assemble. This step is mainly based on Figure 2 、 Figure 3 As shown, the power lines, data lines or connection structures between the modules of the device are connected or assembled, and the device is put into a ready-to-work state.

[0037] (2) Network configuration. The network communication modules at the monitoring site and the calibration site are both equipped with 4G modules that are connected to the network, and wireless communication between them is achieved after network authentication.

[0038] (3) Remote control at the monitoring end. After the device is installed and the network communication is normal, the control instructions are transmitted to the PLC at the calibration site through physical control input or touch screen control input. The PLC has a conversion program built into it, and can convert the control instructions into control instructions corresponding to each electric actuator (electric button / electric servo / electromagnetic switch) through its analog output / digital output module to control its movement.

[0039] (4) Debug and calibrate each electric component on site. Each electric actuator is debugged according to the preset operating procedures. For example, for an electric servo, the preset output shaft rotation angle range is (-180° to 180°). Control commands are input at the monitoring site, and the actual output shaft rotation angle range is observed. If there is a deviation from the expected action, it is generally corrected by adjusting the mechanical installation angle or changing the control command.

[0040] (5) Remote operation and data recording. After the remote calibration device is debugged, first open the air inlet solenoid valve 16 through the control command, and close the air outlet solenoid valve 12 synchronously to ensure that the gas in the flexible container 15 only enters but does not exit. Start the gas distribution system 19, that is, dilute the standard carbon monoxide gas 18 according to the required proportion. After 1 minute of gas distribution, close the gas distribution system, close the air inlet solenoid valve 16 synchronously, open the air outlet solenoid valve 12, and start the exhaust pump 11 until the gas inside the flexible container 15 is emptied. Repeat this cycle for 3 times to remove the residual air in the flexible container 15 and the gas pipeline. Then open the air inlet solenoid valve 16, close the air outlet solenoid valve 12, start the gas distribution system 19 until the flexible container 15 expands naturally, and then close the gas distribution system 19. After the indications of the reference standard 24 and the calibrated equipment are stable, record the standard value and the measured value respectively.

[0041] (6) Process the recorded data and calculate the calibration results, and the remote calibration work is completed.

[0042] The remote calibration device and method for the tunnel carbon monoxide content detector of the present invention can liberate calibration personnel from complicated business trips, effectively utilize limited calibration resources, and greatly reduce travel costs, thus minimizing the cost of the entire calibration work;

[0043] After being inflated, the shape of the flexible standard container can be changed according to the spatial characteristics of the instrument under calibration, with strong environmental adaptability. At the same time, due to the characteristics of the flexible container being made of plastic material, it is not necessary to evacuate the air to create a standard carbon monoxide gas environment with the same pressure as the outside world inside it, reducing the airtightness requirements for the processing of the flexible standard container;

[0044] The gas distribution system can configure carbon monoxide gases with various different concentrations through carbon monoxide standard gases and standard air, without the need to carry multiple bottles of carbon monoxide gases with different concentrations to the calibration site, reducing the material and its transportation costs;

[0045] Based on the remote calibration method, a calibration personnel can simultaneously monitor the calibration of multiple on-site devices, greatly improving the calibration efficiency;

[0046] 6.5 The design of the elastic interface of the sensor under calibration can adapt to sensors under calibration with various different sizes, without the need to process interfaces with different sizes, reducing the complexity of device processing.

Claims

1. Remote calibration device for tunnel carbon monoxide content detector, characterized in that It includes flexible standard container, electric actuator, network communication module and monitoring terminal system; The flexible standard container is used to create a workspace for calibrating the tunnel carbon monoxide content detector, and includes a flexible container, a reference standard module, a gas distribution system module, air inlet and outlet components, an elastic interface for the calibrated sensor, and an adapter bracket. The electric actuator responds to the control signal and includes a servo, a linear motor, and a solenoid valve / switch. The network communication module is used to transmit control instructions from the monitoring site to the calibration site via wireless communication. The monitoring end system monitors the calibration site based on video feedback from the calibration site and includes a monitoring display and a posture perception panel. The monitoring end system inputs calibration control instructions, including physical manipulation input or touch screen input, to control the entire calibration process and perform calibration corrections based on video feedback from the calibration site. The network communication module is used to transmit the calibration control instructions from the monitoring site to the calibration site, and transmit the video of the calibration site to the monitoring site. The calibration site is equipped with a PLC, which is used to parse the calibration control instructions transmitted by the network communication module and transmit them from the output port to the electric button, electric servo, and electromagnetic switch in the form of digital signals or analog signals. The electric button is pressed or released according to the digital signal "0" or "1", and the output shaft of the electric servo rotates the corresponding angle according to the PWM signal or voltage signal to control the knob directly connected to it. The flexible standard container creates a specific concentration of carbon monoxide standard gas inside the flexible container through a series of operations such as gas distribution, exhaust, and inflation to form a calibration workspace. Standard air and carbon monoxide standard gas are input into the gas distribution system together. The gas distribution system is started or the instrument operation is confirmed by pressing a button. The carbon monoxide standard gas of different concentrations is adjusted by the knob and delivered to the flexible container, where the solenoid valve plays the role of opening and closing the gas path; the reference standard is used to measure the carbon monoxide gas concentration in the flexible container to provide a standard value of carbon monoxide concentration. The connecting line of the reference standard passes through the flexible container without leakage through the aviation plug and is connected to the display screen, and the standard value of carbon monoxide concentration is displayed on the display screen; the exhaust pump is used to quickly discharge the gas in the flexible container, and a solenoid valve is provided on the connecting pipeline between it and the flexible container to prevent gas backflow in the calibration working state, which affects the concentration of carbon monoxide gas in the flexible container; the adapter bracket is used to connect the flexible container and the attached parts to the tunnel side wall; one end of the elastic interface of the calibrated sensor is sealed with the flexible container, and the other end is used to connect the calibrated carbon monoxide sensor.

2. A method for applying the device according to claim 1, characterized in that: connecting or assembling; Network configuration: The network communication modules at the monitoring site and the calibration site are both equipped with 4G modules, enabling wireless communication between them after network authentication. Remote control of the monitoring end: After the device is installed and the network communication is normal, the control instructions are transmitted to the PLC at the calibration site through physical control input or touch screen control input. The PLC has a conversion program built into it, and can convert the control instructions into control instructions corresponding to each electric actuator, namely the electric button / electric servo / electromagnetic switch, through its analog output / digital output module, to control its movement. Debug and calibrate all electric components on site; debug the movements of each electric actuator according to the preset operating procedures. For electric servos, the preset output shaft rotation angle range is -180°~180°. Input control commands at the monitoring site and observe the actual rotation angle range of the output shaft. If there is any deviation from the expected movement, adjust the mechanical installation angle or change the control command to make corrections; After the remote calibration device is debugged, first open the air inlet solenoid valve through the control command, and close the air outlet solenoid valve synchronously to ensure that the gas in the flexible container only enters but does not exit, start the gas distribution system, and dilute the standard carbon monoxide gas according to the required proportion. After 1 minute of gas distribution, close the gas distribution system, and simultaneously close the air inlet solenoid valve, open the air outlet solenoid valve, and start the exhaust pump until the gas inside the flexible container is emptied. Repeat this cycle for more than 3 times to remove the residual air in the flexible container and the gas pipeline; then open the air inlet solenoid valve, close the air outlet solenoid valve, start the gas distribution system until the flexible container expands naturally, and then close the gas distribution system. After the indications of the reference standard and the calibrated equipment are stable, record the standard value and the measured value respectively. Process the recorded data, calculate the calibration results, and the remote calibration work is completed.

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