An intelligent control system and control method for online real-time detection of gas concentration

Abstract

The present invention relates to an intelligent control system and control method for online real-time detection of gas concentration in the field of gas detection, comprising a loopback detection gas circuit, wherein the air inlet end and the air outlet end of the loopback detection gas circuit system are both connected to a gas transport pipeline, so that the gas to be measured returns to the gas transport pipeline after passing through the loopback detection gas circuit; a first three-way solenoid valve and an air pump are provided between the detector and the air inlet end of the system, and a second three-way solenoid valve is provided between the detector and the air outlet end of the system; the detector is communicatively connected to the first three-way solenoid valve, the air pump, and the second three-way solenoid valve. The present invention can not only realize automatic cleaning and zeroing of the detector, but also realize seamless switching between the detection gas circuit and the cleaning gas circuit. Combined with the automatic speed regulation function of the air pump, the cleaning process is more efficient, and the cleaning time is significantly shortened. The system can automatically perform cleaning and adjustment, reducing the need for manual intervention and being nearly maintenance-free.

Description

Technical Field

[0001] The present invention relates to the technical field of gas online detection, and in particular to an intelligent control system and control method for online real-time detection of gas concentration. Background Art

[0002] Offline gas concentration monitoring involves regular on-site measurements and recording by personnel, with the frequency potentially being daily or even multiple days. In contrast, online gas concentration monitoring enables multiple measurements throughout the day and provides real-time feedback of test data, providing more timely monitoring. However, the detectors in online monitoring systems operate continuously over long periods of time. Initial zero value drift can change over time, leading to inaccurate concentration readings. For example, an elevated zero value can result in test results that are lower than the actual gas concentration, or even render the gas concentration undetectable. Therefore, regular detector cleaning is crucial to maintain accuracy and sensitivity.

[0003] Chinese Patent Publication No. CN217521115U discloses an online gas content analyzer capable of detecting gas concentrations. The device includes a gas detection branch equipped with a sensor, connected to a branch through which air can flow, enabling switching between gas detection and detector cleaning. While this online gas content analyzer includes a detector cleaning function, enabling multiple gas detections, it cannot maintain real-time gas concentration monitoring over the long term.

[0004] Because these devices discharge the detected gas outside the device, the detection gas path can only be opened when detection is required and closed when it is not. This makes them unsuitable for maintaining gas concentration detection for long periods of time. Otherwise, when the detection device is used on a gas transportation pipeline, it could cause continuous gas leakage. Furthermore, the cleaning efficiency of existing devices is low and time-consuming. The cleaning process requires interrupting the gas detection state. Increased cleaning frequency will inevitably lead to a long cleaning process that will seriously affect gas detection performance.

[0005] Therefore, improving the existing online gas concentration detection system to meet the real-time gas concentration detection needs while ensuring that the cleaning process of the detector does not affect its normal gas detection work has become an important issue that needs to be addressed in the industry. Summary of the Invention

[0006] In order to overcome the problems that existing gas online detection devices cannot maintain the real-time gas concentration detection state and require high-frequency cleaning, the present invention provides an intelligent control system and control method for online real-time gas concentration detection.

[0007] The technical solution of the present invention is as follows:

[0008] The present invention provides an intelligent control system for online real-time detection of gas concentration, comprising a loop detection gas circuit located beside a gas transportation pipeline, the loop detection gas circuit being connected to the gas transportation pipeline through a system air inlet end and a system air outlet end, so that the gas to be detected returns to the gas transportation pipeline after passing through the loop detection gas circuit; along the transmission direction of the gas to be detected, a first three-way solenoid valve, an air pump, a detector, and a second three-way solenoid valve are sequentially provided on the loop detection gas circuit, the first three-way solenoid valve, the air pump, and the second three-way solenoid valve are all communicatively connected with the detector and receive control instructions from the detector; when the detector is switched to a cleaning state, the first three-way solenoid valve connects the cleaning gas and the air pump, and the air pump speeds up; at the same time, the second three-way solenoid valve connects the detector and the exhaust channel; when the detector is switched to a detection state, the first three-way solenoid valve first connects the system air inlet end and the air pump, and the second three-way solenoid valve then connects the detector and the system air outlet end, and the air pump slows down.

[0009] By adopting the above technical solution, the detector detects the concentration of the gas to be tested in real time, and the gas that has passed the concentration detection can be returned to the transportation pipeline, which does not affect the gas transportation volume and can keep the loop detection gas path open for a long time; when the detector needs to be cleaned, the gas transportation pipeline and the loop detection gas path are cut off through the cooperation of the first three-way solenoid valve and the second three-way solenoid valve, and switched to the cleaning channel based on the detector, and the pump pressure of the air pump is increased to increase the flow rate of the cleaning gas, thereby improving the cleaning efficiency of the detector, and the system can return to the gas concentration detection state as soon as possible; after the cleaning work is completed, the first three-way solenoid valve is first switched back to the gas detection state, and the high-speed pump pressure of the air pump is maintained to ensure that the residual cleaning gas in the pipeline is discharged as soon as possible, and then the second three-way solenoid valve is switched back to connect the gas transportation pipeline, and the air pump is reduced to a more stable pump pressure when detecting gas.

[0010] As a preferred technical solution of the present invention, the system air inlet end is connected to the first position of the gas transport pipeline, and the system air outlet end is connected to the second position of the gas transport pipeline, and the direction from the first position to the second position is consistent with the flow direction of the gas to be measured in the gas transport channel.

[0011] By adopting the above technical solution, the gas to be tested in the gas transport channel enters the loop detection gas circuit through the system air inlet end for concentration detection, and then returns to the flow front end of the gas transport channel, ensuring that the gas entering the system for detection is all undetected gas.

[0012] As a preferred technical solution of the present invention, a cooling water tank and a filter are sequentially provided between the system air inlet end and the first three-way solenoid valve, the system air inlet end is arranged at the air inlet of the cooling water tank, the air outlet of the cooling water tank is connected to the air inlet of the filter, and the air outlet of the filter is connected to one of the air inlets of the first three-way solenoid valve.

[0013] By adopting the above technical solution, the water vapor carried by the gas to be measured condenses in the cooling water tank, preventing the water vapor from flowing to the detector behind and avoiding the water vapor from reducing the service life of the detector; the cooling water tank is provided with a drain port, and when the water in the cooling water tank exceeds the preset value, the drain port is automatically opened for drainage; after the gas to be measured enters the filter, the impurities carried by the gas to be measured are filtered out, which is also beneficial to improve the service life of the detector.

[0014] As a preferred technical solution of the present invention, a flow meter is provided between the air pump and the detector, the flow meter is used to count the gas flow to the detector, and the flow meter is connected to the detector signal;

[0015] When the detector is in a detection state, the flow meter transmits real-time flow data to the detector. When there is a deviation between the real-time flow data and the preset flow data, the detector sends a speed regulation instruction to the air pump to increase or decrease the gas flow.

[0016] By adopting the above technical solution, when the detector is in the working state of detecting gas concentration, when the flow meter measures the gas flow rate to be less than the preset value, the detector sends an instruction to increase the pump pressure to the air pump to increase the gas flow to the detector; when the flow meter measures the gas flow rate to be greater than the preset value, the detector sends an instruction to reduce the pump pressure to the air pump to reduce the gas flow to the detector, thereby ensuring that the detector operates at the most appropriate gas flow rate and ensuring detection accuracy.

[0017] Furthermore, a calibration gas three-way switch is provided between the flow meter and the air pump, one of the air inlets of the calibration gas three-way switch is connected to the air pump, and the other air inlet is connected to the calibration gas with a standard concentration, and the air outlet of the calibration gas three-way switch is connected to the flow meter.

[0018] Furthermore, when the detector is finished cleaning and needs to be calibrated, the air pump stops running, and the calibration gas three-way switch connects the calibration gas and the flow meter.

[0019] As a preferred technical solution of the present invention, the input gas circuit or the output gas circuit of the detector is provided with the pressure sensor, and the pressure sensor is used to detect the gas circuit pressure state of the detector. When there is a deviation between the real-time pressure value and the preset pressure value, the detector automatically multiplies the measured concentration value by the compensation coefficient to obtain a gas concentration correction value.

[0020] As a preferred technical solution of the present invention, the exhaust channel is connected to an exhaust gas treatment pool.

[0021] As a preferred technical solution of the present invention, when the detector is in a cleaning state, the air pump flow rate of the air pump is at full speed.

[0022] As a preferred technical solution of the present invention, when the detector is in a detection state, the air pump flow rate of the air pump increases as the distance from the input end of the detector to the gas transport pipeline increases.

[0023] Furthermore, when the distance between the input end of the detector and the gas transport pipeline is 0 to 5 meters, the gas pump is at a gas pump flow rate of 30% of the rated flow rate;

[0024] When the distance between the input end of the detector and the gas transport pipeline is 5 to 10 meters, the gas pump is at a gas pump flow rate of 40% of the rated flow rate;

[0025] When the distance between the input end of the detector and the gas transport pipeline is 10 to 15 meters, the gas pump is at a gas pump flow rate of 50% of the rated flow rate;

[0026] When the distance between the input end of the detector and the gas transport pipeline is 15 to 20 meters, the gas pump is at a gas pump flow rate of 60% of the rated flow rate;

[0027] When the distance between the input end of the detector and the gas transport pipeline is 20 to 25 meters, the gas pump is at a gas pump flow rate of 70% of the rated flow rate;

[0028] When the distance between the input end of the detector and the gas transport pipeline is 25 to 30 meters, the gas pump is at a gas pump flow rate of 80% of the rated flow rate.

[0029] The present invention also provides an intelligent control method for online real-time detection of gas concentration. The intelligent control system for online real-time detection of gas concentration based on the above-mentioned scheme draws the gas from the gas transport channel for detection, and returns it to the gas transport pipeline after detection, forming a loop detection gas circuit that can be detected in real time; after receiving the detector cleaning instruction, the connection between the loop detection gas circuit and the gas transport pipeline is cut off, and one end of the loop detection gas circuit is connected to the cleaning gas, and the other end is connected to the exhaust channel, thereby increasing the air pump flow rate in the loop detection gas circuit.

[0030] The present invention according to the above scheme has the following beneficial effects:

[0031] The present invention can not only realize automatic cleaning and zeroing of the detector and solve the problem of zero drift, but also the detector, the air pump, the first three-way solenoid valve and the second three-way solenoid valve in the system all exchange signals, monitor the working status of the air pump and the solenoid valve in real time, and issue instructions according to the working status of the detector. The air pump, the first three-way solenoid valve and the second three-way solenoid valve can respond quickly to realize seamless switching between the detection gas path and the cleaning gas path. Combined with the automatic speed regulation function of the air pump, the cleaning process is more efficient, the cleaning time is significantly shortened, and the system can quickly return to the gas concentration detection state. The system can automatically perform cleaning and adjustment, reduce the need for manual intervention, and is almost maintenance-free.

[0032] The loop detection gas path forms a loop path with the gas transportation pipeline, which can return the gas to be tested to the gas transportation pipeline after detection. Even if the gas concentration detection state is maintained for a long time, it will not cause any negative impact on the gas transportation. It meets the reliability and safety of the long-term and continuous operation of the online real-time gas concentration detection system, and also ensures the continuity and stability of gas transportation.

[0033] Furthermore, the system can compensate the gas concentration detection value through the pressure sensor to improve the accuracy of the detector detection;

[0034] Furthermore, the air pump of this system has a multi-stage speed regulation function, which can be set according to the actual situation on site to ensure that the airflow and air pressure of the detector are relatively stable, and can be applied to different working conditions, so that the detector can quickly respond to detection sensitivity requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a schematic structural diagram of embodiment 1 of the present invention;

[0036] Figure 2 This is a structural diagram of embodiment 2 of the present invention;

[0037] Figure 3 This is a structural diagram of embodiment 3 of the present invention.

[0038] In the figure,

[0039] 1. Gas transport pipeline; 2. Cooling water tank; 3. Filter; 4. First three-way solenoid valve; 5. Air pump; 6. Calibration gas three-way switch; 7. Flow meter; 8. Detector; 9. Second three-way solenoid valve; 10. Pressure sensor; 11. Waste gas treatment pool. DETAILED DESCRIPTION

[0040] To better understand the objectives, technical solutions, and technical effects of the present invention, the present invention is further explained below with reference to the accompanying drawings and embodiments. It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings. It should also be noted that the embodiments described below are intended only to illustrate the present invention and are not intended to limit the present invention.

[0041] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "first" and "second" are used solely for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of technical features.

[0042] Example 1

[0043] like Figure 1 As shown, an intelligent control system for online real-time detection of gas concentration includes a loop detection gas circuit equipped with a detector 8, and also includes a system air inlet and a system air outlet arranged at both ends of the loop detection gas circuit. The system air inlet and the system air outlet are both connected to the gas transport pipeline 1, so that the gas to be measured returns to the gas transport pipeline 1 after passing through the loop detection gas circuit. Preferably, along the flow direction of the gas in the gas transport pipeline 1, the system air inlet is located in front of the system air outlet, which can effectively avoid the impact of the detected gas on the accuracy of subsequent gas detection. In other embodiments, the system air inlet can also be located on the rear side of the system air outlet.

[0044] After the system completes the detection of the gas to be tested, it can be returned to the transportation pipeline through the loop detection gas path, which does not affect the gas transportation volume and does not cause gas waste. In addition, by setting a separate gas detection device next to the gas transportation pipeline, the present invention can achieve 24-hour real-time online detection of gas concentration.

[0045] A first three-way solenoid valve 4 and an air pump 5 are provided between the detector 8 and the air inlet end of the system, and a second three-way solenoid valve 9 is provided between the detector 8 and the air outlet end of the system. Specifically, one of the air inlets of the first three-way solenoid valve 4 is connected to the gas to be detected, and the other air inlet is connected to the cleaning gas, and the air outlet of the first three-way solenoid valve 4 is connected to the air pump 5; the output port of the air pump 5 is connected to the air inlet of the detector 8, and the air outlet of the detector 8 is connected to the air inlet of the second three-way solenoid valve 9, one air outlet of the second three-way solenoid valve 9 is connected to the exhaust channel, and the other air outlet is connected to the gas transport pipeline 1.

[0046] The detector 8 is communicatively connected to the first three-way solenoid valve 4, the air pump 5, and the second three-way solenoid valve 9. Therefore, the first three-way solenoid valve 4, the air pump 5, and the second three-way solenoid valve 9 can exchange signals with the detector 8 to obtain corresponding execution instructions. In the present invention, the first three-way solenoid valve 4, the air pump 5, and the second three-way solenoid valve 9 simultaneously communicate with the detector 8 and are controlled by the control instructions of the detector 8, so that the first three-way solenoid valve 4, the air pump 5, and the second three-way solenoid valve 9 can be linked with the detector 8, thereby making the operation of each device in the control process of the present invention more accurate and timely.

[0047] When the detector 8 executes the cleaning instruction, the first three-way solenoid valve 4 switches to conduct the cleaning gas and the air pump 5. At the same time, the second three-way solenoid valve 9 switches to conduct the detector 8 and the exhaust channel, and the air pump 5 speeds up. In this embodiment, after the air pump 5 speeds up, it is at a pump flow rate of 100% of the rated flow rate, and the cleaning gas is extracted at the maximum pump pressure to quickly clean the detector 8. The cleaning time is shortened to 60 seconds to 120 seconds. The cleaning gas can be pure air or an inert gas. After cleaning, the detector automatically performs a zeroing action to restore the detector's zero value and feedback the concentration value based on the correct zero value to avoid affecting the accuracy of subsequent concentration detection.

[0048] When the detector 8 finishes cleaning and returns to the detection state, a switching instruction is first sent to the first three-way solenoid valve 4. The first three-way solenoid valve 4 first switches to the air inlet end of the conductive system and the air pump 5, and introduces the gas to be tested into the loop detection air path. After the cleaning gas in the loop detection air path is exhausted, a switching instruction is sent to the second three-way solenoid valve 9. The second three-way solenoid valve 9 switches to the conductive detector 8 and the air outlet end of the system, and the air pump 5 slows down. The pump pressure after the speed reduction is lower than the pump pressure during cleaning. The air pump 5 returns to a lower speed pump pressure state, so that the gas to be tested can be stably passed into the detector, ensuring the accuracy of gas concentration detection. In this embodiment, an air pump 5 with adjustable flow rate is used to meet the user's needs to quickly adjust the air pump 5 to a suitable flow rate according to actual use conditions, so that the detector 8 can quickly respond to the demand during gas concentration detection. When the detector is in the detection state, the air pump flow rate of the air pump increases with the increase of the distance from the input end of the detector to the gas transport pipeline. Specifically:

[0049] When the distance between the input end of the detector 8 and the gas transport pipeline 1 (referring to the distance the gas flows in the channel, the same below) is 0 to 5 meters, the gas pump 5 is at a gas pump flow rate of 30% of the rated flow rate;

[0050] When the distance between the input end of the detector 8 and the gas transport pipeline 1 is 5 to 10 meters, the gas pump 5 is at a gas pump flow rate of 40% of the rated flow rate;

[0051] When the distance between the input end of the detector 8 and the gas transport pipeline 1 is 10 to 15 meters, the gas pump 5 is at a gas pump flow rate of 50% of the rated flow rate;

[0052] When the distance between the input end of the detector 8 and the gas transport pipeline 1 is 15 to 20 meters, the gas pump 5 is at a gas pump flow rate of 60% of the rated flow rate;

[0053] When the distance between the input end of the detector 8 and the gas transport pipeline 1 is 20 to 25 meters, the gas pump 5 is at a gas pump flow rate of 70% of the rated flow rate;

[0054] When the distance between the input end of the detector 8 and the gas transport pipeline 1 is 25 to 30 meters, the gas pump 5 is at a gas pump flow rate of 80% of the rated flow rate.

[0055] It can be seen that when the detector 8 needs to be cleaned, the present invention cuts off the gas transport pipeline 1 from the loop detection gas path through the cooperation of the first three-way solenoid valve 4 and the second three-way solenoid valve 9, switches it to the cleaning channel, and increases the pump pressure of the air pump 5 to increase the flow rate of the cleaning gas, thereby improving the cleaning efficiency of the detector 8, and the system can return to the gas concentration detection state as soon as possible; after completing the cleaning work, first switch the first three-way solenoid valve 4 back to the gas detection state, maintain the high-speed pump pressure of the air pump 5, ensure that the residual cleaning gas in the pipeline is discharged as soon as possible, and then switch the second three-way solenoid valve 9 back to connect to the gas transport pipeline 1, and the air pump 5 drops to a more stable pump pressure when detecting gas.

[0056] In this embodiment, the system's gas inlet is connected to a first location in gas transport pipeline 1, and the system's gas outlet is connected to a second location in gas transport pipeline 1. The direction from the first location to the second location aligns with the flow direction of the gas to be tested within the gas transport channel. Within gas transport pipeline 1, the gas to be tested first passes through the first location, with a portion entering the loop detection gas path. After testing, this portion of gas returns to gas transport pipeline 1 from the second location. This ensures that the gas to be tested entering the loop detection gas path from gas transport pipeline 1 is untested, enabling better real-time monitoring of gas concentration within the pipeline.

[0057] In this embodiment, a cooling water tank 2 and a filter 3 are sequentially disposed between the system's air inlet and the first three-way solenoid valve. The system's air inlet is located at the air inlet of the cooling water tank 2, the air outlet of the cooling water tank 2 is connected to the air inlet of the filter 3, and the air outlet of the filter 3 is connected to one of the air inlets of the first three-way solenoid valve 4. When the detector 8 executes a detection instruction, the first three-way solenoid valve 4 conducts power to the air pump 5 and the filter 3. Under the action of the air pump 5, the gas to be tested is input from the gas transport pipeline 1 and passes through the cooling water tank 2, the filter 3, and the first three-way solenoid valve 4 in sequence. Water vapor carried by the gas to be tested condenses within the cooling water tank 2, thereby reducing or eliminating the water vapor within the gas to be tested and preventing the water vapor from flowing to the detector 8 behind. This can prevent the water vapor from damaging the detector 8 and reducing its service life. The cooling water tank 2 is provided with a drain port. When the condensed water in the cooling water tank 2 accumulates and exceeds a preset value, the drain port automatically opens to drain the water. After the gas to be measured enters the filter 3, the filter 3 dries and filters impurities in the gas to be measured, preventing the impurities from damaging the detector 8, which is also beneficial to improving the service life of the detector 8. The filter 3 is also provided with a drain port to filter water in the gas to be measured and discharge it from the filter.

[0058] In this embodiment, a flow meter 7 is provided between the air pump 5 and the detector 8. The flow meter 7 is used to count the gas flow to the detector 8. The flow meter 7 is connected to the detector 8 signal and can exchange signals with the detector 8 to obtain corresponding execution instructions. In this way, the flow meter 7 can transmit the flow data delivered by the air pump 5 to the detector 8 in real time. When the detector 8 detects an abnormal change in the flow, it sends an instruction to the air pump 5 to execute the speed change, so as to automatically match the appropriate flow rate. In an application example, the system presets the flow data as a reference standard. When the detector 8 is in the working state of detecting the gas concentration, when the flow data detected in real time by the flow meter 7 deviates from the preset flow data, and the two values ​​deviate by ±5%, the detector 8 sends a speed control instruction to the air pump 5 to increase or decrease the pump pressure, so as to increase or decrease the gas flow accordingly. Specifically, when the flow meter 7 measures a gas flow rate that is less than a preset value, the detector 8 sends a pump pressure increase instruction to the air pump 5 to increase the gas flow rate flowing to the detector 8; when the flow meter 7 measures a gas flow rate that is greater than the preset value, the detector 8 sends a pump pressure decrease instruction to the air pump 5 to reduce the gas flow rate flowing to the detector 8, ensuring that the detector 8 operates at the most appropriate gas flow rate and ensuring detection accuracy.

[0059] The deviation range can be adjusted as required, for example, ±2%, ±8%, etc. In this way, by using the flow meter 7 in conjunction with the detector 8 and the air pump 5, the system can cope with sudden operating conditions encountered by the gas transportation pipeline 1, such as changes in the transmission motor power, temperature, outlet flow rate, etc., which cause changes in the pipeline pressure and thus lead to changes in the flow in the loop detection gas path.

[0060] In an optional embodiment, a calibration gas three-way switch 6 is provided between the flowmeter 7 and the air pump 5. One of the air inlets of the calibration gas three-way switch 6 is connected to the air pump 5, and the other air inlet is connected to a calibration gas with a standard concentration. The air outlet of the calibration gas three-way switch 6 is connected to the flowmeter 7. Before the detector 8 is used to detect the gas concentration for the first time, the calibration gas three-way switch 6 is opened to introduce a calibration gas with a standard concentration. The concentration value measured by the detector 8 is compared with the known standard concentration. In this way, the concentration detection of the detector 8 is calibrated in combination with the Lambert-Beer law to ensure the detection accuracy and sensitivity. In other application examples, when the detector 8 is cleaned and needs to be calibrated, the air pump stops running, the second three-way solenoid valve 9 is switched to a state that connects the detector 8 and the exhaust channel, and the calibration gas three-way switch 6 is switched to a state that connects the calibration gas and the flowmeter 7. The cleaned detector can then be calibrated, and the cleaning gas introduced during the cleaning process will not affect the calibration process.

[0061] In an optional embodiment, the calibration gas three-way switch 6 can be installed between the first three-way solenoid valve 4 and the air pump 5, so that one of the air inlets of the calibration gas three-way switch 6 is connected to the first three-way solenoid valve 4, and the other air inlet is connected to the calibration gas (referred to as calibration), and its air outlet is connected to the air pump. In this embodiment, the air pump 5 can play a pumping role in the cleaning process, calibration process, and detection process respectively, so as to control the flow rate of the gas in different processes and realize multiple uses of one pump.

[0062] In this embodiment, the input gas circuit or the output gas circuit of the detector 8 is provided with a pressure sensor 10, which is used to detect the gas circuit pressure state of the detector 8. When there is a deviation between the real-time pressure value and the preset pressure value, the detector 8 automatically multiplies the measured concentration value by the compensation coefficient to obtain a gas concentration correction value, and displays the corrected gas concentration value to the user, so that the user can grasp the accurate concentration of the gas to be measured in real time and eliminate the detection error caused by temperature changes. It should be noted that the molar volume of the gas to be measured with the same concentration is different under different air pressures, and the absorption light intensity changes accordingly, resulting in differences in the detected gas concentration. The air pressure is related to the ambient temperature, and the temperature changes in different time periods in the same area. In this embodiment, a pressure sensor 10 is added to detect the change in gas pressure caused by the temperature change in different time periods in the gas detector 8, and the changed pressure is fed back to the detector 8. The detector 8 multiplies the compensation coefficient corresponding to the pressure with the measured gas concentration value to obtain a gas concentration correction value equivalent to that at normal temperature and pressure.

[0063] The system of the present invention has a calculation function for obtaining compensation coefficients corresponding to different pressures. Specifically, by calculating, processing, and fitting the gas concentration values ​​detected at different temperatures and pressures with the same gas concentration values ​​at normal temperature and pressure, a quantitative coefficient value (i.e., compensation coefficient) that is infinitely close to the gas concentration value at normal temperature and pressure is obtained. In a specific calculation embodiment, a standard gas of a specific concentration is introduced under standard atmospheric pressure (1.01 MPa), and the original signal value of the detector 8 is recorded. Then, under the same environment, only different pressures are changed, such as 1.50 MPa, 2.00 MPa, 2.50 MPa, 3.00 MPa, 3.50 MPa, 4.00 MPa, 4.50 MPa, 5.00 MPa, etc., to obtain the differential signal ratio value (NAD) and differential signal value (ADV) of the signal of the detector 8 at different pressures. According to the equation: y = A1 × exp(-x / t1) + A2 × exp(-x / t2) + y0, where y is the signal change, x is the pressure, and A1, t1, A2, t2, and y0 are the coefficients to be determined. Using the multiple data points (xi, yi) measured above, xi represents the value at different pressures, yi represents the corresponding signal change, and i = 1, 2, 3, etc.

[0064] Perform a curve fit between the signal change and the pressure value to determine the coefficients A1, t1, A2, t2, and y0. The obtained coefficients are then used to reverse-calculate the signal change using the above equation and the pressure value. Compensate for the difference between the calculated signal change and the signal value at the same standard concentration to determine the gas concentration.

[0065] Example 2

[0066] like Figure 2 As shown, an intelligent control system for online real-time detection of gas concentration has the same structure as that of embodiment 1, except that: the air outlet of the second three-way solenoid valve 9 does not exhaust directly to the outside, but an exhaust gas treatment pool 11 is added at the exhaust channel. The exhaust gas treatment pool 11 is used to centrally treat the gas after cleaning the detector 8, effectively removing the harmful gas generated during the cleaning process of the detector 8 and reducing pollution to the atmospheric environment; reducing the safety risks that may be caused by direct emission of harmful gases and protecting the health of people around.

[0067] Example 3

[0068] like Figure 3 As shown, an intelligent control system for online, real-time gas concentration detection has the same structure as the first embodiment, differing in that the second three-way solenoid valve 9 at the output of the detector 8 is eliminated. Instead, the output of the detector 8 serves as the system's gas outlet, directly connected to the gas transport pipeline 1. This embodiment's system structure is suitable for situations where the purge gas has no effect on the gas to be measured within the gas transport pipeline 1, and the gas after cleaning the detector 8 and the detected gas can be discharged back into the gas transport pipeline 1.

[0069] Example 4

[0070] An intelligent control method for online real-time detection of gas concentration is provided. Based on the intelligent control system for online real-time detection of gas concentration of embodiment one or embodiment two, gas from a gas transport channel is drawn out for detection, and after detection, the gas is returned to the gas transport pipeline 1, forming a loop detection gas path capable of real-time detection.

[0071] In this embodiment, during the process of real-time detection of gas in the gas transport pipeline 1, the channel and components such as the detector 8 can also be cleaned. During the cleaning process, the first three-way solenoid valve 4, the air pump 5, and the second three-way solenoid valve 9 simultaneously receive control instructions for cleaning the detector 8. At this time: the first three-way solenoid valve 4 cuts off the gas passage between the loop detection gas path and the gas transport pipeline 1, and connects the cleaning gas to form a non-loop gas passage; the air pump 5 increases the pump speed to increase the cleaning speed; the second three-way solenoid valve 9 is used to discharge the gas during the cleaning process to other locations, or to discharge the gas during the cleaning process into the exhaust gas treatment pool 11.

[0072] In this embodiment, one end of the loop detection gas circuit is connected to the purge gas, and the other end is connected to the exhaust channel, thereby increasing the gas pump flow rate within the loop detection gas circuit. This method can meet the requirements of 24-hour real-time monitoring of gas concentration. The detected gas is returned to the gas transport pipeline 1 without affecting the pipeline's gas transport capacity. Furthermore, because this method has the advantage of efficiently cleaning the detector 8, it can meet the needs of frequent cleaning.

[0073] In this embodiment, while performing real-time detection of gas in the gas transport pipeline 1 and cleaning the pipeline, the detector 8 can also be regularly calibrated and calibrated. During the calibration and calibration process, the first three-way solenoid valve 4 and / or the calibration gas three-way switch 6, the air pump 5, and the second three-way solenoid valve 9 simultaneously receive control instructions for cleaning the detector 8. At this time, the first three-way solenoid valve 4 and / or the calibration gas three-way switch 6 disconnect the gas to be detected / cleaning gas transported by the previous path, and the air inlet of the calibration gas three-way switch 6 is connected to the standard gas. The standard gas enters the detector 8 for detection, and the detection results of the detector 8 are calibrated and calibrated using the known standard gas concentration, so that the detector 8 is in an accurate detection state. In the embodiment where the calibration gas three-way switch 6 is located in front of the air pump 5, the air pump 5 increases the pump speed to quickly discharge the gas to be detected and the cleaning gas originally in the pipeline, thereby achieving a rapid calibration and calibration process. The second three-way solenoid valve 9 is used to discharge the gas during the calibration and calibration process to other locations, or to discharge the gas during the cleaning process into the waste gas treatment tank 11.

[0074] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0075] The above embodiments merely illustrate several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. An intelligent control system for online real-time detection of gas concentration, characterized in that: It includes a loop detection gas circuit located beside the gas transportation pipeline, the loop detection gas circuit is connected to the gas transportation pipeline through the system air inlet end and the system air outlet end, so that the gas to be tested returns to the gas transportation pipeline after passing through the loop detection gas circuit; Along the transmission direction of the gas to be detected, the loop detection gas path is sequentially provided with a first three-way solenoid valve, an air pump, a detector, and a second three-way solenoid valve. The first three-way solenoid valve, the air pump, and the second three-way solenoid valve are all communicatively connected to the detector and receive control instructions from the detector. The system gas inlet is connected to a first position of the gas transport pipeline, and the system gas outlet is connected to a second position of the gas transport pipeline, and the direction from the first position to the second position is consistent with the flow direction of the gas to be measured in the gas transport channel; A cooling water tank and a filter are sequentially provided between the system air inlet end and the first three-way solenoid valve, the system air inlet end is arranged at the air inlet of the cooling water tank, the air outlet of the cooling water tank is connected to the air inlet of the filter, and the air outlet of the filter is connected to one of the air inlets of the first three-way solenoid valve; One of the air inlets of the first three-way solenoid valve is connected to the gas to be detected, and the other air inlet is connected to the cleaning gas. The air outlet of the first three-way solenoid valve is connected to the air pump; the output port of the air pump is connected to the air inlet of the detector, and the air outlet of the detector is connected to the air inlet of the second three-way solenoid valve. One air outlet of the second three-way solenoid valve is connected to the exhaust channel, and the other air outlet is connected to the gas transportation pipeline; When the detector is switched to the cleaning state, the first three-way solenoid valve conducts the cleaning gas and the air pump, and the air pump is accelerated to the full speed state; at the same time, the second three-way solenoid valve conducts the detector and the exhaust channel; When the detector is switched to the detection state, the first three-way solenoid valve first connects the system air inlet and the air pump to introduce the gas to be tested into the loop detection gas circuit. After the cleaning gas in the loop detection gas circuit is exhausted, the second three-way solenoid valve connects the detector and the system air outlet, and the air pump returns to the flow rate during detection. The input gas circuit or the output gas circuit of the detector is provided with a pressure sensor, which is used to detect the gas circuit pressure state of the detector. When there is a deviation between the real-time pressure value and the preset pressure value, the detector automatically multiplies the measured concentration value by the compensation coefficient according to the pressure compensation algorithm to obtain a gas concentration correction value; A flow meter is provided between the air pump and the detector, and is used to count the gas flow to the detector. The flow meter is signal-connected to the detector. When the detector is in a detection state, the flow meter transmits real-time flow data to the detector. When there is a deviation between the real-time flow data and the preset flow data, the detector sends a speed control instruction to the air pump to increase or decrease the gas flow. When the detector is in a detection state, the air pump flow rate of the air pump increases as the distance from the input end of the detector to the gas transport pipeline increases; A calibration gas three-way switch is provided between the flow meter and the air pump. One of the air inlets of the calibration gas three-way switch is connected to the air pump, and the other air inlet is connected to the calibration gas with a standard concentration. The air outlet of the calibration gas three-way switch is connected to the flow meter.

2. The gas concentration online real-time detection intelligent control system according to claim 1 is characterized in that: The exhaust channel is connected to the exhaust gas treatment pool.

3. A gas concentration online real-time detection intelligent control method, characterized in that: Based on the intelligent control system for online real-time detection of gas concentration according to any one of claims 1 to 2, the gas in the gas transport channel is drawn out for detection and returned to the gas transport pipeline after detection, forming a loop detection gas path that can be detected in real time; When the detector switches to the cleaning state, the connection between the loop detection gas circuit and the gas transport pipeline is cut off, and one end of the loop detection gas circuit is connected to the cleaning gas and the other end is connected to the exhaust channel. At the same time, the air pump flow rate in the loop detection gas circuit is increased.

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