Gas concentration real-time detection system capable of automatically rectifying deviation at zero point

Abstract

The utility model relates to a gas concentration real-time detection system capable of automatically rectifying a zero point, which comprises a first three-way electromagnetic valve, a gas pump, a detector and a second three-way electromagnetic valve, a detection gas outlet of a gas conveying pipeline is connected with a gas inlet of the first three-way electromagnetic valve, and the other gas inlet of the first three-way electromagnetic valve is communicated with cleaning gas; a gas outlet of the first three-way solenoid valve is connected with a gas pump which is connected with a detector, the other end of the detector is connected with a gas inlet of the second three-way solenoid valve, one gas outlet of the second three-way solenoid valve is connected with an exhaust channel, and the other gas outlet is connected with a gas conveying pipeline. According to the utility model, automatic cleaning and zero clearing of the detector can be realized, the problem of zero drift is solved, the gas detection gas path and the gas conveying pipeline form a loopback path, gas to be detected can return to the gas conveying pipeline after detection, negative influence on gas conveying is avoided, and the detection efficiency is improved. And the reliability and the safety of long-term and continuous working of the gas concentration online real-time detection system are met.

Description

Technical Field

[0001] The utility model relates to the technical field of on-line gas concentration detection. Specifically, it relates to a real-time gas concentration detection system with automatic zero-point correction. Background Art

[0002] On-line gas concentration detection can achieve all-day real-time detection and real-time feedback of detection data. It can be seen that the detector in the on-line detection system works continuously for a long time. The initial zero-point value of the detector will change with the increase of working time, resulting in inaccurate detection of gas concentration by the detector. For example, when the zero-point value increases, the detection result is lower than the actual gas concentration, and even the gas concentration cannot be detected. Therefore, it is crucial to regularly clean and zero the detector to restore its initial state to maintain the accuracy and sensitivity of detection.

[0003] An on-line analysis device capable of detecting gas content provided by the Chinese utility model patent publication number CN217521115U includes a first discharge port, a three-way solenoid valve, a three-way valve, a two-way solenoid valve, an air pump and a sensor. The second end of the three-way valve is connected to the outside air through the two-way solenoid valve and the air pump in sequence. Through the intermittent on-line detection method, after detecting tetrahydrothiophene for a period of time, the air cleaning is switched to extend the service life of the sensor.

[0004] Although the above device can clean the sensor so that the detector can perform gas detection multiple times, since the detected gas is discharged outside the device, the detection gas path can only be opened when detection is required and closed when detection is not required. It can be seen that the above device is still not suitable for maintaining the gas concentration detection state for a long time, otherwise it will have a negative impact on the gas transportation. Summary of the Utility Model

[0005] In order to solve the problem that the existing on-line gas detection device has a negative impact on the transportation of the gas transportation pipeline when cleaning the detector, the utility model provides a real-time gas concentration detection system with automatic zero-point correction.

[0006] The technical solution of the utility model is as follows:

[0007] A real-time gas concentration detection system with automatic zero-point correction, installed on a gas transportation pipeline, successively including a gas purification unit, a first three-way solenoid valve, an air pump, a detector, and a second three-way solenoid valve. The detection gas outlet of the gas transportation pipeline is connected to the inlet of the first three-way solenoid valve through the gas purification unit. Another inlet of the first three-way solenoid valve is connected to cleaning gas. The outlet of the first three-way solenoid valve is connected to the air pump. The air pump is connected to the detector. The other end of the detector is connected to the inlet of the second three-way solenoid valve. One outlet of the second three-way solenoid valve is connected to an exhaust passage, and the other outlet is connected to the gas transportation pipeline.

[0008] For the present invention according to the above solution, it is characterized in that a flow meter is provided between the air pump and the detector, and the flow meter is used to count the gas flow rate flowing to the detector.

[0009] For the present invention according to the above solution, it is characterized in that a calibration gas three-way switch is provided between the flow meter and the air pump. One inlet of the calibration gas three-way switch is connected to the air pump, and the other inlet is connected to calibration gas with a standard concentration. The outlet of the calibration gas three-way switch is connected to the flow meter.

[0010] For the present invention according to the above solution, it is characterized in that a pressure sensor is provided in the input gas path or the output gas path of the detector, and the pressure sensor is used to detect the gas path pressure state of the detector.

[0011] For the present invention according to the above solution, it is characterized in that an exhaust gas treatment pool is added to the exhaust passage.

[0012] For the present invention according to the above solution, it is characterized in that the gas purification unit includes a cooling water tank and a filter. The inlet of the cooling water tank is connected to the gas transportation pipeline. The outlet of the cooling water tank is connected to the inlet of the filter. The outlet of the filter is connected to the first three-way solenoid valve.

[0013] Furthermore, the cooling water tank is provided with a first drain port, and the first drain port is used to automatically open the drain port for drainage when the water in the cooling water tank exceeds a preset value.

[0014] Furthermore, the filter is provided with a second drain port, and the second drain port is used to drain the water filtered from the gas to be detected out of the filter.

[0015] For the present invention according to the above solution, it is characterized in that the air pump is an air pump with adjustable flow rate.

[0016] The beneficial effects of the present invention according to the above solution are as follows:

[0017] The detection gas path of the present utility model includes a first three-way solenoid valve, an air pump, a detector, and a second three-way solenoid valve. The seamless switching between detection and cleaning is achieved through the first three-way solenoid valve, which can clean the detector in a timely manner so that the detector can perform a zeroing action after cleaning, realizing the zero-point correction of the detector in the detection system. Moreover, the air inlet of the first three-way solenoid valve is connected to the gas transportation pipeline, and the air outlet of the second three-way solenoid valve is connected to the gas transportation pipeline, enabling the gas detection gas path and the gas transportation pipeline to form a loop path. This allows the gas to be measured to return to the gas transportation pipeline after detection. Even if it maintains the gas concentration detection state for a long time, it will not cause any negative impact on the gas transportation, meeting the reliability and safety requirements for the long-term and continuous operation of the on-line real-time gas concentration detection system.

[0018] Furthermore, the air pump has an automatic speed regulation function. By increasing the speed to introduce the cleaning gas, the cleaning process is more efficient, significantly shortening the cleaning duration, enabling the system to quickly return to the gas concentration detection state. This system can automatically perform cleaning and calibration, reducing the need for manual intervention and being nearly maintenance-free. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of Embodiment 1 of the present utility model;

[0020] Figure 2 It is a schematic structural diagram of Embodiment 2 of the present utility model;

[0021] Figure 3 It is a schematic structural diagram of Embodiment 3 of the present utility model.

[0022] In the figure,

[0023] 1. Gas transportation pipeline; 2. Cooling water tank; 3. Filter; 4. First three-way solenoid valve; 5. Air pump; 6. Calibration gas three-way switch; 7. Flowmeter; 8. Detector; 9. Second three-way solenoid valve; 10. Pressure sensor; 11. Waste gas treatment pool. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] In order to better understand the purpose, technical solution, and technical effects of the present utility model, the following further explains and describes the present utility model in conjunction with the 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 and explained in subsequent drawings. At the same time, it is stated that the embodiments described below are only used to explain the present utility model and are not used to limit the present utility model.

[0025] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "first" and "second" are only for convenience of description and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of technical features.

[0026] Embodiment 1

[0027] As Figure 1 shown, a real-time gas concentration detection system capable of automatic zero-point correction includes a gas detection gas path configured with a detector 8. The gas detection gas path includes a gas purification unit, a first three-way solenoid valve, an air pump, a detector, and a second three-way solenoid valve. The detection gas outlet of the gas transportation pipeline is connected to the inlet of the first three-way solenoid valve through the gas purification unit. The other inlet of the first three-way solenoid valve is connected to the cleaning gas. The outlet of the first three-way solenoid valve is connected to the air pump. The air pump is connected to the detector. The other end of the detector is connected to the inlet of the second three-way solenoid valve. One outlet of the second three-way solenoid valve is connected to the exhaust passage, and the other outlet is connected to the gas transportation pipeline. The first three-way solenoid valve and the second three-way solenoid valve are both connected to the gas transportation pipeline 1, so that the gas to be measured returns to the gas transportation pipeline 1 after passing through the gas detection gas path. When the system completes the detection of the gas to be measured, it can return to the transportation pipeline through the gas detection gas path without affecting the gas transportation volume, and the system can perform real-time gas concentration detection for 24 hours.

[0028] The first three-way solenoid valve 4, the air pump 5, and the second three-way solenoid valve 9 communicate with the detector 8 at the same time 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. 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 passage, and the air pump 5 speeds up. In this embodiment, after the air pump 5 speeds up, it is at the air pump flow rate of 100% of the rated flow rate, and the cleaning gas is pumped at the maximum pump pressure to quickly clean the detector 8. The cleaning time is shortened to 60 seconds to 120 seconds. Among them, the cleaning gas can be pure air or inert gas. After the detector is cleaned, it automatically executes a zeroing action to restore the zero value of the detector and feedback the concentration value on the basis of the correct zero value, so as to avoid affecting the accuracy of subsequent concentration detection.

[0029] 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 conduct the gas transportation pipeline and the air pump 5, introducing the gas to be detected into the gas detection gas path. After the cleaning gas in the gas detection gas 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 conduct the detector 8, and the air pump 5 decelerates. The pump pressure after deceleration is lower than the pump pressure during cleaning, and the air pump 5 resumes to the pump pressure state at a lower speed, enabling the gas to be detected to be stably introduced into the detector to ensure the accuracy of gas concentration detection. In this embodiment, an air pump 5 with adjustable flow rate is adopted, which can meet the user's requirement to quickly adjust the air pump 5 to an appropriate flow rate according to the actual operating conditions, so as to achieve the rapid response requirement of the detector 8 during gas concentration detection. When the detector is in the detection state, the flow rate of the air pump increases with the increase of the distance from the input end of the detector to the gas transportation pipeline (referring to the distance that the gas flows in the channel).

[0030] It can be seen that when the detector 8 needs to be cleaned in the present utility model, through the cooperation of the first three-way solenoid valve 4 and the second three-way solenoid valve 9, the gas transportation pipeline 1 is cut off from the gas detection gas path and switched to the cleaning channel, and the pump pressure of the air pump 5 is increased to increase the flow rate of the cleaning gas, improving the cleaning efficiency of the detector 8, so that the system can quickly return to the gas concentration detection state; after the cleaning work is completed, the first three-way solenoid valve 4 is first switched back to the gas detection state, maintaining the high-speed pump pressure of the air pump 5 to ensure that the residual cleaning gas in the pipeline is discharged as soon as possible, and then the second three-way solenoid valve 9 is switched back to connect the gas transportation pipeline 1, and the air pump 5 is reduced to the relatively stable pump pressure when detecting the gas.

[0031] In this embodiment, the gas purification unit includes a cooling water tank 2 and a filter 3. The gas transportation pipeline is connected to 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. 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 the detection instruction, the first three-way solenoid valve 4 conducts the air pump 5 and the filter 3. Under the action of the air pump 5, the gas to be detected is input from the gas transportation pipeline 1 and sequentially passes through the cooling water tank 2, the filter 3, and the first three-way solenoid valve 4. The water vapor carried by the gas to be detected condenses in the cooling water tank 2, reducing or eliminating the water vapor inside the gas to be detected, preventing the water vapor from flowing to the subsequent detector 8, and avoiding damage to the detector 8 caused by the water vapor, thereby reducing the service life of the detector 8. The cooling water tank 2 is provided with a drain port. When the condensed water in the cooling water tank 2 accumulates and exceeds the preset value, the drain port is automatically opened for drainage. After the gas to be detected enters the filter 3, the filter 3 dries and filters the impurities in the gas to be detected, avoiding damage to the detector 8 by the impurities, which is also beneficial to improving the service life of the detector 8. The filter 3 is also provided with a drain port, which can filter and drain the water in the gas to be detected from the filter.

[0032] 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 rate flowing to the detector 8. The flow meter 7 is signal-connected to the detector 8 and can exchange signals with the detector 8 to obtain corresponding execution instructions. Thus, the flow meter 7 can transmit the flow rate data conveyed by the air pump 5 to the detector 8 in real time. When the detector 8 detects an abnormal change in the flow rate, it issues an instruction to the air pump 5 to execute speed change, so as to automatically match an appropriate flow rate. In an application example, the system presets flow rate data as a reference standard. When the detector 8 is in the working state of detecting the gas concentration, if there is a deviation between the flow rate data detected by the flow meter 7 in real time and the preset flow rate data, and the deviation between the two values is ±5%, the detector 8 will send a speed regulation instruction to the air pump 5 to increase or decrease the pump pressure, so as to increase or decrease the gas flow rate accordingly. Specifically, when the flow rate of the gas measured by the flow meter 7 is less than the preset value, the detector 8 sends an instruction to the air pump 5 to increase the pump pressure to increase the gas flow rate flowing to the detector 8; when the flow rate of the gas measured by the flow meter 7 is more than the preset value, the detector 8 sends an instruction to the air pump 5 to decrease the pump pressure to decrease the gas flow rate flowing to the detector 8, ensuring that the detector 8 works at the most appropriate gas flow rate and ensuring the detection accuracy.

[0033] The deviation range can be adjusted according to requirements, such as ±2%, ±8%, etc. In this way, by using the flow meter 7 in cooperation with the detector 8 and the air pump 5, the system can cope with sudden working conditions encountered in the gas transportation pipeline 1, such as changes in the motor power, temperature, outlet flow rate, etc. during transportation, which cause changes in the pressure of the transportation pipeline and thus lead to changes in the flow rate in the loop detection gas path.

[0034] In an alternative embodiment, a calibration gas three-way switch 6 is provided between the flow meter 7 and the air pump 5. One of the intake ports of the calibration gas three-way switch 6 is connected to the air pump 5, and the other intake port is connected to a calibration gas with a standard concentration. The outlet of the calibration gas three-way switch 6 is connected to the flow meter 7. Before the detector 8 is first used to detect the gas concentration, first open the calibration gas three-way switch 6 to introduce the calibration gas with a standard concentration. The concentration value measured by the detector 8 is compared with the known standard concentration, and 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 finishes cleaning and needs to be calibrated, the air pump stops running, the second three-way solenoid valve 9 switches to the state of conducting the detector 8 and the exhaust passage, and the calibration gas three-way switch 6 switches to the state of conducting the calibration gas and the flow meter 7, so that the detector after cleaning can be calibrated.

[0035] In this embodiment, a pressure sensor 10 is provided in the input gas path or the output gas path of the detector 8. The pressure sensor 10 is used to detect the gas path 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 a compensation coefficient to obtain a corrected gas concentration value, and displays the corrected gas concentration value to the user, so as to enable the user to 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 for the gas to be measured with the same concentration, the molar volume of the gas 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 at different times in the same area. In this embodiment, a pressure sensor 10 is added to detect the change in gas pressure caused by the change in temperature at different times in the gas detector 8, and the changed pressure is fed back to the detector 8. After the detector 8 multiplies the compensation coefficient corresponding to this pressure by the measured gas concentration value, a corrected gas concentration value equivalent to normal temperature and pressure is obtained.

[0036] Embodiment Two

[0037] As Figure 2 shown, a real-time gas concentration detection system capable of automatic zero-point correction has the same structure as that in Embodiment One, except that: the air outlet of the second three-way solenoid valve 9 does not directly exhaust to the outside, but an exhaust gas treatment pool 11 is added at the exhaust passage. 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 process of cleaning the detector 8, reducing the pollution to the atmospheric environment; reducing the safety risk that may be caused by the direct emission of harmful gases, and protecting the health of the surrounding personnel.

[0038] Embodiment Three

[0039] A real-time gas concentration detection system capable of automatic zero-point correction has the same structure as that in Embodiment One, except that: the second three-way solenoid valve 9 at the output end of the detector 8 is cancelled, and the detector 8 is directly connected to the gas transportation pipeline 1. The system structure of this embodiment is applicable to the situation where the cleaning gas has no influence on the gas to be measured in the gas transportation pipeline 1, and the gas after cleaning the detector 8 and the detected gas can be discharged back to the gas transportation pipeline 1.

[0040] The technical features of the above embodiments can be combined arbitrarily. For the sake of brief description, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combinations of these technical features do not conflict, they should all be considered as within the scope described in this specification.

[0041] The above embodiments only illustrate several implementation manners of the present utility model. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the utility model patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present utility model, several variations and improvements can still be made, and these all fall within the protection scope of the present utility model. Therefore, the protection scope of the present utility model patent shall be subject to the appended claims.

Claims

1. A real-time gas concentration detection system with automatic zero-point correction, installed on a gas transportation pipeline, characterized in that: It includes a gas impurity removal unit, a first three-way solenoid valve, an air pump, a detector, and a second three-way solenoid valve in sequence. The detection gas outlet of the gas transportation pipeline is connected to the air inlet of the first three-way solenoid valve through the gas impurity removal unit, and the other air inlet of the first three-way solenoid valve is connected to the cleaning gas. The air outlet of the first three-way solenoid valve is connected to the air pump, and the air pump is connected to the detector. The other end 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.

2. A real-time gas concentration detection system capable of automatic zero-point correction according to claim 1, characterized in that: A flow meter is provided between the air pump and the detector, and the flow meter is used to count the gas flow to the detector.

3. A real-time gas concentration detection system capable of automatic zero-point correction according to claim 2, characterized in that: 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, 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.

4. A gas concentration real-time detection system capable of automatic zero point correction according to claim 1, characterized in that: The input gas circuit or the output gas circuit of the detector is provided with a pressure sensor, and the pressure sensor is used to detect the gas circuit pressure state of the detector.

5. A gas concentration real-time detection system capable of automatic zero point correction according to claim 1, characterized in that: The exhaust passage is additionally provided with an exhaust gas treatment pool.

6. A gas concentration real-time detection system capable of automatic zero-point correction according to claim 1, characterized in that: The gas impurity removal unit includes a cooling water tank and a filter, the air inlet of the cooling water tank is connected to the gas transport pipeline, 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 the first three-way solenoid valve.

7. A real-time gas concentration detection system capable of automatic zero-point correction according to claim 6, characterized in that: The cooling water tank is provided with a first drain port, and the first drain port is used to automatically open the drain port for drainage when the water in the cooling water tank exceeds a preset value.

8. A real-time gas concentration detection system capable of automatic zero-point correction according to claim 6, characterized in that: The filter is provided with a second drain port, and the second drain port is used to filter water in the gas to be tested and then discharge it from the filter.

9. A real-time gas concentration detection system capable of automatic zero-point correction according to any one of claims 1 to 8, characterized in that: The air pump is an air pump with adjustable flow rate.

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