Ozone concentration detection method and system based on differential acquisition signal

Abstract

The invention discloses an ozone concentration detection method and system based on differential acquisition signals. The ozone concentration detection method comprises the following steps: introducing to-be-detected gas input into a gas inlet into a measurement gas chamber through a first channel; introducing the to-be-detected gas input into the gas inlet into the standard gas chamber through the second channel and the ozone filter; irradiating the measuring gas chamber and the standard gas chamber through an ultraviolet light source; respectively measuring a first optical signal of the measuring gas chamber irradiated by the ultraviolet light source and a second optical signal of the standard gas chamber through the measuring PCB; and determining the ozone concentration of the to-be-detected gas based on the first optical signal and the second optical signal. According to the gas analysis method, the early discharge phenomenon can be reflected more timely, O3 is adopted as discharge detection characteristic gas, ozone is a discharge early product and is high in concentration, the air discharge phenomenon can be reflected more timely by using the concentration change of ozone to carry out discharge detection, and faults are controlled in the early stage.

Description

Technical Field

[0001] The present invention relates to the technical field of switch cabinet ozone detection, and more specifically, to an ozone concentration detection method and system based on differential acquisition signals. Background Art

[0002] As a common power transmission and distribution equipment, the operating reliability of the switchgear directly affects the power supply quality and safety performance of the power system, and is a vital link in the power system. However, under the influence of system overvoltage, insulation defects, process quality, operating environment and other factors, the switchgear may experience corona discharge, causing damage to the insulation part of the electrical equipment, shortening the service life of the electrical equipment, and in severe cases, causing equipment short circuits and power grid safety accidents. Practice has proved that the discharge phenomenon caused by insulation degradation is one of the early symptoms of insulation problems in electrical equipment, and is also an important indicator for judging the severity of defects. Therefore, it is necessary to study effective detection methods for corona discharge phenomena inside switchgear.

[0003] At present, the main corona discharge detection methods include pulse current method, ultra-high frequency method, etc., but they can only be detected through manual inspection or the placement of cabinets, which is costly and cannot be monitored in time. The gas component analysis method can effectively detect early discharge phenomena, is not easily interfered with, and has flexible equipment. Ozone in air corona discharge is an early discharge product with a high concentration, but the current gas component analysis method of switch cabinets focuses on relatively stable decomposition products such as CO and NO2, ignoring the important information reflected by the change in O3 concentration in the early stage of discharge. Therefore, it is necessary to study the switch cabinet corona discharge phenomenon detection technology based on the O3 analysis method.

[0004] As far as current detection technology is concerned, the performance of conventional single-channel O3 detection equipment in the switch cabinet environment is not stable and is affected by electrical noise interference, detector drift, temperature and humidity, etc. It is necessary to introduce the differential principle to compensate for noise interference, signal drift and other effects during the detection process.

[0005] Therefore, a technology is needed to realize ozone concentration detection technology based on differential acquisition signals, to detect ozone, the decomposition product of air corona discharge, in real time, to control faults in the early stages, to improve the safety of switchgear and reduce maintenance costs. Summary of the invention

[0006] In order to solve the above problems, the present invention provides an ozone concentration detection method and system based on differential acquisition signals to solve the problem of how to perform ozone concentration detection based on differential acquisition signals.

[0007] The technical solution of the present invention provides an ozone concentration detection method based on differential acquisition signals, the method comprising:

[0008] The gas to be measured inputted into the gas inlet is introduced into the measuring gas chamber via the first channel;

[0009] The gas to be tested inputted into the air inlet is introduced into the standard gas chamber via the second channel and the ozone filter;

[0010] Irradiating the measuring gas chamber and the standard gas chamber by an ultraviolet light source;

[0011] The first optical signal of the measuring air chamber irradiated by the ultraviolet light source and the second optical signal of the standard air chamber are measured respectively by measuring the PCB;

[0012] The ozone concentration of the gas to be measured is determined based on the first optical signal and the second optical signal.

[0013] Preferably, irradiating the measuring air chamber and the standard air chamber with an ultraviolet light source comprises:

[0014] The ultraviolet light source irradiates ultraviolet light of equal intensity to the measuring gas chamber and the standard gas chamber simultaneously via a reflector.

[0015] Preferably, it also includes:

[0016] The gas to be measured output from the air inlet is measured by the measuring air chamber and the standard air chamber, and then the gas to be measured is discharged through the air outlet by the suction pump.

[0017] Preferably, determining the ozone concentration of the gas to be measured based on the first optical signal and the second optical signal includes:

[0018] Determining the ozone concentration of the gas to be measured based on the first optical signal and the second optical signal by a host computer module;

[0019] The host computer module includes an early warning unit. When the ozone concentration exceeds a preset threshold, the early warning unit sends out a warning message through a buzzer or an LED light.

[0020] Preferably, the first optical signal and the second optical signal include light intensity signals:

[0021] I=I 0 e -KCL ,

[0022] Where: I 0 is the incident light intensity; I is the outgoing light intensity; K is the absorption coefficient; C is the concentration; L is the optical path length.

[0023] Preferably, determining the ozone concentration of the gas to be measured based on the first optical signal and the second optical signal includes:

[0024] Calculate the gas measurement channel signal U of the first channel 1 :

[0025] U 1 =K 1 I 0 e -KCL

[0026] Calculate the gas standard channel signal U of the second channel 2 :

[0027] U 2 =K 2 I 0

[0028] Among them, K 1 is the first scaling factor of the first channel, K 2 is the second scaling factor of the second channel.

[0029] Preferably, determining the ozone concentration of the gas to be measured based on the first optical signal and the second optical signal includes:

[0030] The formula for calculating the ozone concentration is:

[0031]

[0032] Among them, -1 / KL is the constant Q, lnK 1 -lnK 2 is the value m that changes with the environment, obtained through calibration, lnU 1 -lnU 2 Calculated by a single chip microcomputer, set as X, the ozone concentration is:

[0033] C=QX+Qm.

[0035] Preferably, the method further comprises:

[0036] A data acquisition module is connected to the measurement PCB and the host computer module, and the data acquisition module collects the first optical signal and the second optical signal measured by the measurement PCB by receiving a data instruction sent by the host computer module;

[0037] The data acquisition module further includes an analog-to-digital conversion unit for converting the acquired first optical signal and the second optical signal into digital signals.

[0038] Based on another aspect of the present invention, the present invention provides an ozone concentration detection system based on differential acquisition signals, the system comprising: an air inlet, into which the gas to be measured is introduced; the air inlet is connected to a measuring air chamber through a first channel; the air inlet is connected to a standard air chamber through a second channel; the measuring air chamber and the standard air chamber are respectively connected to a measuring PCB; the measuring PCB is connected to a host computer module;

[0039] The gas to be measured at the air inlet is introduced into the measuring air chamber via the first channel;

[0040] The gas to be tested at the air inlet is introduced into the standard gas chamber via the second channel and the ozone filter;

[0041] An ultraviolet light source irradiates the measuring gas chamber and the standard gas chamber;

[0042] The measuring PCB measures the first optical signal of the measuring air chamber irradiated by the ultraviolet light source and the second optical signal of the standard air chamber respectively;

[0043] The host computer module is used to determine the ozone concentration of the gas to be measured based on the first optical signal and the second optical signal.

[0044] Preferably, the ultraviolet light source irradiates the measuring air chamber and the standard air chamber, comprising:

[0045] The ultraviolet light source irradiates ultraviolet light of equal intensity to the measuring gas chamber and the standard gas chamber simultaneously via a reflector.

[0046] Preferably, it also includes an air pump, which is connected to the measuring air chamber and the standard air chamber;

[0047] The gas to be measured output from the air inlet is measured by the measuring air chamber and the standard air chamber, and then the gas to be measured is discharged through the air outlet by the suction pump.

[0048] Preferably, the host computer module is used to determine the ozone concentration of the gas to be measured based on the first optical signal and the second optical signal, and is also used to:

[0049] Determining the ozone concentration of the gas to be measured based on the first optical signal and the second optical signal by a host computer module;

[0050] The host computer module includes an early warning unit. When the ozone concentration exceeds a preset threshold, the early warning unit sends out a warning message through a buzzer or an LED light.

[0051] Preferably, the first optical signal and the second optical signal include light intensity signals:

[0052] I=I0 e -KCL ,

[0053] Where: I 0 is the incident light intensity; I is the outgoing light intensity; K is the absorption coefficient; C is the concentration; L is the optical path length.

[0054] Preferably, the host computer module is used to determine the ozone concentration of the gas to be measured based on the first optical signal and the second optical signal, and is also used to:

[0055] Calculate the gas measurement channel signal U of the first channel 1 :

[0056] U 1 =K 1 I 0 e -KCL

[0057] Calculate the gas standard channel signal U of the second channel 2 :

[0058] U 2 =K 2 I 0

[0059] Among them, K 1 is the first scaling factor of the first channel, K 2 is the second scaling factor of the second channel.

[0060] Preferably, the host computer module is used to determine the ozone concentration of the gas to be measured based on the first optical signal and the second optical signal, and is also used to:

[0061] The formula for calculating the ozone concentration is:

[0062]

[0063] Among them, -1 / KL is the constant Q, lnK 1 -lnK 2 is the value m that changes with the environment, obtained through calibration, lnU 1 -lnU 2 Calculated by a single chip microcomputer, set as X, the ozone concentration is:

[0064] C=QX+Qm.

[0066] Preferably, the system further comprises: a data acquisition module;

[0067] The data acquisition module is connected to the measurement PCB and the host computer module, and the data acquisition module collects the first optical signal and the second optical signal measured by the measurement PCB by receiving the data instruction sent by the host computer module;

[0068] The data acquisition module further includes an analog-to-digital conversion unit for converting the acquired first optical signal and the second optical signal into digital signals.

[0069] The technical solution of the present invention provides an ozone concentration detection method and system based on differential acquisition signals, wherein the method includes: introducing the gas to be tested input to the air inlet into the measuring gas chamber via the first channel; introducing the gas to be tested input to the air inlet into the standard gas chamber via the second channel and the ozone filter; irradiating the measuring gas chamber and the standard gas chamber by an ultraviolet light source; measuring the first optical signal of the measuring gas chamber irradiated by the ultraviolet light source and the second optical signal of the standard gas chamber by measuring the PCB; determining the ozone concentration of the gas to be tested based on the first optical signal and the second optical signal. The gas analysis method proposed in the technical solution of the present invention can reflect the early discharge phenomenon more timely, and has the advantages of being not susceptible to electromagnetic interference, flexible equipment and low cost, and is more suitable for use in the monitoring of power distribution main equipment. O3 is used as the characteristic gas for discharge detection. Compared with the more stable air discharge decomposition products such as CO and NO2, ozone is an early discharge product with a higher concentration. Discharge detection using its concentration change can reflect the air discharge phenomenon more timely and control the fault in the early stage. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] A more complete understanding of exemplary embodiments of the present invention may be obtained by referring to the following drawings:

[0071] Figure 1 A flow chart of an ozone concentration detection method based on differential acquisition signals according to a preferred embodiment of the present invention;

[0072] Figure 2 A structural diagram of an ozone concentration detection system based on differential acquisition signals according to a preferred embodiment of the present invention; and

[0073] Figure 3 It is a schematic diagram of the structure of the gas collection module according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0074] Now, exemplary embodiments of the present invention are described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0075] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0076] Figure 1 A flow chart of an ozone concentration detection method based on differential acquisition signals according to a preferred embodiment of the present invention;

[0077] The present invention provides an ozone concentration detection method based on differential acquisition signals, which compensates for the influence of noise interference, signal drift and the like in the detection process, optimizes the O3 gas detection method, performs real-time detection of air corona discharge decomposition products, and adopts an algorithm to effectively identify O3-based discharge fault signals, thereby controlling the fault in an early stage, thereby improving the safety of the switch cabinet and reducing maintenance costs.

[0078] In the present invention, the gas to be measured is inhaled by the same air inlet and is divided into two paths. One path of gas enters the measuring gas chamber, which reflects the change relationship of the gas concentration in response to the light of the characteristic wavelength, and obtains the gas measurement channel signal. The other path of gas enters the standard gas chamber after passing through the ozone filter, and obtains the gas standard channel signal. Due to the effect of the ozone filter, the standard gas chamber has no ozone gas, and is used to measure the channel of light intensity that is not absorbed by the gas to be measured. It has nothing to do with the change of gas concentration, and its gas standard channel signal is only related to the background light or external environmental interference. Based on the difference between the two channels, the background and external environmental interference can be eliminated.

[0079] like Figure 1 As shown, the present invention provides an ozone concentration detection method based on differential acquisition signals, the method comprising:

[0080] Step 101: introducing the gas to be tested input into the gas inlet into the measuring gas chamber via the first channel;

[0081] Step 102: introducing the gas to be tested input into the air inlet into the standard gas chamber via the second channel and the ozone filter;

[0082] Step 103: irradiating the measuring air chamber and the standard air chamber with an ultraviolet light source;

[0083] Preferably, the measuring gas chamber and the standard gas chamber are irradiated by an ultraviolet light source, comprising:

[0084] The ultraviolet light source irradiates ultraviolet light of equal intensity to the measuring gas chamber and the standard gas chamber simultaneously through the reflector.

[0085] The ultraviolet light source of the invention irradiates the measuring air chamber and the standard air chamber with equal light intensity simultaneously via a reflecting mirror.

[0086] Step 104: measuring the first optical signal of the measuring air chamber irradiated by the ultraviolet light source and the second optical signal of the standard air chamber respectively through the measuring PCB;

[0087] Step 105: Determine the ozone concentration of the gas to be measured based on the first optical signal and the second optical signal.

[0088] Preferably, it also includes:

[0089] The gas to be tested output from the air inlet is measured through the measuring air chamber and the standard air chamber, and then the gas to be tested is discharged through the air outlet through the suction pump.

[0090] The measuring gas chamber and the standard gas chamber of the present invention discharge the gas to be measured in the measuring gas chamber and the standard gas in the standard gas chamber from the gas outlet via the suction pump.

[0091] Preferably, determining the ozone concentration of the gas to be measured based on the first optical signal and the second optical signal includes:

[0092] Determine the ozone concentration of the gas to be measured based on the first optical signal and the second optical signal through the host computer module;

[0093] The host computer module includes an early warning unit. When the ozone concentration exceeds a preset threshold, the early warning unit sends out a warning message through a buzzer or an LED light.

[0094] The host computer module of the present invention comprises an ozone concentration-based early warning unit, which comprises a buzzer or an LED lamp.

[0095] Preferably, the first optical signal and the second optical signal comprise light intensity signals:

[0096] I=I 0 e -KCL ,

[0097] Where: I 0 is the incident light intensity; I is the outgoing light intensity; K is the absorption coefficient; C is the concentration; L is the optical path length.

[0098] The optical signal of the present invention includes a light intensity signal, I=I 0 e -KCL , where: I0 is the incident light intensity; I is the outgoing light intensity; K is the absorption coefficient; C is the concentration; L is the optical path length, which is the length of interaction between the light and the measured gas from the ultraviolet light source to the measurement PCB.

[0099] Preferably, determining the ozone concentration of the gas to be measured based on the first optical signal and the second optical signal includes:

[0100] Calculate the gas measurement channel signal U of the first channel 1 :

[0101] U 1 =K 1 I 0 e -KCL

[0102] Calculate the gas standard channel signal U of the second channel 2 :

[0103] U 2 =K 2 I 0

[0104] Among them, K 1 is the first scale factor of the first channel, K 2 is the second scaling factor for the second channel.

[0105] The gas to be measured in the present invention is divided into a first channel and a second channel after being sucked into the same air inlet. One channel of gas enters the measuring gas chamber through the first channel, which reflects the change relationship of the gas concentration in response to the light of the characteristic wavelength, and obtains the gas measuring channel signal. The other channel of gas enters the standard gas chamber after passing through the ozone filter in the second channel, and obtains the gas standard channel signal. The two channels have a proportional factor K 1 , K 2 , gas measurement channel signal U 1 , Gas standard channel signal U 2 as follows:

[0106] U 1 =K 1 I 0 e -KCL

[0107] U 2 =K 2 I 0 .

[0108] Preferably, determining the ozone concentration of the gas to be measured based on the first optical signal and the second optical signal includes:

[0109] The formula for calculating ozone concentration is:

[0110]

[0111] Among them, -1 / KL is the constant Q, lnK 1 -lnK 2 is the value m that changes with the environment, obtained through calibration, lnU 1 -lnU 2 Calculated by a single chip microcomputer, set as X, the ozone concentration is:

[0112] C=QX+Qm.

[0114] The ozone concentration of the present invention is:

[0115]

[0116] -1 / KL as constant Q, lnK 1 -lnK 2 is the value m that changes with the environment, obtained through calibration, lnU 1 -lnU 2 It is directly calculated by the single chip microcomputer, set as X, and the ozone concentration is:

[0117] C=QX+Qm.

[0118] Preferably, the method further comprises:

[0119] The data acquisition module is connected to the measurement PCB and the host computer module, and the data acquisition module collects the first optical signal and the second optical signal measured by the measurement PCB by receiving the data instruction sent by the host computer module;

[0120] The data acquisition module also includes an analog-to-digital conversion unit for converting the acquired first optical signal and second optical signal into digital signals.

[0121] The present invention also comprises a data acquisition module connected to the measuring PCB and the upper computer module. The data acquisition module receives control instructions from the upper computer module and uses a data acquisition card to complete signal acquisition processing.

[0122] In a preferred embodiment of the ozone concentration detection device based on differential acquisition signals of the present invention, the data acquisition module further includes an analog-to-digital conversion unit.

[0123] The detection method of the ozone concentration detection device based on the differential acquisition signal includes the following steps:

[0124] The gas to be tested is introduced from the switch cabinet from the air inlet and is divided into the first channel and the second channel after being inhaled. One gas enters the measuring gas chamber through the first channel, and the other gas enters the standard gas chamber after passing through the ozone filter in the second channel.

[0125] The ultraviolet light source illuminates the measuring gas chamber and the standard gas chamber.

[0126] The measuring PCB measures the optical signals of the gas to be measured in the measuring gas chamber and the standard gas in the standard gas chamber respectively under the irradiation of the ultraviolet light source. The optical signals include the light intensity signal, I=I 0 e -KCL , where: I 0 is the incident light intensity; I is the outgoing light intensity; K is the absorption coefficient; C is the concentration; L is the optical path length, which is the length of the interaction between the light and the measured gas from the starting point of the ultraviolet light source at the head of the air chamber to the end of the air chamber;

[0127] The upper computer module is connected to the measurement PCB to generate ozone concentration based on optical signals of the gas to be measured in the measurement chamber and the standard gas in the standard chamber.

[0128] The discharge detection method proposed in the present invention, the gas analysis method can reflect the early discharge phenomenon more timely, and has the advantages of not being susceptible to electromagnetic interference, flexible equipment, and low cost, and is more suitable for use in the monitoring of power distribution main equipment. O3 is used as the characteristic gas for discharge detection. Compared with the more stable air discharge decomposition products such as CO and NO2, ozone is an early discharge product with a higher concentration. Discharge detection using its concentration change can reflect the air discharge phenomenon more timely and control the fault in the early stage. On the basis of single absorption channel detection, a reference channel is introduced to compensate for the influencing factors such as noise interference and signal drift in the detection process, solve the problems of low O3 product content and detection being easily interfered, and make the detection more accurate and reliable. Manual sampling frequency and automatic sampling frequency, when there is no abnormality, the measurement can be carried out according to the manually set sampling frequency, and when there is an abnormality, it will be transferred to the automatic sampling frequency to achieve adaptive acquisition, which greatly improves the service life of the equipment.

[0129] The ozone concentration detection system based on differential acquisition signals provided by the present invention includes a sensor module, a gas acquisition module, a data acquisition module, a host computer module, and a power module. The sensor module is an ozone ultraviolet sensor that meets the requirements of accuracy, stability, durability, and price, and is used to accurately and in real time detect ozone concentration, provide stable and reliable data, and have the ability to work normally in various environments. The sensor module of the present invention is integrated in the measurement PCB. Furthermore, the sensor module is an ultraviolet pulse ozone sensor. The gas acquisition module realizes high-sensitivity collection of ozone gas and adopts the differential circuit principle such as Figure 3 shown.

[0130] When the intensity of a beam is I 0When the input parallel light passes through the gas chamber filled with gas, the absorption relationship of the gas molecules to the light energy follows the Lambert-Beer law. If the gas absorption spectrum is within the incident spectrum range, then after the light passes through the gas, the light intensity will be attenuated at the corresponding spectrum line, and the output light intensity I 0 The relationship between the input light intensity I is:

[0131] I=I 0 e -KCL

[0132] Where: I 0 is the incident light intensity, which is the light intensity before the light passes through the gas being measured; I is the outgoing light intensity, which is the light intensity after the light passes through the gas being measured; K is the absorption coefficient, which depends on the absorption spectrum of the object being measured; C is the concentration, which is the concentration value of the gas being measured; L is the optical path length, which is the length of interaction between the light source and the gas being measured from the light source to the detector.

[0133] The gas to be measured in the present invention is sucked into the same air inlet and is divided into two paths. One path of gas enters the measuring gas chamber, reflecting the change relationship of the gas concentration in response to the light of the characteristic wavelength, and a gas measurement channel signal is obtained. The other path of gas enters the standard gas chamber after passing through the ozone filter, and a gas standard channel signal is obtained. Due to the effect of the ozone filter, there is no ozone gas in the standard gas chamber, and the channel used to measure the light intensity that is not absorbed by the gas to be measured is unrelated to the change of gas concentration. Its gas standard channel signal is only related to the background light or external environmental interference.

[0134] Assume that the two channels have a scaling factor K 1 , K 2 , we can get the gas measurement channel U 1 , U 2 as follows:

[0135] U 1 =K 1 I 0 e -KCL

[0136] U 2 =K 2 I 0

[0137] In actual testing, the physical quantity of light intensity is difficult to be directly and accurately measured. Generally, the light intensity signal is represented by the electrical signal of the detector. In order to eliminate the possible errors in the middle, the above two relationship equations are compared:

[0138]

[0139] The concentration can be calculated as:

[0140]

[0141] For a certain system, -1 / KL can be regarded as a constant Q, and K 1 , K 2 It is only related to the current environment state, and lnK can be set 1 -lnK 2 is a value m that varies with the environment and can be obtained through calibration. 1 -lnU 2 It can be directly calculated by a single chip microcomputer and is set as X. The concentration can be simplified as:

[0142] C=QX+Qm

[0143] In addition, the suction pump is designed with daily sampling frequency and abnormal sampling frequency. When there is no abnormality, measurement can be performed according to the manually set daily sampling frequency. If the measurement finds that the ozone concentration is greater than the abnormal threshold, it is abnormal. When there is an abnormality, it will be switched to the abnormal sampling frequency. The abnormal sampling frequency is higher than the daily sampling frequency, and both can be set to achieve intelligent adaptive collection.

[0144] The data acquisition module receives and responds to the host computer control instructions, and uses the data acquisition card to complete the signal acquisition processing. It has the characteristics of fast processing speed, large memory, large storage capacity and low power consumption.

[0145] The host computer analyzes and displays the gas composition status inside the switch cabinet, realizes human-computer interaction, uses advanced data processing algorithms to clean and integrate data to ensure data accuracy and availability, and uses intelligent algorithms to conduct in-depth analysis and prediction of ozone concentration data.

[0146] like Figure 2 As shown, the present invention provides an ozone concentration detection system based on differential acquisition signals, the system comprising: an air inlet, into which the gas to be measured is introduced; the air inlet is connected to a measuring air chamber through a first channel; the air inlet is connected to a standard air chamber through a second channel; the measuring air chamber and the standard air chamber are respectively connected to a measuring PCB; the measuring PCB is connected to an upper computer module;

[0147] The gas to be measured at the air inlet is introduced into the measuring air chamber via the first channel;

[0148] The gas to be tested at the air inlet is introduced into the standard gas chamber via the second channel and the ozone filter;

[0149] The ultraviolet light source irradiates the measuring gas chamber and the standard gas chamber;

[0150] The measuring PCB respectively measures a first optical signal of the measuring air chamber irradiated by the ultraviolet light source and a second optical signal of the standard air chamber;

[0151] The host computer module is used to determine the ozone concentration of the gas to be measured based on the first optical signal and the second optical signal.

[0152] The present invention discloses an ozone concentration detection system based on differential acquisition signals, a differential gas acquisition module, which comprises:

[0153] Gas inlet, which introduces the gas to be tested from the switch cabinet,

[0154] The measuring gas chamber introduces the gas to be measured from the switch cabinet via the first channel.

[0155] The standard gas chamber introduces the gas to be tested from the switch cabinet through the second channel. The second channel is provided with an ozone filter for removing ozone from the gas to be tested to form a standard gas.

[0156] an ultraviolet light source, which illuminates the measuring gas chamber and the standard gas chamber,

[0157] A measuring PCB, which respectively measures the optical signals of the gas to be measured in the measuring gas chamber and the standard gas in the standard gas chamber under the irradiation of an ultraviolet light source;

[0158] The host computer module is connected to the measurement PCB to generate ozone concentration based on the optical signals of the gas to be measured in the measurement chamber and the standard gas in the standard chamber.

[0159] Preferably, the ultraviolet light source irradiates the measuring gas chamber and the standard gas chamber, comprising:

[0160] The ultraviolet light source irradiates ultraviolet light of equal intensity to the measuring gas chamber and the standard gas chamber simultaneously through the reflector.

[0161] Preferably, the system further comprises an air suction pump connected to the measuring air chamber and the standard air chamber;

[0162] The gas to be tested output from the air inlet is measured through the measuring air chamber and the standard air chamber, and then the gas to be tested is discharged through the air outlet through the suction pump.

[0163] Preferably, the system further comprises a host computer module, which is used to determine the ozone concentration of the gas to be measured based on the first optical signal and the second optical signal, and is also used to:

[0164] Determine the ozone concentration of the gas to be measured based on the first optical signal and the second optical signal through the host computer module;

[0165] The host computer module includes an early warning unit. When the ozone concentration exceeds a preset threshold, the early warning unit sends out a warning message through a buzzer or an LED light.

[0166] Preferably, the first optical signal and the second optical signal comprise light intensity signals:

[0167] I=I0 e -KCL ,

[0168] Where: I 0 is the incident light intensity; I is the outgoing light intensity; K is the absorption coefficient; C is the concentration; L is the optical path length.

[0169] Preferably, the host computer module is used to determine the ozone concentration of the gas to be measured based on the first optical signal and the second optical signal, and is also used to:

[0170] Calculate the gas measurement channel signal U of the first channel 1 :

[0171] U 1 =K 1 I 0 e -KCL

[0172] Calculate the gas standard channel signal U of the second channel 2 :

[0173] U 2 =K 2 I 0

[0174] Among them, K 1 is the first scale factor of the first channel, K 2 is the second scaling factor for the second channel.

[0175] Preferably, the host computer module is used to determine the ozone concentration of the gas to be measured based on the first optical signal and the second optical signal, and is also used to:

[0176] The formula for calculating ozone concentration is:

[0177]

[0178] Among them, -1 / KL is the constant Q, lnK 1 -lnK 2 is the value m that changes with the environment, obtained through calibration, lnU 1 -lnU 2 Calculated by a single chip microcomputer, set as X, the ozone concentration is:

[0179] C=QX+Qm.

[0181] Preferably, a data acquisition module;

[0182] The data acquisition module is connected to the measurement PCB and the host computer module, and the data acquisition module collects the first optical signal and the second optical signal measured by the measurement PCB by receiving the data instruction sent by the host computer module;

[0183] The data acquisition module also includes an analog-to-digital conversion unit for converting the acquired first optical signal and second optical signal into digital signals.

[0184] The invention has been described above with reference to a few embodiments. However, it is readily apparent to a person skilled in the art that other embodiments than the ones disclosed above are equally within the scope of the invention, as defined by the appended patent claims.

[0185] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a / said / the [means, components, etc.]" are to be openly interpreted as at least one instance of the means, components, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not necessarily have to be performed in the exact order disclosed, unless explicitly stated otherwise.

Claims

1. A method for detecting ozone concentration based on differential acquisition signals, the method comprising: The gas to be measured inputted into the gas inlet is introduced into the measuring gas chamber via the first channel; The gas to be tested inputted into the air inlet is introduced into the standard gas chamber via the second channel and the ozone filter; Irradiating the measuring gas chamber and the standard gas chamber by an ultraviolet light source; The first optical signal of the measuring air chamber irradiated by the ultraviolet light source and the second optical signal of the standard air chamber are measured respectively by measuring the PCB; The ozone concentration of the gas to be measured is determined based on the first optical signal and the second optical signal.

2. The method according to claim 1, wherein irradiating the measuring gas chamber and the standard gas chamber with an ultraviolet light source comprises: The ultraviolet light source irradiates ultraviolet light of equal intensity to the measuring gas chamber and the standard gas chamber simultaneously via a reflector.

3. The method according to claim 1, further comprising: The gas to be measured output from the air inlet is measured by the measuring air chamber and the standard air chamber, and then the gas to be measured is discharged through the air outlet by the suction pump.

4. The method according to claim 1, wherein determining the ozone concentration of the gas to be measured based on the first optical signal and the second optical signal comprises: Determining the ozone concentration of the gas to be measured based on the first optical signal and the second optical signal by a host computer module; The host computer module includes an early warning unit. When the ozone concentration exceeds a preset threshold, the early warning unit sends out a warning message through a buzzer or an LED light.

5. The method according to claim 1, wherein the first optical signal and the second optical signal comprise light intensity signals: I=I0e -KCL , in: I0 is the incident light intensity; I is the outgoing light intensity; K is the absorption coefficient; C is the concentration; L is the optical path length.

6. The method according to claim 5, wherein determining the ozone concentration of the gas to be measured based on the first optical signal and the second optical signal comprises: Calculate the gas measurement channel signal U1 of the first channel: U1=K1I0e -KCL Calculate the gas standard channel signal U2 of the second channel: U2=K2I0 Wherein, K1 is a first proportional factor of the first channel, and K2 is a second proportional factor of the second channel.

7. The method according to claim 1, determining the ozone concentration of the gas to be measured based on the first optical signal and the second optical signal, comprising: The formula for calculating the ozone concentration is: Among them, -1 / KL is the constant Q, lnK1-lnK2 is the value m that changes with the environment, which is obtained through calibration, and lnU1-lnU2 is obtained by calculation by the single-chip microcomputer, set as X, and the ozone concentration is: C=QX+Qm.

8. The method according to claim 1, further comprising: A data acquisition module is connected to the measurement PCB and the host computer module, and the data acquisition module collects the first optical signal and the second optical signal measured by the measurement PCB by receiving a data instruction sent by the host computer module; The data acquisition module further includes an analog-to-digital conversion unit for converting the acquired first optical signal and the second optical signal into digital signals.

9. An ozone concentration detection system based on differential acquisition signals, the system comprising: An air inlet, into which the gas to be measured is introduced; the air inlet is connected to the measuring air chamber through a first channel; the air inlet is connected to the standard air chamber through a second channel; the measuring air chamber and the standard air chamber are respectively connected to a measuring PCB; the measuring PCB is connected to a host computer module; The gas to be measured at the air inlet is introduced into the measuring air chamber via the first channel; The gas to be tested at the air inlet is introduced into the standard gas chamber via the second channel and the ozone filter; An ultraviolet light source irradiates the measuring gas chamber and the standard gas chamber; The measuring PCB respectively measures the first optical signal of the measuring air chamber irradiated by the ultraviolet light source and the second optical signal of the standard air chamber; The host computer module is used to determine the ozone concentration of the gas to be measured based on the first optical signal and the second optical signal.

10. The system according to claim 8, wherein the ultraviolet light source illuminates the measuring gas chamber and the standard gas chamber, comprising: The ultraviolet light source irradiates ultraviolet light of equal intensity to the measuring gas chamber and the standard gas chamber simultaneously via a reflector.

11. The system according to claim 8, further comprising an air pump connected to the measuring air chamber and the standard air chamber; The gas to be measured output from the air inlet is measured by the measuring air chamber and the standard air chamber, and then the gas to be measured is discharged through the air outlet by the suction pump.

12. The system according to claim 8, wherein the host computer module is used to determine the ozone concentration of the gas to be measured based on the first optical signal and the second optical signal, and is also used to: Determining the ozone concentration of the gas to be measured based on the first optical signal and the second optical signal by a host computer module; The host computer module includes an early warning unit. When the ozone concentration exceeds a preset threshold, the early warning unit sends out a warning message through a buzzer or an LED light.

13. The system of claim 8, wherein the first optical signal and the second optical signal comprise light intensity signals: I=I0e -KCL , in: I0 is the incident light intensity; I is the outgoing light intensity; K is the absorption coefficient; C is the concentration; L is the optical path length.

14. The system according to claim 13, wherein the host computer module is used to determine the ozone concentration of the gas to be measured based on the first optical signal and the second optical signal, and is also used to: Calculate the gas measurement channel signal U1 of the first channel: U1=K1I0e -KCL Calculate the gas standard channel signal U2 of the second channel: U2=K2I0 in, K1 is a first proportional factor of the first channel, and K2 is a second proportional factor of the second channel.

15. The system according to claim 8, wherein the host computer module is used to determine the ozone concentration of the gas to be measured based on the first optical signal and the second optical signal, and is also used to: The formula for calculating the ozone concentration is: in, -1 / KL is the constant Q, lnK1-lnK2 is the value m that changes with the environment, obtained through calibration, lnU1-lnU2 is obtained through microcontroller calculation, set as X, the ozone concentration is: C=QX+Qm.

16. The system according to claim 8, further comprising: Data acquisition module; The data acquisition module is connected to the measurement PCB and the host computer module, and the data acquisition module collects the first optical signal and the second optical signal measured by the measurement PCB by receiving the data instruction sent by the host computer module; The data acquisition module further includes an analog-to-digital conversion unit for converting the acquired first optical signal and the second optical signal into digital signals.

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