Gas concentration detection method with excellent environmental adaptability

Abstract

The invention discloses a gas concentration detection method with excellent environmental adaptability. The specific gas concentration control method comprises the following steps: gas concentration environment adaptation control, transmitting module temperature control and receiving module temperature control; according to the gas concentration environment adaptation control, the current temperature is obtained through an environment detector installed in an absorption gas chamber, and the current temperature is converted into a temperature digital signal through an environment acquisition unit and then is input into a control unit to compensate an inversion algorithm; the temperature control of the transmitting module is to maintain the power temperature by controlling the working temperature of an illuminator and maintain the stability of the transmitting wavelength, and the temperature control of the receiving module is to maintain the photoelectric conversion efficiency by controlling the temperature of a receiver and reduce the noise. On the basis that the concentration of specific gas can be measured, other concentrations can be accurately measured in real time in different environments, and the absorption line intensity, the absorption linear function, the gas molar volume and the like are corrected from the action mechanism.

Description

Technical Field

[0001] The present invention relates to the technical field of gas detection, and more specifically, to a gas concentration detection method with excellent environmental adaptability. Background Art

[0002] Various types of flammable gases have been widely used in various fields. There are more and more reports of explosion accidents caused by gas leaks. For gas safety, flammable gases need to be detected in more and more scenarios. Traditional detection methods include electrochemical method, catalytic combustion method, gas-sensitive semiconductor technology, etc. Spectral absorption method based on optical absorption technology is gaining more and more attention as a new method. In particular, infrared absorption method and tunable diode laser absorption spectroscopy have good development prospects with high detection sensitivity, large range and non-contact measurement.

[0003] At present, relevant institutions have disclosed relevant technical solutions for optical gas detection devices, but optical gas detection devices are easily affected by the environment. In particular, the detection device needs to be installed in a harsh environment, such as -40℃~70℃. Both the light emitter and the receiver will be affected by the temperature, causing data drift. The inversion of gas concentration will also be affected by the environment. The existing solutions are usually fitted based on empirical formulas such as linear fitting. The above methods are too simple to adapt to a wide temperature range, or a large number of segmented fittings are required. The calibration process is cumbersome and prone to errors, which is not conducive to mass production. For example, my country has a vast territory, and the air pressure in high-altitude areas is only 600hPa. Gas detection equipment produced in low-altitude areas will have serious data distortion when it reaches high-altitude areas. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies in the prior art and provide a gas concentration detection method with excellent environmental adaptability.

[0005] The present invention provides a gas concentration detection method with excellent environmental adaptability, which is achieved through the following technical scheme. The concentration detection device includes an emission module, an absorption chamber, a receiving module and a hardware circuit; the absorption chamber is used for the flow of the gas to be measured, and the emission module is used for emitting a specific light beam, and the emitted light beam is in a divergent, collimated or convergent state; the receiving module is used for receiving the light after passing through the absorption chamber, and converting the light signal carrying the concentration information into an electrical signal; the divergent module and the receiving module are electrically connected to the hardware circuit; the hardware circuit is provided with a control unit, a light emitting driving unit, a receiving and collecting unit, a plurality of temperature collecting units and a temperature control unit.

[0006] Furthermore, the absorption chamber also includes an environmental detector, including but not limited to a temperature sensor, a humidity sensor and a pressure sensor.

[0007] Furthermore, the emission module includes an emission temperature detector and an emission temperature controller in addition to the light emitter.

[0008] Furthermore, the receiving module includes a receiving temperature detector and a receiving temperature controller in addition to the receiver.

[0009] The gas concentration detection device drives the light emitter of the light emitting module to emit a characteristic light beam through the light emitting driving unit of the hardware circuit. After the light beam passes through the absorbing gas and is absorbed by the gas to be tested, the light beam carries the absorption concentration information and reaches the receiver of the receiving module. The receiver converts the light signal carrying the concentration information into an electrical signal. The electrical signal reaches the receiving and collecting unit of the hardware circuit and is converted into a digital signal. It enters the control unit for demodulation and inversion into a concentration value.

[0010] The present invention is a gas concentration control method that can adapt to harsh environments; it includes gas concentration environment adaptation control, transmitting module temperature control, and receiving module temperature control;

[0011] The gas concentration environmental adaptation control obtains the current temperature through the environmental detector installed in the absorption gas chamber, and the temperature is converted into a digital signal by the environmental acquisition unit and then input into the control unit compensation inversion algorithm; the real-time gas temperature will be brought into the inversion algorithm to correct the absorption line intensity, absorption linear function, and gas molar volume to ensure that the concentration value is true and accurate.

[0012] The temperature control of the emission module is achieved by controlling the working temperature of the light emitter to maintain the power temperature and the emission wavelength to be stable. The current temperature of the light emitter is collected by a temperature detector, and the temperature is converted into a digital signal by a temperature collection unit and sent to the control unit. The control unit calculates the temperature read and controls the temperature controller of the emission module through the temperature control unit to adjust the temperature of the light emitter, thereby completing closed-loop control and achieving a stable light-emitting state.

[0013] The receiving module temperature control is to maintain the photoelectric conversion efficiency and reduce noise by controlling the receiver temperature. The current receiver temperature is collected by a temperature detector, and the temperature is converted into a digital signal by a temperature collection unit and sent to the control unit. The control unit calculates the read temperature and controls the temperature controller of the receiving module through the temperature control unit to adjust the temperature of the receiver, thereby completing closed-loop control and achieving a stable receiving state.

[0014] In the process of gas concentration environmental adaptation control in the control method of the present invention, the absorption process of the characteristic light beam by the gas is described by the following formula:

[0015] I(t)=I0e -S(T)φ(ν)PCL

[0016] Among them, I0 is the light intensity emitted by the transmitter, S(T) is the absorption line intensity, φ(v) is the corresponding linear absorption function, P is the current atmospheric pressure of the environment, C is the concentration of the gas to be measured, and L is the optical path length of the absorption chamber.

[0017] The temperature correction relationship of the absorption line intensity during the gas concentration environmental adaptation control process in the control method of the present invention is as follows:

[0018]

[0019] Where T0 is room temperature, such as 293K, and T is the temperature obtained by the environmental detector. Q(T) is the molecular partition function, h is Planck's constant, c is the speed of light in vacuum, E″ is the molecular transition energy, and k is the Boltzmann constant.

[0020] The temperature correction relationship of the linear absorption function in the gas concentration environment adaptation control process in the control method of the present invention is as follows:

[0021]

[0022] Where γ0 is the half-width at half-height of the absorption line, and n is the temperature coefficient.

[0023] Furthermore, the molar volume of the gas to be measured

[0024]

[0025] The molar volume of air at temperature T is

[0026] V air =N A P / RT

[0027] Among them, N A is Avogadro's constant, P is the current air pressure, R is the gas constant, and T is the temperature obtained by the air temperature sensor.

[0028] Furthermore, the VOL of the gas

[0029]

[0030] Through the gas concentration environment adaptation control method, the absorption line intensity, absorption linear function, gas molar volume, etc. are corrected from the mechanism of action.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The gas concentration detection and control method with excellent environmental adaptability proposed in the present invention can ensure that other concentrations can be accurately measured in real time under different environments on the basis of measuring the concentration of a specific gas, and correct the absorption line intensity, absorption linear function, gas molar volume, etc. from the mechanism of action. Therefore, the present invention can be applied to the scene of gas detection of different concentrations, reduce the error in the detection results, obtain accurate detection results in harsh environments, and improve the accuracy, applicability and reliability of the gas concentration detection device. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of a gas concentration detection device with excellent environmental adaptability of the present invention;

[0034] Figure 2 This is a flow chart of a gas concentration control method with excellent environmental adaptability according to the present invention;

[0035] Figure 3 This is a flow chart of the temperature control method of the transmitting (receiving) module in the present invention. DETAILED DESCRIPTION

[0036] In order to be able to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, in the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other. In the following description, many specific details are set forth in order to fully understand the present invention, and the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the art without making creative work are within the scope of protection of the present invention. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by technicians in the technical field of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0037] The present invention provides a gas concentration detection method with excellent environmental adaptability, and the concentration detection device is as follows Figure 1 As shown, it includes an emission module, an absorption chamber, a receiving module and a hardware circuit; the absorption chamber is used for the flow of the gas to be measured, and the emission module is used for emitting a specific light beam, and the emitted light beam is in a divergent, collimated or convergent state; the receiving module is used to receive the light after passing through the absorption chamber, and convert the light signal carrying the concentration information into an electrical signal; the divergent module and the receiving module are electrically connected to the hardware circuit; the hardware circuit is provided with a control unit, a light-emitting driving unit, a receiving and collecting unit, a plurality of temperature collecting units and a temperature control unit;

[0038] The absorption chamber also includes an environmental detector, which is not limited to a temperature sensor, a humidity sensor and a pressure sensor; the transmitting module includes a transmitting temperature detector and a transmitting temperature controller in addition to the light emitter; the receiving module includes a receiving temperature detector and a receiving temperature controller in addition to the receiver;

[0039] The gas concentration detection device drives the light emitter of the light emitting module to emit a characteristic light beam through the light emitting driving unit of the hardware circuit. After the light beam passes through the absorbing gas and is absorbed by the gas to be tested, the light beam carries the absorption concentration information and reaches the receiver of the receiving module. The receiver converts the light signal carrying the concentration information into an electrical signal. The electrical signal reaches the receiving and collecting unit of the hardware circuit and is converted into a digital signal. It enters the control unit for demodulation and inversion into a concentration value.

[0040] The present invention is a gas concentration control method that can adapt to harsh environments; it includes gas concentration environment adaptation control, transmitting module temperature control, and receiving module temperature control;

[0041] The gas concentration environment adaptation control is as follows Figure 2 As shown, the current temperature is obtained by the environmental detector installed in the absorption gas chamber, and the temperature is converted into a digital signal by the environmental acquisition unit and then input into the control unit to compensate the inversion algorithm; the real-time gas temperature will be brought into the inversion algorithm to correct the absorption line intensity, absorption linear function, and gas molar volume to ensure that the concentration value is true and accurate.

[0042] The temperature control of the transmitting module is as follows: Figure 3 As shown, the power temperature is maintained by controlling the working temperature of the light emitter to maintain the emission wavelength stable, the current light emitter temperature is collected by a temperature detector, and the temperature acquisition unit converts the temperature into a digital signal and sends it to the control unit. The control unit calculates the temperature read and controls the temperature controller of the emission module through the temperature control unit to adjust the temperature of the light emitter, completing closed-loop control and achieving a stable light-emitting state.

[0043] The receiving module temperature control is as follows Figure 3 As shown, the photoelectric conversion efficiency is maintained and the noise is reduced by controlling the receiver temperature. The current receiver temperature is collected by the temperature detector, and the temperature is converted into a digital signal by the temperature collection unit and sent to the control unit. The control unit calculates the read temperature and controls the temperature controller of the receiving module through the temperature control unit to adjust the temperature of the receiver, completing the closed-loop control and achieving a stable receiving state.

[0044] In the process of gas concentration environmental adaptation control in the control method of the present invention, the absorption process of the characteristic light beam by the gas is described by the following formula:

[0045] I(t)=I0e -S(T)φ(ν)PCL

[0046] Among them, I0 is the light intensity emitted by the transmitter, S(T) is the absorption line intensity, φ(v) is the corresponding linear absorption function, P is the current atmospheric pressure of the environment, C is the concentration of the gas to be measured, and L is the optical path length of the absorption chamber.

[0047] The temperature correction relationship of the absorption line intensity during the gas concentration environmental adaptation control process in the control method of the present invention is as follows:

[0048]

[0049] Where T0 is room temperature, such as 293K, and T is the temperature obtained by the environmental detector. Q(T) is the molecular partition function, is Planck's constant, c is the speed of light in vacuum, E″ is the molecular transition energy, and k is the Boltzmann constant.

[0050] The temperature correction relationship of the linear absorption function in the gas concentration environment adaptation control process in the control method of the present invention is as follows:

[0051]

[0052] Where γ0 is the half-width at half-height of the absorption line, and n is the temperature coefficient.

[0053] Furthermore, the molar volume of the gas to be measured

[0054]

[0055] The molar volume of air at temperature T is

[0056]

[0057] Among them, N A is Avogadro's constant, P is the current air pressure, R is the gas constant, and T is the temperature obtained by the air temperature sensor.

[0058] Furthermore, the VOL of the gas

[0059]

[0060] Through the gas concentration environment adaptation control method, the absorption line intensity, absorption linear function, gas molar volume, etc. are corrected from the mechanism of action.

[0061] The above is only a preferred embodiment of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A gas concentration detection method with excellent environmental adaptability, characterized in that: The concentration detection device includes an emission module, an absorption chamber, a receiving module and a hardware circuit; the absorption chamber is used for the flow of the gas to be tested, the emission module is used for emitting a specific light beam, and the emitted light beam is in a divergent, collimated or convergent state; the receiving module is used to receive the light after passing through the absorption chamber, and convert the light signal carrying the concentration information into an electrical signal; the divergent module and the receiving module are electrically connected to the hardware circuit; the hardware circuit is provided with a control unit, a light-emitting driving unit, a receiving and collecting unit, a plurality of temperature collecting units and a temperature control unit; The specific gas concentration control method is as follows: including gas concentration environment adaptation control, transmitting module temperature control, and receiving module temperature control; The gas concentration environmental adaptation control obtains the current temperature through the environmental detector installed in the absorption gas chamber, and then inputs the temperature digital signal into the control unit to compensate the inversion algorithm after the temperature is converted by the environmental acquisition unit; the real-time gas temperature will be brought into the inversion algorithm to correct the absorption line intensity, absorption linear function, and gas molar volume to ensure that the concentration value is true and accurate; The temperature control of the emission module is to maintain the power temperature and the emission wavelength stable by controlling the working temperature of the light emitter, collect the current temperature of the light emitter through the temperature detector, convert the temperature into a digital signal through the temperature acquisition unit and send it to the control unit, and the control unit controls the temperature controller of the emission module through the temperature control unit to adjust the temperature of the light emitter after calculation according to the read temperature, so as to complete the closed-loop control and achieve a stable light emission state; The receiving module temperature control is to maintain the photoelectric conversion efficiency and reduce noise by controlling the receiver temperature. The current receiver temperature is collected by a temperature detector, and the temperature is converted into a digital signal by a temperature collection unit and sent to the control unit. The control unit calculates the read temperature and controls the temperature controller of the receiving module through the temperature control unit to adjust the temperature of the receiver, thereby completing closed-loop control and achieving a stable receiving state.

2. The gas concentration detection method with excellent environmental adaptability according to claim 1 is characterized in that: The following formula is used to describe the absorption process of the characteristic light beam by the gas during the gas concentration environment adaptation control process: I(t)=I0e -s(T)φ(v)PCL Among them, I0 is the light intensity emitted by the transmitter, S(T) is the absorption line intensity, φ(v) is the corresponding linear absorption function, P is the current atmospheric pressure of the environment, C is the concentration of the gas to be measured, and L is the optical path length of the absorption chamber.

3. The gas concentration detection method with excellent environmental adaptability according to claim 1 is characterized in that: The temperature correction relationship of the absorption line intensity during the gas concentration environmental adaptation control process is as follows: Among them, T0 is room temperature, T is the temperature obtained by the environmental detector, Q(T) is the molecular partition function, h is Planck's constant, c is the speed of light in vacuum, E″ is the molecular transition energy, and k is the Boltzmann constant.

4. The gas concentration detection method with excellent environmental adaptability according to claim 1 is characterized in that: The temperature correction relationship of the linear absorption function in the process of gas concentration environmental adaptation control is as follows: Where γ0 is the half-width at half-height of the absorption line, and n is the temperature coefficient.

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