CN206146554U - Gas temperature detection device based on but tuning diode laser absorption spectrum - Google Patents

Abstract

The utility model provides a gas temperature detection device based on but tuning diode laser absorption spectrum, but tuning diode laser absorption spectrum gas detection technology field belonged to. System's device includes: emission unit (11), a burning gas absorption pond unit (12), receiving element (13), central control processing unit (14). The utility model discloses an emission unit produces the laser beam that center wavelength be 1390nm, and the light beam is through a burning gas absorption pond, measures the light intemsity variation of laser after burning by receiving element, carries out data processing and measure the temperature's real -time demonstration by central control processing unit at last.

Description

A gas temperature detection device based on tunable diode laser absorption spectrum

technical field

The utility model relates to a gas temperature detection device based on tunable diode laser absorption spectrum, which belongs to the technical field of tunable diode laser absorption spectrum gas detection.

Background technique

At present, temperature measurement technology is divided into contact and non-contact measurement according to the measurement method. The contact measurement is a point measurement, and the temperature response linearity is not high within a specific temperature range, and the detection sensitivity is low. Non-contact temperature measurement does not need to be in contact with the measured object, and will not interfere with the temperature field, and is suitable for temperature measurement under high temperature conditions. When the tuned diode laser absorption spectroscopy technology is used to measure the gas temperature in the combustion field, it will not interfere with the flow field to be measured, and has the advantages of high sensitivity, high spectral resolution, fast response time, and simultaneous measurement of multiple parameters.

Contents of the invention

The utility model provides a gas temperature detection device based on tunable diode laser absorption spectrum to solve the problems of limited contact measurement environment, high precision and low detection sensitivity in the field of high temperature measurement, and further provides a A gas temperature detection device based on a tunable laser absorption spectrum, for this reason, the utility model provides the following technical solution: a gas temperature detection device based on a tunable diode laser absorption spectrum, including: an emission unit, a combustion field gas absorption pool Unit, receiving unit, central control processing unit. The utility model generates a laser beam with a central wavelength of 1390nm through the emitting unit, the beam passes through the gas absorption pool of the combustion field, and the receiving unit measures the light intensity change of the laser after passing through the combustion field, and finally the central control processing unit performs data processing and temperature measurement real-time display.

In the tunable diode laser absorption spectrum gas temperature detection device described in the utility model, the emission unit adopts a tunable semiconductor laser whose working center wavelength is located at 1390nm, and the temperature controller is used to control the working temperature of the tunable semiconductor laser, and the current controller passes the signal to generate The laser loads a 100Hz triangular wave scanning voltage signal into the current terminal of the controller to drive the laser wavelength to scan around 1390nm. Then the laser with the corresponding wavelength enters the gas absorption pool of the combustion field through the optical fiber and the self-made optical fiber collimator.

In the tunable diode laser absorption spectrum gas temperature detection device described in the utility model, the gas absorption pool in the combustion field adopts a five-reflection chamber gas absorption pool with a 30cm optical path in a three-zone combustion furnace to realize a uniform high-temperature gas environment.

In the tunable diode laser absorption spectrum gas temperature detection device described in the utility model, the receiving unit uses the photoelectric conversion detector PDA10CS to measure the light intensity change after the laser passes through the combustion field, convert it into an electrical signal, and then input it into the lock-in amplifier for further processing. Phase-locked detection and output of the second harmonic signal, and finally through the multi-function data acquisition card for signal acquisition.

In the tunable diode laser absorption spectrum gas temperature detection device described in the utility model, the central control processing unit processes the signal collected by the data acquisition card USB2850, uses an embedded operating system to edit, and displays the measurement results in real time on the display screen .

Beneficial effects of the utility model: the emission unit adopts 1392.80nm and 1393.05nm H20 absorption spectrum line pair, because water is an important gas of the combustion product, the utility model can measure the temperature of the combustion field under different combustion conditions, and the two lines of water vapor The spectral line pairs are also calibrated and screened, and the absorption effect on the spectral lines in the gas absorption cell is remarkable, and it has good adaptability to the measurement of gas parameters in harsh environments.

Description of drawings

Fig. 1 is a schematic structural diagram of a tunable diode laser absorption spectrum gas temperature detection device provided by the present invention.

Fig. 2 is a schematic diagram of the detection system of the present invention.

Fig. 3 is the selection of the absorption spectrum absorption peak of water vapor of the present utility model.

detailed description

In order to more clearly explain the characteristics and basic working principles of the utility model, the experimental model is described below in conjunction with the accompanying drawings: This specific embodiment first provides a gas temperature detection teaching method based on tunable diode laser absorption spectroscopy (TDLAS) The experimental device, as shown in Figure 1, includes: a transmitting unit (11), a combustion field gas absorption pool (12), a receiving unit (13) and a central control processing unit (14); the transmitting unit (11) converts the modulated laser Pass through the combustion field gas absorption cell (12) to be measured once through the fiber collimator, the light intensity change after passing through the combustion field is measured by the receiving unit (13), and finally the data processing and processing are performed by the central control processing unit (14). Real-time display of measured temperature.

Among them, as shown in Figure 2, the transmitting unit consists of two tunable DFB lasers and their driving devices, fiber couplers, and collimators. The computer processing unit is used to control and switch the working status of the lasers, so that the laser light source emits light of a specific wavelength. The semiconductor laser beam scans the gas after passing through the fiber coupler. The utility model adopts the ITC5022 laser diode current temperature controller to realize the temperature control and current drive of the DFB laser by driving the LM14S2 butterfly package base.

Embodiment, as shown in Figure 2, the receiving unit uses the photoelectric sensor VIGO mercury cadmium telluride detector to convert the optical signal absorbed by the gas into an electrical signal, and after amplification and filtering, the data acquisition card transmits it to the host computer for spectrum analysis. Signal analysis and processing to obtain temperature. The central control processing unit is programmed by the embedded system using LabVIEW software to process, display and store the data transmitted from the data acquisition card to the host computer, and communicate with the transmitting and receiving unit to detect the working status of the semiconductor laser and the control circuit in real time . In the host computer software, the user can analyze the absorption spectrum, set parameters such as the laser, and calibrate the analysis system, which is convenient for debugging and practical.

The working principle of the tunable diode laser absorption spectrum gas temperature detection device provided by the utility model includes: the basic principle of absorption spectrum measurement, when a beam of light with a continuous wavelength passes through a substance, certain components in the beam will have Attenuated, when the light beam absorbed by the substance is analyzed by the spectrometer, the absorption spectrum of the substance can be obtained, and then the type, concentration, and temperature of the substance to be measured can be deduced according to the data in the absorption spectrum.

The above is only a preferred specific implementation of the utility model, which is based on the realization of the overall concept of the utility model, and the scope of protection of the utility model is not limited thereto, anyone familiar with the technical field Within the technical scope disclosed in the utility model, any changes or replacements that can be easily conceived by a skilled person shall be covered by the protection scope of the utility model. Therefore, the protection scope of the present utility model should be based on the protection scope of the claims.

Claims (5)

1. a kind of gas temperature detection means based on tunable diode laser absorption spectroscopy, it is characterised in that include：Transmitting Unit（11）, combustion field GAS ABSORPTION pool unit（12）, receiving unit（13）And central control processing unit（14）；Transmitter unit （11）Laser after modulation is sent into into optical fiber collimator and passes through combustion field GAS ABSORPTION pool unit to be measured（12）, by receiving unit （13）Light intensity change of the measurement after combustion field, finally by central control processing unit（14）Carry out data processing and measurement temperature The real-time display of degree.

2. the gas temperature detection means based on tunable diode laser absorption spectroscopy according to claim 1, it is special Levy and be, transmitter unit（11）Distributed Feedback Laser, laser controller, current controller and the temperature controller encapsulated using butterfly.

3. the gas temperature detection means based on tunable diode laser absorption spectroscopy according to claim 1, it is special Levy and be, combustion field GAS ABSORPTION pool unit（12）Using five reflection cavity gas absorption cells of three area combustion furnace 30cm light paths come real Existing gas uniform high temperature environment.

4. the gas temperature detection means based on tunable diode laser absorption spectroscopy according to claim 1, it is special Levy and be, receiving unit（13）Using VIGO mercury-cadmium tellurid detector modules, data collecting card.

5. the gas temperature detection means based on tunable diode laser absorption spectroscopy according to claim 1, it is special Levy and be, central control processing unit（14）LabVIEW software programmings are utilized using embedded system.