RU2466362C2 - Method of measuring spatial distribution gas temperature - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: disclosed is a method of measuring spatial distribution of temperature in a heated gas stream using a regular optical label method through controlled input of a silicon carbide multi-element probe into the analysed section of the gas stream. Detection of the signal bearing information on regular luminance contrast, generated by the silicon carbide multi-element probe using a photodetector array is carried out at the effective wavelength in the infrared range of the corresponding transmission window of the atmosphere (medium).

EFFECT: wider range of measuring gas temperature and reduced systematic error of the measurements.

1 dwg

Description

The invention relates to measuring technique, namely to brightness pyrometry, and can be used to measure the temperature distribution of gas flows.

A known method of measuring the spatial distribution of temperatures by placing at a controlled point many thermosensitive quartz piezoresonance sensors with different resonant frequencies. In this case, the desired temperature at controlled points is determined by the previously found temperature dependences of the resonant frequency of quartz piezoresonance sensors (see RU No. 2206878, G01K 7/00, 2003).

The disadvantages of this method are: a narrow range of measured temperatures, due to the extreme operational capabilities of quartz piezoresonance sensors and connecting wires; low functionality and measurement accuracy due to the large thermal inertia of the sensors used, the spread of parameters and degradation, as well as the lack of visualization; the complexity of the technical implementation of the method due to the use in the design of signal transmission lines, an alternating voltage source in the form of a multi-frequency signal generator.

Closest to the proposed invention is the prototype method of regular optical marks, which allows to obtain the spatial temperature distribution in the selected section of the heated gas stream by controlled introduction of a carbide-silicon multi-element probe into the studied section of the gas stream with radiating areas of a circular shape and working on the principle of indirect heating, registration photoreceiver matrix in the visible spectral range of wavelengths λ _e = 0,6 ... 0.72 microns to regular luma ntrast, which is created by emitting sites, and subsequent measurement (calculation) according to the well-known algorithm of brightness temperatures of emitting sites, the values of which are taken as the temperatures of the studied gas flow (see Seleznev B.I., Karachinov D.V., Karachinov V.A., Toricin SB Method of regular optical marks in the pyrometry of heated gas flows. // Optical Journal, 2006, v. 73, No. 5, pp. 69-70).

The disadvantage of this method is the narrow range of the measured gas flow temperatures, in particular the impossibility of measuring the spatial distribution of the gas temperature with absolute values less than 700 ° C due to the low brightness contrast of the emitting areas of the silicon carbide multi-element pyrometric probe, the value of which at the effective wavelength of optical radiation detection λ _e = 0.6 ... 0.72 μm is below the sensitivity threshold of the matrix photodetector.

The objective of the proposed technical solution is to expand the temperature range for measuring the spatial distribution of gas temperature in the temperature range of less than 700 ° C by changing the effective wavelength of registration of a regular photodetector array with a regular photodetector, which is created by the emitting areas of a multi-element pyrometer probe.

The technical result of the proposed solution is expressed in expanding the temperature range for measuring the spatial distribution of the gas temperature in the temperature range of less than 700 ° C due to the fact that the registration of the matrix photodetector regular brightness contrast, which create the emitting area of the multi-element pyrometric probe, is carried out at the effective wavelength of infrared (IR) the range of the corresponding window of transparency of the atmosphere (environment) (see Gossorg J. Infrared thermography. Fundamentals, technology, application s -. M .: Mir, 1988, 416).. In the infrared range, the emissivity of silicon carbide is much higher than in the visible range (see Radiative properties of solid materials. Handbook. / Ed. By A.I. Sheindlin. - M .: Energy, 1974, p. 377), therefore, at gas flow temperatures below 700 ° C, it is technically possible to register the luminance contrast of the emitting areas of a multi-element probe and then calculate the luminance (real) temperatures (see Poreev V.A., Poreev G.V. Experimental determination of the temperature range of a television pyrometer. // Optical cue journal. 2004, v. 71, No. 1. P.70). In addition, carrying out pyrometric measurements in the transparency windows of the atmosphere can significantly reduce the methodological error caused by the absorption of thermal radiation passing through the medium (see Light D.Ya. Optical methods for measuring true temperatures. - M .: Nauka, 1982, p. 33- 39).

To solve this problem, a method is proposed for measuring the spatial distribution of temperatures in a heated gas stream by the method of regular optical marks by controlled input of a carbide-silicon multi-element probe with circular radiating pads into the gas flow section under study, the numerical values of the brightness temperatures of which are taken as the temperatures of the gas stream under study and measured with using the well-known algorithm for the magnitude of their brightness contrast recorded by the matrix photodetector while registering the matrix photodetector of regular brightness contrast is carried out at the effective wavelength of the infrared (IR) range of the corresponding window transparency of the atmosphere (environment).

Figure 1 shows a device for implementing the method.

In the drawing and in the text, the following notation:

1 - section of the investigated gas flow;

2 - multi-element pyrometric probe;

3 - radiating pads;

4 - a device for introducing a pyrometric probe into a gas stream (positioner);

5 - video camera;

6 - input lens system;

7 - selective optical filter;

8 - matrix IR photodetector;

9 - communication channel;

10 - personal computer

11 - positioner controller.

The method is as follows.

A silicon carbide multi-element probe (2) is placed in the studied cross section of the heated gas stream (1) using a positioner system (4), (11), which is heated and radiates thermal energy in the infrared wavelength range due to heat exchange with the gas stream. The input lens system (6) and the selective optical filter (7) of the video camera (4) project regular brightness contrast (image) of the emitting areas (3) of the probe (2) at the effective wavelength in the selected atmospheric transparency window (8).

The signal from the matrix photodetector (8), proportional to the brightness of the emitting areas (3) of the probe (2), after conversion in the video camera (5) through the communication channel (9), enters a personal computer, where, in order to determine (calculate) the temperatures of the emitting areas (3) ) is processed according to the algorithm given in the prototype.

Thus, the present invention allows:

- expand the temperature range for measuring the spatial distribution of gas temperature;

- reduce the methodological error of measuring the spatial distribution of gas temperature;

- expand the scope of the method.

Claims (1)

A method for measuring the spatial distribution of gas temperature by the method of regular optical marks, including the controlled introduction of a silicon carbide multi-element probe with circular emitting pads into the gas flow section under study and measuring the signal from the photodetector matrix, which is proportional to the brightness of the emitting pads, which is processed according to the known algorithm to the values of brightness temperatures radiating sites, and which are taken as the temperature of the investigated gas flow, characterized in that registration matrix photodetector signal carrying information about the regular luminance contrast created silicon carbide multi-element probe, is carried out in an effective wavelength infrared (IR) range corresponding window transparency atmosphere (gauge).