JPS60205363A - Method for determining quantitatively carbon dioxide contained in combustible gas - Google Patents

Abstract

PURPOSE:To measure quickly the content of the carbon dioxide mixed with a combustible gas by using an interferometer gas detector and combustible gas detector. CONSTITUTION:A gaseous mixture composed of a combustible gas and carbon dioxide is introduced through gas introducing ports 23, 27 into respective gas detectors. The gas from the port 23 is converted to quantity of electricity by an interferometer gas detector 24 and is displayed or recorded by a signal regulator 25 and an output transducer 26. The value is of the gaseous mixture composed of the combustible gas and carbon dioxide but the display is corrected by the content of methane. On the other hand, the gas from the port 27 is converted to quantity of electricity by a combustible gas detector 28 and the amt. of the combustible gas is displayed or recorded by a signal regulator 29 and an output transducer 30. The electric signals corresponding to the contents of the gases from the regulators 25, 29 are taken into an operator 33 which operates 33 the content of the gas from the regulator 29 from the content of the gas from the regulator 25. If a coefft. is operated 34 with the value, the content of carbon dioxide is displayed and recorded on an output transducer 35 and is outputted 36 to the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses an interferometer-type gas 81 degree meter that operates on a mixed gas of flammable gas and carbon dioxide, and Flammable gas + active only for gas! 81 is installed once, and the content m of both concentration meters is
This value is multiplied by the correction coefficient used when measuring component gases other than those on which the interferometer type gas concentration scale is calibrated, and the content of carbon dioxide contained in the combustible gas is calculated. This relates to a method for determining m.

In blast furnaces, internal combustion engines, etc., a method of measuring the carbon dioxide content m is used to observe the state of the combustion reaction.

In addition, in coal mines, combustible gases, especially hydrocarbons such as methane and carbon oxide Gas is a powerful indicator, but
These gases are also generated when coal is crushed, so in order to identify spontaneous combustion and underground fires, it is necessary to separately confirm whether coal mining operations are occurring. In such cases, if the content of carbon dioxide generated during combustion can be added to the series of index gases, further improvement in accuracy can be expected.

However, currently, there are methods for measuring the carbon dioxide content, such as those that utilize differences in thermal conductivity, infrared absorption, and refractive index of gases, gas chronographs, probe tubes, and the like. Among these, drilling tools capable of performing automatic III-level measurements for underground use are limited. When carbon dioxide is contained in the mixed gas, a method that uses the difference in thermal conductivity or refractive index uses an absorbent and calculates the content from v1 measured before and after using the absorbent. However, when using an absorbent, in addition to the hassle of replacing it, there is a problem with the life of the absorbent.
It is not suitable for automatic measurement, especially for measurements in places where continuous monitoring is required. Particularly in coal mines, where it is used in flammable gas, various types of a,
Therefore, the actual situation is that installation is limited depending on construction, shape, power, and structure.

The present invention was made in view of the above circumstances, and its purpose is to facilitate gas measurement inside a coal mine. The aim is to provide a measurement method that simultaneously measures two component gases contained in coal mines and obtains the carbon dioxide content from each measurement value. The main purpose is to detect carbon dioxide contained in underground gas. Another object of the present invention is to provide a small gas response device that is capable of identifying a fire from among the gas components contained in combustion products when a fire occurs in a mine.

That is, the present invention detects all of the mixed gas of flammable gas and carbon dioxide using an interference type 1 gas detector, and detects only the combustible gas in the mixed gas of flammable gas and carbon dioxide. Detected by a detector and subtracted the gas content measured by the combustible gas detector from the gas content measured by the interferometer type gas detectorllJ
This relates to a gas detection method in which the content of carbon dioxide is obtained by multiplying this value by a coefficient determined by the gas to be measured adopted by the interferometer type gas detector.

The present invention utilizes two types of gas detectors with different measurement principles, and the interferometer type gas concentration meter shown in FIG. 1 will be explained.

Interferometric IL-type gas concentration meters measure gas content from the difference in refractive index of different Class 211 types.
- Consider the refractive index of a mixture of gas and vapor. Let the refractive indices of gases △ and B be na , nb ,
The refractive index of the mixed gas is 72/n, and the mixing ratio is △,
When B is 4 and 100-(2,4:'?l-) in percentage, the following relationship holds true.

For example, assume that X% of gas is mixed in the air.

If the refractive indexes of air and mixed gas are na and n, respectively, then the refractive index of this mixed gas, 71m, is 71aX72g.
is known and 77 m can be measured, then X can be calculated from equation (2).

The interference t1 type gas fIIi meter determines the content from the difference in the refractive index of gas and steam, so it is calibrated based on the relationship between the refractive index of air and methane, and the difference between air and carbon dioxide 5-carbon. It can also be measured. However, in this case, the gas concentration scale is based on the relationship between air and methane, so it must be corrected. That is, the refractive index of air/'2(2
, the refractive index ηm of methane, and the refractive index nI of carbon dioxide, the relationship between the gas concentration 81 and the indicated value X is as follows, where m is called the indicated index.

The true gas concentration is the indicated value X of the gas concentration meter multiplied by 1/i. When measuring air → carbon dioxide with a gas concentration meter calibrated according to the relationship between air → methane, the reading rate +11
= 1.0! It becomes i and is multiplied by 1/1.05.

Next, the combustible gas concentration meter shown in FIG. 2, in this case a catalytic combustion type gas concentration meter using the combustion method, will be explained.

In a gas detector using the combustion method, the change in electrical resistance caused by the combustion of the gas in the gas heating wire is proportional to the temperature caused by the combustion of the gas, so △q = a - △r = t -
tsx7c = z-a ・m -Q/C (given by 96-).

Here, ΔR: Change in electrical resistance due to combustion of gas in hot streak α: Temperature change in 1h air resistance of hot streak △T: Warm epigastric stomach due to combustion of gas Δ11: Heat generated by combustion of gas...C: Heat Capacity of C-Line Heat 11: Electricity Production of Gas Q: If a bridge circuit is constructed in which molecules of gas burn and heat, changes in gas concentration can be measured as changes in the deflection current of the bridge circuit. can. However, in this case, it is necessary to measure the relationship between the type of gas, the concentration of gas, and the deflection current of the bridge in advance.

The embodiment of the present invention will be described in detail with reference to FIG. 3. Reference numeral 23 denotes a gas inlet port for introducing sample gas into the interference type 1 gas detector;
24 is an interferometer type 1 gas detector, 25 is a signal conditioner that converts the gas detected by the interference type 11 gas detector into an electric layer and amplifies or linearizes it, and 26 is an output that displays and records the mixed gas content. It has been calibrated to display the methane content using the Quadran Ju 4J. 27 is a gas inlet for introducing sample gas into the combustible gas detector, 28 is a combustible gas detector, and 29 is a signal conditioner that converts the gas detected by the combustible gas detector into an electrical quantity and amplifies or linearizes it. , 30 is an output juicer that displays and records the combustible gas content, and is calibrated to display methane content. 31 is an external output terminal for mixed gas containing gas detected by an interferometer type 1 gas detector, 32 is an external output terminal for combustible gas content detected by a combustible gas detector, and 33 is an external output terminal for mixed gas content detected by an interferometer type gas detector. A computing unit that subtracts the combustible gas detected by the combustible gas detector including mixed gas mhs, 34 is 3
A calculator that multiplies the chain obtained in step 3 by a coefficient, 35 is an output transformer that displays and records "contains carbon dioxide."
3G is a carbon dioxide-containing external output terminal, 37 is an input power source, and 38 is an auxiliary power source.

That is, a mixed gas of combustible gas and carbon dioxide is introduced into each gas detector from the gas inlet 23.27. The gas from the inlet 23 is converted into an electrical quantity by the gas detector 24, and then sent to the signal conditioner 25 and the output transformer 26.
displayed or recorded by

This value is a mixture of flammable gas and carbon dioxide,
Display is calibrated for methane content. On the other hand, the gas from the gas inlet 27 is converted to electricity by the gas detector 28.
signal conditioner 29, output reducer 3
Flammable gas is indicated or recorded by 0. An electric signal corresponding to the gas content is taken in from the signal regulator 25, 29 to the computing unit 33, and the computing unit 33 subtracts the gas content from the signal regulator 29 from the gas content from the signal regulator 25. do. If this value is multiplied by the coefficient 1/1.059- obtained from equation (5) in the arithmetic unit 34, the output voltage is J-
The carbon dioxide content is displayed and recorded on the sensor 35 and outputted from the external output terminal 36.

The present invention provides a completely satisfactory and effective measuring method in terms of accuracy, which allows the content of carbon dioxide mixed in combustible gases to be determined rapidly using two types of gas detectors. do. This favorable result is useful for predicting the spontaneous combustion of coal or signs of underground fires in coal mines, for various areas after a disaster occurs, and can be used to check malfunction of various fire detectors, as well as for gas-sensitive fire detection methods. It can also be applied to industrial effects, especially contributing to the prevention of various disasters in coal mines.

Although a catalytic combustion type combustible gas detector has been described as an embodiment of the present invention, a combustible gas sensitive body made of a semiconductor or the like may also be used.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the configuration of the interference H1 type gas concentration meter, Fig. 2 is a block diagram showing the configuration of the combustible gas concentration meter,
FIG. 3 is a perspective view of a mortar 10 showing an embodiment of the present invention. 1...Light source lamp 2...Condensing lens 3...Parallel plane mirror 4...Gas chamber 5.5-...ll! Semi-gas chamber 6. Gas chamber to be measured 1.
- Main prism 8 - Optical path compensation 1 [9 - Objective lens 10 - Photoconductor 11 - Power supply 12 - Meter 13 - Fixed resistance 14 - Gas detection heating line 15 -
4J[He1 heat wire 16.17 ・・Fixed resistance 18.1
9...Variable resistance 20...Power supply 21...Meter 22
・・Fixed resistance 23・・Gas introduction IN 24・・・Product type 1 gas detector 25・・Signal conditioner 26・Output transduer 27
...Gas introduction [128...n1 firewood gas detector 29...
Signal conditioner 30・Output 1 ~ Lancer l -+J31.
32...External output terminal 33.34...Director 35
・Output power output terminal 3G・・External output terminal 37・
・Input power IQ38... Auxiliary power supply 11- Fig. 1〈- Fig. 2

Claims (1)

[Claims] (1) Determine the amount of carbon dioxide in a mixed gas containing flammable gas and carbon dioxide. In order to detect combustible gases, we install an interference type 1 gas detector for mixed gases containing flammable gases and carbon dioxide, and a combustible gas detector that is sensitive only to combustible gases. 1. A method for quantifying carbon dioxide content m, which comprises subtracting the content measured by a gas detector and multiplying this value by a coefficient based on a calibration scale.