Riken Keiki Co., Ltd.

Kenichi Kojima

Tomoo Ishiguro

A composition analysis apparatus for analyzing a composition of a gas includes: a first measurement part measuring concentrations of gases included in a gas to be analyzed; a part calculating converted calorific values, the part including a second measurement part measuring a refractive index of the gas and a speed of a sound propagating through the gas and calculating a converted calorific value of the gas for the refractive index and the sound speed; a part calculating a base miscellaneous gas total error calorific value, the part calculating, based on the converted calorific values, a base error calorific value of an error calorific value attributable to miscellaneous gases included in the gas; and a part calculating a concentration of a first gas not to be measured, the part calculating the concentration of the first gas based on the concentrations of the measured gases and the base error calorific value.

Composition analysis apparatus and composition analysis method

It is an object of the present invention to provide a calorific value measuring device and a calorific value measuring method which enable highly reliable measurement of the calorific value of a by-product gas produced in a steelmaking process. In the present invention, with a by-product gas produced in a steelmaking process being employed as an object gas of which calorific value is to be measured, the refractive index and the sonic speed of the by-product gas are measured so as to compute a refractive index equivalent calorific value Qfrom the value of the refractive index as well as a sonic speed equivalent calorific value Qfrom the value of the sonic speed. On the basis of the concentration Xof carbon monoxide gas contained in the by-product gas, an error calorific value Qis computed by Equation (1) below using a value selected within a range of &#x2212;0.08 to &#x2212;0.03 as a calorific value equivalent coefficient &#x3b6;. On the basis of the refractive index equivalent calorific value Q, the sonic speed equivalent calorific value Qand the error calorific value Qwhich have been computed, the calorific value Q of the by-product gas is determined by Equation (2) below using a value selected within a range of 1.1 to 4.2 as a correction factor &#x3b1;. 

Calorific value measuring device and calorific value measuring method

The present invention has as its object the provision of a methane number calculation method that allows for readily acquiring a methane number of a natural gas, which is a sample gas to be measured, with acceptable reliability irrespective of toe gas composition, and as another object the provision of a methane number measurement device that is capable of monitoring the fuel property of a natural gas to be used as a fuel gas. The present invention includes: acquiring in advance a particular relational expression between the methane number and the basic calorific value of a plurality of types of reference gases, each formed of a natural gas and each having a different methane number value; measuring the basic calorific value of a natural gas, which is a sample gas, as well as the concentration of the nitrogen gas and the concentration of the carbon dioxide gas, both gases being contained in the sample gas; and calculating the methane number of the sample gas from the value of the basic calorific value of the sample gas, the value of the concentration of the nitrogen gas and the value of the concentration of the carbon dioxide gas, and the particular relational expression.

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Kasukabe, Japan

Kenichi Kojima