Method for controlling nox concentration in exhaust gas in combustion facility using pulverized coal

Patent metadata

Field	Value
Publication number	US-2017029328-A1
Application number	US-201615294113-A
Country	US
Kind code	A1
Filing date	Oct 14, 2016
Priority date	Feb 25, 2011
Publication date	Feb 2, 2017
Grant date	—

Abstract

A method for controlling an NOx concentration in an exhaust gas in a combustion facility by: measuring a reaction velocity k i of each of a plurality of chars, each corresponding to a plurality of types of pulverized coals; determining a relationship between the NOx concentration in the exhaust gas and the reaction velocity k i for each of the chars; (iii) blending the plurality of the types of the pulverized coal, wherein a blending ratio of the plurality of the types of the pulverized coal is determined by using, as an index, a reaction velocity k blend of the char of the blended pulverized coal, which corresponds to a target NOx concentration or below, on the basis of the relationship; and supplying the blended pulverized coal to the combustion facility as the fuel of the combustion facility.

First claim

1 . A method for controlling an NOx concentration in an exhaust gas in a combustion facility that uses a pulverized coal as a fuel, comprising, in the following order:
measuring a reaction velocity of each of a plurality of chars represented by k i and corresponding to a plurality of types of pulverized coals; determining a relationship between the NOx concentration in the exhaust gas and the reaction velocity k i for the each of the chars in the plurality of chars; blending the plurality of the types of the pulverized coal, to obtain a blended pulverized coal, wherein a blending ratio of the plurality of the types of the pulverized coal is determined by using, as an index, a reaction velocity of the char of the blended pulverized coal, which is represented by k blend and which corresponds to a target NOx concentration or below, on the basis of the relationship; and supplying the blended pulverized coal to the combustion facility as the fuel of the combustion facility.

2 - 3 (canceled)

4 . The method of claim 1 , wherein the reaction velocity of the each of the plurality of the chars, k i is determined by:
drawing a curve of a time change of weight loss for the each of the plurality of the types of the pulverized coals under the condition of a plurality of temperatures by using a thermal balance; and dividing inclination of a tangent of the curve by a measured partial pressure of oxygen, thereby determining the reaction velocity of the each of the plurality of the chars, k i at the respective temperatures.

Assignees

• Mitsubishi Materials Corp

Inventors

• Takayama Yoshinori
• Shima Hirokazu

Classifications

• F23N2221/10

  Analysing fuel properties, e.g. density, calorific · CPC title

• F23J2219/20

  Non-catalytic reduction devices · CPC title

• F23N5/003

  using detectors sensitive to combustion gas properties (F23N5/02, F23N5/18 - F23N5/26 take precedence) · CPC title

• F23N1/002

  using electronic means (F23N1/04 - F23N1/10 take precedence) · CPC title

• F23B1/00

  Combustion apparatus using only lump fuel · CPC title