Study on correlation between overtemperature of 1 030 MW unit boiler and low-moisture Australian coal

Abstract

Heating surface overtemperature often occurs in a 1 030 MW ultra-supercritical boiler unit that uses blended low-moisture Australian coal. Through a comparison test of blended coal burning， the paper concludes that there is no evident correlation between heating surface overtemperature and the burning of low-moisture Australian coal. Besides， batches of coal samples are comparatively tested and analyzed. The results show that the ignition temperature of low-moisture Australian coal is similar to that of high-quality blended coal， while the burnout temperature of the former is higher； the burning processes of the two kinds of coals are about the same. The boiler tests and laboratory tests show that the grinding characteristics of low-moisture Australian coal and high-quality blended coal are similar， and the former is slightly easier to grind. The analysis results of multiple batches of coal samples exclude the contingency of the coal in the boiler tests. Therefore， here comes to a conclusion that low-moisture Australian coal may aggravate the heating surface overtemperature of the boiler， but it is not the major cause of overtemperature.

Keywords

• ultra-supercritical boiler
• low-moisture australian coal
• thermogravimetric analysis
• combustion characteristics
• grindability
• heating surface overtemperature