On-Line Measurement System for Profiling Coal Quality to Power Plant Combustion

Harrison R. Cooper

For coal-fired power plants, fuel is the major variable operating expense, and efficiency of converting coal to kilowatts is becoming a focus of cost savings as power industries enter a new era of managing economics. Mine mouth (direct supply) generating plants are particularly at risk for efficiency fluctuations. A minimum level of blending toward provision of controlled BTU input is an approach, but costly blending must ultimately be balanced against capability to adjust coal flow and combustion box conditions to actual coal quality factors. Executing combustion control requires effective means of real-time coal measurement.

Technology for automatic and immediate measurement of higher heating value, moisture, and ash has been intro- duced based on pulsed magnetic resonance. The MR analysis technique digitizes hydrogen "free induction decay" data from coal samples to individually determine hydrogen of hydrocarbons and moisture. Ash is measured by indirect correlation. Measurement time is one minute or less after a coal sample is introduced to the analyzer.

A demonstration of the MR real-time analysis technique is provided by frequent (one-hour intervals or less) pulverizer feed samples scanned at a western mine-mouth power station. Profiles of sequential measurements illustrate coal quality variations derived by the tests.

AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California