On-Line, Real Time Coal Measurement and Data Processing to Optimize Boiler Operations

Slagging and fouling of heat transfer surfaces in coal-fired electric utility boilers is a significant intractable problem which can greatly increase fuel use and emissions of CO2, NOx and other gaseous pollutants. Unfortunately, the boiler operator has only limited data on the nature and extent of the slagging and fouling tendencies of the coal used. While the operator can periodically analyze coal samples, the information is not always accurate, because the coal quality changes rapidly in real time. This off-line analysis is therefore of limited use because the information is outdated before it reaches the operator. Meanwhile, commercially-available on-line systems are expensive, are high maintenance, and do not provide direct data on slagging and fouling tendencies. This project will develop a system for the on-line real time measurement of coal properties that can be correlated to the slagging and fouling tendencies of the coal as it is being fed into the boiler. The approach involves the use of a laser induced breakdown spectroscopy instrument to measure the coal while on the conveyor belt. The system will accurately and continuously processes representative coal samples from the conveyor belt. Commercial Applications and other Benefits as described by the awardee: By enabling the boiler operator to take action to address potential slagging and fouling tendencies, power output should increase without additional fuel use. For a single generating unit, potential benefits include a net revenue increase to the utility of 14 million dollars per year, increased NOx credit revenue of 1.5 million dollars per year, reduced fuel use of 0.5 million dollars per year, and reduced boiler maintenance of 0.25 million dollars per year. Sales prospects for the proposed instrument are excellent due to its low cost, well under one year payback and low maintenance