Performance analysis of range sensors for a real-time power plant coal level sensing system

A coal-fired power plant typically has silos, bunkers or stock piles in which the fuel is placed for storage purposes. Real-time feedback sensors are utilized to sense the coal height so data can be sent to downstream systems for further processing. These systems are required to accurately sense the height of coal within the bunker or stock pile. The range information is then fed in a real-time fashion to a control system. Inaccurate measurements can result in severe environmental and safety consequences. There are many types of ranging sensors available in the marketplace. The coal-fired power plant application is especially daunting due to the particularly harsh operating conditions and reliability requirements. This research project analyzes the performance of three types of range sensors: ultrasonic, radar and laser systems. These systems are currently operational at a plant located in the North East Texas area. The ultrasonic and radar sensors were part of legacy systems and the new laser sensor was integrated as a part of this study. The feedbacks signals from each sensor were recorded over time and compared to measured data. The laser sensor proved to be slightly more accurate than the others, but it has some drawbacks that were listed.