International Journal of Advancements in Mechanical and Aeronautical Engineering
Author(s) : AHMAD RASHIDI, AZMI AHMAD, HAMDAN HASSAN, MOOK TZENG LIM, NOOR AKMA WATIE MOHD NOOR
Thermal power plants have begun to shift their choice of fuel to cheaper coals such as lignite to reduce operating costs and to maintain fuel sustainability. However, the properties of the cheaper coals are highly fluctuating and pose challenges to the combustion process, leading to higher slagging or fouling propensities. The slagging process starts with the deposition of ash, which in turn originated from the complex process of soot formation in the flame area. Therefore, any abnormalities such as temperature distribution imbalances can be traced through monitoring techniques at the combustion state within the flame area. In this study, an imaging technique based on the visible wavelength regime was used to capture the temperature profiles of a 700 MW boiler near the burner area for different coal types and boiler operating conditions. The temperature profiles will serve as a point of reference for the plant personnel to determine the combustion state with respect to the boiler operating conditions. Results show that coal types with high ash content will deposit as slag on the heat transfer surfaces, hindering heat transfer, causing the flue gas temperatures to be higher. In addition, the temperature profiles show that that soot blowing activities reduce the differential temperature between the front and rear of the furnace, and can indeed improve the temperature distribution.