Abstract
Industrial boilers are critical mechanical systems widely used across various industries for heating water to elevate temperatures. This process facilitates the generation of steam, often employed in power plants, or provides high-temperature water for applications such as paint plants in the automotive industry. Boiler efficiency is paramount due to the significant production demands they must meet. However, heat and energy losses are inevitable and adversely impact their performance. This dissertation identifies and evaluates these heat losses and proposes mitigation strategies to enhance boiler efficiency.
The study investigates a boiler operating at Sasol Synfuels Power Station, which utilizes pulverized coal as fuel. Key contributors to heat losses include dry flue gases, moisture formation from hydrogen, radiation, convection, and unburned components such as fly ash and bottom ash. Over a 30-day analysis period, efficiency decreased from 91.05% to 78.33% with pulverized coal and from 90.75% to 83.54% with raw coal. This reduction was attributed to factors such as variations in gross calorific value, excess air levels, and moisture content.
Data collected at the plant in Secunda, Mpumalanga, South Africa, was analyzed using established equations. The findings highlight the impact of fuel properties and operating conditions on heat losses and overall efficiency. To mitigate these losses, strategies such as the installation of an air preheater to reduce flue gas temperatures and optimize the gross calorific value of fuel are recommended. Effective maintenance practices and mathematical modeling of heat losses can significantly enhance boiler efficiency, contributing to improved performance of the power generation system.
Minimizing heat losses ensures the boiler operates closer to an ideal system, utilizing efficient fuel and maintaining optimal conditions.