Authors

M. Munadi

Mechanical Engineering Department, Faculty of Engineering, Diponegoro University, Jl. Prof. H. Soedarto, SH, Tembalang-Semarang 50275, Indonesia

Mochammad Ariyanto

Mechanical Engineering Department, Faculty of Engineering, Diponegoro University, Jl. Prof. H. Soedarto, SH, Tembalang-Semarang 50275, Indonesia

Abstract

Electricity demand in Indonesia continues to increase in line with population growth, infrastructure development, and industrial sector growth. Power plants, including coal-fired power plants, remain the backbone of the national energy supply despite the ongoing transition to renewable energy. In coal-fired power plants, boilers play an important role as producers of high-pressure steam to drive turbines. Boiler efficiency is a key indicator of operational performance, where a decrease in efficiency results in increased fuel consumption, operational costs, and emissions. Therefore, monitoring and evaluating boiler efficiency is very important for optimizing the power generation system. This practical work report analyzes the performance of circulating fluidized bed boilers by calculating thermal efficiency based on actual operational data using the direct method. The direct method is the calculation of boiler efficiency by comparing the heat generated by steam to the heat from fuel. From the calculation results, an average efficiency value of 72% was obtained. The calculation results showed a decrease in boiler efficiency compared to design conditions. To identify the causative factors, Fault Tree Analysis (FTA) was used as a systematic identification method. Based on the observations, the decrease in efficiency was primarily caused by plugging at the coal feeder outlet, leaks in the drain valve, and damage to the air preheater (APH) tube due to chemical attack, which emphasizes the importance of preventive maintenance and ongoing performance evaluation to maintain the efficiency and reliability of the generating system.

Keywords

Boiler Efficiency Fault Tree Analysis Power Generations

Citation of this Article

M. Munadi, & Mochammad Ariyanto. (2025). Performance Analysis of Circulating Fluidized Bed Boilers in Steam Power Plants Using the Direct Method. International Current Journal of Engineering and Science (ICJES), 4(11), 20-26. Article DOI: https://doi.org/10.47001/ICJES/2025.411004

Licence Copyright (c) 2026 International Current Journal of Engineering and Science. This work is licensed under a Creative Commons Attribution Non Commercial 4.0 International Licence.

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