INFLUENCE OF USING LOW RANK COAL DUE TO BOILER EFFICIENCY OF SURALAYA COAL FIRED POWER PLANT UNIT 3

• Main Author: TRI F (NIM : 23108326); Tim Pembimbing : Dr. Ir. Toto Hardianto; Prof. Dr. Ir. Aryadi Suwon, ANDIEK
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/14864
• Institution: Institut Teknologi Bandung

Once of coal fired power plant performance mostly related with fuel characteristic. Suralaya coal fired power plant was designed using coal type sub-bituminous B as per ASTM Standard with caloic value is about 5,100 kcal/kg (as received) which has been supplied from Bukit Asam. But decreasing design coal supply is began in early of 2007, so shortage quantity is completed by low rank coal sub-bituminous C with caloric value 4,200 ~ 4,800 kcal/kg (as received). Using its low rank coal can be impacted to decrease boiler efficiency. <br /> <br /> <br /> Boiler efficiency calculation for Suralaya Unit 3 is developed using ASME PTC 4.1- 1964 standard. This standard have compatibility with supporting equipments. Whereas <br /> <br /> <br /> this tesis choose heat loss methode in those standard based on high heating value (HHV) to calculate gross boiler efficiency. From calculation, we can gross boiler efficiency about 87.4 % if use coal caloric value 5,151 kcal/kg (as fired). While use coal caloric value 4,280 kcal/kg (as fired) can get gross boiler efficiency about 84.0 %. So, the gross boiler efficiency decreasing about <br /> <br /> <br /> 3.4 %. Major factor of decreasing boiler efficiency is increasing moisture content in low rank coal. This moisture can increase heat absorption by moisture content in coal <br /> <br /> <br /> and also increase flue gas exit temperature of air heater. <br /> <br /> <br /> Some eforts can be done to increase boiler efficiency during use low rank coal like coal blending or coal drying before entry to boiler bunker. Writer predicting, decreasing surface moisture on coal surface with caloric value 4,273 kcal/kg (as received) can increase gross boiler efficiency from 84.0 % up to 87.1 % near with gross efficiency boiler using design coal with caloric value 5,151 kcal/kg (as received).