Simulation of Effects Off Service Closed Feedwater Heater on Steam Power Plant Performance Using Cycle Tempo 5.0

Abstract Steam power plant needs three important things in its operation, they are safety, reliability, and efficiency. Steam power plant efficiency can be elevated by installing regenerative feedwater heater. Feedwater heater is used to increase the temperature of water needed for combustion process in the boiler, therefore minimizing the fuel used in boiler. Case study is taken from PT. PJB UP Muara Karang Steam Power Plant unit 4 and 5. HPH 4 off service in August 2018 caused thermal efficiency drop about 1.86 % from the previous month. The same case was found in January 2019, in which HPH F off service caused 0.68 % from the previous month. This study’s aim is to find out the effect of off service closed feedwater heater to steam power plant performance using Cycle Tempo 5.0. Steam power plant unit 5 with 172 MW load is modelled on Cycle Tempo. Validation is done by comparing some parameter of simulation result to performance test result with 5% error tolerance. Few variation off service feedwater heater conditions are done by regulating valve for line bypass in order to set feedwater flow into tubes as well as drain flow. NPHR analysis is done by gathering net power and heat needed in boiler for each variation. The result obtained from this study shows that off service feedwater heater cause NPHR enhancement. The highest NPHR increase is achieved when HPH F is on off service condition, with value about 30.58 kCal/kWh. Off service HPH has bigger effect on NPHR increase than LPH on the same condition. Steam power plant efficiency increase continuously with the greater amount of operating feedwater heater. 3 LPH and 2 HPH usage on steam power plant with 172 MW load is assessed as adequate efficient, with all feedwater heater operating at 33.39 %.