PENGARUH PERUBAHAN TERMINAL TEMPERATUR DIFFERENCE (TTD) DAN DARIN COOLER (DCA) FEED WATER HEATER TERHADAP PERFORMA PLTU MENGGUNAKAN SIMULASI CYCLE TEMPO 5.1

Abstract

Feedwater heater (FWH) performance can be monitored periodically by reviewing the terminal temperature difference (TTD) and drain cooler approach (DCA) values. Monitoring this value by comparing the actual condition and the value resulting from commissioning. The lower the TTD and DCA values, the better the work effectiveness of FWH. In general, the TTD value ranges between 2.8 ºC to -2.8 ºC while the DCA is between 5.6 ºC to 1 ºC. In this research, modeling was carried out using a cycle tempo simulation of the Molotabu Gorontalo 2 x 12.5 MW PLTU generator to review how much influence the changes in TTD and DCA values ​​of the low feedwater and hight feedwater heaters have. The variations used respectively are TTD with a value (°C) of 2.8; 2; 0; -2 and -2.8 while DCA) respectively (°C) 5.6; 5; 4 ; 3; 2 and 1. The aim of the research is to find out how heat transfer occurs in the two FWHs resulting from modeling and its effect on the Net Plant Hear Rate (NPHR) and the efficiency of the PLTU system. Based on the simulation results obtained using variations of TTD and DCA on the low feedwater heater, the heat transfer in the heater is 144830 kW and 1761.48 kW. Meanwhile, the high feedwater heater produces heat transfer to the heater of 3400.13 kW and 3795.24 kW. As for energy balance, the lowest gross power was 26.32% and the highest was 26.5%. Based on the analysis results, the highest NPHR value was 21634.24 kg/kJ/h, getting an efficiency value of 25.87%. while the lowest NPHR is 25130.43 kg/kJ/h low NPHR produces the highest efficiency of 26%.