Numerical Study of the Generator Lubricant Cooler Air-Side Flow to Increase the Reliability of GTG#1.3 PLTGU Muara Karang

Abstract

AbstractGenerator lubricant cooling system in gas turbine 1.3 by flowing lubricant in the tube and blowing air from the outside of the tube. The lubricant cooling device is called an air-cooled heat exchanger (ACHE) which has been operating for 9 years. ACHE has experienced a decrease in reliability because it causes the unit to trip 5 times, trips to ACHE occur when the ACHE exit lubricant temperature is more than 320 K. Based on analysis using a fishbone diagram, the cause comes from the failure of fan operation. The purposes of the study are (i) to investigate the cooling capacity of Air-Cooled Heat Exchanger for GTG#1.3 generator lubricant existing conditions, (ii) to determine the effect of the modification of the number of fans operating on cooling capacity, outlet pressure and temperature outlet lubricants with parallel and series arrangement of Air-Cooled Heat Exchanger Generator Lubricant GTG#1.3, and (iii) to investigate the optimal operation pattern of the GTG#1.3 Generator Lubricant Air-Cooled Heat Exchanger. This research was conducted by modeling and simulating ACHE using Computational Fluid Dynamic (CFD) software. The simulation was validated using actual operational data. The results showed that the operation of the ACHE series with 4 fans had the highest cooling capacity of 247.57 kW so that the ACHE outlet lubricant temperature was 312.02 K. Therefore, to obtain reliability and optimal operation, the ACHE series operating model with 4 fans were selected.KeywordsAir-cooled heat exchanger (ACHE)Cooling capacityComputational fluid dynamic (CFD)