STUDI NUMERIK PENGARUH VARIASI DEBIT AIR TERHADAP KARAKTERISTIK DAN POTENSI KAVITASI PADA CONDENSATE MAKEUP PUMP

Condensate Makeup Pump (CMP) is a component of a steam power plant (PLTU) that requires optimal performance in its operations. One of the problems that often occurs with a pump is cavitation, which can cause damage to pump components and reduce efficiency. The discharge setting on the pump affects the flow, pressure, and velocity of the fluid in the system, which has the potential to cause cavitation. This study aims to analyze the effect of variations in water discharge on the characteristics and phenomena of cavitation in CMP using the Computational Fluid Dynamics (CFD) method with ANSYS Fluent software which consists of three main stages, namely: Pre-Processing, Processing, and Post- Processing. In the Pre-Processing stage, the creation of geometric and meshing models is carried out, the Processing stage includes solver and simulation settings, and the Post-Processing stage is to display the simulation results. This study focuses on fluid flow simulation in steady and incompressible conditions, with water as the working fluid at a temperature of 30°C. The simulation results show that along with the increase in capacity (Q) can reduce the head value, increase hydraulic power, shaft power and efficiency, at Q1 produces a value of H = 146.559m; WHP = 0.02kW; BHP = 39.54kW; and η = 0.05%. In condition Q2 produces a value of H = 144.077m; WHP = 6.10kW; BHP = 42.01kW and η = 14.52%. While Q3 produces a value of H = 136.585m; WHP = 37.22kW; BHP =
64.57kW; and η = 57.64%. The potential for the formation of cavitation vapor bubbles at each variation of water discharge occurs at a higher discharge, namely in condition Q3 which is observed from the value of the vapor volume fraction, where the value of the vapor volume fraction for Q1 is an average of 4%, Q2 = 0.5% and Q3 = 31%.
Keywords: Cavitation, CMP, CFD, ANSYS Fluent, PLTUs.