Analysis of The Impact of Sedimentation Dredging on Headloss Repair & Operating Patterns of CWP (Circulating Water Pump) PLTU Lontar

The PLTU Lontar Extension Project (1x315 MW) is a national strategic project being built by PT. PLN (Persero). stage currently in the commissioning phase but hampered indications of sedimentation occurring at intake mouth area ??the Circulating Water System. There are due to high head loss between and upstream box culvert which has an impact on inhibiting flow seawater entering canal. existence obstacles sea water resulted insufficient cooling for needs 8 Pump (CWP) pumps, namely 6 CWP 3 units Existing 2 1 unit Extension. bed level side according basic design -4.5 m after survey (bathymetry, topography, floating sediment, currents, tides) actual condition depth -0.9 m. As one solution, dredging method taken restore conditions design. To find out if there improvement headloss, simulation carried using Hec-ras 2D application. After simulation, it was found that headloss/compression significantly improved hydraulic with rate 42 m3/s pumps running, before 30 cm 18 also flowrate 60 running. , 55 21 right position culvert. This headloss predicted propagate downstream forebay pump pits, so this simulated increase performance circulating CWPs can operate together continuously.