An investigation on the improvement of the operation of Tenom Pangi HPP cooling power system

Abstract

Tenom Pangi Hydro Power Plant (HPP) is the most economical power plant for Sabah Electricity Sdn. Bhd. (SESB) and also the largest hydro station in Sabah, Malaysia with installed capacity of 3 units of 22 MW each. Due to degrading river water quality, the previous duplex strainers or filters with manual backwash of the plant cooling water system (CWS) were not practically efficient to remove the accumulated trash load. The cause of the repeatable failure from the substituted auto-backwash strainers was thoroughly investigated, and it was found that the failure was due to the trapped trash and/or the sediment trapped in the autobackwash filters which ultimately clogged the filter discharge. Several technical solutions were proposed to rectify the problem, but the open canal with auto-strainer system was the optimum solution. The canal solution was selected base on the system reliability, cost benefit, and future water quality of Padas River. Analytical and CFD solution using commercial CFD software were used to design the system. The open canal with auto-strainer system was installed and it was found that a significant amount of sediment and trash have been separated from the river water. This dramatically improves the operational reliability of the station cooling water system while maintains sufficient water flow rate and pressures.