Analysis of Cooling Water Quality Improvement to Increase Cooling Tower Efficiency at Kamojang Geothermal Power Plant Unit 1

This study aims to overcome decreasing cooling tower efficiency at Geothermal Power Plant Kamojang Unit 1. Based on visual observations, there has been a tendency to blockage in the cooling tower's film fill and nozzle areas by mud, sulphate, scale, biofouling, moss, and other impurities. As a coolant, the water quality from the cold basin cooling tower has an essential role in determining the cooling tower performance. Preliminary test results show that cold water from the basin cooling tower contains high sulfate ions and bacteria than typical values. For this purpose, laboratory-scale demineralization with ion exchange is designed for sulfate ion treatment and sodium hypochlorite injection to reduce the bacterial height and validate the treatment, heat transfer, and cooling tower efficiency calculations before and after treatment. The results showed that with demineralization, sulfate levels from 224 ppm to < 5 ppm, and sodium hypochlorite injection, the optimum injection concentration was 2 ppm, from 19000 CFU/ml, it could reduce bacteria to 100CFU/ml. Finally, the improvement in cooling tower efficiency before and after treatment was 17.36%.