Author(s): Pratik Man Singh Pradhan; Pabitra Narayan Joshi; Meg Bahadur Biswakarma; Haakon Stole
Linked Author(s):
Keywords: Thermodynamic efficiency; Sediment; Concentration; Turbine; Run-of-river power plant; Himalayan River; Particle size distribution
Abstract: Sediment induced turbine wear is one of the major problems in the operation of run-of-river power plants built on Himalayan Rivers. The turbine wear results in heavy loss of revenue not only due to drop in turbine efficiency over the time but also repair-maintenance cost and shut down time during repair and maintenance. Jhimruk hydropower plant (JHP) in Nepal is an example of such a plant having 3 units of Francis turbines and 12 MW capacity operating since 1994. This paper describes the methodology and results of sediment and efficiency measurements carried out for one of the three turbines in JHP during a part of monsoon period of 2003. The result of sediment measurement shows that the turbine was exposed to total sediment load of 6,900 tons in the period 1 September to 11 November, 2003. The efficiency loss is found to be 4% at best efficiency point and 8% at 25% load in that period. The loss in efficiency is expected to be more than these figures if the measurement covers entire monsoon rather than a part only. This is because this study does not cover the peak of the monsoon months i. e. July and August and these months are expected to have much higher concentration of sediment in the flows. Some more such researches can help recommend optimum sediment handling measures for run-of-river power plants on Himalayan Rivers.
Year: 2004