HYDRAULIC TRANSIENT ANALYSIS FOR SMALL HYDROPOWER

Abstract

The term hydraulic transient describes the effect of unsteady flow of fluid in pipeline. It is in the form of the rise and fall of pressure from the steady state condition. Therefore it is necessary to analyze hydraulic transient in pipeline for economical design and safety purpose. The governing equations for hydraulic transient are equation of continuity and momentum. Its control is of great importance in hydraulic installations for hydropower, water supply systems, and fluid transport etc. In the present study an attempt has been made to analyse hydraulic transient for hydropower pipeline (penstock) for different material. Nowadays other than conventional material i.e. steel, new material like poly vinyl chloride (PVC), glass reinforced fibre (GRP), concrete are being used in hydropower installation. A existing penstock of small hydropower plant of Rajwakti, in chamoli district, Uttarakhand ,India has been studied for the parameters by using HAMMER software available in IIT Roorkee. Transient caused due to various operation condition of turbine has been considered. It is observed from the analysis that the most vulnerable location for transient pressure is close to the turbine inlet. When the inlet valve of turbine closes suddenly the head rise is more rapid compared on the other operating condition. With the increase of closure time the maximum transient pressure decreases. Material having low modulus of elasticity shows better control on hydraulic transient pressure.