DEVELOPMENT OF EFFICIENT PUMP AS TURBINE (PAT) SYSTEM FOR SHP STATION

Abstract

mall hydropower is a viable alternative for electricity generation in remote, hilly and isolated areas. For these decentralized small hydropower schemes, different turbines are used in the power plant. However, in the range of micro hydro power (upto 100kW) schemes, the conventional turbine may not be readily available. It is not economically viable to order specially designed turbine according to site specification due to non-availability of turbines for Micro and Pico hydro power plants. Hence it becomes uneconomical to tap the potential. To overcome this problem, readily available pumps can be used in turbine mode. These pumps are economical for the Micro and Pico hydro plants due to easily availability of wide range and also reduce the problem of special design and manufacturing skills for good performance. So the approach of using pump as turbine (PAT) can be implemented very effectively for small and micro hydro power schemes. The main problem associated with PAT in micro hydro is its low efficiency as compare to other conventional turbines .A lot of efforts were made by the researchers in order to improve the efficiency of the PAT, However there is no work carried out to improve the surface roughness and modify the outer edges using coating. So in present study a effort is made to improve the pump impeller outlet and surface roughness using coating in order to improve its efficiency and to maintain over a large duration of time to avoid erosion and cavitations etc. In present study an attempt has been made to compare the efficiency of a pump used in turbine mode by providing coating on the impeller. A CFD analysis has been carried out to identify the region of more pressure loss on the impeller. In order to compare the efficiency find the efficiency by software then, pump is first tested experimentally in turbine move. Then a suitable modification is done on the outer edge to smoothen the flow in the impeller. CFX software gives the result that we will easily find the erosion rate by using different coating materials