Design of Kaplan Turbine for Micro Hydro Application

Among all the renewable energy sources available, Micro Hydro Power is considered as the most promising source of energy. The hydraulic turbine being at the heart of a Micro Hydro Power Plant transforms the potential energy of water into mechanical energy in the form of rotation of shaft. Hydraulic turbines can be broadly classified into two categories according to action of water on moving blades. Hydro turbines classification based on action of water over runner are reaction turbines, Impulse turbines are high head turbines, operate at atmospheric pressure. At some of hydropower sites where head is relatively low and discharge is of medium or high order it becomes difficult to operate an impulse type turbine as sufficient speed may not be obtained to drive the end use machine at such sites. It is therefore that reaction turbines are suggested to be used and are considered high speed turbines under medium and low head. Kaplan turbine is one such reaction turbine. This paper focuses on generation of electricity using Micro Hydro Power Plants. The objective of this paper is to describe the designing of full scale Kaplan turbine that is able to generate 30 kW of electricity utilizing a head (2m) and 90 cusec flow rate. The design equations necessary for an efficient design have been incorporated. Design procedures of major components like Blade and Shaft, Guide Vane, Spiral Casing and Draft tube have been explained in detail.