ABSTRACT
This chapter shows how Gilkes, as a manufacturer of water turbines for small hydroelectric schemes, solves the problem of producing a machine which is uniquely designed for each site but keeps the costs to a minimum by using a modular design concept. Turbines are selected and designed to suit the two basic parameters of a site: The effective head of water (pressure) and The flow of water available. Power available from water in a hydro-electric scheme is the product of head (pressure) and the rate of flow of water (discharge) through the turbine. For the purposes of illustrating the modular design concept, the author shall use the Gilkes Turgo Impulse Turbine. Deflectors are used to cut off or reduce the jet of water hitting the turbine runner. They serve two main functions: To control the speed of the turbine by regulating the flow of water onto the runner and To shutdown the turbine, usually in an emergency situation.
