Optimisation Studies for Ohaki Geothermal Power Station

Abstract

Ohaki Geothermal Power Station, to be located some 20 km north of the existing Geothermal Station, will consist of two 40-45 condensing turbo-generators operating in conjunction with two 1 1 back-pressure turbines being transferred from Wairakei. Direct contact barometric draft cooling tower. Incondensible gas content of the steam will be fifteen times greater than at Wairakei and will necessitate large centrifugal exhausters. An optimisation programme has been developed to determine the response of the total turbine, condenser, gas exhauster, cooling tower, circulating pump system over the full range of climatic conditions. The programme has been used to establish design data for the cooling tower, turbo generators, condensers, gas exhausters and the main cooling water pumps. Other uses include determination of the value of using variable flow cooling water pumps and the value of changes in condenser and intercooler design parameters.