Modelling of an ORC Unit of a Geothermal Power Plant

Abstract

Geothermal energy is a very important part of New Zealands electricity supply system. The popularity of small-scale modular plants is noticeable in the new fields of Mokai and Rotokawa. The imported modular units are economical in design, construction and commissioning. However, the design of such plants could be improved by appropriate modelling and simulation. Simulation assists decision making by predicting plant performance even before construction. Engineers and scientists should concentrate on analysis involving modelling and simulation to ensure optimum utilization of geothermal resources. Unfortunately, most of the common commercial software can not be used readily to model geothermal power plant, specifically plants powered by low temperature resources. In this paper steady state model of an Organic Rankine Cycle (ORC) unit of Mokai 1 geothermal power plant has been presented in brief. Input parameters along with the results of simulation are also provided. These models are generic and can be applied to similar combined cycle geothermal power plants with simple adaptation.