Process modeling and operational analysis of thermal and Eeectrical energy production in Hellisheiði geothermal power plant using symmetry software

Abstract

In this thesis, a steady-state process model of the Hellisheiði geothermal power plant was developed and validated using Symmetry software. The model's performance was assessed by comparing its electrical output and thermal energy production with measured data from the power plant. The thermal energy aligned closely with the measured data, as the model incorporated all the key variables required to calculate the thermal energy. In contrast, the turbines' electrical output showed more significant discrepancies, reflecting the model's sensitivity to fluctuation in steam flow. A case study was conducted using the model to evaluate operational impacts. It examined the effect of bypassing high-pressure separation water to the heat exchangers, which reduced the electrical production of turbine unit 11 but allowed for increased hot water production for lower levels of bypassed water. The study quantified the trade-off between hot water production and electrical generation, highlighting the balance required for efficient plant operation.