Exergy and Energy Analysis of a Dry Steam Power Plant with Heller Condenser

Year 2014, Volume: 17 Issue: 1, 7 - 13, 01.02.2014

Duccio Tempesti , Giampaolo Manfrida , Luca Madiai

https://doi.org/10.5541/ijot.76921

Cited By: 1

Abstract

Geothermal power plants are widely used in Larderello region, Tuscany, due to its favourable geological characteristics. The geothermal fluid available at Larderello can be considered as a dry steam, since it contains about 95% of steam at relatively high temperature (200°C), and about 5% of non-condensable gases, mainly carbon dioxide. Due to its thermodynamic properties, the geothermal fluid is currently used in a Dry Steam power plant, where it is directly expanded in turbine. In this paper, some modifications to the structure of the plant are proposed and the plant is modelled using the software EES®. In the model, the geo-fluid flow is ideally separated in two flows, respectively water vapour flow and carbon dioxide flow, treating separately the expansion and the compression processes. Energy and exergy analysis are performed, and the results show a good agreement with the results presented in the literature, where the geo-fluid is modelled as a single flow. Since the water flow rate for the condensing process is significant, the possibility of recovering work through a Heller system is considered. The results show that 85% of the power required for the pumping of the condensing water can be provided by this Heller system

Keywords

Dry steam power plant, Geothermal energy, Exergy analysis, Heller condenser

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