Thermodynamic simulation of solar thermal power stations with liquid salt as heat transfer fluid

Kurzfassung

The Gemasolar solar power tower plant uses molten salt as heat transfer fluid and is therefore the first commercial project to apply this technology. Current research and development in line focusing systems is concentrated on transferring this proved salt technology to solar thermal power stations with parabolic trough collectors. This thesis identifies the economic performance of such a power station. To that end, a transient thermodynamic model is implemented into the commercial software tool EBSILON®Professional. The system behavior of the solar field is modeled in transient and pseudo transient mode for the power block. The model discretized one year into 10 minute intervals in order to calculate the levelized electric costs (LECs) for a 125 MWe reference plant with live steam parameters of 150 bar and 510 °C. The solar field layout is assumed to be a 2 H layout with 352collector loops, each consisting of four Eurotrough ET150 collectors (solar multiple of 2.233). The storage system is able to feed the steam generator for 10 hours. Three different years with different annual averaged direct normal irradiation averaged annual sums were compared. Given the 90% confidence interval (50% ± 45%), the LECs are between 0.117 and 0.190 €/kWhe (2659 kWh/m²/y), 0.136 and 0.221 €/kWhe (2300 kWh/m²/y), and 0.149 and 0.243 €/kWhe (2095 kWh/m²/y). The mode LECs are 0.149 €/kWhe, 0.172 €/kWhe, and 0.190 €/kWhe.