Exergoeconomic comparison of wet and dry cooling technologies for the rankine cycle of a solar thermal power plant

Abstract

This work describes and analyses the Rankine cycle of tne 50 MW parabolic trough power plant Andasol 1 in the Spanish region of Andalusia, a prime example of the use solar energy for electricity generation. By means of an exergoeconomic analysi, all components of the thermal plant are considered individually. Thermodynamic inefficienies withih the system are located, quantified and economically evaluated.Generally, various wet and dry cooling methods come into consideration for the re-cooling of the steam. Andasol 1 uses the more effective wet cooling method, because in the viccinity sufficient water reserves are available. In this work, the water-cooed system is replaced by an air-coole condenser and the two variants are compared under exergoeconomics aspects. Also the impact of a constrution of Andasol 1 in a hotter and drier climate than the norttherm Sahara is simulated. The analys shows that within the air-cooled condenser much more exergy is destroyed than within the wet cooling system. Thereby the achievable condenser pressure in one of the critical process parameters. The electricity production cost in the zone around the Andalucian Granada are 15.27 ct/Wh when using wet cooling and 16.08 ct/kWh in case of dry cooling. In the Sahara, these costs increase to 15.52 ct/kWh for wet cooling and 17.52 ct/kWh for dry cooling technology.