Wet-Dry Cooling Alternatives for Geothermal Power Plants

Abstract

Most of the water produced from a steam-dominated geothermal reservoir is lost to the atmosphere through evaporation in the wet cooling towers used for waste heat disposal of power plants. In order to increase the amount of steam condensate available for reinjection, thus contributing to a greater extent to the recharge of the reservoir, major modifications of the heat rejection system are To evaluate the feasibility of such changes, a technical and economical analysis was carried for a 20 MW power plant, considering the following waste disposal systems: i) conventional wet cooling cycle; ii) dry cooling cycle; hybrid (wet-dry and dry-wet) cycles; iv) air cooled condenser. Heat rejection systems were evaluated on the basis of the unit cost of the additional condensate available for reinjection in the different configurations, with the currently used wet cooling system as the reference case.