Design and testing of a novel air-cooled condenser for concentrated solar power plants

This paper aims at developing a novel air-cooled condenser for concentrated solar power plants. The condenser offers two significant advantages over the existing state of the art. Firstly, it can be installed in a modular format where pre-assembled condenser modules reduce installation costs. Secondly, instead of using large, fixed speed fans, smaller speed controlled fans are incorporated into the individual modules. This facility allows the operating point of the condenser to change in order to maximise plant efficiency at all times. Two condenser designs were proposed and full-scale prototype modules were manufactured for experimental testing. Both designs comprise a bank of circular finned tubes, coupled to an array of axial fans. The air-side thermal and aerodynamic characteristics were measured using a purpose built steady-state test facility. The measurements were correlated and compared well with existing correlations in the relevant literature, thus validating their use in thermodynamic models to predict power plant performance. A plant performance analysis was conducted combing the experimental measurements with output data from a 50MW concentrated solar power plant. This analysis firstly verified that the plant efficiency can be continually maximised by altering the condenser fan speed. Furthermore, under certain conditions plant output can be increased by over 10% by varying fan speed by 10% of the full speed. The study also provides a comparison of the two designs in terms of their effect on the plant output power. With respect to the thermodynamic efficiency and cost-efficiency, the four row condenser substantially outperforms the initial six row design. (C) 2013 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/)