Numerical and experimental study on spray cooling system design for cooling performance enhancement of natural draft dry cooling towers

Abstract

The depletion of total fossil fuels and the concern about the pollution caused by the combustion process motivate people to find clean, and sustainable energy sources. The inexhaustible solar energy offers a clean and climate-friendly energy source. Concentrating solar power (CSP) is the main technology to transform solar energy into electricity. Since most CSP plants are built in arid regions with abundant solar irradiation but limited water resources due to the dry climate, natural draft dry cooling tower (NDDCT) is a good choice to remove waste heat from the power generation process.The small water consumption and easy operation make NDDCT quite attractive in CSP plants.However, power plants experience a significant reduction in power generation in summers due to the deteriorated performance of NDDCT during high ambient temperature periods. To overcome this problem, spray cooling technology is developed to precool the inlet air for thermal performance enhancement of NDDCT under hot weather conditions.With the advantage of simplicity, low capital cost, ease of operation and maintenance, spray cooling system has been developed for NDDCT to improve its cooling efficiency by utilizing the evaporative cooling effect of sprayed water droplets. Although some preliminary studies have been made on spray cooling, most of them are focusing on conceptual design. the design and test of spray cooling system