Design and Evaluation of Potential Cooling Cycles for the Reduction of Water Use in Thermoelectric Power Plants
MetadataShow full item record
Publisher:The Ohio State University
Series/Report no.:The Ohio State University. Department of Mechanical and Aerospace Engineering Honors Theses; 2017
In the U.S., water for thermoelectric power plant cooling constitutes 40% of all freshwater withdrawal and 4% of all freshwater consumption. There are two main kinds of power plant cooling systems, once-through and recirculating, but environmental issues arise from both types, including excessive water consumption and ecological damage from high temperature return water. The purpose of this study is to identify effective while environmentally safe ways to reduce water use at power plants and determine the water savings and potential cost savings resulting from these methods. The strategy to reduce cooling water use that was employed in this study was to lower the temperature of the cooling water at either the inlet or outlet of the working steam condenser. This would allow for a higher temperature differential for the cooling water over the condenser, which, for the same cooling load, would mean a lower water flow rate is required. To achieve this, multiple refrigeration cycles were designed within constraints based on environmental concerns and maximum energy inputs. These cycles were then analyzed for the two types of cooling systems and four different regions in the United States. The most beneficial refrigeration cycle was chosen for each region, and the available cooling from the refrigeration cycles was used to determine water savings for each situation. The most effective refrigeration cycle offers savings of around 3% of the initial flow rate, which can correspond to around 4 billion gallons of water withdrawal savings per year for once-through systems and around 80 million gallons of consumption savings for recirculating systems. This could correspond to millions of dollars of savings per year at a single plant, and this will only increase as demand for water increases and supply continues to decrease. The findings from this research will identify the types of cooling systems that will be beneficial for different regions and power plant types, and can be used to further develop these systems at a larger scale, along with identifying other water saving strategies that merit more research.
Academic Major: Mechanical Engineering
Items in Knowledge Bank are protected by copyright, with all rights reserved, unless otherwise indicated.