The reduction of water consumption and use is emerging as a top priority for all types of thermoelectric power plants. In the United States, thermoelectric power production accounts for approximately 41% of freshwater withdrawals  and 3% of overall fresh water consumption.  On the basis of responses to a 2011 Electric Power Research Institute (EPRI) Request for Information , the feasibility study [4,5,6,7] of a Thermosyphon Cooler Hybrid System (TCHS) , proposed by Johnson Controls, was funded under EPRI’s Technology Innovation (TI) Water-Conservation Program. The objective of this project was to further develop the TCHS design concept for larger scale power plant applications and then perform a thorough technical and economic feasibility evaluation of the TSC Hybrid System and compare it to a variety of other competitive heat rejection systems.
The Thermosyphon Cooler Hybrid System reduces power plant cooling tower evaporative water loss by pre-cooling the condenser loop water through a dry cooling process employing an energy efficient, naturally recirculating refrigerant loop. This paper details the results of a detailed feasibility study that was conducted to compare the cost and performance of the TCHS to a number of other potential wet, dry, and hybrid thermoelectric power plant heat rejection systems operating under varying degrees of water constraint. Installed system cost estimates were developed for the base all wet cooling tower systems, TCHS’s of varying sizes, air-cooled condenser (ACC) hybrid systems of varying sizes, and all dry ACC systems.
Optimized all wet cooling tower and all dry ACC system configurations were developed for five different climatic locations. A comprehensive power plant simulation program that evaluated the fuel and water requirements of the power plants equipped with the different heat rejection systems across the weather conditions associated with all 8,760 hours of a typical meteorological year was developed and then an extensive array of simulations were run each location. The summary data were organized in a separate interactive dynamic system comparison summary program to allow users to gain further insight into the relationships between the various heat rejection systems and the sensitivity of the results to changes in key input assumptions.
This paper details the data presented in the interactive dynamic system comparison summary program. This program displays the key metrics of the Annual Net Cost of Power Production, the Annual Net Power Plant Profit, the Annual Operating Profit, and the Internal Rate of Return as a function of the Percent Annual Water Savings Required for the various heat rejection systems at each of the five studied climatic locations studied. Key results and conclusions are presented.