The report presents a methodology for optimizing design specifications of large, mechanical-draft, dry cooling systems. A multivariate, nonlinear, constrained optimization technique searches for the combination of design variables to determine the cooling system with the lowest annual cost. Rigorous formulations are used in calculating heat transfer and fluid flow. All thermal and mechanical design variables of the cooling system components are analyzed. Thermal variables include ambient air temperature, condenser terminal temperature difference, cooling range, and initial temperature difference. Module variables are tube length, number of rows and passes, and fan power. The methodology employs a computer program with major computational blocks written as subroutines. The program optimizes dry towers with either surface condensers or direct-contact jet condensers. Results of detailed parametric and sensitivity analyses are presented. The relationships of design variables, major components, site variables, and utility economic factors to incremental annual costs are examined for 1000 MWe fossil fuel plants at five U.S. sites. Results, presented in both graphs and tables, show that all design variables affect cooling system cost.

Contract no. 68-03-2215, program element no EHE624A. July 1978. Includes bibliographical references.