Performance Mapping and Life-Cycle Cost Modeling for Heat Exchanger Geometry Optimization in Vapor Compression Chillers

Abstract

With the significance of chillers in end energy use and the environment, chiller manufacturers face different regulations around the globe and changes in consumer demands. In the product development phase, components are put together to meet the cooling capacity and efficiency. However, many configurations are possible to meet such system requirements. An optimization study of heat exchanger geometries within a given chiller configuration is proposed to enable the economic comparison between different configurations. The heat exchangers will be optimized to meet the system requirements while minimizing the life cycle cost of the chiller. The resulting refrigerant cost and heat exchanger raw material cost can be used to compare different chiller configurations to one another. Several topics in chiller modeling will be addressed to conduct heat exchanger optimization within a chiller configuration. A universal method to empirically map heat exchangers will be developed to relieve the computational time associated with nested iterations. Using the mapping method, the iterative finite control volume heat exchanger model will be mapped to a non-iterative empirical map of the heat exchanger. A shell and tube heat exchanger model will be used to demonstrate the universal heat exchanger mapping method. An optimization framework is then formulated and demonstrated with a set of case studies. Lastly, modeling the chiller system and the chiller optimizer will be developed into an easy-to-use software that can carry out heat exchanger optimization study in a chiller configuration and inter-configuration cost comparison of chillers.