Modeling, Simulation and Optimization of Ground Source Heat Pump Systems

Abstract

This study aims at developing and using procedures for modeling, simulating and optimizing ground source heat pump systems used both in commercial and residential applications. The accurate prediction of performance for a GSHP system is not possible without taking into account the variation in thermophysical properties caused by using an antifreeze mixture instead of water. Modeling of thermophysical properties of aqueous mixtures of propylene and ethylene glycol and methyl and ethyl alcohol used as antifreeze mixtures was carried out. The thermophysical properties modeled are thermal conductivity, specific heat capacity, viscosity, and density. The results of the models were compared to models found in literature and the best model for each property was chosen. A visual tool was developed for running multiyear simulations in HVACSIM+. Models for GSHP system components were developed or modified for use in HVACSIM+. Modeling technique in HVACSIM+ for fluid flow networks was improved. A detailed simulation of a residential GSHP system with antifreeze mixtures was developed in HVACSIM+. Life cycle cost analysis was carried out. Optimization of the GSHP system design using GenOpt coupled with HVACSIM+ was developed. Hybrid ground source heat pump (HGSHP) system is a variation of the GSHP system used in cooling-dominated commercial buildings. Simulation methodology was applied to predict the performance of HGSHP systems with pavement heating system as the supplemental heat rejecter. Life cycle cost analysis was carried out.