Development of a ground-coupled heat pump system simulation model using g-function approximation for a residential code-compliant tool

摘要

This study develops a ground-coupled heat pump (GCHP) simulation model for a residential code- compliant simulation tool. To achieve this, this study proposed the g-function approximation method using polynomial curve-fitting equations. In addition, the residential air-source heat pump (ASHP) simulation model (i.e., RESYS in DOE-2.1e) was modified to include a vertical ground heat exchanger module. To check validity of the new GCHP system model, this study compared the simulation results against the results from the other simulation tools. The results between the programs showed good agreement within 5.3％ differences for the annual total site energy use. Using the developed GCHP simulation model, the energy savings for a code-compliant residential building in Houston and Dalas were evaluated in comparison with the ASHP system, and the resultant annual energy savings were about 10％ to 15％ in the total site energy use and 30％ to 40％ in the heating plus cooling energy use.