Comparative Study of Control Strategies for Hybrid GSHP System in the Cooling Dominated Climate

TitleComparative Study of Control Strategies for Hybrid GSHP System in the Cooling Dominated Climate
Publication TypeJournal Article
Year of Publication2015
AuthorsShaojie Wang, Xiaobing Liu, Steve Gates
JournalEnergy and Buildings
Volume89
Pagination222 - 230
Date Published02/2015
ISSN03787788
KeywordsControl strategy, Entering fluid temperature, Heat rejection, Hybrid GSHP
Abstract

The ground source heat pump (GSHP) system is one of the most energy efficient HVAC technologies in the current market. However, the heat imbalance may degrade the ability of the ground loop heat exchanger (GLHX) to absorb or reject heat. The hybrid GSHP system, which combines a geothermal well field with a supplemental boiler or cooling tower, can balance the loads imposed on the ground loop heat exchangers to minimize its size while retaining superior energy efficiency. This paper presents a recent simulation-based study with an intention to compare multiple common control strategies used in hybrid GSHP systems, including fixed setpoint, outside air reset, load reset, and wetbulb reset. A small office in Oklahoma City conditioned by a hybrid GSHP system was simulated with the latest version of eQUEST 3.7. The simulation results reveal that the hybrid GSHP system has the excellent capability to meet the cooling and heating setpoints during the occupied hours, balance thermal loads on the ground loop, as well as improve the thermal comfort of the occupants with the reduced size well field.

DOI10.1016/j.enbuild.2014.12.054
Short TitleEnergy and Buildings