Study of the design Method of an Efficient Ground Source Heat Pump Thermal Source System in a Cold Area

Abstract

The ground source heat pump (GSHP) system-an energy efficiency and environment friendly system-is becoming popular in many parts of China. However, an imbalance usually exists between the annual heat extracted from and rejected to the ground due to the different heating and cooling load of a building, which will consistently deteriorate the heat pump efficiency leading even to the breakdown of the heat pump. This paper brings forward a design method of adding supplemental heat rejection equipment, a cooling tower, in the system to solve the problem in a cold area. Taking an office building in Beijing as an example, the authors simulate the GSHP system with two different connection methods between the cooling tower and vertical buried-pipe heat exchangers (in series and in parallel) using TRNSYS simulation software, and put forward several design schemes that can ensure the whole system continually operates with high efficiency. This also makes it possible to perform a more detailed economic optimization of the GSHP-based system in the future.