Study of Two Layers Horizontal Ground Heat Exchanger Performance Under a Different Operation Mode

Abstract

This paper presents the thermal performance of two-layer horizontal ground heat exchanger at various mass flow rates of water in cooling mode of alternating and continuous operations. Multi-layer composite pipe (MLC) was chosen as the ground heat exchanger tube material. Effects of mass flow rate variation and mode of operations on ground heat exchanger (GHE) performance are discussed. For this purpose, two-layer experimental GHE was fabricated. In alternative operation mode, heat exchange rate was always higher than continues operation mode in GHE. The outcomes achieved from this experimental investigation are utilized to measure the COP of the GHEs. The experimental results showed that the COP values at the alternating operation mode and after six hrs of operation period were ranged from 2.48 at 0.5 ℓ/min to 8.17 at 3 ℓ/min. While in continuous mode, the COP values ranged from 2.28 at 0.5 ℓ/min to 7.37 at 3 ℓ/min. The results also revealed that the GHEs can be used in cooling applications as ground source heat pump system in Iraq that is considered as a hot weather country.