DE-13-C060 -- Development of a Horizontal Slinky Ground Heat Exchanger Model PDF

Slinky ground heat exchangers are increasingly considered among more traditional ground heat exchanger configurations. Although studied for many years as a research topic, the increase in efficiency and reduction in building energy demands has increased the viability of these specialized heat exchangers, especially in cases where limited space is available for burying horizontal heat exchanger tubing. By formulating an accurate simulation model, the feasibility and efficiency of such heat exchangers in different climates and building configurations can be studied. In addition, it will serve as a powerful tool for design and energy analysis of the ground source heat pump (GSHP) systems.

This paper describes the derivation of an analytic solution for modeling the thermal response of horizontal Slinky heat exchangers. The analytic results are presented in the form of temperature response factors. A computer module with fast algorithms is written to calculate temperature response factors of any specified Slinky ground heat exchanger. The factors then can be used as input for a buried pipe model to calculate hourly exit fluid temperature of the heat exchanger. Knowledge of exit fluid temperature is essential for simulation of a GSHP system.