Parametric study and design of an earth-air heat exchanger using model experiment for memorial heating and cooling

Highlights: • The feasibility and performance of model experiment for EAHE study were explored. • The influencing factors on heat transfer effect of the EAHE system were studied. • The optimums burial depth, pipe length, diameter and air velocity were obtained. • A preliminary design scheme for the EAHE system of the YAGM memorial was proposed. -- Abstract: An earth-air heat exchanger (EAHE) system is an effective energy-saving technique for heating and cooling a space by using Earth's subsurface heat. The EAHE system has been widely applied in residential and public buildings, but feasibility research is still needed because of the regional restrictions and influencing factors that may be involved. In this paper, a 1:20 scale model is created to study the influence parameters on the thermal performance of the EAHE due to the limitations of field test. By dimensionless analysis of the momentum and heat conduction equations, the key similarity numbers Re and Fo and the similar scales are proposed. The experimental data were compared with other studies and achieved good agreement. The original soil temperatures at different depths in Xi'an are calculated by MATLAB software. On this basis, a preliminary design scheme for the EAHE system of a memorial is proposed and analyzed by numerical simulation.