Heat transfer by borehole ground heat exchangers involves diverse time–space scales and thus imposes a significant challenge to geothermal engineers. In order to overcome this challenge, this paper develops an analytical full-scale model from the idea of matched asymptotic expansion. The...

This paper presents a new approach to modeling of heat transfer by ground heat exchangers, involving unsteady heat conduction in composite media together with complex geometry. Analytical solutions for continuous line and cylindrical-surface sources are developed based on Jaeger’s...