| Abstract |
This report is an analysis of the performance of a coaxial heat exchanger used for the extraction of heat form a geothermal well, for use in space or process heating. The calculations are based on conductive heat transfer into the well and are therefore a lower bound on the performance of such s system, since in most cases heat will be transferred to well convectively. The analysis makes use of a full solution to the problem including temperature variation with depth, transfer between inner and outer tubes, frication and the cooling of the formation with time. |