Supercritical CO2 Rankine Cycle System with LowTemperature Geothermal Heat Pipe

Extracting thermal energy from the geothermal reservoir, a new design of heat pipe (thermosyphon) is introduced in this paper in details. The analytical result indicated that substantial amount of heat can be transferred into the methanol (the working fluid in the heat pipe) through the outer wall in the region of high-temperature geothermal reservoir, and the heat can be transferred upward by vapour phase effectively to a CO2/methanol heat exchanger at the surface of the ground. In application of the heat pipe, a high-performance energy generation system Rankine cycle with methanol (heat pipe) using the geothermal reservoir, carbon dioxide (CO2) was selected as a model working fluid to run power cycle. The system is feasible for low temperature (low-grade) geothermal reservoir, and should be sustainable in a sense that no hot water (spa) can be wasted, in comparison with the ordinary geothermal power plant. (C) 2017 The Authors. Published by Elsevier Ltd.