Heating Agent Pressure Losses in a Borehole Heat Exchanger

Abstract

One of the possible ways of exploiting thermal energy of rock is heat carrier circulation in a borehole heat exchanger. This method lies in the use of an already existing well, where a heat circulation enhancement system is installed. Heat is exchanged through the mechanism of convection and conduction with the rock mass (Rybach, 1998).
The most important parameter of a heat exchanger is the accessible heating or cooling power when the system operates as a heat storage. Another important factor is the flow pressures in the heat carrier circulation system. It has an effect on the unit cost of heat production or storage.
The methodology of determining heat carrier pressure losses during circulation is presented in the paper. Design characteristics of the heat exchanger were analyzed; variability of temperature was assessed through analysis of changes of density and viscosity of the energy carrier in the well - inside the insulating column and in the annular space.