In order to utilise low enthalpy natural heat sources, a heat pipe using a binary fluid is a good device which can extract heat without using electric power. When the heat flux in ageothermal bore is moderate, a long heat pipe is needed. Wedeveloped a 150 m long, large scale heat pipe of 150mmouter diameter, in which liquid feeding tubes with showeringnozzles were installed. It has an excellent thermalperformance compared with other long vertical evaporators.A demonstration test was carried out in a well withtemperatures between 100 and 150 o C at a geothermal site in Kyushu, Japan. The heat pipe extracted 90 kW heat at aworking temperature of 80 o C. We also calculated theextraction rate for different lengths of the heat pipe anddifferent temperatures of the geothermal source. Similarpipes can be used for heat extraction of high temperature
In addition to heat extraction, we also studied the performance of a turbine which can be installed on top of a heat pipe using a binary fluid. We used a modification of a thermosyphon, with excellent heat and mass transfer characteristics, and incorporated a turbine. The heat transfer in a thermosyphon occurs through the circulation of a binary working fluid through a sequence of evaporation, vapour transfer, condensation and liquid return. It is then possible to convert some of the energy of the vapour stream into electric energy by installing a turbine which is coupled to an electric generator.
ببخشید متن طولانی شد. چون میخواستم مفهوم رو کامل برسونم. پاراگراف دوم بیشتر میتونه کمک کنه.
با تشکر
geothermal fluids
