Distributed Temperature Measurements on a U-pipe Thermosyphon Borehole Heat Exchanger With CO2
2010 (English)In: Refrigeration Science and Technology Proceedings, Sydney, Australia: International Institute of Refrigeration, 2010Conference paper (Refereed)
In thermosyphon Borehole Heat Exchangers, a heat carrier fluid circulates while exchanging heat with the ground without the need of a circulation pump, representing an attractive alternative when compared to other more conventional systems. Normally, the fluid is at liquid-vapor saturation conditions and circulation is maintained by density differences between the two phases as the fluid absorbs energy from the ground. This paper presents some experimental experiences from a 65 meter deep thermosyphon borehole heat exchanger loop using Carbon Dioxide as heat carrier fluid, instrumented with a fiber optic cable for distributed temperature measurements along the borehole depth. The heat exchanger consists of an insulated copper tube through which the liquid CO2 flows downwards, and a copper tube acting as a riser. The results show temperatures every two meters along the riser, illustrating the heat transfer process in the loop during several heat pump cycles.
Place, publisher, year, edition, pages
Sydney, Australia: International Institute of Refrigeration, 2010.
Thermosyphon Borehole Heat Exchanger
IdentifiersURN: urn:nbn:se:kth:diva-73156OAI: oai:DiVA.org:kth-73156DiVA: diva2:488589
9th IIF/IIR Gustav Lorentzen Conference on Natural Working Fluids. Sydney, Australia. April 12-14 2010
QC 201204252012-02-012012-02-012013-02-04Bibliographically approved