Geothermal sonde of pipe and inside tube uses roll-up corrugated pipe or plastics forming annulus with metal inner tube with enclosed temperature compensator for heat exchange technology.

摘要

The outer pipe (5) is corrugated for most its length to give outside diameter of 100 mm and maximum wall thickness of 3 mm. The corrugations can be sinusoidal, trapezoidal or rectangular or form superposed rectangles and to maximum corrugation height of 3-5 mm. The inner tube (15) is heat-insulated (14) in its upper reaches and stands less than 1 mm from the bottom end of the outer pipe (5). A metal sleeve in the annulus (11) compensates for medium volume temperature changes and connecting pipe passes through the outer pipe (5) part (7) into the annulus (11). The length of ground heat sonde is preferably above 12 m but less than 100 m. The casing mass (4) round the sonde in borehole (2) presents flexible cement-bound mix or bentonite.