| 摘要 |
<p>A coaxial borehole heat exchanger 58 comprising an outer tubular metal casing 54 located in a borehole 66, the outer tubular metal casing comprising a series of tubular sections 50, 52 which have opposed ends interconnected by an annular weld 56. The method of installation involves the lower section 50 being placed into the borehole 66 and the upper section 52 being welded to the upper end of the lower section, this process is repeated with multiple sections to reach the required casing length. The casing is surrounded in the borehole by a grout layer (10, fig 5), the grout is corrosion resistant preferably by the inclusion of zinc oxide in the grout.</p> |
