Downhole heat exchanger
|This article needs additional citations for verification. (April 2013) (Learn how and when to remove this template message)|
A downhole heat exchanger, (DHE) also called a borehole heat exchanger, (BHE) is a heat exchanger installed inside a borehole. It is used to capture or dissipate heat to or from the ground. DHT's are used for geothermal heating, sometimes with the help of a geothermal heat pump.
The heat exchanger usually consists of one or two u-tubes through which the carrier fluid, usually water, circulates. The space around the u-tubes is filled with groundwater or backfilled with thermally conductive grout.
Another design uses a single open pipe to flow water downward. The water then returns through the annular gap between the pipe and the casing. This design provides better thermal contact than u-tubes, but risks contamination by groundwater. Since this involves practically no downhole equipment, these systems usually only go by the name of borehole heat exchangers (BHT).
Standing column well
If no casing is installed and groundwater is permitted to charge the system, this arrangement is no longer a BHT, but rather a standing column well.
- "Downhole Heat Exchangers" (PDF). Geo-Heat Center - Oregon Institute of Technology. Retrieved 21 April 2013.
|This article about energy, its collection, its distribution, or its uses is a stub. You can help Wikipedia by expanding it.|