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Title: Downhole heat exchangers

Abstract

The downhole heat exchanger (DHE) eliminates the problem of disposal of geothermal fluid, since only heat is taken from the well. The exchanger consists of a system of pipes or tubes suspended in the well through which clean secondary water is pumped or allowed to circulate by natural convection. These systems offer substantial economic savings over surface heat exchangers where a single-well system is adequate (typically less than 0.8 MWt, with well depths up to about 500 ft) and may be economical under certain conditions at well depths to 1500 ft. Several designs have proven successful; but, the most popular are a simple hairpin loop or multiple loops of iron pipe (similar to the tubes in a U-tube and shell exchanger) extending to near the well bottom. An experimental design consisting of multiple small tubes with headers at each end suspended just below the water surface appears to offer economic and heating capacity advantages. The paper describes design and construction details and New Zealand`s experience with downhole heat exchangers.

Authors:
;  [1]
  1. Oregon Inst. of Tech., Klamath Falls, OR (United States). Geo-Heat Center
Publication Date:
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
691514
DOE Contract Number:  
FG01-99EE35098
Resource Type:
Journal Article
Journal Name:
Geo-Heat Center Quarterly Bulletin
Additional Journal Information:
Journal Volume: 20; Journal Issue: 3; Other Information: PBD: Sep 1999
Country of Publication:
United States
Language:
English
Subject:
15 GEOTHERMAL ENERGY; GEOTHERMAL WATER HEATING; GEOTHERMAL WELLS; HEAT EXCHANGERS; DESIGN; HEAT EXTRACTION; CONSTRUCTION; NEW ZEALAND; PERFORMANCE

Citation Formats

Culver, G., and Lund, J.W. Downhole heat exchangers. United States: N. p., 1999. Web.
Culver, G., & Lund, J.W. Downhole heat exchangers. United States.
Culver, G., and Lund, J.W. Wed . "Downhole heat exchangers". United States.
@article{osti_691514,
title = {Downhole heat exchangers},
author = {Culver, G. and Lund, J.W.},
abstractNote = {The downhole heat exchanger (DHE) eliminates the problem of disposal of geothermal fluid, since only heat is taken from the well. The exchanger consists of a system of pipes or tubes suspended in the well through which clean secondary water is pumped or allowed to circulate by natural convection. These systems offer substantial economic savings over surface heat exchangers where a single-well system is adequate (typically less than 0.8 MWt, with well depths up to about 500 ft) and may be economical under certain conditions at well depths to 1500 ft. Several designs have proven successful; but, the most popular are a simple hairpin loop or multiple loops of iron pipe (similar to the tubes in a U-tube and shell exchanger) extending to near the well bottom. An experimental design consisting of multiple small tubes with headers at each end suspended just below the water surface appears to offer economic and heating capacity advantages. The paper describes design and construction details and New Zealand`s experience with downhole heat exchangers.},
doi = {},
journal = {Geo-Heat Center Quarterly Bulletin},
number = 3,
volume = 20,
place = {United States},
year = {1999},
month = {9}
}