Thermally conductive cementitious grout for geothermal heat pump systems

Patent · Mon Jan 01 00:00:00 EST 2001

OSTI ID:873806

Allan, Marita ^[1]

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1. Old Field, NY

A thermally conductive cement-sand grout for use with a geothermal heat pump system. The cement sand grout contains cement, silica sand, a superplasticizer, water and optionally bentonite. The present invention also includes a method of filling boreholes used for geothermal heat pump systems with the thermally conductive cement-sand grout. The cement-sand grout has improved thermal conductivity over neat cement and bentonite grouts, which allows shallower bore holes to be used to provide an equivalent heat transfer capacity. In addition, the cement-sand grouts of the present invention also provide improved bond strengths and decreased permeabilities. The cement-sand grouts can also contain blast furnace slag, fly ash, a thermoplastic air entraining agent, latex, a shrinkage reducing admixture, calcium oxide and combinations thereof.

• Research Organization: Brookhaven National Laboratory (BNL), Upton, NY (United States)
• DOE Contract Number: AC02-98C1110886
• Assignee: United States of America as represented by Department of Energy (Washington, DC)
• Patent Number(s): US 6251179
• OSTI ID: 873806
• Country of Publication: United States
• Language: English

Related Subjects

thermally
conductive
cementitious
grout
geothermal
heat
pump
systems
cement-sand
cement
sand
contains
silica
superplasticizer
water
optionally
bentonite
method
filling
boreholes
improved
thermal
conductivity
neat
grouts
allows
shallower
bore
holes
provide
equivalent
transfer
capacity
addition
bond
strengths
decreased
permeabilities
contain
blast
furnace
slag
fly
ash
thermoplastic
air
entraining
agent
latex
shrinkage
reducing
admixture
calcium
oxide
combinations
pump systems
bore holes
cementitious grout
provide improved
improved thermal
calcium oxide
thermal conductivity
fly ash
heat pump
heat transfer
thermally conductive
silica sand
geothermal heat
thermal heat
sand grout
provide improve
blast furnace
bond strength
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