Materials characterization of superplasticized cement–sand grout

Allan, M.L.

doi:10.1016/s0008-8846(00)00275-1

Cited by 49 publications

(33 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Replacing the reciprocating compressor by a scroll compressor would lead to increasing cooling effectiveness. (b) The soil type and moisture content on the performance of GSHP have recently been reported by some investigators (Morino and Oka, 1994;Leong et al, 1998;Spilker, 1998;Allan, 2000). Spilker (1998) reported that the length of a ground heat exchanger can be reduced by using sand or thermally improved bentonite grout instead of standard bentonite grout.…”

Section: Potential For Performance Improvementsmentioning

confidence: 92%

Performance evaluation of a vertical ground-source heat pump system in Izmir, Turkey

Hepbaşlı

2002

Int. J. Energy Res.

View full text Add to dashboard Cite

SUMMARYThis study summarizes the cooling performance of a ground-source heat pump system which was installed in a 65-m 2 room in the Solar Energy Institute, Ege University, Izmir (568 degree-days cooling, base: 228C; 1226 degree-days heating, base: 188C) Turkey. The institute, built in 1986, has a liveable floor area of 3000 m 2 , and uses passive solar techniques. The heating and cooling loads of the room were, respectively, 3.8 and 4.2 kW at design conditions. The system was commissioned in May 2000 and the performance tests have been carried out since then. Based upon the measurements, the heat rejection rate to the soil with an average thermal diffusivity of 0.00375 m 2 h À1 in the cooling mode was found to be in average 51 W m À1 of bore depth, while the maximum entering water temperature to the unit was recorded as 35.98C. The cooling coefficient of performance of the heat pump and the whole system was relatively low when compared to other heat pumps operating under conditions at or near design values. The primary reasons for this were discussed in detail and the potential for performance improvements was also suggested.

show abstract

Section: Potential For Performance Improvementsmentioning

confidence: 92%

Performance evaluation of a vertical ground-source heat pump system in Izmir, Turkey

Hepbaşlı

2002

Int. J. Energy Res.

View full text Add to dashboard Cite

show abstract

“…Among these components (Figure 1), the grouting material located between the pipe and the ground is very important due to its crucial functions: allow the borehole stability, make possible an efficient heat transfer between the pipe and the ground and provide a hydraulic barrier that avoids the pollution of the aquifers if leaks are present. Therefore, a suitable grouting material should satisfy the following conditions: (1) to possess a very low hydraulic conductivity; (2) to provide a high thermal conductivity; (3) to guarantee a good coupling pipe-grout that avoids harmful debonding effects [4]; and (4) to possess proper mechanical properties that protects the heat exchange system. However, some of these conditions are sometimes sacrificed for the sake of the grout's workability.…”

Section: Introductionmentioning

confidence: 99%

Experimental characterization and performance evaluation of geothermal grouting materials subjected to heating–cooling cycles

Indacoechea-Vega

Castro‐Fresno

Calzada-Pérez

2015

Construction and Building Materials

View full text Add to dashboard Cite

In recent years, the increasing rise in environmental awareness among energy consumers has led to an increasing use of renewable energies such as the geothermal energy. An important role in the efficient exploitation of the geothermal resource is played by the grouting material placed in the borehole between the pipes and the ground. Actually, the use of proper grouts is essential to provide an effective heat transfer between the ground and the heat carrier fluid in the pipes, and also to comply with the mechanical and environmental demands. However, when it comes to the construction of the GHP installations, the grout is especially required to be easy to work with (workable) and for this reason more water than required is sometimes added. In order to assess the suitability of grouting materials with significant water/solid ratios, the thermal conductivity, mechanical strength and permeability of five different grouts and grout-pipe specimens were measured for their laboratory characterization. In addition, the grouts were subjected to heating and cooling cycles to evaluate their durability with time in terms of the potential degradation of the materials and the loss of quality of the grout-pipe interface. According to the results obtained, the grouts here tested are appropriate for most of the geothermal heat pump installations, especially for those with low to medium ground thermal properties.

show abstract

“…It is commonly assumed that an increase in the thermal conductivity of backfilling grouts may lead to the enhancement of system efficiency during operating the GHP system [6,7]. There is a pitfall in reasoning this hypothesis without consideration of sectional configuration of the GHP system.…”

Section: Three-dimensional Heat Transfer Considering Fluid Flow Throumentioning

confidence: 99%

Numerical characterization of heat transfer in closed-loop vertical ground heat exchanger

Lee

Gil

Choi

et al. 2010

Sci. China Ser. E-Technol. Sci.

View full text Add to dashboard Cite

A series of numerical analyses has been performed on the characteristics of heat transfer in a closed-loop vertical ground heat exchanger (U-loop). A 2-D finite element analysis was conducted to evaluate the temperature distribution over the cross section of the U-loop system involving high-density polyethylene (HDPE) pipe/grout/soil to compare the sectional efficiency between the conventional U-loop and a new latticed HDPE pipe system, which is equipped with a thermally insulating lattice in order to reduce thermal interference between the inlet and outlet pipes. In addition, a 3-D finite volume analysis (FLUENT) was adopted to simulate the operation of the closed-loop vertical ground heat exchanger with the consideration of the effect of a distance between the inlet and outlet pipes, grout's thermal properties, the effectiveness of the latticed HDPE pipe system, and the rate of circulation pump. It was observed that the thermal interference between the two strands of U-loop is of importance in enhancing efficiency of the ground heat exchanger. Consequently, it is recommended to modify the configuration of the conventional U-loop system by equipping the thermally insulating lattice between the two pipe strands. ground heat exchanger, HDPE pipe, latticed pipe, sectional efficiency Citation: Lee C, Gil H, Choi H, et al. Numerical characterization of heat transfer in closed-loop vertical ground heat exchanger.

show abstract

Materials characterization of superplasticized cement–sand grout

Cited by 49 publications

References 6 publications

Performance evaluation of a vertical ground-source heat pump system in Izmir, Turkey

Performance evaluation of a vertical ground-source heat pump system in Izmir, Turkey

Experimental characterization and performance evaluation of geothermal grouting materials subjected to heating–cooling cycles

Numerical characterization of heat transfer in closed-loop vertical ground heat exchanger

Contact Info

Product

Resources

About