TY - JOUR
T1 - Analysis of recovery efficiency in high-temperature aquifer thermal energy storage
T2 - a Rayleigh-based method
AU - Schout, Gilian
AU - Drijver, Benno
AU - Gutierrez-Neri, Mariene
AU - Schotting, Ruud
PY - 2014/2
Y1 - 2014/2
N2 - High-temperature aquifer thermal energy storage (HT-ATES) is an important technique for energy conservation. A controlling factor for the economic feasibility of HT-ATES is the recovery efficiency. Due to the effects of density-driven flow (free convection), HTATES systems applied in permeable aquifers typically have lower recovery efficiencies than conventional (lowtemperature) ATES systems. For a reliable estimation of the recovery efficiency it is, therefore, important to take the effect of density-driven flow into account. A numerical evaluation of the prime factors influencing the recovery efficiency of HT-ATES systems is presented. Sensitivity runs evaluating the effects of aquifer properties, as well as operational variables, were performed to deduce the most important factors that control the recovery efficiency. A correlation was found between the dimensionless Rayleigh number (a measure of the relative strength of free convection) and the calculated recovery efficiencies. Basedona modified Rayleigh number, two simple analytical solutions are proposed to calculate the recovery efficiency, each one covering a different range of aquifer thicknesses. The analytical solutions accurately reproduce all numerically modeled scenarios with an average error of less than 3%. The proposed method can be of practical use when considering or designing an HT-ATES system.
AB - High-temperature aquifer thermal energy storage (HT-ATES) is an important technique for energy conservation. A controlling factor for the economic feasibility of HT-ATES is the recovery efficiency. Due to the effects of density-driven flow (free convection), HTATES systems applied in permeable aquifers typically have lower recovery efficiencies than conventional (lowtemperature) ATES systems. For a reliable estimation of the recovery efficiency it is, therefore, important to take the effect of density-driven flow into account. A numerical evaluation of the prime factors influencing the recovery efficiency of HT-ATES systems is presented. Sensitivity runs evaluating the effects of aquifer properties, as well as operational variables, were performed to deduce the most important factors that control the recovery efficiency. A correlation was found between the dimensionless Rayleigh number (a measure of the relative strength of free convection) and the calculated recovery efficiencies. Basedona modified Rayleigh number, two simple analytical solutions are proposed to calculate the recovery efficiency, each one covering a different range of aquifer thicknesses. The analytical solutions accurately reproduce all numerically modeled scenarios with an average error of less than 3%. The proposed method can be of practical use when considering or designing an HT-ATES system.
KW - Aquifer thermal energy storage
KW - Density-drivenflow
KW - Numerical modeling
KW - The Netherlands
KW - Thermal systems
UR - http://www.scopus.com/inward/record.url?scp=84905709038&partnerID=8YFLogxK
U2 - 10.1007/s10040-013-1050-8
DO - 10.1007/s10040-013-1050-8
M3 - Article
AN - SCOPUS:84905709038
SN - 1431-2174
VL - 22
SP - 281
EP - 291
JO - Hydrogeology Journal
JF - Hydrogeology Journal
IS - 1
ER -