caa a22 4500 606170561 CHVBK 20210128100718.0 cr unu---uuuuu 210128e20150201xx s 000 0 eng 10.1007/s10098-014-0807-7 doi (NATIONALLICENCE)springer-10.1007/s10098-014-0807-7 Performance investigation of high-temperature sensible heat thermal energy storage system during charging and discharging cycles [Elektronische Daten] [Hakeem Niyas, Likhendra Prasad, P. Muthukumar] This paper presents the thermal modelling and performance predictions of high-temperature sensible heat storage (SHS) models of 50MJ capacity designed for solar thermal power plant applications in the temperature range of 523-648K. The SHS unit is a regenerator-type heat exchanger which stores/releases the heat on passing hot/cold heat transfer fluid (HTF) through the tubes embedded into it. A mathematical model of cylindrical configuration with embedded multi-tube is developed employing concrete and cast steel as the storage media. The number of embedded charging/discharging tubes in the storage model is optimized based on the charging time using the finite element method-based simulation tool, COMSOL Multiphysics. Numerically predicted results match well with the data reported in the literature. Thermal performance parameters of SHS bed such as charging/discharging time, energy stored/recovered, charging/discharging energy efficiency and overall efficiency have been evaluated. Axial variations of HTF temperature during charging/discharging cycle are analysed, and the parametric studies are carried out by varying the flow rate of HTF. For cast steel bed, the increase in HTF velocity resulted in the proportional reduction in charging/discharging time, while these effects in concrete were less because of its low thermal conductivity. Springer-Verlag Berlin Heidelberg, 2014 Solar energy nationallicence Sensible heat storage nationallicence TES nationallicence Tube optimization nationallicence Efficiency nationallicence C ps : Specific heat of solid-state SHSM (J/kgK) nationallicence C pf : Specific heat of HTF (J/kgK) nationallicence k s : Thermal conductivity of solid-state SHSM (W/mK) nationallicence k f : Thermal conductivity of HTF (W/mK) nationallicence ρ s : Density of solid-state SHSM (kg/m3) nationallicence ρ f : Density of HTF (kg/m3) nationallicence μ : Dynamic viscosity of HTF (Ns/m2) nationallicence γ : Kinematic viscosity of HTF (mm2/s) nationallicence d : Internal diameter of the charging tubes (m) nationallicence D : Diameter of SHS bed (m) nationallicence L : Length of SHS bed (m) nationallicence n : Number of charging tubes nationallicence Q : Heat storage capacity (J) nationallicence t : Charging time (s) nationallicence T ch : Volume average temperature of SHS bed at the end of charging (K) nationallicence T ini : Initial temperature of SHS bed (K) nationallicence T inlet : HTF inlet temperature (K) nationallicence T outlet : HTF outlet temperature (K) nationallicence T atm : Atmospheric temperature (K) nationallicence Δ T : Charging temperature range (K) nationallicence $$\vec{v}$$ v → : Velocity of HTF (m/s) nationallicence V r : Volume of solid-state SHSM required (m3) nationallicence V a : Actual volume of solid-state SHSM including factor of safety (m3) nationallicence m : Mass of solid-state SHSM (kg) nationallicence η ch : Charging energy efficiency nationallicence η disch : Discharging energy efficiency nationallicence η overall : Overall efficiency nationallicence Niyas Hakeem Department of Mechanical Engineering, Indian Institute of Technology Guwahati, 781039, Guwahati, India aut Prasad Likhendra Department of Mechanical Engineering, Indian Institute of Technology Guwahati, 781039, Guwahati, India aut Muthukumar P. Department of Mechanical Engineering, Indian Institute of Technology Guwahati, 781039, Guwahati, India aut Clean Technologies and Environmental Policy Springer Berlin Heidelberg 17/2(2015-02-01), 501-513 1618-954X 17:2<501 2015 17 10098 https://doi.org/10.1007/s10098-014-0807-7 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10098-014-0807-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Niyas Hakeem Department of Mechanical Engineering, Indian Institute of Technology Guwahati, 781039, Guwahati, India aut NATIONALLICENCE 700 1- Prasad Likhendra Department of Mechanical Engineering, Indian Institute of Technology Guwahati, 781039, Guwahati, India aut NATIONALLICENCE 700 1- Muthukumar P. Department of Mechanical Engineering, Indian Institute of Technology Guwahati, 781039, Guwahati, India aut NATIONALLICENCE 773 0- Clean Technologies and Environmental Policy Springer Berlin Heidelberg 17/2(2015-02-01), 501-513 1618-954X 17:2<501 2015 17 10098