TY - JOUR
T1 - Modeling of high temperature thermal energy storage in rock beds – Experimental comparison and parametric study
AU - Marongiu, Fabrizio
AU - Soprani, Stefano
AU - Engelbrecht, Kurt
PY - 2019
Y1 - 2019
N2 - The increasing penetration of renewables in energy systems requires the
integration of energy storage units into electrical grids as a crucial
aspect. Nevertheless, current ES technologies show, as a common issue,
an excessive capital cost, which prevents them from being implemented on
a large scale. The combination of high temperature thermal energy
storage and bottom steam cycles has recently become an object of
interest as a potential cost-effective alternative to traditional ES. In
this study, a two-dimensional model of an existing high temperature
thermal energy storage rock bed unit with 450 kWhth of
thermal capacity is implemented. A description of the geometry,
equations and boundary conditions is provided, as well as a comparison
of the model results with the experimental data logged from the
reference testing unit. A brief discussion about the solution method and
the relative error on the final results is also presented. A study
regarding the charge phase was performed, with the main focus on the
modification of some parameters of interest such as rock size, air flow
rate, rock type and insulation material. Results are presented in terms
of two-dimensional temperature profiles, charge efficiencies and heat
losses, highlighting the differences between the scenarios considered.
Thermal charge efficiency was found in the range 69–96% for the
considered simulations, and different improvement aspects are suggested
for future studies.
AB - The increasing penetration of renewables in energy systems requires the
integration of energy storage units into electrical grids as a crucial
aspect. Nevertheless, current ES technologies show, as a common issue,
an excessive capital cost, which prevents them from being implemented on
a large scale. The combination of high temperature thermal energy
storage and bottom steam cycles has recently become an object of
interest as a potential cost-effective alternative to traditional ES. In
this study, a two-dimensional model of an existing high temperature
thermal energy storage rock bed unit with 450 kWhth of
thermal capacity is implemented. A description of the geometry,
equations and boundary conditions is provided, as well as a comparison
of the model results with the experimental data logged from the
reference testing unit. A brief discussion about the solution method and
the relative error on the final results is also presented. A study
regarding the charge phase was performed, with the main focus on the
modification of some parameters of interest such as rock size, air flow
rate, rock type and insulation material. Results are presented in terms
of two-dimensional temperature profiles, charge efficiencies and heat
losses, highlighting the differences between the scenarios considered.
Thermal charge efficiency was found in the range 69–96% for the
considered simulations, and different improvement aspects are suggested
for future studies.
U2 - 10.1016/j.applthermaleng.2019.114355
DO - 10.1016/j.applthermaleng.2019.114355
M3 - Journal article
SN - 1359-4311
VL - 163
JO - Applied Thermal Engineering
JF - Applied Thermal Engineering
M1 - 114355
ER -
