Diffuser design influence on the performance of solar thermal storage tanks

1991 ◽  
Vol 15 (7) ◽  
pp. 525-534 ◽  
Author(s):  
A. Al-Maraffie ◽  
A. Al-Kandari ◽  
N. Ghaddar
Keyword(s):  
Thermal Storage ◽  
Solar Thermal ◽  
Storage Tanks

Transient Natural Convection in Enclosures With Application to Solar Thermal Storage Tanks

1992 ◽  
Vol 114 (3) ◽  
pp. 175-181 ◽  
Author(s):  
D. T. Reindl ◽  
W. A. Beckman ◽  
J. W. Mitchell
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Heat Exchangers ◽  
Thermal Storage ◽  
Solar Thermal ◽  
Storage Tanks ◽  
Time Duration ◽  
Source Temperature ◽  
Fluid Field ◽  
Isothermal Fluid

Many previously studied natural convection enclosure problems in the literature have the bounding walls of the enclosure responsible for driving the flow. A number of relevant applications contain sources within the enclosure which drive the fluid flow and heat transfer. The motivation for this work is found in solar thermal storage tanks with immersed coil heat exchangers. The heat exchangers provide a means to charge and discharge the thermal energy in the tank. The enclosure is cylindrical and well insulated. Initially the interior fluid is isothermal and quiescent. At time zero, a step change in the source temperature begins to influence the flow. The final condition is a quiescent isothermal fluid field at the source temperature. The governing time-dependent Navier-Stokes and energy equations for this configuration are solved by a finite element method. Solutions are obtained for 103≤RaD≤106. Scale analysis is used to obtain time duration estimates of three distinct heat transfer regimes. The transient heat transfer during these regimes are compared with limiting cases. Correlations are presented for the three regimes.

Effect of Shroud and Baffle on Heat Transfer in a Solar Thermal Storage Tank

2009 ◽  
Author(s):  
S. K. S. Boetcher ◽  
F. A. Kulacki
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Transfer Rate ◽  
Thermal Storage ◽  
Solar Thermal ◽  
Discharge Process ◽  
Storage Tanks ◽  
Nusselt Numbers ◽  
Enhancing Heat Transfer ◽  
Rayleigh Numbers

Enhancing heat transfer during the charge and discharge of solar thermal storage tanks is an ongoing technical challenge. The types of thermal storage systems considered in the present study comprise an immersed heat exchanger at the top of a solar thermal storage fluid. The discharge process of a thermal store with specified dimensions is numerically simulated over a range of Rayleigh numbers, 105 < RaD <107. The immersed heat exchanger is modeled as a two-dimensional isothermal cylinder which is situated near the top of a water-filled tank with adiabatic walls. An adiabatic shroud whose shape is parametrically varied is placed around the cylinder. In addition, the shroud is connected to an adiabatic baffle situated beneath the cylinder. Nusselt numbers are calculated for different shroud shapes at different Rayleigh numbers. Results show that the shroud is effective in increasing the heat transfer rate. Optimal shroud and baffle geometries are presented as well as qualitative flow results.

scholarly journals Integrated high temperature heat pumps and thermal storage tanks for combined heating and cooling in the industry

2021 ◽  
Vol 189 ◽  
pp. 116731
Author(s):  
Marcel Ulrich Ahrens ◽  
Sverre Stefanussen Foslie ◽  
Ole Marius Moen ◽  
Michael Bantle ◽  
Trygve Magne Eikevik
Keyword(s):  
High Temperature ◽  
Thermal Storage ◽  
Heat Pumps ◽  
Storage Tanks ◽  
Heating And Cooling ◽  
Temperature Heat

A simple and clean method to prepare SiC-containing vitreous ceramics for solar thermal storage in the clay-feldspar system

2020 ◽  
Vol 248 ◽  
pp. 119257 ◽  
Author(s):  
Xinbin Lao ◽  
Xiaoyang Xu ◽  
Weihui Jiang ◽  
Jian Liang ◽  
Huan Liu
Keyword(s):  
Thermal Storage ◽  
Solar Thermal
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