Analytical model for the design of volumetric solar flow receivers

Veeraragavan, Ananthanarayanan, Lenert, Andrej, Yilbas, Bekir, Al-Dini, Salem and Wang, Evelyn N. (2012) Analytical model for the design of volumetric solar flow receivers. International Journal of Heat and Mass Transfer, 55 4: 556-564. doi:10.1016/j.ijheatmasstransfer.2011.11.001

Author Veeraragavan, Ananthanarayanan
Lenert, Andrej
Yilbas, Bekir
Al-Dini, Salem
Wang, Evelyn N.
Title Analytical model for the design of volumetric solar flow receivers
Journal name International Journal of Heat and Mass Transfer   Check publisher's open access policy
ISSN 0017-9310
Publication date 2012-01-31
Year available 2011
Sub-type Article (original research)
DOI 10.1016/j.ijheatmasstransfer.2011.11.001
Volume 55
Issue 4
Start page 556
End page 564
Total pages 9
Place of publication Kidlington, Oxford, United Kingdom
Publisher Pergamon
Collection year 2012
Language eng
Formatted abstract
The development of efficient solar thermal receivers has received significant interest for solar to electrical power conversion and heating applications. Volumetric flow receivers, where the incoming solar radiation is absorbed in the volume of a heat transfer fluid (HTF), promise reduced heat loss at the surface compared to surface absorbers. In order to efficiently store the thermal energy in the volume, nanoparticles can be suspended in the HTF to absorb the incoming radiation. In such systems, compact models are needed to design and optimize the performance. This paper presents an analytical model that investigates the effect of heat loss, particle loading, solar concentration and channel height on receiver efficiency. The analytical model was formulated by modeling the absorption of solar radiation by the suspended nanoparticles as a volumetric heat release inside the flowing HTF. The energy equation was solved with the surface heat losses modeled using a combined radiative and convective heat loss coefficient. The analytical solution provides a convenient tool for predicting the effect of different parameters, in terms of dimensionless numbers (Pe, NuE, G, and θamb), on two-dimensional temperature profiles and system performance. By combining the receiver efficiency with a power generation efficiency, idealized by the Carnot efficiency, an optimum receiver length where the total efficiency is maximized is determined. However, in practice, the maximum efficiency depends on the maximum allowable temperature of the working HTF. As a case study, predictions were made for Therminol® VP-1 with suspended graphite nanoparticles in a 1 cm deep channel with a solar concentration of 10. The model predicts an optimum total system efficiency of 0.35 for a dimensionless receiver length of 0.86. Finally, the analytical model was used to estimate the optimum efficiency and the corresponding optimum receiver length for different design configurations with varying NuE and G. The results from this paper will help guide experimental design of volumetric flow receivers for solar thermal based power systems.
Keyword Analytical model
Volumetric receiver
Heat transfer fluid
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status Non-UQ
Additional Notes Available online 24 November 2011

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Mechanical & Mining Engineering Publications
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Citation counts: TR Web of Science Citation Count  Cited 32 times in Thomson Reuters Web of Science Article | Citations
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Created: Tue, 22 May 2012, 09:39:09 EST by Anand Veeraragavan on behalf of School of Mechanical and Mining Engineering