Abstract - Advanced Accelerator Applications

Solar Energy 80 (2006) 1498–1508
www.elsevier.com/locate/solener
A computational study of salt diﬀusion and heat extraction
in solar pond plants
Celestino Angeli a, Erminia Leonardi
b,*
, Luca Maciocco
c
a
b
Dipartimento di Chimica, Universita` di Ferrara, Via Borsari 46, I-44100 Ferrara, Italy
CRS4, Center for Advanced Studies, Research and Development in Sardinia, Parco Scientiﬁco e Tecnologico, POLARIS,
Ediﬁcio 1, 09010 Pula, CA, Italy
c
ADACAP, Advanced Acceleration Applications, Technoparc-rue Diesel 20, Fr-D1630 St. Genis Pouilly, France
Received 15 March 2005; received in revised form 26 August 2005; accepted 20 October 2005
Available online 2 February 2006
Communicated by: Associate Editor Aliakbar Akbarzardeh
Abstract
The problem of the development of salt concentration proﬁles in a solar pond is investigated, the thermodiﬀusion
contribution is also taken into account, using a one-dimensional mathematical model and a ﬁnite-diﬀerence approach.
A novel scheme of heat extraction from the solar pond is presented, along with preliminary two-dimensional
computational ﬂuid dynamics (CFD) simulations.
2006 Elsevier Ltd. All rights reserved.
Keywords: Solar pond; Salt diﬀusion; Finite diﬀerence 1D numerical methods; Thermodiﬀusion
1. Introduction
A solar pond is an artiﬁcially constructed water
pond several meters deep, ﬁlled with stratiﬁed brine
varying in concentration from near saturation at the
bottom to approximately sea water concentration at
the surface. About 25% of the solar radiation incident at the surface penetrates to the bottom of the
pond and is absorbed there, causing the adjacent
brine to heat up. It consists of three distinct regions:
two convective regions at the top (upper convective
*
Corresponding author. Tel.: +39 070 925 0328; fax: +39 070
925 0216.
E-mail address: [email protected] (E. Leonardi).
zone, UCZ) and the bottom (lower convective
zone, LCZ), separated by a quiescent region (nonconvective zone, NCZ) characterized by strong
temperature and salinity gradients, which prevent
the occurrence of convection currents.
The salt diﬀusion caused by both molecular diﬀusion and thermodiﬀusion (also known as Soret
eﬀect, Soret, 1879) tends to homogenize the system
and therefore must be carefully put under control.
In previous papers (Angeli and Leonardi, 2004,
2005), a one-dimensional model based on a ﬁnite
diﬀerence scheme was used to describe the salt diﬀusion within a solar pond. In the present work, the
analysis of the behaviour of the solar pond has been
extended by considering other eﬀects besides the salt
0038-092X/$ - see front matter 2006 Elsevier Ltd. All rights reserved.
doi:10.1016/j.solener.2005.10.015

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