Javier Muñoz
Grupo de Investigaciones Termoenergåticas ETSII- Madrid Polytechnic University, Spain
José M. Martínez-Val
Grupo de Investigaciones Termoenergåticas ETSII- Madrid Polytechnic University, Spain
Rubén Abbas
Grupo de Investigaciones Termoenergåticas ETSII- Madrid Polytechnic University, Spain
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http://dx.doi.org/10.3384/ecp110573905Published in: World Renewable Energy Congress - Sweden; 8-13 May; 2011; Linköping; Sweden
Linköping Electronic Conference Proceedings 57:31, p. 3905-3912
Published: 2011-11-03
ISBN: 978-91-7393-070-3
ISSN: 1650-3686 (print), 1650-3740 (online)
In this paper the physics of linear receivers is analyzed. This analysis is oriented to evaluate the dependence of the thermal performance of the receiver on the characteristics of the concentrated solar radiation. It will be seen that two thermal regimes can be distinguished in that dependence; what will point out the need of studying at depth the features of systems with moderate concentration factors.
A fundamental question can be formulated as follows: what is the concentration factor required for obtaining the best solar energy exploitation within a design window established by some technical constraints?
best solar energy exploitation within a design window established by some technical constraints? In this performance analysis it has been found that moderate concentration factors (about 20 to achieve 400°C) can be close to optimal in a cost benefit analysis; taking into account temperature constraints. Beyond these values; thermal and exergetic efficiency curves advice to limit the concentration factors to values that could be achievable by linear Fresnel reflecting collectors; avoiding mobile parts such as ball-joints or flexible joints that could be important leak-points; as well as metal-glass welds; which are another cause of failure in trough collectors.
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