Optical and thermal characterization procedure for a variable geometry concentrator: A standard approach

Toward a standard testing methodology for solar thermal collectors with variable-geometry: The direct radiation incidence angle modifier issue

“…Within this project, the Subtask A (Process heat collector development and process heat collector testing) is now dealing with the use of ray-tracing simulation for the testing of line-focusing concentrators, which would save time and money in the experimental procedure. This issue has been addressed in earlier studies (Horta and Osó rio, 2014;Hess and Hanby, 2014;Sallaberry et al, 2014). The main issue is the requirement of in situ measurements in order to characterize large-size solar collectors such as LFRs, PTCs and fixed-mirrors, because it is not feasible to perform such tests in a laboratory for this type of collectors.…”

“…In 2006, a company named Tecnología Solar Concentradora (Tecnología solar concentradora web page) was founded to develop the CCStaR project. Several prototypes have been developed and investigated by the University of the Balearic Islands (UIB), and some experiments have been reported in Sallaberry et al (2014), , Alorda et al (2015), Martínez et al (2011), Pujol Nadal (2012, Pujol et al (2010). Sallaberry et al (2014) tested the CCStaR V2 prototype on the basis of the EN 12975-2 (EN 12975-2, 2006) test method under quasi-dynamic conditions.…”

“…Several prototypes have been developed and investigated by the University of the Balearic Islands (UIB), and some experiments have been reported in Sallaberry et al (2014), , Alorda et al (2015), Martínez et al (2011), Pujol Nadal (2012, Pujol et al (2010). Sallaberry et al (2014) tested the CCStaR V2 prototype on the basis of the EN 12975-2 (EN 12975-2, 2006) test method under quasi-dynamic conditions. Some hypotheses on the optical behavior of the collector were previously checked by experimental testing and using ray-tracing program described in Pujol Nadal and Martínez Moll (2012).…”

“…(1), one of the effects observed is that as the receiver is mobile, the IAM for diffuse solar radiation K d could depend on the position of the receiver with respect to the stationary reflector. But the simulation performed to calculate the optical efficiency for the diffuse radiation at different receiver positions showed that diffuse efficiency is only slightly dependent on the receiver position (Sallaberry et al, 2014). So, the parameter K d was considered constant (also referred to in Hess and Hanby (2014) assuming isotropic modeling of diffuse irradiance for the collector).…”

“…But the problem is that in some cases the range of incidence angles to be tested is not practicable. In particular, for variable-geometry collectors which are heavier and larger (Häberle et al, 2008;Sallaberry et al, 2014) than conventional domestic hot water collectors, not all the incidence angles required by the test standard can be attained, because of the difficulty in directing the collector. A cheaper and easier way should therefore be defined to test such unconventional collectors.…”