EFFICIENCY GAIN OF A SOLAR TROUGH COLLECTOR DUE TO AN IR-REFLECTIVE FILM ON THE NON-IRRADIATED PART OF THE RECEIVER

摘要

In order to reduce the thermal emission from a glass-covered receiver tube of a trough collector, the part of the glass not facing the collector can be covered with an IR-reftecting layer. The advantages of such a covering are discussed in this preliminary study by means of optical and thermal simulations of three configurations of a receiver (two configurations with two different IR-reflecting layers, and one configuration without any IR-reflecting layer). From the simulations, it was observed that one of the layers produce a relative gain of 3.84% of the efficiency over a year (location: south of Italy). An upper bound on the cost of the covering is given.