Parabolic dish collector for domestic purposes with novel receiver design

Abstract

Two parabolic dish collectors with different
properties referring to the reflective material, the receiver
design and the tracking mechanism are tested in this work
in order to examine their thermal performance as part of a
residential solar water heater. In both cases, a parabolic
dish manufactured originally for satellite television receiving
has been used as a carrier for the reflective material which
consists of aluminum strips in the first collector and glass
mirrors in the second one. Novel receiver construction has
been tested for each collector. Using the new construction it
is possible to renounce the automatically tracking
mechanism in the north –south direction in order to
minimize the installation costs. Efficiency measurements of
the collector with aluminum strips yielded 0.59 for the
intercept efficiency and 2.9 W/m2K for the first order
coefficient; whereas the values for the collector with glass
mirrors are 0.71 and 2.1 W/m2K respectively.
Published test reports of flat-plate and evacuated tube
collectors are studied in order to assess the thermal
performance of the designed collectors in this work. The
efficiency curve of the collector with the glass mirrors lies
higher than the average efficiency curve of flat-plate
collectors and evacuated tube collectors.