I
In a solar flat plate heater, some of the heat is absorbed by a fluid while the remaining hea
is lost by convection, bottom surface is insulated. The fraction absorbed is known a
efficiency of the collector. If the flux incident has a value of 0 N/mrat collection
temperature of 60°C. Determine the collector efficiency when it is exposed to surrounding
at 32°C with convection coefficient of 15 W/m°, K. Also find the collector efficiency, i
collection temperature is 45°C
Answers
[Explanation:]
Solar collectors are the key component of active solar-heating
systems. They gather the sun's energy, transform its radiation
into heat, then transfer that heat to a fluid (usually water or air).
The solar thermal energy can be used in solar water-heating
systems, solar pool heaters, and solar space-heating systems.
There are a large number of solar collector designs that have
shown to be functional. These designs are classified in two
general types of solar collectors:
Flat-plate collectors – the absorbing surface is
approximately as large as the overall collector area that
intercepts the sun's rays.
Concentrating collectors – large areas of mirrors or
lenses focus the sunlight onto a smaller absorber.
t inconvenient because of the
difficulty in defining the collector average temperature. It is
convenient to define a quantity that relates the actual useful
energy gain of a collector to the useful gain if the whole
collector surface were at the fluid inlet temperature. This
quantity is known as “the collector heat removal factor