Discuss the below:
Q: At the equator, where the sun at noon is approximately overhead, a near optimum orientation for a flat plate solar hot water heater is in the horizontal position. Suppose a 4 m A? 4 m solar collector for domestic hot water use is mounted on a horizontal roof as shown in the attached sketch. The surface temperature of the glass cover is estimated to be 40°C, and air at 20°C is blowing at a velocity of 15 mph over the roof. Estimate the heat loss by convection from the collector to the air when the collector is mounted
(a) at the leading edge of the roof [Lc = 0] and,
(b) at a distance of 10 m from the leading edge.
GIVEN
A solar collector on a flat, horizontal roof
Collector area 4 m
Glass cover surface temperature (Ts) = 40°C
Air temperature (Tair) = 20°C
Air velocity (Uair) = 15 mph
ASSUMPTIONS
Steady state
The collector surface is connected smoothly to the roof surface
Uniform collector surface temperature
Moisture in the air is negligible
Neglect radiation heat transferlosses
