The front surface of the glass cover of a flat plate solar collector of dimensions 1...
1. A glass plate is used as a cover in a flat plate solar collector. The transmissivity of glass is zero in the entire wavelength except in the band of 0.4 < a <3.0 um, where the value is 0.8. Assuming the sun to be black body at a temperature 5800 K, determine the average hemispherical transmissivity of glass over the entire wavelength range.
A flat-plate solar collector is used to heat atmospheric air flowing through a rectangular channel. The bottom surface of the channel is well insulated, while the top surface is subjected to a uniform heat flux 96,which is due to the net effect of solar radiation absorption and heat exchange between the absorber and cover plates. W Transparent cover plate Absorber plate Rectangular channel Air Tmi, m Beginning with an appropriate differential control volume, obtain an equation that could be used...
Determine the overall heat transfer coefficient (UL) for a Flat Plate Solar Collector inclined at 45 degrees to the horizontal and facing south. The average ambient temperature for the day is 20 degrees C and the observed glass and absorber plate temperatures are 45 degrees C and 69 degrees C respectively. The system is provided with 6 cm thick insulation (glass wool, k = 0.04 W/m degrees C) at the bottom. The air space between the absorber plate and glass...
The interior surface of an oven of internal dimensions 1mx1mx1m has an emissivity of 0.8, and is maintained at a uniform temperature of 500 K. The oven is placed in a very large room where the ambient temperature is 300K. On the front wall of the oven is a square opening of dimensions 100mmx 100mm. To reduce the heat loss through the opening, a thin metallic plate is used to cover the opening. The emissivity of the cover plate surface...
The interior surface of an oven of internal dimensions 1mx1mx1m has an is maintained at a uniform temperature of 500 K. The oven is placed in a very large room the ambient temperature is 300K. On the front wall of the oven is a square opening of dimensions ce of an o where 00mm. To reduce the heat loss through the opening, a thin metallic plate is used to cover the opening. The emissivity of the cover plate surface facing...
An unglazed flat plate solar water heater is orientated perpendicular to the sun such that the incident radiation reaching the plate is 1100 W/m2. The plate has a semi selective coating such that the plate absorptivity and emissivity is equal to unity for all wavelengths up to 2µm, and 0.13 for all λ > 2µm. Coolant flowing in the collector tubes removes heat at such a rate as to maintain the plate temperature at 80°C. Considering the sun to be...
please show me how I can finds the answers of these two examples Example 1: Design of a Solar Heater (Black bodies: no convection) A square flat plate collector is exposed to solar radiation from both the sides. The exposed surface of the plate has an absorptivity of 1.0 for solar radiation. On a clear summer day on the earth's surface the solar radiation flux is approximately 1140 W/m2 and the surrounding air temperature is 25oC. Determine the surface temperature?...
Aluminium plate painted flat black (solar absorptivity 0.98 and emissivity 0.97) Length of absorber plate is 1.2 m, width of absorber plate w = 0.8 m, Ambient air temperature = 25°C, effective sky temperature = 10°C, solar radiation rate = 600 w/m2. Calculate the temperature of the absorber plate?
Q2. Solar flat plate water heater is shown below. Solar collector Controller Hot water to the tap Tank t Cold water food Pump (a) What is the principle on which the solar collector works? Explain. (1.5 marks) (b) What is the principle on which the heat exchanger works? Explain. (1.5 marks) Q3.(a) The wavelength of radio waves is 200 m & its speed iſs 3x108m/s in free space. (1) Find the frequency of the radio waves in space? (1.5 marks)...
A solar panel (5m x 2m) is used for heating domestic water. The absorbing panel has an absorbtivity of 0.93, a top-plate symmetry emissivity of 0.9, and a back-plate emissivity of 0.05. The transmittance through the glass top cover is 0.85. With a peak radiation of 700 W/m^2 the absorber temperature is 100° C and the top-cover is 60° C. if the all the absorber heat is transferred to the water which flows through ducts in the absorber with negligible...