Study on Effect of Number of Transparent Covers and Refractive Index on Performance of Solar Water Heater

Table 1

Specification of flat plate collector.

Description	Specification
Collector dimension (Length × Width)	1.6 m × 1.1 m
Collector type	Flat plate
Absorber dimension (Length × Width)	1.5 m × 1.0 m
Plate to cover spacing	2.5 cm
Spacing between covers	2.5 cm
Thermal conductivity of plate	35 W/m-°C
Plate thickness	2 mm
Cover thickness	2 mm
Plate absorptivity/emissivity	0.95
Outer diameter of lateral tube	18 mm
Inner diameter of lateral tube	14 mm
Tube center to center distance	12 cm
Glass cover absorptivity/emissivity	0.88
K	0.0524 per plate
Adhesive resistance	Negligible
Fluid to tube heat transfer coefficient	205 W/m^2-°C
Water flow rate	70 kg/hr
Inlet water temperature	60°C
Ambient temperature	25°C
Wind speed	3.1 m/s
Back insulation thickness	5 cm
Insulation thermal conductivity	0.04 W/m-°C
Side loss coefficient	10 percent of bottom loss
Collector tilt	Latitude (12.916)
Surface Azimuth angle	0°
Date	January 21st
For January 21st , , value	610 W/m^2, 0.00, 0.242
Location of flat plate collector	VIT University (12.96°N, 79.15°E)