Assignment no.1

Calculate efficiency of evacuated tube solar water heater.

. By knowing efficiency we should recommend the good efficiency of solar water heater for use hot water for solar drying purpose.

In this assignment firstly find the area with the help of metric tape,

There are 32 tubes of solar water heater having 500 litres tank capacity.

for finding area firstly measure the area of one tube i.e shaded area of tube= (l*b) 1.74(m)×0.055(m)=0.0957 m^2

total no.of tubes is 32 so 32×0.0957=3.06 m^2

Measure the temperature of water in 9:00 am is 29°c and 3:00 pm is 45°c the temperature difference is 16°c

The heat energy required to heat water Q output = m× cp×∆t

. = 500×10^3×4.186×16

. = 33.488×10^6joules

. The solar energy available Q input =total area of collector*irradiance × time

. = 3.06*939 × 6×3600

. = 62.06 × 10^6 joules

Efficiency = Q output / Q input × 100

. = (33.488×10^6) / (62.06× 10^6) × 100

. = 53.94 %

Result:-The efficiency of solar water heater is 53.94%