DATE: 01/02/2022
INTRODUCTION: Efficiency is the ratio of energy input and the energy output by 100%.We calculate efficiency because input energy as possible should be transferred into useful energy store.
Procedure:
Firstly we measure the diameter and length of the evacuated tube with the help of metric tape.
Diameter of evacuated tube = 5.5 cm
Length of evacuated tube = 174cm
Now,
Area of one evacuated tube collector= l * b
=5.5*174 = 957 cm2
But here total 32 evacuated tube
Hence,
total area of evacuated tube collector= 957*32 =30624 cm2 =3.06 m2
Temperature of water at 9 am= 42°C
Temperature of water at 5 pm=48°C
Capacity of storage water tank = 500LPD
energy in 1 m2 = 813
Now,
Input = Total area of ETC× Energy in 1 m² ×Time
= 3.06×813×8×3600
= 71.648 × 10⁶ J
Output= Capacity of storage tank × 4.186 × Temperature difference
= 500 × 10³ × 4.186 × 6
= 12.558 × 10⁶ J
Therefore,
Efficiency of solar water heater= Output/Input
= 12.558 × 10⁶ / 71.648 ×10⁶
= 0.1752
= 17%
Result: We got the efficiency of solar water heater is 17%. This efficiency is low hence increases this efficiency with cleaning dust on evacuated tube.
