OCTOBER 19-20, 2012 - YMCA University of Science & Technology

Proceedings of the National Conference on
Trends and Advances in Mechanical Engineering,
YMCA University of Science & Technology, Faridabad, Haryana, Oct 19-20, 2012
Energy balance equations:
At Collector:
(1)
Where,
= Energy from Sun (input Energy) (W)
= Energy from storage tank to collector associated with water recycle (W)
= Energy losses due to imperfectly thermal insulation in collector (W)
= Energy from collector to storage tank (W)
At Storage Tank:
(2)
Where,
= Energy losses due to imperfectly thermal insulation in storage tank (W)
= Energy from storage tank to user (output Energy) (W)
Exergy balance equations:
At Collector:
(3)
Where,
= Exergy from sun (input power) (W)
= Exergy from storage tank to collector associated with water recycle (W)
= Exergy losses due to imperfectly thermal insulation in collector (W)
= Exergy from collector to storage tank (W)
At Storage Tank:
(4)
Where,
= Exergy losses due to imperfectly thermal insulation in storage tank (W)
= Exergy from storage tank to user (output exergy) (W)
= Exergy losses due to irreversibility in storage tank
In utilization procedure, we assume the change in kinetic energy are very small since the solar water heater is driven
by the difference of density of water, namely no great decrease in pressure is involved, so we can calculate exergy
from collector to storage tank ( ) by use the following equation. [23]
(5)
Where,
= Mass flow rate of water (kg/s)
= Outlet temperature of water from collector to storage tank (K)
= Ambient temperature (K)
= Specific heat of water {J/(kg.K)}
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