الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 117 |  |  |
| | | from | 117 | | |
Abstract
Thermal energy storage systems offer a significant benefit to heat transfer
systems, particularly air conditioning systems, by moving the high amount of
electrical power that is consumed by air conditioning for removing cooling loads
from the on-peak period’s high power consumption period to the off-peak period’s
low power consumption period and having the capability of covering or sharing
the cooling loads with more efficiency and energy cost savings. This is a
significant advantage for heat transfer systems, especially air conditioning
systems.In this work, an experimental investigation is illustrated to study the effect of
operation parameters of heat transfer fluid and design parameters of the coil on
the time required for complete charging/discharging processes, the average
charging/discharging rate, average charging/discharging rate enhancement and
charging/discharging time enhancmenet for ice-on-coil system that utilizes bare
U-tube without fins and finned copper U-tube as part of a cold thermal energy
storage system (CTES).An experimental test rig is made up of a finned U-tube that is immersed in
distilled water as a phase change material (PCM) inside an insulated storage tank.
In this study, a total of eight alternative U-tube configurations, one of them is
bare U-tube without fins and the other seven U-tubes with a unique set of fin design criteria, are used. The results showed that the time necessary for complete
charging (solidification) is reduced while the average charging rate is enhanced
with the decrease in HTF inlet temperature, the increase in HTF volume flow rate,
the increase in Fin length ratio and the decrease in pitch ratio. In addition, the
time necessary for complete discharging (melting) is decreased and the average
discharging rate is increased with the increase in HTF inlet temperature, HTF
volume flow rate, Fin length ratio, and the decrease in pitch ratio. Also, during
the charging process, changing HTF volume flow rate from (10 to 20 l/min) on
bare U-tube at constant HTF temperature (-10°C) leads to reduce charging time
by 17 % and increasing average charging rate by 20 %, increasing Fin length ratio
from (0 to ) on finned copper tubes with pitch ratio (s /d =1) leads to reduce
charging time by 60 % and increasing average charging rate by 75%, decreasing
pitch ratio from (1.5 to 0.75) on finned copper tubes with fin length ratio ( L/d
=1) leads to reduce charging time by 20% and increasing average charging rate
by 15%.