الفهرس 
Thermal energy consumption and efficient utilizationOnly 14 pages are availabe for public view
 |  | from | 167 |  |  |
| | | from | 167 | | |
Abstract
Liquid-to-air cross-flow heat exchangers have a low heat transfer coefficient
on the gas side due to poor thermal characteristics of air. One of the conven-
tional solutions of this problem is to attach extended surfaces on the gas side,
thus increasing the surface area of heat to transfer by convection. In this
study, experiments were carried out to evaluate the thermal and hydraulic
performance of four modules of cross flow heat exchangers. One is bare
copper tubes and three wire mesh heat exchangers of different mesh spacing.
Hot distilled water was pumped into the copper tubes at a constant flow rate
of 9 l/min and inlet temperature of 80oC. The heat exchanger was subjected
to external cross airflow inside an air duct of 20 cm x 20 cm cross-sectional
area with an average air velocity of 2.8 m/s up to 14.9 m/s. Results showed
an enhancement of Nusselt number for all wire mesh modules that is an in-
crease of the volumetric heat transfer coefficient of up to 113.9% among the
three tested modules, compared to the bare module. The significance of this
study is to use reasonably-priced wire mesh and maintain enhancement of
the rate of heat transfer.