Eperimental investigation of thermal and pressure drop performance of cross- flow wire mesh heat exchangers

الملخص EN

For the purpose of enhancing the heat transfer performance of cross-flow heat exchangers,
extended surfaces are attached on the gas side, thus increasing the surface area and lowering the
convection heat transfer resistance.

Experiments have been carried out to evaluate the
performance of four modules of cross flow heat exchangers.

All heat exchanger modules have ten
equally-spaced copper tubes in vertical alignment.

A sheet of copper woven wire mesh was
corrugated in the form of rectangular-shape.

Then, it was press-fitted to the tube to form a wire
mesh heat exchanger.

One module has bare copper tubes.

The other three wire mesh heat
exchanger modules were manufactured with 2, 3, and 4 mm wire mesh layer-to-layer spacings for
comparison purposes.

Copper tubes containing hot distilled water flow of the heat exchanger
modules, were subjected to external air flow forced convection heat transfer into an air duct
having a 20 cm x 20 cm cross sectional inside area.

The pressure drop in the air stream and the
temperature of the hot water inlet and outlet were recorded.

The significance of this experimental
work is the use of a low cost and commercially available woven wire mesh sheet as extended heat
transfer surface.

A comparison was made between the results of this study and results of other
enhanced cross-flow heat exchangers, obtained from open literature.

Results showed an
enhancement of the Nusselt number for all the wire mesh finned modules as compared to that of
the bare module.

Volumetric heat transfer coefficient results showed, an average increase of
113.9% , 91.5% , and 81.4% in the 3, 4, and 2 mm wire mesh heat exchangers, respectively, as
compared to the bare heat exchanger module.