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 co 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, 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.