HEAT TRANSFER AND PRESSURE DROP CHARACTERISTICS IN AN EHD-ENHANCED FINNED-TUBE GAS-TO-GAS HEAT EXCHANGER

The potential of the electrohydrodynamic (EHD) enhancement technique when used in conjunction with finned tubes for compound heat transfer enhancement in a gas-to-gas heat exchanger was studied experimentally. Experiments included evaluation of heat transfer and pressure drop characteristics when the electric field was applied to the tube side of the heat exchanger, to the shell side, and simultaneously applied to the tube and shell sides. In each case heat transfer enhancements and pressure drop characteristics are reported as a function o the Reynolds number and electric field potential in the tube and shell sides. It is demonstrated that when used in conjunction with finned tubes, the EHD technique can result an impressive improvement in the performance of the heat exchanger particularly for situations where a low temperature difference between the two working fluids in the heat exchanger prevails.