Convective heat transfer enhancement by corona discharge in a wire–cylinder electrostatic precipitator with the water-cooling system

Abstract

Aiming at the current wet plume problem, we present a novel technique to integrate electrostatic precipitator (ESP) and heat exchanger in order to simultaneously increase heat exchange efficiency, collect water and control particle emission from flue gases. Unlike the conventional ESP, a lab-scale wire–cylinder type ESP with the collection electrode cooling by water is used for investigations in this paper. Our research indicates that the heat transfer coefficient of the ESP rises with reducing gaseous velocity, increasing applied voltage, corona current or gas temperature. The maximum improvement of the total heat transfer coefficient of 271% was achieved at 0.15 m/s, 80 °C and 16 kV of the negative discharge. Moreover, the presence of Particle matters can enhance the heat transfer coefficient by 9%–16%. The ionic wind, which is quantitatively expressed by electro-hydrodynamic number, plays a key role in modifying the gas flow patterns and consequently improving the heat exchange coefficient. For lowering the overall energy consumption, it is suggested that the ESP should be operated at a specific mode of low voltage and high current.