Numerical Study of Heat Transfer for Gravity-Driven Particle Flow along a Vertical Oscillating Pin-Fin Plate

Abstract

Nowadays, moving bed heat exchanger (MBHE) is being gradually applied in the fields of industrial waste heat recovery and solar energy utilization, due to its easy production of clean energy and low cost. However, the heat transfer performance of the MBHE is relatively poor. In the present paper, the heat transfer performance of gravity-driven particle flow in a pin-fin plate heat exchanger unit (PFPHEU) is numerically studied using discrete element method. The effects of pin-fin and plate oscillation on the heat transfer of gravity-driven particle flow along a vertical plate are carefully analyzed. The results show that, the heat transfer coefficient of the static PFPHEU is about 12.5 % less than that of the PWPF due to the higher porosity around the pin-fin compared to the plate without pin-fin (PWPF). The plate oscillation can significantly improve the particle filling rate around pin-fins and enhance the thermal dispersion of particle flow. The heat transfer in a PFPHEU is enhanced, and the heat transfer coefficient of PFPHEU increased by 87.6 % and 113.5 % compared with that of PWPF as the amplitude was 1 mm and 2 mm.