Session: 20-07 Combustion & Heat Transfer

Paper Number: 80808

80808 - Experimental Hydraulic Performance Study of a Primary Surface Recuperator With Cross-Wavy Microchannels for Portable Microturbines 

  Portable microturbines with high power and energy densities are attractive candidates for mobile power sources. Due to the limitation of compressor pressure ratio and turbine inlet temperature, a compact and lightweight recuperator is the mandatory component of this type of microturbines to achieve high thermal efficiency. Typically, microchannels with thin wall thickness are often used for heat transfer enhancement. However, the reduction in channel size may significantly increase the pressure drop of both fluids. Owing to the lack of existing experimental data for ultra-compact microchannel recuperators of portable microturbines, the hydraulic performance of a newly-designed primary surface recuperator with cross-wavy microchannels (CW-PSR) was experimentally studied. The 50 μm-thick heat transfer plates were used for the CW-PSR core, in which the hydraulic diameters of gas and air channels are 848.8 μm and 598.6 μm, respectively. Hence, the compactness of the CW-PSR prototype is about 2428 m²/m³. We tested the hydraulic performance of the CW-PSR both in hot and cold conditions with Reynolds number ranging from 360 to 980. The experimental results show that the pressure drops on both sides increase with increasing mass flow rate, while the hot conditions with high inlet temperature result in larger pressure drops. Besides, it was found that the pressure drop on the air side is much higher than that on the gas side due to the local pressure loss. Finally, a new correlation of friction factor in cross-wavy microchannels was obtained based on experimental results.

Presenting Author: Hui Li Beihang University

Presenting Author Biography: Hui Li is a Ph.D. student in the School of Energy & Power Engineering at Beihang University. His research interest lies in the area of compact heat exchangers design, heat transfer and fluids flow.

Authors:

Hui Li Beihang University
Zhengping Zou Beihang University
Yiming Chen Beihang University
Huan Li Beihang University
Chao Fu Beihang University