Experimental and numerical investigation on hydraulic and thermal performance in the tube-side of helically coiled-twisted trilobal tube heat exchanger

摘要

The numerical and experimental data of the helically coiled-twisted trilobal tube (HCTTT) heat exchanger are compared, the results present that, due to more intense secondary flow of the HCTTT caused by the superposition of overall twist and self-twist, region near the center of the HCTTT has higher turbulent kinetic energy, and the region near the wall of the HCTTT is with the better Field synergy Angle. Two evaluation criteria, Performance Evaluation Criteria (PEG) and Filed synergy number (Fc) are introduced to comprehensively evaluate comprehensive performance, the results present that the HCTTT performs better in the Hydrodynamic and thermal performance than that of the helically coiled elliptical tube (HCET), helically coiled plain tube (HCPT) and trilobal tube (HCTT). In addition, compared to the HCPT, the increment ratio on Nusselt number of HCTTT is more than 19%-31%, while the augmentation ratio of flow resistance is up to 24% 38%. The novel correlations proposed in the HCTTT heat exchanger are consistent with the simulation data.