DOI: 10.11799/ce202506016
Heat transfer characteristics and applications of a direct heat exchanger for mine return air waste heat
JI Xianliang
WANG Yuqiang
Abstract：In the design of the mine inlet and return air direct heat exchanger system,the structural parameters of the direct heat exchanger are generally kept the same under different operating conditions.This leads to low utilization efficiency of mine return air waste heat and an inability to meet the design requirements for the inlet air temperature.To address the issue of insufficient targeted theoretical support for this system and its key parameter design,we established a heat transfer model for the mine inlet and return air direct heat exchanger system and conducted experimental research on typical application cases.Through data fitting,a calculation formula for the Nusselt number of the return air direct heat exchanger was obtained.On this basis,we further investigated the structural parameters of the direct heat exchanger and analyzed the heat transfer characteristics of the system under various parameter conditions.The results indicate that the calculation error of the heat transfer model is within 8%.By exploring the influence of different parameters on the performance of the direct heat exchanger,a reasonable range for the tube outer diameter under certain operating conditions was determined,thereby providing a solid theoretical basis and practical guidance for subsequent engineering design.
Keywords：mine return airsurface heat transfer coefficientdirect heat exchangerheat transfer characteristics
Publication Date：2025-06-30
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：7( 126-132 )