摘要
为提高再生烘干筒加热效率,以SG4000型滚筒为依托,采用CFD-DEM流体力学-离散元耦合方法模拟滚筒加热拌和时骨料颗粒运动以及与热空气热交换,分析了再生滚筒加热RAP料全过程以及不同运行参数下滚筒的加热效果。研究结果表明:烘干筒在稳定加热阶段骨料颗粒空间分布处于动态平衡状态,其中料帘区滞留的骨料数量占90%以上,骨料在料帘区加热效果最为明显;滚筒转速对出料温度具有较大影响,随着转速的增加,滚筒内滞留的颗粒减少,虽然颗粒与热空气接触面积增多,但是其滞留的时间降低,导致骨料整体升温效果下降;滚筒的转速不宜偏低,因为滞留的骨料数量可能超过滚筒最大拌和量。随着滚筒进料率的增加,滚筒内滞留的骨料数量也会增加,骨料颗粒与热空气接触面积减少,造成滚筒加热效果的降低。因此在保证再生沥青混合料及时补给以及滚筒正常工作的前提下,尽量降低骨料的进料率,同时采用较低的转速,从而能最大化滚筒加热效率。
In order to improve the heating efficiency of aggregate dryer,taking SG4000 drum as an example,the movement of aggregate particles and heat exchange with hot air are simulated by coupled CFD-DEM method.Meanwhile,the whole heating process of old material and the heating effect of drum under different operating parameters are analyzed.The results indicate that the spatial distribution of aggregate particles in the drying is in dynamic equilibrium state during the stable heating stage,in which the amount of aggregate retained in the curtain area accounts for more than 90%,and the heating effect of aggregate in the curtain area is the most obvious.The roller speed of dryer has a great influence on the heating effect.With the increase of speed,the particles retained in the drum decrease.Although the contact area between the aggregate particles and the hot air increases,the residence time of particles decreases.The lower rotation speeds of the drum are not recommended,because the amount of retained aggregate may exceed the maximum mixing amount of the drum.With the increase of aggregate feed rate,the amount of aggregate in the drum will increase,and the contact area between the aggregate particles and hot air will decrease,which will reduce the heating effect of the drum.On the premise of ensuring timely replenishment of RAP and normal operation of drum,the feed rate of aggregate shall be reduced as much as possible,and the lower speed shall be adopted to maximize heating efficiency.
作者
朱震海
纪文强
周永杰
黄玉晶
韩东东
赵永利
ZHU Zhen-hai;JI Wen-qiang;ZHOU Yong-jie;HUANG Yu-jing;HAN Dong-dong;ZHAO Yong-li(Zhejiang Communications Investment Group Co.Ltd.,Hangzhou 310000,China;National Demonstration Center for Experimental Road and Traffic Engineering Education(Southeast University),Nanjing 211189,China;School of Transportation,Southeast University,Nanjing 211189,China)
出处
《公路》
北大核心
2022年第3期11-16,共6页
Highway
基金
浙江省交通运输厅科研计划项目,项目编号2019026。
