基于辐射换热的二甲醚超临界蒸发.docVIP

中国工程热物理 工程热力学与能源利用 学术会议论文 编号121002 基于辐射换热的二甲醚超临界蒸发 许伟康，魏明锐，刘近平，余小梅 (武汉理工大学汽车工程学院，武汉 430070) 摘要：以SRK方程为基础，采用GE-EOS方法建立DME-N2系统相平衡，以及高温高压下的扩散系数等物性参数的计算方法，以这些为基础，建立DME单液滴超临界蒸发模型。并考虑热辐射对液滴蒸发的影响。计算结果表明高压下流体物性参数较大地偏离常压值，GE-EOS法计算所得相平衡数据比传统方法更接近实验数据，热辐射可以加快液滴温度上升和减少液滴寿命，Soret效应与Dufour效应在常温常压下可以忽略，但随着压力与温度的升高，这种耦合效应变得明显，并分析了在发动机实际工况下二次破碎对液滴寿命的影响。 关键词：超临界压力；辐射；二次破碎；耦合效应 中图分类号： 文献标识码：A 文章编号：121002 DME supercritical evaporation based on the radiative heat transfer XU Wei-kang, WEI Ming-rui , LIU Jin-ping, YU Xiao-mei (School of Automobile Engineering, Wuhan University of Technology, Wuhan 430070, China) Abstract：Using DME-N2 system Phase equilibrium which is established on the basis of GE-EOS method with modified SRK EOS, and the calculation methods of the fluid physical property parameter such as the diffusion coefficient in high temperature high pressure, DME single droplet supercritical vaporization model is established, which includes the impact of thermal radiation on droplet evaporation. The simulation results show that the fluid physical property parameter in high pressure deviate largely from those in normal pressure, and the calculation results of the DME-N2 phase equilibrium are close to the experimental data more than traditional methods, radiation heat can speed up the temperature rise and reduce the droplet lifetime. Soret effect and Dufour effect can be ignored in NTP(normal pressure and temperature), but the two effects will be more obvious with the rise of pressure and temperature. While the influence of droplet secondary breakup on droplet lifetime at the actual operating condition in the cylinder is analyzed in the paper. Key words：Supercritical Pressure; Radiation; Secondary Breakup; Coupling effect 引言 通常而言，发动机缸内压力可达120atm或更高，气的温度可超过1200K，因此多数燃料喷雾蒸发过程都是在临界温度和压力附近或以上完成的。目前国内大部分的喷雾与燃烧模型都是基于常温常压，所得结果存在一定局限性。 随着高压理论的逐步完善和实验设备的