论文部分内容阅读
为研究宏观温度梯度对Marangoni凝结的影响,设计了一个截面为梯形的试验块。在大范围的酒精气相浓度条件下(0%～50%),用实验的方法研究了宏观温度梯度对Marangoni凝结的影响。对于每个浓度都在不同蒸汽流速和压力下进行了实验并拍摄凝结图片。以凝结实验中所拍摄的实验图片为分析对象,分析不同质量分数、过冷度和流速下的凝结液珠脱离半径。凝结液珠的脱离半径与表面过冷度、凝结表面的横向温差、酒精质量分数、蒸汽流速等因素有关。以纯水的脱离半径公式为基础,考虑温差带来的Marangoni效应和蒸气流速后,拟合出Marangoni凝结凝结液珠的最大脱离半径公式,在大部分过冷度的情况下,计算值与实验数据一致性较好,最大误差为23%。
In order to study the influence of the macroscopic temperature gradient on the Marangoni condensation, a test block with trapezoidal section was designed. Under a wide range of alcohol concentration (0% ~ 50%), the influence of macroscopic temperature gradient on the condensation of Marangoni was studied experimentally. Experiments were performed at each steam flow rate and pressure for each concentration and shots of condensed images were taken. Taking the experimental pictures taken in the coagulation experiment as the analysis object, the detachment radius of the condensate beads with different mass fractions, subcooling degree and flow rate was analyzed. Condensate beads off radius and the surface supercooling, the condensation surface of the lateral temperature difference, alcohol mass fraction, the steam flow rate and other factors. Based on the formula of the detached radius of pure water and considering the Marangoni effect and the vapor velocity caused by the temperature difference, the formula of the maximum detached radius of Marangoni condensation and condensation liquid beads is fitted. In most cases of undercooling, Data consistency is good, the maximum error is 23%.