含不凝气体的蒸汽直接接触冷凝换热研究综述-NSFC.DOCVIP

PAGE \* MERGEFORMAT PAGE \* MERGEFORMAT 3 含不凝气体的蒸汽直接接触冷凝换热研究综述 张俊霞 （榆林学院能源工程学院） 摘 要 蒸汽直接接触冷凝因有着较高的换热系数而在工业领域广泛应用。本文综述了近年含不凝气体的蒸汽直接接触冷凝换热研究进展，给出了纯蒸汽以及含不凝气体的蒸汽接触冷凝换热的特点，包括高热流区的界定、不同参数对蒸汽冷凝的影响、以及轻重不凝气体在气膜层中的浓度分布等。特别讨论了气液界面波动的实验测量和数值模拟工作。基于现有研究成果发现，气液界面波动的检测有较大困难，气液界面波动的发展趋势、影响因素及其对蒸汽冷凝的影响机制和定量描述方面仍有大量工作需要展开。 关键词 直接接触冷凝 不凝气体 波动效应 KH波 Review of direct contact condensation of vapor in the presence of non-condensable gases Junxia Zhang1 1 School of energy engineering, Yulin University, Shaanxi Province, China, 719000 Abstract:Direct contact condensation of vapor has a higher heat transfer coefficients, which has been widely applied in the industrial fields. A review of direct contact condensation of vapor in the presence of non-condensable gases was carried out. The characteristics of direct contact condensation heat transfer for pure vapor and vapor with non-condensable gases were analyzed, such as the determination of the highest heat flux region, the effects of various parameters on condensation of vapor, the concentration distributions of both lighter and heavier non-condensable gases and so on. Especially, the experimental measurements and numerical simulations were discussed for the wave of gas-liquid interface. On the basis of present research findings, it is found that there are larger difficulties in detecting the wave on the gas-liquid interface. There is still a large amount of work to need to be carried out in exploring its developing tendency, the key factors, the formation mechanism and quantitative description. Keywords:Direct contact condensation, non-condensable gas, wave, Kelvin-Helmholtz instability 直接接触冷凝换热器具有防堵塞、体积紧凑和换热效率高等优点，已经被广泛应用于煤化工工业、天然气燃烧、钢铁快速冷却及核工业。由于换热器泄漏、油气中各组分的挥发温度不同等原因，特别是在烟气冷凝余热回收和荒煤气中煤焦油蒸汽的冷凝回收中，含不凝气体的蒸汽冷凝是直接接触冷凝中普遍存在的现象。 本文将从含不凝气体的蒸汽直接接触冷凝换热特点、不凝气体对蒸汽直接接触冷凝换热的影响及气液界面的波动效应几个方面对目前国内外直接接触冷凝研究进展进行综述。 1含不凝气体的蒸汽直接接触冷凝换热的特点 含不凝气体的蒸汽与冷却水直接接触冷凝模式分为四种[1]，蒸汽在下流水柱上的直接接触冷凝，又称为喷射型(jet and sheet type)，如图1中a)所示；蒸汽在水雾中的逆流接触冷凝， 又称为珠状型(drop type)，如图1