Effect of Boiling Condition on Vapor Concentration during Boiling of Liquid Mixture

沸腾条件对液体混合物沸腾过程中蒸气浓度的影响

基本信息

批准号：
10650204
负责人：
UTAKA Yoshio
金额：
$ 2.24万
依托单位：
Yokohama National University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10650204/
关键词：
Nucleate Boiling Mixture Generated Vapor Concentration Condensation Dew Point Method Laser Absorption Method 沸騰蒸気濃度気泡物質伝達

项目摘要

Recently, the utilization of the non-azeotropic working fluid in the cycle is developing for achieving high performance liquid-vapor two-phase cycle and for the various usage of the working fluid. It is important to clarify the characteristic of the vapor-liquid phase change process of the mixtures. The objective of the study is to clarify the effect of the boiling condition of liquid mixture in the nucleate boiling process on the composition of the generated vapor. The vapor concentration measurement was carried out in the bulk vapor layer in the saturated pool boiling process of water-ethanol and ethanol-acetone mixtures from the thin heated wires. Two kinds of measuring method ; the dew-point method by using the dew-point measurement and the known liquid-vapor equilibrium relation, and the laser light absorption method by using the property of infrared light absorption to the vapor of hydrocarbon were adopted. As the result, it was clarified that the vapor concentration in the bulk … More vapor layer which was generated by the nucleate boiling was in equilibrium with bulk liquid and was independent on the boiling conditions such as the degree of surface superheat and liquid layer height etc. Next, the change of the generated vapor temperature was measured in order to clarify the variations of the temperature and concentration change of vapor in the process of the bubble generation and departure. The vapor bubble, which was created on heating surface, had comparatively large degree of superheat. The selective condensation was occurred and the temperature also lowered in the process of the departure of the bubbles. As a result, the vapor in the bubbles attained to be in equilibrium with the bulk conditions almost at the height of 3-5 mm from the heating surface. Moreover, the temperature change of vapor bubble was determined by the elapsed time from the vapor bubble generation. Thus, it was clarified that the concentration of vapor layer existed in equilibrium with the bulk state in the system in which the steady boiling and condensation was occurred. Less

最近，在循环中的非疗法工作流体的利用正在发展，以实现高性能液体蒸气两相循环以及工作流体的各种用法。重要的是要阐明混合物的蒸气液相变化过程的特征。该研究的目的是阐明核沸腾过程中液体混合物对产生蒸气组成的沸腾条件的影响。蒸气浓度测量是在薄加热线的饱和池沸腾过程中的饱和池沸腾过程中进行的蒸气层。两种测量方法；通过使用露点测量和已知的液体蒸气等效关系，以及通过将红外光吸收的特性与碳氢化合物蒸气使用的特性，使用激光吸收方法。结果，澄清说，整体中的蒸气浓度是……核沸腾产生的更多蒸气层与大量液体平衡，并且独立于沸腾条件，例如表面超热和液体层高度等沸腾条件等，接下来，在温度和浓度变化中阐明了生成的蒸气的变化，以阐明生成的蒸气的变化。在加热表面上产生的蒸气气泡具有相对较大的超热。发生了选择性缩合，并且在气泡出发过程中温度也降低。结果，气泡中的蒸气处于平衡状态，与加热面的高度几乎在3-5毫米处。此外，蒸气气泡的温度变化取决于蒸气气泡产生的经过的时间。这就是澄清的，蒸气层的浓度与稳定的沸腾和凝结的系统中的稳定状态平衡。较少的