Heat Transfer Characteristics and transition Mode in condensation Curves

冷凝曲线中的传热特性和过渡模式

• 批准号: 02650150
• 负责人: UTAKA Yoshio
• 金额: $ 0.9万
• 依托单位: Tokyo Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02650150/
• 关键词: Heat Transfer; Phase Change; Dropwise Condensation; Condensation Curve; Transition; Departing Condensate; Organic Vapor; ヒステリシス; 凝縮液流下

An experiment was carried out on the effect of condensate flow from upstream of the condensing surface by using a specially devised condensing block which had relatively large length in the direction of condensate flow. The heat transfer block was composed of thermally independent six copper sub-blocks to measure the local values of heat transfer, and was built to remove the effect of the edge of heat transfer surface. Two kinds of organic vapors, i. e. propylene glycol and ethylene glycol vapors, and octadecanethiol adsorbed on the condensing surface were used as a test vapor and a promoter realizing the lyophobic surface, respectively. The results of the distributions of local heat flux and heat transfer coefficient, the aspect of condensation and the surface fractions covered by condensate flowing from upstream were shown. Further, it was clarified that the number density of the rivulets of depdrting condensate formed in the transition region and the dependencies of maximum heat flux and the surface fraction covered bydeparting condensate at the maximum heat flux point on the direction of condensate flow were determined systematically by using non-dimensional distance normalized by the departing drop diameter.

采用特制的在凝结水流动方向上长度较大的凝结水块，对凝结水流动对凝结水上游流动的影响进行了实验研究。传热块由6个热独立的铜子块组成，用于测量局部换热值，并消除了传热面边缘的影响。以吸附在冷凝表面的两种有机蒸汽（丙二醇和乙二醇蒸汽）和十八烷硫醇分别作为测试蒸汽和促进剂实现疏水表面。给出了局部热流密度和换热系数的分布、凝结方向和上游流动的凝结物覆盖的表面馏分。进一步阐明了用分离液滴直径归一化的无量纲距离，系统地确定了在过渡区形成的分离凝析液小流的数量密度，以及最大热流密度点分离凝析液覆盖的表面分数和最大热流密度点的最大热流密度与凝析液流动方向的关系。

项目成果

Yoshio Utaka: "The Effect of Condensate Flow in the Dropwise Condensation Curves." Proc.ASME/JSME Thermal Engineering Confernce. 1. 451-458 (1991)

Yoshio Utaka：“滴状冷凝曲线中冷凝水流动的影响。”

Yoshio Utaka: "The Effect of Condensate Flow in the Condensation Curves" Proc. 28th National Heat Transfer Symposium of Japan. 3. 874-876 (1991)

Yoshio Utaka：“凝结曲线中凝结水流动的影响”Proc。

Yoshio UTAKA: "The Effect of Condensate Flow in the Dropwise Condensation Curve" Proc.3rd ASME・JSME Thermal Engineering Joint Conference. 2. 451-458 (1991)

Yoshio UTAKA：“滴状冷凝曲线中冷凝水流动的影响”Proc.3rd ASME/JSME 热工联合会议。2. 451-458 (1991)

宇高 義郎: "凝縮曲線における凝縮液流下の影響に関する研究" 日本機械学会論文集. 57. 661-669 (1991)

Yoshiro Udaka：“冷凝水流动对冷凝曲线的影响的研究”日本机械工程师学会学报 57. 661-669 (1991)。

Yoshio Utaka: "The Effect of Condensate Flow in the Dropwise Condensation Curves" Proc. ASME/JSME Thermal Engng. Conf.1. 451-458 (1991)

Yoshio Utaka：“滴状冷凝曲线中冷凝水流动的影响”Proc。