权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Thermal Optimization of Plate-fin Condenser Alternative Refrigerant Mixtures

板翅式冷凝器替代制冷剂混合物的热优化

基本信息

批准号：
08650263
负责人：
KOYAMA Shigeru
金额：
$ 1.34万
依托单位：
KYUSHU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08650263/
关键词：
Condensation Plate-fin heat exchager Alternative refrigerant mixture Vertical surface Heat transfer Numerical Study Experimental Study

项目摘要

This project deals with the cxperimental and numerical research on the thermal optimization of plate-fin condenser for alternative refrigerant mixtures. Alternative refrigerants HFC134a, HCFCI23 and HFC32 and their mixtures are used as the working fluid. The effect of fin configuration on heat transfer characteristics has been clarified through this project.In the numericaI study, the laminar, film condensation on a finned vertical surface is analyzed. Thee-dimensional distribution of the condensed liquid fiIm thickness, the prcssure and the radius of liquid film in heat fiux and the Nusselt number along the vertical direction are obtained. From a series of calculation results, the effects of fin horizontal direction, the distributions of averaged height, fin pich, fin thickness and the radius of concave joint reion of base plate and fin on the liquid film shape are shown, and the effects of the fin shape parameters on heat transfer enhancement ratio are examined. The averged Nusselt number on a vertical finned surface, Nu_m, are correlated by the Bond number Bo, the Galileo number Ga_L, the phase change number Ph, and the averaged Nusselt number Nu_<mo>.ln the cxperimental study, the condensation of NARMs HFC134a/HCFC123 is carried out for a plate-fin heat cxchanger. The heat transfer characteristics of condensation of pure and mixed refrigerants are compared, and cmpirical correlation equations of the liquid film heat transfer with condensation and the single phase heat transfer of refrigerant and cooling water are obtained. The calculation method to predict the condensation chararacteristics of NARMs is dcveloped using the cmpidcal correlation equations obtained experimentally. It is shown that agreement between cxperiment and prediction is good. The mass transfer characteristics are also revealed.

本项目针对替代混合制冷剂的板翅式冷凝器进行热力优化的实验和数值研究。替代制冷剂HFC 134a、HCFCl 23和HFC 32及其混合物用作工作流体。通过本课题的研究，阐明了肋片结构对换热特性的影响。得到了冷凝液膜厚度、热流中液膜压力、液膜半径以及努塞尔数沿着垂直方向的三维分布。通过一系列的计算结果，给出了翅片水平方向、平均高度分布、翅片厚度分布、翅片与底板结合处凹部半径分布对液膜形状的影响，并考察了翅片形状参数对强化传热率的影响。本文用Bond数Bo、Galileo数Ga_L、相变数Ph和平均Nu_m关联了垂直翅片表面上的平均Nu_m<mo>。比较了纯制冷剂和混合制冷剂的冷凝传热特性，得到了冷凝液膜传热和制冷剂与冷却水单相传热的经验关联式。提出了用实验得到的经验关联式预测NARMs凝结特性的计算方法。结果表明，实验与预测结果吻合较好。并揭示了其传质特性。