添加剂对流动沸腾压降的影响

来源期刊：中南大学学报(自然科学版)1995年第2期

论文作者：邱运仁

文章页码：271 - 274

关键词：添加剂; 流动; 沸腾; 压降

Key words：additives; flow; boiling; pressure drop

摘    要：研究了添加剂对垂直铜管内流动沸腾压降的影响。实验介质为水,所用的添加剂为分子量256万的聚丙烯酰胺胶乳（PAM）及十八烷胺（ODA）.测定了添加剂溶液流动沸腾两相流压降,并且用Martinelli分离流模型回归了不同添加剂浓度下的液相摩擦因子f1与液相雷诺券Ret间的函数关系.根据回归的模型方程计算两相流压降,与实验值比较其相对误差为15%左右,研究结果表明,在一定热通量和一定浓度范围内,加入少量添加剂PAM可改善流体的流动,减少流动沸腾的阻力,提高单位压降的沸腾传热系数;但ODA无明显的减阻效果。

Abstract: The effect of additives on pressure drop has been investigated on flow boiling in verticalcopper tube. The additives used in this study are polyacrylamid（PAM ）with molecularweight of about 2.56× 10⁶ and octadecrylamine（ODA）.The pressure drop is determined inflow boiling of additive dilute;the correlation between liquid phase friction factor f₁ andReynold number Re1 is curve-fitted with Martinelli model. The two-phase pressure drop iscalculated with it, and the error is about 15%.The retsults show that in a certain range ofheat flux and concentration the flow properly is improved a lot by adding a little PAM to wa-ter,and the flow drag is reduced in flow boiling.Thus the heat transfer coefficient is im-proved through unite pressure drop,but the effect on the reduction of flow boiling with ODAis not obvious.