程文龙;刘畅;赵锐;陈则韶;
CHENG Wen-long,LIU Chang,ZHAO Rui,CHEN Ze-shao(University of Science & Technology of China,Hefei 230027,China)

• 1:中国科学技术大学
• 2:中国科学技术大学
• 3:中国科学技术大学
• 4:中国科学技术大学 安徽合肥230027

摘要(Abstract)：

利用滴重法测量了氨水溶液在添加剂正辛醇(1-Octanol)和异辛醇(2-EH)作用下的表面张力,该方法的测量误差在3%以内。测量结果显示:在氨水溶液中加入添加剂以后,其表面张力随着添加剂浓度的增加而减小,并最终达到一个稳定值;但是,和LiBr溶液不同,溶液表面气体侧的添加剂蒸汽对氨水溶液表面张力的影响并不明显;对于没有添加剂的氨水溶液,其表面张力随着氨水浓度的增大而近似线性降低;在添加剂作用下,当氨水浓度较低时,其表面张力随着氨水浓度的增加而增大,然而,当氨水浓度较高时,其表面张力随着氨水浓度的增大而降低。根据表面张力的测量结果,可以推测,在氨水浓度较低时,添加剂正辛醇和异辛醇会对氨水吸收过程中的传热传质起到强化作用。
The surface tensions of ammonia-water solution at different concentration without additive and with additive(2-EH and 1-Octanol) were measured by using a drop volume method which accuracy of the apparatus checked against glycerine and glycol was within 3%.For pure ammonia-water solution without additive,the surface tension of ammonia-water solution decreases linearly with the increase of the ammonia concentration.In the presence of additive,just like aqueous LiBr solution,the surface tension of ammonia-water solution decreases quickly with the increase of additive concentration,and at last reaches a stable value.Based on the measurement results in this paper,it is drawn that the effect of additives from the vapor side on the surface tension of ammonia-water solution is not very obvious,which is different from the effect of additive on LiBr solution.The experimental results also shows that at lower ammonia concentration,the surface tension of ammonia-water solution with additive of 1-Octanol or 2-EH increases with the ammonia concentration increase. The opposite concentration gradient of the surface tension between with additive and without additive can trigger the Marangoni convection during the ammonia absorption at low ammonia concentration.

关键词(KeyWords)： 氨水溶液;表面张力;添加剂;吸收
ammonia-water;surface tension;additivea;absorption

Abstract:

Keywords:

基金项目(Foundation): 国家自然科学基金(50206020);; 国家教育部留学回国人员科研启动基金项目

作者(Authors): 程文龙;刘畅;赵锐;陈则韶;
CHENG Wen-long,LIU Chang,ZHAO Rui,CHEN Ze-shao(University of Science & Technology of China,Hefei 230027,China)

参考文献(References)：

• [1]程文龙,陈则韶.添加剂对LiBr溶液吸收蒸汽过程中的强化机理[J].化学物理学报,2004,27(2):179-185.
• [2]Cheng W L,Chen Z S,Akisawa A,et al.Theoretical andExperimental Study of Surface Tension and Dynamic Sur-face Tension of Aqueous Lithium Bromide and Water withAdditive[J].Science in China,Serial E,2003,46(2):191-203.
• [3]Kang Y T,Akisawa A,Kashiwagi T.Visualization andModel Development of Marangoni Convection in NH3-H2OSystem[J].International Journal of Refrigeration,1999,22:640-649.
• [4]Kang Y T,Kashiwagi T.Heat transfer enhancement byMarangoni convection in the NH3-H2O absorption process[J].Internation Journal of Refrigeration,2002,25:780-788.
• [5]Hoffmann L,Ziegler F.Heat and Mass Transfer Enhance-ment by Additive in NH3-H2O[A].In:ISHPC’99,Proc.of the Int.Sorption Heat Pump Conf.[C].Munich,Ger-many,March 24-26,1999.297-299.
• [6]顾惕人,朱王步瑶,李外郎,等.表面化学[M].北京:科学出版社,2001.1-34.
• [7]张洪涛,李友明,胡健.介绍一种简单易行的测定表面张力的仪器[J].纸和造纸,2001,(3):66-67.
• [8]Kulankara S,Herold K E.Theory of Heat/Mass TransferAdditives in Absorption Chillers[J].HVAC&R Research,2000,6(4):369-380.
• [9]程文龙,陈则韶.关于添加剂蒸汽对溴化锂溶液吸收促进作用的实验研究[J].流体机械,2002,30(12):40-43.