Boiling heat transfer and critical heat flux in pool boiling of ammonia-water mixture

氨水混合物池沸腾的沸腾传热和临界热通量

基本信息

批准号：
11650229
负责人：
MONDE Masanori
金额：
$ 2.3万
依托单位：
Saga University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11650229/
关键词：
Ammonia-water Mixture Boiling heat transfer Pool boiling Heat transfer 二成分媒体

项目摘要

Heat transfer coefficient has been measured during pool boiling of ammonia-water mixture at a ammonia mass concentration ranging from C=0.5 to 1 at a higher pressure of P=0.7 to 1.5 MPa and from 0 to 0.3 at a lower pressure of 0.1 to 0.7 MPa. The characteristics of heat transfer can be categorized into three parts depending on heat fluxes such as low, high and second transient heat flux regions. In the present study, the heat transfer coefficients are treated in the two regions of high and second transient heat flux regions. The heat transfer coefficients dramatically decrease in the mass concentration ranging from C=0.1 to 0.9 compared with those for both the pure liquid. However, the heat transfer is found to become around range of 0.97 larger than that for ammonia. On comparison of the measured heat transfer coefficients and several existing correlations, it is found that no correlation can predict the heat transfer coefficients well. Therefore, a new correlation is proposed by revising the Stephan and Korner correlation, since their correlation shows a similar trend. The correlation can be given in the following form :h=1/B ((1-C)/h_1+C/h_2)where B=1+A_0|y_1-(1-C)|(0.88+0.12P), and h_i=d_i(P/P_s)^n(fξq)^b/R of i=1 and 2 are heat transfer coefficients for each pure liquid given by Nishikawa and Fujita. The value of y_1 is mss concentration of water vaporThe heat transfer coefficients can be predicted well by the above correlation with the value listed in Table.

传热系数是在氨水混合物池沸腾过程中测量的，氨质量浓度范围为C=0.5至1，较高压力P=0.7至1.5 MPa，以及0至0.3，较低压力0.1至0.7根据热通量，传热特性可分为三个部分，例如低热通量区域、高热通量区域和瞬态第二热通量区域。与纯液体相比，在高和第二瞬态热通量区域中，传热系数在质量浓度范围内显着降低。比氨的传热系数大0.97。通过比较测量的传热系数和现有的几个相关式，发现没有一个相关式能够很好地预测传热系数，因此，通过修改Stephan和Korner提出了一个新的相关式。相关性，因为它们的相关性显示出相似的趋势：h=1/B ((1-C)/h_1+C/h_2)，其中 B=1+A_0|y_1-(1- C)|(0.88+0.12P)，并且 i=1 和 2 的 h_i=d_i(P/P_s)^n(fψq)^b/R 是给定的每种纯液体的传热系数由 Nishikawa 和 Fujita 提出，y_1 的值是水蒸气的 mss 浓度。通过上述与表中列出的值的相关性可以很好地预测传热系数。