摘要
针对外壁恒温条件下单管冻结相变热传导问题,根据冻结峰面分成冻结区和未冻结区,采用变量替换方法进行了温度场解析分析,获得了冻结峰面半径与冻结时间呈平方根关系,以及采用指数积分函数表示冻结区和未冻结区温度以及相应无量纲温度的计算公式;为数值计算简便,给出了冻结温度场中指数积分函数的高精度低阶多项式表示;获得了冻结管壁热流密度的解析算式。通过算例说明了外壁恒温条件下单管冻结温度场的分布规律,结果显示,冻结温度场呈对数型函数分布,且其曲率随冻结时间的增加而迅速减小,以及未冻区范围约为冻结峰面半径的4倍。
Aiming at the phase transition of thermal conduction in the outer wall temperature constant condition for a single freezing pipe,frozen field and non-frozen field were separated by the freezing frontal edge,the temperature field was analyzed using the method of variable substitution.The results was obtained,such as：the relation between the radius of freezing frontal edge and freezing time follows the square root equation,the temperature distribution of frozen field and non-frozen field and the corresponding formula for calculating the dimensionless temperature are expressed by an exponential integral function.For the easiness of numerical calculation,the higher precision and lower derivative polynomial expression of exponential integral function were given.And the analytical formula about the heat flux of freezing pipe’s wall was obtained.The distribution laws of temperature field for a single freezing pipe in the outer wall temperature constant condition were explained by example in the end.The result shows that the temperature field for a single freezing pipe is similar to a logarithmic function,its curvatures decrease with the increment of the freezing days,and unfrozen surface area is longer about 4 times than the radius of the freezing frontal edge.
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2010年第6期923-927,共5页
Journal of China Coal Society
基金
国家自然科学重点基金资助项目(50534040)
关键词
冻结管
温度场
相变热传导
热流密度
解析方法
freezing pipe
temperature field
phase change of thermal conduction
heat flux
analytical method
