管内盐水流动状态对单管冻结温度场影响规律分析

为获得冻结工程中冻结管内盐水流动状态对温度场的影响规律,分析了冻结管内盐水流动特点与流动状态;基于相似理论,导出了考虑管内盐水流动时单管冻结温度场无量纲数学模型及相应的准则表达式,将众多影响因素简化为5个无量纲准则,大大降低了研究的难度;利用综合数值计算与模拟试验,研究并获得了无量纲盐水温度Ty、雷诺准则Re、傅里叶准则Fo、普朗特准则Pr和格拉晓夫准则Gr对温度场的影响规律,分析获得了冻结壁形成厚度b和冻结管热流密度q与以上5个准则的对应关系;得出管内盐水的流动状态变化对冻结壁的厚度b及热流密度q的影响范围可达30%以上。根据不同冻结阶段温度场的发展特点,提出冻结工程中雷诺准则数Re的推荐值。

Influence law of brine flow state in pipe on single pipe freezing temperature field

In order to obtain the influence law of brine flow state in pipe on single pipe freezing temperature field，the brine flow characteristics and state in freezing pipe were analyzed.Based on similarity theory，the mathematical model and it’s corresponding criterion expression of single pipe freezing temperature field were deduced with the consideration of brine flow state.Furthermore，the corresponding criterion expression was simplified to five dimensionless criteria，which greatly reduces the difficulty of the study.Combining numerical calculation and simulation test，the influence laws of temperature field by dimensionless brine temperature (Ty)，Reynolds criterion (Re)，Fourier criterion (Fo)，Prandtl criterion (Pr) and Guerra Shchev criterion (Gr)，were obtained.The corresponding relationships between the thickness of the freezing wall (b)，freezing pipe heat flux (q)，and above five criteria were obtained.The study shows that the different flow states of brine might affect over 30 percent to the thickness of freezing wall (b) and freezing pipe heat flux (q).Moreover，according to the development characteristics of freezing temperature at different stages，the recommended value of Reynolds criterion (Re) was proposed.