冻结管差异温度强化冻结试验与数值分析

针对立井冻结工程中存在的局部难冻结地层,为对其强化冻结,提出了冻结管差异温度强化冻结方案。为验证差异温度的强化冻结效果,进行了单管冻结试验,同时基于有限体积法(FVM)原理,进行了强化冻结段-35℃、-40℃和-45℃三种条件下的单排管三维数值分析,并研究了冻结管上、下不同温度段的冻结温度场分布规律及冻结壁特征。结果表明:冻结管内可实现差异温度冻结,冻结管强化冻结段可显著增加冻结壁厚度、降低冻结壁平均温度并强化地层的冷能耗散,使局部地层受到强化冻结。

Intensified freezing tests and numerical analysis of finite volume method for different temperature in freezing pipes

Some strata are difficult to be frozen for its thermal properties or water environment in some shaft construction projects by using artificial freezing method. A freezing suggestion of flowing two types of negative temperature solutions in a freezing pipe is proposed to intensify freezing. To verify the effect of such freezing method, single freezing pipe tests are conducted in a model test box using two sets of circulatory systems to provide calcium chloride solution of different negative temperatures. Three dimensional numerical analysis of intensified freezing is calculated by using FVM method. The intensified freezing section of freezing pipe has a boundary condition of different temperature, -35℃,-40℃ and -45℃. The mesh model is calculated to analyze temperature field distribution laws and characteristics of frozen wall in different level of freezing pipe. The results show that the difference of temperature can be realized between adjacent outer walls of the two different temperature sections of a freezing pipe. Such two different temperature freezing method can increase thickness, reduce average temperature and intensify cold energy dissipation.