塑料冻结管冻土温度形成规律

Distribution Regularity of Temperature Field around Plastic Frozen Pipe

为了获得PVC、PPR塑料冻结管在盐水冻结的温度场分布情况,采用物理模拟实验和理论求解相结合的研究方法,研究了PVC管、PPR管和钢管的单管冻结问题,分析了3种不同材质冻结管的冻结情况,获得了冻土区温度分布规律,掌握了PVC、PPR管作为冻结管冻土的发展速率,在同种情况下PPR冻结管的速度最慢,PVC管冻结的冻土帷幕平均发展速度约为钢管冻结发展速度的0.8倍。为采用PVC管作为冻结管,确定盐水冻结时间和计算冻结壁厚度,解决盾构进出洞免拔管问题提供基本参数。

In order to get the temperature field distribution of PVC and PPR pipe as frozen pipes during freezing in salt water,a combination research method,the physical simulation experiment with theoretical solution,is adopted for studying the problem,the single pipe freezing of the PVC pipe,PPR pipe and the steel tube is studied,the frozen condition of freezing pipe with three different materials is analyzed,the temperature distribution regularity of the frozen area and the developing rate of frozen area are ascertained. Under the same condition,the PPR pipe freezing is the slowest,the PVC pipe＇s average freezing rate is about 0. 8 times of that of steel tube. Mastering the permafrost developing rate in case of the PVC pipe as frozen tube,it provides basic data for brine freezing time and calculation of frozen wall thickness,to solve the exempt-pull-out freezing pipe issue for shield in and out of a hole.