Analysis of the Advantages of Liquid Nitrogen Freezing with Multiple Feed-pip
(1 Guangzhou Metro Design & Research Institute Co., Ltd, Guangzhou 510010; 2 Department of Geotechnical Engineering, Tongji University, Shanghai 200092; 3 Key Laboratory of Geotechnical and Underground Engineering of the Ministry of Education, Tongji University,Shanghai 200092)
Abstract：
With conventional liquid nitrogen supplying type, there are problems of uneven distribution of tempera? ture field and unbalanced development of permafrost for the liquid nitrogen freezing.The freezing uniformity can be improved to certain extent by opening on the liquid-supplying copper pipe but it still has the difficulty of distribution controlling of liquid nitrogen. Based on the prototype experiment of liquid nitrogen, this paper analyzes the superiority of multi-pipe liquid supply on system controlling and improvement of uniformity of liquid nitrogen freezing.The research shows that the multi-pipe supply increases the temperatures inside freezing pipe, pipe wall and soil mass and improves the vertical distribution uniformity of permafrost contour along the freezing pipe, overcomes the difficulty to control the distribution at various liquid supplying holes, guaranteeing the temperature stability inside freezing pipes.
GUO Xiaodong1 HU Xiangdong2,
3
.Analysis of the Advantages of Liquid Nitrogen Freezing with Multiple Feed-pip[J] MODERN TUNNELLING TECHNOLOGY, 2020,V57(3): 141-146
2020, Vol. 57 