Differences of Freezing Temperature Field under Opening and Closing Conditions
(1 School of Civil and Transportation Engineering, Hebei University of Technology, Tianjin 300401; 2 Hebei Research Center of Civil Engineering Technology, Tianjin 300401; 3 School of Energy and Environment Engineering, Hebei University of Technology, Tianjin 300401; 4 Tianjin Metro Group Co. Ltd., Tianjin 300051)
Abstract：
The artificial freezing method is commonly applied to the construction of subway cross passages and for shield receiving. The formation and characteristics of the freezing curtain are influenced by factors such as the cold source and geological conditions. The engineering properties of frozen soil and frozen structures are reflected by the distribution and evolution of the temperature. Through a low-temperature heat transfer bench, the variation characteristics of temperature and moisture fields are tested for an opening system and a closing system with a water supply device, and the differences of the two fields with or without the water supply device are analyzed. The results show that the integral value along the tube length should be considered during calculation of the average temperature in the freezing region; the development process of the temperature with a water supply device is slightly faster than that without a water supply device; and the freezing front varies exponentially with time and moves faster with a water supply device.
2017, Vol. 54 