SIMILARITY CRITERION OF FREEZING PIPE AS HEAT
SINK DURING HEAT EXCHANGE
LI Dongyang1，2，LIU Bo1，3
(1. School of Mechanics and Civil Engineering，China University of Mining and Technology，Beijing 100083；2. Guangxi Key Laboratory of Disaster Prevention and Structural Safety，Nanning 530004；3. State Key Laboratory of Geomechanics
and Deep Underground Engineering，Beijing 100083)
Abstract：This article is aimed to solve the similar-transformation problem in using freezing pipes as the heat sink in the freezing model test. Considering the heat exchange between the flowing brine and the freezing pipe is the convection boundary condition，the similarity criterion between the prototype and the model is derived according to the theory of similar simulation. Theoretical analysis shows that the similarity of freezing pipe between prototype and model could be satisfied only if the product of geometric scale ratio and convection heat transfer coefficient scale ratio is equal to thermal conductivity scale ratio of frozen soil. Coefficients of forced convection heat transfer formula for brine at －30 ℃(Reynolds number in 533～2 143) was obtained in the experiment. The results of similar model test show that it is necessary to set brine flow rate of the freezer model in model experiment based on heat sink similarity criterion of freezing pipe in addition to setting brine temperature，especially under laminar condition. Some error would occur in model temperature field if the actual brine flow rate is larger or smaller than the setting value.
2015, Vol. 34 
