Simulation Numerical Study Of Thermosyphon Technology To Massive Concrete Temperature Control Application

With massive concrete structures being widely used in engineer practice,their temperature field and thermal stress problems continue to increasingly attract our attention. There are a lot of temperature control measures about massive concrete structures, but for the vast water resources and energy'area, this paper will present a new temperature control methods- thermosyphon technology.Thermosyphon is a kind of passive cooling device, so far its heat transfer efficiency is the highest in the gas-liquid two phase flow circulation system, it need not the external power supply, its top is the condenser section (exothermic section), its bottom is the evaporator (heat-sink section).It is mostly used in cold regions engineering to protect the frozen soil and improve the heat stabilization of sub grade, while is seldom used in temperature control of massive concrete. Presents an analysis of the temperature distribution and heat transfer in massive concrete structures in the presence of two-phase closed thermosyphons to extract the heat of hydration of cement paste. The result of the analysis and experiment show that the temperature rise in the concrete during the early stages of curing under various conditions can be effectively controlled by changing the thermosyphons'radius and their operating temperature. Controlling the temperature gradients will protect massive concrete structures from thermal cracks and result in high strength and low permeability.This paper presents the model of the massive concrete's temperature field with thermosyphon, massive concrete's temperature field is transiently simulated by using ANSYS software, and finite element simulation analyses the massive concrete temperature field and stress field and after introducing the thermosyphon technique,there are big changes in massive concrete temperature field and thermal stress field. By contrast analysis, in the functional range of thermosyphon, the results show that the thermosyphon method is a very efficient measure for massive concrete temperature control, the heat of hydration could be transferred effectively by using thermosyphon, which lead to a reduction of temperature rise, as well as an acceleration of the rate of temperature rise and a shortage of the period for achieving stable temperature. And the results were compared with field test results of Tsinghua university, confirmed the reliability of simulation experiment results.