Temperature monitoring and simulation analysis of the bottom orifices of Baihetan arch dam when outflowing

Abstract

For flood control, outlet structure is generally installed in the body of the dam. After pouring, the import and export of the orifice will be covered with thermal insulation materials for insulation. When the dam body is used for water storage and diversion, it is necessary to remove the heat preservation quilt. At this time, the lower temperature water will cause a effect called ‘cold shock’ on the surface concrete of the bottom orifices, in addition, under the influence of a combination of external factors such as air and water temperatures, a large temperature gradient will appear on the surface of the concrete, which will easily lead to temperature cracks. In this paper, external environment temperature, water temperature, real-time concrete surface heat exchange coefficient and the effect of solar radiation fever in the high temperature season are considered in the temperature field simulation calculation of single bottom orifice during outflowing. The calculation result indicates the simulation model is highly accurate, and the inaccuracy between the calculated and the measured temperature is within 1 °C, which provides theoretical reference for deep orifices and surface orifices in water discharge, temperature control and crack prevention.