Heat Transfer Coefficient in Flow Convection of Pipe-Cooling System in Massive Concrete

Pipe-cooling has been widely used for reducing hydration heat and controlling cracking in massive concrete structures. Therefore, the heat transfer coefficients in flow convections, which represent the thermal transfer between the inner stream of the pipe and the concrete, must be estimated accurately. In this paper, a device measuring the heat transfer coefficient is developed based on the concept of internal forced convection. The main influencing factors on the heat transfer coefficient in the flow convection are the flow velocity, pipe diameter and thickness, and the pipe material. Using experimental results obtained from the developed device, a general prediction model for heat transfer coefficients is suggested. The proposed prediction model was found to estimate the heat transfer coefficient correctly with respect to the properties of the flow and pipe in comparisons of measured data and the numerical results of a heat transfer analysis conducted on an actual massive concrete structure.