基于热-流耦合的冷却水管降温效果及其参数敏感性分析

水管管径、水管长度、管内流速、流量等因素影响着冷却水管降温效果,为了对上述因素进行优化,基于Ansys中的Fluent和Workbench平台,建立包含热流耦合与湍流模型的三维有限元模型,获得精细的混凝土温度场及水管水温沿程变化,以探讨冷却水管降温机理,以及降温效果与管内流速、管径、管长等变量之间的关系。结果表明,冷却水的流速或流量存在能够使降温效果和成本控制达到最优的值;冷却水管的降温效果与管径呈正相关;冷却水管长度、交替通水流向变换间隔与沿程效应的强度均呈线性关系。无论是流速还是流量,都存在获得较优降温效果时的合理量值;合理控制冷却水管的长度且进行交替通水,可解决沿程效应带来的降温不均匀问题。管长不大于200 m的水管,流向变换间隔时间可选择1 d,通水流量不宜大于2. 5 m3/s。研究成果对于混凝土温控措施中各参数的优化选择具有借鉴意义。

Cooling effect and parameter sensitivity analysis for cooling pipe based on thermal-fluid coupling

The factors such as diameter，length of pipe，velocity and flow rate inside the pipe affect the cooling effect of cooling water pipe. In order to optimize the factors above，the three-dimensional finite element model including thermal—fluid coupling and turbulence model is built based on the Fluent and Workbench in Ansys. The change of concrete temperature field and temperature along the water pipe can be acquired to study on the mechanism of water pipe temperature reduction，and the relationships between cooling effect and other factors such as velocity，diameter and length of water pipe. The result shows that there is an optimal value of velocity or flow rate of cooling water which can satisfy both the cooling effect and cost control. There is a positive correlation between the cooling effect and diameter of water pipe. The length of water pipe and the conversion interval of the flow transformation have linear relationship with the strength of the effect along the process. Both velocity and flow rate exist the reasonable value where the better cooling effect can be acquired. The problem of inhomogeneity temperature reduction caused by the effect along the process can be solved by controlling the length of water pipe reasonably and through the water alternately. The conversion interval of the flow transformation can choose 1 d，and the flow rate should less than 2. 5 m3 / s when the length of water pipe less than 200 m. The study result has a reference value for the parameters optimization of the concrete temperature control.