热-流耦合作用下渡槽冬季水温变化及结冰规律  

Winter water temperature variation and ice formation patterns in aqueducts under thermal-flow coupling

作　　者：刘德仁[1,2] 任玉刚 窦顺 牛亚强 徐鹏举[1] LIU Deren;REN Yugang;DOU Shun;NIU Yaqiang;XU Pengju(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;Road and Bridge Engineering Disaster Prevention Technology National Local Joint Engineering Laboratory,Lanzhou 730070,China;Gansu Tieke Construction Engineering Consulting Co.Ltd.,Lanzhou 730030,China)

机构地区：[1]兰州交通大学土木工程学院,兰州730070 [2]道桥工程灾害防治技术国家地方联合工程实验室,兰州730070 [3]甘肃铁科建设工程咨询有限公司,兰州730030

出　　处：《农业工程学报》2025年第1期144-153,共10页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金项目(42361019)。

摘　　要：寒区引水渡槽在冬季低温环境中极易发生结冰堵塞等灾害,其输水效率受到严重影响,而目前对渡槽冬季运行特性的研究尚缺乏对多因素耦合作用的水温时空变化规律及结冰特性的深入探讨。针对该问题,研究建立了封闭式渡槽非等温流动传热三维耦合数值模型。考虑气温、水流流速、进口水温、太阳辐射及风速的影响,以渡槽水流温降值(ΔT)和温降速率(Δf_(u))为表征参数,探究封闭式渡槽冬季水温时空变化规律,并构建了渡槽水温变化及冰点预测模型。此外,考虑冰水相变对水流流动传热的影响,建立了渡槽水流结冰瞬态计算模型,研究渡槽水流结冰演变特征。结果表明:冬季低温环境中,沿渡槽长度方向的水温降幅整体呈现出先高后低的变化趋势。渡槽截面水流温降值随着流速的减小或初始水温的升高而增大,而水流流速对水温变化的影响最为明显,且在0~1 m/s区间内温降速率最大。同一工况下,渡槽固壁附近的水流温降值约为截面中心的2~4倍,太阳辐射作用导致壁面周侧的夜间水流温降值高于白昼日照期间。根据对渡槽水流结冰规律的研究可知,凝结潜热对水流温度起到一定的补偿作用,以岸冰宽度为结冰量化指标,凝冰量随时间的推移而沿程增加,渡槽背阴侧壁面附近水流比其他区域到达冰点的临界长度更短,且阴侧水体凝冰量约为阳侧的3倍。研究可为渡槽在冬季低温环境中的安全运行提供参考。Water diversion aqueducts are highly susceptible to freezing and blockage at low temperatures in winter,particularly in the cold and arid regions of northern China.There are also significant declines in the water conveyance capacity and structural performance.A great threat has then been posed to the long-term safe operation of water diversion projects in these regions.Therefore,it is crucial to the patterns of winter water temperature and the mechanisms of icing evolution in aqueducts.However,it is still lacking in the winter operational characteristics of aqueducts.This study aims to investigate the spatiotemporal variations of water temperature and icing behavior under the influence of multiple coupled factors.A threedimensional coupled numerical model was developed for the non-isothermal flow heat transfer in a closed aqueduct.Some parameters were then considered,including air temperature(Ta),flow velocity(u),inlet water temperature(T_(0)),solar radiation,and wind speed.The characteristic parameters were selected as the temperature drop value(ΔT)and temperature drop rate(Δf_(u))of the water flow in the aqueduct.A systematic analysis was implemented to explore the temporal and spatial variation patterns of winter water temperature.Additionally,a predictive model was also established for the water temperature and freezing points.The average water temperature was then calculated at the outlet section of the aqueduct under various conditions.The icing locations of the water flow were predicted under specific temperature scenarios.A two-dimensional transient icing model was established to consider the effect of the ice-water phase transition on heat transfer in the water flow in an aqueduct.The icing evolution was also obtained in the aqueduct water flow.The correctness of the model was verified to compare the indoor test data with the simulation.The results show that there was a decrease in the water temperature of the aqueduct over time in winter,especially with the increasing water delivery length.Along the l

关 键 词：温度 热流耦合 渡槽 冰水相变 数值模拟 

分 类 号：TV674[水利工程—水利水电工程]