矩形渡槽设计坡度与冬季水温变化关系预测  

Prediction of the Relationship between the Design Slope of the Rectangular Aqueduct and the Change of Water Temperature in Winter

作　　者：梁卓 季日臣[1] LIANG Zhuo;JI Ri-chen(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学土木工程学院,兰州730070

出　　处：《科学技术与工程》2022年第21期9306-9313,共8页Science Technology and Engineering

基　　金：国家自然科学基金(51969011)。

摘　　要：为了预测矩形渡槽坡度与水温的变化关系,避免渡槽在冬季输水期出现冰害现象,以西北地区某渡槽工程为背景,利用稳态热传导理论,采用Ansys Workbench软件建立三维有限元模型,利用牛顿冷却公式、对流换热公式以及曼宁公式进行计算。结果表明:当流量不变时,水温随坡度的变化而变化,当坡度达到1/1 100时,水流出口温度到达最小值,在设计时应当避免;当水深不变,坡度减小2.4倍时,水温下降值增大约1.6倍,可以看出,坡度变化对水温的影响比较明显。当水深为1.5 m,环境温度为-17℃,设计坡度为1/1 300时,水流出口温度低于0℃;当环境温度为-25℃,设计坡度小于等于1/750时,水流出口温度低于0℃,因此在渡槽设计时,应结合修建地区的输水流量或水深来设计最优坡度。In order to predict the change relationship between the slope and water temperature of the rectangular aqueduct and avoid the phenomenon of ice damage during the water conveyance period in winter,taking an aqueduct project in northwest China as the background,the steady-state heat conduction theory was used,the three-dimensional finite element model was established by Ansys Workbench software,and the calculation was carried out by Newton s cooling formula,convection heat transfer formula and Manning formula.The results show that when the flow rate is constant,the water temperature changes with the change of the slope.When the slope reaches 1/1100,the water outlet temperature reaches the minimum value,which should be avoided in the design.When the water depth remains unchanged and the slope decreases by 2.4 times,the water temperature drop value increases by about 1.6 times.It can be seen that the influence of the slope change on the water temperature is obvious.When the water depth is 1.5 m,the ambient temperature is-17℃,and the design gradient is 1/1300,the water outlet temperature is lower than 0℃.When the ambient temperature is-25℃and the design gradient is less than or equal to 1/750,the water outlet temperature is lower than 0℃.Therefore,when designing the aqueduct,the optimal slope should be designed in combination with the water flow or water depth in the construction area.

关 键 词：矩形渡槽 冬季输水期 坡度 水温预测 

分 类 号：TV672.3[水利工程—水利水电工程]