摘要
为了研究长大渡槽在冬季寒冷时期输水的结冰问题,为渡槽提供保温措施奠定理论依据,以庄浪河渡槽为背景,根据稳态传热过程进行理论分析,采用ANSYS FLORTAN软件建立水体温度计算模型,利用牛顿冷却公式、对流换热公式、曼宁公式进行计算,求得水温下降值与水深变化之间的关系。结果表明:水温下降值随水深的增大而减小,当水深增大1.5倍时,水温下降值减小约1.7倍;当水深增大4.2倍时,水温下降值减小约7倍,所以应该尽量保持槽体内较高流量,控制最小水深以保证槽内水体不产生冰花。当水深小于1 m,外界温度为-25℃的极端低温情况时,槽内水体会结冰,可以考虑顶部加盖或者粘贴保温板来保温,从而达到安全输水的目的。研究成果对于渡槽的耐久性和使用寿命及冬季输水的可行性具有重要意义,也可以为类似工程提供理论依据。
In order to study the problem whether the water in the large-scale aqueduct freezes during the cold winter and provide the decision-making basis for the thermal insulation measures of the aqueduct structure,taken the Zhuanglang River aqueduct as an example,conducted theoretical analysis based on the steady heat transfer process,established the water temperature calculation model by ANSYS FLORTAN software,and calculated by using Newton cooling formula,convection heat transfer formula and Manning formula obtaining the relationship between heat loss and water depth.The result shows that,the water temperature value decreases as the water depth and the temperature increases.When the water depth increases by 1.5 times,the water temperature decreases by about 1.7 times,while when the water depth increases by 4.2 times,the water temperature decreases by about 7 times.Therefore,there should maintain a high flow rate and control the minimum water depth to ensure that the water in the aqueduct bridge does not produce ice scum.The water in the aqueduct bridge freezes while the water depth is less than 1 m and the environment temperature is-25℃.In order to ensure the purpose of safety water delivery,the top cover or paste insulation board should be considered to use.The result is of great significance to the durability and service life of aqueduct and to the feasibility of water delivery in winter,also can provide theoretical basis for similar projects.
作者
李文
季日臣
王志
LI Wen;JI Richen;WANG Zhi(School of Civil Engineering,Lanzhou Jiaotong University,Gansu 730070,Lanzhou,China;Architectural Design Institute for Anhui Jianzhu University,Anhui 230001,Hefei,China)
出处
《水利水电技术》
北大核心
2019年第6期128-133,共6页
Water Resources and Hydropower Engineering
基金
长江学者和创新团队发展计划(IRT1139)
国家自然科学基金项目(51669010)
关键词
长大渡槽
冬季
输水期
结冰水深
large-scale aqueduct bridge
winter
water delivery period
frozen depth of water
