【摘要】 为了研究封闭渡槽在冬季低温环境下的安全运行状况,结合中国北方寒冷地区某无压输水渡槽工程实际,通过在室内环境箱中进行渡槽比例模型试验,研究了渡槽在冬季输水过程中,水流温度受外界环境温度及流速的影响。为保证渡槽在冬季寒冷条件下的安全运行,在渡槽模型表面粘贴聚氨酯保温材料,研究了聚氨酯保温板对渡槽的保温效果,并与不粘贴保温材料时渡槽内的水流温度进行了对比。经试验发现,渡槽外壁黏贴聚氨酯保温板在防止渡槽水流温度降低方面的作用明显,减小了约45%的水流温度降低值,研究成果可为北方寒冷地区同类型工程的设计与安全运营提供参考。更多还原

【Abstract】 Areas of northern China are mainly in the temperate monsoon climate zone and temperate continental climate zone, it is cold in winter, and the air temperature is low, which has a big influence on water diversion facilities, especially aqueduct. As for closed aqueduct water diversion projects which need to be operated in winter with non-pressure water delivery in cold regions of northern China, it is of great significance to study and research the safe operation under low temperature environment in winter. With the rapid development of the construction of water diversion projects, the original research results about aqueducts mainly lie in the structural stress of the aqueduct, then the effects of fluid-solid coupling, earthquake, wind and temperature stress, and other factors are gradually considered, seismic and reliability theory is also introduced into the design of diversion facilities. For water diversion projects in northern China, the problem of the safety of water diversion under low temperature environments in winter should also be considered. The present study in freezing disease of water diversion project and safety operation in winter is relatively less, which are mainly in the fields of monitoring analysis and numerical calculation analysis. In this paper, according to an aqueduct engineering practice with non-pressure water delivery in cold region of northern China, a scale model test of an aqueduct is undertaken in an indoor environment cabinet to study the anti-freezing and insulation effects of pasting polyurethane insulation board on the surface of the aqueduct under low temperature environment in winter. In order to study the insulation effects of polyurethane insulation board on aqueduct, the tests are mainly divided into two cases: pasting and without pasting polyurethane insulation board on the surface of the aqueduct model. By the tests, the influence of the external environment temperature and rate of flow on water flow temperature during the process of water delivery of the aqueduct in winter were studied. It is concluded from the test that pasting polyurethane insulation board on aqueduct surface has obvious effects on preventing the water temperature in the aqueduct from decreasing, reducing about 45% of the water temperature reduction. In order to ensure the insulation effects of polyurethane insulation board, polyurethane insulation board should be pasted on the surface of aqueducts closely to prevent phenomena of bulging and shedding. The aqueduct is exposed to the atmosphere and is seriously affected by the temperature, so when setting aqueduct in actual water diversion project, it should not be set too long to ensure the safe operation of these projects. Test results in the paper can provide design basis and reference for the same closed aqueduct water diversion project in cold regions of northern China.更多还原