输水渠道大流量分水口门的分级分水方式

Multi-stage Diversion Modes for Large Flow Dividing Gates in Water Transportation Channel

本文以南水北调中线工程典型分水口为研究对象,采用一维非恒定流模型对不同分水口运行方式进行计算分析,研究渠道相应的水力响应现象,包括水位升高降落幅度、速率及其影响范围,建立了分水口分水比与水面线的相关关系,提出了分水口分级分水的运行方式.针对设计分水流量占渠道设计输水流量50%的西黑山分水口,计算认为:1h内一次分水流量增加最好不大于16m3/s,二次分水流量增加总量最好不大于20m3/s,将2次分水延长到2h内完成,能够较好控制水位下降速度,从而减小对渠道安全的影响.

Taking the typical dividing gates of South-North Water Transfer Midline Project as a research object, this paper calculates and analyzes the operation modes of different flow dividing gates with one dimension unsteady flow model. The corresponding hydraulic response, including the changing magnitude, velocity, and the influencing range of water level is studied, the correlation of the water diversion rate and the water surface profile is established, and the multi-stage operation mode of water diversion is proposed. Take the Gate Xiheishan, whose designed water diversion discharge is half of the designed discharge of the channel, as an example, it is recommended that, in 1 hour, the increment of dividing flow should be less than 16m^3/s by once and 20m^3/s by twice. Nevertheless, the decreasing velocity of water level would be better controlled and the influence to channel would be less if the water diversion operation by second time is accomplished in 2 hours.