高水头明流泄洪洞进口闸墩体型优化及掺气减蚀措施研究

发布时间：2018-11-18 20:32

【摘要】：随着高坝工程的不断涌现,泄水建筑物的运行水头也在不断提高。针对高水头深孔明流泄洪洞,在进口段加设中墩,可以克服工作闸门在设计、锻造和运行方面的限制,但也会带来中墩尾部危害性水翅冲击洞顶和边墙;随着泄洪洞运行水头的不断提高,最大泄水流速超过25.00m/s,易遭受空蚀破坏,实践证明,掺气减蚀技术是解决空蚀破坏最有效的方法。本论文主要研究的内容包括两个方面:中墩结构体型的优化和掺气减蚀措施的研究,其研究成果如下:(1)依据模型试验观察,传统直立式中墩在上游各级库水位下,洞身流态较差,均在尾墩合并处引起强烈的危害性水翅,而且水翅并不断地冲击洞顶和边墙,给泄洪洞的安全运行带来威胁。(2)借鉴三板溪泄洪洞中墩体型的设计思想,提出能量分配型中墩,使中墩左右两股水流从上至下沿中墩外壁逐渐汇合,分散水流汇合后引起的冲击力,经模型试验验证,能量分配型中墩能较好的减弱中墩引起的危害性水翅,改善泄洪洞水流流态。(3)结合河口村1#泄洪洞的实际工作水头和经常局部开启进行凑泄的运用要求,根据已建工程经验,布设偏心铰弧门突扩突跌通气设施。依据经验公式估算相关水力指标参数,并结合模型试验观察分析,该突扩突跌通气设施体型设计合理,掺气充分,能达到掺气减蚀的目的。(4)通过模型试验观察和分析,在工作闸门后两侧边墙增设导水板,解决在上游各级库水位下,偶尔会出现不同程度水翅冲击闸门铰现象,改善洞身水流流态。
[Abstract]:With the continuous emergence of high dam projects, the running head of drainage structures is also increasing. For the high head deep hole discharge tunnel, adding middle pier in the inlet section can overcome the limitation of design, forging and operation of the working gate, but it will also bring the harmful water wing at the end of the middle pier to impact the roof and side wall of the tunnel. With the increasing of the running head of flood discharge tunnel, the maximum velocity of discharge is more than 25.00 m / s, which is easy to be destroyed by cavitation erosion. The practice shows that the aeration erosion reduction technology is the most effective method to solve cavitation erosion damage. The main contents of this paper include two aspects: the optimization of the structure shape of the middle pier and the study of the aeration erosion reduction measures. The results are as follows: (1) according to the model test, the traditional vertical middle pier is under the water level of the upstream reservoir. The flow state of the tunnel body is poor, which causes strong harmful water wings in the combination of the tail piers, and the water wings constantly impact the roof and the side wall of the tunnel, which threaten the safe operation of the flood discharge tunnel. (2) drawing lessons from the design idea of the pier shape in the Sanbanxi flood discharge tunnel, The energy distribution type middle pier is put forward, which makes the two streams of water from top to bottom converge gradually along the outer wall of the middle pier and disperse the impact force caused by the confluence of water flow, which is verified by the model test. The energy distribution type middle pier can better weaken the dangerous water wing caused by the middle pier, and improve the flow state of flood discharge tunnel. (3) combined with the actual working head of the Hecou Village 1# flood discharge tunnel and regular local opening, it is necessary to make use of it. According to the experience of the construction project, the eccentric hinge arc door sudden expansion and fall ventilation facilities are installed. According to the empirical formula, the parameters of hydraulic index are estimated, and combined with the observation and analysis of model test, it is found that the aeration facility is reasonably designed and fully aerated, and can achieve the purpose of aeration and corrosion reduction. (4) observation and analysis of model test are carried out. In order to solve the problem of water wing impingement on the gate hinge in different degrees under the water level of the upstream reservoir the water guide plate is added to the side wall behind the working gate to improve the water flow state of the tunnel body.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TV135.2

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