不同关阀规律与出水口形式对管路水锤的影响

为了研究事故工况下管线末端阀门不同关闭方式对管线末端水锤及整体水锤压力的影响,针对长距离有压输水管道建模计算存在管线简单、求解信息种类少、数据量大的特点,采用特征线法对山东莱城发电厂供水管路水力瞬态过程进行了模拟,分析了不同关阀规律对管道末端水锤的影响.结果表明,出口阀门的关闭规律对末端水锤的影响很大,由于受阀门自身限制,出口阀门按最优关闭规律关闭时仍会产生较大末端水锤,需要使用其他防护措施消除或降低末端水锤.提出并验证了一种可以有效降低末端水锤的新型管路出水口,通过对比验证发现,使用新型出水口后管线的最大内水压力由128 MPa下降至70 MPa,可以有效降低水锤压力峰值,防止由于出口阀门故障或失电而产生的管道事故,进而提高输水管道的安全稳定性,且改造成本较低.研究结果可为管道的末端水锤防护提供新的思路.

Influence of different valve closing rules and outlet form on pipeline water hammer

In order to study the impact of different closing methods of pipeline end valves on the water hammer at the end of the pipeline and the overall water hammer pressure under accident conditions,aiming at the characteristic of the modeling and calculation of long-distance pressurized water pipelines with simple pipelines,fewer types of solution information and large amounts of data,the characteristic line method was used to simulate the hydraulic transient process of the water supply pipeline of Shandong Laicheng Power Plant,and the influence of different valve closing laws on the water hammer at the end of the pipeline was analyzed.The results show that the closing law of the outlet valve has a great influence on the end water hammer.Due to the limitation of the valve itself,a large end water hammer will still be generated when the outlet valve is closed according to the optimal closing law.Other protective measures are required to eliminate or reduce the end water hammer.A new type of pipeline water outlet that can effectively reduce water hammer at the end is proposed and verified.Through comparison and verification,it is found that the maximum internal water pressure of the pipeline drops from 128 MPa to 70 MPa after using the new type of water outlet,which can effectively reduce the peak water hammer pressure and prevent pipeline accidents caused by outlet valve failure or loss of power,and will further improve the safety and stability of water pipelines,and the cost of transformation will be lower.Research results provide new ideas for water hammer protection at the end of the pipeline.