摘要
运用水锤理论及特征线法,结合某高扬程泵站工程,对压力波动预止阀在泵站水锤防护过程中的作用和有关工作参数设定方法进行了研究.通过计算压力波动预止阀在13种开启方式和10种关闭方式下的水力瞬变过程,发现压力波动预止阀能够有效防护系统最高压力,但在某些情况下也可能使系统最低压力进一步降低.压力波动预止阀低压开启时间、维持开启时间和关闭时间是影响水锤防护效果的关键参数,3个参数之间存在最佳组合,能够使输水管线最高压力控制在最低水平,最低压力下降程度最小.对于压力波动预止阀的开启过程,要求在事故停泵后第1个压力波峰到来之前完全开启;为了防止因外泄量过多导致系统最低压力进一步降低,建议维持开启时间要短.随着压力波动预止阀关闭时间的增长,系统最高压力不断降低,越有利于高压水锤的防护.研究结果对新建及现有的带有压力波动预止阀的高扬程泵站水锤防护,具有重要参考价值.
Effects of surge anticipation valve on water hammer process in a pumping station with high head were analyzed by means of the water hammer theory and method of characteristics,the optimized combinations of the related parameters of the valve were explored as well.The transient processes were analyzed under 13 opening and 10 closing modes for the surge anticipation valve.It was found that the surge anticipation valve can effectively suppress the highest pressure in the pumping station system;unfortunately it also can reduce the lowest pressure in the system in some circumstances.The opening time period,fully opening time period and closing time period are the three key parameters that affect the protective effect on water hammer pressure for a surge anticipation valve.There is an optimal combination among them to keep the highest pressure being at the lowest level and with a minimum drop in the lowest pressure.Also,it was found that the valve must be fully opened before the first pressure wave arrives under the accidental pump-stop condition.To avoid further declination in the lowest pressure caused by too much water leakage,it is suggested that the fully opening time period should maintain short.The highest pressure in the system declines with increasing closing time period;so a longer closing time period is more in favor of protective effect on water hammer pressure for an anticipation valve.The results may be useful to water hammer protection with surge anticipation valves in a newly built or existing pumping station with high head.
出处
《排灌机械工程学报》
EI
北大核心
2013年第5期413-417,共5页
Journal of Drainage and Irrigation Machinery Engineering
基金
"十二五"国家科技支撑计划项目(2012BAD08B03)
国家自然科学基金资助项目(51139007)
水利部科技推广计划项目(1261222210012)
关键词
泵站
高扬程
压力波动预止阀
水锤
水力过渡过程
pumping station
high head
surge anticipation valve
water hammer
hydraulic transient
