摘要
以江西省某供水工程为例,针对重力流和加压泵刚性串联供水系统的停泵水锤防护问题,基于停泵水锤计算模型,从泵出口阀驱动方式选择、最小水锤压力防护标准拟定、泵出口阀关闭规律优化、空气阀水锤防护效果等方面开展水锤防护研究。结果表明,该类供水系统在事故停泵、泵出口阀拒动工况下,水泵将最终稳定在正转、正流、负扬程的制动耗能工况区,因此泵出口阀必须采用外力驱动才能实现机组断流。事故停泵后,水泵上游段将首先产生升压波而水泵段将首先产生降压波,由于水泵进水管不允许进气,水泵上、下游管段的最小水锤压力可分别按+2m和-2m控制。根据实例工程特点,泵出口阀两段关闭优于线性关闭,但对水泵出水管线中的负压和汽化现象无改善作用;在水泵下游管段合理设置防水锤型空气阀,可有效改善负压状况。
Taking a water supply project in Jiangxi Province as an example,the water hammer prevention of water supply system with rigid series connection between gravity flow and boosting pump is studied from the aspects of pump outlet valve driving mode selection,the minimum water hammer pressure protection standard,pump outlet valve closing rule optimization and air valve water hammer protection effect.The results show that for this type water supply system,the pump will eventually stabilize in the braking energy dissipation zone with positive rotation,positive flow and negative lift under the condition of the accident pump-stopping and the pump outlet valve refusing to close.So,the pump outlet valve must be external force driving valve to achieve cut-off the flow of unit;After the accident pump-stopping,a positive pressure wave will be generated in the pipeline between upstream reservoir and pump,while a negative pressure wave will be generated in the pipeline between pump and downstream reservoir.Because that the pump inlet pipeline does not allow air intake,therefore,the minimum water hammer pressure protection standard of the pipeline between upstream reservoir and pump should be controlled by above 2 m,while that of the pipeline between pump and downstream reservoir can be appropriately lowered to-2 m;For the example water supply system,the effect of two-stage closure of the pump outlet valve is better than that of linear closure,but it has no improvement on the negative pressure and vaporization in the pipe-line between pump and downstream reservoir.The reasonable setting of water hammer preventing type air valves in the pipeline between pump and downstream reservoir can effectively improve the negative pressure condition.
作者
高宇洋
李玲玲
刘志勇
GAO Yu-yang;LI Ling-ling;LIU Zhi-yong(School of Power and Mechanical Engineering,Wuhan University,Wuhan 430072,China;Yunnan Institute of Water&Hydropower Engineering Investigation,Design and Research,Kunming 650021,China)
出处
《水电能源科学》
北大核心
2024年第11期150-154,共5页
Water Resources and Power
基金
国家重点研发计划(2021YFC3000205-06)
云南省高层次人才及创新团队(2018HC024)。
关键词
重力流和增压泵串联
泵出口阀
停泵水锤防护
空气阀
gravity flow connection with boosting pump in series
pump outlet valve
pump-stopping water hammer prevention
air valve
