基于瞬变流计算的特征线法，建立了真空破坏阀和单向调压塔数学模型，应用于管线末端含虹吸断流结构的输水工程。针对管线系统水锤防护问题，提出了真空破坏阀单独防护、真空破坏阀和空气阀联合防护、真空破坏阀和单向塔联合防护三种防护方案。结合管道压力控制要求，分析对比了危险工况下水泵事故掉电时三种防护方案对管线系统水力过渡过程的影响。结果表明，针对管线末端含虹吸断流结构的输水工程，真空破坏阀单独防护方案下，泵后部分管段压力降至汽化压力；真空破坏阀和空气阀联合防护方案下，虽然管道压力没有降至汽化压力，但是不能满足空气阀防护下-5 m最小压力控制标准要求；真空破坏阀与单向塔联合防护方案下，单向塔防护范围内管线最小压力为0.55 m，满足单向塔防护下管线不出现负压的控制标准要求，该方案有较好的水锤防护效果。研究结果可为管线末端含虹吸断流结构的输水工程水锤防护提供参考。

Based on the method of characteristics, the mathematical models of vacuum breaking valve and one-way surge tank were established and applied to the water conveyance project with siphon breaking structure at the end of pipeline. In view of the problem of water hammer protection in pipeline systems, three protection schemes were proposed: single vacuum breaking valve scheme, vacuum breaking valve-air valve scheme and vacuum breaking valve-one-way surge tank scheme. Combined with the control requirements of pipe pressure, when pumps are in power outage accident at dangerous conditions, three protection schemes were assessed in terms of the influence of hydraulic transition process of pipeline systems. The results show that, for the water conveyance project with siphon breaking structure at the end of pipeline, the pressure of some pipe sections behind the pump drops to the vaporization pressure in single vacuum breaking valve scheme. In vacuum breaking valve-air valve scheme, although the pipeline pressure does not reduce to the vaporization pressure, it cannot meet the minimum pressure control standard requirement of -5 m under the protection of the air valve. In vacuum breaking valve-one-way surge tank scheme, the minimum pressure of the pipeline within the protection range of the one-way surge tank is 0.55 m, which meets the requirement of the control standard that the pipeline does not exhibit negative pressure under the protection of the one-way surge tank, and this scheme has a good water hammer protection effect. The research results can provide reference for water hammer protection in water conveyance project with siphon break structure at the end of pipeline.

国家重点研发计划(2016YFC0401810)；江苏省第五期“333工程”培养资金(BRA2018061)