倒流防止器压力损失试验与流场数值模拟

Pressure Loss Test and Flow Field Numerical Simulation of Backflow Preventer

低阻力倒流防止器能够有效解决供水系统回流污染问题,具备密封性能好、压力损失小的优点,受到业界广泛关注和好评。介绍了低阻力倒流防止器的结构特点及工作原理,运用阀门流量流阻装置对LHS743X-16Q DN100倒流防止器进行了压力损失试验。试验结果合格,并验证了其低阻力特性。数值模拟了倒流防止器全开状态、不同流速下的流场分布,由速度分布云图观测到中腔主流介质呈现出S形流动,由压力分布云图观测到压力主要是以2个止回阀瓣为分割呈现3段式分布。对比分析试验结果与模拟结果,判定倒流防止器工作过程基本可达全开,并验证了数值模拟方法的可行性,为倒流防止器结构设计与优化提供一种有效参考手段。

Low resistance backflow preventer is widely concerned and praised by the industry,because it can effectively solve the problem of backflow pollution of water supply system,and has the advantages of good sealing performance and small pressure loss.The structure characteristic and working principle of low resistance backflow preventer are introduced in this paper.The pressure loss test of LHS743X-16Q DN100 backflow preventer is carried out by using valve flow resistance device.The test result is qualified and its low resistance characteristic is verified.The flow field distribution is numerically simulated under the condition of fully open backflow preventer and different flow velocity.From the velocity distribution cloud diagram,it is observed that the main medium in the middle chamber presented S-type flow,and from the pressure distribution cloud diagram,it is observed that the pressure is mainly divided into two check discs and presented a three-section distribution.By comparing and analyzing the test results and simulation results,it is concluded that the working process of the backflow preventer is basically open,and the feasibility of the numerical simulation method is verified,which provides an effective reference for the structural design and optimization of the backflow preventer.