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空气阀能在事故工况时通过进气消除管线上的负压,但会因排气速度过快而引发更加严重的弥合水锤升压,因此对传统的高速进排气阀内部结构进行优化,增加了能减缓排气速度的缓冲阀瓣。利用计算流体力学(CFD)的数值模拟方法对结构优化后的空气阀进行数值模拟分析,模拟中通过改变进排气时的压差得到了空气阀的流量曲线。模拟结果表明:空气阀的流量系数与压差有关,而不是一个固定不变的值;采用孔口面积比为0.1的缓冲阀瓣能在排气阶段减缓排气速度,且不影响进气消除负压功能。通过工程算例验证了结构优化后空气阀的水锤防护效果优于传统的高速进排气阀。
The air valve can eliminate the negative pressure on the pipeline through air intake during accident conditions, but will cause more severe water hammer boost due to the exhaust speed too fast, so the internal structure of the traditional high-speed air intake and exhaust valve is optimized , Increase the buffer valve can slow down the exhaust valve. Numerical simulation of the optimized air valve was carried out by numerical simulation method of Computational Fluid Dynamics (CFD). The flow curve of the air valve was obtained by changing the pressure difference between intake and exhaust. The simulation results show that the flow coefficient of the air valve is related to the pressure difference rather than a fixed value. The buffer valve flap with orifice area ratio of 0.1 can slow down the exhaust velocity during the exhaust phase without affecting the air intake elimination Negative pressure function. The engineering example is used to verify that the water hammer protection effect of the optimized air valve is better than that of the conventional high speed inlet and outlet valve.