不同开口度下的煤矿水液压安全阀的气蚀特性

针对煤矿水液压安全阀存在的严重气蚀问题,建立双排阀口的CFD模型,分析了不同启动次序和开口度的阀腔气相体积分数和压力分布云图,并得到其影响规律及最佳的阀口开启次序。研究表明:3种开启方式下,开口度为0.8~1.2 mm时气蚀均较为严重;同步开启时,综合抗气蚀效果最差,开口度为0.8~1.2 mm时极易形成涡旋,且对气蚀现象有扩大作用;阀口1,2依次开启时,阀腔内部的气穴气蚀现象也较明显,最大气相体积分数值达98.3%,气穴范围也较大;阀口2,1依次开启时,其阀口1附近尾椎部分高压区域可以补偿压降,从而降低阀芯内部流场最大气相体积分数,且在阀口2开口度为0.8~1.2 mm时,相对其他2种开启方式,最大气相体积分数和面积分别降低了25.7%,18.6%,抗气蚀效果最佳。

Cavitation Characteristics of Hydraulic Safety Valves for Coal Mine Water with Different Openings

To study the serious cavitation problem of coal mine water hydraulic safety valve, CFD model of double-row valve opening is established to analyze the nephogram of air phase volume fraction and pressure distribution in valve chamber with different starting order and opening degree. Then, the effect of opening degree on pressure and air phase distribution for different starting order are obtained, and the optimal valve opening order is obtained. The results show that the cavitation is more severe in all three opening modes when the opening degree is 0.8~1.2 mm; synchronous opening of the integrated anti-cavitation effect is the worst, the opening degree of 0.8~1.2 mm is very easy to form a vortex, and the cavitation phenomenon has an expanding effect; when the valve port 1 and 2 are opened sequentially, cavitation phenomenon of the valve chamber is relatively obvious, the largest air phase volume fraction is 98.3% and cavitation range is also large. When the valve port 2 and 1 are opened sequentially, the high-pressure area of the tailbone near port 1 can compensate for the pressure drop to reduce the maximum volume fraction of the air phase of the internal flow field of the spool, and the opening degree of port 2 is 0.8~1.2 mm when compared with the other two opening methods, the maximum volume fraction of the air phase and the area are reduced by 25.7% and 18.6%, which has the best effect of cavitation resistance.