高压降控制阀内空化流动特性实验与数值研究

Experimental and numerical study on cavitation flow characteristics in the control valve

针对高压降工况控制阀存在的严重空化、高能耗及振动噪声等问题,采用实验研究与LES数值研究相结合的方法对控制阀内空化流动特性开展研究,捕捉空腔初生、发展及脱落等流动细节特征,研究不同空腔演化阶段的流动能量传递与损失特性,分析不同工况条件对阀门流通能力的影响规律.结果表明:控制阀节流空化过程中,阀座喉管与渐扩段区域空化程度较高;空化流动条件下,总机械能损失由节流局部能量损失与空化附加能量损失叠加而成;随压差增大,总流阻中空化附加流阻占比由5.3%逐渐增加至26.7%,空化程度越严重,空化附加流阻越高,造成控制阀总流阻上升与流通能力下降.

Control valves under high pressure drop working conditions prevalently have some problems such as severe cavitation,high energy consumption,vibration and noise.The method of combining experimental research with LES numerical study was adopted to study the cavitation flow characteristics in the control valve.The flow details were captured,the flow energy transfer and loss characteristics at different cavity evolution stages were studied,and the influence of different operating conditions on the valve flow capacity was analyzed.The results showed that the degree of cavitation in the valve seat throat and the expansion section area is relatively higher.Under cavitation flow conditions,the total mechanical energy loss is composed of local throttling energy loss and additional cavitation energy loss.As the pressure drop increases,the proportion of cavitation additional flow resistance in the total flow resistance gradually increases from 5.3%to 26.7%.The cavitation additional flow resistance increases with the degree of cavitation,resulting in an increase in the total flow resistance and a decrease in the flow capacity.