摘要
为了研究干气密封在高速高压运转下受到外力作用导致密封腔内不规则变形时的流动特性.考虑力和热作用2种情况下,分别获得密封环的变形量及其气膜厚度的近似解析式.将力变形量叠加至热弹变形中,获得热力耦合作用下密封腔内气膜厚度的近似解析式,进而获得密封腔的理论流量,并对比分析无变形、热弹变形、力变形以及热力耦合变形4种情况下的理论流量与实测流量.研究结果表明:密封腔内流量随介质压力增大而增大;当仅考虑力作用时,所获得的流量值大于试验值;仅考虑热弹作用时,流量值虽然小于试验值,但误差较大,与其他几种情况相比,热力耦合作用下密封腔内的流量值与试验值的误差较小.在工程运用中,考虑热力耦合变形为优化槽型结构参数提供了理论基础,进而达到控制流量的目的.
To study flow characteristics in the gap of a spiral-grooved dry gas seal that is subject to irregular deformation caused from external forces under high speed and pressure operating conditions,a set of analytical solutions for deformation of sealing ring and gas film thickness are obtained when the ring is underwent either a mechanical force or a thermal load. Then an approximately analytical solution for the gas film thickness is got when the seal is in the thermal-mechanical coupling state by placing the deformation due to the mechanical force upon that because of the thermal load. Based on that solution,a theoretical leakage flow rate through the gap is derived. At last,the theoretical leakage flow rates are compared with their experimental values in four cases,that is without any deformation,with thermal deformation,with mechanical deformation and with thermal-mechanical coupling deformation.The results show that the leakage flow rate increases with increasing pressure. In the case with the mechanical deformation,the predicted leakage flow rate is larger than the experimental value. The leakage is not only less than the experimental value but also shows a larger error against the experiment in the case with the thermal deformation. Comparing with the other cases,the error of leakage flow rate between prediction and measurement is the smallest in the case with the thermal-mechanical coupling deformation. For the application in engineering,the proposed method that considers the thermal-mechanical coupling deformation can provide a theoretical basis for spiral groove structure optimization, and then the objective that controls the leakage flow rate can be achievable.
出处
《排灌机械工程学报》
EI
北大核心
2013年第9期788-793,799,共7页
Journal of Drainage and Irrigation Machinery Engineering
基金
国家自然科学基金资助项目(51165020)
关键词
干气密封
热力耦合
热弹变形
泄漏量
力变形
dry gas seal
thermal-mechanical couple
thermo-elastic deformation
leakage
force deformation
