剖分式机械密封传热及耦合变形的数值研究

Numerical Investigation on Heat Transfer and Thermal-structural Coupled Deformation of Split Mechanical Seals

为研究剖分式机械密封变形规律,建立剖分式机械密封三维传热模型,计算剖分环端面摩擦热、摩擦热分配系数及对流换热系数,研究主轴转速、冲洗量对剖分环温度场、热变形及热-力耦合变形的影响,同时分析箍紧力对剖分环热-力耦合变形的影响。研究结果表明:温度最高点位于密封端面内径侧,且碳石墨剖分静环的密封端面温度比碳化硅动环的高,密封端面和分型面在温度场作用下产生正锥度变形,而箍紧力可以减小密封端面及分型面的变形;剖分动静环的端面和分型面热变形锥度随转速的增大,均呈现增大趋势,端面的耦合变形锥度也随之增大;冲洗量增大,剖分动环端面和分型面热变形锥度减小,端面耦合变形锥度减小,剖分静环变形规律相反;箍紧力增大,剖分动环、静环端面耦合变形锥度增大。

A three-dimensional heat transfer model of the non-contact split mechanical seal was established to study the deformation law of split mechanical seal.The frictional heat,heat partition coefficient and the convective heat transfer coefficient were calculated,the influences of shaft speed and flushing on steady-state temperature field,thermal deformation and thermal-structural coupled deformation of the split mechanical seal were analyzed,and the effect of clamping pressure on thermal-structural coupled deformation was studied.The results show that the highest temperature is located on the inner diameter of the seal end face,and the temperature of the seal end face of split stationary ring is significantly higher than that of the split rotating ring.The positive coning deformation of the seal end face and parting surface is generated by temperature field,however,the deformation can be effectively suppressed by clamping pressure. When the shaft speed is increased,the positive coning deformation of the seal face and parting surface of split rotating and stationary rings is increased,and the thermal-structural coupling deformation of seal face is also increased.When the flushing is intensified,the thermal and thermal-structural positive coning deformation of seal face and parting surface of split rotating ring is decreased,while the deformation of split stationary ring is increased. When the clamping pressure is increased,the thermalstructural coupling deformation of split rotating and stationary rings is increased.