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利用有限元建立了计算干式螺杆真空泵转子温度场的数值方法,考虑了热传导及转子表面与工作介质的对流换热因素对温度场的影响,采用相似准则方程—迪特斯-玻尔特(D ittus-Boe lter)公式计算了对流换热系数。计算结果表明:转子温度场由进气端至排气端近似为线性增长,排气端温度约为120℃。随着转子转速降低,排气端温度迅速降低,当转速在2000 r/m in以下时,转子由进气端至排气端的温度变化在30℃以下。实验结果验证了上述结论,误差在15%以内。本文的研究工作不仅提供了干式螺杆真空泵转子的温度分布,也为进一步研究转子的热变形,合理确定泵腔内各密封间隙提供了理论与实验依据。
The numerical method for calculating the rotor temperature field of dry screw vacuum pump was established by using the finite element method. The influences of heat conduction and convection heat transfer between the rotor surface and working medium on the temperature field were considered. By using the similar criterion equation - Dieters-Bolt D ittus-Boe lter formula to calculate the convection heat transfer coefficient. The calculation results show that the rotor temperature field increases linearly from the inlet end to the exhaust end, and the exhaust end temperature is about 120 ℃. As the rotor speed decreases, the temperature at the exhaust end decreases rapidly. When the rotor speed is below 2000 r / min, the temperature change from the intake end to the exhaust end of the rotor is below 30 ° C. The experimental results verify the above conclusion, the error is within 15%. The research work in this paper not only provides the temperature distribution of the rotor of the dry-type screw vacuum pump, but also provides theoretical and experimental basis for further research on the thermal deformation of the rotor and the reasonable determination of the seal clearance in the pump chamber.