电动涡旋压缩机背压油路的分析与优化

Analysis and Optimization of Back Pressure Oil Circuit of Electric Scroll Compressor

针对某型号电动涡旋压缩机在转速3 000r/min以上运行时排气量小于额定排气量的问题,分析得出动涡盘所受背压力不足是引起排气量不足的原因;利用哈根-伯肃叶定律导出背压腔之前油路各段的沿程摩擦损失和局部阻力损失的计算式,利用Matlab编程计算了背压力,验证了引起排气量不足的原因;选取油路中对背压力影响最大的局部结构进行结构优化,分别利用数值计算和Fluent模拟计算方法计算了不同结构下的背压力,两种算法所得结果吻合良好,均可得到合理的背压力,说明这种优化方法可行;最后计算了不同转速下背压力的变化规律曲线。

Considering the fact that the gas displacement is less than the rated gas displacement when an electric scroll compressor is operating at a speed of over 3000 r/min, the cause of insufficient gas displacement was analyzed to show that, the insufficient back pressure mainly incurs it. Through making use of the Hagen-Poiseuille law to derive a calculation formula for the friction loss and local resistance loss in each section of the oil path before the back pressure cavity, the back pressure was calculated by Matlab programming to verify the reason of insufficient displacement. Optimizing the local structure which influences the back pressure much in the oil path and calculating the back pressures under different structures with numerical calculation and Fluent simulation calculation method respectively show that the results from two calculation methods are consistent and through them, that reasonable back pressure can be obtained and it shows that this optimization method is feasible. Finally, the curve of the change law of back pressure at different speeds was drawn and calculated.