三叶转子罗茨真空泵内气体过程的热力学计算

Thermodynamic calculation for pumping process in the trilobal Roots vacuum pump

本文以三叶转子罗茨泵为研究对象,从其基本结构和工作原理出发,对泵内被抽气体的输运过程进行热力学分析。对被抽气体在泵内经历的过程作时序分析,将其分解为吸气、输运、反冲、排气四个阶段,详细讨论各个阶段的特点和机理。应用热力学基本原理,建模计算气体返流量,对吸气、输运、排气进行定量分析,得到被抽气体的压强、容积、总质量、总内能等热力学参数随时间变化的计算公式;探究排气功率与进出口压力之间的关系。

In this paper, the trilobal Roots pump is taken as the research object, starting from its basic structure and working principle, its internal gas transport process was analyzed thermodynamically. Taking the gas as the research object, the time sequence analysis was carried out, and the process of the gas in the pump was decomposed into intake, transport, recoil,discharge, and discussing the characteristics and mechanism of each stage in detail. The knowledge of thermodynamics and the amount of backflow were taken into account. Calculating gas backflow through model. The quantitative analysis of each phase was carried out, and the time-variation formulas of thermodynamic parameters were deduced, such as pressure, volume, mass, and internal energy. The formula was used to explore the relationship between exhaust power and import and export pressure.