不同叶数MVR蒸汽罗茨风机的设计与分析

Design and Analysis of MVR Steam Roots Blower with Different Lobe Number

为了探究不同叶数罗茨风机在MVR系统中的运行性能,对蒸发负荷为200kg/h的二叶、三叶、四叶渐开线型MVR蒸汽罗茨风机进行了热力学设计及叶轮型线设计。采用CFD数值模拟的方法,结合动网格技术,分别对这三个模型的内部流场进行了非定常可压缩数值模拟,得到了多变压缩功率、绝热效率及EER性能曲线并与理论值进行了对比;同时探讨了其出口脉动情况。结果表明:模拟值与理论值变化趋势一致,表明模型设计合理;升压的选择对风机以及整个MVR系统的性能有着重要的影响;通过对比分析最终选择三叶罗茨风机作为MVR系统的蒸汽压缩设备。

In order to explore the performance of Mechanical Vapor Recompression（MVR）steam roots blower with different lobe number,the design of thermodynamic and lobe profile for involute type MVR steam roots blower with two-lobe,three-lobe and four-lobe whose steam flow rate 200kg/h was carried out. The unsteady compressible flow flied of the three models were numerically investigated by means of Computational Fluid Dynamics（CFD） and dynamic mesh technique. The performance curves of polytropic compression power,adiabatic efficiency and Energy Efficiency Ratio（EER）were obtained and compared with the theoretical value,the fluctuation performance of outlet pressure and temperature were also analyzed. Research shows that the simulation results are in good agreement with theoretical results. Its means model design is reasonable. The choice of pressure rise has a significant impact on the performance of roots blower and the MVR system. The three-lobe roots blower was selected as the vapor compression equipment in MVR system through comparison and analysis.