不同转速下超临界二氧化碳离心压缩机内部流动性能分析

Internal flow performance analysis of supercritical carbon dioxide centrifugal compressor at different rotational speeds

为研究不同转速对超临界二氧化碳离心压缩机内部流动的影响,通过数值计算,得出70%,80%和100%三种不同转速下超临界二氧化碳离心压缩机的全工况性能曲线,并详细分析了超临界二氧化碳离心压缩机内部不同叶高处相对马赫数分布。在100%转速时,小流量工况下叶片通道出现相对马赫数较低的情况;在大流量工况下,叶片通道出现通道激波,压缩机做功能力受到影响。结果表明:在不同转速下,超界二氧化碳离心压缩机最高效率点工况的等熵效率随转速升高而降低。

In order to study the effect of different speeds on the internal flow of supercritical carbon dioxide centrifugal compressors,the full-condition performance curves of supercritical carbon dioxide centrifugal compressors at 3 different speeds of 70%,80%and 100%were obtained through numerical calculations,and a detailed analysis of the relative Mach number distribution at different leaf heights inside the supercritical carbon dioxide centrifugal compressor.At 100%speed,the blade channel has a lower relative Mach number under low flow conditions;Under high flow conditions,the blade channel has a channel shock wave,which affects the performance of the compressor.The results show that the isentropic efficiency of the highest efficiency point of the transboundary carbon dioxide centrifugal compressor decreases as the speed increases at different speeds.