机械蒸汽再压缩式热泵用于降膜蒸发系统的研究

Application of mechanical vapor recompression heat pump in falling film evaporation

介绍了一种机械蒸汽再压缩式（MVR）降膜蒸发系统的工艺流程,以水为介质,自主开发并搭建实验平台,采用罗茨风机驱动.使用理论分析和实验相结合的研究方法,探究了本系统在不同的蒸发压力及压缩比下合适的操作域,继而研究了二次蒸汽量、补充水量与压缩比及蒸发压力之间的关系,最后探讨了供热系数COP与压缩比的关系.结果显示,补充水量约占二次蒸汽量的3％ ～9％,且补充水的量随着压缩比的提高而提高;蒸发压力不变,蒸汽冷却冷凝放热量随着压缩比的增大而增大;压缩比不变,蒸汽冷却冷凝放热量随着蒸发压力的提高而提高;本系统最佳操作压缩比为1.9.

The process flow of mechanical vapor recompression （MVR） falling film evaporation system is introduced. Using water as the experimental material, a self-developed experimental platform driven by roots blower is established. By combining theoretical and experimental analysis, the appropriate operational area under different evaporation pressure and the compression ratio are explored. The relationship of the flow of secondary steam, water added, the compression ratio and evaporation pressure is investigated. The relationship between coefficient of performance （COP） and the compression ratio is also discussed. The results show that the flow of added water is account for 3% to 9% of the flow of the secondary steam. The flow of added water increases when the compression ratio rises. Heat energy arises with increasing the compression ratio when evaporation pressure is fixed. Similarly, the increase of evaporation pressure with a fixed compression ratio also leads to the increase of heat energy. The optimum operation of the system compression ratio is 1.9.