三效MVR系统的流程模拟及性能研究

Process simulation and performance study of three-effect MVR system

基于多效蒸发与MVR技术的优点,将2种工艺进行结合,提出多效MVR节能工艺的新思路,介绍了三效MVR蒸发系统的工作原理。通过Aspen Plus模拟了整个系统的工艺流程,并对三效MVR进行了性能分析。为了减少换热强度,应该尽量降低蒸发压强,这样原料需要预热的温度也会减小;压缩机的蒸汽压缩比维持在1. 6~2. 0比较合适;进料浓度不宜过大,高浓度进料液需适当稀释后再进行蒸发;为了提高此蒸发系统的制热能效比,需适当地减小压缩比;考虑到整个系统的节能效果,此系统在低温低压下运行较为合适。

Based on the advantages of multi-effect evaporation and mechanical vapor recompression(MVR)technologies,a new idea of multi-effect MVR energy-saving process is put forward by combining these two technologies.The working principle of three-effect MVR evaporation system is introduced.The process flow chart of the whole system is established by Aspen Plus simulation software,and the performance of three-effect MVR is analyzed.In order to reduce the heat transfer intensity,the evaporation pressure shall be reduced as far as possible,so that the temperature for the feedstock to preheat will be lower.The steam compression ratio of the compressor is suggested to maintain between 1.6 and 2.0.Higher concentration of raw material shall be diluted properly before evaporation.To improve the heating energy efficiency ratio of the evaporation system,the compression ratio shall be appropriately reduced.Taking into account the energy saving effect of the whole system,this system is suitable for operating at low temperature and low pressure.