Abstract: In order to evaporate and concentrate the thermo-sensitive materials with properties of high viscosity, easy scaling and strong corrosion, a jacketed MVR (Mechanical Vapor Recompression) heat pump evaporation concentration system was designed. Water was used as the test medium for a series of experimental studies. Such parameters as temperature difference, compression ratio, evaporation capacity, coefficient of heat transfer, COP (Coefficient of Performance), SMER (Specific Moisture Extraction Rate), adiabatic efficiency and volumetric efficiency were influenced by operational and structural parameters like evaporating pressure, frequency of compressor and heat transfer area. The performance of the system when the compressor was running at afrequency of 50 Hz was much better than that under other conditions at a lower frequency. The most appropriate range of evaporating pressure was from 65 kPa to 85 kPa when a single evaporating kettle was running, and it was unnecessary to supplement external steam. Two evaporating kettles could be simultaneously used for industrial evaporation concentration by supplementing only a small quantity of external steam. Energy saving of both cases mentioned above was significant.

Key words: jacket, MVR, heat pump, evaporation, concentration, separation, heat transfer

摘要： 为解决具有高黏度、易结垢、强腐蚀性等特点的热敏性物料的蒸发浓缩,设计了夹套式MVR(机械蒸汽再压缩)热泵蒸发浓缩系统,并以水为实验介质进行了相关的实验研究。实验结果表明,温差、压缩比、蒸发量、传热系数、COP(制热性能系数)、SMER(单位能耗蒸发量)、绝热效率、容积效率等各项指标均受蒸发压力、压缩机频率、换热面积的影响;压缩机在频率50 Hz下运转时的系统性能大大优于低频率运转;单台蒸发釜在蒸发压力为 65～85 kPa之间运行较为合适,且不需要补热;两台蒸发釜完全可以同时应用于工业蒸发浓缩过程,但需要少量的补热;两者节能效果均十分显著。

关键词: 夹套, MVR, 热泵, 蒸发, 浓缩, 分离, 传热