In order to ensure the operation economy and stability of mechanical vapor recompression (MVR) system, the matching characteristics of centrifugal vapor compressor and evaporator in the MVR system were studied. In view of the change of heat transfer coefficient of evaporator under new operation, operation and scaling conditions, the concept of temperature resistance characteristic curve of evaporator operation was put forward, and it was superposed with the temperature rise characteristic curve of centrifugal vapor compressor, so as to carry out matching analysis of centrifugal vapor compressor and evaporator. Through analysis, it was found that the design flow of centrifugal vapor compressor was too large or the heat transfer area of evaporator was too small, which would lead to insufficient matching and easy surge, thus affecting the operation stability of MVR system. However, the design flow of centrifugal vapor compressor was too small or the heat transfer area of evaporator was too large, which led to excessive matching, resulting in poor operating economy of the MVR system, and may even cause the MVR system to be unable to establish thermal self cycle. The results showed that the centrifugal vapor compressor had unstable surge during the startup of MVR system, and the unstable area could be avoided by temporary adjustment of system parameters or by taking auxiliary measures. The surge margin of centrifugal vapor compressor should be more than 20% and the design margin of heat transfer area of evaporator should be 30% during design; the deviation between actual evaporation temperature and design temperature during MVR system operation should be controlled within ±5 ℃. The research results can provide reference for the design and debugging of MVR system.

Keywords： mechanical vapor recompression ; centrifugal vapor compressor ; evaporator ; matching ; surge