Effect of droplets on water vapor compression performance

Mechanical vapor recompression (MVR) technology has broad prospects for application in saving energy. The compression in the MVR system often involves mixing vapor and liquid, and therefore, studies of the process can help establish a theoretical model to solve the problem of controlling compression temperature and improving the compression process's efficiency. However, the mixed phase-change in water vapor compression is complex and differs from that in air wet compression. In this paper, we studied droplets' effect on water vapor compression performance and the mechanism of heat and mass transfer during the process. A 2D single droplet evaporation model for water vapor compression was established and analyzed with Python, and a 3D numerical simulation was solved with CFD software to investigate the effect on water vapor compression of droplet diameter, ambient pressure and temperature, spray flow rate, and flow velocity. The results showed that the compressor's outlet temperature can be reduced by reducing the droplet diameter and increasing the spray flow rate, thus decreasing the work required for compression. The results also indicated that a high pressure ratio and superheat can enhance the cooling effect greatly.