Abstract:

Numerical simulation model of steam ejector was established by application of the modified thermal dynamic method.The performance variation under different operating condition was calculated for the steam ejector used in thermal vapor compression desalination system coupling with the subroutine of thermo-dynamics of water and steam.The effects of motive steam pressure，suction pressure and mixed vapor pressure on entrainment ratio were analyzed.The results of the simulation indicated that entrainment ratio decreased with increasing compression pressure when compression pressure exceeded design value，and entrainment ratio maintained at a constant value when compression vapor pressure was lower than design value.The increase of suction pressure could improve the performance of steam ejector.Steam ejector performance would worsen when the pressure of motive steam was different from the design value.The decrease（lower than design point）or increase（higher than design point）of motive steam pressure resulted in worsened performance of steam ejector.