MVR, centrifugal compressor, losses, impeller
In order to reducing energy costs and CO2 foot-print, mechanical vapor recompression system (MVR) is used for thermal separation processes such as evaporation and distillation are energy intensive instead of multiple-effect evaporation system. For medium and high capacities, centrifugal compressor (fan) is the most commonly used type for gas compression with a limited operational range and control of the compressors is crucial for safe and efficient operation. The model based on first principles is developed for dynamic performance, which is determined from the compressor geometry and not from the experimentally determined characteristic performance curves. Impeller losses are studied: incidence, skin friction, choking, jet-wake mixing, blade loading, hub to shroud, tip clearance, shock and distortion losses. The vaneless diffuser outlet is calculated using a one-dimensional numerical solution to the underlying differential equations. Dynamic model of a centrifugal compressor capable of system simulation computational environment is presented. A model has been created for simulation of a separation and gas compression system. Based on the theory for centrifugal compressors and control theory a control strategy has been applied to the model based on the available equipment. The model has been used to investigate how the gas compression system responds to changes in the compressor inlet flows and conditions. The model has been used to investigate the performance of the gas compression system at off-design conditions. The surge line for the compressor can also be determined from the simulation results. Furthermore, the model presented here provides a valuable tool for evaluating the system performance as a function of various operating parameters.