Numerical analysis on the performance of mechanical vapor recompression system for strong sodium chloride solution enrichment

Operating parameters of the system are calculated based on the system model. Performance indicators are analyzed according to the parameters calculated above. The influence of the input parameters on the evaporating performance of the system is studied, including the frequency of compressor, temperature of inlet weak solution, concentration of inlet weak solution. With the increase of frequency of compressor or the increase of inlet solution temperature, evaporation rate, quantity of heat transfer and power consumption of compressor increase accordingly. Power consumption of the compressor to evaporate per ton of water reaches 16.8 kWh, when the suction pressure is 25 kPa, the concentration of the inlet weak solution is 18%, and the frequency of compressor is 100 Hz. Concentration of solution has a great effect on the boiling point elevation of the solution. Therefore, when the concentration of solution is high, power consumption of compressor increases significantly, and COP decreases sharply. When the inlet concentration increases 1%, the power consumption of the compressor to evaporate per ton of water increases 8.2%, and COP decreases 2.7%.