Experimental research and model optimization of a novel mechanical vapor compression evaporation system driven by Roots steam compressor

Abstract

Roots steam compressor has unique advantages in the mechanical vapor compression (MVC) evaporation system due to its lower cost and convenient operation compared with the centrifugal or screw steam compressor. A novel MVC evaporation system driven by Roots steam compressor was proposed and experimentally studied with using the water medium, which can save energy by 79.55–89.36% and operation cost by 61.70–81.41% compared with the traditional single effect (SE) evaporation system. Exergy analysis showed that Roots steam compressor had the greatest exergy destruction (142.92–296.84 kJ kg−1) and the lowest exergy efficiency (4.46–9.85%). Models of the heat transfer coefficient (HTC), coefficient of performance (COP), specific water evaporation (SWE) and specific energy consumption (SEC) were developed based on the experiments to predict the thermo-economic performance and obtain the optimal process parameters, such as the evaporating temperature (90–105 °C), the evaporating pressure (70–130 kPa), heat transfer temperature difference (9–12 °C) and compression pressure difference (28–40 kPa). It will be optimized and improved by mastering the thermo-economic performance of MVC evaporation system driven by Roots steam compressor.