Analysis of a single-effect mechanical vapor compression desalination system using water injected twin screw compressors

• A single-effect MVC system using a water-injected twin screw compressor was proposed.
• A mathematical model was developed for analysing the performance of such an MVC system.
• The operational characteristics of the twin screw compressor were investigated.
• The single-effect MVC performance was compared with data reported in literature.
• The effect of key parameters on system performance was investigated.

The mechanical vapor compression (MVC) desalination system is very attractive and competitive for small and medium scale water production. This paper presents a comprehensive analysis of a single-effect MVC desalination system using water injected twin screw compressors. The operational characteristics of the twin screw compressor including inlet volume flow rate, compressor pressure ratio, and mass fraction of injected water are investigated. The specific power consumption and the specific heat transfer area of the MVC system are then analyzed based on these characteristics. The results are comparable with data reported in literature for similar single-effect MVC desalination systems. Further comparison is performed for a single-effect MVC system using a twin screw compressor with/without water injection. The results demonstrate that the single-effect MVC desalination system using water injected twin screw compressor is a very promising technology for water production capacities less than 600 m3/d. It also shows that the temperature difference between boiling vapor and compressed vapor at compressor exit can be as high as 10 °C.