Performance investigation of Freezing Desalination Coupled with Carbon Dioxide Refrigeration System

The world is currently facing the prospect of a severe global shortage of fresh water. Desalination of seawater can provide an almost inexhaustible source of freshwater if it can be made affordable. Freezing is a well-known technique for water desalination. The carbon dioxide refrigeration system is used for cooling required in the freezing desalination system and the evaporator and condenser of the refrigeration system are respectively crystallized and melted in the freezing desalination system. In this paper the basic principles of freeze concentration processes are presented and a model of a freeze desalination that coupled with CO2 refrigeration has been developed based on the theories of heat and mass transfer. To examine the performance of the system, a parametric study is performed to investigate the effect of different parameters such as FD feed temperature, feed concentration, distillate temperature, distillate concentration and FD recovery ratio on COP and energy consumption have been explored. It can be concluded that increasing the feed concentration and feed temperature is accompanied with the reduction of COP and a raise in SEC. Increasing the ice fraction also increases the SEC system. Freezing desalination System in the present study is comparable in energy consumption to reverse osmosis desalination system.