An experimental study of a newly designed freezing desalination unit equipped with reversed vapor compression cycle

Abstract

A newly designed freezing desalination system was constructed. The system operates on the principle of reversed vapor compression. It is equipped with two identical heat exchangers, one of them works as an evaporator and the other as a condenser. A three-way valve was used to reverse the operation of heat exchangers, causing the ice in the evaporator to melt. The performance of the newly designed system was evaluated in both the forward and the reversed cycles. Electric current, power consumption, pressure drop, water productivity, and specific consumption were all investigated. The experiments were conducted with ice ratios of 0.27, 0.39, 0.45, 0.54, and 0.65 with cycle operating periods of 110, 135, 180, 240, and 300 min. The results showed that the electrical current, power consumption, and pressure drop were decreased with the reversed cycle. The maximum energy-saving percentage was 13% for cycle operation time 300 min. The amounts of freshwater reached 19 L for cycle operation times of 300 min from 30 L saline water. It is recommended to run our newly designed system at an ice ratio of 0.45 since these results save 1.5% in the reversed cycle, which is the most used cycle in the new design.

Keywords

• Freezing desalination
• Vapor compression
• Reversed