The scarcity of freshwater resources in the marine environment drives advancement of conventional desalination technologies. It is appealing to recover waste thermal energy to power desalination process. With the fast expansion of the global fleet of liquefied natural gas (LNG) powered vessels and the number of LNG terminals, it is envisaged that LNG cryogenic energy becomes an important form of waste thermal energy apart from engine exhaust. A freshwater generator assisted by LNG cryogenic energy is proposed and investigated in the paper. A semi-dynamic model of the proposed system is used to predict performance and optimal parameters. Feed-in seawater, cooling medium, and configurations of the evaporator and the condenser are three key factors to influence the freshwater production rate and required cryogenic energy. The optimal design is able to provide 1021.7 kg/h freshwater from feed-in seawater of 1296 kg/h and LNG evaporation of 3150 kg/h. A scenario study on an LNG powered cruise ferry predicted that freshwater of 16,991 kg is generated in the 48-hour voyage with the fluctuating LNG cryogenic energy from evaporation, which varies between 212 kW and 973 kW.
|Early online date||30 Dec 2020|
|Publication status||Published - 15 Mar 2021|
Bibliographical noteFunding Information:
The authors thank for the financial support from the EPSRC (the Engineering and Physical Sciences Research Council) of the United Kingdom through the research project ( EP/S00193X/2 ).
- Flash evaporation
- Freshwater generator
- LNG cryogenic energy
- Thermal distillation
ASJC Scopus subject areas
- Chemical Engineering(all)
- Materials Science(all)
- Water Science and Technology
- Mechanical Engineering