The scope of the project was to design and engineer a cold energy recovery system that vaporizes and heats up the LNG for feeding the engine, and utilizes the cooled down heat exchange media as cooling agent for onboard air conditioning & refrigerating plants. The Designed LNG Energy Recovery System had to been approved in principle by DNV- GL for use on board vessel according to IMO – IGF Code.
The use of LNG bunkering on board commercial vessels is increasing, while some ships are converted or built “on purpose”, others are ordered as “LNG Ready”.
One of the main characteristics of LNG is the cryogenic temperature at liquid phase which must remain low, even if the storage pressure rises. Both Dual Fuel Engines and Pure Gas Engines need to be fed with Natural Gas vaporised and heated up to a certain temperature (normally well above 20°C). This means that the LNG stored on board in the liquid phase, must be vaporized and heated up. To vaporize LNG to the required characteristics, a certain quantity of heating energy is needed.
On-board commercial vessels, there are systems that require cooling media to cool them down during operation and having abundant cold LNG available that needs to be vaporized and heated up drives the idea to use the heating needs of LNG to cool down the systems that require controlled cold energy to work properly.