Liquified natural gas (LNG) has become popular as marine fuel in the cruise-ship sector. It is a more environmentally friendly energy source, compared to other alternatives. Thus, LNG-fueled engines together with new alternative fuels are key to achieve emission reductions in the marine industry. MEYER Group is currently building several LNG-fueled cruise-ships.

Building LNG-fueled cruise-ships brings challenges such as increase in delivery costs, as purchasing and installing LNG fuel tanks, vaporization systems and engines increases the capital investment. Current cost of LNG system construction ranges from 15 to 30% higher compared to conventional fueled vessels. Therefore, efficient commissioning of LNG fuel systems is crucial to achieve cost benefits. Moreover, for cruise-ship industry, tighter regulations require additional safety measures for designing, commissioning and operating LNG-marine systems and their automation.

Semantum and MEYER Group have collaborated to apply simulation-aided methods to test the control application of a cruise-ship LNG fuel system. A simulation model of the process is used to test the control application the LNG vaporization system.

In this project, model in the loop (MIL) and software in the loop (SIL) configurations are used to verify LNG fuel system (process) design. Furthermore, this approach is useful to analyze fuel system behavior under different operation conditions, assess transient impact on fuel and auxiliary systems of common operating conditions, and to test behavior of stabilizing control loops.

This approach enabled testing, even before the real system was operational, reducing commissioning time and enabling a smoother path towards the factory acceptance tests. This also allowed verifying the process design before the equipment procurement. Additionally, integrated testing of the process and the control application using a realistic process model was key to perform required adjustments in a more agile manner before the system is under operation.