Reference project Automation of a High Pressure LNG Fuel Gas Supply System
A secure foundation for climate-friendly propulsion in shipping
Shipping faces numerous challenges. It is one of the biggest sources of emissions worldwide. Since the beginning of 2020, new limits have been in place for the sulfur content of fuels. An important contribution to improving the global climate is therefore to avoid using heavy fuel and instead use low-emission fuels such as liquefied natural gas (LNG) or methanol.
This is particularly true when sailing in SECA zones (Sulphur Emission Control Area). Today, these regions are referred to as ECA zones (Emission Control Area).
SpiraTec AG was commissioned with the planning and implementation of the automation of a high-pressure fuel gas supply system. This is intended to ensure a safe and efficient supply of LNG as a marine fuel. Compliance with numerous national and international regulations was particularly challenging.
The liquefied natural gas is carried on the ship at a temperature of -162°C in specially insulated tanks. In order to use LNG as fuel in the ship’s engine, the liquefied natural gas (LNG) is processed in the fuel gas supply system for combustion. In several process steps, the LNG is converted into a warm, gaseous medium with a pressure of approx. 300 bar and supplied to the propulsion system.
The automation used for this is based on highly available programmable logic controllers, while fail-safe systems monitor the safety-relevant functions. These automation and monitoring functions are visualized in a higher-level monitoring system and support the operator with safe, reliable operation of the system.
Project highlights
- Planning and implementation of the automation of a high-pressure fuel gas supply system
- Control and regulation of the entire regasification process – from -162 °C cold LNG to warm, gaseous medium at approx. 300 bar
- Use of engine waste heat from the HT circuit
- Safe bunkering of LNG tanks using SpiraTec process control
- Fulfilment of extensive requirements of the responsible classification society, in this case DNV (Det Norske Veritas), and cooperation with the US Coast Guard
- Verification of explosion protection and functional safety (comparable to SIL)
- Design and testing of switchgear in accordance with UL standards
- Use of a fail-safe and redundant Siemens PCS7 system
- Extensive simulations and tests to significantly reduce commissioning effort on board
- Successful FAT with customer, classification society, and UL, as well as successful gas trial on board
Another focus of the project was on increasing operational safety. Integrated remote maintenance access enables maintenance processes to be efficiently supported and remote diagnostics to be carried out. This allows deviations in plant operation to be detected at an early stage, service calls to be better planned, and interruptions in the fuel supply to be reliably prevented. In addition, remote diagnostics can be used to identify sources of error, which simplifies the planning of necessary service personnel.
In the course of the project, all necessary evidence for explosion protection and functional safety was provided. The switchgear was manufactured by onoff automation services gmbh, a subsidiary of SpiraTec AG, in accordance with the UL standard (Underwriters Laboratories). A redundant, fail-safe Siemens PCS7 system was used for automation. A comprehensive testing and simulation program prior to installation significantly reduced the commissioning effort on board. The project was completed with a successful factory acceptance test (FAT) and a final gas trial together with the crew and classification society.
