Variable compression ratio retrofits: an emissions option for LNG fleets, says WinGD
Some 170 WinGD Variable Compression Ratio systems have been ordered, many of them for retrofit (Source: WinGD)
WinGD has published a white paper outlining variable compression ratio (VCR) technology as a retrofit option for cutting emissions from LNG-fuelled vessels ahead of the IMO’s 2030 targets. The company argues that the majority of ships trading at the end of the decade are already in service, placing greater emphasis on improving the efficiency of existing machinery rather than relying solely on newbuilds.
VCR technology is offered as standard on WinGD’s X-DF2.0 engines and can be retrofitted to earlier X-DF LNG dual-fuel engines. The system can also be applied to RT-flex50DF engines, of which around 50 are currently in operation worldwide, expanding the potential retrofit market. By adjusting the compression ratio dynamically during operation, the technology improves combustion across a wide load range, reducing fuel consumption in both gas and diesel modes and lowering methane slip at partial loads.
According to WinGD, the retrofit has been developed to limit operational impact. It is fully integrated into the engine control system, requires no additional crew input and can be installed during scheduled drydockings, allowing owners to align emissions improvements with routine maintenance.
Since its introduction in 2023, more than 170 VCR systems have been ordered. While early uptake was concentrated in LNG carriers, recent orders include car carriers, bulk carriers and container ships, indicating broader interest in retrofit-led emissions reductions.
