Two-stroke engine designers build deeper data connections

The data demands of modern ship operators are driving improvements in engine control, remote monitoring and sensor technology

Demand for more control functions and the integration of new components are behind the overhaul of the control architecture for one of the main designers of marine two-stroke engines. WinGD is to roll out a new engine control system with improved processing power from next year. WinGD Integrated Control Electronics (WiCE) will replace the current WECS and UNIC control systems, each initially designed more than 15 years ago.

General manager control and automation Dr Wolfgang Östreicher explains that the high data acquisition and control demands on a modern engine meant that current control systems had become heavily loaded. A modern dual-fuel engine, for example, requires monitoring and control for liquid fuel injection, lubrication, gas admission, pre-injection and NOx sensing among others, with further demands if NOx aftertreatment is used with diesel operation.

“You can add new modules as more components are needed, but then communication between modules becomes the bottleneck,” he says.

The increasing digitalisation of shipping, as well as the prospect of having to integrate other hybrid power sources, are only expected to increase the burden on engine control systems. WiCE will address these issues by adding a dedicated communications module, including a firewall, through which the system can link to diagnostics systems and receive software updates. The bus system, which allows communication between modules, will receive a substantial upgrade compared to existing control systems.

“The increasing digitalisation of shipping, as well as the prospect of having to integrate other hybrid power sources, are expected to increase the burden on engine control systems”

The system is fully modular at both software (system and applications) and hardware levels. It will be prepared for future upgrades, with each component being verified and validated separately. This will mean that when adding new modules, only that module and the performance of the system will need to be validated, rather than re-validating all other modules.

Crew operating the engine onboard should not notice a difference between the new WiCE interface and earlier WECS or UNIC architecture, except for a more modern design. WinGD expects crew familiar with two-stroke engines to be able to use the controls after one five-day training period.

Closed-loop combustion

German cylinder monitoring specialist Imes has also been redesigning its products in light of modern engine developments. It has developed a robust new cylinder pressure sensor specifically for the very precise and reliable data demands of the latest engines, particularly those deploying closed-loop combustion control. This control methodology allows engines to operate with high efficiency even when running on gases of varying qualities.

Due to higher indicated mean effective pressures on gas engines, cylinder pressure sensors are subject to more extreme operating and environmental conditions. The new sensor, with a front membrane and M10 or M14 thread, has been developed to withstand these conditions while fulfilling the demand for accuracy with minimal calibration drift.

The sensor transmits pressure through a measuring spring. Areas with equal tensile and compressive strength are created on the measuring surface, which is a part of the measuring spring. As the measuring surface is subject to deformations, a resistor bridge in high temperature thin film is applied to it. Depending on the amount of strain, a voltage signal will be measured proportional to the pressure change.

The measuring spring is resistant to abnormal combustion with extremely high pressure rises of up to 1000 bar/ms, and achieves a high thermodynamic accuracy for engine control purposes. It is designed for more than one trillion load cycles. A high temperature-resistant ceramic for temperatures of up to 400°C provides the basis for the sensor’s electrical connections, while wire bonding means the electrical connection can withstand more than 350°C.

Evaluations on a single cylinder test engine and compared against a water-cooled piezoelectric sensor have confirmed its accuracy. The sensor has also been successfully tested on dual-fuel ship engines. They have been installed on Swedish asphalt carrier Bit Viking, which is driven by six-cylinder Wärtsilä 50DF engines, since March 2017. The sensors have also been tested on the 18-cylinder dual-fuel engine of a Caribbean power barge. Imes will be presenting the results of these trials and a description of its development work at CIMAC Congress in June.

In order to harness these growing abilities to accurately monitor and control engines, new digital infrastructure is also required. MAN CEON will be the platform through which all of MAN Energy Solutions’ future digital services are delivered and is expected to offer a growing range of paid-for remote services. It will be standard to all new MAN engines, turbines and compressors from this year and already delivers a remote monitoring and optimisation service launched recently by the company’s after-sales division MAN PrimeServ.

MAN head of digital and strategy Per Hansson says that the platform was designed to monitor several thousands of customer installations in parallel, with a data-processing capacity that “exceeds that of many major social-media platforms”.

He says: “All of our machines are equipped with hundreds of sensors that transmit data constantly. MAN CEON enables the efficient collection, storage and evaluation of these data volumes. We are monitoring down to the level of small sub-components, much like with a ‘digital twin’, with high-resolution data available on demand.”

Less than 100 vessels with MAN two-stroke engines have had remote diagnostics through a secure VPN tunnel for up to a decade. These will be migrated to MAN CEON. Four-stroke engines have also been monitored by PrimeServ for more than a decade.

“MAN CEON builds on this by providing access to the data in near real-time to enable pro-active advice and through providing those customer teams access to the same monitoring and analysis tools that our MAN PrimeServ teams are using,” says Mr Hansson.

That last comment is poignant. It has been claimed that companies often pursue digitalisation without a sense of direction. Giving shipowners the same level and immediacy of engine insight as service engineers is a worthy goal that will make a lasting impact on the efficiency of shipping.