How can you improve fuel efficiency and reduce emissions of propulsion systems?

Engine tuning, which is mostly looking at fine tuning fuel injection and exhaust valve timings should be used only after confirming there are no underlying issues with the fuel injection, turbocharging and combustion chamber components. Once it is confirmed and the engine timings are tuned optimally, the most practical ways of obtaining least fuel consumption is to ensure the combustion pressure (Pmax) is similar to the values seen during the shoptrial of the engine during shop trial (using the same grade of fuel as now), improve combustion by optimising scavenge air temperature (reduce) and inject fuel within the viscosity range suggested in the fuel test report.

Also with the engine data, you may find that the engine room environment is reducing the air density available to the engine. Air density loss from exterior of the vessel to the engine inlet will result in lost power and efficiency. Air density is often confused with boost pressure. The turbo can compensate for air density changes with boost control. This normally means that the wastegate stays closed more and creates more heat and back pressure behind the turbo. This is less efficient and can effect the lifespan of critical engine components. In addition to engine sensors, compartment or engine room sensors and external ambient sensors to monitor temperature, humidity and pressure.

Human Element in Maritime Energy Management In maritime progress, one often ignored aspect is human involvement. Despite advanced tech, efficient energy management relies heavily on skilled operators. Training is essential, yet it has diminished over time. Not all experts make good mentors, and knowledge can fade. Combining energy efficiency measures is tough, with focus often on one aspect. To succeed, we need effective implementation and trained users. Prioritize improvement, not just compliance. Until full automation, human factors remain vital for safety and efficiency. Technology is crucial, but human expertise is irreplaceable in maritime energy management.

Engine tuning can be helpful in improving the fuel efficiency but care must be taken care for NOx emissions. For improvement in fuel consumptions leads to compromising of NOX emissions. By decreasing the bore of engine as per real power requirement and thereby tuning the engine would lead to more remarkable results.

Most modern engines have an “ auto tuning” function which aids in optimum performance of the engine . However the challenge still lies in the quality of the fuel being utilised which does affect the combustion . The alternate fuels can be a solution if the quality is more uniform .

Going slow will make much more difference. Top speed on a ship requires way more power than slow sailing. This should also reduce maintenance issues a little bit.

1. Using a propeller that is the correct size and pitch for the vessel can reduce drag and improve fuel efficiency. 2. By monitoring the propeller slip, its deviations & by taking corrective actions further. 3. Reducing speed is also one such way of reducing emissions & also, by maintaining the vessel & its propulsion system always in good condition.

?propeller design ensuring?that?the?turbocharger?does?not?surge?under?any?circumstances?and?allowing?the?air?to?fuel?ratio?to?be?at?the?proper?ratio,?which?results?in?ideal?emission?when?all?other?fuel-related?elements?are?in?balance.

Understanding the optimal time to initiate hull maintenance is critical. Hull performance can vary depending on factors such as vessel type, routes, applied paint, and external conditions. Similar to how you maintain a car based on the manufacturer's recommendations, vessels have recommended maintenance schedules. However, unforeseen factors and conditions can alter these schedules. Extracting data through noon reports or high frequency data from these vessels provides valuable insights to determine when maintenance is needed. This analysis enables us to pinpoint instances when fuel consumption exceeds a threshold due to hull fouling, resulting in an elevated production of carbon byproducts.

This is critical on all hulls but especially on higher speed hulls. Resistance goes up exponentially as speed increases. Even what would be considered minor hull growth on a displacement or semi displacement hull can have tremendous impacts on performance of higher speed hulls. We have seen as much as 15 knots of speed lost on some of our vessels.

Monitoring hull performance using a standard methodology like ISO 19030 along with well defined maintenance plan giving importance from the decision of surface preparation can help in reducing emissions & further applying an antifouling system that has a very good inservice performance.

This becomes more critical especially after prolonged stopped conditions of the ships; especially in tropical climate areas which can accelerate fouling on the hull . Hull maintenance can assist in better engine performance and fuel efficiency .

"Alternative fuels" typically refer to LNG, Ammonia, Biofuels, Hydrogen, etc. A way to minimize emissions involves identifying an alternative fuel. Another approach is opting for a superior conventional fuel with a higher TRUE WORTH INDEX (TWI). A higher TWI allows for reduced SFOC, enabling less fuel consumption to reach your destination and ultimately decreasing emissions. Despite significant advancements in exploring various alternate fuels within the maritime industry, there has been a delay in addressing the optimization of the current conventional fuel usage. TWI aids in the selection of higher-quality fuels that can effectively lower emissions without requiring modifications to the vessels. Feel free to inquire for additional details

Contrary to what’s written above, most alternative fuel have lower energy density compared to the conventional marine fuel such as heavy fuel oil or marine diesel oil, and certainly are more expensive

Alternate fuels’ energy density is still not on the same level as the fossil fuels . However they do contribute in a major way towards lower emissions . The design changes required for storage and handling does involve higher capital expenses whose returns gets paid back over a couple of years .

Energy recovery has always been part of most ship designs . However the quantity of recovery always has a high scope for improvement .

Effective turbocharging is critical on diesel engines. Maintenance is critical and possible uogrades could prove to be critical as well. This could also include anti lag devices to reduce emissions at lower speeds.

Using newer engines and motors are typically more fuel-efficient than older models. This is because they are designed with features that reduce friction and heat loss, also improves combustion efficiency.

In My experience, energy management is a key tool that is in hand without a lot of effort or investment. To give a simple example- having economic speed for the major part of the voyage and suddenly at the last few days or few hours speeding up Exorbitantly to arrive on time. Or running a high speed to arrive early and then end up waiting at the anchorage in a port. Energy management with connected voyage optimization tools is something that will really help the industry in the immediate course.

This data can also drive specific considerations at the time of a refit. Are we underpowered or overpowered? Should we consider diesel electric hybrid configurations for better efficiency.

Operational factors’ consideration to be prioritised during the design stages for effective implementation of energy management .

I have come across an additive ‘Boost PLUS’, which have been tried out on a few vessels with proven fuel consumption reduction of nearly 11%. There’s a lot I can write about this, however suggest relevant industry professionals contact Mr. Atul Dua on Atul.dua@unidaan.com Atul is ex MD of Wartsila, and was based at Jeddah. Am sure we have have been marketed with such additives/claims, however, urged people to just spend some time to get familiar with this Product.