Ammonia is one of the fuels the maritime industry is looking towards to replace more traditional fossil fuels, building towards IMO 2030 and IMO 2050 targets. Ammonia is created from hydrogen and nitrogen. It also has a higher energy density than hydrogen, making it better suited for use as fuel in long-haul shipping.

Charge air cooler

With a forced induction engine, the compression of air also makes it hotter, which isn’t ideal for power or efficiency. That’s where a charge air cooler – also known as an intercooler – comes in. Sitting between the turbocharger and engine, a charge air cooler takes the compressed hot air from the turbo and cools it down before feeding it into the intake manifold, helping to increase efficiency and power.

Compressor housing and diffusor

This is the stator part of the compressor stage. The engine requires air pressure in the intake receiver rather than velocity. To convert the velocity into static pressure, the stator must slow down the air flow, by recompressing it. As this is the case for the turbine nozzle ring, a large turbocharger compressor typically comprises an additional blades ring, called the vane diffusor. This diffusor is inserted between the compressor wheel and the housing, in a way to better organize the air recompression process, with the optimal flow direction at the outlet of the wheel. The recompression is better achieved within the housing, whose divergent shape allows the gases to be further slowed down and compressed.

Compressor map

The compressor map is the fingerprint or the signature of the compressor. It represents its thermodynamic characteristics, linking air flow, pressure ratio, wheel rotational speed and efficiencies. This map also displays the operational limits of the compressor stage, like surge, choke and overspeed. This graphic representation allows linking the compressor and the engine operating points, and thus checking if both machines are correctly matched. This is the starting point for selecting the right turbocharger for a given engine and application.

Compressor wheel

This is the rotor part of the compressor stage. Driven into high rotational speed by the turbine through the shaft, the compressor wheel breaths the fresh air from the filter, starts compressing it, and brings it into rotation around its axle with high tangential velocity and kinetic energy.


Decarbonization is the reduction of carbon dioxide emissions through the adoption of low-carbon power sources, such as solar power, wind power and other sustainable alternatives. The aim is to reduce the number of greenhouse gases (GHG) that are released into the atmosphere, which is essential when it comes to meeting global temperature standards set by the Paris Agreement international treaty on climate change.

Diesel Cycle

In 1893, Rudolf Diesel ran his first engine in Augsburg (Germany), with a compression self-ignition process. His idea was to get as close as possible to the ideal Carnot cycle, which allowed his new engine to outclass the already existing technologies: The Diesel engine was born. Rudolf Diesel’s vision was to create, mainly based on scientific considerations, a cheap and energy efficient engine for small business, as a means of improving social conditions.


Energy Efficiency Existing Ship Index (EEXI) is a technical index created by the IMO to measure the efficiency of a ship’s design, calculating everything from the vehicle’s propulsion system to its transport capacity and speed. Created to measure the CO2 emissions per cargo ton and mile, EEXI is a valuable tool in the journey towards cutting greenhouse gas emissions for IMO 2030 and IMO 2050.


Engine part-load optimization (ELPO) is a tuning method that optimizes fuel-oil consumption during the part-load operation of four-stroke engine, helping to improve fuel efficiency and save costs for shipping owners and operators. There are multiple ways that owner/operators can approach EPLO, such as engine derating, turbocharger cut-out and turbocharger upgrades, and our story on engine efficiency will help you to find out more.


In 1876, the German Nikolaus Otto developed a gaseous fuel, compressed charge four-stroke cycle that would become known as the Otto-Cycle. This is the principle that still powers most car engines today. He based an engine on this cycle after 14 years of effort: it is a system characterized by four piston strokes (intake, compression, expansion-power and exhaust), under two engine revolutions.

Green hydrogen

Green hydrogen is one of the possible solutions for future fuels. Unlike regular (blue) hydrogen, which is created using fossil fuels, green hydrogen is produced using renewable energy through electrolysis. Using an electrical currant to separate the hydrogen from oxygen in water, green hydrogen is created using renewable electricity sources such as solar or wind power.

High, medium and low-speed

Diesel engines can be split into three different types: High-speed, medium-speed and low-speed. High-speed engines run at around 1200rpm or more and can generally be found in smaller applications such as cars, trucks or construction vehicles, or powering generators. As the name suggests, medium-speed engines run at around 400rpm or more and are often found in larger applications including smaller boats and larger electrical generators. Low-speed engines run at less than 400rpm and are most typically found in larger ships.


The International Maritime Organization (IMO) is the global standard-setting authority for the safety, security and environmental performance of international shipping. Its main role is to create a regulatory framework for the shipping industry that is fair and effective, universally adopted and universally implemented, leading to targets such as IMO 2030 and IMO 2050.


LNG (liquified natural gas) is an  alternative fuel that is bridging the gap as the marine industry works towards a cleaner future. Although still a fossil fuel, LNG is actually 95% methane, and the combustion of natural gas generally results in emissions of water vapor and small amounts of carbon dioxide. Although the shipping industry is working towards decarbonization and targets such as IMO 2030 and IMO 2050, LNG is a reasonable interim solution, as associated CO2 emissions are 30 to 50% lower than those produced by traditional combustible fuels.


Methanol is an alternative fuel generally produced by steam-reforming natural gas to create a synthesis gas. Lower production costs make it a more affordable option than other alternative fuel sources such as hydrogen and ammonia, and it has also been used in the past as an alternative for traditional fuels for domestic vehicles.


A microgrid is a self-sufficient energy source that’s generally designed to serve local power needs. Despite the name, there are no constraints on size, with the ability to connect clusters of microgrids to create larger, more powerful, systems. A microgrid could provide power to just a couple of homes, or it could also be used to provide electricity to thousands. What microgrids do generally have in common, however, is the fact that they tend to be decentralized and self-contained, making them the perfect power source for more remote locations.

Miller Cycle

Internal combustion engines may run on similar principles, but they don’t all feature the same operating cycles. While many engines feature a four-stroke cycle, comprising intake, compression, expansion-power and exhaust, the Miller Cycle, originally patented by the American Ralph Miller in 1957 and still used today, differs by having a longer expansion stroke than the compression stroke, which is synonym of better thermodynamic efficiency. This is generally done by closing the intake valves earlier than on a normal engine. Used alongside a turbocharger or supercharger, the part of the forced induction (cooled compression) into the global compression is larger, leading lower maximal cycle temperatures and better [NOx emissions and efficiency] trade-off, while improving combustion stability and keeping away the knocking in the case of spark-ignited engines. Miller Cycle engines can be more efficient as a result.

Otto Cycle

In 1876, the German Nikolaus Otto developed a spark-ignited gaseous fuel, compressed charge 4-stroke cycle that would become known as the Otto-Cycle. This is the principle that still powers most car engines today. He based an engine on this cycle after 14 years of effort; it is a system characterized by four piston strokes (intake, compression, expansion-power and exhaust), under two engine revolutions. Austrian watchmaker Christian Reithmann is also credited with having patented a 4-stroke engine during the early 1860s, and the Frenchman Alfonse Beau de Rochas described and patented the cycle exactly as N. Otto built it in 1862.

Service agreement

Unexpected or unscheduled downtime in the maritime industry can cost businesses millions of dollars, which is why it’s so important to keep on top of maintenance and servicing. That’s where service agreements come in, helping companies to ensure the continued efficiency and reliability of parts. Not only does this help to keep engines running as efficiently as possible, it can also help to reduce total cost of ownership and the administrative workload of maintenance management. Check out how Vedanta Limited – Cairn Oil & Gas is benefitting from ABB Turbocharging’s service agreement here.

Slow steaming

Whatever your form of transport – from walking to riding a bike or driving a car – travelling as quickly as possible is never the most energy efficient way to get around. At a certain point, going faster will always take more effort and use more fuel. The same is true for shipping, where the costs of inefficiency can be huge. As such, the owners and operators of cargo ships engage in a practice known as slow steaming, where they deliberately reduce the speed of their vessels to reduce fuel consumption and cut carbon emissions.

Turbine housing and nozzle ring

This is the stator part of the turbine stage. The turbine housing takes the exhaust gases from the engine and directs them onto the turbine wheel, by accelerating them through a pre-expansion process. In the case of large turbochargers, a nozzle ring is added between the housing and the wheel to improve the efficiency of this pre-acceleration by directing the gases toward the wheel blades with an optimal direction. The turbine efficiency itself is thereby strongly improved, and a larger part of the exhaust energy is then turned into mechanical power.

Turbine Wheel

This is the rotor part of the turbine stage. The turbine wheel features a number of finely designed blades, which turn the wheel when hit by the accelerated exhaust gases coming from the stator. This rotational power is further increased by the reaction of the gases continuing to expand themselves between the wheel blades. As the engine power increases, more exhaust gases are expelled, with increased internal energy, and directed into the turbine housing, turning the turbine wheel at faster speeds.


A turbocharger is an auxiliary component that helps to improve internal combustion engine power density and efficiency. To do so, the turbocharger turbine recovers a part of the exhaust energy which would have been otherwise lost, by expanding exhaust gases around a rotating wheel. This turbine wheel is driven into rotation and its mechanical power is transmitted to the compressor, which vacuums fresh air from ambient and compresses it toward the engine intake receiver. This gives the engine a higher air mass per cycle. This additional boost can multiply the output power of a given engine by up to six times in comparison to a naturally aspirated, non-turbocharged engine, and can also result in a substantial fuel consumption and CO2 reduction of up to 70%.

Turbocharger cartridge

While there are plenty of different components within a turbocharger, including compressor and turbine wheels, shafts, bearings, nozzles and other parts, the turbocharger cartridge groups some of these components together, making maintenance, replacements and upgrades both easier and more affordable. Instead of having to put numerous parts together, or replace the turbocharger as a whole, it is possible to buy a turbocharger cartridge instead. This can simply be swapped out for the old cartridge, including both the compressor and turbine wheels, the shaft that connects them, and other parts that make up the heart of the turbocharger.

Two-stage turbocharging

Turbochargers help to boost the efficiency of internal combustion engines by reusing exhaust gases energy, but that efficiency can be further increased through the use of two and even three stage turbocharging. Two-stage turbochargers feature two compressor and turbine stages, with the initial stage typically being low-pressure, which in turn feeds into a high-pressure stage. This enables engine builders to increase compression ratios far higher than those found on single-stage turbochargers. Also, thanks to the thermodynamic benefit of intercooling between both compressors, two-stage solutions such as ABB Turbocharging’s Power2 provide turbocharging efficiency above 75%, compared to 65% for conventional turbochargers. The engine efficiency is thereby positively impacted and thanks to thermal load reduction, its lifetime can also be improved as well.


While the majority of larger engines run on the four-stroke Otto-Cycle, there are still a number of engines that run a simple two-stroke cycle. In place of intake, compression, expansion-power and exhaust strokes, the end of the combustion stroke and the beginning of the compression stroke happen simultaneously, resulting in an engine cycle that only requires two revolutions of the crankshaft.

Variable turbine geometry (VTG)

ABB’s Variable turbine geometry (VTG) technology can continuously alter the geometry of a turbocharger’s turbine nozzle ring, helping to control the boost pressure that a turbocharger supplies to an engine. This provides more flexibility when it comes to adjusting the air-to-fuel ratio for varying ambient conditions. VTG can also broaden the engine operating range by increasing the boost pressure at low engine speed and/or load, without degrading the performance and efficiency at rated power. The benefits can be seen when it comes to both turbocharger efficiency and operating costs, with engines in long-haul locomotives saving as much as 4% on average on fuel, for example, across a wider range of temperatures and altitudes. In short, VTG provides more performance and additional flexibility in any situation.