Smart Valve Technology in the Marines

“The 15 largest seagoing vessels in the world emit more harmful sulfur oxides annually than all 760 million cars worldwide!”

This is a quote from Dietmar Oeliger, Head of Transport Policy at NABU. Shipping is also significantly involved in the emission of nitrogen oxides and particulate matter from internal combustion engines. Here, too, ships emit far more worldwide than automobiles, not least because the world’s highest volume of freight is transported by sea (see picture below). The rapidly growing number of cruise ships is also contributing to the aggravation of the situation. In port cities, pollutant emissions from ships are particularly problematic.

There is an urgent need for action to reduce pollutant emissions from ships. Technical solutions to the problem are needed and, in particular, should also bring economic benefits to facilitate implementation, especially since environmental regulations in shipping are slow to take effect worldwide due to national peculiarities. Important environmental requirements for shipping:

IMO (International Maritime Organization) is a specialized agency of the United Nations responsible for the safety and prevention of marine pollution. The rules on exhaust emissions issued by the IMO are commonly known as the “Tier I … III” standards. These standards define in particular the NOx and SOx emissions of diesel engines. Tier I and Tier II are globally applicable guidelines, while Tier III is only required in so-called “NECAS” (N Ox-Eemission Control Areas). In the “NOx Emission Control Areas” there is a stricter rule regarding NOx emissions.

The United States Environmental Protection Agency (EPA) is an independent agency of the United States Government dedicated to environmental protection and human health. EPA Tier 4f applies to all U.S.-flagged vessels. EPA calls for stricter limits for ships than IMO Tier III in the NECA zones (NOx Emission Control Areas). These limits are described in EPA regulations.

The shipbuilding industry must play its part in global environmental protection. The goal of shipbuilders, equipment suppliers and ship owners must be a “maritime energy transition” that makes shipping CO2-neutral in the long term and also free of harmful emissions.

In the combustion process in diesel engines, nitrogen oxides are also formed, the elimination of which is very complex and cost-intensive in the exhaust gas flow. Existing technologies, such as the selective catalytic reduction of nitrogen oxides with ammonia (via urea solution) or NOx storage catalysts, are problematic because they are complicated, expensive or limited in effect.

The diesel engine dominates the propulsion of ships and is not easy to replace here due to its high thermodynamic efficiency and the associated economy and resource conservation. Unfortunately, marine diesel engines emit significant amounts of pollutants such as sulfur dioxide, nitrogen oxides and particulate matter. The pressure is growing to operate marine diesel engines in an environmentally friendly manner. There is a need for action here. Shipping must be provided with appropriate technical solutions for environmental protection.

Smart Water Injection from KTW reduces consumption and pollutants!

The generally positive effect of water injection in terms of pollutant emissions and efficiency of the diesel engine has been demonstrated. If water is sprayed directly into the combustion chamber, this has the advantage that the flame in the combustion chamber can only be influenced by water after ignition of the flame, in particular a layered water injection is possible.

Only the independent injection of fuel and water allows an optimal influence on the combustion and the combustion temperature by water (R. Plöntzke and H. Zellbeck ( MTZ Motorentechnische Zeitschrift 77 (2016) 4 p.28) and thus the overcoming of the immanent process instability. KTW’s engineers used this technology in racing decades ago.

Here, the Smart Valve technology developed by KTW provides the future-oriented solution. At the Wissenschaftlichen-Technische Zentrum für Motoren and  Maschinenforschung Roßlau gGmbH (WTZ), a series of tests were carried out with a solenoid valve from KTW Technology. The WTZ has appropriate technical Centre facilities such as an engine test bench with marine diesel. The valve was placed in the intake duct.

The first tests are promising: water injection valve systems can cool the intake air and help to force more air into the cylinders of the engines through better compression. For diesel engines, nitrogen oxide emissions can be reduced by 50 to 60% and fuel consumption by 5 to 10%. This significantly reduces particulate matter and CO2 emissions. The investment, e.g. for retrofitting a ship engine, amounts to a few thousand euros. A new ship engine, on the other hand, costs several hundred thousand euros – they are designed for an unlimited runtime. In contrast to the car engine, sea giants are worth replacing individual parts in the event of a defect.

From a water content of 30%, the International Maritime Organization (IMO) fell below Tier II nitrogen oxide limit. Depending on the ignition jet quantity, nitrogen oxide reduction rates of up to 50% (60%H2O) are possible.

The combination of the many features of the KTW valve shows its uniqueness and allows a further reduction of the environmental impact of the otherwise very efficient diesel engines. The valve can be switched very quickly, is highly precise, extremely wear-resistant and, in principle, not complex to manufacture. It is very suitable for the planned process because it is very durable and reliable due to the electromagnetic design, it enables the required service life for the first time and is directly switching. The valve is made of stainless steel and the only moving part in the valve is a caliber. This means that there are no corrosion and lubrication problems that cause all known valves, such as needle valves or piezo valves, to fail at an early stage. In various versions, the valve covers a displacement of 0.5 l per cylinder to 13 l per cylinder and thus for the first time the necessary flow can be generated to inject significant amounts of water into large diesel. Previously known valves achieved NOx reductions of 5% and would also have to be used in larger numbers.

Considerable sales and savings potential!

Even though diesel engines have been declared obsolete in Germany, the industry must look beyond borders and can help to ensure that existing large diesel engines can be used in a more environmentally friendly way. After all, this involves an annual consumption of 44 billion liters of diesel p.a. and 3 – 6 billion kg of NOx worldwide in the shipping sector. And the trucks registered in Germany alone consume 14 billion liters of diesel p.a.

The path towards alternative drive systems is unavoidable. If existing savings potentials can be exploited, this opportunity should be seized in the interests of climate protection, instead of relying solely on the lengthy conversion process.

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