Exhaust system for Yachting

Emission Limits

Xeamos has the know-how to design exhaust systems with the integrated NOx and PM reduction, sound attenuation and wet or dry exhaust. We guarantee that the required emission limits are met and comply with the required class requirements. We hold multiple IMO Tier III certifications for the most common engine brands and models.

Knowledge of propulsion systems

Nowadays there is a lot of variety in propulsion systems such as diesel-direct, diesel-electric and hybrid propulsion. Generators are operated either in fixed or variable speed mode while propellers can be fixed or controllable pitch. All these parameters have an impact on the operation and load profile of the engines and their exhaust characteristics. Xeamos exhaust after-treatment systems are optimized to work smoothly with your propulsion system.

Integration with your Power Management System

Electrical regeneration of diesel particle filters results in a significant load on the on-board power system. With this in mind Xeamos has developed bespoke control features because our electrical heaters also have to minimize the impact on a yacht’s power network. One feature is that the engagement of the electrical heater can be supressed by the PMS because you don’t want a second generator to kick in during times that multiple electrical consumers are active. At the appropriate time, when the generator allows for the additional heater load, the heater is released.
Another feature is the heater power limit function. In this case the electrical power to the heater is quickly reduced to prevent loading of the generator above a set limit. Last but not least the heater can be applied as a load bank for the generator as well. During the “harbor” function a certain base load is added to your generator, resulting in a more effective DPF system with lower hydrocarbon emission.

Electrical integration

Xeamos offers many options where it comes to integration of the electrical controls of various sub-systems in the exhaust line. Our control systems enable control and monitoring of the main and bypass shut-off valves in the wet exhaust system. Even the active control of the exhaust back pressure for certain complex engines is possible.

Class-critical alarm signals are available as hard-wired contacts. In addition, all information from our after-treatment systems is made available by MOD bus and can be used to mimic the performance of your exhaust after-treatment system in the AMS interface.

Sound attenuation

Engine rooms in most yachts have limited space for an exhaust system, making the need for integration of emission reduction and silencers inevitable. Using our knowledge of acoustics, we offer solutions to integrate DPF, SCR and silencers according to your requirements. The sound attenuation is tuned to the engine characteristics to give an optimum reduction of the ignition frequencies and its harmonics, suppressing that annoying exhaust hum.

Exhaust design

We can offer backpressure calculations of the complete exhaust system to stay within the limits of the engine manufacturer. As the main contractor we ensure all parts in the exhaust system are taken into account. Wet (underwater) exhaust systems in particular require specific knowledge to make a reliable calculation of backpressure. As wet exhaust requires an experts’ touch, Xeamos engineers always team up with leading partners in this field.

Mechanical Integration

Xeamos engineers calculate the thermal expansion of the exhaust system, advise on the best support points and select the correct anti-vibration mounts. Additional supports can be added to the structure of our after-treatment systems to simplify the installation of thermal insulation. When useful, our engineers can create 3D models of the relevant sections of the engine room to support integration and installation during refit projects.

Reactor housing design

The reactor housing for our SCR and/or DPF systems is designed for the specified operating conditions. The pressure drop, flow uniformity and temperature distribution are accurately simulated using advanced CFD software. Mechanical stress calculations are made with our FEM software tools using worst-case scenarios of maximum exhaust temperatures and pressures. The effect of low-cycle fatigue on the steel has to be taken into account to prevent premature failure of the system, especially with wet underwater exhausts. Different (stainless) steel types can be applied depending on the application and customer requirements. A higher-than-standard quality of welding is applied to yacht applications.  

Relevant products

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