The partnership between MAN Diesel & Turbo and Aspin Kemp & Associates (AKA) enables the development of new high speed hybrid powered ship propulsion Solutions.
This hybrid design integrates MAN 175D engines with additional electric motor power, supported by auxiliary genset(s) and/or batteries, to give a complete propulsion drive train suitable for any applications using azimuth thruster propellers, such as harbour tugs. The propulsion control system offers a number of different operational modes including: stop, idle, transit and assist as well as a conventional, non-hybrid option. This new propulsion management provides two key advantages: Firstly, the operational running hours of diesel engines are significantly reduced, as the main engines are only called into service when the vessel power demand requires. Secondly, when the main and auxiliary engines are operating, they are running at their most optimized and efficient point. By this optimization of engine performance and operational capability, hybrid propulsion management minimizes emissions, fuel consumption and maintenance costs.
The attached video shows a typical layout of diesel-hybrid propulsion technology solution, including two main MAN 175D diesel engines and two MAN powered auxiliary gensets. The available operation modes shown are described as follows:
Stop Mode: The Stop Mode is applied when no shore power is available and the onboard system can be powered from the batteries alone. Once the batteries are discharged to below a preset level, say 20%, the batteries are charged by the auxiliary gensets, while also powering the onboard Systems.
Transit Mode 1: In this mode, the thrusters are electrically driven by the motors which, in turn, are supplied by the DC switchboard. This means that propulsion at low speed can be achieved purely by the electrical system without the main engines running. To ensure that the auxiliary gensets run at an optimum load point they are also charging the batteries.
Assist Mode: This mode is selected when high propulsion power is required and the main engines are fully utilized for this purpose. In this case the electrical machines are acting as generators and supplying power to the vessel systems along with the batteries, thereby saving the auxiliary gensets. In this case, the auxiliary generators will run only when the batteries are down to less than 20% charge, when they can be started and charge the batteries.
Non-hybrid mode: In this mode, the vessel propulsion is independent from the hybrid system and is running very similar to a conventional one. But, as can be seen the main and auxiliary engines can be operating at very inefficient load levels. It is also important to realize that because this hybrid layout is a very flexible system then other modes can be introduced to optimize propulsion functions according to operational requirements.
If you would like to receive further and more detailed information concerning the hybrid powered ship propulsion solutions for the MAN 175D, please contact MAN Diesel & Turbo.