Conference Agenda

MAST Med 2022 Grand Hyatt, Central Athens, Greece

Wed 2 Nov 2022

12:00 Wed 2 Nov 2022

12:00–13:30

1C: Surface

Naval Propulsion Innovations II

Propulsion Innovations

Increasing Efficiency and DP Capability and Reducing Hydro-acoustic Signature (Electric Voith Schneider Propeller "eVSP")

  • Mr Dirk Juergens
    Vice President Design Technical Sales
    J.M. Voith SE & Co. KG
    Germany

For modern naval vessels, especially mine countermeasures ships, it is becoming increasingly important that ships can perform Dynamic Positioning (DP) maneuvers very efficiently: DP maneuvers have to be carried out with the lowest possible energy consumption and with low hydro-acoustic signature.

Voith has developed a very quiet electric Voith Schneider Propeller (eVSP) for this purpose. The eVSP is based on the well-known and mature technology of the classic mechanical Voith Schneider Propeller.

With the eVSP, a modern permanent magnet synchronous motor (PMSM) is integrated directly into the propeller. This significantly increases efficiency, reduces energy consumption, and requires less material and installation space.

The PMSM torque motor of the eVSP substitutes the following elements of the classic VSP: bevel gear, primary gearbox, asynchronous e-motor, shaft lines, cooling/controls of the primary gearbox and the asynchronous e-motor.

Due to the very high torque of the direct-integrated PMSM, completely new operating modes can be run in the ship, e.g. a variable RPM Dynamic Positioning (DP) mode. In the paper, comparative dynamic DP calculations in the time domain will be presented. For a 90m offshore vessel with 7920 operating hours, the use of the eVSP saves 370.2 t of diesel and 962.4 t of CO2 per year compared to the classic VSP. Due to the fast variation of the thrust with the eVSP, an efficient reduction of the rolling motions is possible. Numerical calculations of ships with active Voith Roll Stabilization are also presented.

Since the eVSP is a gearless ship propulsion system, a very low signature for underwater noise can be achieved. A prediction of underwater noise for a 120 m research vessel to meet SILENT R class will be presented.

In addition, the presentation will address which ships are currently being equipped with the eVSP.

Waste Heat Recovery Analysis of a Dual-Loop ORC System Coupled to the Main Diesel Engines of a Guided Missiles Fast Patrol Boat

  • Ensign Athanasios Vallis
    Naval Officer
    Hellenic Navy
    Greece

In the present study, a waste heat recovery analysis is performed of a dual-loop bottoming system comprised of two organic Rankine cycles (ORC), which is coupled to the main diesel engines of a fast patrol boat of LA COMBATTANTE III type of the Hellenic Navy. The waste heat recovery bottoming system is comprised of two loops: One high-temperature (HT) loop based on a subcritical ORC, which is used for harvesting waste heat from the exhaust gases of the main diesel engines and one low-temperature (LT) loop based on a subcritical ORC, which is used for harvesting waste heat from engine coolant, from engine charge air cooler and from the condenser of the HT loop. A parametric investigation is conducted to examine the effect of various organic mediums and thermodynamic parameters on the energy performance indicators of both loops of the bottoming system to identify the optimum working fluid pair and the optimum thermodynamic parameters of the bottoming system. Subsequently, a heat transfer analysis is carried out so as to dimension the necessary heat exchangers of the proposed system. A mission analysis of the fast patrol boat is also performed using the optimum dual-loop ORC system, which showed that its application can lead to considerable fuel saving with pertinent economic benefits and CO2 and SO2 emission savings.

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