scholarly journals Comparison of COGES and Diesel-Electric Ship Propulsion Systems

2016 ◽  
Vol Special edition (1) ◽  
pp. 131-148
Author(s):  
Vedran Mrzljak ◽  
Tomislav Mrakovčić
Keyword(s):  
Diesel Engines ◽  
Gas Turbines ◽  
Electric Propulsion ◽  
Cost Effective ◽  
Propulsion System ◽  
Pollutant Emissions ◽  
Propulsion Systems ◽  
Ship Propulsion ◽  
Passenger Ships ◽  
Electric Ship

Diesel-electric ship propulsion is a frequent shipowners choice nowadays, especially on passengerships. Despite many diesel engines advantages, their primary disadvantage is emission of pollutants. As environmental standards become more stringent, the question of optimal alternative to diesel-electric propulsion arises. COGES (COmbined Gas turbine Electric and Steam) propulsion system is one of the proposals for alternative propulsion system, primarily due to significant reduction of pollutant emissions. On the other hand, gas turbines have higher specific fuel consumption in comparison with diesel engines what represents their noticeable disadvantage. However, some analyzes suggested that COGES propulsion system could be still cost-effective in comparison to diesel-electric propulsion, particularly on passenger ships where higher initial investment can be compensated by increasing the number of passenger cabins. This paper shows a comparison of above mentioned propulsion systems, which can be useful for the optimal ship propulsion system selection

Verification, Validation and Accreditation of Ship Electric Propulsion Simulation System

2013 ◽  
Vol 433-435 ◽  
pp. 1915-1920
Author(s):  
Bing Li ◽  
Li Hong Li ◽  
Fan Ming Liu
Keyword(s):  
Electric Propulsion ◽  
System Simulation ◽  
Simulation System ◽  
Propulsion System ◽  
Verification And Validation ◽  
Ship Propulsion ◽  
Validation Methods ◽  
Electric Ship ◽  
Expert Theory ◽  
Modelling Simulation

in this paper, the concepts of modelling, simulation, verification and validation are described in order to analyse their necessities in electric ship propulsion system simulation. Traditional verification and validation methods are outlined before a new method based on expert theory and verification and validation methods of software testing is proposed to verify if the simulation program meets customers needs and respective software protocols, according to the characteristics of electric ship propulsion system.

MT30: The Heart of Future Integrated Power and Propulsion Systems

2014 ◽  
Author(s):  
Oliver Rath
Keyword(s):  
Gas Turbines ◽  
Electric Propulsion ◽  
Propulsion System ◽  
Propulsion Systems ◽  
Marine Propulsion ◽  
Wide Range ◽  
Prime Movers ◽  
The Republic ◽  
The Uk ◽  
System Configurations

The MT30 has been developed specifically for 21st century marine propulsion and has now been applied in a wide range of different propulsion system configurations in the US Navy, the UK Royal Navy and the Republic of Korea Navy. Both naval and commercial marine propulsion systems are increasingly seeking more power from fewer prime movers to facilitate lower cost of ownership. In naval systems, the move to partial or full-electric propulsion for larger escorts and the introduction of single boost gas turbines for smaller escorts has allowed a reduction in the number of installed prime movers, while retaining and often enhancing survivability and redundancy. The Rolls-Royce MT30 marine gas turbine can be regarded as an enabling technology in this area to allow a wide variety of propulsion system options to be realised. This paper describes the current trends in Naval propulsion systems with particular focus on the platform design, operational and through-life benefits of the MT30 in the context of different system arrangements. A variety of different systems are covered with a particular focus on hybrid electromechanical and all-electric systems.

scholarly journals Optimisation of a Diesel-Electric Ship Propulsion and Power Generation System Using a Genetic Algorithm

2021 ◽  
Vol 9 (6) ◽  
pp. 587
Author(s):  
Raphael Zaccone ◽  
Ugo Campora ◽  
Michele Martelli
Keyword(s):  
Genetic Algorithm ◽  
Electric Propulsion ◽  
Load Sharing ◽  
Linear Constraints ◽  
Pollutant Emissions ◽  
Propulsion Systems ◽  
Ship Propulsion ◽  
Optimal Load ◽  
Design Speed ◽  
High Flexibility

In recent decades, the design of ship propulsion systems has been focusing on energy efficiency and low pollutant emissions. In this framework, diesel–electric propulsion has become a standard for many ship types and has proven its worth for flexible propulsion design and management. This paper presents an approach to the optimal design of diesel–electric propulsion systems, minimising the fuel consumption while meeting the power and speed requirements. A genetic algorithm performs the optimisation, used to determine the number and type of engines installed on-board and the engines’ design speed and power, selecting within a dataset of four-stroke diesel engines. The same algorithm is then adapted and applied to determine the optimal load sharing strategy in off-design conditions, taking advantage of the high flexibility of the diesel–electric propulsion plants. In order to apply the algorithm, the propulsion layout design is formulated as an optimisation problem, translating the system requirements into a cost function and a set of linear and non-linear constraints. Eventually, the method is applied to a case study vessel: first, the optimal diesel–electric propulsion plants are determined, then the optimal off-design load sharing and working conditions are computed. AC and DC network solutions are compared and critically discussed in both design and off-design conditions.

scholarly journals Modeling and Investigation of a Turboprop Hybrid Electric Propulsion System

Aerospace ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 123 ◽  
Author(s):  
Maria Cameretti ◽  
Andrea Del Pizzo ◽  
Luigi Di Noia ◽  
Michele Ferrara ◽  
Ciro Pascarella
Keyword(s):  
Fuel Consumption ◽  
Gas Turbines ◽  
Electric Propulsion ◽  
Internal Combustion Engines ◽  
Propulsion System ◽  
Pollutant Emissions ◽  
Noise Emission ◽  
Hybrid Propulsion ◽  
Hybrid Electric ◽  
Hybrid Configuration

Hybrid electric propulsion in the aviation field is becoming an effective alternative propulsion technology with potential advantages, including fuel savings, lower pollution, and reduced noise emission. On the one hand, the aeroengine manufacturers are working to improve fuel consumption and reduce pollutant emissions with new combustion systems; on the other hand, much attention is given to reducing the weight of the batteries increasing the energy density. Hybrid electric propulsion systems (HEPS) can take advantage of the synergy between two technologies by utilizing both internal combustion engines (ICEs) and electric motors (EMs) together, each operating at their respective optimum conditions. In the present work, some numerical investigations were carried out by using a zero-dimensional code able to simulate the flight mission of a turboprop aircraft, comparing fuel consumption and pollutant emissions of the original engine with other two smaller gas turbines working in hybrid configuration. An algorithm has been implemented to calculate the weight of the batteries for the different configurations examined, evaluating the feasibility of the hybrid propulsion system in terms of number of non-revenue passengers.

scholarly journals Assessment of a hybrid propulsion system for short-mid range application with a low-order code

2021 ◽  
Vol 312 ◽  
pp. 11005
Author(s):  
Alberto Amerini ◽  
Leonardo Langone ◽  
Riccardo Vadi ◽  
Antonio Andreini
Keyword(s):  
Environmental Sustainability ◽  
Electric Propulsion ◽  
Propulsion System ◽  
Pollutant Emissions ◽  
Propulsion Systems ◽  
Hybrid Propulsion ◽  
Electric System ◽  
Hybrid Configuration ◽  
And Control ◽  
Low Order

The increase in air traffic expected in the next years must be accompanied by innovation to ensure the lowest possible environmental impact. Hybrid electric-thermal propulsion systems are currently being investigated and could represent a breakthrough for environmental sustainability in the sector. However, the transition to electric propulsion remains challenging due to the current level of energy density related to storage systems, the additional components associated with power conversion and control systems, not to mention the cost of all the associated equipment. The purpose of this study is to carry out a preliminary assessment of a hybrid propulsion system for a short-mid range aircraft. This study investigates the series hybrid configuration, where a turboshaft, a high temperature superconducting (HTS) electric motor, batteries and power converters interact to provide the necessary propulsion for flight. A zero-dimensional procedure is developed to estimate the mass and efficiency of the powertrain components for a selected flight mission. Thermal engines are modeled with the low-order code and coupled with the components of the electric system through a python routine. A comparison in terms of weight and emissions is reported for the designed hybrid propulsion system and the conventional one. The analysis shows that the weight of the two propulsion systems is similar but, the presence of batteries, even considering a higher level of technology than the current one, leads to a significant increase in the weight of the hybrid aircraft. The second part of the study focuses on pollutant emissions, showing that the hybrid system can reduce CO2 emissions by 58% and NOx emissions by 68% compared to the conventional system. Despite the excellent premise, the reduction in payload for the hybrid aircraft causes a reduction in pollutant emissions per passenger only for NOx. For this reason, further technological improvement is needed to make hybrid propulsion advantageous in terms of both payload and pollutant emissions.

Marine Gas Turbine Performance Model for More Electric Ships

2011 ◽  
Author(s):  
George M. Koutsothanasis ◽  
Anestis I. Kalfas ◽  
Georgios Doulgeris
Keyword(s):  
Gas Turbine ◽  
Fuel Consumption ◽  
Diesel Engines ◽  
Gas Turbines ◽  
Electric Propulsion ◽  
Operating Conditions ◽  
Prime Mover ◽  
Creep Life ◽  
Hull Fouling ◽  
Turbine Performance

This paper presents the benefits of the more electric vessels powered by hybrid engines and investigates the suitability of a particular prime-mover for a specific ship type using a simulation environment which can approach the actual operating conditions. The performance of a mega yacht (70m), powered by two 4.5MW recuperated gas turbines is examined in different voyage scenarios. The analysis is accomplished for a variety of weather and hull fouling conditions using a marine gas turbine performance software which is constituted by six modules based on analytical methods. In the present study, the marine simulation model is used to predict the fuel consumption and emission levels for various conditions of sea state, ambient and sea temperatures and hull fouling profiles. In addition, using the aforementioned parameters, the variation of engine and propeller efficiency can be estimated. Finally, the software is coupled to a creep life prediction tool, able to calculate the consumption of creep life of the high pressure turbine blading for the predefined missions. The results of the performance analysis show that a mega yacht powered by gas turbines can have comparable fuel consumption with the same vessel powered by high speed Diesel engines in the range of 10MW. In such Integrated Full Electric Propulsion (IFEP) environment the gas turbine provides a comprehensive candidate as a prime mover, mainly due to its compactness being highly valued in such application and its eco-friendly operation. The simulation of different voyage cases shows that cleaning the hull of the vessel, the fuel consumption reduces up to 16%. The benefit of the clean hull becomes even greater when adverse weather condition is considered. Additionally, the specific mega yacht when powered by two 4.2MW Diesel engines has a cruising speed of 15 knots with an average fuel consumption of 10.5 [tonne/day]. The same ship powered by two 4.5MW gas turbines has a cruising speed of 22 knots which means that a journey can be completed 31.8% faster, which reduces impressively the total steaming time. However the gas turbine powered yacht consumes 9 [tonne/day] more fuel. Considering the above, Gas Turbine looks to be the only solution which fulfills the next generation sophisticated high powered ship engine requirements.

The Prospects for Lightweight Ship Propulsion Systems

1978 ◽  
Author(s):  
S. C. Kuo ◽  
T. L. O. Horton ◽  
H. T. Shu ◽  
W. R. Seng
Keyword(s):  
Gas Turbines ◽  
Economic Feasibility ◽  
Closed Cycle ◽  
Propulsion Systems ◽  
Ship Propulsion ◽  
Parametric Analyses ◽  
Propulsion Power

A comprehensive systems study was made to evaluate the technological and economic feasibility of utilizing open- and closed-cycle gas turbines for providing advanced lightweight propulsion power for future Navy ship applications. Extensive parametric analyses were made of the performance and weight characteristics for the propulsion engine cycles selected, and applicable turbomachinery technologies were reviewed to estimate their future advances expected. The payload capabilities and endurance limitations resulting from utilization of different propulsion systems in the 40,000 -to 300,000-shp range for selected ship types were identified.

scholarly journals Large-Scale Electric Propulsion Systems in Ships Using an Active Front-End Rectifier

2019 ◽  
Vol 7 (6) ◽  
pp. 168
Author(s):  
Hyeonmin Jeon ◽  
Jongsu Kim ◽  
Kyoungkuk Yoon
Keyword(s):  
Phase Angle ◽  
Electric Propulsion ◽  
Large Scale ◽  
Measurement Data ◽  
Propulsion System ◽  
Propulsion Systems ◽  
Zero Crossing ◽  
Electric Propulsion System ◽  
Front End ◽  
Harmonic Content

In the case of the electric propulsion system on the vessel, Diode Front End (DFE) rectifiers have been applied for large-sized ships and Active Front End (AFE) rectifiers have been utilized for small and medium-sized ships as a part of the system. In this paper, we design a large electric propulsion ship system using AFE rectifier with the proposed phase angle detector and verify the feasibility of the system by simulation. The phase angle derived from the proposed phase angle detection method is applied to the control of the AFE rectifier instead of the zero-crossing method used to detect the phase angle in the control of the conventional AFE rectifier. We compare and analyze the speed control, Direct Current (DC)-link voltage, harmonic content and measurement data of heat loss by inverter switch obtained from the simulation of the electric propulsion system with the 24-pulse DFE rectifier, the conventional AFE rectifier, and the proposed AFE rectifier. As a result of the simulation, it was confirmed that the proposed AFE rectifier derives a satisfactory result similar to that of a 24-pulse DFE rectifier with a phase shifting transformer installed according to the speed load of the ship, and it can be designed and applied as a rectifier of a large-sized vessel.

Sign in / Sign up

Export Citation Format

Share Document