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Journal ArticleDOI

Review of propulsion systems on LNG carriers

TL;DR: The main characteristics of the propulsion systems, and the advantages and drawbacks that come along with these, from its very beginnings up to the systems installed to date are described in this article.
Abstract: Vessel ozone depleting emission regulations are regulated in Annex VI of the MARPOL Convention, wherein the maximum levels of NOx, SOx and suspended particles are established These increasingly strict regulations, together with the increase in natural gas consumption and its price, have conditioned propulsion systems implemented on board vessels This article reviews the different propulsion systems used on board vessels for the transport of Liquefied Natural Gas (LNG) The study describes the main characteristics of the propulsion systems, and the advantages and drawbacks that come along with these, from its very beginnings up to the systems installed to date The described propulsion systems include both gas and steam turbines, combined cycles, 2 and 4 stroke internal combustion engines, as well as reliquefaction plants, while encompassing mechanical, electric and Dual Fuel (DF) technology systems The propulsion systems implemented have undergone continual alteration in order to adjust to market needs, which were always governed by both efficiency and the possibility of consuming boil-off gas (BOG), always in compliance with the strict antipollution regulations in force The current direction of LNG vessel propulsion systems is the installation of 2-stroke DF low pressure engines due to their high efficiency and their possibility of installing a BOG reliquefaction plant Another great advantage of this propulsion system is its compliance with the IMO TIER III emission regulations, without the need to install any supplementary gas treatment system
Citations
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Journal ArticleDOI
01 Nov 2020-Fuel
TL;DR: In this article, a review of emission regulations and emission factors (EFs), environmental effects and available emission reduction solutions for marine diesel engines is presented, which shows that the integrated multi-pollutant treatment for ship emissions holds great promise.

146 citations

Journal ArticleDOI
TL;DR: In this article, the main solutions being currently developed or adopted for low and medium speed Diesel engines have been reviewed from a qualitative, and sometimes quantitative, point of view, focusing more on their potential with respect to possible waste heat recovery systems utilization, such as, in particular, steam Rankine cycles and organic Rankine Cycles.

113 citations

Journal ArticleDOI
TL;DR: In this article, the authors identify promising technologies and practices that are applicable to onboard energy systems of all-electric ships and also reveal energy efficiency sensitivity of allelectric ships to different applications, which should be eventually combined with alternative technology-based and operational-based measures as implemented on conventional propulsion ships in order to realize full potential for energy efficient operation.
Abstract: There has been mounting concerns over energy consumption and environmental impacts due to an increase in worldwide shipping activities. The International Maritime Organization has adopted regulations to impose limits on greenhouse gas emissions originated from fuel combustion of marine vessels. Such regulations are introduced in terms of energy efficiency design index and energy efficiency operational indicator. Extensive electrification of ship propulsion and shipboard power systems has been vastly proposed in the literature to make onboard energy systems more efficient. However, energy efficiency in the context of maritime transport is becoming even more stringent. Various technologies and operational practices therefore are being proposed to ensure full compliance with the tightening restrictions. The methods to increase energy efficiency and environmental performance of all-electric ships to satisfy such requirements involve integration of energy storage with a contribution of intelligent power management to optimize power split between various power generation sources; a tendency toward DC power distribution due to eliminating the need of all generators to be synchronized at a specific frequency; installation of unconventional propulsors for greater maneuverability requirements while keeping fuel consumption low; adoption of low carbon content fuel like liquefied natural gas for dual fuel diesel electric propulsion; establishment of onboard renewable energy systems for alternative clean power options; fuel cell integration in complementary operation with conventional diesel generators. This paper identifies promising technologies and practices that are applicable to onboard energy systems of all-electric ships and also reveals energy efficiency sensitivity of all-electric ships to different applications. The proposed strategies should be eventually combined with alternative technology-based and operational-based measures as implemented on conventional propulsion ships in order to realize full potential for energy efficient operation.

111 citations

Journal ArticleDOI
TL;DR: In this article, a technological review has been carried out to determine the most promising alternative marine fuels considering the simultaneous reduction of sulphur oxides, nitrogen oxides and carbon dioxide emissions as well as sustainability.

106 citations

References
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Journal ArticleDOI
01 Aug 2013-Energy
TL;DR: In this paper, the economic upturn that can result from the use of LNG as fuel for merchant ships and to assess the effects of its utilization in terms of environmental impact is analyzed.

216 citations

Journal ArticleDOI
Satish Kumar1, Hyouk Tae Kwon, Kwangho Choi, Jae Hyun Cho1, Wonsub Lim1, Il Moon1 
TL;DR: In this article, the authors provide an overview on demand and supplies of natural gas in the past as a function of gas prices, gas technology (gas sweetening, liquefaction, shipping and re-gasification), and gas market and how they have changed recently.

187 citations

01 Jan 2012
TL;DR: In this article, the economic upturn that can result from the use of LNG as fuel for merchant ships and to assess the effects of its utilization in terms of environmental impact is analyzed.
Abstract: Today, most merchant vessels use Heavy Fuel Oils (HFOs) for ship propulsion. These fuels are cost effective but they produce significant amounts of noxious emissions. In order to comply with International Maritime Organization (IMO) rules, Liquefied Natural Gas (LNG) is becoming an interesting option for merchant ships. The aim of the research presented in this paper is to analyse the economic upturn that can result from the use of LNG as fuel for merchant ships and to assess the effects of its utilization in terms of environmental impact. In the first part of the study, a statistical analysis of maritime traffic is carried out in order to identify which merchant ship types could most benefit from using LNG as fuel for ship propulsion. Traffic data of world ships related to the months of May 2008, 2009 and 2010 are analysed. Roll-on/Roll-off vessels (RoRo) and tanker ships spend most of their sailing time in Emission Control Areas (ECA) consequently appear to be the best candidates for LNG use. In particular, the use of LNG is most profitable for tanker ships in the range of 10,000–60,000 DWT (deadweight). In the second part of the study, operational costs and pollutant emission reduction, following LNG implementation, are calculated for a 33,000 DWT tanker ship. Results show that LNG leads to a reduction of 35% of operational costs and 25% of CO2 emissions. The possibility of improving energy efficiency on board is analysed considering that combustion gases, produced by LNG, are cleaner, thus simplifying the introduction of exhaust gas heat recovery. Two options are considered: simple heat recovery and heat recovery to drive a turbine (ORC). The results show that it is possible to achieve a reduction in fuel consumption of up to 15%.

158 citations

Journal ArticleDOI
01 May 2013-Energy
TL;DR: In this paper, the effects of liquid natural gas on a heavy-duty diesel engine were evaluated using a dual-fuel engine with a pilot amount of diesel as an ignition source.

150 citations