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TECHNICAL AND OPERATIONAL MEASURES FOR REDUCTION OF GREENHOUSE GAS EMISSIONS FROM SHIPS
减少船舶温室气体排放的技术和业务措施
1. Introduction
介绍
Following the assessment of the amount of emissions to air from shipping in chapter 3 and the effect on climate and ozone described in chapter 4, this chapter focus on alternatives for reduction of emissions to air from ships. In the following both technical and operational measures are presented.
继在第3章中向空气中的排放量评估航运后，在第4章描述气候和臭氧的影响，本章重点介绍减少船舶排放到空气中的替代品。在下面的技术和业务措施中。
The assessment of various options was performed with both a short term and long term perspective. In the context of this report, short term is closely related to availability of technical measures. As applicability of various measures may be different for new and existing ships, the discussion of the various technical alternatives was divided into one part concerning new ships and one part concerning existing ships.
评估各种选项，以短期和长远的角度来看。在这份报告的背景下，短期内是密切相关的技术措施的可用性。
2. Short-term considerations – applying state-of-the-art knowledge
短期考虑 - 国家的最先进的应用知识
2.1. Hull and propeller: new ships
船体和螺旋桨：新船
This section focuses on the energy savings that can be obtained by application of current technology within hydrodynamics (hull and propeller http://ukthesis.org/ibm/ ) on new ships. Energy savings can then be easily converted into emission reductions.
本节重点介绍在流体力学中目前的技术应用，可以得到新船（船体和螺旋桨）节约能源。然后，可以很容易地转换成减排节能。
International merchant shipping is a highly economically optimised business. Fuel cost is a major operating cost of most merchant ships. Ship designs are usually fairly well optimised with respect to maximum profitability. Thus, one should expect that there is not much efficiency to be gained by better design and selection of propulsion systems without changing the external economic conditions. Also in this section, measures that are not currently profitable will be discussed.
国际商船是一个高度经济优化业务。燃料成本是一个主要的经营成本，大多数商船中，船舶设计通常是相当不错的，在最大盈利方面进行了优化。
Retarded fuel injection timing is the simplest way to reduce NOx from a ship diesel engine. This measure can be implemented without hardware modification or extra cost. Retarded timing alone have a ne
Retarded fuel injection timing is the simplest way to reduce NOx from a ship diesel engine. This measure can be implemented without hardware modification or extra cost. Retarded timing alone have a negative effect on fuel consumption (specific CO2 increases). Reduction of the NOx emission level in the range of 6-8 g/kWh is possible, but at a cost of an increased fuel consumption of 5-7 g/kWh. Most measures imply retrofit and engine modifications aiming for an improved combustion in order to reduce CO2 and NOx emissions. The possible measures descried in the following are all primarily for NOx reduction and imply additional or modified equipment installed.
大部分措施意味着改造和引擎的修改，旨在改善燃烧，以减少二氧化碳和氮氧化物排放量。可能在下面描述的措施中都主要用于NOx还原，意味着额外的或修改过的安装设备。
Low NOx combustion:
低NOx燃烧
Some engine manufacturer can offer retrofit/upgrading packages for ”low NOx combustion” without increase of fuel consumption. A low NOx combustion upgrade on an existing engine implies to some extent engine component retrofit. The reduction of NOx emission is in the range of 4-6 g/kWh [Wärtsilä NSD, 1997].
Water injection:
Water injection to reduce NOx is an effective measure (50-60% NOx reduction) which can be retrofitted on existing engines. The main components are the combined injector, common rail water supply system and electronically control system. Retrofit cost figures are estimated to approximately 25 USD pr. kilowatt. The operating cost inclusive maintenance is about 4-5 % of fuel costs [Wärtsilä NSD, 1998, Diesel & Gas Turbine, 1999].
Emulsion:
乳液
Fuel emulsion (adding water in fuel) is a NOx reduction measure where the necessary equipment can be installed on existing engines. The reduction potential without penalty on fuel efficiency is in the range of 20-25%.
乳化燃料（燃料中加入水）是一个必要的设备，可以安装在现有发动机的NOx还原措施。在未经燃油效率罚款的还原电位是在20％至25％的范围内。
Humid Air Motor (HAM):
Implementation of the HAM technique on existing engines can result in up to 60% reduction of
NOx emission level. The technique is however new and the long-term operational effect is not fully proven. In existing ship it is in most cases difficult to install the HAM equipment, mainly because of the rearrangement of the air supply system to the engine and the additional space required. Most engines have a turbo-charger and aftercooler system that is heavily integrated and matched for the specific engine. Engine manufacturers may be reluctant to modify this original integrated system solution [Bunes et .al, 1998, Munters Europa 1998].
Miller Cycle:
The Miller principle and measures as described on new engines are also valid for existing engines.
Exhaust Gas Re-circulation (EGR): Several problems need to be addressed and solved before EGR will be an applicable measure for existing or new ships. The main challenge is the re-entrance of particul
Exhaust Gas Re-circulation (EGR):
Several problems need to be addressed and solved before EGR will be an applicable measure for existing or new ships. The main challenge is the re-entrance of particulates damaging for the engine, especially when running on HFO and therefore very limited application is foreseen
[EPA 1998, DNV, 1998].
SCR:
A properly operating SCR installation can remove up 95 % of NOx components from the exhaust. It can be installed on existing machinery as retrofit packages, which includes the reactor, urea storage/dosing and control system. For installation on an existing ship there are some practical limitations due to the need for space. Although the reactor can replace the exhaust silencer it can be rather costly to install. In addition to the space for the reactor, there is also need for storage space for urea.
一个正常操作的SCR安装，可以去除高达95％的氮氧化物组件排气。它可以安装在现有的机械改装套件，其中包括在反应器中，尿素存储/定量给料和控制系统。
CO and HC
Efforts on upgrading an existing engine normally also pay off with minor reductions on CO and HC emissions. In the overall perspective these gains are very small as the CO and HC emissions from the diesel combustion process are very low initially. Due to this reduction measures for CO and HC have not been further assessed in this report.
SOx
氧化硫
The SOx emissions are related to the quality of the fuel. Only a dramatic turnover from high sulphur to low sulphur fuel oil can have a major impact on SOx emissions from the existing fleet.
SOx的排放与燃料的质量。只有一个戏剧性的营业额从高含硫量的低硫燃料油，对现有车队中的SOx的排放有重大影响。
Table 5-7 - Emission reduction in existing ships – applicability
表5-7 - 现有船舶减排适用性
Figure 5-4 above compares NOx reduction measure and cost for new ships. The figure is to a large extent valid also for similar measures on existing ship machinery for the techniques that is possible to implement. The NOx/CO2 trade off (Figure 5-5) will also be valid for measures on existing machinery systems.
NOx/CO2对现有的机械系统，权衡（图5-5）有效的措施。
Table 5-8 summarises the potential for fuel savings on existing ships by machinery measures.
表5-8总结了通过机械措施，现有船舶节省燃油的潜力。
Table 5-8 – CO2 reduction potential in existing ships - machinery measures
表5-8 - 现有船舶CO2减排潜力 - 机械措施
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