天然气/柴油双燃料发动机的试验研究

以柴油机为原型,增加了天然气供气系统,开发了天然气/柴油双燃料发动机。采用闭环控制系统对天然气进气量进行实时控制,发动机采用双阶段双燃料模式运行,实现了全负荷工况下天然气对柴油85%左右的替代率,在保持原机动力性的基础上实现了良好的经济性。     

柴油/天然气双燃料发动机柴油燃烧策略的研究

基于自主研发的第三代并行式柴油/天然气双燃料发动机电控系统,利用FIRE软件建立柴油/天然气双燃料发动机柴油喷射系统的多次喷射模型。同时,通过进气压力控制过量空气系数,实现柴油/天然气双燃料发动机稀薄燃烧方式。针对高负荷工况,研究了多次喷射策略和稀薄燃烧方式对双燃料发动机最大压力升高率及NOx排放的影响。结果表明:发动机工作在高负荷及柴油替代率为80%时,采用双燃料稀薄燃烧方式能使NOx排放降低,但最大压力升高率仍可能超过安全临界值1MPa/(°)。采用合适的预喷射量与预喷射时刻能降低最大压力升高率。通过多次喷射和稀薄燃烧方式相结合的燃烧策略对缸内燃烧方式进行组织,可以实现双燃料发动机高替代率燃烧,并使高负荷时NOx排放达到或者低于国Ⅴ标准限值。     

柴油、天然气双燃料发动机的燃烧特性分析

研究了柴油,天然气双燃料发动机的燃烧特性,并着重分析了引燃柴油供给系统参数对双燃料发支持性的影响。以试验为基础,首先简要比较了柴油,天然气双燃料发动机与柴油机的燃烧特性,并对比了负荷对双燃料发动机燃烧特性的影响。然后分析了最小循环喷油量,引燃柴油量,引燃油喷射压力,喷嘴参数及供油提前角等引燃柴油供给系统参数对最高爆发压力,燃烧放热率,着火开始时间、累积燃烧放热率等柴油,天然气双燃料发动机燃烧特性的     

大功率190柴油/天然气双燃料发动机的试验研究

柴油/天然气双燃料发动机具有良好的使用特性,它是将天然气与空气混合后引入气缸内,形成可燃混合气,与喷入气缸内的柴油共同作用输出功率。本文重点介绍了大功率190柴油/天然气双燃料发动机的配置原理以及试制试验过程,并对双燃料发动机的动力性、经济性、可靠性做了分析。     

可变EGR对柴油-天然气发动机排放特性影响的研究

对柴油-天然气双燃料发动机采用可变EGR时的排放特性进行了研究,试验发动机65%的功率由天然气提供,其余由柴油提供.研究结果表明:柴油-天然气双燃料发动机采用EGR时,在较低负荷能有效降低排放,但在较高负荷会有热效率降低和CO排放较高的缺点;而采用可变EGR时,可以明显降低NOx、HC、CO和碳烟排放,并且热效率几乎可保持基础发动机的水平.     

钻井用柴油/天然气双燃料发动机的研究

论文通过对钻井用柴油/天然气双燃料发动机的特性分析,指出了钻井用双燃料发动机必需具备的一些特征。提出了一种智能的柴油/天然气双燃料发动机控制方案,并对该控制方案进行了阐述,一种以柴油的最低燃油位置曲线为目标以控制燃气阀开度为手段的闭环控制。通过控制程序的MAP图参数的设置,使燃油和燃气供应量逐渐逼近期望值,实现了燃气和燃油供应的动态调整。最后通过试验,验证了该方案的可行性,该双燃料发动机动力性好,动态响应快,抗负荷冲击能力强,运行可靠,操作方便,柴油替代率达到了75%以上,完全能适应钻井动力的需求。通过该技术,降低了石油天然气钻探成本,降低了机组排放,有助于石油天然气钻探行业节能减排的目标实现。     

钻井用柴油/天然气双燃料发动机的研究

论文通过对钻井用柴油/天然气双燃料发动机的特性分析,指出了钻井用双燃料发动机必需具备的一些特征.提出了一种智能的柴油/天然气双燃料发动机控制方案,并对该控制方案进行了阐述,一种以柴油的最低燃油位置曲线为目标以控制燃气阀开度为手段的闭环控制.通过控制程序的MAP图参数的设置,使燃油和燃气供应量逐渐逼近期望值.实现了燃气和燃油供应的动态调整.最后通过试验,验证了该方案的可行性,该双燃料发动机动力性好,动态响应快,抗负荷冲击能力强,运行可靠,操作方便,柴油替代率达到了75%以上,完全能适应钻井动力的需求.通过该技术,降低了石油天然气钻探成本,降低了机组排放,有助于石油天然气钻探行业节能减排的目标实现.     

双燃料发动机技术浅析

对柴油/天然气双燃料发动机的基本燃烧过程及工作特点:换气短路损失,高压缩比,小负荷工作等作了介绍,并对双燃料发动机的两种典型结构预燃室双燃料发动机、直喷式双燃料发动机以及双燃料发动机未来主要的发展趋势作了阐述。     

CNG/柴油双燃料发动机供气技术发展与趋势

详细介绍并分析了CNG/柴油双燃料发动机的天然气预混合供气、进气喷射、缸内直接喷气技术,指出了CNG/柴油双燃料发动机技术的发展趋势是:将天然气电控多点顺序气口喷射和柴油共轨喷射技术相互结合。     

“本质安全”8240ZCDF型柴油/天然气双燃料发动机的研制

8240ZCDF型柴油/天然气双燃料发动机是本公司新开发的新能源发动机,该发动机既可以在纯柴油模式下运行,也可以在柴油/天然气双燃料模式下运行,安全标准满足国内最高安全标准—中国船级社《天然气燃料动力船舶规范》中"本质安全"标准。该发动机采用了先进的天然气电子控制多点喷射技术,柴油替代率达80%以上,按照中国船级社"本质安全"标准进行总体设计,该发动机可以满足船用推进及发电、陆用发电等多种用途,具有柴油替代率高,NOx、CO2排放低、经济性高等特点。     

Effect of engine parameters and type of gaseous fuel on the performance of dual-fuel gas diesel engines—A critical review

Petroleum resources are finite and, therefore, search for their alternative non-petroleum fuels for internal combustion engines is continuing all over the world. Moreover gases emitted by petroleum fuel driven vehicles have an adverse effect on the environment and human health. There is universal acceptance of the need to reduce such emissions. Towards this, scientists have proposed various solutions for diesel engines, one of which is the use of gaseous fuels as a supplement for liquid diesel fuel. These engines, which use conventional diesel fuel and gaseous fuel, are referred to as ‘dual-fuel engines’. Natural gas and bio-derived gas appear more attractive alternative fuels for dual-fuel engines in view of their friendly environmental nature. In the gas-fumigated dual-fuel engine, the primary fuel is mixed outside the cylinder before it is inducted into the cylinder. A pilot quantity of liquid fuel is injected towards the end of the compression stroke to initiate combustion. When considering a gaseous fuel for use in existing diesel engines, a number of issues which include, the effects of engine operating and design parameters, and type of gaseous fuel, on the performance of the dual-fuel engines, are important. This paper reviews the research on above issues carried out by various scientists in different diesel engines. This paper touches upon performance, combustion and emission characteristics of dual-fuel engines which use natural gas, biogas, producer gas, methane, liquefied petroleum gas, propane, etc. as gaseous fuel. It reveals that ‘dual-fuel concept’ is a promising technique for controlling both NO_x and soot emissions even on existing diesel engine. But, HC, CO emissions and ‘bsfc’ are higher for part load gas diesel engine operations. Thermal efficiency of dual-fuel engines improve either with increased engine speed, or with advanced injection timings, or with increased amount of pilot fuel. The ignition characteristics of the gaseous fuels need more research for a long-term use in a dual-fuel engine. It is found that, the selection of engine operating and design parameters play a vital role in minimizing the performance divergences between an existing diesel engine and a ‘gas diesel engine’.     

使用双燃料发动机与普通柴油机作钻机动力的经济性分析

本文简要介绍2000型柴油／天然气双燃料发动机的技术特点,以及双燃料发动机与普通柴油机的区别,并以配备DJ40钻机动力为例,从经济效益方面对双燃料发动机与普通柴油机进行了对比分析,最终为优选双燃料发动机提供依据。     

低热值燃气-柴油双燃料发动机动力性能计算

推导了低热值燃气-柴油双燃料发动机动力性能计算公式,并对由单缸、四冲程、水冷、直喷式柴油机改装的生物制气-柴油双燃料发动机的动力性能进行了计算分析。结果表明：双燃料发动机能够达到原柴油机的动力水平;其动力性能随引燃油量的减小而降低;在新鲜空气充足的前提下,供给更多的燃气,双燃料发动机的动力性能增强;燃气替代率有一最大值,超过该值后,随替代率增大,动力性能急剧下降;燃气低热值越高,替代率便可越大。计算得出的生物制气-柴油双燃料发动机在标定点和最大转矩点的最大生物制气替代率和对应的燃气进气比,与试验结果相吻合。     

Emissions from sawdust biomass and diesel blends fuels

Biomass producer gas presents a very promising alternative fuel to diesel since it is a renewable and clean burning fuel having similar properties to those of diesel. In this outline, a multi-cylinder diesel engine is experimentally optimized for maximum diesel savings, lower emissions, and without any excessive vibration of the engine using sawdust biomass as producer gas. Emission parameters of the double-fuel engine at diverse gas flow rates are contrasted with those of diesel at distinctive load conditions. The study brings out that the greatest diesel reserve happens to be 80% at 8 kW load without any engine issue in dual-fuel mode. Carbon monoxide (CO), hydrocarbon (HC), and carbon dioxide (CO₂) emissions in dual-fuel mode are more contrasted with diesel at all test extents. Smoke opacity and oxide of nitrogen (NO) emission values in dual-fuel mode are less contrasted with diesel.     

生物制气-柴油双燃料发动机放热规律试验研究

采用气化炉热解气化各种农林废弃的生物质,产生可燃生物制气,用作为以柴油引燃的双燃料发动机的主要燃料。测量生物制气-柴油双燃料发动机气缸压力,计算分析放热规律。双燃料发动机与燃用纯柴油时的发动机相比,燃烧始点延迟,最大燃烧压力降低,最大放热率和排气温度增加,后燃较严重。负荷增大时,双燃料发动机燃烧始点提前,最大燃烧放热率增高,最高燃烧温度升高,后燃较严重。供油提前角提前时,后燃减小,燃烧过程明显改善。     

Combustion of simulated biogas in a dual-fuel diesel engine

Technology related to biogas has been steadily developed over the last 50 years from small individually designed units to larger production plants. The development, however, has largely taken place on the side of biogas production and anaerobic waste treatment. Utilization of the gas produced by these methods has only recently been the subject of more scientific evaluation. The transformation of energy through biogas into the thermodynamically higher valued mechanical energy successfully and economically is now the most important research area in this field.Of the engine work already published, most concerns spark-ignited engines. The authors’ research work concerns the use of biogas in dual-fuel diesel engines. It examines engine performance using simulated biogas of varying quality representing the range of methane:carbon dioxide composition which may be encountered in gas from different sources. The total programme includes the effects of biogas quality and of the proportion of energy from pilot fuel injection over a range of speeds and loads, investigations into the performance parameters over a range of compositions of gaseous mixture. A two-cylinder, indirect-injection diesel engine of stationary type is being used as the first experimental test bed in this work and the variation of quality is provided by mixing natural gas and carbon dioxide. A data acquisition system for in-cylinder pressure and crank angle is being used successfully and some emissions measurements are also available, particularly for CO and O₂.One of the authors is from India where there is thought to be considerable potential for exploiting the gaseous products from resources such as biogas, landfill and sewage gas through small stationary dual-fuel engines for irrigation and CHP applications. The nature of combustion process in the dual-fuel engine is examined by the authors through pressure-crank angle data and studies of characteristics affecting engine efficiency.     

电控柴油天然气(双燃料)发动机性能研究

本文主要对电控柴油天然气(双燃料)发动机的台架试验性能进行了研究，试验时通过控制数字电磁阀脉宽来决定每循环进入气缸的燃气量，用少量柴油引燃，达到双燃料柴油机的性能。试验结果表明，燃料发动机的动力性能、综合排放性能得到改善；天然气的最高替代率85％以上。可见，压缩天然气采用电子控制多点顺序喷射这一先进技术，使发动机达到了较好的综合性能指标。     

生物制气-柴油双燃料发动机NOx计算模型

采用气化炉热解气化各种农林废弃的生物质，产生可燃生物制气，作为双燃料发动机的主要燃料。双燃料发动机由单缸、四冲程、水冷、直喷式柴油机改装，生物制气通入发动机进气管，在进气过程中吸入气缸。在油滴蒸发准维燃烧模型的基础上，结合单区模型和详细化学反应动力学机理，建立生物制气-柴油双燃料发动机的NOx生成模型，计算结果与试验结果吻合较好。供油提前角提前，生物制气-柴油双燃料发动机NOx排放量增加；引燃柴油量减小时，NOx排放量减小。     

基于LABVIEW的柴油／酒精双燃料发动机燃料控制装置的研究

针对目前柴油/酒精双燃料发动机燃料系混合比难于控制，导致柴油，酒精双燃料发动机的研究发展缓慢的现状，在不改变发动机供油系统的前提下，利用LABVIEW软件自带的虚拟仪器设计双燃料喷射系统，实现柴油，酒精混合比的人为控制。