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.     

Z6170ZLCZ/S-8型双燃料发动机开发

介绍了Z6170ZLCZ/S-8型双燃料发动机的总体设计方案,重点阐述了双燃料发动机的天然气进气及控制系统,以及如何实现双燃料模式燃烧。在纯柴油模式及双燃料模式下进行了发动机性能对比分析。试验结果表明:Z6170ZLCZ/S-8型双燃料发动机燃油替代率最高可达75%,综合燃油替代率为70%,其它性能均达到设计要求。     

Z6170ZLCZ/S-8型双燃料发动机开发

介绍了Z6170ZLCZ/S-8型双燃料发动机的总体设计方案,重点阐述了双燃料发动机的天然气进气及控制系统,以及如何实现双燃料模式燃烧。在纯柴油模式及双燃料模式下进行了发动机性能对比分析。试验结果表明:Z6170ZLCZ/S-8型双燃料发动机燃油替代率最高可达75%,综合燃油替代率为70%,其它性能均达到设计要求。     

双燃料发动机油气双闭环控制策略应用研究

根据改装的双燃料发动机特点设计了基于当量燃料的油气控制策略,该控制策略通过柴油天然气双闭环实现两种燃料的合理控制,并在改装成双燃料发动机的潍柴X6170上进行试验。试验表明,在不改变原柴油机主要结构下,改装双燃料发动机能够替代原柴油机作为船舶动力,燃油消耗降低且排放相应减少,能够平稳进行油气切换,替代率过大时对HC排放及排气温度影响较大。     

LNG柴油双燃料发动机多点顺序喷射试验研究

为将纯柴油发动机改造为LNG/柴油双燃料多点顺序喷射发动机,在不改变原型机结构前提下设计了一套天然气供给系统。为验证该供气系满足否满足原型机在额定工况下的需求,设计了进气道喷射模拟试验台。试验验证表明:该天然气供给系统能够满足发动机在额定工况下燃气供应量及喷射控制的需求,且整套系统能够根据发动机不同工况调整天然气的喷射量。试验结果可为发动机在双燃料模式下运行提供前期数据支撑。     

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。     

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。     

论燃气／柴油双燃料发动机的油气转换和调速问题

论燃气／柴油双燃料发动机的油气转换和调速问题新疆石油局塔西南勘探开发公司苏贵斌燃气／柴油双燃料发动机是在柴油发动机的基础上增加一套供气系统后构成的，因此它有两种工作状态，即可以用燃气（天然气、煤气、液化石油气、高炉发生气和沼气等）运行，也可以用柴油运...     

如何实现210双燃料发动机自动控制

主要介绍了210型双燃料发动机的总体设计方案,重点描述了该型双燃料发动机的天然气控制系统,以及如何在试验过程中实现自动控制。试验结果表明:210型双燃料发动机实现了自动控制,双燃料模式下最高燃油替代率为80%,从而获得了较好的经济性能,其它性能指标也均达到设计要求。     

“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。     

柴油/天然气电控双燃料技术研究

针对双燃料发动机的特点介绍了电控双燃料系统的原理;并对所研究的双燃料发动机的失效模式及效应进行了分析。性能试验表明:在不对原柴油机喷油角度、压缩比等参数进行任何改动,只增加燃气供应系统和电控双燃料系统的情况下,在75%负荷下天然气的替代率达到83%,经济性好;同时,排放较纯柴油有较大的改善;发动机的排温、最高燃烧压力及调速性能与柴油机的相近。     

F6L912Q风冷柴油机双燃料系统方案研究

探讨了F6L912Q风冷柴油机双燃料系统改装方式,研究了天然气燃料供给系统的组成、工作原理及电控系统设计方案,通过对F6L912Q发动机燃用纯柴油和柴油天然气双燃料的试验结果对比分析表明：双燃料发动机的动力性能得到改善,F6L912Q风冷柴油机改装成的双燃料系统方案设计是合理的.     

Dual fuel mode operation in diesel engines using renewable fuels: Rubber seed oil and coir-pith producer gas

Partial combustion of biomass in the gasifier generates producer gas that can be used as supplementary or sole fuel for internal combustion engines. Dual fuel mode operation using coir-pith derived producer gas and rubber seed oil as pilot fuel was analyzed for various producer gas–air flow ratios and at different load conditions. The engine is experimentally optimized with respect to maximum pilot fuel savings in the dual fuel mode operation. The performance and emission characteristics of the dual fuel engine are compared with that of diesel engine at different load conditions. Specific energy consumption in the dual-fuel mode of operation with oil-coir-pith operation is found to be in the higher side at all load conditions. Exhaust emission was found to be higher in the case of dual fuel mode of operation as compared to neat diesel/oil operation. Engine performance characteristics are inferior in fully renewable fueled engine operation but it suitable for stationary engine application, particularly power generation.     

Hydrogen energy share enhancement in a heavy duty diesel engine under RCCI combustion fueled with natural gas and diesel oil

The aim of this study is to enhance hydrogen energy share in a RCCI engine. The engine under consideration is fueled with diesel oil and natural gas enriched with hydrogen or syngas and is set to operate at 9.4 bar gross indicated mean effective pressure (Mid- Load). The syngas used in this study consists of hydrogen and carbon monoxide which are mixed together on a volumetric ratio of 80:20. A fixed amount of diesel oil is injected per cycle into the combustion chamber of the RCCI engine. Based on two different strategies, hydrogen or syngas mixed with exhaust gas recirculation are admitted gradually along with natural gas while ensuring that always the low temperature combustion concept is fulfilled. The RCCI engine operation is simulated through commercial software coupled with chemical kinetics solver. The simulation results show that without any engine diesel knock occurrence, by adding hydrogen to natural gas, the share of hydrogen energy could be increased up to 40.43% while the engine power output is reduced only by about 1%. Also, syngas addition to natural gas causes that the share of hydrogen energy could be increased up to 27.05% while improves the engine power more than 4%. At the same time, by considering two mentioned strategies, the overall hydrocarbon fuel consumption per cycle can be reduced by up to 46.60% and 33.86%, respectively. Moreover, having the gross indicated efficiency of well over 50% and significant reduction in the engine emissions compared to RCCI combustion fueled solely with natural gas and diesel oil are achievable.     

Performance of rapeseed oil blends in a diesel engine

The concept that 100% vegetable oil cannot be used safely in a direct-injection diesel engine for long periods of time has been stressed by many researchers. Short-term engine tests indicate good potential for vegetable oil fuels. Long-term endurance tests may show serious problems in injector coking, ring sticking, gum formation, and thickening of lubricating oil. These problems are related to the high viscosity and nonvolatility of vegetable oils, which cause inadequate fuel atomization and incomplete combustion. Fuel blending is one method of reducing viscosity. This paper presents the results of an engine test on three fuel blends. Test runs were also made on neat rapeseed oil and diesel fuel as bases for comparison. There were no significant problems with engine operation using these alternative fuels. The test results showed increases in brake thermal efficiency as the amount of rapeseed oil in the blends increases. Reduction of power-output was also noted with increased amount of rapeseed oil in the blends. Test results include data on performance and gaseous emissions. Crankcase oil analyses showed a reduction in viscosity. Friction power was noted to increase as the amount of diesel fuel in the blend increases.     

Use of pyrolysis oil in a test diesel engine to study the feasibility of a diesel power plant concept

The economic viability of power production in a diesel power plant utilizing flash pyrolysis oil produced from sawmill wastes in Finland has been investigated. A combination of biomass feedstock costs, pyrolysis oil fuel properties (ignition quality, lubricating properties, combustion speed and duration, emissions, etc.) and their effect on power plant investments and maintenance will ultimately determine electricity busbar costs and the economic competitiveness of the concept. Pyrolysis oil is not a suitable fuel for a conventional diesel engine as such. The preliminary tests with additive treated pyrolysis oil demonstrated, however, that once ignition has taken place, pyrolysis oil burns rapidly. Pyrolysis oil may be a suitable primary fuel for a diesel engine with a pilot injection system, which secures the ignition of the main fuel.     

Effect of hydrogen addition on RCCI combustion of a heavy duty diesel engine fueled with landfill gas and diesel oil

The aim of this study is to investigate the effects of hydrogen addition on RCCI combustion of an engine running on landfill gas and diesel oil. A single cylinder heavy– duty diesel engine is set in operation at 9.4 bar IMEP. A certain amount of diesel fuel per cycle is fed into the engine and hydrogen is added to landfill gas while keeping fixed fuel energy content. The developed simulation results confirm that hydrogen addition which is the most environmental friendly fuel causes the fuel consumption per any cycle to reduce. Also, the peak pressure is increased while the engine load is reduced up to 4%. Landfill gas which is enriched with hydrogen improves the rate of methane dissociation and reduces the combustion duration at the same time the engine operation would not be exposed to diesel knock. Moreover, hydrogen addition to landfill gas would reduce engine emissions considerably.     

Theoretical study of the effects of engine parameters on performance and emissions of a pilot ignited natural gas diesel engine

With the increasing concern regarding diesel vehicle emissions and the rising cost of the liquid diesel fuel as well, more conventional diesel engines internationally are pursuing the option of converting to use natural gas as a supplement for the conventional diesel fuel (dual fuel natural gas/diesel engines). The most common natural gas/diesel operating mode is referred to as the pilot ignited natural gas diesel engine (PINGDE) where most of the engine power output is provided by the gaseous fuel while a pilot amount of the liquid diesel fuel injected near the end of the compression stroke is used only as an ignition source of the gaseous fuel–air mixture. The specific engine operating mode, in comparison with conventional diesel fuel operation, suffers from low brake engine efficiency and high carbon monoxide (CO) emissions. In order to be examined the effect of increased air inlet temperature combined with increased pilot fuel quantity on performance and exhaust emissions of a PINGD engine, a theoretical investigation has been conducted by applying a comprehensive two-zone phenomenological model on a high-speed, pilot ignited, natural gas diesel engine located at the authors' laboratory. The main objectives of the present work are to record the variation of the relative impact each one of the above mentioned parameters has on performance and exhaust emissions and also to reveal the advantages and disadvantages each one of the proposed method. It becomes more necessary at high engine load conditions where the simultaneous increase of the specific engine parameters may lead to undesirable results with nitric oxide emissions.     

柴油机燃用LPG的高原特性实验研究

在高原环境条件下,针对柴油机燃用LPG的经济性,动力性和排放排性进行了研究,柴油机掺烧LPG后,在一定的掺烧比下,动力性有所提高,经济性有所改善,碳煤排放降低幅放较大,但发动机振动和大,噪声和排温升高,试验结果为在高原地区推广应用PLG／柴油双燃料发动机提供了依据。