电控柴油机喷油器响应特性研究

建立了电控柴油机喷油器的仿真模型,试验验证了仿真模型的有效性。在此基础上,探讨了电控柴油机喷油器的主要结构参数对喷油器响应特性的影响,提出了提高喷油器响应特性的一些方法,仿真结果为电控柴油机喷油器的优化设计提供理论依据。     

电控喷油器响应特性仿真分析

本文以德尔福(DELPHI)共轨电控喷油器为研究对象,以系统轨压在160MPa下的喷油规律试验研究为基础,以HYDSIM为仿真平台,建立了电控喷油器仿真模型。通过试验,验证了系统模型;运用模型,研究了对喷油器响应特性的影响因素,并以提高电控喷油器响应特性为出发点,探讨了各关键结构参数的设计原则。通过分析计算,为电控喷油器结构参数的合理选择和设计提供了理论依据。     

节流式电控喷油器的实验研究

作者对自行设计的节流式电控喷油器进行了试验台试验和喷射过程的电子计算机模拟计算,并实现了电控喷油系统在单缸105柴油机上的实机运行。实验和理论分析表明:节流式电控喷油器能满足电控柴油机对喷油器的要求并在改进喷射特性方面有较大的潜力。本文介绍了节流式电控喷油器的结构,通过试验台试验分析了节流式电控喷油器的特点及其主要参数对喷射特性的影响,并介绍了电控喷油器的实机运行情况。     

电控喷油器响应特性影响研究

分别从理论分析和模拟计算的角度,定性、定量地分析了电控喷油器各关键结构参数对其响应特性的影响规律。以德尔福(DELPH)I共轨电控喷油器为研究对象,以系统轨压在160MPa下的喷油规律试验研究为基础,以HYDSIM为仿真平台,建立了电控喷油器仿真模型。通过试验,验证了系统模型;运用模型,研究了对喷油器响应特性的影响因素,并以提高电控喷油器响应特性为出发点,探讨了各关键结构参数的设计原则。通过分析计算,为电控喷油器结构参数的合理选择和设计提供了理论依据。     

船用柴油机蓄压式电控喷油器计量特性数字孪生才型研究

为实时准确地观测电控喷油器的喷油量,实现喷油过程的闭环控制,针对某船用柴油机蓄压式电控喷油器结构特征,根据其燃油流动过程和蓄压腔压力变化规律,利用理论机理计算与神经网络修正相结合的方法,建立了电控喷油器计量特性数字孪生模型.通过建立快速原型样机进行在线试验验证,对比喷油器计量特性数字孪生模型观测值与平台实测值.试验结果...     

电控喷油器的优化设计

根据电控喷油器各部件的结构特点、耦合关系及物理性质，建立了电控喷油器电磁阀驱动、电磁阀、液力、机械系统耦合的数学模型，完成了仿真计算并获得了各因素对电控喷油器性能影响的空间图谱；系统地研究了电控喷油器结构参数对喷油器动态响应的影响。以仿真结果为基础，以系统的响应和经济性为目标，建立了系统的多元回归方程。通过多目标规划，对系统的结构参数进行了优化。利用分析结果，设计了相应的零部件。在喷油器动态特性测试台架上，对经过优化设计的喷油器进行了动态响应特性等测试。测试结果与仿真结果有较好的一致性；喷油器针阀开启和关闭响应时间均叮达0．2ms，喷油规律波形与控制脉冲波形基本一致。     

船用低速柴油机电控喷油器多参数优化匹配

为了更好地优化电控喷油器性能,笔者基于自主设计的一种船用低速机电控喷油器结构,借助AMESim 软件搭建了电控喷油器的仿真模型,利用专用试验平台试验验证了模型的准确性。随后通过开展各结构参数对电控喷油器性能影响灵敏度量化分析,筛选出对电控喷油器性能影响较大的结构参数,并采用正交试验和遗传算法两种优化法相结合的数值模拟方法,以提高电控喷油器针阀响应速率为目标,对电控喷油器开展了参数优化匹配,得到了关键结构参数对电控喷油器针阀动态响应特性的影响权重和最佳参数组合。结果表明：出油量孔直径是对针阀响应特性影响权重最大的结构参数,控制活塞直径和进油量孔直径次之,而控制腔容积和针阀弹簧预紧力 影响相对较小;应用正交试验法优化后,与原参数方案相比,参数优化后针阀上升时间缩短了1ms,针阀下降时间缩短了1.4ms;通过应用遗传算法优化,相比于原参数方案,参数优化后电控喷油器针阀响应特性明显改善,针阀上升时间下降了40.9%,针阀下降时间缩短了29.1%。     

高压共轨电控喷油器结构参数仿真分析

阐述了共轨喷油器的工作原理,根据喷油器各部分的液力特性,以DELPHI共轨电控喷油器为研究对象,以系统轨压在160 MPa下的喷油规律试验研究为基础,利用AVL_Hydsim软件建立了喷油器的仿真模型,为了验证模型的准确性,将仿真计算结果与试验结果进行比较,在此基础上分析了喷油器不同结构参数对喷油规律的影响,并以改善电控喷油器喷油规律为出发点,探讨了各关键结构参数的设计原则,通过分析计算,为电控喷油器结构参数的合理选择和设计提供理论依据。     

基于响应特性的电控喷油器关键参数设计研究

合理选取电控喷油器的结构参数是提高其响应特性的关键,目前对响应特性的研究还只是简单分析结构参数单因素变化对响应特性的影响,而没有考虑优化各结构参数组合,以达到提高响应特性的目的。以经典的直接控制式电控喷油器为研究对象,利用Amesim软件开展仿真计算,研究了电控喷油器多个关键参数对响应特性的综合影响,明确了各关键参数的取值原则,可用于指导电控喷油器结构参数设计。     

船用柴油机蓄压式电控喷油器计量特性数字孪生模型研究

为实时准确地观测电控喷油器的喷油量,实现喷油过程的闭环控制,针对某船用柴油机蓄压式电控喷油器结构特征,根据其燃油流动过程和蓄压腔压力变化规律,利用理论机理计算与神经网络修正相结合的方法,建立了电控喷油器计量特性数字孪生模型。通过建立快速原型样机进行在线试验验证,对比喷油器计量特性数字孪生模型观测值与平台实测值。试验结果表明:当电控喷油器每循环喷油量大于1 000 mm~3时,喷油量计算误差在3%以内;当每循环喷油量小于1 000 mm~3时,喷油量计算误差在10%以内。     

高压共轨式喷油器的无量纲几何参数对喷油规律和喷油特性一致性影响的研究

通过数值模拟方法,发现高压共轨式喷油器针阀液压控制腔的液力过程和作用在针阀上液压力的相互关系,对油器的时间响应特性,喷油器供油规律和供油量具有重要影响。在喷油器制造中将表现为喷油定时和喷油量的不致性,值得指出的是,这种不一致是无法通过控制软件进行修正的。     

A review on deposit formation in the injector of diesel engines running on biodiesel

For the short-term use of diesel engines, biodiesel can provide a comparable engine performance to that of using fossil diesel fuel. However, some arising problems including the reduction of the engine performance, the increase in lacquer deposits, and excessive carbon blacks in the combustion chamber and in the injectors resulting in an increase in the emissions and the damage to the engine have been indicated. Deposits formed inside or outside the injector may have an adverse influence on the engine performance and the fuel injection system. In this study, a review of the formed deposits in the injector of diesel engines fueled with biodiesel was conducted. The physicochemical mechanism of the deposit formation in the injector including injector nozzles, injector holes, and injector tips was mentioned. Moreover, the test-cycles for determining the deposit formation level in the injector were also introduced. Especially, the effects of the key factors such as biodiesel components, temperature, and injector configurations on the formation level of deposits were reviewed, and the utilization of the cativation mechanism in the controlling strategy of the deposits was presented. Besides, the impacts of deposits in the injector on the spray characteristics, combustion, and diesel engine operation process were also referred.     

Disintegration process and performance of a coaxial porous injector

In order to understand the breakup performance of coaxial porous injectors, the sprays of coaxial porous injectors with two different porous material cylinder lengths were compared with those of conventional shear coaxial injectors. To allow comparison, the wall injection lengths were designed to be equivalent to the value of the recess depth. Cold flow sprays were visualized using back-lit photography methods and analyzed quantitatively with a laser diffraction apparatus, in order to study the effects of the momentum flux ratio and Weber number on the breakup for each type of injector. In case of the shear coaxial injector, the large liquid core was observed in low air mass flow rate condition. However, the destabilization of the liquid jet from the coaxial porous injector is almost complete within the inner region, near the injector face plate. Additionally, better breakup performance in low gas flow rate condition was obtained when the porous cylinder length decreased, while the shear coaxial injectors showed better breakup efficiency when the recess length increased. In conclusion, the different breakup process caused by the radial momentum in the inner region of the porous injector disintegrated the liquid core.     

共轨用新型电控喷油器结构及性能研究

根据船用柴油机共轨燃油系统工作特点及技术发展趋势,基于AMESim软件平台针对头部带蓄压器的新型喷油器结构建立仿真模型,研究其设计要点。结论表明:新型喷油器结构可以有效抑制系统中多个喷油器喷射过程中的互相干扰,蓄压器入口节流孔大小及蓄压容积的选取是影响新型结构喷油器性能的关键结构参数。     

基于生物质锅炉的模糊自适应PID控制系统仿真研究

在MATLAB/SIMULINK平台上,通过实验的方法建立了模糊自适应PID系统的仿真模型,给出了模糊自适应PID仿真的具体实现方法,并进行生物质锅炉控制子系统仿真应用研究,通过常规PID控制算法与模糊自适应PID控制算法对干扰信号的反应过程仿真结果对比,表明了模糊PID控制策略使系统具有强抗干扰性、灵活性和适应性强的优点,又具有控制精度高的优势。     

Influence of injector technology on injection and combustion development – Part 1: Hydraulic characterization

An experimental study of two real multi-hole Diesel injectors is performed under current DI Diesel engine operating conditions. The aim of the investigation is to study the influence of injector technology on the flow at the nozzle exit and to analyse its effect on the spray in evaporative conditions and combustion development. The injectors used are two of the most common technologies used nowadays: solenoid and piezoelectric. The nozzles for both injectors are very similar since the objective of the work is the understanding of the influence of the injector technology on spray characteristics for a given nozzle geometry. In the first part of the study, experimental measurements of hydraulic characterization have been analyzed for both systems. Analysis of spray behaviour in evaporative conditions and combustion development will be carried out in the second part of the work. Important differences between both injectors have been observed, especially in their transient opening and closing of the needle, leading to a more efficient air–fuel mixing and combustion processes for the piezoelectric actuated injector.     

共轨式喷油器响应特性理论与试验研究

针对喷油器喷油定时与喷油量的不一致性问题,建立了共轨式喷油器的物理、数学模型。通过计算机仿真,得出喷油器时间响应特性随结构、控制等参数的变化规律。试验结果表明：所建立的模型可以用来定量地分析各种结构和控制参数对喷油过程的影响。     

燃油喷嘴小油量非线性区补偿算法研究

随着机动车排放标准的日趋严格和不断升级,汽油直喷(gasoline direct injection, GDI)发动机需要采用更加先进而复杂的喷射模式和控制策略才能满足其要求。而先进的喷射模式和控制策略则需要控制GDI喷油器在特性曲线非线性的小油量区域进行喷射,且各喷油器特性曲线之间的离散性很大。如果从机械设计或加工工艺上提高小油量喷射的一致性,则难度很大且成本很高。基于轨压降的小油量补偿策略,通过对补偿原理与方法进行深入的研究和试验分析,成功开发和实施了GDI喷油器小油量补偿策略,并在某量产GDI喷射器上进行了补偿效果的验证。试验结果表明,进行了油量补偿后的油量一致性有较大改善,满足了GDI喷油器的小油量喷射要求。     

电控喷油器动态特性分析及关键参数测试研究

本文建立了计算电压驱动型喷油器针阀开启和落座时间的数学模型，在明确喷油器的各基本参数后对模型微分方程进行数值求解，得到喷油器线圈中电流的变化规律曲线，根据所得电流曲线的特点设计了一套系统用来测量喷油器针阈开启、落座时间。不同电源电压下，针阀开启时间的计算值与实测值基本一致，表明所开发出的测量系统是可行的。     

Experimental Research on Performance of Supersonic Steam-Driven Jet Injector and Pressure of Supersonic Steam Jet in Water

An experimental investigation was carried out to find the lifting-pressure performance of a steam-driven jet injector for various configuration parameters. The pressure profiles along the mixing chamber were measured with constant inlet steam and water parameters; the results indicated that the injector had a self-adaptive characteristic and the outlet water mass flow rate had an invariable characteristic. The lifting-pressure coefficient was affected significantly by the area ratio of the secondary nozzle and area ratio of the mixing chamber, and the influences were discussed. Moreover, the pressure distribution characteristic of a supersonic steam jet in water was studied under different steam pressures and water temperatures. The results indicated that the pressure distributions were affected by flow and condensation characteristics that were described by steam pressure and water temperature; the maximum axial pressure ratio was also discussed. Predictions of the distance of the maximum axial pressure by an empirical correlation showed good agreement with the experimental results.