合肥工大成功研制全国首台治理柴油机尾气装置

近日,合肥工业大学成功研制治理柴油机尾气装置-柴油机颗粒物捕集系统DPF,可清除柴油机尾气排放中的颗粒物(PM2.5)成效显著,攻克了城市柴油车辆尾气排放污染难题。该项目使用主动再生技术DPF系统,通过对柴油机排气系统进行改造,以特定材料制成壁流式的过滤通道载体,过滤捕集尾气的颗粒物,当捕集器中的颗粒物充满到设定程度后,通过特殊设计的再生设备,将捕集到的颗粒物氧化,生成二氧化碳排出。捕集器可以一直循环使用。采用该技术装置后,柴油机尾气黑烟消失,噪音降低。     

柴油机排气颗粒物电晕放电下荷电特性的研究

柴油机排气颗粒物粒径小,不易沉降,严重危害人体健康。这里设计并制造了一种电收集柴油机颗粒物的预荷电系统,并通过试验论证了该系统的有效性。对柴油机尾气分流采样,样气中的颗粒物通过线-筒式的负高压电晕放电装置荷电。尾气颗粒物在自制的法拉第杯中被收集,通过与之相连的数字电荷仪测量出收集颗粒物带电量,并用微克天平测量收集到的颗粒物的质量,从而计算得到柴油机尾气颗粒物的荷质比。试验探究了柴油机尾气颗粒物荷电效果与尾气流速之间的关系,验证了柴油机颗粒物可以用带电的方法收集。为柴油机颗粒物通过电晕放电收集提供了理论依据,该技术及产品未来有望用于柴油车尾气后处理系统之中。     

尾气温度及氧含量对颗粒物捕集器热再生的影响

柴油机颗粒物捕集器是柴油机颗粒物后处理最有效的方法,长时间使用会使颗粒物堆积造成堵塞,DPF再生的效率受到很多因素的影响,本文通过AVL的方法建立模型,进行仿真,研究柴油机尾气温度和尾气中氧含量对DPF热再生的影响。     

基于等离子体的柴油机尾气净化方法研究

面对日益严格的排放法规,等离子体NOx/PM后处理综合控制技术逐渐成为柴油机尾气后处理策略的发展趋势.本文介绍了等离子体柴油机尾气净化技术的机理和研究状况.研究表明电晕放电和介质阻挡放电等离子体净化柴油机尾气有着能耗过高的缺陷,在应用中不得不结合催化剂同时使用.为解决这一问题,笔者提出了电弧放电用于柴油机尾气净化的新思路,分析证明该思路具有一定的可行性.     

排气背压对柴油机燃油经济性影响研究

当前大气污染问题严重,颗粒物捕集器(DPF)是处理柴油机尾气中所含颗粒物的主要方法。但随着颗粒物捕集器应用时间增长,颗粒物不断堆积,排气阻力不断增加。当排气阻力达到一定值时,柴油机性能会明显受到影响。本文基于GT-Power研究了柴油机排气阻力对柴油机燃油经济性的影响,为颗粒物捕集器的再生时机提供了依据。     

井下装载机柴油机尾气危害及净化方法

矿山井下开采空间狭小、通风条件差,井下装载机作业时产生的尾气难以及时、顺畅排放到矿井之外,由此造成井下空间污染严重,给工作人员的健康带来极大危害。本文主要讲述井下装载机柴油机尾气的危害,提出净化方法,并介绍水洗式尾气过滤装置。     

对车用柴油机国IV以上技术路线的思考

目前我国车用柴油机执行国Ⅲ排放标准,不久将实施国Ⅳ排放标准。对于柴油机来说,从国Ⅲ排放标准升级到国Ⅳ排放标准,仅仅依靠机内净化已无法满足排放要求,必须对排出的废气进行机外净化处理。也就是说国Ⅳ柴油机需要在进一步改进国Ⅲ发动机整机技术,尤其是优化燃烧的基础上加装机外尾气处理装置。     

一种船用中速柴油机减排技术方案设计

本文针对某型船用中速柴油机在启动或低负荷工况加载荷时尾气排放质量差,黑烟明显问题,利用尾气颗粒物在高温环境中与氧气在催化剂作用下发生反应原理,提出了一种降低在该工况黑烟排放的反应器装置技术方案设计,并进行了几何建模与仿真计算,结果显示能够适用减排需求。     

低温等离子体降低柴油机NOx的研究

根据低温等离子体的净化机理,设计了一种新型低温等离子体净化装置,对柴油机不同负荷下,尾气中的氮氧化物进行处理试验。试验发现,净化装置净化效果明显,净化效率最高可达50%左右。该装置体积小、重量轻、功耗低,加以改进,对于汽车尾气排放控制具有很好发展前景。     

基于尿素热解的柴油车尾气净化装置的设计研究

现有柴油车尾气净化器基本上都采用催化剂净化的模式,而且多数的柴油机尾气净化器只能进行单一净化,不能对尾气进行多效的全面净化处理。为了克服现有技术的不足与缺点,设计研究了一种基于尿素热解的柴油车尾气净化方法以及净化装置,使其可大幅抑制多种有害气体的排放。     

微粒捕集器对柴油机性能影响的研究

柴油机排气微粒捕集技术是实现柴油机微粒排放控制的一个非常有效的技术，然而，微粒捕集器也会对柴油机的性能产生一定的影响。通过大量的柴油机台架试验，研究了微粒捕集器对ＹＣ６１０８柴油机的动力性、燃油经济性以及排放性能的影响，研究结果可以为微粒捕集器的正确使用及再生控制策略的确定提供依据。     

降低施工机械及车辆尾气排放的措施

分析了柴油机尾气排放的成分及成因，指出了净化措施，介绍了机外尾气净化装置的总体结构和结构设计。     

工矿设备驱动柴油机的废气净化装置性能研究

简要介绍矿用柴油机所排废气的主要成分以及净化处理的有效方法,指出废气净化对柴油机性能的影响和改进方向.     

The experimental investigations of recirculated exhaust gas on exhaust emissions in a diesel engine

The effects of recirculated exhaust gas on the characteristics of NOx and soot emissions under a wide range of engine loads were experimentally investigated by using a four-cycle, four-cylinder, swirl chamber type, water-cooled diesel engine operating at three engine speeds. The purpose of this study was to develop the EGR-control system for reducing NOx and soot emissions simultaneously in diesel engines. The EGR system is used to reduce NOx emissions, and a novel diesel soot removal device with a cylinder-type scrubber for the experiment system was specially designed and manufactured to reduce soot contents in the recirculated exhaust gas to the intake system of the engine. The experiments were performed at the fixed fuel injection timing of 4° ATDC regardless of experimental conditions. It was found that soot emissions in exhaust gases were reduced by 20 to 70% when the scrubber was applied in the range of the experimental conditions, and that NOx emissions decreased markedly, especially at higher loads, while soot emissions increased owing to the decrease in intake and exhaust oxygen concentrations, and the increase in equivalence ratio as the EGR rate is elevated.     

柴油发动机模拟排气试验台的研制

设计并建造了一个模拟多种柴油机尾气的试验台。试验台的热源由柴油燃烧提供,烟气的温度和流量由控制系统调节实现。试验台能够模拟出和实际柴油机工作时尾气特性(温度、压力、流量)相似的热烟气。模拟的柴油机尾气的试验台和SCR(选择性催化还原)系统相结合,可以降低试验成本,并使试验的可信度更高,为给定热源条件下SCR系统的设计提供一定的理论和实验依据。     

低温等离子体治理发动机尾气的研究

根据低温等离子体的净化机理,采取电晕放电方式,研发出一种新型低温等离子体净化装置,并进行发动机的尾气处理试验.试验发现,净化装置对发动机尾气的净化效果明显.净化效率最高可达60%左右.该装置结构合理、可靠性好以及无二次污染,具有很好的发展前景.     

低温等离子体处理柴油机有害排放的比较研究

分析了低温等离子体转化柴油机排气中有害成分的反应机理,设计了三种不同结构类型的低温等离子体反应器,并进行了基于发动机台架的实验研究。研究结果表明,低温等离子体对柴油机排气中的颗粒物及NO有较好的转化作用,采用全流式低温等离子反应器,延长排气在反应器中的滞留时间,有利于提高能量利用率及排气中颗粒物、NO的分解转化率。     

Characterization of engine oil additive packages on diesel particulate emissions

This study investigated the impact of engine oil formulation on particulate matter (PM) characteristics from a light-duty diesel engine. The test engine was a 1.6 L Euro-5 diesel engine operated from low- to high-speed and high-load conditions. Specially formulated nonadditive containing base oil and genuine oil were evaluated. For diesel PM characterization, physicochemical analytic procedures were conducted on engine oil formulation, oil flushing, PMs sampling, morphology, and particle constituent determination. Size-resolved particle number (PN) concentration at the engine-out position was evaluated by differential mobility spectrometer (DMS). Nucleation mode particles originating from engine oil consumption during the expansion stroke had a higher concentration from genuine oil than those from base oil. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were used to analyze the morphology patterns and atomic compositions with engine oil packages. From the SEM analysis, spherical PM of nucleation and accumulation mode particles were agglomerated on a quartz filter. In the XPS spectrum, more engine oil additive fractions of Ca, P, and Zn were found in the PM sample from genuine oil. In conclusion, the variation of physicochemical engine oil properties and additive amounts had strong contributions to engine oil derived PN emissions, morphology, and additive metal compositions in the exhaust gas stream.

     

Relation between particulate emissions and exhaust smoke level in premixed charge compression ignition engine

For simplicity in measurement, the smoke level or opacity of the exhaust gas is often measured in diesel engine tests for the purpose of estimating the level of particulate emissions in the belief that smoke level is proportional to the particulate emissions. Existence of the correlation between these two has been well established in conventional diesel engines, but it is not clear yet whether the linear relationship stays in PCCI engines, which are known to emit significantly less NOx but more hydrocarbons than the conventional diesel engines. The objective of this study was to investigate the existence of the correlation between the smoke level and particulate mass in a directly fuel-injected PCCI engine with a DOC in the exhaust system. The smoke and PM are simultaneously measured before and after the DOC, while the single-cylinder diesel engine is operated in either diesel or PCCI combustion mode under various operation conditions. The study reveals that many more hydrocarbons and particulates are emitted in PCCI combustion than in the diesel combustion, and the strong correlation between the engine-out smoke level and particulate emissions in the diesel combustion does not exist in PCCI combustion. The correlation, however, comes back in the post-DOC measurements where most of SOF contained in PM is removed by the DOC.     

Specific engine performance and gaseous emissions characteristics of European test cycle and worldwide harmonized driving cycle for a heavy-duty diesel engine

This study compares the engine operating behavior and regulated gaseous emissions characteristics between the reference European cycles (ESC/ETC) and the worldwide harmonized driving cycles (WHSC/WHTC), which will be applied in the Euro VI heavy-duty diesel engine emissions regulations, for the diesel particulate filter (DPF) equipped Mercedes 12 L diesel engine. The speed and load distribution for two additional representative harmonized cycles which cover a more realistic operating range for a heavy duty engine were established to verify the engine performance over wide range of the cycle work, fuel consumption, and exhaust system temperature as well as engine coolant temperature for repeated validation tests. The WHTC, including an additional test with cold start and transient operation before the hot start, had a substantial influence on the THC, CO, NOx, and PM exhaust emissions levels because of the engine heat-up time and temperature rising characteristics of aftertreatment device. Moreover, the different engine operating conditions of the WHSC influenced on the specific engine performance and gaseous emissions behavior unlike those of the ESC. Finally, the statistical analysis results through repeated tests validated the stationary and transient cycles running at the fully warm-up condition, however, those of WHTC were closely dependent on the inclusion of cold start condition or aggressive acceleration gradient of engine speed and load trace.