矿用防爆柴油机标准分析与研究

无轨辅助运输技术是当今世界上最先进的煤矿辅助运输技术,矿用柴油发动机作为无轨辅助运输设备的主要心脏部件之一,其许多参数都和煤矿安全密切相关。本文阐述了矿用防爆柴油机要求和特点、采用的技术措施、标准现状,同时对目前矿用防爆柴油机的标准进行了结构分析,提出了防爆柴油机标准要增加的内容。     

柴油/甲醇燃烧颗粒的碳结构参数分析

为探讨非道路柴油机燃用柴油/甲醇混合燃料排气颗粒中碳结构的演变规律,降低非道路柴油机的颗粒(PM)排放,采用激光拉曼光谱仪,结合分峰拟合方法,重点针对甲醇掺混比对非道路柴油机燃烧颗粒的碳结构参数和演变规律进行分析,并用颗粒氧化特性试验对拟合分析结果进行验证. 结果表明,随着燃料中甲醇掺混比(以w计)的增加:①NO_x、CO、HC比排放呈上升趋势,与柴油相比,甲醇掺混比为15%时,3种污染物比排放分别升高约12%、49%、62%;颗粒比排放降幅明显,约为59%. ②由于颗粒碳原子和碳键的伸缩振动,在1 350和1 590 cm-1附近出现2个较为强烈并有一定重合的拉曼振动峰;颗粒中C—C的伸缩振动以及弯曲振动加剧,在345 cm-1附近出现较为强烈的拉曼振动峰. ③表征颗粒中无定形成分的D3峰的相对强度(R3值)明显升高,表明颗粒中的碳团簇含量增加,石墨晶体结构的无序程度升高;表征颗粒中石墨化程度的D1~D4、G峰的FWHM(半宽度)和D/G相对强度整体呈上升趋势,说明颗粒的石墨化程度降低,颗粒较容易被氧化. ④颗粒的活化能逐渐降低,也说明掺混甲醇后,颗粒具有较好的氧化性能,有利于加速颗粒在缸内的氧化速度,缩短颗粒捕集器中过滤体的再生时间,降低柴油机的颗粒排放.      

柴油机排气微粒过滤催化处理技术及进展

介绍了柴油机微粒后处理催化捕集器特点 ,评述了过滤器催化再生方法 ,综述了蜂窝陶瓷载体涂层及催化剂活性组分研究现状。重点阐述了微粒再生催化剂研究进展及其发展趋势     

发动机厂生产车间色彩配置对安全的影响剖析

随着工业的飞速发展,在现代化工厂建设中,建立较完善的劳动条件不仅取决于生产技术、卫生条件和建筑设计等多方面措施,厂房内部及设备合理的色彩修饰也起着重要的作用。科学技术的高度发展使技术与艺术相结合已成为必然趋势,设计具体车间的色彩配置立足减轻劳动强度,改善工作环境,提供科学管理车间的可能性出发,充分运用了美学、人体工程学原理及艺术造型的方法,使其在实用功能、人机关系和视觉心理上达到了充分协调。本文简要论述了发动机厂生产车间内色彩的选择与搭配的原则,同时为规范发动机厂生产车间色彩管理工作,确保车间的统一性、协调性和特殊性,运用色彩的属性对车间内饰及设备设施进行了配置,建立良好的生产秩序,创造良好的工作环境,减少疲劳,提高生产的安全性、经济性及生产率。     

Accelerated ash accumulation method for diesel particulate filter and its characterization: a review

ABSTRACT

It is well known that high-efficiency wall-flow particulate filter is the most commonly used technology that can effectively reduce both particulate matter (PM) and particulate number (PN) to comply with the latest emission legislations. Ash, defined as the noncombustible, non-evaporative residue derived mostly from lubricants, has critical impact on engine backpressure, particulate filter filtration efficiency and durability performance, therefore, the investigation of ash impact on particulate filter is of great importance. Due to cost-saving potential, several published methods from different laboratories for accelerated ash loading under carefully controlled conditions are described in this review, including some characterization methods that have been used for the evaluation of filter performance. In addition, the impact of ash deposit on back pressure and regeneration performance are also discussed in this review.     

La1-x Cex Cuy Mn1-yO3／HZSM-5催化剂低温去除柴油机碳烟和NOx

为实现对柴油机碳烟和NOx的低温同步去除,采用柠檬酸络合法制备分子筛负载钙钛矿型金属复合氧化物催化剂,应用x衍射分析仪（XRD）和电镜扫描仪（SEM）对催化剂性能进行表征,并在微型固定床反应器中对催化剂低温去除碳烟和NOx进行活性评价。利用程序升温反应（TPR）技术,进行催化剂活性评价、柴油机负荷和排放等特性实验。结果表明,A位用适量Ce部分取代La,B位用适量cu部分取代Mn,可使碳颗粒燃烧温度降低,CO2选择性好,NOx转化率升高。La0.4 Ce0.6 Cu0.2 Mn0.8O3／HZSM-5催化剂的最大NOx转化率为81．0％,Ti、Tm和Tf分别为250、350和475℃,表明该催化剂具有较好的催化活性,能在低温条件下去除碳烟和NOx。     

Analysis of methanol and organometallic MnO2 fuels as alternative fuels in a diesel engine

In this study, methanol and organometallic MnO₂ fuels were used to improve the properties of diesel fuel. In addition, the effect of methanol fuel on engine oil and a piston ring was also examined experimentally in a four-cylinder, direct injection diesel engine running at 200 bar. Three different diesel fuels were prepared by adding 5, 10 and 15% methanol to diesel fuel. In order to prevent phase separation, 1% dodecanol was added to the mixture. Organometallic compounds of manganese were synthesised to prepare the solutions. The most effective amount and performance of anti-freeze were determined. From the results, it was observed that carbon monoxide emissions decreased and NOx emissions increased with the increase in the amount of methanol. On the other hand, organometallic MnO₂ increased the cetane number and decreased the freezing point, viscosity and flame temperature.     

Effects of thermal barrier coating on the performance and combustion characteristics of a diesel engine fueled with biodiesel produced from waste frying cottonseed oil and ultra-low sulfur diesel

In this study, the top surfaces of piston and valves of a four-strokes and direct-injection diesel engine have been coated—with no change in the compression ratio—with a 100 μm of NiCrAl lining layer via plasma spray method and this layer has later been coated with main coating material with a mixture of 88% of ZrO₂, 4% of MgO and 8% of Al₂O₃ (400 μm). Then, after the engine-coating process, ultra-low sulfur diesel (ULSD) as base fuels and its blend with used frying cottonseed oil derived biodiesel in proportion of 20%, volumetrically, have been tested in the coated engine and data of combustion and performance characteristics on full load and at different speeds have been noted. The results, which were compared with those obtained by uncoated-engine operation, showed that thermal efficiency increased, and engine noise reduced. Cylinder gas pressure values obtained from the diesel engine which has been coated with thermal barriers have been found to be somewhat higher than those of the uncoated-engine. Also, maximum pressure values measured in both engines and under the same experimental conditions through the use of test fuel have been obtained after TDC. Moreover, heat release rate and heat release have occurred earlier in the coated-engine. NOx emissions were increased while CO and HC emissions were remained almost the same with a little bit decrease.     

Selection of optimum fish oil fuel blend to reduce the greenhouse gas emissions in an IC engine—A hybrid multiple criteria decision aid approach

The increasing demand on energy due to population growth and rising of living standards has led to considerable use of fossil fuels which has in turn, had an adverse impact on environmental pollution and depletion of fossil fuels in Internal Combustion (IC) engine sector. Alternative fuel blend evaluation in IC engine fuel technologies is a very important strategic decision involving decisions balancing within a number of criteria and opinions from different decision maker of IC engine experts. The selection of appropriate source of biodiesel and proper blending of biodiesel plays a major role in alternate energy production. This paper describes an application of hybrid Multi Criteria Decision Making (MCDM) technique for the selection of optimum biodiesel blend in the IC engine. The proposed model, Analytical Network Process (ANP) is integrated with Technique for Order Performance by Similarity to Ideal Solution (TOPSIS) to evaluate the optimum blend. Here the ANP is used to determine the relative weights of the criteria, whereas TOPSIS is used for obtaining the final ranking of alternative blends. An efficient pair-wise comparison process and ranking of alternatives can be achieved for optimum blend selection through the integration of ANP and TOPSIS. The obtained preference order for the blends are as B20 > B40 > Diesel > B60 > B80 > B100. This paper highlights a new insight into MCDM techniques to evaluate the best fuel blend for the decision makers such as engine manufactures and R&D engineers to meet the fuel economy and emission norms to empower the green revolution.     

库房火灾事故中弹药热安全性研究

为研究不同火灾条件下弹药发生慢速烤燃的升温速率,以典型地面仓库和舰船舱室火灾为研究对象,建立仿真模型,模拟计算发生火灾时弹药贮存环境的热激源强度及其演化规律,针对发动机在此类环境下的热安全性开展仿真计算,分析其响应规律。研究结果表明：不同火灾条件下弹药慢速烤燃的升温速率有很大区别且往往高于标准慢速烤燃试验常用的升温速率3.3 K/h。随着慢速烤燃升温速率的提高,发动机烤燃点火时间提前,点火时刻发动机中间位置温度下降,两端温度升高,且点火位置向发动机喉部移动。研究结果可以指导弹药库房的设计及弹药安全性增强设计。