波形竖管降膜蒸发流动与传热性能的理论研究

本文简介波形竖管降膜蒸发流动与传热的过程,通过理论分析建立波形竖管降膜蒸发传热的数学模型。采用国外一些研究者得到的理论分析与实验结果,利用无穷泰勒级数将含有多重积分的数学模型展开,得到简单实用的半经验——半理论数学模型解析式。     

Investigation of tailpipe and evaporative emissions from China IV and Tier 2 passenger vehicles with different gasolines

The limited understanding of vehicular emissions in China, especially evaporative emissions, is one obstacle to establishing tighter standards. To evaluate tailpipe and evaporative emissions, two typical China IV vehicles and one Tier 2 vehicle with an onboard refuelling vapour recovery (ORVR) system were selected and tested. One of the China IV vehicles was fuelled with gasoline, E10 and M15, respectively, to investigate the effect of fuel properties on vehicular emissions. For each vehicle, cold-start tailpipe emission tests were conducted first, followed by an evaporation test. Based on the emission factors and real-world vehicle activity data, the annual tailpipe and evaporative hydrocarbon (HC) emissions of each vehicle were calculated and compared. The results show that E10 and M15 significantly reduced the tailpipe CO and particle number (PN) emissions but seriously aggravated the NOx emissions, especially for M15. The hot soak losses (HSLs) and diurnal breathing losses (DBLs) were slightly impacted by the fuel properties. The annual evaporative emissions with E10 and M15 were higher than that with gasoline. The ORVR system effectively controlled the evaporative emissions, especially for DBLs. Evaporative emissions from the China IV vehicles were 1.1–1.4 times the tailpipe HC emissions. Additionally, the evaporative emission factors of the China IV vehicles were almost 50% lower than the standard (2.0 g/test), whereas their annual evaporative emissions were almost 1.8–2.8 times higher than those from the Tier 2 vehicle. Therefore, controlling evaporative emissions currently remains a great need in China, and the ORVR might be a recommended evaporative control technology.     

Experimental investigation of evaporation rate and exhaust emissions of diesel engine fuelled with cotton seed methyl ester and its blend with petro-diesel

An experimental study to measure the evaporation rates, engine performance and emission characteristics of cotton seed biodiesel (cotton seed oil methyl ester) and its blends in different volumetric proportions with diesel is presented. The thermo-physical properties of all the fuel blends have been measured and presented. Evaporation rates of neat cotton seed biodiesel, neat diesel and their bends have been measured under slow convective environment of air flowing with a constant temperature. Evaporation constants have been determined by using the droplet regression rate data. The neat fuels and fuel blends have been utilized in a test engine with different load conditions to evaluate the performance, combustion and emission characteristics of the fuels. The specific fuel consumption values of the two blends, viz. B25 and B75 are found to be same. At the highest load, B0 records the lowest CO volume followed by B100. From the observed evaporation, performance and emissions characteristics, it is suggested that a blend of B50 and B75 can be optimally used in standard diesel engine settings.     

WS—93型除锈剂在CA1046轻型车车架酸洗线上的应用

介绍了ＣＡ１０４６轻型车架在酸洗线上采用ＷＳ－９３型除锈剂进行除锈处理，实践结果表明；该工艺不但提高了车架的酸洗质量，而且降低了产品的生产成本，阐述了车架用钢材的特点和酸洗原理，分析了酸洗工艺过程，提出了酸洗操作时的注意事项。     

普通汽油与乙醇汽油的蒸发性分析

蒸发性是汽油性能的重要评价指标之一。为了了解乙醇汽油的蒸发性,本文将几种不同混合比例的乙醇汽油与普通汽油进行了馏程试验和饱和蒸汽压试验对比研究。试验结果:表明,低比例乙醇汽油的蒸发性有一定程度的提高,这对推广使用乙醇汽油具有参考价值。     

汽车车灯内部结雾的热分析及应对措施

空气中的水蒸气遇冷会在车灯透镜罩内产生珠状凝结，从而严重影响汽车车灯的照明和外观，中将热设计的概念引入到车灯设计中，对车灯内部结雾的凝结机理，影响因素等进行了分析，指出车灯材料，灯内流场，温度场和浓度场的分布是影响结雾的决定因素，并由此提出了应对措施，对车灯的优化设计具有指导意义。     

LPG汽车供气系统关键部件特性研究

以某LPG/汽油两用燃料商务车为研究对象,针对其供气系统关键部件进行了性能测试。设计了供气系统喷气控制的驱动电路硬件和软件,主要对燃气喷射控制阀和蒸发减压阀的喷射精度和响应时间进行了测试试验。试验结果表明,不同气压状态下和不同供电电压下,喷气量与喷气脉冲占空比呈线性关系;燃气喷射控制阀在正常电压波动范围内工作稳定;蒸发减压阀可保持燃气喷射控制阀供气压力基本稳定。     

汽油车燃油蒸发污染物的控制系统研究

本文介绍燃油蒸发污染物控制系统（包括活性碳罐、清洗阀等主要部件）的研制、试验分析及对发动机性能影响，表明整个系统设计合理、工作可靠、净化节能效果明显。