生物质燃油/柴油混合燃料燃烧特性

在测定生物质燃油物理特性的基础上,将生物质燃油和柴油配比,筛选出不同体积分数的混合燃料E110(10%1号生物质燃油和90%柴油混合)、E210(10%2号生物质燃油和90%柴油混合)、E120(20%1号生物质燃油和80%柴油混合)、E220(20%2号生物质燃油和80%柴油混合)。用这些混合燃料与柴油进行了台架对比试验。结果表明,在不改变发动机结构的情况下,燃用混合燃料是可行的,发动机性能没有明显的变化,节油效果显著。     

荷电喷雾燃烧的研究

进行了燃油荷电喷雾的实验研究，设计了燃油荷电喷雾实验台，测量了荷质比、雾滴粒径等，并将PIV技术应用于荷电喷雾流场研究。实验结果表明：在相同条件下，燃油荷电后将使雾滴粒径有较大幅度的降低，喷雾流场变得均匀、松散，燃烧及排放得到明显改善。     

多缸柴油机燃烧过程缸间差异统计分析

分析了多缸柴油机产生缸间差异的原因,提出了采用统计学STUDENT试验方法判别多缸发动机缸间差异产生的原因。实测了一台四缸直喷式柴油机气缸压力,分析其平均指示压力、燃烧始点、最大气缸压力和最大压力升高率及对应相位等参数的波动与缸间差异,并对平均指示压力缸间差异进行统计分析。结果表明,该柴油机燃烧过程缸间差异较大,其产生的原因并非偶然,而是存在技术原因,需要进行改进。     

小缸径直喷增压柴油机燃烧及放热规律研究

柴油机的燃烧过程与其动力性、经济性、排放特性、噪声及强度等直接有关,在很大程度上影响柴油机的综合性能。本文根据实测小缸径直喷增压柴油机不同负荷及转速时的气缸压力,分析其燃烧过程特性及放热规律。结果表明,为降低最大燃烧压力及NOx排放,小缸径直喷增压柴油机采用的喷油提前角较小,柴油机在大部分工况下,燃烧始点较迟,最大压力升高率、最大燃烧压力较低,其对应相位较迟,放热规律也较低。     

烧柴砖瓦窑节能理论与实践

本文阐述了砖瓦节柴窑设计的理论依据,并成功地用于实践。与旧式窑相比,热利用效率提高了一倍多,节柴60％以上,砖质量符合国家标准,当年就可回收成本。     

Characterization of residues from thermal treatment of treated wood and extraction of Cu, Cr, As and Zn

Thermal treatment of chromated copper arsenate (CCA) impregnated waste wood is a way to utilize the energy resource of the wood and at the same time to reduce the volume of the waste. An issue of concern in relation to the thermal treatment is As emission to the air. Meanwhile, there is still a matter to cope with when methods to avoid As emission are implemented: the residues with increased concentrations of Cu, Cr and As. In the present paper two different residues after thermal treatment are characterized: a mixed bottom and fly ash from combustion of CCA impregnated wood, and a charcoal from pyrolysis of treated waste wood. By SEM/EDX it was seen that the charcoal still showed wood structure with both tracheids and rays and that Cu, Cr and As were found inside this wood structure. Cu was found alone while Cr and As were often found together. By chemical analysis it was found, too, that the charcoal contained a high concentration of Zn, probably from paint. Chemical extraction experiments in HNO₃ were conducted with the charcoal and it was found that the order of extraction (in percentage) was Zn > Cu > As > Cr. A SEM/EDX investigation of the mixed ash from combustion showed the presence of small particles with wood structure with elevated Cu and Cr concentrations, but most particles were irregular shaped matrix particles rich in Si, Al and K. Cr was abundant in many different particles including the lignin skeleton of the small, unburned wood pieces, but also inside silica-based matrix particles. Ca was often found associated with char-like (porous) particles, indicating that Ca-arsenates had been formed during combustion. Cu was often associated with Cr in the unburned wood pieces, whereas it was less abundant inside the silica-based matrix particles. Cu was also found in an almost pure form in a small layer on the surface of some matrix particles indicating condensation of volatile Cu species. Chemical extraction with inorganic acids showed the order of percentages mobilized as: As > Cu > Cr.     

增压中冷柴油机燃用葵花籽油的燃烧和排放特性研究

葵花籽油具有与柴油相近的物理特性和燃烧特性,因此柴油机可以在不改变其结构的前提下直接燃烧葵花籽油。然而,葵花籽油的黏度高、热值低和挥发性差会使柴油机直接燃用葵花籽油时动力性下降。本文通过增加每循环供油量在保证柴油机动力性不变的前提下对比研究柴油机燃用葵花籽油的燃烧和排放特性。研究结果表明:柴油机燃用葵花籽油时着火晚、滞燃期长,大负荷时放热峰值高,燃油消耗率和NOx排放浓度增加,HC,CO和碳烟的排放有明显降低,但排气温度基本不变。     

喷油器参数对直喷柴油机喷油及燃烧过程的影响研究

利用CFD软件对1115型柴油机在采用不同喷油器参数时的喷油及燃烧过程进行数值模拟,并分析了不同情况下的柴油机缸内燃油浓度场、示功图,排放等。结果表明:随着喷油器孔数增加、孔径减小,油柱破碎时间缩短,燃油蒸发雾化速度加快,空气利用率提高;油束贯穿距离下降,燃油碰壁现象减弱,燃烧室壁面附近的燃油量减少;油气混合速度提高,滞燃期内形成的可燃混合气量增加,燃油燃烧速率和压力升高率上升,碳烟排放量下降,但发动机零部件机械负荷和燃烧噪声增加、NOx排放量上升。     

基于皱折火焰面分形理论的火花点火发动机准维燃烧模型

提出了一个火花点火发动机准维燃烧模型。该模型是在双区热力学过程的基础上,采用基于皱折火焰面分形理论来描述火花点火发动机气缸内的湍流燃烧及火焰传播速度,并确定了其他子现象的计算方法。利用该模型,对在快速压缩膨胀机中模拟的沼气发动机燃烧过程进行了模拟计算。计算结果与实测值吻合较好,证实了该模型的合理性。     

柴油机燃油喷雾和燃烧过程的数值模拟

介绍了作者开发的柴油机燃油喷雾和燃烧过程三维数值模拟程序的数学模型。以ＺＨ１１０５型柴油机的３种燃烧室为例,用该计算程序对燃油喷雾和燃烧过程进行了具体模拟计算,并与试验结果进行了对比,结果证明,程序具有较好的预测内燃机燃油喷雾和燃烧过程的能力。