利用导向喷射塔盘改造两苯塔

应用导向喷射塔盘对两苯塔进行技术改造,取得了良好的效果。导向喷射塔盘可在塔径不变的情况下,通过改造塔盘达到提高生产能力的目的,充分体现导向喷射塔盘通量和处理能力大的特点。导向喷射塔盘效率高,可提高产品收率和降低能耗。改造后,粗苯处理能力提高,能够满足新增粗苯的加工要求,轻苯收率提高2%,产量增加200t/a,并节省蒸汽29%。     

多孔介质固阀塔盘流体力学性能的研究

为了提高石油化工塔器的处理能力和效率,开发了一种新型多孔介质固阀塔盘.采用空气-水冷模实验的方法,对其流体力学性能进行研究.研究结果表明,多孔介质固阀能够有效改善塔盘气体分布情况,提高塔盘流体力学性能,有效提高塔盘通量和传质效率.     

浅析精馏一塔的工艺操作

分析了影响精馏一塔生产能力和分离效果的原因，通过提高温度，加强合成小回收和精馏七塔的操作，将尾气管线由Ｄｇ５０改为Ｄｇ１００，可使塔压大幅度下降，提高了该塔塔顶ＨＡｃ含量合格率和塔釜醛含量合格率。     

机械通风横流式冷却塔组的节能试验研究

以多主机空调系统中的机械通风横流式冷却塔组为研究对象,对独立运行的塔组和连通运行的塔组以及在塔组中是否实行风路控制进行了冷却效果的比较。结果表明,在试验所测试的条件下,实行风路控制的连通运行的塔组与独立运行的塔组相比,单位负荷冷吨数提高了36.55%;与未采用风路控制的连通运行塔组相比,风机停用塔的平均风量提高37.65%,总风量提高6.9%,节能效果明显。     

低负荷下邻苯塔的波动原因及对策

邻二甲苯塔采用带有隔板的热虹吸式再沸器的大筛孔筛板塔.该塔在低负荷区运行时,因塔釜易出现干釜现象,塔回流无法提高,不能满足正常分离的需要.作者针对此问题,采取了部分塔底液导入进料线的方法,提高了塔的操作弹性,解决了塔釜的干釜问题.     

填料塔在高压馏中的应用

高压蒸馏与真空和常压操作相比,填料塔中的气液均匀分布变得更加困难,并导致气相返混增加,填料分离效率下降,但经过适当的设计,填料塔不但可以提高高压蒸馏的生产能力,而且效率也得到提高,文中介绍高压蒸馏填料塔的特点和近年来的进展,并总结了国内外高压蒸填料塔新塔设计和老塔改造的成功经验。     

填料塔在高压蒸馏中的应用

高压蒸馏与真空和常压操作相比,填料塔中的气液均匀分布变得更加困难,并导致气相返混增加,填料分离效率下降,但经过适当的设计,填料塔不但可以提高高压蒸馏的生产能力,而且效率也得到提高。文中介绍高压蒸馏填料塔的特点和近年来的研究进展,并总结了国内外高压蒸馏填料塔新塔设计和老塔改造的成功经验。     

具有热集成的甲醇多效精馏新工艺及其模拟

在分析现有甲醇双效精馏工艺存在不足的基础上,提出了一种节能的五塔甲醇多效精馏新工艺.五塔新工艺在现有四塔工艺的加压塔之后增加了1台中压塔,精甲醇按适当比例分别由加压塔、中压塔、常压塔和回收塔塔顶采出,使原加压塔和常压塔负荷减少约30%;同时适当提高了新回收塔的操作压力,使加压塔与中压塔、中压塔与常压塔、回收塔与预塔形成...     

甲苯二异氰酸酯光气回收系统的扩产改造

为了提高原甲苯二异氰酸酯(TDI)光气回收系统生产负荷,解决进料光气、惰性气体含量增加导致操作不稳定问题,采用Aspen plus软件对系统的甲苯吸收塔、甲苯解吸塔和甲苯精制塔进行了模拟分析和优化,考察了理论板数、进料位置、中间冷却器、塔径等影响因素,提出了保留原甲苯吸收塔和甲苯精制塔,新设计了甲苯解吸塔.原甲苯吸收塔增加2个中间冷却器、改变部分物料进料位置,新增塔代替原甲苯精制塔提馏段等措施,提高了生产负荷和操作稳定性,降低了设备投资费用.     

回收六塔冷凝器分层器的改造

回收六塔分层器是将六塔气相蒸出的醋酸异丙酯和水经冷凝器冷却后再分层开来，使上层的异丙酯能够回流六塔循环使用，下层为分离水送往七塔处理。分层的效果对六塔的生产起着非常重要的作用。本文介绍了如何通过分层器的改造来提高分层效果，提高了六塔的生产能力。     

超声对无沸腾区浸液式喷雾冷却的影响研究

超声由于空化和声流机制可起到强化换热效果,为研究其在高热流下对喷雾冷却传热特性的影响,设计并搭建了以H₂O为工质的浸液式喷雾冷却实验平台,在无沸腾区范围内考察了不同喷雾高度、压力和热通量下超声场对喷雾冷却换热性能的影响。研究表明：超声浸液喷雾冷却的换热效果要优于浸液式喷雾冷却,在高热通量152 W/cm²情况下更加明显;强化换热效果会随着喷雾压力的升高而减小,在最佳喷雾高度10 mm和喷雾压力0.1 MPa条件下,浸液超声式喷雾冷却相比浸液式换热效果最高提升14.4%;超声对换热的改善作用随着喷雾高度增加而提升,喷雾高度18 mm时最高强化比29.1%。     

Macroscopic spray characteristics and breakup performance of dimethyl ether (DME) fuel at high fuel temperatures and ambient conditions

The purpose of this work was to investigate, both experimentally and numerically, the spray behavior and atomization characteristics of dimethyl ether (DME) at high fuel temperatures and under various ambient conditions. In order to compare the theoretical and measured spray characteristics of DME fuel, macroscopic characteristics such as spray tip penetration and spray cone angle were investigated using spray visualization system with a heating system. DME atomization performance was calculated under various conditions from KIVA-3 V code and studied via analysis of the overall Sauter mean diameter (SMD) map, which is related to ambient gas temperature, ambient pressure, and fuel temperature.DME spray was found to exhibit behavior that differs from diesel spray under atmospheric condition. However, at high ambient pressure conditions, DME and diesel sprays display similar behavior. At ambient atmospheric condition, the spray cone angle of DME fuel is larger than that of diesel spray due to the occurrence of flash boiling. Variation in DME fuel temperature had little effect on spray tip penetration and spray cone angle characteristics. An increase in ambient air temperature caused an increase in DME spray cone angle due to an enhancement of the flash boiling effect. However, the DME spray cone angle showed a decreasing trend at high ambient pressure conditions when the ambient air temperature was increased. This was due to the disappearance of flash boiling and the evaporation of droplets at the exterior of the spray cone. In the overall SMD map, the increase of the ambient gas temperature and fuel temperature induced the increase of DME overall droplet size. On the other hand, the ambient gas pressure have slightly influenced on the overall SMD at a low ambient gas temperature and low fuel temperature, but the effect of the ambient gas pressure is significant at high ambient gas temperature and high fuel temperature. At high ambient gas temperature, the increase of the ambient gas pressure causes the increase of the overall SMD. At high DME fuel temperature, the decrease of the ambient gas pressure induces the increase of the overall SMD.     

Detailed analysis of air flow and spray loss in a pharmaceutical coating process

In the pharmaceutical industry, more than half of all tablets receive a film coating. A commonly used technique is drum coating, where a film solution is applied to the moving tablets by a spray nozzle. Important process parameters include the amount and temperature of drying air, as well as spray nozzle position. Among other influences, the proper adjustment of these parameters has a great impact on spray loss, defined as the fraction of spray liquid that does not form a film on the tablets. Often, the lack of scientific data hinders a process setup based on engineering principles, resulting in operational conditions based on trial‐and‐error approaches. Here, we show how a coating system can be numerically modeled by means of computational fluid dynamics (CFD) techniques. Furthermore, we present how different parameters affect the efficiency of the process, leading to a deeper understanding of the coating device. © 2011 American Institute of Chemical Engineers AIChE J, 2012     

Influence of ethanol blends on the combustion performance and exhaust emission characteristics of a four-cylinder diesel engine at various engine loads and injection timings

The aim of this work is to investigate the effect of ethanol blending to diesel fuel on the combustion and exhaust emission characteristics of a four-cylinder diesel engine with a common-rail injection system. The overall spray characteristics, such as the spray tip penetration and the spray cone angle, were studied with respect to the ethanol blending ratio. A spray visualization system and a four-cylinder diesel engine equipped with a combustion and emission analyzer were utilized so as to analyze the spray and exhaust emission characteristics of the ethanol blending diesel fuel. Ethanol blended diesel fuel has a shorter spray tip penetration when compared to pure diesel fuel. In addition, the spray cone angle of ethanol blended fuels is larger. It is believed that the lower fuel density of ethanol blended fuels affects the spray characteristics. When the ethanol blended fuels are injected around top dead center (TDC), they exhibit unstable ignition characteristics because the higher ethanol blending ratio causes a long ignition delay. An advance in the injection timing also induces an increase in the combustion pressure due to the sufficient premixed duration. In a four-cylinder diesel engine, an increase in the ethanol blending ratio leads to a decrease in NO_x emissions due to the high heat of evaporation of ethanol fuel, however, CO and HC emissions increase. In addition, the CO and HC emissions exhibit a decreasing trend according to an increase in the engine load and an advance in the injection timing.     

旋流压力式喷嘴低压喷淋液滴粒径的实验研究

以自来水为喷淋介质,对旋流压力式喷嘴低压喷淋液滴粒径进行了测试,分析了压力、喷孔直径和喷嘴流量对液滴索特平均直径(d_(SMD))的影响规律,研究了旋流压力式喷嘴液滴尺寸的分布规律。采用跨径(K)和均匀度指数(N)来揭示喷嘴低压喷淋质量。实验结果表明,d_(SMD)较大,超过250μm；d_(SMD)随喷孔直径增大而增大,随压力和喷嘴流量增大而减小；喷淋液滴尺寸分布均匀性较好,K小于0．65,N大于4。实验结果可以为旋流压力式喷嘴设计和改进提供重要的实验依据。     

一种新的密闭型湿式冷却塔的数学模型研究

为了保证喷淋水和空气的传质面积,在传统的密闭型湿式冷却塔中需要增加冷却水和喷淋水的换热面积,使其满足传质面积的要求,从而导致了密闭型湿式冷却塔的造价比较高.本研究提出了一种新型结构的密闭型湿式冷却塔,冷却水与喷淋水通过铜管换热,且在冷却塔中布置塑料管增加空气和喷淋水的传质面积,喷淋水和空气在铜管和塑料管表面进行热质交换...     

空心喷嘴喷淋特性实验研究

为使大型水平管降膜多效蒸发海水淡化装置的横管降膜蒸发器均匀布液,自主设计并搭建了一套离心喷嘴喷淋特性实验台及径向喷淋密度测量装置,通过高速摄影仪拍摄的喷淋照片对喷淋外缘进行标注测量,得到喷嘴各喷淋锥角,对旋流式空心喷嘴的流量、喷淋锥角和径向喷淋密度等喷淋参数随入口压力、喷淋高度的变化规律进行实验探究分析。结果表明,流量随入口压力增加而增加,但入口压力越大,流量增长速度越缓慢;正常工况下,喷淋锥角由喷嘴出口扩张段角度决定,与喷嘴扩张角保持一致,在重力作用下出现向内的收缩圆弧液膜边;喷淋形状为规则的环形喷淋,入口压力增加使有效喷淋区域整体向中心压缩,喷淋密度峰值变大,两波峰的对称性得到改善,压力为349 kPa时,喷淋密度基本完全对称,增加喷淋高度则情况相反。根据此喷淋密度分布特点,在设计横管蒸发布液器时合理控制工况压强,根据峰谷叠加原理可有效消除无效喷淋区域。     

气泡雾化喷嘴泡状流出口喷雾脉动特征

采用实验和仿真方法,对一特定气泡雾化喷嘴泡状流时混合室内的气液两相混合形态以及喷孔出口喷雾脉动特征进行了研究。研究结果表明,泡状流时气泡尺寸呈近似正态分布,气泡尺寸随液相质量流量和气液质量比增大而减小;喷雾形态和喷孔出口气液流动参数存在较大脉动,喷雾锥角脉动超过20°;气泡数量密度小且气泡直径较大时,喷雾平均锥角相对较小,且喷雾脉动现象比较严重;随着气泡数量密度增加,喷雾平均锥角呈现先快速增大后缓慢增大趋势,而喷雾锥角变异系数先快速增大随后逐渐减小并趋于稳定;复杂的流场结构是喷孔内气泡表观形态发生较大变化以及喷孔出口气液流动参数产生较大脉动的主要原因。     

Influence of two-stage injection and exhaust gas recirculation on the emissions reduction in an ethanol-blended diesel-fueled four-cylinder diesel engine

The purpose of this study is to investigate the effects of two-stage injection and exhaust gas recirculation (EGR) on the spray behavior and exhaust emission characteristics in diesel-ethanol fuel blends fueled four-cylinder diesel engine. The spray behavior is analyzed from the spray development process, spray tip penetration, and spray cone angle, which are obtained from the spray images. The combustion and exhaust emission characteristics are measured from the four-cylinder diesel engine with a common-rail injection system.The experimental results revealed that the increase of the pilot injection amount causes the fast development of the injected pilot spray, and the penetration difference among the main sprays is less than that among the pilot sprays. An increase in the ethanol blending ratio causes an increase in the ignition delay in the pilot combustion, but the main combustion is little influenced by the ethanol blending. The increase in the pilot injection amount shows the reduction effects of NO_x emissions when the pilot injection timing is advanced beyond BTDC 20°. The concentration of soot emissions shows a decreasing pattern according to the advance of the pilot injection and the decrease in the pilot injection amount. The CO emissions increase with the advance of the pilot injection timing, the increase in the pilot injection amount, and the ethanol blending ratio. In addition, the increase in the ethanol blending ratio and the advance of the pilot injection timing induce an increase in the HC emissions. The increase in the pilot injection amount induces a slight increase in the HC emissions.     

水基SiC浆料的喷雾造粒特性

以水为液体介质,制备分散稳定的水基SiC料浆,并利用喷雾造粒技术对水基SiC浆料进行造粒,研究了碳化硅浆料固含量及喷雾干燥工艺对造粒粉特性的影响。研究结果表明:浆料固相含量对造粒粉体粒径分布影响明显,粉体粒径随固含量的增加而增大。在最佳的干燥工艺条件下,碳化硅粉体流动性得到较大改善,素坯密度增加,陶瓷力学性能提高。