德士古水煤浆气化流程技术新进展

德士古水煤浆气化技术是二十世纪四十年代美国德士古石油公司在重油气化基础上发展的气化技术,经过开发七十年代推出了具有代表性的加压水煤浆气化技术。此技术于上世纪八十年代进入了中国。德士古水煤浆气化技术包括了煤浆制备、水煤浆气化、灰水处理等技术。根据热量回收方法气化炉分为全废锅流程气化工艺、半废锅流程气化工艺和激冷式流程气化工艺。神宁集团煤炭化学工业分公司甲醇厂德士古废锅流程气化技术全套设备为原首钢德士古全废锅流程气化技术。     

生物质气化技术研究现状及其发展

生物质气化技术是洁净利用生物质能的有效方法之一。综述了生物质气化剂气化技术及其影响可燃气成分的主要因素,着重介绍几种常见的生物质气化剂在气化过程中发生的主要化学反应和在国内外的研究及应用现状。通过气化技术性能的对比,提出了研究开发经济上可行、效率较高的气化剂气化技术,同时阐明了我国生物质气化技术上亟待解决的难题,为我国在今后生物质气化剂气化领域的发展提供方向。     

燃料气制取技术的特点

分析了目前较为适用的几种工业燃料气制取技术,即固定床气化技术、恩德炉气化技术、灰熔聚气化技术、科达循环流化床气化技术及U-gas气化技术;介绍了各种气化技术的工艺原理和特点,并对其选用方法进行了讨论。     

国产化大型加压气流床煤气化技术

综述了国内大型加压气流床煤气化技术——多喷嘴气化技术、航天粉煤加压气化技术、非熔渣-熔渣气化技术、两段干粉气化技术和多元料浆气化技术的发展及应用情况。     

三相态煤加压气化技术研发及方案讨论

介绍了三相态煤加压气化技术开发的依据,详细介绍了三相态煤加压气化技术工艺流程和特点,对比了三相态煤加压气化技术与水煤浆加压气化技术的指标。鉴于三相态煤加压气化技术结合了水煤浆加压气化技术高稳定性和粉煤加压气化高有效气成分的特点,展望了该技术在未来煤化工领域应用前景及经济价值的潜能。     

无烟块煤在碎煤加压气化工艺中的应用

UGI作为国家限制类气化技术已无法满足现代大型工业化的要求,碎煤加压连续气化技术可作为无烟块煤气化技术的未来发展方向。实践运行结果表明使用无烟块煤气化具有气化温度高、气化效率高、蒸汽消耗量少及煤气水易处理等优点。同时根据无烟块煤气化特性,应对碎煤加压气化技术进行优化升级。本文介绍了无烟煤在碎煤加压气化炉上的运行情况,无烟块煤气化的发展方向。     

灰粘聚流化床粉煤气化技术及其在工业生产中的应用

煤气化就是将固体煤转变为煤气。煤气化技术大致可分为：移动床（固定床）气化技术、流化床气化技术、气流床气化技术、熔融床气化技术4大类。     

组合气化技术在煤制天然气项目中的应用

分析激冷型粉煤气化技术和碎煤加压熔渣气化技术的特点及缺点,结合煤制天然气项目的实际运行情况,提出了激冷型粉煤气化+碎煤加压气化的组合气化方案,并从装置规模、技术路线、技术经济和能耗等方面将其与单一的激冷型粉煤气化技术进行比较。结果表明组合气化技术能够有效解决块、末煤平衡问题,减少废水排放量,而且在综合能耗、煤耗和投资收益方面均优于采用单一的激冷型粉煤气化技术。     

煤炭气化产业的发展现状和工业化前景

论述了煤炭地面气化技术和地下气化技术的技术特点、发展现状和工业应用;对比和分析了固定床、流化床和气流床气化炉的气化特点和工程应用概况;提出了目前国内可采用优先发展工业化成熟的Texaco气化技术和自主开发的对置式多喷嘴气化技术,适时发展具有广阔发展潜力的干煤粉气化技术的参考性意见。     

BGL高温熔渣气化技术将成褐煤气化新途径

英国埃德文特有限公司BGL高温熔渣气化技术在我国的第1个大型商业化推广项目在内蒙古呼伦贝尔建设。 BGL高温熔渣气化技术是在原鲁奇固定床加压气化炉基础上改进而来,结合了熔渣气化技术高气化率和高气化强度的优势以及鲁奇气化技术氧耗低和炉体结构廉价的优势,克服了流化床熔渣气化技术高能耗和鲁奇固定床加压气化技术低效率和废水处理成本高的弱点。     

生物质气流床气化前的处理工艺

针对生物质气化过程面临的问题,利用慢速热解方法作为生物质气流床气化的前处理工艺并考察其可行性. 分析讨论了热解后半焦的化学组成和输送特性,并使用ASPEN PLUS模拟软件计算比较了原料与半焦的气化结果. 结果表明,半焦的能量密度随热解温度的升高而升高;热解温度在300~400℃之间,半焦的质量产率和能量产率对于气化工艺比较有利;热解后半焦的内摩擦角、休止角明显降低,堆积密度明显提高. 使用ASPEN PLUS模拟软件进行计算比较,热解温度为400℃时的气化效果最理想.     

加压气流床煤气化工艺的发展现状及存在问题

介绍了国内外开发的主要加压气流床煤气化工艺的发展现状,包括德士古气化、E-Gas气化、壳牌和普兰福气化、GSP气化、多喷嘴水煤浆加压气流床气化、两段喷干煤粉的气流床加压气化等,列举出这些气化技术中目前存在的主要问题,并对其解决途径进行了探讨,提出了一些建议。     

喷射器内湍流混合的多尺度模拟

利用宏观混合分数方差和微观混合分数方差定量表征宏观混合和微观混合状态,对喷射器内的湍流混合进行了多尺度模拟和研究,并计算出了达到完全混合所需要的特征混合时间。对不同操作条件下的多尺度混合情况进行了模拟计算和分析。结果表明：在引射流速度不变的情况下,增加喷嘴速度,可以降低达到完全混合所需要的时间;在喷嘴速度不变的情况下,增加引射流速度,可以增加达到完全混合所需要的时间;在喷嘴和引射流速度比不变的情况下,增加两者绝对速度,可以降低达到完全混合所需要的时间;在本文所研究的情况下,喷射反应器内湍流混合过程由微观混合控制。     

Effect of entrainment on combustion efficiency high ash anthracites in fluidized bed combustors

The characteristics of the freeboard combustion of Korean low grade anthracites were studied in two fluidized bed combustors, which employed over-bed feeding and non-recycle of cyclone captured solids. The total combustion efficiency was ruled mainly by entrainment of fed coal particles and more or less by the freeboard combustion of entrained coal particles. The conversion of entrained coal particles increased with the bed temperature and decreased with the higher coal feed rate per bed area.     

生物质气流床气化技术的研究进展

阐述了发展生物质气流床气化技术的背景和意义,分析了生物质气流床气化技术的特征,重点介绍了国内外生物质气流床气化技术的研究进展,指出了目前该技术研究的重点及难点问题。     

脱除再生催化剂携带烟气的研究进展

根据催化剂在输送立管和脱气罐内的流动特点,分析了催化裂化过程中再生催化剂产生携带烟气的原因和脱气的原理。阐述了适合脱除再生催化剂携带烟气的方法和操作条件。为了保证催化剂流动稳定,脱气量存在最佳值,指出达到这种理想状况时催化剂的流动情况,并提出用其他气体置换烟气的方法来进一步减少再生催化剂对烟气的携带量。     

Simulation of entrainment of agglomerates from plate surfaces by shear flows

The entrainment process of agglomerates deposited on plate surfaces by shear flows was simulated using the three-dimensional modified discrete element method (mDEM) and influences of several factors on entrainment process were examined. In the case shear induced force is too weak, deposits are only deformed and particles are barely entrained, however, above some critical value particles are entrained by flows forming agglomerates. It was also clarified that the steric-bulky deposit undergoes the stronger hydrodynamic force and is easy to be entrained. There are two entrainment mechanisms corresponding to the parameter A_s/A which indicates the relative strength of adhesive force between particle and plate surface to that between particles. In case of large A_s/A where the adhesion between particle and plate surface is predominant, the number of entrained particles monotonically decreases as A_s/A increases due to the enhanced binding force. By contrast for small A_s/A, the number of entrained particles is not heavily dependent on A_s/A due to the mechanism in which the upstream side of deposit is lifted and the deposit is deformed extensively then large agglomerates are entrained. The boundary between those two entrainment mechanisms exists at A_s/A=0.5-0.6 which is in good agreement with the theoretical prediction.     

Characterization of multi-scale porosity in cement paste by advanced ultrasonic techniques

The effectiveness of advanced ultrasonic techniques to quantitatively characterize the capillary porosity and entrained air content in hardened cement paste is examined. Direct measurements of ultrasonic attenuation are used to measure the volume fraction and average size of entrained air voids and to assess variations in intrinsic porosity - as influenced by water-to-cement ratio (w/c) - in hardened cement paste samples. For the air entrained specimens, an inversion procedure based on a theoretical attenuation model is used to predict the average size and volume fraction of entrained air voids in each specimen, producing results in very good agreement with results obtained by standard petrographic methods and by gravimetric analysis. In addition, ultrasonic attenuation measurements are related to w/c to quantify the relationship between increasing porosity (with increasing w/c) and ultrasonic wave characteristics.     

Effect of Humidity on Constant Output and Breath Enhanced Nebulizer Designs When Tested in the EN 13544-1 EC Standard

Aqueous aerosols produced by nebulizers used in clinical situations can rapidly change size as the patient inhales. This is caused by air with a relative humidity (RH) lower than inside the nebulizer being entrained and mixed with nebulized aerosol during the inhalation maneuver. A way to assess the change in size is to measure the aerosol in a test method that reflects the clinical situation. The EC standard, EN 13544-1, offers a first step towards this assessment. In this paper we have tested two nebulizer designs, one conventional constant output nebulizer and one breath-enhanced nebulizer, using the proposed standard in order to assess the effect of the relative humidity of entrained ambient air on nebulized aerosol size properties. The results indicate that aerosol size from the conventional nebulizer is greatly affected by the RH of the entrained air, while the breath-enhanced nebulizer is not affected. The results agree with theoretical expectations of how the entrained air interacts with nebulized aerosol. In the breath-enhanced nebulizer, the air is passed through the nebulizer interior and becomes saturated with moisture drawn from the relatively large nebulizer reservoir solution. With the conventional constant output nebulizer, ambient air is drawn over the nebulizer and draws its moisture from the relatively small volume of nebulized aerosol released from the nebulizer. For the conventional nebulizer design, we found a large decrease in measured nebulized aerosol size with decreasing relative humidity--3.1 w m MMAD at 75% RH fell to 1.9 w m MMAD at 20% RH. For the breath-enhanced nebulizer design, the MMAD was stable between a similar humidity range. The results indicate that aerosol size is dependent on relative humidity of the entrained air for the constant output jet nebulizer design that has no air entrainment through the nebulizer. We found no significant effect of ambient humidity of entrained air on nebulized aerosol size from the breath-enhanced nebulizer design.     

跨临界CO2热泵系统的喷射器特性

在自行研制的跨临界CO₂热泵热水器实验台上,通过调节系统中阀门开度控制喷射器的进出口压力和温度,研究喷射器的流量、喷射系数、压缩比和效率的变化规律。实验结果表明:同时增大工作流体压力和引射流体压力可以提高喷射器的工作性能,减小工作流体压力或者增大引射流体压力可以提高喷射器的工作完善度。高效率喷射器的研制是优化跨临界CO₂热泵系统的关键要素。