排烟增湿脱硫活化反应器内液滴──脱硫剂颗粒碰撞的数值模拟

排烟增湿脱硫活化反应器内液滴──脱硫剂颗粒碰撞的数值模拟唐庆，徐旭常（清华大学热能工程系北京１０００８４）关键词液滴－颗粒碰撞，脱硫，数值模拟要有效的控制ＳＯＺ的污染，降低燃煤电厂排烟中ＳＯＺ的浓度显得尤为重要。在众多的烟气脱硫技术中，排烟增湿活化脱...     

蒸汽活化提高脱硫剂钙利用率的实验研究

本文用小型热态流化床实验台对以ＣａＯ为主要成分的钙基脱硫剂石灰乏吸收剂在１５０～６００℃的温度范围内进行了蒸汽活化处理,进而实验研究了这种处理对提高脱硫剂钙利用率的效果。结合化学成分分析和Ｘ射线衍射的结果初步探讨了蒸汽活化的机理。研究表明,脱硫剂对水蒸汽的物理吸附明显受活化温度的影响,蒸汽活化后的钙利用率提高显著,可能存在一个最佳活化时间。     

温度对脱硫剂钙利用率和蒸汽活化效果的影响

在中温烟气脱硫过程中,蒸汽活化对于提高脱硫剂的钙利用率和脱硫效率起到了显著的作用。为了确定温度对于蒸汽活化效果的影响,研究了200～800℃的蒸汽温度范围内钙利用率的变化,给出了合适的蒸汽活化温度。进而分别在400、600、800℃条件下研究了脱硫反应温度与蒸汽活化温度的关系,提出了中温循环流化床烟气脱硫的适用温度范围。     

增湿活化反应器内喷水脱硫试验研究

本文介绍在热态脱硫试验台上进行的生石灰和消石灰的喷水活化脱硫试验,研究了Ca/S比、饱和温距、入口烟气SO2浓度、烟气速度及水喷嘴雾化风对脱硫效率和钙利用率的影响规律,对两种脱硫剂的脱硫活性进行了比较,并对喷水增湿提高脱硫效率的机理进行了分析。研究表明,喷水增湿使两种脱硫剂的活性都有明显提高,生石灰具有价格优势。     

磁能活性水的生物效应研究

我们用动物实验研究了磁处理的磁能活化水的生物效应．这个磁能活化水是用4400Gs的磁场处理后得到的．在磁能活化水对高血脂Wister大鼠的血常规指标、血液流变学指标、血液生化指标、肝组织中有关自由基代谢的生化指标以及老鼠的脾脏系数的影响的研究中发现，在高脂饲料的喂养下实验组大鼠的胆固醇含量明显低于对照组大鼠，同时实验组大鼠的体重增重也明显小于对照组大鼠，说明磁能活化水有一定的降血脂的能力．同时，在血液流变学的指标测定中看出实验组大鼠的高切粘度明显低于对照组的，说明饮用磁能活化水的大鼠的红细胞变形性要好于饮用普通水的大鼠．     

苯甲酰甲酸热分解分应机理的理论研究

本文用ＡＭ１方法研究了苯甲酰甲酸热分解反应，计算所得活化势垒为１７８．３２９ｋＪ／ｍｏｌ，这与实验值一致。     

重点排烟作用下地下通道顶棚烟气温度分布研究

本文通过改变重点排烟量及火源功率,研究了在不同重点排烟方式下,顶部重点排烟量对地下通道顶棚烟气温度分布的影响。研究发现:在无重点排烟条件下,由于热烟气的卷吸,以及与顶棚之间的传热影响,通道内的顶棚纵向烟气温升在不同火源功率下均随距离的增加而不断衰减。不同顶部重点排烟方式及火源功率下的顶棚烟气温度衰减趋势相同,且重点排烟量越大,顶棚纵向温度越低。本文引入了重点排烟量影响因子β,该影响因子随着重点排烟量的增加呈现指数增加。建立了顶部不同重点排烟模式下地下通道顶棚烟气温度分布模型,模型预测值与实验测量值吻合较好。     

高层建筑环形走廊机械排烟口合理布置优化研究

合理布置机械排烟口能够有效提高高层建筑疏散走道的排烟效率。采用1/3缩尺核心筒高层建筑烟气流动试验台,研究了排烟口4种不同宽高比和4种不同安装高度对环形走廊机械排烟效果的影响,对比分析了走廊内的烟气温度、烟气蔓延速度和走廊能见度。实验结果表明,宽高比为2的机械排烟口的排烟效果最佳;当排烟口上沿距顶棚的距离小于0.3 m时,对人员安全疏散较为有利。研究结论可为高层建筑环形走廊机械排烟系统设计及防排烟设计规范相关参数的修订提供参考。     

中温烟气脱硫过程中CO2对脱硫剂钙利用率的影响

本文在300～600℃的中温区段,实验研究了CO2在烟气脱硫过程中与钙基脱硫剂发生碳酸盐还原反应,削弱脱硫效果的规律,发现石灰钙利用率随温度升高呈跳跃式变化,并因碳酸盐反应程度的迅速增加而在500℃附近出现低谷.由此明确了减小碳酸盐反应效应,提高脱硫剂钙利用率的途径,为进一步发展中温烟气脱硫工艺提供了重要依据.     

喷钙脱硫系统中增湿活化器的作用以及液滴和固体颗粒的碰撞实验研究

本文介绍了喷钙脱硫系统的实验研究结果，在调试工况和Ｃａ／Ｓ＝２．１３下采用增湿活化器能增加脱硫率１２．２％；此值和液滴蒸发所需时间有关。本文还利用多脉冲激光全息冷态试验台，对雾化液滴与固体颗粒的碰撞做了初步研究，证实了碰撞的存在，为增湿脱硫机理中的碰撞模型提供了依据。     

煤在链条炉内燃烧过程中氟排放规律及抑制研究

本文报道了在一台0．5T／H蒸发量的链条炉试验台上所进行的煤燃烧过程中氟化物迁移、排放规律及抑制生成的研究,试验表明,在链条炉燃烧条件下,约有80％氟将排入大气,采用开发的废弃钙基除氟剂,在燃烧过程中能使除氟率达到45～80％,表明这是一种较理想有潜力的除氟剂．文中还报道了在煤燃烧产生的烟气中气态氟及尘态氟的比例关系．     

The combined effect of H2O and SO2 on CO2 uptake and sorbent attrition during fluidised bed calcium looping

The effect of steam and sulphur dioxide on CO₂ capture by limestone during calcium looping was studied in a novel lab-scale twin fluidised bed device (Twin Beds – TB). The apparatus consists of two interconnected batch fluidised bed reactors which are connected to each other by a duct permitting a rapid and complete pneumatic transport of the sorbent (limestone) between the reactors. Tests were carried out under typical calcium looping operating conditions with or without the presence of H₂O and/or SO₂ during the carbonation stage. Carbonation was carried out at 650°C in presence of 15% CO₂, 10% steam (when present) and by investigating two SO₂ levels, representative of either raw (1500?ppm) or pre-desulphurised (75?ppm) typical flue gas derived from coal combustion. The sorbent used was a reactive German limestone. Its performance was evaluated in terms of CO₂ capture capacity, sulphur uptake, attrition and fragmentation. Results demonstrated the beneficial effect of H₂O and the detrimental effect of SO₂ on the CO₂ capture capacity. When both species were simultaneously present in the gas, steam was still able to enhance the CO₂ capture capacity even outweighing the negative effect of SO₂ at low SO₂ concentrations. A clear relationship between degrees of Ca carbonation and sulphation was observed. As regards the mechanical properties of the sorbent, both H₂O and SO₂ hardened the particle surface inducing a decrease of the measured attrition rate, that was indeed always very low. Conversely, the fragmentation tendency increased in presence of H₂O and SO₂ most likely due to the augmented internal stresses within the particles. Clear bimodal particle size distributions for in-bed sorbent fragments were observed. Microstructural scanning electron microscope and porosimetric characterisations aided in explaining the observed trends.     

Co-extraction of water vapor and helium from natural gas

A study of the sorption properties of a composite sorbent prepared from pseudoboehmite and synthetic sodium-borosilicate glass microspheres was performed with the aim of using the sorbent in membrane-sorption processes of helium extraction from natural gas with its simultaneous drying. Experimentally, permeability of the composite sorbent under study with respect to helium and its impermeability to air and methane has been demonstrated. Under experimental conditions, the absolute moisture content of the gas mixture having passed through the sorbent has reduced from 21.1 to 0.013 g/m³. The rate of helium adsorption by the composite sorbent has increased nearly by two orders of magnitude in comparison with the initial microspheres. It was found that the degree of saturation of the sorbent with water vapor had almost no influence on the rate of helium adsorption. A possibility of optimal use of the composite sorbent by combining the process of natural-gas drying from water vapor and the process of helium extraction from natural gas is shown. This possibility permits shortening of the process sequence for natural gas pre-conditioning prior to helium extraction.     

火焰原子光谱法分析有机功能试剂改性纳米SiO2对水中Cr2072-的吸附行为

以纳米二氧化硅(Nano-SiO2)为原料,硅烷偶联剂(KH-550)作为交联剂首先合成了氨丙基纳米二氧化硅(Nano-APSG),然后加入有机功能试剂季磷盐(COOH-Ph-CH2-P(C6H5)3Br)通过有机合成反应合成有机功能试剂改性纳米二氧化硅材料(Si|(CH2)3-NH-CO-Ph-CH2-P(C6H5)3Br),利用红外、粒径、热重分析等对结构进行了表征.通过火焰原子吸收光谱法研究此有机功能试剂改性纳米二氧化硅材料对水中Cr2O12-离子的吸附行为,考察了吸附的最佳pH、震荡时间、吸附剂用量等因素的影响,实验结果表明,在pH1,吸附剂用量为0.1 g,震荡时问为30 min时吸附剂对Cr2O72-离子的吸附效率可达95%以上,实验结果表明这种新型的功能材料可实现对废水中Cr2O72离子的分离与处理.     

Influence of ultrasound on cadmium ion removal by sorption process

This study presents the removal of Cd(II) from aqueous solution by the sorption process in the presence (sono-sorption) and absence (conventional method) of ultrasound. Batch experiments were conducted to study the main parameters such as sorbate concentration, amount of sorbent, contact time, and ultrasound intensity. In addition, the sorbate/sorbent concentration ratios were studied in two different ways: (a) in a constant sorbate concentration and variable amount of sorbent, (b) in a constant amount of sorbent and variable sorbate concentration. The results indicated that under proper conditions, there was a possibility to remove cadmium ion very fast and efficiently from aqueous solution. In addition, the intensity of ultrasound and the sorbate/sorbent concentration ratio were two important factors for the removal of this pollutant and therefore, this study was focused mostly on these two variables.     

La/酸化膨润土吸附剂的表征与除磷性能

以酸化改性膨润土为载体,采用浸泡法制备了稀土La掺杂的La/酸化膨润土吸附剂.通过XRD和FTIR对其结构进行了表征,探讨了膨润土的改性机理,研究了该吸附剂对废水的除磷性能.结果表明：酸化过程洗掉了膨润土中的杂质和氧化铝,稀土镧的掺杂在膨润土层间及表面引入了一定数量的羟基化合物,改善了膨润土的层间结构并生成了新的La-O-Si键,实现了La与膨润土的复合,提高了膨润土的吸附性能.     

煤粉炉喷钙脱硫过程的总体模型与模拟

1前言我国燃煤中约有三分之一用于火力发电,减少火电厂SO。排放是治理酸雨和SO。污染的重中之重。炉内喷钙脱硫结合尾部增湿活化技术（LIFAC）因流程简单、投资省、运行费用低而且效率较高,特别适用于燃烧中、低硫煤锅炉的改造,是一种具有广泛应用前景的技术［1］本文?..     

Mathematical modeling of a sorption process for the retention of acid from a solution

Mechanisms of the formation of additional capacity of sorbent in sorption experiments of nitric acid and the separation of acid and salt in solution are studied using mathematical modeling. A method for the calculation of the dielectric constant and the ratio of concentrations of molecules and electrolyte ions in the inner layer of the sorbent is proposed. A mathematical model is constructed, simulation results are presented, and their comparison with experimental data is performed.     

铬蓝黑R负载活性炭对Cr（Ⅲ）和Pb（Ⅱ）的吸附性能

研究了新型吸附材料铬蓝黑R（钙试剂）负载改性的活性炭对样品中Cr（Ⅲ）和Pb（Ⅱ）的固相萃取（SPE）并用电感耦合等离子体-原子发射光谱法（ICP-AES）进行检测.优化了pH值、吸附剂用量、流速等条件以达到定量吸附（≥95％）,同时研究了洗脱剂的最佳洗脱条件以及共存离子干扰等问题.本法测定Cr（Ⅲ）和Pb（Ⅱ）的检出限分别为0.91ng·mL-1和0.65ng·mL-1,将其应用于土壤沉积物、猪肝、黄河水中的Cr（Ⅲ）和Pb（Ⅱ）含量的测定,加标回收率在98％-101％之间;用于测定标准物质中Cr（Ⅲ）和Pb（Ⅱ）的含量,结果与标准物参照值一致.     

注蒸汽井井筒内参数计算新模型

从动量定理角度出发建立求解蒸汽压降方程,而从能量守恒角度出发建立求解蒸汽干度变化的方程,采用节点分析方法和数值计算方法对模型求解.计算过程中借鉴传统的气液两相流Beggs Brill方法计算水蒸汽混合物的物性参数.通过对辽河油田齐40块和杜80块10口井井筒的压力、温度和干度分布计算表明该模型计算精度较高.