Experimental studies of air-blast atomization on the CO_(2)capture with aqueous alkali solutions

In this work,an air-blast atomizing column was used to study the CO2 capture performance with aqueous MEA(mono-ethanol-amine)and Na OH solutions.The effects of gas flow rate,the liquid to gas ratio(L/G),the CO2 concentration on the CO2 removal efficiency(η)and the volumetric overall mass transfer coefficient(KGav)were investigated.The air-blast atomizing column was also compared with the pressure spray tower on the studies of the CO2 capture performance.For the aqueous MEA and Na OH solutions,the experimental results show that theηdecreases with increasing gas flow rate and CO2 concentration while it increases with increasing L/G.The effects on KGavare more complicated than those forη.When the CO2 concentration is low(3 vol%),KGavincreases with increasing gas flow rate while decreases with increasing L/G.However,when the CO2 concentration is high(9.5 vol%),as the gas flow rate and L/G increases,KGavincreases first and then decreases.The aqueous MEA solution achieves higherηand KGavthan the aqueous Na OH solution.The air-blast atomizing column shows a good performance on CO2 capture.

Response of droplet parameters to liquid viscosity in the flow field of an air-blast sprayer

The physical properties of sprayed droplets such as viscosity affect their deposition on the target.In order to understand the response characteristics of droplet parameters to the viscosity of a spray solution,a three-dimensional model of the external flow field of an air-blast sprayer based on computational fluid dynamics(CFD)was established according to the actual spray range and the sprayer duct structure.The change rules of droplet diameter and droplet density with distance under different viscosities of the spray solution in the flow field were obtained through numerical solution of the CFD model.The reliability of the model was verified by a chi-squared test comparing the numerical calculations with the results of field experiments.The results showed that the change rule of droplet parameters in an airflow field under different values of the spray solution viscosity was consistent.With the increase in the axial distance,the droplet size decreased initially,then increased,and finally decreased,while the droplet density gradually decreased.Moreover,the greater the spray solution viscosity,the shorter the conveying distance of the droplets in the axial direction,although viscosity was helpful in reducing the droplet drift.In addition,at the same axis distance,with the increased viscosity of the spray solution,the droplet size increased,and the sedimentation of the droplets was more rapid,while the density of the droplets decreased.The results provided a new framework for the study of air-blast spraying technology and serve as a reference for the optimization of the sprayer structure and the preparation method for spray solutions.

High Strain-Rate and Shock Response of Carbon SupercompositeTM

This study focuses on assessing the dynamic behaviors of carbon SupercompositeTM laminates when subjected to high strain-rates and air blast loads, using a shock tube for testing. The investigation aims to understand the response of these advanced materials under extreme conditions, which is crucial for applications in aerospace, military, and other high-performance industries. SupercompositeTM (CZE) prepreg, made up of a 3K plain weave carbon fabric with milled carbon fibers as interlaminar reinforcements impregnated with epoxy, is used to create SupercompositeTM (CZE) laminates. A woven carbon composite (CBE) laminate was also created using 3K plain weave Carbon/Epoxy (CBE) prepreg. Both types of laminates were designed and fabricated using the autoclave process. The dynamic behaviors of CZE and CBE laminate under transverse compression loads were evaluated using a modified Split Hopkinson Pressure Bar (SHPB). The study found that the 3D reinforcement with milled carbon fibers significantly affected the dynamic behavior of the CZE laminate. Stereo imaging videos, captured using two SHIMADZU high-speed video cameras in shock tube experiments, recorded the time history of back surface deflection. The plate specimens exhibited low deflections without any visible damage. The experimentally observed center point deflections of the CZE plates decayed sooner than those of the CBE laminates, indicating an improvement in damping due to the presence of 3D reinforced milled carbon fibers. This research shows that optimized utilization of milled carbon fibers as 3D reinforcement can withstand high stress in the thickness direction and higher energy absorption when subjected to impact and high strain-rate loading.

深孔轴向多段间隔装药孔壁冲击压力分布

为确定地下垂直长深孔爆破时合理的空气间隔长度,基于爆轰波理论,分析了多段间隔装药爆破条件下孔壁冲击压力随间隔长度变化的内在分布规律函数;依据Mises准则,得出了不同岩性时合理的间隔长度参考值,并通过数值模拟和现场爆破试验进行了验证。结果表明,空气间隔段孔壁冲击压力沿炮孔轴线从两端向中间骤降,但在中点周围略微增大,压力曲线呈两端大、中间小、中点周围略微凸起的“W”形对称分布。

侧面爆破粉尘时空分布模拟分析

从开放性细颗粒物污染治理角度出发,建立建筑物拆除爆破产尘的几何计算模型,运用计算流体力学(CFD)工具,对给定环境风速下的建筑物周围压力场和速度场进行了模拟分析,并对侧面折叠爆破粉尘按R-R(Rosin-Rammler)分布,使用气流-粒子双向耦合的DPM模型研究了爆炸粉尘的时空分布。结果表明,下风侧因建筑物存在导致风速、压力急剧变化而产生涡流,涡流是影响爆破粉尘时空分布的关键因素之一。在时间上,爆破粉尘有气流拖曳运动状态和扩散态;在空间上,因重力作用致下部空间的粉尘浓度较大。

Experimental Studies on Fuel Spray Characteristics of Pressure-Swirl Atomizer and Air-Blast Atomizer

In this work,the effects of fuel temperatures and pressure drops on the flow field and spray characteristics of a pressure-swirl atomizer were discussed using the Particle Imaging Velocimetry(PIV),Planar Laser Induced Fluorescence(PLIF)and Laser Particle Size Analyzer(LPSA)methods.Then the air-blast atomizer was selected to study the interaction of initial atomization and flow field.The effect of fuel-air ratio on the air-blast atomizer were also considered,where the fuel-air ratio was varied by adjusting mass flow rate of the air and fuel respectively.The results show that the spray angle of the pressure-swirl atomizer increases first and changes a little after the pressure drop higher than 0.5 MPa.However,more fuel concentrate on the central region,which is mainly caused by the increase of the proportion of small droplets with lower centrifugal force.The fuel temperature can improve the spray angle only in lower pressure drop,and it has a little effect under higher pressure drops.In addition,the fuel pressure drop has an obvious influence on the fuel distribution and flow field near the nozzle exit compared with the downstream.For the air-blast atomizer,the spray angle increases compared with the pressure-swirl atomizer for the introduction of swirl air.Furthermore,the spray angle decreases with the air mass rate increasing,and it increases with the fuel mass rate increasing.The distribution of velocity and droplet near the nozzle exit is influenced by the air mass rate,and the fuel mass rate mainly affects the distribution in the downstream.The fuel accumulates in the annular area below the nozzle,and the distribution of it changes little with the development along the axial direction.

梅蓄电站二期上引水洞爆破开挖诱发空气超压对上库事故闸门的影响分析

爆破开挖过程中产生的空气超压可能会影响周边建构筑物的安全。梅州抽水蓄能电站二期引水平洞的爆破作业区,距离在一期工程中已建好并投入运行的二期工程引水上平洞上库钢质事故闸门仅81 m,爆破作业可能会影响事故闸门的稳定运行。为此,以梅州抽水蓄能电站二期引水上平洞的爆破开挖为对象,开展了爆破空气超压现场监测工作,分析了爆破空气超压的分布规律及其对梅州抽水蓄能电站上库事故闸门的安全影响,为分析爆破空气超压对上库事故闸门的安全影响提供了支撑。现场的爆破空气超压监测数据表明:距离爆破掌子面约80 m的事故闸门前的空气超压水平分布在0.63~3.46 kPa,远小于建议的相应的爆破安全控制标准100 kPa;闸门前使用胶帘等防护设施可以有效减小闸门位置的空气超压,实测的第4次和第5次爆破空气超压减小了55%以上;单段装药量及总装药量得到有效控制时,实测的空气超压值远低于建议的控制标准;现场宏观调查及其他检测数据也未见异常,爆破施工未影响上库事故闸门的安全运行。

质量参数对空爆荷载梁构件振动位移的影响

为研究质量参数对空爆荷载梁构件振动位移的影响,以等效单自由度法为基本方法,理论推导了柔性及刚性2类梁构件含质量参数在弹性、塑性各阶段的振动位移解,选择矩形截面、圆截面为梁构件典型截面,设计并计算了质量参数在1.00~1.20范围内的13种典型工况。结果表明:对于空爆荷载柔性及刚性2类梁构件,增大其截面面积后,仅考虑质量参数计算振动位移时误差较大,应按质量参数及产生的附加刚度参数耦合效应分析;对于矩形截面梁构件,采用质量参数与刚度参数耦合计算时,其最大弹性位移、最大弹塑性位移和残余变形降低幅度分别约为仅采用质量参数计算结果的4.75、3.28和2.96倍;对于圆截面梁构件,则分别为3.57、2.56和2.32倍;该结论在柔性梁构件及刚性梁构件均适用且无明显差异。

基于Workbench的高炉送风装置直吹管有限元分析

文中针对高炉送风装置的直吹管进行了静力学分析和模态分析,研究其结构及振动特性。在静力学分析方面,利用有限元方法建立了直吹管的数值模型,并对其进行分析,以了解筒体的整体变形及等效应力情况。模态分析方面,提取了直吹管前20阶模态的固有频率,并对前6阶的振频、振型和振幅进行了详细分析。研究结果显示,直吹管的固有频率随阶数递增,符合无阻尼振动的特征。此外,前6阶模态的振型和振幅得到了全面解析。通过静力学分析和模态分析,深入了解了高炉送风装置直吹管在静力学和振动方面的特性,为进一步的结构设计和优化提供参考。

装药结构对硬质岩隧洞轮廓成型效果的影响研究

硬质岩隧洞的轮廓成型效果对提高围岩稳定性和降低支护成本具有重要意义。以优化隧洞轮廓孔单孔装药量和装药结构为目标,首先,理论分析了隧洞爆破中轮廓孔装药参数的取值范围;其次,分别以1200 g、900 g、750 g、600 g的单孔装药量进行了硬质岩隧洞爆破试验,并借助激光扫描仪对隧洞轮廓成型效果进行了扫描分析;最后,利用断裂力学模型分析了不同单孔装药量的隧洞轮廓成型效果。结果表明:当硬质岩隧洞的轮廓孔装药参数在合理范围内时,单孔装药量越小,爆破产生的孔间裂缝数量越少,岩体损伤范围也越小;当装药量由1200 g降低至600 g时,隧洞轮廓超挖体积由6.53 m^(3)降低至2.02 m^(3),但由孔位误差导致的轮廓欠挖体积由0.15 m^(3)增大0.26 m^(3);断裂力学模型在硬质岩隧洞轮廓爆破的模拟中优于损伤模型,模型计算得隧洞轮廓上的半孔数与观察值吻合较好。研究成果可为类似硬质岩隧洞爆破开挖中轮廓成型效果优化提供技术与方法借鉴。

唐钢2号高炉风温提升研究

对唐钢2号高炉进行热风炉制约条件的束缚及高炉操作制度的持续优化,并进行理论系统分析,采取调整烧炉参数、严格执行标准化操作等一系列提高风温的措施,使唐钢2号高炉风温水平得到显著提高,降低了生产成本。

Air-blast anti-fouling cleaning for aquatic optical sensors

In order to solve the problem of fouling of submerged optical instruments,an air-blast cleaning mechanism was integrated into an optical sensor used for measuring suspended sediment concentration(SSC)in natural waters.Laboratory experiments in a manually created fouling environment were conducted to observe the fouling process on sensor cases made of different materials,and to verify the effectiveness of air-blast cleaning in reducing fouling.Results indicated that sensors with an aluminum case experienced more serious bio-fouling than that with polyethylene case,and the air-blast cleaning mechanism was capable of reducing fouling effect on sensor signals.So the submerged optical instruments should avoid using metal materials.The duration and frequency of air-blast cleaning can be determined and adjusted depending on actual field conditions.

基于爆破针阀的火炬放空气回收系统泄压装置研究

火炬系统是海上石油平台用于处理生产过程中产生的可燃气的安全与环保设施,为达到节约能源、提高经济效益、减轻环境污染等目的,通常会采用各种技术和设备,对火炬系统的放空气进行有效的处理和回收,从而实现资源的高效利用。通过对火炬放空气回收系统的研究,分析了爆破针阀的技术原理和动作特性,提出了基于爆破针阀的泄压装置在火炬放空气回收系统中的应用方法,大幅提高了火炬系统泄压装置的稳定性。

高炉重矿渣水泥稳定基层混合料性能研究

利用包钢高炉重矿渣碎石粗集料和石灰岩细集料,设计制备了C-C-2级配水泥稳定基层混合料,进行了其强度及抗冻性能研究。结果表明,水泥(PO32.5)剂量为3%时,C-C-2重矿渣水泥稳定混合料的7 d无侧限抗压强度可以达到5.0 MPa以上。随着水泥剂量的增加,混合料的7 d无侧限抗压强度增大。水泥剂量为4%时,C-C-2重矿渣水泥稳定混合料的最大干密度最大,同时,对于提高重矿渣水泥稳定混合料的180 d抗压强度和抗冻性能效果显著。

钻爆法隧道洗尘消热与台车周边作业环境营造

台车周边施工作业人员面临的职业健康危害是钻爆法隧道施工中普遍存在的问题。基于此,提出了洞外压入送风协同洞内起拱点处空气品质营造装置局部空气净化的通风方案,并以广西天巴高速廷社隧道为试验隧道,对两种通风方式下隧道内台车周边的粉尘浓度、空气温度进行了监测和对比,利用FLUENT软件对游离SiO_(2)粉尘浓度场的演化进行了数值模拟。结果表明:在安设空气品质营造装置的条件下通风20 min后,台车处粉尘浓度高、水化热现象均得到了明显的缓解。研究结果对改善钻爆法施工隧道作业环境具有重要的指导意义。

喷嘴数量对顶燃式热风炉性能影响的数值模拟

燃烧器是热风炉的核心部件,而喷嘴的结构是决定其性能的关键因素之一。本文基于2 350 m~3高炉配置的顶燃式热风炉,构建一个融合湍流、燃烧和传热的热风炉三维数学模型,采用数值模拟方法研究喷嘴数量对热风炉性能的影响。研究结果表明,当燃烧器配置15个喷嘴时,可以有效提高热风炉燃烧和送风性能。相比于18个喷嘴的配置,采用15个喷嘴的热风炉蓄热量提高了35.76%,送风初始温度提高50.8 K,有效送风时间延长265 s。

热风炉空燃比并行协作粒子群滑模控制策略

针对热风炉燃烧控制存在的纯滞后、大惯性和强干扰等问题,提出了一种基于并行协作骨干粒子群(Parallel Cooperative Bare-Bones Particle Swarm Optimization,PCBBPSO)优化全局滑模控制(Global Sliding Mode Control,GSMC)的热风炉空燃比控制策略;为改善热风炉空燃比控制系统动态特性,引入全局滑模策略,对燃烧系统进行优化控制,以提高系统稳定性,同时,基于热风炉燃烧系统存在的强干扰特性,利用并行协作骨干粒子群对干扰补偿进行调节以减小其对系统的影响,并求取最优控制率;仿真结果表明:与普通粒子群优化全局滑模和普通粒子群优化PID相比,该控制方法达到稳定用时分别减少了26.4 s和9.3 s,能够保持没有超调量,拥有良好稳定的跟踪和抗干扰效果;将该控制策略应用于某钢铁有限公司2200 m 3高炉配套热风炉,工程数据表明:在该空燃比策略的控制下,热风炉空燃比上下波动幅度仅为8.20%,拥有波动小、稳定性好和抗干扰性强等特点,动态响应较好,能够满足热风炉工程实际应用的需要。

高炉开风口机的仿真优化

针对当前高炉炼铁工艺中采用人工对风口封泥进行凿开时存在的效率低、安全性低等问题,研究了一款适用于生产中的开风口机,该设计基于Simulink仿真软件构建了开风口机设备的简化模型,重点对不同主气道直径和活塞直径对开风口机性能的影响进行分析,得出了最佳尺寸,可进一步提高封泥凿开的效率和安全性。

冲渣水余热在高炉脱湿鼓风方面的应用

利用负压闪蒸技术获取高炉冲渣水余热,将提取出的负压蒸汽作为溴化锂制冷机动力源制取冷水,冷水进入高炉鼓风机前端脱湿器实现高炉鼓风脱湿。将高炉冲渣水余热提取负压蒸汽技术与乏汽型溴化锂制冷实现高炉鼓风脱湿技术结合使用,解决了冲渣水利用过程中因固体杂质的存在对设备堵塞等问题,也对设备、管线的设计、控制、维护提出了更高的要求。

两座210m高烟囱定向爆破拆除空中对碰技术研究

位于镇江市谏壁发电厂内的两座高210 m的烟囱需进行拆除,受周边环境和正常运行的两台100万机组的影响,振速不能过大。经分析论证,选择两座烟囱相对定向倒塌、空中相碰的方案是影响最小的最优方案,通过选择切口位置、精确定位倒塌方向、开设定向窗、多层次全方位防护等措施,结合对碰模拟分析结果以及现场测试数据等技术手段,最终两座烟囱在空中实现对碰,且周边保护目标安全无恙,此爆破方法为国内首例,对类似工程有一定的借鉴作用。