期刊文献+
共找到960篇文章
< 1 2 48 >
每页显示 20 50 100
Experimental study on secondary air mixing along the bed height in a circulating fluidized bed with a multitracer-gas method
1
作者 Qingyu Zhang Leming Cheng +3 位作者 Kun Li Qixun Kang Qiang Guo Chaogang Wu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第6期54-62,共9页
A multitracer-gas method was proposed to study the secondary air(SA)mixing along the bed height in a circulating fluidized bed(CFB)using carbon monoxide(CO),oxygen(O_(2)),and carbon dioxide(CO_(2))as tracer gases.Expe... A multitracer-gas method was proposed to study the secondary air(SA)mixing along the bed height in a circulating fluidized bed(CFB)using carbon monoxide(CO),oxygen(O_(2)),and carbon dioxide(CO_(2))as tracer gases.Experiments were carried out on a cold CFB test rig with a cross-section of 0.42 m×0.73 m and a height of 5.50 m.The effects of superficial velocity,SA ratio,bed inventory,and particle diameter on the SA mixing were investigated.The results indicate that there are some differences in the measurement results obtained using different tracer gases,wherein the deviation between CO and CO_(2) ranges from 42%to 66%and that between O_(2) and CO_(2) ranges from 45%to 71%in the lower part of the fluidized bed.However,these differences became less pronounced as the bed height increased.Besides,the high solid concentration and fine particle diameter in the CFB may weaken the difference.The measurement results of different tracer gases show the same trends under the variation of operating parameters.Increasing superficial velocity and SA ratio and decreasing particle diameter result in better mixing of the SA.The effect of bed inventory on SA mixing is not monotonic. 展开更多
关键词 Circulating fluidized bed secondary air injection Gas mixing Multitracer-gas method
下载PDF
Secondary electron yield of air-exposed ALD-Al_(2)O_(3) coating on Ag-plated aluminum alloy
2
作者 Xue-Man Wan Tian-Cun Hu +3 位作者 Jing Yang Na Zhang Yun He Wan-Zhao Cui 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第11期265-271,共7页
Secondary electron yield(SEY)of air-exposed metals tends to be increased because of air-formed oxide,hydrocarbon,and other contaminants.This enhances the possibility of secondary electron multipacting in high-power mi... Secondary electron yield(SEY)of air-exposed metals tends to be increased because of air-formed oxide,hydrocarbon,and other contaminants.This enhances the possibility of secondary electron multipacting in high-power microwave systems,resulting in undesirable occurrence of discharge damage.Al_(2)O_(3) coatings have been utilized as passive and protective layers on device packages to provide good environmental stability.We employed atomic layer deposition(ALD)to produce a series of uniform Al_(2)O_(3) coatings with appropriate thickness on Ag-plated aluminum alloy.The secondary electron emission characteristics and their variations during air exposure were observed.The escape depth of secondary electron needs to exceed the coating thickness to some extent in order to demonstrate SEY of metallic substrates.Based on experimental and calculated results,the maximum SEY of Ag-plated aluminum alloy had been maintained at 2.45 over 90 days of exposure without obvious degradation by applying 1 nm Al_(2)O_(3) coatings.In comparison,the peak SEY of untreated Ag-plated aluminum alloy grew from an initial 2.33 to 2.53,exceeding that of the 1 nm Al_(2)O_(3) sample.The ultra-thin ALDAl_(2)O_(3) coating substantially enhanced the SEY stability of metal materials,with good implications for the environmental dependability of spacecraft microwave components. 展开更多
关键词 secondary electron yield(SEY) atomic layer deposition air exposure MULTIPACTOR
下载PDF
Efficacy of graphene nanocomposites for air disinfection in dental clinics: A randomized controlled study
3
作者 Ya-Qiong Ju Xiang-Hua Yu +3 位作者 Jing Wu Ying-Hui Hu Xiang-Yong Han Dan Fang 《World Journal of Clinical Cases》 SCIE 2024年第28期6173-6179,共7页
BACKGROUND Aerosols containing disease-causing microorganisms are produced during oral diagnosis and treatment can cause secondary contamination.AIM To investigate the use of graphene material for air disinfection in ... BACKGROUND Aerosols containing disease-causing microorganisms are produced during oral diagnosis and treatment can cause secondary contamination.AIM To investigate the use of graphene material for air disinfection in dental clinics by leveraging its adsorption and antibacterial properties.METHODS Patients who received ultrasonic cleaning at our hospital from April 2023 to April 2024.They were randomly assigned to three groups(n=20 each):Graphene nanocomposite material suction group(Group A),ordinary filter suction group(Group B),and no air suction device group(Group C).The air quality and air colony count in the clinic rooms were assessed before,during,and after the procedure.Additionally,bacterial colony counts were obtained from the air outlets of the suction devices and the filter screens in Groups A and B.RESULTS Before ultrasonic cleaning,no significant differences in air quality PM2.5 and colony counts were observed among the three groups.However,significant differences in air quality PM2.5 and colony counts were noted among the three groups during ultrasonic cleaning and after ultrasonic treatment.Additionally,the number of colonies on the exhaust port of the suction device and the surface of the filter were significantly lower in Group A than in Group B(P=0.000 and P=0.000,respectively).CONCLUSION Graphene nanocomposites can effectively sterilize the air in dental clinics by exerting their antimicrobial effects and may be used to reduce secondary pollution. 展开更多
关键词 GRAPHENE NANOCOMPOSITES Oral clinic air disinfection secondary contamination
下载PDF
Modeling and Simulation Study on Reverse Swirl of Secondary Air in Large Tangentially Fired Boiler
4
作者 李彦鹏 张强 +1 位作者 顾璠 徐益谦 《Journal of Southeast University(English Edition)》 EI CAS 2000年第2期87-94,共8页
Based on the porosity method and the improved non uniform QUICK scheme, this paper describes a three dimensional computer simulation to predict the flow characteristics in a tangentially fired boiler. The model is ap... Based on the porosity method and the improved non uniform QUICK scheme, this paper describes a three dimensional computer simulation to predict the flow characteristics in a tangentially fired boiler. The model is applied to a 600?MW boiler modeling under different operating conditions of reverse swirl of secondary air. The numerical results achieve reasonable agreement with experimental data. The calculated results of flow field, the pressure distribution, the relative diameter of tangential circle, angular momentum flux in furnace and the velocity distribution index in horizontal gas pass are analyzed in detail. And then the effects of the reverse swirl of secondary air on flue gas imbalance are discussed. Finally a reasonable operating condition of the reverse swirl of secondary air is presented. 展开更多
关键词 tangentially fired boiler flue gas imbalance reverse swirl of secondary air numerical simulation
下载PDF
Effect of the secondary air distribution layer on separation density in a dense-phase gas–solid fluidized bed 被引量:3
5
作者 Lv Bo Luo Zhenfu +3 位作者 Zhang Bo Zhao Yuemin Zhou Chenyang Yuan Wenchao 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2015年第6期969-973,共5页
Dry coal separation has been the most significant process in the field of coal beneficiation to date, because of its special advantage of operation with no water consumption. Mineral dry separation research has receiv... Dry coal separation has been the most significant process in the field of coal beneficiation to date, because of its special advantage of operation with no water consumption. Mineral dry separation research has received wide attention, particularly in countries and regions experiencing drought and water shortages. During the process of dense coal gas-solid fluidized bed beneficiation, the material is stratified according to its density; the high density material layer remains at the bed bottom, and thus the high density coarse particle bed becomes an important infuencing factor in fluidized bed stability. In the steady fluidization stage, a small number of large radius bubbles are the direct cause of unsteady fluidization in the tradi- tional fluidized bed. The dispersion effect of the secondary air distribution bed for air flow is mainly apparent in the gas region; when the particle size exceeds 13 mm, the secondary air distribution bed has a synergistic effect on the density stability of the upper fluidized layer. When the particle size is small, especially when less than 6 ram, particles will constantly move, accounting for instability of the secondary air distribution bed and distorting the stability of the upper fluidized bed. Under optimum operation conditions, the probable deviation E of gas-solid separation fluidized with a high density coarse particle layer can be as low as 0.085 g/cm3. 展开更多
关键词 secondary air distribution layerDry coal separationGas-solid fluidized bedParticle size
下载PDF
Simulation on Soot Emission Control in Stoker-Fired Boiler by Secondary Air
6
作者 Qingcheng Wang 《Journal of Environmental Science and Engineering(A)》 2012年第1期46-48,共3页
A work on soot emission control simulation in stoker-fired boiler by secondary air has been done. Some models such as k-e, combustion, radiation, and soot Khan-Greeves have been adopted. Soot production and emission h... A work on soot emission control simulation in stoker-fired boiler by secondary air has been done. Some models such as k-e, combustion, radiation, and soot Khan-Greeves have been adopted. Soot production and emission has been reduced by secondary air; the highest mass concentration is reduced from 7.46 × 10^-14 to 6.94 × 10^15; mass concentration of soot is decreased from 1.12 ×10^-15 to 9.25 ×10^-32 in the upper areas. 展开更多
关键词 SOOT stoker-fired boiler secondary air simulation.
下载PDF
基于改进的粒子群优化算法的暖通空调制冷机房BIM自动优化布置方法
7
作者 梁若冰 梁浩然 马宏博 《暖通空调》 2024年第11期52-59,共8页
采用结合Revit API和MATLAB的编程模式,对Revit平台进行了有效的二次开发,从而实现了暖通空调制冷机房设备的自动化布置设计,不仅有效地实现了设备布置方案的自动生成,还支持了布置方案的预览与验证,显著提高了设计效率和准确性。该研... 采用结合Revit API和MATLAB的编程模式,对Revit平台进行了有效的二次开发,从而实现了暖通空调制冷机房设备的自动化布置设计,不仅有效地实现了设备布置方案的自动生成,还支持了布置方案的预览与验证,显著提高了设计效率和准确性。该研究的创新之处在于成功将粒子群优化算法与BIM技术相结合,为暖通空调系统的自动化设计提供了新的视角,并验证了BIM在暖通空调领域正向设计中的应用潜力。 展开更多
关键词 BIM正向设计 暖通空调 制冷机房 粒子群优化算法 自动化 二次开发
下载PDF
核爆炸早中期电磁脉冲产生的数值模拟方法
8
作者 王建国 《电波科学学报》 CSCD 北大核心 2024年第5期787-796,共10页
由于核电磁脉冲(nuclear electromagnetic pulse,NEMP)电场与爆炸当量、爆高、方位角、大气参数和观测位置等密切相关,NEMP产生的数值模拟是非常复杂的问题。本文评述了核爆炸电磁脉冲产生过程的数值模拟方法,包括NEMP产生的物理模型、... 由于核电磁脉冲(nuclear electromagnetic pulse,NEMP)电场与爆炸当量、爆高、方位角、大气参数和观测位置等密切相关,NEMP产生的数值模拟是非常复杂的问题。本文评述了核爆炸电磁脉冲产生过程的数值模拟方法,包括NEMP产生的物理模型、γ射线和中子在大气中输运及康普顿电流源、大气电导率模型和电磁场求解方法;给出了NEMP的典型数值模拟结果,主要包括早期电磁脉冲和中期电磁脉冲联合模拟结果,并分析了早期电磁脉冲和中期电磁脉冲峰值、起止时间和频谱等特征参数。 展开更多
关键词 核电磁脉冲(NEMP) 中子次级γ射线 大气电导率 早期电磁脉冲 中期电磁脉冲
下载PDF
空调二次泵系统在地铁车站中的应用
9
作者 杨礼桢 《制冷》 2024年第1期22-26,共5页
杭州地铁机场轨道快线工程杭州西站为地铁四线换乘车站,地铁车站体量大、空调系统末端多、运营要求高。针对本工程特点,经过比较分析水系统采用二次泵变流量系统,根据不同区域负荷特点和运营需求进行分区划分,可有效的降低空调水系统输... 杭州地铁机场轨道快线工程杭州西站为地铁四线换乘车站,地铁车站体量大、空调系统末端多、运营要求高。针对本工程特点,经过比较分析水系统采用二次泵变流量系统,根据不同区域负荷特点和运营需求进行分区划分,可有效的降低空调水系统输送能耗,为运营后的稳定运行和场所管理创造了了良好条件。同时,文中给出了二次泵系统分区划分、设备选型及运行控制方案,并对选用条件进行了验证,可为类似工程提供参考。 展开更多
关键词 地铁车站 空调水系统 二次泵
下载PDF
低负荷下CFB锅炉二次风优化对NO_(x)排放影响的数值模拟 被引量:2
10
作者 侯跃华 刘海玉 +4 位作者 申欣 康红红 谢玉婷 金燕 吴杨 《中国电机工程学报》 EI CSCD 北大核心 2024年第9期3588-3597,I0021,共11页
为控制循环流化床(circulating fluidized bed,CFB)锅炉低负荷下NO_(x)的原始排放,以某350 MW超临界CFB锅炉为研究对象,基于计算颗粒流体力学(computational particle fluid dynamics,CPFD)方法对40%负荷下燃烧过程进行数值模拟。分析... 为控制循环流化床(circulating fluidized bed,CFB)锅炉低负荷下NO_(x)的原始排放,以某350 MW超临界CFB锅炉为研究对象,基于计算颗粒流体力学(computational particle fluid dynamics,CPFD)方法对40%负荷下燃烧过程进行数值模拟。分析了不同二次风角度、新增二次风量对NO_(x)排放的影响。结果表明:随着射流角度的减小,炉膛出口NO浓度逐渐降低,CO浓度无明显增加。部分二次风上移后炉膛密相区氧浓度降低,不完全燃烧增加,还原性氛围增强,抑制了NO的生成。当新增风量从10%增加到30%时,NO排放浓度降低了17.2%。但随着比例的进一步提高,炉膛密相区的缺氧环境造成燃烧效率下降,温度大幅降低。因此,在不影响燃烧的前提下可以通过提高新增二次风比例来降低NO的原始排放浓度。 展开更多
关键词 循环流化床 计算颗粒流体力学 低负荷 二次风分级 氮氧化物
下载PDF
黄河三角洲地区大气复合污染特征、成因与VOCs来源解析 被引量:3
11
作者 宁倩 贺美 +8 位作者 纪元元 尹浩 李吉东 尚凡一 张珂 杨勇建 李红 高锐 庄思源 《环境科学研究》 CAS CSCD 北大核心 2024年第3期439-454,共16页
为了解黄河三角洲区域细颗粒物(PM_(2.5))和臭氧(O_(3))大气复合污染特征和成因,本文利用2021年和2022年夏秋季黄河三角洲中心城市东营市、滨州市的挥发性有机物(VOCs)连续观测数据及常规污染物数据,识别对O_(3)和二次有机气溶胶(SOA)... 为了解黄河三角洲区域细颗粒物(PM_(2.5))和臭氧(O_(3))大气复合污染特征和成因,本文利用2021年和2022年夏秋季黄河三角洲中心城市东营市、滨州市的挥发性有机物(VOCs)连续观测数据及常规污染物数据,识别对O_(3)和二次有机气溶胶(SOA)生成有显著贡献的VOCs物种并对VOCs进行来源解析,同时利用基于观测的化学盒子模型探讨O_(3)的生成敏感性.结果表明:①黄河三角洲地区PM_(2.5)和O_(3)浓度“双高”的大气复合污染主要出现在秋季,夏季东营市和滨州市首要污染物均为O_(3),距离入海口越远的站点O_(3)超标天占比越高;秋季东营市和滨州市首要污染物均为PM_(2.5),且超标情况相近.②烯烃和含氧挥发性有机物(OVOCs)对臭氧生成潜势(OFP)的贡献大,优势物种为乙醛;芳香烃对SOA生成潜势(SOAFP)的贡献大,优势物种为1,2,3-三甲苯.③东营市夏秋季O_(3)生成均处于VOCs和NO_(x)协同控制区,且夏季O_(3)对NO_(x)更为敏感;滨州市夏秋季O_(3)生成分别处于VOCs和NO_(x)协同控制区、VOCs控制区,且夏季O_(3)对NO_(x)敏感性更高,秋季对VOCs敏感.④油气挥发源、工业排放源和机动车尾气排放源为该区域VOCs的主要来源,且VOCs来源解析结果存在空间上和季节上的差异.夏季,区域溶剂源和生物源VOCs的贡献率增加,东营市溶剂源贡献率(28.2%)明显高于滨州市(6%),机动车尾气排放源贡献率(11.5%)低于滨州市(29.6%);秋季,区域燃烧源和生物质燃烧源贡献率增加,东营市(25.9%)油气挥发源贡献率明显低于滨州市(42.4%).研究显示,黄河三角洲地区夏季应实施VOCs和NO_(x)的协同减排,秋季应优先控制VOCs排放;其次需要加强对油气挥发源、工业排放源和机动车尾气源VOCs的管控. 展开更多
关键词 黄河三角洲 大气复合污染 臭氧生成潜势 二次有机气溶胶(SOA)生成潜势 来源解析
下载PDF
燃煤锅炉燃烧利用矿井乏风甲烷改造经济性及运行影响分析
12
作者 郭前鑫 魏琳 +5 位作者 王虎 谢国威 何超 王志超 刘超 赵勇纲 《现代化工》 CAS CSCD 北大核心 2024年第10期208-213,共6页
为处理矿井大流量乏风中的超低浓度甲烷,拟采用将乏风作为锅炉二次风进行处理利用。对此类工程改造的锅炉引风、投资运行成本、项目改造收益、锅炉效率影响进行了分析。结果表明,矿井乏风甲烷利用工程改造减小了原来锅炉烟气的产生量,... 为处理矿井大流量乏风中的超低浓度甲烷,拟采用将乏风作为锅炉二次风进行处理利用。对此类工程改造的锅炉引风、投资运行成本、项目改造收益、锅炉效率影响进行了分析。结果表明,矿井乏风甲烷利用工程改造减小了原来锅炉烟气的产生量,且烟气量改变很小,无需对锅炉侧进行改造。管道及保温材料的采购与安装是此类改造工程的主要投资部分。该类项目的主要收益为乏风处理的碳汇补贴收益。乏风流速越低,工程投资成本变高,但运行成本变低,有助于项目的长周期盈利。绘制了不同输运长度下乏风总量与瓦斯绝对涌出量的20年期盈利平衡曲线。提出了优化矿井侧及二次风侧的乏风输送系统,并对乏风温度、湿度等因素对锅炉效率的影响进行了分析。对矿井乏风利用项目的立项及可行性分析提供了指导。 展开更多
关键词 乏风甲烷 二次风 工程投资 经济性 锅炉效率
下载PDF
基于气体-飞灰流动特性的二次风系统结构优化
13
作者 荣俊 袁东辉 +3 位作者 张维蔚 杨光 王研凯 韩义 《洁净煤技术》 CAS CSCD 北大核心 2024年第S01期210-218,共9页
为降低低负荷下煤粉锅炉二次风系统风机耗电率、减少随二次风进入炉膛的飞灰对喷嘴附近水冷壁的磨损,以350 MW超临界四角切圆燃烧煤粉锅炉二次风系统为研究对象,采用数值模拟方法计算并分析了气体和飞灰流动特性,在此基础上对二次风系... 为降低低负荷下煤粉锅炉二次风系统风机耗电率、减少随二次风进入炉膛的飞灰对喷嘴附近水冷壁的磨损,以350 MW超临界四角切圆燃烧煤粉锅炉二次风系统为研究对象,采用数值模拟方法计算并分析了气体和飞灰流动特性,在此基础上对二次风系统结构进行优化。计算结果表明,原始结构时,同一角沿高度各燃烧器喷嘴的二次风量分配与配风方式有关,同一层4个角的风量分配基本相同;飞灰进入大风箱后,易在底部沉积,AA层辅助风速度最高、携带的飞灰浓度最大。结构优化后,可有效消除总风管内二次风的旋转趋势,减弱大风箱底部的气流旋涡,使进入各燃烧器喷嘴的飞灰浓度更均匀,降低喷嘴附近水冷壁的磨损风险。结构优化前后,二次风系统进出口压差最大可降低89.5 Pa。 展开更多
关键词 二次风系统 结构优化 二次风 飞灰颗粒 流动特性
下载PDF
基于欧拉-拉格朗日方法的流化床配风比例对炉膛磨损的数值模拟研究
14
作者 崔续桐 朱健 +2 位作者 赵博 刘晨 王林 《节能技术》 CAS 2024年第5期401-405,共5页
循环流化床锅炉作为一种高效清洁煤燃烧技术已被广泛使用。为了探明因磨损而导致的流化床异常停机、泄漏等问题,本文基于欧拉-拉格朗日离散方法对冷态下的气固循环流化床炉膛内气固两相流动进行数值模拟计算,通过对比三种不同一、二次... 循环流化床锅炉作为一种高效清洁煤燃烧技术已被广泛使用。为了探明因磨损而导致的流化床异常停机、泄漏等问题,本文基于欧拉-拉格朗日离散方法对冷态下的气固循环流化床炉膛内气固两相流动进行数值模拟计算,通过对比三种不同一、二次风比例下的炉膛水冷壁磨损情况、颗粒堆积情况以及壁面剪切应力的波动性,发现较大的配风比例会导致流化床炉膛的整体磨损量减小,壁面剪切应力波动性减小,主要原因是合理地提高一次风量可以提高锅炉燃烧效率,使炉膛内颗粒燃烧更完全,减少了煤料颗粒在炉膛内停留堆积的数量,颗粒分布更均匀,从而减少了炉膛内颗粒碰撞冲蚀磨损的发生。 展开更多
关键词 循环流化床 一、二次风 锅炉炉膛 磨损
下载PDF
二次风倾斜角度对高温预热燃料贫氧燃烧火焰特性影响试验
15
作者 方能 卢玉 +3 位作者 张博文 梁晨 李伟 任强强 《洁净煤技术》 CAS CSCD 北大核心 2024年第S01期191-197,共7页
预热燃烧是气化飞灰资源化处置的有效途径,通常搭配主燃室空气分级以协同实现高效清洁燃烧,因此,研究高温预热燃料的贫氧燃烧火焰特性非常有必要。搭建了250 kW高温预热燃料火焰特性试验平台,通过高温火焰可视化监测及其图像编程处理,... 预热燃烧是气化飞灰资源化处置的有效途径,通常搭配主燃室空气分级以协同实现高效清洁燃烧,因此,研究高温预热燃料的贫氧燃烧火焰特性非常有必要。搭建了250 kW高温预热燃料火焰特性试验平台,通过高温火焰可视化监测及其图像编程处理,研究了主燃室二次风倾斜角度对气化飞灰预热燃烧的贫氧火焰特性的影响规律。试验表明,随着二次风倾斜角度从30°增大到60°,贫氧燃烧火焰逐渐远离热烧嘴出口,脱火距离无量纲值从1.04增大到3.73,火焰宽度无量纲值则从4.09逐渐减小至3.47。当主燃室二次风倾斜角度为30°和45°时,燃烧系统的碳转化率分别为71.6%和70.3%。综合考虑二次风倾斜角度对热烧嘴运行稳定和气化飞灰燃尽的影响,主燃室二次风倾斜角度的优选值为45°。 展开更多
关键词 气化飞灰 预热燃烧 贫氧燃烧 二次风倾斜角 火焰特性
下载PDF
耦合空气系统的燃气轮机拓扑自构建建模方法
16
作者 郑培英 周泽均 +2 位作者 钟易成 董威 刘家兴 《航空发动机》 北大核心 2024年第3期33-39,共7页
为了实现通用性强、可扩展性好、灵活高效的整机性能模型通用建模,提出了一种拓扑自构建的燃气轮机整机性能通用建模方法。基于面向对象思想,采用模块化技术构建通用部件库,再通过拓扑接口关联部件组成整机模型,建立了适用于不同燃气轮... 为了实现通用性强、可扩展性好、灵活高效的整机性能模型通用建模,提出了一种拓扑自构建的燃气轮机整机性能通用建模方法。基于面向对象思想,采用模块化技术构建通用部件库,再通过拓扑接口关联部件组成整机模型,建立了适用于不同燃气轮机类型的整机性能仿真模型。耦合了多支路复杂空气系统迭代求解模型,将其作为部件嵌入整机模型,以取代现有的定比例引气量计算方法。采用跨平台图形开发框架及图像可视化技术,开发了人机交互友好的整机性能预测平台。采用典型双轴燃气轮机算例,与试验结果进行了对比验证。结果表明:对于动力涡轮出口温度,采用恒定引气比方式和当前耦合方法的计算结果与试验结果对比得到的最大误差分别为3.36%和1.31%;对于出口压力的计算在多数工况下的计算精度也有所提高。提出的拓扑自构建的燃气轮机整机性能通用建模方法实现了部件自由搭建及整机拓扑自构建,且耦合空气系统后,整机性能仿真精度显著提高。 展开更多
关键词 拓扑自构建 空气系统 整机性能模型 燃气轮机
下载PDF
Effects of Interaction between Axial and Radial Secondary Air and Reductive Intensity in Reduction Region on Combustion Characteristics and NO_(x) Emission of Coal Preheated by a Self-Preheating Burner
17
作者 SU Kun DING Hongliang +2 位作者 OUYANG Ziqu ZHANG Jinyang ZHU Shujun 《Journal of Thermal Science》 SCIE EI CSCD 2024年第1期249-267,共19页
The study focused on the effects of the interaction between axial and radial secondary air and the reductive intensity in reduction region on combustion characteristics and NO_(x) emission in a 30 kW preheating combus... The study focused on the effects of the interaction between axial and radial secondary air and the reductive intensity in reduction region on combustion characteristics and NO_(x) emission in a 30 kW preheating combustion system.The results revealed that the interaction and reductive intensity influenced the combustion in the down-fired combustor(DFC) and NO_(x) emission greatly.For the temperature distribution,the interaction caused the position of the main combustion region to shift down as R_(2-12)(ratio of axial secondary air flow to radial secondary air flow) decreased or λ_(2)(total secondary air ratio) increased,and there was the interplay between both of their effects.As R_(3-12)(ratio of first-staged tertiary air flow to second-staged tertiary air flow)increased,the decrease in the reductive intensity also caused the above phenomenon,and the peak temperature increased in this region.For the NO_(x) emission,the interaction affected the NO_(x) reduction adversely when λ_(2) or R_(2-12) was higher,and the range of this effect was larger,so that the NO_x emission increased obviously as they increased.The decrease in the reductive intensity caused the NO_(x) emission increased under the homogeneous reduction mechanism,while was unchanged at a high level under the heterogeneous reduction mechanism.For the combustion efficiency,the interaction improved the combustion efficiency as λ_(2) increased when R_(2-12) was lower,while reduced it as λ_(2) increased excessively when R_(2-12) was higher.The proper decrease in the reductive intensity caused the combustion efficiency increased obviously,while was hardly improved further when the intensity decreased excessively.In this study,the lowest NO_(x) emission was only 41.75 mg/m^(3) without sacrificing the combustion efficiency by optimizing the interaction and reductive intensity. 展开更多
关键词 self-preheating interaction of axial and radial secondary air reductive intensity combustion characteristic NO_(x)emission
原文传递
基于Flowmaster的小流量供水设备调节性能模拟
18
作者 陈佳中 王彤 +5 位作者 尚渝钧 曹仙桃 尚鑫宇 宋佳奇 王文成 郭小宝 《水电能源科学》 北大核心 2024年第7期151-154,141,共5页
现有的二次供水研究对小流量工况关注较少,小流量工况下主泵低效运行、频繁启停问题正成为制约城市供水“最后一公里”低能耗、高质量发展的痛点。为此,建立Flowmaster仿真模型对“工频辅泵+气压罐”小流量供水模式进行模拟,探究了需求... 现有的二次供水研究对小流量工况关注较少,小流量工况下主泵低效运行、频繁启停问题正成为制约城市供水“最后一公里”低能耗、高质量发展的痛点。为此,建立Flowmaster仿真模型对“工频辅泵+气压罐”小流量供水模式进行模拟,探究了需求侧不同小流量下气压罐的调节性能。结果表明,“工频辅泵+气压罐”可很好减少水泵启停次数,保持系统稳定。进一步研究了气压罐预充压力对调节性能的影响,阐明了预充气泄漏带来的负面影响,并提出相关工程建议。 展开更多
关键词 Flowmaster 小流量 工频辅泵+气压罐 调节性能 二次供水
下载PDF
某700t/d垃圾焚烧炉二次风配风优化数值模拟
19
作者 崔二光 解铮 +3 位作者 陈国喜 徐楠 胡源 刘军 《工业加热》 CAS 2024年第9期22-27,32,共7页
为揭示垃圾焚烧炉二次风配风对炉内垃圾燃烧过程的影响规律,针对郑州市某日处理量700 t/d的垃圾焚烧炉-余热锅炉,采用计算流体力学软件Fluent和FLIC耦合的方法,研究了不同二次风布置形式和配风风速下的炉内垃圾燃烧特性,分别计算了九种... 为揭示垃圾焚烧炉二次风配风对炉内垃圾燃烧过程的影响规律,针对郑州市某日处理量700 t/d的垃圾焚烧炉-余热锅炉,采用计算流体力学软件Fluent和FLIC耦合的方法,研究了不同二次风布置形式和配风风速下的炉内垃圾燃烧特性,分别计算了九种工况下的炉内温度场以及各气体的质量分数分布。结果表明:各工况湍动能最大的区域主要集中在焚烧炉喉部;在增大上二次风风速情况下,炉膛火焰均偏向右侧水冷壁,易造成右侧水冷壁腐蚀;在增大下二次风风速情况下,炉膛温度分布均匀,火焰贴壁现象得到缓解;在二次风平行布置且增大上二次风风速情况下,炉膛出口NO平均浓度最低,为328.84 mg/m^(3)。 展开更多
关键词 配风优化 垃圾焚烧 二次风 数值模拟
下载PDF
武汉某研发生产项目空调系统设计与分析
20
作者 唐瑞 徐鸿 严阵 《暖通空调》 2024年第9期45-50,共6页
介绍了武汉市某研发生产项目空调系统设计,舒适性空调采用冰蓄冷技术,冷水机组位于蓄冰装置上游,输配水系统为变流量二级泵系统,二级泵分环路设置。数据中心采用水侧自然冷却技术,配置闭式蓄冷罐作为应急冷源,输配水系统为变流量一级泵... 介绍了武汉市某研发生产项目空调系统设计,舒适性空调采用冰蓄冷技术,冷水机组位于蓄冰装置上游,输配水系统为变流量二级泵系统,二级泵分环路设置。数据中心采用水侧自然冷却技术,配置闭式蓄冷罐作为应急冷源,输配水系统为变流量一级泵系统。空调末端划分内外区,采用变风量空调系统,内外区合用1套热回收型新风机组。室外空气湿球温度低于5℃时,开启冷却塔+板式换热器免费供冷,降低系统运行费用。 展开更多
关键词 数据中心 空调系统 舒适性空调 冰蓄冷 变风量 热回收型新风机组 二级泵
下载PDF
上一页 1 2 48 下一页 到第
使用帮助 返回顶部