oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Numerical simulation of performance of chevron mist eliminator in wet-FGD
湿法烟气脱硫系统中折板式除雾器性能的数值模拟

Chen Kaihu,Song Cunyi,Li Qiang,Liu Feng,
陈凯华
,宋存义,李强,刘枫

环境工程学报 , 2007,
Abstract: A CFD software was used to simulate the characteristics of flow fields and performance of chevron mist eliminator in wet-FGD. A mathematical model was established for simulating the separation efficiency and pressure drop of the mist eliminator. The N-S equations are closed with SST equations and DPM, which is based on Euler-Lagrange method. By calculating the separation efficiency and pressure drop of various mist eliminators with different structural parameters and working parameters, their effects on efficiency and press drop have been analyzed. The results can be used for designing and optimizing mist eliminator in wet-FGD.
折板式汽液分离元件的性能  [PDF]
张晓晨,张铭,阮国岭,胡孔诚
过程工程学报 , 2012,
Abstract: 采用空气-水体系,对折板式汽液分离元件进行冷态模拟实验,研究了气速、液滴粒径、折板形式、间距及安装方式等参数对折板分离效率和压降的影响.结果表明,气速控制在1~6m/s,液滴粒径控制在50~80mm,折板采用立式和卧式安装,形式采用V形和W形,间距为10~50mm,对分离性能均有一定的影响,折板间距为20mm的分离元件具有较高的分离效率.通过对冷态实验数据进行数学回归分析,获得描述折板性能的经验公式,与实验值误差在10%内,同时在海水淡化中试试验装置中验证了折板式汽液分离元件的分离性能.
带肋U型通道中的汽雾/空气流动与换热数值研究
Numerical Investigation for Flow and Heat Transfer Characteristics of Air/Mist Coolant in Ribbed Two??Pass Channel
 [PDF]

张峰,王新军,李军
- , 2015, DOI: 10.7652/xjtuxb201509010
Abstract: 采用SST湍流模型对静止带肋U型通道中的汽雾/空气流动与换热特性进行了数值研究,分析了不同汽雾初始直径和初始质量浓度对汽雾/空气冷却性能的影响,比较了汽雾/空气、空气和蒸汽3种冷却工质的换热性能。研究表明:汽雾初始直径越大,汽雾流动距离越大,并存在一个最佳的初始直径;汽雾质量浓度增加,汽雾流动距离增大,汽雾的换热效果、阻力损失和热力性能因子增大;在雷诺数为40 000时,汽雾/空气的通道平均努塞尔数因子相对于蒸汽和空气分别增加了8.6%和25.39%,热力性能因子分别增加了6.58%和23.47%。
The flow and heat transfer characteristics of air/mist coolant in non??rotating ribbed two??pass rectangular channel were numerically investigated with SST turbulence model. The effect of mist initial diameter and mist initial mass concentration on the mist/air cooling parameters was analyzed. Three kinds of coolants, mist/air, air and steam, were comparatively discussed for the heat transfer performance. The results show that the mist flow distance increases with increasing mist initial diameter and there exists an optimum mist diameter; the mist flow distance, the averaged channel Nusselt number, the flow resistance and the thermal performance factor increase with the mist initial mass concentration. For the case of Re=40 000, the averaged channel Nusselt number of mist/air increases by 8.6% and 25.39% compared with steam and air respectively, and that of the thermal performance factor increases by 6.58% and 23.47%
燃机透平静叶尾缘柱肋通道内的汽雾/空气 冷却流动与换热特性数值研究
Numerical Investigation for Flow and Heat Transfer Characteristics of Air and Air/Mist Cooling in Gas Turbine Stator Trail Edge Path
 [PDF]

周子杰,王新军,费昕阳
- , 2016, DOI: 10.7652/xjtuxb201611004
Abstract: 基于通过提高燃气进口温度来提升燃气轮机热效率和增加出力的思想,采用ANSYS-CFX商用软件对模化的燃气轮机透平静叶尾缘楔形柱肋冷却通道中流动与换热特性进行了数值模拟,对比研究了冷却工质为空气和汽雾/空气时的冷却性能,以及不同的雷诺数和雾滴初始直径下雾滴在流动过程中的分布、努塞尔数、摩擦系数以及热力综合效率的变化情况。研究表明:雾滴初始直径越大、雷诺数越大,雾滴的流动距离越长;相同雷诺数条件下,相对于空气冷却,加入不同初始直径的雾滴可提高通道底面平均努塞尔数,换热效果强化越明显;底面平均努塞尔数的增幅与雷诺数和雾滴初始直径有关,为了达到最佳冷却效果,应考虑雾滴蒸发吸热和扰流两方面的影响;在冷却空气中加入雾滴后流动摩擦系数变化较小,综合考虑换热性能与流动阻力,加入汽雾可使热力综合效率最高提高26%。该结果可为燃机设计提供参考。
Increasing the turbine inlet temperature is a feasible method to improve the cycle thermal efficiency and power output of a gas turbine. The heat transfer and flow characteristics of air and air/mist cooling in the trail edge path of a gas turbine stator are numerically investigated with ANSYS??CFX. The simulations for different working fluids (air and air/mist) are carried out to find their cooling performance difference. The changes of mist distribution, Nusselt number, flow friction factor and thermodynamic efficiency are analyzed in the cases of different Reynolds number and different initial diameter of mist. The results show that the mist flow distance goes up when Reynolds number and mist initial diameter increase. At the same Reynolds number, the bottom averaged Nusselt number increases when spraying mist with different initial diameter into cooling air. The enhancement of the bottom averaged Nusselt number is related to Reynolds number and the initial mist diameter. To reach the highest cooling performance, the evaporating and disturbance effects of mist ought to be taken into consideration. Spraying mist into cooling air slightly affects the friction factor, but the increase of thermodynamic efficiency can reach up to 26% considering both heat transfer and flow friction
Experimental Study in a Spray Filled Tower for Flow Visualization and Drift Eliminators Characteristics  [PDF]
A.K.M. Mohiuddin
Journal of Applied Sciences , 2005,
Abstract: This study demonstrates the result of an experiment in a spray filled forced draft cooling tower. Air distribution at some specific points within the tower was investigated. The pressure drop and drift loss characteristics of cellular type drift eliminators and those made of wood and cement-asbestos were also experimentally investigated. The experiments were conducted with one, two and three stages of cellular type drift eliminators and that for wooden and cement-asbestos drift eliminators with two and three stages only with various orientation angle, θ of the eliminator plates. The results showed that the pressure drop and drift loss were strong functions of number of stages, n and air flow rate. In case of wooden and cement-asbestos drift eliminators, pressure drop and drift loss were strongly dependent on θ as well. For various flow rates of the air, the flow patterns inside the tower were found similar. The study establishes the superiority of the cellular type drift eliminators over the others.
Results of cooling of dies with water mist  [PDF]
S. Pietrowski,R. W?adysiak
Journal of Achievements in Materials and Manufacturing Engineering , 2007,
Abstract: Purpose: Intensification of die casting of car silumins wheels with use of the water mist instead of compressed air dies cooling in low pressure casting process were presented in the paper.Design/methodology/approach: Examinations of casting process parameters were carried out on the industrial workstation of casting car wheels under the low pressure and also with Magma computer simulating system.Findings: The temperature and the range of its variation were presented in characteristic points of the casting and the cooled die with use the compressed air and with the water mist. A scheme of the device for generating the water mist cooling the die and also the pictures of simulation of wheels casting process for researched cooling methods was given.Research limitations/implications: The manufacturing technologies with the permanent mould.Practical implications: Using the water mist to cooling of dies in die casting and low pressure casting process to intensify of cooling the die and to reduce the amount of casting spoilage.Originality/value: Using the water mist to cooling increases intensity of cooling of the die and the cast. It makes shorter the cycle of casting process as well as reduces the porosity of casts and increases mechanical properties: Rp0,2, Rm, A5 and HB.
Design and performance of chromium mist generator
Tirgar, Aram;Golbabaei, Farideh;Nourijelyani, Keramat;Shahtaheri, Seyed Jamaleddin;Ganjali, Mohammad Reza;Hamedi, Javad;
Journal of the Brazilian Chemical Society , 2006, DOI: 10.1590/S0103-50532006000200018
Abstract: chromium mist generator is an essential tool for conducting researches and making science-based recommendations to evaluate air pollution and its control systems. the purpose of this research was to design and construct a homogenous chromium mist generator and the study of some effective factors including sampling height and distances between samplers in side-by-side sampling on chromium mist sampling method. a mist generator was constructed, using a chromium electroplating bath in pilot scale. concentration of cro3 and sulfuric acid in plating solution was 125 g l-1 and 1.25 g l-1, respectively. in order to create permanent air sampling locations, a plexiglas cylindrical chamber (75 cm height, 55 cm i.d) was installed the bath overhead. sixty holes were produced on the chamber in 3 rows (each 20). the distance between rows and holes was 15 and 7.5 cm, respectively. homogeneity and effective factors were studied via side-by-side air sampling method. so, 48 clusters of samples were collected on polyvinyl chloride (pvc) filters housed in sampling cassettes. cassettes were located in 35, 50, and 65 cm above the solution surface with less than 7.5 and/or 7.5-15 cm distance between heads. all samples were analyzed according to the niosh method 7600. according to the anova test, no significant differences were observed between different sampling locations in side-by-side sampling (p=0.82) and between sampling heights and different samplers distances (p=0.86 and 0.86, respectively). however, there were notable differences between means of coefficient of variations (cv) in various heights and distances. it is concluded that the most chromium mist homogeneity could be obtained at height 50 cm from the bath solution surface and samplers distance of < 7.5 cm.
Design and performance of chromium mist generator  [cached]
Tirgar Aram,Golbabaei Farideh,Nourijelyani Keramat,Shahtaheri Seyed Jamaleddin
Journal of the Brazilian Chemical Society , 2006,
Abstract: Chromium mist generator is an essential tool for conducting researches and making science-based recommendations to evaluate air pollution and its control systems. The purpose of this research was to design and construct a homogenous chromium mist generator and the study of some effective factors including sampling height and distances between samplers in side-by-side sampling on chromium mist sampling method. A mist generator was constructed, using a chromium electroplating bath in pilot scale. Concentration of CrO3 and sulfuric acid in plating solution was 125 g L-1 and 1.25 g L-1, respectively. In order to create permanent air sampling locations, a Plexiglas cylindrical chamber (75 cm height, 55 cm i.d) was installed the bath overhead. Sixty holes were produced on the chamber in 3 rows (each 20). The distance between rows and holes was 15 and 7.5 cm, respectively. Homogeneity and effective factors were studied via side-by-side air sampling method. So, 48 clusters of samples were collected on polyvinyl chloride (PVC) filters housed in sampling cassettes. Cassettes were located in 35, 50, and 65 cm above the solution surface with less than 7.5 and/or 7.5-15 cm distance between heads. All samples were analyzed according to the NIOSH method 7600. According to the ANOVA test, no significant differences were observed between different sampling locations in side-by-side sampling (P=0.82) and between sampling heights and different samplers distances (P=0.86 and 0.86, respectively). However, there were notable differences between means of coefficient of variations (CV) in various heights and distances. It is concluded that the most chromium mist homogeneity could be obtained at height 50 cm from the bath solution surface and samplers distance of < 7.5 cm.
Effects of water mist addition on kerosene pool fire
XiaoMeng Zhou,Jun Qin,GuangXuan Liao
Chinese Science Bulletin , 2008, DOI: 10.1007/s11434-008-0437-8
Abstract: The use of water mist to extinguish fire is a problem of particular interest since the banning of halogen-based agents for environmental reasons. This interest is reflected in the large number of researches performed on the main fire-extinguishing mechanisms of water mist: heat extraction, oxygen displacement and attenuation of heat fluxes. In contrast, there are still little known about the chemical and some other aspects of water mist addition on the pool fire. In this paper, a phenomenological study was conducted of the effect of water mist addition on the kerosene pool fire through the measurement of the heat release rate, CO, CO2 and O2 species concentration in combustion. The experimental results show that there is a significant enhancement effect at the beginning stage of water mist addition. Then, the flame size was decreased abruptly. By physical suppression effect combined with chemical effect, the experiments’ results are explained especially. The study of effects of water mist on pool fire will be useful for optimizing designation of water mist fire-suppression system, improving the fire suppression efficiency and extending their application field.
Experimental studies on interaction of water mist with class K fires
Yudong Fang,Yongfeng Zhang,Lin Lin,Guangxuan Liao,Xin Huang,Beihua Cong
Chinese Science Bulletin , 2006, DOI: 10.1007/s11434-006-2221-y
Abstract: Interaction of water mist with cooking oil fires is studied experimentally and theoretically. A LDV/APV system is used to measure the velocity and diameter of water mist at different pressures in the experiments, and the effect of water mist velocity and diameter on fire extinguishment efficiency is investigated. The experimental results show that water mist has excellent surface cooling effect; it can control and extinguish cooking oil fires quickly without re-ignition. The critical temperature (Τ fo) is calculated by energy balance equation, and the fire plume momentum is calculated and compared with that of water mist in order to determine the critical velocity (ν wy) of fire extinguishment. This paper provides references for cooking oil fires extinguishment with water mist.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.