共查询到17条相似文献,搜索用时 62 毫秒
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结合沉积坯的实际沉积过程,利用跟踪计算沉积坯表面轮廓线坐标而建立沉积坯形状的预测模型,模拟结果与实验基本吻合,表明该方法可以获得较合理外形的沉积坯;使用有限元分析方法,对沉积坯动态凝固过程做出了表征,并对其温度场做出数值模拟,结果表明,利用数值模拟方法可以理解喷射沉积动态凝固过程,有效优化沉积工艺,对获得优质沉积材料具有一定指导意义. 相似文献
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采用自行设计加工的变喷嘴距喷射器,在双蒸发压缩/喷射制冷实验平台上,研究了喷嘴距对喷射器和系统性能的影响规律,并与传统压缩制冷循环的性能进行对比。研究结果表明:喷射器存在一个最优喷嘴距能使引射系数(μ)、升压比(PLR)、系统性能系数(COP)和压缩比(CR)均达到最大值;在所研究的工况范围内,最优喷嘴距为?5 mm,与喷嘴距为+15 mm相比,μ最大可提高24.56%,PLR最大可提高7.34%,COP最大可提高11.5%,CR最大降低了3.47%;在不同冷却水进水温度和冷媒水进水温度下,双蒸发压缩/喷射制冷循环比传统压缩制冷循环性能更优,COP最大可分别提高33.97%和24.73%。研究结果可为双蒸发压缩/喷射制冷系统喷射器设计和系统运行参数优化提供参考。 相似文献
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高速短程纺技术能生产三维卷曲短纤维,该技术的关键之一是热流体喷射装置。本文介绍了热流体喷射装置的演变与特点及它的加工机理和某些已应用的实际装置。 相似文献
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对6、8、12 mm 3种孔径的筛网筛选和未筛选的木屑颗粒粒径进行了分析,颗粒粒径大多数在0.25~0.83 mm之间,且分别占总量的81.42%、77.19%、73.67%和70.66%,含量依次降低。孔径越小,固化成型得率和灰分含量越低,而废料的比率越高。采用孔径12 mm工业筛网时,成型机运转偶有堵料。结合生产实际,选用前半筛网8 mm、后半筛网6 mm筛选滚筒。同时,原料含水率对木屑固化成型的影响研究结果表明,原料含水率30%左右最佳,此含水率条件下,干燥炉膛的出口温度应控制在130~140℃。并进行了干燥、固化成型的中试试验,干燥成型得率85%,成型机可连续稳定工作140~280 h,每小时机制棒平均产量266.1 kg,平均制得机制棒270根,耗电量33.0 kWh,燃料用量47.6 kg,与目前国内的成型机相比,具有较大优势。 相似文献
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《Drying Technology》2012,30(15):1720-1729
Standard ANSYS FLUENT software was used to model a dust explosion inside a counter current spray-drying tower by replacing the dust with a flammable gas–air mixture. Two sets of computational fluid dynamics (CFD) calculations for a dust explosion in the tower were carried out at a uniform gas concentration and variable concentration in the dryer, which reflect the distribution of wet and dry powder zones in the spray dryer. The CFD calculation showed that a dust explosion developed from the ignition point mostly to the upper part of the tower. The temperature, velocity, and reaction profiles followed the same upward pattern. Results of the calculations allowed us to determine the position and parameters of venting devices that should be installed to minimize the risk of damage to the dryer construction. 相似文献
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根据质量守恒和能量守恒定律建立喷水减温器的机理模型。为了提高模型精度,利用粒子群优化算法对喷水减温器的机理模型参数进行优化,并利用Matlab进行仿真,仿真结果很好地证明了模型的精确性。 相似文献
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Aidan Leach Rana Sabouni Franco Berruti Cedric Briens 《American Institute of Chemical Engineers》2013,59(3):719-728
Gas‐atomized liquid injections into fluidized beds are commonly used in industrial processes such as fluid coking, fluid catalytic cracking (FCC), and pharmaceutical granulation, where it is important to optimize the distribution of the injected liquid to prevent the formation of unwanted liquid–solid agglomerates and maximize product yields. This injection is typically a two‐phase, gas‐atomized liquid injection. One issue with such a liquid injection is that most of the liquid is deposited at the end of the jet tip within the reactor. This study proposes introducing artificial fluctuations into the injection flow, which causes the jet penetration to vary, allowing for a more even spread of liquid throughout a fluidized bed reactor. The effect of artificial pulsations in the atomized injection, of various frequency and amplitude, was investigated in this study. Using pulsations, greatly enhanced the liquid distribution on the bed particles. © 2012 American Institute of Chemical Engineers AIChE J, 59: 719–728, 2013 相似文献