共查询到18条相似文献,搜索用时 78 毫秒
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对采用我国目前的冲制、高温真空钎焊、焊料等工艺制造的4类10种不同规格尺寸的回热器超片进行了表面性能试验研究和分析比较.试验得到的10组j-Re与f-Re曲线为板翅式不锈钢回热器的设计提供了可靠依据. 相似文献
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不断要求节省燃料促进了然气轮机的高效设计和高效运行。为了节省更多的燃料,回热器必须在较高温度和压力下工作,并且必须经受频繁的启,仃循环。本文介绍了回热器的设计思想、设计方法及确定其最终设计的全尺寸试验,特别强调回热器和所用材料试验的重要性。作为可靠设计的需要,本文还将工作条件下的材料数据与表列数据作了比较。 相似文献
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选取矩形截面平直翅片板翅式换热器的矩形单通道运用fluent软件进行数值模拟。首先对不同波高和波距的三组九种几何尺寸的翅片在同一工况下进行数值模拟,选出每组中传热和阻力综合性能最优者。然后对选出的三种翅片在不同工况下进行数值模拟,最终选出一种传热和阻力综合性能最优的。并对实物换热器进行试验研究,同时将试验结果和数值模拟结果进行对比分析,验证了数值模拟的正确性。 相似文献
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本文主要阐述了板翅式换热器的翅片形状对换热效果及阻力特性的影响,并给出了二种不同形状散热翅片的试验数据及曲线. 相似文献
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文章基于5 kW非共轴聚光型模拟器自行设计了太阳能热化学反应器,并建立了聚集辐照下反应器热性能数学模型。采用该模型计算并探究了太阳能模拟器功率、反应器内壁材料发射率、工作压力和进气速度对反应器内温度分布的影响规律。结果表明:增加太阳能模拟器功率以及反应器内壁面发射率将导致沿反应器中心线分布的温度升高;在同一进气速度下,随着工作压力的增加,沿反应器中心线分布的温度会升高;在同一工作压力下,随着进气速度的增加,沿反应器中心线分布的温度也会升高。该研究结果对反应器参数优化及其热应力分析具有一定的参考意义。 相似文献
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Ahmet Z. Sahin 《国际能源研究杂志》1998,22(13):1199-1204
An analytical study is performed to demonstrate the effect of viscous dissipation on the performance of a counter-flow recuperator. Four liquids, namely, water, transformer oil, engine oil, and glycerol are selected as working fluids. It is shown that a considerable decrease in performance is obtained when the viscous frictional heating is considered. The optimum size of recuperator is found to be finite and depends on the thermal properties of the running fluids. The effect of viscous heating on the temperature variation in the recuperator is also discussed. © 1998 John Wiley & Sons Ltd. 相似文献
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Fan Weicheng Zhou Hong Department of Engineering Thermophysics University of Science Technology of China Hefei Anhui China 《热科学学报(英文版)》1992,1(1):64-69
The importance of radiative heat transfer in the simulation of indoor-fire has been studied.Computer codeshave been developed based on four-flux model and discrete transfer model,respectively.Evaluation of the codesagainst exact analytic solution and experimental data shows that the discrete transfer model gives numericalresults with acceptable accuracy while the four-flux model underpredicts the heat fluxes although the gen-eral trend is reasonable.Numerical studies have been performed of two-dimensional,axisymmetric turbulent,buoyancy-controlled indoor fire.The computational results show that neglecting radiation in the simulationcan cause overprediction of 500K in the maximum temperature and less uniform velocity field compared to theprediction by discrete transfer model.The four-flux method has been found to produce less uniform velocityand temperature values than discrete transfer model,but is more economic in computation. 相似文献
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