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通过工程改造项目介绍了蜂窝状蓄热体和蓄热小球混装的新型蓄热体结构,分析得出新型结构成本低,蓄热能力可提高20%以上,对于全新蓄热式加热炉蓄热室的设计具有指导和借鉴意义。实践表明,采用此种结构具有高效、优质、节能和低污染等诸多优点,具有广阔的开发应用前景。 相似文献
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为提高工程实际应用中固体蓄热器蓄热体的蓄热能力,以碱性耐火材料MgO砖作为蓄热介质,设计一种新型蓄热体结构,基于物理参数非定值的热分析方法,对新型蓄热体结构的蓄热性能及温度分布情况进行分析。结果表明:目标蓄热时间下,传统蓄热体温度分布梯度较大,温度分布以蓄热体中心点为核心呈面性递减,整体温差值为227.0 K,新型蓄热体温度分布以横向轴线呈线性递减,整体温差值为107.8 K,较传统蓄热体整体温差值减小119.2 K,监测点温度偏差率降低5.7%;目标蓄热时间下,传统蓄热体网格节点温度在设计蓄热温度873 K温度段占比仅为8.7%,而在高温段占比达到70.1%,整体温度分布不均,新型蓄热体网格节点温度在设计蓄热温度873 K温度段占比达60.4%,未形成明显高温段,整体温度分布更优;目标蓄热温度下,新型蓄热体结构的实际蓄热容量达到理论蓄热容量的96%,较传统蓄热体提升16%,同时相同蓄热容量下体积仅有传统蓄热体的83%,能有效提高蓄热体蓄热能力,相应降低蓄热成本,有利于市场推广。 相似文献
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在10kW的电热固体蓄热装置上,对其蓄热过程进行了实验研究,得到了不同加热方式、不同控制温度下蓄热体内温度分布规律、升温速度和蓄热量。 相似文献
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设计一种采用分组投切的固体蓄热装置,并以此设计搭建总加热功率150 kW的固体蓄热实验装置,搭建热物理参数非定值的数值计算方法,模拟出炉体的温度场分布,并与定值参数进行对比,得到热物理参数非定值与定值的温度曲线和蓄热量曲线;通过数值模拟和实验数据相结合的方法,确定非定值法数值计算方法的可行性;设计一种分组投切的加热方式,对分组加热的固体蓄热装置进行蓄热量及温度分析。结果表明,采用整体加热的炉体温度梯度分布区间较大,传感器点温度有温差;采用分组加热的炉体温度梯度分布区间相对缩小,传感器间温度几乎相等,相同蓄热目标温度下,提高蓄热量6.0%。 相似文献
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介绍了一种用蓄热材料建成的南向集热蓄热被动式太阳房结构和和特性,利用平板式空气太阳能集热器的特性方程分析,得出了室内温度分布的瞬态方程,并分析了该太阳房在沈阳地区24h室温及室内壁温的平均波动,根据计算,该太阳房比传统房节能96%。 相似文献
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600 MW回转式空气预热器传热模型的解析-数值法 总被引:1,自引:0,他引:1
传统的数值迭代法只给出了两分仓回转式空气预热器稳态时端面的二维温度变化曲线,并不能直观地反映空气预热器从启停到正常运行时真实的温度分布.对回转式空气预热器的换热机理进行详细分析,提出采用解析-数值混合计算方法求解换热模型的数学方程,并用该方法模拟600 MW回转式空气预热器金属板和介质温度分布场,结果表明,解析-数值混合计算法,不仅克服了传统迭代法的精度不高、不易收敛的缺点,而且它可以真实地反映出空气预热器整个运行工况金属板和介质的温度分布情况,容易发现引起低温腐蚀的金属最低温度位置,因此对回转式空气预热器安全经济运行提供了更加科学的理论依据. 相似文献
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In this paper, heat transfer of the ceramic honeycomb regenerator was numerically simulated based on the computational fluid dynamics numerical analysis software CFX5. The longitudinal temperature distribution of regenerator and gas were obtained. The variation of temperature with time was discussed. In addition, the effects of some parameters such as switching time, gas temperature at the inlet of regenerator, height of regenerator and specific heat of the regenerative materials on heat saturating time were discussed. It provided primarily theoretic basis for further study of regenerative heat transfer mechanism. 相似文献
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根据回转式空气预热器的传热机理进行了理论分析,给出了相应的传热计算模型.并根据空气预热器的动态平衡过程和结构特性,结合金属蓄热板径向温度场的二维分布假设,提出采用解析-数值混合计算方法求解换热模型的数学方程,并将解析-数值方法与传统的矩阵迭代法分别计算某电厂的实际空气预热器从启动到正常运行阶段蓄热板和工质温度分布,结果表明传统的矩阵迭代法计算对特征值的要求很严格,而解析-数值方法对任意特征值均可以收敛,并且计算结果的工程精度也很高,因此对电厂安全经济运行提供了可靠的理论依据. 相似文献
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蜂窝蓄热体对于改善空气燃烧过程,降低NOx起着至关重要的作用。本文通过Pointwise和Fluent软件建立了蜂窝蓄热体三维数值模型,从不同的换向时间、孔型、边长、材料的角度对比了蜂窝蓄热体的换热特性,并对实际工作中节能效率进行了理论计算。结果显示,当换向时间从15s增长到45s时,正方形蓄热体的温度效率从78.5%降低到63.1%。当边长、壁厚相同时,圆形蓄热体的温度效率最高,压降也最大;六边形蓄热体的温度效率最低,但压降最小。总结发现,孔隙率的减小可以有效的提高温度效率,但是同时会增大流动的压力损失。在实际应用中可据此选择合适的孔隙率。同时得到,在实际运行中,当a=2mm时,圆形蓄热体的节能效率最高(26.9%),六边形节能效率最低(24.4%)。 相似文献
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Glass manufacturing is an energy intensive process where fossil fuel is used to maintain high temperature (about 1700 °C) for glass melting. Heat recovery from flue gas (1350–1500 °C) is usually in the form of combustion air pre-heating (900–1200 °C) using a regenerator. Dust from flue gas which is carried over from the furnace gets deposited in the regenerator storage matrix path. This leads to a deterioration of regenerator efficiency. A regenerator model is developed to estimate the actual performance of the regenerator and to compare it with the target performance. The proposed model is based on mass and energy balance of streams along with heat transfer characteristic equations. The model is illustrated for a 130 TPD (Ton per Day) furnace regenerator of an industrial glass plant at Mumbai, India. Model results for the regenerator studied indicate a blockage of 50% on the doghouse side and 22% on the non-doghouse side of the regenerator. The actual performance of the regenerator is found to be 7% lower than its target performance for the doghouse side regenerator. The model developed can also be used in other industrial sectors like steel, chemical etc. 相似文献
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Modeling and effect of leakages on heat transfer performance of fixed matrix regenerators 总被引:2,自引:0,他引:2
The following undesired leakages are inherent in operation of fixed matrix regenerators: gas pressure leakages due to pressure difference such as leakages through the valves and through cracks in regenerator housing for very high temperature heat recovery, and carryover leakages from the hot gas to cold gas and vice versa. The objective of this paper is to present a methodology for evaluation of the leakages and to determine quantitatively the detrimental influence of pressure leakages on the regenerator heat transfer performance. In this respect, a drop (reduction) in actual regenerator heat transfer effectiveness due to various leakages is presented in the paper. The results clearly suggest that a drop in the effectiveness due to leakages can be significant and depends on the category of leakages. The flow leakages due to the cracks in the regenerator housing have the most impact on reducing the regenerator performance. 相似文献
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基于FLUENT的热风炉蓄热室传热及操作制度研究 总被引:2,自引:0,他引:2
为获得热风炉蓄热室内气体及格砖温度随时间的变化规律,用FLUENT软件建立了热风炉蓄热室温度场计算的简化模型,并进行了蓄放热过程的模拟计算.在分析不同操作制度下热风炉工作特点的基础上,比较计算了具代表性的三座热风炉在二烧一送、一烧二送和半交叉并联三种操作制度下的风温变化状况和热效率.模拟计算结果表明:该方法可以得到符合设计计算精度要求的模拟结果,可以方便地进行蓄热室传热特征分析,预测热风炉在不同操作制度下的工作特点,为热风炉生产选择优化操作制度提供了便捷有效的方法. 相似文献
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Bo Wang Limin Qiu Daming Sun Kai Wang Weijuan Yang Junhu Zhou 《International Journal of Heat and Mass Transfer》2011,54(23-24):5070-5076
To explore the effects of Gedeon streaming on the onset and damping behaviors, infrared imaging is applied for the first time in a traveling-wave thermoacoustic engine to observe the temperature evolution of the regenerator. Under conditions of with and without Gedeon streaming, the temperature distribution differences of the regenerator in the onset and damping processes are compared and analyzed. Based on the visual images, the dimensionless temperature distribution reveals some phenomena that have not been revealed by traditional measurement methods. Analysis of the thermal and mass flows is made to further understand the mechanism of the onset and damping processes. 相似文献
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An experimental method of regenerator evaluation is proposed in this paper. The configuration of the experimental equipment used in the method is similar to that of an alpha-configuration Stirling engine with a phase angle of 180°. The temperature of the hot side heat exchanger is controlled by an electric heater, and the heat sink was room air. An air conditioner controlled the temperature of the room air. The temperature and pressure of the working fluid were measured during the piston motion. A #18 stainless steel mesh was used as a regenerator matrix for a low temperature differential Stirling engine (LTDSE). The regenerator efficiency can be calculated based on the measurement results. The product of the swept volume, the density of the working fluid, the specific heat and the difference in the working fluid temperatures between the hot side and the cold side is greater than the amount of the internal energy fluctuation. The reason for this is assumed to be the temperature fluctuation in the region between the two heat exchangers. The walls of the region are made of acrylic resin. The amount of the temperature fluctuation in the region is assumed to be uniform. The regenerator efficiency is calculated as a function of the temperature fluctuation in the region. The evaluation method does not require a fast-response thermocouple. The prediction of the regenerator efficiency is possible basted on some experimental results of same matrix. Polyurethane foam and #18 stainless steel mesh, layered parallel to the stream line of the working fluid, were each tested. These materials can realize a non-rectangular regenerator without the generation of waste. Non-rectangular regenerator includes regenerator that can be installed into narrow gaps. The regenerator efficiency of the stainless steel mesh layered parallel to the stream line of the working fluid was significantly less in comparison to that of the normal mesh layers. In the polyurethane foam case, a pressure loss was observed. 相似文献