高导热长寿炉衬材料在高炉上的应用

鞍钢10^#高炉引进美国UCAR热模压碳砖、胶泥、填料等高热导率长寿炉衬材料。紧靠冷却壁砌筑,增强整体导热性,这与我国传统的高炉砌筑定位方法截然不同,高炉炉衬材料、砌筑方式与施工实践值得借鉴。     

马琴型外燃式热风炉高温长寿探讨

高炉现代化推动和促进了热风炉加热技术的发展与进步。高温热风炉的应用使热风温度提高，炉衬寿命延长。鞍钢6#高炉马琴型外燃式热风炉安全高效运行26年，实现了高温长寿的目标，其炉衬结构、砌筑施工实践值得借鉴。     

开发铸铜冷却梯级及其在炼铁高炉中的应用

已开发铸铜冷却梯级,它可延长炼炉高炉的炉龄。利用有限元法进行数学分析、研究常规的铸铁冷却梯级与铸铜冷却梯级的热和机械性能.由于较高的热情况,铸铜冷却梯级的温度低于铸铁冷却梯级的温度.前者温度分布比较均匀.因此,由于温差大,铸铜冷却梯级的热应力要比铸铁低得多.观察实际高炉上被测试的梯级,根据梯级表面上结借层估算出经过铸铜梯级的热通量级与铸铁梯级相同。当粉煤喷射率较高时,高炉下部产生圆周气流。在这种高热负荷条件下,铸铜梯级对延长高炉炉龄特别有效‘开发铸铜冷却梯级及其在炼铁高炉中的应用@邵本逑     

小型矿热炉大修后开炉方法的最佳化

小型矿热炉大修后开炉方法的最佳化吴魏民巨化集团公司建材厂小型矿热炉大修时，一般都经过喷水冷却、清出炉内物料、机械和电气设备检修、修补或重砌炉衬的过程。由于大修后的新炉衬已处于常温状态，在投料冶炼前，要烘炉焙烧电极，提高炉衬温度。在传统的开炉方法中，人...     

高炉陶瓷杯炉衬技术应用

陶瓷杯炉衬是现代大型高炉长寿综合技术。鞍钢新1#高炉引进日本NDK微孔超微孔碳砖和法国SAVOIE陶瓷杯炉衬关键技术和材料,国外设计、耐火材料供应、工程监理;国内招标,中标承建施工。炉衬结构、耐火材料及其砌筑方式值得国内高炉借鉴。消化、移植、创新开发具有中国特色的高炉长寿炉衬技术。     

光伏板风冷及水冷技术研究进展

太阳能清洁、无污染,利用光伏板可将光能转换为高品位的电能。光伏板一般由前板玻璃、热熔胶薄膜、电池、背板组成,温度是影响光伏电池性能的主要因素,对光伏电池采取冷却措施可提高其光电转换率,增加系统发电量。空气和水作为常见冷却介质可有效降低光伏电池运行温度。对近年来国内外关于光伏板空冷和水冷的相关研究成果进行综述,梳理了空冷和水冷两种冷却方式下光伏板温降和能效提升的情况,同时介绍了采用数值计算方法研究光伏板表面水膜冷却的工作进展。分析发现,空冷条件下,光伏板平均温度与太阳辐照度和环境温度呈线性分布,其中太阳辐照度和环境温度的相关系数分别为0.03和0.92,且辐射在光伏板传热方面的影响不可忽略;另外,光伏板表面水膜冷却条件下,环境温度居主导地位,水膜分布不均造成电池温度分布不均,间接影响其使用寿命。     

不同蒸发冷却装置工作的影响因素及对比

采用CFD模拟了2种蒸发冷却装置,讨论了一次空气入口温度和喷淋水温度对蒸发冷却装置效率的影响。通过模拟一、二次空气出口处的温度分布,水蒸气相分布以及装置内整个通道的温度分布,得到影响2个蒸发冷却装置的传热性能的变化规律。同时,比较2个蒸发冷却装置的传热性能,给出了一种确定蒸发冷却装置性能的方法。对于管式蒸发冷却装置,选择管径为5 mm和10 mm,管间距为5 mm和10 mm的装置进行模拟。对于板式蒸发冷却,取板长度为500 mm和1 000 mm,并且板宽度为6 mm,8 mm和10 mm用于模拟。通过模拟得到装置尺寸对蒸发冷却效率的影响。     

一维炉衬不稳定态传热的数值计算

根据能量平衡原理导出利用节点网络方程组求解一维炉衬不稳定态传热的数学模型。按照通常的间歇式工业炉的工况因素，列出３种边界条件（按预定升温制度升、降温，按固定热流升、降温，空炉随炉冷却）用ＦＯＲＴＲＡＮ语言编制成通用程序。为了提高计算结果的精度，程序编制时考虑了对炉衬材料的导热系数和比热的温度修正。计算结果详尽（第一计算所在时间间隔内的计算结果包括炉衬各层分界结点的温度、内表供热流量、外表散热流量、     

涡轮第二级动叶冷却结构设计研究

以某涡轮第二级动叶为研究对象,结合参数化特征建模技术研究设计冷却结构,并研究了温度分布,结果表明:叶片的改型对于流道内的温度分布影响很小,而叶片内部温度的分布有一定变化.在叶片后腔所在区域底部截面上,温度下降了10 K左右,在中部截面和顶部截面上冷却效果没有明显改善.     

一维炉衬不稳定态传热的数值计算(1)

根据能量平衡原理导出利用节点网络方程组求解一维炉衬不稳定态传热的数学模型。按照通常的间歇式工业炉的工况因素,列出3种边界条件(按预定升温制度升、降温,按固定热流升、降温,空炉随炉冷却)用FORTRAN语言编制成通用程序。为了提高计算结果的精度,程序编制时考虑了对炉衬材料的导热系数和比热的温度修正。计算结果详尽(每一计算所在时间间隔内的计算结果包括炉衬各层分界结点的温度、内表供热流量、外表散热流量、以及整个作业周期内的累积量和炉衬的蓄热量)。     

MULTIPLE ENGAGEMENT WET CLUTCH HEAT TRANSFER MODEL

To optimize the thermal performance of transmission wet clutches during multiple engagements, a general thermal numerical model has been developed. At every cycle, temperatures are computed throughout the clutch materials until a periodic steady state is achieved. One cycle is characterized by (a) an engagement period where the separator plate is contacting the friction lining with heat being generated while some cooling is provided by the oil passing through friction material grooves; (b) a locked stage of separator plate and friction lining contact during which the heat generation is zero while oil cooling through the grooves continues; and (c) a cooling period with the separator plate completely disengaged from the friction lining while the oil cools both surfaces. Temperatures are calculated from the transient numerical solution of the heat conduction equation in two dimensions. The finite difference technique based on an implicit numerical scheme is employed. This approach is verified by comparison with a known solution as well as experimental data, and a sample run is presented for conditions representative of an actual clutch assembly.     

Model based design and test of cooling plates for an air-cooled polymer electrolyte fuel cell stack

Design of an effective cooling system in polymer electrolyte membrane fuel cells (PEMFCs) is vital for the heat management and overall performance of stacks. Depending on the stack size and application, either air or water-cooling can be used to extract excess heat and maintain the desired temperature distribution throughout the stack.A computational model previously assembled by the authors has been used to design cooling plates for a typical air-cooled stack configuration. The aim of these designs was to minimise temperature differences between cells, and dissipate heat from the stack. Three different cooling plate designs are analysed both computationally and experimentally within stacks containing electrically heated pads in place of active MEAs.Good agreement was achieved between the model and experiment, and results showed that implementing a cooling plate is an effective way to balance temperature variation within a stack and minimise thermal issues. It was found that the temperature variation may be minimised by implementing plates with wider cooling channels. As a result, more air may be forced through the channels with less resistance, which minimises the power required by the air blower, and hence the parasitic load on the system.     

热处理钢板气雾冷却数学模型的开发与应用

针对某钢厂新建的热处理钢板气雾冷却装置,基于有限差分传热仿真计算,开发了相应的热处理钢板气雾冷却数学模型,其中详细考虑了钢板在冷却区内所经历的多种传热边界条件,包括水冲击传热、辊子接触传热、辐射传热和自然对流传热。通过现场的钢板表面温度测试工作表明,模型预测值与实际测试值之间的吻合情况良好,模型具有较高的仿真精度。应用该模型,按照一定的热处理工艺要求(主要指对出口温度和钢板表面/中心温降速率的控制),对气雾冷却区进行了冷却水表的理论设计(即各种厚度规格钢板所对应的冷却水流量),其设计结果已成功地应用于生产现场。     

Heat transfer analysis of blast furnace stave

The three-dimensional mathematical model of temperature and thermal stress field of the blast furnace stave is built. The radiation heat transmitted from solid materials (coke and ore) to inner surface of the stave, which has been neglected by other studies, is taken into account. The cast steel stave is studied and the finite element method is used to perform the computational analysis with soft ANSYS. Numerical calculations show very good agreement with the results of experiment. Heat transfer analysis is made of the effect of the cooling water velocity and temperature, the cooling channel inter-distance and diameter, the lining material, the cooling water scale, the coating layer on the external surface of the cooling water pipe as well as the gas clearance on the maximum temperature and thermal stress of the stave hot surface. It is found that reducing the water temperature and increasing the water velocity would be uneconomical. The heat transfer and hence the maximum temperature and thermal stress in the stave can be controlled by properly adjusting operating conditions of the blast furnace, such as the gas flow, cooling channel inter-distance and diameter, lining material, coating layer and gas clearance.     

An Investigation of Optimized Length Scales of the Heat Treatment of Metallic Plates

A moving metallic plate subject to heating and cooling boundary conditions is considered in this work. The plate is heated by an imposed heat flux, and cooled down by an array of impinging jets through convection and radiation. The objective of the present work is determination of operating conditions for controlling the temperature distribution at the end of both heating and cooling sections. The results show that the temperature distribution becomes more uniform across the heating section with an increase in the heating length. An increase in the distance from the impinging jet to the plate causes an increase in the temperature values across the cooling section, and a decrease in the diameter of the impinging jet causes a decrease in the temperature values across the cooling section. It is also shown that an increase in cooling length and the addition of another impinging jet help to reduce the temperature values and increase the uniformity of the structure across the cooling section. Optimized values of the pertinent parameters for both hardening and tempering heat treatments were investigated.     

A comprehensive thermal analysis for the fast discharging process of a Li-ion battery module with liquid cooling

Appropriate temperature range and distribution is necessary for Li-ion battery module, especially in real application of electric vehicles and other energy storage devices. In this study, a comprehensive design of liquid cooling–based thermal management system for a Li-ion battery module's fast discharging process is investigated, and thermal analysis and numerical computation are conducted. The effects of different flow directions, different shapes of the liquid channels, different widths of channels, different thicknesses of cold plate, and the comparison between uniform and nonuniform channels' distribution are analyzed. Simulation results indicate that the liquid cooling system provides acceptable cooling performance in preventing heat runaway of the battery module under 5C discharging current rate. A five-channel cooling plate can reduce the maximum temperature with appropriate design. Additionally, specific flow direction mini-channels, different shapes of the liquid-channels, and nonuniform channels are designed to compare the maximum temperature and uniformity of temperature distribution in the module. Maximum temperature can be improved through the increase of channel width and thickness of the cooling plate. The original design is proved to be the best design considering the maximum temperature, maximum temperature deviation, and final temperature standard deviation of the fast discharging process.     

Conjugate heat transfer analysis of copper staves and sensor bars in a blast furnace for various refractory lining thickness

Lining erosion is the most important factor for determining the campaign life of a blast furnace. To provide information about the heat transfer of the copper stave in the belly of the No. 1 blast furnace at CSC (China Steel Corporation), a conjugate heat transfer model, including the heat transfer of the stave and sensor bar in thermal conduction and radiation transmission from the gas temperature inside the blast furnace and convection heat transfer in cooling pipe, was developed for the steady state process. The simulations focus specifically on the effects of the gas temperature, the geometric thickness of the cooling stave, the slag layer thickness and the material and diameter of the sensor bar. The results show that the refractory lining and the slag shell provide significant protection for the stave body. A copper sensor bar can be used to measure the residual lining thickness of the cooling stave. To estimate a more reasonable stave thickness, several key factors, such as the diameter and material of the sensor bar, were examined in this study. The results can serve as important reference information for blast furnace operation and the prediction of its campaign life.     

Thermal analysis on the cooling performance of a porous evaporative plate for building

In this paper, a wet porous cooling plate has been used for a building wall. Cooling can be achieved due to the evaporation in the porous layer. A mathematical model on the heat and mass transfer in the unsaturated porous media is developed to analyze the influences of ambient conditions and the porous layer thickness on the cooling performance of the porous evaporative plate. With a decrease in ambient relative humidity and an increase in ambient temperature, more cooling of the porous evaporative plate can be supplied for the inside of the room. The heat exchange between the inside surface of the porous plate and the air in the room should be intensified to achieve a higher cooling efficiency of the porous plate. The ambient wind speed and the thickness of the porous plate also have significant influence on the average temperature of the porous plate. All these results should be taken into account for the utilization of the porous evaporative cooling plate. © 2010 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20284     

平壁,球形壁砌体非稳态热损失计算

本文对平壁、球形壁砌体的非稳态传热计算用有限差分法进行了分析,提出平壁多层砌体的外表面温度、界面层温度以及砌体内部温度场计算公式。提出球形壁砌体的温度场和外表面层温度计算公式。用计算机进行了实例计算,结果表明,外表面层温度计算值与实测值误差仅为8.6％,吻合较好。