共查询到20条相似文献,搜索用时 93 毫秒
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热力学中的多方过程研究 总被引:1,自引:1,他引:1
张忠厚 《辽宁工程技术大学学报(自然科学版)》2006,25(Z1):333-334
为解决现有热力学中对一般的多方过程没有进行深入研究的问题,根据热力学的基本理论计算,给出了一般多方过程的功、内能增量和转递的热量的计算公式,讨论了P-V图中斜直线为多方过程的条件,提供了判断多方过程吸放热问题的一种简单方法和在不同区间判断多方过程吸放热问题的基本方法.弥补了热力学对多方过程研究的不足. 相似文献
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对某些文献和教科书上关于多方过程定义的质疑,探讨了多方过程气体比热容与温度的关系,并给出多方过程一种实质性定义。讨论了有关多方过程的一些具体问题,及多方过程的实际应用。 相似文献
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本文通过导出多方过程摩尔热容量C的表达式和讨论摩尔热容量C与多方过程指数n间的关系及给出C-n关系曲线,可使学生对理想气体的多方过程更全面、直观地理解。1多方过程摩尔热容量C的表达式多方过程是在气体中进行的实际过程,它满足pVn=常数(1)式中n为一... 相似文献
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赵蔚琳 《济南大学学报(自然科学版)》1994,(4)
通过对3根充液量不同的钠热管进行实验,分析研究了充液量对钠热管启动运行过程的影响。结果发现φ25mm×2.5mm长为1m的钠热管内充约78g质量的钠为最佳,充液量过多或过少都将影响钠热管的正常工作。 相似文献
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Least dissipation principle of heat transport potential capacity and its application in heat conduction optimization 总被引:1,自引:0,他引:1
In the viewpoint of heat transfer,heat transport potential capacity and its dissipation are defined based on the essence of heat transport phenomenon,Rspectively,their physical menings are the overall heat transfer capability and the dissipation rate of the heat transfer capacity.Then the least dissipation principle of heat transport potential cpacity is presented to enhance the heat conduction efficiency in the heat conduction optimization .The principle is, for a conduction process with the constant integral of the thermal conductivity over the region ,the optimal distribution of thermal conductivity,which corresponds to the highest heat conduction efficiency ,is characterized by the least dissipation of heat transport potential capacity .Finally the principle is applied to some cases in heat conduction optimization. 相似文献
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Least dissipation principle of heat transport potential capacity and its application in heat conduction optimization 总被引:2,自引:0,他引:2
GUO Zengyuan CHENG Xinguang & XIA Zaizhong Department of Engineering Mechanics Key Lab of Enhanced Heat Transfer Energy Conservation of Education Ministry Tsinghua University Beijing China Correspondence should be addressed to Guo Zengyuan 《科学通报(英文版)》2003,48(4)
The heat conduction following the Fourier law widely exists in nature and engineering. Usually, the thermal resistance is applied to evaluating the perform-ance of the heat conduction, i.e. the less resistance corre-sponds to the better performance. Therefore, the heat conduction is often enhanced by means of using high conductivity materials or reducing the thermal contact resistance. The more general performance criterion is the heat duty for the given temperature difference DT, or the temp… 相似文献
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套类零件的热处理变形及控制 总被引:1,自引:0,他引:1
分析了套类零件的热处理变形机理及变形规律,结合套类零件的设计过程和热处理工艺。进行了深入地研究,从中制定出合理的热处理工艺,对套类零件的热处理变形进行有效地控制.实践证明:采取合理地设计、加工和热处理工艺,可以减小和控制套类零件的热处理变形,达到减少精加工工序或免精加工的目的. 相似文献
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Generalized thermal resistance for convective heat transfer and its relation to entransy dissipation 总被引:2,自引:0,他引:2
In order to further analyze and optimize convective heat transfer process further, the concepts of heat flux weighted average heat temperature and heat flux weighted average heat temperature difference in multi-dimensional heat transfer system were introduced in this paper. The ratio of temperature differ- ence to heat flux is defined as the generalized thermal resistance of convective heat transfer processes, and then the minimum thermal resistance theory for convective heat transfer optimization was devel- oped. By analyzing the relationship between generalized thermal resistance and entansy dissipation in convective heat transfer processes, it can be concluded that the minimum thermal resistance theory equals the entransy dissipation extremum theory. Finally, a two-dimensional convective heat transfer process with constant wall temperature is taken as an example to illustrate the applicability of generalized thermal resistance to convective heat transfer process analysis and optimization. 相似文献
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理想气体任意可逆过程吸放热的三种分析方法 总被引:2,自引:0,他引:2
在热力学中,对理想气体任意可逆过程的吸、放热缺乏有效的判断和计算方法,本文提出三种简便的计算和判断理想气体任意过程的吸、放热的方法. 相似文献
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地源热泵的套管式地下换热器传热研究 总被引:4,自引:0,他引:4
依据能量平衡,建立了地下浅埋套管式换热器传热模型,求解并分析了影响传热的主要因素,提出了强化换热的措施,给出了相应的函数关系图。 相似文献
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换热器管板的全位置自动化焊接工艺 总被引:1,自引:0,他引:1
在详细分析换热器钛合金管板自动焊接工艺特点的基础上,利用自行研发的全数字管板焊接系统进行了换热器管板的全位置自动焊接工艺试验,探讨了换热器管板焊接中影响焊接质量的相关因素,获得了合理的工艺,即峰值电流80~100A、基值电流20~30A、电流脉冲频率5~10Hz、脉冲占空比50%、机头转速3~4 r/min、采用脉冲方式进行电流上升和下降,并在1GW超临界火电机组换热器管板的焊接生产中证明了所确定的焊接工艺能满足实际施工的需要. 相似文献
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王振民;张栋;李晋;黄石生 《华南理工大学学报(自然科学版)》2010,38(5)
电力电站发电机组换热器中管板与换热管之间的角接接头环形焊缝质量是整台换热器制造质量的关键,须采用全位置自动化精密焊接工艺。本文在详细分析换热器管板自动焊接工艺特点的基础上,利用自行研发的全数字管板焊接系统进行了换热器管板全位置自动焊接工艺试验研究,探讨了换热器管板焊接主要工艺参数对焊接质量的影响规律,获得了换热器管板精密焊接的工艺规范,并在100万KW超临界发电机组换热器管板的焊接生产中进行了验证。 相似文献