充气热管空气预热器的设计及应用

文章介绍充气热管空气预热器的开发应用。采用平界面模型,确定充气热管冷却段的有效长度。通过实际工程应用,结果认为采用充气热管换热器具有十分良好的防腐蚀及防堵灰性能。     

井筒重力热管传热特性的研究

井筒重力热管是利用热管将油藏自身能量即井底热量传递到井筒上部,在无需外加动力条件下实现对井筒近井口流体加热,改善井口流体温度分布,防止近井口结蜡和絮凝,从而降低采油成本。本文利用N-S方程,根据液膜内微元体的质量守恒、动量守恒和热平衡原理,模拟分析重力热管冷凝段冷却温度、加热段加热功率、冷凝段、绝热段长度以及热管内径等参数对热管运行的影响。研究变参数下热管内液膜厚度变化以及冷凝和蒸发换热系数的变化,进而分析得出变参数时重力热管传热特性,为优化重力热管参数和提高热管的换热性能提供了理论依据,从而使重力热管在最佳传热状态下运行,提高其换热效率。     

一种新型可变导热管传热与控制温度机理分析与实验

首次提出了一种新型可变导热管换热装置,用于增压沸腾流化床发电系统中出灰管的冷却与温度控制。分析与实验表明：在出灰管内灰渣流动不稳定,即外界加热负荷或者冷却条件显著变化时,热管的工作温度几乎不变,能够控制在要求的范围内;热管工作温度随充气量增大而增高,但控制温度特性没有明显改变;与常规热管不同,可变导热管内蒸汽温度沿冷凝段轴向显著变化,蒸汽凝结受到了抑制,热管传热量有所减少。     

热管式聚光光伏冷却集热装置的应用研究

文章设计了一种热管式聚光光伏冷却集热装置,利用热管原理来改变翅片式风冷光伏散热器、管路式水冷光伏散热器的设计思路,通过将热管端蒸发段的介质输送到冷凝端进行换热的相变过程,使得光伏基板的热量迅速传递到冷凝端水箱中,达到降温和集热的双重效果。热管式聚光光伏冷却集热装置不仅能够对光伏组件进行快速冷却,使整个光伏组件换热面温度分布均匀,提高光伏系统的发电效率,还可将多余热量进行收集利用,提高发电收益,在聚光光伏发电领域中具有广阔的市场前景。     

热管换热器在工业炉上的应用

一、概述上海金桥节能设备厂，地处浦东金桥出口加工区，是研制开发热管技术的专业工厂。热管技术是六十年代开始发展起来的高新技术，按热管工质回流方法不同，大致分为标准热管和重力热管。我厂开发的属重力热管，该热管是一种内部形成真空并充适量介质的密封管，它是相变传热，即热管的一端（蒸发段）受热时，管内介质沸腾汽化弥漫至另一端（冷凝段），在另一端由于受到散热冷却，使汽雾凝结成液态回流至蒸发段，如此往复循环，热量由一端传至另一端，两端具有良好的等温性，传热速度快、效率高。由于我厂热管介质的特异性，热管工作温度…     

加热温度对钠钾合金热管启动和传热性能影响

实验研究加热温度分别为300、500、550、600及650℃时,钠钾合金热管(NaK-55)的启动特性和传热性能。实验采用循环冷却水冷却热管冷凝段,并通过冷却水进出口温度计算钠钾合金热管的传热量和传热系数。实验结果表明:在300～550℃的加热温度范围内热管无法完全启动,此时热管的传热量和传热系数很低;在600和650℃的加热温度下热管完全启动并且达到传热平衡,热管传热量和传热系数大幅提高。     

充气热管空气预热器的设计分析及应用

对充气热管空气预热器的结构进行分析和应用介绍,采用平界面模型,确定充气热管冷却段的有效长度。在原始参数相同的条件下,对充气和不充气的热管换热器进行试验,分析热管最低控制工作温度、排烟温度和换热面积之间的差异。工业试验和实际应用结果表明：在变工况和高硫煤(5％-7％)的条件下采用充气热管空气预热器具有十分优良的防腐蚀和防积灰的性能。     

热管散热技术在小山电站励磁整流系统的应用

针对小山电站2号机励磁系统冷却方式存在的若干问题,对现有励磁冷却方式进行改进,采用热管冷却方式,风扇作为备用。从热管冷却的优点进行了分析比较,通过2号机的实际温升试验,进一步阐明了采用热管技术既简化了冷却风机操作及维护,减少了噪声,也提高了设备的可靠性。     

燃气轮机冷却技术综述

详细地阐述了对气膜冷却、内部强化换热以及热管冷却等的影响因素,目前的应用状况以及发展前景.重点集中在内部强化换热和热管冷却.本文可以使刚开始接触燃气轮机冷却技术的人员对冷却技术有个整体的了解,还可以对研究设计人员提供必要的参考依据.     

一种新型CPC聚光热电联产系统

开发了一种新型热管冷却式CPC聚光热电联产系统(PV/T),建立了系统的数学模型。系统采用了蒸发段截面为半圆形的异形热管冷却,整个系统只有普通平板热水器的大小。CPC聚光器截取后的高度为100mm,入口宽度为62 mm,几何聚光比为4.13。采用了光学模拟软件对聚光器进行了光线追踪模拟与辐照度分析,随着入射角度的减小,光斑向聚光器对称中心偏移,最大能流密度逐渐减小,接收面光线分布趋于均匀,但依然存在光线集中现象。     

热管用于笔记本电脑智能温控散热的分析

随着笔记本电脑性能的不断提升,传统的单一风冷散热已经满足不了要求,传热性能优越的热管便应用于笔记本电脑散热。分析了热管用于智能温控散热系统的传热机理,并建立了传热模型．分析了用于笔记本散热的热管的热阻和总传热系数,结合实例进行了定量计算。计算结果表明热管配合智能温控风扇,能很好满足笔记本散热的要求。     

重力对微槽平板热管传热性能的影响

系统地研究了重力对微槽平板热管传热性能的影响,分析了工作温度、冷却方式和倾角等影响因素。通过对比实验发现重力对热管的轴向液膜分布影响非常明显,在周向只在大充液率时有明显的影响,从而使得倾角较大地影响了热管的传热能力。研究表明深槽平板热管具有优良的传热性能,在微电子器件冷却等微小空间散热方面有着良好的应用前景。     

Study on heat transfer characteristics of reservoir embedded loop heat pipe (Influence of condenser cooling method on heat transfer characteristics)

As heat generation in satellites increases, securing sufficient radiator panel area is an important problem. Deployable radiators, whose radiator panels are deployed post‐launch in space to increase the effective radiator panel area of the satellite, is becoming an important thermal control technology. A reservoir embedded loop heat pipe (RELHP) is applied to the deployable radiator for a thermal transport device. This paper presents the heat transport dynamic characteristics of a RELHP using a radiant cooling condenser and liquid forced convection cooling condenser by an experimental study. It was found that heat leak into the liquid line, flexible line, and reservoir increases the length of the sub‐cooling region in the condenser. In the case of the radiant cooling condenser, the sub‐cooling region length is shorter than that of a liquid forced convection cooling condenser. Furthermore, vapor temperature is mainly decided by the radiation capacity of the radiator panel, because liquid temperature returned into the evaporator rises with an increase in radiator panel temperature. In addition, time length from start‐up until steady state is greater than the liquid forced convection cooling condenser case, because the radiator panel has a large heat capacity. © 2008 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20229     

热管型吸附器的性能模拟及优化分析

针对一种热管型吸附器结构形式，对具有翅片的热管型吸附器内传热特性进行了数值模拟，并基于此对热管型吸附器的吸附制冷系统的性能进行了分析，此外讨论了热管的传热极限以及管外传热特性对吸附器的影响。     

Major applications of heat pipe and its advances coupled with sorption system: a review

Heat pipe utilizes continuous phase change process within a small temperature drop to achieve high thermal conductivity. For decades, heat pipes coupled with novel emerging technologies and methods (using nanofluids and self-rewetting fluids) have been highly appreciated, along with which a number of advances have taken place. In addition to some typical applications of thermal control and heat recovery, the heat pipe technology combined with the sorption technology could efficiently improve the heat and mass transfer performance of sorption systems for heating, cooling and cogeneration. However, almost all existing studies on this combination or integration have not concentrated on the principle of the sorption technology with acting as the heat pipe technology for continuous heat transfer. This paper presents an overview of the emerging working fluids, the major applications of heat pipe, and the advances in heat pipe type sorption system. Besides, the ongoing and perspectives of the solid sorption heat pipe are presented, expecting to serve as useful guides for further investigations and new research potentials.     

Testing Thermal Properties of Cooling Device with Heat Pipes to Improve His Heat Transfer Ability

This paper deals about testing thermal properties of the cooling device with heat pipes at inclination position, in consequence of using the natural convection to improve heat transfer properties. Head point testing of cooling device is monitoring temperature on the aluminium block of energy converter, heat pipes and ribs under temperature condition 30 ℃ in thermostatic chamber. Testing of the device was performed at tilt angles positions 0, 10 and 20° from the vertical level. The heat flux loaded to energy converter was 450 W. The next goal of the paper is to research on influence working position of the wick heat pipe on their thermal performance. In this research heat pipes were made with capillary structure sintered from copper powder granularity 100, 63 and 50 μm filled with water and ethanol. Next heat pipe thermal performance was performed by measuring heat source and working positions. Knowledge of these two research goals can bring potential improvements in purpose of cooling device for effective heat sink from high power electronic components.     

Enhanced heat transfer with full circumferential ribs in helical pipe

This paper describes an experimental study of heat transfers in the smooth-walled and rib-roughened helical pipes with reference to the design of enhanced cooling passages in the cylinder head and liner of a marine propulsive diesel engine. The manner in which the repeated ribs modify the forced heat convection in the helical pipe is considered for the case where the flow is turbulent upon entering the coil but laminar in further downstream. A selection of experimental results illustrates the individual and interactive effects of Dean vortices and rib-flows on heat transfer along the inner and outer helixes of coils. The experimental-based observations reveal that the centrifugal force modifies the heat transfer in a manner to generate circumferential heat transfer variation with better cooling performance on the outer edge relative to its inner counterpart even with the agitated flow field caused by the repeated ribs. Heat transfer augmentation factor in the range of 1.3 ~ 3 times of the smooth-walled l     

Simulation of the transient temperature distribution in a high-power semiconductor device cooling apparatus using heat pipes

This study describes the transient temperature distributions in a cooling apparatus for high-power semiconductor devices used in electric-railcar drive systems. The cooling apparatus is composed of heat pipes, air-cooled fin arrays, and a metal block which is used for attaching several semiconductor packages, In our numerical simulation model, we substituted solid elements for the heat pipes, and determined their thermal properties by experiment. As a result, we could obtain transient temperature distributions for the cooling apparatus through a heat conduction analysis. Calculated results showed that when the amount of heat generated in the devices changes, the temperature of the cooling apparatus changes more slowly than that of the devices. A comparison between the transient-temperature distribution calculations and the experiments confirmed the accuracy of the modeling and prediction method. Thus, these calculations can be used to provide data for packaging design, especially concerning thermal stress and fatigue in the packages. © 1998 Scripta Technica, Inc. Heat Trans Jpn Res, 26(2): 107–115, 1997