Heat Pipe

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热导管技术介绍

Qmax变化比例
-10% -5% 0% 0%
6以上
热管设计时应尽量减少打扁的厚度，折弯的角度，弧度，形成正段差 Heat Pipe Technology
13
Thermal Performance (Q-max of groove and composite Heat Pipe) 沟槽管 2.0~2.5 2.6~3.0 3.1~3.5 3.6~4.0 4.1~4.5 4.6以上 Qmax变化比例 -10% -8% -5% 0% 0% 0% 复合管 2.0~2.5 2.6~3.0 3.1~3.5 3.6~4.0 4.1~4.5 4.6以上 Qmax变化比例 30% 30% 30% 20% 10% 0%
高效导热技术——热管
林梓荣 Novark Technology Inc
Heat Pipe Technology
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热管概述
• • • • • • • 热管应用的技术背景热管的运行机理热管的组成热管毛细结构的类型热管的特性热管的需求热管的制作流程
Heat Pipe Technology
5
热管毛细结构的类型
沟槽（Groove）
粉末烧结(Sinter) 纤维(Fiber)
网状（Mesh）
Heat Pipe Technology
6
热管的特性
（1）很高的导热性；热管内部主要靠工作液体的汽、液相变传热，热阻很小，因此具有很高的导热能力。导热系数是铜的几十倍。（2）优良的等温性；热管各处温度基本等于工质蒸汽是处于饱和状态下的温度。（3）热流密度可变性；热管可以独立改变蒸发段或冷却段的加热面积，即以较小的加热面积输入热量，而以较大的冷却面积输出热量。（4）热流方向可逆性；即热管任意一端受热就可作为蒸发段，而另一端向外散热就成为冷凝段。（5）热管可做成热二极管或热开关；所谓热二极管就是只允许热流向一个方向流动，而不允许向相反的方向流动；热开关则是当热源温度高于某一温度时，热管开始工作，当热源温度低于这一温度时，热管就不传热。（6）适应性大，可按应用场合制作成不同的形状。

heat pipe 设计原理及制造

熱管之應用
1.電子電力機半導體元件的冷卻 2. 改善熱交換器的效能 3.電力電纜的冷卻 4.馬達的冷卻 5.高緯度地區的道路融雪 6.太空船的熱控制元件
PS2
D/T
熱管的市場前景
熱導管產品市場範圍相當廣泛，未來將是許多電子電器產品散熱必備的基本之件。舉凡電源供應器、投影機、筆記型電腦、工業電腦 ,遊戲機及桌上型電腦，皆有其散熱考量之應用。
Manufacture Process
2. Shrink End
Grinding Speed: 3600 rpm. Capacity: 2880 pcs/8hrs.
Manufacture Process
3. Mesh Insertion
Insert Pressure: 8kgf/cm² Capacity: 3150 pcs/8hrs.
A B C D
Cpk
Process Ability
(總合Ca與Cp二值之指數)有兩個公式可以求得
(1) Cpk = (1-|Ca|)‧Cp When Ca = 0, Cpk = Cp (2) Cpk = Zmin/3 = Su-X/3ðor the min. of -(SL-X)/ 3ð
A B C Cpk = |Cp| 1.33≦Cpk 1.00≦Cpk < 1.33 Cpk < 1.00
0.00
1.20 0.80 (1.20)
1.6
0.5 1.1 0.6 1.1
1
1.4 1.5 0.4 1.2 1.3 0.9 1.6 1.1 1.3 1.2
30 1.047 0.305 1.60 0.40 1.20
1.1 0.7 1.3 1 0.6 1.2

5.热管(heat-pipe)&热版(heat-plate)设定篇

各种热管内部的相变分析
Icepak由于定义为一套相对简单的热流分析软件，虽然它是用Fluent作为计算核心，但要计算相变及毛细现象等问题，就会违背简单易学的准则，故Icepak在分析热管时可以用宏观的方式来模拟分析，而不能探讨内部相变及毛细现象等问题。若要探讨内部现象，可以用Fluent&CFX来做分析的工具。
方法一利用Icepak内建resistor network来假设热管行为。缺点是无法观测热管的外观。
方法二利用Icepak内建的热阻参数来假设热管行为。优点是可以保留热管外观，缺点是无法观测热管温度变化。
方法三利用Icepak内建的材料热传导系数来假设热管行为。优点是可以观察热管温度分布，缺点是计算慢。
东方科技Biblioteka ICEPAK热管(heat pipe)&热板(heat plate)设定
Luan Pengwen
2011-11
热管起源 1963年美国加州大学的格鲁佛氏发明了热管，目的是为了解决因机器本身运作所产生的高温发热问题，并使机器可以维持在正常工作温度之内。工作原理热管的传热现象包括：传导、蒸发、对流、冷凝。由于利用到物质相变时可吸收或散发热量的现象，因此使得管成为具备极高热传导效率的设备。热管结构基本上，是将液体加在一根细长、中空、两头封闭的金属管中，金属管的内壁有一层毛细物体，而不同的金属管材料与内部的液体物质则须要根据工作环境进行不同的选择，金属管的材料最常见的有黄铜、镍、不锈钢、钨及其他合金材料。

热管HeatPipe课件

同时也会增加热阻。因此，需要根据实际应用需求进行权衡。
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隔绝材料选择
为了实现热管的热量传输，需要选择合适的隔绝材料将热量封在管内，
同时防止空气和湿气的进入。
热管制造工艺
制造工艺流程
热管的制造工艺包括多个环节，如管材切割、清洗、焊接、抽真空等，每个环节都对最终的热管性能产生影响。
焊接质量
焊接质量直接影响热管的密封性和传热性能，高质量的焊接可以保证热管在使用过程中不会出现泄漏现象。
抽真空工艺
为了减小空气对热管传热性能的影响，制造过程中需要对热管进行抽真空处理，这一工艺对最终的热管性能至关重要。
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热管性能测试
热管传热性能测试
传热效率
测试热管在不同工况下的传热效率，包括热管长度、直径、工质、操作压力等参数变化对传热效率的影响。
传热温差
研究热管启动时间和达到稳态传热的时间，以及各部分之间的温差分布，以评估热管的传热性能。
总结词
热管应用拓展研究主要关注将热管技术应用于新的领域和场景，以扩大其应用范围和提升其应用价值。
详细描述
随着技术的不断发展，热管的应用领域也在不断扩大。目前，热管已经广泛应用于电子设备散热、太阳能热利用、余热回收等领域。未来，随着人们对节能减排和高效能源利用的需求不断增加，热管有望在更多领域得到应用，如建筑节能、新能源汽车等。
建筑节能领域
研究热管在建筑节能领域的应用，如利用热管进行建筑物的采暖和制冷，提高建筑物的能
源利用效率。
感谢您的观看
THANKS
当热管一端受热时，管内工质蒸发汽化，蒸汽在压力差作用下向另一端流动，并在另一端冷凝放热，将热量传递出去。
热管内部发生的相变传热和热对流等物理现象，使其具有优良的传热性能，能够实现快速、稳定、可靠地传递热量。

三维热管工作原理及应用

三維热管工作原理及应用
Applications in Energy Recovery 三维热管在能量回收中的应用
典型能量回收系统示意图
三維热管工作原理及应用
Applications in Energy Recovery 三维热管在能量回收中的应用
能量回收的目的： 1、减小供热（冷）装置的容量。 2、减少诸多设备如制冷和供热设备、空气处理设备、水泵、管路等的投资。 3、减少全年的能源消耗量。 4、降低运行费用。 5、减少对环境的污染，减少温室气体的排放，保护环境，保护地球。
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三維热管工作原理及应用
Applications in Energy Recovery 三维热管在能量回收中的应用
三维热管在能量回收中的优势：
1、结构紧凑，单位体积的传热面积大，机组占用空间相对较小。 2、没有转动部件，不额外消耗能量，空气阻力低，“净节能效率”高。 3、运行安全可靠，使用寿命长，基本不需要维护，降低运行管理费用。 4、水平固定安装，自动双向传热，冬夏季节都可进行能量回收。 5、换热效率较高，反应灵敏，新排风温差较小时，也能取得一定的回收效益。 6、性能稳定，整个寿命周期内，可以保持持续的高效换热。 7、新、排风间不会产生交叉污染。 8、内部充注环保型冷媒，对室内、室外空气不会造成污染。
下部蒸发端，液态介质吸收热量。
B. Fluid boils to vapor phase. 液体沸腾产生蒸汽成为汽态。
C. Heat releases from the upper part of cylinder;
Vapor condenses to liquid phase.
蒸汽上升到管子的上部冷凝端，释放热量给周围环境后，

热管式热交换器设计说明

本科毕业设计说明书热管式热交换器（烟气余热回收空气预热器）Heat pipe heat exchanger (flue gas heat recovery air preheater)摘要热管是一种依靠管内工质的蒸发，凝结和循环流动而传递热量的部件。

由热管元件组成的，利用热管原理实现热交换的换热器称之为热管换热器。

热管换热器最大的特点是：结构简单，传热效率高、动力消耗小。

其越来越受到人们的重视，是一种应用前景非常好的换热设备。

目前，它被广泛应用于动力、化工、冶金、电力、计算机等领域。

本文就热管换热器的发展现状、趋势、应用及设计做了一个简要的论述，着重探讨了热管换热器的设计。

在讨论热管换热器的设计过程中，主要针对热力计算，设备结构计算、元件参数的选择做了一个合理构建。

关键词：热管；热管热交换器；设计计算；ABSTRACRely on heat pipe is a pipe working fluid evaporation, condensation and recycling the flow of heat transfer member. Components of the heat pipe, heat pipe principle the use of heat exchange heat exchanger called the heat pipe heat exchanger. Heat pipe heat exchanger biggest feature is: simple structure, high heat transfer efficiency, power consumption is small. Which more and more people's attention, is a very good application prospects heat transfer equipment. Currently, it is widely used in power, chemical, metallurgy, electric power, computers and other fields. In this paper, the development of heat pipe heat exchanger status, trends, application and design to make a brief discussion, focused on the heat pipe heat exchanger design. In discussing the heat pipe heat exchanger design process, mainly for thermal calculation, equipment, structural calculations, component selection of parameters made a reasonable construction.Key words：Heat pipe；Heat pipe heat exchanger；Design calculations；目录第一章绪论 (1)第一节热管及热管换热器概述 (1)第二节热管及其应用 (3)1.2.1热管的构造原理 (3)1.2.2热管的工作原理 (7)1.2.3热管的基本特性 (8)1.2.4热管分类 (8)1.2.5热管技术 (9)1.2.6热管技术特点 (10)第二章热管换热器 (12)第一节热管换热器技术优势 (12)第二节热管换热器的分类 (12)第三节换热器应用前景 (14)第三章热管气-气换热器设计中应注意的问题 (16)第四章热管气-气换热器设计步骤 (17)第一节计算步骤 (17)第二节符号说明 (19)第三节标注说明 (20)致谢 (22)参考文献 (23)附录 (25)外文资料及翻译 (35)任务书 (55)第一章绪论第一节热管的发展及现状在现有的传热元件中，热管是我们所知的最高效的传热元件之一，它能将大量热量通过其特别小的截面积远距离地传输而不需要外加动力。

Heat Pipe介绍及选用

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nfidential Data / Do not Copy / DCPM-001009V1 / Level 2
Thermal Performance (Q-max of Heat Pipe by L=150mm)
END
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onfidential Data / Do not Copy / DCPM-001009V1 / Level 2
Heat Pipe 的特性應用
* * * * * * * * * * 高速度的熱傳導效果重量清且結構簡單溫度分怖平均, 可做均溫或等溫動作熱傳輸量大熱傳送距離長無主動元件, 不耗電無重力場環境下亦可使用無熱傳方式限制, 蒸發及凝結端可互換容易加工以改變熱傳輸方向耐用/壽命長/可信賴度高, 易存放保管
Pipe Diameter Final Forming Thickness
(Q-max deviation: 10%)
3 mm
4 mm
5 mm
Байду номын сангаас
6 mm
8 mm
T = 2.0mm
9W
16 W
20 W
28 W
31 W
T = 2.5mm
13 W
17 W
31 W
45 W
62 W
T = 3.0mm
最大熱傳導效能測試. 最大彎曲/扁平後之洩漏測試. 最大彎曲/扁平後之效能測試. 壽命及熱衝擊測試.
Dongguan Yijie Hardware Precision hardware products Page 6

HEAT PIPE TYPE HEAT EXCHANGER FOR BATHTUB

专利名称：HEAT PIPE TYPE HEAT EXCHANGER FOR BATHTUB发明人：SASAKI CHIKA申请号：JP21665889申请日：19890823公开号：JPH0379949A公开日：19910404专利内容由知识产权出版社提供摘要：PURPOSE:To prevent the neat release at the stop time of combustion by a method wherein wicks are not used for heat pipes and the heat pipes, the inside surfaces of which are smooth and having little capillary phenomenon, are so installed that the heated side of the heat pipes is laid lower than their heat release side. CONSTITUTION:At a bathtub 1 iron-made heat pipes which use water as working fluid and have no wicks are installed in the condition of penetrating through the bathtub. Heat releasing parts 4 are plated by chromium, are arranged so that the heated side 6 of the heat pipes are laid downwards, and to the parts fins 11 to improve neat absorption effect are attached. City gas is burnt by a combustion burner 7 to heat the heated side of the heat pipes and combustion exhaust gas 10 is discharged outdoors from a chimney 8. At the heated heat pipes the working fluid starts to vapor ize and moves to the heat release side to heat water 2. Condensed working fluid returns back to the downward heated side by the gravity and heats repeatedly the water in the bathtub. Even though the heating by a bath furnace is stopped when the temp. of the water in the bathtub becomes proper, the heat pipes are not operated because wicks are not used for the pipes and the heat of hot water in the bathtub is not re leased from the parts of the bath furnace and the decreasein the temp. of the hot water in the bathtub can be prevented.申请人：FURUKAWA ELECTRIC CO LTD:THE更多信息请下载全文后查看。

Heat pipe assemblies

专利名称：Heat pipe assemblies发明人：David William Grunow,Daniel WilliamKehoe,Matthew B. Mendelow申请号：US14018957申请日：20130905公开号：US09261924B2公开日：20160216专利内容由知识产权出版社提供专利附图：摘要：Heat pipe assemblies for Information Handling Systems (IHSs). In someembodiments, an IHS may comprise a motherboard including a Central Processing Unit (CPU); a cooling system coupled to the motherboard, the cooling system including a heatpipe, the CPU coupled to a first side of the heat pipe; and a daughterboard coupled to the motherboard and including a Graphics Processing Unit (GPU) coupled to a second side of the heat pipe. In other embodiments, a method may include providing a motherboard including a CPU; coupling a cooling system to the motherboard, the cooling system including a heat pipe, the CPU coupled to a first side of the heat pipe; and coupling a daughterboard to the motherboard, the daughterboard including a GPU coupled to a second side of the heat pipe.申请人：Dell Products, L.P.地址：Round Rock TX US国籍：US代理机构：Fogarty, L.L.C.更多信息请下载全文后查看。

Heat pipe switch

专利名称：Heat pipe switch发明人：Charles Chester Roberts, Jr.申请号：US05/619700申请日：19751006公开号：US04026348A公开日：19770531专利内容由知识产权出版社提供摘要：Thermal energy transfer apparatus having a controllably variable thermal conductance comprises a heat pipe having a capillary wick structure therein, a circulating supply of working fluid which is controlled by a heater, and a thermostatic heater control which is responsive to the temperature of the hot end of the heat pipe. As working fluid condenses it is removed from the heat pipe. Liquid working fluid is recirculated into the heat pipe in discrete quantities by vapor bubble injection under the control of the heater and the heater control. If no fluid is injected into the heat pipe, the thermal conductance will decrease as condensate is removed. If fluid is injected into the heat pipe, thermal conductance will increase as fluid is supplied to the heat pipe.申请人：BELL TELEPHONE LABORATORIES, INCORPORATED代理人：John C. Albrecht更多信息请下载全文后查看。

热管HeatPipe

致冷晶片應用
利用熱管的優良散熱方法,加上致冷晶片熱源的一端讓熱管散熱,而冷源那一端則讓原本的溫度更低,使得可以達到冷氣機或是冰箱的功能.
回流，其他的毛細結構則多少仍有導管方
位、角度的限制。
工作流體
工作流體也要能與毛細結構適切搭配，流體的黏滯係數低，則毛細回流的速度快，如此可更快完成循環，可提升散熱效率。
熱導管最常用的工作流體為水。
熱管優點及特性
溫度分佈均勻熱阻小熱反應快速傳熱量大重量輕體積小:熱管為中空金屬，因此重量將比同
熱管原理構造
熱管三基本元件： 1.管材 2.毛細結構 3.工作流體。熱導管本身是一個密閉的管狀容器，且一
般為「長條管」型態，容器內裝有少許的「液體」，管的內壁運用技術處理使其具有「毛細結構」熱管
管材的要求
管材取向包括：
1.不能與管內的毛細結構、工作流體產生化學作用（運作穩定性）
體積金屬輕得多。結構簡單:熱管為封閉管，沒有需要持續添加工作
液的問題。無磨耗壽命長:熱管沒有活動零件，不會有磨損的
問題。無需電源
迴路型熱管(Loop Heat Pipe )
動作原理
迴路型熱管之優點
高傳熱量。低熱阻。可靠耐用。遠距熱輸送。應用於人造衛星的熱控系統上，能源與電
子冷卻等領域上。
熱管產品應用
熱交換器應用
空氣加熱器
產業及電力設備音響電晶體散熱
自然能源、民生家庭
便攜式產品，3C
液晶螢幕 PDA，NB
熱管應用於能源轉換
用高效率的熱交換技術或相關的熱交器，來提高熱能設備效率和減少能源損失。
由熱管組裝成的熱管熱交換器可用來有效地回收工業製程的廢熱、空調換氣的廢熱及增進空調除溼系統的效率…..等。

热管HeatPipe课件

热管的分类
根据工作介质、形状和工作温度等方面，热管可以分为多种类型，适应不同的应用需求。
ห้องสมุดไป่ตู้
热管的工作原理
热管的基本原理
热管通过蒸发和冷凝过程中的相变传热来实现热量的高效传导。
热管的传热机理
热管的传热机制包括蒸发、对流、传导和冷凝等过程，各个环节相互作用，实现热能的传递。
热管的性能参数
热管的性能测试方法
热管的质量检测要求
热管的性能测试包括传热测试、热阻测试和可靠性测试等，用于评估热管的工作性能。
热管的质量检测要求包括材料检测、密封性检测和工作性能检测等，确保热管的质量和可靠性。
热管的发展与趋势
1
热管的未来发展趋势
2
热管的发展趋势包括尺寸缩小、传热效率提高、材料性能改进等，以应对
不断增长的热管理需求。
热管的发展历程
热管的发展经历了多个阶段，从早期的实验研究到如今的广泛应用，不断推动着热传导技术的进步。
热管的案例分析
热管的应用案例分析
通过具体的案例分析，展示了热管在不同领域中的应用效果，以及解决方案的创新和优势。
热管在产品中的案例分析
通过对产品中热管应用的分析，探讨了热管在提高产品性能和可靠性方面的作用和贡献。
热管的性能参数包括热阻、温差、热传导能力等，这些参数决定了热管的传热效率。
热管的应用
热管在电子领域的应用
热管被广泛应用于电子器件的散热，提高了电子产品的性能和可靠性。
热管在航空航天领域的应用
热管在航空航天领域中用于导热管道和温度控制系统等，提供了高效的热管理解决方案。
热管在地球工程领域的应用
热管在地球工程领域中用于地热能利用、热泵系统等方面，促进了能源的高效利用。

HEAT PIPE TYPE HEAT EXCHANGER

申请人：FURUKAWA ELECTRIC CO LTD:THE
更多信息请下载全文后查看来自专利内容由知识产权出版社提供
专利名称：HEAT PIPE TYPE HEAT EXCHANGER 发明人：TAKAHASHI TAKESHI 申请号：JP1203390 申请日：19900122 公开号：JPH03217795A 公开日：19910925
摘要：PURPOSE:To obtain a heat pipe type heat exchanger without generating dewing even when the same is attached to a sealed box body or a sealed chamber by providing a heat insulating layer near a partitioning plate to intercept a heat absorbing part from a heat dissipating part. CONSTITUTION:A plurality of sheets of plate fins 6 are fitted to a plurality of heat pipes 5 through a partitioning plate 7 and push plates 8 are attached to the upper and lower part of the plate fins while a part near the intermediate part of the heat pipe is filled with heat insulating material 19 to provide a heat insulating layer 10. Solid type heat insulating material, such as a silica board, a glass wool board and the like capable of being applied with machining works, is used conveniently by cutting it into a predetermined configuration. When a using temperature is high, the heat insulating material, such as rock wool, fiber ceramics and the like capable of being used at a high temperature, is employed. The heat pipe type heat exchanger, equipped with the heat insulating layer, can be prevented from generating dewing on the partitioning plate even when the same is attached to a sealed box body or a sealed chamber and a difference between an indoor temperature and an atmospheric temperature is large.

Heat Pipe

铜管内径2 mm, 8弯， 32 组
18
微小型振荡流热管
19
微小型振荡流热管实验系统
20
North China Electric Power University
10
振荡流热管（Oscillating振荡流热管（Oscillating-Flow Heat Pipe) 当管径足够小时，当管径足够小时，在真空下封装在管内的工质将在管 1994年日本学者H.Akachi发明了脉动热管（Pulsating Heat Pipe) 内形成液、相间的柱塞。在加热段，内形成液、汽相间的柱塞。在加热段，汽泡或汽柱与振荡流热管原理管壁之间的液膜因受热而不断蒸发，导致汽泡膨胀，管壁之间的液膜因受热而不断蒸发，导致汽泡膨胀，并推动汽液柱塞流向冷端冷凝收缩，从而在冷、并推动汽液柱塞流向冷端冷凝收缩，从而在冷、热端之间形成较大的压差。由于汽液柱塞交错分布，之间形成较大的压差。由于汽液柱塞交错分布，因而在管内产生强烈的往复振荡运动，在管内产生强烈的往复振荡运动，从而实现高效热传递。
North China Electric Power University
4
热管的工程应用：热管的工程应用：（1）温度控制（如：航天器）；温度控制（航天器）；热量传递；（2）热量传递；
空气烟气空气预热器示意图大功率晶体管冷却
5
传统热管的广泛应用与局限
加热炉烟气余热回收热管换热器
七热管 1942年，美国俄亥俄通用发动机公司的Gargler首次提出热管设想 1964年，美国Los Alamos 科学实验室的Grover等发明了第一根：
（1）传热能力强：一根钢－水热管传热能力强：一根钢－的传热能力大致相当于同样尺寸紫铜棒导热能力的1500倍棒导热能力的1500倍；（2）传热温差小；传热温差小；（3）结构简单、工作可靠、传输距结构简单、工作可靠、离长；离长；（4）热流密度可调（通过改变加热热流密度可调（段和放热段的长度或加装肋片）；段和放热段的长度或加装肋片）；（5）采用不同的工质可适用不同的温度范围（－～2200度（－200 温度范围（－200～2200度）

heatpipe

Heat pipes for electronics coolingapplicationsScott D. Garner, PE., Thermacore IncFigure 1: Heat pipe operationIntroductionAll electronic components, from microprocessors to high end power converters, generate heat and rejection of this heat is necessary for their optimum and reliable operation. As electronic design allows higher throughput in smaller packages, dissipating the heat load becomes a critical design factor. Many of today's electronic devices require cooling beyond the capability of standard metallic heat sinks. The heat pipe is meeting this need and is rapidly becoming a main stream thermal management tool.Heat pipes have been commercially available since the mid 1960's. Only in the past few years, however, has the electronics industry embraced heat pipes as reliable, cost-effective solutions for high end cooling applications. The purpose of this article is to explain basic heat pipe operation, review key heat pipe design issues, and to discuss current heat pipe electronic cooling applications.Heat Pipe OperationA heat pipe is essentially a passive heat transfer device with an extremely high effective thermal conductivity. The two-phase heat transfer mechanism results in heat transfer capabilities from one hundred to several thousand times that of an equivalent piece of copper.As shown in Figure 1, the heat pipe in its simplest configuration is a closed, evacuated cylindrical vessel with the internal walls lined with a capillary structure or wick that is saturated with a working fluid. Since the heat pipe is evacuated and then charged with the working fluid prior to being sealed, the internal pressure is set by the vapor pressure of the fluid.As heat is input at the evaporator, fluid is vaporized, creating a pressure gradient in the pipe. This pressure gradient forces the vapor to flow along the pipe to a cooler section where it condenses giving up its latent heat of vaporization. The working fluid is then returned to the evaporator by the capillary forces developed in the wick structure.Heat pipes can be designed to operate over a very broad range of temperatures from cryogenic (< -243°C) applications utilizing titanium alloy/nitrogen heat pipes, to high temperature applications (>2000°C) using tungsten/silver heat pipes. In electronic cooling applications where it is desirable to maintain junction temperatures below 125-150°C, copper/water heat pipes are typically used. Copper/methanol heat pipes are usedif the application requires heat pipe operation below 0°C.Heat Pipe DesignThere are many factors to consider when designing a heat pipe: compatibility of materials, operating temperature range, diameter, power limitations, thermal resistances, and operating orientation. However, the design issues are reduced to two major considerations by limiting the selection to copper/water heat pipes for cooling electronics. These considerations are the amount of power the heat pipe is capable of carrying and its effective thermal resistance. These two major heat pipe design criteria are discussed below.Limits To Heat TransportThe most important heat pipe design consideration is the amount of power the heat pipeis capable of transferring. Heat pipes can be designed to carry a few watts or several kilowatts, depending on the application. Heat pipes can transfer much higher powers for a given temperature gradient than even the best metallic conductors. If driven beyond its capacity, however, the effective thermal conductivity of the heat pipe will be significantly reduced. Therefore, it is important to assure that the heat pipe is designed to safely transport the required heat load.The maximum heat transport capability of the heat pipe is governed by several limiting factors which must be addressed when designing a heat pipe. There are five primary heat pipe heat transport limitations. These heat transport limits, which are a function of the heat pipe operating temperature, include: viscous, sonic, capillary pumping, entrainment or flooding, and boiling. Figures 2 and 3 show graphs of the axial heat transport limits asa function of operating temperature for typical powder metal and screen wicked heat pipes. Each heat transport limitation is summarized in Table 1.Heat Transport Limit Description Cause Potential SolutionViscousViscous forces preventvapor flow in the heat pipeHeat pipe operating belowrecommended operatingtemperatureIncrease heat pipeoperating temperature orfind alternative workingfluidSonicVapor flow reaches sonicvelocity when exiting heatpipe evaporator resulting ina constant heat pipetransport power and largetemperature gradientsPower/temperaturecombination, too muchpower at low operatingtemperatureThis is typically only aproblem at start-up. Theheat pipe will carry a setpower and the large ^Twill self correct as theheat pipe warms upEntrainment/Flooding High velocity vapor flowprevents condensate fromreturning to evaporatorHeat pipe operating abovedesigned power input or attoo low an operatingtemperatureIncrease vapor spacediameter or operatingtemperatureCapillary Sum of gravitational, liquidand vapor flow pressuredrops exceed the capillarypumping head of the heatpipe wick structureHeat pipe input powerexceeds the design heattransport capacity of theheat pipeModify heat pipe wickstructure design or reducepower inputBoilingFilm boiling in heat pipeevaporator typically initiatesat 5-10 W/cm2 for screenwicks and 20-30 W/cm2 forpowder metal wicksHigh radial heat flux causesfilm boiling resulting inheat pipe dryout and largethermal resistancesUse a wick with a higherheat flux capacity orspread out the heat load Table 1: Heat pipe heat transport limitationsFigure 2: Predicted heat pipe limitationsAs shown in Figures 2 and 3, the capillary limit is usually the limiting factor in a heat pipe design.Figure 3: Predicted heat pipe limitsThe capillary limit is set by the pumping capacity of the wick structure. As shown in Figure 4, the capillary limit is a strong function of the operating orientation and the type of wick structure.Figure 4: Capillary limits vs. operating angleThe two most important properties of a wick are the pore radius and the permeability. The pore radius determines the pumping pressure the wick can develop. The permeability determines the frictional losses of the fluid as it flows through the wick. There are several types of wick structures available including: grooves, screen, cables/fibers, and sintered powder metal. Figure 5 shows several heat pipe wick structures.It is important to select the proper wick structure for your application. The above list is in order of decreasing permeability and decreasing pore radius.Grooved wicks have a large pore radius and a high permeability, as a result the pressure losses are low but the pumping head is also low. Grooved wicks can transfer high heat loads in a horizontal or gravity aided position, but cannot transfer large loads against gravity. The powder metal wicks on the opposite end of the list have small pore radii and relatively low permeability. Powder metal wicks are limited by pressure drops in the horizontal position but can transfer large loads against gravity.Effective Heat Pipe Thermal ResistanceThe other primary heat pipe design consideration is the effective heat pipe thermal resistance or overall heat pipe T at a given design power. As the heat pipe is a two-phase heat transfer device, a constant effective thermal resistance value cannot be assigned. The effective thermal resistance is not constant but a function of a large number of variables, such as heat pipe geometry, evaporator length, condenser length, wick structure, and working fluid.Figure 5: Wick structuresThe total thermal resistance of a heat pipe is the sum of the resistances due to conduction through the wall, conduction through the wick, evaporation or boiling, axial vapor flow, condensation, and conduction losses back through the condenser section wick and wall.Figure 6 shows a power versus T curve for a typical copper/water heat pipe.Figure 6: Predicted heat pipe Delta-TTThe detailed thermal analysis of heat pipes is rather complex. There are, however, a few rules of thumb that can be used for first pass design considerations. A rough guide for a copper/water heat pipe with a powder metal wick structure is to use 0.2°C/W/cm2 for thermal resistance at the evaporator and condenser, and 0.02°C/W/cm2 for axial resistance.The evaporator and condenser resistances are based on the outer surface area of the heat pipe. The axial resistance is based on the cross-sectional area of the vapor space. This design guide is only useful for powers at or below the design power for the given heat pipe.For example, to calculate the effective thermal resistance for a 1.27 cm diametercopper/water heat pipe 30.5 cm long with a 1 cm diameter vapor space, the following assumptions are made. Assume the heat pipe is dissipating 75 watts with a 5 cm evaporator and a 5 cm condenser length. The evaporator heat flux (q) equals the power divided by the heat input area (q = Q/A evap; q = 3.8 W/cm2). The axial heat flux equals the power divided by the cross sectional area of the vapor space (q=Q/A vapor; q = 95.5W/cm2).The temperature gradient equals the heat flux times the thermal resistance.T = q evap * R evap + q axial * R axial + q cond * R condT = 3.8 W/cm2 * 0.2°C/W/cm2 + 95.5 W/cm2 * 0.02°C/W/cm2+ 3.8 W/cm2 * 0.2°C/W/cm2T = 3.4°CIt is important to note that the equations given above for thermal performance are only rule of thumb guidelines. These guidelines should only be used to help determine if heat pipes will meet your cooling requirements, not as final design criteria. More detailed information on power limitations and predicted heat pipe thermal resistances are given in the heat pipe design books listed in the reference section.Heat Pipe Electronic Cooling Applications:Perhaps the best way to demonstrate the heat pipes application to electronics cooling is to present a few of the more common examples. Currently, one of the highest volume applications for heat pipes is cooling the Pentium processors in notebook computers. Due to the limited space and power available in notebook computers, heat pipes are ideally suited for cooling the high power chips.Fan assisted heat sinks require electrical power and reduce battery life. Standard metallic heat sinks capable of dissipating the heat load are too large to be incorporated into the notebook package. Heat pipes, on the other hand, offer a high efficiency, passive, compact heat transfer solution. Three or four millimeter diameter heat pipes can effectively remove the high flux heat from the processor. The heat pipe spreads the heat load over a relatively large area heat sink, where the heat flux is so low that it can be effectively dissipated through the notebook case to ambient air. The heat sink can be the existing components of the notebook, from Electro-Magnetic Interference (EMI) shielding under the key pad to metal structural components. Various configurations of notebook heat pipe heat sinks are shown in Figure 7.Figure 7: Typical notebook heat pipe heat sinkTypical thermal resistances for these applications at six to eight watt heat loads are 4 - 6°C/watt. High power mainframe, mini-mainframe, server and workstation chips may also employ heat pipe heat sinks. High end chips dissipating up to 100 watts are outside the capabilities of conventional heat sinks. Heat pipes are used to transfer heat from the chip to a fin stack large enough to convect the heat to the supplied air stream. The heatpipe isothermalizes the fins eliminating the large conductive losses associated with standard sinks. The heat pipe heat sinks, shown in Figure 8, dissipate loads in the 75 to 100 watt range with resistances from 0.2 to 0.4°C/watt, depending on the available air flow.Figure 8: High end CPU heat pipe heat sinkIn addition, other high power electronics including Silicon Controlled Rectifiers (SCR's), Insulated Gate Bipolar Transistors (IGBT's) and Thyristors, often utilize heat pipe heat sinks. Heat pipe heat sinks similar to the one shown in Figure 9, are capable of cooling several devices with total heat loads up to 5 kW. These heat sinks are also available in an electrically isolated versions where the fin stack can be at ground potential with the evaporator operating at the device potentials of up to 10 kV. Typical thermal resistances for the high power heat sinks range from 0.05 to 0.1°C/watt. Again, the resistance is predominately controlled by the available fin volume and air flow.Figure 9: High power IGBT heat pipe heat sink。

ThermingDissipine散热新材——HeatPipe热管

ThermingDissipine散热新材——HeatPipe热管智能手机性能不断提升的今天，除续航这一老大难问题以外，散热也是经常困扰厂家和用户的一个大问题，现在智能手机上传统的散热设计已经不能用户的需求了。

日本古河电工(Furukawa Electric)、台湾超众科技(Chaun-Choung Technology)、Auras以及泰硕电子(TaiSol Electronics)、科思博科技(CASPAR Technology)，这几家公司在未来的几个月内可能将收获大量的订单，因为传闻苹果、三星和HTC，都计划在新一代的智能手机当中，使用超薄热管技术加强散热；而科思博科技(CASPAR Technology)在VR头盔领域的散热技术更是受到设计师的强烈欢迎。

高性能微电子芯片及应用系统的微型化和高集成化，导致散热空间狭小及高热流密度问题，使得采用铝或铜材料的常规空气强制对流散热方式已难以满足今后进一步发展要求。

热管是利用相变传热的微热管具有极高导热率、体积小、重量轻、具有良好的等温性、无需额外电力驱动等优点。

极大提高了芯片至环境间的热传导速率，实现芯片发热量的快速散失。

热管广泛应用于计算机笔记本CPU散热器、投影仪、数码产品、变频器、大功率LED路灯及LED汽车前大灯、大功率IC等微电子和光电领域。

可为航空航天、石油化工、医疗保健（便携设备、深冷治疗、放射治疗等）、节能新能源（太阳能、余热回收）等多个领域提供热控制解决方案，克服高能耗，高集成度产品开发过程中遇到的热瓶颈问题。

•随着手机、平板的硬件越来越强大，不可避免地造成功耗与热量随之攀升，更高效的散热手段就必不可少了，超薄热管正式顺应这种趋势而产生的。

•目前，日本和台湾的多家散热厂商都已经做好了量产0.6毫米超薄热管的准备，而且并不满足，准备在此基础上继续缩减25％，也就是做到仅仅0.45毫米（已有公司可以做到0.2mm极致厚度的产品，但不具量产性）。

热传培训基础之热管培训基础

三、Heatpipe 基础 ——热管的结构（5）
常用工作介质：
工质
氨 R11 甲醇水氟里昂钠锂
凝固点（℃）正常沸点（℃）工作范围（℃）
-78
-33
-60~100
-111
24
-40~120
-98
64
10~130
0
100
30~300
12
257
150~395
98
892
600~1200
179
0.200 3
0.150
0.100
0.050 5
0.000
Time
Life Test Cont’d
Rca 222222222222222222222222222222222000000000000000000000000000000000000000000000000000000000000000000333333333333333333333333344444444.................................000000000000001111111111100000000778888888899990000111112212344567.................................230011222300122223001120212102110603616037037120370382715563878946
三、Heatpipe 基础 ——目录
概述热管的工作原理热管的特性热管的热传导极限热管的结构热管的测试热管的应用
三、Heatpipe 基础 ——概述
1963 年美国 Los Alamos 国家实验室的 G.M.Grover 发明了一种称作为『热管』的传热组件，它充分利用热传导原理与致冷介质快速热传递性质，在很小的温差下就能有很大传热量，然后透过热管将发热物体的热量迅速传递到体外，其导热能力超过了目前任何已知金属的导热能力，具有热的超导体的美誉。