查询词典 convection heat transfer

The method of CFD numerical simulation is employed to replace experimental investigation. Hence, STAR-CD of the commercial software is used to simulate the outer flow field and heat transfer performance of integrated heat sink with heat pipes cooled by airflow. It is found that simulated results agree with experimental results well, which indicates that simulation method is reasonable and reliable. Further, simulated computations for different fin thickness, fin pitches and air velocities are performed to analyze their effects on heat transfer performance of heat sink. Finally, a new optimized structure of integrated heat sink with heat pipes is provided to meet future demands for cooling CPU and its heat transfer is also evaluated. For multi-heat source and higher dissipation power of electronic devices, the integrated heat sink with heat pipes attatched fins stagged in different positions of channels is presented and its flow and temperature fields are also simulated to enhance heat transfer. As a conclusion, all mentioned above are useful for the design of heat sink with excellent efficiency of heat dissipation and further research.

应用商业软件Star-CD对CPU集成热管散热器的外部流场和传热特性进行了数值模拟，将数值模拟结果和试验结果对比，验证了所提出的数值计算方法是可靠和可行的；利用此数值模拟方法对CPU集成热管散热器在不同散热翅片间距、厚度和气流速度下散热器的流动与传热性能进行了数值计算，分析了这些参数的变化对散热器传热性能的影响；针对未来CPU冷却的要求，确定了与最优气体流速匹配的最佳翅片间距、厚度的CPU集成热管散热器的新结构；利用试验评测了根据数值模拟提供的新结构开发出的新CPU集成热管散热器的传热性能；最后在场协同强化传热的理论的基础上，对CPU集成热管散热器的散热翅片错位排列来强化散热器的散热，满足未来大功率、多热源的电子元件的散热，为今后进一步优化散热器提供了依据。

Some parameters such as Indoor radiation heat transfer, convective heat transfer, MRT, OT, radiation heat transfer coefficient, convective heat transfer coefficient, and PMV-PPD were calculated under a steady condition. From the result, we can conclude, when operation under the combination system and worst-case test, if floor temperature is about 21℃, supply air temperature is 21℃, air velocity is 1m/s, the equlvalent coefficient of heat transfer between floor temperature and OT is 13.6w/m2k, where 5.68w/m2k is equlvalent coefficient of radiant heat transfer, 9.48w/m2k is convective heat transfer coefficient. And when air velocity is higher, supply air temperature is lower, the radiant heat transfer between floor and others is lower. In the whole experiment, the floor temperature was keeping above the indoor air dew point, and condensation was not appeared.

通过分析计算，在复合式系统运行中，最不利室外环境下，当地面温度维持在21℃左右，送风温度21℃，送风风速1m/s，此时地板对作用温度的当量综合换热系数为13.6w/m2k，其中当量辐射换热系数为5.68w/m2k，对流换热系数为9.48w/m2k，并且送风速度越高、送风温度越低，地板与其他壁面的辐射换热量有一定程度的降低，但总供冷量增加；在整个实验中地板温度始终高于地板上层空气的露点温度，并未发现有结露现象；室内空气温度梯度能满足0.1m-1.1m的温差小于3℃的要求，并且适当提高送风温度可以进一步提高人体的热舒适性。

First is enhances the boiler the heat energy transfer rate,(1) changes the vertical chimney to the horizontal-type chimney, reduces the speed of flow, Increase the time which the actuating medium and the boiler hot flame doing heat change;(2) changes the high temperature system sole medium sole heat transfer area to many kinds of medium the multi-channel heat transfer area(2-6 medium, 2-6 heat transfer area, this article takes four medium, 4 heat transfer areas confer elaboration), the increase heat transfer flow path through many times heat absorption,Lets the pot furnace coal flame heat energy as far as possible much transmit gives the actuating medium, Enables the quantity transfer rate from the present 60%--75% enhances to is bigger than 95

第一是提高锅炉的热能转移率，（1）将立式烟囱改为卧式烟囱，降低流速，增加工作介质与锅炉热焰气的热交换时间；（2）将高温系统单一介质的单一换热区改为多种介质的多道换热区（2—6种介质， 2—6道换热区，本文取四种介质，4道换热区加予论述），增加换热流程，通过多次吸热，让工作介质尽可能多地把锅炉煤焰气的热能传递给工作介质，使能量转移率从现在的60%--75%提高到大于95

On the basis of the conservation equation of continuous medium and in combination with mechanics of fluid through porous media and the heat transfer theory in porous media, conservation equations in porous media (continuous equation, momentum equation and energy equation ) are derived, When constructing the downhole temperature model, heat transfer in a wellbore is considered as the heat transfer in a vertical tube, the flow in a wellbore considered as sufficiently parallel flow, heat transfer in injection zones considered as heat conduction and convection in porous media, the flow in injection zones considered as flow through porous media, heat transfer in adjacent rocks considered as heat conduction in porous media.

在建立井下温度场模型时，把井筒的传热看作是竖直圆管中传热问题，把井筒的流动看作是充分发展的层流流动；把注入层中的传热看作是多孔介质中导热和对流的传热问题，把注入层中的流动看作是渗流；把围岩中的传热看作是多孔介质中导热问题。

Experiment results show as follows in the processing of semiconductor etching, chemical heat centers in the semiconductor material, and is convected gradiently in all directions; the vertical heat convection velocity is obviously swifter than the horizontal; the process of heat convection can be real- timely recorded, and the heat convection situation can be gotten in any small area at any time by infrared camera which makes the analyse and understanding of heat convection characteristic in the processing of wet etching more intuitionistic.

实验结果表明：在半导体腐蚀过程中，化学热以半导体材料为中心，向四周梯度状对流；向上的热对流速率明显大于水平的热对流速率；红外热像仪可以实时纪录热对流过程，并获得任意时刻、任意小区域的热对流情况，使得对湿法腐蚀过程中热对流特性的分析和理解更加直观。

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Based on a computing model of floor heating residences, indoor thermal environment and heat distribution under the effect of heat charge/discharge, operation control and solar radiation has been concluded. Concept and formula of equivalent heat supply has been put forward which indicate that actual heat supply will be equal to the sum of design heat supply and equivalent heat supply. Recommend coefficient has been given taken Dalian as an example. Computed according to the new method, design heat supply can be reduced to 37% in cloudy day and 43.3% in sunny day, energy saving effect is very obvious. In Tromb wall solar house, effect of concrete wall on indoor temperature swing and attenuation of temperature wave is very obvious. While the outdoor air-temperature swing exceeds 10℃, indoor air-temperature swing belows 3℃. In the experiment, maximal difference in temperature between inner surface and outer surface of the 300mm wall exceeded 10℃. Heat storage and collector efficiency varies adversely according to solar radiation. Factors such as thickness, material, absorptance of the wall and permeation of the glass cover all have big influence on heat storage and collector efficiency. There exsisted an optimal thickness of the wall, which can make the best of heat storage and collector efficiency. Most of the heat stored in conventional Trombe wall during the daytime has been lost to the outside at night without heat preservation. Heat preservation on the outside surface of the wall has effectively improved heat release performance of the wall at night, heat supply to the room has increased too.

通过建立的地板采暖系统动态热性能分析模型，得出了在蓄放热特性、运行方式和太阳辐射等因素耦合作用下的室内热环境及热量分配比例，提出了等效供热量的概念及计算公式，指出实际所需供热量应等于设计供热量加上等效供热量，并以大连为例，给出了等效供热量的修正系数，以新方法计算，阴天可减少设计供热量37％，晴天最大可以减少设计供热量43.3％，节能效果显著；集热蓄热墙式太阳房中，混凝土蓄热墙的室温均一化效果和对温度波的削减作用非常明显，当室外温度波动最大幅度超过10℃时，室温波幅不超过3℃，实验中300mm厚墙体内外表面温差超过10℃；墙体蓄热效率与集热效率随太阳辐射照度的变化呈相反的变化趋势；墙体厚度、材料、表面吸收率以及盖板透过率等因素对集热和蓄热效率均有较大的影响，存在一个最佳的墙体厚度值，使得墙体集热和蓄热综合性能最优；传统的蓄热墙夜间没有外保温，辐射散热损失很大，研究表明墙体外保温方式明显改善了蓄热墙夜间的散热性能，增加了向室内的供热量。

Firstly, the mechanism of heat transfer enhancement by oscillation heat surface is discussed in natural convection scene. For different oscillation amplitude and Rayleigh number, the frequency that the heat transfer rate of oscillation heat surface is higher than non-oscillation condition is found and called critical oscillation frequency. The limitation enhancement of similar physical model is still researched by this study in mixed and forced convection scenes for different amplitude and Grashof number. Generally, that a heat surface subject to a oscillation motion is advantageous to convective heat transfer is a well-known tuition.

首先探讨在垂直管道内振动高温面於自然对流领域内提升高温面热传效率的机制，并且针对不同的振幅与雷利数求得加入振动条件后，高温面散热效果可以优於稳态非振动高温面散热效果的临界振动频率；进而探讨当垂直管道流进入混合对流与强制对流范围时，在不同的振幅与葛瑞秀夫数下，亦可发现加入振动条件后，振动高温面之散热效果可以优於稳态非振动高温面散热效果的临界振动频率。

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In actual reactors, the cooling condition outside the hexcan-wall of blocked fuel subassembly is analogous to its counterparts in the SCARABEE BE+ experiments. The upward and downward heat transfer could be neglected, while the radial heat transfer plays a key role in slowdown the accident scenario. As time goes on, the dominant radial heat transfer mechanism is liquidus sodium convection at first, and then gradually transforms into sodium condensation near the inner surface of the hexcan-wall, and finally becomes volume heated boiling pool convection.

对实际快堆中发生全堵的燃料组件而言，其外部的冷却条件与SCARABEE BE+系列实验非常相似；2）堵流组件向上和向下的传热可忽略不计，径向传热对事故有较强的延缓作用；3）随着时间推进，径向传热的主导机理依次为液态钠单相对流、钠蒸汽在组件盒内壁冷凝、体热源沸腾池散热。

Listen,point and check your answers.

听，指出并且检查你的答案。

Warming needle is one of effective treatment methods for knee arthralgia aggravated by cold,and it is simple,safety,so it should be developed in clinical acupuncture and moxibustion extensively.

但以本院科针灸门诊在2005年1月—2006年6月期间共收治膝痛患者100余例，经过临床的诊断后，其中施以温针治疗的48例，疗效显著，报道如下。1临床资料本组病例48