传热

Since the initial start of buried pipelines results in three-dimen-sional unstable heat transmission , and at initial start the temperature change of the soil around a pipeline is affected by the temperature inside the pipeline and the ground surface temperature annual fluctuation, the differential equation for heat transmission and the boundary value may be line...

埋地输油管道启输过程是三维非稳定传热问题，启输过程中管周土壤温度场的变化受管内热水温度和启输前地表面温度年波幅的影响，可将传热微分方程和边值条件线性组合成两个定解问题，用电子计算机进行数值求解，得出计算公式，以确定预热阶段管路任一点任一时刻的热水介质温度。

It plays an important part in saving energy and decreasing the volume and weight of heat exchanger.

本文所研究的被称为强化传热革命的三维内肋管就是应用于各种换热器中单相强迫对流换热的新型强化传热管。

In the area of high technology of China, the developing technology of cryogenic thermodynamic process and heat transfer has resulted in the Shenzhou-V man-carrying space ship, Fengyun-III meteorological satellite and magnetic suspension train. Manufacturing of fuel (liquid hydrogen and liquid oxygen) of a cryogenic rocket, the cryocooler used to cool down infrared sensors, cryogenic-condensation vacuum pump used in manufacturing of semiconductors, super-conduct quantum interferometer and liquefied natural gas technology are all outcomes of the studies on cryogenic thermodynamic process and heat transfer. In these areas, there are many unexploited sub-areas. Therefore, cryogenic thermodynamic process and heat transfer is a developing study area, and is await more jobs by the younger generation.

在高科技领域，我国空间探索用&神州五号&载人飞船的成功发射、&风云三号&气象卫星的可靠运转以及磁悬浮列车技术等都与低温热力过程与传热技术的研究进展密切相关的，低温火箭发动机液氢液氧燃料的生产、红外传感器冷却的低温制冷机、半导体制造业用的低温冷凝真空泵、超导量子干涉仪与液化天然气的储运等技术都是低温热力过程与传热技术研究发展的产物，且有很多新技术有待于开发，是一个与时俱进、不断开拓的领域，有待于有志者去开发。

On the basis of analyzing the thermodynamic properties and cycle performance of pure refrigerants, the paper optimizes their concentration while screening NARMs used in wide variable-temperature heat source. The practical applications of NARMs, such as R22/R123, R123/R125 etc., are studied in geothermal heat pump, seawater heat pump, air dehumidification system and dual-evaporator domestic refrigerator. The results show that the NARMs can match the limitation of a pinch point at the air-side exit of heat exchanger, reduce the unreasonable heat transfer temperature difference, and improve the COP of system. The above conclusion is proved by measuring the cycle performance of R12, MP39 and R11/R22 in a two-evaporator experimental system.

其次，本文在工质热物性和变工况循环性能分析基础上，筛选和优化了适应外部大变温热源约束条件的非共沸混合工质及其浓度配比；讨论了相变温差较大的非共沸混合工质（如R22/R123、R123/R125等）在地热源供热热泵、海水源供热热泵、双门冰箱和热泵空气除湿的应用，计算分析表明制冷与热泵系统采用相变温差较大的非共沸混合工质有利于弱化传热过程的&窄点&的约束，减小传热过程中的不合理温差，提高系统COP值；通过建立双蒸发温度循环系统试验装置，对R12、R22/R11和R22/R152a/R124循环性能进行实验研究，结果与理论分析一致。

The invention is suitable for pipe shell type heat exchanger, better heat transfer effect can be achieved by adopting the arrangement method for heat transfer pipe according to the invention, and heat exchanger having different temperature difference of intake water and outtake water can be conveniently combined.

本发明适用于管壳式换热器，在换热装置中采用本发明的传热管的排列方法，可以达到较好的传热效果，而且可以方便地组合成不同进、出水温差的换热器。

The quasi steady state analytical method is used to calculate the temperature in the heat structure.

用集总参数法来计算热传导；在正常的工况下，用含两个传热区的两相对流传热模型，计算流体与管壁间的换热。

The flowand heat transfer performances of two-row bundles with different fin spacing are carriedout. The effects of fin spacing on air-side heat transfer coefficient and flow resistance arediscussed.

对不同翅片间距的两排管管束流动和传热性能进行了分析，得到翅片间距变化对空气侧表面传热系数和流动阻力的不同作用规律。

In the model, coefficient E is defined to evaluate the resistance in heat transfer between water and air.

从传热传质的基本原理入手，详细分析了饱和器内水气之间的传热传质过程，建立了饱和器的一维数学模型。

On the basis of simplifying, the heat load formula and heat transfer model of paint-drying box is put forward.

归纳整理出了钢瓶热载体烤漆系统中的烤漆炉热负荷计算公式，初步提出了钢瓶热载体烤漆系统中的烤漆炉的传热模型并整理出了传热计算方法。

By means of numerical simulation in different heat conduction processes,the steady-state temperature field in upper arm skin tissue,the temperature distribution and the burn depth threshold after 15 s exposure to a heat source at 90 ℃,the su...

通过数值模拟，获得了不同皮肤组织结构模型下上臂皮肤组织内的稳态温度场和90℃高温热源作用15 s后皮肤组织内的温度分布，以及皮肤组织热损伤深度的变化、常热流作用下皮肤组织表面的温升曲线和表面绝热条件下皮肤组织内的稳态温升分布。研究结果表明，皮肤组织的多层传热数学模型更能真实地描述皮肤组织内的传热过程，因此值得在实际工作中推广应用。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。