Lesson4.1.pptVIP

content Words Expressions and Technical Terms text text text text text text text Lesson 4.1 Heat Transter words 1 Expressions and Technical Terms 2 Text 3 热量传递 transfer[tr?ns`f?:] n./v. 调动，转移，迁移 operation [??p?`rei??n] n. 操作 thermal [`??:ml] adj. 热的，热量的，温热的；由热造成的 conduction [`k?nd?k??n] n. 传导 convection [k?n`rek??n] n. 对流 radiation [?reidi`ei??n] n. 辐射 其他 mechanism [`mek?nit?m] n. 机理，原理 momentum [m?`ment?m] n. 【物理学】动量 electricity [i?lek`trisiti] n. 电流，静电，电荷 conductor [k?n`d?kt?] n. 【物理学】导体；导管，导线 opaque [?u`peik] adj. 不透明的; (对电、热等)不传导性的 random [`r?nd?m] adj. 随机的；【物理学】无规则的 furnace [`f?:nis] n. 炉子；熔炉；高炉 chemical engineering 化学工程 temperature gradient 温度梯度 results from 由…而造成[产生] unbound electron 自由电子 thermal conductivity 热传导系数 electrical conductivity 导电性 buoyancy force 浮力 in turn 反过来 natural convection 自然对流 . Heat, as a form of energy, cannot be created or destroyed. Heat can be transferred from one substance to another. 热能作为能量的一种形式既不能产生也不能被破坏,热只能从一种物质转移到另一个物质中. . Practically all the operations that are carried out by the chemical engineering involve the production or absorption of energy in the form of heat The laws governing the transfer of heat and the types of apparatus that have for their main object the control of flow are therefore of great important. 实际上化学工程中所有的操作过程都涉及到能量以热的形式的产生和吸收,因此决定传热的定律和为了传热而控制流动的设备的类型是相当重要的. . When two objects at different temperatures are brought into thermal contact, heat flows from the object at the higher temperature to that at the lower temperature. The net flow is always in the direction of the temperature decrease. The mechanisms by which the heat may flow are three: conduction, convection, and radiation 当处于不同温度的两种物体进行热交换时,热总是从温度高的物体转移到温度低的物体中,传热的方向总是向着温度较低的方向进行.传热的基理主要有三种:热传导,对流,辐射。 . If a temperature gradient exists in a continuous substance, heat can flow unaccompanied by any observable motion of matter. Heat flow of this kind is called conduction. 如果温度梯度在一个连续性无之中存在时,热交换就可以进行,并且在热交换中不会发生任何可观察到的物质运动