建筑环境-能源应用工程专业英语5.ppt

;Topics; heat transfer equipment 传热设备 heat exchanger 热交换器 boiler 锅炉 condenser 冷凝器 radiator 散热器 refrigerator 冰箱 solar collector 太阳能集热器 heat transfer rate 传热(速)率 temperature difference 温差 factor of safety 安全系数 experimental error 实验误差 operating condition 运行条件 heat transfer coefficient 传热系数 under these adverse conditions 在最不利工况下 three forms of heat transfer: conduction 传导 convection 对流 radiation 辐射;Heat Sensible Heat Latent Heat;Conduction;For steady-state heat conduction in one dimension, the Fourier law is;The fundamental equation for unsteady-state conduction in solids or fluids in which there is no substantial motion is;Is there any mistakes?;Heat transfer involving motion in a fluid due to the difference in density and the action of gravity is called natural convection or free convection. Heat transfer coefficients associated with gases for natural convection are generally much lower than those for forced convection. Forced air coolers and heaters, forced air- or water-cooled condensers and evaporators, are examples of equipment that transfer heat primarily by forced convection. When fluid flows over a flat plate, a boundary layer forms adjacent to the plate. The velocity of the fluid at the plate surface is zero and increases to its maximum free stream value just past the edge of the boundary layer.;Radiation, one of the basic mechanisms for energy transfer between different temperature regions, is distinguished from conduction and convection in that it does not depend on an intermediate material as a car