What is heat transfer, heat transfer is wha
Objects are able to heat transfer, but the heat conduction performance of different material is different. Easy to heat transfer object is called a good conductor of heat, not easy to heat transfer object called a poor conductor of heat, metals are good conductors of heat. Porcelain, wood and bamboo, leather, water is a poor conductor. Metal is most good at heat transfer in silver, followed by copper and aluminum. Heat transfer is the worst, cotton, wool, feathers, fur, asbestos, cork and other soft materials. Asbestos often used as insulation materials. Liquid, besides mercury, are not good at heat transfer, gas are not good at heat transfer more than liquid
Heat conduction is no macroscopic movement at the time of the heat transfer phenomena in the medium, its all can happen in solid, liquid and gas, but strictly speaking, only is the pure heat conduction in solids, and fluid even in static state, which will be due to the temperature gradient caused by the natural convection resulting from the density difference, therefore, the heat convection and heat transfer in the fluid at the same time.
Rely on material molecules, atoms, or the movement of electrons (including mobile and vibration), the heat from the process of high temperature to low temperature part of the object, is one of the three basic methods of heat transfer. All objects, regardless of its internal presence of relative motion between the particle, as long as there is a temperature difference, there is heat conduction. Industry, there are many is given priority to with heat conduction heat transfer process, such as rubber products heat vulcanization, and the heat treatment of steel forgings, etc. In the kiln, heat transfer equipment and the design calculation of heat insulation and the temperature of the catalyst particle distribution analysis, the heat transfer law occupies an important position. In high temperature and high pressure equipment (such as ammonia synthesis tower and the waste heat boiler, etc.) of large-scale ethylene plant design, also need heat transfer law to calculate the equipment temperature distribution of each heat transfer within the partition for thermal stress analysis.
Each point within the object or system, the temperature difference between heat conduction is the necessary condition. Caused by heat conduction heat transfer rate (hereinafter referred to as thermal conductive rate) is determined by the distribution of temperature within the object. Temperature field is as a flash object or the total temperature distribution of each point in the system.
