传热（英语：Heat transfer），或作热传递，是热能从高温向低温部分转移的过程，传热有三种方式：

根据传热的方式和工艺要求，设计热交换器，几乎各种化学工业都有热交换过程，需要各种热交换器。

Heat transfer is the exchange of thermal energy between physical systems. The rate of heat transfer is dependent on the temperatures of the systems and the properties of the intervening medium through which the heat is transferred. The three fundamental modes of heat transfer are conduction, convection and radiation. Heat transfer, the flow of energy in the form of heat, is a process by which a system changes its internal energy, hence is of vital use in applications of the First Law of Thermodynamics. Conduction is also known as diffusion, not to be confused with diffusion related to the mixing of constituents of a fluid.