Heat transfer in heat exchanger is a common phenomenon. Due to high temperature difference and produce heat from the transfer to low temperature, and momentum transfer, mass transfer and classified as three transfer process.
In nature, the heat transfer is a common phenomenon. Two objects or between different parts of the same object, as long as there is a temperature difference between, there will be an heat transfer, until the same everywhere temperature so far. In the chemical production process, the general meeting of the material heating, cooling or heat preservation, involves heat transfer.
In addition, there are many occasions, heat transfer with other transfer is performed at the same time. For example in the dry operation, the quality of heat transfer and transfer occur at the same time; And in the reactor, the momentum of heat transfer and transfer, mass transfer and chemical reaction happening at the same time.
Heat transfer of heat transfer, a popular heat and radiation heat transfer three ways. Heat conduction rely on the molecules of a material, the atomic or electronic mobile or (and) vibration to transfer heat the heat transfer fluid and molecular momentum transfer similar.
Convection heat transfer fluid depend on the macro movement to the mass transfer heat, so it can only exist in a fluid, with momentum relay. Radiation heat transfer is through transfer heat wave and did not require material for the media.