What is the heat transfer principle of finned tube?
1. Heat transfer principle of finned tube
In order to understand the heat transfer principle of finned tube, let's first understand what is the heat transfer coefficient. The heat transfer coefficient refers to the heat transfer per unit temperature difference and unit heat exchange area, which can reflect the heat transfer capacity between fluid and wall.
Finned tube is a heat exchanger composed of round tube or smooth tube. How to improve the heat transfer of circular tube? One of the most effective methods is to use extended surface on the outer surface of the tube, that is, to make finned tube. It is assumed that the actual heat transfer area of finned tube is several times of the original smooth tube surface area. Although the heat transfer coefficient of flue gas is still very low, the heat transfer effect reflected on the surface area of the smooth tube will be greatly increased, so that the whole heat transfer process will be enhanced, and the metal consumption of the equipment will be reduced and the economy will be improved when the total heat transfer is fixed.
2. Application examples of finned tube
(1) Heat pipe air preheater series
Application: it can absorb waste heat from flue gas to heat combustion supporting air to reduce fuel consumption and improve combustion conditions, so as to achieve the purpose of energy saving; it can also absorb waste heat from flue gas to heat other gas media such as gas.
(2) Heat pipe economizer series
Application: heat is absorbed from flue gas to heat water supply. The heated water can be returned to boiler (as economizer) or used alone (as water heater), so as to improve energy utilization and achieve the purpose of energy saving.
(3) Heat pipe waste heat boiler (evaporator) series
Application: heat pipe is used as heat transfer element to absorb the waste heat of flue gas with high temperature to generate steam. The steam generated can be combined into steam pipe network (to reach the pipe network pressure), and can also be used for power generation (large steam volume and stable heat source) or other purposes.
