What is the purpose of the fins on finned tube coils?
The fins on a coil accomplish two major functions: they straighten the air out as it comes in contact with the entering-air side of the coil, and they perform some of the heat transfer. Understand the basics of finned tube coils and maximize coil capacity and efficiency.
What is a fin tube heat exchanger?
Finned tubes are the main components of heat exchangers. They are a series of tubes where fins have been added on the outside to increase the contact area with the outside fluid, to exchange heat and between the fluid inside the tube and the fluid outside the tube.
How do you calculate the heat transfer coefficient of a heat exchanger?
The overall heat transfer coefficient R = Resistance(s) to heat flow in pipe wall (K/W) Other parameters are as above. The heat transfer coefficient is the heat transferred per unit area per kelvin. Thus area is included in the equation as it represents the area over which the transfer of heat takes place.
What is finned tube evaporator?
The finned evaporators are the bare tube type of evaporators covered with the fins. When the fluid (air or water) to be chilled flows over the bare tube evaporator lots of cooling effect from the refrigerant goes wasted since there is less surface for the transfer of heat from the fluid to the refrigerant.
Will adding more fins on a surface cause the overall heat transfer coefficient and heat transfer to increase?
Fins enhance heat transfer from a surface by increasing heat transfer surface area for convection heat transfer. However, adding too many fins on a surface can suffocate the fluid and retard convection, and thus it may cause the overall heat transfer coefficient and heat transfer to decrease.
Where are finned tubes used?
Fin tube heat exchangers are used in air conditioners and car radiators. The purpose of using a finned tube in an air conditioner is to cool the air passing through it. In a car radiator, it cools the liquid in the tube with the air passing through in crossflow.
How do you convert heat transfer coefficient units?
Complete list of heat transfer coefficient units for conversion
- watt/square meter/K.
- 1 watt/square meter/%b0C = 1 watt/square meter/K.
- 1 joule/second/square meter/K = 1 watt/square meter/K.
- 1 calorie (IT)/second/square centimeter/%b0C = 41868.00000482 watt/square meter/K.
What does the heat transfer coefficient depend on?
The fluid motion enhances heat transfer (the higher the velocity the higher the heat transfer rate). The convective heat transfer coefficient h strongly depends on the fluid properties and roughness of the solid surface, and the type of the fluid flow (laminar or turbulent).
What is fin efficiency?
Fin efficiency is defined as the ratio of actual heat flow of the fin to that which would be obtained with a fin of constant temperature uniformly equal to the base surface temperature, that is, one with infinite thermal conductivity.