Heat Transfer in Condensers:
In a water-cooled condenser the heat transfer is described by the Equation given below
...3.18
Here U indicates the overall heat transfer coefficient depends on the surface area A of the condenser and ?t indicate the overall temperature difference. Given figure illustrate the components of the heat-transfer resistance in a water-cooled condenser, like as the outside metal wall, refrigerant film, scaling on water-side surface & inside- water film. The whole resistance is attained by adding all the resistances that are in series.
![2423_Heat Transfer in Condensers1.png](https://www.expertsmind.com/CMSImages/2423_Heat%20Transfer%20in%20Condensers1.png)
Thermal Resistance in Water-Cooled Condenser
![1012_Heat Transfer in Condensers2.png](https://www.expertsmind.com/CMSImages/1012_Heat%20Transfer%20in%20Condensers2.png)
Here
U0 = Overall heat-transfer coefficient depend on the outside surface area
h0= Condensing film coefficient of heat transfer
A0 = Outside or refrigerant-side area
k = Thermal conductivity of the tube material
Am = Mean tube surface area
hf = Coefficient of heat transfer through the scale
Ai = Inside or water-side area
hi= Water-side coefficient of heat transfer.
Therefore the overall heat-transfer coefficient may be found out from the above Equation 3.19 after determining the individual resistances.