Refrigeration Heat Exchanger Design (Evaporator and Condenser)

AI Thread Summary
The discussion focuses on estimating the total heat transfer area for the evaporator and condenser in a domestic refrigeration system using a vapor compression cycle. The user seeks realistic values for the heat transfer area and overall heat transfer coefficient, specifically for the cold side of the system, to aid in calculating the overall heat transfer coefficient. They provide specific parameters, including heat removed (7.93 KW) and temperature values, to facilitate the estimation process. The project aims to determine the optimal heat transfer ratio between the hot and cold sides, emphasizing the importance of accurate area estimation over coefficient estimation. The user notes that evaporators typically feature fins to enhance heat transfer efficiency due to greater resistance on the air side.
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Hi There

Based on a Vapour compression refrigeration system:
Does anyone out there know a good estimate or any real values for the total heat transfer area for the hot and cold sides of a domestic refrigeration system? i.e. the sum of the areas of the evaporator and the condenser.

For the Evaporator:
QL=UL.AL.(TL-T1)

AL=heat transfer area of cold side (Low side)=?
UL=overal heat trans. coefficient of cold side.=?
QL=heat removed from cold side = 7.93 KW
TL=refrigerator temp. = 3degs C + 273.15=276.12 Kelvin
T1= Refrigerant evaporating temp. =0degs C + 273.15= 273.15 Kelvin

I am trying to estimate this area so I can calculate the overal heat transfer coefficient which I need for other calculations. So far the outcome of estimating the area and finding the heat transfer coefficient based on it has not been realistic.

If it helps:
The aim of my project is to find the optimal heat transfer ratio between hot and cold side, there is theory on this which I am following, I just need some realistic values for area and heat transfer coefficient. I think it is more logical to estimate the area and find the h.t. coefficient based on that rather than the other way around.
 
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Normally evaporators have some kind of fins (maybe just a plate that evaporator tubes are pressed into) as the resistance on the air side is much greater than that of the refrigerant to heat exchanger side.
 

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