Regarding the design of a finned Tube Evaporators, Here Lando cooling exporter would like to give you a brief introduction on how to quickly design of finned tube evaporator in a water chiller system.
We use to calculate the different working conditions, the evaporator heat transfer temperature difference △ T, and heat transfer coefficient K values. with these △ T and K values, we can quickly calculate the evaporation area, we use the above simulation values to do a quick trial calculation of the evaporation area and evaporator Excel table, for the subsequent actual design.
The △T and K values shown above are those simulated by CoilDesigner in the previous lesson, which is still accurate based on empirical values in our industry.
We make the following table to calculate the evaporation area needed for different conditions, and then select the largest evaporation area as the heat transfer area needed for our design, and design the size of the evaporator based on this area; as follows.
Then select the above and design the evaporator size according to the following table.
Then let’s design a set of the evaporator for a 12HP unit (BITZER: 4TES-12Y-40S), the ambient temperature range: -40℃~55℃, evaporation temperature: -45℃~5℃; through the compressor selection software, we can get the cooling capacity and refrigerant flow rate of the compressor with different evaporation temperatures as follows.
The different evaporation temperatures of the compressor correspond to the following cooling capacity and refrigerant flow rates.
We enter the cooling capacity for different conditions into a trial Excel sheet as follows.
From the above calculation, the maximum evaporation area is 72.81 m2. Enter the following trial tool.
We take the results of the above design, enter them into the CoilDesigner software, and do a review, set the parameters.
Flow Path Mapping.
Set inlet/outlet parameters.
The following calculations are obtained.
We do not show the results for the other state points, but the final summary table is as follows.
As shown in the table above, the heat transfer of each state point is sufficient, and the design of the evaporator can be considered reasonable.
(also find some information from here )
Here need to be clear, if our heat exchanger tube diameter and tube spacing, row spacing is not the same, the K value deviates, So you need to make it according to their mold to calculate the different K values and △ T values when you design of finned heat exchanger!
Regarding the chiller system design, please check the below information to know more.
If you have any other technical questions, please kindly contact us at sales@cnlando.com.
