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7.3
CALCULATION OF THE EQUIVALENT PRESSURE DROP
For a correct and quick dimensioning of refrigerant lines please refer to the following table, developed for R410A refrigerant.
Table 1:
Cooling capacity corresponding to different tubes diameter referred to different pressure drops or speed values.
This table refers to the pressure drop values or speed values (for the liquid line) indicated in the column heading.
If different pressure drops are needed, the cooling capacity shall be corrected with the following formula:
Where:
Pf: cooling capacity
P : cooling capacity shown in table 1
Le : equivalent length of the table 1
Leff : actual equivalent length
ΔT : required pressure drop
ΔTtab: pressure drop shown in table 1
The equivalent length can be calculated as follows:
A fictitious length for each curve or branch or concentrated drop shall be added to the real lengths, corresponding to the linear tube
length that would give the same pressure drop caused by the curve or by the branch.
