EDM WQL H RC 524 1604

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WQL/WQH/WQRC 524-1604
12
Correction Factors
Unit capacity, absorbed power, brine ow rate, brine pressure drop, have to be corrected according to following formula:
Corrected unit capacity:
Q
CORRECTED/GLYCOL
= Q
NOMINAL
x K
c
x K
c
E,P
Where K
c
= capacity corrective factor according to LWT (∆T = 5 [K])  refer to Table 1
K
c
E
= capacity corrective factor according to glycol percentage (ETHYLENE GLYCOL)  refer to Table 2
K
c
P
= capacity corrective factor according to glycol percentage (PROPYLENE GLYCOL)  refer to Table 4
Corrected unit absorbed power:
P
CORRECTED/GLYCOL
= P
NOMINAL
x K
i
x K
i
E,P
Where K
i
= absorbed power corrective factor according to LWT (∆T = 5 [K])  refer to Table 1
K
i
E
= absorbed power corrective factor according to glycol percentage (ETHYLENE GLYCOL)  refer to Table 2
K
i
P
= absorbed power corrective factor according to glycol percentage (PROPYLENE GLYCOL)  refer to Table 4
Corrected brine ow rate:
G
CORRECTED/GLYCOL
= G
RE-CALCULATED
x K
f
E,P
Where G
RE-CALCULATED
= flow rate according to P
CORRECTED/GLYCOL
(P
CORRECTED/GLYCOL
x 860 / ∆T / 3600)
K
f
E
= flow rate corrective factor according to glycol percentage (ETHYLENE GLYCOL)  refer to Table 2
K
f
P
= flow rate corrective factor according to glycol percentage (PROPYLENE GLYCOL)  refer to Table 4
Corrected brine pressure drop:
∆P
CORRECTED/GLYCOL
= ∆P
RE-CALCULATED
x K
p
E,P
Where ∆P
RE-CALCULATED
= pressure drop according to G
CORRECTED/GLYCOL
(K
BPHE
x (G
CORRECTED/GLYCOL
)
2
)
K
p
E
= pressure drop corrective factor according to glycol percentage (ETHYLENE GLYCOL)  refer to Table 2
K
p
P
= pressure drop corrective factor according to glycol percentage (PROPYLENE GLYCOL)  refer to Table 5
Table 1
K
c
K
i
Leaving water
temperature
[LWT] (°C)
(∆T=5 [K])
7 1 1
4 0.887 0.94
2 0.816 0.9
0 0.748 0.865
-2 0.685 0.826
-4 0.624 0.788
-6 0.568 0.753
-8 0.513 0.718
-10 0.461 0.683
Table 2
Ethylene Glycol Percentage % 0 10 20 30 35 40
Freezing point (1) °C 0 -4 -10 -17 -21 -25
Minimum leaving water temperature allowed °C 6 2 -2 -6 -8 -8
Capacity corrective factor (2) K
c
E
1 0.995 0.985 0.97 0.963 0.955
Absorbed power corrective factor (2) K
i
E
1 0.998 0.995 0.985 0.983 0.98
Flow rate corrective factor K
f
E
1 1.015 1.05 1.085 1.123 1.16
Pressure drop corrective factor (3) K
p
E
1 1.07 1.16 1.235 1.283 1.33
(1) ASHRAE Handbook Fundamentals.
(2) Valid for LWT=7 °C. If LWT < 7°C consider Kc x KcE and Ki x KiE.
(3) Valid for LWT > 5 °C. If LWT < 5 °C then refer to Table 3.