Application data (cont)
EXAMPLE — SI
I Determine concentration of inhibited ethylene
glycol (EG) solution required to protect the sys-
tem to −17.8 C (at zero flow).
From Solution Crystallization Point correction curve at
right: 35% EG concentration is required for solution
crystallization at −17.8 C.
Consider the 30HR080 unit selected in the Selection
Procedure section on page 17.
II Correct unit capacity.
On Capacity Correction curve at right, read 0.965 cor-
rection factor at 35% concentration.
Corrected Capacity = 0.965 x Rated Capacity
= 0.965 x 273.1
= 263.4 kW
III Correct cooler water flow rate (L/s).
On Cooler Flow Correction curve at right, read 1.112
correction factor at 35% concentration.
Cooler Water Flow
(at corrected capacity)
=
kW x .239
D
T
=
263.4 x .239
5.6
= 11.2 L/s
Cooler Water Flow
(35% EG)
= 1.112 x 11.2 = 12.5 L/s
IV Correct cooler pressure drop.
On Cooler Pressure Drop Correction curve at right,
read 1.28 correction factor at 35% concentration.
On Cooler Pressure Drop curve (page 19), for 12.5 L/s
of water, Pressure Drop = 36.4 kPa.
For 35% EG solution,
Pressure Drop
= 1.28 x 36.4
= 46.6 kPa
V Correct compressor power input (kW).
On Power Correction curve at right, read 0.988 cor-
rection factor at 35% concentration.
Corrected Power Input = 0.988 x 69.6
= 68.8 kW
ETHYLENE GLYCOL PERFORMANCE
CORRECTION FACTORS AND SOLUTION
CRYSTALLIZATION POINTS
Correction factors apply to published chilled water
performance ratings from 40 to 60 F
(4.4 to 15.6 C) leaving water temperature.
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