To determine the glycol factor, please see
Glycol concentration and correcting tables, see on page
9
(Recommended ethylene glycol concentrations) for ethylene glycol or (Recommended propylene
glycol concentrations) for propylene glycol. For design outlet temperature, please see the recommended
glycol concentration and the glycol factor in this concentration. This is the minimum concentration to be
used for design outlet temperature. If a greater concentration is required, the glycol factor can be
determined by means of
Glycol concentration and correcting tables, see on page 9
(Ethylene glycol
in other concentrations) or (Propylene glycol in other concentrations).
Selection method
1. Determine the correct cooler model by selecting the one that is closest to the capacities required by
the design conditions of the glycol outlet and air inlet temperatures.
2. Apply the fouling correcting factors that correspond to the fouling, altitude and glycol concentration
factor, to the capacity and power values in the capacity tables. Make sure the corrected capacity is
still sufficient for your needs.
3. Using the corrected capacities of the cooler, set the design temperature range, or the flow rate, to
balance the formulae appearing in
Selection guide (YLCA/YLHA), see on page 4
.
4. Always recheck to make sure these selections are within the specified design limits.
Selection example
A cooler is required to chill ethylene glycol from 1 to ‑4 °C, with an output of 75 kW.
The following design conditions are applicable:
• Fouling factor: 0,088m °C/kW
• Altitude: 1 200m
• Ambient air: 25℃
• Glycol concentration: 30% w/w
For a ‑4 °C ethylene glycol outlet, the concentration recommended in Figure 1 is 30%. Therefore, the
specified concentration is appropriate.
From Table
Cooling capacities YLCA 40 ÷ 150 (35% ethylene glycol), see on page 32
, we infer that a
YLCA-120 unit, at the established design conditions, gives a capacity of 76.8 kW and a consumption of
28.8 kW.
With the design fouling factor, use the capacity correcting factors x 0.987 and power x 0.995 (see
Fouling
factors, see on page 8
).
On design altitude, apply the capacity correcting factors x 9.973 and power x 1.020 (see
Altitude
factors, see on page 11
).
On design glycol concentration, apply the capacity correcting factors x 1.015 and power x 1.005 (see
Correcting factors for other glycol concentrations, see on page 11
).
Applying these factors to the selection: YLCA ‑120
Capacity = 76.8 x 0.987 x 0.973 x 1.015 = 74.9 kW
Comp. power = 28.8 x 0.995 x 1.020 x 1.005 = 29.4 kW
For the specified glycol concentration and an outlet temperature of ‑4°C, figure 3 shows a glycol factor
of 0.248. Therefore, the flow rate can be determined with the formula indicated in section
Selection guide
(YLCA/YLHA), see on page 4
.
74.9 [kW] =
(1 ‑ (-4)) x Flow rate [l / s]
0,248
Flow rate =
74.9 x 0.248
= 3.71 [l / s] or 13374 [l / h]
5
This covers the Limits of Use.
Quick installation guide
1
Selection guide (YLCA/YLHA) 1.4
7
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