Selection Guide With Glycol - York YCSA 120 T Technical Information

All valves are within operating limits.
- Available pressure in hydraulic circuit of a unit with kit.
- From Table 6 we infer that the YCSA-H 120 TP, with a
16 340 l/h flow, has an available pressure of 289 kPa.
- Pressure drop in hydraulic circuit of a unit without kit.
- From Table 7 we infer that the YCSA-H 120 T, with a 16
340 l/h flow, has a pressure drop of 21 kPa.
- Pressure drop in filter.
- From Table 8, 2 1/2" filter, we infer that with a 16 340 l/h
flow, said filter has a pressure drop of 2.2 kPa.
Selection guide with glycol (cool only units)
Necessary information
The following information is needed to select a YCSA water
chiller:
1. Cooling capacity needed.
2. Design cold water/glycol input and output temperatures.
3. Design water/glycol flow.
4. Design input temperture of air to air conditioning unit.
Normally, this will be the design ambient temperature of
summer air, unless influenced by the situation or other
factors.
5. Altitude above sea level.
6. Design gumming coefficient of the evaporating unit.
Note: Points 1, 2 and 3 should be related by means of the
following formulae:
Cooling capacity (kW) =
In which Dt = liquid intake temp. - liquid output temp.
To determina the glycol factor, please see Figure 1 for eth-
ylene glycol, or Figure 3 for propylene glycol. For design
output temperature, please see the recommended glycol
concentration and the glycol factor in this concentration. This
is the minimum concentration to be used for design output
temperature. If a greater concentration is required, the glycol
factor can be determined by means of Figure 2 on ethylene
glycol or Figure 4 on propylene glycol.
Selection method
1. Determine the correct size of chiller by selecting the one
that is closest to the capacities required by the design con-
ditions of the glycol outlet and air intake temperatures.
2. Apply the gumming correcting factors that correspond to
the gumming coefficient, altitude and glycol concentra-
tion, and to the capacity tables. Make sure the corrected
capacity is still sufficient for your needs.
3. Using the corrected capacities of the chiller, set the design
temperature range, or the flow, to balance the formulae
appearing in the "Necessary information" section.
4. Always recheck to make sure these selections are within
the design operating limits.
18
Dt (°C) x Flow (litres/second)
Glycol factor
Selection example
Achiller is required to chill ethylene glycol from 1 to -4°C with
a capacity of 75 kW.
The following design conditions are applicable:
Gumming coefficient:
Altitude:
Ambient air:
Concentration of glycol:
For a -4°C, ethylene glycol output, the concentration recom-
mended in Figure 1 is 30%. Therefore, the specified concen-
tration is appropriate.
From Table 2 (capacities with 35% glycol), we infor that a
YCSA-120 unit, at the established design conditions, gives
a capacity of 81.8 kW and a consumption of 29.5 kW
With the desing gumming coefficient, use the capacity cor-
recting factors x 0.987 and power x 0.995 (Table 9).
On design altitude, apply the capacity correcting factors x
9.973 and power x 1.020 (Table 10).
On design glycol concentration, apply the capacity correcting
factors x 1.015 and power x 1.005 (Table 3).
Applying these factors to the selection: YCSA-120
Capacity = 81.8 x 0.987 x 0.973 x 1.015 = 79.7 kW
Comp. power = 29.5 x 0.995 x 1.020 x 1.005 = 30 kW
For the specified glycol conectration and a -4°C output
temperature, Figure 3 shows a 0.248 glycol factor. Thus, the
flow can be determined with the formula appearing in the
"Necessary information" section.
(1 - (-4)) x Flow (l/s)
79.7 kW =
79.7 x 0.248
Flow =
5
This covers the limits of use.
The evaporating unit pressure drop can be determined
by taking the water pressure drop value (Table 7) for a
YCSA-120 unit and multiplying it by the correcting factor (see
Fig. 5) for a 30% concentration and an average temperature
of -1.5°C, that is to say, 1 + (-4 )
16 kPa x 1.22 = 19.5 kPa.
0.088m °C/kW
1 200m
25°C
30% w/w
0.248
= 3.95 (l/s) or 14 231 (l/h)
= -1.5
2