McQuay AGR 070AS, Руководство по эксплуатации

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10 AGR 070A through 100A IOMM AGR-1
Figure 7, Refrigerant Piping (Some Components Are Optional)
Glycol Solutions
The system glycol capacity, glycol solution flow rate in GPM, and pressure drop through the cooler
may be calculated using the following formulas and data from Table 4 or Table 5.
1. Capacity -- Find the reduced capacity by multiplying the chiller’s capacity with water by the
capacity correction factor.
2. Flow -- To determine evaporator gpm (or Delta-T) knowing Delta-T (or gpm) and capacity:
table) (from
) ( 24
GPM Glycol tion FlowCorrec
T Delta
glycol capacity
×
−
×
=
For Metric Applications -- To determine evaporator L/s (or Delta-T) knowing Delta-T (or L/s)
and kW:
table) (from
18 . 4
L/s Glycol tion FlowCorrec
T Delta
kW
×
− ×
=
3. Pressure drop -- To determine pressure drop through the evaporator, when using glycol, enter
the water pressure drop curve on page 12 at the water flow rate. Multiply the water pressure drop
by PD correction factor from Table 4 or Table 5 to obtain corrected glycol pressure drop.
4. To determine the unit's power consumption when using glycol, multiply the water system kW by
factor kW.
Test coolant with a clean, accurate glycol solution hydrometer (similar to that found in service
stations) to determine the freezing point. Obtain percent glycol from the freezing point table below.
On glycol applications it is normally recommended by the supplier that a minimum of 25% solution
by weight be used for protection against corrosion.
Note: The procedure
does not specify the
type of glycol. Use
the derate factors
found in Table 4 for
corrections when
using ethylene glycol
and those in Table 5
for propylene glycol.