York YLCA Series, Техническая информация

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Selection guide (YLCA and YLHA PLUS)
Necessary information
The following information is needed to select a YLCA water
chiller:
1. Cooling capacity needed.
2. Design cold water input and output temperatures.
3. Design water flow, if any of the temperatures in above
point 2 is unknown.
4. Design input temperature of air to the condensing 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:
l/h cold water x °C differential
Cooling capacity kW =
860
Selection example
A chiller is required to chill water from 13° C to 7° C, with a
cooling capacity of 5 kW.
Here are other design conditions:
Ambient air entering the condensing unit: 35° C
Gumming coefficient:
0.044m 2 °C/kW
Altitude: At sea level
Table 10. Gumming coefficients
Table 11. Altitude factors
Taking a quick look at Table 1 we can see that a YLCA-5 unit
gives an approximate required capacity of 5.38 kW.
As the factors appearing in Tables 10 and 11 are not appli-
cable, conditions will be as follows:
Cooling capacity:
5.38 kW
Power consumed: 1.87 kW
Water temperature: 13° C to 7° C (
∆
t = 6)
5.38 x 860
Water flow: = 771 l/h
6
Available pressure in hydraulic circuit of a unit.
- From Table 6 we infer that the YLCA - 5 MC, with a 771 l/h
flow, has an available pressure of 56 kPa.
Pressure drop in filter.
- From Table 7. 1" filter, we infer that with a 771 l/h flow, said
filter has a pressure drop of 1.3 kPa.
YLHA PLUS selection method
1. Determine the correct size of the YLHA PLUS unit by
selecting a model from Tables 3 and 5 that is closest to
the cooling and heating capacities required in the design
conditions of the water outlet and air intake tempera-
tures.
2. Apply gumming correcting factors (Table 10) and altitude
(Table 11) to the capacity and power values that appear
in the corresponding capacity tables in cool and heat.
Make sure the corrected capacity is still sufficient for your
needs.
3. Using the corrected capacities of the unit, select the de-
sign temperature differential, or the flow.
4. Check to make sure that these selections are within the
YLCA/YLHA PLUS operating limits.
YLHA PLUS selection example
A YLHA PLUS 5 heat pump operating at a 35° C ambient
temperature should chill water from 13° C to 7° C, with a
5 kW cooling capacity.
A 4 kW heating capacity is required in 0° C design ambi-
ent temperature and a hot water output temperature of
45° C.
The gumming coefficient is 0.044 m² °C/kW, with the unit
operating at sea level (no corrections).
With a quick glance of capacity Tables 3 and 5, we see that
a YLHA PLUS 5 heat pump gives the approximate required
capacities:
Cooling capacity = 5.40 kW
Total unit absorbed power = 1.91 kW
Cold water temperature = 13° C to 71 C (
∆
t: 6° C)
Hot and cold water flow = 774 l/h
Heating capacity = 4.15 kW
Total unit absorbed power
in heat mode
= 1.88 kW
Hot water output temperature = 45° C
Hot water temp.
4.15 x 860
differential = = 4.60° C
774
Thus. hot water return
temperature is
= 40.4° C
Evaporating unit
Gumming coeff.
m
2
°C/kW
Capacity factor
Comp. absorbed
power factor
0.044 1.000 1.000
0.088 0.987 0.995
0.176 0.964 0.985
0.352 0.926 0.962
Altitude (m) Capacity factor
Comp. absorbed
power factor
0 1.000 1.000
600 0.987 1.010
1 200 0.973 1.020
1 800 0.958 1.029
2 400 0.943 1.038