Mitsubishi Electric CITY MULTI, Техническое и сервисное руководство

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14 15
OCH673D
4 DATA
4-1. SELECTION OF COOLING/HEATING UNITS
<Cooling>
Design Condition
Outdoor Design Dry Bulb Temperature
45ºC
Total Cooling Load 10.6 kW
Room1
Indoor Design Dry Bulb Temperature 27ºC
Indoor Design Wet Bulb Temperature 20ºC
Cooling Load 4.6 kW
Room2
Indoor Design Dry Bulb Temperature 24ºC
Indoor Design Wet Bulb Temperature 18ºC
Cooling Load
6.0 kW
<Other>
Indoor/Outdoor Equivalent Piping Length 60 m
Capacity of indoor unit Unit: kW
P•FY series Model Number
for indoor unit
Model 10 Model 15 Model 20 Model 25 Model 32 Model 40 Model 50 Model 63 Model 71 Model 80 Model 100 Model 125 Model 140
Model
Capacity
1.2 1.7 2.2 2.8 3.6 4.5 5.6 7.1 8.0 9.0 11.2 14.0 16.0
M series
S series
P series
Model Number
for indoor unit
Model 15 Model 18 Model 20 Model 22 Model 25 Model 35 Model 42 Model 50 Model 60 Model 71 Model 80 Model 100
Model
Capacity
1.5 1.8 2.0 2.2 2.5 3.5 4.2 5.0 6.0 7.1 8.0 10.0
1. Cooling Calculation
(1) Temporary Selection of Indoor Units
Room1
PEFY-P50 5.6 kW (Rated)
Room2
PEFY-P71 8.0 kW (Rated)
(2) Total Indoor Units Capacity
P50 + P71 = P121
(3) Selection of Outdoor Unit
The P125 outdoor unit is selected as total indoor units capacity is P121
PUMY-P125 14.0 kW
(4) Total Indoor Units Capacity Correction Calculation
Room1
Indoor Design Wet Bulb Temperature Correction (20ºC) 1.03 (Refer to Figure 1)
Room2
Indoor Design Wet Bulb Temperature Correction (18ºC) 0.94 (Refer to Figure 1)
Total Indoor Units Capacity (CTi)
CTi = Σ (Indoor Unit Rating × Indoor Design Temperature Correction)
= 5.6 × 1.03 + 8.0 × 0.94
= 13.3 kW
(5) Outdoor Unit Correction Calculation
Outdoor Design Dry Bulb Temperature Correction (45ºC) 0.86 (Refer to Figure 2)
Piping Length Correction (60 m) 0.90 (Refer to Figure 3)
Total Outdoor Unit Capacity (CTo)
CTo = Outdoor Rating × Outdoor Design Temperature Correction × Piping Length Correction
= 14.0 × 0.86 × 0.90
= 10.8 kW
(6) Determination of Maximum System Capacity
Comparison of Capacity between Total Indoor Units Capacity (CTi) and Total Outdoor Unit Capacity (CTo)
CTi = 13.3 > CTo = 10.8, thus, select CTo.
CTx = CTo = 10.8 kW
(7) Comparison with Essential Load
Against the essential load 10.8 kW, the maximum system capacity is 10.8 kW: Proper outdoor units have been selected.
(8) Calculation of Maximum Indoor Unit Capacity of Each Room
CTx = CTo, thus, calculate by the calculation below
Room1
Maximum Capacity × Room1 Capacity after the Temperature Correction/(Room1,2 Total Capacity after the Temperature Correction)
= 10.8 × (5.6 × 1.03)/(5.6 × 1.03 + 8.0 × 0.94)
= 4.7 kW
OK: fulfills the load 4.6 kW
Room2
Maximum Capacity × Room2 Capacity after the Temperature Correction/(Room1,2 Total Capacity after the Temperature Correction)
= 10.8 × (8.0 × 0.94)/(5.6 × 1.03 + 8.0 × 0.94)
= 6.1 kW
OK: fulfills the load 6.0 kW
Note: If CTx = CTi, please refer to the <Heating> section to calculate the Maximum Indoor Unit Capacity of Each Room.
Go on to the heating trial calculation since the selected units fulfill the cooling loads of Room 1, 2.
Indoor Temperature [°CW.B.]
Ratio of cooling capacity
15 16 17 18 19 20 21 22 23 24
0.4
0.6
0.8
1.0
1.2
Figure 1 Indoor unit temperature correction
To be used to correct indoor unit only
Figure 2 Outdoor unit temperature correction
To be used to correct outdoor unit
only
Figure 3 Correction of refrigerant piping length
0 20 40 60 80 100 120 140 160 180
0.50
0.55
0.60
0.65
0.70
0.75
0.80
0.85
0.90
0.95
1.00
9.4
6.3
12.5
16.2
Capacity ratio
Piping equivalent length (m)
Total capacity of indoor unit
Total capacity of indoor unit
0 20 40 60 80 100 120 140 160 180
0.50
0.55
0.60
0.65
0.70
0.75
0.80
0.85
0.90
0.95
1.00
10.5
7.0
14.0
18.2
Capacity ratio
Piping equivalent length (m)
Ratio of cooling capacity
Outdoor Temperature [°C D.B.]
Indoor Temperature
-5.0 0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 50.0 52.0
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
19°C W.B