Heat Recovery DC Inverter Multi VRF Unit
25
4.4.2 Refrigerant adding
R (Quantity of added refrigerant) = A (Quantity of refrigerant added to c
onnection pipe) + ∑B
(Quantity of refrigerant added to each module)
（
1
）
A (Quantity of refrigerant added to connection pipe) is calculated as below:
A (Quantity of refrigerant added to connection pipe) =
∑ Length of liquid pipe x Quantity of
refrigerant added to liquid pipe per meter)
Diameter of liquid pipe (mm)
Φ28.6 Φ25.4 Φ22.2 Φ19.05 Φ15.9 Φ12.7 Φ9.52 Φ6.35
kg/m
0.680
0.520
0.350
0.250
0.170
0.110
0.054
0.022
（
2
）
∑B (Quantity of refrigerant added to each module) is calculated as below:
Quantity of refrigerant added to each module (kg)
②
Module capacity (kW)
Indoor/outdoor unit rated capacity
allocation ratio: C
①
Sets of allocated
indoor unit
22.4
28.0
33.5
40.0
45.0
50%≤C≤70%
≤4 sets
0
0
0
0
0
＞
4 sets
0.5
0.5
0.5
0.5
0.5
70%≤C≤90%
≤4 sets
0.5
0.5
0.5
1
1
＞
4 sets
1
1
1
1.5
1.5
90%
＜
C≤105%
≤4 sets
1
1
1.5
2
2
＞
4 sets
2
2
3
3.5
3.5
105%
＜
C≤135%
≤4 sets
2
2
2.5
3
3
＞
4 sets
3.5
3.5
4
5
5
Note:
①
Indoor/outdoor unit rated capacity allocation ratio C = Sum of rated cooling capacity of indoor
unit / Sum of rated cooling capacity of outdoor unit
②
If all of the indoor units are GMV-NX series fresh air indoor units, the quantity of refrigerant
added to each module is 0kg.
For example:
Example 1:
The outdoor units are composed of 3 modules: GMV-Q280WM/B-X, GMV-Q400WM/B-X,
GMV-Q450WM/B-X. The indoor units are 8 sets of GMV-ND140PLS/A-T.
In this case, C (Indoor/outdoor unit rated capacity allocation ratio) = 140×8/
（
280+400+450
）
=99%, and there are more than 4 sets of indoor unit. According to the table above,
The quantity (B) of refrigerant added to GMV-Q280WM/B-X is 2kg;
The quantity (B) of refrigerant added to GMV-Q400WM/B-X is 3.5kg;
The quantity (B) of refrigerant added to GMV-Q450WM/B-X is 3.5kg
So, ∑B (Quantity of refrigerant added to each module) = 2+3.5+3.5=9kg
Suppose that A (Quantity of refrigerant added to connection pipe) =
∑ Length of liquid pipe x
Quantity of refrigerant added to liquid pipe per meter) = 25kg
R (Quantity of added refrigerant in total) =25+9=34kg
Example 2:
The outdoor unit is made up of 1 module: GMV-Q450WM/B-X. The indoor unit is 1 set of fresh air