Page 174 - Defrosting for Air Source Heat Pump

168 Defrosting for Air Source Heat Pump

32
Circuit 1 Circuit 2 Circuit 3
28
T > T > T
1 2 3
24
Temperature of tube surface ( o C) 16 8 T > T > T 3
20

2
1
12

4
148 s 196 s 198 s
0

80 100 120 140 160 180 200 220
Time (s)

Fig. 6.16 Measured tube surface temperatures at the exits of the three refrigerant circuits during
defrosting in Case 2.

32
Circuit 1 Circuit 2 Circit 3
28 T > T > T
1 2 3
24
Temperature of tube surface ( o C) 20 T > T > T 3

16

12
1
2
8
4
138 s 185 s
0
80 100 120 140 160 180 200 220
Time (s)

Fig. 6.17 Measured tube surface temperatures at the exits of the three refrigerant circuits during
defrosting in Case 3.