Page 175 - Defrosting for Air Source Heat Pump

Frosting evenness coefficient 169

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

12

4
125 s 220 s 235 s
0

80 100 120 140 160 180 200 220 240 260
Time (s)

Fig. 6.18 Measured fin surface temperature at the center of three refrigerant circuits during
defrosting in Case 1.

32
Fin in Circuit 1
28 Fin in Circuit 2
Fin in Circuit 3 T > T > T
1 2 3
24
Temperature of fin surface ( o C) 16 T > T > T 1
20

12

3
2
8
4
125 s
150 s 185 s 218 s
0
80 100 120 140 160 180 200 220 240 260
Time (s)

Fig. 6.19 Measured fin surface temperature at the center of three refrigerant circuits during
defrosting in Case 2.