Page 286 - Defrosting for Air Source Heat Pump

280 Defrosting for Air Source Heat Pump

(A) (B)

(C) (D)

(E) (F)

Fig. 9.21 Measured temperature of the melted frost collected in cylinders during defrosting.
(A) Case 1, (B) Case 2, (C) Case 3, (D) Case 4, (E) Case 5, and (F) 5 Cases.

defrosting, the pressure differences were obviously lower. It further demonstrated that
when frost accumulation is around that in Case 2, the system defrosting performance
in stability is the best.
During defrosting, the energy mainly comes from two sources, the indoor air ther-
mal and the electricity consumed by the compressor and fans. Here, the two energy
sources are separately presented in Figs. 9.24 and 9.25. As seen from Fig. 9.24, the
peaks of thermal energy taken from the indoor air came at 120 s in Case 1, 115 s