Page 324 - Defrosting for Air Source Heat Pump
P. 324
Technoeconomic performances 319
28,000
Heating season with frost formation
26,000 Heating season without frost formation
Cooling season
24,000
(h)
n 22,000
o
i 168.75
t
a
r 21,459.38 0.79%
u 20,000
d
g
n 18,000
i
t
a
r
e
p 16,000
o 16,200
m
e 14,000
t
s
y
S 12,000
10,000 10,800
8000
Case D3 Case D4
Two typical cases
Fig. 10.8 System operating durations in three seasons in the 15 operating years.
80,000
Heating season without frost formation
Indoor thermal consumption on defrosting
70,000
Electricity cost on defrosting
Electricity cost on frosting
60,000
53,917.29
) 48,589.22
Y 50,000
N
C 22,404.26
(
t 40,000 41.55% 20,692.1
s
o
c 42.59%
g )
n 30,000 %
i
n 5
u 4
R . 8
20,000 5 (
3 27,897.12 (57.41%)
0
. 28,893.29 26,035.71
10,000 3 1
5 53.59% 53.58%
,
1
3
0
Case D3 Case D4
Two typical cases
Fig. 10.9 Running costs in two heating seasons in the 15 operating years.
In heating season with frost formation, the running cost difference between the two
cases is $542.17. That means that after the valves were installed on the ASHP unit, the
total running cost in this season could save about 11.47%. The economic performance
of the new ASHP unit was effectively improved. In heating season without frost for-
mation, the total running cost difference between the two cases became $256.72,