2011 International Conference on Alternative Energy in Developing Countries and Emerging Economies
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From 6 a.m. to 9 p.m. due to the generated heat from the
operated blower transferred to the outflow air thus the
outflow temperature was higher than the soil temperature.
10
15
20
25
30
35
40
45
50
6:00AM
7:00AM
8:00AM
9:00AM
10:00AM
11:00AM
12:00PM
1:00PM
2:00PM
3:00PM
4:00PM
5:00PM
6:00PM
Temperature
(
0
C)
Time (hr)
inletair
outletair
modelGH
soilat 1 m
Fig. 6. Temperature of working fluid in a typical day of summer.
15
20
25
30
35
40
45
50
55
6:00AM
7:00AM
8:00AM
9:00AM
10:00AM
11:00AM
12:00PM
1:00PM
2:00PM
3:00PM
4:00PM
5:00PM
6:00PM
Air Temperature
(
0
C)
Time (hr)
modelGH controlGH ambient
Fig. 7. The variation of temperature changes for model GH, control GH
and surrounding in a typical day of summer.
During daytime, the GH temperature would increase
by solar transmission and slightly varied at 4 p.m. when
the radiation was down. However, in both GHs remaining
accumulative heat and temperatures were higher than
surroundings obviously. The results in Fig. 7 presented at
3 p.m. the maximum temperatures of model GH with
ETS, control GH and surrounding were 48.85
o
C, 50.60
o
C and 39.40
o
C, respectively. During operation time, the
ETS in a typical day of summer could reduce inside
temperature by the range of 0 - 4
o
C since 11 a.m. to 6
p.m. The cooling hour was longer than that in a
representative day of winter by about 2 hours.
From Fig. 8, the characteristics of RH changes were
opposite to the temperature changes. The maximum RHs
in the model GH, control GH and the atmosphere were
highest in the morning equal to 92.18 %, 95.44 % and
97.46 %, respectively. The RH increased and decreased
periodically until 3 p.m. with the minimum values of
20.97 %, 18.57 % and 31.57 %. In a typical day of
summer, the RH difference would be lower than the trials
in winter. As a result of the evaporation rate of water
vapor which was increased by heat loads in Model GH
the RH may be less than control RH by around 0 - 5 %.
0
10
20
30
40
50
60
70
80
90
100
6:00AM
7:00AM
8:00AM
9:00AM
10:00AM
11:00AM
12:00PM
1:00PM
2:00PM
3:00PM
4:00PM
5:00PM
6:00PM
Relative Humidity
(%)
Time (hr)
modelGH controlGH ambient
Fig. 8. The variation of relative humidity changes for model GH, control
GH and ambient air in a typical day of summer.
C. Rainy season micro climate
TABLE
III
H
OURLY WEATHER DATA OF RAINY SEASON
,
A TYPICAL DAY
ON
A
UGUST
8, 2010
Time (h)
Solar
radiation
(W/m
2
)
Ambient
temp.
(
o
C)
Ambient
RH.
(%)
Soil temp.
at 1 m
(
o
C)
6 a.m.
27.37
23.00
99.15
28.70
7 a.m.
80.92
23.80
97.51
28.70
8 a.m.
106.00
25.20
92.06
28.60
9 a.m.
95.15
25.70
88.33
28.60
10 a.m.
195.47
26.30
86.99
28.60
11 a.m.
843.81
29.50
72.48
28.70
12 a.m.
924.13
32.10
61.52
28.60
1
p.m.
867.53
34.10
54.94
28.60
2
p.m.
918.03
33.70
52.10
28.60
3
p.m.
262.23
32.80
56.57
28.60
4
p.m.
592.67
34.20
54.51
28.50
5
p.m.
293.08
32.40
60.06
28.40
6
p.m.
142.94
30.30
66.74
28.40
10
15
20
25
30
35
40
45
6:00AM
7:00AM
8:00AM
9:00AM
10:00 AM
11:00 AM
12:00PM
1:00 PM
2:00 PM
3:00 PM
4:00 PM
5:00 PM
6:00 PM
Temperature
(
o
C)
Time (hr)
inletair
outletair
modelGH soilat 1 m
Fig. 9. Temperature of working fluid in a typical day of rainy season.
Table II presents the weather data in a typical day of
rainy season on August 8, 2010. It found that the solar
radiation was similar to a typical day of summer. The
average maximum radiation was in the range 900 - 1,000
