Temperature plots

The measurements collected from the sensors were recorded as a function of air velocities through the PV module test section (Dehra, 2004): (i) Hybrid ventilation without use of fan pressure; and (ii) Hybrid ventilation with use of fan pressure. The temperature measurements were obtained from the PV module test section as a function of air velocities. The temperatures were obtained for glass coated PV module, air passage and insulating panel in the wooden frame. The set of sample measurements obtained from outdoor experiments is presented in Table 2. The temperature plots for PV module, insulating panel and air for different hybrid ventilation conditions are illustrated in Figs. 5 and 6. The temperature plots are obtained against the height of PV module test section for the data provided in Tables 2 to 4. The variation of mean temperatures of PV module, insulating panel and air with approximately steady solar noon irradiation with varying mass flow rates for the case of fan-induced hybrid ventilation and buoyancy-induced hybrid ventilation are plotted in Figs. 7 to 9.

S

Ep

T T

1 o 1 s

V

Run No.

(W m-2)

(W)

u

0

и

0

(m s-1)

Fan-induced hybrid ventilation

1

716.1

30.7

15.2 22.4

0.68

2

716.1

30.7

13.4 22.4

0.53

Buoyancy-induced hybrid ventilation

3

697.5

28.9

13.2 25.1

0.13

4

697.5

28.8

13.3 24.9

0.17

Run No.

Tp(b) Tp(m)

Tp(t) Tb(b)

Tb(m)

Tb(t) Ta(b)

Ta(m)

Ta(t)

(° C) (° C)

(° C) (° C)

(° C)

(° C) (° C)

(° C)

(° C)

Fan-induced hybrid ventilation

1

35.4 33.8

36.8 20.6

24.7

29.1 18.8

21.7

19.4

2

35.9 34.6

37.9 20.9

25.0

29.5 19.3

22.5

19.9

Buoyancy-induced hybrid ventilation

3

40.8 44.9

46.8 27.9

34.8

38.0 21.3

29.5

29.8

4

39.9 45.0

46.8 28.4

35.0

38.3 21.7

28.3

29.8

Distance as per locations Tp(b)

Tp(m)

Tp(t)

Tb(b)

Tb(m)

shown in Fig. 4

(° C)

(° C)

(° C)

(° C)

(° C)

y (cm)

15

55

94

15

55

z (cm)

60

60

60

60

60

x (mm)

6.2

6.2

6.2

96.2

96.2

Distance as per locations Tb(t)

Ta(b)

Ta(m)

Ta(t) Air velocity

shown in Fig. 4

(° C)

(° C)

(° C)

(° C)

sensor

y (cm)

94

15

55

94

99

z (cm)

60

60

60

60

60

x (mm)

96.2

51.2

51.2

51.2

51.2

Note: x is

horizontal; y is vertical; z is adjacent 3rd axis of x-y plane

Fan-induced hybrid ventilation
Run No. 2

 

image151

-PV Module Temperature

 

Подпись: 00.2 0.4 0.6 0.8 1

image153

Height of PV Module Test Section (m)

Подпись: 00.2 0.4 0.6 0.8 1

Height of PV Module Test Section (m)

Fig. 5.(b) Temperature plot of insulating panel for fan-induced hybrid ventilation with height of PV module test section

Подпись:Подпись: 0.2 0.4 0.6 0.8 123 —і

22

?

‘g 21

з

2

a 20

J

19

18 – 0

Height of PV Module Test Section (m)

Fig. 5.(c) Temperature plot of air for fan-induced hybrid ventilation with height of PV module test section

image157

Fig. 6.(a) Temperature plot of PV module for buoyancy-induced hybrid ventilation with height of PV module test section

Подпись: Buoyancy-induced hybrid air ventilation Run No. 4 31

— 29

0

О

■ЦТ 27

0 25 о

23

21

19

0. Подпись:2 0.4 0.6 0.8 1

Height of PV Module Test Section (m)

Fig. 6.(c) Temperature plot of air for buoyancy-induced hybrid ventilation with height of PV module test section

Fig. 7. Variation of mean temperatures of PV module, air and insulating panel with solar irradiation under fan-induced hybrid ventilation

о

<D

Q.

11:00:00 11:14:24 11:28:48 11:43:12 11:57:36 12:12:00 12:26:24

Time

Fig. 8.(a) Variation of mean temperatures of PV module, air and insulating panel with solar irradiation under buoyancy-induced hybrid ventilation

PV Module Temperature Difference
—O – Insulating Panel Temperature Difference

…. &…. Air T emperature Difference

-4> – Mass Flow Rate

Подпись: 12 10 8 6 4 2 0 Подпись: 10:58:00 11:12:24 11:26:48 11:41:12 11:55:36 12:10:00 12:24:24 Подпись: о fc 5

image163
image164 Подпись: 1- 704 12:28:48

image166Подпись: о E .2 S' T3 1_ ГО ф t o. Ш B о I E Подпись: 712

image169 Подпись: —□ - Insulating Panel Temperature ■ X "Room Air Temperature HH Solar Irradiation T 724
Подпись: 720 716
Подпись: 708

0.07

0.06

0.05

0.04

0.03

0.02

0.01

0

Time (Hrs.)

Fig. 8.(b) Temperature difference for PV module, insulating panel and air with height of PV module test section for under fan-induced hybrid ventilation

image173

11:00:00 11:14:24 11:28:48 11:43:12 11:57:36 12:12:00 12:26:24

Time

Fig. 9. Temperature difference for PV module, insulating panel and air with height of PV module test section under buoyancy-induced hybrid ventilation