Sharp JX-9400 Technical Information Seite 65

  • Herunterladen
  • Zu meinen Handbüchern hinzufügen
  • Drucken
  • Seite
    / 211
  • Inhaltsverzeichnis
  • LESEZEICHEN
  • Bewertet. / 5. Basierend auf Kundenbewertungen
Seitenansicht 64
To interpret the recorded tracer gas concentrations and obtain the age of
air, the background (or supply) concentration should first be subtracted from
all measurements, and the elapsed time should be calculated by subtracting
the starting time from all time values. In the following formulae, the net
tracer gas concentration, C
r
, is the difference between the concentration
measured at location r and the concentration of this gas in the outdoor air.
The probability function of the age of air can be calculated from the
concentration ratio:
Step-up FðÞ¼1
Cð t t
0
Þ
C
1
Decay FðÞ¼
Cðt t
0
Þ
Cðt
0
Þ
ð3:7Þ
Figure 3.5 shows the concentration ratio calculated from the recorded
concentration illustrated in Figure 3.4.
0
5
10
15
20
25
09:00 09:10 09:20 09:30 09:40 09:50 10:00 10:10 10:20
Concentration [ppm]
Step-up
Decay
C
Injection
t
o
t
o
Figure 3.4 Record of tracer gas concentration in the exhaust duct during the
measurement of the age of air
0.0
0.2
0.4
0.6
0.8
1.0
0 200 400 600 800 1000 0 200 400 600 800 1000
F(t)
-1.4
-1.2
-1.0
-0.8
-0.6
-0.4
-0.2
0.0
Time [s]
log[F(t)]
Step-up
Decay
Step-up
Decay
Time [s]
Figure 3.5 Probability functions of the age of air, calculated from the recorded
concentration illustrated in Figure 3.4
Note: Left is a linear scale and right is a logarithmic scale, showing an exponential decay
after 700 s.
44 Ventilation and Airflow in Buildings
Seitenansicht 64
1 2 ... 60 61 62 63 64 65 66 67 68 69 70 ... 210 211

Kommentare zu diesen Handbüchern

Keine Kommentare