Combustion Phenomena of High Temperature Air Combustion - High Temperature Air Combustion: From Energy Conservation to Pollution Reduction - page 108

TABLE 2.6
Heat flux of CO 2 in Consideration of Wedge Shape Distribution (in the case
of 1-m mean effective thickness)

Tgm = 1000K Tg = 500 - 1500K
Pam = 0.5atm Pa = 0.1 - 0.9atm

2

Q kW/m

a

T g P a

(Case C)

(Case A) 2.42 (Case B) 2.74 5.85

(Case D) 2.41 (Case E) 3.71 (Case F) 4.33

(Case G) 2.41 (Case H) 1.66 (Case I) 6.87

have to be studied together with the radiation of gas. Handling of this factor, however,
is different depending on whether the diameter of the particles is considerably larger
than the radiation wavelength or nearly the same. In the former case, the radiation
is scattered by reflection effect at the particle surfaces, whereas in the latter case the
scattering is caused by interference. However, when the particle diameter becomes
smaller yet, the scattering effect becomes nearly identical to that of gas radiation.

2.4 FUNDAMENTALS OF LIQUID FUEL FLAMES

2.4.1 L IQUID F UEL F LAME C HARACTERISTICS AND S TABILITY

An experiment on a spray combustion was carried out in highly preheated, diluted
air with a view to comparing the results of LPG gas as the fuel. The spray pressure
to be jetted out from the nozzles, the oxygen content, and the measuring temperature
were changed to investigate the spray combustion. Further, photographs of the flame
forms were taken in detail by a digital camera within the combustible range to study
what differences in the combustible range existed according to both the highly
preheated, diluted air temperature and the oxygen content. Both the changing state
of the flame form and the changing of its color were also investigated.

2.4.1.1 Experimental Apparatus

The spraying experiment was carried out using an injection nozzle that was arranged
to go straight to the high temperature air generator, manufactured by Nippon Furnace