الفهرس 
CHAPTER (1) : INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Summary
The present work reports the results of theoretical and experimental studies to
find the relationship between geometrical and thermal similarity in heating furnaces.
A geometrically similar experimental virtually furnace model l: l0 of one full – scale
furnace installed in a battery of four such furnaces at Alexandria Petroleum Company
( Alexandria, Egypt ) was constructed for this study. The furnace model is fired by
natural gas. It is surrounded by a cooling water jacket divided into six separate
segments; five of them represent the radiation zone of the furnace model while the sixth
one forms the convection zone.
Experiments were done to study the combustion aerodynamics, the heat flux
distribution along the furnace model as well as the rate of heat transfer. Also, the overall
resultant gas temperature and the average total heat transfer coefficient from the
combustion gases to the furnace walls, were estimated in this investigation.
Furthermore, a mathematical model was constructed also in this study for computing the
different characteristics of the furnace model performance. The study in this model was
based on two well-proven sub-models. The first sub-model is called the Well-Stirred
Model while the second one is called the Zonal Exchange Method. A specially devised
computer program was constructed for carrying out the calculations for this model.
The measurements taken on the furnace model were as follows: the gas temperature,
surface wall temperatures, air mass flow rate, fuel mass flow rate, cooling water flow
rate, inlet and outlet temperatures, flame jet mean velocity and the total heat transfer to
the different segments of the furnace model. These measurements were carried out
under different operating parameters of natural gas injection pressure, excess air factor
and number of operating nozzles in the burner used. A comparison between
mathematical model and experimental results of the rate of heat transfer and thermal
efficiency of the furnace model was made. Fair agreement between them was obtained.
Then, the experimental results previously obtained on the full-scale lubricating
oil heating furnace [26] were compared to the present results on the 1/10 geometrically
similar experimental model, where
αF.S (Full-scale at A/F = 20 ) = 0.02 (kW/m2.˚C)
αM (Model 1/10 scale at A/F = 20 ) = 0.201 (kW/m2.˚C)