الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
All process heaters consume large amounts of fuel to produce the necessary
heat that must be transferred to the material brought into the furnace. Energy
costs represent up to 65% of the cost of running a
chemical/petrochemical/refining complex. Furnace and heater fuel is the
largest component of this cost.
Therefore, it is important to have an efficient monitoring system for all the
fired heater operational parameters to reach the optimum performance point
at which maximum heat delivery to the process-side fluid is ensured with
minimum fuel consumption and stack emissions (SOx, NOx) in addition to
undertaking acceptable safety levels.
One critical variable to monitor in many furnaces after startup is the tube metal
temperatures in the radiation section. Excessive tube metal temperatures
accelerate tube creep (sagging tubes), hydrogen attack, and external
(vanadium attack, oxidation) and internal corrosion of the tube wall.
The objective of this work is to develop a program, which can calculate tube
metal temperature accurately, and continuously at the same time instead of
using external pyrometers that measure it intervally if there is not
thermocouples already installed on tube metal surface. This program can give
a good study of the operating parameters inside the heater, which affect
average tube metal temperature and give best scenario to reduce average tube
metal temperature without affecting heater efficiency.
It can also be a predictive tool that can calculate any further change of the
average tube metal temperature if -for example- capacity of the heater is
intended to be increased. It can be applied on fired heaters, which also have
already tube metal thermocouples and correct any possible misreading.
The program has been applied for two case studies, which have been already
designed, and maximum tube metal temperature has been calculated and
stated in their data sheets. In addition, program has been applied for two case
studies, which already have tube metal thermocouples that measure tube metal
temperature and compare the result from program with the reading from
thermocouples to determine percentage deviation of program from actual
reading.