Oven simulatie

1. weyer special | fired heater simulation weyer group
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FIRED HEATER
SIMULATION www.weyer-group.com

2. weyer special | fired heater simulation
Fired heater simulation
Direct fired heaters are generally used in processes where the process temperature required is greater than 300 °C. A dis-
tinction is made here between process heaters and refinery heaters. The most widely used refinery heaters are those which
are used for heating or evaporating hydrocarbons. There can be 20 different heaters in a typical refinery. For this common
type of furnace, a range of different validated simulation tools are available on the market. The weyer group uses Xfh deve-
loped by HTRI, the tool widely used in the refinery industry for the modeling of furnaces. The following describes the scope
of a simulation such as this, as well as the use of the simulation results.
Our services: 1 What is simulated? Properly characterizing the actual func-
tion of the furnace is essential to achie-
The weyer group has extensive experi-
 Furnace recalculations ving a result that is useful and accurate.
ence in the rigorous thermodynamic si-
 Recalculations in the weyer group employees have in-depth
mulation of these types of process
knowledge of the refinery and petroche-
event of a product heaters.
mical industries, which allows us to
change First, sophisticated software is used to create a simulation based on the proper
 Burner optimisation map out the complete geometry of the design and operating conditions. We
furnace. The arrangement of the pipe- can import chemical property data from
 Design of new pipe- work and headers, of both the convec- process simulators (Pro/II and Aspen
work tion and radiation zones, are faithfully Hysis) used by the weyer group or data
reproduced from customer documentation. supplied by the customer. The use of
 Furnace documen-
The geometry of the firebox and the ar- boiling point analyses according to
tation rangement of the burners, including the ASTM D86 or true boiling point is also
type of burner, can be modeled in exac- possible.
ting detail using our system. And of
course air preheaters and natural 2 How are the results used?
draught furnaces can also be modeled. The applications for this type of furnace
simulation are wide and varied:
weyer special | fired heater simulation | page 2

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conditions thanks to rigorous heater simu- synthesis gas. These furnaces are often
 Life Cycle Analysis
lation. The following results from the si- specially designed for their particular ap-
Information on the lifespan of the tubes mulation can then be used to define the plication. There is, for example, a signifi-
can be produced from the simulation best “operating window” for the case at cant difference between cracking furna-
results according to API 530. The hand: ces for the production of ethylene, which
Maximum Tube Metal Temperature use naphtha and those which use LPG.
• Tube wall temperatures
(MTMT) can be predicted from the opera- Semi-empirical simulation tools are used to
• Burner flame lengths
ting point of the furnace, and is used as model furnaces such as these, which have
• Film temperatures
the basis of strength calculations. The ope- been designed specifically for the applica-
• Pressure profile in the pipe
ration of the fired heater can also be eva- tion. The weyer group employees, who
• Fired heater internal pressure profile
luated retrospectively on the basis of TRD are experienced in process simulation, are
• Flow regimes in the pipes
508 and information can be provided familiar with a number of these tools, such
(one- / two-phase flows)
about the current state of the furnace. as Spyro manufactured by KTI for ethylene
The operating window forms the basis for
The operation of a furnace is more reliable plants. So, weyer offers the capability not
fired heater automation, the safety
with furnace simulations: Potential tube only to simulate general service refinery
concept and a corresponding operating
failures which could lead to the release of heater applications, but also process fired
manual. It can allow you to avoid opera-
hydrocarbons into the combustion heaters as well.
ting conditions which could result in
chamber, can be identified at an early
damage to the furnace.
stage. Repair measures can be planned
into normal maintenance turnarounds,
avoiding an unplanned outage.  Fired heater optimisation
A rigorous fired heater simulation provides
valuable information regarding expected
throughputs, energy consumption and ef-
ficiency. You can also examine the effects
of modifications or retrofits of existing fur-
naces before they are put into service. This
can significantly reduce re-commissioning
times.
It is possible, for example, to examine the
effects of
• new pipe geometries
• fin tubes versus smooth-bore Your benefit:
pipes
• alternative burner arrangements  Enhanced process reliability with life
or the cycle analysis
• refitting of fans
 ptimised fired heater operating point
O
 Identifying the ”operating window” As mentioned at the outset, so-called
Process furnaces very rarely only have one process fired heaters are used in the basic  Pre-planning of
specific use. It is far more likely in practice chemical industry, much like they are in • Revamps
that the uses, throughputs and also refinery operations. However, chemical re- • Recoiling
product temperatures to be achieved actions take place in these furnaces during • Product changes
change frequently. Optimum operating the flow of reactants through the heated
windows for a process fired heater can be zones. These furnaces are used, for  Standardised documentation indepen-
identified for many different operating example, for the production of ethylene or dent of the fired heater manufacturer
weyer special | fired heater simulation | page 3

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Your Contact
www.weyer-group.com
The weyer group is an independent association of engineering and consulting
companies based in Germany, Austria and Switzerland.
Starting with the expectations and wishes of its customers, the weyer group has
developed a wide range of skills and expertise since it was founded over 30 years ago.
www.weyer-group.com