U.S. patent application number 17/613956 was filed with the patent office on 2022-07-14 for automatic air-flow settings in combustion systems and associated methods.
This patent application is currently assigned to OnPoint Technologies, LLC. The applicant listed for this patent is OnPoint Technologies, LLC. Invention is credited to Chad CARROLL, Thomas KORB, Ryan MORGAN, Mark VACCARI.
Application Number | 20220221149 17/613956 |
Document ID | / |
Family ID | 1000006299079 |
Filed Date | 2022-07-14 |
United States Patent
Application |
20220221149 |
Kind Code |
A1 |
CARROLL; Chad ; et
al. |
July 14, 2022 |
AUTOMATIC AIR-FLOW SETTINGS IN COMBUSTION SYSTEMS AND ASSOCIATED
METHODS
Abstract
Systems and methods iteratively solve a fired-systems model of
the process heater based on fuel information, a target heat release
of the plurality of burners, ambient air information, and available
airflow at each of the plurality of burners to identify optimized
burner air register settings to achieve a target global excess
oxygen level to be sensed by the oxygen sensor. The optimized
burner air register settings may be output to a heater controller
of the process heater for control of the process heater.
Inventors: |
CARROLL; Chad; (Tulsa,
OK) ; KORB; Thomas; (Tulsa, OK) ; MORGAN;
Ryan; (Tulsa, OK) ; VACCARI; Mark; (Broken
Arrow, OK) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
OnPoint Technologies, LLC |
Wichita |
KS |
US |
|
|
Assignee: |
OnPoint Technologies, LLC
Wichita
KS
|
Family ID: |
1000006299079 |
Appl. No.: |
17/613956 |
Filed: |
June 19, 2020 |
PCT Filed: |
June 19, 2020 |
PCT NO: |
PCT/IB2020/055823 |
371 Date: |
November 24, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62864997 |
Jun 21, 2019 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F23N 2235/04 20200101;
F23N 3/002 20130101; F23N 2225/04 20200101; F23N 2223/04 20200101;
F23N 2237/02 20200101; F23N 2235/06 20200101; F23N 5/006 20130101;
F23N 1/022 20130101 |
International
Class: |
F23N 5/00 20060101
F23N005/00; F23N 3/00 20060101 F23N003/00; F23N 1/02 20060101
F23N001/02 |
Claims
1. A combustion system comprising: a heater having a heater
housing; an air source coupled to the process heater via air
ductwork; a plurality of burners configured to combust a fuel
source with the air source to produce thermal energy, each burner
including a burner air register configurable to one of a plurality
of burner air register settings to control input of the air source
into the burner; and, an oxygen sensor configured to generate a
sensed oxygen level inside the heater; a processor; and a memory
operatively coupled to the processor and storing: an air-side
analyzer comprising computer readable instructions that when
executed by the processor operate to: iteratively solve a
fired-systems model of the process heater based on fuel
information, a target heat release of the plurality of burners,
ambient air information, and available airflow at each of the
plurality of burners to identify optimized burner air register
settings to achieve a target global excess oxygen level to be
sensed by the oxygen sensor, and, output the optimized burner air
register settings to a heater controller of the process heater.
2. The combustion system of claim 1, the plurality of burners being
separated into burner zones within the heater housing.
3. The combustion system of claim 2, each burner zone having a
respective target heat release; the computer readable instructions
that operate to iteratively solve the fired-systems model further
operating to: solve the fired-systems model according to each
respective target heat release of each burner zone.
4. The combustion system of claim 2, each burner zone having a
respective target excess oxygen level; the computer readable
instructions that operate to iteratively solve the fired-systems
model further operating to: solve the fired-systems model to
achieve each respective target excess oxygen level of each burner
zone.
5. The combustion system of claim 4, each respective target excess
oxygen level of each burner zone being above, below, or equal to a
target global oxygen level, and the cumulative excess oxygen
equaling the target global excess oxygen level.
6. The combustion system of claim 1, the ambient air information
being sensed by sensors proximate the heater housing or obtained
from a third-party weather server.
7. The combustion system of claim 1, the available airflow at each
burner being known based on information about each respective
burner.
8. The combustion system of claim 1, the available airflow at each
burner being determined by the air-flow analyzer based on the
pressure differential across each burner.
9. The combustion system of claim 8, the pressure differential
being determined based on ductwork air pressure sensor data and
in-heater pressure data.
10. The combustion system of claim 9, the in-heater pressure data
defining draft within the heater.
11. The combustion system of claim 9, the in-heater pressure data
being interpolated for each of the plurality of burners from
pressure sensor data from a pressure sensor located at a known
location from each of the plurality of burners.
12. The combustion system of claim 1, the fired-systems model being
generated based on manual testing data of the heater.
13. The combustion system of claim 1, the fired-systems model being
defined by physics-based models of air-flow within the heater
housing.
14. The combustion system of claim 1, the fired-systems model being
defined by computational fluid dynamics (CFD) of the heater.
15. The combustion system of claim 1, the fired-systems model being
tuned based on real-time sensed data from within the heater,
computational fluid dynamics data of the heater, historical data of
the heater and/or other heaters similar to the heater, or any
combination thereof.
16. The combustion system of claim 1, the computer readable
instructions that operate to iteratively solve the fired-systems
model further operating to: identify optimized stack damper
settings and/or optimized air-flow handling settings to achieve a
target global excess oxygen level to be sensed by the oxygen
sensor.
17. The combustion system of claim 1, the computer readable
instructions that iteratively solve the fired-systems model
operating to: solve the fired-systems model based on one or more
constraints.
18. The combustion system of claim 17, the one or more constraints
requiring the optimized burner air register settings to include at
least one burner air register at full-open setting.
19. The combustion system of claim 1, the computer readable
instructions that when executed by the processor further operate
to: iteratively solve the fired-systems model based on a desired
number of burner air register changes over a future period of time
to identify optimized stack damper settings and/or optimized
air-handling settings to define a necessary draft range within the
heater that can withstand weather variations over the future period
of time.
20. The combustion system of claim 19, the computer readable
instructions that when executed by the processor further operate
to: identify the optimized stack damper settings and/or optimized
air-handling settings that define the necessary draft range and
maintain predicted operational cost below a predefined operational
cost threshold.
21. The combustion system of claim 1, the computer readable
instructions that when executed by the processor further operate
to: receive sensed data from within the heater after implementation
of the optimized burner air register settings, the optimized stack
damper settings, the optimized air-flow handling settings, or any
combination thereof; and output an alert when the sensed data
varies from expected data.
22. The combustion system of claim 21, the alert including an
audible, visual, or tactile indication on the heater
controller.
23. The combustion system of claim 21, the alert including a
remediation action that shuts down the heater.
24. The combustion system of claim 1, the air-side analyzer being
located remotely from the heater controller; the output the
optimized burner air register settings to a heater controller of
the process heater including transmitting the optimized burner air
register settings to the heater controller.
25. A method for automatic air-register settings in a combustion
system, the method comprising: iteratively solving a fired-systems
model of a process heater, of the combustion system, based on fuel
information, a target heat release of a plurality of burners in the
process heater, ambient air information, and available airflow at
each of the plurality of burners to identify optimized burner air
register settings to achieve a target global excess oxygen level to
be sensed by an oxygen sensor that senses oxygen level inside the
process heater; and, output the optimized burner air register
settings to a heater controller of the process heater.
26. The method of claim 25, further comprising: receiving sensed
data from within the heater after implementation of the optimized
burner air register settings, the optimized stack damper settings,
the optimized air-flow handling settings, or any combination
thereof; and outputting an alert when the sensed data varies from
expected data.
27. The method of claim 26, the alert including an audible, visual,
or tactile indication on the heater controller.
28. The method of claim 26, the alert including a remediation
action that shuts down the heater.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to, and benefits from U.S.
Provisional Application Ser. No. 62/864,997, filed Jun. 21, 2019.
This application is also related to each of: U.S. Provisional
Application Ser. No. 62/864,954, filed Jun. 21, 2019; U.S.
Provisional Application Ser. No. 62/864,967, filed Jun. 21, 2019;
U.S. Provisional Application Ser. No. 62/864,992, filed Jun. 21,
2019; U.S. Provisional Application Ser. No. 62/865,007, filed Jun.
21, 2019; U.S. Provisional Application Ser. No. 62/865,021, filed
Jun. 21, 2019; and U.S. Provisional Application Ser. No.
62/865,031, filed Jun. 21, 2019. The entire contents of each of the
aforementioned applications are incorporated herein as if fully set
forth.
BACKGROUND
[0002] Process heaters have multiple burners (sometimes up to 200+
burners per furnace) and each one has its own manual air register
(also referred to as a damper) that can be used to throttle the
airflow to a component of the heater (such as a burner). Some
burner designs have multiple air register control handles. Many
times, the air register handles are designed differently per burner
technology.
[0003] Some applications require various air register setting per
burner within the firebox based on the elevation at which the
burner is installed or the fired heat release of each burner.
[0004] The "ideal air register setting" on each burner is
historically very difficult to determine. Historically the system
operator, by evaluating the excess O2 measured in the furnace, and
manually adjusts the burner air registers to reduce the excess
O.sub.2 in the heater box.
BRIEF DESCRIPTION OF THE FIGURES
[0005] The foregoing and other features and advantages of the
disclosure will be apparent from the more particular description of
the embodiments, as illustrated in the accompanying drawings, in
which like reference characters refer to the same parts throughout
the different figures. The drawings are not necessarily to scale,
emphasis instead being placed upon illustrating the principles of
the disclosure.
[0006] FIG. 1 depicts an example system of a process heater with
automatic air register setting determination, in embodiments.
[0007] FIG. 2 depicts a typical draft profile throughout a heater
(e.g., the heater of FIG. 1).
[0008] FIG. 3 depicts a plurality of example process tube
types.
[0009] FIG. 4 depicts a diagram showing air temperature and
humidity effects on sensed excess O.sub.2 levels.
[0010] FIG. 5 depicts a schematic of air and fuel mixture in a
pre-mix burner, in embodiments.
[0011] FIG. 6 depicts a schematic of air and fuel mixture in a
diffusion burner, in embodiments.
[0012] FIG. 7 depicts an example cutaway diagram of a burner, which
is an example of the burner of FIG. 1.
[0013] FIG. 8 depicts an example air register handle and indicator
plate 804 that is manually controlled.
[0014] FIG. 9 depicts example burner tips with different shapes and
sizes.
[0015] FIG. 10 depicts example burner tips with the same shape, but
different drill hole configurations.
[0016] FIG. 11 depicts a block diagram of the heater controller of
FIG. 1 in further detail, in embodiments.
[0017] FIG. 12 depicts an example air analyzer (e.g., the air
analyzer of FIG. 11), including an air-flow optimizer, in
embodiments.
[0018] FIG. 13 depicts an example diagram indicating physical
geometry of a COOLstar.RTM. burner indicating pressure losses
throughout the burner, in an embodiment.
[0019] FIG. 14 depicts a heater with six rows of burners and six
fired control zones.
[0020] FIG. 15 shows results from a fired-systems model showing how
the air distributes to each of the plurality of burners of FIG. 14
as a function of the duct design with the burner air registers full
open, for example.
[0021] FIG. 16 depicts an example air ductwork having four air
supply zones each coupled to a single air input.
[0022] FIG. 17 shows a CFD model of a forced (or balanced) draft
system including a single airside pressure sensor.
[0023] FIG. 18 depicts a comparison of optimized (recommended) air
register settings after optimization using the air-flow optimizer
compared to the manually adjusted air-register settings, in an
example.
[0024] FIG. 19 depicts a comparison of optimized (recommended) air
register settings after optimization using the air-flow optimizer
compared to the manually adjusted air-register settings, in an
example.
[0025] FIG. 20 depicts visual impact on optimized burner air
register settings after implementation of the airflow optimizer, in
an embodiment.
[0026] FIG. 21 depicts additional benefits that are achieved after
implementation of the airflow optimizer, in an embodiment.
[0027] FIGS. 22-23 depict the stoichiometric ratio (air/fuel ratio)
of before and after, respectively, implementation of the airflow
optimizer, in an embodiment.
[0028] FIG. 24 depicts a method for generating optimized air-flow
settings in a combustion system, in embodiments.
[0029] FIG. 25 shows an example graph illustrating weather changes
(such as seasonal changes) that impact the excess oxygen readings
as compared to the designed/tuned conditions.
[0030] FIG. 26 depicts a method for generating optimized air-flow
settings that achieve a desired combustion system control range
over a period of time, in an embodiment.
[0031] FIG. 27 depicts an example of clogged fins on process
tubes.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0032] FIG. 1 depicts an example system 100 of a process heater
with intelligent monitoring system, in embodiments. The system 100
includes a heater 102 that is heated by one or more burners 104
located in the housing 103 thereof. Heater 102 can have any number
of burners 104 therein, each operating under different operating
conditions (as discussed in further detail below). Moreover,
although FIG. 1 shows a burner located on the floor of the heater
102, one or more burners may also be located on the walls and/or
ceiling of the heater 102 without departing from the scope hereof
(indeed, heaters in the industry often have over 100 burners).
Further, the heater 102 may have different configurations, for
example a box heater, a cylindrical heater, a cabin heater, and
other shapes, sizes, etc. as known in the art.
[0033] Burner 104 provides heat necessary to perform chemical
reactions or heat up process fluid in one or more process tubes 106
(not all of which are labeled in FIG. 1. Any number of process
tubes 106 may be located within the heater 102, and in any
configuration (e.g., horizontal, vertical, curved, off-set,
slanted, or any configuration thereof). Burner 104 is configured to
combust a fuel source 108 with an oxidizer such as air input 110 to
convert the chemical energy in the fuel into thermal energy 112
(e.g., a flame). This thermal energy 112 then radiates to the
process tubes 106 and is transferred through the process tubes 106
into a material therein that is being processed. Accordingly, the
heater 102 typically has a radiant section 113, a convection
section 114, and a stack 116. Heat transfer from the thermal energy
112 to the process tubes 106 primarily occurs in the radiant
section 113 and the convection section 114.
[0034] Airflow into the heater 102 (through the burner 104)
typically occurs in one of four ways natural, induced, forced, and
balanced.
[0035] A natural induced airflow draft occurs via a difference in
density of the flue gas inside the heater 102 caused by the
combustion. There are no fans associated in a natural induced
system. However, the stack 116 includes a stack damper 118 and the
burner includes a burner air register 120 that are adjustable to
change the amount of naturally induced airflow draft within the
heater 102.
[0036] An induced airflow draft system includes a stack fan (or
blower) 122 located in the stack (or connected to the stack) 116.
In other or additional embodiments, other motive forces than a fan
are be used to create the induced draft, such as steam injection to
educts flue gas flow through the heater. The stack fan 122 operates
to pull air through the burner air register 120 creating the
induced-draft airflow within the heater 102. The stack fan 122
operating parameters (such as the stack fan 122 speed and the stack
damper 118 settings) and the burner air register 120 impact the
draft airflow. The stack damper 118 may be a component of the stack
fan 122, or separate therefrom.
[0037] A forced-draft system includes an air input forced fan 124
that forces air input 110 into the heater 102 via the burner 104.
The forced fan 124 operating parameters (such as the forced fan 124
speed and the burner air register 120 settings) and the stack
damper 118 impact the draft airflow. The burner air register 120
may be a component of the forced fan 124, but is commonly separate
therefrom and a component of the burner 104.
[0038] A balanced-draft system includes both the air input forced
fan 124 and the stack fan 122. Each fan 122, 124 operate in
concert, along with the burner air register 120 and stack damper
118 to control the airflow and draft throughout the heater 102.
[0039] Draft throughout the heater 102 varies depending on the
location within the heater 102. FIG. 2 depicts a typical draft
profile 200 throughout a heater (e.g., heater 102). Line 202
depicts a desired draft that is consistent with the design of the
heater and components therein. Line 204 depicts a high draft
situation where pressure in the heater is more negative than
desired (and thus further negative compared to atmospheric pressure
outside of the heater). Line 206 depicts a low draft situation
where pressure in the heater is more positive than desired (and
thus closer to or greater than atmospheric pressure outside of the
heater). As shown, by line 202, heaters are often designed to have
a -0.1 pressure at the arch of the heater.
[0040] Draft throughout the heater 102 is also be impacted based on
the geometry of the heater and components thereon. For example,
draft is strongly a function of heater 102 height. The taller the
heater 102, the more negative the draft will be at the floor of the
heater 102 to maintain the same draft level at the top of the
heater 102 (normally -0.1 in H.sub.2O). The components greatly
impact the draft. For example, FIG. 3 depicts a plurality of
process tube types. The convection section process tubes 106 may or
may not have heat sink fins thereon to manage the heat transfer
from the thermal energy 112 to the process tube 106. These
convection section fins may plug or corrode overtime-varying the
required draft within a heater as compared to the designed draft
for the same heater with the same components. As the convection
section flue gas channel open area begins to decrease, a greater
pressure differential is required to pull the same quantity of flue
gas through the convection section.
[0041] Referring to FIG. 1, pressure (indicating draft) within the
heater 102 is measured at a variety of locations in the heater
respectively via one of a plurality of pressure sensors. Floor
pressure sensor 126(1) measures the pressure at the floor of the
heater 102. Arch pressure sensor 126(2) measures the pressure at
the arch of the heater 102 where the radiant section 113
transitions to the convection section 114. Convection pressure
sensor 127 measures the pressure of the convection section 114.
Stack pressure sensor 129, if included, measures the pressure of
the stack 116.
[0042] The pressure sensors 126, 127, 129 may include a manometer,
or a Magnehelic draft gauge, where the pressure readings are
manually entered into process controller 128 (or a handheld
computer and then transferred wirelessly or via wired connection
from the handheld computer to the process controller 128) including
a sensor database 130 therein storing data from various components
associated with the heater 102. The pressure sensors 126, 127, 129
may also include electronic pressure sensors and/or draft
transmitters that transmit the sensed pressure to the process
controller 128 via a wired or wireless connection 133. The wireless
or wired connection 133 may be any communication protocol,
including WiFi, cellular, CAN bus, etc.
[0043] The process controller 128 is a distributed control system
(DCS) (or plant control system (PLC) used to control various
systems throughout the system 100, including fuel-side control
(e.g., control of components associated with getting fuel source
108 into the heater 102 for combustion therein), air-side control
(e.g., control of components associated with getting air source 110
into the heater 102), internal combustion-process control (e.g.,
components associated with managing production of the thermal
energy 112, such as draft within the heater 102), and
post-combustion control (e.g., components associated with managing
the emissions after production of the thermal energy 112 through
the stack 116). The process controller 128 typically includes many
control loops, in which autonomous controllers are distributed
throughout the system 100 (associated with individual or multiple
components thereof), and including a central operator supervisory
control.
[0044] Operating conditions within the heater 102 (such as draft,
and the stoichiometry associated with creating the thermal energy
112) are further impacted via atmospheric conditions, such as wind,
wind direction, humidity, ambient air temperature, sea level, etc.
FIG. 4 depicts a diagram 400 showing air temperature and humidity
effects on sensed excess O.sub.2 levels. The changes in operating
conditions are often controlled by monitoring and manipulating the
draft conditions within the heater 102. The stack dampers 118 are
commonly digitally controlled, and therefore often controllable
from the operating room of the system 100, via the process
controller 128. However, many systems do not include burner air
registers 120 that are digitally controlled. Because of this,
system operators often control draft within the heater 102 using
just an electronic stack damper (e.g., stack damper 118) thereby
avoiding timely and costly manual operation of each burner air
register (e.g., burner air register 120) associated with each
individual burner (e.g., burner 104). This cost grows depending on
the number of burners located in each heater--each heater may have
over 100 burners therein.
[0045] In addition to the draft as discussed above, burner geometry
plays a critical role in managing the thermal energy 112 produced
in the heater 102. Each burner 104 is configured to mix the fuel
source 108 with the air source 110 to cause combustion and thereby
create the thermal energy 112. Common burner types include pre-mix
burners and diffusion burners. FIG. 5 depicts a schematic 500 of
air and fuel mixture in a pre-mix burner, in embodiments. In a
pre-mix burner, kinetic energy of the fuel gas 502 draws some
primary air 504 needed for combustion into the burner. The fuel and
air mix to create an air/fuel mixture 504 having a specific
air-to-fuel ratio prior to igniting to create the thermal energy
112. FIG. 6 depicts a schematic 600 of air and fuel mixture in a
diffusion burner, in embodiments. In a diffusion burner, air 604
for combustion is drawn (by induced- or natural-draft) or pushed
(by forced-, or balanced-draft) into the heater before mixing with
the fuel 602. The mixture burns at the burner gas tip 606.
[0046] FIG. 7 depicts an example cutaway diagram of a burner 700,
which is an example of the burner 104 of FIG. 1. Burner 700 is an
example of a diffusion burner. Burner 700 is shown located mounted
in a heater at the heater floor 702. Proximate the burner 700 in
the heater floor 702 is a manometer 704, which is an example of the
pressure sensors 126, 127, 129 discussed above. The manometer 704
may be another type of pressure sensor without departing from the
scope hereof. Burner 700 is shown for a natural or induced-draft
heater system, and includes a muffler 706 and a burner air register
708. Ambient air flows through the muffler 706 from outside the
heater system. In a forced or balanced-draft system, the muffler
706 may not be included and instead be replaced with an intake
ducting from the forced fan (e.g., forced fan 124 in FIG. 1). The
burner air register 708 is an example of the burner air register
120 discussed above with respect to FIG. 1, and may be manipulated
via an air register handle 710 to one of a plurality of settings
defining how open or closed the air register 708 is. As discussed
above, the air register handle 710 is typically manually controlled
(although sometimes is fitted with an actuator, or provided with
mechanical linkage and an actuator so a single actuator manipulates
a plurality of burners). FIG. 8 depicts an example air register
handle 802 and indicator plate 804 that is manually controlled. The
input air then travels through the burner plenum 712 towards the
burner output 714 where it is mixed with input fuel and ignited to
combust and produce thermal energy (e.g., thermal energy 112 of
FIG. 1).
[0047] The fuel travels through a fuel line 716, and is output at a
burner tip 718. The fuel may be disbursed on a deflector 720. The
burner tip 718 and deflector 720 may be configured with a variety
of shapes, sizes, fuel injection holes, etc. to achieve the desired
combustion results (e.g., flame shaping, emissions tuning, etc.).
FIG. 9 depicts example burner tips with different shapes and sizes.
FIG. 10 depicts example burner tips with the same shape, but
different drill hole configurations. Furthermore, one or more tiles
722 may be included at the burner output 714 to achieve a desired
flame shape or other characteristic.
[0048] Referring to FIG. 1, control of the system 100 occurs both
manually and digitally. As discussed above, various components,
such as burner air register 120 are commonly manually controlled.
However, the system 100 also includes a variety of sensors
throughout the heater 102, the fuel-side input, and the air-side
input used to monitor and control the system using the process
controller 128.
[0049] At the stack 116, an oxygen sensor 132, a carbon monoxide
sensor 134, and NO.sub.x sensor 136 can be utilized to monitor the
condition of the exhaust and emissions leaving the heater 102 via
the stack 116. Each of the oxygen sensor 132, carbon monoxide
sensor 134, and NO.sub.x sensor 136 may be separate sensors, or
part of a single gas-analysis system. The oxygen sensor 132, carbon
monoxide sensor 134, and NO.sub.x sensor 136 are each operatively
coupled to the process controller 128 via a wired or wireless
communication link. These sensors indicate the state of combustion
in the heater 102 in substantially real-time. Data captured by
these sensors is transmitted to the process controller 128 and
stored in the sensor database 130. By monitoring the combustion
process represented by at least one of the oxygen sensor 132,
carbon monoxide sensor 134, and NO.sub.x sensor 136, the system
operator may adjust the process and combustion to stabilize the
heater 102, improve efficiency, and/or reduce emissions. In some
examples, other sensors, not shown, can be included to monitor
other emissions (e.g., combustibles, methane, sulfur dioxide,
particulates, carbon dioxide, etc.) on a real-time basis to comply
with environmental regulations and/or add constraints to the
operation of the process system. Further, although the oxygen
sensor 132, carbon monoxide sensor 134, and NO.sub.x sensor 136 are
shown in the stack 116, there may be additional oxygen sensor(s),
carbon monoxide sensor(s), and NO.sub.x sensor(s) located elsewhere
in the heater 102, such as at one or more of the convection section
114, radiant section 113, and/or arch of the heater 102. The above
discussed sensors in the stack section may include a flue gas
analyzer (not shown) prior to transmission to the process
controller 128 that extract, or otherwise test, a sample of the
emitted gas within the stack 116 (or other section of the heater)
and perform an analysis on the sample to determine the associated
oxygen, carbon monoxide, or NO.sub.x levels in the sample (or other
analyzed gas). Other types of sensors include tunable laser diode
absorption spectroscopy (TDLAS) systems that determine the chemical
composition of the gas based on laser spectroscopy.
[0050] Flue gas temperature may also be monitored by the process
controller 128. To monitor the flue gas temperatures, the heater
102 may include one or more of a stack temperature sensor 138, a
convection sensor temperature sensor 140, and a radiant temperature
sensor 142 that are operatively coupled to the process controller
128. Data from the temperature sensors 138, 140, 142 are
transmitted to the process controller 128 and stored in the sensor
database 130. Further, each section may have a plurality of
temperature sensors--in the example of FIG. 1, there are three
radiant section temperature sensors 142(1)-(3). The above discussed
temperature sensors may include a thermocouple, suction pyrometer,
and/or laser spectroscopy analysis systems that determine the
temperature associated with the given temperature sensor.
[0051] The process controller 128 may further monitor air-side
measurements and control airflow into the burner 104 and heater
102. Air-side measurement devices include an air temperature sensor
144, an air-humidity sensor 146, a pre-burner air register air
pressure sensor 148, and a post-burner air register air pressure
sensor 150. In embodiments, the post-burner air pressure is
determined based on monitoring excess oxygen readings in the heater
102. The air-side measurement devices are coupled within or to the
air-side ductwork 151 to measure characteristics of the air flowing
into the burner 104 and heater 102. The air-temperature sensor 144
may be configured to sense ambient air temperatures, particularly
for natural and induced-draft systems. The air-temperature sensor
144 may also be configured to detect air temperature just prior to
entering the burner 104 such that any pre-heated air from an
air-preheat system is taken into consideration by the process
controller 128. The air-temperature sensor 144 may be a
thermocouple, suction pyrometer, or any other temperature measuring
device known in the art. The air humidity sensor 146 may be a
component of the air temperature sensor, or may be separate
therefrom, and is configured to sense the humidity in the air
entering the burner 104. The air temperature sensor 144 and air
humidity sensor 146 may be located upstream or downstream from the
burner air register 120 without departing from the scope hereof.
The pre-burner air register air pressure sensor 148 is configured
to determine the air pressure before the burner air register 120.
The post-burner air register air pressure sensor 150 is configured
to determine the air pressure after the burner air register 120.
The post-burner air register air pressure sensor 150 may not be a
sensor measuring the furnace draft at the burner elevation, or
other elevation and then calculated to determine the furnace draft
at the burner elevation. Comparisons between the post-burner air
register air pressure sensor 150 and the pre-burner air register
air pressure sensor 148 may be made by the process controller to
determine the pressure drop across the burner 104, particularly in
a forced-draft or balanced-draft system. Air-side and temperature
measurements discussed herein may further be measured using one or
more TDLAS devices 147 located within the heater 102 (at any of the
radiant section 113, convection section 114, and/or stack 116).
[0052] Burner 104 operational parameters may further be monitored
using a flame scanner 149. Flame scanners 149 operate to analyze
frequency oscillations in ultraviolet and/or infrared wavelengths
of one or both of the main burner flame or the burner pilot
light.
[0053] FIG. 1 also shows an air handling damper 152 that is located
prior to the burner air register 120. The air-handling damper 152
includes any damper that impacts air-flow into the heater 102, such
as a duct damper, variable speed fan, fixed-speed fan with air
throttling damper, etc.) In certain system configurations, a single
air input (including a given fan 124) supplies air to a plurality
of burners, or a plurality of zones within a given heater. There
may be any number of fans (e.g., forced fan 124), temperature
sensors (e.g., air temperature sensor 144), air humidity sensors
(e.g., air humidity sensor 146), air pressure sensors (e.g.,
pre-burner air register air pressure sensor 148) for a given
configuration. Further, any of these air-side sensors maybe located
upstream or downstream from the air handling damper 152 without
departing form the scope hereof.
[0054] The process controller 128 may further monitor fuel-side
measurements and control fuel flow into the burner 104. Fuel-side
measurement devices include one or more of flow sensor 154, fuel
temperature sensor 156, and fuel-pressure sensor 158. The fuel-side
measurement devices are coupled within or to the fuel supply
line(s) 160 to measure characteristics of the fuel flowing into the
burner 104. The flow sensor 154 may be configured to sense flow of
the fuel through the fuel supply line 160. The fuel-temperature
sensor 156 detects fuel temperature in the fuel supply line 160,
and includes known temperature sensors such as a thermocouple. The
fuel-pressure sensor 158 detects fuel-pressure in the fuel supply
line 160.
[0055] The fuel line(s) 160 may have a plurality of fuel control
valves 162 located thereon. These fuel control valves 162 operate
to control the flow of fuel through the supply lines 160. The fuel
control valves 162 are typically digitally controlled via control
signals generated by the process controller 128. FIG. 1 shows a
first fuel control valve 162(1) and a second fuel control valve
162(2). The first fuel control valve 162(1) controls fuel being
supplied to all burners located in the heater 102. The second fuel
control valve 162(2) controls fuel being supplied to each
individual burner 104 (or a grouping of burners in each heater
zone). There may be more or fewer fuel control valves 162 without
departing from the scope hereof. Further, as shown, there may be a
grouping of fuel-side measurement devices between individual
components on the fuel supply line 160. For example, a first flow
sensor 154(1), first fuel temperature sensor 156(1), and first
fuel-pressure sensor 158(1) are located on the fuel supply line 160
between the fuel source 108 and the first fuel control valve
162(1). A second flow sensor 154(2), second fuel temperature sensor
156(2), and second fuel-pressure sensor 158(2) are located on the
fuel supply line 160 between the first fuel control valve 162(1)
and the second fuel control valve 162(2). Additionally, a third
flow sensor 154(3), third fuel temperature sensor 156(3), and third
fuel-pressure sensor 158(3) are located on the fuel supply line 160
between the second fuel control valve 162(2) and the burner 104.
The third fuel temperature sensor 156(3), and third fuel-pressure
sensor 158(3) may be configured to determine flow, temperature, and
pressure respectively of an air/fuel mixture for pre-mix burners
discussed above with respect to FIG. 5.
[0056] The process controller 128 may also measure process-side
temperatures associated with the processes occurring within the
process tubes 106. For example, system 100 may further include one
or more tube temperature sensors 168, such as a thermocouple, that
monitor the temperature of the process tubes 106. The temperature
sensor 168 may also be implemented using optical scanning
technologies, such as an IR camera, and/or one of the TDLAS devices
147. Furthermore, the process controller 128 may also receive
sensed outlet temperature of the fluid within the process tubes 106
from process outlet temperature sensor (not shown), such as a
thermocouple. The process controller 128 may then use these sensed
temperatures (from the tube temperature sensors 168 and/or the
outlet temperature sensor) to control firing rate of the burners
104 to increase or decrease the generated thermal energy 112 to
achieve a desired process temperature.
[0057] FIG. 11 depicts a block diagram of the process controller
128 of FIG. 1 in further detail, in embodiments. The process
controller 128 includes a processor 1102 communicatively coupled
with memory 1104. The processor 1102 may include a single
processing device or a plurality of processing devices operating in
concert. The memory 1104 may include transitory and or
non-transitory memory that is volatile and/or non-volatile.
[0058] The process controller 128 may further include communication
circuitry 1106 and a display 1108. The communication circuitry 1106
includes wired or wireless communication protocols known in the art
configured to receive and transmit data from and to components of
the system 100. The display 1108 may be co-located with the process
controller 128, or may be remote therefrom and displays data about
the operating conditions of the heater 102 as discussed in further
detail below.
[0059] Memory 1104 stores the sensor database 130 discussed above,
which includes any one or more of fuel data 1110, air data 1118,
heater data 1126, emissions data 1140, process-side data 1170, and
any combination thereof. In embodiments, the sensor database 130
includes fuel data 1110. The fuel data 1110 includes fuel flow
1112, fuel temperature 1114, and fuel-pressure 1116 readings
throughout the system 100 regarding the fuel being supplied to the
burner 104. For example, the fuel flow data 1112 includes sensed
readings from any one or more of the flow sensor(s) 154 in system
100 transmitted to the process controller 128. The fuel temperature
data 1114 includes sensed readings from any one or more of the fuel
temperature sensor(s) 156 in system 100 transmitted to the process
controller 128. The fuel-pressure data 1116 includes sensed
readings from any one or more of the fuel-pressure sensor(s) 158 in
system 100 transmitted to the process controller 128. In
embodiments, the fuel data 1110 may further include fuel
composition information that is either sensed via a sensor located
at the fuel source 108 or that is determined based on an inferred
fuel composition such as that discussed in U.S. Provisional Patent
Application No. 62/864,954, filed Jun. 21, 2019 and which is
incorporated by reference herein as if fully set forth. The fuel
data 1110 may also include data regarding other fuel-side sensors
not necessarily shown in FIG. 1, but known in the art.
[0060] In embodiments, the sensor database 130 includes air data
1118 regarding the air being supplied to the burner 104 and heater
102. The air data 1118 includes air temperature data 1120, air
humidity data 1122, and air pressure data 1124. The air temperature
data 1120 includes sensed readings from any one or more of the air
temperature sensor(s) 144 in system 100 transmitted to the process
controller 128. The air humidity data 1122 includes sensed readings
from any one or more of the air humidity sensor(s) 146 in system
100, and/or data from local weather servers, transmitted to the
process controller 128. The air pressure data 1124 includes sensed
readings from any one or more of the pre-burner air register air
pressure sensor 148, and a post-burner air register air pressure
sensor 150 (or any other air pressure sensor) in system 100
transmitted to the process controller 128. The air data 1118 may
also include data regarding other air-side sensors not necessarily
shown in FIG. 1, but known in the art.
[0061] In embodiments, the sensor database 130 includes heater data
1126. The heater data 1126 includes radiant-section temperature
data 1128, convection-section temperature data 1130, stack-section
temperature data 1132, radiant-section pressure data 1134,
convection-section pressure data 1136, and stack-section pressure
data 1138. The radiant-section temperature data 1128 includes
sensed readings from the radiant temperature sensor(s) 142 of
system 100 that are transmitted to the process controller 128. The
convection-section temperature data 1130 includes sensed readings
from the convection temperature sensor(s) 140 of system 100 that
are transmitted to the process controller 128. The stack-section
temperature data 1132 includes sensed readings from the stack
temperature sensor(s) 138 of system 100 that are transmitted to the
process controller 128. The radiant-section pressure data 1134
includes sensed readings from the radiant pressure sensor(s) 126 of
system 100 that are transmitted to the process controller 128. The
convection-section pressure data 1136 includes sensed readings from
the convection pressure sensor(s) 127 of system 100 that are
transmitted to the process controller 128. The stack-section
pressure data 1136 includes sensed readings from the stack pressure
sensor(s) 129 of system 100 that are transmitted to the process
controller 128. The heater data 1126 may also include data
regarding other heater sensors not necessarily shown in FIG. 1, but
known in the art.
[0062] In embodiments, the sensor database 130 further includes
emissions data 1140. The emissions data 1140 includes O.sub.2
reading(s) 1142, CO reading(s) 1144, and NO.sub.x reading(s) 1146.
The O.sub.2 reading(s) 1142 include sensed readings from the oxygen
sensor 132 transmitted to the process controller 128. The CO
reading(s) 1144 include sensed readings from the carbon monoxide
sensor 134 transmitted to the process controller 128. The NO.sub.x
reading(s) 1146 include sensed readings from the NO.sub.x sensor
136 transmitted to the process controller 128. The emissions data
1140 may also include data regarding other emissions sensors not
necessarily shown in FIG. 1, but known in the art.
[0063] In embodiments, the sensor database 130 includes
process-side data 1170 regarding the conditions of the process
tubes 106 and the process occurring. The process-side data 1170
includes process tube temperature 1172, and the outlet fluid
temperature 1174. The process tube temperature 1172 may include
data captured by the process tube temperature sensor 168, discussed
above. The outlet fluid temperature 1174 may include data captured
by an outlet fluid sensor (not shown), such as a thermocouple. The
process-side data 1170 may also include data regarding other
process-side sensors not necessarily shown in FIG. 1, but known in
the art.
[0064] Data within the sensor database 130 is indexed according to
the sensor providing said readings. Accordingly, data within the
sensor database 130 may be used to provide real-time operating
conditions of the system 100.
[0065] The memory 1104, in embodiments, further includes one or
more of a fuel analyzer 1148, an air analyzer 1150, a draft
analyzer 1152, an emissions analyzer 1154, a process-side analyzer
1176, and any combination thereof. Each of the fuel analyzer 1148,
air analyzer 1150, draft analyzer 1152, emissions analyzer 1154,
and process-side analyzer 1176 comprise machine readable
instructions that when executed by the processor 1102 operate to
perform the functionality associated with each respective analyzer
discussed herein. Each of the fuel analyzer 1148, air analyzer
1150, draft analyzer 1152, emissions analyzer 1154, and
process-side analyzer 1176 may be executed in serial or parallel to
one another.
[0066] The fuel analyzer 1148 operates to compare the fuel data
1110 against one or more fuel alarm thresholds 1156. One common
fuel alarm threshold 1156 includes fuel-pressure threshold that
sets a safe operation under normal operating condition without
causing nuisance shutdowns of the system 100 due to improperly
functioning burner 104 caused by excess or low fuel-pressure. The
fuel alarm thresholds 1156 are typically set during design of the
system 100. The fuel analyzer 1148 may analyze other data within
the sensor database 130 not included in the fuel data 1110, such as
any one or more of air data 1118, heater data 1126, emissions data
1140, process-side data 1170, and any combination thereof to ensure
there is appropriate air to fuel ratio within the heater to achieve
the stoichiometric conditions for appropriate generation of the
thermal energy 112.
[0067] The air analyzer 1150 operates to compare the air data 1118
against one or more air alarm thresholds 1158. One common air alarm
threshold 1158 includes fan operating threshold that sets a safe
operation condition of the forced fan 124 and/or stack fan 122
under normal operating condition without causing nuisance shutdowns
of the system 100 due to improper draft within the heater 102
caused by excess or low air pressure throughout the system 100. The
air alarm thresholds 1158 are typically set during design of the
system 100. The air analyzer 1150 may analyze other data within the
sensor database 130 not included in the air data 1118, such as any
one or more of fuel data 1110, heater data 1126, emissions data
1140, process-side data 1170, and any combination thereof to ensure
there is appropriate air to fuel ratio within the heater to achieve
the stoichiometric conditions for appropriate generation of the
thermal energy 112.
[0068] The draft analyzer 1152 operates to compare the heater data
1126 against one or more draft alarm thresholds 1160. One common
draft alarm threshold 1160 includes heater pressure threshold that
sets safe operation conditions of the heater 102 under normal
operating condition without causing nuisance shutdowns or dangerous
conditions of the system 100 due to positive pressure within the
heater 102 (such as at the arch of the heater 102). The draft alarm
thresholds 1160 are typically set during design of the system 100.
The draft analyzer 1152 may analyze other data within the sensor
database 130 not included in the heater data 1126, such as any one
or more of fuel data 1110, air data 1118, emissions data 1140,
process-side data 1170, and any combination thereof to ensure there
is appropriate operating conditions within the heater 102 to
achieve the stoichiometric conditions for appropriate generation of
the thermal energy 112.
[0069] The emissions analyzer 1154 operates to compare the
emissions data 1140 against one or more emission alarm thresholds
1162. One emissions alarm threshold 1162 include a minimum and
maximum excess oxygen level that sets safe operation conditions of
the heater 102 under normal operating condition without causing
nuisance shutdowns or dangerous conditions of the system 100 due to
too little or too much oxygen within the heater 102 during creation
of the thermal energy 112. Other emission alarm thresholds 1162
include pollution limits set by environmental guidelines associated
with the location in which system 100 is installed. The emission
alarm thresholds 1162 are typically set during design of the system
100. The emissions analyzer 1154 may analyze other data within the
sensor database 130 not included in the emissions data 1140, such
as any one or more of fuel data 1110, air data 1118, heater data
1126, process-side data 1170, and any combination thereof to ensure
there is appropriate operating conditions within the heater 102 to
achieve the stoichiometric conditions for appropriate generation of
the thermal energy 112.
[0070] The process-side analyzer 1176 operates to compare the
process-side data 1170 against one or more process thresholds 1178.
One common process threshold 1178 includes a desired outlet
temperature to achieve efficient process conversion in the process
tubes 106. Another example process threshold 1178 includes a
maximum temperature threshold of the process tube 106 at which the
process tube 106 is unlikely to fail. The process-side analyzer
1176 may analyze other data within the sensor database 130 not
included in the process-side data 1170, such as any one or more of
fuel data 1110, air-data 1118, heater data 1126, emissions data
1140, and any combination thereof to ensure there is appropriate
air to fuel ratio within the heater to achieve the stoichiometric
conditions for appropriate generation of the thermal energy
112.
[0071] The fuel analyzer 1148, the air analyzer 1150, the draft
analyzer 1152, the emissions analyzer 1154, and the process-side
analyzer 1176 operate to create one or more of control signals
1164, alarms 1166, and displayed operating conditions 1168. The
control signals 1164 include signals transmitted from the process
controller 128 to one or more components of the system 100, such as
the dampers 118, air registers 120 (if electrically controlled),
fans 122, 124, and valves 162. The alarms 1166 include audible,
tactile, and visual alarms that are generated in response to
tripping of one or more of the fuel alarm threshold 1156, air alarm
threshold 1158, draft alarm threshold 1160, and emission alarm
threshold 1162. The displayed operating conditions 1168 include
information that is displayed on the display 1108 regarding the
data within the sensor database 130 and the operating conditions
analyzed by one or more of the fuel analyzer 1148, air analyzer
1150, draft analyzer 1152, emissions analyzer 1154, and
process-side analyzer 1176.
[0072] Referring to FIG. 1, one or more of the fuel analyzer 1148,
the air analyzer 1150, the draft analyzer 1152, the emissions
analyzer 1154 and the process-side analyzer 1176 may be entirely or
partially implemented on an external server 164. The external
server 164 may receive some or all of the data within the sensor
database 130 and implement specific algorithms within each of the
fuel analyzer 1148, the air analyzer 1150, the draft analyzer 1152,
the emissions analyzer 1154 and the process-side analyzer 1176. In
response, the external server 164 may transmit one or more of the
control signals 1164, the alarms 1166, and/or the displayed
operating conditions 1168 back to the process controller 128.
Automatic Air Register/Damper Setting Control
[0073] The present disclosure acknowledges that, because of the
manual nature required to achieve excess oxygen within the heater
(e.g., as sensed by the oxygen sensor 132) by manually altering
each burner air register (e.g., air register 120), the furnace is
often left in a high oxygen state, or a low oxygen state with a
more negative draft than desirable (e.g., stronger pull of air into
the heater) to move the excess oxygen control to the stack damper
118 that can be controlled remotely from the operating room (e.g.,
via the process controller 128). Such common operating process
results in inefficiencies in operating the process heater because
the airflow throughout the burners and heater are not operating
under optimal conditions--even if the target excess oxygen levels
are reached. The present disclosure resolves this problem by
iteratively solving a fired-systems model of the system using known
geometry of the heater, burner, air inlet ductwork, and other
features of the system to optimize the air register and/or damper
settings throughout the system.
[0074] FIG. 12 depicts an example air analyzer (e.g., air analyzer
1150 of FIG. 11), including an air-flow optimizer 1202, in
embodiments. Airflow optimizer 1202 includes computer readable
instructions that when executed by a processor (e.g., processor
1102), operate to generate one or more of optimized burner air
register settings 1206, optimized stack damper settings 1208, and
optimized air handling settings 1210, and any combination
thereof.
[0075] The airflow optimizer 1202, in an embodiment, operates to
iteratively solve a fired-systems model 1204 of the system (e.g.,
system 100) to identify optimized burner air register settings 1206
to achieve the target excess oxygen level 1214. The fired-systems
model 1204 may be for an entire combustion system (e.g., from the
air-input and the fuel-input through the exit of the stack), or may
be for one or more specific components within a given combustion
system (such as one or more of a burner model, an air ductwork
model, a model of draft within the heater, a model of heat transfer
surrounding process tubes, etc.). The fired-systems model 1204
model may be based on any one or more of combustion chemistry,
combustion kinetics, air and fuel fluid dynamics, heat transfer,
process side modeling, computational fluid dynamics modeling, and
other various types of combustion modeling. The fired-systems model
1204 may account for various system constraints and operational
characteristics. For example, by iteratively solving the
fired-systems model 1204, the airflow optimizer 1202 analyzes,
based on a known fuel information 1212, target heat release 1214
per heater zone, ambient air information 1216, and available
airflow 1218 at each burner, what burner air register setting 1206
is appropriate to obtain a target excess oxygen level 1220.
[0076] The fuel information 1212 includes the fuel data 1110
discussed above and identifies the fuel flow 1112, fuel temperature
1114, and fuel pressure 1116 capable of being supplied to each
burner 104. The fuel information 1212 may further identify the fuel
composition such that the fired-systems model 1204 may determine
the heat release provided by each burner according to each
potential burner air register setting.
[0077] The target heat release 1214 is input into the system 100
(e.g., at the process controller 128) by a system operator, or
determined by the process controller 128 based on the necessary
heat supplied by each burner 104, or plurality of burners 104 in a
burner zone within the heater to obtain the necessary thermal
energy 112 to properly perform the chemical process on the material
within the process tubes 106 or to heat up the fluid in the process
tubes 106. The target heat release 1214 may include a plurality of
target heat releases 1214 each representing a given zone within the
heater 102.
[0078] The target excess oxygen level 1220 is input into the system
100 (e.g., at the process controller 128) by a system operator, or
determined by the process controller 128 based on the necessary
heat supplied by each burner 104, or plurality of burners 104 in a
burner zone within the heater to obtain the necessary thermal
energy 112 to properly perform the chemical process on the material
within the process tubes 106 or to heat up the fluid in the process
tubes 106. The target excess oxygen level 1220 may include a
plurality of target excess oxygen levels 1220 defined for each of a
plurality of zones within the heater 102. The target excess oxygen
level 1220 for each zone may be above, below, or equal to a target
global oxygen level of the overall system such that the cumulative
excess oxygen provided by each zone equals the target global excess
oxygen level. In other words, the summation of the total fuel/zone
and the summation of the total air/zone must not be greater than
the summation of global total fuel and the summation of total
global air input into the system that achieves a desired global
excess oxygen level after combustion of the fuel and air to create
the thermal energy.
[0079] The ambient air information 1216 includes the air data 1118
including the air temperature 1120, air humidity 1122, and air
pressure 1124 that is either sensed by sensors proximate or at the
heater 102, or obtained from a third-party weather server.
[0080] The available airflow 1218 at each burner 104 includes the
amount of air capable of being provided into the heater 102 by each
burner 104 for each burner air register setting (e.g., each setting
the air register handle 802 defining the controllable range shown
on indicator plate 804 in FIG. 8). In certain embodiments, the
available airflow 1218 is known based on information about the
burner. In certain embodiments, the available airflow 1218 is
determined by the airflow optimizer 1202 by analyzing the pressure
differential across each burner 104. Referring back to FIG. 1, in
many systems, only a single air pressure sensor (e.g., air pressure
sensor 148 is located within the airflow ductwork (e.g., ductwork
151), and the air-pressure sensor 150 is not included in the
system. Thus, the airflow optimizer 1202 may receive this ductwork
air pressure sensor data 1222 (e.g., from the air pressure sensor
148) and the in-heater pressure data 1224 (e.g., including one or
more of the radiant-section pressure data 1134, convection-section
pressure data 1136, and stack-section pressure data 1138
respectively based on the pressure sensors 126, 127, and 129). The
airflow optimizer 1202 may then calculate the available airflow
1218 based on the pressure differential across each burner 102 as
determined from the ductwork air pressure sensor data 1222 and the
in-heater pressure data 1224. The available airflow 1218 may be
further based on sensed airflow, as opposed to calculating the
pressure differential across the burner, such as airflow sensed by
an anemometer located within the ductwork 151.
[0081] The in-heater pressure data 1224 defines the draft within
the heater 102. The more negative the draft, the more air that will
be pulled through the burners 104--as discussed above,
conventionally heaters are often controlled to more negative draft
than desirable to transfer control to the stack damper 118 and/or
stack fan 122, which are controllable from the process controller
128. In a natural and induced draft system, the air pressure
defined by the ductwork air pressure sensor data 1222 is the same
as the ambient air pressure because there is nothing pushing air
into the ductwork 151 (e.g., the forced fan 124). In a forced and
balanced draft system, the air pressure defined by the ductwork air
pressure sensor data 1222 may be influenced based on the fan
settings of the forced fan 124.
[0082] In certain embodiments, the in-heater pressure data 1224 for
at the location of a given burner may be interpolated from data
sensed by a pressure sensor at a physical location away from the
given burner. For example, in certain systems, the pressure within
the heater 102 is sensed at the heater arch. Pressure at other
levels within the heater 102, separated from the location of the
sensed pressure, may then be determined based on fluid dynamics
calculations.
[0083] In certain embodiments, the ductwork air pressure sensor
data 1222 for a given burner may be interpolated from data sensed
by a pressure sensor at a physical location within the ductwork 151
away from the burner, or interpolated from information such as a
forced fan setting of the forced fan 124.
[0084] Accordingly, in certain embodiments, the fired-systems
model(s) 1204 is further based on one or more of the heater housing
geometry 1226, process tube geometry 1228, burner geometry 1230,
and air supply ductwork geometry 1232, or any combination
thereof.
[0085] The geometry (such as the shape and height) of the heater
housing 1226 plays an important role in defining how the draft
within the heater will travel through the heater. This affects how
the air will be input and output from the system through convection
influenced by the draft.
[0086] The process tube geometry 1228 includes the orientation of
the process tubes (e.g., tubes 106), as well as size, shape, etc.
such as shown in FIG. 3, above. As discussed above, the
characteristics of the process tubes may influence the draft in the
heater and thus influence the air-flow throughout the system 100
and available airflow from each burner 104 therein.
[0087] The geometry of the burner 1230 includes the number,
location, and physical geometry of the burners, the burner zones
within the heater, as well as burner settings for each burner, such
as the controllable range of the burner air registers (e.g., burner
air register 120) such as the controllable range shown on indicator
plate 804 in FIG. 8. FIG. 13 depicts an example diagram indicating
physical geometry of a COOLstar.RTM. burner indicating pressure
losses throughout the burner, in an embodiment. The physical
geometry of the burner 1230 may impact the airflow capable of being
supplied into the heater 102 based on the path that the air must
flow through the burner. FIG. 14 depicts a heater with six rows of
burners and twelve fired control zones. In FIG. 14, each half row
of burners (10 burner clusters) may be controlled to independent
heat release rates (e.g., by altering the fuel flow rate via
manipulation of a fuel supply valve to satisfy the process
temperature demands below each cluster of burners, such as fuel
supply valve 162 of FIG. 1, and correspondingly altering the
air-flow rate by utilizing a more closed air register handle
setting) to satisfy the air flow rate demand of each cluster of
burners.
[0088] The geometry of the air ductwork 1232 includes the geometry
of the airflow ductwork (e.g., ductwork 151) throughout the system
100. This includes any air handling damper (e.g., air handling
register 152), the air-flow zones, and the geometry of each of the
above. FIG. 15 shows results from a fired-systems model 1500
showing how the air distributes to each of the plurality of burners
of FIG. 14 as a function of the duct design with the burner air
registers full open, for example. If the burner is not firing the
exact same percentage of expected airflow distribution percentage,
each burner will not be firing at equal stoichiometry. Since the
fired percentage varies frequently to adjust based on process
outlet temperatures for tubes near each cluster of burners, the air
must be modulated as well. In many systems, it is not modulated
properly because the insights of air fuel ratio per burner are not
available and adding additional hardware (such as airflow
measurement devices) to each individual burner is expensive and
requires excessive and undesirable maintenance to upkeep said
airflow measurement devices. FIG. 16 depicts an example air
ductwork having four air supply zones 1602(1)-(4) each coupled to a
single air input 1604. Depending on the configuration of the
system, in certain embodiment, each zone 1602 may have a distinct
pressure. Solving of the fired-systems model 1204 using the
geometry of the air ductwork 1232 provides significant insight into
the airflow of the system and allows the air-flow optimizer 1202 to
understand actual air-flow potential for each burner of the
system.
[0089] In embodiments, the fired-systems model 1204 is solved based
on further information of the system 100, such as one or more of a
current or future stack damper setting 1234, a current or future
stack fan setting 1236 (if included in system 100, such as in
induced- or balanced-draft systems), a current or future forced fan
setting 1238 (if included in system 100, such as in forced- or
balanced-draft systems).
[0090] The current stack damper setting 1234 includes information
about the stack damper (e.g., stack damper 118), as well as control
ranges associated therewith, such that the optimized burner air
register settings 1206 are not generated in a manner that is
improper in view of the current hardware and controllability
associated with the stack damper.
[0091] The current stack fan setting 1236 includes information
about the stack fan (e.g., stack fan 122), as well as control
ranges associated therewith, such that the optimized burner air
register settings 1206 are not generated in a manner that is
improper in view of the current hardware and controllability
associated with the stack fan.
[0092] The current forced fan setting 1238 includes information
about the forced fan (e.g., forced fan 124), as well as control
ranges associated therewith, such that the optimized burner air
register settings 1206 are not generated in a manner that is
improper in view of the current hardware and controllability
associated with the forced fan.
[0093] By iteratively solving the fired-systems model 1204, the
airflow optimizer 1202 changes variables in the fired-systems model
1204 for each iteration and determines if the overall excess oxygen
level expected to be generated by all burners meets the target
excess oxygen level 1220 while still obtaining the target heat
release 1214 for each given burner, or zone including a plurality
of burners.
[0094] Airflow optimization by the airflow analyzer 1150 may be
triggered for a variety of reasons. For example, any one or more of
weather changes above a predefined threshold (e.g., humidity
changes, temperature changes, pressure changes, etc.), input fuel
composition changes, process-side material changes, and other
changes that otherwise impact operation and efficiency of the
combustion system may trigger airflow optimization. In certain
embodiments, the fired-systems model 1204 is iteratively solved,
but the optimized settings 1206, 120-8, and/or 1210 are not output
unless the adjustment will provide a cost benefit to the operator
above a predefined threshold.
[0095] As another example, when the measured excess oxygen sensed
by the O2 sensor 132 starts to divert from a prediction, one or
more TDLAS measurements (from the TDLAS device(s) 147) within the
heater can be leveraged to identify the specific areas/regions
within the heater that are most likely the cause of the deviation.
Using the fired-systems model 1204 for that identified area, TDLAS,
historical data, and AI, the air-flow analyzer 1150 can indicate
which burners/zones within the heaters require maintenance.
Further, if the fired-systems model 1204 verifies appropriate
settings of the airflow to the burners 104, then another potential
issue can be flagged, such as tramp air, and analyzed for (such as
discussed in U.S. Provisional No. 62/864,967, filed Jun. 21, 2019
and which is incorporated by reference as if set forth in its
entirety).
[0096] In embodiments, the fired-systems model 1204 is generated by
manually testing the differential pressure of the burners at each
burner air register setting for given draft levels. In further or
alternative embodiments, the fired-systems model 1204 is generated
based on physics-based modeling of the combustion system or
specific components thereof (such as the heater 102, or the burner
104). Embodiments utilizing a physics-based modeling provide the
advantage that, because the physics modeling requires minimal
computational power, optimized air register settings 1206, stack
damper settings 1208, and optimized air handling settings 1210 may
be generated quickly. This allows the operator of the system 100 to
compensate for unexpected or abnormal weather variations, changes
in fuel compensation, changes in hardware of the system 100,
etc.--all of which greatly impact the operational conditions inside
the heater 102. In further or alternative embodiments, the
fired-systems model 1204 is based further on computational fluid
dynamics (CFD) modeling of the system 100. FIG. 17 shows a CFD
model of a forced (or balanced) draft system including a single
airside pressure sensor 1702. The system shown in FIG. 17 includes
twelve rows of ten burners. The burners located towards the middle
of each row receive significantly less airflow due to the
configuration of the ductwork. Advantageously, utilizing CFD in the
model 1204 allows the model to be fine-tuned thereby providing more
accurate information and thus more accurate optimized air register
settings 1206, stack damper settings 1208, and optimized air
handling settings 1210.
[0097] In further or alternative embodiments, the fired-systems
model 1204 is solved based on further real-time sensed data 1240 of
the system 100. Over time, due to the harsh conditions of the
environment in the process heater 102, the pre-stored information
about the geometry of the system and components therein changes due
to build up on the components. For example, burner tips can develop
coke therein that blocks the drilled holes. Accordingly, the
real-time sensed data 1240 may include information captured and
stored in the sensor database 130, discussed above. The real-time
sensed data 1240 additionally allows the output optimized air
register settings 1206 to be verified in real-time. For example,
after verification that the heater has been configured according to
the optimized burner air register settings 1206 (or other optimized
settings discussed herein), the airflow optimizer 1202 may compare
real-time sensed data 1240 against the solved physics-based
fired-systems model 1204 to verify that the desired output is
obtained.
[0098] In embodiments, the airflow optimizer 1202 generates the
optimized settings (e.g., optimized burner air register settings
1206, optimized stack damper settings 1208, and optimized air
handling damper settings 1210) based on further historical data
1242. The historical data 1242 may include historically sensed data
from the system 100, and/or may include historical data regarding
similar systems that are recorded at an external server (e.g.,
external server 164).
[0099] In some embodiments, the historical data 1242 represents an
artificial intelligence data, such as a neural network, that the
airflow optimizer 1202 may infer any unknown geometry of the system
100, unknown setting of the system 100, or discrepancy in a solved
fired-systems model than expected result. This provides the airflow
optimizer 1202 to infer characteristics of the system 100 that are
unknown due to inaccurately installed hardware, corroded hardware,
or other deviations from known plan that are required to solve the
fired-systems model 1204. As an example of where artificial
intelligence and/or machine learning provides an impact, in some
instances, the error associated between the solved physics-based
model and the testing data is still significant. In these cases, a
combined approach of physics based calculations and paired with
data science will enable a hybrid model to be developed that
leverages the "easy to calculate" physics based properties, but
leaves the "hard to quantify" information to the ML algorithm. For
example, when there is a burner with a combustion section within
the burner itself. The combustion process creates a positive
pressure section within a part of the burner that would otherwise
be negative. Because the pressure associated and generated from the
combustion process would be very difficult to represent with
physics-based modeling approaches, parts of the burner may be
modeled with physics based models combined with other parts that
have been "learned" based on test data sets. The test data sets may
come from physical testing or sometimes CFD can be used to generate
data sets for reduced order ML models.
[0100] Accordingly, the fired-systems model 1204 may be based on
any one or more of manually testing of the heater system,
physics-based modeling of the heater system, CFD modeling of the
heater system, real-time sensed data of the heater system,
historical data of the system or other systems, and any combination
thereof.
[0101] In embodiments herein, the fired-systems model 1204 (or any
predicted data, expected data, estimated data, or other outputs
from a fired-system model discussed herein) is calculated using,
for example, physics-based modeling of the heater system based on
sensed data (e.g., the real-time sensed data and/or historical data
of the system), and artificial intelligence gleaned data. In such
embodiments, the systems and methods herein may accommodate error
ranges to provide a confidence region around the output of the
fired-systems model 1204 (or any predicted data, expected data,
estimated data, or other outputs from a fired-system model
discussed herein). The sensors used to capture sensed data (e.g.,
the real-time sensed data and/or historical data of the system) may
not be entirely accurate resulting in a sensor-based calculation
uncertainty value. The sensor-based calculation uncertainty value
is typically a fixed percentage that can change based on a
calculated value (e.g., sensors are X % efficient when measuring
temperatures across a first range, and Y % efficient across a
second range). Similarly, the artificial intelligence engine may
have an AI uncertainty that varies based on given inputs to the
artificial intelligence engine. The AI engine, for example, models
historical combined data distributions and analyzes statistical
deviations of the current distribution on a scale of 0 to 100%. The
confidence region allows a given prediction by the physics-based
calculations and/or the AI-based engine to accommodate variances in
the associated data. This then prevents false identifications of
conditions within the process heater 102 in the system.
[0102] In embodiments, including a forced draft fan (e.g., forced
draft fan 124), the airflow optimizer 1202 iterates under one or
more constraints 1244. For example, the constraint may require the
optimization algorithm to leave at least one burner in the entire
network with a "full open" burner air register setting. This
constraint ensures the achieved solution minimizes the overall
system pressure demand which is beneficial as it reduces the energy
consumed by the forced draft fan.
[0103] In embodiments, additional or alternative air-side settings
may be optimized using the airflow optimizer 1202. For example, the
fired-systems model 1204 may be iteratively solved to additionally
or alternatively generate one or both of optimized stack damper
settings 1208, and optimized air handling register settings 1210.
The optimized stack damper settings 1208 include electronic control
settings that may automatically control the stack damper (e.g., the
stack damper 118 of FIG. 1), as well as manual recommendations for
controlling the stack damper. The optimized air-handling register
settings 1210 include electronic control settings that may
automatically control the air handling damper (e.g., the air
handling register 152 of FIG. 1), as well as manual recommendations
for controlling the air handling damper.
[0104] FIG. 18 depicts a comparison of optimized (recommended) air
register settings after optimization using the air-flow optimizer
1202 compared to the manually adjusted air-register settings, in an
example. The system in FIG. 18 included a multi zone firebox
consisting of 21 burners. FIG. 18 shows a screenshot of the
displayed (e.g., displayed on display 1108) of optimized burner air
register settings per burner. In the system shown in FIG. 18, the
indicator position on each burner was configurable between 0 and 9
with adjustments available in increments of 0.5, with 0 being
closed and 9 being full open.
[0105] Multi-Zonal Optimization
[0106] FIG. 19 depicts a comparison of optimized (recommended) air
register settings after optimization using the air-flow optimizer
1202 compared to the manually adjusted air-register settings, in an
example. In the FIG. 19, there are over 168 burners that must be
adjusted to achieve the correct airflow per burner to make a single
O.sub.2 sensor (e.g., oxygen sensor 132) achieve the correct
cumulative value. Without direct and real-time feedback on a per
burner basis, this is nearly impossible. FIG. 19 also illustrates
that the optimized burner settings 1206 need not be for each
individual burner, but may be grouped according to zone, row,
column or any other desired grouping without departing from the
scope hereof.
[0107] In the system shown in FIG. 19, there are six burner zones
(1906(1)-1906(6)). During analysis of the fired-systems model 1204
associated with the system shown in FIG. 19, each zone 1906 may be
indicated with a specific heat release (e.g., target heat release
1214) for that zone. Each row within the "recommended air register
settings" indicates a different height within the heater, and thus
the draft at each row is different. Accordingly, the iteratively
solved fired-systems model 1204 accounts for the airflow at each
burner, within each zone 1906, and at each height within the heater
(to compensate for the varying draft at the given heights).
Furthermore, as discussed above, the target heat release for each
zone may be different. In the example shown in FIG. 19, the target
heat release (e.g., target excess oxygen level 1214) for the floor
zone 1906(5) is significantly greater than the target heat release
for the zone 1906(6). In embodiments, the biased air/fuel ratio per
burner zone could be intentional to target reduced emissions levels
or improved heat flux at the process tubes. In embodiments, the
target excess oxygen level (e.g., target excess oxygen level 1220)
for the floor zone 1906(5) may be greater than the global target
excess oxygen level of all zones, while the target excess oxygen
levels of the zones 1906(1)-(4), and 1906(6) may be equivalent or
below the global target excess oxygen level because the excess air
input from the burners in the floor zone 1906(5) will travel upward
within the heater (due to draft in the heater) and be consumed
during combustion associated with the zones 1906(1)-(4), and
1906(6).
[0108] FIG. 20 depicts visual impact on optimized burner air
register settings after implementation of the airflow optimizer
1220, in an embodiment. The left image in FIG. 20 indicates
improperly configured burner air registers. The flame (e.g.,
thermal energy 112) is travelling up the wall of the heater. In
contrast, the right image in FIG. 20 shows the burner flames after
optimized burner air register settings. The thermal energy in the
right image is consistent throughout the burner, indicating proper
damper settings.
[0109] FIG. 21 depicts additional benefits that are achieved after
implementation of the airflow optimizer 1202, in an embodiment.
FIG. 21 shows example reduction in heat release per fuel feed rate
by adjusting between historical improper burner air register
adjustments and proper air register adjustments using airflow
optimizer 1220 with better flame quality (such as the flame quality
shown in the right image of FIG. 20). When knowledge of the fuel
air ratio per burner is also available, emissions (such as CO and
NO.sub.x) are also be reduced systematically, and further yet,
burner safety trip settings can be modified such as described in
U.S. Provisional Application Ser. No. 62/865,007, filed Jun. 21,
2019 and which is incorporated herein in its entirety as if fully
set forth.
[0110] FIGS. 22-23 depict the stoichiometric ratio (air/fuel ratio)
of before and after, respectively, implementation of the airflow
optimizer 1220, in an embodiment. The graphs in FIGS. 22-23 show
stoichiometric ratio levels for six burner rows, and the ratio for
each half burner row. The ideal stoichiometric ratio for each row
is 1.1. As seen, the outer rows are being supplied too little air
in FIG. 22, at a stoichiometric ratio of approximately 0.85, and
the inner rows are being supplied too much air at a stoichiometric
ratio of approximately 1.25-1.275. Thus, the stoichiometric ratio
during the manual (prior art) method of controlling burner air
registers was inefficient. However, after implementation of the
airflow optimizer 1220, nearly all burners were operating with a
balanced air to fuel ratio at or near the desired stoichiometric
ratio of 1.1.
[0111] FIG. 24 depicts a method 2400 for generating optimized
air-flow settings in a combustion system, in embodiments. Method
2400 is implemented in the system 100 shown and discussed above in
FIGS. 1-23, and in particular using the air-flow optimizer 1202
discussed above.
[0112] In block 2402, the method 2400 generates a fired-systems
model. In one example of block 2402, the fired-systems model 1204
is generated. In embodiments of block 2402, the fired-systems model
may be generated may by manually testing the differential pressure
of the burners at each burner air register setting for given draft
levels. In further or alternative embodiments, the fired-systems
model is generated based on physics-based modeling of the heater.
In further or alternative embodiments, the fired-systems model 1204
is based further on computational fluid dynamics (CFD) modeling of
the system 100. In further or alternative embodiments, the
fired-systems model is generated based on real-time sensed data
(e.g., real-time sensed data 1240) of the system. Accordingly, the
fired-systems model 1204 may be based on any one or more of
manually testing of the heater system, physics-based modeling of
the heater system, CFD modeling of the heater system, real-time
sensed data of the heater system, historical data of the system or
other systems, and any combination thereof.
[0113] In embodiments of method 2400 including block 2404, the
method 2400 tunes the fired-systems model. In an example of block
2404, the fired-systems model 1204 is tuned based on one or more of
real-time sensed data 1240, CFD modeling, historical data 1242, or
any combination thereof.
[0114] In block 2406, the method 2400 obtains fuel information, a
target heat release, ambient air information, and available airflow
at each burner within a process heater. In one example of block
2406, the air analyzer 1150 receives the fuel information 1212,
target heat release 1214, ambient air information 1216, and
available draft at each burner 1218. In embodiments of block 2406,
the received fuel information, a target heat release, ambient air
information, and available airflow at each burner within a process
heater may be for a single zone, or may be received based on
multiple zones within the process heater.
[0115] In block 2408, the method 2400 solves the generated
fired-systems model with a set of variables to achieve a target
excess oxygen level. In one example of block 2408, the air-flow
optimizer 1202 solves the fired-systems model 1204 with a set of
variables defined at least in part by air register settings (and/or
stack damper settings, and/or air handling settings) to determine
if the set of variables results in a target excess oxygen level
1220. In embodiments including multiple zones of burners, the set
of variables may include differing target excess oxygen levels for
each zone within the heater 102, each of the differing target
excess oxygen levels being above, equal, or below a global target
excess oxygen level, but accumulating to equal the global target
excess oxygen level.
[0116] In block 2410, the method 2400 determines if the variables
used in block 2408 solve the fired-systems model. If yes, method
2400 proceeds to block 2412, else method 2400 proceeds to block
2414. In block 2412, the method 2400 determines if the variables
used in block 2408 meets a constraint associated with the
fired-systems model. If yes, method 2400 proceeds to block 2416,
else method 2400 proceeds to block 2414. In one example of block
2412, the air-flow optimizer 1202 determines if constraints 1244
are met.
[0117] In block 2414, the method 2400 changes one or more variables
in the fired-systems model and then repeats blocks 2408-2414
iteratively until the fired-systems model is solved to the target
excess oxygen level and all constraints are met. Then the method
proceeds with block 2416.
[0118] If the method 2400 has generated optimized burner air
register settings, in block 2416, the method 2400 outputs the
optimized burner air register settings equivalent to the variables
used to solve the fired-systems model to the target excess oxygen
level while meeting all constraints during the iteration of steps
2408-2414. In one embodiment of block 2416, the air-flow optimizer
1202 outputs the optimized burner air register settings 1206.
[0119] If the method 2400 has additionally or alternatively
generated optimized stack damper settings, in block 2418, the
method 2400 outputs the optimized stack damper settings equivalent
to the variables used to solve the fired-systems model to the
target excess oxygen level while meeting all constraints during the
iteration of steps 2408-2414. In one embodiment of block 2418, the
air-flow optimizer 1202 outputs the optimized stack damper settings
1208.
[0120] If the method 2400 has additionally or alternatively
generated optimized air handling settings, in block 2420, the
method 2400 outputs the optimized air handling settings equivalent
to the variables used to solve the fired-systems model to the
target excess oxygen level while meeting all constraints during the
iteration of steps 2408-2414. In one embodiment of block 2418, the
air-flow optimizer 1202 outputs the optimized air handling settings
1210.
[0121] In block 2422, the method 2400 operates the heater according
to the optimized settings generated in one or more of the above
blocks 2416-2420.
[0122] Stack Damper Optimized Settings
[0123] As discussed above, in certain embodiments, the airflow
optimizer 1202 additionally or alternatively generates optimized
stack damper settings 1208. These settings advantageously optimize
the draft within the system and allows efficient and consistent
airflow through the burners. However, the optimized stack damper
settings 1208 may provide an additional advantage--allowing the
operator to set a desired draft level within the heater 102 that
allows for only certain number of burner air register handle
changes over a given future time period.
[0124] Each burner 104 is installed in the heater as a system, and
operators must modulate stack dampers, in combination with burner
air registers, to get the ideal amount of draft within the furnace
and the correct excess oxygen. In forced draft or induced draft
systems, the operators or burner operating system must modulate the
induced draft and forced draft fans.
[0125] Normally, operators are instructed to operate their furnace
as approximately 0.1 in H.sub.2O of negative pressure at the
furnace arch and use the burner air register to tune the amount of
air entering into the system, as shown in FIG. 2. While the heater
102 is designed for specific conditions, the heater draft is
significantly impacted by the ambient air conditions. FIG. 25 shows
an example graph illustrating weather changes (such as seasonal
changes) that impact the excess oxygen readings as compared to the
designed/tuned conditions.
[0126] Because of the necessity for frequent draft adjustments, the
stack dampers are commonly fitted with an actuator. The actuator
enables the operator to adjust the draft of the heater remotely,
from the operating control room, such as via the process controller
128. In contrast, the burner air registers are not often fitted
with actuators and as such must be manually changed. This manual
operation of the burner air register handles is time consuming,
particularly on heaters having upwards of 200 burners. Because of
this, draft and excess air movements (that should be adjusted by
the burner air register) are often handled by the stack damper
(e.g., stack damper 118), by increasing or decreasing the draft
within the firebox via stack damper. To account for swings in
ambient conditions and varying firing rate required, the operator
commonly chooses to set the arch (bridge wall) draft a larger draft
(0.5 in H.sub.2O WC (water column) negative pressure is not
uncommon). This decision made for convenience has some negative
impacts in that the draft selected negatively impacts the
efficiency of the heater (and requires additional cost). These
negative impacts are not visible to the operator, and as a result,
while the operator meets the desire of limiting the number of
operator manual air register tuning rounds to the burner air
register handles, the operator may be incurring significant costs
by keeping the draft at an undesired level.
[0127] To provide more efficient control of the stack damper 118
(and/or stack fan 122, and/or forced fan 124), while maintaining
the operator's desire to limit the number of operator manual air
register tuning rounds to the burner air register control handles
and meeting desired cost and equipment efficiency for operating the
system.
[0128] Accordingly, in embodiments the airflow optimizer 1202
additionally or alternatively generates optimized stack damper
settings 1208 and/or air handling settings 1210, the fired-systems
model 1204 may be solved further based on desired number of
operator manual air register tuning rounds 1246 to change the
burner air register settings, and operational cost 1248 of
achieving differing draft levels.
[0129] For example, if an operator never wants to go adjust burner
air registers throughout the year, the solved fired-systems model
1204 will output the draft (most likely a relatively high number)
that will be capable of operation throughout the year with no
burner air register adjustments, and the associated optimized stack
damper settings 1208 and/or air handling settings 1210 to achieve
that draft. If the operator is willing to go adjust burner air
registers four times per year (one for each seasonal change), then
the solved fired-systems model 1204 will output the draft that will
still allow the burners to achieve their controllable region.
[0130] Being having a fired-systems model that represents the draft
through every section of the heater enables multi-variable
optimization relative to the air and draft adjustments within the
heater. It allows the operator to minimize draft (which will reduce
the amount of tramp air, and reduce the energy consumption from the
ID fan if present), maximize controllability throughout operating
swings, and decide up-front the number of operator manual air
register tuning rounds to the heater that are tolerable for burner
air register adjustments while knowing the associated cost that
said decisions make.
[0131] FIG. 26 depicts a method 2600 for generating optimized
air-flow settings that achieve a desired combustion system control
range over a period of time, in an embodiment. Method 2600 is
implemented, for example, in the air-flow analyzer 1202 discussed
above with reference to system 100 of FIGS. 1-25. Method 2600 may
be implemented in alternative to method 2400, or in addition
thereto.
[0132] Method 2600 begins with steps 2402 and 2404 discussed above
with respect to method 2400.
[0133] In block 2602, the method 2600 obtains a of desired number
of operator manual air register tuning rounds to change the burner
air register settings. In one example of block 2602, the air
analyzer 1150 receives the desired number of operator manual air
register tuning rounds 1246 to change the burner air register
settings via interaction with the operator through process
controller 128. Block 2602 may be a component of block 2406 of
method 2400.
[0134] In block 2604, the method 2600 solves the generated
fired-systems model with a set of variables to achieve a necessary
draft range within the heater that can withstand weather variations
over a given period of time while maintaining the number of desired
operator manual air register tuning rounds to change the burner air
register settings. In one example of block 2604, the air-flow
optimizer 1202 solves the fired-systems model 1204 with a set of
variables defined at least in part by air register settings (and/or
stack damper settings, and/or air handling settings) to determine a
necessary draft range within the heater that can withstand
predicted weather variations over a future period of time (e.g.,
one year, half a year, multiple seasons, etc.) while maintaining
the number of desired operator manual air register tuning rounds to
change the burner air register settings. Block 2604 may be a
component of block 2408.
[0135] In block 2606, the method 2600 determines if the variables
used in block 2606 solve the fired-systems model with a realistic
and/or achievable draft. If yes, method 2600 proceeds to block
2608, else method 2600 proceeds to block 2610. In block 2608, the
method 2600 determines if the variables used in block 2608 meets a
constraint associated with the fired-systems model. If yes, method
2600 proceeds to block 2612, else method 2600 proceeds to block
2610. In one example of block 2608, the air-flow optimizer 1202
determines if constraints 1244 are met, wherein the constraints
1244 include an operational cost 1248. Accordingly, if a realistic
draft is achievable while only changing the burner air registers
according to a desired number of times over a given period (e.g.,
one year, half a year, etc.), but the predicted operational cost
for achieving that realistic draft is too high (e.g., above a
threshold defined by the operational cost 1248), the variables may
be altered again to determine if changing the selected stack damper
and/or air-handling settings used to solve the fired-systems model
will lower the operational cost. Blocks 2606 and 2608 may be
components of blocks 2410 and 2412, respectively.
[0136] In block 2610, the method 2600 changes one or more variables
in the fired-systems model and then repeats blocks 2604-2610
iteratively until the fired-systems model is solved to achieve a
realistic/achievable draft and all constraints are met. Then the
method proceeds with block 2612. Block 2610 may be a component of
block 2414.
[0137] If the method 2600 has generated optimized burner air
register settings, in block 2612, the method 2600 outputs the
optimized burner air register settings equivalent to the variables
used to solve the fired-systems model to the generate an achievable
draft level while meeting all constraints during the iteration of
steps 2604-2610. In one embodiment of block 2612, the air-flow
optimizer 1202 outputs the optimized burner air register settings
1206. Block 2612 may be a component of block 2416.
[0138] If the method 2600 has additionally or alternatively
generated optimized stack damper settings, in block 2614, the
method 2600 outputs the optimized stack damper settings equivalent
to the variables used to solve the fired-systems model to the
generate an achievable draft level while meeting all constraints
during the iteration of steps 2604-2610. In one embodiment of block
2614, the air-flow optimizer 1202 outputs the optimized stack
damper settings 1208. Block 2614 may be a component of block
2418.
[0139] If the method 2600 has additionally or alternatively
generated optimized air handling settings, in block 2616, the
method 2600 outputs the optimized air handling settings equivalent
to the variables used to solve the fired-systems model to the
generate an achievable draft level while meeting all constraints
during the iteration of steps 2604-2610. In one embodiment of block
2616, the air-flow optimizer 1202 outputs the optimized air
handling settings 1210. Block 2616 may be a component of block
2420.
[0140] In block 2618, the method 2600 operates the heater according
to the optimized settings generated in one or more of the above
blocks 2612-2616. Block 2618 may be a component of block 2422.
[0141] Anomaly Detection based on Optimized Settings
[0142] Once the air-flow optimizer 1202 generates the optimized
burner air register settings 1206, optimized stack damper settings
1208, and optimized air handling settings 1210, and any combination
thereof, the expected draft, stack damper setting, burner air
register settings, induced draft fan or forced draft fan settings
(if included), can be compared to what is sensed, and used as an
anomaly detection for when there could be a faulty hardware
condition that would cause the hydraulic system to respond
differently than the calculation. Anomaly detection may also occur
without the optimized settings, but instead using manually recorded
data regarding the register settings, damper settings, and other
air handling settings.
[0143] As discussed above, the air-flow optimizer 1202 may further
analyze real-time sensed data 1240. If this real-time sensed data
1240 begins to deviate from expected values, based on the generated
and implemented optimized burner air register settings 1206,
optimized stack damper settings 1208, and optimized air handling
settings 1210, and combination thereof, then the air-flow optimizer
1202 may generate an alert 1250. The alert 1250 may be an audible,
visual, or tactile indication on the process controller 128, or
another device such as a mobile device of a heater operator. The
alert 1250 may also include a remediation action that automatically
controls the heater 102, and components associated therewith, to
compensate for the deviation of sensed values from expected
values.
[0144] One example of how the sensed values could deviate from the
expected values is, if a process tube 106 developed a leak, the
leak would add volume/mass into the heater 102 and change the
heater/system level hydraulics of the draft (or the readings in the
emissions data 1140). As such, the alert 1250 will indicate
incorrect emission levels in the heater, and/or identify the
location of the leak and recommend maintenance thereon. If the leak
causes unsafe conditions, the alert 1250 may include a remediation
action that shuts down the system for safety concerns.
[0145] Another example of how the sensed values could deviate from
the expected values is, if the process tubes 106 include fins, such
as discussed above with respect to FIG. 3, the fins may become
clogged due to the harsh conditions in the heater 102. FIG. 27
depicts an example of clogged fins on process tubes. These clogged
fins will greatly impact the draft through the heater 102, and thus
the sensed data will not be consistent with the expected data. As
such, the alert 1250 will indicate incorrect draft in the heater,
and/or identify the location of the draft discrepancy and recommend
maintenance thereon. If the clogged fins cause unsafe conditions,
the alert 1250 may include a remediation action that shuts down the
system for safety concerns.
[0146] As discussed above, any predicted data, expected data,
estimated data, or other outputs from a fired-system models
discussed herein may be calculated using, for example,
physics-based modeling of the heater system based on sensed data
(e.g., the real-time sensed data and/or historical data of the
system), and artificial intelligence gleaned data. In such
embodiments, the systems and methods herein may accommodate error
ranges to provide a confidence region around the output of the
predicted data, expected data, estimated data, or other outputs
from a fired-system model. The sensors used to capture sensed data
(e.g., the real-time sensed data and/or historical data of the
system) may not be entirely accurate resulting in a sensor-based
calculation uncertainty value. The sensor-based calculation
uncertainty value is typically a fixed percentage that can change
based on a calculated value (e.g., sensors are X % efficient when
measuring temperatures across a first range, and Y % efficient
across a second range). Similarly, the artificial intelligence
engine may have an AI uncertainty that varies based on given inputs
to the artificial intelligence engine. The AI engine, for example,
models historical combined data distributions and analyzes
statistical deviations of the current distribution on a scale of 0
to 100%. The confidence region allows a given prediction by the
physics-based calculations and/or the AI-based engine to
accommodate variances in the associated data. This confidence
region prevents false identifications of conditions within the
process heater 102 in the system when the sensed values deviate
within a certain range about a predicted value, the range being
defined by the confidence region.
[0147] FIGS. 28-33 depict graphs indicating heater operation over
time when the fins of process tubes become clogged due to harsh
conditions in the heater, in an embodiment. FIG. 34 depicts data
table represented by the graphs of FIGS. 28-33. Conventionally, an
operator is unaware of the clogging of process tube fins that
results in an improper draft within the heater (e.g., heater 102).
As previously illustrated, convection fouling is a build-up of
debris on the tubes and extended surfaces in the convection. This
causes an increase in thermal resistance reducing the heat
transferred to the process and increased flue gas side pressure
drop. Convection fouling causes a decrease in efficiency.
Conventionally, the operator does not have enough insight into the
heater operation to be fully aware of what is causing this decrease
in efficiency. The operator is unable to visually see the fin
clogging unless the operator is continuously viewing through a
viewport of the heater 102, which is unrealistic. Because of this,
the heater is typically controlled to fire at a higher rate forcing
more duty to be absorbed in the radiant section. The overall
absorbed duty/coil outlet temperature must be maintained to allow
for proper process of the material in the process tubes. Increased
thermal resistance can be seen as a decrease in coil crossover
temperature (if available), increase in firing rates, increase in
bridgewall temperature, and an increase in stack temperature. Along
with increased thermal resistance, this fouling forces the flue gas
across a decreasing cross-sectional area along its flow path. This
throttling effect increases the flue gas side pressure drop across
the convection. This can be seen with an increase in open
percentage of the stack damper to compensate and maintain the draft
pressure at the bridgewall.
[0148] The air-flow optimizer 1202, described above, utilizes the
fired-systems model 1204, real-time sensed data 1240, and
historical data 1242 to calculate expected values of the heater 102
at any given time. Comparison of these expected values to the
real-time sensed data 1240 allows the air-flow optimizer 1202 to
automatically detect and diagnose anomalies in the air flow, such
as convection fouling (e.g., clogging of the fins/heat sinks of
process tubes 106). In FIGS. 28-34 (where FIG. 34 is a table of the
data in FIGS. 28-33), it is seen that during time slot 1 (start of
run, "SOR"), the heater 102 is operating as expected, where the
modeled convection section dP matches the convection section dP
sensed. However, as time passes, the modeled convection section dP
begins to deviate from the measured convection section dP. At a
certain point, the delta between the measured and modeled
convection section dP may become greater than a predetermined
threshold, at which the air-flow optimizer 1202 may generate the
alert 1250 indicating cleaning of the process tubes 102 is
necessary.
[0149] The air-flow optimizer 1202 provides insight that operators
conventionally previously did not have. Operators were typically
unaware of what the convection section dP should be. Instead,
operators had to manually visually inspect process tubes 106 to
determine if the process tubes 106 were clogged. In contrast, the
present system and methods are capable of flagging an anomaly when
the heater's efficiency is lower than what it historically was
(e.g., via monitoring the varying heater efficiency over time as
shown in FIGS. 28-34) for the current process conditions (absorbed
duty, inlet temperature, outlet temperature, etc.) and raise some
questions. The present system is able to determine that the problem
is not internal fouling (coking) occurring in the radiant tubes
because the process pressure drop and tube metal temperatures are
within the expected range. The present system is able to determine
that the problem is convection fouling because, for the current
firing rate there is an increase in bridgewall temperature, stack
temperature, and the stack damper is more open than expected as
indicated by the fired-systems model 1204.
[0150] When combined with generation of the optimized settings as
discussed above, the present systems and methods are able to
invalidate potential anomalies, such as improper air register
settings, as causing the discrepancy in expected versus measured
values.
[0151] The above discussed anomaly detection may occur in either
methods 2400 or 2600 during operation of the heater in blocks 2422
and 2618, respectively. Furthermore, the above discussed anomaly
detection may be performed by other "analyzers" described herein,
such as the fuel analyzer 1148, the draft analyzer 1152, the
emissions analyzer 1154, and the process-side analyzer 1176. Each
of these analyzers may operate to detect different anomalies, as
well.
[0152] Cloud Computing Embodiments:
[0153] In embodiments, a portion or all of the airflow analyzer
1150 may be implemented remotely from the process controller 128,
such as in the network-based "cloud", where the airflow analyzer
1150 and the process controller 128 is a portion of an edge
computing scheme. For example, geometry information in the air
analyzer 1150, and airflow optimizer 1202 may be stored at the
external server 164, such that after the fired-systems model 1204
is solved to generate the optimized burner air register settings
1206 (and/or optimized stack damper settings 1208, and/or optimized
air handling damper settings 1210). These generated settings are
then transmitted from the external server 164 to the process
controller 128 for display on the display 1108 or automatic control
of the hardware associated with each optimized setting. The data
necessary for analysis by the airflow analyzer 1150 may be gathered
at the process controller 128 (such as at the system DCS or PLC
(plant control system) and transmitted to the external server 164
for analysis by the airflow analyzer 1150 0. Alternatively, or
additionally, one or more of the devices capturing the current
operating parameters 1402 may be an embedded device having data
transmission capability that transfers its respective data directly
to the external server 164 for analysis by the airflow analyzer
1150.
[0154] System Component Validation:
[0155] Continued understanding on the modeling side (either via the
the airflow analyzer 1150, or other physics-based modeling, or
analytics discussed herein or in any of the provisional
applications incorporated by reference as discussed above) allows
for the process controller 128 to monitor and validate the
measurement devices that populate the data within the sensor
database 130. Because the modeling provides optimized control
settings, the analyzers discussed herein are able to compare the
measured data to the expected data generated via calculations. If
the measured data varies with respect to the calculated data, the
system is able to troubleshoot the particular reason for that
discrepancy.
[0156] For example, a variation in a fuel-side calculation may
indicate that the calculated heat release based on pressure with
clean burner tips is higher than a given fuel mass flow
measurement. In such situation, the fuel analyzer 1148 may
implement the following troubleshooting: (i) identify that one or
more of the burners are out of service, (ii) determine if one or
more of the fuel valves are full-open (even though they are
supposed to be at a specific setting), (iii) determine if the
burner tips have additional fouling that is visually identifiable,
(iv) determine if the burner tips have a different orifice diameter
than expected, and (v) determine if the pressure transmitter or
flow meter providing the measurements are in need of
calibration.
[0157] As another example, a variation in a fuel-side calculation
may indicate that the calculated heat release based on pressure
with clean burner tips is lower than a given mass flow measurement.
In such situation, the fuel analyzer 1148 may implement the
following troubleshooting: (i) confirm quantity of out-of-service
burners, (ii) verify that the out-of-service burners are truly out
of service, (iii) determine if there are gas leaks within the
combustion system (visually observed by small "candle flames" until
the tip is plugged), (iv) determine if flame patterns match
conditions indicating missing burner tips or burner tips that have
ports that are eroded, (v) confirm burner tip orifice diameter,
(vi) determine improper line loss calculations, (vii) determine if
the pressure transmitter or flow meter providing the measurements
are in need of calibration.
[0158] As another example, a variation in an air-side calculation
may indicate that the calculated oxygen is higher than a measured
oxygen level. In such situation, the air-side analyzer 1150 (or the
emissions analyzer 1154) may implement the following
troubleshooting process: (i) confirm the number of burners
out-of-service, (ii) confirm that the air register settings are
accurate within the model, (iii) analyze the burners for blocked
air passages, such as blocked air inlets, refractory fallen into
burner throats, wall burner air-tip fouling, loos burner
insulation, flashback or combustion back pressure within the
burner, (iv) determine potential leaks within the process tubes
(and shut down if so), (v) verify ambient air conditions, (vi)
check wind speeds, (vii) calibrate air-side measurement devices
such as the air-pressure and O2 analyzer.
[0159] As another example, a variation in an air-side calculation
may indicate that the calculated oxygen is lower than a measured
oxygen level. In such situation, the air-side analyzer 1150 (or the
emissions analyzer 1154) may implement the following
troubleshooting process: (i) confirm the number of burners
out-of-service, (ii) confirm that the air register settings are
accurate within the model, (iii) analyze for tramp-air entering the
system (such as via sight ports, lighting ports, gas tip riser
mounting plates, etc.), (iv) determine potential leaks within the
process tubes (and shut down if so), (v) verify ambient air
conditions, (vi) check wind speeds, (vii) analyze for additional
gas leakage into the system, (viii) calibrate air-side measurement
devices such as the air-pressure and O2 analyzer.
Definitions
[0160] The disclosure herein may reference "physics-based models"
and transforming, interpolating, or otherwise calculating certain
data from other data inputs. Those of ordinary skill in the art
should understand what physics-based models incorporate, and the
calculations necessary to implement said transforming,
interpolating, or otherwise calculating for a given situation.
However, the present disclosure incorporates by reference chapter 9
of the "John Zink Hamworthy Combustion Handbook", which is
incorporated by reference in its entirety (Baukal, Charles E. The
John Zink Hamworthy Combustion Handbook. Fundamentals. 2nd ed.,
vol. 1 of 3, CRC Press, 2013) for further disclosure related to
understanding of fluid dynamics physics-based modeling and other
calculations. It should be appreciated, however, that
"physics-based models" and transforming, interpolating, or
otherwise calculating certain data from other data inputs is not
limited to just those fluid dynamics calculations listed in chapter
9 of the John Zink Hamworthy Combustion Handbook.
[0161] Changes may be made in the above methods and systems without
departing from the scope hereof. It should thus be noted that the
matter contained in the above description or shown in the
accompanying drawings should be interpreted as illustrative and not
in a limiting sense. The following claims are intended to cover all
generic and specific features described herein, as well as all
statements of the scope of the present method and system, which, as
a matter of language, might be said to fall therebetween.
[0162] Any of the functionality described herein may be combined,
in any combination, with the functionality described in the
applications incorporated by reference as discussed above. Such
combinations include using given outputs from the various described
"analyzers" to identify further insights into the control of the
described combustion systems, as will be appreciated by those of
ordinary skill in the art. Examples of combinations are produced
below:
[0163] (A1) In a first aspect, a combustion system includes: a
heater having a heater housing; an air source coupled to the
process heater via air ductwork; a plurality of burners configured
to combust a fuel source with the air source to produce thermal
energy, each burner including a burner air register configurable to
one of a plurality of burner air register settings to control input
of the air source into the burner; an oxygen sensor configured to
generate a sensed oxygen level inside the heater; a processor; and
a memory operatively coupled to the processor. The memory stores an
air-side analyzer comprising computer readable instructions that
when executed by the processor operate to: iteratively solve a
fired-systems model of the process heater based on fuel
information, a target heat release of the plurality of burners,
ambient air information, and available airflow at each of the
plurality of burners to identify optimized burner air register
settings to achieve a target global excess oxygen level to be
sensed by the oxygen sensor, and, output the optimized burner air
register settings to a heater controller of the process heater.
[0164] (A2) In an embodiment of (A1), the plurality of burners are
separated into burner zones within the heater housing.
[0165] (A3) In an embodiment of (A2), each burner zone having a
respective target heat release; the computer readable instructions
that operate to iteratively solve the fired-systems model further
operating to: solve the fired-systems model according to each
respective target heat release of each burner zone.
[0166] (A4) In an embodiment of any of (A1)-(A3), each burner zone
having a respective target excess oxygen level; the computer
readable instructions that operate to iteratively solve the
fired-systems model further operating to: solve the fired-systems
model to achieve each respective target excess oxygen level of each
burner zone.
[0167] (A5) In an embodiment of any of (A1)-(A4) each respective
target excess oxygen level of each burner zone being above, below,
or equal to a target global oxygen level, and the cumulative excess
oxygen equaling the target global excess oxygen level.
[0168] (A6) In an embodiment of any of (A1)-(A5), the ambient air
information being sensed by sensors proximate the heater housing or
obtained from a third-party weather server.
[0169] (A7) In an embodiment of any of (A1)-(A6), the available
airflow at each burner being known based on information about each
respective burner.
[0170] (A8) In an embodiment of any of (A1)-(A7), the available
airflow at each burner being determined by the air-flow analyzer
based on the pressure differential across each burner.
[0171] (A9) In an embodiment of (A8), the pressure differential
being determined based on ductwork air pressure sensor data and
in-heater pressure data.
[0172] (A10) In an embodiment of any of (A9), the in-heater
pressure data defining draft within the heater.
[0173] (A11) In an embodiment of any of (A9)-(A10), the in-heater
pressure data being interpolated for each of the plurality of
burners from pressure sensor data from a pressure sensor located at
a known location from each of the plurality of burners.
[0174] (A12) In an embodiment of any of (A1)-(A11), the
fired-systems model being generated based on manual testing data of
the heater.
[0175] (A13) In an embodiment of any of (A1)-(A11), the
fired-systems model being defined by physics-based models of
air-flow within the heater housing.
[0176] (A14) In an embodiment of any of (A1)-(A13), the
fired-systems model being defined by computational fluid dynamics
(CFD) of the heater.
[0177] (A15) In an embodiment of any of (A1)-(A14), the
fired-systems model being tuned based on real-time sensed data from
within the heater, computational fluid dynamics data of the heater,
historical data of the heater and/or other heaters similar to the
heater, or any combination thereof.
[0178] (A16) In an embodiment of any of (A1)-(A15), the computer
readable instructions that operate to iteratively solve the
fired-systems model further operating to: identify optimized stack
damper settings and/or optimized air-flow handling settings to
achieve a target global excess oxygen level to be sensed by the
oxygen sensor.
[0179] (A17) In an embodiment of any of (A1)-(A16), the computer
readable instructions that iteratively solve the fired-systems
model operating to: solve the fired-systems model based on one or
more constraints.
[0180] (A18) In an embodiment of any of (A17), the one or more
constraints requiring the optimized burner air register settings to
include at least one burner air register at full-open setting.
[0181] (A19) In an embodiment of any of (A1)-(A18), the computer
readable instructions that when executed by the processor further
operate to: iteratively solve the fired-systems model based on a
desired number of burner air register changes over a future period
of time to identify optimized stack damper settings and/or
optimized air-handling settings to define a necessary draft range
within the heater that can withstand weather variations over the
future period of time.
[0182] (A20) In an embodiment of any of (A19), the computer
readable instructions that when executed by the processor further
operate to: identify the optimized stack damper settings and/or
optimized air-handling settings that define the necessary draft
range and maintain predicted operational cost below a predefined
operational cost threshold.
[0183] (A21) In an embodiment of any of (A1)-(A20), the computer
readable instructions that when executed by the processor further
operate to: receive sensed data from within the heater after
implementation of the optimized burner air register settings, the
optimized stack damper settings, the optimized air-flow handling
settings, or any combination thereof; and output an alert when the
sensed data varies from expected data.
[0184] (A22) In an embodiment of any of (A21), the alert including
an audible, visual, or tactile indication on the heater
controller.
[0185] (A23) In an embodiment of any of (A21)-(A22), the alert
including a remediation action that shuts down the heater.
[0186] (A24) In an embodiment of any of (A1)-(A23), the air-side
analyzer being located remotely from the heater controller; the
output the optimized burner air register settings to a heater
controller of the process heater including transmitting the
optimized burner air register settings to the heater
controller.
[0187] (B1) In a second aspect, a method for automatic air-register
settings in a combustion system includes: iteratively solving a
fired-systems model of a process heater, of the combustion system,
based on fuel information, a target heat release of a plurality of
burners in the process heater, ambient air information, and
available airflow at each of the plurality of burners to identify
optimized burner air register settings to achieve a target global
excess oxygen level to be sensed by an oxygen sensor that senses
oxygen level inside the process heater; and, output the optimized
burner air register settings to a heater controller of the process
heater.
[0188] (B2) In an embodiment of (B1), the plurality of burners
being separated into burner zones within the heater housing.
[0189] (B3) In an embodiment of any of (B1)-(B2), each burner zone
having a respective target heat release; the iteratively solving
the fired-systems model including solving the fired-systems model
according to each respective target heat release of each burner
zone.
[0190] (B4) In an embodiment of any of (B1)-(B3), each burner zone
having a respective target excess oxygen level; the iteratively
solving the fired-systems model including solving the fired-systems
model according to each respective target excess oxygen level of
each burner zone.
[0191] (B5) In an embodiment of any of (B4), each respective target
excess oxygen level of each burner zone being above, below, or
equal to a target global oxygen level, and the cumulative excess
oxygen equaling the target global excess oxygen level.
[0192] (B6) In an embodiment of any of (B1)-(B5), further
comprising receiving the ambient air information from sensors
proximate the heater housing or obtaining the ambient air
information from a third-party weather server.
[0193] (B7) In an embodiment of any of (B1)-(B6), the available
airflow at each burner being known based on information about each
respective burner.
[0194] (B8) In an embodiment of any of (B1)-(B7), further
comprising determining the available airflow at each burner based
on the pressure differential across each burner.
[0195] (B9) In an embodiment of any of (B8), further comprising
determining the pressure differential based on ductwork air
pressure sensor data and in-heater pressure data.
[0196] (B10) In an embodiment of any of (B9), the in-heater
pressure data defining draft within the heater.
[0197] (B11) In an embodiment of any of (B9)-(B10), further
comprising interpolating the in-heater pressure data for each of
the plurality of burners from pressure sensor data from a pressure
sensor located at a known location from each of the plurality of
burners
[0198] (B12) In an embodiment of any of (B1)-(B11), the
fired-systems model being generated based on manual testing data of
the heater.
[0199] (B13) In an embodiment of any of (B1)-(B12), the
fired-systems model being defined by physics-based models of
air-flow within the heater housing.
[0200] (B14) In an embodiment of any of (B1)-(B13), the
fired-systems model being defined by computational fluid dynamics
(CFD) of the heater.
[0201] (B15) In an embodiment of any of (B1)-(B14), the
fired-systems model being tuned based on real-time sensed data from
within the heater, computational fluid dynamics data of the heater,
historical data of the heater and/or other heaters similar to the
heater, or any combination thereof.
[0202] (B16) In an embodiment of any of (B1)-(B15), further
comprising identifying optimized stack damper settings and/or
optimized air-flow handling settings to achieve a target global
excess oxygen level to be sensed by the oxygen sensor
[0203] (B17) In an embodiment of any of (B1)-(B16), further
comprising solving the fired-systems model based on one or more
constraints.
[0204] (B18) In an embodiment of any of (B17), the one or more
constraints requiring the optimized burner air register settings to
include at least one burner air register at full-open setting.
[0205] (B19) In an embodiment of any of (B1)-(B18), further
comprising: iteratively solving the fired-systems model based on a
desired number of burner air register changes over a future period
of time to identify optimized stack damper settings and/or
optimized air-handling settings to define a necessary draft range
within the heater that can withstand weather variations over the
future period of time.
[0206] (B20) In an embodiment of any of (B1)-(B19), further
comprising: identifying the optimized stack damper settings and/or
optimized air-handling settings that define the necessary draft
range and maintain predicted operational cost below a predefined
operational cost threshold.
[0207] (B21) In an embodiment of any of (B1)-(B20), further
comprising: receiving sensed data from within the heater after
implementation of the optimized burner air register settings, the
optimized stack damper settings, the optimized air-flow handling
settings, or any combination thereof; and outputting an alert when
the sensed data varies from expected data.
[0208] (B22) In an embodiment of any of (B21), the alert including
an audible, visual, or tactile indication on the heater
controller.
[0209] (B23) In an embodiment of any of (B21)-(B22), the alert
including a remediation action that shuts down the heater.
* * * * *