Patent Application
20250179366
The present disclosure relates to coke ovens, and more particularly, to a system and method for monitoring and manipulating a coke oven battery to control its exhaust stack opacity and to maintain battery temperatures to increase coke oven battery energy efficiency and structural longevity.
Coke is typically produced by heating coal in a coke oven. Coke ovens are assembled together in a slotted arrangement in a coke oven battery, which may have anywhere from 40 to over 100 side-by-side cooking or coking chambers or ovens separated from each other by heating walls. Gas is burned within the walls to heat the coal arranged in the ovens. The floor bricks of each oven rest upon corbels. Below the corbels is an area called the regenerator, which acts at least in part as a heat-exchanger. The regenerator is filled with bricks that have a relatively large amount of surface area per unit volume, generally due to slots formed in the bricks. In the regenerator, exhaust waste heat is used to pre-heat incoming combustion air as well as cool the exhaust waste prior to discharge. The regenerator supports the corbels. In turn, the corbels support the coke oven floor bricks and the heating walls. The heating walls, floor bricks, and corbels have traditionally been made of silica brick due to its high heat conductivity, high temperature resistance, and stable thermal expansion characteristics at operating temperature.
Due to current regulations, for example the 1990 Clean Air Act Amendment, waste exhaust from coke ovens being expelled into the air is monitored, and failure to comply with regulations can be punishable by significant fines. Compliance with such regulations causes operators to manipulate the coke oven battery in a manner that is detrimental to both the energy efficiency and the longevity of the coke oven battery, eventually leading to failure of coke oven components, such as the heating walls.
Thus, there has been a long-felt need for a system and method of monitoring and manipulating a coke oven or coke oven battery that improves compliance with opacity regulations but does not jeopardize the energy efficiency or longevity of the coke oven walls and/or of the whole battery.
The present disclosure is directed to one or more exemplary embodiments of a coke oven battery modulation system.
In an exemplary embodiment, the coke oven battery modulation system comprises a coke oven battery, a coke oven gas supply fluidly connected to the coke oven battery via a first conduit, an exhaust stack fluidly connected to the coke oven battery via a second conduit, a mixed gas supply fluidly connected to the first conduit via a third conduit, a nitrogen supply fluidly connected to the first conduit via a fourth conduit, the fourth conduit including a first valve and a first actuator operatively arranged to adjust the first valve, at least one sensor, and a controller operatively arranged to receive data from the at least one sensor and communicate with the first actuator to adjust the first valve.
In an exemplary embodiment, the at least one sensor comprises a specific gravity sensor. In an exemplary embodiment, the specific gravity sensor is operatively arranged to detect a specific gravity of fluid within the first conduit. In an exemplary embodiment, the nitrogen supply is fluidly connected to the third conduit via a fifth conduit, and the fifth conduit comprises a second valve and a second actuator operatively arranged to adjust the second valve. In an exemplary embodiment, the at least one sensor comprises a specific gravity sensor operatively arranged to detect a specific gravity of the fluid within the third conduit. In an exemplary embodiment, the controller is operatively arranged to receive data from the specific gravity sensor and communicate with the second actuator to adjust the second valve.
In an exemplary embodiment, the coke oven battery modulation system further comprises a supplemental fuel gas supply connected to the first conduit via a fifth conduit, the fifth conduit comprising a second valve and a second actuator operatively arranged to adjust the second valve. In an exemplary embodiment, the controller is operatively arranged to receive data from the at least one sensor and communicate with the second actuator to adjust the second valve. In an exemplary embodiment, the at least one sensor comprises an opacity monitor operatively arranged to detect an opacity of the exhaust stack.
The present disclosure is directed to one or more exemplary embodiments of a method for monitoring a coke oven battery system.
In an exemplary embodiment, the method includes a coke oven battery, a stack, and a fuel supply conduit, and the method comprises receiving an input from one or more sensors, determining that an opacity of the stack is greater than a first predetermined threshold, determining that a specific gravity of coke oven gas supplied to the coke oven battery in the fuel supply conduit is less than a second predetermined threshold, and increasing a flow of nitrogen gas to the fuel supply conduit.
In an exemplary embodiment, the step of determining that the opacity of the stack is greater than the first predetermined threshold comprises receiving opacity data from the one or more sensors, and calculating the opacity as a rolling average of the opacity data. In an exemplary embodiment, the step of determining that the specific gravity of the coke oven gas supplied to the coke oven battery in the fuel supply conduit is less than the second predetermined threshold comprises receiving coke oven gas specific gravity data from the one or more sensors, and calculating the specific gravity of the coke oven gas as a rolling average of the coke oven gas specific gravity data.
In an exemplary embodiment, the step of determining that the specific gravity of the coke oven gas supplied to the coke oven battery in the fuel supply conduit is less than the second predetermined threshold comprises receiving coke oven gas specific gravity data from a specific gravity sensor, and calculating the specific gravity of the coke oven gas from the coke oven gas specific gravity data. In an exemplary embodiment, the step of increasing a flow of nitrogen gas to the fuel supply conduit comprises sending a signal to an actuator to open a valve to increase the flow of the nitrogen gas.
In an exemplary embodiment, the method further comprises determining that the opacity of the stack is greater than a third predetermined threshold, determining that a specific gravity of mixed gas supplied to the coke oven battery in a mixed gas supply conduit is less than a fourth predetermined threshold, and increasing a flow of nitrogen gas to the mixed gas supply conduit.
In an exemplary embodiment, the step of determining that the specific gravity of the mixed gas supplied to the coke oven battery in the mixed gas supply conduit is less than the fourth predetermined threshold comprises receiving mixed gas specific gravity data from the one or more sensors, and calculating the specific gravity of the mixed gas as a rolling average of the mixed gas specific gravity data. In an exemplary embodiment, the step of determining that the specific gravity of the mixed gas supplied to the coke oven battery in the mixed gas supply conduit is less than the fourth predetermined threshold comprises receiving mixed gas specific gravity data from a specific gravity sensor, and calculating the specific gravity of the mixed gas from the mixed gas specific gravity data.
In an exemplary embodiment, the step of increasing the flow of nitrogen gas to the mixed gas supply conduit comprises sending a signal to an actuator to open a valve to increase the flow of the nitrogen gas. In an exemplary embodiment, the method further comprises before the step of determining that the opacity of the stack is greater than the third predetermined threshold, determining that mixed gas is being supplied to the coke oven battery. In an exemplary embodiment, the third predetermined threshold is greater than or equal to the first predetermined threshold.
These and other objects, features, and advantages of the present disclosure will become readily apparent upon a review of the following detailed description of the disclosure, in view of the drawings and appended claims.
The accompanying drawings are incorporated herein as part of the specification. The drawings described herein illustrate embodiments of the presently disclosed subject matter and are illustrative of selected principles and teachings of the present disclosure, in which corresponding reference symbols indicate corresponding parts. However, the drawings do not illustrate all possible implementations of the presently disclosed subject matter and are not intended to limit the scope of the present disclosure in any way.
It is to be understood that the invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific assemblies and systems illustrated in the attached drawings and described in the following specification are simply exemplary embodiments of the inventive concepts defined herein. Hence, specific dimensions, directions, or other physical characteristics relating to the embodiments disclosed are not to be considered as limiting, unless expressly stated otherwise. Also, although they may not be, like elements in various embodiments described herein may be commonly referred to with like reference numerals within this section of the application.
Furthermore, it is understood that this disclosure is not limited to the particular methodology, materials and modifications described and as such may, of course, vary. It is also understood that the terminology used herein is for the purpose of describing particular aspects only, and is not intended to limit the scope of the claims.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this disclosure pertains. It should be understood that any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the example embodiments.
Where used herein, the terms “first,” “second,” and so on, do not necessarily denote any ordinal, sequential, or priority relation, but are simply used to more clearly distinguish one element or set of elements from another, unless specified otherwise.
Where used herein, the term “about” when applied to a value is intended to mean within the tolerance range of the equipment used to produce the value, or, in some examples, is intended to mean plus or minus 10%, or plus or minus 5%, or plus or minus 1%, unless otherwise expressly specified.
It should be appreciated that the term “substantially” is synonymous with terms such as “nearly,” “very nearly,” “about,” “approximately,” “around,” “bordering on,” “close to,” “essentially,” “in the neighborhood of,” “in the vicinity of,” etc., and such terms may be used interchangeably as appearing in the specification and claims. It should be appreciated that the term “proximate” is synonymous with terms such as “nearby,” “close,” “adjacent,” “neighboring,” “immediate,” “adjoining,” etc., and such terms may be used interchangeably as appearing in the specification and claims. The term “substantially” is intended to mean values within ten percent of the specified value.
Where used herein, the term “exemplary” is intended to mean “an example of,” “serving as an example,” or “illustrative,” and does not denote any preference or requirement with respect to a disclosed aspect or embodiment.
It should be understood that use of “or” in the present application is with respect to a “non-exclusive” arrangement, unless stated otherwise. For example, when saying that “item x is A or B,” it is understood that this can mean one of the following: (1) item x is only one or the other of A and B; (2) item x is both A and B. Alternately stated, the word “or” is not used to define an “exclusive or” arrangement. For example, an “exclusive or” arrangement for the statement “item x is A or B” would require that x can be only one of A and B. Furthermore, as used herein, “and/or” is intended to mean a grammatical conjunction used to indicate that one or more of the elements or conditions recited may be included or occur. For example, a device comprising a first element, a second element and/or a third element, is intended to be construed as any one of the following structural arrangements: a device comprising a first element; a device comprising a second element; a device comprising a third element; a device comprising a first element and a second element; a device comprising a first element and a third element; a device comprising a first element, a second element and a third element; or a device comprising a second element and a third element.
Moreover, as used herein, the phrases “comprises at least one of” and “comprising at least one of” in combination with a system or element is intended to mean that the system or element includes one or more of the elements listed after the phrase. For example, a device comprising at least one of: a first element; a second element; and a third element, is intended to be construed as any one of the following structural arrangements: a device comprising a first element; a device comprising a second element; a device comprising a third element; a device comprising a first element and a second element; a device comprising a first element and a third element; a device comprising a first element, a second element and a third element; or a device comprising a second element and a third element. A similar interpretation is intended when the phrase “used in at least one of:” is used herein.
Referring now to the figures,
Regenerator 20 comprises a plurality of piers or pillars 22, which are spaced apart to form regenerator regions 24. In an exemplary embodiment, each of pillars 22 comprises a plurality of bricks or blocks. Pillars 22 support corbels 40. In an exemplary embodiment, each of corbels 40 comprises a plurality of blocks. In an exemplary embodiment, each of corbels 40 comprises a plurality of blocks arranged in a plurality of tiers.
Corbels 40 are arranged on top of pillars 22 and support the oven section of coke oven battery 10. Specifically, corbels 40 support floor 28, heating walls 30, and coal 190 placed in ovens 34. Corbels 40 further allow air to flow between flues 32 and regenerator 20. In an exemplary embodiment, corbels 40 allow gas to be injected into flues 32. For example, gas or fuel is injected into corbels 40 horizontally via hole 42 and flows vertically through holes 46 and into flues 32. Air flows upwardly through holes 48 and into flues 32 where it mixes with the fuel and combusts to heat heating walls 30, thus cooking or coking the coal arranged in ovens 34 transforming it into coke. Exhaust gasses or fluids are created from such combustion within flues 32 and these hot exhaust gasses may flow down through holes 48 and into regenerator regions 24, thereby preheating the incoming gas and/or air. In an exemplary embodiment, air flows upwardly through holes 48 and exhaust gasses created from the combustions flow down through hole 50 (see
Floor 28 is arranged on and/or engaged with corbels 40. Floor 28 is operatively arranged to support the coal in ovens 34. Floor 28 may comprise a plurality of blocks. In an exemplary embodiment, the plurality of blocks are arranged in tiers. Heating walls 30 are arranged on corbels 40 and/or floor 28 and comprise flues 32 arranged therein, respectively. In an exemplary embodiment, heating walls 30 comprise bricks, blocks and/or modules. Flues 32 are in fluid communication with holes 46, holes 48, and/or holes 50 (see
In an exemplary embodiment, the transformation of coal into coke results in the production of coke oven gas (COG). COG is recycled and used as fuel. As such, each oven 34 is equipped with duct or passageway 52 (i.e., standpipes) through which COG travels to be collected by COG collecting main 54. The COG is then refined and injected as fuel into holes 42. As such, coke oven battery 10 may be in essence self-sustaining (although as a preliminary initial step coke oven battery 10 must be heated up via an alternative fuel source). In an exemplary embodiment, the COG collected by COG collecting main 54 may be sent to a by-product plant for treatment, for example by-products plant 60 (see
It is essential that the temperature TI of the air and/or exhaust gasses (i.e., the fluid) in stack 100 be greater than the temperature TO of the ambient air outside of stack 100. It is this this temperature gradient ΔT that creates the natural draft that in turn facilitates the natural flow of fluid through system 12 (i.e., the fluid flow), and as such no fans or pumps may be required. In an exemplary embodiment, the temperature T1 of the fluid in stack 100 is 200° F. to 500° F. higher than the temperature TO of the ambient air outside of stack 100 (i.e., a ΔT of 200° F. to 500° F.).
As shown in
In an exemplary embodiment, coke oven battery modulation system 12 further comprises a plant bleeder or bleeder flare 78 operatively arranged to release and burn COG when the gas plant pressure in the main (i.e., conduit 180) rises above a certain pressure. Bleeder flare operation sensor 90 is operatively arranged to detect if bleeder 78 is on or off. In an exemplary embodiment, bleeder flare operation sensor 90 transmits data related to the status of bleeder flare 78 to a remote location, for example, coke oven battery modulation program 132.
In an exemplary embodiment, coke oven battery modulation system 12 may further comprise valve 62 operatively arranged to modulate the COG supplied to gas gun 110 supply main. In an exemplary embodiment, valve 62 is controlled by actuator 64. In an exemplary embodiment, coke oven battery modulation system 12 further comprises fuel pressure sensor 66. Fuel pressure sensor 66 is operatively arranged to detect fuel pressure being supplied to gas gun 110 supply main and communicate with actuator 64 to adjust valve 62 such that the correct fuel pressure and fuel flow is being supplied to gas gun or guns 110.
In an exemplary embodiment, coke oven battery modulation system 12 further comprises gas mixing station 70 which provides natural gas, air, or a mixture of gas and air to gas gun 110 via conduit 76. Gas mixing station 70 is operatively arranged to mix gas (e.g., natural gas) from gas supply 72 and air from air supply 74, and inject it along with COG into gas gun 110 via conduits 76 and 180 respectively.
In an exemplary embodiment, coke oven battery modulation system 12 may further comprise temperature sensor 80 operatively arranged to detect a temperature of heating walls 30. In an exemplary embodiment, coke oven battery modulation system 12 may further comprise one or more flue pressure sensors 82 operatively arranged to detect a pressure in flue 32. The differential of pressure between flue 32 and oven 34 is important to regulate since a high pressure in oven 34 and a low pressure in flue 32 may drive COG through heating walls 30 and into flue 32, which could lead to an increase in opacity. Coke oven battery modulation system 12 may further comprise flue caps 56.
Coke oven battery modulation system 12 further comprises opacity sensor or monitor 102 operatively arranged to measure the opacity within stack 100. In an exemplary embodiment, sensor 102 is a continuous opacity monitoring system (COMS). Opacity is the fraction of light lost in crossing through the inside of stack 100 due to lack of transparency. Variable fluid flow and composition in stack 100 causes the opacity therein to fluctuate.
Regulations (e.g., the Clean Air Act) set certain requirements on emissions in order to reduce and control air pollution. One type of requirement is that the opacity of stack 100 be less than a first predetermined threshold (e.g., 20%), or a fine may be issued to the operator of that coke oven battery. The opacity requirement may be measured as an average over a period of time. For example, if the 24-hour average opacity in stack 100 is greater than or equal to 20%, a first fine is issued. Additionally, if the average opacity for a period of time is greater than a second predetermined threshold (e.g., 60%), which is greater than the first predetermined threshold, an additional fine may be issued. For example, if a 6-minute rolling average opacity in stack 100 is greater than or equal to 60%, both a first fine for exceeding the first 20% threshold and a second fine for exceeding the second 60% threshold may be issued. The second fine may be exponentially higher than the first fine.
Supplemental fuel gas source 140 is operatively arranged to inject supplemental fuel gas into conduit 180, for injection into coke oven battery 10, via conduit 142. In an exemplary embodiment, supplemental fuel gas source 140 comprises a natural gas, hydrogen, or propane source. In an exemplary embodiment, the supplemental fuel gas may be a mixture of two or more of natural gas, hydrogen, or propane. In an exemplary embodiment, the supplemental fuel gas may be a fuel gas mixture comprising a gas other than natural gas, hydrogen, and/or propane. In an exemplary embodiment, coke oven battery modulation system 14 may further comprise valve 144 operatively arranged to modulate the supplemental fuel gas supplied to conduit 180. In an exemplary embodiment, valve 144 is controlled by actuator 146. Actuator 146 may be controlled by and operatively arranged to communicate with controller 130. Controller 130 thus adjusts valve 144 such that the correct amount/pressure of supplemental fuel gas is being supplied to conduit 180.
Gas source 150 is operatively arranged to inject gas into conduit 180 and/or conduit 76, for injection into coke oven battery 10. In an exemplary embodiment, gas source 150 is a nitrogen gas source. As shown, gas source 150 is arranged to inject gas into conduit 180 via conduit 152. In an exemplary embodiment, coke oven battery modulation system 14 may further comprise valve 154 operatively arranged to modulate the nitrogen gas supplied to conduit 180. In an exemplary embodiment, valve 154 is controlled by actuator 156. Actuator 156 may be controlled by and operatively arranged to communicate with controller 130. Controller 130 thus adjusts valve 154 such that the correct amount/pressure of nitrogen gas is being supplied to conduit 180.
Nitrogen gas being injected into conduit 180 may be mixed with COG from by-products plant 60. Coke oven battery modulation system 14 further comprises specific gravity sensor 86. Specific gravity sensor 86 is operatively arranged to detect the specific gravity of the gas in conduit 180, for example, passing thereby, and communicate such data with controller 130. Controller 130 receives specific gravity data from sensor 86, as well as information from other sensors, and determines whether to increase or decrease the supply of supplemental fuel gas from supplemental fuel gas source 140 (i.e., by adjusting valve 144) and/or increase or decrease the supply of nitrogen gas from nitrogen gas source 150. The fuel gas in conduit 180 flowing by sensor 86 may comprise COG, supplemental fuel gas, nitrogen gas, or a mixture of any thereof.
For demonstration purposes only,
In an exemplary embodiment gas source 150 is further arranged to inject gas (e.g., nitrogen gas) into conduit 76 via conduit 162. In an exemplary embodiment, coke oven battery modulation system 14 may further comprise valve 164 operatively arranged to modulate the nitrogen gas supplied to conduit 76. In an exemplary embodiment, valve 164 is controlled by actuator 166. Actuator 166 may be controlled by and operatively arranged to communicate with controller 130. Controller 130 thus adjusts valve 164 such that the correct amount/pressure of nitrogen gas is being supplied to conduit 76.
Nitrogen gas being injected into conduit 76 is mixed with mixed gas from gas mixing station 70. Coke oven battery modulation system 14 further comprises specific gravity sensor 84. Specific gravity sensor 84 is operatively arranged to detect the specific gravity of the gas in conduit 76, for example, passing thereby, and communicate such data with controller 130. Controller 130 receives specific gravity data from sensor 84, as well as information from other sensors, and determines whether to increase or decrease the supply of nitrogen gas from nitrogen gas source 150. The gas in conduit 76 flowing by sensor 84 may comprise air, natural gas, nitrogen gas, or a mixture of any thereof.
In an exemplary embodiment, coke oven battery modulation system 14 further comprises input 170. Input 170 allows an operator to manually enter information such as set points, desired grand average temperatures, and measured grand average temperatures, for example of battery walls 30 and/or flues 32. The grand average temperature refers to the average temperature of a plurality of flues 32 (e.g., two-hundred flues 32). In an exemplary embodiment, an operator may also use input 170 to enter pressure measurements from flues 32, for example as measured by flue pressure sensors 82. In an exemplary embodiment, input 170 may comprise a human-machine interface (HMI), graphic user interface (GUI) or touch screen, keyboard, and/or other user interface device capable of allowing an operator to input data into controller 130.
Controller 130 is operatively arranged to receive data from one or more sensors, for example, opacity sensor 102, temperature sensor 80, pressure sensor 82, specific gravity sensor 84, and/or specific gravity sensor 86, and communicate with actuators to displace one or more valves in order to modulate the coke oven battery system. Controller 130 may communicate with one or more sensors and actuators via a network, which may be, for example, a local area network (LAN), a metropolitan area network (MAN), a wide area network (WAN) such as the Internet, or a combination thereof, and can include wired, wireless, or fiber optic connections.
Controller 130 may be a hardware device that receives data from one or more sensors and modulates the coke oven battery system using coke oven battery modulation program 132. In an exemplary embodiment, controller 130 may include a computer. In an exemplary embodiment, controller 130 may include internal and external hardware components, as depicted and described in further detail with respect to
Coke oven battery modulation program 132 can receive inputs from one or more sensors, for example, opacity sensor 102, temperature sensor 80, pressure sensor 82, specific gravity sensor 84, and/or specific gravity sensor 86, determine one or more necessary actions to modulate the coke oven battery system, and send signals to one or more actuators to carry out the one or more necessary actions, based on the various methods disclosed herein. Coke oven battery modulation program 132 can generally include any software capable of modulating a coke oven battery system to maintain a tolerable opacity without adversely impacting proper fluid flow rate (i.e., draft with respect to stack 100) or proper heating in coke oven battery 10. In an exemplary embodiment, coke oven battery modulation system 14 further comprises a database (not shown). Coke oven battery modulation program 132 is capable of storing data in the database such that, over a period of time (e.g., 10 years), coke oven battery modulation program 132 can view the long-term effects of its decision making in an effort to learn, for example through the use of artificial intelligence (AI).
In step 202, coke oven battery modulation program 132 receives an input. As previously described, the input may comprise data from one or more sensors, for example, opacity sensor 102, temperature sensor 80, pressure sensor 82, specific gravity sensor 84, specific gravity sensor 86, and/or an operator via input 170. In an exemplary embodiment, data received in step 202 is a rolling average value over a period of time, for example, opacity of stack 100, specific gravity of COG from by-products department 60, specific gravity of mixed gas from gas mixing station 70, the operation status of mixed gas from gas mixing station 70, etc. In an exemplary embodiment, data received in step 202 is in real time, and coke oven battery modulation program 132 calculates the rolling average over a period of time, for example, six hours.
In step 204, coke oven battery modulation program 132 calculates a baseline opacity. In an exemplary embodiment, the baseline opacity is calculated by filtering out all the opacity data greater than a threshold (e.g., 40%). This removes the “opacity spikes” from the rolling average opacity in an effort to modulate coke oven battery 10 in a more gradual fashion. Specifically, opacity sensor 102 may send opacity data to coke oven battery modulation program 132 every period of time (e.g., two minutes). Some of that opacity data may include a data point that is either outside of the norm, or an outlier data point (e.g., 60%). Since modulating a coke oven system based on such spikes or outliers may be ineffective or trigger unnecessary or unwanted over-modulation, coke oven battery modulation program 132 may remove such outliers prior to performing subsequent modulation decision making. Periods of high opacity above the baseline threshold are likely to be caused by events or operational conditions that are not amenable to control by fuel flow and/or fuel specific gravity or heating value modulation. Modulating combustion under these circumstances, in a manner proportional to the spiked opacity, is not likely to have any effect positive or negative on either the spike opacity or its causes but it is likely to cause negative side effects on other parameters, including but not limited to fluid flow heating values, fluid flow temperature, fluid flow oxygen levels, fluid flow pressure, available draft, and battery temperatures. In an exemplary embodiment, in step 204, coke oven battery modulation program 132 calculates the baseline opacity during a predetermined rolling average period (e.g., six hours).
In step 206, coke oven battery modulation program 132 determines whether the opacity in stack 100 is greater than a first predetermined threshold. In an exemplary embodiment, the first predetermined threshold is 15%.
If, in step 206, coke oven battery modulation program 132 determines that the opacity in stack 100 is not greater than the first predetermined threshold (i.e., less than or equal to the first predetermined threshold), then coke oven battery modulation program 132 proceeds to step 202.
If, in step 206, coke oven battery modulation program 132 determines that the opacity in stack 100 is greater than the first predetermined threshold, then in step 208 coke oven battery modulation program 132 determines if the specific gravity of COG is less than a second predetermined threshold. Specifically, specific gravity sensor 86 may send COG specific gravity data to coke oven battery modulation program 132 every period of time (e.g., two minutes). In an exemplary embodiment, in step 212, coke oven battery modulation program 132 first calculates the rolling average specific gravity of COG over a rolling average period (e.g., four hours), and then in step 206 coke oven battery modulation program 132 determines if the rolling average specific gravity of COG is less than the second predetermined threshold. In an exemplary embodiment, the second predetermined threshold is 0.432.
If, in step 208, coke oven battery modulation program 132 determines that the specific gravity of COG is not less than the second predetermined threshold (i.e., greater than or equal to the second predetermined threshold), then coke oven battery modulation program 132 proceeds to step 202.
If, in step 208, coke oven battery modulation program 132 determines that the specific gravity of COG is less than the second predetermined threshold, then in step 210 coke oven battery modulation program 132 adds, or increases the flow of, nitrogen gas to COG. For example, coke oven battery modulation program 132 may, using actuator 156, open valve 154 or displace valve 154 to a more open position such that nitrogen gas from nitrogen gas source 150 can be added to conduit 180 and mix with COG. Adding nitrogen gas to COG increases the specific gravity of COG and decreases the heating value or British thermal unit (BTU) of COG.
Coke oven battery modulation program 132 then proceeds to step 202. It should be appreciated that steps 202-212 are directed to adding nitrogen gas to COG, for example in conduit 180. Adding nitrogen gas to COG may help stabilize COG when there is a lower volume of COG and/or the COG has a higher heating value (i.e., richer COG). A richer COG may occur during operations outages due to lack of air infiltration from aspiration during oven charging combined with continued production of rich COG from previously charged ovens. Thus, adding nitrogen to COG stabilizes the COG heating value and increases the volume of COG available by adding nitrogen to control the COG specific gravity.
In step 214, coke oven battery modulation program 132 determines whether the mixed gas system is operational. For example, coke oven battery modulation program 132 determines if gas mixing station 70 is supplying mixed gas to conduit 180. In an exemplary embodiment, mixing station operation (i.e., on/off) sensor 88 sends data to coke oven battery modulation program 132, and coke oven battery modulation program 132 thereby determines if mixed gas is being supplied to conduit 180.
If, in step 214, coke oven battery modulation program 132 determines that the mixed gas system is not operational (i.e., mixed gas is not being supplied to conduit 180 to mix with COG), then coke oven battery modulation program 132 proceeds to step 202.
If, in step 214, coke oven battery modulation program 132 determines that the mixed gas system is operational, then in step 216 coke oven battery modulation program 132 determines whether the opacity in stack 100 is greater than a third predetermined threshold. Coke oven battery modulation program 132 may utilize a baseline opacity or a rolling average baseline opacity in the determination in step 216, for example, as determined in step 204. In an exemplary embodiment, the third predetermined threshold is 15%.
If, in step 216, coke oven battery modulation program 132 determines that the opacity in stack 100 is not greater than the third predetermined threshold (i.e., less than or equal to the third predetermined threshold), then coke oven battery modulation program 132 proceeds to step 202.
If, in step 216, coke oven battery modulation program 132 determines that the opacity in stack 100 is greater than the third predetermined threshold, then in step 218 coke oven battery modulation program 132 determines whether the specific gravity of the mixed gas is less than a fourth predetermined threshold. Specifically, specific gravity sensor 84 may send mixed gas specific gravity data to coke oven battery modulation program 132 every period of time (e.g., two minutes). In an exemplary embodiment, in step 212, coke oven battery modulation program 132 first calculates the rolling average specific gravity of mixed gas over a rolling average period (e.g., ten minutes), and then in step 218 coke oven battery modulation program 132 determines if the rolling average specific gravity of the mixed gas is less than the fourth predetermined threshold. In an exemplary embodiment, the fourth predetermined threshold is 0.796.
If, in step 218, coke oven battery modulation program 132 determines that the specific gravity of the mixed gas is not less than the fourth predetermined threshold (i.e., is greater than or equal to the fourth predetermined threshold), then coke oven battery modulation program 132 proceeds to step 202.
If, in step 218, coke oven battery modulation program 132 determines that the specific gravity of the mixed gas is less than the fourth predetermined threshold, then in step 220 coke oven battery modulation program 132 adds, or increases the flow of, nitrogen gas to the mixed gas. For example, coke oven battery modulation program 132 may, using actuator 166, open valve 164 or displace valve 164 to a more open position such that nitrogen gas from nitrogen gas source 150 can be added to conduit 76 and mixed with the mixed gas.
Coke oven battery modulation program 132 then proceeds to step 202. It should be appreciated that steps 202-204 and 212-220 are directed to adding nitrogen gas to the mixed gas, for example in conduit 76.
In step 252, coke oven battery modulation program 132 receives an input. For example, coke oven battery modulation program 132 may receive opacity data (e.g., rolling average opacity data) from opacity sensor 102.
In step 254, coke oven battery modulation program 132 determines a set point for the COG specific gravity. In an exemplary embodiment, coke oven battery modulation program 132 uses chart 258 to determine the set point for the COG specific gravity control from the opacity data received in step 252. As shown, chart 258 may comprise a graph or step function correlating rolling average opacity data to preferred set point, namely, for adding nitrogen gas to COG based on the opacity of stack 100. In an exemplary embodiment, chart 258 comprises a predetermined step function.
In step 256, coke oven battery modulation program 132 communicates with actuator 156 to adjust valve 154. In an exemplary embodiment, in step 256, coke oven battery modulation program 132 communicates the determined set point to actuator 156 or a controller thereof. Valve 154 is then adjusted to the proper setting to achieve the set point.
In step 260, coke oven battery modulation program 132 determines a set point for the mixed gas specific gravity. In an exemplary embodiment, coke oven battery modulation program 132 uses chart 266 to determine the set point for the mixed gas specific gravity control from the opacity data received in step 252. As shown, chart 266 may comprise a graph or step function correlating rolling average opacity data to preferred set point, namely, for adding nitrogen gas to mixed gas based on the opacity of stack 100. In an exemplary embodiment, charge 266 comprises a predetermined step function.
In step 262, coke oven battery modulation program 132 determines if the mixed gas system is operational, similar to step 214 described above with respect to
If, in step 262, coke oven battery modulation program 132 determines that the mixed gas system is operational, then in step 264, coke oven battery modulation program 132 communicates with actuator 166 to adjust valve 164. In an exemplary embodiment, in step 264, coke oven battery modulation program 132 communicates the determined set point to actuator 166 or a controller thereof. Valve 164 is then adjusted to the proper setting to achieve the set point.
In step 302, coke oven battery modulation program 132 receives an input. As previously described, the input may comprise data from one or more sensors, for example, opacity sensor 102, an operator input via input 170, bleeder flare operation sensor 90, boiler fuel switch sensor 92, etc. In an exemplary embodiment, data received in step 302 is a rolling average value over a period of time, for example, opacity of stack 100. In an exemplary embodiment, data received in step 302 is in real time, and coke oven battery modulation program 132 calculates the rolling average over a period of time, for example, six hours.
In step 304, coke oven battery modulation program 132 calculates a baseline opacity. In an exemplary embodiment, the baseline opacity is calculated by filtering out all the opacity data greater than a threshold (e.g., 40%). This removes the “opacity spikes” from the rolling average opacity in an effort to modulate coke oven battery 10 in a more gradual fashion. Specifically, opacity sensor 102 may send opacity data to coke oven battery modulation program 132 every period of time (e.g., two minutes). Some of that opacity data may include a data point that is either outside of the norm, or an outlier data point (e.g., 60%). Since modulating a coke oven system based on such spikes or outliers may be ineffective or trigger unnecessary or unwanted over-modulation, coke oven battery modulation program 132 may remove such outliers prior to performing subsequent modulation decision making. Periods of high opacity above the baseline threshold are likely to be caused by events or operational conditions that are not amenable to control by fuel flow and/or fuel specific gravity or heating value modulation. Modulating combustion under these circumstances, in a manner proportional to the spiked opacity, is not likely to have any effect positive or negative on either the spike opacity or its causes but it is likely to cause negative side effects on other parameters, including but not limited to fluid flow heating values, fluid flow temperature, fluid flow oxygen levels, fluid flow pressure, available draft, and battery temperatures. In an exemplary embodiment, in step 304, coke oven battery modulation program 132 calculates the baseline opacity during a predetermined rolling average period (e.g., six hours).
In step 306, coke oven battery modulation program 132 determines whether the opacity in stack 100 is less than a fifth predetermined threshold. Coke oven battery modulation program 132 may utilize the baseline opacity calculated in step 304 or a rolling average baseline opacity (i.e., as determined in step 212 of
If, in step 306, coke oven battery modulation program 132 determines that the opacity in stack 100 is not less than the fifth predetermined threshold (i.e., is greater than or equal to the fifth predetermined threshold), then in step 308, coke oven battery modulation program 132 determines whether the opacity in stack 100 is greater than a sixth predetermined threshold. In an exemplary embodiment, the sixth predetermined threshold is 15%.
If, in step 308, coke oven battery modulation program 132 determines that the opacity in stack 100 is not greater than the sixth predetermined threshold (i.e., is less than or equal to the sixth predetermined threshold), then coke oven battery modulation program 132 proceeds to step 302.
If, in step 308, coke oven battery modulation program 132 determines that the opacity in stack 100 is greater than the sixth predetermined threshold, then in step 310 coke oven battery modulation program 132 proceeds to nitrogen stabilization flow chart 200 shown in
If, in step 306, coke oven battery modulation program 132 determines that the opacity in stack 100 is less than the fifth predetermined threshold, then in step 312 coke oven battery modulation program 132 determines whether bleeder flare 78 is open.
If, in step 312, coke oven battery modulation program 132 determines that bleeder flare 78 is open, then coke oven battery modulation program 132 proceeds to step 302.
If, in step 312, coke oven battery modulation program 132 determines that bleeder flare 78 is not open (i.e., closed), then in step 314 coke oven battery modulation program 132 determines whether boilers 68 are on COG (i.e., whether boilers 68 are using fuel from the COG supply line in the boiler house).
If, in step 314, coke oven battery modulation program 132 determines that boilers 68 are not on COG, then coke oven battery modulation program 132 proceeds to step 302.
If, in step 314, coke oven battery modulation program 132 determines that boilers 68 are on COG, then in step 316 coke oven battery modulation program 132 adds, or increases the flow of, supplemental fuel gas to COG. For example, coke oven battery modulation program 132 may, using actuator 146, open valve 144 or displace valve 144 to a more open position such that supplemental fuel gas from supplemental fuel gas source 140 can be added to conduit 180 and mix with COG. Supplemental fuel gas is added to COG to stabilize the Wobbe index of the COG, for example to a predetermined set point. The Wobbe index of a gas (e.g., COG) is defined as the heating value of the gas divided by the square root of its specific gravity. Lean COG can be stabilized by adding supplemental fuel gas to control its specific gravity and to obtain the desired Wobbe index.
In an exemplary embodiment, when the COG is rich (i.e., the COG has a high heating value) coke oven battery modulation program 132 may add or increase the supply of nitrogen gas thereto (i.e., via actuator 156 and valve 154), and when the COG is lean (i.e., the COG has a low heating value) coke oven battery modulation program 132 may add or increase the supply of supplemental fuel gas thereto (i.e., via actuator 146 and valve 144).
Computing device 400 includes communications fabric 402, which provides for communications between one or more processing units 404, memory 406, persistent storage 408, communications unit 410, and one or more input/output (I/O) interfaces 412. Communications fabric 402 can be implemented with any architecture designed for passing data and/or control information between processors (such as microprocessors, communications and network processors, etc.), system memory, peripheral devices, and any other hardware components within a system. For example, communications fabric 402 can be implemented with one or more buses.
Memory 406 and persistent storage 408 are computer readable storage media. In this embodiment, memory 406 includes random access memory (RAM) 416 and cache memory 418. In general, memory 406 can include any suitable volatile or non-volatile computer readable storage media. Software is stored in persistent storage 408 for execution and/or access by one or more of the respective processors 404 via one or more memories of memory 406.
Persistent storage 408 may include, for example, a plurality of magnetic hard disk drives. Alternatively, or in addition to magnetic hard disk drives, persistent storage 408 can include one or more solid state hard drives, semiconductor storage devices, read-only memories (ROM), erasable programmable read-only memories (EPROM), flash memories, or any other computer readable storage media that is capable of storing program instructions or digital information.
The media used by persistent storage 408 can also be removable. For example, a removable hard drive can be used for persistent storage 408. Other examples include optical and magnetic disks, thumb drives, and smart cards that are inserted into a drive for transfer onto another computer readable storage medium that is also part of persistent storage 408.
Communications unit 410 provides for communications with other computer systems or devices via a network. In this exemplary embodiment, communications unit 410 includes network adapters or interfaces such as a TCP/IP adapter cards, wireless Wi-Fi interface cards, or 3G, 4G, or 5G wireless interface cards or other wired or wireless communications links. The network can comprise, for example, copper wires, optical fibers, wireless transmission, routers, firewalls, switches, gateway computers and/or edge servers. Software and data used to practice embodiments of the present disclosure can be downloaded to computing device 400 through communications unit 410 (i.e., via the Internet, a local area network, or other wide area network). From communications unit 410, the software and data can be loaded onto persistent storage 408.
One or more I/O interfaces 412 allow for input and output of data with other devices that may be connected to computing device 400. For example, I/O interface 412 can provide a connection to one or more external devices 420 such as a keyboard, computer mouse, touch screen, virtual keyboard, touch pad, pointing device, or other human interface devices. External devices 420 can also include portable computer readable storage media such as, for example, thumb drives, portable optical or magnetic disks, and memory cards. I/O interface 412 also connects to display 422.
Display 422 provides a mechanism to display data to a user and can be, for example, a computer monitor. Display 422 can also be an incorporated display and may function as a touch screen, such as a built-in display of a tablet computer.
The present disclosure may be a system, a method, and/or a computer program product. The computer program product may include a computer readable storage medium (or media) having computer readable program instructions thereon for causing a processor to carry out aspects of the present disclosure.
The computer readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the computer readable storage medium includes the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as punch-cards or raised structures in a groove having instructions recorded thereon, and any suitable combination of the foregoing. A computer readable storage medium, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission media (e.g., light pulses passing through a fiber-optic cable), or electrical signals transmitted through a wire.
Computer readable program instructions described herein can be downloaded to respective computing/processing devices from a computer readable storage medium or to an external computer or external storage device via a network, for example, the Internet, a local area network, a wide area network and/or a wireless network. The network may comprise copper transmission cables, optical transmission fibers, wireless transmission, routers, firewalls, switches, gateway computers and/or edge servers. A network adapter card or network interface in each computing/processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium within the respective computing/processing device.
Computer readable program instructions for carrying out operations of the present disclosure may be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state-setting data, or either source code or object code written in any combination of one or more programming languages, including an object oriented programming language such as Smalltalk, C++ or the like, and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The computer readable program instructions may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). In some embodiments, electronic circuitry including, for example, programmable logic circuitry, field-programmable gate arrays (FPGA), or programmable logic arrays (PLA) may execute the computer readable program instructions by utilizing state information of the computer readable program instructions to personalize the electronic circuitry, in order to perform aspects of the present disclosure.
Aspects of the present disclosure are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the disclosure. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer readable program instructions.
These computer readable program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer readable program instructions may also be stored in a computer readable storage medium that can direct a computer, a programmable data processing apparatus, and/or other devices to function in a particular manner, such that the computer readable storage medium having instructions stored therein comprises an article of manufacture including instructions which implement aspects of the function/act specified in the flowchart and/or block diagram block or blocks.
The computer readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer implemented process, such that the instructions which execute on the computer, other programmable apparatus, or other device implement the functions/acts specified in the flowchart and/or block diagram block or blocks.
The flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions.
It will be appreciated that various aspects of the disclosure above and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
This application claims the benefit under 35 U.S.C. § 119 (e) of U.S. Provisional Application No. 63/606,126, filed Dec. 5, 2023, which application is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63606126 | Dec 2023 | US |
