US20210341140A1 - System and methods for controlling operation of a recovery boiler to reduce fouling - Google Patents

Abstract

In some aspects, a computer-implemented method of reducing a rate of fouling in a recovery boiler system is provided. A computing device receives boiler operating information for a period of time. The boiler operating information includes boiler operating parameters and a rate of fouling for the period of time. The boiler operating parameters include one or more boiler input parameters. The computing device performs a regression analysis to determine at least one correlation between the boiler operating parameters and the rate of fouling. The computing device causes at least one boiler input parameter to be adjusted based on the at least one correlation to minimize the rate of fouling. In some aspects, a system configured to perform such a method is provided. In some aspects, a computer-readable medium having instructions stored thereon that cause a computing device to perform such a method is provided.

Description

• The invention relates to a computer-implemented method of reducing a rate of fouling in a recovery boiler system and a system configured to perform such a method.
SUMMARY
• In some aspects, a system comprising a boiler, a fouling sensor, a boiler controller device, and an analysis computing device is provided. The fouling sensor is associated with a component of the boiler. The analysis computing device includes at least one processor and a computer-readable medium. The computer-readable medium has computer-executable instructions stored thereon that, in response to execution by the at least one processor, cause the analysis computing device to perform actions comprising receiving boiler operating information for a period of time, wherein the boiler operating information includes boiler operating parameters and a rate of fouling for the period of time; performing a regression analysis to determine at least one correlation between the boiler operating parameters and the rate of fouling; adjusting at least one boiler input parameter based on the at least one correlation to minimize the rate of fouling; and transmitting the at least one adjusted boiler input parameter to the boiler controller device for implementation.
• In some aspects, a computer-implemented method of reducing a rate of fouling in a recovery boiler system is provided. A computing device receives boiler operating information for a period of time. The boiler operating information includes boiler operating parameters and a rate of fouling for the period of time. The boiler operating parameters include one or more boiler input parameters. The computing device performs a regression analysis to determine at least one correlation between the boiler operating parameters and the rate of fouling. The computing device causes at least one boiler input parameter to be adjusted based on the at least one correlation to minimize the rate of fouling.
• In some aspects, a non-transitory computer-readable medium is provided. The medium has computer-executable instructions stored thereon that, in response to execution by one or more processors of a computing device, cause the computing device to perform actions comprising: receiving, by the computing device, boiler operating information for a period of time, wherein the boiler operating information includes boiler operating parameters and a rate of fouling for the period of time, and wherein the boiler operating parameters include one or more boiler input parameters; performing, by the computing device, a regression analysis to determine at least one correlation between the boiler operating parameters and the rate of fouling; and causing, by the computing device, at least one boiler input parameter to be adjusted based on the at least one correlation to minimize the rate of fouling.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
• To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the figure number in which that element is first introduced.
• FIG. 1 diagrammatically shows the components of a non-limiting example aspect of a kraft black liquor recovery boiler system according to various aspects of the present disclosure.
• FIG. 2 diagrammatically illustrates how the recovery boiler is mounted in a steel beam support structure according to various aspects of the present disclosure.
• FIG. 3 diagrammatically illustrates some of the components of the superheater system which are independently suspended within the boiler according to various aspects of the present disclosure.
• FIG. 4 is a block diagram that illustrates a non-limiting example aspect of computing device components of a recovery boiler system according to various aspects of the present disclosure.
• FIG. 5 is a flowchart that illustrates a non-limiting example aspect of a method for minimizing a rate of fouling of a recovery boiler system according to various aspects of the present disclosure.
• FIG. 6 is a block diagram that illustrates a non-limiting example aspect of a computing device appropriate for use as a computing device with aspects of the present disclosure.
DETAILED DESCRIPTION
• In the paper-making process, chemical pulping yields, as a by-product, black liquor, which contains almost all of the inorganic cooking chemicals along with the lignin and other organic matter separated from the wood during pulping in a digester. The black liquor is burned in a recovery boiler. The two main functions of the recovery boiler are to recover the inorganic cooking chemicals used in the pulping process and to make use of the chemical energy in the organic portion of the black liquor to generate steam for a paper mill. The twin objectives of recovering both chemicals and energy make recovery boiler design and operation very complex.
• In a kraft recovery boiler, superheaters are placed in the upper furnace in order to extract heat by radiation and convection from the furnace gases. Saturated steam enters the superheater section, and superheated steam exits at a controlled temperature. The superheater is constructed of an array of tube panels. The superheater surface is continually being fouled by ash that is being carried out of the furnace chamber. The amount of black liquor that can be burned in a kraft recovery boiler is often limited by the rate and extent of fouling on the surfaces of the superheater. This fouling reduces the heat absorbed from the liquor combustion, resulting in low exit steam temperatures from the superheaters and high gas temperatures entering the boiler. The boiler is shutdown for cleaning when either the exit steam temperature is too low for use in downstream equipment or the temperature entering the boiler bank exceeds the melting temperature of the deposits, resulting in gas side pluggage of the boiler bank. Kraft recovery boilers are particularly prone to the problem of superheater fouling, due to the high quantity of ash in the fuel (typically more than 35%) and the low melting temperature of the ash.
• There are three conventional methods of removing deposits from the superheaters in kraft recovery boilers, listed in increasing order of required down-time and decreasing order of frequency: 1) sootblowing; 2) chill-and-blow; and 3) waterwashing.
• Sootblowing is the process of blowing ash deposit off the superheater with a blast of steam from nozzles called sootblowers. Sootblowing occurs essentially continuously during normal boiler operation, with different sootblowers turned on at different times. Sootblowing reduces boiler efficiency, since 5-10% of the boiler's steam is typically used for sootblowing. Each sootblowing operation reduces a portion of the nearby ash deposit, but the ash deposit nevertheless continues to build up over time. As the deposit grows, sootblowing becomes gradually less effective and results in impairment of the heat transfer.
• When the ash deposit reaches a certain threshold where boiler efficiency is significantly reduced and sootblowing is insufficiently effective, deposits are removed by the second cleaning process called “chill-and-blow” (also called “dry cleaning” because water is not used), requiring the partial or complete cessation of fuel firing in the boiler for typically 4-12 hours, but not complete boiler shutdown. During this time, the sootblowers continuously operate to cause the deposits to debond from the superheater sections and fall to the floor of the boiler. This procedure may be performed as often as every month, but the frequency can be reduced if the sootblowing is performed optimally (at the optimum schedule and in the optimum sequence). As with sootblowing, the chill-and-blow procedure reduces a portion of the nearby ash deposit, but the ash deposit nevertheless continues to grow over time. As the deposit grows, the chill-and-blow procedure becomes gradually less effective and must be performed more often.
• The third cleaning process, waterwashing, entails complete boiler shutdown for typically two days, causing significant loss in pulping capacity at a mill. In a heavily fouled recovery boiler, it may be required every four months, but if the chill-and-blow process is properly timed (i.e. before large deposits form in the boiler bank section), then the shutdown and waterwashing can be avoided for even a year or longer.
• As each of these cleaning processes reduces the efficiency of the boiler or entails shutdown of the boiler, it is clear that it is desirable to minimize the time spent during the cleaning processes. What is desired is an effective technique for adjusting operation of the boiler. This is may be achieved in such a way that fouling of the boiler is minimized, and thereby the amount of time spent or parasitic energy used executing one or more of these cleaning processes is reduced.
• FIG. 1 diagrammatically shows the components of a typical kraft black liquorrecovery boiler system100. Black liquor is a by-product of chemical pulping in the paper-making process. The initial concentration of “weak black liquor” is about 15%. It is concentrated to firing conditions (65% to 85% dry solids content) in anevaporator118, and then burned in arecovery boiler106.
• Theboiler106 has a furnace section, or “furnace122”, where the black liquor is burned, and a convectiveheat transfer section104, with abullnose128 in-between. Combustion converts the black liquor's organic material into gaseous products in a series of processes involving drying, devolatilizing (pyrolyzing, molecular cracking), and char burning/gasification. Some of the organics are converted to a solid carbon particulate called char. Burning of the char occurs largely on achar bed108 which covers the floor of thefurnace122, though some char burns in flight. As carbon in the char is gasified or burned, the inorganic compounds in the char are released and form a molten salt mixture called smelt, which flows to the bottom of thechar bed108, and is continuously tapped from thefurnace122 throughsmelt spouts110. Exhaust gases pass through an induceddraft fan138 and are filtered through anelectrostatic precipitator136, and exit through astack102.
• Thevertical walls124 of the furnace are lined with vertically alignedwall tubes126, through which water is evaporated utilizing the heat of thefurnace122. Thefurnace122 has primarylevel air ports112, secondarylevel air ports114, and tertiarylevel air ports120 for introducing air for combustion at three different height levels. Black liquor is sprayed into thefurnace122 out of black liquorblack liquor guns116.
• The convectiveheat transfer section104 contains the following three sets of tube banks (heat traps) which successively, in stages, heat the feedwater to superheated steam: 1) aneconomizer134, in which the feedwater is heated to just below its boiling point, 2) the boiler bank132 (or “steam generating bank”), in which, along with thewall tubes126, the water is evaporated to steam, and 3) asuperheater system130, in which a series of parallel flow elements with intermediate headers is used to increase the steam temperature from saturation to the final superheat temperature.
• FIG. 2 diagrammatically illustrates how therecovery boiler106 is mounted in a steelbeam support structure208, showing only the boiler's profile and components that are of current interest. Theentire recovery boiler106 is suspended in the middle of the steelbeam support structure208 byboiler hanger rods202. Theboiler hanger rods202 are connected between theroof206 of theboiler106 and theoverhead beams210 of the steelbeam support structure208. Another set of hanger rods, hereinafter called “superheater hanger rods” or simply “hanger rods212”, suspend only thesuperheater system130. That is, thesuperheater system130 is suspended independently from the rest of theboiler106. The open-air area between theboiler roof206 and theoverhead beams210 is called thepenthouse204.
• FIG. 3 diagrammatically illustrates some of the components of thesuperheater system130 which are independently suspended within theboiler106. Thesuperheater system130 in this aspect has threesuperheater platen310,312,314. While three superheaters are shown, it is within the terms of the invention to incorporate more superheaters as needed. For clarity, the following discussion describes the construction ofsuperheater platen310 or speaks in terms ofsuperheater platen310, with the understanding that the construction ofsuperheater platen312 andsuperheater platen314 is the same.
• Thesuperheater platen310 has typically 20-50platens306. Steam enters theplatens306 through a manifold tube called aninlet header308, is superheated within the platens, and exits the platens as superheated steam through another manifold tube called anoutlet header304. Theplatens306 are suspended from theinlet header308 andoutlet header304, which are themselves suspended from the overhead beams210 (FIG. 2) byhanger rods212. Typically 10-20hanger rods212 are evenly spaced along the length of eachinlet header308 andoutlet header304, affixed by conventional means, such as welding, to the header below and to theoverhead beams210 above, as described below. Thesuperheater system130 has typically 20hanger rods212—10 hanger rods for theinlet header308 and 10 hanger rods for theoutlet header304. Each hanger rod has a threaded top around which a tension nut is turned to adjust the rod's tension. The tension of each hanger rod is adjusted typically after every 1-3 waterwashings to keep the tension uniform (balanced) among all thehanger rods212 of asingle superheater platen310.
• When clean (just after thorough waterwashing), eachsuperheater platen310 weighs typically 5000 kg, and each superheater hanger rod carries a load of typically 5000 kg. Subsequently, just before the next waterwashing is needed, deposits (fouling) add an additional weight on eachsuperheater platen310 of typically 2000 kg, resulting in an additional load on each hanger rod of typically 2000 kg, resulting in an additional strain on each hanger rod of typically 5.0×10⁻⁵cm/cm, which is measurable by commonly available methods, such as with astrain gage302.
• The strain (after zeroing off the strain that was read just after the previous waterwash), summed over all thehanger rods212 suspending asuperheater platen310, is proportional to the weight of the deposit on that superheater. Each additional kg of deposit yields an additional strain of typically 2.0×10−8 cm/cm, which is measurable by strain sensors, such asstrain gage302. Hence, the weight of the deposit on eachsuperheater platen310 can be directly determined by measuring the strain on itscorresponding hanger rods212.
• A typical system for determining deposit weight on asingle superheater platen310 might comprise twenty (20) strain gages affixed to the twenty (20)hanger rods212, respectively, of the superheater, a computer having data acquisition capability (not shown) connected to the60 strain gages, and a computer program. Under the program's control, the computer periodically (typically every minute) records strain readings from the20 strain gages (from eachsuperheater platen310,312,314), calculates the sum of the strain readings, subtracts the sum of the strain readings taken just after a previous washdown, and then multiplies the result by a calibration factor to yield the current deposit weight.
• In equation form, the formula is:
• 
  Deposit weight=(Sum of strain gage readings currently−Sum of strain gage readings just after a previous waterwash)×calibration factor;
• 
  or, equivalently stated:
• 
  Deposit weight=(ΣSt−ΣSo)×C,
• where
• ΣSt=Sum of strain gage readings at any time t
• ΣSo=Sum of strain gage readings just after a previous waterwash, considered as at time zero.
• C=calibration constant to convert strain to weight.
• While thestrain gage302 allows for the determination of the weight of thesuperheater platen310, and this weight may be converted into an amount of fouling of thesuperheater platen310, it is desirable to minimize the rate of fouling in order to extend the intervals between which dry cleaning and/or waterwashing is performed. The relationship between various boiler operating parameters and the rate of fouling is complex, so simple manual tuning of the boiler in order to minimize fouling is not efficient. What is desired are techniques for determining complex relationships between boiler operating parameters and the rate of fouling in order to determine boiler input parameters that will minimize the rate of fouling.
• FIG. 4 is a block diagram that illustrates a non-limiting example aspect of computing device components of a recovery boiler system according to various aspects of the present disclosure. As shown, the recovery boiler system may include aboiler controller device402 and ananalysis computing device404. Theboiler controller device402 and theanalysis computing device404 can be used to determine boiler input parameters that will minimize the rate of fouling, and to implement those input parameters during operation of therecovery boiler system100.
• In some aspects, theboiler controller device402 is a computing device that electronically controls one or more components of therecovery boiler system100. In some aspects, theboiler controller device402 may include an ASIC, an FPGA, or another customized computing device for controlling the components of therecovery boiler system100. In some aspects, theboiler controller device402 may include a computing device such as a desktop computing device, a laptop computing device, a server computing device, a mobile computing device, or any other type of computing device. In some aspects, more than one computing device may be used to collectively provide the functionality described as part of theboiler controller device402.
• As shown, theboiler controller device402 includes at least oneprocessor406, anetwork interface410, aboiler component interface414, and a computer-readable medium416. In some aspects, thenetwork interface410 may include any suitable communication technology for communicating with theanalysis computing device404, including but not limited to a wired communication technology (including but not limited to Ethernet, USB, and FireWire), a wireless communication technology (including but not limited to 2G, 3G, 4G, 5G, LTE, Bluetooth, ZigBee, Wi-Fi, and WiMAX), or combinations thereof. In some aspects, theboiler component interface414 communicatively couples theboiler controller device402 to one or more adjustable components of therecovery boiler system100, including but not limited to theblack liquor guns116, theevaporator118, the primarylevel air ports112, the secondarylevel air ports114, and the tertiarylevel air ports120.
• As shown, the computer-readable medium416 includes logic that, in response to execution by the at least oneprocessor406, causes theboiler controller device402 to provide aninformation reporting engine426 and aninput control engine428. In some aspects, theinformation reporting engine426 receives information from one or more components of therecovery boiler system100, and transmits the information to theanalysis computing device404. In some aspects, theinput control engine428 receives commands from theanalysis computing device404, and adjusts the adjustable components of therecovery boiler system100 based on the commands.
• In some aspects, theanalysis computing device404 may include a computing device such as a desktop computing device, a laptop computing device, a mobile computing device, a server computing device, one or more computing devices of a cloud computing system, or any other type of computing device. In some aspects, more than one computing device may be used to collectively provide the functionality described as part of theanalysis computing device404.
• As shown, theanalysis computing device404 includes at least oneprocessor408, anetwork interface412, and a computer-readable medium418. In some aspects, thenetwork interface412 may include any suitable communication technology for communicating with thenetwork interface410 of theboiler controller device402.
• As shown, the computer-readable medium418 includes logic that, in response to execution by the at least oneprocessor408, causes theanalysis computing device404 to provide aninformation gathering engine420, ananalysis engine422, and aninput adjustment engine424. In some aspects, theinformation gathering engine420 receives information from at least theinformation reporting engine426 of theboiler controller device402. In some aspects, theanalysis engine422 analyzes the information gathered by theinformation reporting engine426 in order to determine correlations between various boiler operating parameters and the rate of fouling. In some aspects, theinput adjustment engine424 uses the correlations determined by theanalysis engine422 in order to determine adjustments to one or more boiler input parameters, and transmits those adjustments to theboiler controller device402 for implementation. Further details of the actions performed by each of these components are provided below.
• “computer-readable medium” refers to a removable or nonremovable device that implements any technology capable of storing information in a volatile or non-volatile manner to be read by a processor of a computing device, including but not limited to: a hard drive; a flash memory; a solid state drive; random-access memory (RAM); read-only memory (ROM); a CD-ROM, a DVD, or other disk storage; a magnetic cassette; a magnetic tape; and a magnetic disk storage.
• “engine” refers to logic embodied in hardware or software instructions, which can be written in a programming language, such as C, C++, COBOL, JAVA™, PHP, Perl, HTML, CSS, JavaScript, VBScript, ASPX, Microsoft .NET™, Go, Python, and/or the like. An engine may be compiled into executable programs or written in interpreted programming languages. Software engines may be callable from other engines or from themselves. Generally, the engines described herein refer to logical modules that can be merged with other engines, or can be divided into sub-engines. The engines can be implemented by logic stored in any type of computer-readable medium or computer storage device and be stored on and executed by one or more general purpose computers, thus creating a special purpose computer configured to provide the engine or the functionality thereof. The engines can be implemented by logic programmed into an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or another hardware device.
• FIG. 5 is a flowchart that illustrates a non-limiting example aspect of a method for minimizing a rate of fouling of a recovery boiler system according to various aspects of the present disclosure. In themethod500, at least one correlation between a boiler operating parameter and the rate of fouling is determined, such that the operation of the boiler can be automatically adjusted in order to minimize the rate of fouling.
• From a start block, themethod500 proceeds to block502, where arecovery boiler system100 is operated by aboiler controller device402 according to one or more boiler input parameters. In some aspects, the boiler input parameters may include any controllable aspect of operating therecovery boiler system100. In some aspects, a chemical composition of the black liquor may be an example of a boiler input parameter. For example, a chloride content of the black liquor may have an affect on a rate of fouling. Accordingly, the chloride levels could be reduced by reducing the ash recovered from theelectrostatic precipitator136, or by utilizing various technologies that selectively remove the chloride from this ash and then recycle the clean ash to the weak black liquor. In some aspects, the types of make-up chemicals could be altered to reduce the amount of chloride in the black liquor. In some aspects, a technique used to spray the black liquor may be another example of a boiler input parameter. For example, theblack liquor guns116 may be adjustable via a liquor gun setting to spray the black liquor into theboiler106 at different flow rates and/or at different droplet sizes.
• In some aspects, a technique used to introduce air into the boiler may be another example of a boiler input parameter. For example, a setting may be adjusted in order to change the amount of air admitted by at least one of the primarylevel air ports112, the secondarylevel air ports114, and/or the tertiarylevel air ports120, and/or to use the primarylevel air ports112, the secondarylevel air ports114, and/or the tertiarylevel air ports120 to change air pressures in one or more locations within theboiler106.
• Atblock504, a cleaning cycle of therecovery boiler system100 is initiated and completed. In some aspects, the cleaning cycle ofblock504 is being performed during operation of therecovery boiler system100. As discussed above, a cleaning method usable during operation of theboiler106 is sootblowing. Sootblowing may be performed by a plurality of sootblowers, which may not all be active at once. Accordingly, a “cleaning cycle” of sootblowing would include enough time such that all of the sootblowers have been activated at least once, and theentire boiler106 has been cleaned at least once. By allowing a complete cleaning cycle to be completed, enough information will be collected to compensate for any short-term anomalies in the detected fouling rate due to unequal effectiveness of individual sootblowers. In some aspects, more than one cleaning cycle of therecovery boiler system100 may be completed atblock504 while therecovery boiler system100 is being operated.
• Atblock506, during operation and cleaning of therecovery boiler system100, aninformation reporting engine426 of theboiler controller device402 transmits boiler operating parameters to aninformation gathering engine420 of ananalysis computing device404. The time period for which the boiler operating parameters are transmitted includes at least the cleaning cycle described inblock504. In some aspects, the time period may include multiple weeks or multiple months.
• In some aspects, the boiler operating parameters may include the boiler input parameters. In some aspects, the boiler operating parameters may also include other information regarding the operation of therecovery boiler system100, including but not limited to temperatures of theboiler106 in various locations, an amount of black liquor processed by therecovery boiler system100, pressure drops through the heat transfer surfaces, and/or operating loads on the induceddraft fan138. In some aspects, the boiler operating parameters may include weight information generated by at least onestrain gage302. In some aspects, the boiler operating parameters may be provided as one or more time series of boiler operating parameter values.
• Atblock508, during operation and cleaning of therecovery boiler system100, theinformation gathering engine420 gathers a time series of fouling amount values. In some aspects, theinformation gathering engine420 may extract the weight information received within the boiler operating parameters, and may determine the time series of fouling amount values by subtracting a tare weight of the elements suspended by the at least onestrain gage302 from each weight value. Atblock510, ananalysis engine422 of theanalysis computing device404 determines a rate of fouling based on the time series of fouling amount values. In some aspects, the rate of fouling may be determined for each step in the time series, such that changes in the rate of fouling over time can be determined.
• Atblock512, theanalysis engine422 performs a regression analysis on the boiler input parameters and the rate of fouling. In some aspects, the regression analysis may be configured to detect correlations between changes in the boiler input parameters and changes in the rate of fouling. In some aspects, the regression analysis may detect correlations between single boiler input parameters and changes in the rate of fouling. In some aspects, the regression analysis may detect correlations between combinations of two or more boiler input parameters and changes in the rate of fouling. In some aspects, the regression analysis may also detect correlations between one or more boiler operating parameters other than the boiler input parameters and the changes in the rate of fouling, and/or may determine additional correlations between those boiler operating parameters and the boiler input parameters. For example, the regression analysis may detect a correlation between a boiler operating temperature and the rate of fouling, and an additional correlation between a liquor gun setting and the boiler operating temperature.
• Any suitable regression analysis, including but not limited to a classification and regression tree (CART) analysis, may be used. In some aspects, CART analysis recursively partitions observations in a matched data set, comprising a categorical (for classification trees) or continuous (for regression trees) dependent (response) variable and one or more independent (explanatory) variables, into progressively smaller groups. Each partition may be a binary split. During each recursion, splits for each explanatory variable are examined and the split that maximizes the homogeneity of the two resulting groups with respect to the dependent variable is chosen. When examining boiler input parameters and the rate of fouling, one non-limiting example approach is to divide the behavior of the boiler into times of “low-fouling” and “high-fouling,” and to develop a CART classification tree using the boiler input parameters to create homogenous groups that separate the low-fouling conditions from the high-fouling conditions. Ranges of the boiler input parameters that promote low-fouling conditions can then be selected as control ranges.
• Atblock514, aninput adjustment engine424 of theanalysis computing device404 determines an adjusted boiler input parameter based on a result of the regression analysis. For example, theinput adjustment engine424 may use a correlation between a liquor gun setting and the rate of fouling determined by the regression analysis to determine an adjustment to the liquor gun setting. As another example, theinput adjustment engine424 may use a correlation between settings for one or more air ports and the rate of fouling to determine an adjustment to one or more air ports. As yet another example, theinput adjustment engine424 may use a correlation between the chemistry of the black liquor and the rate of fouling to determine an adjustment to the chemistry. As still another example, theinput adjustment engine424 may use correlations of combined boiler input parameters with the rate of fouling to determine a combined optimal setting, or a combined optimal setting with one boiler input parameter (such as a chemistry) held constant, and may determine the adjusted boiler input parameters based on the combined optimal setting.
• Atblock516, theinput adjustment engine424 causes the adjusted boiler input parameter to be used by therecovery boiler system100 to minimize fouling. In some aspects, theinput adjustment engine424 may cause the adjusted boiler input parameter to be automatically implemented by therecovery boiler system100. For example, theinput adjustment engine424 may transmit the adjusted boiler input parameter to aninput control engine428 of theboiler controller device402, and theinput control engine428 may automatically adjust the boiler input parameters to minimize fouling. In some aspects, such adjustment of the boiler input parameters may include transmitting a command to an actuator for theblack liquor guns116 or one or more air ports in order to change a setting on theblack liquor guns116 or one or more air ports. In some aspects, such adjustment of the boiler input parameters may include transmitting commands to actuators for valves controlling the amount of precipitator ash purged or sent to the ash cleaning system of the recovery boiler to reduce chloride levels. In some aspects, instead of causing the adjusted boiler input parameter to be automatically implemented, theinput adjustment engine424 may present the adjusted boiler input parameter to an operator, and the operator may create commands to change settings of components of therecovery boiler system100 to adjust the boiler input parameter as presented.
• Themethod500 then proceeds to an end block and terminates.
• FIG. 6 is a block diagram that illustrates aspects of anexemplary computing device600 appropriate for use as a computing device of the present disclosure. While multiple different types of computing devices were discussed above, theexemplary computing device600 describes various elements that are common to many different types of computing devices. WhileFIG. 6 is described with reference to a computing device that is implemented as a device on a network, the description below is applicable to servers, personal computers, mobile phones, smart phones, tablet computers, embedded computing devices, and other devices that may be used to implement portions of aspects of the present disclosure. Some aspects of a computing device may be implemented in or may include an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other customized device. Moreover, those of ordinary skill in the art and others will recognize that thecomputing device600 may be any one of any number of currently available or yet to be developed devices.
• In its most basic configuration, thecomputing device600 includes at least oneprocessor602 and asystem memory604 connected by a communication bus606. Depending on the exact configuration and type of device, thesystem memory604 may be volatile or nonvolatile memory, such as read only memory (“ROM”), random access memory (“RAM”), EEPROM, flash memory, or similar memory technology. Those of ordinary skill in the art and others will recognize thatsystem memory604 typically stores data and/or program modules that are immediately accessible to and/or currently being operated on by theprocessor602. In this regard, theprocessor602 may serve as a computational center of thecomputing device600 by supporting the execution of instructions.
• As further illustrated inFIG. 6, thecomputing device600 may include anetwork interface610 comprising one or more components for communicating with other devices over a network. Aspects of the present disclosure may access basic services that utilize thenetwork interface610 to perform communications using common network protocols. Thenetwork interface610 may also include a wireless network interface configured to communicate via one or more wireless communication protocols, such as Wi-Fi, 2G, 3G, LTE, WiMAX, Bluetooth, Bluetooth low energy, and/or the like. As will be appreciated by one of ordinary skill in the art, thenetwork interface610 illustrated inFIG. 6 may represent one or more wireless interfaces or physical communication interfaces described and illustrated above with respect to particular components of thecomputing device600.
• In the exemplary aspect depicted inFIG. 6, thecomputing device600 also includes astorage medium608. However, services may be accessed using a computing device that does not include means for persisting data to a local storage medium. Therefore, thestorage medium608 depicted inFIG. 6 is represented with a dashed line to indicate that thestorage medium608 is optional. In any event, thestorage medium608 may be volatile or nonvolatile, removable or nonremovable, implemented using any technology capable of storing information such as, but not limited to, a hard drive, solid state drive, CD ROM, DVD, or other disk storage, magnetic cassettes, magnetic tape, magnetic disk storage, and/or the like.
• Suitable implementations of computing devices that include aprocessor602,system memory604, communication bus606,storage medium608, andnetwork interface610 are known and commercially available. For ease of illustration and because it is not important for an understanding of the claimed subject matter,FIG. 6 does not show some of the typical components of many computing devices. In this regard, thecomputing device600 may include input devices, such as a keyboard, keypad, mouse, microphone, touch input device, touch screen, tablet, and/or the like. Such input devices may be coupled to thecomputing device600 by wired or wireless connections including RF, infrared, serial, parallel, Bluetooth, Bluetooth low energy, USB, or other suitable connections protocols using wireless or physical connections. Similarly, thecomputing device600 may also include output devices such as a display, speakers, printer, etc. Since these devices are well known in the art, they are not illustrated or described further herein.
• In the foregoing description numerous specific details are set forth to provide a thorough understanding of the aspects. One skilled in the relevant art will recognize, however, that the techniques described herein can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring certain aspects.
• The order in which some or all of the process blocks appear in each process should not be deemed limiting. Rather, one of ordinary skill in the art having the benefit of the present disclosure will understand that some of the process blocks may be executed in a variety of orders not illustrated, or even in parallel.
• The above description of illustrated aspects of the invention, including what is described in the Abstract, is not intended to be exhaustive or to limit the invention to the precise forms disclosed. While specific aspects of, and examples for, the invention are described herein for illustrative purposes, various modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize.
• These modifications can be made to the invention in light of the above detailed description. The terms used in the following claims should not be construed to limit the invention to the specific aspects disclosed in the specification. Rather, the scope of the invention is to be determined entirely by the following claims, which are to be construed in accordance with established doctrines of claim interpretation.
• In general, the invention describes:
• A system, comprising a boiler; a fouling sensor associated with a component of the boiler; a boiler controller device; and an analysis computing device that includes at least one processor and a computer-readable medium having computer-executable instructions stored thereon that, in response to execution by the at least one processor, cause the analysis computing device to perform actions comprising: receiving boiler operating information for a period of time, wherein the boiler operating information includes boiler operating parameters and a rate of fouling for the period of time, and wherein the boiler operating parameters include one or more boiler input parameters; performing a regression analysis to determine at least one correlation between the boiler operating parameters and the rate of fouling; adjusting at least one boiler input parameter based on the at least one correlation to minimize the rate of fouling; and transmitting the at least one adjusted boiler input parameter to the boiler controller device for implementation and/or preferably, wherein the boiler includes a heat exchange element, and wherein the fouling sensor is associated with the heat exchange element and/or preferably wherein the fouling sensor is a weight sensor configured to generate values indicating a weight of the heat exchange element and/or preferably wherein receiving the rate of fouling for the period of time includes: receiving a time series of fouling amount values; and determining the rate of fouling based on the time series of fouling amount values and/or preferably wherein performing the regression analysis to determine the at least one correlation between the boiler operating parameters and the rate of fouling includes performing a CART analysis on the boiler operating information and/or preferably further comprising one or more sootblowers configured to operate according to a cycle, and wherein receiving boiler operating information for the period of time includes receiving boiler operating information for a period of time that includes at least one complete cycle and/or preferably further comprising: one or more valves configured to control an amount of precipitator ash purged or sent to an ash cleaning system in order to affect a chloride level; and one or more actuators configured to control the one or more valves; wherein the at least one boiler input parameter includes a valve setting; wherein transmitting the at least one adjusted boiler input parameter to the boiler controller device for implementation includes transmitting the valve setting to the one or more actuators; and wherein the one or more actuators are configured to adjust the one or more valves based on the valve setting; and/or preferably further comprising one or more liquor guns, wherein the at least one boiler input parameter includes a liquor gun setting, wherein transmitting the at least one adjusted boiler input parameter to the boiler controller device for implementation includes transmitting the liquor gun setting to the boiler controller device, and wherein the boiler controller device is configured to change operation of the one or more liquor guns based on the liquor gun setting and/or preferably further comprising one or more air ports, wherein the at least one boiler input parameter includes settings for one or more air ports, wherein transmitting the at least one adjusted boiler input parameter to the boiler controller device for implementation includes transmitting adjusted settings for one or more air ports to the boiler controller device, and wherein the boiler controller device is configured to change operation of the one or more air ports based on the adjusted settings for the one or more air ports.
• A computer-implemented method of reducing a rate of fouling in a recovery boiler system, the method comprising: receiving, by a computing device, boiler operating information for a period of time, wherein the boiler operating information includes boiler operating parameters and a rate of fouling for the period of time, and wherein the boiler operating parameters include one or more boiler input parameters; performing, by the computing device, a regression analysis to determine at least one correlation between the boiler operating parameters and the rate of fouling; and causing, by the computing device, at least one boiler input parameter to be adjusted based on the at least one correlation to minimize the rate of fouling and/or preferably wherein receiving the rate of fouling for the period of time includes:
• receiving, by the computing device, a time series of fouling amount values; and
  determining, by the computing device, the rate of fouling based on the time series of fouling amount values; and/or preferably wherein receiving the time series of fouling amount values includes receiving the time series of fouling amount values from a weight sensor configured to weigh a heat exchange element and/or preferably wherein performing the regression analysis to determine the at least one correlation between the boiler operating parameters and the rate of fouling includes performing a CART analysis on the boiler operating information and/or preferably wherein the recovery boiler system includes one or more sootblowers configured to operate according to a cycle, and wherein receiving boiler operating information for the period of time includes receiving boiler operating information for a period of time that includes at least one complete cycle and/or preferably wherein causing the at least one boiler input parameter to be adjusted based on the at least one correlation to minimize the rate of fouling includes at least one of causing a chemistry of boiler inputs to be adjusted, causing a liquor gun setting to be adjusted, and causing settings for one or more air ports to be adjusted.
• A non-transitory computer-readable medium having computer-executable instructions stored thereon that, in response to execution by one or more processors of a computing device, cause the computing device to perform actions comprising: receiving, by the computing device, boiler operating information for a period of time, wherein the boiler operating information includes boiler operating parameters and a rate of fouling for the period of time, and wherein the boiler operating parameters include one or more boiler input parameters; performing, by the computing device, a regression analysis to determine at least one correlation between the boiler operating parameters and the rate of fouling; and causing, by the computing device, at least one boiler input parameter to be adjusted based on the at least one correlation to minimize the rate of fouling, and/or preferably wherein receiving the rate of fouling for the period of time includes: receiving, by the computing device, a time series of fouling amount values; and determining, by the computing device, the rate of fouling based on the time series of fouling amount values and/or preferably wherein performing the regression analysis to determine the at least one correlation between the boiler operating parameters and the rate of fouling includes performing a CART analysis on the boiler operating information and/or preferably wherein the recovery boiler system includes one or more sootblowers configured to operate according to a cycle, and wherein receiving boiler operating information for a period of time includes receiving boiler operating information for a period of time that includes at least one complete cycle and/or preferably wherein causing the at least one boiler input parameter to be adjusted based on the at least one correlation to minimize the rate of fouling includes at least one of causing a chemistry of boiler inputs to be adjusted, causing a liquor gun setting to be adjusted, and causing settings for one or more air ports to be adjusted.

Claims (20)

What is claimed is:

1. A system, comprising:

a boiler;

a fouling sensor associated with a component of the boiler;

a boiler controller device; and

an analysis computing device that includes at least one processor and a computer-readable medium having computer-executable instructions stored thereon that, in response to execution by the at least one processor, cause the analysis computing device to perform actions comprising:

receiving boiler operating information for a period of time, wherein the boiler operating information includes boiler operating parameters and a rate of fouling for the period of time, and wherein the boiler operating parameters include one or more boiler input parameters;

performing a regression analysis to determine at least one correlation between the boiler operating parameters and the rate of fouling;

adjusting at least one boiler input parameter based on the at least one correlation to minimize the rate of fouling; and

transmitting the at least one adjusted boiler input parameter to the boiler controller device for implementation.

2. The system ofclaim 1, wherein the boiler includes a heat exchange element, and wherein the fouling sensor is associated with the heat exchange element.

3. The system ofclaim 2, wherein the fouling sensor is a weight sensor configured to generate values indicating a weight of the heat exchange element.

4. The system ofclaim 1, wherein receiving the rate of fouling for the period of time includes:

receiving a time series of fouling amount values; and

determining the rate of fouling based on the time series of fouling amount values.

5. The system ofclaim 1, wherein performing the regression analysis to determine the at least one correlation between the boiler operating parameters and the rate of fouling includes performing a CART analysis on the boiler operating information.

6. The system ofclaim 1, further comprising one or more sootblowers configured to operate according to a cycle, and wherein receiving boiler operating information for the period of time includes receiving boiler operating information for a period of time that includes at least one complete cycle.

7. The system ofclaim 1, further comprising:

one or more valves configured to control an amount of precipitator ash purged or sent to an ash cleaning system in order to affect a chloride level; and

one or more actuators configured to control the one or more valves;

wherein the at least one boiler input parameter includes a valve setting;

wherein transmitting the at least one adjusted boiler input parameter to the boiler controller device for implementation includes transmitting the valve setting to the one or more actuators; and

wherein the one or more actuators are configured to adjust the one or more valves based on the valve setting.

8. The system ofclaim 1, further comprising one or more liquor guns, wherein the at least one boiler input parameter includes a liquor gun setting, wherein transmitting the at least one adjusted boiler input parameter to the boiler controller device for implementation includes transmitting the liquor gun setting to the boiler controller device, and wherein the boiler controller device is configured to change operation of the one or more liquor guns based on the liquor gun setting.

9. The system ofclaim 1, further comprising one or more air ports, wherein the at least one boiler input parameter includes settings for one or more air ports, wherein transmitting the at least one adjusted boiler input parameter to the boiler controller device for implementation includes transmitting adjusted settings for one or more air ports to the boiler controller device, and wherein the boiler controller device is configured to change operation of the one or more air ports based on the adjusted settings for the one or more air ports.

10. A computer-implemented method of reducing a rate of fouling in a recovery boiler system, the method comprising:

receiving, by a computing device, boiler operating information for a period of time, wherein the boiler operating information includes boiler operating parameters and a rate of fouling for the period of time, and wherein the boiler operating parameters include one or more boiler input parameters;

performing, by the computing device, a regression analysis to determine at least one correlation between the boiler operating parameters and the rate of fouling; and

causing, by the computing device, at least one boiler input parameter to be adjusted based on the at least one correlation to minimize the rate of fouling.

11. The computer-implemented method ofclaim 10, wherein receiving the rate of fouling for the period of time includes:

receiving, by the computing device, a time series of fouling amount values; and

determining, by the computing device, the rate of fouling based on the time series of fouling amount values.

12. The computer-implemented method ofclaim 11, wherein receiving the time series of fouling amount values includes receiving the time series of fouling amount values from a weight sensor configured to weigh a heat exchange element.

13. The computer-implemented method ofclaim 10, wherein performing the regression analysis to determine the at least one correlation between the boiler operating parameters and the rate of fouling includes performing a CART analysis on the boiler operating information.

14. The computer-implemented method ofclaim 10, wherein the recovery boiler system includes one or more sootblowers configured to operate according to a cycle, and wherein receiving boiler operating information for the period of time includes receiving boiler operating information for a period of time that includes at least one complete cycle.

15. The computer-implemented method ofclaim 10, wherein causing the at least one boiler input parameter to be adjusted based on the at least one correlation to minimize the rate of fouling includes at least one of causing a chemistry of boiler inputs to be adjusted, causing a liquor gun setting to be adjusted, and causing settings for one or more air ports to be adjusted.

16. A non-transitory computer-readable medium having computer-executable instructions stored thereon that, in response to execution by one or more processors of a computing device, cause the computing device to perform actions comprising:

receiving, by the computing device, boiler operating information for a period of time, wherein the boiler operating information includes boiler operating parameters and a rate of fouling for the period of time, and wherein the boiler operating parameters include one or more boiler input parameters;

performing, by the computing device, a regression analysis to determine at least one correlation between the boiler operating parameters and the rate of fouling; and

causing, by the computing device, at least one boiler input parameter to be adjusted based on the at least one correlation to minimize the rate of fouling.

17. The computer-readable medium ofclaim 16, wherein receiving the rate of fouling for the period of time includes:

receiving, by the computing device, a time series of fouling amount values; and

determining, by the computing device, the rate of fouling based on the time series of fouling amount values.

18. The computer-readable medium ofclaim 16, wherein performing the regression analysis to determine the at least one correlation between the boiler operating parameters and the rate of fouling includes performing a CART analysis on the boiler operating information.

19. The computer-readable medium ofclaim 16, wherein the recovery boiler system includes one or more sootblowers configured to operate according to a cycle, and wherein receiving boiler operating information for a period of time includes receiving boiler operating information for a period of time that includes at least one complete cycle.

20. The computer-readable medium ofclaim 16, wherein causing the at least one boiler input parameter to be adjusted based on the at least one correlation to minimize the rate of fouling includes at least one of causing a chemistry of boiler inputs to be adjusted, causing a liquor gun setting to be adjusted, and causing settings for one or more air ports to be adjusted.

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