Rising global energy demands have led to an increase in demand for clean, sustainable energy. A leading technology for reducing greenhouse gas (GHG) emission for existing coal-power infrastructure is gasification, which has sparked an interest in reactor modelling for design and performance analysis. Reduced order models (ROMs) have seen an increase in popularity for entrained flow gasifiers, as they offer a low-computational alternative to conventional computational fluid dynamic (CFD) modelling while maintaining the integrity of important operational parameters, such as carbon conversion and syngas yield. However, ROMs require more physical parameter inputs than are normally required for CFD modelling, such as the geometry of the gas-solid jet (specifically the jet half-angle). Experiments were conducted to understand the relation between the required input parameters for ROMs, such as fuel flow rate, transport gas flow rate, and jet half-angle, and develop useful correlations for ROM systems. A new configuration for pneumatic conveying was developed and tested at the pilot-scale system at NRCan CanmetENERGY. It was used to study the pneumatic conveying of pulverized fuels, specifically the influence of operating parameters such as pressure drop and gas flow rates on the fuel flow rate, and the geometry of the gas-solid fuel jet (notably the jet half-angle) injected into the gasifier. The mean fuel flow rate of pulverized fuels was shown to increase with increasing pressure drop and with decreasing gas flow rates in the fuel transfer line. The jet half-angle was shown to increase as the solid loading ratio in the jet core was decreased. Finally, the relative fuel flow variability was observed to be significantly influenced by the design of the pneumatic conveying system, with the fluctuations increasing with increasing pressure drop and with decreasing gas flow rate, similar to the mean flow rate.

Government regulations to reduce pollutants and increasing environmental awareness in the power generation industry have encouraged coal power plants to begin firing biomass in their boilers. Biomass generally consists of larger particles which produce longer flames than coal for a given burner. The length of the flame is important in fixed-volume boilers because of its influence on heat transfer, corrosion, deposition, and pollutant formation. Many pulverized fuel burners employ a series of co-annular tubes with various flows of fuel and air to produce a stabilized flame. A variable swirl burner with three co-annular tubes, each of variable diameter, has been used to collect flame length data for nearly 400 different operating conditions of varying swirl, fuel type, air flow rate, enhanced oxygen flow rate and oxygen addition location. A model based on the length required to mix fuel and air to a stoichiometric mixture was developed. Inputs to the model are the flow rates of fuel, air, and oxygen, swirl vane position and burner geometries. The model was exercised by changing flow rates and burner tube diameters one at a time while holding all others constant. Physical explanations for trends produced were given.The model also requires two constants, one of which is solved for given a case without swirl, and the other is found by fitting experimental data. The constants found in this study appear to be accurate exclusive to the BYU burner. Thus burner designers will need to obtain minimal amounts of data to predict constants for their reactor and then employ the model to predict flame length trends. The resulting correlation predicts 90% of the flame lengths to be within 20% of the measured value. The correlation provides insights into the expected impact of burner flow rates and geometry changes on flame length which impacts particle burnout, NOx formation and heat transfer.

Oxy-combustion is a developing technology that enables carbon dioxide (CO2) capture. Flame temperature and emissivity data were taken on a 150 kWth, pulverized-coal, burner flow reactor (BFR) that has been modified to run oxy-combustion with pure CO2 as simulated recycled flue gas. Data were taken at 78 conditions in which three parameters were varied, namely: the swirl angle of the fuel stream, the location of the oxidizer as it exited the burner, and the flow rate of diluent (pure CO2) added to the outer, secondary stream. At each condition, digital color images were obtained using a calibrated RGB camera. The images were used to determine lift-off length, temperature, and emissivity. The mathematical theory of two-color pyrometry and the calibration process used to measure the camera sensitivity is presented. The two most commonly used emissivity models in two-color pyrometry, the Hottel and Broughton and gray models, were investigated to determine which was the most appropriate for use in an oxy-coal flame. A significant difference of 7% in the temperature and 24% in the emissivity results were found when processing an image with the Hottel and Broughton and gray emissivity models. The Hottel and Broughton model was selected for processing, because the Hottel and Broughton model is more appropriate for soot which appeared to dominate flame emissions. Using the two-color data, several trends were documented. Flame temperature was seen to decrease with increasing CO2 flow rate. Within a given flame along the axial direction, temperature was seen to correlate with emissivity. As emissivity increased, flame temperature was seen to decrease. Many flames were lifted from the burner exit. Lift-off length was decreased and the flames became more attached by: 1) Increasing the amount of swirl given to the fuel stream, 2) Adding O2 to the center primary tube or 3) Decreasing the flow of secondary CO2. At higher center oxygen flow rates (above 8.5 kg/hr), the O2 jet velocity was large causing increased entrainment and mixing which degraded burner performance.

The need for electric power across the globe is ever increasing, as is the need to produce electricity in a sustainable method that does not emit CO2 into the atmosphere. A proposed technology for efficiently capturing CO2 while producing electricity is pressurized oxy-combustion (POC). The objective of this work is to design, build, and demonstrate a burner for a 20 atmosphere oxy-coal combustor. Additionally, working engineering drawings for the main pressure vessel and floor plan drawings for the main pressure vessel, exhaust, and fuel feed systems were produced. The POC reactor enables the development of three key POC technologies: a coal dry-feed system, a high pressure burner, and an ash management system. This work focuses on the design of a traditional diffusion flame burner and the design of the main reactor. The burner was designed with the intent to elongate the flame and spread heat flux from the reacting fuel over a longer distance to enable low CO2 recycle rates. This was done by matching the velocities of the fuel and oxidizer in the burner to minimize shear between incoming jets in order to delay the mixing of the coal and oxygen for as long as possible. A spreadsheet model was used to calculate the jet velocities and sizes of holes needed in the burner, comprehensive combustion modeling was outsourced to Reaction Engineering International (REI) to predict the performance of burner designs. Using the guidance of the modeling results, a burner design was selected and assembled. The burner consists of a center tube where the primary fuel will flow, two concentric secondary tubes making an inner and an outer annulus, and eight tertiary lances. The burner and reactor are ready to be tested once issues involving the control system are resolved. Measurements that will be taken once testing begins include: axial gas and wall temperature, radiative heat flux, outlet gas temperature, and ash composition.

<p>This licentiate thesis describes development of modellingtools, experimental physical modelling and numerical modellingto simulate real combustion processes for advanced industrialutility boiler before and after retrofit.</p><p>The work presents extended study about formation,destruction and control of pollutants, especially NOx, whichoccur during combustion process.</p><p>The main aim of this work is to improve mixing process incombustion chamber. To do this, the optimization of placementand direction of additional air and fuel nozzles, the physicalmodelling technique is used. By using that method, it ispossible to obtain qualitative information about processes,which occur in the real boiler. The numerical simulationsverify the results from physical modelling, because duringmathematical modelling quantitative informations about flow andmixing patterns, temperature field, species concentration areobtained.</p><p>Two 3D cases, before and after retrofit, of pulverized fuelfired boiler at 125 MW output thermal power are simulated. Theunstructured mesh technique is also used to discretize theboiler. The number of grid was 427 656 before retrofit and 513362 after retrofit. The comparisons of results of numericalsimulation before and after retrofit are presented. The resultsfrom physical modelling and numerical simulation are alsoshown.</p><p>Results present that nozzles of additional air and fuel givea considerably better mixing process, uniform temperature fieldand CO2 mass fraction. The whole combustion chamber worksalmost as a "well stirred reactor", while upper part of boilerworks as a "plug flow reactor".</p><p>Differences between from measured of temperatures andpredicted temperatures are not too big, the maximum differenceis about 100 K. It seems, that calculated temperatures showgood agreement with measurement data.</p><p>The results illuminate the potential of physical andnumerical modelling methods as promising tools to deal with thecomplicated combustion processes, even for practicalapplication in the industry.</p><p><b>Keywords:</b>air staging, fuel staging, boiler, furnace,computational fluid dynamics, numerical simulation, pollutants,physical modeling, pulverized fuel combustion.</p>

abstract: Carbon capture and sequestration (CCS) is one of the important mitigation options for climate change. Numerous technologies to capture carbon dioxide (CO2) are in development but currently, capture using amines is the predominant technology. When the flue gas reacts with amines (Monoethanaloamine) the CO2 is absorbed into the solution and forms an intermediate product which then releases CO2 at higher temperature. The high temperature necessary to strip CO2 is provided by steam extracted from the powerplant thus reducing the net output of the powerplant by 25% to 35%. The reduction in electricity output for the same input of coal increases the emissions factor of Nitrogen Oxides, Mercury, Particulate matter, Ammonia, Volatile organic compounds for the same unit of electricity produced. The thesis questions if this tradeoff between CO2 and other emissions is beneficial or not. Three different methodologies, Life Cycle Assessment, Valuation models and cost benefit analysis are used to identify if there is a net benefit to the society on implementation of CCS to a Pulverized coal powerplant. These methodologies include the benefits due to reduction of CO2 and the disbenefits due to the increase of other emissions. The life cycle assessment using ecoindicator'99 methodology shows the CCS is not beneficial under Hierarchical and Egalitarian perspective. The valuation model shows that the inclusion of the other emissions reduces the benefit associated with CCS. For a lower CO2 price the valuation model shows that CCS is detrimental to the environment. The cost benefit analysis shows that a CO2 price of at least $80/tCO2 is required for the cost benefit ratio to be 1. The methodology integrates Montecarlo simulation to characterize the uncertainties associated with the valuation models. / Dissertation/Thesis / sima pro / excel sheets / M.S. Civil and Environmental Engineering 2012

A injeção de carvão pulverizado (PCI — pulverized coal injection) nos altos-fornos (AFs) é uma tecnologia utilizada pelas usinas siderúrgicas para aumentar a produtividade e diminuir o consumo de coque no AF. Nas últimas décadas as taxas de injeção de carvão pulverizado aumentaram na maior parte dos AFs. O principal problema associado à utilização de altas taxas de PCI é a geração de char (carvão incombusto) na zona de combustão. Este material percorre um caminho ascendente junto ao fluxo gasoso, podendo acumular-se e assim prejudicar a permeabilidade do AF. A presença, nas amostras sólidas recolhidas do gás de saída do AF, de altos teores de char pode ser o resultado da injeção de um carvão pulverizado com uma combustibilidade inadequada e de uma operação instável do AF. Portanto, conhecer a proporção de char que sai do AF contribuirá na seleção do tipo de carvão utilizado e na otimização da prática de PCI. Análises químicas das amostras de pó do AF revelam, sem distinguir, a presença de materiais carbonosos. A microscopia ótica foi utilizada para estudar estas amostras sólidas, mas apresenta certas limitações. A difração de raios-X (DRX) é uma técnica padrão para caracterizar a estrutura cristalina dos materiais. Ela também pode ser utilizada para quantificar as dimensões dos cristalitos (Lc, La, etc.) dos materiais carbonosos. Uma vez que a estrutura do coque é mais ordenada que a do char, seria possível quantificar a proporção destes materiais nas amostras de pó do AF através da DRX combinada a análises químicas. O objetivo principal deste trabalho foi identificar e quantificar os componentes carbonosos (char e finos de coque) presentes no pó de balão (PB) do AF, por DRX e análise elementar de carbono. O efeito da temperatura sobre a grafitização do coque também foi avaliado, a fim de identificar a possível origem dos finos de coque gerados no AF. Três amostras de PB coletadas de um AF, uma em operação a coque e duas a PCI, foram selecionadas. Os pós foram fracionados e analisados quimicamente. Após, as frações destas amostras foram moídas, desmineralizadas e analisadas por DRX e análise elementar de carbono. Amostras de char produzidas em laboratório e respectivos carvões foram utilizados como padrões para a quantificação. Amostras de coque foram tratadas termicamente a diferentes temperaturas, sendo posteriormente analisadas por DRX. Este estudo mostrou que a DRX pode ser usada como técnica padrão para identificar as estruturas do char e do coque podendo ser utilizada para quantificar a proporção destes materiais carbonosos no pó de balão do AF. Além disto, observou-se que quanto maior a temperatura de tratamento térmico mais ordenada fica a estrutura cristalina do coque. / In a Blast Furnace (BF), Pulverized coal injection (PCI) is the most popular injection technology used worldwide to reduce coke consumption and to increase the productivity. In the last decades the PCI injection rates raised in the most of BFs. One of the problems during the PCI operation in BF is the unburnt char formation. Higher char levels in the BF stack could impact burden permeability. The off gas BF solid samples contain char, coke fines, metallic oxides, etc. The quantification of the carbonaceous materials content in these samples could be used to improve the PCI performance in operating BF. Chemical analysis in the BF dust samples reveal without differentiates some carbonaceous material. The optical microscopy was used to study these solid samples but with some restrictions. XRD (X-ray diffraction) is a standard means of characterizing the structure of materials. This technique has been utilized to determine the crystallite sizes (Lc, La, etc.), in carbonaceous materials. Since the coke structure is more ordered than the char structure, it would be possible to quantify the proportion of these materials in the off-gas BF samples by chemical analysis in combination with XRD. The aim of this work is to identify and quantify carbonaceous components (coal, char and coke fines) in the flue dust BF samples through the use of the XRD technique and ultimate analysis. Besides, the effect of temperature on coke graphitization will be studied aiming to identify the possible origin of coke fines in the BF dust. Four dusts collected in the off-gas BF, two at all coke and two at PCI operations, were selected for this investigation. The dusts were fractioned and chemically analyzed. After the fractions were grounded, demineralized and analyzed by ultimate analysis and XRD. Besides, were investigated the atomic structure of raw coals and its laboratory char, and raw coke and its laboratory heattreated samples. This study has shown that the XRD technique could be used as a standard procedure to identify the char and coke structures and could be used to quantify the fines proportions of these carbonaceous materials in the BF flue dust. It was concluded that the bigger the annealing temperature the more ordered becomes the atomic coke structure.

A injeção de carvão pulverizado (PCI — pulverized coal injection) nos altos-fornos (AFs) é uma tecnologia utilizada pelas usinas siderúrgicas para aumentar a produtividade e diminuir o consumo de coque no AF. Nas últimas décadas as taxas de injeção de carvão pulverizado aumentaram na maior parte dos AFs. O principal problema associado à utilização de altas taxas de PCI é a geração de char (carvão incombusto) na zona de combustão. Este material percorre um caminho ascendente junto ao fluxo gasoso, podendo acumular-se e assim prejudicar a permeabilidade do AF. A presença, nas amostras sólidas recolhidas do gás de saída do AF, de altos teores de char pode ser o resultado da injeção de um carvão pulverizado com uma combustibilidade inadequada e de uma operação instável do AF. Portanto, conhecer a proporção de char que sai do AF contribuirá na seleção do tipo de carvão utilizado e na otimização da prática de PCI. Análises químicas das amostras de pó do AF revelam, sem distinguir, a presença de materiais carbonosos. A microscopia ótica foi utilizada para estudar estas amostras sólidas, mas apresenta certas limitações. A difração de raios-X (DRX) é uma técnica padrão para caracterizar a estrutura cristalina dos materiais. Ela também pode ser utilizada para quantificar as dimensões dos cristalitos (Lc, La, etc.) dos materiais carbonosos. Uma vez que a estrutura do coque é mais ordenada que a do char, seria possível quantificar a proporção destes materiais nas amostras de pó do AF através da DRX combinada a análises químicas. O objetivo principal deste trabalho foi identificar e quantificar os componentes carbonosos (char e finos de coque) presentes no pó de balão (PB) do AF, por DRX e análise elementar de carbono. O efeito da temperatura sobre a grafitização do coque também foi avaliado, a fim de identificar a possível origem dos finos de coque gerados no AF. Três amostras de PB coletadas de um AF, uma em operação a coque e duas a PCI, foram selecionadas. Os pós foram fracionados e analisados quimicamente. Após, as frações destas amostras foram moídas, desmineralizadas e analisadas por DRX e análise elementar de carbono. Amostras de char produzidas em laboratório e respectivos carvões foram utilizados como padrões para a quantificação. Amostras de coque foram tratadas termicamente a diferentes temperaturas, sendo posteriormente analisadas por DRX. Este estudo mostrou que a DRX pode ser usada como técnica padrão para identificar as estruturas do char e do coque podendo ser utilizada para quantificar a proporção destes materiais carbonosos no pó de balão do AF. Além disto, observou-se que quanto maior a temperatura de tratamento térmico mais ordenada fica a estrutura cristalina do coque. / In a Blast Furnace (BF), Pulverized coal injection (PCI) is the most popular injection technology used worldwide to reduce coke consumption and to increase the productivity. In the last decades the PCI injection rates raised in the most of BFs. One of the problems during the PCI operation in BF is the unburnt char formation. Higher char levels in the BF stack could impact burden permeability. The off gas BF solid samples contain char, coke fines, metallic oxides, etc. The quantification of the carbonaceous materials content in these samples could be used to improve the PCI performance in operating BF. Chemical analysis in the BF dust samples reveal without differentiates some carbonaceous material. The optical microscopy was used to study these solid samples but with some restrictions. XRD (X-ray diffraction) is a standard means of characterizing the structure of materials. This technique has been utilized to determine the crystallite sizes (Lc, La, etc.), in carbonaceous materials. Since the coke structure is more ordered than the char structure, it would be possible to quantify the proportion of these materials in the off-gas BF samples by chemical analysis in combination with XRD. The aim of this work is to identify and quantify carbonaceous components (coal, char and coke fines) in the flue dust BF samples through the use of the XRD technique and ultimate analysis. Besides, the effect of temperature on coke graphitization will be studied aiming to identify the possible origin of coke fines in the BF dust. Four dusts collected in the off-gas BF, two at all coke and two at PCI operations, were selected for this investigation. The dusts were fractioned and chemically analyzed. After the fractions were grounded, demineralized and analyzed by ultimate analysis and XRD. Besides, were investigated the atomic structure of raw coals and its laboratory char, and raw coke and its laboratory heattreated samples. This study has shown that the XRD technique could be used as a standard procedure to identify the char and coke structures and could be used to quantify the fines proportions of these carbonaceous materials in the BF flue dust. It was concluded that the bigger the annealing temperature the more ordered becomes the atomic coke structure.

A injeção de carvão pulverizado (PCI — pulverized coal injection) nos altos-fornos (AFs) é uma tecnologia utilizada pelas usinas siderúrgicas para aumentar a produtividade e diminuir o consumo de coque no AF. Nas últimas décadas as taxas de injeção de carvão pulverizado aumentaram na maior parte dos AFs. O principal problema associado à utilização de altas taxas de PCI é a geração de char (carvão incombusto) na zona de combustão. Este material percorre um caminho ascendente junto ao fluxo gasoso, podendo acumular-se e assim prejudicar a permeabilidade do AF. A presença, nas amostras sólidas recolhidas do gás de saída do AF, de altos teores de char pode ser o resultado da injeção de um carvão pulverizado com uma combustibilidade inadequada e de uma operação instável do AF. Portanto, conhecer a proporção de char que sai do AF contribuirá na seleção do tipo de carvão utilizado e na otimização da prática de PCI. Análises químicas das amostras de pó do AF revelam, sem distinguir, a presença de materiais carbonosos. A microscopia ótica foi utilizada para estudar estas amostras sólidas, mas apresenta certas limitações. A difração de raios-X (DRX) é uma técnica padrão para caracterizar a estrutura cristalina dos materiais. Ela também pode ser utilizada para quantificar as dimensões dos cristalitos (Lc, La, etc.) dos materiais carbonosos. Uma vez que a estrutura do coque é mais ordenada que a do char, seria possível quantificar a proporção destes materiais nas amostras de pó do AF através da DRX combinada a análises químicas. O objetivo principal deste trabalho foi identificar e quantificar os componentes carbonosos (char e finos de coque) presentes no pó de balão (PB) do AF, por DRX e análise elementar de carbono. O efeito da temperatura sobre a grafitização do coque também foi avaliado, a fim de identificar a possível origem dos finos de coque gerados no AF. Três amostras de PB coletadas de um AF, uma em operação a coque e duas a PCI, foram selecionadas. Os pós foram fracionados e analisados quimicamente. Após, as frações destas amostras foram moídas, desmineralizadas e analisadas por DRX e análise elementar de carbono. Amostras de char produzidas em laboratório e respectivos carvões foram utilizados como padrões para a quantificação. Amostras de coque foram tratadas termicamente a diferentes temperaturas, sendo posteriormente analisadas por DRX. Este estudo mostrou que a DRX pode ser usada como técnica padrão para identificar as estruturas do char e do coque podendo ser utilizada para quantificar a proporção destes materiais carbonosos no pó de balão do AF. Além disto, observou-se que quanto maior a temperatura de tratamento térmico mais ordenada fica a estrutura cristalina do coque. / In a Blast Furnace (BF), Pulverized coal injection (PCI) is the most popular injection technology used worldwide to reduce coke consumption and to increase the productivity. In the last decades the PCI injection rates raised in the most of BFs. One of the problems during the PCI operation in BF is the unburnt char formation. Higher char levels in the BF stack could impact burden permeability. The off gas BF solid samples contain char, coke fines, metallic oxides, etc. The quantification of the carbonaceous materials content in these samples could be used to improve the PCI performance in operating BF. Chemical analysis in the BF dust samples reveal without differentiates some carbonaceous material. The optical microscopy was used to study these solid samples but with some restrictions. XRD (X-ray diffraction) is a standard means of characterizing the structure of materials. This technique has been utilized to determine the crystallite sizes (Lc, La, etc.), in carbonaceous materials. Since the coke structure is more ordered than the char structure, it would be possible to quantify the proportion of these materials in the off-gas BF samples by chemical analysis in combination with XRD. The aim of this work is to identify and quantify carbonaceous components (coal, char and coke fines) in the flue dust BF samples through the use of the XRD technique and ultimate analysis. Besides, the effect of temperature on coke graphitization will be studied aiming to identify the possible origin of coke fines in the BF dust. Four dusts collected in the off-gas BF, two at all coke and two at PCI operations, were selected for this investigation. The dusts were fractioned and chemically analyzed. After the fractions were grounded, demineralized and analyzed by ultimate analysis and XRD. Besides, were investigated the atomic structure of raw coals and its laboratory char, and raw coke and its laboratory heattreated samples. This study has shown that the XRD technique could be used as a standard procedure to identify the char and coke structures and could be used to quantify the fines proportions of these carbonaceous materials in the BF flue dust. It was concluded that the bigger the annealing temperature the more ordered becomes the atomic coke structure.

Abstract The blast furnace process is the most common way throughout the world to produce pig iron. The primary fuel and reducing agent in a blast furnace is coke. Coke is a fossil fuel and the most expensive raw material in iron production. Blast furnace ironmaking is an energy-intensive process, which results in high energy costs. Auxiliary fuels are injected into the blast furnace to replace expensive coke. They provide energy for the blast furnace operation and act as a source of reduction agents for iron oxides. Coke replacement with high auxiliary fuel injection levels leads to permeability changes in a blast furnace shaft, because of the increased amount of unburnt coal. In this thesis, fuel injection with two different auxiliary fuels, heavy oil and pulverized coal, was studied using computational fluid dynamics (CFD) modeling. The aim was to improve the combustion of auxiliary fuels by increasing the understanding of the phenomena in the blast furnace tuyere-raceway area. The atomization model for modeling the heavy oil combustion was selected and validated using the results of an experimental rig from the literature. The atomization model was applied to study the effect of different nozzles on heavy oil mixing with the air blast. In addition, the model was used to study the effect of lance position on the combustion efficiency of heavy oil. A pulverized coal combustion model was developed and validated with experimental data from the literature. Pulverized coal combustion was modeled with different lance positions to evaluate its effect on combustion efficiency. Based on the results, heavy oil mixing in the air blast can to a great extent, be boosted by the nozzle design. Furthermore, the heavy oil combustion is more efficient when the lance position is farthest from the tuyere nose. But the increasing temperature inside the tuyere causes ablation of the tuyere walls, which creates a constraint for the lance position. The results from the pulverized coal combustion study show that the model works well for the tuyere-raceway area. In addition, the effect of lance position on the combustion efficiency of the pulverized coal is very small, and the lance should be positioned as close to the tuyere nose as possible to avoid fouling of the tuyere walls and the ignition inside the tuyere. / Tiivistelmä Suurin osa maailman raakaraudasta valmistetaan masuuniprosessilla. Masuunin ensisijainen polttoaine ja rautaoksidien pelkistin on koksi. Koksi on fossiilinen polttoaine ja kallein raaka-aine masuunissa. Raudanvalmistus on erittäin energiaintensiivistä, joten valmistuksen energiakustannukset ovat korkeat. Lisäpolttoaineinjektiota käytetään masuunissa korvaamaan osa koksista sekä energian tuottajana että pelkistimenä. Injektiomäärät pyritään kasvattamaan mahdollisimman suuriksi, mutta injektiomäärien kasvaessa palamattoman kiinteän polttoaineen määrä kasvaa ja koksipatjan kaasunläpäisevyys heikkenee. Väitöskirjatutkimuksessa luotiin virtauslaskentamalli hormin ja palo-onkalon alueelle kahta lisäpolttoainetta (raskas polttoöljy, kivihiilipöly) varten. Sen avulla tutkittiin palamista hormin ja palo-onkalon alueella tavoitteena lisätä tietoa palamista rajoittavista tekijöistä. Pisaroitumismalli valittiin ja validoitiin kirjallisuusdatan perusteella raskaan polttoöljyn toimiessa lisäpolttoaineena. Mallia käytettiin tutkittaessa erilaisia suuttimia palamisilman ja polttoaineen sekoittumisen tehostamiseen. Lisäksi sitä käytettiin mallinnettaessa lanssin sijainnin vaikutusta raskaan polttoöljyn palamistehokkuuteen. Kivihiilipölylle luotiin palamismalli, joka validoitiin olemassa olevan kokeellisen datan perusteella. Tätä mallia hyödynnettiin tutkittaessa kaksoislanssin sijainnin vaikutusta palamistehokkuuteen. Tulosten perusteella voidaan todeta, että öljylanssin suuttimella on suuri vaikutus palamisilman ja polttoaineen sekoittumiseen. Lisäksi voidaan päätellä, että raskaan polttoöljyn palaminen tehostuu siirrettäessä lanssia syvemmälle hormiin, mutta syttyminen tapahtuu liian aikaisin ja kasvava lämpötila voi sulattaa hormin seinämät. Tämä aiheuttaa rajoituksen lanssin sijainnille hormissa. Kivihiilipölyn palamisen mallin todettiin toimivan erittäin hyvin hormin ja palo-onkalon alueilla. Tämän ohella havaittiin, että lanssin sijainnilla oli hyvin pieni vaikutus palamisasteeseen, jolloin lanssi kannattaa sijoittaa mahdollisimman lähelle hormin suuta, jotta vältetään hormiin kohdistuva ylimääräinen lämpökuorma ja hormin likaantuminen.