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Natural gas quality assessment is a relevant issue. A critical analysis of calorimeter designs for measuring the calorific value of natural gas was carried out. The most common methods for determining the calorific value of natural gas are as follows: direct by gas calorimeters; indirect by gas chromatographs; indirect, based on correlations. The advantages of isoperibolic calorimeters of measuring calorific value of natural gas directly in the consumer’s conditions are substantiated. The design of a portable calorimeter containing a thermostated shell, calorimetric tank, Peltier element with tank, circulating pump, gas burner, thermostat systems, metered supply of natural gas and air, fuel ignition, sensors, combustion analyzer and control and measurement unit, was developed. The geometric dimensions of the calorimetric tank are optimized, materials and technologies of manufacturing parts are specified. The metrological analysis of the developed portable calorimeter was carried out. A method for measuring the calorific value of natural gas directly in the conditions of household consumers and transport enterprises was developed. The results of testing the prototype calorimeter in the laboratory confirmed its high performance and metrological characteristics, and the deviation of the measurement of the calorific value of natural gas from that determined using a gas chromatograph was 0.6%.

Burning experiments are analyzed for 59 successfully ignited tests using a gas burner (BRE) to emulate the steady burning of 25 mm diameter flat surface materials. More than half of the tests resulted in long burns of at least 2 and as long as 5 min. Mixtures of ethylene and nitrogen allow for 23.6 and 47.2 kJ/g heats of combustion (LHV). Nominal ambient conditions range from 40% to 21% oxygen and pressures of 1 to about 0.56 bar. NASA human habitat atmospheres have been used. Generally, it has been found that nominal oxygen mole fractions of 26% and above can allow steady flames. The flames are thin blue in color and grow slowly over time for minutes. Some self-extinguish, some had periodic oscillations, and others appear to have become steady and were shut down. Theoretical analyses show the shutdown flames were steady in growth, and all of the test endpoints were more than 94% of steady state in flame heat flux. Flame heat flux for set mass flux allowed the estimation of heats of gasification to relate to steady solid materials that might burn in microgravity. Radiometers allowed the computation of flame radiative fraction that appeared to correlate well with the measured flame height. Results are shown for heat flux, flame height and base radius, radiative fraction as a function of fuel mixture mass flux, and various oxygen and pressure atmospheres.

Ignition within gas burner ejectors can lead to off design conditions and has significant influence on the burner behavior. Thus ignition in the ejector should be prevented. In the present study the influence of combustion reactions on the performance of gas burner injectors is investigated. To investigate if ignition is possible, simulated ignition delay times, using a detailed reaction mechanism, are compared to predicted mean residence times of the gas in the ejector. Gas burner ejectors are designed using one dimensional analytic equations, based on energy and momentum conservation equations and conventional isentropic equations. 1D results are compared to 2D computational fluid dynamics (CFD) simulations, to take into account non-ideal mixing effects along the ejector. Results are validated with experiments with air at room temperature. 1D results show very good agreement not only with CFD simulations for the case of non-reactive flows, but also with performed experiments. It is shown that the assumption of ideal mixing along the ejector and thus the comparison of the ignition delay time to the gas mean residence time, to predict ignition in the ejector, is not valid. Ignition in the ejector is possible, even if the ignition delay time is more than thirty times higher than the mean residence time. In addition to that, it is shown, that ignition and the choice of reaction mechanism have significant influence on the predicted gas burner ejector performance. Thus, the accurate prediction of ignition delay time and the use of a detailed reaction kinetic are mandatory to correctly predict the burner ejector behavior.

The paper presents results of theoretical numerical research dealing with CO and NOx emission performed in the process of optimization of the performance of low-power atmospheric burners. The theoretical part of this paper, whose main goals were better understanding of the complex issues of methodology and establishment of performance prediction and optimization of low-power atmospheric gas burner included numerical variation of independent parameters, such as burner geometry, the coefficients of primary and secondary air and different gaseous fuels including biogas. The findings of theoretically obtained performance prediction and optimization of atmospheric burners were experimentally investigated in purpose built test rigs for a number of variable parameters. The obtained results fully justified the proposed models of performance prediction and burner optimization.

The article discusses the design and operation features of two-wire gas burners developed at the Gas Institute of the National Academy of Sciences of Ukraine. These are jet-diffusion type burners and jet burners, the creation of which is based on the concept of burning gaseous fuels using a highly efficient unified tubular technology developed in conjunction with specialists from the National Technical University of Ukraine «Igor Sikorsky Kyiv Polytechnic Institute». A description of burners and burner devices of the jet diffusion type of the SG and SGL series is provided. The design of the SGL series burners provides for the possibility of interconnecting individual modules, which ensures the creation of heat generators of almost unlimited power. It is shown that such heat generators can operate in a wide range of excess air, this allows to get a coolant of any required temperature. Heat generators of this type operate in many industries. In jet burners created by tubular technology, as a result of the interaction of gas jets and air jets, diffuse gas flames are formed, which provide high reliability of the burners with possible fluctuations in the gas-air ratio. Also shown are the designs of burners created as a combination of these combustion technologies. The design of turbulent vortex burners, which provides a high degree of stabilization of the flame through the use of a central jet diffusion burner, is described. These burners are equipped with steam and hot water boilers, as well as melting furnaces. When operating these burners, it is possible to achieve 10 % of the natural gas consumption of the nominal load, which allows the operation of heating furnaces in the hot reserve with short-term shutdowns of technological equipment. Библ. 15, рис. 12.

Introduction. Currently, the industry produces a wide range of foam generators to produce fire-extinguishing foams, and the foams they produce differ significantly in their expansion ratio and, consequently, fire resistance. Since heat fluxes have the main destructive effect on the foam, the purpose of this paper is to establish the patterns of destruction of foam of different expansion ratio when heated.Methods of research. The foam with expansion ratio from 7.5 to 80 was used for the tests. It was obtained by mechanical beating of 6 % solution of foaming agent PO-6RZ. The thermal stability of the foam was studied when the heat flow from the gas burner flame affects the foam layer. During the experiment, the change in the height of the foam column in time was recorded.Results and Discussion. The results of measurements, presented in the form of dependence of foam layer destruction rate on time, quantity of released liquid phase on 1 m2·s, dependence of foam layer destruction rate on its density allowed revealing a number of patterns. The destruction rate of foam with an expansion ratio of up to 30 remains constant throughout the entire duration of thermal exposure. As the foam expansion ratio increases, the rate of destruction at the initial stage of heat flux exposure increases. With a foam expansion ratio of more than 50, there is initially a sharp increase in the rate of destruction, which subsequently decreases as the foam column decreases. In the conditions of the experiment, the best characteristics were shown by the foam with an expansion ratio of 50, because in the foam with a smaller expansion ratio the syneresis makes a significant contribution to its destruction, and the foams with a larger expansion ratio are destroyed by the mechanical effect of convective flame flows.Conclusion. The study of the foam destruction patterns under thermal impact allowed establishing the fact that its destruction is limited by the rate of impoverishment of the upper layers with liquid.

Evaporation of a water–methanol solution droplet is experimentally studied. This process is mathematically modeled. Based on the results of a comparative analysis of the results of physical and numerical studies, the parameters of the evaporation of a water–methanol solution droplet are determined for the purpose of using its combustion in mathematical modeling. The results of numerical studies of the combustion of a gas flame with the injection of the water–methanol solution droplets into it in an industrial plant are presented. These results satisfactorily correlate with experimental data.

Studies have been carried out on the purification of biogas from sulfur compounds, carbon dioxide and water vapor for subsequent use in micronizer burners. The possibility of bringing it to the parameters of natural gas of the following composition: methane (CH4) – 85 % vol., carbon dioxide СО2 – 11 % vol., water vapor – 9 mg/m3, hydrogen sulfide H2S - 20 mg/m3 with minimal energy costs for its preparation is demonstrated. The basic relationships are obtained for assessing the design and technological parameters of the infrared radiation burners operation. Experimental studies of the flame stability limits on perforated ceramic nozzles have shown that flashback through them is possible when the thermal power is increased to a certain critical value. In this case, the thermal power depends on the type of gas and the air content in the combustible mixture. The heat balance equations have been derived to optimize the designs and operation modes of infrared radiation burners. The design of 40 gas burners was improved by changing the geometric dimensions and shape for a uniform distribution of biogas supplied and sustainable combustion over the entire area of the burner. It was established that the temperature of the heating surface of the GIK-8 burner on gas mixtures with a CO2 content of 18-34 % is 900-950 ° C, which does not differ from the nominal temperature when operating on natural gas. The infrared heating system was modernized, adapted for burning purified biogas with methane content up to 98 %, in particular, the biomethane feed and control system, the additional biogas input system, and the automatic burner control system were improved.

The fire modeling community currently lacks full-scale data from tests conducted in realistic residential-style structures. Controlled gas burner tests were conducted in purpose-built single- and two-story structures instrumented throughout with thermocou- ples, pressure transducers, and bi-directional probes. Experi- ments consisted of sequences of ventilation events. The data collected in these tests was intended to provide several new val- idation cases for the fire modeling community.

This paper presents the results of an experimental study on the combustion process of methane mixed with NH3 in flameless mode. At a time of striving for CO2-free power, NH3 became a potential energy storage carrier fuel from renewable sources. Flameless combustion features low emissions and is a very efficient technology used in the power sector, as well as steel production, ceramics, etc. Industrial furnaces were tested in the context of pure methane combustion with an addition of NH3, up to 5%. Flameless combustion conditions were achieved with a regenerative gas burner system (high regenerative system). The burner consists of four ceramic regenerators allowing for continuous preheating of air, even up to 50 K lower than the temperature of the combustion chamber wall. Constant power of the introduced fuel was kept at 150 kW and the fuel-air equivalence ratio ranged from 0.75 to 0.95. The results have shown a growth of molar fraction of NO in flue gases when NH3 content in the fuel rose. The increase is more significant for the tests with a higher amount of oxygen in the combustion chamber (a lower fuel-air equivalence ratio). An addition of 5% of NH3 into the fuel caused an emission of NO at the levels of 113 ppmv and 462 ppmv (calculated to O2 = 0%), respectively for low and high fuel-air equivalence ratios.

The improvement of thermodynamic and environmental indicators of energy facilities is a vital and topical problem. Numerical simulation methods are used to investigate the processes of combustion and formation of hazardous substances by computation, and to work out recommendations on increasing the effectiveness of fuel combustion. The paper examines the impact of atmospheric air humidity on the process of combustion of a stoichiometric methane-air mixture in a burner. The combustion process is simulated in the 3D unsteady statement in Cartesian coordinates. In the investigation, the combustion of the methane-air mixture is considered in one stage. Air humidity is considered in the 0 to 100% range. The monoxide nitrogen formation process is described using the extended Zeldovich-Fenimore mechanism. A comparative study has found that increasing air humidity up to 100% reduces the mass emission of monoxide nitrogen by a factor of 1.27, as compared to dry air. The study results can be used for designing equipment that uses methane as fuel.

On the basis of gas-burning devices of the GS series, new devices have been developed, in which gas channels are installed for operation in the mode of maximum or minimum flame length. This allows to increase the stability of the flame at low temperatures of the working space (below the natural gas ignition temperature), which in turn provides an increase in the economic performance of the tunnel kiln firing ceramic bricks. Bibl. 5, Fig. 2.

Gas burner has been widely utilized to many industrial fields and personal outdoor activities and so on. Portable small-sized gas burner is, especially, useful in personal outdoor activities. The performance and safety of portable small-sized gas burner is important because it uses gas as fuel. The purpose of this study was to investigate the possibilities of performance improvement of portable small-sized gas burner through flow and structural analysis, respectively. As the results, it showed that mass fraction of butane gas in all cases(Type 1, Type 2, Type 3) was about 12~18% and further safety load of 3 stand leg was below 10 kgf.

The performance of thermodynamic cycle strongly depends on the properties of working fluids. A gas-fuelled hot water system based on coupling of an organic Rankine cycle and an air source heat pump cycle (ORC-ASHP) was investigated in this paper. This system is integrated with a gas burner to provide heat for ORC. The power generated in ORC is used to drive the air source heat pump cycle. Comparisons on the system performance are presented for seven different organic working fluids, with emphasis on the effect of thermodynamic properties of the working fluids. In terms of fuel-to-heat efficiency, benzene, toluene and cyclohexane have better performance for the high temperature heat source. The results indicate that working fluids presenting higher decomposition temperatures shows a higher fuel-to-heat-efficiency. When benzene is used as working fluids, the fuel-to-heat efficiency reaches 161.7% and 139.47% to provide 50 °C and 65 °C hot water respectively.

The accuracy of the exhaust flow measurement contributes significantly to the uncertainty of calorimetry measurements for large fire testing. Less than ideal flow characteristics such as skewed velocity distributions are typical of these large-scale flows and make it difficult to achieve the desired measurement accuracy. Consensus standards for fire testing recommend either bi-directional probes or orifice plates to determine exhaust flow. Both have limited accuracy in the presence of less than ideal flow conditions. Averaging pitot probes are an off-the-shelf technology widely used to monitor flows for industrial processes. They have been utilized in a system of large fire calorimeters to demonstrate differences of less than 5% between heat release rate measurements by oxygen consumption calorimetry and the theoretical heat output from a gas burner. Differences exceeded 5% for a small set of conditions but were still less than 10%. Both levels of agreement are within the confirmation requirements of the consensus standards and were achieved without a system calibration as recommended by the standards. Including this technology as an alternate method to measure exhaust flow would be an improvement to relevant fire testing standards and to the overall accuracy of calorimetry measurements for large fire testing.

The combustion effect of natural gas-air mixed combustion is optimised through an effective and rational design of the burner structure, thereby reducing the emission of atmospheric pollutants and achieving energy saving and emission reduction. This paper starts from the geometric model of the burner and uses Computational Fluid Dynamics (CFD) technology to numerically simulate the combustion distribution in the burner, which results in the combustion distribution of the burner after optimising the structure. The guiding effect of the blower guide vanes on the airflow is weak, and the back pressure effect of the guide vanes mounting body is significant, which reduces the primary air volume and prolongs the combustion history in the central region of the flame; The temperature field is evenly distributed and the combustion is well distributed; CH4 and CO in the furnace chamber are basically burned out and the NO concentration in the furnace chamber is about 800 ppm, which basically meets the emission standard and the combustion effect is good. This paper has certain guiding significance for the study of burner structure.

Reinforced concrete (RC) submerged floating tunnels (SFTs) represent a possible solution for crossing wide, deep fjords, and is considered for the E39 highway route along the Norwegian west coast. With regard to SFTs, the specific accidental scenario that is under investigation is the combined action of fire and subsequent internal explosion, as this is a crucial safety design condition for this type of structure. To assess the structural performance of reinforced concrete structures under combined fire and blast actions, gas burner equipment and a shock tube device were used to generate high temperature and blast loading, respectively, on RC circular slabs. A proper set of instruments consisting of thermocouples embedded in the specimens, accelerometers and ultrasonic pulse velocity (UPV) equipment made it possible to capture the behaviour of the slabs under the combined fire and blast actions and to distinguish the specific role of fire and blast. Simplified numerical tools such as an equivalent elastic single degree of freedom (SDOF) model and a linear elastic finite element (FE) model were used to interpret the experimental results. By considering all combinations of three fire exposure times and two shock waves, the effect of damage accumulation from a combined action of fire and subsequent internal explosion was mapped. A reliable benchmark for numerical models was obtained.

One of the main methods used to generate thermal energy is the combustion process. Burners are used in both industrial and residential applications of the open combustion process. The use of fuels that reduce polluting gas emissions and costs in industrial and residential processes is currently a topic of significant interest. Hydrogen is considered an attractive fuel for application in combustion systems due to its high energy density, wide flammability range, and only produces water vapor as waste. Compared to research conducted regarding hydrocarbon combustion, studies on hydrogen burners have been limited. This paper presents the design and evaluation of an oxyhydrogen gas burner for the atmospheric combustion process. The gas is generated in situ with an alkaline electrolyzer with a production rate of up to 3 sL min−1. The thermal efficiency of a gas burner is defined as the percentage of the input thermal energy transferred to the desired load with respect to a given time interval. The experimental results show a thermal efficiency of 30% for a minimum flow rate of 1.5 sL min−1 and 76% for a flow rate of 3.5 sL min−1. These results relate to a 10 mm height between the burner surface and heated container.

Concrete is prone to spalling when exposed to fire. During fire tests, the strains of concrete elements are hard to identify, both from the fire-exposed face and the non-exposed face. This paper presents a field experiment which employed the original CivEng digital image correlation (DIC) method developed at the Cracow University of Technology to measure the strain fields of elements exposed to heating by a pin-point gas burner. The paper presents experimental proof that it is possible to analyze the deformation of both unheated and fire-exposed sides of heated concrete by the DIC method. The strain fields, crack patterns and modes of crack development are presented. The study shows the encouraging results of employing the DIC method to test concrete behavior under fire attack.

Магістерська дисертація на здобуття ступеня магістра за освітньо-науковою програмою підготовки на тему «Застосування інноваційної мікрофакельної технології газоспалювання для підвищення енерго-екологічної ефективності котла КВГМ-20»: 86 с., 31 рис., 26 табл., 5 дод., 25 джерел. Об’єкт дослідження – процеси факельного спалювання природного газу у топках водогрійних котлів КВГМ-20. Мета роботи – на основі комплексного аналізу та моделювання процесів сумішоутворення природного газу та повітря у штатному та мікрофакельному пальникових пристроях котла КВГМ-20 розробити технічні рішення покращення енергетичної ефективності та рівня екологічної чистоти роботи котла. В роботі на основі результатів літературного огляду за напрямком досліджень, моделювання на 3D-моделі та натурних випробувань доведено недосконалість процесів сумішоутворення, суттєву нерівномірність розподілу швидкостей та теплових потоків у топці котла і, як наслідок, низький рівень енергоефективності та екологічної чистоти енергоперетворення при роботі штатного регістрового пальника, розглянуто економічні та екологічні передумови та доцільність використання нових газоспалювальних технологій. Запропоновано для використання в даному котельному агрегаті унікальну уніфіковану і універсальну інноваційну мікрофакельну технологію спалювання газоподібного палива з високим рівнем енергоефективності та екологічної чистоти. За результатами проведеного моделювання та експериментів отримано аналітичні та емпіричні характеристики аеродинамічних і теплових особливостей роботи топки котла КВГМ-20 з пальниковою системою на базі мікрофакельної технології, які свідчать про наявність комплексу позитивних ефектів. Отримані результати дозволяють з використанням мікрофакельної технології газоспалювання підвищити рівень ефективності та екологічної безпеки експлуатації з одночасним подовженням робочого моторесурсу котла за рахунок здійснення короткострокової і маловитратної модернізації його пальникової системи. На базі запропонованих рішень розроблено стартап-проект, щодо застосування мікрофакельної технології в умовах українського енергоринку. Master's thesis for obtaining a Master's degree in an educational and scientific training program on the topic: “Application of innovative micro-flare gas combustion technology to increase the energyenvironmental efficiency of the KVGM-20 boiler”: 86 p., 31 figures, 26 tables, 5 appendixes, 25 sources. The object of study is the processes of micro-flare combustion of natural gas in the furnaces of boilers KVGM-20. The purpose of the work is to develop technical solutions for improving energy efficiency and the level of ecological cleanliness of the boiler operation on the basis of complex analysis and modeling of natural gas and air mixing processes in standard and micro-flare burners of KVGM-20 boiler. Based on the results of literature review in the field of research, 3D modeling and field tests, the imperfection of mixing processes, significant uneven distribution of velocities and heat flows in the boiler furnace and, as a consequence, low energy efficiency and environmental cleanliness of energy conversion burner, economic and ecological preconditions and expediency of using new gas combustion technologies are considered. A unique unified and universal innovative micro-flare technology of gaseous fuel combustion with a high level of energy efficiency and ecological cleanliness is offered for use in this boiler unit. According to the results of modeling and experiments, analytical and empirical characteristics of aerodynamic and thermal features of the KVGM-20 boiler furnace with a burner system based on microflare technology were obtained, which indicate the presence of a set of positive effects. The obtained results allow to increase the level of efficiency and ecological safety of operation with the use of micro-flare gas combustion technology with simultaneous extension of the working motor resource of the boiler due to short-term and low-cost modernization of its burner system. Based on the proposed solutions, a startup project has been developed for the application of microflare technology in the Ukrainian energy market. Магистерская диссертация на соискание степени магистра по образовательно-научной программе подготовки на тему «Применение инновационной микрофакельной технологии газосжигания для повышения энерго-экологической эффективности котла КВГМ-20»: 86 с., 31 рис., 26 табл., 5 доп., 25 источников. Объект исследования - процессы факельного сжигания природного газа в топках водогрейных котлов КВГМ-20. В работе на основе результатов литературного обзора по направлению исследований, моделирования на 3D-модели и натурных испытаний доказано несовершенство процессов смесеобразования, существенную неравномерность распределения скоростей и тепловых потоков в топке котла и, как следствие, низкий уровень энергоэффективности и экологической чистоты энергопреобразования при работе штатного регистрового горелки, рассмотрены экономические и экологические предпосылки и целесообразность использования новых газоспалювальних технологий. Предложено для использования в данном котельном агрегате уникальную унифицированную и универсальную инновационную микрофакельную технологию сжигания газообразного топлива с высоким уровнем энергоэффективности и экологической чистоты. По результатам проведенного моделирования и экспериментов получены аналитические и эмпирические характеристики аэродинамических и тепловых особенностей работы топки котла КВГМ-20 с горелкой системой на базе микрофакельной технологии, свидетельствующие о наличии комплекса положительных эффектов. Полученные результаты позволяют с использованием микрофакельной технологии газосжигания повысить уровень эффективности и экологической безопасности эксплуатации с одновременным удлинением рабочего моторесурса котла за счет осуществления краткосрочной и малозатратной модернизации его горелочной системы. На базе предложенных решений разработан стартап-проект по применению микрофакельной технологии в условиях украинского энергорынка.

Boilers have contributed significantly to the production of energy and other processes in industry. Understanding the combustion characteristics inside a boiler is essential to increase the efficiency and reduce environmental-related concerns. The novelty of this work is associated with a detailed analysis of the effectiveness of a developed co-firing coal-natural gas burner and the arrangements of the burners in the boiler for efficient combustion. Comparisons were made between the front-wall, the opposite-wall, and the tangential firing types. The characteristics of the flow, the coal particle motion, the temperature distribution, the concentrations of species, and NOx emission levels are examined. The results showed that each burner in the front-wall-fired type creates independent long flame zones. In an opposite-wall fired type, the flames of burners impinge upon the center of the furnace to create turbulence. Results show that front-wall and opposite-wall firing configurations exhibit hot peak zones and temperature imbalances near the furnace sidewall. This emphasizes the need for heavily swirling vanes in the main burner to shorten the flame length and mix the fuel and oxidant well for efficient combustion. The state-of-the-art tangentially fired configuration produced a fireball, ensuring thorough mixing in the furnace and allowing for the complete combustion and uniform distribution of the temperature such that NOx reduction occurs preferentially. Additionally, these results confirm the advantage of combusting coal with natural gas in the main burner, as doing so reduces NOx emissions up to 19%. The technological options identified offer potential for interested manufacturers, researchers, and others in related industries to improve the performance and reduce the emissions of industrial dual-fuel-fired combustion utilities.

Thermal barrier coatings (TBCs) as a kind of temperature-resistance materials have been widely applied in super high temperature components in aircraft engines. However, TBCs are subjected to harsh service environment such as high temperature oxidation and erosion, which lead to the coating failure. It is important to investigate the effect of fire temperature, angle and velocity of particle on erosion to understand the failure mechanism. In this paper, the temperature and velocity distributions of erosion particles in high temperature gas burner rig are investigated by using the fluid–solid coupling method with the discrete random walk model. The results show that a non-uniform distribution of temperature appears in different positions of the central axis, and the temperature of particle is affected obviously by the gas stream and particle size. The trajectory of particles and velocity diagrams under different particle size are determined by coupling the continuous phase with the erosion particles.

This paper concerns the flame extinguishing with the use of acoustic waves. A small laboratory stand allowing to generate acoustic waves in the horizontal direction was used for that purpose. The speaker extinction power and the acoustic extinction pressure were selected to quantify the process. Varying frequencies (30–50 Hz) burner powers (3.45-11.72 kW) and distances between the acoustic source and the flame (0.02–0.06 m) were investigated. It was shown that the lower the frequency is it is easier to extinguish the flame. It was also found that the fuel load has a minor impact on the extinction pressure. The results are supplemented with the visualisation of the flame behaviour under the influence of acoustic waves performed with the use of Schlieren apparatus. It was shown that the extinction is a result of cumulative effect of acoustic mean flow and oscillatory perturbations.

The thermal radiation impact of organic peroxide fireballs is experimentally assessed using an infrared camera. Fireballs are generated while liquid peroxide filled steel drums are subjected to gas burner fire at different heating rates. Three large burning clouds are observed with varying flame characteristics. Thermal radiation properties are assessed by infrared images with the presented methods. Despite of the two-dimensional temperature fields, the flames are treated and characterized as three-dimensional objects. Fireball diameters and heights are calculated based on a representing radiating sphere with the same cloud volume. By the use of the solid flame model and assumptions for emissivity and transmissivity, heat fluxes and thermal radiation doses against distance are predicted. Thermal safety distances are presented based on the maximum irradiance and the allowed exposure time. The validation of the maximum and time-dependent radiation fields is achieved through heat flux sensors in varying distances to the fireball. The results prove the use of an infrared camera and a volume based size calculation to fully assess the thermal radiation hazards of fireballs.

Controlled gas burner experiments were conducted in single- and two-story residential style structures instrumented with pressure transducers, thermocouples, and bi-directional probes throughout the structures. Exterior doors and window openings were vented in a controlled sequence to investigate the effect of the resulting flow paths on fire-induced flow dynamics and thermal conditions in the structures. The data collected in these experiments provides validation cases for the fire modeling community which currently lacks full-scale data from experiments in realistic residential style structures. The Fire Dynamics Simulator was used to model each scenario in a validation exercise that also investigated the sensitivity of the pressure predictions to the model parameters. The model was capable of predicting the qualitative changes in pressure measurements due to ventilation events as well as the apparent elevation of the neutral plane. Peak pressures were predicted to within 6% on average and quasi-steady static pressures were predicted to within 24% on average. The mean instantaneous error between the experimental pressures and those predicted with the “Localized Leakage” method was approximately 53% compared to 67% with the “Pressure Zone Leakage” method prior to the first ventilation event.

Burning experiments are analyzed for 29 steady burning flames using a gas burner (BRE) to emulate condensed-phase burning of 25 mm diameter flat surface. Mixtures of ethylene and nitrogen allow for 23.6 and 47.2 kJ/g heats of combustion (LHV). Ambient conditions range from 21 to 40% oxygen and pressures of 0.56 to 1 bar. The results are compared to predictions from analytic models developed to determine the flame radiation fraction, flame convective and radiative heat fluxes, flame shape, and heats of gasification for steady burning. Steady burning is theoretically decided by ensuring the flame temperature is above a critical value of 1100 K. Good agreement is achieved between experiment and predicted steady results. Further computations are made to determine the effect of ambient pressure and oxygen on burning for heats of combustion of 23.6 and 47.2 kJ/g, diameters up to 100 mm, and vaporization temperatures of 80 and 350 oC. It is found that for the range of analyzed conditions, heats of gasification of about 1 to 5 kJ/g, steady burning would result over a range of about 1 to 6 g/m2s. Low pressure appears to yield more stable flames. The results have implications on how the fire safety of materials in microgravity should be determined.

In this paper, a series of experiments was conducted by using a gas burner to characterize the flame geometry under the inclined surface condition and trench configuration. The inclination angle was systematically varied from 0° to 26°. The centerline temperature distribution of the inclined surface was measured and the flame geometry parameters were obtained by the post-processing of the side-view images. Results show that the flame tilt angle appears a linear decrease with the increase of the inclination angle for both the inclined surface and trench configuration experiments, and decreases faster for the trench configuration. The flame length shows a non-monotonic variation with the inclination angle and a transformation process of flame from the plume-type to attachment type is observed. There is no significant effect of the aspect ratio on the flame geometry parameters. The flame attachment length fluctuated with time was obtained. A variable-interval time-average (VITA) method was used to determine the level-crossing rate and the peak frequency location. The peak frequency location has a linear relationship with the horizontal flame length. The flame attachment length and the centerline temperature increase sharply from 15° to 20° under the inclined surface condition, indicating the occurrence of flame attachment.

The flame attachment behaviors over an inclined surface were investigated by a gas burner, and its effects on the temperature, heat flux, and the velocity distribution were explored by the heat flux meter, infrared thermography and particle image velocimetry (PIV) systems. The results showed that a sudden increase in flame attachment length occurred when the inclination angle of the surface increased from 15 to 20o, which caused the sharp increase of the temperature, the heat flux as well as the flame spread parameter ψ . Combined with PIV, it was found that a large velocity difference appeared between the upstream and downstream of the flame when the inclination angle increased from 15 to 20o. The vortexes induced by the velocity difference moved upward periodically along the edge of the flame, increased the turbulence intensity and accelerated flame attachment greatly. By introducing the local Richardson number (Rix) and the dimensionless local total heat flux, it was found that the plume was dominated by the momentum near the burner while dominated by the buoyancy in the distance. The turning point of the two regimes occurred at the ratio between the flame length to the burner hydraulic diameter of 0.5 and Rix ≈10, and the local heat flux distribution of downstream fire was further obtained.

Natural gas, when compared to other solid, liquid or gaseous fuels, offers a cleaner and more environmentally friendly combustion. Nevertheless, it also produces unwanted pollutant species such as nitrogen oxides (NOx) and carbon monoxide (CO) when fired in combustors of industrial gas turbines under high temperature and pressure. These emissions of NOx and CO are harmful for human and nature and need to be kept below the regulatory limits. This problem has been the subject of numerous research and development activities for decades. The current state of the art provides well-developed firing systems for industrial gas turbines, which ensure NOx and CO emission levels well below the legal limits [1 - 5]. A comprehensive overview of the characteristics currently available gas turbines on the German market is offered by the revised version of the ASUE brochure from 2015 in [6], where beyond the reference list about industrial and municipal gas turbines, NOx reduction methods and achieved NOx emission values are recorded. Nevertheless, there still is the need for additional research in order to contribute to both the simplification of the still complicated design of the overall combustor concepts and the further reduction of harmful emissions.

In order to ascertain the effects of the hydrogen addition and the primary air-fuel ratio on burner performance and emissions, we conduct tests on a commercial atmospheric gas burner using pure methane and a blend of hydrogen/methane. Relevant statistical image features are extracted from a UV–VIS camera equipped with narrow-band optical filters. Radical image results agrees with spectrometric data, showing the relevance of the OH∗ intensity radiation coming from the outer non-premixed zone. The double-cone flame structure is evident, showing a growing secondary non-premixed cone as the primary air-fuel ratio is decreased. In addition, the direct relationship found between flame radical imaging features and NOx emissions has been used to develop a predictive model by integrating classification techniques and neural networks. The research confirms UV–VIS chemiluminescence imaging techniques as powerful tools aimed at combustion monitoring, with huge prospects of being integrated within advanced emission control techniques for commercial burners.

The thermo-chemical biomass gasification is a technique by which a combustible gas called Producer Gas (PG) can be generated from biomass. The raw PG can be directly burnt in a gas burner for heating application. If PG is required to be used in internal combustion engines or to be used as a chemical feedstock for the manufacture of various chemicals, then the raw PG must to be cleaned to remove tar, particulate matter and water vapour. Many gas scrubbing methods are available to clean raw PG. Refrigeration is a method in which the raw PG is cooled to a low temperature so that the water vapour present in PG can be condensed and removed from it. Some of the volatile matter also get condensed as tar. The condensed water would wash away a certain quantity of tar and particulate matter, thus helping in their separation from the main PG stream. So, knowledge of specific humidity of PG + water vapour mixture is essential in order to properly design a refrigeration system for treating raw PG, downstream of a large scale biomass gasifier. The cooling load on the refrigeration plant can be calculated precisely from the knowledge of specific humidity of PG + water vapour mixture, mass flow rate of PG and its enthalpy. In this work, a correlation has been developed to determine the specific humidity of PG + water vapour mixture in the temperature range of 20°C - 60°C, at an absolute pressure of 1.013 bar. The composition of dry PG assumed in the present work is CO: 17%, H2: 18%, CH4: 2%, CO2: 14% and N2: 49%. The result has been compared with those of air + water vapour mixture, natural gas + water vapour mixture and martian atmosphere + water vapour mixture which are available in the literature.

In the field of industrial furnace construction, the radiant tubes used for heating are critical components. The radiant tubes, which contain a gas burner, are used for separating the oxidizing gas from the furnace atmosphere. An industrial furnace used e.g. for heat treatment of steel strip consists of several hundreds of radiant tubes. Mechanical stresses reduce the lifetime of radiant tubes considerably. For profitable use, a long lifetime is crucial. Therefore, an expanded lifetime of radiant tubes is one of the most decisive parameters in the design of industrial furnaces. This work deals with the capability of radiant tubes made of structured steel sheets. The objectives are a significant increase in lifetime as well as material savings. In addition, further advantages such as an increase in radiant surface are aimed at. The tubes were deformed in a Zwick/Roell testing machine. A vault structured tube and tube without surface structuring were compared with respect to force compensation effects and creep strength. The experimental results were supported by FEM simulation. The compensation of the maximum stresses and deformation is verified by simulation, which explains the effect of structuring on the lifetime of radiant tubes., Procedia Manufacturing, 47, ISSN:2351-9789, 23rd International Conference on Material Forming

Heating sector is one of the key emitters of greenhouse gas, and thus innovations are needed to improve the energy efficiency of heating technologies. In this paper, a recently proposed gas fuelled heat pump system that integrates an Organic Rankine Cycle (ORC) with an air-sourced heat pump (ASHP) has been further investigated. The heat produced by the gas burner is used to drive an ORC power system to produce mechanical power, which is then directly used to drive a vapour compression heat pump. Two different designs of the combined system were modelled, and their performances were compared and analysed. In the first design, the cold water is firstly heated in the heat pump condenser and then further heated in the ORC condenser to achieve the required final temperature. In the second design, the water is firstly heated in the ORC condenser and then further heated in the heat pump condenser. The results showed that the first design can achieve better overall fuel-to-heat efficiency. Using Aspen Plus, a dynamic model has then been developed to study the optimal control strategies for this design when ambient air temperature changes. The results revealed that, for the ambient temperature ranging from 7 ˚C to 15 ˚C, increasing air mass flow rate is sufficient to maintain the overall system performance. While when ambient temperature is below 7 ˚C, more heat is required from the gas burner that would reduce the fuel-to-heat efficiency.