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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%.

The utilization of low calorific gas contributes to the energy conservation and environment protection. In order to improve the utilization efficiency, a porous media burner combining the alumina pellets and ceramic foam was established. The effects of the pellets diameter and pore density of ceramic foam on the combustion characteristics were studied, and the burner starting was also investigated to optimize the porous structure. The results showed that the maximum temperature increased first and then decreased with the increasing of pore density, but it decreased with the increasing of pellets diameter with certain conditions. The smaller pore density of the ceramic foam and the larger diameter of the pellets were conducive to the rapid start-up of the burner. Through the combination of ceramic foam and pellets from the radical direction, the flame can propagate quickly to the inside of the burner. As the inlet velocity increased, the flame location moved to the downstream layer. However, the flame location moved to the upstream layer with a higher equivalence ratio.

Experimental investigations of a new burner for gas ranges have been conducted. We present a modified construction diagram of a burner with a new heat-transfer intensifier in the form of tapered-screw fins on the surface of a metal rod that has shown its efficiency and made it possible to raise the cost effectiveness of natural gas combustion compared to a base burner.

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.

Cooking is an important domestic activity requiring energy. Traditionally, solid fuels, like firewood and charcoal, are used as the resources for supplying energy for cooking. However, burning of solid fuels inside the households causes indoor pollution and adversely affects the health of the users and other occupants. Various governmental and world bodies, like the UN, encourage people to shift from the traditional fuels to clean and sustainable options, of which gaseous fuel is an important one. Natural gas and liquefied petroleum gas (LPG), which are used for domestic cooking, are fired in gas burners designed for the cookstoves. Though the use of gaseous fuels lowers the household air pollution, early domestic gas burners were low in thermal performance with efficiency value of around 40%. Continuous research and development in the design and analysis of the stoves have led to a significant improvement in the thermal performance of commercial gas burners yielding efficiency exceeding 65%. Efforts are still on to improve the thermal and emission performance of the burners further without sacrificing user comfort and flexibility through innovative designs. This article presents a review on the design, development, and technological advancements in the gas burner technology for domestic stoves, and analyzes the effects of various parameters on their thermal and emission performance.

The present study investigates experimentally flame lengths in the two directions underneath a horizontal ceiling (x-direction: parallel to the longer side of the burner; y-direction: perpendicular to the longer side of the burner) produced by line-source fire. It is noted that the previous classical equations are limited for axi-symmetrical sources where only one-dimensional radial flame length is considered. They are non-applicable for the two-dimensional impinged ceiling flow induced by non-axi-symmetrical line-source in despite that it is also a basic source condition in fire science essentially and practically. Experiments are conducted employing a line-source gas burner using propane as fuel. The flame lengths due to impingement upon the ceiling in the two directions are measured, and their difference are quantified, at various heat release rates and ceiling heights. Experimental results show that the flame length in x-direction is shorter than that in y-direction. Their difference decreases with increasing of ceiling height, meanwhile increases with increasing of heat release rate. A new global formula is derived to describe the flame lengths underneath the ceiling based on the analysis of un-symmetrically distributed un-burnt fuel mass flows after impingement in the two directions reflected by their characteristic lengths, which are proposed to be the fire plume impinging zone characteristic dimensions in the two directions determined by the initial source dimensions, ceiling height and air entrainment. The proposed new function well represents the flame lengths globally in both directions. It provides for the first time a general model for describing the flame lengths underneath a ceiling of line-source fire plume impingement.

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.

Thermocouples were used to measure gas temperatures as a function of distance to the edge of a rectangular burner. Experiments varied the energy release rate, burner aspect ratio, wind speed, and s...

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.

A plasma electrical installation for gasification of various organic wastes has been developed. Its constituent parts are a hydraulic supply of packaged waste to the reaction zone, a gas burner with thermal power of 42 kW, an electric arc plasma torch with power of 50 kW, and a bottom melting ash chamber. In the test mode of electric furnace operation it has been shown that plasma gasification of organic materials produces a synthesis gas suitable for application in heat and electric power engineering. The results of thermodynamic calculations are in satisfactory agreement with the obtained experimental data.

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.

The results of an experimental study of a new gas burner that can be effectively used in domestic gas stoves are presented. The presented modified design of a burner with new heat-transfer enhancers made it possible to reduce heat loss to the environment and increase the efficiency of burning natural gas.

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 domestic cooking-gas burner consumed the highest amount of Liquefied Petroleum Gas (LPG) not over 5.78 kW ( 280 mmH2O) based on Thailand Industrial Standard (TIS 2312-2549) is modified by using the open-cellular porous media. The Nickel-Chrome (Ni-Cr) with pores per inch (PPI) of 8.5 and porosity (ε) of 0.92 is selected as porous media. To investigate the performance of a new cooking-gas porous burner, three outlet diameters of mixing tube (Dout) between primary air and LPG, i.e., 27, 35 and 43 mm., are examined. The temperatures at bottom vessel (TV) and water (TW) are monitored. The exhaust gas (CO and NOX) is also observed. Thermal efficiency (η) of three modified burners are estimated in accordance with TIS 2312-2549. From the experiment, the TVis increased with Doutleading to the boiling time (t) of TWfor reaching to about 99°C (depend on TIS 2312-2549) in the case of Dout= 43 mm gives the fastest. The CO and NOXof all burners are not difference and are in relative low level: CO is in the range of 140 to 180 ppm and NOXis not over 70 ppm. The ηthis raised with increasing Doutin which yield as 47.53, 52.86 and 54.77% for Doutof 27, 35 and 43 mm., respectively.

This study proposes a novel design of an atmospheric gas burner that introduces the concept of heat recirculation combustion by means of porous media combustion technology. A combustor and heat recirculation unit, used for preheating the combustion air, are part of the assembly of the porous material. The combustor is a self-aspirating annular porous medium burner (APMB) formed by a packed bed of alumina spheres with a diameter of 10 mm. A porous radiant recirculation heater was integrated into the APMB to obtain an elevated air temperature. To stabilize flames at the middle of the porous media packed bed, the flow velocity of the mixture has to be equal to the flame propagation velocity, making this a critical criterion for the design of the burner. A critical variable required to determine the flame velocity is the primary equivalence ratio. It was predicted using the empirical formula derived from the experimental data, and considers the momentum equation and pressure drop in the porous medium burner. Operation of the burner with firing rates from 21 to 44 kW resulted in evaluated air temperatures of 136–252 °C, yielding maximal temperatures greater than the adiabatic flame temperature. The NOx emissions were low because of the combustion within a porous medium. The CO emissions were high compared with the conventional burner but still conformed to the requirements of the national standard.

Fire risk analysis for cables in a vertical cable tray is important for fire protection design in nuclear power plants. One important characteristic of vertical cable tray fires is the upward spreading of the cable flame along the cable tray, which should be considered as a time-varying fire source. Experiments involving vertical cable tray fires with a spacing of 0 and 8 mm between cable lines were conducted in confined compartments with dimensions of 3 m × 3 m × 3 m (length × width × height). The cable in a 0.3 m wide × 2 m long vertical cable tray was ignited using a line-source gas burner of a 20-kW premixed flame system. The experiments indicate that a room with a vertical cable tray fire could be divided into three zones with respect to thermal characteristics. Notably, a middle zone having reduced temperature was observed, even though the intensity of burning did not decrease. By considering the effect of a time-varying fire source, an expression for predicting the ceiling jet temperature was proposed. For the prediction of the maximum ceiling jet temperature, the relative errors were less than 18.8%; for the entire cable fire process, the normalized Euclidean distances were less than 20.4%. The available literature data concerning a vertical cable tray fire in a confined room were used to validate this expression. It is further confirmed that the proposed expression predicts well the literature data for vertical cable tray fires in a confined space. This new expression can be used for estimating the hazards from a vertically spreading fire in a compartment in nuclear power plants.

In this study, a series of experiments were performed to investigate the flame height of double rectangular pool fires with different aspect ratios and distances in open space. Two identical rectangular gas burners with the same heat release rate were used as the fire sources. Four gas burners with the same surface area but with different aspect ratios were used. Different distances between two gas burners were considered. The experimental results indicated that the flame height decreased sharply with the increase of distance and subsequently exhibited a slight change with further increase of distance. The buoyancy force in the region between these two pools is the main factor to influence the flame height. A characteristic length D , which depends on the gas burner geometrical shape and distance, were proposed, and the experimental data indicate that the value of coefficient C decreases with the increase of D . A correlation has been achieved which can estimate the flame height of the rectangular pool fires with different aspect ratios in open space.

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.