Search

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.

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.

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.

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.

In climate regions with large seasonal variations in solar radiation, such as the Pacific Northwest of the United States, a solar thermal energy collector might not economically satisfy year-round domestic water heating demands, requiring an auxiliary unit, such as a natural gas-fired water heater. Previous studies have shown that the burner efficiency of a gas-fired water heater varies depending on the log-mean temperature difference between the cold fluid (water) and the hot fluid (combustion gases). In a solar/gas hybrid water heating system, where solar collectors are used in conjunction with a gas-fired heater, the partial heating of water provided by solar input reduces the log-mean temperature difference value for the gas heater, reducing the efficiency of the gas burner. Since this efficiency reduction varies depending on the amount of pre-heating provided by solar energy input, it is difficult to accurately predict the actual cost and energy savings offered by solar/gas hybrid water heaters in different climates and operation scenarios. Hence, to predict the actual energy and cost savings under various design conditions, the performance of solar/gas hybrid systems must be better understood. The objective of this work is to experimentally determine the thermal performance of a solar/gas water hybrid water heating system with a 6.44 m2 flat plate solar collector array and a 22.3 kW natural gas burner in Corvallis, Oregon, USA. Under different temperature lifts and solar insolation values, the system was operated at three different modes of heating: solar, gas, and combined solar/gas mode. The overall system thermal efficiency value for each mode is calculated. The efficiency of the solar collector heating system was found to be 41.97%, 39.82%, and 35.05% at initial water temperature of 20, 30, and 51.5 °C, respectively. For initial water temperatures of 20, 30, and 51.5 °C, the efficiency of the gas burner was found to be 69.2%, 66.4%, and 65.5% at the HHV, and 76.7%, 73.6%, and 72.6% at the LHV of natural gas, respectively. In the combined solar/gas heating mode, the efficiency of the gas burner decreased with increasing solar fraction. For solar fractions of 4.93%, 9.40%, 11.39%, and 14.27%, the efficiency of the gas burner in terms of the HHV of natural gas was found to be of 69.08%, 66.80%, 66.17%, and 65.18%, respectively. Based on the experimental results, a configuration that would provide higher overall system efficiency for combined solar/gas heating is suggested.

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.

Gas burner is the key component of coal-water slurry gasifier system. However, due to the sulfidation at high temperature, gas burner often fails in advance, which affects the stable operation of the system. In this work, Al-Mo coatings were deposited by plasma spraying with a Mo bonding layer. The sulfidation and oxidation behavior of the Al-Mo coatings was studied and compared with those of Mo coatings and Inconel 600 alloy at 973, 1073 and 1173 K. Results show that both the high-temperature sulfidation resistance and the high-temperature oxidation resistance of Al-Mo coatings are superior to those of Mo coatings. The high temperature sulfidation resistance of coatings is better than that of Inconel 600 alloy. Plasma-sprayed Al-Mo coatings with a Mo bonding layer are promising candidates for the corrosion protection of steels in a sulfur/oxide-rich atmosphere.

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.

A modular framework to model the steady off-design behavior of micro-CHP natural gas boilers based on Rankine technology is presented. The system charge integration into the model eliminates the use of any assumptions (i.e. subcooling, superheating, condensing pressure, etc.) which makes the presented model completely predictive. It is illustrated in the modelling a micro-CHP that satisfies the hot waters and central heating domestic needs (35 kWt) and produces electricity (≤1.5 kWe). A library of sub models of components with empirical (rotary vane pump and vapor scroll expander), semi-empirical (compact plates condenser) and spatially detailed physical (gas burner and evaporator) models is used to construct a model, using R245fa as thermal fluid. The model is calibrated and validated in tests in which 0.1 kg/s of water was heated from 20 °C to 30–36 °C, and 80–500 W mechanical power was delivered at the expander shaft, sweeping restrict ranges of three control variables: burner thermal power of combustion (10–14.5 kWt), pump (500–740 rpm) and expander (2500–2750 rpm) rotation speeds. The model predicts most output variables with acceptable errors, e.g., less than ±10% for the expander outlet pressure (190–220 kPa, abs) or the temperatures at the outlet of the evaporator (80–150 °C) or the expander (60–120 °C).

Biomass as carbon-neutral fuel is a promising alternative to mitigate global warming problems. Biomass conversion into producer gas (PG) through air gasification allows the co-firing of PG burners with fossil fuel burners in boilers for large scale power generation. However, PG is highly diluted with nitrogen which reduces the heating value resulting in significantly higher PG flow, eliminating the possibility of using conventional compact gas burner designs. To burn the low-grade PG, special design for the combustor is required. Novel combustor design which combined three theories of swirl vane, cyclonic and staged combustion to facilitate PG combustion in compact geometry was elaborately investigated. Flow hydrodynamics and combustion characteristics of low-grade PG were studied using ANSYS-FLUENT simulation software. Design of Experiments (DOE) method was applied to optimize the design of the combustor geometry. The arrangement of simulations was designed based on the instruction of DOE. The optimum geometry design of combustor was 500 mm combustor length, 150 mm combustor diameter, 60° swirl vane angle and 0.4 secondary inlets position to total combustor length ratio. The combustor achieved optimum performance of 1965 K outlet temperature, 18 ppm CO emissions and 33 ppm NOx emissions at slight lean condition with equivalence ratio of 0.9.

Multiple fire interaction is a fundamental combustion phenomenon which often occurs in forest fires and urban fires. This paper presents a systematical study of two identical buoyant fires on a slope in a facility consisting of a slope apparatus and a couple of gas burner systems. The test repeatability is justified for the proposed facility. The effects of fire spacing, fire power, slope angle and burner layout are intensively investigated on the flame merging probability and flame geometry of two interactive fires. The flame merging probability is found to well correlate the spacing normalized by the flame height of no spacing, and the variation of flame merging behavior with spacing can be divided into the consistent, intermittent, and independent regimes. However, the burner layout affects the critical dimensionless spacing that distinguishes the three regimes, due to the difference of air flow field between the side by side and tandem layouts. Data analysis clarifies the effect of slope and spacing on the flame length, flame tilt angle and flame attachment length, and a semi-empirical correlation is developed for the flame height of no spacing.

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.

A series of 1:20 small-scale tunnel experiments have been carried out as a scaled down representation of a previously undertaken large-scale heavy goods vehicle (HGV) cargo load tunnel fire experiment. The small-scale tunnel has dimensions of 0.365 m (W) × 0.260 m (H) × 11.9 m (L) and a maximum forced ventilation velocity of 0.68 m/s is adopted corresponding to the velocity of 3 m/s used at large-scale. A gas burner and cribs constructed of medium density fireboard (MDF) have been used as the fuel sources with temperatures, heat release rate (HRR) and velocity data recorded in the small-scale tunnel experiments. A scaled down HRR curve derived from the large-scale experiment was reproduced by the gas burner. Temperatures in the small-scale gas burner experiment can effectively represent those at large-scale during the fire growth and decay stages although measurements at the fully developed stage are lower than the results from the large-scale tunnel experiment. In the small-scale tunnel experiments using the cribs time delays are applied to correct the recorded data in order to obtain the instantaneous HRR. Temperature profile comparisons between the small-scale crib and large-scale HGV cargo load experiments are not applicable since the HRR curves from the crib experiments only approximately reproduce the large-scale HRR profile.

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.

To study the influence of stack effect on air flow and flame shapes of gas burner fires, a set of experiments was conducted in a 1/3th scale building model. One 0.15 m square porous gas burner with propane as fuel was used with 6 different HRRs (heat release rates) of 13.54, 27.08, 40.63, 54.17, 67.71 and 81.25 kW. The window at different floors was opened respectively for different HRRs. Results show that the upper average smoke temperatures in the fire room are higher than that in the atria for the smaller HRR. With the increase of HRR, the upper average smoke temperatures in the fire room are lower than that in the atria. The heat pressure induced by smoke in the stairwell increases with the HRR and the height of opened window. The relationships between the non-dimensional air flow velocity, HRR and height from fire source to the centerline of opened window are put forward based on the experimental results. The non-dimensional mean flame length is also proportional to the 2/5 power of non-dimensional HRR, but shows smaller than the Heskestad’s equation. For the propane porous gas burner, whose HRR is independent of the heat feedback to the burner surface, the average flame tilt angle increases with HRR, but the increment becomes relatively small for the larger HRR.

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.

Three dimensional numerical simulations were performed to optimize the geometrical parameters of a fuel-staged low NO x gas burner. The effect of the primary gas injection angle (α), the staged gas injection angle (β) and position of the staged gun (H) on flame size and NO emission was analyzed based on the contours of temperature, stoichiometric mixture fraction, rate of thermal NO and the global NO emission. The predicted results were validated with the experimental measurements of the full scale burner (1.4 MW) at different excess air factors. The results indicate that H is the most important factors affecting the NO emission, followed by β and α respectively. The chemical flame heights increase with the increase of β and the decrease of H but the effect of α is negligible. Finally, α = 70°, β = 30° and H = 36 mm are recommended as the optimized results.

Fire whirls can be generated during large outdoor fires such as post-earthquake urban fires, and their consequences are often devastating. Therefore, when assessing the post-earthquake fire risk in urban areas, the conditions of fire whirls generation must be understood. There have been attempts to determine the critical crosswind velocity that maximizes the occurrence of fire whirls. However, it does not account for the substantially varying frequency of fire whirl generation among different cases. From a fire-risk perspective, steadily generated fire whirls need to be distinguished from intermittently generated ones, but such a distinction has not been attempted to date. In this study, the probabilistic aspect of fire whirl generation around an L-shaped gas burner in a crosswind was experimentally investigated in a wind tunnel. The test parameters were the heat release rate per unit length (32.5–86.8 kW/m) and the crosswind velocity (0.115–0.696 m/s). Fire whirl was observed in 10 out of 19 cases, but the duration period (i.e., frequency) of the fire whirl generation varied substantially among the cases. The variation of the generation frequency was successfully generalized by the Froude number, Fr, a characteristic value of the counter-flow around the fire source. The Strouhal number, St, which is often used to characterize periodic pulsation of buoyant diffusion flames, was also found to be an appropriate value characterizing the coherency within the unsteady fire whirl generation phenomena.

This study presents a quantitative analysis and interpretation about the effects of natural air flow, opening size and fire location on flame length in the underground vertical channel like car elevator or staircase. The gas burner of 0.1 × 0.1 m with five heat release rates (HRR) is used and eight locations are considered in 1/7 scale model. The air flow structure inside the vertical channel is investigated by CFD simulation. Hydraulic diameter and a characteristic length is proposed to calculate the flame length. A specific correlation between the flame length and dimensionless HRR is established to estimate the degree of fire disasters in the vertical channel with different opening size and locations.

High-frequency temperature measurements were carefully conducted for a 15 kW buoyant turbulent ethylene diffusion flame over a 15.2 cm diameter gas burner with air co-flow. A dual-thermocouple probe, consisting of two fine-wire thermocouples with 25 μ m and 50 μ m wire diameters, was used to determine a compensated turbulent gas temperature. A sensitivity analysis shows that temperatures resolved using this dual-thermocouple technique are less sensitive to changes in thermocouple bead size, therefore, uncertainty is greatly reduced even when soot deposition on the thermocouple bead occurs in sooty flames. Mean and root-mean square (rms) fluctuations of gas temperature were recorded in a two-dimensional plane across the flame centerline. The mean gas temperature monotonically decreases away from the flame centerline at most flame heights, except for 1 diameter above the burner, where a temperature dip is observed. The rms temperature peaks shift from the edge of the flame to the center as the height increases. This is due to the enhanced mixing between fuel and air, which is further shown using probability density functions of the local gas temperature. A systematic temperature dataset with high spatial resolution is established for sooty flames, which is valuable for future soot and radiation model validation.

The smoke and air flow through a horizontal opening was investigated using a model-scale room equipped with a horizontal opening on the ceiling. A smoke layer was created under the ceiling using a small gas burner. The pressure difference across the horizontal opening was changed by controlling the air supply to and exhaust from the space above the opening. Smoke and air flow patterns were either downward uni-directional flow of air, bi-directional flow of air and smoke or uni-directional flow of smoke upward. By changing the pressure difference across the opening, critical pressure differences to cause uni-directional flow were determined. It was found that the critical pressure was 0.98 of the smoke layer buoyancy for the onset of upward uni-directional smoke flow, and 0.47 for downward uni-directional air flow. From the measured carbon dioxide concentration, the mass flow rates of smoke and air were calculated and correlated with the non-dimensional pressure difference in the case of bi-directional flows.

The article contains the results of the research intp microcutting processes of different materials with single abrasive grains. The research was conducted on the face-grinding machine with a special device installed which allows setting the separate abrasive grains and do microcutting. One of the factors changing during the research is the temperature of the processed sample. A different temperature of the sample was achieved with the help of the gas burner. The results of the research made it possible to define the coefficient of thermomechanical fatigue for each combination of processing mode and type of the material and its changing due to the temperature of the grinding sample. The results will help to develop the methodology of projecting effective grinding operations in a wide variety of technological conditions, with respect to the working capacity of the abrasive tool.

The objective of this study is to explore mechanisms for ignition and extinction for condensed-phase fuels via the use of a gas-fueled burner. Flames were generated with a porous 25 mm circular burner using mixtures of methane and propane with nitrogen. The procedure was to specify a set of mass fluxes of nitrogen-fuel mixture that corresponded to the flash- fire- and extinction points and for the minimum mass flux where steady burning was achieved. The results show an increase in the critical mass flux with a decreased heat of combustion. The data fall into two regimes depending on the mixture flow rate; one buoyancy-driven (Fr

A series of experiments are conducted to analyze and discuss ceiling maximum thermal smoke temperature and longitudinal decay along the centerline of the tunnel with different transverse fire source locations. The size of scale model tunnel is 72 m (length) × 1.5 m (width) × 1.3 m (height). Three transverse gas burner locations were considered, such as Location A (close to the wall), Location B (near the wall), Location C (centerline of the tunnel), the corresponding distance between the centerline of the gas burner and the tunnel wall are 0.2 m, 0.475 m and 0.75 m, respectively. It was found that Li model underestimates the maximum thermal smoke temperature beneath the ceiling with different transverse fire source locations. Thus a dimensionless coefficient λ is put forward to consider the effect of different horizontal fire source location on thermal smoke temperature profile. The predictions by the modified model of this work agree well with the measured data in the maximum thermal smoke considering different transverse fire source locations. The revised thermal smoke temperature decay formula along the centerline of the tunnel is introduced, and the deduced values of coefficient K c down are correlated linearly with transverse fire location.

This paper presents a new approach to manufacture a threshold temperature sensor based on a biconical optical fibre taper. The presented sensor employs the influence of variable state of concentration of some isotropic materials like wax or paraffin. Application of the above- mentioned materials is an attempt to prove that there is a possibility to obtain a low-cost, repeatable and smart sensor working as an in-line element. Optical fibre taper was obtained from a standard single mode fibre (SMF28®) by using a low pressure gas burner technique. The diameter of the manufactured tapers was 6.0 ± 0.5 μm with the length of elongation equal to 30.50 ± 0.16 mm. The applied technology allowed to produce tapers with the losses of 0.183 ± 0.015 dB. Application of materials with different temperature transition points made it possible to obtain the threshold work at the temperatures connected directly with their conversion temperature. External materials at the temperatures above their melting points do not influence the propagation losses. For each of them two types of the protection area and position of the optical fibre taper were applied.

It is known that the Pressurized Water Reactors (PWRs), which are the most common type of nuclear reactor existing today, usually used to provide a base load electricity. In order to be able to compete with other generation types (fossil and renewables), it would be desirable to develop PWRs with flexible load following capabilities to cope with varying electricity demand, especially in deregulated markets. The thermal efficiency of PWRs can be increased by fitting the power plant with conventional fossil fuel superheaters. This hybrid system has been hypothesised to be able to adjust the power output and the cycle efficiency of PWRs. Such mode of operation would also improve the efficiency of converting the fossil fuel heat because it is applied only at the superheater stage. There are several ways to supply the heat to the superheaters, for example, by using the exhaust gas from the gas turbines and using the conventional gas burner. In this paper, the thermodynamic performance of the hybrid system (PWR with superheater) is investigated for large reactor and Small Modular Reactor (SMR) application. The thermal efficiency of the AP1000 can be improved from 30.2% to 45.8% (with CCGT), 35.6% (with gas burner), and 36.6% (gas burner with reheating). The thermal efficiency of the SMR can be improved from 33.4% to nearly 45% (with CCGT), 35.5% (with gas burner), and 37.4% (gas burner with reheating). The analysis results show that it is possible for the hybrid system to operate between 65% and the full power load.

This paper investigates experimentally the thermal buoyant smoke back-layering flow length beneath the tunnel ceiling with combination ceiling extraction and longitudinal ventilation, especially focusing on the condition that the ceiling extraction is employed at upstream side of the fire source, which has not previously been reported. Experiments are conducted in a model tunnel. A square gas burner was used to simulate the fire source, whose side dimension is 0.3 m. The heat release rates (HRRs) of fire source were 30 kW, 40 kW and 50 kW. Ceiling extraction opening with circular outlet of 0.3 m diameter was located at 1 m upstream from the fire source. Six different longitudinal ventilation velocities with six different ceiling extraction flow velocity were considered. Thermocouples are employed to measure the longitudinal temperature profile of the thermal smoke flow beneath the tunnel ceiling, to determine the upstream back-layering flow length. It was found that the upstream back-layering flow length increases with increase in heat release rate, meanwhile decreases with increase in longitudinal ventilation velocity or ceiling extraction velocity. A new non-dimensional factor was proposed to predict the thermal smoke back-layering flow length, which is shown to be in good agreement with the experimental results.

This paper investigates the longitudinal and transverse temperature profiles of a strong plume impinging flow, induced by a turbulent porous gas burner impinging on the sidewall confined ceiling of a long-narrow tunnel-like structure. A series of model scale experiments were conducted for fires against a tunnel sidewall with increasing vertical burner heights (0, 0.17 and 0.35 m), 8 different HRRs (heat release rate) from 15.94 to 106.28 kW were used. Measurements of the vertical temperature profiles against the sidewall and radial horizontal temperature profiles under the ceiling are presented. Results show that for the strong impingement plume, the temperatures at the impingement point can be well correlated by the three-regime of buoyant plume, intermittent flame and continuous flame. The horizontal temperature profiles under the ceiling show obviously asymmetric. It is confirmed that the characteristic length scale of plume radius at ceiling level is sufficiently applicable for predicting the ceiling excess temperatures of strong plume impingement flow, and the correlations of the ceiling excess temperature in both transverse and longitudinal directions are proposed and validated by comparing them with previous research.

Open-air fires are a common method of waste disposal in low infrastructure areas and these fires are often placed in burn pits to provide physical safety measures. This paper seeks to understand how the distance between the fuel surface and the pit opening (ullage) affects fire behavior by using a gas burner. The gas used is methane with a varying fuel supply (2, 4, 6 g/min) to represent different types of waste loading. As the ullage is varied, distinct flame fluctuations are observed inside the pit and aspects of flame dynamics at different fuel flow rates are espoused. A semi-empirical correlation for the entrainment of the ambient air into the flame is developed.

This paper presents the thermal and energy analysis of a Solar-LP gas hybrid drying plant built in Zacatecas, Mexico. It is focused on the dehydration of agricultural products. The drying system is a forced convection hot air type with a drying chamber. For the air heating required in the drying process, there are two solar thermal systems: a direct air heating system (48 solar air heaters with an area of 111.1 m2) and an indirect air heating system (40 solar water collectors with an area of 92.4 m2 and 6000 L of thermal storage). Also, there is a backup system of conventional energy (LP gas burner). Two hybrid tests were carried out to dry Nopal (Opuntia ficus-indica) initially operating with the direct system, after that with the indirect system and complementing the energy demand of drying with the conventional system. The effective drying time was 14.3 and 11.7 h, removing a total of 179 and 183 kg of water, respectively. The air temperature at the entrance of the drying chamber was around 59 °C. The solar fraction obtained for this hybrid mode of operation was around 80%. The thermal analysis of the direct and indirect air heating system, together with the conventional system, are presented and discussed. The performance of the solar systems is finally compared with a conventional LP gas drying system via a cost and return on investment analysis.

Uniform air distribution inside drying chamber is key factor to reduce energy consumption along with drying uniformity. A detailed thermal analysis (energy and exergy based) was performed for a newly developed inline-airflow solar hybrid dryer (coupled with solar evacuated tube collector and gas burner). The experiments were performed using green chilies at 60 °C under three modes of heating sources i.e. dual (gas + solar), gas and solar. Thermal analysis revealed that energy utilization varied in the ranges of 0–17 kJ/sec (dual), 0–16 kJ/sec (gas), 0–13 kJ/sec (solar), energy utilization ratios were in the ranges of 0–56.8% (dual), 0–60% (gas), 0–47.8% (solar) while values of exergy losses were 2.26–5.41 kJ/kg (dual), 2.45–5.56 kJ/kg (gas) 1.48–4.00 kJ/kg (solar), and exergy efficiencies were in the ranges of 33.95–74.11% (dual), 24–73.58% (gas),17–69% (solar). Heating component that comprised of heat exchanger–evacuated tube collector handled major part of energy possessing higher exergetic factor (54.37) and improvement potential rate (2.016). The values of specific evaporation and product energies were calculated 5.16, 5.77, 4.45 MJ/kg and 22.28, 24.90, 19.19 MJ/kg for dual, gas and solar modes of heating respectively. The study provides a detailed and sequential procedure to conduct thermal analysis of an industrial drying unit employing hybrid source of heating for design assessment and optimization.

In this article the authors present theoretical and experimental studies of gas-burning devices with the chordal feed of gas jets. The optimum diameter of the nozzles providing for the necessary range of gas jets for a high-quality mixing of fuel gas and air in the mixing chamber of minimum length is determined by calculation. The analysis of the parameters of the flame indirectly proves the reliability of the calculated data. The chordal flow of the gas jets and optimization of their range will significantly reduce the overall structural dimensions of the gas burner units. Short-flame gas-burning devices formed the basis for the creation of the Autonomous heat gun intended for repair and maintenance of engineering networks. Obtaining of a good heat gun is ensured by the motor fan capable of generating a high-pressure jet without connection to an external electrical network. Using of the autonomous heat gun in the housing and communal services is very promising in comparison with similar devices.

Tunnel is a special long-narrow building structure. The thermal buoyancy-driven upstream reversing smoke back-layering flow produced by the burning of heat source is harmful for human evacuation. This paper reveals the effect of the distance between ceiling extraction (opening) distance and heat source on the thermally-driven smoke back-layering flow length beneath the ceiling in a tunnel with combination of ceiling extraction and longitudinal ventilation, which has not previously been reported. Experiments are conducted in a reduced-scale tunnel [72 m (length) × 1.5 m (width) × 1.3 m (height)]. A porous gas burner is used to provide steady heat source and its relative distance from the ceiling extraction (opening) is varied. It is found that the thermally-driven smoke back-layering flow length increases as the heat source-ceiling extraction (opening) distance increases. A new model is theoretically deduced to predict the smoke back-layering flow length including the factor of heat source-ceiling extraction (opening) distance, by accounting for the energy loss due to extraction which is calculated based on the local longitudinal temperature profile estimation. The predictions by the proposed model are in good agreement with the experimental results.

Porous ceramic burners have been shown as a promising technology to produce heat and lighting by burning low calorific fuels like modern biomass. Among ceramics, yttria (Y2O3) presents considerable luminescent proprieties for gas burner technology. By colloidal processing of yttria, this work aims to produce luminescence ceramic nettings with potential to be used as gas burners. Processing parameters such as mean particle size, zeta potential and flow behavior were evaluated in order to prepare suitable suspensions for replica method. Yttria nanoparticles presented light emission with λ = 550 nm when being thermal stimulated at 150 °C. Besides, the nano sized powders d50 = 113.8 nm and specific surface area of 13.6 m2 g−1 could be highly stabilized at pH 10.5. Suspensions with 30 vol% of solids, pH 10.5, 1 wt% of dispersant and 0.3 wt% of binder presented shear thinning behavior and thixotropy suitable for replica method. As a result, samples sintered at 1600 °C/1 h showed homogeneous morphology of struts and porous microstructure desirable for gas recirculation and burning process.

Employing the IR at 10 μm we record, process, and visualize the combustion ignition process and propagation in a domestic stovetop gas heater, during the first half of a second after the electrical spark has initiated it. We record the IR imagery at a rate of 770 frames per second. Only 315 frames are employed to record the propagation around the heater rim in about 0.4 s. Due to the rapidity of the combustion evolution, the exposure time of 80 μs was implemented electronically. To the best of our knowledge, this is the first reporting of the exact processes that take place during the combustion initiation, including precise determination of time and place of this occurrence. Furthermore, we believe that this work presents the first description of the combustion evolution during the initial half a second after the successful ignition. The visualization led the designers to implement a more effective and safe design of the electric spark sequence, fuel influx ducts, and the combustion chamber configuration.

Design and control strategy suggestions for direct expansion solar assisted heat pump (DX-SAHP) water heaters are stated as a result of a novel steady-state primary energy consumption analysis based on a model developed around the fluid-independent Carnot cycle. The study is devoted to devices committed to hot sanitary water production and supplemented by an instantaneous gas burner. The paper addresses several suggestions about the correct design and the optimal working conditions needed to minimize the use of primary energy, based on averaged working conditions. The maximization of primary energy savings has been selected as the criterion to define our concept of “optimal performance” since this approach benefits from the use of a direct language that permits a larger, also non-specialized, audience to acquire the basic concepts of optimal behavior, increasing the transfer of knowledge to actual embodiments. Apart from the particular criterion selected in this study, the focus is on the proposed steady state approach which, without any use of refrigerant fluid properties, allows us to extract general rules as a function of the main features of the plant and of its relevant interactions with the surroundings, making all the relationship between the involved variables explicit and meaningful. Results obtained using the present approach agree with data coming from an already consolidated dynamic simulator.

This paper investigates the buoyancy-driven smoke flow layering length (both upstream and downstream) beneath the ceiling with combination of point extraction and longitudinal ventilation in tunnel fires. A theoretical model is developed based on previous back-laying model with only longitudinal ventilation, with modified actual heat release rate, as well as modified upstream and downstream opposing longitudinal air flow velocities by the induced flow velocity due to point extraction. Experiments are carried out in a reduced scale model tunnel with dimensionless of 72 m×1.5 m×1.3 m. A LPG porous gas burner is used as fire source. The smoke flow layering length both upstream and downstream are identified based on temperature profiles measured along the ceiling, for different experiment conditions. CFD simulations with FDS are also performed for the same scenarios. Results show that with combination of point extraction and longitudinal ventilation, the smoke flow layering length is not symmetric where it is longer downstream than that upstream. The upstream smoke layering length decreases, while the downstream layering length increases with increase in longitudinal ventilation velocity; and they both decrease with increase in point extraction velocity. The predictions by the proposed theoretical model agree well with the measurements and simulation results.

In many research or technical expertise studies the maximum noise level of a boiler is associated with the maximum thermal load of the burner. However, this type of air injected burners presents a complex running cycle with different functioning periods, where different parts (engine, fan, flame) of the burner are running separately or in the same time. In this study we are focused on the analysis, by experimental measurements, of the entire functioning cycle of a boiler by pointing out the noise differences and their importance when doing an experimental acoustical investigation. The entire 1/3 octave spectrum of the sound pressure level (SPL) was recorded during a complete running cycle by means of logging software associated to the sound meter. The sound equivalent level was calculated for each period of the running cycle and compared to the norms and with two theoretical prediction models that take into account the heating power and the boiler room volume. It was found that the most accurate data are obtained when the measurements are done in one-third octave. The maximum noise level was established to be not for the maximum thermal load period, but for the ventilation period of the boiler (before gas injection) with 82.1 dB at 125 Hz. A shut down delay was detected at the end of the cycle with 13 s for higher frequencies, due to the vibration of the boiler parts. Two 3D graphical representations point out the most important frequencies characterizing each running state of the burner. Compared to the noise curve (NC85) the minimum differences between the admissible values and the ones produced by the burner were found to be around 5.5 dB and therefore no acoustical treatment was needed. The results of the SPL prediction models matched the experimental data only for some of the boiler cycle periods and for only some of the frequencies. This type of detailed experiment investigation of the burner noise highlights the periods of the running cycle and the frequencies where the noise level requires acoustical treatment.

This article addresses burner design and flame measurement based on the heat flux method which is among the most precise ways of determining the laminar burning velocity of premixed flames. Chemical data are available for gaseous fuel flames using a variety of burner setups. However, the data for the laminar burning velocities of liquid fossil fuels and alternative biofuel blends, are still either incomplete, inaccurate or vary strongly for different setups, burner types and boundary conditions. A modified heat flux approach is found to increase the accuracy of the results of laminar burning velocities. For this purpose, a heat flux gas burner was combined with a novel liquid-fuel injection evaporating system called ‘HeatFluxER’ to achieve precise data for various biofuels and blends. Nevertheless, the purpose of this work is to obtain a robust inexpensive system for reproducible measurements. The gained measurement data of ethanol and isooctane depending on the initial gas temperature are in good agreement with recently presented studies of other groups and setups.

The effect of tunnel slope on the fire induced hot gas temperature profile beneath the ceiling has not been clarified nor included in existing models. Thus, in this paper experiments are carried out in a reduced scale model tunnel with dimensions of 6 m (length) × 1.3 m (width) × 0.8 m (height), which is positioned within a 72 m long wind tunnel. The slopes of the model tunnel are varied at three typical different degrees, 0%, 3% and 5%. A LPG porous gas burner is used as fire source. Both the maximum gas temperature and the temperature distribution along the tunnel ceiling are measured and compared with previous models. Results show that those models overestimates the maximum temperature beneath the ceiling of a slopping tunnel fire. The gas temperature decays faster along the ceiling for tunnels with higher slope. Empirical correlations are then proposed to modify the current models to include the tunnel slope factor. The predictions by the modified equations of this work agree well with the measured data in both the maximum temperature and temperature decay beneath the ceiling of the tunnel with different slopes.

Enclosure fires with an opening are commonly distinguished by two distinct phases namely, internal combustion with no flames ejected out (over-ventilated conditions), and internal combustion extending to external combustion having flames continuously ejected outside (under-ventilated conditions). A transitional phase not previously reported is investigated in this paper with flames being ejected out intermittently with a certain probability. Experiments were carried out in a 0.8 m cubic enclosure for seven different opening geometries. A Liquefied Petroleum Gas (LPG) porous gas burner was used as a fire source with fuel supply rate controlled by a flow meter. The intermittent ejection of flames was recorded by a digital CCD camera. The fraction of the time that the flames are outside the opening is defined as a probability, P. It is found that this probability P increases with the increase in fuel supply rate above a lower critical value (at P = 0) until an upper critical value (at P = 1). These critical lower and upper fuel supply rates or equivalently the corresponding total heat release rates (HRRs), are well correlated using the so called ventilation factor ( A H ) of the enclosure, where A is the area of the opening and H is height with length scales in meter. The ventilation factor ( A H ) is proportional to the rate of air mass inflow for under-ventilated conditions. The values of the lower and upper critical HRR in excess of 1500 A H (kW) (corresponding to heat released inside at under-ventilated conditions) are normalized by a characteristic HRR value applicable for the specific opening geometry. It is proposed that the intermittent ejection of flames is due to the probability of ignition and buoyant turbulent fluctuation of gases ejected from the opening which are affected by both the excess fuel amount and the temperature inside the enclosure which is equal to the temperature of the gases exiting the enclosure. Consequently, a simple mathematical model quantifies the ejection probability P as a function of normalized excess HRR Q ˙ ex ∗ and opening factor parameter A H / A T , where AT is the total exposed surface area of the enclosure. Indeed, the first parameter Q ˙ ex ∗ is related to the excess fuel amount that is ejected outside the enclosure as the conditions change from over-ventilated to under-ventilated, whereas the second parameter A H / A T is related to the heat losses to the wall which together with the heat released inside the enclosure determine the temperature inside the enclosure. It is shown that the lower critical normalized excess HRR depends on the parameter A H / A T . It is also found that the normalized lower-to-upper critical HRR difference is constant. The results are significant for combustion and fire safety science, because the conditions for which the external flame can be continuously sustained outside are clarified based on the characterization of the intermittent transition regime. For example, it is expected that the intermittent presence of flames outside will result in increased production of carbon monoxide when no combustion occurs of the excess fuel, although the radiation impact of the flames outside the enclosure will be reduced.

Effect of calcining temperature and time on the content of free CaO in hydroxyapatite of natural origin is presented. Hydroxyapatite was obtained from pork bones in the course of a three-stage process: hydrolysis with the application of lactic acid, pre-calcination at 600 °C and main calcination stage within the temperature range of 750–950 °C. Calcination was conducted in an electrically heated stationary chamber oven in air atmosphere and in a laboratory scale rotary kiln equipped with a gas burner. The FT-IR spectra confirmed that all organic substances were removed during the calcination process. An increase in free calcium oxide content in hydroxyapatite from 0.003% to 0.023% was caused by the increase of calcining temperature from 750 °C to 950 °C respectively. Calcining time at 950 °C gave a distinct impact upon free CaO content ranging from 0.014% (2 h) to 0.023% (3 h). Hydroxyapatite calcined in the rotary kiln contained the lowest amount of free calcium oxide: 0.002% (750 °C) and 0.003% (950 °C). A method of neutralizing of free calcium oxide, present in calcined hydroxyapatite powders of natural origin, through CaO transformation into hydroxyapatite by application of diluted thermic phosphoric acid has been developed.

Fire experiments were carried out in a scale model, consisting of an 0.8 m cubic fire compartment with six window like geometries and an attached 3 m (wide) × 5 m (high) facade wall. A propane porous gas burner with controlled fuel supply rate was the fire source. Gas temperature profiles were measured inside the compartment and near the facade wall. The outside spill flame heights were recorded by a CCD Digital camera. Temperature and flame heights are correlated with heat release rate and the window geometry using physically non-dimensional analysis. The steady gas temperatures inside the compartment are determined by an overall energy balance between the heat release rate inside the compartment and the wall conduction and opening radiation heat losses using an effective overall heat loss coefficient. Flame heights on the facade are non-dimensionally correlated by the excess fuel heat release rate outside the enclosure and a characteristic length scale for the window. These results agree with previous results in the literature. Vertical gas temperatures near the facade wall outside the enclosure are non-dimensionally correlated with the total convective heat flow rate above the flames and the same characteristic window length scale as the flame height, with the additional necessary determination of a virtual origin of the convective flow above the flame. These results and correlations are new and a significant improvement over previous results in the literature.

The aim of the research on the Delft jet-in-hot coflow (DJHC) burner is to gain understanding in the interplay of turbulence and chemistry in conditions as encountered in devices operating in flameless combustion mode, and to test the validity of numerical models when applied to these flameless combustion conditions. Datasets on velocities, temperatures and qualitative OH data of several Dutch natural gas flames in the DJHC burner have been obtained and are discussed in this paper. It was found that the mean velocity and turbulent stresses are not significantly affected by the chemical reactions, which is in line with the very moderate increase of mean temperatures in the flames. Even at heights where flame structures are present, peak temperatures do not always approach the adiabatic flame temperature. With both flame luminescence and OH-PLIF measurements, it is seen that chemical reactions begin to occur at a lower location when the jet velocity (and thereby the jet Reynolds number) is increased. By analysing the velocity and temperature data in the near-nozzle region, the entrainment of coflow fluid into the turbulent jet has been quantified. The increased entrainment of the higher Reynolds number jet, in combination with the positive temperature gradient in radial direction in the near field of the jet, is shown to be responsible for the decrease of the height where reactions start to occur.

Incorporation of Solid-oxide fuel cells (SOFC) into hybrid systems with CHP capabilities is an attractive option for clean and efficient decentralised electricity generation. SOFC system operation on practical liquid fuels requires an efficient preparation system for the formation of a homogeneous reformate mixture. This can be accomplished with the use of a stabilized cool flame vapouriser (SCFV) combined with a thermal partial oxidation (T-POX) reformer, and such systems are already under development. The successful and efficient thermochemical operation of an SOFC system requires an accurate determination of the optimum conditions for each constituent component (e.g. fuel processing unit, fuel cell stack, off-gas burner) and for the integrated system. The present work demonstrates a computational methodology for the thermochemical assessment of a novel SOFC system operated on liquid fuels. Simulations have been performed, both at component and system levels, using a reactor network approach, involving a simplified flow and mixing representation, while retaining full detailed chemistry. Computations are performed at a component level with reactor networks specially formulated for the SCFV and the T-POX reactors, derived on the basis of CFD calculations, coupled with detailed kinetic mechanisms for n-heptane, a reasonable diesel fuel surrogate. Model predictions are compared against experimental data, wherever possible. The individual components are integrated at a system level and parametric analyses are performed so as to determine optimum conditions for efficient and clean operation.