Direct demonstration of complete combustion of gas-suspended powder metal fuel combustion using bomb calorimetry

Abstract Off-the-shelf calorimeters are typically used for hydrocarbon-based fuels and not designed for simulating metal powder oxidation in gaseous environments. We have developed a method allowing a typical bomb calorimeter to accurately measure heat released during combustion and achieve nearly 100% of the reference heat of combustion from powder fuels such as aluminum. The modification uses a combustible organic dispersant to suspend the fuel particles and promote more complete combustion. The dispersant is a highly porous organic starch-based material (i.e., packing peanut) and allows the powder to burn as discrete particles thereby simulating dust-type combustion environments. The demonstrated closeness of measured Al heat of combustion to its reference value is evidence of complete metal combustion achieved in our experiment. Beyond calorific output under conditions simulating real reactive systems, we demonstrate that the calorimeter also allows characterization of the temporal heat release from the reacting material and this data can be extracted from the instrument. The rate of heat release is an important additional parameter characterizing the combustion process. The experimental approach described will impact future measurements of heat released during combustion from solid fuel powders and enable scientists to quantify the energetic performance of metal fuel more accurately as well as the transient thermal behavior from combusting metal powders.

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The Synergy of Two Biofuel Additives on Combustion Process to Simultaneously Reduce NOx and PM Emissions

Energies ◽

10.3390/en14102784 ◽

2021 ◽

Vol 14 (10) ◽

pp. 2784

Author(s):

Jerzy Cisek ◽

Szymon Lesniak ◽

Winicjusz Stanik ◽

Włodzimierz Przybylski

Keyword(s):

Heat Release ◽

Combustion Rate ◽

Combustion Process ◽

The Other ◽

Fuel Additive ◽

Exhaust Gas ◽

Synergy Effect ◽

Engine Exhaust ◽

Other Hand ◽

Heat Released

The article presents the results of research on the influence of two fuel additives that selectively affect the combustion process in a diesel engine cylinder. The addition of NitrON® reduces the concentration of nitrogen oxides (NOx), due to a reduction in the kinetic combustion rate, at the cost of a slight increase in the concentration of particulate matter (PM) in the engine exhaust gas. The Reduxco® additive reduces PM emissions by increasing the diffusion combustion rate, while slightly increasing the NOx concentration in the engine exhaust gas. Research conducted by the authors confirmed that the simultaneous use of both of these additives in the fuel not only reduced both NOx and PM emissions in the exhaust gas but additionally the reduction of NOx and PM emissions was greater than the sum of the effects of these additives—the synergy effect. Findings indicated that the waveforms of the heat release rate (dQ/dα) responsible for the emission of NOx and PM in the exhaust gas differed for the four tested fuels in relation to the maximum value (selectively and independently in the kinetic and diffusion stage), and they were also phase shifted. Due to this, the heat release process Q(α) was characterized by a lower amount of heat released in the kinetic phase compared to fuel with NitrON® only and a greater amount of heat released in the diffusion phase compared to fuel with Reduxco® alone, which explained the lowest NOx and PM emissions in the exhaust gas at that time. For example for the NOx concentration in the engine exhaust: the Nitrocet® fuel additive (in the used amount of 1500 ppm) reduces the NOx concentration in the exhaust gas by 18% compared to the base fuel. The addition of a Reduxco® catalyst to the fuel (1500 ppm) unfortunately increases the NOx concentration by up to 20%. On the other hand, the combustion of the complete tested fuel, containing both additives simultaneously, is characterized, thanks to the synergy effect, by the lowest NOx concentration (reduction by 22% in relation to the base). For example for PM emissions: the Nitrocet® fuel additive does not significantly affect the PM emissions in the engine exhaust (up to a few per cent compared to the base fuel). The addition of a Reduxco® catalyst to the fuel greatly reduces PM emissions in the engine exhaust, up to 35% compared to the base fuel. On the other hand, the combustion of the complete tested fuel containing both additives simultaneously is characterized by the synergy effect with the lowest PM emission (reduction of 39% compared to the base fuel).

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Combustion properties of Bromus tectorum L.: influence of ecotype and growth under four CO2 concentrations

International Journal of Wildland Fire ◽

10.1071/wf05055 ◽

2006 ◽

Vol 15 (2) ◽

pp. 227 ◽

Cited By ~ 11

Author(s):

Robert R. Blank ◽

Robert H. White ◽

Lewis H. Ziska

Keyword(s):

Bromus Tectorum ◽

Combustion Process ◽

Co2 Concentration ◽

High Elevation ◽

Total Heat ◽

Tissue Concentrations ◽

Complete Combustion ◽

Co2 Concentrations ◽

Combustion Properties ◽

Heat Released

We grew from seed the exotic invasive annual grass Bromus tectorum L., collected from three elevation ecotypes in northern Nevada, USA. Plants were exposed to four CO2 atmosphere concentrations: 270, 320, 370, and 420 μmol mol–1. After harvest on day 87, above-ground tissue was milled, conditioned to 30% relative humidity, and combustion properties were measured using a cone calorimeter. Plants exposed to 270 μmol mol–1 CO2 had significantly less total heat released than plants exposed to higher CO2 concentrations. Total heat released was least for the low-elevation ecotype, statistically similar for the mid-elevation ecotype, and significantly increased for the high-elevation ecotype. Plant attributes that significantly correlated with heat release included tissue concentrations of lignin, glucan, xylan, potassium, calcium, and manganese. The data suggest that a decline in tissue concentrations of lignin, xylan, and mineral constituents, as CO2 concentration increases from 270 μmol mol–1 to higher levels, affects the combustion process. We suspect that as tissue concentrations of lignin and inorganics decline, char formation decreases, thereby allowing more complete combustion. Changes in combustion parameters of B. tectorum induced by different CO2 concentrations and elevation ecotype may be a strong consideration to understanding fire behaviors of the past, present, and future.

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Chemical Aspects of In-Situ Combustion - Heat of Combustion and Kinetics

Society of Petroleum Engineers Journal ◽

10.2118/3599-pa ◽

1972 ◽

Vol 12 (05) ◽

pp. 410-422 ◽

Cited By ~ 117

Author(s):

J.G. Burger

Keyword(s):

Porous Media ◽

Combustion Front ◽

Combustion Process ◽

Heat Of Combustion ◽

Oxidation Reactions ◽

In Situ Combustion ◽

Oxidation Of Hydrocarbons ◽

Kinetics Of ◽

Heat Released

Abstract General remarks on the oxidation reactions of hydrocarbons involved in in-situ combustion are followed by estimates of heat releases. A formula is derived for computing the heat of combustion in the high-temperature zone. Reaction kinetics in porous media applied to the in-situ combustion porous media applied to the in-situ combustion process is discussed. It is observed that there is process is discussed. It is observed that there is some similarity between the kinetics of reverse and partially quenched combustion processes. The influence of additives on crude oil oxidation in porous media is illustrated by effluent gas analysis experiments. Some information concerning the values of the kinetic parameters of the reaction controlling the velocity of a reverse combustion front is derived from the interpretation of laboratory experiments, using a numerical model. Introduction A great deal of laboratory and field work has been done on thermal recovery methods. The importance and limitations of these techniques have been extensively studied. However, some of the chemical and physical problems involved that needed to be elucidated were studied as part of a research program carried out by the Institut Francais du Petrole. Specific problems are created by in-situ combustion since both the possibility of combustion-front propagation and the air requirement are controlled by the extent of the exothermic oxidation reactions. Actually, the propagation velocity of a forward combustion front depends on the fuel formation and combustion, which are controlled by the kinetics of these processes; furthermore, the peak temperature is related to the heat released by oxidation and combustion reactions. Therefore, a quantitative estimation of the parameters related to the chemical aspects of the parameters related to the chemical aspects of the process is a necessary step in studying combustion process is a necessary step in studying combustion through a porous medium. General and theoretical considerations on heats of reaction and kinetics are presented and illustrated by experimental data and numerical interpretation of the results. HEAT RELEASED IN THE OXIDATION OF HYDROCARBONS DESCRIPTION OF OXIDATION REACTIONS A great number of reaction products are produced by the oxidation of hydrocarbons. By taking into account the formation of bonds between one carbon atom and oxygen, it is possible to derive the most important processes. Complete combustion, (1) 2 2 2 2H H3R C R + ---- O → RR + CO + H O Incomplete combustion, (2) 2 2H H R C R + O → RR + CO + H O Oxidation to carboxylic acid, (3) 2 2 2H OH H3 OR C H + --- O → R - C + H O Oxidation to aldehyde, (4) H H R C Oxidation to ketone, (5) 2 2H O H R C R ' + O → R - C - R; + H O Oxidation to alcohol, (6) R' R; R C H SPEJ p. 410

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Research on the combustion process in the Fiat 1.3 Multijet engine fueled with rapeseed methyl esters

Open Engineering ◽

10.1515/eng-2021-0057 ◽

2021 ◽

Vol 11 (1) ◽

pp. 535-547

Author(s):

Dariusz Kurczyński ◽

Piotr Łagowski ◽

Michał Warianek

Keyword(s):

Heat Release ◽

Methyl Esters ◽

Combustion Process ◽

Diesel Oil ◽

Operating Conditions ◽

First Principle ◽

Engine Test ◽

Test Bed ◽

Basic Parameters ◽

Heat Released

Abstract The aim of the paper is to analyze and evaluate the basic parameters of the combustion process in a modern Fiat 1.3 Multijet diesel engine, fuelled esters (FAME) and diesel oil. During the tests on an engine test bed, the pressure waveforms in the cylinder were measured, on the basis of which the averaged actual indicator graphs were established in the determined engine operating conditions. On their basis, the pressure increase rates were determined and heat release characteristics were prepared based on the equation of the first principle of thermodynamics. The characteristics of the relative amount of heat released and the characteristics of the relative heat release rate were determined. The use of rapeseed methyl esters to supply the engine had an impact on the parameters of the combustion process as compared to its supply with diesel oil. Differences in the waveforms of heat release characteristics of the engine powered by the tested fuels are significantly greater at low loads. At the lowest engine loads, esters burn much faster than diesel oil. With the increase in engine load, the differences in the waveform of heat release characteristics during combustion of these fuels were significantly smaller.

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The Effect of RME-1-Butanol Blends on Combustion, Performance and Emission of a Direct Injection Diesel Engine

Energies ◽

10.3390/en14102941 ◽

2021 ◽

Vol 14 (10) ◽

pp. 2941

Author(s):

Wojciech Tutak ◽

Arkadiusz Jamrozik ◽

Karol Grab-Rogaliński

Keyword(s):

Diesel Engine ◽

Heat Release ◽

Direct Injection ◽

Specific Energy Consumption ◽

Combustion Process ◽

Constant Load ◽

Combustion Stability ◽

Performance And Emission ◽

Energy Share ◽

The Stability

The main objective of this study was assessment of the performance, emissions and combustion characteristics of a diesel engine using RME–1-butanol blends. In assessing the combustion process, great importance was placed on evaluating the stability of this process. Not only were the typical COVIMEP indicators assessed, but also the non-burnability of the characteristic combustion stages: ignition delay, time of 50% heat release and the end of combustion. The evaluation of the combustion process based on the analysis of heat release. The tests carried out on a 1-cylinder diesel engine operating at a constant load. Research and evaluation of the combustion process of a mixture of RME and 1-butanol carried out for the entire range of shares of both fuels up to 90% of 1-butanol energetic fraction. The participation of butanol in combustion process with RME increased the in-cylinder peak pressure and the heat release rate. With the increase in the share of butanol there was noted a decrease in specific energy consumption and an increase in engine efficiency. The share of butanol improved the combustion stability. There was also an increase in NOx emissions and decrease in CO and soot emissions. The engine can be power by blend up to 80% energy share of butanol.

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Combustion Thermodynamics of Ethanol, n-Heptane, and n-Butanol in a Rapid Compression Machine with a Dual Direct Injection (DDI) Supply System

Energies ◽

10.3390/en14092729 ◽

2021 ◽

Vol 14 (9) ◽

pp. 2729

Author(s):

Ireneusz Pielecha ◽

Sławomir Wierzbicki ◽

Maciej Sidorowicz ◽

Dariusz Pietras

Keyword(s):

Heat Release ◽

Combustion Chamber ◽

Internal Combustion Engines ◽

Direct Injection ◽

Combustion Process ◽

Combustion Efficiency ◽

Injection System ◽

Rapid Compression Machine ◽

Process Indicators ◽

Rapid Compression

The development of internal combustion engines involves various new solutions, one of which is the use of dual-fuel systems. The diversity of technological solutions being developed determines the efficiency of such systems, as well as the possibility of reducing the emission of carbon dioxide and exhaust components into the atmosphere. An innovative double direct injection system was used as a method for forming a mixture in the combustion chamber. The tests were carried out with the use of gasoline, ethanol, n-heptane, and n-butanol during combustion in a model test engine—the rapid compression machine (RCM). The analyzed combustion process indicators included the cylinder pressure, pressure increase rate, heat release rate, and heat release value. Optical tests of the combustion process made it possible to analyze the flame development in the observed area of the combustion chamber. The conducted research and analyses resulted in the observation that it is possible to control the excess air ratio in the direct vicinity of the spark plug just before ignition. Such possibilities occur as a result of the properties of the injected fuels, which include different amounts of air required for their stoichiometric combustion. The studies of the combustion process have shown that the combustible mixtures consisting of gasoline with another fuel are characterized by greater combustion efficiency than the mixtures composed of only a single fuel type, and that the influence of the type of fuel used is significant for the combustion process and its indicator values.

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Analysis of chemical effects on reflected-shock flow fields in combustible gas

Journal of Fluid Mechanics ◽

10.1017/s0022112085003378 ◽

1985 ◽

Vol 160 ◽

pp. 29-45 ◽

Cited By ~ 4

Author(s):

Yasunari Takano ◽

Teruaki Akamatsu

Keyword(s):

Heat Release ◽

Chemical Reactions ◽

Induction Time ◽

Combustion Process ◽

Chemical Species ◽

Flow Fields ◽

Rate Equations ◽

Reflected Shock ◽

Combustible Gas ◽

Analytical Results

This paper analyses effects of chemical reactions on reflected-shock flow fields in shock tubes. The method of linearized characteristics is applied to analyse gasdynamic disturbances due to chemical reactions. The analysis treats cases where combustible gas is highly diluted in inert gas, and assumes that flows are one-dimensional and that upstream flows in front of the reflected-shock waves are in the frozen state. The perturbed gasdynamic properties in the reflected-shock flow fields are shown to be expressible mainly in terms of a heat-release function for combustion process. In particular, simple relations are obtained between the heat-release function and the physical properties at the end wall of a shock tube. As numerical examples of the analysis, the present formulation is applied to calculate gasdynamic properties in the reflected-shock region in a H2–O2–Ar mixture. Procedures are demonstrated for calculation of the heat-release function by numerically integrating rate equations for chemical species. The analytical results are compared with rigorous solutions obtained numerically by use of a finite-difference method. It is shown that the formulation can afford exact solutions in cases where chemical behaviours are not essentially affected by gasdynamic behaviours. When the induction time of the combustion process is reduced to some extent owing to gasdynamic disturbances, some discrepancies appear between analytical results and rigorous solutions. An estimate is made of the induction-time reduction, and a condition is written down for applicability of the analysis.

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Analysis of Incylinder Pressure and Temperature Variation in a Four-Stroke S. I. Engine Using Wiebe’s Combustion Model

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.984-985.957 ◽

2014 ◽

Vol 984-985 ◽

pp. 957-961

Author(s):

Vijayashree ◽

P. Tamil Porai ◽

N.V. Mahalakshmi ◽

V. Ganesan

Keyword(s):

Heat Release ◽

Combustion Process ◽

Pressure Variation ◽

Spark Ignition Engine ◽

Working Fluid ◽

Combustion Model ◽

Cylinder Pressure ◽

Crank Angle ◽

Experimental Values ◽

Release Model

This paper presents the modeling of in-cylinder pressure variation of a four-stroke single cylinder spark ignition engine. It uses instantaneous properties of working fluid, viz., gasoline to calculate heat release rates, needed to quantify combustion development. Cylinder pressure variation with respect to either volume or crank angle gives valuable information about the combustion process. The analysis of the pressure – volume or pressure-theta data of a engine cycle is a classical tool for engine studies. This paper aims at demonstrating the modeling of pressure variation as a function of crank angle as well as volume with the help of MATLAB program developed for this purpose. Towards this end, Woschni heat release model is used for the combustion process. The important parameter, viz., peak pressure for different compression ratios are used in the analysis. Predicted results are compared with experimental values obtained for a typical compression ratio of 8.3.

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Real-time capable simulation of diesel combustion processes for HiL applications

International Journal of Engine Research ◽

10.1177/1468087417726226 ◽

2017 ◽

Vol 19 (2) ◽

pp. 214-229 ◽

Cited By ~ 5

Author(s):

Daniel Neumann ◽

Christian Jörg ◽

Nils Peschke ◽

Joschka Schaub ◽

Thorsten Schnorbus

Keyword(s):

Heat Release ◽

Real Time ◽

Fuel Injection ◽

Combustion Process ◽

Boost Pressure ◽

Diesel Combustion ◽

Main Challenge ◽

Combustion Properties ◽

Input Variables ◽

Improved Model

The complexity of the development processes for advanced diesel engines has significantly increased during the last decades. A further increase is to be expected, due to more restrictive emission legislations and new certification cycles. This trend leads to a higher time exposure at engine test benches, thus resulting in higher costs. To counter this problem, virtual engine development strategies are being increasingly used. To calibrate the complete powertrain and various driving situations, model in the loop and hardware in the loop concepts have become more important. The main effort in this context is the development of very accurate but also real-time capable engine models. Besides the correct modeling of ambient condition and driver behavior, the simulation of the combustion process is a major objective. The main challenge of modeling a diesel combustion process is the description of mixture formation, self-ignition and combustion as precisely as possible. For this purpose, this article introduces a novel combustion simulation approach that is capable of predicting various combustion properties of a diesel process. This includes the calculation of crank angle resolved combustion traces, such as heat release and other thermodynamic in-cylinder states. Furthermore, various combustion characteristics, such as combustion phasing, maximum gradients and engine-out temperature, are available as simulation output. All calculations are based on a physical zero-dimensional heat release model. The resulting reduction of the calibration effort and the improved model robustness are the major benefits in comparison to conventional data-driven combustion models. The calibration parameters directly refer to geometric and thermodynamic properties of a given engine configuration. Main input variables to the model are the fuel injection profile and air path–related states such as exhaust gas recirculation rate and boost pressure. Thus, multiple injection event strategies or novel air path control structures for future engine control concepts can be analyzed.

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A Study on the Calculation of Heat Release Rate to Compensate the Error Due to Single Zone Assumption in Diesel Engine

ASME 2005 Internal Combustion Engine Division Fall Technical Conference (ICEF2005) ◽

10.1115/icef2005-1298 ◽

2005 ◽

Author(s):

Seung Hyup Ryu ◽

Ki Doo Kim ◽

Wook Hyeon Yoon ◽

Ji Soo Ha

Keyword(s):

Diesel Engine ◽

Heat Release ◽

Computational Analysis ◽

Combustion Process ◽

Operating Conditions ◽

Zone Model ◽

Specific Heats ◽

Start Of Injection ◽

Release Analysis ◽

Improved Model

Accurate heat release analysis based on the cylinder pressure trace is important for evaluating combustion process of diesel engines. However, traditional single-zone heat release models (SZM) have significant limitations due mainly to their simplified assumptions of uniform charge and homogeneity while neglecting local temperature distribution inside cylinder during combustion process. In this study, a heat release analysis based on single-zone model has been evaluated by comparison with computational analysis result using Fire-code, which is based on multi-dimensional model (MDM). The limitations of the single-zone assumption have been estimated. To overcome these limitations, an improved model that includes the effects of spatial non-uniformity has been applied. From this improved single-zone heat release model (Improved-SZM), two effective values of specific heats ratios, denoted by γV and γH in this study, have been introduced. These values are formulated as the function of charge temperature changing rate and overall equivalence ratio by matching the results of the single-zone analysis to those of computational analysis using Fire-code about medium speed marine diesel engine. Also, it is applied that each equation of γV and γH has respectively different slopes according to several meaningful regions such as the start of injection, the end of injection, the maximum cylinder temperature, and the exhaust valve open. This calculation method based on improved single-zone model gives a good agreement with Fire-code results over the whole range of operating conditions.

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