Investigation on the performance,emissions and combustion characteristics of CRDI engine fueled with tallow methyl ester biodiesel blends with exhaust gas recirculation

This paper demonstrates the study of performance, combustion and emission characteristics of a common rail diesel injection (CRDI) engine with the influence of exhaust gas recirculation (EGR) (5, 15 and 25%) at various fuel injection pressures (400, 500 and 600 bar) under the effective load conditions (0, 25, 50, 75 and 100%). The experiments were carried out in a controlled manner using the CRDI engine fuelled with 80% (D80) diesel (98% purity) blended with 20% (B20) tallow biodiesel. The engine has been operated at a rated speed of 1500 rpm on all load conditions, fuel injection timings of 10°, 15° and 20° bTDC, fuel injection pressures of 400, 500 and 600 bar, respectively. Combustion-influenced performance characteristics such as variation of in-cylinder pressure and net heat release rate in J deg^?1 are also studied with the above operating conditions. It was observed that the usage of 20% biofuel blend shows considerable improvement in combustion, and it further enhances with an increase in the injection pressures. Besides, EGR (up to 25%) reduced significant pollutants at higher operating pressures (600 bar) at higher load conditions. It was also observed that CO₂ emission increased with increase in the % EGR with an increase in the load conditions. However, for CO emission increased up to 50% load condition and subsequently tends to decrease due to improved combustion at higher load; hence higher temperature. NO_x, smoke opacity continue to increase with the increase in pressure and the percentage increase in EGR due to its attainment of adiabatic temperature, which leads to the pathway for the Zeldovich mechanism. The present work shows light on the usage of tallow methyl ester produced from the wastes in the tannery industry as alternate biofuel operating the CRDI engines without compromising its combustion and emission characteristics to deliver the same power as petro-diesel.

     

Experimental investigation on the effect of natural gas premixed ratio on combustion and emissions in an IDI engine

Journal of Thermal Analysis and Calorimetry - Usage of natural gas in an internal combustion engine that has different combustion technologies is considered a possible solution to reduce engine...     

An experimental investigation of the injection timing effect on the combustion phasing and emissions in reactivity-controlled compression ignition (RCCI) engine

Journal of Thermal Analysis and Calorimetry - Nowadays, due to the environmental problems caused by pollution and high fossil fuels prices, the study on the internal combustion engines have...     

Numerical simulation of natural gas/diesel dual-fuel engine for investigation of performance and emission

Journal of Thermal Analysis and Calorimetry - Due to global concerns about the emissions, limited hydrocarbon fuel resources and high fuel prices, a lot of researches have been done to improve the...     

Biofuels today and tomorrow: effects of fuel composition on exhaust gas emissions

Due to current and future policy targets, and rapid technical developments, biofuel options are already available and in use in commercial applications. However, there is still doubt about which of the more promising alternatives will be widely accepted in future within the transportation sector. This includes aspects of biofuel properties and their effects on exhaust gas emissions and engine technology. This article addresses the status of current technology, reviews the progress of commercialisation of biofuel production, and gives an outline of its future development. Moreover, it provides an insight into the influence of biofuel composition on the internal combustion process and exhaust gas emissions. To assess biofuel sustainability, all aspects such as fuel production, fuel chemical composition, combustion behaviour, engine technology, and exhaust gas emissions have to be taken into account. Potential application fields and emerging challenges for measurement technology are identified in all these areas.     

Correction to: An experimental investigation of the injection timing effect on the combustion phasing and emissions in reactivity-controlled compression ignition (RCCI) engine

Journal of Thermal Analysis and Calorimetry - Unfortunately, in the original publication of the article the second author’s first name was inadvertently misspelled. The corrected author name...     

Effects of equivalence and fuel ratios on combustion characteristics of an RCCI engine fueled with methane/n-heptane blend

Rising fuel costs and efforts for reducing greenhouse gases have led researchers to propose optimized models of combustion which have high efficiency and low emissions. Reactivity controlled compression ignition (RCCI) engines are attractive due to their high efficiency and low NO_x and soot emissions over a wide range of operating conditions. In this study, methane and n-heptane are used as low and high reactive fuels, respectively, to create suitable fuel stratification within the cylinder. Modeling is carried out by AVL FIRE coupled with a chemical kinetics solver to investigate the effects of fuel ratio, initial temperature and equivalence ratio on the combustion performance and emission characteristics. Methane/n-heptane ratios are varied according to the energy ratio of each fuel while total input energy and total equivalence ratios are fixed. By increasing methane energy ratio from 65% to 85% in the constant intake temperature and pressure, the mixture Octane number increases, which would lead to an increase in ignition delay up to 5 crank angles. As a result, IMEP would be enhanced and also NO_x emission decreases because of lower combustion temperature. By increasing intake temperature, the maximum in-cylinder pressure, heat release rate and NO_x emission would increase significantly while soot emission decreases, and also ringing intensity increases up to 10%. On the other hand, increasing intake temperature reduces volumetric efficiency; as a result, IMEP is reduced by 11%. Also by increasing equivalence ratio from 0.35 to 0.55 in a constant energy ratio, noticeable growth in the maximum amount of pressure and temperature could be achieved; consequently, NO_x emission would increase significantly, IMEP increases by 43%, and ISFC decreases by 30%. The results indicate that these parameters have significant effects on the heavy-duty RCCI engine performance and emissions.

     

Numerical investigation into the effects of ordered particle packing and slip flow on the performance of chromatography

The pressure drop and the plate height of chromatography columns packed with particles in the face‐centered cubic, the body‐centered cubic and the simple cubic configurations are calculated by a volume averaging method model. It is found that the Kozeny‐Carman equation provides a reasonable prediction of the pressure drop when particles are in the face‐centered cubic configuration, but overestimates the pressure drop when particles are in the body‐centered cubic and the simple cubic configurations. The face‐centered cubic configuration has the advantage to provide a smaller longitudinal dispersion coefficient than the body‐centered cubic, the simple cubic, and the random configurations. The pressure drop and the plate height for slip flow through particles in the face‐centered cubic configuration are lower than that for no‐slip flow. The values of the smallest reduced plate height of columns packed with particles in the face‐centered cubic configuration for no‐slip flow and slip flow are about 0.084 and 0.059, respectively. The plate height of the ordered particle packing structures is smaller and the effect of slip flow on the plate height is less remarkable than results reported in literature.     

The relation between dioxin concentration from exhaust gas of diesel engine and chlorine content

In this paper, an experiment has been used to study the effect of pyrolysis stage (from injection to combustion) to dioxin exhaust from diesel engine. The characteristics of diesel fuel pyrolysis have been applied in order to calculate the mean molecular weight in varied temperatures and measure the concentration of inorganic chlorine (HCl). On the other hand, measuring the chlorine content of these particles after diesel pyrolysis enables researchers to find out the pyrolysis temperature that has the lowest possibility to produce dioxin. Additionally, the post-pyrolysis carbon particle diameter has been observed through electronic microscope so as to evaluate the combustion condition of the combustion stage. Result from this study would be helpful for researchers to understand the probability of dioxin formation.     

Numerical investigation on the performance and anti-freezing design verification of atomization equipment in an icing cloud simulation system

Journal of Thermal Analysis and Calorimetry - Aircraft icing occurs when flying through the cloud containing supercooled water droplets or ice crystals, posing a threat to flight safety. To...     

Numerical simulation of dimethyl ether/natural gas blend fuel HCCI combustion to investigate the effects of operational parameters on combustion and emissions

Journal of Thermal Analysis and Calorimetry - Homogeneous charge compression ignition (HCCI) combustion phasing control is one of the most difficult challenges of operating this new concept of...     

Systematic investigation of the effects of temperature and pressure on gas transport through polyurethane/poly(methylmethacrylate) phase-separated blends

Polyurethane (PU) and polyurethane–poly(methylmethacrylate) (PMMA) blend membranes were used in gas separation studies. The effects of blend composition, temperature, and pressure on the permeability, diffusivity, and solubility of CO₂, H₂, O₂, CH₄, and N₂ were investigated. The separation factors of some gas pairs were also evaluated. Positron annihilation lifetime spectroscopy was applied to assess free volume changes as a function of blend composition and temperature. Free volume size increases by approximately 30% with increasing temperature from 10 to 40 °C for all blends studied. The permeability of all gases decreases by approximately 55% with the addition of 30 wt% of PMMA. The permeation process is governed by diffusion, except that of CO₂. In relation to the behavior of gas transport as a function of temperature, some important observations are (i) CO₂ presents the lowest permeation activation energy value (28 kJ/mol), and (ii) gas pair selectivity increases at low temperatures and is high for gas pairs that present differences in permeation activation energies as high as 15 kJ/mol for the CO₂/CH₄ gas pair. Furthermore, the study with pressure variations shows that: (i) at elevated pressure, the PU and the blend membrane permeability to CO₂ and H₂ increases by approximately 35%, and (ii) oxygen-to-nitrogen selectivity increases with pressure as a consequence of the decrease in the permeability to nitrogen in the case of the 30%-PMMA blend.     

High resolution gas chromatographic determination of the atmospheric reactivity of engine-out hydrocarbon emissions from a spark-ignited engine

The reactivities of engine-out exhaust hydrocarbon (HC) emissions in photochemical smog formation have been determined for three fuels (isooctane, an aromatic blend, and a gasoline) in a single-cylinder, spark-ignited engine. High resolution capillary GC was used to determine the mole fractions of the exhaust hydrocarbon species. Temperature programmed chromatography on a single capillary column was sufficient to separate the major exhaust species. A library of approximately 160 hydrocarbon species was used to identify typically 90–95 % of the HC species present. GC-MS was used selectively to verify peak assignments. The effect of engine operating parameters (fuel-to-air ratio, spark timing, and speed) on reactivity was examined. Engine operating parameters affect both total emissions [g/mile] and the specific atmospheric reactivity [g ozone/g HC emissions] of these emissions. Changing the operating parameters to control total emissions may not be as effective as expected in controlling the total reactivity [g ozone/mile] of the emissions because the specific reactivity can also change simultaneously. Effects of changes in operating parameters differ significantly as the type of fuel is varied. The ability to measure exhaust hydrocarbon species emissions accurately and quickly will increase in importance as reactivity-based emissions standards come into widespread use.     

The performance,emissions, and combustion characteristics of an unmodified diesel engine running on the ternary blends of pentanol/safflower oil biodiesel/diesel fuel

Journal of Thermal Analysis and Calorimetry - The objective of the present study is to scrutinize the influence of a binary blend of diesel–safflower oil biodiesel and ternary blends of...     

高效液相色谱法测定氨纶企业废气中4种酰胺类化合物

采用高效液相色谱法测定氨纶企业废气中4种酰胺类化合物.使用内部装有高纯水的多孔玻璃板吸收管采集空气和废气样品,用0.22μm针式滤器过滤吸收液,使用Shim-pack GIST C18色谱柱(250 mm×4.6 mm,5μm)分离,以乙腈–水作为流动相等度洗脱,用紫外检测器单波长检测,色谱峰面积外标法定量.甲酰胺、二...     

Numerical study on thermal performance of TiO2, Fe3O4 and NiCr/engine oil in an inclined wavy pip

The essential intention of the existing article is to illustrate the effect of wall properties on flow and thermal behavior, through a sinusoidal inclined wavy pipe. To succeed this phenomena we assume a sinusoidal pipe consist of wavy surface, whose walls traveling down to its borders and located at an inclined position, moreover titanium dioxide (TiO₂), ferrosoferric oxide (Fe₃O₄) and nichrome (80% Ni and 20% Cr) are considered as nano-particles and unused engine oil is assumed as a base fluid. The arising mathematical equations for thermal and flow ratio with wall slip impact are solved by mathematica. Also, evaluate graphically the thermal and flow behavior of nanofluids for multi values of solid volume fractions (η), rigidity parameter (M₁), stiffness parameter (M₂), viscous damping parameter (M₃), Grashof number (G_r), slip parameter (β) and heat generation parameter (H) also discuss the streamlines for different values of solid volume fraction.     

Numerical investigation on the heat transfer performance inside sublimator driven coldplate for aerospace applications

Journal of Thermal Analysis and Calorimetry - Sublimator offers effective heat rejection for the spacecraft, which work in warm environments or with peak heat loads, by evaporating or sublimating...     

A CFD analysis on the effect of tube curvature,hot flow control valve profile,and inlet swirl on the thermal performance of curved vortex tubes

Journal of Thermal Analysis and Calorimetry - The influence of tube curvature, conical valve geometry, and initial swirl on the thermal performance of vortex tubes is numerically investigated....     

Quantifying temperature and flow rate effects on the performance of a fixed-bed chromatographic reactor

Chromatographic reactors are based on coupling chemical reactions with chromatographic separation in fixed-beds. Temperature and flow rate are important parameters for the performance of such reactors. Temperature affects mainly adsorption, chemical equilibria, mass transfer and reaction kinetics, whereas flow rate influences residence time and dispersion. In order to evaluate the mentioned effects, the hydrolysis reactions of methyl formate (MF) and methyl acetate (MA) were chosen as case studies. These reactions were performed experimentally in a lab-scale fixed-bed chromatographic reactor packed with a strong acidic ion exchange resin. The chosen reactions can be considered to represent a relative fast (MF) and a relative slow (MA) reaction. The processes which take place inside the reactor were described and simulated using an isothermal equilibrium dispersive model. The essential model parameters were determined experimentally at different temperatures and flow rates. The performance of the chromatographic reactor was evaluated at several discrete constant temperature levels by quantifying product purity, productivity and yield. The work provides insight regarding the influence of temperature and flow rate on values of the model parameters and the performance criteria.