Increase In Nitrogen Oxides Research Articles

Mechanical properties evaluation and microstructural analysis study of ceramic-coated IC engine cylinder liner

In the automotive industry, the primary objectives are to bring down the fuel consumption and boost power. The diesel engine has the best performance of any conventional internal combustion engine because of its extraordinarily high compression ratio. Gasoline engines consume more fuel per unit of power than diesel ones, whilst the two have the same performance. Only 40% of the power generated by an engine is utilized for productive purposes on average. Thirty percent of the remaining heat is lost through the exhaust, and another thirty percent is dissipated as heat losses by the cooling system. Ceramic and YSZ Coatings are applied to the cylinder liners and the piston head to transform the heat generated by the combustion process into meaningful mechanical work. As a result, the engine's heat transmission will be reduced, increasing efficiency. The higher gas temperature is expected to minimize the concentration of incomplete combustion products at the expense of an increase in nitrogen oxides (NOx). Scanning Electron Microscopy (SEM) and optical microscopy studied an engine cylinder liner's top-ring reversal point surface texture. Experiments were done on a single spark ignition engine during the break-in stage and the texture of the cylinder liner is studied.

Investigating and optimizing the mixture of hydrogen-biodiesel and nano-additive on emissions of the engine equipped with exhaust gas recirculation

The current research was conducted with the aim of investigating the combined effect of diesel, biodiesel, hydrogen, aluminum oxide nanoparticles (Al2O3) and Exhaust Gas Recirculation (EGR) system on diesel engine emissions and performance. Data analysis showed that with a 30% increase in biodiesel, the amounts of Hydrocarbons (HC) and Carbon Monoxide (CO) decreased by 11.7% and 14.9%, respectively. However, it reduced power and torque. Increasing the share of EGR in the intake air decreased the power and torque due to the decrease of oxygen, and by adding 30% of the exhaust gas to the intake air, it reduced the amount of HC by 3.2%. However, it caused an increase in CO. By increasing the concentration of Al2O3 from 30 ppm to 60 ppm, the amount of HC decreased by 5.4%. Further increase to 90 ppm reduced CO by 5.8% but increased nitrogen oxides (NOx) by 8%. However, the torque increased by 4.89%. Increasing hydrogen by 10% of intake air volume increased power and torque by 16%, but also increased CO by 7.19%. However, further increase of hydrogen decreased power and torque. The optimal point obtained for Al2O3, hydrogen, biodiesel and EGR compounds was 61, 10, 20 and 15% ppm, respectively.

Influence of air and water vapor on EEDF, plasma parameters, and the main RONS in atmospheric pressure low temperature helium plasmas: Global model approach

A zero-dimensional global model is developed with an aim to study the influence of air and water vapor on an electron energy distribution function, electron density, and temperature as well as on the chemical composition of atmospheric pressure helium plasmas, with special focus on the main reactive oxygen and nitrogen species important for applications of low temperature plasmas. The main channels for the production and consumption of electrons and electron energy gain and loss are examined by a global model based on a parametric study with variations of the mole fractions of air and water vapor. The calculations are done for 100, 1000, and 10 000 ppm of air in plasma, and for each of these values, the content of water vapor is taken to be 100, 1000, 2000, …, to 10 000 ppm. The variations of the most important production and consumption processes for reactive oxygen and nitrogen species are analyzed in detail. According to the results presented in this paper, water vapor highly contributes to electronegativity of the plasma through pronounced attachment of electrons, which then leads to an increase in electron temperature. For high water vapor content, vibrational excitations of water molecules are one of the main electron energy loss processes, leading to a further effect on the plasma composition. Water decreases concentrations of atomic oxygen, nitrogen, and ozone, while there is an increase in nitrogen oxide, OH, H2O2, and HO2 concentrations. Cross-sectional data for electron scattering on ground and excited state neutrals are mainly taken from the Quantemol-DB database.

Recent advancement in the application of metal based nanoadditive in diesel/biodiesel fueled compression ignition engine: A comprehensive review on nanofluid preparation and stability, fuel property, combustion, performance, and emission characteristics

AbstractBiodiesel has emerged as a promising renewable fuel, which can help reduce dependency on fossil fuel and has potentiality to replace petrodiesel partially. Usage of biodiesel results in decreased carbon monoxide, hydrocarbon, and particulate matter emission. However, it has some drawbacks such as increased nitrogen oxides (NOx) emission, lower calorific value, and poor engine performance, which restrict wide usage of biodiesel as a potential substitute in compression ignition engine. There is a scope to overcome these problems by applying metal based nanoparticles (NPs) as fuel additive. This article reviews the preparation and stability of nanofluid and the effect of metal based NPs on fuel properties, combustion, performance, and emission characteristics. It has been concluded that inclusion of nanoadditives increases cetane number and calorific value of blended fuel. According to the most authors, metal based NP doped biodiesel blend enhances ignition characteristics, improves engine performance, and reduces emissions including NOx compared to biodiesel blend without additive. However, some concerns and challenges identified in this article need to be addressed to make this technology feasible for commercial application in near future.

Increase in nitrogen oxides due to exhaust gas recirculation valve manipulation

Exhaust gas recirculation (EGR) is a known method of reducing nitrogen oxides (NOX), but the impact of its deactivation on emissions has not been quantified. This paper, therefore, considers the impact of deactivating the EGR valve on NOX emissions in a diesel Euro 5 vehicle. The measurements were performed during nine driving cycles and in all cases, a significant increase in NOX emissions was found when the EGR valve was deactivated. NOX emissions increased between 176% and 407%, depending on the cycle driven. Measurement results indicate the origin of significant amounts of NOX emissions. Recommendations are to inform regulatory authorities about the effects of such manipulations in order to adopt more stringent measures and introduce them during periodic technical inspection of vehicles with the view to preventing such interventions.

Qingda granule alleviate angiotensin ⅱ-induced hypertensive renal injury by suppressing oxidative stress and inflammation through NOX1 and NF-κB pathways

Hypertension has become one of the important diseases harmful to human health. In China, Qingda granule (QDG) has been used to treat hypertension for decades. Previous studies by our team have shown that oxidative stress may be one of the pathways through which QDG inhibits hypertension-induced organs injury. However, the specific molecular mechanism of its anti-hypotension and renal oxidative stress response were unclearly. This study investigated QDG’s potential protective mechanism against hypertension-induced renal injury. Mice were infused with Angiotensin Ⅱ (Ang Ⅱ, 500 ng/kg/min) or equivalent saline solution (Control) and administered oral QDG (1.145 g/kg/day) or saline for four weeks. QDG treatment mitigated the elevated blood pressure and reduced renal pathological changes induced by Ang Ⅱ. As per the RNA sequencing results, QDG affects oxidative stress signaling. In agreement with these findings, QDG significantly attenuated the Ang Ⅱ-induced increase in Nitrogen oxides 1 (NOX1) and reactive oxygen species and the decrease in superoxide dismutase in renal tissue. Additionally, QDG significantly inhibited Interleukin 6 (IL-6), Tumor necrosis factor α (TNF-α), and Interleukin 1β (IL-1β) expression in renal tissues and blocked the phosphorylation of P65 (NF-κB subunit) and IκB. These results were confirmed in vitro. Overall, QDG reduced Ang Ⅱ-induced elevated blood pressure and renal injury by inhibiting oxidative stress and inflammation caused by NOX1 and NF-κB pathways. The results of this study provide an experimental basis for the clinical application of QDG, and to open up a new direction for the clinical treatment of hypertension.

Influence of nanoparticles on emission and performance characteristics of biodiesel-diesel blends in a DI diesel engine

ABSTRACT In this experimental work, the effects of copper oxide (CuO) nanoparticles on emissions and performance of 4.4 kW diesel engine powered by palm biodiesel were studied. Palm biodiesel of 20% by volume was blended with diesel fuel (B20). Each test fuel blend was doped with CuO nanoparticles with concentrations of 25, 50, and 75 ppm. Experimentations were carried out for 0%, 25%, 50%, 75%, and 100% engine loads at a constant speed of 1500 rpm. Different parameters, such as brake thermal efficiency (BTE), brake-specific energy consumption (BSEC), carbon monoxide (CO), carbon dioxide (CO2), hydrocarbons (HC), nitrogen oxides (NOx), and smoke opacity were analysed. From the results, it is observed that by using CuO nanoparticles along with B20, BTE (1.18%-7.69%) were significantly increased and BSFC (4.12%-6.76) were lowered. Besides, by using CuO nanoparticles, there were also substantial reductions in CO (2.21%-8.86%). Furthermore, there is an insignificant increase in HC (0.3%-9.78%), CO2 (2.38%-5.97%), and NOx (1.75%-5.27%) emissions when compared to B20 blend. However, when compared to diesel fuel all the emissions were low for all biodiesel blends except NOx emission. Overall, it is concluded that CuO could be considered as a appropriate petroleum additive for palm biodiesel blends.

Effects of start of injection and exhaust gas recirculation on dual fuel combustion of isobutanol with diesel and waste cooking oil biodiesel in a diesel engine at higher loads

Dual fuel combustion (DFC) is one of the current emission reduction methods adopted widely for diesel engines. In DFC, high-octane fuels (alcohol) are port injected and high cetane fuels (diesel, biodiesel) are directly injected into the cylinder. However, DFC is reported to increase nitrogen oxides (NOx) compared to conventional combustion mode (CCM) at higher loads. Hence, to mitigate NOx emission in DFC of isobutanol (IB) with diesel, B20, and B100 fuels at higher loads (80 and 100%), the influences of start of injection (SOI) and exhaust gas recirculation (EGR) are investigated. The baseline SOI of DFC fixed at 27°CA before top dead center (bTDC) is retarded to 25, 23, and 21°CA bTDC, and varying EGR (10, 15, and 20%) is implemented at the baseline SOI. Significant NOx reductions of 47.11, 52.53, and 54.45% at the SOI of 21°CA bTDC (at 100% load) and 41.74, 46.38, and 47.81% at 20% EGR (at 80% load) are achieved in the DFC of diesel, B20, and B100 respectively, vis-a-vis their CCM. In DFC of D-IB and B20-IB, retarded SOIs and 10% EGR exhibited better NOx/smoke trade-off than their CCM. Overall, all the DFCs with SOI of 25°CA bTDC as well as 10% EGR is suitable operating conditions compared to CCM.

Emissions of NOx from blending of hydrogen and natural gas in space heating boilers

As part of climate change commitments, the United Kingdom is considering an incremental transition from natural gas to hydrogen for domestic heating, blending up to 20% of hydrogen (by volume) into the national gas network. We consider the possible impacts of this policy on nitrogen oxides (NOx) emissions, a minor waste by-product from combustion. A meta-analysis of changes in NOx emissions from hydrogen/natural gas blends used in gas burners is undertaken, with focus on mixtures between 5% and 20% v/v. Literature reports are highly variable: for a 5% hydrogen blend, changes in NOx emissions, when compared to burning pure natural gas, vary over the range –12% to +39%, with a mean change across 14 studies of +8%. These estimates required an important assumption to be made that, when not explicitly described, all literature data on changes in NOx emissions and/or concentrations were suitably corrected for the reduced energy density and heat output arising once hydrogen is added. A NOx increase can be rationalized through the increased adiabatic flame temperature generated from hydrogen combustion. The associated range of plausible damage costs of a 5% hydrogen blend is estimated to fall within the range –117 million GBP to +362 million GBP per year; 20% hydrogen (the maximum that could be accommodated with existing infrastructure) would lead to a change in emissions in the range –50 to +154% with a change in damage costs of between –467 million GBP and +1,146 million GBP per year. The mean change is estimated at 292 million GBP per year. For existing poor performing boilers, an economic case can be made for scrappage and replacement based primarily on NOx damage costs avoided. The response of older boilers to added hydrogen is a critical evidence gap that needs filling before further decisions on hydrogen as a heating fuel are made.

Experimental Investigation and RSM Modeling of the Effects of Injection Timing on the Performance and NOx Emissions of a Micro-Cogeneration Unit Fueled with Biodiesel Blends

The (partial or total) substitution of petro-diesel with biodiesel in internal combustion engines (ICEs) could represent a crucial path towards the decarbonization of the energy sector. However, critical aspects are related to the controversial issue of the possible increase in Nitrogen Oxides (NOx) emissions. In such a framework, the proposed study aims at investigating the effects of biodiesel share and injection timing on the performance and NOx emissions of a diesel micro combined heat and power (CHP) system. An experimental campaign has been conducted considering the following operating conditions: (i) a reference standard injection timing (17.2° BTDC), an early injection timing (20.8° BTDC), and a late injection timing (12.2° BTDC); (ii) low (0.90 kW), partial (2.45 kW), and full (3.90 kW) output power load; and (iii) four fuel blends with different biodiesel (B) shares (B0, B15, B30, and B100). Experimental data were also elaborated on thanks to the response surface modelling (RSM) technique, aiming at (i) quantifying the influences of the above-listed variables and their trends on the responses, and (ii) obtaining a set of predictive numerical models that represent the basis for model-based design and optimization procedures. The results show: (i) an overall improvement of the engine performance due to the biodiesel presence in the fuel blend —in particular, B30 and B100 blends have shown peak values in both electrical (29%) and thermal efficiency (42%); (ii) the effective benefits of late SOI strategies on NOx emissions, quantified in an overall average NOx reduction of 27% for the early-to-late injection, and of 16% for the standard-to-late injection strategy. Moreover, it has emerged that the NOx-reduction capabilities of the late injection strategy decrease with higher biodiesel substitution rates; through the discussion of high-prediction-capable, parametric, data-driven models, an extensive RSM analysis has shown how the biodiesel share promotes an increase of NOx whenever it overcomes a calculated threshold that is proportional to the engine load (from about 66.5% to 85.7% of the biodiesel share).

RETRACTED: Exploration over combined impacts of modified piston bowl geometry and tert-butyl hydroquinone additive-included biodiesel/diesel blend on diesel engine behaviors

Nowadays, the use of biodiesel for diesel engines has been attracting researchers aiming to improve engine characteristics although the engine performance could be decreased while utilizing biodiesel. In this aspect, optimizing the piston bowl geometry is one of the useful approaches to enhance the efficiency of the biodiesel-powered diesel engine. In this study, the standard piston of an existing diesel engine was modified into two different combustion bowls, namely Symmetrical Stepped Curved-V (SSCV) and Symmetrical Spline-V (SSV), to evaluate the CI engine performance powered with mixtures of sesame-originated biodiesel, diesel fuel, and tert-butyl hydroquinone (TBHQ) additive through two-stage experiment. In the first phase, experiments were carried out on two modified piston bowls powered by diesel and S20 (20% sesame biodiesel + 80% diesel fuel). Resultantly, SSV piston revealed superior engine characteristics to SSCV piston and standard piston due to enhanced air–fuel mixing and more complete combustion of SSV piston-based engine. Indeed, SSV piston operation exhibited an 8.68% of increased brake thermal efficiency (BTE), 6.54% of curtailed brake-specific fuel consumption (BSFC), 4.76% of lowered carbon monoxide (CO), 4.84% of decreased unburnt hydrocarbon (HC), and 2.22% of lowered smoke opacity but with increased nitrogen oxide (NOx) by 14.14% in comparison to diesel. In the 2nd phase, to control the NOx emission effectively, a TBHQ additive was added to the S20 sample at different proportions (500 mg and 1000 mg) to analyze the test engine behaviors with modified piston shapes. As a result, S20 + 500 mg TBHQ at 100% load improved BTE by 5.79% and reduced BSFC by 4.36% in the case of SSV piston. Moreover, it curtailed emissions of CO, HC, NOx, and smoke opacity by 13.33%, 15.49%, 12.09%, and 9.44%, respectively, when equated with diesel. Overall, S20 + 500 mg TBHQ could be thought of as a possible alternative fuel on SSV piston as it resulted in superior performance and emission characteristics in the existing standard engine. The current study's findings could pave the way for the development of diesel engines with modified piston geometry that is more efficiently compatible with biodiesel blends and additives.

Effect of Injection Parameters on the Performance of Compression Ignition Engine Powered with Jamun Seed and Cashew Nutshell B20 Biodiesel Blends

Renewable fuels are alternative resources that find use in the power generation, agricultural, and transportation sectors. The sustainable utility of these renewable fuels mostly addresses the socio-economic issues of a country and reduces its dependency on fossil fuels. In addition, being environmentally friendly allows them to handle global warming more effectively. Two B20 fuel blends were produced using methyl esters of cashew nutshell and jamun seed oils to test the performance of the common rail direct injection engine. To improve the engine performance, injection parameters such as nozzle geometry, injection time, and injector opening pressure are used. Improved brake thermal efficiency and lower emissions of smoke, hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxides (NOx) were achieved with the help of advancing the injection timing, raising the injector opening pressure, and increasing the number of injector nozzle holes. In addition to reducing the ignition delay, extending the combustion duration, and increasing the peak pressure, the revised injection settings also boosted the heat release rates. At the maximum load, compared to CHNOB B20, JAMNSOB B20 showed a significant rise in the brake thermal efficiency (BTE) by 4.94% and a considerable decrease in smoke emissions (0.8%) with an increase in NOx (1.45%), by varying the injection timing, injection pressure, and nozzle geometry of the common rail direct injection (CRDI) engine.

Performance, Exhaust Emissions and Optimization Using Response Surface Methodology of a Water in Diesel Emulsion on Diesel Engine

The use of water in diesel is an alternative to counteracting the increase in nitrogen oxide (NOx) emissions from diesel engines. However, some other criteria such as combustion performance and thermal efficiency were slightly reduced due to the impact of water content in diesel fuel. In other words, optimizing the balance between engine performance and emissions has always been a major problem in automotive industries. The purpose of this article is to demonstrate the use of RSM (response surface methodology) to improve the performance and emissions of a compression ignition (CI) engine which works on 5%, and 10% water mixes dubbed WD5 and WD10. This mixture of water emulsion to diesel is produced by using emulsifier ultrasonic. Tests were then performed on the Isuzu 4JJ1 4-cylinder 3000cc test bed engine with water cooled. Changes to engine load 20% to 50% and speeds of 1000rpm to 3000rpm. Experimental results data is then included in the Design Expert software to analyze the performance, emissions and optimization values using CCD Techniques in RSM. In performance analysis, pure diesel and WD5 are comparable with respect to power, heat efficiency of brakes and brakes of certain fuel consumption (BSFC). At higher loads, increased BTE levels and a neat BSFC drop were found. However, the combustion period is shorter. NOx and CO data slightly decreased with the same increase in water percentage at the same engine speed and load. However, the CO2 data showed a sharp increase with the increase in water content in fuel. Optimum engine operating parameters found as 5% water ratio, 50% of load and 2446 rpm while the best output parameters found as 103.7 Nm. of torque, 26.3 kW power, 43.8% BTE, 172 g/kWh BSFC, 521.8ppm NOx and 3.1% of CO.

Effect of ammonia addition on combustion and emission characteristics of hydrogen-fueled engine under lean-burn condition

Hydrogen (H 2 ) is a carbon-free fuel with many excellent combustion characteristics, but abnormal combustion is one of the main obstacles to the promotion and application of hydrogen-fueled engines. This experimental study aims to investigate the suppression of the heat release rate (HRR) of a hydrogen-fueled engine through the addition of ammonia (NH 3 ). The engine was run at 1300 rpm, with manifold absolute pressure (MAP) of 61 kPa and NH 3 addition ratio of 0% and 2.2%, under lean-burn conditions. The results showed that the addition of small amounts of ammonia reduced the combustion rate of the fuel mixture, prolonged the flame development period (CA0-10) and propagation durations (CA10-90) of the engine, and reduced the peak in-cylinder pressure and peak HRR under lean-burn conditions. The addition of ammonia increased the peak indicated mean effective pressure (IMEP) and the peak indicated thermal efficiency (ITE) of the engine. The addition of ammonia resulted in increased nitrogen oxides (NOx) emissions. • The effect of ignition timing of an H 2 /NH 3 dual-injection engine was studied. • Reduces the peak heat release rate after ammonia was added. • CA0-10 and CA10-90 were extended after ammonia was added. • The peak IMEP and ITE were increased after ammonia was added.

Improvement of stomatal resistance and photosynthesis mechanism of Noah-MP-WDDM (v1.42) in simulation of NO<sub>2</sub> dry deposition velocity in forests

Abstract. Rapid urbanisation and economic development in China have led to a dramatic increase in nitrogen oxide (NO2) emissions, causing serious atmospheric nitrogen pollution and relatively high levels of nitrogen deposition. However, despite the importance of nitrogen deposition, dry deposition processes in forested areas are still insufficiently represented in current global and regional atmospheric chemistry models, which constrains our understanding and prediction of spatial and temporal patterns of nitrogen transport in forest ecosystems in southern China. The offline 1-D community Noah land surface model with multi-parameterisation options (Noah-MP) is coupled with the WRF-Chem dry deposition module (WDDM) and is applied to further understand and identify the key processes that affect forest canopy dry deposition. The canopy stomatal resistance mechanism and the nitrogen-limiting scheme for photosynthesis in Noah-MP-WDDM are modified to improve the simulation of reactive nitrogen oxide dry deposition velocity. This study finds that the combined improved stomatal resistance mechanism and nitrogen-limiting scheme for photosynthesis (BN-23) agree better with the observed NO2 dry deposition velocity, with the mean bias being reduced by 50.1 %. At the same time, by comparing the different mechanisms of the two processes of canopy stomatal resistance and leaf nitrogen-limiting factors, this study also finds that the diurnal changes in dry deposition velocity simulated by each regional model present four sets of distributions. This is mainly due to the different ways that each integrated mechanism handles the opening and closing of stomata at noon and the way the nitrogen-limiting factor acts.

Optical and thermodynamic investigations of a methane and hydrogen blend fueled large bore engine

The following paper presents thermodynamic and optical investigations of the natural flame and OH radical chemiluminescence of a hydrogen enriched methane combustion compared to natural gas combustion. The engine under investigation is a port-fueled unscavenged prechamber 4.8 L single cylinder large bore engine. The blends under consideration are 2%V, 5%V,10%V, and 40%V of hydrogen expected to be blended within existing natural gas grids in a short and mid-term timeline in order to store green energy from solar and wind. These fuel blends could be used for stabilization of the energy supply by reconverting the renewable fuel CH4/H2 in combined heat and power plants. As expected, admixture of hydrogen extends the ignition limits of the fuel mixture toward lean ranges up to an air-fuel equivalence ratio of almost 2. No negative effect on combustion is observed up to an admixture of 40%V hydrogen. At 40%V hydrogen, abnormal combustion like backfire occurs at an air-fuel equivalence ratio of 1.5. The higher mixtures exhibit increased nitrogen oxide emissions due to higher combustion chamber temperatures, while methane slip and CO emissions are reduced due to more complete combustion. The optical investigation of the natural flame and OH radical chemiluminescence are in good agreement with the thermodynamic results verifying the more intense combustion of the fuel blends by means of the chemiluminescence intensity. Further, lube oil combustion and a continuing luminescence after the thermodynamic end of combustion are observed.

Diesel engine behavior using coconut oil methyl esters and its blends

Diesel engines are renowned for its reliable performance. However, it continues to be a major polluter in terms of nitrogen oxides and smoke. Many researches are working on the adaptability of vegetable oil methyl ester (biodiesel) for lowering emissions of smoke, hydrocarbons, and carbon monoxide. This may be performed by delivering more amount of oxygen available within the cylinder. Also, it is possible to do this by increasing the oxygen content of the intake air or by using oxygenated fuels (biodiesel), although certain biodiesels increase nitrogen oxide emissions. The biodiesel investigated in this study is coconut oil methyl ester (COME), and the outcomes of its blend are compared to diesel fuel operation. Transesterification was used to produce the fuel from coconut oil. COME's fatty acid composition and fuel characteristics were determined. COME is composed of around 90% saturated fatty acids. Apart from neat COME operation, the trials were carried out for various COME and diesel fuel blends of 20%, and 30%, COME in the fuel blend. The laboratory results reveal that neat COME and its blend operation resulted in decreased brake thermal efficiency, increase in NOx, and decrease in smoke and hydrocarbon emissions. However, it is concluded that COME and its blend can be used as an alternative fuel for compression ignition engines with a sacrifice of thermal efficiency.

A novel method to overcome the shortcomings of turbocharging a single cylinder diesel engine

Single-cylinder diesel engines are generally not turbocharged because of highly pulsating exhaust gas flow, resulting in increased speed fluctuations and reduced turbine performance. In the present work, a novel and simple method is proposed wherein an exhaust plenum is placed before the turbine to reduce the flow fluctuations. A production light-duty naturally aspirated (NA) diesel engine modified into the turbocharged version was incorporated with an exhaust plenum. Steady-state experiments were performed with the base naturally aspirated engine, the turbocharged version without an exhaust plenum (conventional pulse turbocharging), and the turbocharged version with the exhaust plenum. The present work attempts to establish the limitations of conventional pulse turbocharging in a single-cylinder diesel engine unavailable in the existing literature. Though the conventional pulse turbocharged version could deliver a boost pressure of about 2 bar (absolute), a brake power reduction of 40% and the associated drop in brake mean effective pressure was observed compared to the base NA engine due to high exhaust back pressures. The pumping work was four times higher in conventional pulse turbocharging than the NA engine, thus reducing the performance. After validating the simulation models, a one-dimensional simulation tool was used to evaluate the effect of incorporating exhaust plenum before the turbine. Simulated results predicted the brake power output within a 3% error for the NA and plenum turbocharging configurations. An optimal plenum volume was arrived at using the validated simulation model. Subsequent experiments on the turbocharged engine with the plenum in place showed a significant improvement in the engine performance and reduced exhaust emissions compared to the NA version. Brake power output was enhanced by 25%, which indicated improved thermal efficiency of 2%. Compared to the NA version, the soot, carbon monoxide (CO) and unburned hydrocarbon HC emissions were reduced by 93%, 88%, and 53%, respectively. However, an increase in oxides of nitrogen (NOx) emissions was seen, which can be controlled with suitable mitigation methods taking advantage of the significantly lower soot levels. Thus, the proposed method of placing an exhaust plenum before the turbine makes turbocharging viable on single-cylinder diesel engines with performance improvement and emission reduction when suitable NOx mitigation measures are adopted.

Combustion and spray breakup characteristics of biodiesel for cold start application

This study investigates the split injection spray characteristics of neem (unsaturated) biodiesel and diesel at cold (283 K) and hot (333 K) weather conditions. The novelty of this work lies in achieving the improved spray atomization and smooth engine combustion characteristics of unsaturated neem biodiesel using a split injection strategy. Biodiesel in a hot condition significantly improves spray dispersion and mixing. The Single-injection case of diesel shows fast combustion, rapid heat release, and increased nitrogen oxide (NOx) emissions. Split injection introduces fuel in steps, provides more time for fuel-air mixing, and delays the start of combustion (SoC). Diesel and biodiesel with split injection show smooth heat release, low combustion temperatures, and NOx emissions. Cold condition atomization of biodiesel remains a challenge even using the split injection strategy and requires biodiesel preheating.

Influence of nano additives with cashew nut shell bio-oil in CI diesel engine

Biodiesel is a unique diverse fuel source that aims to enhance the worth of fossil fuels and the endurance and hygiene of diesel engines. This cuts requirement on overseas fuels and decreases greenhouse gas productions because of closed carbon chain. The increased nitrogen oxide emissions and their irreconcilability with cold weather environments and the many advantages of biodiesel such as regular fuel filters, fuel reservoirs and fuel fuels for engine components are outweighed. The growth and the inclusion of nanoparticles for fuel additives have another potential to overcome the shortcomings. Cashews are high in tropical biomass surplus used to generate energy such as cerium oxide. Cobalt oxide and aluminums oxide can increase the property of non-additive CNSL and reduce deficiencies.