Brake Specific Fuel Consumption Research Articles

Optimization of multi‐response biodiesel fueled diesel engine parameters using Taguchi grey relational analysis and analytical hierarchy process

AbstractCompression ignition engines are currently optimized to run on petrodiesel fuel, but due to its increasing demand and depletion of fossil fuel reserves, alternative fuels must be utilized. In this article, an attempt was made to optimize the operating parameters of an unmodified compression ignition engine fueled with linseed methyl ester biodiesel. The input parameters were compression ratio, load, and fuel blend, while output responses included brake‐specific fuel consumption (BSFC), brake thermal efficiency (BTE), and exhaust gas temperature (EGT), peak cylinder pressure (PCP), the rate of pressure rise (RPR), and net heat release rate (NHR), hydrocarbon (HC), carbon monoxide (CO), NOx, and Smoke. The aim was to determine the optimal combination of input parameters for minimal emissions and better performance and combustion parameters, with a minimum number of experiments. The study used Taguchi's L9 orthogonal array with a grey relational analysis approach (GRA) to obtain the optimum combination of input parameters. The study found that fuel blend B10, CR 18, and load 100% were the optimal input parameter combinations using the TGRA method. The S/N ratio analysis of grey relational grade (GRG) showed the optimal input factor levels to be fuel B10, CR 16, and load 100%, which was confirmed by the AHP method. The analysis of variance (ANOVA) showed that the load was the most influential factor, followed by CR and fuel. The confirmatory results showed an improvement of 56.1%, indicating that biodiesel can be efficiently used in an unmodified compression ignition engine by varying these influencing factors.

The influence of thermal barrier coating (TBC) on diesel engine performance powered by using Mimusops elengi methyl ester with TiO2 nanoadditive

This current exploration aims for enhancing engine performance by using Mimusops elengi methyl ester 20% and 80% diesel with 25 ppm TiO2 [MEME20 + 25 ppm of titanium oxide] nanoparticle additive for the low heat rejection (LHR) engine. The coating of the piston crown was made with an insulation of two layers, initially, bond coat of nickel chromium aluminium yttrium (NiCrAlY) 50 µm and a topcoat 250 µm (5% yttrium + 2% neodymium oxide + 93% zirconium oxide) using the plasma spray coating technique. In comparison to diesel, the engine performance with MEME 20 + 25 ppm of titanium oxide resulted in enhancement in brake thermal efficiency (BTE) of 7.06% and a decrease in brake specific fuel consumption (BSFC) of 16.38%. The CO, HC and smoke values were curtailed by 35.66%, 31.8% and 19.66%, respectively, equated with diesel fuel. The NO x and EGT were increased by 22.23% and 9.33%, respectively, with full load at 1500 rpm.

Performance of Various Fuels: Gasoline, Liquefied Petroleum Gas and Biogas from Agricultural Biomass Waste in a Two-Stroke Internal Combustion Engine

The Philippines is an agricultural country with massive agricultural waste. The Biofuels Law (Republic Act 9367) aims to minimize the dependence on fossil fuels and encouraged the use of bio-based fuel sources as an alternative fuel in rural areas where farming is the only source of income, and energy is scarce. Biogas is a renewable energy carrier consisting of methane and carbon dioxide mixture. Because of its improved mixing ability with air, clean-burning nature and high-octane number that resists knocking, biogas is an excellent alternative source of energy for internal combustion engines. The single-cylinder two-stroke spark-ignition (43 cm3) was designed to be fed with a variety of fuel in order to assess engine performance parameters such as brake power, brake speed, brake-specific fuel consumption (BSFC) and thermal efficiency at different throttling positions (low- and high-load throttle). This study evaluated the engine performance of biogas (cow, swine and cow-swine manure), liquefied petroleum gas (LPG) and gasoline with two-stroke engine oil (2T) in a dynamometer without modifying the compression ratio. To optimize its use as a fuel for power generation, biogas was purified using hydrogen sulfide adsorption and carbon dioxide absorption. The results showed that biogas fuel from swine manure generated the highest electrical power load of 761 W with a methane concentration of 51% and a BSFC of 1.4 kg/kW-h. The LPG achieved the highest engine speed at 14,700 rpm with 549 W. In conclusion, the purified biogas fuel can be used in a small-scale internal combustion engine.

Investigations on reactivity controlled compression ignition combustion with different injection strategies using alternative fuels produced from waste resources

Reactivity-controlled compression ignition (RCCI) is a promising low-temperature combustion (LTC) strategy that results in low oxides of nitrogen (NOx) and soot emissions while maintaining high thermal efficiency. At the same time, RCCI leads to increased unburned hydrocarbon (HC) and carbon monoxide (CO) emissions in the exhaust, particularly under low loads. The current work experimented novel port-injected RCCI (PI-RCCI) strategy to overcome the high unburned emission limitations at low load conditions in RCCI. PI-RCCI is a port injection strategy in which low-reactivity fuel (LRF) is injected using a low-pressure injector, and the high-reactivity fuel (HRF) is injected through a high-pressure common rail direct injection (CRDI) injector. The low volatile HRF is injected into a heated fuel vaporizer maintained at 180°C in the intake manifold during the suction stroke. Modifying a single-cylinder, light-duty diesel engine with the necessary intake and fuel injection systems allows engine operation in both RCCI and PI-RCCI modes. Alternative fuels from waste resources such as waste cooking oil biodiesel (WCO) and plastic waste oil (WPO) are used as the HRF and LRF fuel in RCCI and PI-RCCI. To achieve maximum thermal efficiency in RCCI, the premixed energy ratio and the start of injection of the direct-injected fuel are optimized at all load conditions. The engine performance and exhaust emissions characteristics in PI-RCCI are compared with RCCI as a baseline reference. The results show a 70% and 48% reduction in CO and HC emissions, respectively, in PI-RCCI than in RCCI. Further, the brake thermal efficiency (BTE) was enhanced by around 20%, and the brake-specific fuel consumption (BSFC) was reduced by 13% in PI-RCCI. The NOx emissions decreased without any considerable changes in soot emission in PI-RCCI. The current study shows that fuels derived from waste resources can be used in RCCI and PI-RCCI modes with better engine performance and lower emissions.

The Effect of Biodiesel, Ethanol, and Water on the Performance and Emissions of a Dual-Fuel Diesel Engine with Natural Gas: Sustainable Energy Production through a Life Cycle Assessment Approach

Diesel fuel (DF) is a significant power supply in agricultural, industrial, and transportation applications. Establishing sustainable and renewable fuel substitutes for diesel has become increasingly common due to the rising expense of petroleum resources and the pollution rate crises. A biodiesel-DF mixture in a dual-fuel (DuF) diesel engine (DE) can bring favorable environmental results. In the present study, three rates of ethanol (0, 2, and 4%), two rates of biodiesel (0 and 5%), and four rates of water (0, 0.3, 0.6, and 0.9%) were blended with DF. All these samples were considered pilot fuel (PF) in the DuF combustion process with an 80% natural gas (NG) replacement percentage. The combustion process was investigated from engine emissions and performance, power cost, and life cycle assessment (LCA) to obtain a sustainable fuel formulation. As a result, water, ethanol, and the combination of water-ethanol and NG can enhance the DE’s performance by rising the inside pressure of the cylinder. The presence of oxygen content in ethanol can improve the combustion process by pushing the combustion towards complete combustion. The optimum engine performance point at full load was obtained with a fuel sample containing 1.57% biodiesel, 4.38% ethanol, 1.1% water, and 80% NG. In optimum condition, the brake power (BP) was 24.16 kW, and the brake-specific fuel consumption (BSFC) was 60.64 g/kWh. This fuel sample produces 0.46, 364.08, 1.66, and 1088.29 g/kWh of BSCO, BSCO2, BSNOx, and BSO2, respectively. At this point, the energy production cost was $0.783/kWh. The environmental impacts of the combustion process at optimal fuel formulation were 0.34249, 1.00 E + 02 , 1.53 E + 00 , and 1.94 E − 06 , respectively, for ecosystem quality (EQ) (PDF ∗ m2 ∗ yr), resources (R) (MJ primary), climate change (CCh) (kg CO2 eq), and human health (HH) (DALY). Accordingly, the best fuel combination was selected to be NG+B1.5E4.3W1.1.

Development of a fuzzy logic model for the prediction of spark-ignition engine performance and emission for gasoline–ethanol blends

Abstract Due to the enormous of fossil fuels and the ensuing increase in automobiles, an unprecedented scenario has arisen with pollution levels that are out of human control. In this study, a fuzzy logic model is developed to predict how well a spark-ignition engine running on gasoline and ethanol mixes would operate. A test engine was operated on pure gasoline and gasoline–ethanol fuel mixtures in a range of ratios at varying engine speeds. In order to estimate outputs such as brake-specific fuel consumption (BSFC), brake thermal efficiency, nitrogen oxides (NOx), hydrocarbon emissions, and carbon monoxide, a fuzzy logic model, a sort of logic model application, has been developed using experimental data. The developed fuzzy logic model’s output was compared to the results of the trials to see how well it performed. The output parameters were indicated, including braking power, thermal, volumetric, and mechanical efficiency. The input parameters were engine speed and ethanol mixes. Regression coefficients were nearly equal for training and testing data. According to the study, a superior method for accurately forecasting engine performance is the fuzzy logic model. To eliminate proportionality signs from equations, regression analysis is used. It is accurate to develop mathematical relations based on dimensional analysis. Based on the root mean square errors, BSFC is a minimum of 6.12 and brake power is a maximum of 8.16; lower than 2% of errors occur on average.

Performance and emissions of a diesel engine burning blends of Jatropha and waste cooking oil biodiesel

Blending of biodiesels is a straightforward but efficient solution to the issue of improving biodiesel characteristics in cold climates. A comparison of emissions and performance of a diesel engine powered by methyl ester blends made from jatropha and waste cooking oil (WCO) was investigated. Jatropha oil was converted into biodiesel through esterification and transesterification, but WCO biodiesel was produced by transesterification. Volume percentages of WCO and jatropha biodiesels as 5, 10, 15, 20, and 100% were prepared. Peak improvements in brake thermal efficiency (BTE) were 7% and 6% for JB20 and WB10 + JB10, respectively, at 75% of engine output power over diesel fuel. Maximum reductions in brake specific fuel consumption (BSFC) related to diesel oil were for JB20 and WB10 + JB10 6 and 5%, respectively. For JB100, the maximum increase in exhaust gas temperature over diesel oil was 45%. For WB10 + JB10, the maximum reduction in carbon dioxide (CO2) emission about pure diesel was 10%. WB10 + JB10 blend had carbon monoxide (CO) emission reduction up to 6% than fossil diesel. For WB10 + JB10, the maximum reduction in nitrogen oxides (NOx) emission relative to crude diesel was 10%. WB10 + JB10 had the greatest reduction in smoke emission when compared to diesel oil as 22%. WB10 + JB10 had the largest reduction in unburned hydrocarbons (HC) of 14% over diesel oil at 75% of output power. In comparison to other fuels, the WB10 + JB10 and JB20 biodiesel blends produce better engine performance and lower emissions as compared to other biodiesel blends. As an alternative fuel in conventional diesel engines, it is recommended to use a mixture of jatropha and WCO biodiesels of 10% by volume.

Numerical investigations on the effects of EGR routes on the combustion characteristics and efficiency of a heavy-duty SI methanol engine

Exhaust gas recirculation (EGR) is one effective strategy to improve the thermal efficiency of the heavy-duty spark-ignition (SI) methanol engine. The high EGR tolerance of methanol engine raises new requirements for the EGR system. In this study, the influences of three different EGR routes, high-pressure EGR (HP-EGR), low-pressure EGR (LP-EGR), and high-low-pressure EGR (HLP-EGR) on the engine performance were studied by the one-dimensional simulation with the predictive combustion sub-model. The investigation was conducted at 1000 rpm and 1400 rpm, and 50% and 100% full load. Results show that EGR routes influence both the combustion characteristics and pumping mean effective pressure (PMEP), thus affecting the brake specific fuel consumption (BSFC). The EGR route with the lower internal EGR rate has a lower in-cylinder temperature at the compression stroke, a weaker knock tendency and a more advanced combustion phase. The effects of EGR routes on BSFC are more significant at the higher engine speed. The optimal BSFC of HP-EGR is lower than that of HLP-EGR and LP-EGR by up to 16.4 g/k·Wh and 21.2 g/k·Wh. Considering the engine performance at all engine operating conditions, HP-EGR is the optimal EGR route while LP-EGR is the worst one for the heavy-duty SI methanol engine.

Enhancement of the applicability of Jatropha biodiesel in a diesel engine using n-heptanol and multiwalled carbon nanotube additives

ABSTRACT Jatropha is a promising ecological fuel source for diesel engines owing to its benefits, including sustainability, accessibility, and reasonable price. Nevertheless, some disadvantages, like a slightly low heating value, high latent heat of vaporisation, and high viscosity, hinder its wide application in diesel engines. Thus, the current study intended to enhance the usability of Jatropha biodiesel in diesel engines by using multiwalled carbon nanotubes (MWCNTs) with four dosages of 25, 50, 75, and 100 mg/L added with a blend of 80% Jatropha biodiesel and 20% n-heptanol (JH). The peak cylinder pressure and heat release rate for the JH blend were reduced by 3% for both. At the same time, they were boosted by 4% for both due to the addition of MWCNTs to the JH blend. The brake thermal efficiency (BTE) was reduced by 5% for the JH blend compared with diesel, while the brake specific fuel consumption (BSFC) was raised by 4%. The BTE and BSFC were enhanced by 4% for JH-MWCNT blends compared with the JH. The NOx, smoke opacity, CO, and UHC were diminished on average by 25%, 40%, 30%, and 15%, correspondingly, for the JH blend associated with diesel.

Parametric study of GNPs nano addition in water diesel emulsified fuel on diesel engine at variable injection timings

ABSTRACT The current investigation is to determine the influence of graphene nanoplatelets (GNPs) in Water Diesel Emulsified Fuel (WDEF) of a compression ignition (CI) engine by changing injection timing (IT). The WDEF includes 94% diesel, 5% water, and 1% QPAN-80 and is referred to as D94W5Q1. For better stability, GNPs are added to D94W5Q1 at different doses (30, 60, and 90 ppm) utilizing ultrasonication, and the samples are referred to D94W5Q1-GNPs30, D94W5Q1-GNPs60, and D94W5Q1-GNPs90. The samples were run on a diesel engine at a uniform speed, fixed compression ratio (CR), and IT of 1500 rpm, 18:1, and 23°bTDC. The lower emissions of hydrocarbons (HC), carbon monoxide (CO), nitrogen oxide (NOx), and smoke were observed to be 61.72, 51.16, 48.45, and 25.51%, respectively, and enhanced Brake thermal efficiency (BTE) of 1.95% resulted for D94W5Q1-GNPs60, which is determined as an optimum blend. This optimum blend was evaluated further at various ITs of 19, 21, 23, and 25°bTDC, and the experimental values demonstrated higher BTE, in-cylinder pressure (CP), and heat release rate (HRR) of 3.49, 9.13, and 4.64% respectively, and reduced Brake Specific Fuel Consumption (BSFC) of 3.08%. Furthermore, the emissions were decreased for HC, CO, and smoke by 5.84, 22, and 8.91%, respectively, but the NOx value was raised by 3.01% at 25°bTDC. Finally, the D94W5Q1-GNPs60 blend at advanced IT enhances the overall engine performance.

Emission Reduction and Performance Enhancement of CI Engine Propelled by Neem Biodiesel-Neem Oil-Decanol-Diesel Blends at High Injection Pressure

Diesel emissions have resulted in air pollution, which is harmful to the sustaining of life. The concerns of energy security and poor air quality have propelled researchers to seek alternate and environment-friendly fuels for the transport sector, keeping diesel engines at the core. Thus, a quaternary blend (diesel-biodiesel-vegetable oil-alcohol) proves to be a promising key to address the above problems. This experimental work focuses aims on investigating the performance and emissions of a diesel engine powered with quaternary blends by changing the fuel injection pressure. The quaternary blend comprised of diesel, neem biodiesel, pure neem oil, and decanol was used to prepare quaternary blends of varied volumetric proportions. This study involves the testing of quaternary blends at varied fuel injection pressure (IP) ranging from 400–500 bar. The engine load varied from 10 Nm to 20 Nm, and the shaft speed was constant at 2000 rpm. It was evident from the outcomes that the least DBODec45 resulted in minimum carbon monoxide (CO) and un-burnt hydrocarbon (UHC) emissions, which were obtained to be 83.33% and 54.5% less than diesel at 500 bar and at a load of 10 Nm and 20 Nm, respectively. Moreover, the blend containing 45% of decanol led to the lowest NOx and smoke concentrations. The lowest brake-specific fuel consumption (BSFC) was achieved at 500 bar and 20 Nm for the same blend and was found to be 3.22% higher than diesel. Moreover, at the same IP and load, DBODec45 led to highest BTE, which was 3.26% lower than pure diesel.

Utilization of additives in biodiesel blends for improving the diesel engine performance and minimizing emissions through a modified Taguchi approach

Biodiesel from Jatropha oil is produced through catalyzed homogeneous transesterification. Hydrogen peroxide (H2O2) is considered as additive. Blends of Jatropha considered in the present study are 60% diesel, (40-A)% biodiesel and A% additive, varying A from 0 to 10. Identifying optimal input variables (such as additive volume percentage, injection pressure, and load) is important for improving the engine performance and reducing emissions. Air-fuel ratio; brake specific fuel consumption (BSFC); and brake thermal efficiency (BTE) are the engine performance characteristics. Carbon monoxide (CO); carbon dioxide (CO2); exhaust gas temperature (EGT); nitrogen oxide (NOx); and smoke opacity are the emission characteristics. 27 experiments need to be performed for the assigned 3 levels and 3 input variables. The Taguchi's L9 orthogonal array (OA) is chosen to perform only 9 experiments to obtain the optimal solution. The expected range of performance characteristics and emissions was obtained following a modified Taguchi approach. Empirical relationships are developed and verified through engine performance and emission characteristics.

Effect of injecting mixed-biodiesel upon performance and emission characteristics of a direct injection single fuelled diesel engine

The continued expansion in use of the transportation fuels, rising pollutants via cars, and higher costs of carbon fuels have prompted investigation into sustainable energy. Numerous renewable resources have indeed been investigated as well as experimented into internal combustion engines, including biodiesel, bio oil, biogas, and fisher trospch fuel. The morphological attributes of biofuel derived from mahua oil and jojoba oil have been investigated in this study. The resulting mixture biofuel has been combined with gasoline in various quantities and assessed for performance and exhaust emissions inside a single cylinder 4-stroke water cooled DI engine. Results depicted mixed biodiesel blend of 20% i.e. PBD20 has improved BTE (brake thermal efficiency) of 1.46% while BSFC (brake specific fuel consumption) was on higher side which increased by 6.25% when compared to diesel. Considering emission analysis, PBD20 depicts 7.72% lower hydrocarbon emission with slight increment in oxides of nitrogen by 3.05% higher than diesel at peak loading condition. The acquired findings are compared to conventional fuel and provided in this research. Jojoba oil and mahua oil have dynamic performances that are nearly identical to gasoline.

Energy and exergy assessment of diesel-tallow biodiesel blend in compression ignition engine for engine design variables

Biodiesel has been accepted as an alternate fuel to power engines. Biodiesel, prepared by transesterification of tallow as a feedstock, is used to fuel a compression ignition (CI) engine. An Exergy-energy analysis is compared with baseline diesel at various engine design variables. Brake-specific fuel consumption (BSFC), fuel energy, thermal efficiency, heat loss, energetic efficiencies, and exergy destruction through exhaust gases were determined for a single cylinder, direct injection, variable compression ratio (VCR) CI engine. Data analysis provides optimal operating conditions for the efficient combustion of B20 blend fuel. Optimal performance was obtained at a compression ratio of 17.5 and injection pressure of 210 bar, with energy efficiency observed as 31.69% and the maximum efficiency observed for diesel was 32.67%. Exergetic efficiency values were 24.97% and 26.37%, respectively. Based on the data, it is proposed that B20 tallow-based biodiesel can be used as an efficient and sustainable fuel.

The combustion and emission improvements for diesel–biodiesel hybrid engines based on response surface methodology

With the rapid technological progress of society and increasingly stringent environmental regulations, further reduction of emissions has become an important issue for environmental protection. This study developed a response surface model with the biodiesel blending ratio (BBR), load, and exhaust gas recirculation (EGR) as independent variables and brake thermal efficiency (BTE), brake specific fuel consumption (BSFC), and NOx, and CO emission rates as dependent variables. Simulations were performed and calculated. The results of the response surface approach with the objectives of maximizing the BTE of the engine and minimizing BSFC, NOx emissions, and CO emissions show that when the BBR is 20%, the EGR rate is 15%, and the engine load is 74.52%, pollutant emissions are significantly reduced while the engine power’s performance is maximized.

Experimental study and optimization of performance characteristics of compression ignition hydrogen engine with diesel pilot injection

World's energy demand is majorly met by fossil fuels. An increase in the demand for energy and the depletion of fossil fuels leads to look for the alternate source of energy. Hydrogen is one of the most viable alternate sources of alternate energy. This paper presents the performance study of a Compression Ignition engine using a fuel combination of diesel and hydrogen-diesel. The performance parameters have been analyzed with two input factors, load and Compression Ratio and three output responses, Brake Thermal efficiency (BTE), Brake Specific Fuel Consumption (BSFC) and Volumetric efficiency. The experimental results indicate the improvement in BTE, reduction in BSFC and volumetric efficiency. The BTE was improved by 6.38%, BSFC was reduced by 4.87% and Volumetric efficiency got reduced by 1.89% when hydrogen-diesel fuel is used in place of neat diesel. The experiments have been designed with the help of Design Expert® 13.0.5 using Response Surface Method. The experiments are conducted using Optimal (Custom) design. Mathematical relations are developed between the process parameters and the input factors using regression analysis. The optimal solution has been obtained using the desirability approach. The confirmation experiments have been performed on the optimal solution to verify with the experiment results. Results of the confirmation test shows that the developed mathematical are appropriate for the use in CI engine.

Design of the Organic Rankine Cycle for High-Efficiency Diesel Engines in Marine Applications

Over the past few years, fuel prices have increased dramatically, and emissions regulations have become stricter in maritime applications. In order to take these factors into consideration, improvements in fuel consumption have become a mandatory factor and a main task of research and development departments in this area. Internal combustion engines (ICEs) can exploit only about 15–40% of chemical energy to produce work effectively, while most of the fuel energy is wasted through exhaust gases and coolant. Although there is a significant amount of wasted energy in thermal processes, the quality of that energy is low owing to its low temperature and provides limited potential for power generation consequently. Waste heat recovery (WHR) systems take advantage of the available waste heat for producing power by utilizing heat energy lost to the surroundings at no additional fuel costs. Among all available waste heat sources in the engine, exhaust gas is the most potent candidate for WHR due to its high level of exergy. Regarding WHR technologies, the well-known Rankine cycles are considered the most promising candidate for improving ICE thermal efficiency. This study is carried out for a six-cylinder marine diesel engine model operating with a WHR organic Rankine cycle (ORC) model that utilizes engine exhaust energy as input. Using expander inlet conditions in the ORC model, preliminary turbine design characteristics are calculated. For this mean-line model, a MATLAB code has been developed. In off-design expander analysis, performance maps are created for different speed and pressure ratios. Results are produced by integrating the polynomial correlations between all of these parameters into the ORC model. ORC efficiency varies in design and off-design conditions which are due to changes in expander input conditions and, consequently, net power output. In this study, ORC efficiency varies from a minimum of 6% to a maximum of 12.7%. ORC efficiency performance is also affected by certain variables such as the coolant flow rate, heat exchanger’s performance etc. It is calculated that with the increase of coolant flow rate, ORC efficiency increases due to the higher turbine work output that is made possible, and the condensing pressure decreases. It is calculated that ORC can improve engine Brake Specific Fuel Consumption (BSFC) from a minimum of 2.9% to a maximum of 5.1%, corresponding to different engine operating points. Thus, decreasing overall fuel consumption shows a positive effect on engine performance. It can also increase engine power output by up to 5.42% if so required for applications where this may be deemed necessary and where an appropriate mechanical connection is made between the engine shaft and the expander shaft. The ORC analysis uses a bespoke expander design methodology and couples it to an ORC design architecture method to provide an important methodology for high-efficiency marine diesel engine systems that can extend well beyond the marine sector and into the broader ORC WHR field and are applicable to many industries (as detailed in the Introduction section of this paper).

Production of oxy-hydrogen gas and the impact of its usability on CI engine combustion, performance, and emission behaviors

The greenhouse gases in the environment emitted from emissions of IC engine raises great concern for the survival of human beings, and it has a detrimental effect on the environment. There is a significant requirement to switch the energy source towards renewable as much as possible. From this viewpoint, oxy-hydrogen (HHO) gas was produced and tested in a CI engine. The HHO gas was supplied as a secondary fuel into the combustion chamber at the flow rates of 0–6 Litres/min (LPM) in the interval of 1 LPM through the intake manifold with the air along with biodiesel derived from novel feedstock Bauhinia variegate, injected at the blending percentage of 20%. The experiments were conducted at a constant crankshaft speed of 1500 rpm and varying load from 0 to 100% with intervals of 25%. The addition of biodiesel with conventional diesel fuel causes a decrease in brake thermal efficiency (BTE) and an increase in the brake-specific fuel consumption (BSFC) of the engine owing to its lower calorific value. This shortcoming has been overcome by inducting HHO gas at the intake manifold, resulting in an improved BTE and BSFC due to its high flame speed and high heating value leading to improved combustion. The result also indicates that the fuel enriched with HHO reduces significant exhaust emissions of carbon monoxide and unburned hydrocarbon except for NOx. The combustion characterization reveals that mixing HHO gas in biodiesel blends increases the peak in-cylinder gas pressure and heat release rate. The ideal flow rate of HHO was found at 3 LPM for maximum combustion, performance characteristics and minimum emissions characteristics, except NOx which continuously rises with increasing flow rate. The study reveals that the use of bauhinia variegate biodiesel in CI engines worsens the engine characteristics, but the induction of HHO gas can be a very promising renewable fuel to improve the worsening engine characteristics in terms of combustion, performance, and environmental issues.

Performance optimization of gasoline engine fueled with ethanol/n-butanol/gasoline blends using response surface methodology

In this research work, the effect of adding oxygenates, ethanol and n-butanol, on the performance and emission characteristics of a multi-point fuel ignition (MPFI) engine is analyzed. The test engine was operated at 20 Nm load with speed between 1600 and 2800 rpm. The performance, combustion and emission characteristics of the engine were analyzed for different oxygenates (ethanol and n-butanol) and gasoline blends (EB5, EB10, EB15, EB20). A response surface methodology (RSM) model was developed using experimental data. The desirability function approach was used to predict the optimum values of the engine performance and emissions. The predicted optimum values of blend, load and speed are 20%, 20 Nm and 2702 rpm, respectively. For the optimum predicated values, the experiments found 20.9%, 0.46 kg/kWh, 0.0145%, 136.45 ppm, 4587 ppm for Brake thermal efficiency (BTE), Brake specific fuel consumption (BSFC), Carbon monoxide (CO), Hydrocarbon (HC) and Oxides of nitrogen (NOx), respectively. The study found less than 5% variation between the experimental and predicted results for the engine performance and emissions. The study also found that the ethanol/n-butanol/gasoline (EB–gasoline) blends produced better performance and emission results as compared to n-butanol–gasoline (B–gasoline) blends. The EB–gasoline blends displayed 1.8% higher efficiency as compared to B–gasoline blends.

Performance improvement and CO and HC emission reduction of variable compression ratio spark-ignition engine using n-pentanol as a fuel additive

This study tests binary and ternary n-pentanol, ethanol, and petrol blends to increase spark-ignition (SI) engine performance and minimize CO and HC emissions. To improve brake thermal efficiency (BTE) and reduce emissions, adding ethanol into gasoline is one of the practices used in Automobiles. But the literature reported some performance limitations and problems with adding a high ethanol concentration to gasoline as phase separation problem occurs in fuel tank due to the hygroscopic nature of ethanol, a higher ethanol concentration may corrode some parts of the fuel supply system. Ethanol has a lower calorific value than gasoline, so a higher ethanol concentration in blends beyond a specific limit reduces BTE. N-pentanol as a fuel additive in gasoline can better solve these problems due to its high caloric value compared to ethanol. Also, when n-pentanol is mixed with gasoline and exposed to moisture, it does not separate in stages as in the ethanol case. Accordingly, this research aims to evaluate n-pentanol's viability as a fuel additive in petrol and ethanol-gasoline blends at different compression ratios. The experiments were carried out on a single-cylinder, four-stroke spark-ignition engine running at a constant speed. Different blends of n-pentanol with gasoline and ethanol were tested, and results were compared against gasoline and E10 (the optimal blend of ethanol-gasoline, 10/90 v/v %). Various parameters were examined, including BTE, brake-specific fuel consumption (BSFC), and different exhaust pollutants. The effects of compression ratio values on these parameters were also recorded. The 1.5 vol% pentanol with E10 (E10P1.5) mix has the best overall characteristics, including low BSFC, high BTE, and low CO and HC emissions compared to petrol and E10 fuels. E10P1.5 shows a maximum enhancement in BTE, low BSFC, CO reduction, and HC reduction by 23.79%, 19.80%, 37.79%, and 19.46%, respectively, over gasoline. Compared to E10, the improvement is 3.64% for BTE, 4.59% for BSFC, 8.88% for CO emission reduction, and 4.13% for HC emission reduction.