High-speed Engine Research Articles

Characteristics of the S-CO2 Brayton cycle for full-scale multi-condition diesel engines

With the diesel engine test data of the flue gas as the initial conditions and the boundaries, the arrangement of the S-CO2 recompression Brayton cycle (SCRBC) was established and the optimization of the S-CO2 Brayton cycle (SCBC) system for 6EX340EF, 6L16/24, and CHD622V20 diesel engine were studied. Additionally, the model accuracy was validated with the test data from Sandia National Laboratories (SNL). Meanwhile, the parameter optimization determined the optimal system operating conditions via a multi-objective genetic algorithm (MOGA). Finally, the feasibility of the SCBC applied in flue gas waste heat recovery (WHR) for marine engines was comprehensively assessed from the efficiency, net output power, fuel consumption rate, and exergy. The results showed that with the recompression Brayton cycle layout in the optimal configuration, the low-speed marine diesel engine could reach 1.68% of the maximum total efficiency improvement and 6.43 g/kWh of the fuel consumption rate reduction at 100% load, the maximum net output power increased to 178.14 kW; the medium-speed marine diesel engine could reach 2.37% of the maximum total efficiency improvement and 11.60 g/kWh of the fuel consumption rate reduction at 100% load, the maximum net output power increased to 31.69 kW; the high-speed marine diesel engine could reach 1.00% of the maximum total efficiency improvement and 5.58 g/kWh of the fuel consumption rate reduction at 25% load, the maximum net output power increased to 21.54 kW. By comparing the SCRBC of the marine diesel engine, the high-speed engine has the highest efficiency of flue gas WHR, followed by the medium-speed engine and finally, the low-speed engine. The cooler, flue gas heat exchanger, and high-temperature recuperator (HTR) modules were the weak points of the SCRBC system through the exergy analysis, and further optimization of the SCRBC system can be extended to other engines to improve efficiency and emission.

Pengaruh Penggunaan Knalpot Standard dan Knalpot Racing Terhadap Daya dan Torsi pada Motor Supra GTR K56 150 CC

At this time, motorcycles, especially performance, are very important, where many young people now really want to increase the performance of their motorbikes. This study examines the difference in performance between the use of standard exhaust and racing exhaust on a Supra GTR K56 150 cc motorcycle. The experimental method is used by using a dynometer to measure the power and torque of the vehicle. The results showed that the use of racing exhaust resulted in an increase in power of 1.86 hp at 9000 rpm and a widening of the peak power at high engine speed. In addition, the racing exhaust also provides more controlled acceleration and a smoother power increase compared to the standard exhaust. Even though the performance increase is not significant, changing the exhaust to a racing exhaust can give a different response when the vehicle is used at high engine speed. In conclusion, the use of racing exhaust on a 150 cc Supra GTR motorcycle can produce higher performance and better response compared to the standard factory default exhaust.

Evaluation of Different Gasoline Formulations on a High-speed Engine

Evaluation of Different Gasoline Formulations on a High-speed Engine

Assessing the effect of air-throttling on ignition dynamics in a hydrogen-fueled scramjet under various fuel-injection strategies using LES

Air-throttling has been experimentally substantiated as a potent technique for augmenting the ignition of fuel jets in high-speed scramjet engines. Nonetheless, the elucidation of its combustion enhancement mechanism remains conspicuously scant in the extant literature. In this work, a comprehensive numerical investigation was conducted to assess the ignition dynamics of a hydrogen-fueled cavity-stabilized scramjet combustor under various fuel-injection and air-throttling strategies using large-eddy simulation. The results demonstrated that air-throttling could improve the ignition environment by augmenting backpressure, fuel residence time, and mixture homogeneity. Remarkably, the subsonic region was improved by over 30%, and the maximum Mach number was limited to no more than 2.25. Additionally, the enhanced ignition modes under two injection strategies were quite different. For the passive injection, the flame developed rapidly as a result of the deflagration of lean mixture in the interval of Zmix = [0.01, 0.02]. Nevertheless, the direct injection resulted in an additional deflagration-to-detonation transition phenomenon in the expansion section due to the ignition of rich mixture in the interval of Zmix = [0.0225, 0.03]. Both injection strategies exhibited severe flow separation and flame flashback. After removing air-throttling, the flame became dispersed with large-amplitude fluctuations, emphasizing the importance of precise control of air-throttling parameters and operating sequence. These findings advanced the current understanding of the intricate interactions between pilot-hydrogen and air-throttling, thereby elucidating their pivotal role in promoting ignition within high-speed environments.

Mean pressure gradient effects on the performance of ramjet cavity stabilized flames

Premixed cavity stabilized flames are experimentally investigated in a high-speed ramjet engine under the influence of varying mean pressure gradients. The ramjet cavity incorporates a backward facing step with an aft ramp for flame stabilization in high Reynolds number. The ramjet engine is subject to varying wall geometry to form converging, diverging, and nominal configurations in order to investigate the effects of mean pressure gradients on engine performance. High-speed particle image velocimetry (PIV) and chemiluminescence imaging diagnostics are simultaneously employed to capture the reacting flow fields and flame dynamics. Imposing a larger favorable pressure gradient is shown to shrink the recirculation zone and alter shear layer dynamics, which leads to increased drag on the cavity. Additionally, inducing a stronger favorable pressure gradient is shown to excite a shear layer instability mode, characterized by a Strouhal number of St=0.1. Proper orthogonal decomposition (POD) results reveal that the instability mode is comprised of large-scale oscillations that occupy the entire cavity flow region, indicating that the excited oscillations are the manifestation of a global vortex shedding instability that occurs under non-reacting conditions. The results demonstrate that the performance and stability of the ramjet cavity flame can be influenced by the mean pressure gradient, which is vital for the design of high-speed air-breathing propulsion systems such as dual-mode scramjets.

Evaluation of Performance Improvement of Gasoline Fuels by Adding Propanol, Ethanol, and Diisopropyl Ether along with Metal Oxides of CeO2 and Fe2O3

Many studies focusing on the composition of gasoline with any type of fuel additives have shown that the overall engine performance has a significant impact on reducing emissions. In this research work, ethanol, isopropanol, and diisopropyl ether as oxygenated additive with cerium oxide (CeO2) and iron(III) oxide (Fe2O3) as metal nanoparticles were combined with pure gasoline. Due to the more oxygen they have in their structure, these alcohol additives reduce pollutants and complete combustion. Metal nanoparticles also improve the performance of the engine due to the proper potential. To check the efficiency of the new fuel, a four-stroke engine connected to a dynamometer and an analyzer tested different conditions: speed of 1500 and 2000 rpm and loading percentage of 30 and 40%. Analyzed data include the engine power, and the amount of CO, CO2, HC, and NOx released. The power of the engine on gasoline fuel was 14.43 at 1500 rpm, and once the test was repeated with mixed fuel with additives, it increased to 17.5, which indicates an improvement in engine performance. The amount of CO emissions at 1500 rpm with gasoline fuel was 3.25, and once repeating the test with the same engine rpm with mixed fuel, it decreased to 1.68. The amount of CO2 at 1500 rpm with gasoline fuel was 3.8 and repeating the test with mixed gasoline, it was 5.7. The amount of HC emission with gasoline was 65, and it was 62 when tested with mixed fuel. The amount of NOx released in comparison of gasoline fuel with mixed fuel reached from 264 to 533. The performance improvement and pollutant emissions are fully described in the conclusion section. The analyzed data were calculated and transformed into a model. Among the additives used, isopropanol and CeO2 nanoparticles had better results in optimizing the fuel, reducing the pollutants, and increasing the engine performance. The optimization results show that the use of isopropanol (5%) and CeO2 (1.39 wt. %) as well as diisopropyl ether (4 wt. %) at high engine speed (1504.97 rpm) can be improved engine performance and reduce exhaust gas emissions.

The Removal of CH4 and NOx from Marine LNG Engine Exhaust by NTP Combined with Catalyst: A Review.

Compared to diesel, liquefied natural gas (LNG), often used as an alternative fuel for marine engines, comes with significant advantages in reducing emissions of particulate matter (PM), SOx, CO2, and other pollutants. Promoting the use of LNG is of great significance for achieving carbon peaking and neutrality worldwide, as well as improving the energy structure. However, compared to diesel engines, medium- and high-speed marine LNG engines may produce higher methane (CH4) emissions and also have nitrogen oxide (NOx) emission issues. For the removal of CH4 and NOx from the exhaust of marine LNG engines, the traditional technical route of combining a methane oxidation catalyst (MOC) and an HN3 selective catalytic reduction system (NH3-SCR) will face problems, such as low conversion efficiency and high operation cost. In view of this, the technology of non-thermal plasma (NTP) combined with CH4-SCR is proposed. However, the synergistic mechanism between NTP and catalysts is still unclear, which limits the optimization of an NTP-CH4-SCR system. This article summarizes the synergistic mechanism of NTP and catalysts in the integrated treatment process of CH4 and NOx, including experimental analysis and numerical simulation. And the relevant impact parameters (such as electrode diameter, electrode shape, electrode material, and barrier material, etc.) of NTP reactor energy optimization are discussed. The work of this paper is of great significance for guiding the high-efficiency removal of CH4 and NOx for an NTP-CH4-SCR system.

Effects of ozone addition on the kinetics and efficiencies of methane conversion at fuel-rich conditions

Compression–expansion processes have the potential of converting mechanical work to chemical energy at fuel-rich conditions, allowing for the storage of fluctuating renewable energies. In this work, the conversion of methane and natural gas (NG) is investigated for this purpose. A focus is on using ozone as a reaction promoter for the otherwise slow reaction. The kinetics of fuel-rich methane/NG oxidation with ozone addition is investigated experimentally and numerically. To this end, ignition delay times (IDTs) for CH4/O2/O3/Ar and NG/O2/O3/Ar mixtures are measured in a rapid compression machine (RCM). It is shown that a reaction mechanism obtained by simply combining a previously developed mechanism for methane conversion (PolyMech2.0) with an ozone sub-mechanism does not accurately predict IDTs. Sensitivity analyses identify reactions in the methane submechanism that become more important for ignition delay time when ozone is added in comparison to mixtures without O3. The rate coefficients of these reactions are modified within their uncertainty ranges to better match the experimentally obtained IDTs. The resulting kinetic model, named PolyMech 3.0, predicts the IDTs obtained in RCM-experiments well. Analysis reveals a two-fold promoting effect of ozone addition on methane/air ignition: Ozone causes a temperature rise by the reactions associated with its decomposition. Ozone also forms reactive products such as hydrogen and oxygen radicals, which can then promote reactions of the hydrocarbons. Quantitative analysis shows that the latter effect is more pronounced. Using PolyMech 3.0, parametric simulation studies for methane conversion in four-stroke engine cycles are carried out to explore the effects of ozone addition on chemical energy storage and efficiencies of engine-based polygeneration processes. Results show that with ozone addition, methane conversion can take place at high engine speeds, while without ozone, there is nearly zero conversion of fuel rich methane mixtures because of the low reactivity. Therefore, ozone addition allows for reasonable efficiencies across a wider range of operating conditions.

Research on optimizing turbo-matching of a large-displacement PFI hydrogen engine to achieve high-power performance

The output power of hydrogen engines is restricted due to the low volume energy density of hydrogen and lean burn, thus a turbocharger is necessary to boost the power intensity, especially for large-displacement hydrogen engines. However, turbine selection for hydrogen engines is complex comparing gasoline engines because of the different exhaust components and low exhaust temperature. In this research, the turbocharger-matching of a 5.13 L hydrogen engine is studied, and the results show the original turbine, whose maximum reduced mass flow is 0.00966 (kg/s)·Kˆ0.5/kPa, cannot achieve the desired power performance at high speeds. The reduced mass flow rate can be calculated, taking into account the effect that exhausts composition and temperature. The accuracy of the method is validated using data from a 2.3 L turbocharged H2ICE at various engine speeds and throttle openings, and the error between the measured and calculated expansion ratio is less than 5% mostly. At last, a well-matching turbine for high engine speeds of the 5.13 L hydrogen engine to meet the desired power of 120 kW, whose maximum reduced mass flow is extended to 0.0156 (kg/s)·Kˆ0.5/kPa, is selected according to the method, and the maximum power reaches 128.9 kW with a maximum torque of 662.6 N m, improving by 38.7% and 7.7% respectively comparing with the original turbine. However, the output torque reduces by 15.6% at 1200 rpm. The reduced mass flow rate varies significantly in comparison to the turbines that are well suited for low and high engine speeds respectively, thus the Variable Geometry Turbine may be the solution for both low and high speeds simultaneously for hydrogen engines.

Enabling off-highway diesel engine downsizing and performance improvement using electrically assisted turbocharging

Internal combustion engine (ICE) downsizing through various turbocharging configurations is generally known by the powertrain design community as an effective means to reduce frictional losses, increase waste heat recovery, and improve fuel efficiency while increasing engine power density. However, often is the case that turbocharging strategies, including variable geometry turbochargers, and regulated two-stage turbochargers, incur the performance tradeoff between transient response and fuel economy (pumping losses) at high engine speeds. For off-highway vehicles having particularly transient and high-powered duty cycles, efforts to improve this tradeoff and increase operational flexibility have turned to evaluating various electrified air system architectures. In this study, a 4.5 L diesel-ICE configured with an electrically driven compressor (eBooster®) is placed in series with a conventional turbocharger and integrated into a 48 V mild-hybrid powertrain architecture. The objective of this powertrain configuration is to enable engine downsizing by 34%, replacing the current 6.8 L ICE platform with the hybridized 4.5 L ICE concept. The commercial 1-D simulation software GT-SUITE is used for powertrain system development and system optimization. Development and validation of the GT-SUITE model and air system controls is concurrently supported through experimental data collection. The simulation model development includes using machine learning methods for optimizing exhaust gas dilution, injection timing, and eBooster® power to improve steady-state and transient brake-specific fuel consumption while minimizing criteria pollutant emissions. It was found that total specific fluid consumption over the standardized non-road transient engine duty cycle could be reduced by 18% over the current 6.8 L engine by using an optimized eBoosted 4.5 L engine. The hybridized 4.5 L engine concept concurrently showed sufficient transient response capability and nearly an order of magnitude reduction in duty cycle total soot production.

Numerical study on the use of ammonia/hydrogen fuel blends for automotive spark-ignition engines

The importance of new alternative fuels has assumed great relevance in the last decades to face the issues of global warming and pollutant emissions from energy production. The scientific community is responsible for developing solutions to achieve the necessary environmental restriction policies. In this context, ammonia appears as a potential fuel candidate and energy vector that may solve the technological difficulties of using hydrogen (H2) directly in internal combustion engines. Its high hydrogen content per unit mass, higher energy density than liquid hydrogen, well-developed infrastructure and experience in handling and storage make it suitable to be implemented as a long-term solution. In this work, a virtual engine model was developed to perform prospective simulations of different operating conditions using ammonia and H2-enriched ammonia as fuel in a spark-ignition (SI) engine, integrating a chemical kinetics model and empirical correlations for combustion prediction. In addition, specific conditions were evaluated to consider and to understand the governing parameters of ammonia combustion using computational fluid dynamics (CFD) simulations. Results revealed similar thermal efficiency than methane fuel, with considerable improvements after appropriate H2-enrichment. Moreover, increasing the intake temperature and the turbulence intensity inside the cylinder evinced significant reductions in combustion duration. Finally, higher compression ratios ensure efficiency gains with no evidence of abnormal combustion (knocking), even at high compression ratios (above 16:1) and low engine speeds (800 rpm). Numerical simulations showed the direct influence of the flame front surface area and the turbulent combustion velocity on efficiency, reflecting the need for optimizing the SI engines design paradigm for ammonia applications.

Evaluation of the environmental and cost impact of a small diesel engine with ethanol-diesel and isopropanol-diesel fuel at varying engine loads and speeds

Nowadays, alcohol additives such as ethanol and isopropanol are used to minimize emissionsresulting from combustion in diesel engines. While these blends contribute to reducing emission values, itis also important to consider their environmental and cost implications. Therefore, this experimental studyfocuses on the emission characteristics and the environmental and cost impact of alcohol additives in dieselfuel. The experiments were conducted at low and medium engine torques (3 Nm and 6 Nm) and variousengine speeds (1000, 1500, 2000, and 2500 rpm). Additionally, three different test fuels were used in theexperiments, including standard diesel fuel, as well as diesel fuel with volumetric additions of 7% ethanol(E7) and 7% isopropanol (IP7) alcohol additives. The emission values of all test fuels were measured, andan analysis of environmental influence and cost was conducted. Upon examining the results, it is evidentthat the addition of alcohol to diesel fuel significantly increased the environmental influence and cost atlow engine speeds, while it led to a decrease at high engine speeds. Furthermore, the increase in engineload contributed to emission reduction due to higher combustion temperatures, thereby contributing to adecrease in both cost and environmental influence.

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.

Development of knowledge management in investigating the rheological behavior of SiO2/SAE50 nano-lubricant by response surface methodology (RSM)

The development of knowledge management in dynamic viscosity enables the effective use of fluid to optimize processes and innovations. By collecting, organizing, sharing and applying knowledge, professionals in various industries can take advantage of the potential of dynamic viscosity for optimal performance. Robust model results were developed to predict the viscosity of SiO2/SAE 50 nanofluid (NF) using RSM with a knowledge management approach in laboratory conditions of temperatures T = 25–50 °C, solid volume fractions in the range of SVF= 0–1.5% and shear rates in the range of SR= 666.5–7998 s−1 has been reported to establish a background in using the mentioned NF at high engine speed. After examining the four statistical models Linear, Quadratic, Cubic and Quartic in terms of statistical parameters extracted from ANOVA and measurement charts of the models, it was determined that the model Quartic has high precision compared to the three models in predicting the desired response. Thus, the values of R2 = 0.9923, Predicted R2 =0.9887 and Adjusted R2 = 0.9906 were reported for the selected model; and the MOD values of the Quartic model are − 7 < MOD < +8. Also, a correlation relationship consisting of three independent parameters has been presented to predict viscosity, and it has been determined that viscosity dependence on SR, and NF behavior is non-Newtonian. Comparison of base fluid (BF) viscosity contour with and without the use of nanoparticles (NPs) at high engine speed has shown that the use of SiO2 NPs has led to an increase in viscosity. Also, the use of SiO2 nanoparticles has led to an increase in viscosity by 33.27% and 25% respectively at the minimum and maximum temperature at high engine speed. Finally, the viscosity optimization was done by minimizing the amount of NP consumption and the maximum viscosity at high engine speed in laboratory conditions, and the optimal value was obtained as 212.063 mPa.sec

The effects of biodiesel produced from waste cooking oils on vibroacoustic properties of a heavy-duty diesel engine

This paper aims to investigate the vibroacoustic properties of biodiesel produced from waste cooking oils and petroleum-based diesel fuel depending on engine speed and load. Tests were conducted on a diesel engine with a 6 L cylinder volume which is used in today’s heavy-duty commercial vehicles. The engine tests were performed at various speeds and a constant engine load of 100 Nm. A vibration transducer and microphone were used to obtain the experimental data to determine vibroacoustic properties. The root mean square and coherence methods have been used for vibration analysis. The results show that the vibration amplitude of B100 at high engine speeds is slightly higher than that of pure petroleum-based diesel fuel (PBDF). B100 has a maximum 8.5% higher vibration amplitude relative to PBDF at an engine speed of 1500 rpm, where the engine is in the maximum torque intensity. Coherence analysis showed that the engine sound increased with increasing engine speed. The highest sound pressure level was 94.9 dB with B100 at an engine speed of 2000 rpm.

Improvement of magnetic properties via normalizing annealing for high-strength Fe-4.5wt.%Si electrical steel

Both excellent magnetic and mechanical properties are desired for electrical steels used in high-speed motors and engines of electric vehicles. Existing high-strength electrical steels (HSES) usually sacrifice magnetic properties for a trade-off of strengthening effect. In this work, Fe-4.5wt.%Si alloy was employed to fabricate HSES by dislocation and solution strengthening, and the magnetic properties were further improved by normalizing annealing after hot rolling. The effect of normalizing annealing (NA) on micro structure and magnetic/mechanical properties was investigated. The iron loss of the cold-rolled sheets can be significantly decreased with NA treatment. The iron loss P1.0T/400Hz of 20.7 W/kg with a yield stress of 656 MPa, and P1.0T/400Hz of 30.3 W/kg with a yield stress of 865 MPa can be achieved.

Fundamentals and Some Results of Numerical Modeling the Cylinder-Piston Group Jet-Oil Supply in a High-speed Four-Stroke Internal Combustion Engine

Fundamentals and Some Results of Numerical Modeling the Cylinder-Piston Group Jet-Oil Supply in a High-speed Four-Stroke Internal Combustion Engine

Effect of Cyclohexane on the Combustion Characteristics of Multi-Component Gasoline Surrogate Fuels.

It has been discovered that there is a dynamic coupling between cycloalkanes and aromatics, which affects the number and types of radicals, thereby controlling the ignition and combustion of fuels. Therefore, it is necessary to analyze the effects of cyclohexane production in multicomponent gasoline surrogate fuels containing cyclohexane. In this study, a five-component gasoline surrogate fuel kinetic model containing cyclohexane was first verified. Then, the effect of cyclohexane addition on the ignition and combustion performance of the surrogate fuel was analyzed. This study shows that the five-component model exhibits good predictive performance for some real gasoline. Meanwhile, the addition of cyclohexane decreases the ignition-delay time of the fuel in the low and high temperature bands, which is caused by the early oxidation and decomposition of cyclohexane molecules, generating more OH radicals; in the medium temperature band, the isomerization and decomposition reactions of cyclohexane oxide cC6H12O2 dominate the temperature sensitivity of the ignition delay, affecting the small molecule reactions that promote the generation of reactive radicals such as OH, thus inhibiting the negative temperature coefficient behavior of the surrogate fuel. The laminar flame speed of the surrogate fuels increased with the increase in the proportion of cyclohexane. This is due to the fact that the laminar flame speed of cyclohexane is higher than that of chain and aromatic hydrocarbons, and the addition of cyclohexane dilutes the ratio of chain and aromatic hydrocarbons in the mixture. In addition, engine simulation studies have shown that at higher engine speeds, the five-component surrogate fuel containing cyclohexane requires lower intake-gas temperatures to achieve positive ignition and are closer to the in-cylinder ignition of real gasoline.

Conversion of a Small-Size Passenger Car to Hydrogen Fueling: Evaluating the Risk of Backfire and the Correlation to Fuel System Requirements through 0D/1D Simulation

Hydrogen is an effective route for achieving zero carbon dioxide emissions, with a contained cost compared to electric powertrains. When considering the conversion of spark ignition (SI) engines to H2 fueling, relatively minor changes are required in terms of added components. This study looks at the possibility of converting a small-size passenger car powered by a turbocharged SI unit. The initial evaluation of range and peak power showed that overall, the concept is feasible and directly comparable to the electric version of the vehicle in terms of powertrain performance. Injection phasing effects and cylinder imbalance were found to be potential issues. Therefore, the present work applied an 0D/1D simulation for investigating the effects of hydrogen fueling with respect to the likelihood of backfire. A range of engine speeds and load settings were scrutinized for evaluating the possibility of achieving the minimal risk of abnormal combustion due to pre-ignition. Ensuring the correct flow was predicted to be essential, especially at high loads and engine speeds. Fuel delivery phasing with respect to valve intake and closing events was also found to be a major factor that influenced not only backfire occurrence but conversion efficiency as well. Interactions with the electronic control unit were also evaluated, and additional requirements compared to standard conversion kits for LPG or CNG fueling were identified.

The production of the hydro-processed renewable diesel (HRD) and its performances from a turbo-charged diesel engine

The development of the hydro-processed renewable diesel (HRD) is proposed in this study based on a lab-scale fixed-bed catalytic reactor. The HRD was produced at temperature of 380 °C, pressure of 6 MPa, weight hourly space velocity (WHSV) of 4.5 h−1 and hydrogen-to-oil ratio of 1000. The performance and emission characteristics of the pure diesel (D100), HRD blended diesel (20% HRD in diesel, H20) and biodiesel (20% biodiesel fuel blend, B20) have been evaluated with the help of turbo-charged diesel engine setup under steady-state operations. Investigations were conducted on regulated emissions including CO, CO2, HC, NOx and smoke. The addition of HRD did not evidently reveal a high impact on CO and NOx emissions. Compared with D100, the CO2 emissions of adding HRD have been reduced by 7.4%. The HC emissions for H20 were relatively lower than those for D100, especially at high engine speeds. Compared with the addition of biodiesel, the smoke reduction of HRD was more significant. The overall average opacity of D100 and B20 were 4.055% and 2.689%, respectively, while the overall average opacity of H20 was only 0.277%. The engine using B20 or H20 mixed fuel can achieve performance close to that of the engine using D100 fuel, since the braking thermal efficiency was close to a value of about 34%. H20 fuel provided better combustion stability than D100 since the average coefficient of variation (COV) of H20 was 0.81% and the average COV of D100 was 0.90%. H20 is better than pure diesel and B20 in terms of engine performance.