Higher Cylinder Pressure Research Articles

Hydrogen-natural gas fuel blending in a “rich burn” engine with 3-way catalyst

Interest in hydrogen (H2) fuels is growing, with industry planning to produce it with stranded or excess energy from renewable sources in the future. Natural gas (NG) utility companies are now taking action to blend H2 into their preexisting pipelines to reduce greenhouse gas (GHG) emissions from burning NG. Stoichiometric (“rich burn”) NG engines that operate on pipeline NG and will receive blended fuel as more gas utilities expand H2 production. These engines are typically chosen for their low emissions owing to the 3-way catalyst control, so the focus of this paper is on the change in emissions like carbon monoxide (CO) and nitrogen oxides (NOx) as the fuel is blended with up to 30% H2 by volume. The Caterpillar CG137-8 natural gas engine used for testing was originally designed for industrial gas compression applications and is a good representative for most “rich burn” engines used across industry for applications such as power generation, gas compression, and water pumping. A significant greenhouse gas (GHG) emissions reduction is observed as more H2 is added to the fuel. Increasing H2 in the fuel changes combustion behavior in the cylinder, resulting in faster ignition and higher cylinder pressures, which increase engine-out NOx emissions. Post-catalyst CO and NOx both decrease slightly with increasing H2 while operating at the optimal “air-fuel” equivalence ratio (λ). A “rich burn” engine with 3-way catalyst can tolerate up to 30% H2 (by vol.) while still meeting NOx and CO emissions limits. However, at elevated levels of H2, increased engine-out NOx emissions narrow the λ range of operation. As H2 is added to NG pipelines, some “rich burn” engine systems may require larger catalysts or more precise λ control to accommodate the increased NOx production associated with a H2-NG blend. Sudden step-increases in H2 cause dramatic changes in λ, resulting in large emissions of post-catalyst NOx during the transition. Comparable changes in H2 at elevated concentrations cause larger spikes in NOx than at lower concentrations. Better tuned engine controllers respond more quickly and produce less NOx during H2 step-transitions.

Investigation on NOx control of a CI engine through the collective effect of hydrogen and biodiesel blend at modified compression ratio

The main challenges with using biodiesel in CI engines are higher NOx emissions and reduced brake thermal efficiency. These biodiesel-related issues can be handled by concurrently introducing gaseous fuels along with primary fuel into CI engines. This study examines the effects of hydrogen in a dual fuel mode operation with diesel and Calophyllum inophyllum biodiesel blend (B20) at different compression ratios on the engine's performance, combustion, and emission characteristics. A single-cylinder, 4-stroke, variable compression ratio engine operating at 1500 rpm was used for the research. A standard compression ratio (SCR) of 17.5 and a modified compression ratio (MCR) of 15.5 at a constant hydrogen flow rate of 6 L per minute (lpm) were used with diesel and B 20. The addition of hydrogen with diesel and B20 resulted in higher cylinder pressure and heat release rate when compared to pure diesel and B20 operation. This resulted in a shorter delay period (by an average of 9.4 % and 7.1 %) with lower peak pressure than pure diesel and B20 operation. During the dual fuel mode of H2 with B 20 at a modified compression ratio, the maximum heat release rate was decreased and its occurrence was retarded. NOx, UBHC, and CO emissions of the engine were decreased significantly by an average of 20.8% 43.7, %, and 22 % respectively with 37.7 % increase in smoke opacity. The increase in NOx emission with the use of H2 with diesel was reduced by operating H2 with B20 and at a reduced compression ratio. This lower emission was achieved with a compromise of a marginal decrease in engine brake thermal efficiency.

Optimized design of silicone oil torsional damper for diesel generator

Abstract Due to the high cylinder pressure and high-performance requirements, the silicone oil damper of an inline six-cylinder diesel generator needs to be optimized to reduce the crankshaft stress. The centralized mass method was used to simplify the crankshaft system. A multi-body dynamic model was established, and the crankshaft stress and torsional vibration amplitude were simulated. The results show that the excessive shear stress at generator crank pin 5 is due to the resonance between the first-order intrinsic frequency of the shaft system and the 3rd harmonic torsional vibration. The shear stress was analyzed for different damper thicknesses and stiffnesses, and it was found that the shear stress at crank pin 5 was minimized when the damper thickness was 60 mm and the torsional stiffness was 250,000 N·m/rad. The torsional amplitudes at different speeds and frequencies were measured in the bench test, and the results were consistent with the calculations. The designed silicone oil torsional damper meets the requirements of the 2000-hour bench test.

Isentropic and exergy analyses of marine steam turbine segments at several loads

This research presents isentropic and exergy analyses of marine steam turbine segments at three loads. Turbine segment is a part of any cylinder which is placed between the steam entrance to the cylinder and first steam extraction, between steam extractions and finally between last steam extraction and steam exit from the cylinder. Division of each cylinder to the segments allows insight into the various cylinder parts operation and an observation is the cylinder properly balanced. The analyzed marine steam turbine is composed of two cylinders – High Pressure Cylinder (HPC) and Low Pressure Cylinder (LPC), while each cylinder has two segments. The dominant part of real mechanical power produced in HPC is actually produced in the first HPC part (segment 1), while in LPC, the dominant part of real mechanical power is produced in the last LPC part (segment 4). Segments 1 and 3 have the highest improvement potential (inlet segments of both HPC and LPC) due to the highest isentropic losses and exergy destructions. HPC is much better balanced cylinder because along with isentropic, also exergy efficiencies between its segments (segment 1 and segment 2) at all loads differ lower than 7%, while the same cannot be stated for the LPC which exergy efficiencies between segments (segment 3 and segment 4) at all loads differ more than 20%. Very low isentropic and exergy efficiencies of the segment 3, at all observed loads, indicate that this turbine segment is highly problematic and at least some of the turbine stages mounted in this segment have difficulties in operation or potential malfunction. In addition, segment 3 is also the highest influenced by the ambient temperature change in comparison to other segments. The ambient temperature increase from 5 °C up to 45 °C can decrease segment exergy efficiency between 1.31% and 3.17%, if all the segments and all loads of the analyzed marine steam turbine are observed.

Towards optimized excess air ratio and substitution rate for a dual fuel HPDI engine

The diesel-piloted high-pressure direct-injection (HPDI) natural gas engine is a significant application of natural gas in heavy-duty engines. However, there is limited research focusing on quantitative optimization of the excess air coefficient and natural gas substitution rate of HPDI engines. In order to support the design and development of HPDI engines, this article investigates the effects of excess air coefficient and substitution rate on a dual fuel HPDI engine combustion performance and emission characteristics. Results show that increasing the excess air coefficient results in higher cylinder pressure, but it has minimal effect on the heat release rate. A higher excess air coefficient can also lead to higher nitrogen oxides (NOx) emissions, lower soot emissions, methane (CH4) and total hydrocarbon (THC) emissions significantly decrease at 50% loads (Case2 and Case4), but these increase at 70% loads (Case1 and Case3). Furthermore, increasing the substitution rate markedly reduces greenhouse gas emissions, though it comes with the drawback of heightened combustion instability, and there is a trade-off between engine combustion cycle variations and greenhouse gas emissions as the substitution rate changes. The above research findings will provide optimization guidance for the engineering development of HPDI engines.

Effective utilization of waste pork fat as a potential alternate fuel in CRDI research diesel engine – Waste reduction and consumption technique

This work utilized the conventional transesterification process to convert waste pork fat into pork fat biodiesel. The produced biodiesel was meant to serve as a diesel fuel substitution for common rail direct injection (CRDI) diesel engines. Butylated Hydroxytoluene (BHT) as an antioxidant doping with waste pork fat biodiesel-diesel blend has not been analyzed in CRDI diesel engines. Therefore, to improve the ignition process and reduce the engine exhaust emissions in a research CRDI diesel engine, the BHT was employed to combine with diesel-biodiesel mixtures in this work. BHT antioxidants are partially mixed (BHT 50, 100, and 150 ppm) to improve the physicochemical qualities of test fuel and enhance the combustion process of diesel-biodiesel blends (B20). The antioxidant purity was analyzed by energy dispersive X-ray analysis (EDX), structures were analyzed by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) analyzer spectrograph was utilized to study the biodiesel chemical components. After mixing the BHT, the overall phase of the base fuel remained constant. The experiment outcomes revealed that the biodiesel had higher cylinder pressure than the other test fuels, and the BHT100 ppm blend had a higher heat release rate (HRR). B20BHT100 blend shows 3.98% higher brake thermal efficiency (BTE) at full load operation than pure biodiesel but lowered to diesel fuel. Biodiesel (B100) decreases the smoke opacity by 4.5% compared to diesel fuel. BHT has been incorporated into the biodiesel blend to minimize oxides of nitrogen (NOx) emissions at all loads. The B20BHT150 blend decreased NOx emissions by 5.06% more than diesel fuel at maximum load. Compared to pure biodiesel, the B20 blends reduce carbon monoxide (CO) emissions by 7.1% and hydrocarbon emission (HC) by 12.5%. This research found that adding BHT to biodiesel blends lowers NOx emissions with a slight impact on performance.

Combined Impact of EGR Rate and Magnetic Intensity on Performance and Emission of C.I. Engine Operated with Blended Fuel

The combined impact of the MFC and EGR methods on the performance of the C.I. engine is investigated experimentally in this study. The work focused on biodiesel fuel under the effect of different EGR rates 10-30% with the optimal value of fuel polarization. At first, the magnetic intensity optimization was done with other engine design parameters by using diesel fuel alone. The study covered a wide range of engine parameters to select the optimal valves. Using the Taguchi approach and orthogonal array L16 to solve the five factors, such as: CR (15,16,17, and 18), IP (175,200,225, and 250 bar), MFC (4000,6000,8000, and 12000 Gauss), load (25,50,75, and 100%), and TI (19, 21, 23, and 27 degree b TDC). The results showed that the diesel engine's optimum parameters were CR=18, IP=200bar, MFC=8000 Gauss, load 100%, and TI=23° b TDC. The results indicated that the coefficient of determination has an excellent level (i.e.), R2 =97.05% Peak fisher valve F=8.37, with normally distributed and significant coefficients in the model, was utilized to test the model capability. The outcome shows that the 10WCO+10% EGR+8000G has higher cylinder pressure and the BTE increased by 12.5% if compared with DF, and lower brake specific fuel consumption.

Combined experimental and simulative approach for friction loss optimization of DLC coated piston rings

Piston rings cause significant friction losses within internal combustion engines. Especially the first compression ring, which is pressed onto the liner by high cylinder pressure, contributes significantly to the total friction loss of the piston assembly. The tribological behavior of the oil scraper ring is mainly related to the pretensioning force and can lead to high losses even at low and idle speed. Due to this, there is always a markable risk of wear for the contact surfaces of the piston rings and the cylinder. “Diamond-like carbon” coatings on the surface of the piston rings can prevent wear and are able to reduce friction in the ring-liner-contact. The purpose of this work was to investigate the tribological benefit of this coating-system on the compression and oil scraper ring. Experimental studies were carried out on a fired single-cylinder engine using the Indicated Instantaneous Mean Effective Pressure-method (IIMEP) for the crank angle-resolved detection of the piston assembly’s friction force. To be able to determine the component-related fractions of the friction loss and to quantify the hydrodynamic and asperity related parts locally and time dependent, an EHD/MBS model of the engine was created in AVL EXCITE and a simulative investigation was performed. This simulation was validated by the experimental work and provided detailed information about the individual contact conditions and gap height of each tribological contact of the piston group. The combined approach of measurement and simulation enabled the prediction of tribological aspects and performance in parameter studies on a virtual engine test bed.

Constraint performance pressure tracking control with asymmetric continuous friction compensation for booster based brake-by-wire system

Pressure control of the electro-hydraulic brake-by-wire system (EHB) is of great significance in achieving precise braking maneuvers for the brake-by-wire vehicle. In this study, a high accuracy main cylinder pressure tracking method with exact performance boundary is proposed for the mainstream motor-booster EHB system. By considering the clearance in the mechanical transmissions, a more applicable continuous friction model is derived based on experimental identification and used as direct feedforward input to facilitate the pressure tracking controller design. A constraint adaptive robust controller is proposed by combining adaptive robust control and prescribed performance mechanism to realize constraint pressure tracking. The unknown key parameter is estimated through a new adaptive law driven by both tracking error and observation error. System disturbance is observed by an extended state observer using the estimated parameter. The stability of the closed-loop system is proved based on the Lyapunov theory. Hard-ware-in-loop tests with various typical pressure tracking scenarios were performed to verify the superiority in pressure tracking with no violation of the predefined error boundary.

Influence of 1-pentanol as the renewable fuel blended with hydrogen on the diesel engine characteristics and trade-off study with variable injection timing

Biofuels are considered as one of the best viable and inexhaustible alternatives to conventional diesel fuel. Alcohols have become very important and popular in the present scenario due to their characteristic fuel properties and production nature. This study examines the influence of 1-pentanol and hydrogen on various performance characteristics of CRDI diesel engines. The experiment was carried out with a load range of 25%–100% in 25% percent increments, at 1500 rpm constant engine speed. The influence of injection-timing at 9°, 12°and 15°bTDC was first investigated using 30% 1-pentanol as fuel to observe the effect on engine parameters in comparison with base fluid. Compared to conventional and retarded injection timings, 1-pentanol displayed better emission and performance characteristics at higher injection timings. Additionally, at 15°bTDC, 30% 1-pentanol was used with 12 LPM hydrogen in a dual fuel mode. Compared to plain diesel, the hydrogen-enriched fuel resulted in a 1.50% lower HRR (heat release rate) and 6.77% higher cylinder pressure at 75% load. Thus, it is evident that hydrogen enrichment at 75% load effectively reduces hydrocarbon and nitrogen oxide emissions by 6.66% and 10%, respectively, and improves thermal efficiency by 5%. The experiment revealed that 1-pentanol performs effectively at higher injection timings and that hydrogen improved the performance even further. Furthermore, the long-term viability of hydrogen and 1-pentanol as an energy source is well demonstrated in future scenarios.

Initial Results on a New Light-Duty 2.7-L Opposed-Piston Gasoline Compression Ignition Multi-Cylinder Engine

Abstract Gasoline compression ignition (GCI) is a cost-effective approach to achieving diesel-like efficiencies with low emissions. The fundamental architecture of the two-stroke Achates Power Opposed-Piston (OP) Engine enables GCI by decoupling piston motion from cylinder scavenging, allowing for flexible and independent control of cylinder residual fraction and temperature leading to improved low-load combustion. In addition, the high peak cylinder pressure and noise challenges at high-load operation are mitigated by the lower brake mean effective pressure (BMEP) operation and faster heat release for the same pressure rise rate of the OP Engine. These advantages further solidify the performance benefits of the OP Engine and demonstrate the near-term feasibility of advanced combustion technologies, enabled by the opposed-piston architecture. This paper presents initial results from steady-state testing on a brand new 2.7-L OP GCI multi-cylinder engine (MCE) designed for light-duty truck applications. Successful GCI operation calls for a high compression ratio (CR), leading to higher combustion stability at low loads, higher efficiencies, and lower cycle HC + NOX emissions. Initial results show a cycle average brake thermal efficiency (BTE) of 31.7%, which is already greater than 11% conventional engines, after only ten weeks of testing. Emissions results suggest that Tier 3 Bin 160 levels can be achieved using a traditional diesel after-treatment system. Combustion noise was well controlled at or below the United States Council for Automotive Research limits. In addition, initial results on catalyst light-off mode with GCI are also presented.

Effects of intake air conditions and micro-pilot (MP) injection timing on micro-pilot dual fuel (MPDF) combustion characteristics in a single cylinder optical engine

The effects of intake air conditions and micro-pilot injection timing on the characteristics of micro-pilot dual fuel combustion were examined to enhance the combustion stability in marine engines. A minimum amount of diesel fuel was injected as the ignition source, and most of the fuel energy was obtained from methane gas. First, the intake air flow rate was varied. In addition, the methane gas flow rate and micro-pilot injection timing were changed depending on the intake air flow rate. Second, the micro-pilot injection timing was varied under intake air temperatures of 35 °C and 55 °C. The intake air and methane gas flow rates were maintained. Results indicated that increasing the intake air and methane gas flow rates promoted autoignition in the end-gas region. Nevertheless, the standard deviation of the peak cylinder pressure was within 3.1 bar. Under the intake air temperature of 35 °C, advancing and retarding the micro-pilot injection led to misfiring, which increased the standard deviation of the peak cylinder pressure to 10.2 bar and 9.6 bar, respectively. Knocking combustion was occurred when the micro-pilot injection was retarded under the intake air temperature of 55 °C. This phenomenon increased the standard deviation of the peak cylinder pressure to 6.9 bar. Premixed ignition in the end-gas region combustion corresponded to the optimal engine operating conditions for marine engines because of the low combustion variation even under high cylinder pressures of approximately 170 bar to 220 bar. However, high NOx emissions occurred under these conditions.

Investigation study for the effect using LPG on characteristics of gasoline engine

ABSTRACT This paper presents an experimental study of the effectusing LPG instead of gasoline fuel on single-cylinder spark-ignition engine characteristics. The experiments were carried out at different engine loads and variable engine speed of (2400–3600) rpm. Significantreductionin brake specific fuel consumption by (5.42%)when LPG fuel was used as compared to gasoline. The use of LPG leads to a decrease in volumetric efficiency and brake thermal efficiency. The concentration CO and CO2 emissions is decreased by (11.54%, 14.4%) respectively with LPG compared to gasoline, except for the concentration of NOx, which increases by (10.8%) due to higher cylinder pressure and temperature in the case of LPG fuel compared to gasoline. The obtained results are validated with the same case study numerically with the help of simulation software Diesel-rk as well as with the results of other researchers.

Investigation on the combustion and emission characteristics of diesel engine fueled with diesel/methanol/n-butanol blends

In this work, the diesel engine fueled with diesel/methanol/n-butanol blended fuel was employed to investigate the effects of different fuel blending ratios on the spray, combustion, and emission characteristics of diesel engine in term of cylinder pressure, cylinder temperature, heat release rate, brake specific fuel consumption, brake power, brake thermal efficiency, NOx emission, soot emission, CO emission, and HC emission. The model was developed by a three-dimensional CFD model in CONVERGE and was verified by the experiment results. In addition, an improved chemical kinetic mechanism including 359 reactions and 77 species was employed to simulation the combustion processes. The results showed that diesel/methanol/n-butanol blends played an essential role in the fuel spray and combustion processes. The blended fuel had longer ignition delay, higher cylinder pressure, and higher peak heat release rate compared with diesel. Moreover, the occurrence of micro-explosion improves the blending of fuel and air. More specifically, the diesel/methanol/n-butanol blends could reduce NOx, CO, soot, and HC emissions. It can be found that the best blending ratio of blended fuel is 70%diesel + 20%methanol + 10%n-butanol. Therefore, the diesel/methanol/n-butanol blended fuel can improve the combustion and emission characteristics of the engine.

Noise emission of combustion engines and road vehicles - a historical review

This paper deals with the historical development of the noise emission of cars, trucks and their petrol and diesel engines; it focus on the European Union and the time period between 1910 and 2020. Combustion engines were and are important noise sources of road vehicles. Until around 1970 engine noise levels were increased strongly by higher speeds, by higher cylinder pressures and especially for truck engines by the introduction of the diesel combustion process. The noise emission was mainly caused by the drive train until the 1960ies for cars and until the 1970ies for trucks. Since then the development of acoustically more advantageous engines was forced by noise regulations and simultaneously enabled by technical advancements. As a consequence of the acoustical optimization of the engines the tire/road noise became dominant. Despite of the technical advancements the road noise stress of the population is still much too high. Therefor the necessary short-term reduction of noise stress has to be realized by regulatory measures.

Market Fuel Effects on Low Speed Pre-Ignition

<div class="section abstract"><div class="htmlview paragraph">Low-Speed Pre-ignition (LSPI) is an undesirable abnormal combustion phenomenon observed in turbocharged, direct-injection spark-ignition engines and is characterized by early heat release, high cylinder pressures and severe, potentially damaging knock. LSPI has been studied for more than a decade and engine design, operating conditions and fuel and engine oil formulations have all been identified as contributing factors. A significant focus on engine oil has led to the establishment of the Sequence IX engine test and the second-generation of GM dexos® oil requirements, as well as a convergence of engine oil detergent causality. Conclusions about the effects of fuel on LSPI have been more varied, but as part of a recently completed research consortium, the LSPI tendency of market fuels with a range of properties, including composition, boiling point distribution, ethanol content and particulate matter index (PMI) were evaluated. Tests were performed in a 2-liter GM LHU engine and each test comprised of at least 24 repeats of a high-load, low-speed, steady-state test segment, with engine boundary conditions and calibration adjusted to amplify LSPI. All market fuel tests were bracketed by baseline tests and severity adjustments were made to account for changes in engine condition. It was found that the PMI and certain boiling points correlated the best with the frequency of LSPI events. In addition, decreased LSPI severity, quantified by the peak-to-peak knock values, was found to correspond with increased octane numbers and higher ethanol content of the market fuels.</div></div>

Performance and ecological parameters of a diesel engine fueled with diesel and plastic pyrolyzed oil (PPO) at variable working parameters

Plastics are one of the major pollutants to the environment. An investigation is carried out in converting low density polyethylene (LDPE) to oil by pyrolysis method with the aid of catalyst for the use in internal combustion engines. Experiments were conducted at different speeds (1200, 1500 and 1800 rpm) and variable loads (low, medium and full) with constant compression ratio engine to evaluate the performance and ecological parameters. Plastic pyrolyzed oil (PPO) is blended with diesel fuel in 20:80 volume proportion to get D80PO20 blended mixture which is employed in engine in order to assess its characteristics. Encouraging outcomes have been obtained as cylinder pressure in combustion is of same order as that of diesel fueled engine. The results showed that increasing engine speeds resulted in higher cylinder pressure and brake thermal efficiency. Also, high nitrogen oxide (NOX) and low brake specific energy consumption (BSFC) has been identified. Lower smoke (BSN) and NOX emissions are noticed from engine tail pipe with D80PO20 blended mixture.

Comparison of Exergy and Various Energy Analysis Methods for a Main Marine Steam Turbine at Different Loads

This paper present energy and exergy analysis of the main marine steam turbine, which is used for the commercial LNG (Liquefied Natural Gas) carrier propulsion, at four different loads. Energy analysis is performed by using four different methods. The presented analysis allows distinguishing advantages and disadvantages of all observed energy analysis methods and its comparison to exergy analysis of the same steam turbine. Each analysis is based on the measurement results obtained in main turbine exploitation conditions. Main turbine is composed of two cylinders – High Pressure Cylinder (HPC) and Low Pressure Cylinder (LPC). At low turbine loads, the dominant power producer is HPC, while at middle and high loads the dominant power producer is LPC. Energy analysis Method 1 which is based on the same principles as exergy analysis, should be avoided if the majority of turbine losses are not known. Other observed energy analysis methods can be applied in the analysis of any steam turbine, with a note that increase in ideal (isentropic) steam expansion process divisions will result with an increase in energy losses and with a decrease in energy efficiency. Energy analysis Method 2 which consist of only one ideal (isentropic) steam expansion process, for the whole turbine and at all observed loads, results with the lowest energy losses (in the range between 639.98 kW and 6434.17 kW) as well as with the highest energy efficiency (in a range between 53.70% and 79.40%) in comparison to other applicable energy analysis methods. For the observed loads, whole main turbine exergy destruction is in range from 608.64 kW to 5922.86 kW, while the exergy efficiency range of the whole turbine is between 54.94% and 80.73%. Exergy analysis and all three applicable energy analysis methods show that increase in the main turbine load results with simultaneous increase in turbine losses and efficiencies (both energy and exergy).

Influence of Al2O3nano additives in ternary fuel (diesel-biodiesel-ethanol) blends operated in a single cylinder diesel engine: Performance, combustion and emission characteristics

The present work is dedicated to the experimental analysis on the influence of fuel borne additives on ternary fuel blend operated in a single cylinder DI diesel engine. Alumina (Al2O3) nanoparticles were chosen as fuel additives at dosing levels of 10 ppm, 20 ppm and 30 ppm respectively and the ternary fuel (TF) is prepared by blending 70% diesel, 20%Jatropha biodiesel and 10% ethanol. Performance characteristics like brake thermal efficiency (BTE) and brake specific energy consumption (BSEC), emission characteristics like HC, CO, NOx and smoke along with combustion characteristics like cylinder pressure, HRR (Heat release rate) and CHRR (Cumulative heat release rate) were considered for analysis. Based on experimentation, it is observed that, TF blended with 20 ppm alumina nano additive (TF20) resulted in higher BTE and lowered BSEC by 7.8% and 4.93%, lowered HC, CO, NOx and smoke emissions by 5.69%, 11.24%, 9.39% and 6.48% in comparison with TF. Moreover, TF20 resulted in higher cylinder pressure, HRR and CHRR of about 72.67 bar, 76.22 J/oCA and 1171.1 J respectively which are higher than diesel and TF. Hence, it is concluded that addition of 20 ppm alumina nano additive in TF can enhance the engine performance and combustion as well as lower the exhaust pollutants simultaneously.

Effect of hydrogen and 1-Hexanol on combustion, performance and emission characteristics of CRDI CI engine

The effect of hydrogen and 1-Hexanol on engine characteristics was scrutinized in a diesel engine. The experiment was conducted at a variable load of 20% to 80% in step of 20% load and speed of the engine (2000 rpm) was constant throughout the experiment. Initially, the effect of injection time (9°BTDC, 12°BTDC and 15°BTDC) on engine characteristics were studied with 30% 1-Hexanol as fuel and compared with diesel fuel operation. 1-Hexanol showed excellent performance and emission characteristics at advanced injection time compared to standard and retard injection time. Then 10LPM of hydrogen was used in a dual fuel mode with 30% of 1-Hexanol at 15°BTDC. At 80% load, the hydrogen enrichment showed 6.77% higher cylinder pressure and 1.50% lower heat release rate compared to neat diesel. The Hydrogen enrichment improves the thermal efficiency by 5% at 80% load compared to neat diesel and also reduces the nitrogen oxide by 6.66% and hydrocarbon emission by 10% compared to neat diesel. From the experiment, it was noted that 1-Hexanol performance well at advanced injection time and further increment in the performance was made with hydrogen. It is concluded that 1-Hexanol and hydrogen will be a sustainable renewable energy source.