The article deals with the effects made by using various n-butanol-diesel fuel blends on the combustion history, engine performance and exhaust emissions of a turbocharged four-stroke, four-cylinder, CRDI 1154HP (85 kW) diesel engine. At first, load characteristics were taken when running an engine with normal diesel fuel (DF) to have ‘baseline’ parameters at the two ranges of speed of 1800 and 2500 rpm. Four a fossil diesel (class 1) and normal butanol (n-butanol) fuel blends possessing 1 wt%, 2 wt%, 3 wt%, and 4 wt% (by mass) of n-butanol-bound oxygen fractions were prepared by pouring 4.65 wt% (BD1), 9.30 wt% (BD2), 13.95 wt% (BD3), and 18.65 wt% (BD4) n-butanol to diesel fuel. Then, load characteristics were taken when an engine with n-butanol-oxygenated fuel blends at the same speeds. Analysis of the changes occurred in the autoignition delay, combustion history, the cycle-to-cycle variation, engine efficiency, smoke, and exhaust emissions NOx, CO, THC obtained with purposely designed fuel blends was performed on comparative bases with the corresponding values measured with ‘baseline’ diesel fuel to reveal the potential developing trends.
The article presents the effects caused by the variation of fuel-oxygen mass content and widely differing chemical and physical properties of a fossil diesel (DF) and hydrotreated renewable diesel (HRD) fuel blends involving ethanol (E) or biodiesel (B) on ignition delay, combustion phenomenon, heat release characteristics, and maximum in-cylinder pressure of a turbocharged CRDI diesel engine. The diesel-HRD fuel blends (12 in total) involving anhydrous (200 proof) ethanol OE0-OE5 or rapeseed biodiesel OB0-OB5 in such proportions by mass to assure a wide range of the variation of fuel-bound oxygen mass fraction 0-4.52 wt% (CN = 55.5) were tested for relative air-fuel ratios, λ = 1.30, 1.25 and 1.20, at the respective speeds of 1500, 2000, and 2500 rpm. Analysis of changes in the ignition delay, combustion history, and the peak in-cylinder pressure produced by using purposely designed fuel blends was performed on comparative bases with the corresponding values measured with ‘base-line’ blends OE0 or OB0 to reveal the potential developing trends. It was found that the reasonably higher fuel oxygen content improved combustion, boosted heat release rates, and shortened burn angle MBF 90, when running mainly at the high engine speed of 2500 rpm. Experiments revealed that fuel-oxygen mass content should be neither too high nor too low, but just enough to assure complete combustion and a low coefficient of the cyclic variation (COV) of operational parameters.
PL
Artykuł przedstawia wpływ zmian proporcji masowych paliwo-tlen oraz znacznie różniących się właściwościami chemicznymi i fizycznymi oleju napędowego (DF) oraz hydrorafinowanych mieszanek oleju napędowego (HRD) oraz etanolu (E) i biodiesla (B), na opóźnienie samozapłonu, zjawisko spalania, charakterystykę oddawania ciepła oraz maksymalne ciśnienie w cylindrze turbodoładowanego silnika o ZS typu CRDI. Przebadano mieszanki paliwowe: olej napędowy - HRD (łącznie 12), w tym bezwodny etanol OE0-OE5 (próba 200) oraz biodiesel OB0-OB5 na bazie rzepaku w takich proporcjach masowych, aby zapewnić szeroki zakres zmian zawartości masowej tlenu związanego w paliwie w zakresie 0-4,52% (CN = 55,5), dla względnego współczynnika nadmiaru powietrza λ = 1,30, 1,25, 1,20 przy prędkościach obrotowych 1500, 2000 oraz 2500 obr./min. Przeprowadzono analizę porównawczą opóźnienia samozapłonu, sprawności spalania oraz szczytowego ciśnienia wytworzonego wewnątrz cylindra, przy zasilaniu celowo opracowanymi mieszankami paliwowymi, w odniesieniu do odpowiednich wartości zmierzonych dla mieszanek „bazowych” OE0 i OB0, aby wykryć potencjalny trend zmian. Stwierdzono, że odpowiednio wyższa zawartość tlenu w paliwie poprawiła spalanie, podniosła sprawność cieplną oraz zmniejszyła kąt spalania MBF 90, głównie przy pracy na wysokich obrotach 2500 obr/min. Eksperymenty pokazały, że proporcja masowa paliwo-tlen nie powinna być ani zbyt niska, ani zbyt wysoka, ale wystarczająca, by zapewnić całkowite spalanie oraz niski współczynnik zmian cyklicznych (COV) parametrów eksploatacyjnych.
The article presents bench test results of a four-stroke, four-cylinder, naturally aspirated, DI diesel engine operating with neat JP-8 fuel (J) and its blends with Diesel fuel (D) in following proportions by volume: 90/10 (J+10D), 70/30 (J+D30), 50/ 50 (J+D50), 30/70 (J+D70), and 100% diesel fuel (DF). The purpose of the research was to analyse and compare changes occurred in the autoignition delay, combustion events, engine performance efficiency, emissions, and smoke of the exhaust when running on JP-8 fuel, jet-diesel fuel blends, and diesel fuel at a full (100%) engine load and speed of 1400 min–1 at which maximum torque occurs and rated speed of 2200 min–1. It was found that the start of injection (SOI) and the start of combustion (SOC) occurred earlier in an engine cycle and the autoignition delay decreased by 9.0% and 12.7% due to replacement of aviation JP-8 fuel with diesel fuel at a full load and the latter speeds. Maximum in-cylinder pressure was 6.8% and 4.0% higher when operating with diesel fuel, whereas brake thermal efficiency was 3.3% and 7.7% higher, and brake specific fuel consumption 2.8% and 7.0% lower when using fuel blend J+D50 compared with the respective values measured with neat JP-8 fuel. Emissions of nitric oxide (NO) and nitrogen oxides (NOx) were 13.3% and 13.1% higher from a straight diesel running at speed of 1400 min–1, and 19.0% and 19.5% higher at a higher speed of 2200 min–1. The carbon monoxide (CO) emissions and total unburned hydrocarbons (HC) decreased 2.1 times and by 12.3% when running with fuel blend J+D70 at speed of 2200 min–1 compared with those values measured with jet fuel. Smoke of the exhaust was 53.1% and 1.9% higher when using fuel blend J+D10 than that of 46.9% and 70.0% measured with jet fuel at speeds of 1400 and 2200 min–1. The engine produced 34.5% more smoke from combustion of fuel blend J+D70 at the low speed of 1400 min–1, but smoke converted to be 11.3% lower when operating at a higher speed of 2200 min–1.
This article presents the test results of injection processes of diesel-bioethanol fuel blends on a high pressure common rail injection system. The injection characteristics were analyzed using the injection rate measuring instrumentation. The injection rate, cycle injection quantity, injection delay and injection duration were analyzed across a range of injection pressure and injection energizing time. As the results show, the peak injection rate and delay of diesel-ethanol blends are lower compared to diesel fuel. The injection duration and discharge coefficients of diesel-ethanol blends were lower than those of diesel fuel. It was observed that fuel density and fuel viscosity have significant influence on the injection characteristics.
The article presents bench test results of a DI (60 kW) Diesel engine D-243 operating on class 2 Diesel fuel (DF) as baseline fuel and its 5vol%, 10vol% and 15vol% blends with anhydrous ethanol. The purpose of the research was to investigate the effect of the ethanol addition to Diesel fuel on the autoignition delay, combustion, engine performance efficiency and emissions of the exhaust. The results of engine operation on ethanol- Diesel blends are compared with baseline parameters of normal Diesel running at full (100%) load and rated 2200 rpm speed.
The article focuses on bench testing results of a four-stroke, four-cylinder, direct-injection, naturally aspirated diesel engine operating on the normal 95vol% (class C) diesel fuel + 5vol% RME (DF), F-34 jet fuel (JF) and jet fuel F-34 treated with the cetane improver (JF+0.12vol%). The purpose of the research is to investigate the availability to use of military F-34 jet fuel for land-based direct injection diesel engine powering and examine the effect of F-34 fuel and F-34 fuel treated with 0.12vol% 2-ethylhexyl nitrate on the autoignition delay, combustion, engine performance, emissions and smoke opacity of the exhausts. The peak in-cylinder gas pressure generated from JF and JF+0.12vol% is lower by 4.3% and 2.8% at 1400 min–1 speed, and 2.5% and 5.7% at 2200 min–1 speed compared to that 86.6 MPa and 82.5 MPa of the normal diesel. At rated 2200 min–1 speed, the use of treated jet fuel leads to smoother engine performance under all loads and the maximum cylinder pressure gradient lowers by 9.4% as against that 15.9 bar/deg of base diesel. The minimum brake specific fuel consumption (bsfc) for F-34 and treated F-34 fuels decreases by 4.8% and 3.5% at 1400 min–1 speed and increases by 2.7% and 3.7% at 2200 min–1 speed compared to 249.5 g/kWh and 251.8 g/kWh values of base diesel. Maximum NO emissions produced from fuels JF and JF+0.12vol% decrease by 11.5% and 7.0% at 1400 min–1, and 17.1% and 17.3% at 2200 min–1 speed compared to 1705 ppm and 1389 ppm emanating from the normal diesel. Maximum CO emissions produced from jet fuel JF and JF+0.12vol% decrease by 39.3% and 16.8% compared to that 4988 ppm produced from base diesel running at 1400 min–1 speed. At 2200 min-1 speed, the ecological effect of using fuel F-34 fuel decreases and the CO sustains over the whole load range at the same level and increases by 2.5% and 3.0% with regard to the normal diesel operating under high load. The HC emission also is lower by 78.3% and 58.8% for low and high loads compared to 230 ppm and 1820 ppm of the normal diesel running at 1400 min–1 speed. The smoke opacity ,generated from fuels JF and JF+0.12vol% sustains at lower levels over the all load range with the maximum values decreased by 14.6% and 8.1% with regard to 94.9% of the normal diesel operating at 1400 min–1 speed. The test results show that military F-34 fuel is a cleaner-burning replacement of diesel fuel and suggests fuel economy with reduced all harmful species, including NO, NO2, NOx, CO, HC, and smoke opacity of the exhausts.
The article deals with bench testing results of a DI (60 kW) diesel engine D-243 operating on reference (DF) arctic class 2 diesel fuel (80vol%), anhydrous (200 proof) ethanol (15vol%) and rapeseed methyl ester (5vol%) blend B15E5. The purpose of the research is to investigate the effect of simultaneous ethanol and RME addition in the diesel fuel on brake specific fuel consumption (bsfc), the brake thermal efficiency (çe) and noxious emissions, including NO, NO2, NOx, CO, CO2, HC and smoke opacity of the exhausts. The bsfc of the diesel engine operating on three-component fuel B15E5 under maximum load of bmep = 0.75, 0.76 and 0.68 MPa is higher by 10.3%, 10.7% and 9.6% because of both net heating value lower by 6.18% and brake thermal efficiency lower by 3.4%, 3.7% and 2.8% relative to that of reference diesel at 1400, 1800 and 2200 min-1 speeds. The maximum NOx emission produced from oxygenated blend B15E5 was reduced by 13.4%, 18.0% and 12.5% and smoke opacity diminished by 13.2%, 1.5% and 2.7% under considered loading conditions relative to that of a neat diesel fuel. The CO amounts produced from three-component fuel B15E5 were lowered by 6.0% for low 1400 min-1 speed only and they increased by 20.1% and 28.2% for higher 1800 and 2200 min-1 speeds and the HC emissions were also higher by 35.1%, 25.5% and 34.9% throughout a whole speed rage comparing with respective values measured from neat diesel fuel.
The article presents the bench testing results of a four stroke, four cylinder, direct injection, unmodified, naturally aspirated diesel engine operating on neat rapeseed oil (RO) and its 2.5vol% (ERO2.5) and 7.5vol percent (ERO7.5) blends with ethanol. The purpose of the research was to investigate the effect of ethanol inclusion in the RO and preheating temperature on bio-fuel viscosity, engine brake power, specific fuel consumption, break thermal efficiency and emission composition changes, especially NO, NO2, NOx, CO, CO2, HC and smoke opacity of the exhausts. Inclusion in the RO 2.5 and 7.5vol% of ethanol the blend viscosity at ambient temperature of 20 centigrade diminishes by 9.2 and 28.3%. During operation under constant air-to-fuel equivalence ratio gamma = 1.6, blends ERO2.5 and ERO7.5 ensure the brake mean effective pressure (bmep) lower at the maximum torque 1800 min-1 by 0.5 and 2.3% (bmep=0.770 mpa) and at rated 2200 min1 speed by 2.4 and 9.1% (bmep=0.740 mpa), correspondingly, than that of neat RO case. The bsfc at maximum torque (248.7 g/kwh) and rated power (247.5 g/kwh) for blends ERO2.5 and ERO7.5 is higher by 1.3-4.4% and 4.2-10.7% and the brake thermal efficiency lower by 0.5-1.5% and 3.3-7.6%, respectively. The tests revealed that during operation of the fully loaded engine at rated 2200 min-1 speed, ethanol inclusion in the RO up to 7.5vol% diminishes NO, nox, HC, CO2 emissions, smoke opacity and temperature of the exhausts however it may increase simultaneously NO2, NO2/NOx and CO emissions.
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The purpose of this research is to determine the effect of Diesel fuel blending with rapeseed oil (RO) and RME on the brake specific fuel consumption of a direct-injection Diesel engine, fuel energy conversion efficiency and evaluate the quantitative emission composition changes and smoke opacity of the exhausts. Test results show that the application for engine fuelling of Diesel fuel and rapeseed oil RO25 (1:4 by volume) as well as rapeseed methyl ester RME20 (1:5 by volume) blends at low-to-moderate revolutions does not affect greatly the brake specific fuel consumption (bsfc) however at the rated speed and fully opened throttle the bsfc for blends RO25 and RME20 is higher by 4.7% and 11.9%, respectively. The maximum emission of nitrogen oxides NOx at the rated power for blend RO25 is lower by 11.7% and for blend RME20 is higher by 44.7% related to Diesel fuel. The smoke opacity, emissions of carbon dioxide CO2, monoxide CO and unburned hydrocarbons HC released into atmosphere from the engine run at fully opened throttle on blend RO25 are more or less similar to that of Diesel fuel whereas during operation at the rated power on blend RME20, because of higher specific fuel consumption, the smoke opacity increases to 42.6% and emission of CO2 to 9.9%.
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One of the methods that allows reduce the specific fuel consumption of Diesel engines and avoid possihle damage ofthe environment by harmful exhaust gases is application ofthe fuel additives. The purpose of this research is to determine the influence of the fuel additive SO-2E on the fuel consumption of a direct-injection Diesel engine and to evaluate the quantitative emission composition changes and smoke opacity of the exhausts. Investigations were conducted on the four cylinder, four stroke, naturally aspirated, water cooled. 59 kW Diesel engine D-243. Test results show that the application of fuel additive SO-2E in proportion 1:500 (by volume) does not have significant Influence on the brake specific fuel consumption. The total emission of nitrogen oxides Nox at the rated performance regime due to the usage of the fuel additive reduces by 11.6 percent, primary because of lower NO concentration. The carbon monoxide CO emission from fully loaded engine at the rated speed due to application of the fuel additive SO-2E increases up to 20 percent, although at other performance regimes the additive influence is minor. The smoke opacity from treated fuel at light-to-moderate loads slightly decreases, however at the engine rated speed it becomes by 5 - 10 percent higher.
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