Effect Of Injection Timing Research Articles

단기통 디젤엔진에서 바이오디젤 연료의 분사시기가 연소, 배기배출물 및 에너지 효율에 미치는 영향

단기통 디젤엔진에서 바이오디젤 연료의 분사시기가 연소, 배기배출물 및 에너지 효율에 미치는 영향

The effects of exhaust gas re-circulation and injection timing on combustion performance and emissions of biodiesel and its blends with 2-methylfuran in a diesel engine

In this study, the influences of injection timing and exhaust gas re-circulation on combustion and emissions characteristics of biodiesel/2-methylfuran blends are investigated on a modified water-cooled 4-cylinder four-stroke direct injection compression ignition engine. The experimental conditions are, respectively, to adjust injection timing and exhaust gas re-circulation ratio at 0.38 MPa break mean effective pressure with the engine speed at 1800 rpm constantly. With injection timing in advance, the peak cylinder pressure rose while maximum heat re-lease rate first decreased and next slightly raised. Ignition delay and brake specific fuel consumption reduced first and then raised while combustion duration and break thermal efficiency had the opposite trend. The NOx emissions in-creased, and HC emissions first reduced significantly and then slightly increased, while 1,3-butadiene and acetaldehyde emissions presented a reduction tendency. As exhaust gas re-circulation ratio increased gradually, ignition delay as well as combustion duration was prolonged. brake specific fuel consumption increased and break thermal efficiency declined. HC, CO, 1,3-butadiene, and acetaldehyde emissions raised while NOx emissions reduced significantly. Biodiesel could be-have well in a Diesel engine and thus a feasible alternative fuel for diesel. More-over, methylfuran addition into biodiesel could raise break thermal efficiency and the break thermal efficiency of BM20 is higher than BM10. However, both BM10 and BM20 appeared a combustion deterioration when injection timing at 2.5?CA before top head center.

Effects of diesel and methanol injection timing on combustion, performance, and emissions of a diesel engine fueled with directly injected methanol and pilot diesel

A three-dimensional simulation model coupled with detailed chemical kinetics mechanism is applied to investigate a diesel engine fueled with directly injected methanol and pilot diesel. The diesel is injected before top dead center (TDC) to act as a pilot, and then methanol is also directly injected afterwards diesel injection as the main fuel. The effects of diesel and methanol injection timing on the combustion, performance, and emissions are investigated. The results show that: advanced diesel and methanol injections have higher in-cylinder pressure peak; and the in-cylinder pressure peak decreases with the increase of dwell. The ignition delay reduces first and then remains unchanged with the increase of dwell. 50% burn point (CA50) increases in a nearly linear way with the increase of dwell. There are four different combustion phenomena with varied dwell. Too small dwell leads to misfire or roar combustion, and too large dwell is detrimental to fuel economy. Advanced diesel and methanol injections contribute to lower equivalent indicated specific fuel consumption (EISFC) and soot emission, but lead to higher ringing intensity (RI) and nitrogen oxides (NOx) emission.

Impact of Pentanol Addition and Injection Timing on the Characteristics of a Single-Cylinder Diesel Engine

In this study, first, the effects of addition of 10% (Pen10), 20% (Pen20), and 30% (Pen30) pentanol on the performance, combustion, and emissions of a diesel engine were investigated. Then, the effect of injection timing for Pen30 fuel was investigated by changing the original injection timing of 20 to 22 and 24° BTDC (before top dead center). The engine tests were performed under different loads at 2400 rpm. The results indicated that, with the advancing of the diesel injection timing and increasing the pentanol ratio in the fuel blends, the ignition delay increased and the start of combustion delayed. The maximum heat release rate and cylinder pressure values of pentanol blends were found to be higher than those of diesel fuel. Both the maximum cylinder pressure and the maximum heat release rate increased with the advancing of the diesel injection timing to 22 and 24° BTDC. Brake-specific fuel consumption value of Pen30 was higher than that of diesel fuel at the original injection timing, and it decreased as the injection timing was advanced to 22 and 24° BTDC as compared to that of the original injection timing. NOx emission decreased with the increasing pentanol fraction. Also, NOx emissions increased significantly at 24° BTDC injection timing but decreased slightly at 22° BTDC injection timing. Smoke emissions of the pentanol blends are lower than those of the diesel fuel under all operating conditions as well as decreased with the advancing injection timing.

PSVI-19 Evaluating the effects of day of iron injection after farrowing on nursery performance and hematological criteria

Abstract Weaned pigs (n = 311; 5.9 kg BW) were used in a 59-d study evaluating the effects of Fe injection timing after birth on nursery pig performance and hematological criteria. Pigs were weaned at 21 d and allotted to pens based on preweaning Fe treatment with BW balanced across pens within a treatment with 5 or 6 pigs/pen and 10 pens/treatment. The preweaning treatments were a negative control receiving no Fe injection or 200-mg of injectable Fe (Gleptoforte, Ceva Animal Health, Lenexa, KS) provided in a single injection on d 2, 4, 6, 8, or 10 after birth. All pigs were fed common diets after weaning that contained 110 mg/kg of added Fe as FeSO4 provided from the trace mineral premix. Growth data were analyzed as a completely randomized design with pen as the experimental unit. Hematological criteria were measured as a repeated measure with pig as the experimental unit. Overall, increasing the age of pigs receiving a 200-mg Fe injection from 2 to 4 or 6 d after birth increased (quadratic; P = 0.013) d 80 ending BW with a decrease in BW when Fe was provided on d 8 or 10 (Table 1). Not providing an Fe injection after birth worsened (P < 0.05) ADG, ADFI, and d 80 ending BW. Significant treatment×day interactions (P < 0.001) were observed for Hgb and Hct values. These interactions occurred because pigs not receiving an Fe injection after birth had values that increased from d 21 to 35 while pigs receiving an Fe injection had values that decreased from d 21 to 35. While it is common practice to provide an Fe injection within the first 48 hours of birth, these results suggest delaying injection until d 4 or 6 may increase nursery final weight.

363 Evaluating the effects of day of iron injection after farrowing on preweaning performance and hematological criteria

Abstract Newborn pigs (n = 324; 1.6 kg BW) were used in an 19-d study evaluating the effects of Fe injection timing after birth on preweaned pig performance and blood criteria. A total of 27 litters were used, with the number of pigs per sow equalized on each day of farrowing. Two d after farrowing, all piglets were weighed, and six barrows and six gilts within each litter were allotted to 1 of 6 treatments in a CRD. Treatments consisted of a negative control receiving no Fe injection or 200 mg of injectable Fe (Gleptoforte, Ceva Animal Health, Lenexa, KS) provided on d 2, 4, 6, 8, or 10 after farrowing. Piglets were weighed and bled on d 2, 12, and 21 after birth to determine growth performance and blood Fe status. Overall, increasing the age that piglets received a 200 mg Fe injection until 4 or 6 d after birth tended to increase (quadratic; P = 0.065) ADG (Table 1). Not providing an Fe injection tended to decrease (P = 0.070) overall ADG and decreased (P = 0.0003) d 21 BW compared to all other treatments. Significant treatment×day interactions (P < 0.001) were observed for hemoglobin (Hgb) and hematocrit (Hct). The interactions occurred because pigs injected with 200 mg of Fe on d 2, 4, 6, or 8 after birth had increasing values until d 21 after birth, while pigs receiving a 200 mg Fe injection on d 10 after birth had decreasing values to d 12 then increasing values to d 21. Pigs not provided an Fe injection after birth had decreasing values to d 21. These results suggest that providing a 200 mg Fe injection on d 4 or 6 after farrowing provided the greatest preweaning growth performance and blood Fe status until weaning.

Effects of injection timing and compression ratio on the combustion performance and emissions of a two-stroke DISI engine fuelled with aviation kerosene

In recent years, many civilian and military unmanned aerial vehicles (UAVs) have been powered by spark ignition (SI) piston engines fuelled with gasoline. However, the safety problems associated with the storage and transportation of gasoline are forcing manufacturers and researchers to develop an SI piston engine fuelled with heavy fuel, such as light diesel or aviation kerosene. In this study, the effects of injection timing and compression ratio on the combustion characteristics and emissions of a two-stroke engine fuelled with aviation kerosene rocket propellant 3 (RP-3) are investigated. The engine tests were carried out on a two-stroke, air cooled, direct injection, spark ignition engine at three compression ratios (7.2, 6.2, and 5.2) and injection timings from 120° crank angle (CA) before top dead center (BTDC) to 240° CA BTDC. The engine was run at 4000 rpm, 100% throttle opening, and spark timing at knock limited spark advance.The results showed that the brake power (BP) increased and the coefficient of variation of the indicated mean effective pressure (COVIMEP) decreased with the advance in injection timing. The best brake thermal efficiency (BTE) was obtained at a direct injection timing of 150 °CA BTDC. Hydrocarbon (HC) and nitric oxide (NO) emissions increased while carbon monoxide (CO) emission decreased as the direct injection timing advanced. The compression ratios were decreased from 7.2 to 5.2, and the maximum values of BP and BTE were obtained at the compression ratio of 6.2. However, the HC and NO emissions at the compression ratio of 6.2 were greater than those under other compression ratios.

Effects of Injection Timing on Combustion and Emission Performance of Dual-Fuel Diesel Engine under Low to Medium Load Conditions

A throttle can be installed on the intake pipe of a natural gas (NG)/diesel dual-fuel engine to control the excess air ratio of the air-fuel mixture by adjusting the air intake. Building on a previously proposed NG/diesel dual-fuel supply strategy using the adjustment of excess air ratio, this work further studied the effects of different injection timing schemes on output power, fuel efficiency, and pollutant emissions of a dual-fuel engine under low to medium load conditions. In the experiment, the engine was operated at a speed of 1600 r/min, under either low (27.1 N·m) or medium (50.6 N·m) loads, and the NG substitution rate was either 40%, 60%, or 80%. The effect of different injection timing schemes on the combustion performance of the engine under low to medium load conditions was studied based on in-cylinder pressure changes detected by a pressure sensor. Experimental results showed that under medium-speed low-load conditions and a NG substitution rate of 40%, setting the diesel injection timing to 27 °CA BTDC increased the engine output power by 9.03%, reduced the brake specific energy consumption (BSEC) by 13.33%, and effectively reduced CO, CO2, and HC emissions. Under medium-speed medium-load conditions with a NG substitution rate of 80%, setting the diesel injection timing to 25 °CA BTDC increased the engine output power by 14.62%, reduced the BSEC by 11.73%, and significantly reduced CO, CO2, and HC emissions.

Combined effect of oxygenates and injection timing for low emissions and high performance in a diesel engine using multi-response optimisation

This study applies L9 orthogonal array of Taguchi design to obtain an optimum combination of oxygenated additive, its blending proportion with diesel and injection timing in a naturally aspirated, direct-injection diesel engine with an objective to achieve maximum reduction in smoke emissions with minimum increase in NOx emissions and minimum decrease in brake thermal efficiency (BTE) at various load conditions. Experiments are designed based on design of experiments (DOE) method to reduce the number of trials. Multi-response signal-to-noise ratio (MRSN) technique is incorporated into the conventional taguchi design to obtain the optimum level of factors according to the set objective. Confirmation experiment is conducted to verify the predicted optimum combination of factors and the results were compared in the same engine operated with baseline diesel fuel injected at its original injection timing. The results indicated that the response variables presented significant improvements with the predicted combination, thus validating the use of Taguchi method in reducing emissions and improving performance simultaneously.

A Novel NOx Correlation for CI Engine Using Multidimensional Detailed Chemistry

This paper presents a numerical investigation on a single cylinder direct injection compression ignition engine. Calculations are achieved with kiva3v2 code involving a reduced C7H16 reaction mechanism and a set of sixty species. The study has been carried out on predicted NO and NOx emission levels at the exhaust phase during the late slow diffusion combustion using the asymptotic approach. Simulations have been achieved for five loads (20%, 40%, 60%, 80% and 100%) at 1500 rpm. Predicted values of averaged pressures, O2, CO and CO2 levels in the exhaust manifold have been validated by the ones measured on engine test bench. Algebraic correlations proposed for predicted NO and NOx levels use fuel, O2, N2 concentrations and the maximum in-cylinder temperature. The numerical results of NO and NOx concentrations at the exhaust are in perfect concordance with the measured ones. In addition, numerical investigations help analyzing and predicting the injection timing effect on engine performances as well as NOx emissions. According to the results obtained, the closer the start of injection is to top dead center, the lower the NOx levels at the exhaust are.

Separation, Analysis and Validation of Metal Ions in Aqueous Samples Using Capillary Electrophoresis

Capillary electrophoresis (CE) has been developed as one of the powerful separation techniques for the analysis of inorganic and organic ions in complex matrices in the recent past. In aqueous samples, most of the inorganic ions are having weak absorption profiles in the UV-Vis region of the spectrum. These low absorption profile ionic species are commonly detected by indirect UV absorbance with the addition of an absorbing co-ion (chromophore) into the electrolyte. The inorganic cations oftenly require an additional complexing agent to selectively alter their similar mobilities and proper separation. The indirect detection at 214 nm was performed with α-hydroxyisobutyric acid (α-HIBA)-4-aminopyridine background electrolyte (BGE) that has a characteristic absorbance at 214 nm. The BGE was applied for the separation, analysis, and validation of metal ions in water samples. The metal ions such as K+, Na+, Ca2+, Mg2+, Mn2+, Fe2+, Cd2+, Pb2+, Ni2+ and Zn2+ were separated successfully in this study. Also, the effect of electrolyte pH, applied voltage and injection time for the separation of cations was investigated.

Effects of Pilot Injection Timing on The Engine Performance of A Diesel Dual Fuel Engine

The combustion process in dual fuel diesel engines occurs sequentially starting with premix burning. The premix burning starts with the ignition delay process. The presence of CNG causes the ignition delay process to become longer, thereby reducing engine performance and increasing emissions on dual fuel diesel engines. This study uses diesel engine type Diamond DI 800 with dual fuel indirect injection model system. The method used a variation of diesel pilot injection timing 110 CA, 130 CA, 150 CA, 170 and 190 CA BTDC. Testing is done with a constant engine speed of 1500 rpm and loading 500 to 3000 watts with 500-watt intervals. The results show that by advancing the diesel pilot injection timing where brake horsepower and the average effective pressure between single fuel and dual fuel is not too far as the current and voltage changes generated by the generator are not too small. While optimal thermal efficiency increased by 4.11%, while CO and HC emissions decreased respectively by 10.85% and 8.28% at occurred at the pilot injection timing 170 CA BTDC but still under the single fuel engine.

Effects of Pilot Injection Timing on The Engine Performance of A Diesel Dual Fuel Engine

The combustion process in dual fuel diesel engines occurs sequentially starting with premix burning. The premix burning starts with the ignition delay process. The presence of CNG causes the ignition delay process to become longer, thereby reducing engine performance and increasing emissions on dual fuel diesel engines. This study uses diesel engine type Diamond DI 800 with dual fuel indirect injection model system. The method used a variation of diesel pilot injection timing 110 CA, 130 CA, 150 CA, 170 and 190 CA BTDC. Testing is done with a constant engine speed of 1500 rpm and loading 500 to 3000 watts with 500-watt intervals. The results show that by advancing the diesel pilot injection timing where brake horsepower and the average effective pressure between single fuel and dual fuel is not too far as the current and voltage changes generated by the generator are not too small. While optimal thermal efficiency increased by 4.11%, while CO and HC emissions decreased respectively by 10.85% and 8.28% at occurred at the pilot injection timing 170 CA BTDC but still under the single fuel engine.

The Role of Hyaluronidase for the Skin Necrosis Caused by Hyaluronic Acid Injection-Induced Embolism: A Rabbit Auricular Model Study.

Skin necrosis is considered the most serious complication of hyaluronic acid dermal filler injection procedures. To effectively treat skin necrosis, hyaluronidase injection is one of the essential preventative treatments, and yet optimal complication management remains an unmet need. Therefore, this paper investigates the effects of hyaluronidase injection timing on the treatment of skin necrosis. In an in vitro experiment, the carbazole method was used to determine the degradation time of hyaluronic acid gels in a large volume of hyaluronidase. In vivo experimental rabbit ear models were developed to simulate the skin necrosis caused by hyaluronic acid and the test animals distributed into five groups. Except one control group, the other four groups were injected with a large volume of hyaluronidase as treatment at 2h, 4h, 8h and 16h, respectively, after models were built. The necrosis degree of models was analyzed with necrotic area and histologic examination on the postoperative 7th day. Besides, temperatures of rabbit ears were observed to demonstrate the healing process of flap models. The average necrotic area of flaps in the 2-h and 4-h injection groups showed a significant difference compared with that of the control group (p < 0.05; p < 0.05). The histologic examination showed that there were HA embolisms, vascular thrombolytic recanalization and arteriovenous thromboses in the survival area. In addition, the mean temperatures of the rabbit ear flaps fluctuated over time and showed clear differences between distal and proximal parts. The area of flap necrosis positively correlates with injection timing of the large volume of hyaluronidase. More importantly, when injection timing is within 4h, treatment effectiveness will be significantly improved. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Effects of second injection timing on combustion characteristics of the spark ignition direct injection gasoline engines with dimethyl ether enrichment in the intake port

Dimethyl ether (DME), as a sustainable fuel, could be used as an ignition improver in spark ignition engines to improve the performance under lean conditions. Direct injection engines could gain higher thermal efficiency than the port fuel injection engines. To study the effects of second injection (SOI2) timing on the engine combustion characteristics, experiments were conducted on an engine with independent DME port injection and gasoline direct injection systems. Tests were performed at a constant engine speed of 1400 rpm and manifolds absolute pressure of 60 kPa under excess air ratios of 1.2 and 1.3. The start of injection during intake was kept constant at 300 oCA BTDC and the SOI2 timing was varied from 90 to 150 oCA BTDC. Split injection ratio was 1:1. Results showed that a higher brake thermal efficiency (BTE), lower cyclic variation, HC and particle emissions were obtained for DME-gasoline blends engines. Moreover, the ideal SOI2 timing could make the heat release more concentrated and ease the cyclic variation, which enhance BTE and reduce HC, NOx and particle number emissions. In addition, when more fuel was obtained, the combustion temperature was increased, improving BTE and reducing HC emissions under lean combustion conditions.

Effect of EUP Injection Parameters on the Combustion Characteristics of Diesel Engine

With the increasingly stringent requirements for energy conservation and emission re-duction of diesel engine, electronic control of diesel fuel injection system is necessary. EUP (elec-tronic unit pump) can precisely control the fuel injection process which can reduce the exhaust emission and fuel consumption effectively. In this paper a EUP diesel engine is used as the research object. Through the combination of simulation and experiment, the effect of injector diameter and injection timing on the combustion of the engine is studied. The results show that the above param-eters have an important effect on the gas mixture formation and combustion process of the diesel engine in the cylinder. By selecting the appropriate parameters, the optimized diesel engine can meet the non-road national stage III emission regulation.

Investigation of intake pressure and fuel injection timing effect on performance characteristics of diesel engine

The low fuel consumption and efficient power usage in diesel engine has made diesel engine as the more appealing option in comparison with other type of engines. To raise the performance of DI (direct injection) diesel engine further, injection timing and intake pressure variation were studied under 2000 RPM (rotation per minute) engine rotation. This experiment used DI diesel engine with single cylinder. The length of stroke was set to 96.9 mm, the diameter of bore was set to 85 mm and the compression ratio of the engine was 16.3. The variations of main injection timing were set for 1° after TDC (top dead centre) as advanced injection timing, and 3° after TDC as retarded injection timing. Boost pressures for intake pressure were varied with 20 in increments and started from 0 KPa to 60 KPa. In-cylinder pressure characteristics and heat release rate were used to evaluate the engine performance. The experiment indicated, as the boost pressure raises, the heat release rate and in-cylinder pressure are increased. The main injection timing advancement from 3° after TDC to 1° after TDC causes increase to the peak of in-cylinder pressure after TDC in DI diesel engine. This phenomenon is due to the slower combustion in retarded injection timing. For heat release rate, the advancement of injection timing causes the differences between various intake pressures to be more apparent.

Effect of fuel injection pressure and timing on Polanga (Calophyllum Inophyllum) biodiesel blends for engine performance and emissions analysis

ABSTRACTTo evaluate the performance and emissions of a diesel engine fuelled by biodiesel blends produced from polanga oil, the engine was run to investigate the effects of injection pressure and timing on engine operation with varying biodiesel blends concentrations. Consequently, commercial diesel fuel blended with different polanga biodiesel in different percentages (0%, 10%, 20%, 30%, and 40%). The average reduction in the thermal performance of the biodiesel fuels, was reduced proportionally with the biodiesel blends. B20 blend operates closest to that of diesel oil whereas, the engine operated with any higher injection timing, ranging from 27 to 31° bTDC, the emission constituents of CO, UHC, CO2, and smoke are the least and remains constant in the injection timing between 27 to 31°bTDC. Polanga based biodiesel blends provide a better result at an injection timing of 31°bTDC and injection pressure of 240 bar leading towards minimum emission. Up to 20% polanga biodiesel blends improvement in the engine performance and reduction in the emissions was observed without any modifications to CI engine.

Effect of injection timing on the ignition process of n-heptane spray flame in a methane/air environment

There is significant interest in using pilot fuel as a source of ignition to enhance the performance of a natural gas engine. The pilot fuel injection timing is a critical factor that influences the combustion phasing and emissions characteristics. In this study, the effect of injection timing on the development of n-heptane spray flame in a methane/air environment is performed by using large eddy simulation (LES) in a constant-volume combustion vessel under engine-like conditions. The results indicate that injection retarding accelerates the ignition of n-heptane spray and reduces the interval between the ignition of n-heptane and methane/air mixture. The contributions of premixed and non-premixed combustion on heat release are distinguished by introducing the flame index (FI). Furthermore, the reason why retarding injection leads to earlier ignition is investigated by sensitivity analysis in a zero-dimension simulation. It is concluded that although methane addition delays the ignition of n-heptane, the pre-ignition oxidative reactions of methane/air mixture occurs prior to the n-heptane injection, thereby increasing the temperature and pressure and producing significantly intermediate radicals and consequently promoting the n-heptane ignition. Additionally, the n-heptane spray flame, in turn, further ignites the methane/air mixture and induces the high-temperature combustion. The results also indicate that the influence of temperature on the ignition is maximum, which is followed by the influence of important intermediate species, formaldehyde (CH2O), while the influence of pressure is minor. The present study provides a theoretical basis for an in-depth understanding of the effect of injection timing on the combustion of dual-fuel engines.

A study of urea injection timing to predict the NOx conversion in SCR systems

The automotive industry has been restricted by several regulations to reduce pollutant from diesel engines. To fulfill the emission regulation, advanced engine technology purposes to control pollutant reduction and lowering the unburnt HC, CO2 and CO level. However, it is difficult to meet the NOx limits of the world standard like a European standard (EURO VI) and American standard (US TIER 2 BIN 5). Selective catalytic reduction (SCR) with ammonia (NH3) has been successfully to remove NOx from diesel engines. However, uniform ammonia distribution is usually difficult to achieve. Therefore, a study on the effects of urea injection timing to predict NOx reduction efficiency is needed. In this study, the simulations and experimental work to obtain constant and stable conditions in the SCR system were conducted. Because the constant condition can optimize the ammonia uniformity. The engine in experiment was compute from engine turned on to find the desired temperature and airflow, and the simulation was performed using a commercial code of STAR-CCM+. The numerical results were validated using experimental results of ammonia concentration distribution.