Study on cyclic variation rate of fuel flow in the nozzle during fuel injection

2021 ◽  
Vol 13 (2-3) ◽  
pp. 113-123
Author(s):  
Wen Hua ◽  
Zhang Xin-yu ◽  
Jiang Yu-long ◽  
Zhao Ling-yao
Keyword(s):  
Diesel Engine ◽  
Flow Pattern ◽  
Working Condition ◽  
Fuel Injection ◽  
Injection Pressure ◽  
Cyclic Variation ◽  
Injection Nozzle ◽  
Fuel Flow ◽  
Variation Rate ◽  
The Difference

The fuel flow pattern in the fuel injection nozzle of diesel engine is a complex and changeable phenomenon, which is easily affected by various factors, bringing the differences of flow patterns between multiple injection cycles. To solve the above problem, a visual experimental platform of fuel injection nozzle was built, in which the 100 injection cycles of diesel engine on the same working condition were photographed via shadowgraphy to study the difference in fuel flow pattern in the nozzle by ensemble average processing method. The cyclic variation rate K of fuel flow pattern is defined. Results demonstrate that the fuel flow pattern tends to be the same in multiple fuel injection cycles, but there is a strong randomness at the starting of injection and after ending of injection; the K can be reduced by decreasing the injection pressure and the inclination angle of orifice, so that the fuel flow pattern in the nozzle tends to be consistent.

scholarly journals Numerical investigation of injection parameters and piston bowl geometries on emission and thermal performance of DI diesel engine

2021 ◽  
Vol 3 (6) ◽  
Author(s):  
Ikhtedar Husain Rizvi ◽  
Rajesh Gupta
Keyword(s):  
Diesel Engine ◽  
Thermal Performance ◽  
Equivalence Ratio ◽  
Fuel Injection ◽  
Injection Pressure ◽  
Injection Nozzle ◽  
Piston Bowl ◽  
Injection Parameters ◽  
Nozzle Size ◽  
Engine Emission

AbstractTightening noose on engine emission norms compelled manufacturers globally to design engines with low emission specially NOx and soot without compromising their performance. Amongst various parameters, shape of piston bowls, injection pressure and nozzle diameter are known to have significant influence over the thermal performance and emission emanating from the engine. This paper investigates the combined effect of fuel injection parameters such as pressure at which fuel is injected and the injection nozzle size along with shape of piston bowl on engine emission and performance. Numerical simulation is carried out using one cylinder naturally aspirated diesel engine using AVL FIRE commercial code. Three geometries of piston bowls with different tumble and swirl characteristics are considered while maintaining the volume of piston bowl, compression ratio, engine speed and fuel injected mass constant along with equal number of variations for injection nozzle size and pressures for this analysis. The investigation corroborates that high swirl and large turbulence kinetic energy (TKE) are crucial for better combustion. TKE and equivalence ratio also increased as the injection pressure increases during the injection period, hence, enhances combustion and reduces soot formation. Increase in nozzle diameter produces higher TKE and equivalence ratio, while CO and soot emission are found to be decreasing and NOx formation to be increasing. Further, optimization is carried out for twenty-seven cases created by combining fuel injection parameters and piston bowl geometries. The case D2H1P1 (H1 = 0.2 mm, P1 = 200 bar) found to be an optimum case because of its lowest emission level with slightly better performance.

scholarly journals The Effect of High Fuel Injection Pressure on CRDI Diesel Engine Fueled with Algae Biofuel

2020 ◽  
Vol 9 (1) ◽  
pp. 2614-2619
Keyword(s):  
Diesel Engine ◽  
Fuel Injection ◽  
Direct Injection ◽  
Injection Pressure ◽  
Experimental Investigations ◽  
Brake Thermal Efficiency ◽  
Algae Biofuel ◽  
The Difference ◽  
Fuel Injection Pressure ◽  
Injection Pressures

Experimental investigations were conducted to determine the performance & emission features of a common rail direct injection (CRDI) system using algae biofuel to aid diesel engine. The algae biofuel-diesel blends were taken in two different proportions, B10 & B15 (10% and 15% of algae biofuel is mixed with diesel on a volumetric approach). The tests were conducted on CRDI diesel engine at various injection pressures from 600 to 1050 bar with the difference of 150 bar. From the results it was exposed that at high fuel injection pressure (1050 bar), brake thermal efficiency (BTE) improved and brake specific fuel consumption (BSFC) reduced when related with other injection pressures. CO, HC &/smoke density significantly decreases with rise in injection pressures. However, NOx emissions are shown to be increased. At different load conditions, biodiesel algae are associated with higher exhaust gas temperatures.

Influence of Injection Pressure on Performance and Emission Characteristics of Nerium Methyl Ester Operated DI Diesel Engine

2014 ◽  
Vol 592-594 ◽  
pp. 1632-1637
Author(s):  
Ramalingam Senthil ◽  
C. Paramasivam ◽  
Rajendran Silambarasan
Keyword(s):  
Diesel Engine ◽  
Methyl Ester ◽  
Fuel Injection ◽  
Cetane Number ◽  
Load Condition ◽  
Injection Pressure ◽  
Emission Characteristics ◽  
Operational Parameters ◽  
Performance And Emission ◽  
Standard Design

Nerium methyl ester, an esterified biofuel, has an excellent cetane number and a reasonable calorific value. It closely resembles the behaviour of diesel. However, being a fuel of different origin, the standard design limits of a diesel engine is not suitable for Nerium methyl ester (NME). Therefore, in this work, a set of design and operational parameters are studied to find out the optimum performance of Nerium methyl ester run diesel engine. This work targets at finding the effects of the engine design parameter viz. fuel injection pressure (IP) on the performance with regard to specific fuel consumption (SFC), brake thermal efficiency (BTHE) and emissions of CO, CO2, HC, NOxwith N20 as fuel. Comparison of performance and emission was done for different values of injection pressure to find best possible condition for operating engine with NME. For small sized direct injection constant speed engines used for agricultural applications, the optimum injection pressure was found as 240bar.Methyl esters from Nerium, with properties close to diesel; show better performance and emission characteristics. Hence Nerium (N20) blend can be used in existing diesel engines without compromising the engine performance. Diesel (25%) thus saved will greatly help the interests of railways in meeting the demand for fuel,as diesel trains are operated at maximum load condition.

Experimental investigation of dwell time characteristics in high-pressure double-solenoid-valve fuel injection system

2019 ◽  
Vol 233 (13) ◽  
pp. 3281-3292
Author(s):  
Dan Xu ◽  
Qing Yang ◽  
Xiaodong An ◽  
Baigang Sun ◽  
Dongwei Wu ◽  
...  
Keyword(s):  
Fuel Injection ◽  
Injection Pressure ◽  
Solenoid Valve ◽  
Injection System ◽  
Fuel Injection System ◽  
Pilot Injection ◽  
Main Injection ◽  
Injection Interval ◽  
The Difference ◽  
Variation Rule

The double-solenoid-valve fuel injection system consists of an electronic unit pump and an electronic injector. It can realize the separate control of fuel supply and injection and has the advantages of adjusting pressure by cycle and flexible controlling of the injection rate. The interval angle between the pilot and main injection directly affects the action degree and the characteristics of two adjacent injections, affecting engine performance. This work realizes multiple injection processes on the test platform of a high-pressure double-solenoid-valve fuel injection system, with maximum injection pressure reaching 200 MPa. In this study, the interval between driven current signal of pilot injection termination and that of main injection initiation is defined as the signal interval (DT1), whereas the interval between pilot injection termination and main injection initiation is defined as the injection interval (DT2). The differences between the signal and the injection intervals are calculated, and the variation rule of the difference with respect to the signal interval is analyzed. Results show that the variation rule of the difference with the signal interval first decreases, then increases, and finally decreases. The variation rule of the delay angle from the start of needle movement to the start of fuel injection is found to be the root cause of this rule. The influence of the injection pressure on needle deformation and fuel flow rate of the nozzle results in the variation rule. In addition, the influence of the cam speed, temperature, and pipe length on the difference between the signal and injection interval is determined. This research provides guidance for an optimal control strategy of the fuel injection process.

scholarly journals Influence of Fuel Injection Pressure on the Emissions Characteristics and Engine Performance in a CRDI Diesel Engine Fueled with Palm Biodiesel Blends

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3837 ◽  
Author(s):  
Sam Ki Yoon ◽  
Jun Cong Ge ◽  
Nag Jung Choi
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Fuel Injection ◽  
Injection Pressure ◽  
Biodiesel Fuel ◽  
Nox Emissions ◽  
Oxides Of Nitrogen ◽  
Fuel Blend ◽  
Engine Load ◽  
Fuel Injection Pressure

This experiment investigates the combustion and emissions characteristics of a common rail direct injection (CRDI) diesel engine using various blends of pure diesel fuel and palm biodiesel. Fuel injection pressures of 45 and 65 MPa were investigated under engine loads of 50 and 100 Nm. The fuels studied herein were pure diesel fuel 100 vol.% with 0 vol.% of palm biodiesel (PBD0), pure diesel fuel 80 vol.% blended with 20 vol.% of palm biodiesel (PBD20), and pure diesel fuel 50 vol.% blended with 50 vol.% of palm biodiesel (PBD50). As the fuel injection pressure increased from 45 to 65 MPa under all engine loads, the combustion pressure and heat release rate also increased. The indicated mean effective pressure (IMEP) increased with an increase of the fuel injection pressure. In addition, for 50 Nm of the engine load, an increase to the fuel injection pressure resulted in a reduction of the brake specific fuel consumption (BSFC) by an average of 2.43%. In comparison, for an engine load of 100 Nm, an increase in the fuel injection pressure decreased BSFC by an average of 0.8%. Hydrocarbon (HC) and particulate matter (PM) decreased as fuel pressure increased, independent of the engine load. Increasing fuel injection pressure for 50 Nm engine load using PBD0, PBD20 and PBD50 decreased carbon monoxide (CO) emissions. When the fuel injection pressure was increased from 45 MPa to 65 MPa, oxides of nitrogen (NOx) emissions were increased for both engine loads. For a given fuel injection pressure, NOx emissions increased slightly as the biodiesel content in the fuel blend increased.

Progress on the Investigation of Coal-Water Slurry Fuel Combustion in a Medium-Speed Diesel Engine: Part 5—Combustion Studies

1992 ◽  
Vol 114 (3) ◽  
pp. 515-521 ◽  
Author(s):  
B. D. Hsu ◽  
G. L. Confer ◽  
Z. J. Shen
Keyword(s):  
Diesel Engine ◽  
Fuel Injection ◽  
Injection Pressure ◽  
Combustion Efficiency ◽  
Fuel Combustion ◽  
Injection Timing ◽  
Water Slurry ◽  
Medium Speed ◽  
Engine Part ◽  
Coal Water Slurry

In the GE 7FDL single-cylinder research diesel engine, coal-water slurry (CWS) fuel combustion optimization studies were conducted using electronically controlled CWS and pilot accumulator injectors. The most important performance parameters of peak firing pressure, combustion efficiency (coal burnout), and specific fuel comsumption were evaluated in relationship to CWS and pilot injection timing, CWS injector hole size, shape, and number, CWS fuel injection spray angles and injection pressure. Heat release diagrams, as well as exhaust samples (gaseous and particulate), were analyzed for each case. Interesting effects of fuel spray impingement and CWS fuel “Delayed Ignition” were observed. With the engine operating at 2.0 MPa IMEP and 1050 rpm, it was able to obtain over 99.5 percent combustion efficiency while holding the cylinder firing pressure below 17 MPa and thermal efficiency equivalent to diesel fuel operation.

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