Numerical Analysis Versus Experimental Investigation of a Distributor-Type Diesel Fuel-Injection System

1994 ◽  
Vol 116 (4) ◽  
pp. 814-830 ◽  
Author(s):  
A. E. Catania ◽  
C. Dongiovanni ◽  
A. Mittica ◽  
M. Badami ◽  
F. Lovisolo
Keyword(s):  
Experimental Investigation ◽  
Numerical Analysis ◽  
Fuel Injection ◽  
Injection Pressure ◽  
Injection System ◽  
Return Flow ◽  
Computer Assisted ◽  
Fuel Injection System ◽  
Flow Restriction ◽  
Nozzle Hole

A production distributor-type fuel-injection system for diesel engines has been extensively investigated via computer-assisted simulation and experimentation. The investigation was mainly aimed at assessing and validating a sophisticated computational model of the system, developed with specific attention given to the pump and to some important aspects concerning the injection pressure simulation, such as the dynamic effects of the injector needle lift, the flow unsteadiness, and compressibility effects on the nozzle-hole discharge coefficient. The pump delivery assembly was provided with a valve of the reflux type. This presented a flat in the collar, forming a return-flow restriction with the seat, and had no retraction piston. A single-spring injector, with a reduced sac volume, was fitted to the system. The numerical analysis of transient flow phenomena linked to the mechanical unit dynamics, including possible cavitation occurrence in the system, was performed using an implicit finite-difference algorithm, previously set up for in-line injection equipment. Particular care was exercised in modeling the distributor pump so as to match the dynamics of the delivery-valve assembly to the pressure wave propagation in the distributor and its outlets. The so-called minor losses were also taken into account and it was ascertained that sudden expansion and contraction losses were significant for the type of pump examined. The experimental investigation was performed on a test bench at practical pump speeds. Pressures were measured in the pumping chamber, at two different pipe locations, and upstream to the needle seat opening passage. This last measurement was taken in order to evaluate the nozzle-hole flow coefficient with the support of the simulation, using experimental values of the needle lift, injection rate, and injected fuel quantity as known variables. The numerical and experimental results were compared and discussed, showing the validity of the model. The injection pressure time history and the influence of the delivery return-flow restriction on the system performance were numerically examined.

scholarly journals Organization of Six-Cylinder Tractor Diesel Working Process

2021 ◽  
Vol 20 (5) ◽  
pp. 427-433
Author(s):  
G. M. Kuharonak ◽  
M. Klesso ◽  
A. Predko ◽  
D. Telyuk
Keyword(s):  
Combustion Chamber ◽  
Fuel Injection ◽  
Injection Pressure ◽  
Common Rail ◽  
Injection System ◽  
Fuel Injection System ◽  
Rotary Valve ◽  
Original Design ◽  
Working Process ◽  
Common Rail System

The purpose of the work is to consider the organization of the working process of six-cylinder diesel engines with a power of 116 and 156 kW and exhaust gas recirculation. The following systems and components were used in the experimental configurations of the engine: Common Rail BOSСH accumulator fuel injection system with an injection pressure of 140 MPa, equipped with electro-hydraulic injectors with seven-hole nozzle and a 500 mm3 hydraulic flow; direct fuel injection system with MOTORPAL fuel pump with a maximum injection pressure of 100 MPa, equipped with MOTORPAL and AZPI five-hole nozzle injectors; two combustion chambers with volumes of 55 and 56 cm3 and bowl diameters of 55.0 and 67.5 mm, respectively; cylinder heads providing a 3.0–4.0 swirl ratio for Common Rail system, 3.5–4.5 for mechanical injection system. The recirculation rate was set by gas throttling before the turbine using a rotary valve of an original design. The tests have been conducted at characteristic points of the NRSC cycle: minimum idle speed 800 rpm, maximum torque speed 1600 rpm, rated power speed 2100 rpm. It has been established that it is possible to achieve the standards of emissions of harmful substances: on the 116 kW diesel engine using of direct-action fuel equipment and a semi-open combustion chamber; on the 156 kW diesel using Common Rail fuel supply system of the Low Cost type and an open combustion chamber.

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.

Experimental investigation on a 3000 bar fuel injection system for a SCR-free non-road diesel engine

Fuel ◽  
2019 ◽  
Vol 243 ◽  
pp. 342-351 ◽  
Author(s):  
Giulio Boccardo ◽  
Federico Millo ◽  
Andrea Piano ◽  
Luigi Arnone ◽  
Stefano Manelli ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Diesel Engine ◽  
Fuel Injection ◽  
Injection System ◽  
Fuel Injection System

Biodiesel Combustion and Emissions in Engines Using Modern Common-Rail Fuel Injection Systems

2008 ◽  
Author(s):  
Prashanth K. Karra ◽  
Matthias K. Veltman ◽  
Song-Charng Kong
Keyword(s):  
Fuel Injection ◽  
Injection Pressure ◽  
Exhaust Gas Recirculation ◽  
Common Rail ◽  
Injection System ◽  
Injection Timing ◽  
Fuel Injection System ◽  
Nox Emissions ◽  
Exhaust Gas ◽  
Gas Recirculation

This study performed experimental testing of a multi-cylinder diesel engine using different blends of biodiesel and diesel fuel. The engine used an electronically-controlled common-rail fuel injection system to achieve a high injection pressure. The operating parameters that were investigated included the injection pressure, injection timing, and exhaust gas recirculation rate. Results showed that biodiesel generally reduced soot emissions and increased NOx emissions. The increase in NOx emissions was not due to the injection timing shift when biodiesel was used because the present fuel injection system was able to give the same fuel injection timing. At high exhaust gas recirculation rates, emissions using regular diesel and 20% biodiesel blends are very similar while 100% biodiesel produces relatively different emission levels. Therefore, the increase in NOx emissions may not be a concern when 20% biodiesel blends are used with high exhaust gas recirculation rates in order to achieve low temperature combustion conditions.

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