Effect of Injection Rate on the Performance and Emissions of a Direct-Injection Gasoline Engine in Comparison With the Port-Injection Operation

2001 ◽  
Author(s):  
Seiichi Shiga ◽  
Kazumitsu Kobayashi ◽  
Eiji Hayakawa ◽  
Takashi Matsuura ◽  
Hisao Nakamura ◽  
...  
Keyword(s):  
Gasoline Engine ◽  
Direct Injection ◽  
Combustion Efficiency ◽  
Injection Rate ◽  
Spray Angle ◽  
Spray Characteristics ◽  
Droplet Concentration ◽  
A Value ◽  
Performance And Emissions ◽  
Direct Injection Gasoline Engine

Abstract This paper presents a study on the effect of injection rate on the performance and emissions of a direct-injection gasoline engine operated with seven kinds of DI injection and a port-injection. The injection pressures were set at 0.3 and 7 MPa for port injection and DI operation modes respectively. The spray characteristics of DI injectors were obtained by measuring the SMD, droplet concentration and spray angle. The engine was run at a constant speed and load of 1000 rpm and 0.22 MPa of BMEP. The BSFC reduction of DI from port injection was 13% at most in which 4% was derived from the decrease in pumping loss and the remaining 9% was due to the improvement of the cycle efficiency. As for the injection rate effect in DI operation, the BSFC takes the minimum at a value of the injection rate where the maximum difference reached to 7%. It was revealed that this is due to the variation of the combustion efficiency and then corresponds to the behavior of droplet concentration. Soot emission correlated well with the SMD. Thus the performance and emissions were mostly explained by the spray characteristics.

K-1926 Effect of Injection Rate and Fuel Property on the Combustion Characteristics in a Direct-Injection Gasoline Engine

2001 ◽  
Vol II.01.1 (0) ◽  
pp. 485-486
Author(s):  
Eiji Hayakawa ◽  
Kazumitsu Kobayashi ◽  
Takashi Matsuura ◽  
Seiichi SHIGA ◽  
Hisao Nakamura ◽  
...  
Keyword(s):  
Gasoline Engine ◽  
Direct Injection ◽  
Injection Rate ◽  
Combustion Characteristics ◽  
Fuel Property ◽  
Direct Injection Gasoline Engine

Effect of Optimization Criteria on Direct-Injection Homegeneous Charge Compression Ignition Gasoline Engine Performance and Emissions Using Fully Automated Experiments and Microgenetic Algorithms

2004 ◽  
Vol 126 (1) ◽  
pp. 167-177 ◽  
Author(s):  
M. Canakci ◽  
R. D. Reitz
Keyword(s):  
Gasoline Engine ◽  
Fuel Injection ◽  
Direct Injection ◽  
Engine Performance ◽  
Function Optimization ◽  
Spray Angle ◽  
Injection Timing ◽  
Compression Ignition ◽  
Performance And Emissions ◽  
Engine Performance And Emissions

Homogeneous charge compression ignition (HCCI) is a new low-emission engine concept. Combustion under homogeneous, low equivalence ratio conditions results in modest temperature combustion products, containing very low concentrations of NOx and PM as well as providing high thermal efficiency. However, this combustion mode can produce higher HC and CO emissions than those of conventional engines. Control of the start of combustion timing is difficult with pre-mixed charge HCCI. Accordingly, in the present study charge preparation and combustion phasing control is achieved with direct injection. An electronically controlled Caterpillar single-cylinder oil test engine (SCOTE), originally designed for heavy-duty diesel applications, was converted to a direct-injection gasoline engine. The engine features an electronically controlled low-pressure direct injection-gasoline (DI-G) injector with a 60 deg spray angle that is capable of multiple injections. The use of double injection was explored for emission control, and the engine was optimized using fully automated experiments and a microgenetic algorithm optimization code. The variables changed during the optimization include the intake air temperature, start of injection timing, and the split injection parameters (percent mass of fuel in each injection, dwell between the pulses) using three different objective (merit) functions. The engine performance and emissions were determined at 700 rev/min with a constant fuel flow rate at 10 MPa fuel injection pressure. The results show the choice of merit or objective function (optimization goal) determines the engine performance, and that significant emission reductions can be achieved with optimal injection strategies. Merit function formulations are presented that minimized PM, HC, and NOx emissions, respectively.

The effects of cylinder deactivation on the thermal behaviour and fuel economy of a three-cylinder direct injection spark ignition gasoline engine

2018 ◽  
Vol 233 (11) ◽  
pp. 2838-2849
Author(s):  
Michael McGhee ◽  
Ziman Wang ◽  
Alexander Bech ◽  
Paul J Shayler ◽  
Dennis Witt
Keyword(s):  
Fuel Economy ◽  
Gasoline Engine ◽  
Thermal State ◽  
Direct Injection ◽  
Spark Ignition ◽  
Combustion Efficiency ◽  
Spark Ignition Engine ◽  
Engine Fuel ◽  
Cylinder Deactivation ◽  
Direct Injection Spark Ignition

The changes in thermal state, emissions and fuel economy of a 1.0-L, three-cylinder direct injection spark ignition engine when a cylinder is deactivated have been explored experimentally. Cylinder deactivation improved engine fuel economy by up to 15% at light engine loads by reducing pumping work, raising indicated thermal efficiency and raising combustion efficiency. Penalties included an increase in NOx emissions and small increases in rubbing friction and gas work losses of the deactivated cylinder. The cyclic pressure variation in the deactivated cylinder falls rapidly after deactivation through blow-by and heat transfer losses. After around seven cycles, the motoring loss is ~2 J/cycle. Engine structural temperatures settle within an 8- to 13-s interval after a switch between two- and three-cylinder operation. Engine heat rejection to coolant is reduced by ~13% by deactivating a cylinder, extending coolant warm-up time to thermostat-opening by 102 s.

Sign in / Sign up

Export Citation Format

Share Document