Experiment and Analysis of a Direct Injection Gasoline Engine Operating with 2-stroke and 4-stroke Cycles of Spark Ignition and Controlled Auto-Ignition Combustion

2011 ◽  
Author(s):  
Y. Zhang ◽  
Hua Zhao ◽  
M. Ojapah ◽  
A. Cairns
Keyword(s):  
Gasoline Engine ◽  
Direct Injection ◽  
Spark Ignition ◽  
Auto Ignition ◽  
Direct Injection Gasoline Engine

scholarly journals Investigation of transition between spark ignition and controlled auto-ignition combustion in a V6 direct-injection engine with cam profile switching

2008 ◽  
Vol 222 (10) ◽  
pp. 1911-1926 ◽  
Author(s):  
N Kalian ◽  
H Zhao ◽  
J Qiao
Keyword(s):  
Gasoline Engine ◽  
Fuel Injection ◽  
Direct Injection ◽  
Spark Ignition ◽  
High Lift ◽  
Auto Ignition ◽  
Operating Region ◽  
Low Load ◽  
Cam Profile ◽  
Direct Fuel Injection

Controlled auto-ignition (CAI) combustion, also known as homogeneous charge compression ignition (HCCI), can be achieved by trapping residuals with early exhaust valve closure in a direct-fuel-injection in-cylinder four-stroke gasoline engine (through the employment of low-lift cam profiles). Because the operating region is limited to low-load and midload operation for CAI combustion with a low-lift cam profile, it is important to be able to operate spark ignition (SI) combustion at high loads with a normal cam profile. A 3.0l prototype engine was modified to achieve CAI combustion, using a cam profile switching mechanism that has the capability to switch between high- and low-lift cam profiles. A strategy was used where a high-lift profile could be used for SI combustion and a low-lift profile was used for CAI combustion. Initial analysis showed that for a transition from SI to CAI combustion, misfire occurred in the first CAI transitional cycle. Subsequent experiments showed that the throttle opening position and switching time could be controlled to avoid misfire. Further work investigated transitions at different loads and from CAI to SI combustion.

Managing controlled auto-ignition combustion by injection on a direct-injection gasoline engine

2007 ◽  
Vol 221 (9) ◽  
pp. 1125-1137 ◽  
Author(s):  
Y Li ◽  
H Zhao ◽  
N Brouzos ◽  
B Leach
Keyword(s):  
Gasoline Engine ◽  
Direct Injection ◽  
Injection Timing ◽  
Split Injection ◽  
Gasoline Engines ◽  
Auto Ignition ◽  
Direct Injection Gasoline Engine ◽  
Early Closure ◽  
Exhaust Valves ◽  
Early Injection

Controlled auto-ignition (CAI) combustion in gasoline engines has great potential for reducing both NO x emissions and fuel consumption, but its application is still hindered by the lack of direct control of combustion phasing and by the limited CAI operation range. In this paper, the effect of injection timing and split injection on CAI combustion is presented in a single-cylinder direct-injection gasoline engine with an air-assisted injector. The CAI combustion was achieved by trapping some of the burned gases within the cylinder by using low-lift short-duration camshafts and early closure of the exhaust valves. During the experiments, the engine speed was varied from 1200 to 2400 r/min and the air-fuel ratio was altered from stoichiometric to the misfire limit. Both single and split injections were investigated at different injection timings and fuel quantities. The experimental results show that injection timing has an important effect on CAI combustion for single and split injections. Early injection produces faster and more stable combustion, less hydrocarbon and CO emissions, but very rapid heat release rates and higher NO x emissions. The CAI operation range could be extended significantly by early injection. Split injection gives even further extension of the CAI range in both stoichiometric and lean mixture operations. These results indicate that optimizing the injection timing and using split injection is an effective way to control and extend CAI operation in a direct-injection gasoline engine.

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