hcci engine
DESCRIPTION
Strategies to control combustion in HCCI engines: Modelling Investigations Ali M. Aldawood Supervisor: Dr Markus Kraft. HCCI Engine. Control Problem in HCCI Engine. Advance Combustion start Retard. SOC. Engine load. Control Problem in HCCI Engine. Misfire area. - PowerPoint PPT PresentationTRANSCRIPT
Strategies to control combustion in Strategies to control combustion in HCCI engines: Modelling InvestigationsHCCI engines: Modelling Investigations
Ali M. AldawoodAli M. Aldawood
Supervisor: Dr Markus KraftSupervisor: Dr Markus Kraft
Ali M [email protected]
Control Problem in HCCI Engine
Engine load
Adv
ance
C
ombu
stio
n st
art
R
etar
d
SOC
Ali M [email protected]
Control Problem in HCCI Engine
Engine load
Adv
ance
C
ombu
stio
n st
art
R
etar
d
Knocking limit
Misfire area
SOC
Ali M [email protected]
Control Problem in HCCI Engine
Engine load
Upper load
Lower load
Adv
ance
C
ombu
stio
n st
art
R
etar
d
Knocking limit
Misfire area
SOC
Operating window
Ali M [email protected]
Control Problem in HCCI Engine
Engine load
Adv
ance
C
ombu
stio
n st
art
R
etar
d
Knocking limit
Misfire area
SOC
Controlled timing
Ali M [email protected]
Investigate two fuel-based strategies to control the combustion timing
Detailed-chemistry, full-cycle model to simulate a single-cylinder HCCI engine
Closed-loop control of combustion timing using octane number or hydrogen ratio
Purpose of Study
Engine load
Knocking limit
Misfire area
SOC
Ad
van
ce
Co
mb
ust
ion
sta
rt
Re
tard
Controlled timing
Ali M [email protected]
Sandia’s Cummins Sandia’s Cummins Diesel EngineDiesel Engine
Modelled Engine
Ali M [email protected]
Coupling GT-Power with SRM
Intake Compression Power Exhaust
GT-Power Stochastic Reactor Model GT-Power
Closed-Volume
EVO
0o 180o 360o 540o 720o
Firing TDC
IVC
GT-Power simulates the open-volume (intake and exhaust) portion of the cycle
SRM simulates the closed-volume (compression, combustion and expansion) portion of the cycle
Pressure
Ali M [email protected]
Octane Number & Hydrogen Control
A closed-loop controller is integrated in the model.
Either octane number or hydrogen ratio is varied to control the combustion phasing.
Ali M [email protected]
Octane Number & Hydrogen Control
A closed-loop controller is integrated in the model.
Either octane number or hydrogen ratio is varied to control the combustion phasing.
Ali M [email protected]
Hydrogen Addition – Load Transients
3.5
4.0
4.5
5.0
5.5
6.0
6.5
1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0
BM
EP (
bar)
0.35
0.4
0.45
0.5
0.55
0.611 21 31 41 51 61 71 81
Cycles
Equi
vale
nce
ratio
Equivalence ratio
BMEP
3
5
7
9
11
1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0
CA50
(de
g ATD
C)
0.07
0.1
0.13
0.16
0.19
Hyd
roge
n ra
tio
Actual CA50 Target CA50
Controller output(hydrogen ratio)
Time (sec)
Ali M [email protected]
Conclusion
Full-cycle HCCI engine model is integrated with Full-cycle HCCI engine model is integrated with Stochastic Reactor Model and closed-loop Stochastic Reactor Model and closed-loop controlcontrol
Integrated model provided effective tool to Integrated model provided effective tool to simulate HCCI transients and investigate simulate HCCI transients and investigate combustion control strategiescombustion control strategies
Results suggest that both octane number and Results suggest that both octane number and hydrogen addition are effective for HCCI hydrogen addition are effective for HCCI combustion controlcombustion control
