Homogeneous charge compression ignition of LPG and gasoline using variable valve timing in an engine

Fuel ◽  
2007 ◽  
Vol 86 (4) ◽  
pp. 494-503 ◽  
Author(s):  
Kitae Yeom ◽  
Jinyoung Jang ◽  
Choongsik Bae
Keyword(s):  
Homogeneous Charge Compression Ignition ◽  
Variable Valve Timing ◽  
Compression Ignition ◽  
Valve Timing ◽  
Variable Valve ◽  
Homogeneous Charge

A physics-based approach to the control of homogeneous charge compression ignition engines with variable valve actuation

2005 ◽  
Vol 6 (4) ◽  
pp. 361-375 ◽  
Author(s):  
G M Shaver ◽  
M J Roelle ◽  
P A Caton ◽  
N B Kaahaaina ◽  
N Ravi ◽  
...  
Keyword(s):  
Internal Combustion Engines ◽  
Homogeneous Charge Compression Ignition ◽  
Control Strategies ◽  
Combustion Process ◽  
System Control ◽  
Compression Ignition ◽  
Variable Valve Actuation ◽  
Variable Valve ◽  
Homogeneous Charge ◽  
Valve Actuation

Homogeneous charge compression ignition (HCCI) is a promising low-temperature combustion strategy for reducing NOx emissions and increasing efficiency in internal combustion engines. However, HCCI has no direct combustion initiator and, when achieved by reinducting or trapping residual exhaust gas with a variable valve actuation (VVA) system, becomes a dynamic process as the temperature of the residual gas couples one cycle to the next. These characteristics of residual-affected HCCI present a challenge for control engineers and a barrier to implementing HCCI in a production engine. In order to address these challenges, this paper outlines physics-based control strategies for both the VVA system and the HCCI combustion process. The results show that VVA system control can provide arbitrary valve timings on a cycle-to-cycle basis, enabling tight control of HCCI. By abstracting these valve timings further into an inducted gas composition and an effective compression ratio, model-based controllers can be developed to control simultaneously load and combustion timing in an HCCI engine.

Dynamic Modeling of Residual-Affected Homogeneous Charge Compression Ignition Engines with Variable Valve Actuation

2004 ◽  
Vol 127 (3) ◽  
pp. 374-381 ◽  
Author(s):  
Gregory M. Shaver ◽  
J. Christian Gerdes ◽  
Matthew J. Roelle ◽  
Patrick A. Caton ◽  
Christopher F. Edwards
Keyword(s):  
Internal Combustion Engines ◽  
Homogeneous Charge Compression Ignition ◽  
Control Volume ◽  
Practical Method ◽  
Ignition Process ◽  
Compression Ignition ◽  
Propane Combustion ◽  
Variable Valve Actuation ◽  
Variable Valve ◽  
Homogeneous Charge

One practical method for achieving homogeneous charge compression ignition (HCCI) in internal combustion engines is to modulate the valves to trap or reinduct exhaust gases, increasing the energy of the charge, and enabling autoignition. Controlling combustion phasing with valve modulation can be challenging, however, since any controller must operate through the chemical kinetics of HCCI and account for the cycle-to-cycle dynamics arising from the retained exhaust gas. This paper presents a simple model of the overall HCCI process that captures these fundamental aspects. The model uses an integrated Arrhenius rate expression to capture the importance of species concentrations and temperature on the ignition process and predict the start of combustion. The cycle-to-cycle dynamics, in turn, develop through mass exchange between a control volume representing the cylinder and a control mass modeling the exhaust manifold. Despite its simplicity, the model predicts combustion phasing, pressure evolution and work output for propane combustion experiments at levels of fidelity comparable to more complex representations. Transient responses to valve timing changes are also captured and, with minor modification, the model can, in principle, be extended to handle a variety of fuels.

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