A mean-value model for control of homogeneous charge compression ignition (HCCI) engines

Abstract

Abstract-A Mean Value Model (MVM) for a HomogeneousCharge Compression Ignition (HCCI) engine is presented. Using a phenomenological zero-dimensional approach with five continuous and three discrete states we first model the effects of the Exhaust Gas Recirculation (EGR) valve, the exhaust Rebreathing Lift (RBL), and the fueling rate on the state of charge in the cylinder at intake valve closing. An Arrhenius integral is then used to model the start of combustion, θsoc. A series of simple algebraic relations that captures the combustion duration and heat release is finally used to model the state of charge after the HCCI combustion and the Location of Peak Pressure (LPP). The model is parameterized and validated using steady-state test data from an experimental engine at the General Motors Corporation.The simple model captures the temperature, pressure, airto-fuel ratio, and inert gas fraction of the exhausted mass flow. This characterization is important for the overall HCCI dynamics because the thermodynamic state (pressure, temperature) and concentration (oxygen and inert gas) of the exhausted mass flow affect the next combustion event. The high dilution level in HCCI engines increases the significance of this internal feedback that generally exists to a smaller extent in conventional spark-ignition and compression-ignition internal combustion engines.

Control-oriented mixing model for Homogeneous Charge Compression Ignition engines

“…Thus, all flow energy imparted by the intake flow is assumed to be partitioned into work, and internal energy changes in Region 2 are ignored. Combining equations (1), (9), and (10), the result for the rate of change of Region 1 is…”

“…(10) where A cyl is the cross-sectional area of the cylinder and ρ is the fluid density. In (9), it is also assumed that the pressure on both sides of the divider equalizes instantaneous, keeping Region 1 and Region 2 in equilibrium. Thus, all flow energy imparted by the intake flow is assumed to be partitioned into work, and internal energy changes in Region 2 are ignored.…”

Simulation of misfire and strategies for misfire recovery of gasoline HCCI

“…To investigate misfire or delayed combustions it is necessary to use a model simulating chemical kinetics instead of using an Arrhenius or knock-integral based combustion prediction combined with an instantaneous heat release or a fixed burn rate [9], [12]. To achieve this, an already developed chemical reaction model [14] is coupled with an airflow and an injection model.…”

“…Most of it focused on the emissions and the control of HCCI within its stable operating region. A multitude of simulation models have been developed for this purpose, ranging from complex CFD models [7] to zerodimensional models [8], [9], [10].…”

A control - oriented model of combustion process in a HCCI diesel engine

“…While this level of detail is necessary for accurately predicting the overall process of HCCI combustion (in particular the emissions), these models are too detailed for control-oriented purposes. For these applications, simple models capable of capturing the properties most relevant for control with good accuracy and low computational and calibration efforts are more appropriate [9], [10].…”