Systems and methods for heating intake air during cold HCCI operation

A method of controlling intake airflow of an engine, comprising:

• generating a mode signal based on an engine speed signal and an engine load signal;
• generating a temperature signal based on at least one of a coolant temperature of the engine and an oil temperature of the engine;
• indicating transitioning from a spark ignition (SI) mode to a homogeneous charge compression ignition (HCCI) mode via the mode signal;
• both transitioning from the SI mode to the HCCI mode and generating a valve control signal based on the mode signal, the temperature signal, and a plurality of valve position signals that indicate positions of a first throttle valve and a second throttle valve;
• controlling positions of:
• the first throttle valve to regulate a first flow rate of intake air out of the first throttle valve and into an intake manifold of the engine based on the valve control signal;
• and
• the second throttle valve to regulate a second flow rate of intake air through a heat exchanger and into the intake manifold based on the valve control signal;
• and
• actuating the first throttle valve and the second throttle valve based on the valve control signal.

A system for an engine comprising:

• a mode determination module that generates a mode signal based on an engine speed signal and an engine load signal,
• wherein the mode signal indicates transitioning from a spark ignition (SI) mode to a homogeneous charge compression ignition (HCCI) mode;
• a throttle valve control module that both transitions from the SI mode to the HCCI mode and generates a valve control signal based on the mode signal, a temperature signal, and a plurality of valve position signals that indicate positions of a first throttle valve and a second throttle valve,
• wherein the throttle valve control module controls positions of:
• the first throttle valve to regulate a first flow rate of intake air out of the first throttle valve and into an intake manifold of the engine based on the valve control signal, wherein the first throttle valve receives intake air from an air filter via a first conduit;
• and
• the second throttle valve to regulate a second flow rate of intake air from the first conduit, through a heat exchanger and into the intake manifold based on the valve control signal, wherein the second throttle valve is connected downstream from the heat exchanger and receives intake air from a second conduit connected between the heat exchanger and the second throttle valve, wherein the second conduit is separate from the first conduit, and wherein the first throttle valve is connected upstream from the heat exchanger;
• and
• a valve actuation module that actuates the first throttle valve and the second throttle valve based on the valve control signal.