Polarized light multiplexer
AssigneeNissan Motor Co., Ltd.
InventorYasuhisa Kitahara
Life of this patent
Estimating the term…
Abstract
An exhaust gas purification system for an internal combustion engine (1) is provided which comprises a Nox trap catalyst (13) and an air/fuel ratio controller (20) for controlling the exhaust gas purification system so that an exhaust air/fuel ratio is made rich in a premix combustion mode when it is the time for purifying trapped NOx of the NOx trap catalyst and the NOx trap catalyst is activated (S13) and that the exhaust air/fuel ratio is made rich in a diffusion combustion mode when it is the time for purifying trapped NOx of the Nox trap catalyst and the Nox trap catalyst is not activated (S15). An exhaust gas purification method is also provided.
Claims34
An exhaust gas purification system for an internal combustion engine including:
- a NOx trap catalyst disposed in an exhaust passage of the engine for trapping NOx in an inflow exhaust gas when an air/fuel ratio of the exhaust gas is lean and releasing trapped NOx when the air/fuel ratio of the exhaust gas is rich;
- and
- a control unit for controlling the NOx trap catalyst in accordance with an activated condition of the NOx trap catalyst;
- the control unit comprising:
- a purification time determining section for determining whether it is the time for purifying NOx trapped by the NOx trap catalyst;
- a catalyst activation determining section for determining whether the Nox trap catalyst is activated;
- a combustion mode switching section for switching a combustion mode of the engine between a diffusion combustion mode and a premix combustion mode in accordance with an operating condition of the engine;
- and
- an air/fuel ratio control section for controlling an exhaust air/fuel ratio so that the exhaust air/fuel ratio is made rich in the premix combustion mode when it is the time for purifying trapped NOx of the NOx trap catalyst and the NOx trap catalyst is activated and that the exhaust air/fuel ratio is made rich in the diffusion combustion mode when it is the time for purifying trapped NOx of the Nox trap catalyst and the Nox trap catalyst is not activate.
An exhaust gas purification system for an internal combustion engine comprising:
- a NOx trap catalyst disposed in an exhaust passage of the engine for trapping NOx in an inflow exhaust gas when an air/fuel ratio of the exhaust gas is lean and releasing trapped NOx when the air/fuel ratio of the exhaust gas is rich;
- purification time determining means for determining whether it is the time for purifying NOx trapped by the NOx trap catalyst;
- catalyst activation determining means for determining whether the Nox trap catalyst is activated;
- combustion mode switching means for switching a combustion mode of the engine between a diffusion combustion mode and a premix combustion mode;
- and
- air/fuel ratio control means for controlling so that the exhaust air/fuel ratio is made rich in the premix combustion mode when it is the time for purifying trapped NOx of the NOx trap catalyst and the NOx trap catalyst is activated and that the exhaust air/fuel ratio is made rich in the diffusion combustion mode when it is the time for purifying trapped NOx of the Nox trap catalyst and the Nox trap catalyst is not activated.
An exhaust gas purification method for an internal combustion engine having a NOx trap catalyst disposed in an exhaust passage for trapping NOx in an inflow exhaust gas when an air/fuel ratio of the exhaust gas is lean and releasing trapped NOx when the air/fuel ratio of the exhaust gas is rich, the exhaust gas purification method comprising:
- determining whether it is the time for purifying NOx trapped by the NOx trap catalyst;
- determining whether the Nox trap catalyst is activated;
- switching a combustion mode of the engine between a diffusion combustion mode and a premix combustion mode in accordance with an operating condition of the engine;
- and
- controlling an exhaust air/fuel ratio so that the exhaust air/fuel ratio is made rich in the premix combustion mode when it is the time for purifying trapped NOx of the NOx trap catalyst and the NOx trap catalyst is activated and that the exhaust air/fuel ratio is made rich in the diffusion combustion mode when it is the time for purifying trapped NOx of the Nox trap catalyst and the Nox trap catalyst is not activated.
An exhaust gas purification system for an internal combustion engine including:
- a NOx trap catalyst disposed in an exhaust passage of the engine for trapping NOx in an inflow exhaust gas when an air/fuel ratio of the exhaust gas is lean and releasing trapped NOx when the air/fuel ratio of the exhaust gas is rich;
- and
- a control unit for controlling the NOx trap catalyst in accordance with an activated condition of the NOx trap catalyst;
- the control unit comprising:
- a purification time determining section for determining whether it is the time for purifying NOx trapped by the NOx trap catalyst;
- a catalyst activation determining section for determining whether the Nox trap catalyst is activated;
- a combustion mode switching section for switching a combustion mode of the engine between a diffusion combustion mode and a premix combustion mode in accordance with an operating condition of the engine;
- and
- an air/fuel ratio control section for controlling an exhaust air/fuel ratio so that the exhaust air/fuel ratio is made rich in the premix combustion mode when it is the time for purifying trapped NOx of the NOx trap catalyst and the NOx trap catalyst is activated and that the exhaust air/fuel ratio is made rich in the diffusion combustion mode when it is the time for purifying trapped NOx of the Nox trap catalyst and the Nox trap catalyst is not in activated.
An exhaust gas purification system for an internal combustion engine comprising:
- a NOx trap catalyst disposed in an exhaust passage of the engine for trapping NOx in an inflow exhaust gas when an air/fuel ratio of the exhaust gas is lean and releasing trapped NOx when the air/fuel ratio of the exhaust gas is rich;
- purification time determining means for determining whether it is the time for purifying NOx trapped by the NOx trap catalyst;
- catalyst activation determining means for determining whether the Nox trap catalyst is activated;
- combustion mode switching means for switching a combustion mode of the engine between a diffusion combustion mode and a premix combustion mode;
- and
- air/fuel ratio control means for controlling so that the exhaust air/fuel ratio is made rich in the premix combustion mode when it is the time for purifying trapped NOx of the NOx trap catalyst and the NOx trap catalyst is activated and that the exhaust air/fuel ratio is made rich in the diffusion combustion mode when it is the time for purifying trapped NOx of the Nox trap catalyst and the Nox trap catalyst is not activated.
An exhaust gas purification method for an internal combustion engine having a NOx trap catalyst disposed in an exhaust passage for trapping NOx in an inflow exhaust gas when an air/fuel ratio of the exhaust gas is lean and releasing trapped NOx when the air/fuel ratio of the exhaust gas is rich, the exhaust gas purification method comprising:
- determining whether it is the time for purifying NOx trapped by the NOx trap catalyst;
- determining an activated condition of the Nox trap catalyst;
- switching a combustion mode of the engine between a diffusion combustion mode and a premix combustion mode in accordance with an operating condition of the engine;
- and
- controlling an exhaust air/fuel ratio so that the exhaust air/fuel ratio is made rich in the premix combustion mode when it is the time for purifying trapped NOx of the NOx trap catalyst and the NOx trap catalyst is activated and that the exhaust air/fuel ratio is made rich in the diffusion combustion mode when it is the time for purifying trapped NOx of the Nox trap catalyst and the Nox trap catalyst is not activated.
Dependencies are inferred from the claim text.