Exhaust gas treatment apparatus and exhaust gas treatment method for internal combustion engine

Patent metadata

Field	Value
Publication number	US-2016273433-A1
Application number	US-201615072573-A
Country	US
Kind code	A1
Filing date	Mar 17, 2016
Priority date	Mar 18, 2015
Publication date	Sep 22, 2016
Grant date	—

Abstract

An exhaust gas treatment apparatus for an internal combustion engine includes: an exhaust gas treatment unit arranged in an exhaust passage of the internal combustion engine, the exhaust passage being configured such that i) exhaust gas flowing along a part of a wall face, which defines the exhaust passage, burbles away from the part of the wall face in an exhaust gas burble zone and ii) as a result of burble of exhaust gas away from the part of the wall face of the exhaust passage in the exhaust gas burble zone, exhaust gas disproportionately flows into the exhaust gas treatment unit or the amount of exhaust gas flowing into the exhaust gas treatment unit reduces. A plasma actuator is also provided arranged at the part of the wall face of the exhaust passage in the exhaust gas burble zone, the plasma actuator being configured to generate air current toward the exhaust gas treatment unit along the part of the wall face in exhaust gas inside the exhaust passage.

First claim

What is claimed is:

1 . An exhaust gas treatment apparatus for an internal combustion engine, the exhaust gas treatment apparatus comprising:
an exhaust gas treatment unit arranged in an exhaust passage of the internal combustion engine, the exhaust passage being configured such that i) exhaust gas flowing along a part of a wall face, which defines the exhaust passage, burbles away from the part of the wall face in an exhaust gas burble zone and ii) as a result of burble of exhaust gas away from the part of the wall face of the exhaust passage in the exhaust gas burble zone, exhaust gas disproportionately flows into the exhaust gas treatment unit or an amount of exhaust gas flowing into the exhaust gas treatment unit reduces; and a plasma actuator arranged at the part of the wall face of the exhaust passage in the exhaust gas burble zone, the plasma actuator being configured to generate air current in exhaust gas toward the exhaust gas treatment unit along the part of the wall face inside the exhaust passage.

2 . The exhaust gas treatment apparatus according to claim 1 , wherein
a sectional shape of the part of the wall face of the exhaust passage in the exhaust gas burble zone, taken along a flow direction of exhaust gas, includes a convex curved line.

3 . The exhaust gas treatment apparatus according to claim 1 , further comprising:
a flow rate acquisition device configured to acquire a flow rate of exhaust gas flowing through the exhaust passage; and a controller configured to control an amount of energy that is input to the plasma actuator, wherein the exhaust gas treatment unit includes a catalytic converter configured to purify exhaust gas, and the controller is configured to control the plasma actuator such that the amount of energy that is input to the plasma actuator increases as the acquired flow rate of exhaust gas increases.

4 . The exhaust gas treatment apparatus according to claim 3 , further comprising:
a temperature acquisition device configured to acquire a temperature of the catalytic converter, wherein the controller is configured to, when the acquired temperature of the catalytic converter is higher than or equal to an activation lower limit temperature of the catalytic converter, input energy to the plasma actuator.

5 . The exhaust gas treatment apparatus according to claim 1 , wherein
the exhaust gas treatment unit includes a catalytic converter configured to purify exhaust gas, the exhaust gas treatment apparatus further comprises:
a temperature acquisition device configured to acquire a temperature of the catalytic converter; and
a controller configured to control an amount of energy that is input to the plasma actuator, and
the controller is configured to, when the acquired temperature of the catalytic converter is higher than or equal to an activation lower limit temperature of the catalytic converter, input energy to the plasma actuator.

6 . The exhaust gas treatment apparatus according to claim 4 , wherein
the controller is configured to, when the acquired temperature of the catalytic converter is lower than or equal to an upper limit temperature of the catalytic converter, input energy to the plasma actuator.

7 . The exhaust gas treatment apparatus according to claim 3 , wherein
the catalytic converter includes a cylindrical heat insulation partition surrounding a zone of part of the catalytic converter along a flow direction of exhaust gas, and the zone surrounded by the heat insulation partition includes a zone into which exhaust gas disproportionately flows as a result of burble of exhaust gas away from the part of the wall face of the exhaust passage in the exhaust gas burble zone.

8 . The exhaust gas treatment apparatus according to claim 7 , wherein
a length of the heat insulation partition along the flow direction of exhaust gas is shorter than a length of the catalytic converter along the flow direction of exhaust gas, and an upstream end of the heat insulation partition along the flow direction of exhaust gas is located at an upstream end of the catalytic converter along the flow direction of exhaust gas.

9 . The exhaust gas treatment apparatus according to claim 7 , wherein
the heat insulation partition is an air layer.

10 . The exhaust gas treatment apparatus according to claim 4 , wherein
the acquired temperature of the catalytic converter is a temperature of a zone different from a zone into which exhaust gas disproportionately flows because of the exhaust gas burble zone.

11 . The exhaust gas treatment apparatus according to claim 3 , further comprising:
a particulate filter configured to trap particulate matter contained in exhaust gas, wherein the particulate filter is arranged downstream of the catalytic converter.

12 . The exhaust gas treatment apparatus according to claim 1 , wherein
the exhaust passage is branched into two by a partition wall extending along a flow direction of exhaust gas, the exhaust gas treatment unit includes an exhaust heat recovery device arranged in one of the branched exhaust passages and configured to exchange heat between exhaust gas flowing through said one of the branched exhaust passages and coolant of the internal combustion engine, the exhaust gas burble zone is located at a portion at which the exhaust passage is branched, and the exhaust passage is configured such that the amount of exhaust gas flowing into said one of the branched exhaust passages reduces as a result of burble of exhaust gas away from a part of a wall face of the exhaust passage in the exhaust gas burble zone.

13 . The exhaust gas treatment apparatus according to claim 12 , further comprising:
a coolant temperature sensor configured to acquire a temperature of coolant of the internal combustion engine; and a controller configured to, when the acquired temperature of coolant is lower than a temperature set in advance, input energy to the plasma actuator.

14 . An exhaust gas treatment method for an internal combustion engine,
an exhaust passage of the internal combustion engine being configured such that exhaust gas flowing along a part of a wall face, which defines the exhaust passage at a portion upstream of a catalytic converter for purifying exhaust gas from the internal combustion engine, disproportionately flows into an exhaust gas treatment unit arranged in the exhaust passage as a result of burble of exhaust gas away from the part of the wall face in an exhaust gas burble zone, a plasma actuator being arranged at the part of the wall face of the exhaust passage in the exhaust gas burble zone, the plasma actuator being configured to generate air current along the wall face of the exhaust passage in exhaust gas inside the exhaust passage, the exhaust gas treatment method comprising: acquiring a temperature of the catalytic converter; and when the acquired temperature of the catalytic converter is higher than or equal to an activation lower limit temperature of the catalytic converter, inputting energy to the plasma actuator.

15 . An exhaust gas treatment method for an internal combustion engine,
an exhaust passage of the internal combustion engine being configured such that exhaust gas flowing along a part of a wall face, which defines the exhaust passage at a portion upstream of a catalytic converter for purifying exhaust gas from the internal combustion engine, disproportionately flows into the catalytic converter as a result of burble of exhaust gas away from the part of the wall face in an exhaust gas burble zone, a plasma actuator being arranged at the part of the wall face of

Assignees

• Toyota Motor Co Ltd

Inventors

• Yamamoto Kosuke

Classifications

• H05H1/2406

  using dielectric barrier discharges, i.e. with a dielectric interposed between the electrodes · CPC title

• F01N2550/02

  Catalytic activity of catalytic converters · CPC title

• F01N13/143

  with air filling the space between both walls · CPC title

• F01P2025/08

  Temperature · CPC title

• F01N3/2892 Primary

  Exhaust flow directors or the like, e.g. upstream of catalytic device · CPC title