Internal combustion engine

Patent metadata

Field	Value
Publication number	US-2017306894-A1
Application number	US-201715437606-A
Country	US
Kind code	A1
Filing date	Feb 21, 2017
Priority date	Apr 20, 2016
Publication date	Oct 26, 2017
Grant date	—

Abstract

An internal combustion engine includes, in addition to an LPL-EGR system, two water vapor separation film modules for fresh air and for EGR gas. A module for fresh air is provided in an intake passage between a connecting portion with an EGR passage, and an air cleaner. A module for EGR gas is provided in the EGR passage on an upstream side of an EGR cooler. The module is connected to a pressure reducing pump through a suction passage. The module is connected to a pressure reducing pump through a suction passage.

First claim

What is claimed is:

1 . An internal combustion engine, comprising:
a gas passage through which gas flows that flows into a cylinder; a cooling portion which is provided in the gas passage and which cools the gas that flows into the cylinder; a water vapor separating portion that constitutes one part of the gas passage on an upstream side in a gas flow direction relative to the cooling portion, and that comprises a water vapor permeable film which, when installed so as to separate two spaces which have different partial water vapor pressures, allows water vapor to permeate from a space in which a partial water vapor pressure is higher toward a space in which a partial water vapor pressure is lower; and a pressure reducing portion which reduces a partial water vapor pressure of an outer space which is separated from an inner space into which gas from the gas passage flows by the water vapor permeable film so that a difference in partial water vapor pressures arises between the inner space and the outer space.

2 . The internal combustion engine according to claim 1 , further comprising a pressure reduction amount adjustment portion that, when it is predicted that a relative humidity on a downstream side in the gas flow direction relative to the cooling portion in the gas passage will be higher than 100%, adjusts a pressure reduction amount of the partial water vapor pressure in the outer space that is reduced by the pressure reducing portion, so that the relative humidity becomes substantially equal to 100%.

3 . The internal combustion engine according to claim 1 , wherein a pressure reduction amount of the partial water vapor pressure in the outer space that is reduced by the pressure reducing portion is increased as a humidity of fresh air that flows into the cylinder rises.

4 . The internal combustion engine according to claim 3 , wherein the pressure reduction amount is increased as a pressure on a downstream side in the gas flow direction relative to a compressor of a turbocharger which is provided in the gas passage rises.

5 . The internal combustion engine according to claim 3 , wherein the pressure reduction amount is increased as a temperature of cooling water that is caused to exchange heat at the cooling portion with gas that flows into the cylinder decreases.

6 . The internal combustion engine according claim 3 , wherein the pressure reduction amount is increased as a flow rate of cooling water that is caused to exchange heat at the cooling portion with gas that flows into the cylinder rises.

7 . The internal combustion engine according to claim 1 ,
wherein the gas passage is an EGR passage which connects an intake passage and an exhaust passage; the cooling portion is an EGR cooler that cools EGR gas which flows through the EGR passage; and the water vapor separating portion constitutes one part of the EGR passage on an upstream side in the gas flow direction relative to the EGR cooler of the EGR passage.

8 . The internal combustion engine according to claim 1 ,
wherein the gas passage is an intake passage in which a compressor of a turbocharger is provided; the cooling portion is an intercooler that cools gas which is compressed by the compressor; and the water vapor separating portion constitutes one part of the intake passage on an upstream side in the gas flow direction relative to the compressor of the intake passage.

9 . The internal combustion engine according to claim 1 ,
wherein the gas passage is an intake passage in which a compressor of a turbocharger is provided, and an EGR passage which connects an upstream side of the intake passage in a gas flow direction relative to the compressor and a downstream side of an exhaust passage in a gas flow direction relative to a turbine of the turbocharger; the cooling portion is an intercooler which cools gas that is compressed by the compressor, and an EGR cooler which cools EGR gas that flows in the EGR passage; and the water vapor separating portion comprises one part of the intake passage that is on an upstream side in the gas flow direction relative to a connecting portion with the EGR passage of the intake passage, and also comprises one part of the EGR passage that is on an upstream side in the gas flow direction relative to the EGR cooler of the EGR passage.

Assignees

• Toyota Motor Co Ltd

Inventors

• Kikuchi Kazuki

Classifications

• F02M26/14

  in relation to the exhaust system · CPC title

• F02M26/17

  in relation to the intake system · CPC title

• F02M26/06 Primary

  Low pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust downstream of the turbocharger turbine and reintroduced into the intake system upstream of the compressor · CPC title

• F02M26/32

  Liquid-cooled heat exchangers · CPC title

• F02M26/35

  with means for cleaning or treating the recirculated gases, e.g. catalysts, condensate traps, particle filters or heaters · CPC title