Patent US6360732B1 successfully refreshed from Google Patents.
US6360732B1
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US
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Exhaust gas recirculation cooling system
Assignee: Caterpillar Inc
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Filing: 2000-08-10
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Granted: 2002-03-26
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Expires: 2020-08-10
Abstract
Abstract A twin-turbocharged internal combustion engine improves compression efficiency and improves response by serial arrangement of a first turbocharger and a second turbocharger. An exhaust gas recirculation (EGR) system using boost cooling reduces emissions of nitrogen oxides (NOx). The EGR system cools recirculated exhaust gas by exchanging heat with compressed, cooled combustion air in an EGR heat exchanger. The second turbocharger has a variable geometry turbine to control flow of recirculated exhaust gas.
Inventors
- 👤 Brett M. Bailey
- 👤 David A. Pierpont
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:32
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/0025; F02D41/0047; F02D41/0065; F01; F01N; F01N13/00; F01N13/08; F01N13/10; F01N13/107; F02B; F02B37/00; F02B37/004; F02B37/005; F02B37/013; F02B37/02; F02B37/025; F02B37/12; F02B37/16; F02D41/0002; F02D41/0007; F02D41/02; F02D41/14; F02D41/1438; F02D41/1444; F02D41/146; F02D41/1461; F02M; F02M26/00; F02M26/13; F02M26/22; F02M26/23; F02M26/25; F02M26/42; F02M26/43; F02M26/02; F02M26/08; F02M26/27; F02M26/45; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12; Y02T10/40
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
183 words
An internal combustion engine comprising: an engine block; a cylinder head connected with said engine block; an exhaust manifold fluidly connected with said cylinder head; an inlet manifold fluidly connected with said cylinder head; a first turbocharger having a first turbine and a first compressor, an inlet portion of said first turbine being fluidly connected with said exhaust manifold through a first fluid conduit; a second turbocharger having a second turbine and a second compressor, an inlet portion of said second turbine being fluidly connected with said exhaust manifold through a second fluid conduit, an outlet portion of said first compressor being fluidly connected with an inlet portion of said second compressor; an outlet portion of said second compressor being connected with said intake manifold through a compressed gas conduit; an exhaust gas recirculation conduit fluidly connecting said second fluid conduit with said intake manifold; a bypass conduit fluidly connecting said compressed gas conduit with the inlet portion of said first turbine; and an exhaust gas recirculation heat exchanger being adapted to thermally connect said exhaust gas recirculation conduit with said bypass conduit.
Claim 2
Dependent Claim
183 words
An internal combustion engine comprising: an engine block; a cylinder head connected with said engine block; an exhaust manifold fluidly connected with said cylinder head; an inlet manifold fluidly connected with said cylinder head; a first turbocharger having a first turbine and a first compressor, an inlet portion of said first turbine being fluidly connected with said exhaust manifold through a first fluid conduit; a second turbocharger having a second turbine and a second compressor, an inlet portion of said second turbine being fluidly connected with said exhaust manifold through a second fluid conduit, an outlet portion of said first compressor being fluidly connected with an inlet portion of said second compressor; an outlet portion of said second compressor being connected with said intake manifold through a compressed gas conduit; an exhaust gas recirculation conduit fluidly connecting said second fluid conduit with said intake manifold; a bypass conduit fluidly connecting said compressed gas conduit with the inlet portion of said first turbine; and an exhaust gas recirculation heat exchanger being adapted to thermally connect said exhaust gas recirculation conduit with said bypass conduit.
Claim 3
Dependent Claim
28 words
The internal combustion engine as specified in claim 1 wherein the outlet portion of said second turbine is fluidly connected with an inlet portion of said first turbine.
Claim 4
Dependent Claim
26 words
The internal combustion engine as specified in claim 1 wherein at least one of said second turbine and said first turbine is a variable geometry turbine.
Claim 5
Dependent Claim
28 words
The internal combustion engine as specified in claim 1 further comprising an aftercooler connected with the compressed gas conduit downstream of the outlet portion of said second compressor.
Claim 6
Dependent Claim
66 words
The internal combustion engine as specified in claim 1 further comprising a boost cooling valve connected with said bypass conduit, said boost cooling valve being moveable between an open position and a closed position, said closed position substantially inhibiting fluid communication between said compressed gas conduit and said first turbine, said open position substantially permitting fluid communication between said compressed gas conduit and said first turbine.
Claim 7
Dependent Claim
23 words
The internal combustion engine as specified in claim 5 wherein said boost cooling valve is upstream of said exhaust gas recirculation heat exchanger.
Claim 8
Dependent Claim
25 words
The internal combustion engine as specified in claim 5 wherein said boost cooling valve is variably movable between said open position and said closed position.
Claim 9
Dependent Claim
23 words
The internal combustion engine as specified in claim 1 further comprising a mixer connecting said compressed gas conduit and said second fluid conduit.
Claim 10
Dependent Claim
52 words
The internal combustion engine as specified in claim 1 further comprising an EGR valve positioned in the EGR conduit, said EGR valve having an open position and closed position, wherein said closed position exhaust gas is substantially inhibited from passing between said exhaust manifold and said inlet manifold through said EGR conduit.
Claim 11
Dependent Claim
24 words
The internal combustion engine as specified in claim 9 wherein said EGR valve is variably movable between the open position and the closed position.
Claim 12
Independent Claim
79 words
A method of controlling an exhaust gas recirculation system for an internal combustion engine comprising the steps: sensing an engine operating parameter; reducing restrictions to a flow of exhaust gas through an EGR conduit wherein said engine operating parameter indicates production of NOx; reducing restrictions to a flow of combustion air through a bypass conduit wherein said engine operating parameter indicates production of NOx; and exchanging heat between said flow of combustion air and said flow of exhaust gas.
Claim 13
Independent Claim
79 words
A method of controlling an exhaust gas recirculation system for an internal combustion engine comprising the steps: sensing an engine operating parameter; reducing restrictions to a flow of exhaust gas through an EGR conduit wherein said engine operating parameter indicates production of NOx; reducing restrictions to a flow of combustion air through a bypass conduit wherein said engine operating parameter indicates production of NOx; and exchanging heat between said flow of combustion air and said flow of exhaust gas.
Claim 14
Dependent Claim
33 words
The method as specified in claim 11 wherein said sensing is a pressure sensor positioned in an intake manifold, said pressure sensor is adapted to measure an air pressure of a combustion gas.
Claim 15
Dependent Claim
20 words
The method as specified in claim 11 wherein said reducing step is controlling a variable geometry turbine of a turbocharger.
Claim 16
Dependent Claim
19 words
The methods as specified in claim 11 wherein said reducing step is an EGR valve in said EGR conduit.
References Cited (Backward Citations)
US3250068A
Cited
US4756285A
Cited
US5142866A
Cited
US5313798A
Cited
US5517976A
Cited
US5611202A
Cited
US6003315A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-03-25 | 2005-09-24 | 2006-03-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-03-25 | 2009-09-24 | 2010-03-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-03-25 | 2013-09-24 | 2014-03-26 | $7700.00 | Window Closed / Lapsed |