Exhaust system with exhaust gas recirculation and multiple turbochargers, and method for operating same

Patent metadata

Field	Value
Publication number	US-9546591-B2
Application number	US-201414554659-A
Country	US
Kind code	B2
Filing date	Nov 26, 2014
Priority date	Nov 26, 2014
Publication date	Jan 17, 2017
Grant date	Jan 17, 2017

Abstract

An exhaust system includes a first turbine having an inlet that is fluidly coupled to an exhaust conduit; a valve assembly having an inlet port, a first outlet port, and a second outlet port, the inlet port of the valve assembly being in fluid communication with the exhaust conduit; a second turbine having an inlet that is fluidly coupled to the first outlet port of the valve assembly via a first outlet port conduit, and fluidly coupled to an outlet of the first turbine via a first turbine outlet conduit; and a controller operatively coupled to the valve assembly. The valve assembly has a first configuration that blocks fluid communication between the inlet port and the first outlet port, and the valve assembly has a second configuration that effects fluid communication between the inlet port and the first outlet port.

First claim

We claim:

1. An exhaust system, comprising:
an exhaust conduit configured to receive a flow of exhaust gas from an internal combustion engine;
a valve assembly disposed in an exhaust bypass conduit and having an inlet port, a first outlet port, and a second outlet port, the inlet port of the valve assembly being in fluid communication with the exhaust conduit via the exhaust bypass conduit;
wherein the valve assembly has a first configuration that blocks fluid communication between the inlet port and the first outlet port; and
wherein the valve assembly has a second configuration that effects fluid communication between the inlet port and the first outlet port;

a first turbine having an inlet that is fluidly coupled to the exhaust conduit via a first turbine inlet conduit, the first turbine inlet conduit extending from the exhaust conduit to the inlet of the first turbine;
a first compressor operatively coupled to the first turbine via a first shaft;
a second turbine having an inlet that is fluidly coupled to the first outlet port of the valve assembly via a first outlet port conduit, and fluidly coupled to an outlet of the first turbine via a first turbine outlet conduit, the first turbine outlet conduit being distinct from the first outlet port conduit; and
a controller operatively coupled to the valve assembly, the controller being configured to effect simultaneous fluid communication between the inlet of the second turbine and the outlet of the first turbine via the first turbine outlet conduit, and between the inlet of the second turbine and the first outlet port of the valve assembly via the first outlet port conduit, by actuating the valve assembly to the second configuration.

2. The exhaust system of claim 1 , further comprising:
a second compressor operatively coupled to the second turbine, an outlet of the second compressor being fluidly coupled to an inlet of the first compressor via a first compressor inlet conduit; and
an exhaust gas recirculation (EGR) conduit effecting fluid communication between the second outlet port of the valve assembly and the first compressor inlet conduit.

3. The exhaust system of claim 2 , wherein the first configuration of the valve assembly blocks fluid communication between the inlet port of the valve assembly and the second outlet port of the valve assembly.

4. The exhaust system of claim 3 , wherein the second configuration of the valve assembly blocks fluid communication between the inlet port of the valve assembly and the second outlet port of the valve assembly.

5. The exhaust system of claim 3 , wherein the second configuration of the valve assembly effects fluid communication between the inlet port of the valve assembly and the second outlet port of the valve assembly.

6. The exhaust system of claim 2 ,
wherein the valve assembly has a third configuration that effects fluid communication between the inlet port and the first outlet port;
wherein the second configuration of the valve assembly effects a first flow resistance between the inlet port and the first outlet port of the valve assembly;
wherein the third configuration of the valve assembly effects a second flow resistance between the inlet port and the first outlet port of the valve assembly; and
wherein the first flow resistance is different from the second flow resistance.

7. The exhaust system of claim 6 , wherein the controller is further configured to adjust a flow split between an exhaust gas flow through the first turbine and an exhaust gas flow through the second turbine by actuating the valve assembly between the second configuration and the third configuration, the exhaust gas flow through the first turbine and the exhaust gas flow through the second turbine each being greater than zero.

8. The exhaust system of claim 2 ,
wherein the valve assembly includes a bypass valve and an EGR valve;
wherein the inlet port of the valve assembly is an inlet port of the bypass valve;
wherein an outlet port of the bypass valve is fluidly coupled to an inlet of the EGR valve via an EGR valve conduit; and
wherein the bypass valve is operable between a first configuration that blocks fluid communication between the inlet port of the bypass valve and the EGR valve conduit, and a second configuration that effects fluid communication between the inlet port of the bypass valve and the EGR valve conduit.

9. The exhaust system of claim 1 , wherein the controller is further configured to block fluid communication between the exhaust conduit and the inlet to the second turbine via the valve assembly by actuating the valve assembly to the first configuration.

10. An internal combustion engine, comprising:
a plurality of engine cylinders, each engine cylinder of the plurality of engine cylinders including a piston configured to reciprocate therein;
an intake manifold fluidly coupled to the plurality of engine cylinders via a plurality of intake valves;
an exhaust manifold fluidly coupled to the plurality of engine cylinders via a plurality of exhaust valves;
a valve assembly disposed in an exhaust bypass conduit and having an inlet port, a first outlet port, and a second outlet port, the inlet port of the valve assembly being in fluid communication with the exhaust manifold via the exhaust bypass conduit;
wherein the valve assembly has a first configuration that blocks fluid communication between the inlet port and the first outlet port; and
wherein the valve assembly has a second configuration that effects fluid communication between the inlet port and the first outlet port;

a first turbine having an inlet that is fluidly coupled to the exhaust manifold via a first turbine inlet conduit, the first turbine inlet conduit extending from the exhaust manifold to the inlet of the first turbine;
a first compressor operatively coupled to the first turbine, an outlet of the first compressor being fluidly coupled to the intake manifold;
a second turbine having an inlet that is fluidly coupled to the first outlet port of the valve assembly via a first outlet port conduit, and fluidly coupled to an outlet of the first turbine via a first turbine outlet conduit, the first turbine outlet conduit being distinct from the first outlet port conduit; and
a controller operatively coupled to the valve assembly, the controller being configured to effect simultaneous fluid communication between the inlet of the second turbine and the outlet of the first turbine via the first turbine outlet conduit, and between the inlet of the second turbine and the first outlet port of the valve assembly via the first outlet port conduit, by actuating the valve assembly to the second configuration.

11. The internal combustion engine of claim 10 , wherein the exhaust manifold includes an exhaust pulse converter.

12. The internal combustion engine of claim 11 ,
wherein the inlet port of the valve assembly is fluidly coupled to a diffuser of the exhaust pulse converter; and
wherein an outlet of the diffuser of the exhaust pulse converter is fluidly coupled to the inlet of the first turbine.

13. The internal combustion engine of claim 11 ,
wherein the exhaust pulse converter includes a first ejector conduit and a second ejector conduit;
wherein the plurality of engine cylinders includes a first engine cylinder, a second engine cylinder, a third engine cylinder, a fourth engine cylinder, a fifth engine cylinder, and a sixth engine cylinder;
wherein the first engine cylinder, the second engine cylinder, and the third engine cylinder are fluidly combined and coupled to the first ejector conduit via a first ejector manifold; and
wherein the fourth engine cylinder, the fif

Assignees

• Caterpillar Inc

Inventors

• Ge Xinyu
• Liang Hong Liang

Classifications

• F02B37/013

  with exhaust-driven pumps arranged in series · CPC title

• F02D2200/101

  Engine speed · CPC title

• F02B37/025

  Multiple scrolls or multiple gas passages guiding the gas to the pump drive · CPC title

• F02B27/04

  in exhaust systems only, e.g. for sucking-off combustion gases · CPC title

• F02D41/0007

  for control of turbo-charged or super-charged engines (control of the pumps per se F02B37/12) · CPC title