US 8,783,015 B2 · Shared EGR system and method for a dual-module engine

Abstract

In systems in which there is insufficient pressure difference between the intake and the exhaust to drive the EGR, an EGR pump is provided. In a dual-engine system, disclosed herein, the EGR system, i.e., the EGR cooler and EGR pump, is shared to obviate the need for two of each. Shutoff valves may be provided between the EGR system and a secondary of the two engines to isolate the secondary engine when it is not operating. When the engines are OPOC engines, exhaust aftertreatment devices, such as diesel oxidation catalysts and/or diesel particulate filters, may be placed upstream of where the EGR gases tee off from the engine's exhaust to thereby maintain a high pressure ratio across an exhaust turbine located downstream in the engine's exhaust.

Claims17

Dependent claims

An internal combustion engine system, comprising:

a first internal combustion engine;
a second internal combustion engine;
a first diesel particulate filter (DPF) disposed in an engine exhaust downstream of the first engine;
a second DPF disposed in an engine exhaust downstream of the second engine;
a first tee disposed downstream of the first DPF, the first tee having a first EGR leg and a first exhaust leg;
a second tee disposed downstream of the second DPF, the second tee having a second EGR leg and a second exhaust leg;
an EGR system fluidly coupled with the first EGR leg and with the second EGR leg, the EGR system comprising:
an EGR cooler and an EGR pump;
a first turbocharger having a turbine disposed in the first exhaust leg;
a second turbocharger having a turbine disposed in the second exhaust leg;
a bypass duct fluidly coupling an inlet and an outlet of the EGR pump;
controllable valve disposed in the bypass duct;
and
an electronic control unit (ECU) coupled to the controllable valve.

11 more elements

A method to control a dual-engine system having a primary engine and a secondary engine, the method comprising:

determining whether a demand for starting the secondary engine has occurred;
conducting the following in response to the determination that starting of the secondary engine has been demanded:
rotating the secondary engine;
providing fuel to the secondary engine;
and
opening shutoff valves which isolate the secondary engine from a shared EGR system;
determining whether a demand for stopping the secondary engine has occurred:
conducting the following in response to the determination that stopping of the secondary engine has been demanded:
turning off fuel to the secondary engine;
and
closing shutoff valves to isolate the secondary engine from a shared EGR system wherein the shared EGR system comprises an EGR pump and a bypass duct fluidly coupling an inlet and an outlet of the EGR pump and a controllable valve disposed in the bypass duct.

8 more elements

An internal combustion engine system, comprising:

a first internal combustion engine;
a second internal combustion engine;
a first diesel oxidation catalyst (DOC) disposed in an engine exhaust downstream of the first engine;
a second DOC disposed in an engine exhaust downstream of the second engine;
a first tee disposed downstream of the first DOC, the first tee having a first EGR leg and a first exhaust leg;
a second tee disposed downstream of the second DOC, the second tee having a second EGR leg and a second exhaust leg;
an EGR system fluidly coupled with the first EGR leg and with the second EGR leg, the EGR system comprising:
an EGR pump;
a first turbocharger having a turbine disposed in the first exhaust leg;
and
a second turbocharger having a turbine disposed in the second exhaust leg wherein a driveshaft of the EGR pump is driven by a crankshaft of the primary engine.

8 more elements

Dependencies are inferred from the claim text.

Shared EGR system and method for a dual-module engine

Life of this patent

Shared EGR system and method for a dual-module engine

Life of this patent

Abstract

Claims17