# US 8,783,015 B2 · Shared EGR system and method for a dual-module engine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,783,015 B2 - Document ID: US8783015B2 - Status: Granted - Kind: B2 - Application number: 13/711,683 - Filed: 2012-12-12 - Published: 2013-06-20 - Granted: 2014-07-22 - Earliest claimed: 2011-12-15 - Assignees: EcoMotors, Inc. - Applicants: EcoMotors, Inc. - Inventors: Peter Hofbauer - Web page: https://patentgrep.com/patent/US8783015B2 ## CPC - F01N 3/035: with catalytic reactors - F01N 3/021: by means of filters - F01N 13/011: {having two or more purifying devices arranged in parallel} - F01N 13/107: {More than one exhaust manifold or exhaust collector} - F02B 37/001: {using exhaust drives arranged in parallel} - F02B 37/007: with exhaust-driven pumps arranged in parallel {, e.g. at least one pump supplying alternatively} - F02M 26/34: with compressors, turbines or the like in the recirculation passage - F02M 26/35: with means for cleaning or treating the recirculated gases, e.g. catalysts, condensate traps, particle filters or heaters - F02M 26/43: in which exhaust from only one cylinder or only a group of cylinders is directed to the intake of the engine - F01B 21/02: the machines or engines being all of reciprocating-piston type - F01N 13/04: having two or more silencers in parallel, e.g. having interconnections for multi-cylinder engines - F02B 73/00: Combinations of two or more engines, not otherwise provided for - F02D 25/02: to synchronise speed - F02D 41/0065: {Specific aspects of external EGR control (constructional details of EGR system F02M26/00)} - Y02T 10/12: Improving ICE efficiencies - F01N: GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES (arrangements in connection with gas exhaust of propulsion units in vehicles B60K13/00; combustion-air intake silencers specially adapted for, or arranged on, internal-combustion engines F02M35/00; protecting against, or damping, noise in general G10K11/16) - F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G) - F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF - F01B: MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES (of rotary-piston or oscillating-piston type F01C; of non-positive-displacement type F01D; internal-combustion engines F02B; combustion-product engine plants F02G; machines or engines, other than of positive-displacement type, for liquids F03B; positive-displacement engines driven by liquids F03C; wind motors F03D; positive-displacement machines for liquids F04B; rotary-piston, or oscillating-piston, positive-displacement machines for liquids F04C) - F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## 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. ## Claims ### Claim 1 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. ### Claim 2 (depends on 1) The system of claim 1, further comprising: first and second outlet ducts from the EGR system wherein the first outlet duct is fluidly coupled to an engine intake of the first engine and the second outlet duct is fluidly coupled to an engine intake of the second engine. ### Claim 3 (depends on 2) The system of claim 2 wherein: the first turbocharger further includes a compressor disposed in the engine intake of the first engine and the compressor is located upstream of the location where the first outlet duct fluidly couples to the engine intake of the first engine; and the second turbocharger further includes a compressor disposed in the engine intake of the second engine and the compressor is located upstream of the location where the second outlet duct fluidly couples to the engine intake of the second engine. ### Claim 4 (depends on 2) The system of claim 2, further comprising: a first shutoff valve located in the second EGR leg; a second shutoff valve disposed in the second outlet duct from the EGR system; and an electronic control unit electronically coupled to the first and second shutoff valves. ### Claim 5 (depends on 1) The system of claim 1 wherein the EGR pump is a positive-displacement pump. ### Claim 6 (depends on 1) The system of claim 1, further comprising: a first diesel oxidation catalyst (DOC) disposed in the engine exhaust of the first engine and located upstream of the first DPF; and a second DOC disposed in the engine exhaust of the second engine and located upstream of the second DPF. ### Claim 7 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. ### Claim 8 (depends on 7) The method of claim 7 wherein in response to the determination that stopping of the secondary engine has been demanded, the following is further conducted: braking the secondary engine. ### Claim 9 (depends on 7) The method of claim 7 wherein the dual-engine system further includes: at least a first aftertreatment device disposed in an engine exhaust downstream of the primary engine; at least a second aftertreatment device disposed in an engine exhaust downstream of the secondary engine; a first tee disposed downstream of the first aftertreatment device, the first tee having a first EGR leg and a first exhaust leg; a second tee disposed downstream of the second aftertreatment device, the second tee having a second EGR leg and a second exhaust leg; and an EGR system fluidly coupled with the first EGR leg and with the second EGR leg, the EGR system further comprising: an EGR cooler. ### Claim 10 (depends on 9) The method of claim 9 wherein the dual-engine system further includes: a first turbocharger having a turbine disposed in the first exhaust leg and a compressor disposed in an engine intake of the primary engine; and a second turbocharger having a turbine disposed in the second exhaust leg and a compressor disposed in an engine intake of the secondary engine. ### Claim 11 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. ### Claim 12 (depends on 11) The system of claim 11, further comprising: first and second outlet ducts from the EGR system wherein the first outlet duct is fluidly coupled to an engine intake of the first engine and the second outlet duct is fluidly coupled to an engine intake of the second engine. ### Claim 13 (depends on 12) The system of claim 12 wherein: the first turbocharger further includes a compressor disposed in the engine intake of the first engine and the compressor is located upstream of the location where the first outlet duct fluidly couples to the engine intake of the first engine; and the second turbocharger further includes a compressor disposed in the engine intake of the second engine and the compressor is located upstream of the location where the second outlet duct fluidly couples to the engine intake of the second engine. ### Claim 14 (depends on 12) The system of claim 12, further comprising: a first shutoff valve located in the second EGR leg; a second shutoff valve disposed in the second outlet duct from the EGR system; and an electronic control unit electronically coupled to the first and second shutoff valves. ### Claim 15 (depends on 11) The system of claim 11 wherein the first and second engines are OPOC engines. ### Claim 16 (depends on 11) The system of claim 11, further comprising: a first diesel particulate filter (DPF) disposed in the engine exhaust of the first engine immediately adjacent to the first DOC; and a second DPF disposed in an engine exhaust of the second engine immediately adjacent to the second DOC. ### Claim 17 (depends on 11) The system of claim 11, further comprising: a bypass duct fluidly coupling an inlet of the EGR pump with an outlet of the EGR pump; a controllable valve disposed in the bypass duct; and an electronic control unit electronically coupled to the controllable valve.