# US 2014/0150423 A1 · Two-stage turbocharger assembly with single low-pressure turbocharger > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0150423 A1 - Document ID: US20140150423A1 - Status: Published application - Kind: A1 - Application number: 14/090,377 - Filed: 2013-11-26 - Published: 2014-06-05 - Earliest claimed: 2011-06-27 - Assignees: Napier Turbochargers Limited - Inventors: Francis Joseph Geoffrey HEYES - Web page: https://patentgrep.com/patent/US20140150423A1 ## CPC - F02B 37/002: {the exhaust supply to one of the exhaust drives can be interrupted} - F02B 29/04: Cooling of air intake supply - F02B 37/001: {using exhaust drives arranged in parallel} - F02B 37/004: {with exhaust drives arranged in series} - F02B 37/007: with exhaust-driven pumps arranged in parallel {, e.g. at least one pump supplying alternatively} - F02B 37/013: with exhaust-driven pumps arranged in series - F02B 37/18: by bypassing exhaust {from the inlet to the outlet of turbine or to the atmosphere} - Y02T 10/12: Improving ICE efficiencies - F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A two-stage turbocharger assembly for an internal combustion engine is provided. The assembly has a single low pressure turbocharger, and more than two high pressure turbochargers arranged in parallel with each other. The compressor outlet of the single low pressure turbocharger is operatively connected to the compressor inlets of the high pressure turbochargers. The turbine outlets of the high pressure turbochargers are operatively connected to the turbine inlet of the single low pressure turbocharger. ## Claims ### Claim 1 A two-stage turbocharger assembly for an internal combustion engine, the assembly having: a single low pressure turbocharger, and a plurality of high pressure turbochargers arranged in parallel with each other, a compressor outlet of the low pressure turbocharger being operatively connected to compressor inlets of the high pressure turbochargers, and turbine outlets of the high pressure turbochargers being operatively connected to a turbine inlet of the low pressure turbocharger; wherein the assembly has more than two of the high pressure turbochargers. ### Claim 2 (depends on 1) The two-stage turbocharger assembly of claim 1 having at least four of the high pressure turbochargers. ### Claim 3 (depends on 1) The two-stage turbocharger assembly of claim 1 wherein one or more of the high pressure turbochargers can be controllably switched on-line and off-line to vary the compressor and turbine characteristics of the assembly. ### Claim 4 (depends on 3) The two-stage turbocharger assembly of claim 3 wherein each of the switchable high pressure turbochargers has a valve controlling a flow of exhaust gas to the turbine inlet or from the turbine outlet and thereby changing the on-line or off-line status. ### Claim 5 (depends on 3) The two-stage turbocharger assembly of claim 3 wherein each of the switchable high pressure turbochargers has a valve controlling a flow of compressed air to the compressor inlet or from the compressor outlet and thereby changing the on-line or off-line status. ### Claim 6 (depends on 4) The two-stage turbocharger assembly of claim 4 wherein the valve is a butterfly valve, a globe valve or a gate valve. ### Claim 7 (depends on 1) The two-stage turbocharger assembly of claim 1 wherein each high pressure turbocharger has a waste gate allowing exhaust gas to bypass the turbine. ### Claim 8 (depends on 1) The two-stage turbocharger assembly of claim 1 wherein the low pressure turbocharger has a waste gate allowing exhaust gas to bypass the turbine. ### Claim 9 (depends on 1) The two-stage turbocharger assembly of claim 1 further having one or more intercoolers operatively connecting the compressor outlet of the low pressure turbocharger to the compressor inlets of the high pressure turbochargers. ### Claim 10 (depends on 9) The two-stage turbocharger assembly of claim 9 further having a diverter line in parallel with the intercooler allowing the intercooler to be bypassed. ### Claim 11 (depends on 1) The two-stage turbocharger assembly of claim 1 further having one or more charge air coolers operatively connecting the compressor outlets of the high pressure turbochargers to a combustion chamber of an internal combustion engine. ### Claim 12 (depends on 1) The two-stage turbocharger assembly of claim 1 wherein the high pressure turbochargers are substantially identical to each other. ### Claim 13 (depends on 1) The two-stage turbocharger assembly of claim 1 wherein the high pressure turbochargers are mountable at a cylinder head of an internal combustion engine. ### Claim at position 14 (depends on 13) 14 The two-stage turbocharger assembly of claim 13 wherein each high pressure turbocharger is adapted to send compressed air to and receive exhaust gas from one or more respective combustion chambers of the internal combustion engine, the high pressure turbochargers being arranged in the assembly so that each high pressure turbocharger is adjacent the respective chamber when mounted at the cylinder head, and the high pressure turbochargers being divided into two or more groups, the high pressure turbochargers of each group not serving the combustion cylinders of the other group. ### Claim 15 (depends on 14) The two-stage turbocharger assembly of claim 14 wherein each group includes one or more of the high pressure turbochargers. ### Claim 16 (depends on 1) An internal combustion engine fitted with the two-stage turbocharger assembly of claim 1. ### Claim 17 (depends on 16) The internal combustion engine of claim 16 having a plurality of exhaust gas manifolds, each exhaust gas manifold sending exhaust gas to a respective subset of the high pressure turbochargers. ### Claim 18 (depends on 17) The internal combustion engine of claim 17 wherein each subset includes one or more of the high pressure turbochargers.