Efficient bypass valve for multi-stage turbocharging system

• Main Author: GRAY CHARLES L. JR.,HAUGEN DAVID JAMES
• Format: Patent
• Language: English
• Published: 12.09.2007
• Subjects: ACTUATING-FLOATS; BLASTING; COCKS; COMBUSTION ENGINES; COMBUSTION ENGINES IN GENERAL; DEVICES FOR VENTING OR AERATING; ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; INTERNAL-COMBUSTION PISTON ENGINES; LIGHTING; MECHANICAL ENGINEERING; TAPS; THERMAL INSULATION IN GENERAL; VALVES; WEAPONS

A more efficient multi-stage turbocharging system and method for internal combustion engine systems is set forth. The present invention recovers the loss of a portion of exhaust energy that conventionally occurs in bypassing exhaust flow from one stage to another in a multi-stage turbocharging system. The preferred method of preserving such exhaust energy is through converting a portion of the exhaust energy of the bypassed flow from pressure to kinetic energy (velocity) by passing the bypassed flow through a VGT vane outlet or other variable geometry valve/nozzle, and then not allowing the accelerated flow to dissipate energy before reaching the subsequent stage's turbine wheel, where the accelerated flow may then be converted to a mechanical rotational force by the lower pressure turbine's wheel. Preferred hardware for achieving the object of the invention is also set forth, including a preferred two-volute low pressure turbocharging system with a VGT mechanism in one turbine volute only, or an alternative low pressure turbocharger with two low pressure turbines on a common shaft (again, preferably, with a VGT mechanism in one turbine only).The present invention recovers the loss of a portion of exhaust energy conventionally occurring in bypassing exhaust flow from one stage to another in a multi-stage turbocharging system. The method of preserving such exhaust energy is through converting a portion of the exhaust energy of the bypassed flow from pressure to kinetic energy (velocity) by passing the bypassed flow through a VGT vane outlet or other variable geometry valve/nozzle, and then not allowing the accelerated flow to dissipate energy before reaching the subsequent stage's turbine wheel, where the accelerated flow may then be converted to a mechanical rotational force by the lower pressure turbine's wheel.