Turbine-Generator Valve Deactivation for Split Exhaust Speed Control
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Solution Overview
Problem
Existing split exhaust manifold systems in vehicle engines face challenges in controlling turbine-generator speed and reducing generator output without increasing production costs and packaging space, particularly during cold-start conditions and high turbine speeds.
Innovation Solution
The system selectively deactivates blowdown valves in response to threshold turbine speeds or generator output differences, reducing exhaust energy delivered to the turbine and directing it to the catalyst for faster warm-up, thereby avoiding the need for a wastegate and its associated actuator.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a wastegate valve and actuator are added to control turbine speed and generator output, then turbine over-speed conditions can be limited and generator output can be controlled, but production cost and packaging space increase
Solution Approach 1:
The patent extracts the exhaust flow control function from a separate wastegate valve and actuator system, and instead integrates it into the existing exhaust valve deactivation mechanism. By taking out the need for a dedicated wastegate actuator and using the already-present exhaust valve control system, the patent reduces device complexity while maintaining turbine speed control capability.
Solution Approach 2:
The patent makes the exhaust valve system multi-functional by having it serve both its original purpose of exhaust gas discharge and the additional function of turbine speed control. By deactivating the exhaust valve to close the exhaust port, the same valve mechanism that normally manages exhaust flow also controls turbine inlet flow, eliminating the need for a separate wastegate actuator.
2Speed
If a wastegate valve is added to bypass exhaust flow around the turbine, then maximum turbine speed can be limited, but system cost and packaging space increase
Solution Approach 1:
The patent implements self-service by using the exhaust valve's own deactivation to control turbine speed, rather than requiring a separate wastegate system. The exhaust valve system serves itself to perform dual functions: normal exhaust discharge and turbine speed limitation, thereby reducing production costs by eliminating redundant components.
3Temperature
If exhaust flow is directed to the catalyst during cold-start conditions, then catalyst warm-up is expedited, but turbine speed control is needed
Solution Approach 1:
The patent applies multi-functionality by using the exhaust valve deactivation mechanism to achieve both catalyst warm-up and turbine speed control. During cold-start conditions, deactivating the exhaust valve directs all exhaust flow to the catalyst for rapid warm-up, while the same mechanism can limit turbine speed, eliminating the need for separate control systems.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces turbine over-speed conditions, improves turbine-generator efficiency, and expedites catalyst warm-up while minimizing system costs and packaging, by utilizing valve deactivation to manage exhaust energy distribution.
Implementation Method 1
delivering exhaust from a first exhaust valve of a cylinder to an exhaust turbine via a first exhaust manifold, the turbine driving a generator
Data Source
AI summary
Methods and systems are provided for reducing exhaust energy delivered to a turbine of a turbine-generator coupled to a split exhaust engine system in order to reduce turbine over-speed conditions and/or to reduce a generator output. In one example, a method may include deactivating a blowdown exhaust valve utilized to deliver a blowdown portion of exhaust energy to the turbine.