Turbine-Compressor Assembly Mode Switching
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Solution Overview
Problem
Turbochargers are limited in energy extraction due to mechanical and thermal constraints, and they have limited benefits at low engine loads and low engine speeds where exhaust energy is reduced, necessitating a system that can efficiently manage energy extraction and conversion across varying operational conditions.
Innovation Solution
A turbine-compressor assembly with a controller that selectively switches between operating modes to optimize energy extraction and conversion, using valves to direct fluids and adjust power flow, allowing the system to operate as either a turbine or compressor based on engine conditions, thereby enhancing energy utilization and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single stage turbocharger is used, then the structure is simple, but energy extraction is limited due to mechanical and thermal constraints
Solution Approach 1:
The exhaust energy extraction system is segmented into multiple stages: a first turbine extracts energy at high pressure/temperature, and a second turbine extracts additional energy from the same exhaust stream after it passes through the first turbine. This segmentation allows progressive energy extraction without requiring a completely separate system for each stage, thus improving energy utilization while maintaining reasonable structural complexity.
Solution Approach 2:
The second turbine is nested within the exhaust flow path after the first turbine, creating a cascaded energy extraction system. The exhaust gases flow sequentially through both turbines, with the second turbine utilizing the remaining energy in the exhaust stream. This nesting approach maximizes energy extraction from the same exhaust flow without requiring parallel independent systems.
2Loss of energy
If a two-stage turbocharger is used to extract additional energy, then energy extraction improves, but device complexity increases
Solution Approach 1:
The first turbine-compressor assembly serves dual functions: it acts as a conventional turbocharger for the engine during normal operation, and simultaneously provides a power source that can drive the second turbine or charge an energy storage device. This multi-functionality reduces the need for separate dedicated energy recovery components, thereby limiting the increase in overall device complexity.
Solution Approach 2:
An intermediary mechanism (such as a clutch or control system) is introduced to manage the coupling between the first and second turbines, and to control when energy is transferred to the energy storage device versus when it drives the second turbine. This intermediary allows flexible operation modes and simplifies the overall system by providing a unified control approach rather than requiring completely separate control systems for each function.
3Power
If exhaust energy is extracted at high engine loads, then power generation is maximized, but energy extraction is reduced at low engine loads and speeds
Solution Approach 1:
The system dynamically adjusts its operation based on engine conditions through a controller that monitors engine load and speed. At high engine loads, the system operates in power generation mode where both turbines extract energy and drive generators. At low engine loads, the system transitions to a mode where the first turbine-compressor assembly acts as a conventional turbocharger while the second turbine charges an energy storage device. This dynamic adaptation ensures effective energy utilization across the full range of operating conditions.
Solution Approach 2:
The system changes operational parameters (such as turbine coupling status, generator loading, and energy storage charging/discharging rates) based on engine operating conditions. The controller adjusts these parameters to optimize energy extraction efficiency at both high and low engine loads, transforming the system's behavior to match the available exhaust energy levels and power demands.
4Use of energy by moving object
If more energy is extracted from exhaust, then fuel efficiency improves, but mechanical and thermal constraints limit the extraction amount
Solution Approach 1:
Instead of attempting to extract all available energy from the exhaust (which would exceed mechanical and thermal constraints), the system extracts a controlled portion of energy at each turbine stage. The first turbine extracts energy within its design constraints, and the second turbine extracts additional energy from the remaining exhaust stream. This partial extraction approach at each stage achieves cumulative energy recovery without overloading any single component beyond its reliability limits.
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
The system increases energy extraction and efficiency by adjusting power flow and operating modes, reducing emissions and extending component lifespan, particularly at low engine loads and speeds, by optimizing energy use and air pressure delivery.
Implementation Method 1
The compressor is driven by the turbine using energy extracted from exhaust gases of the engine
Implementation Method 2
The compressor increases the pressure and flow rate of intake air
Implementation Method 3
The generator extracts energy from exhaust gases of the reciprocating engine system
Data Source
AI summary
A turbine-compressor assembly includes a turbine-compressor device fluidly coupled with a heat source, a compressor, and a turbine via plural valves. A power device is coupled with the turbine-compressor device via a shaft. A controller can control operation of the plural valves to control the movement of fluids within the assembly to selectively switch between the turbine-compressor device operating in one of plural operating modes. In a first mode of operation, the turbine-compressor device can generate electrical power and direct the electrical power to the power device to control an amount of power provided to or extracted from the shaft by the power device. In a second mode of operation, the turbine-compressor device can receive electrical power from the power device to consumer the electrical power.