Centripetal Turbine Variable Geometry Valve
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Turbines in internal combustion engine systems face efficiency drops when operating at part load conditions due to suboptimal incident angles of exhaust gas flow, leading to reduced air flow and combustion efficiency.
Innovation Solution
A centripetal turbine with a housing featuring fixed vanes at different angles in separate passages around the turbine wheel, and a variable geometry valve to selectively control gas flow through these passages, optimizing gas entry angles for varying load conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a turbine is designed for maximum efficiency at full load conditions, then efficiency at rated speed is improved, but efficiency at part load conditions deteriorates
Solution Approach 1:
The turbine housing is divided into multiple passages (first passage, second passage, third passage) with different vane configurations. Each passage is optimized for specific operating conditions, allowing the system to segment the flow paths based on load requirements. This segmentation enables the turbine to maintain high efficiency across different operating ranges by directing flow through appropriate passages.
Solution Approach 2:
The system incorporates a variable geometry valve that dynamically adjusts which passages are active based on operating conditions. The valve can selectively open or close passages to match the incident angle requirements of different load conditions. This dynamic adjustment allows the turbine to adapt its geometry in real-time, maintaining optimal efficiency from part load to full load operations.
2Ease of manufacture
If fixed vanes with consistent circumferential angle are used, then manufacturing is simplified, but part load performance deteriorates
Solution Approach 1:
Instead of using a single set of fixed vanes, the system segments the flow paths into multiple passages, each with its own fixed vanes optimized for specific operating conditions. This allows each passage to have simple fixed vane geometry while the overall system achieves variable performance characteristics through multi-passge configuration.
Solution Approach 2:
The multiple passages with different vane angles serve multiple functions: passage 1 with its specific vane angle optimizes for certain operating conditions, passage 2 optimizes for other conditions, and passage 3 provides additional flow paths. The variable geometry valve orchestrates which passages are active, making the system universally effective across the entire operating range while each individual passage maintains manufacturing simplicity.
3Loss of energy
If variable angle vanes are pivoted to change angle, then part load efficiency is improved, but system reliability deteriorates
Solution Approach 1:
Instead of making the vanes themselves variable and movable (which reduces reliability), the invention inverts the approach by making the passages variable through the variable geometry valve. The fixed vanes remain stationary and reliable, while the valve selectively opens or closes different passages to achieve variable angle effects. This inversion maintains component reliability while achieving the desired performance variation.
Solution Approach 2:
The system segments the control mechanism into a variable geometry valve that manages multiple fixed passages rather than making each passage variable. This segmentation allows the use of simple, reliable fixed vanes in each passage while the valve provides the variable control function, distributing the complexity to a single control component rather than multiple moving vanes.
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 configuration maintains high efficiency across a broader range of operating conditions, particularly improving part load performance and overall engine efficiency by ensuring optimal gas flow at different power levels.
Implementation Method 1
The turbocharger began as a device to capture energy that was wasted in the exhaust system of a naturally aspirated engine by passing exhaust gases over a series of blades on a turbine wheel to produce a rotary power output
Implementation Method 2
The housing has fixed vanes in the passages adjacent the periphery of the turbine wheel and has a device to selectively permit flow through the first passage, second passage and both passages. The fixed vanes in the first and second passages have different angles with respect to the turbine housing.
Implementation Method 3
The housing has first and second passages leading from the inlet to discrete and separate portions around the periphery of the turbine wheel
Data Source
Figure 1
Figure 2
AI summary
An engine system incorporating an air breathing, reciprocating internal combustion engine (10) having an inlet(12) for air and an exhaust (14) for products of combustion. A centripetal turbine (22) receives products of the combustion and has a housing (44) in which a turbine wheel (50) is rotatable. The housing (44) has first and second passages (58, 60) leading from the inlet (46) to discrete, approximately 180°, portions of the circumference of the turbine wheel (50). The passages (58, 60) have fixed vanes (66, 68) adjacent the periphery of the turbine wheel (50) and the angle of the vanes (66, 68) in one of the passages (58, 60) is different than those in the other so as to accommodate different power levels providing optimum approach angles between the gases passing the vanes (66, 68) and the blades (52) of the turbine wheel (50). Flow through the passages (58, 60) is controlled by a flapper valve (70) to direct it to one or the other or both passages (58, 60) depending upon the load factor for the engine (10).