Double-Flow Turbine Movable Partition for Exhaust Pressure Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Supercharged internal combustion engines face a conflict in optimizing operation both with small and large amounts of exhaust gas, as grouping cylinders for pulse charging benefits low loads but worsens performance at higher loads due to pressure fluctuations and residual gas issues, while maximizing exhaust gas volume for dynamic charging compromises low-load efficiency.
Innovation Solution
A two-flow turbine system with a displaceable wall piece that connects or separates exhaust gas flows upstream of the impeller, allowing adaptation to different operating conditions by varying the exhaust gas volume, thereby optimizing both pulse and dynamic charging modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If cylinders are grouped for pulse charging with separate exhaust flows, then low-load efficiency is improved, but high-load performance deteriorates due to pressure fluctuations and residual gas issues
Solution Approach 1:
The patent applies a movable partition wall that can dynamically change position between retracted and extended states. When retracted, the partition allows mixed exhaust flow for high-load operation. When extended, it creates separate exhaust channels for pulse charging at low loads. This dynamic structural change enables the system to adapt to different operating conditions and resolve the contradiction between low-load efficiency and high-load performance.
2Reliability
If exhaust gas volume is maximized for dynamic charging, then high-load performance is improved, but low-load efficiency deteriorates due to loss of pressure wave effects
Solution Approach 1:
The patent segments the exhaust system into two separate channels using a movable partition wall. Each channel can be independently controlled to maintain optimal exhaust gas volume characteristics. At low loads, the partition creates separate channels that preserve pressure wave effects for pulse charging. At high loads, the partition retracts to allow volume maximization for dynamic charging, thus resolving the contradiction between these two operating modes.
3Quantity of substance
If a single exhaust pipe is used to maximize exhaust gas volume, then dynamic charging is improved, but pulse charging efficiency deteriorates due to pressure wave damping
Solution Approach 1:
The movable partition wall dynamically reconfigures the exhaust system architecture. In the extended position, it divides the exhaust system into separate pipes that preserve pressure waves for pulse charging. In the retracted position, it allows convergence into a single large-volume exhaust pipe for dynamic charging. This dynamic transformation resolves the contradiction between exhaust gas volume and pulse charging efficiency.
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 solution enables efficient operation across varying exhaust gas amounts by minimizing pressure fluctuations and residual gas issues, achieving high turbine pressure ratios at low loads and smooth, constant pressure at higher loads, thus optimizing engine performance.
Implementation Method 1
At the beginning of the charge exchange, when the exhaust valve opens near bottom dead center, the combustion gases flow at high velocity through the exhaust port into the exhaust system due to the high pressure level prevailing in the cylinder towards the end of combustion and the associated high pressure differential between the combustion chamber and the exhaust pipe
Implementation Method 2
This pressure-driven flow process is accompanied by a high pressure peak, also known as the pre-exhaust surge, which propagates along the exhaust pipe at the speed of sound
Implementation Method 3
a twin-scroll turbine, which comprises an impeller (3) mounted on a rotatable shaft (4) in a turbine housing (2)
Data Source
Figure 1a~1c
Figure 2a~2d
AI summary
The internal combustion engine has a radial double-flow turbine (1) arranged in exhaust system, and impellers (3a,3b) which are mounted on a rotatable shaft (4) in a turbine housing (2). The double-flow turbine includes flow portions (8,9) which are connected with exhaust lines and are extended towards the impellers. The flow portions are separated from each other by a housing wall (5), and are connected with one another by forming an opening (5a) in housing wall, at upstream of impellers.