EGR System Pressure Loss Reduction via Planar Flow Path
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Solution Overview
Problem
Internal combustion engines with exhaust gas turbochargers and exhaust gas recirculation systems face high pressure losses due to complex flow paths and component arrangements, leading to increased fuel consumption and emissions, which are exacerbated by the need for expensive control mechanisms like electrically controlled flaps.
Innovation Solution
A simplified and cost-effective exhaust gas recirculation system is designed with a straight flow path and minimal deflections, where the exhaust gas recirculation line is arranged in a plane next to the engine, reducing pressure losses by minimizing deflections and using a throttle valve as a cost-effective control mechanism, and integrating components like the EGR cooler and particle filter for efficient thermal management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional EGR system with curved lines and multiple deflections is used, then exhaust gas recirculation can be achieved, but pressure losses are high
Solution Approach 1:
The EGR system is divided into separate functional sections: a first EGR line with minimal deflections for primary exhaust gas transport, and a second EGR line with deflections for supplementary flow control. This segmentation allows each section to be optimized for its specific function, reducing overall pressure losses while maintaining recirculation capability.
Solution Approach 2:
The patent introduces a spatial arrangement where the first EGR line is positioned to provide a substantially deflection-free flow path, while the second EGR line handles the necessary flow adjustments. This dimensional separation of flow paths reduces the cumulative effect of deflections on pressure losses.
2Loss of energy
If electrically controlled flap is used to regulate pressure drop, then pressure control can be achieved, but system cost increases
Solution Approach 1:
The patent replaces expensive electrically controlled flaps with a mechanically simpler throttle valve that can be actuated by less sophisticated means. This substitution significantly reduces system cost while maintaining adequate pressure control capability through the dual EGR line configuration.
Solution Approach 2:
The dual EGR line system allows pressure control to be achieved through the natural flow characteristics and geometric configuration of the lines themselves, rather than requiring active electronic control systems. The system uses its own structural features to regulate pressure drop.
3Ease of manufacture
If throttle valve is used upstream of compressor to control pressure, then cost is reduced, but compressor pumping or oil leakage occurs
Solution Approach 1:
The first EGR line acts as an intermediary flow path that provides a controlled resistance to exhaust gas flow, allowing pressure regulation without creating excessive vacuum upstream of the compressor. This intermediate solution avoids the direct throttling problem that causes compressor pumping and oil leakage.
Solution Approach 2:
Different EGR lines are designed with different flow characteristics: the first line provides minimal resistance with substantial deflections, while the second line provides additional control capability. This local differentiation of flow path qualities allows pressure control without excessive vacuum generation.
4Temperature
If EGR cooler with U-shaped flow is used, then cooling function is achieved, but pressure losses increase
Solution Approach 1:
The cooling function is separated from the primary exhaust gas transport path. The first EGR line provides minimal resistance flow, while cooling is achieved through the second EGR line or separate cooling sections, allowing thermal management without compromising flow 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 configuration achieves low pressure losses and reduced fuel consumption, enabling high exhaust gas recirculation rates with minimal installation space and operational costs, eliminating the need for expensive electric control flaps.
Implementation Method 1
to generate the pressure gradient required for the exhaust gas transport
Implementation Method 2
an EGR cooler is used in front of the compressor to protect it from too high component temperatures
Implementation Method 3
either the exhaust gas back pressure must be increased by means of a damper after the extraction point or the suction vacuum before the compressor must be reduced by means of a throttle valve
Data Source
Figure 1
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Figure 4
AI summary
The engine has an exhaust gas return line, an exhaust gas return cooler and an exhaust gas return valve that are arranged in an exhaust gas return system. A plane (E) runs laterally adjacent to a longitudinal side of the engine, and is defined by an axis (A) and a point (P) that lies in an inlet surface of the cooler. The cooler is directly arranged downstream of a branch for non-return exhaust gas in an exhaust gas path. The return line extends from the cooler to an air supply such that the return exhaust gas is supplied in a flow direction over a feed-in point.