Compressor Bypass for LP-EGR Condensate Control
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Solution Overview
Problem
Low-pressure exhaust gas recirculation (LP-EGR) systems face challenges with condensate formation in intake air systems due to temperature differences, leading to increased noise and potential damage to compressor blades, as existing condensate collectors are not effective in mitigating vapor condensation and can cause packaging restraints.
Innovation Solution
A compressor bypass system that redirects charge air upstream and downstream of the compressor impeller, introducing it at an acute angle to the inner wall of the intake passage via an annular outlet to create a barrier against condensate formation, and can be activated based on weather conditions to increase charge air quantity and reduce condensate droplets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If LP-EGR is used to redirect exhaust gas to the intake passage upstream of the compressor, then energy is conserved by driving the turbine, but condensate forms on intake surfaces due to temperature differences
Solution Approach 1:
A condensate collector is introduced as an intermediary component in the LP-EGR passage to intercept and remove water vapor before it condenses on intake surfaces. The collector acts as a mediator between the warm LP-EGR and the cooler intake system, preventing direct contact between the vapor and cold surfaces that would cause condensation.
Solution Approach 2:
The system changes the temperature parameter of the LP-EGR by allowing it to cool gradually in the passage before reaching the intake manifold. This controlled temperature reduction prevents sudden condensation by ensuring the gas temperature remains above the dew point throughout the intake system.
2Object-affected harmful factors
If a condensate collector is placed in the LP-EGR passage to collect vapors, then vapor condensation is reduced, but packaging space is constrained and the solution is not universal
Solution Approach 1:
The condensate collector is designed with a universal mounting configuration that can be adapted to various vehicle platforms and engine layouts. The collector integrates with existing LP-EGR passage geometry rather than requiring additional dedicated space, making the solution applicable across different vehicle models without major packaging modifications.
Solution Approach 2:
The condensate collector is nested within the existing LP-EGR passage structure, utilizing the available space within the intake system rather than adding external components. This nested configuration minimizes the overall packaging footprint while maintaining effective vapor collection functionality.
3Reliability
If condensate collector and passage to compressor wheel are added to prevent erosion, then compressor blade damage is reduced, but packaging restraints increase
Solution Approach 1:
The condensate collection and drainage functionality is extracted as a separate, integrated component within the LP-EGR system rather than requiring a complex dedicated protection system for the compressor. The collector captures condensate and provides a controlled drainage path that protects compressor blades without adding extensive packaging requirements.
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 compressor bypass system effectively decreases condensate formation on intake passage surfaces, reduces noise emissions, and prevents damage to compressor blades by creating a barrier and artificially increasing charge air quantity, thereby enhancing compressor efficiency and torque characteristics.
Implementation Method 1
water may condense in the intake air forming droplets or impinge onto surfaces of the components. This is due to a higher temperature of LP-EGR and a lower temperature of the intake system and/or intake air.
Implementation Method 2
a method for bypassing charge air to an intake system via a compressor bypass drawing charge air upstream and downstream of a compressor impeller
Data Source
AI summary
Methods and systems are provided for a compressor bypass passage. In one example, a method may include flowing bypassed charge air through an annular passage into an intake passage.