Wastegate Control for Charge Air Cooler Condensate

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Solution Overview

Problem

Existing engine systems face issues with condensate formation in charge air coolers due to increased induction pressure, which can lead to engine misfire and combustion instability, particularly when the wastegate remains closed under conditions where increased boost is not required, causing induction pressure buildup and condensate formation.

Innovation Solution

A method to adjust the wastegate and compressor recirculation valve based on engine operating conditions to decrease induction pressure when condensate forming conditions are detected, such as high humidity or induction pressure exceeding atmospheric pressure, thereby reducing the likelihood of condensate formation in the charge air cooler.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the wastegate is kept closed to maintain boost pressure, then the engine power is improved, but condensate formation in the charge air cooler increases

Engineering Contradiction:

Improveengine powerVSAvoidcondensate formation

Core Design Contradiction:

PowerVSObject-affected harmful factors

Solution Approach 1:

The wastegate control system transitions from a static closed position to a dynamic controlled opening, adjusting the wastegate position based on real-time detection of condensate formation conditions (high humidity, high induction pressure) to dynamically balance power output and condensate prevention

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the induction pressure parameter by opening the wastegate when condensate formation conditions are detected, thereby reducing the induction pressure to below dew point conditions and preventing condensate formation while maintaining acceptable power levels

Inventive Principle:

Principle #35Parameter changes

2Object-affected harmful factors

If the wastegate is opened to reduce induction pressure and prevent condensate formation, then condensate formation is reduced, but engine power decreases

Engineering Contradiction:

Improvecondensate formationVSAvoidengine power

Core Design Contradiction:

Object-affected harmful factorsVSPower

Solution Approach 1:

Instead of fully opening the wastegate which would excessively reduce power, the system applies partial action by opening the wastegate only to the extent necessary to reduce induction pressure below dew point conditions, achieving sufficient condensate prevention while minimizing power loss

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The wastegate is opened periodically or intermittently based on detected condensate formation conditions rather than remaining continuously open, allowing the system to maintain power when conditions are favorable and prevent condensate when conditions require intervention

Inventive Principle:

Principle #19Periodic action

3Object-affected harmful factors

If the wastegate is opened during acceleration to reduce condensate formation, then condensate formation is reduced, but turbo lag increases

Engineering Contradiction:

Improvecondensate formationVSAvoidturbo lag

Core Design Contradiction:

Object-affected harmful factorsVSLoss of time

Solution Approach 1:

The control system dynamically detects engine operating conditions including acceleration states and adjusts wastegate timing accordingly, delaying wastegate opening until after the critical acceleration phase to minimize turbo lag while still preventing condensate formation during steady-state conditions

Inventive Principle:

Principle #15Dynamics

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 approach effectively reduces condensate formation in the charge air cooler by managing induction pressure, minimizing the risk of engine misfire and combustion instability while avoiding turbo lag by opening the wastegate only during steady-state conditions and using the compressor recirculation valve during non-steady-state conditions.

Implementation Method 1

Condensate may form in the CAC when the ambient air temperature decreases, or during humid or rainy weather conditions, where the intake air is cooled below the water dew point temperature

Methodology Applied

Scientific EffectCondensation: Condensation

Implementation Method 2

Engines may utilize a wastegate to divert exhaust gas flow around a turbine of the turbocharger to control an amount of boost provided to an intake manifold of the engine

Methodology Applied

Scientific EffectPressure control:

Implementation Method 3

Engines may utilize a turbocharger or supercharger to compress ambient air entering the engine in order to increase power

Methodology Applied

Scientific EffectCompression: Compression

Implementation Method 4

during certain engine operating conditions, a compressor recirculation valve may be opened in addition to opening the wastegate to increase the induction pressure reduction

Methodology Applied

Scientific EffectPressure reduction:

Data Source

PatentUS9181859B2Wastegate control to reduce charge air cooler condensate

Publication Date: 2015.11.10 FORD GLOBAL TECH LLC

AI summary

Methods and systems are provided for adjusting a wastegate in response to condensate forming conditions in a charge air cooler (CAC). In one example, a wastegate may be opened in response to an induction pressure greater than a threshold pressure when the induction pressure is greater than required to produce a manifold pressure required for a torque demand. Further, a compressor recirculation valve may be opened to further reduce the induction pressure during certain driving conditions.