Gasoline Particulate Reduction via Optimized Port and Direct Injection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Gasoline engine vehicles with direct injection emit higher levels of particulate matter, which are harmful to human health and pose challenges for meeting stringent emission regulations, especially for turbocharged and supercharged engines.

Innovation Solution

The use of a fuel management system that optimizes the ratio of direct injection to port fuel injection, combined with techniques like spark retard and variable valve timing, to minimize particulate emissions by controlling the amount of directly injected fuel and avoiding piston wetting, while also employing air preheating through variable valve timing to improve vaporization during cold starts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If direct injection is used to increase engine efficiency and knock resistance, then engine performance is improved, but particulate emissions increase significantly

Engineering Contradiction:

Improveengine efficiencyVSAvoidparticulate emissions

Core Design Contradiction:

PowerVSObject-generated harmful factors

Solution Approach 1:

The fuel injection system is segmented into two separate injection paths: port fuel injection (PFI) and direct injection (DI). The PFI system handles the majority of fuel delivery to minimize particulates, while the DI system provides only the minimum necessary fuel for knock resistance, thereby maintaining engine efficiency while dramatically reducing particulate emissions

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system dynamically adjusts the fraction of direct injected fuel based on engine operating conditions (torque, speed, knock sensor feedback). By changing the DI fuel fraction parameter in real-time, the system maintains optimal knock resistance while minimizing particulate-generating conditions

Inventive Principle:

Principle #35Parameter changes

2Reliability

If the amount of directly injected fuel is increased to prevent knock, then knock resistance is improved, but piston wetting occurs and particulate emissions increase

Engineering Contradiction:

Improveknock resistanceVSAvoidpiston wetting

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system applies partial direct injection, using only the minimum fraction of DI fuel necessary to achieve knock resistance rather than full injection. This partial action provides sufficient knock protection while keeping the fuel quantity below the threshold that causes piston wetting and excessive particulates

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The knock sensor provides real-time feedback on combustion stability, allowing the control system to adjust the DI fuel fraction dynamically. This feedback loop ensures knock resistance is maintained with the minimum necessary fuel, avoiding piston wetting conditions

Inventive Principle:

Principle #23Feedback

3Object-generated harmful factors

If port fuel injection is used instead of direct injection, then particulate emissions are reduced, but knock resistance and engine efficiency decrease

Engineering Contradiction:

Improveparticulate emissionsVSAvoidknock resistance

Core Design Contradiction:

Object-generated harmful factorsVSPower

Solution Approach 1:

The system merges the advantages of both PFI and DI by combining their functions. PFI provides clean fuel delivery with minimal particulates, while DI provides knock resistance. The hybrid system captures the benefits of both approaches, achieving low particulates while maintaining knock protection

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The dual injection system serves multiple functions: PFI handles bulk fuel delivery and vaporization, DI handles knock resistance and stratified charge formation. This multi-functionality allows the system to achieve both low emissions and high performance across diverse operating conditions

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 reduces particulate emissions to levels comparable to those of port fuel injection-only engines, potentially eliminating the need for gasoline particulate filters and achieving greater reduction than standalone filters, while maintaining engine efficiency and performance.

Implementation Method 1

control of the amount of directly injected fuel so as to avoid a threshold increase in particulates due to piston wetting

Methodology Applied

Scientific EffectFuel injection: Injector

Implementation Method 2

reduction of cold start emissions by use of air preheating using variable valve timing

Methodology Applied

Scientific EffectAir preheating: Heating

Implementation Method 3

direct injection increases engine efficiency and performance by increasing knock resistance though evaporative cooling

Methodology Applied

Scientific EffectEvaporative cooling: Evaporative Cooler

Data Source

PatentUS10288005B2Gasoline particulate reduction using optimized port and direct injection

Publication Date: 2019.05.14 ETHANOL BOOSTING SYSTEM LLC

AI summary

Additional approaches for the reduction of particulate emissions in gasoline engines using optimized port+direct injection are described. These embodiments include control of the amount of directly injected fuel so as to avoid a threshold increase in particulates due to piston wetting and reduction of cold start emissions by use of air preheating using variable valve timing.