SIDI Cold Start Fuel Control via Segmented Injection

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Solution Overview

Problem

Cold start issues in spark ignition direct injection (SIDI) engines arise when the fuel's flash point temperature is exceeded, preventing vaporization and combustion, leading to difficulties in engine startup without auxiliary devices, which increase vehicle costs.

Innovation Solution

A cold start control system that includes a startup control module and a fuel actuator module, which set a cold start mode, determine target combustion parameters, and inject a predetermined amount of fuel at high pressure near the spark plug during cranking, warming the cylinder without igniting the entire fuel charge, enabling vaporization and combustion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a predetermined amount of fuel less than required for combustion stroke is injected during cranking, then the fuel can vaporize and combust properly, but the engine may not have enough fuel to initiate a combustion stroke

Engineering Contradiction:

Improvecombustion initiation reliabilityVSAvoidfuel amount

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The fuel injection process is segmented into two distinct phases: a first fuel injection during cranking that provides sufficient fuel for vaporization and combustion initiation, and a second fuel injection after combustion starts that provides additional fuel to sustain and strengthen the combustion stroke. This segmentation allows each injection to be optimized for its specific purpose, ensuring reliable combustion initiation while maintaining adequate fuel supply for the combustion stroke.

Inventive Principle:

Principle #1Segmentation

2Reliability

If auxiliary devices are used to enable cold start below flash point temperature, then engine startup is possible, but vehicle cost increases

Engineering Contradiction:

Improvecold start capabilityVSAvoidauxiliary devices

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The system changes the fuel injection parameters (amount, timing, and pressure) based on engine operating conditions, particularly during cold starts. By injecting a predetermined amount of fuel at high pressure during cranking, the system creates optimal conditions for fuel vaporization and combustion initiation without requiring auxiliary heating devices, thereby reducing vehicle cost while maintaining cold start capability.

Inventive Principle:

Principle #35Parameter changes

3Temperature

If high pressure fuel injection is used during cranking, then fuel vaporization is promoted, but fuel may ignite prematurely before intended combustion timing

Engineering Contradiction:

Improvefuel vaporization temperatureVSAvoidpremature ignition

Core Design Contradiction:

TemperatureVSObject-generated harmful factors

Solution Approach 1:

The system performs preliminary fuel injection during cranking to prepare the fuel-air mixture for combustion, but deliberately delays the actual combustion ignition until the intended timing. The first fuel injection occurs during cranking to promote vaporization, and only after combustion has been properly initiated does the system proceed to the second fuel injection that sustains the combustion stroke, preventing premature ignition while ensuring proper vaporization.

Inventive Principle:

Principle #10Preliminary action

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

Enables SIDI engine startup at temperatures below the fuel's flash point without auxiliary devices, improving reliability and reducing vehicle costs by selectively controlling fuel injection to promote vaporization and ignition.

Implementation Method 1

Methodology Applied

Scientific EffectCombustion: Combustion

Implementation Method 2

enabling vaporization and combustion

Methodology Applied

Scientific EffectVaporization: Evaporation

Data Source

PatentUS10371083B2Systems and methods for fuel control during cold starts

Publication Date: 2019.08.06 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A cold start control system for a vehicle having a spark ignition direct injection (SIDI) engine includes a startup control module and a fuel actuator module. The startup control module sets a mode of operation to a cold start mode. In response to setting the mode to the cold start mode, the startup control module determines target combustion parameters and a predetermined amount of fuel, wherein the predetermined amount of fuel is less than an amount of fuel required to initiate a combustion stroke of the SIDI engine. The startup control module controls injection of the predetermined amount of fuel, during cranking of the SIDI engine, based on the target combustion parameters. The fuel actuator module injects the predetermined amount of fuel, during cranking, based on the target combustion parameters.