Turbulent Jet Ignition Cold Start Using Compression Heating
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Solution Overview
Problem
Turbulent jet ignition (TJI) systems face challenges in igniting the primary fuel/air charge during engine cold starts and light load conditions, requiring additional spark plugs that increase costs and packaging, limiting their applicability.
Innovation Solution
An electrified powertrain configuration that uses electric motors to pre-heat the primary combustion chamber, eliminating the need for a secondary spark plug by generating drive torque to increase temperature and facilitate ignition using the TJI system, and incorporating exhaust gas recirculation and valve control systems to recycle heat energy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an additional conventional spark plug is added to enable stable combustion at low temperatures and low loads, then the reliability of ignition is improved, but the device complexity and cost increase
Solution Approach 1:
The electric motor serves dual purposes: as a motor during vehicle operation and as a compression device to preheat the combustion chamber during cold starts. This self-service approach eliminates the need for dedicated heating devices or additional spark plugs, reducing system complexity while maintaining ignition reliability.
Solution Approach 2:
The electric motor is designed to perform multiple functions: propulsion assistance during normal operation and combustion chamber preheating during cold starts. This multi-functionality eliminates the need for separate dedicated components for each function, thereby reducing overall system complexity and cost.
2Reliability
If an additional conventional spark plug is added to enable stable combustion at low temperatures and low loads, then the reliability of ignition is improved, but the packaging size increases
Solution Approach 1:
The electric motor performs dual functions as both a propulsion device and a compression/heating device. By eliminating the need for additional spark plugs and associated mounting space, the overall packaging volume is reduced while maintaining ignition reliability during cold starts.
3Use of energy by moving object
If the primary fuel/air charge is made leaner to improve engine efficiency, then the energy efficiency is improved, but the ignition reliability deteriorates at cold start conditions
Solution Approach 1:
The electric motor performs preliminary compression and heating of the combustion chamber before the cold start occurs. This preliminary action raises the temperature and pressure in the combustion chamber, creating favorable conditions for igniting lean fuel/air charges during cold starts, thereby maintaining both efficiency and ignition reliability.
Solution Approach 2:
The electric motor temporarily changes the temperature and pressure parameters in the combustion chamber during cold starts. By elevating these parameters before ignition, the system enables reliable combustion of lean fuel/air charges that would otherwise be difficult to ignite at low temperatures.
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 solution reduces costs and packaging, enables TJI technology implementation on any engine without redesign, and ensures reliable ignition at cold starts and light loads by leveraging electric motor torque and heat recycling.
Implementation Method 1
control the one or more electric motors to generate drive torque to physically power the engine for a period to increase a temperature within the particular primary combustion chamber
Implementation Method 2
combust a pre-charge of fuel/air in a pre-chamber of a particular cylinder using a respective first spark plug and expel heat energy therefrom into a respective primary combustion chamber
Implementation Method 3
incorporating exhaust gas recirculation and valve control systems to recycle heat energy
Data Source
AI summary
Electrified powertrain control techniques include, in response to a detected cold start request for an engine, controlling one or more electric motors to generate drive torque to physically power an engine for a period to increase a temperature within a primary combustion chamber of a cylinder of the engine, and after the period, starting the engine by combusting a primary charge of fuel/air within the primary combustion chamber using a turbulent jet ignition (TJI) system to combust a pre-charge of fuel/air in a respective pre-chamber of the cylinder using a respective first spark plug and expelling heat energy therefrom into the primary combustion chamber of the cylinder, thereby eliminating a need for a respective second park plug of the TJI system that is associated with the cylinder and configured to heat and promote combustion within the primary combustion chamber.