Lube Oil Controlled Ignition Combustion Engine
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Solution Overview
Problem
High-power density internal combustion engines using spark ignition or dual-fuel technologies experience abnormal combustion due to uncontrolled lubricating oil autoignition, which limits power density and is costly and complex, with existing methods like RCCI and PPCI requiring secondary fuel injection and having narrow engine load-speed windows.
Innovation Solution
Lube Oil Controlled Ignition (LOCI) utilizes the existing lubricating oil within the engine, directly injecting a small amount into the combustion chamber to achieve consistent autoignition, eliminating the need for secondary fuel and allowing for controlled combustion duration and a wide engine load-speed window through adaptive intake valve control timing based on lubricating oil autoignition temperature, fuel methane number, engine load, and compression ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If spark ignition or dual-fuel technologies are used to initiate combustion, then combustion can be initiated reliably, but abnormal combustion occurs due to uncontrolled lubricating oil autoignition
Solution Approach 1:
The patent converts the harmful effect of lubricating oil autoignition into a beneficial ignition source. By controlling the injection timing and quantity of lube oil, the system uses the oil's autoignition properties to reliably initiate combustion of the natural gas charge, transforming what was previously an uncontrolled harmful phenomenon into a controlled and useful ignition mechanism.
Solution Approach 2:
The patent changes key parameters including lube oil injection timing (delivered near top dead center), injection quantity (small controlled amounts), and compression ratio (optimized for autoignition). These parameter changes enable the lube oil to autoignite reliably at the desired moment, providing controlled ignition while preventing abnormal combustion.
2Reliability
If secondary fuel injection is used (RCCI, PPCI), then combustion control is improved, but device complexity and cost increase
Solution Approach 1:
The patent makes the lubricating oil serve multiple functions: it provides engine lubrication and simultaneously acts as the ignition source for combustion. This eliminates the need for separate secondary fuel injection systems required by RCCI or PPCI technologies, reducing device complexity while maintaining reliable combustion control.
Solution Approach 2:
The system uses the engine's existing lubricating oil, already present in the engine system, to perform the ignition function. This self-service approach eliminates the need for additional fuel storage, injection systems, and control mechanisms that would be required if a separate secondary fuel system were implemented.
3Productivity
If HCCI is used, then combustion efficiency is improved, but engine load-speed window becomes narrow
Solution Approach 1:
The patent introduces dynamic control of lube oil injection timing and quantity, allowing the system to adapt to different engine operating conditions. By adjusting the injection parameters in real-time based on engine load and speed, the system maintains efficient combustion across a wide operating range, overcoming the narrow window limitation of conventional HCCI.
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
LOCI prevents abnormal combustion, achieving consistent and efficient ignition with reduced secondary fuel usage and a broader operational window, enhancing engine efficiency and stability while minimizing exhaust emissions.
Implementation Method 1
a temperature greater than 800 K approaching the cylinder head and liner
Implementation Method 2
wherein the pre-mixed air-fuel mixture is burnt as a result of auto-ignition of the mist of lubricating oil present in the combustion volume
Data Source
AI summary
In certain embodiments, Lube Oil Controlled Ignition (LOCI) Engine Combustion overcomes the drawbacks of known combustion technologies. First, lubricating oil is already part of any combustion engine; hence, there is no need to carry a secondary fuel and to have to depend on an additional fuel system as in the case of dual-fuel technologies. Second, the ignition and the start of combustion rely on the controlled autoignition of the lubricating oil preventing the occurrence of abnormal combustion as experienced with the Spark Ignition technology. Third, LOCI combustion is characterized by the traveling of a premixed flame; hence, it has a controllable duration resulting in a wide engine load-speed window unlike the Homogeneous Charge Compression Ignition technology where the engine load-speed window is narrow. Adaptive Intake Valve Closure may be used to control in-cylinder compression temperature to be high enough to realize the consistent auto ignition of the lubricating oil mist.