Engine Oil Composition for Turbocharged Gasoline Preignition
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Solution Overview
Problem
Turbocharged downsized engines and premix combustion engines experience preignition issues, which are exacerbated by engine oils, leading to energy loss and restrictions on fuel efficiency and torque, while reducing metallic detergents compromises detergency and acid-neutralization performance.
Innovation Solution
A lubricating oil composition with controlled calcium borate content and specific additives is used to suppress preignition, maintaining detergency and acid-neutralization performance by limiting calcium oxide formation in the ash.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If engine oil is used in turbocharged downsized engines, then lubrication is provided, but preignition occurs leading to energy loss and reduced fuel efficiency
Solution Approach 1:
The patent changes the chemical composition parameters of the engine oil by controlling the calcium-to-magnesium detergent ratio (Ca/Mg ratio between 0.3-2.0) and limiting calcium oxide content in ash to 15 mass% or less. This parameter optimization suppresses preignition while maintaining lubrication performance in turbocharged downsized engines.
Solution Approach 2:
The patent uses a composite detergent system combining calcium detergents and magnesium detergents in specific proportions. This composite approach leverages the benefits of both detergent types while minimizing the harmful effects of calcium oxide formation, thereby reducing preignition energy loss.
2Object-affected harmful factors
If metallic detergent content is reduced to suppress preignition, then preignition is suppressed, but detergency and acid-neutralization performance deteriorate
Solution Approach 1:
The patent optimizes the Ca/Mg ratio parameter within 0.3-2.0 and controls total metallic detergent content while limiting calcium oxide in ash to 15 mass% or less. This parameter optimization maintains sufficient detergency and acid-neutralization performance while suppressing preignition.
Solution Approach 2:
The patent employs a composite detergent system with both calcium and magnesium detergents in balanced proportions. This composite formulation ensures adequate detergency and acid-neutralization capabilities while the controlled calcium oxide content suppresses preignition.
3Reliability
If calcium detergent content is increased to improve acid-neutralization, then acid-neutralization performance is improved, but preignition is exacerbated
Solution Approach 1:
The patent carefully balances the calcium detergent content by controlling the Ca/Mg ratio between 0.3-2.0 and limiting calcium oxide in ash to 15 mass% or less. This optimized parameter range provides sufficient acid-neutralization performance while minimizing preignition caused by excessive calcium oxide formation.
Solution Approach 2:
The patent uses a composite detergent system where calcium and magnesium detergents work synergistically. The magnesium detergent component helps suppress preignition while the calcium detergent provides acid-neutralization, achieving both goals simultaneously through proper formulation ratios.
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
The method effectively suppresses preignition without deteriorating detergency or acid-neutralization performance, even with high magnesium detergent levels, enhancing engine efficiency and reducing ash-related fouling.
Implementation Method 1
The internal combustion engine has a mean effective pressure of no less than 1.3 MPa, wherein an integrated intensity ratio of peaks of CaO in a X-ray diffraction spectrum of an ash is no more than 16.5%, the ash being obtained by incinerating the lubricating oil composition in an air at 950°C
Implementation Method 2
an integrated intensity ratio of peaks of CaO in a X-ray diffraction spectrum of an ash is no more than 16.5%
Data Source
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AI summary
A method for lubricating an internal combustion engine, the method comprising: supplying a specific lubricating oil composition to a cylinder of an internal combustion engine, wherein the internal combustion engine has a mean effective pressure of no less than 1.3 MPa; wherein an integrated intensity ratio of peaks of CaO in an X-ray diffraction spectrum of an ash is no more than 16.5%, the ash being obtained by incinerating the lubricating oil composition in an air at 950°C, and the internal combustion engine is a turbocharged gasoline engine.