Engine Oil Temperature Model Using Dilution Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Internal combustion engines, particularly spark-ignition engines, face challenges in accurately determining engine oil temperature due to fuel and inert gas dilution, which affects lubrication, viscosity, and heating behavior, leading to inaccuracies in oil temperature modeling and slow engine heating.
Innovation Solution
A method and system that uses an oil temperature model incorporating parameters like coolant temperature, air mass flow, and air/fuel ratio to account for dilution effects, with a boiling characteristic curve for each component mass stored in a control device, allowing for precise temperature determination and correction of heating behavior.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If fuel and inert gas pass into the crank casing via piston rings, then the engine operates normally, but the engine oil becomes diluted which slows down heating and reduces lubrication effectiveness
Solution Approach 1:
The patent implements a feedback mechanism by continuously monitoring engine operating parameters (coolant temperature, air mass flow, intake manifold pressure, air/fuel ratio) and using these inputs in an oil temperature model to dynamically calculate and correct oil temperature predictions, compensating for the dilution effect caused by fuel passing into the crank casing
Solution Approach 2:
The patent changes the parameters of the oil temperature model by incorporating multiple engine operating parameters (coolant temperature, air mass flow, intake manifold pressure, air/fuel ratio) and adjusting the model's correction factor based on these varying parameters to account for changing dilution conditions during engine operation
2Ease of operation
If fuel accumulates in the engine oil during cold operation, then the engine can be operated, but the oil temperature model does not correspond to the real profile, leading to inaccurate temperature determination
Solution Approach 1:
The patent uses feedback from multiple engine sensors (coolant temperature sensor, air mass flow sensor, intake manifold pressure sensor, air/fuel ratio sensor) to continuously update and correct the oil temperature model, ensuring accurate temperature determination despite fuel accumulation in the oil
Solution Approach 2:
The patent replaces the need for direct mechanical oil temperature measurement with a computational approach, using an oil temperature model that processes electrical signals from various sensors to calculate and predict oil temperature, substituting physical temperature sensing with mathematical modeling
3Measurement precision
If an oil temperature sensor is used to measure oil temperature, then accurate temperature data is obtained, but the device complexity and cost increase
Solution Approach 1:
The patent makes existing engine sensors serve multiple functions - the coolant temperature sensor, air mass flow sensor, intake manifold pressure sensor, and air/fuel ratio sensor are not only monitoring their primary parameters but also providing inputs for oil temperature calculation, eliminating the need for a dedicated oil temperature sensor
Solution Approach 2:
The engine's existing sensor system serves itself by providing data for oil temperature determination through the oil temperature model, making the system self-sufficient without requiring additional dedicated measurement devices for oil temperature
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 enhances the accuracy of engine oil temperature modeling, improves pilot control, and enables more precise torque determination and diagnostic capabilities by considering the influence of dilution on thermal conductivity and vapor pressures, applicable to both spark-ignition and diesel engines.
Implementation Method 1
When the internal combustion engine is heated to the operating temperature, the accumulated fuel begins to boil and becomes gaseous
Data Source
AI summary
Various embodiments include a method for determining the temperature of an engine oil in an internal combustion engine comprising: acquiring a value of a parameter characterizing a current operating point of the internal combustion engine; and calculating the temperature of the engine oil using an oil temperature model. The oil temperature model depends at least in part on dilution of the engine oil caused by different components in the engine oil and accounts for modified heating behavior of the engine oil based on the dilution.