Early Intake Valve Closing Oil Consumption Control
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Solution Overview
Problem
Early intake valve closing in internal combustion engines during Miller cycling can lead to reduced in-cylinder pressure below crankcase pressure, causing oil consumption issues due to operational challenges.
Innovation Solution
A multi-cylinder internal combustion engine system that uses a Variable Geometry Turbine (VGT) and other means to increase intake manifold pressure when in-cylinder pressure drops below crankcase pressure, including operating an EGR pump, bypassing the low-pressure turbine of a two-stage turbocharger, bleeding air from the brake system, and utilizing an electric compressor, all controlled by a sensor system to prevent oil consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If early intake valve closing is used for Miller cycling, then efficiency improves and NOx reduces, but in-cylinder pressure drops below crankcase pressure causing oil consumption
Solution Approach 1:
The patent applies preliminary anti-action by increasing intake manifold pressure before the early intake valve closing event occurs. This pre-pressurization prevents the in-cylinder pressure from dropping below crankcase pressure during the expansion stroke, thereby counteracting the oil consumption problem before it occurs. The intake manifold pressure is elevated in advance through turbocharger control or other pressure increase mechanisms.
Solution Approach 2:
The patent changes the pressure parameter of the intake manifold by increasing it above normal operating levels. This parameter change ensures that even when the intake valve closes early and the cylinder volume increases, the starting pressure in the cylinder is high enough to prevent pressure from falling below crankcase pressure, thus preventing oil consumption while maintaining Miller cycle efficiency.
2Object-generated harmful factors
If early intake valve closing is used for Miller cycling, then NOx emissions reduce, but in-cylinder pressure drops below crankcase pressure causing operational challenges
Solution Approach 1:
The system applies preliminary anti-action by pre-increasing the intake manifold pressure before early intake valve closing occurs. This ensures that the in-cylinder pressure maintains adequate levels throughout the cycle, preventing the reliability issues associated with pressure dropping below crankcase pressure, while preserving the NOx reduction benefits of Miller cycling.
Solution Approach 2:
The patent modifies the pressure parameter of the intake system by elevating intake manifold pressure. This parameter change enables the engine to operate reliably with early intake valve closing by ensuring pressure remains above crankcase pressure, while maintaining the emissions benefits of the Miller cycle.
3Loss of substance
If intake manifold pressure is increased to prevent oil consumption, then oil consumption reduces, but system complexity increases due to additional control mechanisms
Solution Approach 1:
The patent utilizes multi-functionality by employing existing engine components, such as the turbocharger, for an additional function. The turbocharger not only provides normal forced induction but is also controlled to increase intake manifold pressure specifically during early intake valve closing conditions to prevent oil consumption. This avoids adding dedicated complexity while solving the oil consumption problem.
Solution Approach 2:
The system applies self-service by using the engine's own existing infrastructure to solve its problem. The intake system and turbocharger, already present for normal operation, are leveraged to provide the additional pressure needed during Miller cycle operation with early intake valve closing, eliminating the need for separate dedicated pressure increase mechanisms.
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
Effectively reduces or prevents oil consumption by maintaining adequate intake manifold pressure during early intake valve closing, enhancing the operational efficiency and emissions control of the engine.
Implementation Method 1
a VGT for receiving an exhaust flow from the plurality of cylinders... control operation of the VGT to increase intake manifold pressure
Implementation Method 2
operating of an exhaust gas recirculation (EGR) pump... to increase intake manifold pressure
Data Source
AI summary
Systems, apparatus, and methods are disclosed that include an internal combustion engine having a plurality of cylinders and controlling the intake manifold pressure during early intake valve opening to reduce or prevent oil consumption.