Partial Cylinder Deactivation with Intake Throttling
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Solution Overview
Problem
Existing internal combustion engines face inefficiencies in fuel consumption and pollutant emissions due to the limitations of partial cylinder deactivation, particularly in diesel engines, where deactivated cylinders continue to participate in charge exchange, leading to increased charge exchange losses and reduced charge-air flow, which restricts the load range and effectiveness of partial deactivation.
Innovation Solution
The implementation of an internal combustion engine design with load-dependently switchable cylinders, equipped with inlet-side throttle elements to adjust charge-air flow and outlet valves to control exhaust gas discharge, allowing for reduced charge-air flow to deactivated cylinders and preventing backflow, thereby optimizing efficiency and reducing emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If partial cylinder deactivation is implemented in diesel engines, then fuel consumption is improved, but charge exchange losses increase and charge-air flow is reduced
Solution Approach 1:
The patent divides the multi-cylinder engine into two distinct groups: a first group of cylinders that remain permanently active, and a second group of cylinders that can be deactivated. This segmentation allows selective deactivation of specific cylinders while maintaining operation of others, thereby reducing fuel consumption during low-load conditions without requiring complete engine shutdown. The segmented approach enables partial deactivation strategy that improves overall fuel efficiency while managing charge exchange losses.
Solution Approach 2:
The patent implements dynamic control of cylinder deactivation based on real-time operating conditions. The control device continuously monitors engine load and dynamically adjusts which cylinders are deactivated, allowing the engine to adapt to varying load requirements. This dynamic approach enables the engine to maintain optimal efficiency across different operating conditions by switching between different cylinder activation patterns.
2Device complexity
If deactivated cylinders continue to participate in charge exchange, then engine structure is simplified, but charge-air flow is reduced and deactivation effectiveness is limited
Solution Approach 1:
The patent segments the engine's cylinder groups into those that participate in charge exchange and those that are isolated during deactivation. By providing separate intake and exhaust line arrangements for the first and second cylinder groups, the system enables selective isolation of deactivated cylinders from the charge exchange process, preventing charge-air flow reduction while maintaining structural simplicity.
Solution Approach 2:
The patent extracts the charge exchange function from deactivated cylinders by providing separate intake and exhaust pathways. When cylinders in the second group are deactivated, their intake and exhaust lines can be isolated or closed off, effectively taking out their participation in charge exchange. This extraction maintains overall engine structural simplicity while enhancing deactivation effectiveness by preventing charge-air flow reduction.
3Ease of operation
If throttle flap is closed further to reduce load, then load control is achieved, but pressure loss increases and efficiency decreases
Solution Approach 1:
The patent changes the fundamental parameter of load control from throttle flap positioning to cylinder deactivation. Instead of controlling load by closing the throttle flap (which increases pressure loss), the system controls load by selectively deactivating cylinders, thereby changing the effective displacement and power output without introducing additional throttling losses. This parameter change eliminates the trade-off between load control and pressure loss.
Data Source
AI summary
Methods and systems are provided for an internal combustion engine having at least two cylinders configured in such a way that they form two groups, at least one cylinder of a first group being a cylinder which is operational in the event of a partial deactivation of the engine, and at least one cylinder of a second group being formed as a load-dependently switchable cylinder. An inlet-side throttle element is provided with at least one intake line of the switchable cylinder, by means of which the size of the flow cross section of the intake line can be varied, whereby the charge-air flow rate supplied to the deactivated cylinder in the event of a partial deactivation of the engine can be adjusted. Each outlet opening of a load-dependently switchable cylinder is equipped with a partially variable valve drive, with an outlet valve which opens or shuts off the outlet opening.