Turbo Compressor Surge Prevention via Valve Actuation Control

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Solution Overview

Problem

Internal combustion engines (ICE) face instability and damage due to compressor surge, which occurs when the mass flow of air varies periodically, potentially reversing direction and causing undesirable operating regions that can lead to noise and damage.

Innovation Solution

A method and control arrangement that limit valve actuation changes of the exhaust and intake valves based on compressor data, including surge limit data, to maintain a turbo compressor mass flow above a limit mass flow value, preventing operation in unstable regions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If valve actuation changes are increased to improve engine performance, then engine power and efficiency are improved, but compressor surge risk increases causing instability and damage

Engineering Contradiction:

Improveengine powerVSAvoidcompressor stability

Core Design Contradiction:

PowerVSReliability

Solution Approach 1:

The patent implements dynamic adjustment of valve actuation parameters (timing, duration, lift) based on real-time compressor operating conditions. The control system continuously monitors compressor mass flow and pressure ratio, and dynamically modifies valve actuation changes to maintain compressor operation within stable regions while optimizing engine performance. This dynamic control resolves the contradiction by adapting valve actuation to current compressor state rather than using fixed actuation patterns.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes physical parameters of valve actuation (timing angle, duration, lift magnitude) based on compressor operating parameters. By adjusting these actuation parameters in response to compressor mass flow and pressure ratio measurements, the system maintains engine performance while preventing compressor surge. The parameter changes enable the system to operate at the boundary between stable and unstable compressor regions without entering the surge zone.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If valve actuation is limited to prevent compressor surge, then compressor stability is improved, but engine performance and productivity deteriorate

Engineering Contradiction:

Improvecompressor stabilityVSAvoidengine output

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent employs feedback control where the control system continuously monitors compressor operating parameters (mass flow, pressure ratio) and adjusts valve actuation accordingly. The feedback loop compares actual compressor operation against stable operating regions and modifies valve actuation changes in real-time. This feedback mechanism allows the system to maintain compressor stability while maximizing engine output by operating at the optimal boundary of stable compressor regions rather than using conservative fixed limits.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system dynamically determines the maximum allowable valve actuation changes based on current compressor operating conditions. Rather than applying fixed conservative limits that reduce engine performance, the system calculates and applies the largest valve actuation changes that keep the compressor within stable operating regions. This dynamic optimization resolves the contradiction by enabling higher productivity when compressor conditions permit while maintaining stability when conditions are marginal.

Inventive Principle:

Principle #15Dynamics

3Adaptability or versatility

If compressor operating range is expanded to improve engine versatility, then adaptability is improved, but risk of operating in unstable regions increases

Engineering Contradiction:

Improveengine adaptabilityVSAvoidcompressor surge risk

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent uses preliminary action by pre-establishing compressor surge maps and stable operating region boundaries before actual engine operation. These pre-characterized stable regions are stored in the control system and used to guide valve actuation decisions. By having the stable operating regions predetermined and available before operation, the system can safely expand into broader compressor operating ranges while avoiding unstable regions, thus improving adaptability without increasing surge risk.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The feedback control system continuously monitors actual compressor operation against pre-established stable operating regions. When the compressor approaches the boundaries of stable regions during expanded operation, the feedback mechanism automatically adjusts valve actuation to maintain operation within stable zones. This real-time feedback enables the system to operate with high versatility across wide compressor ranges while the protective feedback control prevents entry into unstable surge regions.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS12146446B2Controlling valve actuation of an internal combustion engine to prevent compressor surge

Publication Date: 2024.11.19 SCANIA CV AB

AI summary

The disclosure concerns a method and a control arrangement for controlling valve actuation of an ICE comprising an exhaust valve, an intake valve, and a turbo compressor. The method comprises and the control arrangement is configured to: limiting/limit valve actuation changes of the exhaust and intake valves based on compressor data including surge limit data for the turbo compressor and one or both of a current turbo compressor rotational speed and a current turbo compressor pressure ratio, to maintain a turbo compressor mass flow above a limit mass flow value.