Turbocharger Compressor Temperature Modeling Under Pumping Conditions

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Solution Overview

Problem

Existing methods for modeling compressor inlet and outlet temperatures in turbochargers fail to accurately account for compressor pumping, leading to deviations in turbocharger speed modeling, especially at maximum speeds, and do not consider the influence of compressor pumping on temperature corrections, which is critical for component protection and power management in internal combustion engines.

Innovation Solution

A method that determines pressure and mass flow gradients across the compressor to detect compressor pumping, using temperature correction factors and corrected pressure to model inlet and outlet temperatures, incorporating heat transfer effects and compressor pumping influences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If compressor pumping is not considered in temperature modeling, then the modeling is simpler, but the precision of compressor inlet and outlet temperature modeling deteriorates

Engineering Contradiction:
Improvecompressor temperature modeling precisionVSAvoidmodeling complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by detecting compressor pumping conditions before they significantly affect temperature modeling accuracy. The control unit continuously monitors pressure and mass flow gradients to identify pumping conditions in advance, then applies appropriate temperature correction factors proactively rather than reactively, improving modeling precision while maintaining manageable complexity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements parameter changes by introducing temperature correction factors that adjust the modeled temperature based on detected compressor pumping conditions. When pumping is detected (through pressure and mass flow gradient thresholds), the correction factor modifies the temperature calculation to account for the pumping effect, thereby improving precision without requiring a complete redesign of the modeling system.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If compressor pumping is not detected, then the detection system is simpler, but the accuracy of turbocharger speed modeling deteriorates

Engineering Contradiction:
Improveturbocharger speed modeling accuracyVSAvoiddetection system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses pressure gradient and mass flow gradient as intermediary parameters to detect compressor pumping indirectly. Instead of directly measuring pumping conditions, the control unit calculates gradients from readily available pressure and flow data, using these gradients as mediators to infer pumping status. This approach improves speed modeling accuracy while avoiding the need for complex direct pumping detection hardware.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces potential mechanical pumping detection mechanisms with a computational approach. By using the control unit to calculate pressure and mass flow gradients and compare them against thresholds, the system substitutes electronic/computational detection for what could have been mechanical sensors or direct mechanical measurement systems, achieving accurate detection with manageable complexity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If temperature correction factors dependent on compressor pumping are not used, then the control algorithm is simpler, but the reliability of component protection deteriorates

Engineering Contradiction:
Improvecomponent protection reliabilityVSAvoidcontrol algorithm complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements feedback by continuously monitoring pressure and mass flow gradients, detecting when compressor pumping conditions occur, and applying temperature correction factors accordingly. The control unit uses this feedback loop to adjust temperature modeling in real-time, ensuring reliable component protection by accounting for pumping effects when they are present, while keeping the algorithm simple by only activating corrections when needed rather than continuously.

Inventive Principle:
Principle #23Feedback

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

Enhances the precision of compressor temperature modeling by accurately accounting for compressor pumping, improving turbocharger speed modeling and enabling effective power management and component protection in internal combustion engines.

Implementation Method 1

a compressor (3) for compressing charge air for the internal combustion engine (2)

Methodology Applied
Scientific EffectAdiabatic compression: Adiabatic Heating

Implementation Method 2

Heat transfer effects and compressor pumping influences

Methodology Applied
Scientific EffectHeat transfer: Convection

Data Source

PatentEP3957845B1Method for modelling a compressor inlet temperature and / or a compressor outlet temperature of a compressor, a control device and a motor vehicle
Publication Date: 2026.04.08 VOLKSWAGEN AG
  • EP3957845B1 patent drawingFigure 1
  • EP3957845B1 patent drawingFigure 2
  • EP3957845B1 patent drawingFigure 2

AI summary

The invention relates to a method for modeling a compressor inlet temperature and/or a compressor outlet temperature of a compressor (3) taking into account compressor pumping, wherein the method comprises: - determining a pressure gradient (∇pv) across the compressor (3); - determining a mass flow gradient (∇ṁv,min) across the compressor (3); - determining that compressor pumping is present when the pressure gradient (∇pv) exceeds an upper pressure gradient limit (∇pv,lim) and the mass flow gradient (∇ṁv,min) falls below a lower mass flow gradient limit (∇ṁv,m); and - Determining the compressor inlet temperature (T1,α) with a temperature correction factor (ΔTVP,α) dependent on the compressor pumps and/or determining the compressor outlet temperature (T2) based on a corrected compressor outlet pressure (p2,α) that depends on the compressor pumps.