Hydrodynamic Coupling for Compressor Speed Regulation

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Solution Overview

Problem

Compressor systems face inefficiencies in regulating delivery volume and pressure, leading to high energy consumption and limited flexibility, especially in partial load ranges, due to limitations in control methods and design, which are exacerbated by geographical and environmental conditions.

Innovation Solution

A compressor system incorporating a pre-compressor and main compressor with a hydrodynamic fluid coupling allows for independent speed adjustment of the pre-compressor, enabling variable volume flow and pressure regulation, and intermediate cooling to optimize efficiency and flexibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional electric motors are used to drive compressors, then the drive speed is determined by mains frequency, but the ability to regulate delivery volume is insufficient

Engineering Contradiction:
Improvedelivery volume regulationVSAvoidspeed control flexibility
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

A hydrodynamic coupling is introduced as an intermediary device between the electric motor and the compressor. This coupling allows independent speed adjustment of the compressor from the motor, enabling continuous delivery volume regulation without affecting the motor's fixed speed operation. The hydrodynamic coupling acts as a speed variator that decouples the motor speed from the compressor speed.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the intake controller is closed to reduce volume flow, then the delivery volume is reduced to almost zero, but the drive power consumption remains very high

Engineering Contradiction:
Improvevolume flow controlVSAvoiddrive power consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The system dynamically adjusts the compressor speed via the hydrodynamic coupling to match the actual delivery requirements. Instead of using a fixed-speed motor with throttling control, the compressor speed can be continuously varied to operate efficiently across different load conditions, maintaining optimal power consumption at each operating point.

Inventive Principle:
Principle #15Dynamics

3Productivity

If frequency-controlled drives are used to regulate compressor speed, then volume flow regulation is improved, but the efficiency deteriorates in the partial load range

Engineering Contradiction:
Improvevolume flow regulationVSAvoidefficiency in partial load range
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The hydrodynamic coupling serves as a mechanical intermediary that enables smooth, stepless speed variation without the energy losses associated with frequency converters. The fluid coupling transmits power hydrodynamically, maintaining high efficiency across the entire speed range, especially in partial load conditions where frequency converters suffer from low efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Temperature

If liquid injection is used in screw compressors, then cooling effect is achieved, but hydraulic losses increase significantly at higher speeds

Engineering Contradiction:
Improvecooling effectVSAvoidhydraulic losses
Core Design Contradiction:
TemperatureVSLoss of energy

Solution Approach 1:

The system changes the operating parameters by enabling variable speed operation. Instead of operating at fixed high speed with liquid injection causing hydraulic losses, the compressor speed can be optimized for each operating condition. At lower speeds, liquid injection cooling is more effective with reduced hydraulic losses, while at higher speeds the system can adjust accordingly.

Inventive Principle:
Principle #35Parameter changes

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 configuration achieves up to 15% improvement in overall efficiency, reduces manufacturing costs, and expands the operational range by allowing flexible adjustment of operating pressures and volume flows, while maintaining high performance across varying environmental conditions.

Implementation Method 1

A compressor system with pre-compressor (20) and main compressor (30) has a hydrodynamic fluid coupling (55)

Methodology Applied
Scientific EffectHydrodynamic coupling: Hydraulic Press

Implementation Method 2

intermediate cooling to optimize efficiency

Methodology Applied
Scientific EffectHeat removal: Cooling

Data Source

PatentEP3146215B1Multi-stage compressor with hydrodynamic coupling
Publication Date: 2018.12.26 WENZEL HARALD
  • EP3146215B1 patent drawingFigure 1
  • EP3146215B1 patent drawingFigure 2

AI summary

A compressor system for producing a compressed gas, more particularly air, comprising at least one main compressor (30) which is supplied with pre-compressed gas with the aid of a pre-compressor (20), wherein the at least one main compressor (30) and also the at least one pre-compressor (20) are driven by a shared drive motor (40) or by separate drives, and at least one pre-compressor (20) is linked to a fluid coupling (55) that changes the drive speed of the pre-compressor (20).