Compressor system with multiple compressor elements and associated operating method

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Solution Overview

Problem

Existing compressor systems with multiple compressor elements face inefficiencies due to imbalanced lubricant distribution and excessive lubricant circulation during part load operations, leading to operational imbalances and reduced compression efficiency.

Innovation Solution

A compressor system with an equalization line connecting the suction sides of multiple compressor element housings, featuring an equalization valve that opens during full load operation to allow fluid and lubricant flow for pressure equalization and closes during part load operation to prevent lubricant redistribution, ensuring optimized lubricant distribution and preventing unwanted recirculation of refrigerant gas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the equalisation line remains open during part load operation, then pressure equalisation is maintained, but lubricant redistributes excessively from the inactive compressor element housing, causing imbalanced lubrication and reduced compression efficiency

Engineering Contradiction:
Improvepressure equalisationVSAvoidcompression efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The equalisation valve transitions from a static open state to a dynamically controlled component that switches between open and closed states based on operational load conditions. During full load operation, the valve remains open to maintain pressure equalisation between compressor element housings. During part load operation with one compressor element inactive, the valve closes to prevent excessive lubricant redistribution, thereby maintaining optimal lubrication levels and compression efficiency in the active compressor element.

Inventive Principle:
Principle #15Dynamics

2Stability of the object's composition

If the equalisation line remains open during part load operation, then fluid communication is maintained, but recirculation of refrigerant gas occurs, leading to unwanted lubricant circulation and operational inefficiencies

Engineering Contradiction:
Improvefluid communicationVSAvoidoperational efficiency
Core Design Contradiction:
Stability of the object's compositionVSLoss of energy

Solution Approach 1:

The equalisation valve dynamically adjusts fluid communication based on operational conditions. During full load operation, the valve remains open to maintain fluid communication and pressure equalisation between compressor element housings. During part load operation when one compressor element is inactive, the valve closes to prevent recirculation of refrigerant gas and unwanted lubricant circulation through the equalisation line, thereby eliminating energy losses and improving operational efficiency.

Inventive Principle:
Principle #15Dynamics

3Productivity

If the equalisation valve closes during part load operation, then lubricant distribution is optimised, but pressure equalisation between compressor element housings is reduced

Engineering Contradiction:
Improvecompression efficiencyVSAvoidpressure equalisation
Core Design Contradiction:
ProductivityVSStress or pressure

Solution Approach 1:

The equalisation valve implements dynamic pressure management by adapting its state to operational load conditions. During full load operation with both compressor elements active, the valve remains open to maintain pressure equalisation between housings. During part load operation with one compressor element inactive, the valve closes to prevent pressure imbalances that would cause excessive lubricant flow, thereby optimising lubricant distribution and maintaining compression efficiency in the active element.

Inventive Principle:
Principle #15Dynamics

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 enhances volumetric compression efficiency by maintaining optimal lubricant distribution during full load operations while preventing imbalances and inefficiencies associated with excessive lubricant circulation during part load operations, resulting in improved system performance.

Implementation Method 1

an equalisation line that fluidly connects the first and second compressor element housings at the suction side in order to allow for equalisation of pressure between the first and second compressor element housings

Methodology Applied
Scientific EffectPressure equalisation: Pressure Gradient

Implementation Method 2

an equalisation valve on the equalisation line for opening and closing the connection between the first and second compressor element housings via the equalisation line

Methodology Applied
Scientific EffectValve control: Valve

Implementation Method 3

a first compressor element for compression of the refrigerant fluid, a second compressor element for compression of the refrigerant fluid

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP3855093B1Compressor system with multiple compressor elements and associated operating method
Publication Date: 2023.07.19 CARRIER CORP
  • EP3855093B1 patent drawingFigure 1~2b

AI summary

A compressor system 12 is provided for compression of refrigerant fluid. The compressor system 12 comprises first and second compressor elements 2, 6, with first and second compressor element housing 4, 8. An equalisation line 28 fluidly connects the first and second compressor element housings 4, 8 at the suction side in order to allow for equalisation of pressure between the first and second compressor element housings 4, 8 as well as flow of lubricant between the compressor element housings 4, 8. An equalisation valve 60 on the equalisation line 28 is used to open and close the connection between the first and second compressor element housings 4, 8. The compressor system 12 is arranged for full load operation using both the first and second compressor elements 2, 6 as well as for part load operation in which one of the compressor elements 2, 6 is not utilised. The equalisation valve is opened during full load operation and is closed during part load operation to thereby prevent movement of lubricant and/or refrigerant fluid between the first and second compressor element housings 2, 6 during part load operation.