Compressor Piston Dummy for Liquid Cooling

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Solution Overview

Problem

Generic compressors with liquid pistons face inefficiencies due to reduced heat transfer and cooling effects at the top dead center area, leading to decreased thermal efficiency in the compression process.

Innovation Solution

A piston dummy is integrated within the liquid piston chamber, accelerating the liquid and enhancing heat transfer through turbulent flow when reaching top dead center, ensuring better cooling and efficient liquid discharge.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the liquid surface is kept smooth to prevent liquid exit and optimize dead space, then reliability is improved, but heat transfer and cooling effect deteriorate

Engineering Contradiction:
Improveprevention of liquid exitVSAvoidcooling effect
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The liquid piston is segmented into two functional parts: a smooth outer surface that contacts the cylinder wall (preventing liquid exit) and an inner piston dummy with turbulent surface features (enhancing heat transfer). This segmentation allows simultaneous achievement of reliability and cooling effectiveness.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different surface qualities are applied to different locations: the outer liquid surface maintains smoothness for reliable sealing, while the inner piston dummy surface introduces turbulence promoters for enhanced local heat transfer at the hottest area (top dead center).

Inventive Principle:
Principle #3Local quality

2Temperature

If external cooling jackets are added to improve cooling capacity, then temperature control is improved, but device complexity increases

Engineering Contradiction:
Improvecooling capacityVSAvoidcooling system structure
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The liquid piston serves dual functions: it acts as both the compressing medium and the cooling medium. By inducing turbulence within the liquid piston itself, the system achieves self-cooling without requiring separate external cooling jackets or additional cooling systems.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The liquid piston is designed to perform multiple functions simultaneously: compression, sealing, and cooling. The piston dummy integrated within the liquid piston enables the liquid to provide its own cooling through internal turbulence, eliminating the need for dedicated cooling components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Temperature

If the liquid is accelerated in the annular gap at top dead center, then heat transfer is improved, but liquid discharge efficiency may deteriorate

Engineering Contradiction:
Improveheat transferVSAvoidliquid discharge efficiency
Core Design Contradiction:
TemperatureVSProductivity

Solution Approach 1:

The piston dummy is designed to dynamically interact with the liquid at different stroke phases: at top dead center it creates turbulence for heat transfer, while during the discharge phase it allows smooth liquid flow through its optimized geometry, ensuring both cooling and discharge efficiency.

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

The compressor achieves improved cooling at the top dead center area, reducing compression temperatures and energy requirements, thereby increasing overall efficiency.

Implementation Method 1

the liquid is accelerated in the annular gap defined by the piston dummy and the piston chamber wall... a turbulent flow is also formed in the liquid

Methodology Applied
Scientific EffectTurbulent flow: Turbulence

Implementation Method 2

the liquid is in contact with the cylinder head to be cooled for longer than in the case of the prior art compressor designs. Due to the acceleration of the liquid in the annular gap, a turbulent flow is also formed in the liquid, which results in an additional cooling effect.

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP2430316B1Compressor with a dummy piston
Publication Date: 2014.01.22 LINDE AG
  • EP2430316B1 patent drawingFigure 1~3

AI summary

The invention relates to a compressor comprising a liquid which can be displaced in a piston chamber and which acts as a piston. According to the invention, a piston dummy (5) is arranged in the liquid (3) and can displace with said liquid. Said piston dummy (5) is preferably embodied such that when the top dead point is reached, said piston dummy accelerates the liquid (3) in the annular gap which it defines with the piston chamber wall.