Low pressure refrigerant system

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Solution Overview

Problem

Existing chiller systems face contamination issues due to air leaks, which degrade performance, and existing purge units are complex and lose refrigerant during the removal process.

Innovation Solution

A refrigeration system incorporating a gas permeable membrane with a porous inorganic material to separate contaminants from refrigerant, using a retentate return flow path and a prime mover to exhaust contaminants, while maintaining refrigerant circulation and controlling the purge operation based on pressure and temperature sensors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing purge units use a vapor compression cycle to separate non-condensable contaminant gas from refrigerant, then contaminants can be removed from the system, but the purge units become complicated and refrigerant is lost in the process

Engineering Contradiction:
Improvecontaminant removal effectivenessVSAvoidpurge unit complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the contaminant separation function from the complex vapor compression cycle and implements it through a simple membrane separation unit. The membrane selectively allows non-condensable gases to pass through while retaining refrigerant, achieving contaminant removal without the complexity of compression and phase change equipment.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The membrane acts as an intermediary component that selectively separates contaminants from refrigerant based on permeability differences. This intermediary mechanism replaces the need for complex vapor compression equipment while maintaining effective separation, and the retentate return flow path ensures refrigerant is recovered and returned to the system.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If existing purge units use a vapor compression cycle to separate contaminants, then non-condensable gases can be removed, but refrigerant is lost during the process

Engineering Contradiction:
Improvecontaminant removal effectivenessVSAvoidrefrigerant loss
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent applies the discarding and recovering principle by separating contaminants through the membrane while recovering the refrigerant in the retentate stream. The retentate return flow path ensures that refrigerant that passes through the membrane or is retained is returned to the heat transfer fluid circulation loop, preventing refrigerant loss while maintaining effective contaminant removal.

Inventive Principle:
Principle #34Discarding and recovering

3Productivity

If air leaks are allowed to occur in low pressure chiller sections, then system operation continues, but refrigerant performance degrades due to contamination

Engineering Contradiction:
Improvesystem continuous operationVSAvoidchiller performance
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent implements continuous contaminant removal through the membrane separation unit, which operates continuously alongside the heat transfer fluid circulation. This continuous separation action maintains refrigerant purity over time, preventing performance degradation while allowing the system to operate continuously even in the presence of air leaks.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The system uses sensors to detect contaminant levels and system performance parameters, providing feedback that triggers the purge system to activate when contamination reaches threshold levels. This feedback mechanism ensures refrigerant purity is maintained within acceptable ranges, preserving chiller performance while allowing continuous operation.

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

Effectively removes contaminants like nitrogen and oxygen from the refrigerant without losing refrigerant, enabling continuous operation and improved system performance by promoting contaminant separation and retention within the system.

Implementation Method 1

The membrane includes a porous inorganic material with pores of a size to allow passage of contaminants through the membrane and restrict passage of the refrigerant through the membrane

Methodology Applied
Scientific EffectPermeation: Permeation

Implementation Method 2

The membrane includes a porous inorganic material with pores of a size to allow passage of contaminants through the membrane and restrict passage of the refrigerant through the membrane

Methodology Applied
Scientific EffectMolecular sieve: Molecular Sieve

Data Source

PatentEP3483526B1Low pressure refrigerant system
Publication Date: 2020.05.20 CARRIER CORP
  • EP3483526B1 patent drawingFigure 1
  • EP3483526B1 patent drawingFigure 2~3
  • EP3483526B1 patent drawingFigure 4~5

AI summary

Disclosed is a refrigeration system including a heat transfer fluid circulation loop configured to allow a refrigerant to circulate therethrough, a purge outlet from the heat transfer fluid circulation loop, and at least one gas permeable membrane having a first side in communication with the purge outlet. The membrane includes a porous inorganic material with pores of a size to allow passage of contaminants through the membrane and restrict passage of the refrigerant through the membrane. A retentate return flow path connects the first side of the membrane to the heat transfer fluid circulation loop.