Refrigerant Composition Transfer Method for Phase-Transition Stability

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Solution Overview

Problem

The challenge lies in maintaining the compositional integrity of refrigerant compositions containing difluoromethane, pentafluoroethane, and 1,1,2-tetrafluoroethane during transfer, as the phase transition leads to significant compositional changes due to varying boiling points, affecting performance and safety, and existing methods struggle to predict and control these changes effectively.

Innovation Solution

Adjusting the proportions of difluoromethane, pentafluoroethane, and 1,1,2-tetrafluoroethane in the refrigerant composition before transfer to specific ranges (e.g., 33.4-33.5 wt% for difluoromethane, 14.6-16.0 wt% for pentafluoroethane, and 50.5-52.0 wt% for 1,1,2-tetrafluoroethane) ensures that the compositional change during transfer remains within tolerance limits, even at high transfer rates, by transferring the composition from a liquid phase in an airtight container at temperatures below 40°C.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the refrigerant composition is extracted from the liquid phase during transfer, then the phase transition is avoided, but the compositional change of the liquid phase still occurs due to pressure decrease and gas phase expansion

Engineering Contradiction:
Improvecompositional stabilityVSAvoidperformance reliability
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The patent applies preliminary action by adjusting the component proportions in the refrigerant composition before transfer begins. Specifically, the composition is pre-adjusted to contain higher amounts of low-boiling-point components (HFC-32 and HFC-134a) and lower amounts of high-boiling-point component (HFC-125) compared to the final desired composition. This preliminary adjustment compensates for the expected compositional drift during transfer, ensuring that even after evaporation and phase transition effects occur, the final composition remains within acceptable tolerance ranges for performance and safety.

Inventive Principle:
Principle #10Preliminary action

2Stability of the object's composition

If the proportion of low boiling point components is increased in the supply source, then the compositional change during transfer is compensated, but the initial composition deviates from the target specification

Engineering Contradiction:
Improvecompositional stabilityVSAvoidcomposition precision
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by systematically varying the proportions of HFC-32, HFC-125, and HFC-134a in the refrigerant composition. The invention establishes specific numerical ranges for these components (e.g., HFC-32: 33.4-33.5 wt%, HFC-125: 14.6-16.0 wt%, HFC-134a: 50.5-52.0 wt%) that optimize the balance between compensating for transfer-induced compositional changes and maintaining acceptable initial composition. This quantitative parameter adjustment allows prediction and control of compositional drift during transfer while ensuring the final composition meets performance and safety specifications.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If the transfer rate is increased to improve efficiency, then the transfer time is reduced, but the compositional change due to phase transition becomes more significant

Engineering Contradiction:
Improvetransfer efficiencyVSAvoidcompositional stability
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The patent applies preliminary action by pre-adjusting the component proportions to account for high-rate transfer effects. The composition is formulated with elevated levels of low-boiling-point components before transfer begins, specifically compensating for the greater extent of evaporation and phase transition that occurs during rapid transfer operations. This allows high transfer rates to be maintained while still achieving final compositions within acceptable tolerance ranges.

Inventive Principle:
Principle #10Preliminary action

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 method ensures that the compositional change of the refrigerant composition during transfer falls within a predetermined tolerance range, thereby maintaining performance and safety standards, and preventing decreases in refrigerant efficiency or combustion risks.

Implementation Method 1

When the refrigerant composition undergoes phase transition, such as evaporation or condensation, a component having a low boiling point is likely to evaporate, while a component having a high boiling point is likely to condense

Methodology Applied
Scientific EffectPhase transition: Phase Change

Implementation Method 2

a component having a low boiling point is likely to evaporate

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP3521397B1Method for transfer-filling refrigerant composition
Publication Date: 2021.11.10 DAIKIN INDUSTRIES LTD
  • EP3521397B1 patent drawingFigure 1~2
  • EP3521397B1 patent drawingFigure 3

AI summary

Provided is a method for transferring a refrigerant composition containing three components (difluoromethane, pentafluoroethane, and 1,1,1,2-tetrafluoroethane) such that the compositional change of the liquid phase due to the phase transition that occurs in the supply source when transferring the refrigerant composition falls within a tolerance range. The method for transferring a refrigerant composition containing difluoromethane, pentafluoroethane, and 1,1,1,2-tetrafluoroethane includes transferring a refrigerant composition from a liquid phase in a supply source to a supply destination, wherein the liquid phase of the refrigerant composition in the supply source before the transfer contains 32.5 to 33.5 wt% of difluoromethane, 14.3 to 16.0 wt% of pentafluoroethane, and 50.5 to 53.2 wt% of 1,1,1,2-tetrafluoroethane.