Method for operating a refrigeration cycle device

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Solution Overview

Problem

HFO1123 refrigerant is prone to disproportionation under specific conditions of high temperatures and pressures, leading to adverse chemical reactions in refrigeration cycle apparatus.

Innovation Solution

A method using a zeotropic refrigerant mixture with a first refrigerant having a lower boiling point and a second refrigerant with a higher boiling point, where a component separation circuit separates and stores the mixed refrigerant to maintain a higher composition ratio of the high-boiling second refrigerant, thereby suppressing disproportionation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If HFO1123 refrigerant is used to achieve low GWP and good performance, then environmental benefits and refrigeration performance are improved, but the refrigerant is prone to disproportionation under high temperature and pressure conditions

Engineering Contradiction:
Improverefrigeration performanceVSAvoiddisproportionation reaction
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A component separation circuit is introduced as an intermediary system between the compressor and the refrigeration cycle. This circuit separates the refrigerant mixture into different components based on their boiling points, preventing the low-boiling-point HFO1123 from entering high-temperature zones where disproportionation occurs, while allowing high-boiling-point refrigerants to act as protective intermediaries in critical areas.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention changes the composition ratio parameter of the refrigerant mixture dynamically. By adjusting the proportion of high-boiling-point refrigerants in different circuit segments, the system optimizes performance while preventing disproportionation. The component separation circuit enables different composition ratios in different parts of the system, with higher concentrations of stable refrigerants in high-temperature zones.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the composition ratio of low-boiling-point refrigerant is increased to improve performance, then refrigeration efficiency is enhanced, but the risk of disproportionation increases under high temperature and pressure

Engineering Contradiction:
Improverefrigeration efficiencyVSAvoidchemical stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The invention applies different composition qualities to different locations in the refrigeration system. Low-boiling-point HFO1123 is concentrated in low-temperature zones where it provides superior refrigeration efficiency, while high-boiling-point refrigerants are concentrated in high-temperature zones near the compressor where they provide chemical stability and prevent disproportionation. This spatial differentiation of composition quality resolves the contradiction between efficiency and stability.

Inventive Principle:
Principle #3Local quality

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 method effectively reduces the composition ratio of the first refrigerant in critical areas, preventing disproportionation and ensuring high-performance operation of the refrigeration cycle apparatus while maintaining safety and efficiency.

Implementation Method 1

a zeotropic refrigerant mixture containing at least first refrigerant and second refrigerant having a higher boiling point than the first refrigerant at a same pressure

Methodology Applied
Scientific EffectZeotropic separation: Distillation

Implementation Method 2

separating and storing, by the component separation circuit, from the main circuit, mixed refrigerant containing the first refrigerant having a higher composition ratio

Methodology Applied
Scientific EffectBoiling point difference separation: Fractionation

Data Source

PatentEP3128257B1Method for operating a refrigeration cycle device
Publication Date: 2020.04.22 AGC INC
  • EP3128257B1 patent drawingFigure 1~2
  • EP3128257B1 patent drawingFigure 3~4

AI summary

An object of the present invention is to provide a safe and advanced refrigeration cycle apparatus that can prevent refrigerant that may cause disproportionation from being placed under the condition of serial reactions even when the refrigerant is used for the refrigeration cycle apparatus. A refrigeration cycle apparatus operating with standard composition refrigerant that is a zeotropic refrigerant mixture containing at least first refrigerant and second refrigerant having a higher boiling point than the first refrigerant at the same pressure, the refrigeration cycle apparatus including a main circuit in which a compressor, a first heat exchanger, an expansion valve, and a second heat exchanger are sequentially connected, and a component separation circuit connected to the main circuit, the first refrigerant having a property of disproportionation, the component separation circuit being configured to separate and store, from the main circuit, mixed refrigerant containing the first refrigerant having a higher composition ratio than in the standard composition refrigerant in an operation of a separation-storage mode separating the components of the standard composition refrigerant.