Refrigeration cycle device

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Solution Overview

Problem

Existing refrigeration cycle apparatuses lack efficient control over heat exchange in air and refrigerant heat exchangers, limiting their ability to achieve high-efficiency operation across varying outdoor air temperatures.

Innovation Solution

A refrigeration cycle apparatus with a controller that adjusts the heat exchange in both air and refrigerant heat exchangers based on outdoor air temperature, using a combination of air heat exchangers and refrigerant-refrigerant heat exchangers to optimize subcooling and reduce electrical input, featuring a compressor, condenser, subcooling devices, and a bypass channel for efficient refrigerant flow control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a refrigerant-refrigerant heat exchanger is used for adjusting capability or controlling high pressure, then reliability is improved, but the device cannot achieve high-efficiency operation across varying outdoor air temperatures due to lack of subcooling control

Engineering Contradiction:
Improvecompressor reliabilityVSAvoidoperational efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The subcooling function is divided into two separate heat exchangers: a first subcooling device (air heat exchanger) for efficient heat exchange control and a second subcooling device (refrigerant-refrigerant heat exchanger) for reliability. This segmentation allows each device to specialize in its strength while working together to resolve the contradiction between reliability and efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The controller dynamically switches between using the first subcooling device primarily (for efficiency) and the second subcooling device primarily (for reliability) based on outdoor air temperature conditions. This multi-functional approach allows the system to adapt to different operating conditions and achieve both efficiency and reliability as needed.

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

2Device complexity

If subcooling control is not implemented, then device complexity is reduced, but efficient operation cannot be achieved across varying outdoor air temperatures

Engineering Contradiction:
Improvecontrol system complexityVSAvoidoperational efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The controller receives feedback from outdoor air temperature sensors and automatically adjusts the operation of the two subcooling devices accordingly. This feedback mechanism enables efficient operation across varying temperatures without requiring complex manual intervention or overly complicated control systems.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system uses the outdoor air temperature itself as the control parameter, allowing the environment to dictate the optimal operating mode. The controller automatically determines whether to prioritize the first or second subcooling device based on temperature conditions, enabling self-adjusting efficient operation without external intervention.

Inventive Principle:
Principle #25Self-service

3Device complexity

If only one type of heat exchanger is used, then device complexity is reduced, but the system cannot optimize both efficiency and reliability under different operating conditions

Engineering Contradiction:
Improveheat exchanger configurationVSAvoidadaptability to operating conditions
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The system dynamically switches between different heat exchanger configurations based on outdoor air temperature. At certain temperature ranges, the first subcooling device is activated; at other ranges, the second subcooling device takes precedence. This dynamic adaptability allows the system to optimize performance across varying conditions without requiring a permanently complex fixed configuration.

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 enables high-efficiency operation by optimizing subcooling ratios and reducing electrical input, thereby minimizing power consumption and enhancing the coefficient of performance (COP) while maintaining stable control across different operating conditions.

Implementation Method 1

an air heat exchanger that causes heat exchange between the air and refrigerant

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

a refrigerant-refrigerant heat exchanger that causes heat exchange between refrigerants

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 3

a compressor 2, a condenser 3, a reservoir 5

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP2913608B1Refrigeration cycle device
Publication Date: 2022.11.23 MITSUBISHI ELECTRIC CORP
  • EP2913608B1 patent drawingFigure 1
  • EP2913608B1 patent drawingFigure 2
  • EP2913608B1 patent drawingFigure 3A~3C

AI summary

A refrigeration cycle apparatus includes a compressor 2, a condenser 3, a first subcooling device 6 configured to cause heat exchange between refrigerant and air and to subcool the refrigerant, a second subcooling device 8 configured to cause heat exchange between first and second streams of the refrigerant obtained by branching by a branch pipe 14 and to subcool the first stream of the refrigerant, a flow control device 12 configured to adjust a flow rate of the second stream of the refrigerant, which is obtained by the branching, and to cause the second streams of the refrigerant to pass through the second subcooling device, a bypass path 11 that allows the refrigerant passing through the flow control device 12 and the second subcooling device 8 to flow therethrough, an expansion valve 9, an evaporator 10, all of which are connected by a refrigerant pipe and constitute a refrigerant circuit, and a controller 20 configured to control an amount of heat exchanged in the first subcooling device 6 and an amount of heat exchanged in the second subcooling device 8 based on a temperature of the air.