Refrigeration cycle device

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Solution Overview

Problem

Conventional refrigerating cycle devices face challenges in raising the compressor temperature efficiently, especially when the motor rotational speed exceeds a certain threshold, leading to suboptimal heating of the refrigerant.

Innovation Solution

A refrigerating cycle device with a compressor, motor, and wiring switch part that switches between different wiring states to manage efficiency, specifically switching to a lower efficiency state when the motor's rotational speed exceeds a predetermined value to increase compressor temperature and enhance refrigerant heating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the motor operates at high rotational speed with highest efficiency wiring state (delta connection), then energy efficiency is improved, but compressor temperature and refrigerant heating capability deteriorate

Engineering Contradiction:
Improvemotor energy efficiencyVSAvoidcompressor temperature
Core Design Contradiction:
Use of energy by moving objectVSTemperature

Solution Approach 1:

The patent applies dynamics by making the wiring state adjustable rather than fixed. The wiring switch part dynamically changes the motor's wiring configuration between delta connection (high efficiency) and star connection (lower efficiency, higher temperature) based on operational requirements such as defrosting mode or heating demand, allowing the system to adapt between efficiency and temperature generation needs

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the electrical parameter configuration of the motor by switching between different wiring states (delta and star connections). This parameter change alters both the efficiency characteristic and the temperature generation characteristic of the motor, enabling the system to optimize for either efficiency or heating capability depending on the operational scenario

Inventive Principle:
Principle #35Parameter changes

2Temperature

If the motor is operated with higher electrical current to heat up the motor, then refrigerant heating capability is improved, but energy efficiency deteriorates

Engineering Contradiction:
Improverefrigerant temperatureVSAvoidenergy efficiency loss
Core Design Contradiction:
TemperatureVSLoss of energy

Solution Approach 1:

The patent implements periodic switching between different operational modes. During defrosting or heating periods, the system switches to star connection to generate heat. During normal cooling operation periods, it switches to delta connection for efficiency. This periodic alternation between heating-focused and efficiency-focused modes allows the system to meet diverse operational requirements

Inventive Principle:
Principle #19Periodic 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

Effectively raises the compressor temperature and heats the refrigerant efficiently by switching to a lower efficiency wiring state at higher motor speeds, improving the heating process.

Implementation Method 1

The motor generates power for compressing the refrigerant by rotating a rotor with voltage applied to a plurality of wirings

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The wiring switch part switches between a plurality of wiring states by changing connection between the plurality of wirings

Methodology Applied
Scientific EffectElectrical resistance: Electrical Resistance

Implementation Method 3

the motor is operated with a higher electrical current and is therefore intentionally heated up to increase the compressor discharge temperature

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP3786544B1Refrigeration cycle device
Publication Date: 2022.05.04 MITSUBISHI ELECTRIC CORP
  • EP3786544B1 patent drawingFigure 1
  • EP3786544B1 patent drawingFigure 2
  • EP3786544B1 patent drawingFigure 3

AI summary

A refrigerating cycle device includes a compressor (111), a motor, and a wiring switch part (116). The compressor compresses a refrigerant. The motor generates power for compressing the refrigerant by rotating a rotor with voltage applied to a plurality of wirings. The motor is disposed in the compressor (111). The wiring switch part (116) switches between a plurality of wiring states by changing connection between the plurality of wirings. When a rotational speed of the rotor exceeds a predetermined value, the wiring switch part (116) switches to a first wiring state of the plurality of wiring states. The first wiring state differs from a second wiring state of the plurality of wiring state. Efficiency of the second wiring state is highest at the rotational speed.