Refrigeration cycle device and control method

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Solution Overview

Problem

Conventional refrigeration systems struggle to maintain both comfortable room temperature and humidity levels simultaneously, making it difficult to achieve optimal comfort conditions.

Innovation Solution

A refrigeration cycle device with independent control of indoor fan speed and compressor frequency, utilizing room temperature and evaporation temperature detectors, to individually manage room temperature and humidity through a control device that calculates optimal fan and compressor settings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional cooling operation is used to maintain room temperature, then room temperature comfort is improved, but room humidity control deteriorates

Engineering Contradiction:

Improveroom temperatureVSAvoidhumidity control capability

Core Design Contradiction:

TemperatureVSAdaptability or versatility

Solution Approach 1:

The patent divides the control functions into separate units: a room temperature control unit that controls the indoor fan based on room temperature, and an evaporation temperature control unit that controls the compressor based on evaporation temperature. This segmentation allows independent optimization of temperature and humidity control, resolving the contradiction where conventional single-mode control cannot simultaneously maintain both comfort temperature and comfortable humidity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system dynamically switches between different control modes (cooling operation and dehumidifying operation) based on real-time conditions. The room temperature control unit and evaporation temperature control unit operate with different control priorities and strategies, enabling the system to adapt its behavior to maintain both temperature and humidity within comfortable ranges under varying operating conditions.

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If dehumidifying operation is used to control room humidity, then humidity comfort is improved, but room temperature control deteriorates

Engineering Contradiction:

Improvehumidity control capabilityVSAvoidroom temperature

Core Design Contradiction:

Adaptability or versatilityVSTemperature

Solution Approach 1:

By separating the control functions into distinct room temperature control and evaporation temperature control units, the system can prioritize humidity control through the evaporation temperature control unit while the room temperature control unit independently manages temperature. This prevents the temperature deterioration that occurs in conventional dehumidifying operation.

Inventive Principle:

Principle #1Segmentation

3Device complexity

If single control mode is used for both temperature and humidity, then system simplicity is improved, but control precision deteriorates

Engineering Contradiction:

Improvecontrol system structureVSAvoidtemperature and humidity control precision

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The control device is segmented into functionally independent control units: a room temperature control unit with its own controller that calculates fan rotation speed, and an evaporation temperature control unit with its own controller that calculates compressor frequency. This segmentation enables precise independent control of temperature and humidity without significantly increasing overall system complexity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Both control units operate with feedback mechanisms: the room temperature control unit uses room temperature detection to adjust fan speed, and the evaporation temperature control unit uses evaporation temperature detection to adjust compressor frequency. This feedback control ensures high precision in maintaining both temperature and humidity at target values.

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

Enables simultaneous control of room temperature and humidity, ensuring comfortable conditions are maintained even under varying loads, enhancing dehumidification capacity and preventing operational discontinuities.

Implementation Method 1

a compressor that compresses a refrigerant

Methodology Applied

Scientific EffectCompression: Compression

Implementation Method 2

an evaporator; an evaporation temperature detector that detects an evaporation temperature of a refrigerant in the evaporator

Methodology Applied

Scientific EffectEvaporation: Evaporation

Data Source

PatentUS20250334311A1Refrigeration cycle device and control method

Publication Date: 2025.10.30 MITSUBISHI ELECTRIC CORP

AI summary

A refrigeration cycle device includes a compressor, a condenser, an expansion valve, an evaporator, an indoor fan, a control device that controls a rotation speed of the indoor fan and a frequency of the compressor, a room temperature detector that detects a room temperature, and an evaporation temperature detector that detects an evaporation temperature of a refrigerant in the evaporator. The control device includes a room temperature control unit that calculates the rotation speed of the indoor fan at which the room temperature is caused to approach a predetermined room temperature, and an evaporation temperature control unit that calculates the frequency of the compressor at which the evaporation temperature is caused to approach a predetermined refrigerant temperature. The room temperature is individually controlled by the indoor fan, and the evaporation temperature is individually controlled by the compressor.