Refrigeration cycle device and refrigeration cycle system

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Solution Overview

Problem

Semiconductor gas sensors used for refrigerant detection experience changes in detection characteristics when exposed to gases for extended periods, leading to potential overlooking of leaks or false detections, which can result in increased indoor refrigerant concentrations.

Innovation Solution

A refrigeration cycle apparatus and system that includes a controller which operates an air-sending fan to diffuse leaked refrigerant and stops electric supply to the refrigerant detection unit when the fan's rotation speed exceeds a threshold, reducing the detection unit's exposure time and maintaining its characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the electric refrigerant detection unit is continuously supplied with electricity to maintain detection capability, then the detection reliability is improved, but the detection characteristics change due to long-term exposure to gases

Engineering Contradiction:
Improvedetection reliabilityVSAvoiddetection characteristics
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent implements periodic action by controlling the electric refrigerant detection unit to operate only during necessary detection periods rather than continuously. The controller activates the detection unit when refrigerant leakage is suspected and deactivates it when not needed, thereby maintaining detection reliability while preventing characteristic degradation from prolonged gas exposure.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent applies discarding and recovering by temporarily deactivating the electric refrigerant detection unit after it has served its detection purpose. The controller manages the power supply to the detection unit, cutting power when detection is complete and restoring it when needed again, thus preserving the unit's detection characteristics while maintaining operational reliability.

Inventive Principle:
Principle #34Discarding and recovering

2Speed

If the air-sending fan operates at high rotation speed to rapidly diffuse leaked refrigerant, then the safety response speed is improved, but the energy consumption increases

Engineering Contradiction:
Improverefrigerant diffusion speedVSAvoidenergy consumption
Core Design Contradiction:
SpeedVSUse of energy by moving object

Solution Approach 1:

The patent implements dynamics by enabling the air-sending fan to variable its rotation speed according to operational conditions. The controller adjusts the fan speed dynamically - operating at high speed when refrigerant leakage is detected to ensure rapid diffusion, and at lower speeds during normal operation to reduce energy consumption, thus balancing safety response with energy efficiency.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent applies parameter changes by modifying the rotation speed parameter of the air-sending fan based on system state. The controller changes the fan's operational parameters (rotation speed) in response to detection signals, increasing speed for rapid refrigerant diffusion when needed and decreasing speed for energy conservation during normal conditions.

Inventive Principle:
Principle #35Parameter changes

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 approach reduces the change in detection characteristics of the refrigerant detection unit, ensuring reliable leak detection and preventing local increases in refrigerant concentration, thereby enhancing safety and efficiency.

Implementation Method 1

the indoor air-sending fan is rotated when the leakage of the refrigerant is detected so that indoor air is sucked through an air inlet formed in the casing of the indoor unit and air is blown off to the indoor space through an air outlet. In this manner, the leaked refrigerant can be diffused.

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3321607B1Refrigeration cycle device and refrigeration cycle system
Publication Date: 2019.12.25 MITSUBISHI ELECTRIC CORP
  • EP3321607B1 patent drawingFigure 1
  • EP3321607B1 patent drawingFigure 2
  • EP3321607B1 patent drawingFigure 3

AI summary

Provided is a refrigeration cycle apparatus including a refrigerant circuit configured to circulate refrigerant, a heat exchanger unit accommodating a heat exchanger of the refrigerant circuit, and a controller configured to control the heat exchanger unit, in which the heat exchanger unit includes an air-sending fan, and an electric refrigerant detection unit, the controller is configured to operate the air-sending fan when the controller detects leakage of the refrigerant on the basis of a detection signal from the electric refrigerant detection unit, and the controller is configured to stop electric supply to the electric refrigerant detection unit when a rotation speed of the air-sending fan becomes equal to or larger than a first threshold value under a state in which the electric refrigerant detection unit is supplied with electricity.