Refrigeration cycle apparatus and refrigeration cycle system

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Solution Overview

Problem

Existing refrigeration apparatuses consume unnecessary energy and allow local refrigerant concentration increases due to inefficient fan operation and faulty refrigerant detection unit usage, with changed or failed sensors being continuously used.

Innovation Solution

A refrigeration cycle apparatus with a controller that operates an air-blowing fan based on refrigerant concentration changes and uses nonvolatile memory to track leakage and failure histories, ensuring the fan stops when refrigerant leakage ceases and faulty units are replaced.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the air-blowing fan is driven continuously until refrigerant concentration becomes zero, then refrigerant leakage is prevented, but unnecessary energy is consumed

Engineering Contradiction:
Improverefrigerant leakage preventionVSAvoidenergy consumption of air-blowing fan
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The controller continuously monitors refrigerant concentration through the detection unit and adjusts fan operation in real-time. When concentration drops below a threshold, the fan stops; when concentration rises again, the fan restarts. This closed-loop feedback system eliminates continuous operation while ensuring safety.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The fan operation transitions from static continuous running to dynamic on-demand operation. The system adapts fan speed and runtime based on real-time refrigerant concentration conditions, optimizing energy consumption while maintaining refrigerant safety.

Inventive Principle:
Principle #15Dynamics

2Use of energy by moving object

If the air-blowing fan is stopped after fixed time or manual switch, then energy consumption is reduced, but local refrigerant concentration may increase

Engineering Contradiction:
Improveenergy consumption of air-blowing fanVSAvoidlocal refrigerant concentration increase
Core Design Contradiction:
Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The detection unit provides continuous feedback on refrigerant concentration, allowing the controller to extend or maintain fan operation until concentration is truly safe. This prevents premature shutdown that would cause local concentration buildup.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system continues fan operation preliminarily beyond fixed time limits when detection units indicate elevated refrigerant levels. This ensures complete dispersion before shutdown, preventing subsequent concentration increases.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If the refrigerant detection unit is continuously used after exposure to refrigerant atmosphere, then detection capability is maintained, but detection characteristics change

Engineering Contradiction:
Improvecontinuous operation of detection unitVSAvoiddetection characteristics of sensor
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

When detection units show signs of degradation from refrigerant exposure, the system replaces them with fresh sensors. This ensures measurement precision is maintained while allowing continuous system operation through periodic sensor replacement.

Inventive Principle:
Principle #34Discarding and recovering

Solution Approach 2:

The system proactively replaces detection units before complete failure occurs, based on usage history and performance monitoring. This preliminary replacement prevents detection errors while maintaining continuous operational capability.

Inventive Principle:
Principle #10Preliminary action

4Device complexity

If the failed refrigerant detection unit is kept in continuous use, then system simplicity is maintained, but detection reliability decreases

Engineering Contradiction:
Improvesystem configuration simplicityVSAvoiddetection reliability of failed unit
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The system automatically detects sensor failures and replaces failed detection units with functional ones. This maintains system simplicity through automated management while ensuring detection reliability by removing failed components.

Inventive Principle:
Principle #34Discarding and recovering

Solution Approach 2:

The controller monitors detection unit health through feedback signals and automatically triggers replacement when failures are detected. This feedback-driven replacement maintains both simplicity and reliability.

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

Prevents unnecessary energy consumption and local refrigerant concentration increases by accurately stopping fan operation and replacing faulty detection units, ensuring safe and efficient operation.

Implementation Method 1

a refrigerant detection unit configured to detect a concentration of leaked refrigerant and to output a detection signal to the controller

Methodology Applied
Scientific EffectHot-wire type semiconductor gas sensor detection:

Implementation Method 2

refrigerant is diffused or exhausted by the air-blowing fan driven by the controller when a refrigerant leakage occurs

Methodology Applied
Scientific EffectAir blowing convection: Convection

Data Source

PatentEP3435007B1Refrigeration cycle apparatus and refrigeration cycle system
Publication Date: 2020.02.26 MITSUBISHI ELECTRIC CORP
  • EP3435007B1 patent drawingFigure 1
  • EP3435007B1 patent drawingFigure 2
  • EP3435007B1 patent drawingFigure 3

AI summary

Provided is a refrigeration cycle apparatus including: a refrigeration cycle (40, 310) configured to circulate refrigerant by a compressor (3); a heat exchanger unit (1, 2, 400, 300) configured to accommodate at least a heat exchanger (7, 202, 5, 201) of the refrigeration cycle (40, 310); and a controller (30, 301, 401) configured to control the heat exchanger unit (1, 2, 400, 300), the heat exchanger unit (1, 2, 400, 300) comprising a refrigerant detection unit (99) configured to detect the refrigerant; the controller (30, 301, 401) comprising a control board (31b) to which the refrigerant detection unit (99) is unremovably connected, and a nonvolatile memory provided on the control board (31b), the nonvolatile memory being provided with a first failure history storage area for storing any one of first information indicating a state of having no failure history in the refrigerant detection unit (99) and second information indicating a state of having a failure history in the refrigerant detection unit (99), wherein changing of the information stored in the first failure history storage area is allowed only in one way from the first information to the second information, and the controller (30, 301, 401) is configured to change the information stored in the first failure history storage area from the first information to the second information when the refrigerant detection unit (99) fails, stop the compressor when the information stored in the first failure history storage area is changed from the first information to the second information, and prevent the compressor from starting until the information stored in the first failure history storage area is changed from the second information to the first information by replacement of the control board.