Refrigeration cycle apparatus and refrigeration cycle system

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Solution Overview

Problem

Existing refrigeration apparatuses consume unnecessary energy due to continuous operation of air-blowing fans after refrigerant leakage detection, leading to increased indoor refrigerant concentration and potential safety issues with faulty or compromised refrigerant detection units.

Innovation Solution

Implementing a system where the air-blowing fan is triggered to stop once refrigerant leakage ceases, using a controller to monitor refrigerant concentration changes and prevent continuous operation, and ensuring that compromised detection units are not reused.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the air-blowing fan is driven continuously after refrigerant leakage detection, then the refrigerant concentration is prevented from increasing, but unnecessary energy is consumed

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

Solution Approach 1:

The controller continuously monitors the detection signal from the refrigerant detection unit and uses this feedback to dynamically control the air-blowing fan operation. When the detection signal indicates refrigerant leakage (first threshold exceeded), the fan is driven; when the signal returns to normal (below second threshold), the fan stops. This closed-loop feedback control ensures the fan operates only when necessary, preventing both refrigerant concentration buildup and unnecessary energy consumption.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system transitions from static continuous operation to dynamic conditional operation. The air-blowing fan's operational state is dynamically adjusted based on real-time refrigerant concentration detection, allowing the system to adapt its energy consumption to actual safety needs rather than maintaining constant operation.

Inventive Principle:
Principle #15Dynamics

2Use of energy by moving object

If the air-blowing fan is stopped when refrigerant detection returns to normal, then energy consumption is reduced, but refrigerant may leak again after stopping

Engineering Contradiction:
Improveenergy consumption of air-blowing fanVSAvoidrefrigerant leakage prevention
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The controller uses continuous feedback from the refrigerant detection unit to monitor refrigerant concentration levels. The fan is stopped only when the detection signal confirms that refrigerant concentration has returned to a safe level (below the second threshold), providing feedback-based confirmation that stopping the fan is safe and preventing premature cessation that could allow renewed leakage.

Inventive Principle:
Principle #23Feedback

3Productivity

If the refrigerant detection unit is kept in continuous use after exposure to refrigerant atmosphere, then detection capability is maintained, but detection characteristics are changed leading to false readings

Engineering Contradiction:
Improvedetection unit availabilityVSAvoiddetection characteristic accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The system performs preliminary assessment of the detection unit's operational status by evaluating the detection signal characteristics. When the detection unit has been exposed to refrigerant atmosphere, the controller identifies the change in detection characteristics and takes preliminary action to prevent false readings, such as extending the monitoring period or adjusting detection thresholds before resuming normal operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent acknowledges that refrigerant detection units have limited service life after exposure to refrigerant atmosphere due to characteristic changes. Rather than attempting to restore or recalibrate these units, the system effectively treats them as single-use components that should be replaced after exposure, prioritizing detection accuracy over component reuse.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

4Reliability

If the refrigerant detection unit is replaced after failure, then detection reliability is improved, but system complexity increases

Engineering Contradiction:
Improvedetection unit reliabilityVSAvoidsystem maintenance complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The controller continuously monitors the detection signal for signs of unit failure or characteristic degradation. When failure is detected through feedback analysis, the system automatically triggers a replacement protocol, simplifying the maintenance process by providing clear failure indicators and automated replacement guidance rather than requiring complex diagnostic procedures.

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

This solution prevents unnecessary energy consumption and reduces the risk of increased refrigerant concentration, ensuring safer operation by stopping the fan when leakage is no longer detected and preventing the reuse of faulty detection units.

Implementation Method 1

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

Methodology Applied
Scientific EffectGas 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 EffectForced convection: Forced Convection

Data Source

PatentEP3527916B1Refrigeration cycle apparatus and refrigeration cycle system
Publication Date: 2020.08.12 MITSUBISHI ELECTRIC CORP
  • EP3527916B1 patent drawingFigure 1
  • EP3527916B1 patent drawingFigure 2
  • EP3527916B1 patent drawingFigure 3

AI summary

Provided is a refrigeration cycle system, comprising: a refrigeration cycle apparatus comprising a refrigeration cycle (40) configured to circulate refrigerant, and a controller (30) configured to control the refrigeration cycle (40); and a refrigerant detection unit (605, 608) configured to detect the refrigerant. The controller (30) comprises a control board (615a, 616a) to which the refrigerant detection unit (605, 608) is unremovably connected. The controller (30) is configured to change the information stored in the leakage history storage area from the first information to the second information when detecting the leakage of the refrigerant, stop the compressor when the information stored in the leakage 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 leakage history storage area is changed from the second information to the first information by replacement of the control board.