Refrigerant Pipe Closure for False Leak Detection in Air Conditioners

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Solution Overview

Problem

Conventional air conditioning apparatuses face challenges in accurately determining whether refrigerant leakage sensor detection is erroneous, leading to potential further refrigerant leakage during the determination process, as they do not effectively close the refrigerant pipe before assessing the detection.

Innovation Solution

The air conditioning apparatus includes an outdoor unit, an indoor unit with a refrigerant leakage sensor, a refrigerant pipe, an opening/closing device, and a control unit that closes the pipe and operates the air blowing fan when the sensor detects a high refrigerant concentration, then determines if the detection is erroneous by monitoring changes in concentration after the pipe is closed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the refrigerant pipe remains open while determining whether detection is erroneous, then the determination process can proceed normally, but refrigerant leakage cannot be suppressed

Engineering Contradiction:
Improvereliability of erroneous detection determinationVSAvoidrefrigerant leakage
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The control unit closes the opening/closing device before initiating the erroneous detection determination process. This preliminary action ensures the refrigerant pipe is sealed prior to any operations that might cause leakage, allowing the system to safely determine whether the sensor detection is erroneous without risking further refrigerant loss.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system applies a counter-action by closing the refrigerant pipe before the determination process. This preventive measure counteracts the potential harmful effect of refrigerant leakage that could occur during the determination process, allowing safe evaluation of sensor accuracy.

Inventive Principle:
Principle #9Preliminary anti-action

2Reliability

If the air blowing fan operates continuously, then refrigerant leakage can be detected more quickly, but false detection increases in environments with smoke or gas

Engineering Contradiction:
Improvespeed of refrigerant leakage detectionVSAvoidaccuracy of refrigerant concentration detection
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The control unit operates the air blowing fan in periodic cycles rather than continuously. The fan operates for a predetermined time period, then stops, allowing the refrigerant concentration to stabilize. This periodic operation enables multiple measurements to be taken at different times, helping distinguish between actual refrigerant leakage and false detections caused by environmental factors like smoke or gas.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The control unit monitors refrigerant concentration over multiple time periods and uses this feedback to determine whether detection is erroneous. By comparing concentration readings taken at different times and conditions, the system can identify patterns that indicate false detection versus actual leakage, improving measurement precision.

Inventive Principle:
Principle #23Feedback

3Loss of time

If the determination process is simplified, then the system response time is reduced, but the accuracy of erroneous detection determination decreases

Engineering Contradiction:
Improvedetermination process timeVSAvoidaccuracy of erroneous detection determination
Core Design Contradiction:
Loss of timeVSMeasurement precision

Solution Approach 1:

The control unit performs a predetermined number of determination processes, which may be more than the minimum single check. This partial repetition of the determination process allows the system to gather sufficient data to accurately distinguish erroneous detection from actual leakage while maintaining a reasonable response time through automated sequential evaluation.

Inventive Principle:
Principle #16Partial or excessive 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

This configuration allows for more reliable suppression of refrigerant leakage and accurate determination of erroneous detection, even in environments filled with smoke or gas, by controlling the air direction plate and fan operation to prevent false alarms.

Implementation Method 1

a refrigerant leakage sensor configured to detect a refrigerant

Methodology Applied
Scientific EffectSensor detection:

Implementation Method 2

an air blowing fan, an air outlet for blowing out air fed by the air blowing fan

Methodology Applied
Scientific EffectFan-driven air movement: Fan

Implementation Method 3

an opening/closing device configured to open and close the refrigerant pipe

Methodology Applied
Scientific EffectMechanical valve closure: Valve

Data Source

PatentEP3869113B1Air conditioning apparatus
Publication Date: 2024.10.09 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP3869113B1 patent drawingFigure 1
  • EP3869113B1 patent drawingFigure 2
  • EP3869113B1 patent drawingFigure 3

AI summary

Provided is an air conditioning apparatus capable of determining whether detection of a refrigerant leakage sensor is erroneous detection while more reliably suppressing refrigerant leakage. An air conditioning apparatus 1 includes: an outdoor unit 20; an indoor unit 30 including an air blowing fan, an air outlet 310 for blowing out air fed by the air blowing fan, an air direction plate 320 capable of opening and closing the air outlet 310, and a refrigerant leakage sensor 307 configured to detect a refrigerant; a refrigerant pipe connecting the outdoor unit 20 and the indoor unit 30; an opening/closing device configured to open and close the refrigerant pipe; and a control unit 100 configured to, when the refrigerant leakage sensor 307 detects a refrigerant concentration higher than a predetermined value, close the opening/closing device and determine whether the detection of the refrigerant leakage sensor 307 is erroneous detection.