Refrigeration device and method for detecting filling of wrong refrigerant

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Solution Overview

Problem

In refrigeration apparatuses, incorrect refrigerant charging can lead to reduced refrigeration capacity, abnormal pressure increases, and potential damage due to incompatibility, as operators may mistakenly charge a different refrigerant, which existing systems fail to detect reliably.

Innovation Solution

A method and apparatus that determine the saturation temperature characteristics of the charged refrigerant by deriving them from pressure and temperature, issuing an alarm if different from the normal refrigerant, and prohibiting operation if incompatible, ensuring accurate detection and prevention of capacity decreases or damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If refrigerant charging is performed manually by operator, then charging operation can be completed, but risk of charging wrong refrigerant type increases

Engineering Contradiction:
Improverefrigerant charging operationVSAvoidrefrigerant type accuracy
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system measures pressure and temperature of the charged refrigerant, derives saturation temperature characteristics, and compares them with stored characteristics of the correct refrigerant type. This feedback mechanism automatically verifies whether the correct refrigerant has been charged, eliminating reliance on manual operator accuracy while maintaining ease of operation.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces manual visual identification and operator judgment with an automated measurement and comparison system. Pressure and temperature sensors automatically detect refrigerant properties, and a processor compares these measurements against stored reference data, substituting human judgment with objective instrumental measurement.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If saturation temperature characteristics are derived and compared, then wrong refrigerant detection accuracy improves, but system complexity increases

Engineering Contradiction:
Improverefrigerant identification accuracyVSAvoiddetection system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system uses existing pressure and temperature sensors already present in the refrigeration apparatus for their primary cooling control functions, and simultaneously utilizes these same measurements for refrigerant type identification. This multi-functionality approach avoids adding dedicated detection hardware, thereby improving measurement precision without proportionally increasing device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent transforms readily available pressure and temperature parameters into saturation temperature characteristics through mathematical derivation. By comparing these derived characteristics against stored reference profiles, the system achieves high refrigerant identification accuracy using simple computational processing rather than complex physical measurement apparatus.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If alarm and prohibition mechanisms are implemented, then prevention of damage improves, but operational convenience decreases

Engineering Contradiction:
Improvedamage preventionVSAvoidsystem operation convenience
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The system performs refrigerant type verification immediately after charging is completed, before the refrigeration apparatus is started for normal operation. By detecting wrong refrigerant types in advance and issuing alarms or prohibition signals before startup, the system prevents damage without interfering with the actual operation of the refrigeration function.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The control unit acts as an intermediary between the refrigerant charging process and the refrigeration operation. It mediates by verifying refrigerant type characteristics and conditionally permitting or prohibiting startup based on the verification result, thereby preventing damage while maintaining operational convenience for legitimate cases.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 effectively detects and prevents issues related to incorrect refrigerant charging, ensuring reliable operation and preventing damage by accurately identifying and addressing deviations in refrigerant characteristics, thus enhancing the reliability of refrigeration apparatuses.

Implementation Method 1

a characteristics determiner (101) configured to derive saturation temperature characteristics of a refrigerant charged into the refrigerant circuit (20) from a pressure and a temperature of the refrigerant

Methodology Applied
Scientific EffectPressure measurement:

Implementation Method 2

a heat exchanger temperature detector and a pressure detector. At the time of stopping its operation, when a temperature of the exchanger is detected by the temperature detector

Methodology Applied
Scientific EffectTemperature detection:

Implementation Method 3

the pressure detector detects a pressure in the cycle at that time

Methodology Applied
Scientific EffectPressure detection:

Data Source

PatentEP2801772B1Refrigeration device and method for detecting filling of wrong refrigerant
Publication Date: 2021.03.17 DAIKIN INDUSTRIES LTD
  • EP2801772B1 patent drawingFigure 1
  • EP2801772B1 patent drawingFigure 2
  • EP2801772B1 patent drawingFigure 3

AI summary

A method for detecting whether a different refrigerant has been charged into a refrigeration apparatus (10) including a refrigerant circuit (20) includes: a charging step of charging a refrigerant into the refrigerant circuit (20); a characteristics determination step of determining whether saturation temperature characteristics of the refrigerant charged in the charging step are identical to saturation temperature characteristics of a previously determined normal refrigerant, the saturation temperature characteristics of the refrigerant being derived from a pressure and a temperature of the refrigerant; and an alerting step of, when, in the characteristics determination step, a determination is made that the saturation temperature characteristics of the charged refrigerant are different from those of the normal refrigerant, issuing an alarm indicating that the charged refrigerant is different from the normal refrigerant.