Compressor Abnormality Detection Using Multi-Period Index Comparison

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Solution Overview

Problem

In typical refrigeration cycle apparatuses, determining compressor deterioration requires specific refrigerant conditions matching initial and elapsed installation times, necessitating a special operation that disrupts normal cooling operations.

Innovation Solution

An abnormality determination device calculates a deviation degree from normal state using index values from different operational periods, allowing for compressor abnormality determination or estimation of abnormality occurrence time without a special operation, using data from normal operations and pre-trip inspections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a special operation is performed to determine compressor deterioration by comparing operation state amounts at reference time and elapsed time, then the determination accuracy is improved, but normal cooling operation is disrupted

Engineering Contradiction:
Improvedetermination accuracyVSAvoidoperational efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The system performs preliminary actions by continuously collecting and storing operation state amounts during normal operation before deterioration determination is needed. This allows the reference time data to be automatically prepared in advance during regular cooling operations, eliminating the need for special pre-determination operations that would disrupt productivity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system maintains continuity of useful action by performing compressor deterioration determination during normal cooling operation without interruption. The control unit continuously acquires operation state amounts and performs comparisons in real-time, allowing both cooling function and deterioration determination to occur simultaneously without disrupting operational efficiency.

Inventive Principle:
Principle #20Continuity of useful action

2Reliability

If the refrigerant condition at reference time matches the refrigerant condition at elapsed time, then the determination reliability is improved, but a special operation is required

Engineering Contradiction:
Improvedetermination reliabilityVSAvoidoperational simplicity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The system uses feedback by continuously monitoring refrigerant conditions and operation state amounts, storing them for later comparison. The control unit retrieves stored reference time data and compares it with current elapsed time data, automatically determining whether refrigerant conditions match. This eliminates the need for manual special operations while maintaining determination reliability through systematic data comparison.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-service by automatically managing the entire deterioration determination process without requiring special manual operations. The control unit autonomously acquires data, stores reference values, retrieves them when needed, compares operation state amounts, and determines compressor status. This automation maintains determination reliability while simplifying operation significantly.

Inventive Principle:
Principle #25Self-service

3Reliability

If operation state amounts are compared between reference time and elapsed time, then compressor deterioration can be detected, but the system complexity increases

Engineering Contradiction:
Improvedeterioration detection capabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The control unit performs multiple functions: it controls the compressor operation, monitors refrigerant conditions, stores operation state amounts, retrieves stored data, compares current and reference values, and determines deterioration status. By making the control unit universal and multi-functional, the system achieves reliable deterioration detection without adding separate dedicated hardware components, thus limiting the increase in system complexity.

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

Data Source

PatentEP3859250B1Abnormality determination device, freezing device including this abnormality determination device, and abnormality determination method for compressor
Publication Date: 2022.11.16 DAIKIN INDUSTRIES LTD
  • EP3859250B1 patent drawingFigure 1
  • EP3859250B1 patent drawingFigure 2
  • EP3859250B1 patent drawingFigure 3

AI summary

An abnormality determination device (60) includes a calculator (66) calculating a deviation degree of a compressor (11) from a normal state based on data related to operation of a refrigeration apparatus (1) and a determination unit (62) determining whether the compressor (11) has an abnormality or estimating an abnormality occurrence time based on a calculation result of the calculator (66). The calculator (66) calculates a first index value from data related to operation of the refrigeration apparatus (1) in a first period and a second index value from data related to operation of the refrigeration apparatus (1) in a second period that differs in length from the first period. The calculator (66) calculates the deviation degree of the compressor (11) from the normal state based on the first index value and the second index value. The determination unit (62) determines whether the compressor (11) has an abnormality or estimates an abnormality occurrence time based on the deviation degree of the compressor (11) from the normal state.