Reefer Unit Abnormality Detection From Pre-Trip Trend Data

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Solution Overview

Problem

The transporting refrigeration apparatus faces inaccurate abnormality determination due to varying operation conditions during container transportation, as the cargo and set temperature differ, leading to inconsistent operation of the refrigeration apparatus.

Innovation Solution

An abnormality determination device that uses time series test data from pre-trip inspections to identify changes in operation trends, determining abnormalities and estimating abnormality occurrence times by comparing polytropic indices and compressor current ratios across multiple test operating modes, thereby stabilizing the analysis despite varying conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If pre-trip inspection is conducted multiple times with different test operating modes, then the abnormality determination becomes more comprehensive, but the measurement precision deteriorates due to varying operation conditions

Engineering Contradiction:
Improveabnormality determination accuracyVSAvoidabnormality detection precision
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent segments the test operating modes into distinct categories (e.g., cooling mode, heating mode, idle mode) and performs separate abnormality determinations for each mode. By dividing the comprehensive inspection into mode-specific assessments, the system maintains high measurement precision within each mode while achieving comprehensive coverage across all operating conditions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the operational parameters (temperature settings, compressor speed, fan rotation) according to different test modes, and adjusts the abnormality determination criteria accordingly. For example, different temperature thresholds and performance ranges are applied for cooling versus heating modes, ensuring precise detection adapted to each operating condition.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If the refrigeration apparatus operates under different conditions during transportation, then the adaptability improves, but the abnormality determination accuracy deteriorates

Engineering Contradiction:
Improveoperation condition variabilityVSAvoidabnormality determination accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent implements dynamic abnormality determination that adapts to different operating conditions. The system automatically adjusts the reference values and thresholds based on the current test mode and actual operating parameters, allowing accurate abnormality detection whether the apparatus is in cooling, heating, or idle state during transportation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent modifies the determination parameters (temperature differentials, pressure ranges, current consumption levels) according to the specific operating mode. This ensures that the abnormality criteria are appropriately calibrated for each condition, maintaining high detection accuracy across diverse transportation scenarios.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3859251B1Abnormality determination device for transporting freezing device, transporting freezing device including this abnormality determination device, and abnormality determination method for transporting freezing device
Publication Date: 2023.09.13 DAIKIN INDUSTRIES LTD
  • EP3859251B1 patent drawingFigure 1
  • EP3859251B1 patent drawingFigure 2
  • EP3859251B1 patent drawingFigure 3

AI summary

An abnormality determination device for a transporting refrigeration apparatus includes a determination unit (67) that determines an abnormality of the transporting refrigeration apparatus (1) installed on a container. In pre-trip inspection that is conducted before the container is loaded on a transporting device, a test operation is performed for test operating modes. The pre-trip inspection is conducted multiple times. The abnormality determination device (60) is configured to obtain at least part of time series test data related to a same one of the test operating modes in the pre-trip inspection. The determination unit (67) is configured to determine whether the transporting refrigeration apparatus (1) has an abnormality based on a change trend of the time series test data related to a same one of the test operating modes when the pre-trip inspection is conducted multiple times, and when there is no abnormality, estimate an abnormality occurrence time.