Refrigeration Cycle State Analyzer Using Segmented p-h Chart Regions

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Solution Overview

Problem

Existing air-conditioning apparatus state analyzer systems face difficulties in accurately diagnosing the factor and degree of abnormality due to variations in refrigeration cycle charts, making it challenging for users to identify issues without specialized knowledge.

Innovation Solution

A state analyzer system that displays specific state information and normal regions on a p-h chart, allowing users to visually recognize the position of specific state information relative to the normal region, facilitating easy diagnosis of abnormalities in the air-conditioning apparatus.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If refrigeration cycle charts are displayed on a p-h chart to analyze air-conditioning apparatus state, then the state information can be visualized, but it becomes difficult to diagnose the factor and degree of abnormality due to shape differences caused by various environmental factors

Engineering Contradiction:
Improvestate information visualizationVSAvoidabnormality diagnosis difficulty
Core Design Contradiction:
Loss of informationVSDifficulty of detecting and measuring

Solution Approach 1:

The patent divides the refrigeration cycle analysis into multiple discrete points along the cycle path. Instead of analyzing the entire cycle chart as a single entity, the system segments the cycle into specific state points (such as evaporator outlet, compressor inlet, etc.) and evaluates each point independently against predefined normal ranges. This segmentation allows for precise identification of which specific portion of the cycle is abnormal, making diagnosis much easier despite environmental variations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transforms the visual shape comparison problem into a parameter-based evaluation by measuring specific parameters (pressure, temperature, enthalpy) at discrete points along the refrigeration cycle. By converting the qualitative shape difference into quantitative parameter deviations from normal values, the system can objectively diagnose abnormalities regardless of overall cycle shape variations caused by environmental factors.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the entire refrigeration cycle chart is compared for shape differences, then overall state changes can be observed, but the specific factor and degree of abnormality cannot be easily identified

Engineering Contradiction:
Improveoverall state monitoringVSAvoiddiagnosis ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent segments the refrigeration cycle into multiple specific state points and evaluates each point independently. This allows the system to maintain reliable overall state monitoring while making the diagnosis process easier by identifying exactly which segment is abnormal and by how much, rather than requiring users to interpret overall shape differences.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary evaluation layer that compares measured state points against predefined normal range data. This intermediary layer translates complex cycle chart variations into simple pass/fail evaluations at each point, making the diagnosis process easier while maintaining reliable overall monitoring through cumulative point assessment.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If non-overlap ratio between refrigeration cycle charts is used to determine maintenance necessity, then a quantitative metric is obtained, but the specific abnormality factor and degree remain unclear

Engineering Contradiction:
Improvemaintenance determination precisionVSAvoidabnormality factor information
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent segments the cycle evaluation into multiple discrete state points, each contributing to the overall maintenance determination. Instead of a single non-overlap ratio for the entire cycle, the system calculates deviations at each point, providing both precise quantitative measurement for maintenance timing and specific information about which cycle portion is abnormal.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent adds a dimensional aspect to the evaluation by measuring not just the overall deviation (non-overlap ratio) but also the positional distribution of deviations along the cycle path. This multi-dimensional approach preserves both the quantitative precision needed for maintenance scheduling and the qualitative information about abnormality factors.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP3745055B1State analysis system and state analysis device
Publication Date: 2024.03.06 MITSUBISHI ELECTRIC CORP
  • EP3745055B1 patent drawingFigure 1
  • EP3745055B1 patent drawingFigure 2
  • EP3745055B1 patent drawingFigure 3~4

AI summary

Provided is a state analysis device and a state analyzer system that include a specific state determination unit configured to determine specific state information representing a state of refrigerant at a specific position in a refrigeration circuit and a normal region determination unit configured to determine a normal region in a state space within which the specific state information is present when an air-conditioning apparatus operates under a normal state. The state analysis device and the state analyzer system allow a display unit to display the specific state information and the normal region.