Radiant Panel Valve Fault Detection in Parallel Refrigerant Air Conditioners

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Solution Overview

Problem

In air conditioners with a refrigerant circuit connecting an indoor heat exchanger and a radiation panel in parallel, defects in the valve structure can lead to issues such as dew condensation and inappropriate radiation panel temperatures during different operating modes, due to improper refrigerant flow control.

Innovation Solution

An air conditioner design that includes a defect detector using temperature sensors to monitor the radiation panel and indoor heat exchanger temperatures, allowing for the detection of valve structure defects by comparing these temperatures and determining the open/close state of the valve, thereby preventing misidentification of refrigerant flow issues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the valve structure is used to control refrigerant flow to the radiation panel, then the radiation panel temperature can be adjusted for different operating modes, but defects in the valve structure cause improper refrigerant flow leading to dew condensation and inappropriate temperatures

Engineering Contradiction:
Improveoperating mode adjustmentVSAvoidvalve structure defect
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent implements a feedback mechanism by installing temperature sensors on both the radiation panel and indoor heat exchanger, and using a defect detector to compare their temperature differences. This feedback system monitors the actual refrigerant flow status and compares it against expected values, enabling automatic detection of valve defects and providing signals for corrective action, thus resolving the reliability issue while maintaining adaptability.

Inventive Principle:
Principle #23Feedback

2Reliability

If temperature sensors and defect detector are added to monitor radiation panel temperature, then valve structure defects can be detected, but the device complexity increases

Engineering Contradiction:
Improvedefect detection capabilityVSAvoidsensor and detector addition
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses the temperature difference between the radiation panel and indoor heat exchanger as an intermediary indicator to detect valve defects. Instead of directly monitoring valve status, the system measures temperatures at two points and uses their difference as a proxy for refrigerant flow status. This intermediary approach enables defect detection using simple temperature sensors and basic comparison logic, avoiding complex direct valve monitoring mechanisms.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If the radiation panel and indoor heat exchanger are connected in parallel in the refrigerant circuit, then flexible refrigerant flow control is achieved, but defects in the valve structure lead to refrigerant leaking to the wrong path

Engineering Contradiction:
Improverefrigerant flow controlVSAvoidrefrigerant leakage
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The parallel connection enables flexible refrigerant flow control, and the patent adds a feedback monitoring system using temperature sensors on both the radiation panel and indoor heat exchanger. The defect detector continuously compares temperature differences to detect when refrigerant is leaking to the wrong path, providing real-time feedback that allows the system to identify and respond to flow control failures, thus maintaining the benefits of parallel connection while mitigating harmful leakage effects.

Inventive Principle:
Principle #23Feedback

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 valve structure defects, preventing dew condensation and ensuring appropriate radiation panel temperatures during cooling, warm-air heating, and radiation heating operations, thereby enhancing the reliability and efficiency of the air conditioner.

Implementation Method 1

a panel temperature sensor 26...an indoor heat exchanger temperature sensor 27

Methodology Applied
Scientific EffectThermal energy measurement:

Implementation Method 2

the defect detector 73 detects occurrence of a defect in the indoor motor-operated valve 23, based on the panel pipe fitting temperature TP detected by the panel outgoing temperature sensor 26...and the indoor heat exchanger temperature Te detected by the indoor heat exchanger temperature sensor 27

Methodology Applied
Scientific EffectTemperature difference detection:

Implementation Method 3

the indoor heat exchanger 20...the radiation panel 30...evaporating the expanded refrigerant

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 4

a blower situated at the body and effecting service entrance of indoor air to the indoor heat exchanger

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP2667109B1Air conditioner
Publication Date: 2020.05.06 DAIKIN INDUSTRIES LTD
  • EP2667109B1 patent drawingFigure 1
  • EP2667109B1 patent drawingFigure 2
  • EP2667109B1 patent drawingFigure 3

AI summary

In order to detect abnormalities in a valve mechanism, this indoor unit has an indoor heat exchanger disposed inside the indoor unit, and a radiation panel disposed on the outer surface of the indoor unit. A refrigerant circuit connecting the indoor unit and an outdoor unit has: a principal channel on which an outdoor motor-operated valve (64), an outdoor heat exchanger, and a compressor (60) are disposed in that order; a first channel on which the indoor heat exchanger is disposed; and a second channel on which the radiation panel is disposed. The first channel, during heating operation, connects a branching section disposed downstream side of the compressor (60) on the principal channel, and a merging section disposed upstream side of the outdoor motor-operated valve (64). The second channel connects the branching section and the merging section to the first channel in parallel. An indoor motor-operated valve (23) is disposed on the second channel between the radiation panel and the merging section. In addition, an abnormality detector (73) for detecting abnormalities that occur in the indoor motor-operated valve (23) is provided.