Refrigeration Relay Unit Temperature-Based Indoor Unit Identification

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Solution Overview

Problem

Conventional refrigerating and air-conditioning apparatuses face challenges in identifying which indoor unit is connected to each branch port, requiring costly DIP switches and complex communication protocols, limiting compatibility between different manufacturers' units and increasing component costs.

Innovation Solution

The apparatus includes a relay unit with outlet and inlet temperature sensors for each branch port, allowing the relay-unit controller to identify connected indoor units based on temperature differences, eliminating the need for DIP switches and simplifying communication protocols.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If DIP switches are used to identify connected indoor units, then identification accuracy is improved, but device complexity and component cost increase

Engineering Contradiction:
Improveidentification accuracyVSAvoidcomponent cost
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical DIP switch system with a thermal field-based identification system. Temperature sensors detect heat medium temperature changes in the heat exchanger, and the control unit identifies connected indoor units based on these thermal patterns, eliminating mechanical setting components entirely.

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

Solution Approach 2:

The system performs self-identification of connected indoor units automatically during operation. The control unit monitors temperature changes in each heat exchanger and autonomously determines which indoor units are connected, without requiring manual configuration or external intervention.

Inventive Principle:
Principle #25Self-service

2Reliability

If DIP switches are used for setting connected-indoor-unit numbers, then identification reliability is improved, but ease of operation deteriorates due to troublesome setting tasks

Engineering Contradiction:
Improveidentification reliabilityVSAvoidsetting process
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The system automatically identifies connected indoor units by monitoring temperature changes in the heat medium flowing through each heat exchanger. The control unit processes thermal data and determines connections without requiring user intervention, making the system both reliable and easy to operate.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The control unit continuously monitors temperature feedback from sensors in each heat exchanger and uses this information to identify connected indoor units. This closed-loop feedback mechanism ensures reliable identification while eliminating manual setting operations.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If communication protocols are implemented for temperature data transmission, then measurement capability is improved, but device complexity increases due to protocol requirements

Engineering Contradiction:
Improvetemperature data transmissionVSAvoidcommunication protocol
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex communication protocol requirements with direct thermal field measurement. Temperature sensors physically detect temperature changes in the heat medium, and the control unit processes these analog signals locally, eliminating the need for sophisticated digital communication protocols between components.

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

4Adaptability or versatility

If flow control valves are controlled and temperature changes measured for automatic determination, then adaptability is improved, but device complexity increases due to communication requirements

Engineering Contradiction:
Improveautomatic determination capabilityVSAvoidcommunication system
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system uses thermal field detection instead of complex communication systems for automatic determination. Temperature sensors measure heat medium temperature changes directly at each heat exchanger, and the control unit processes these thermal signals to automatically identify connected indoor units without requiring inter-device communication protocols.

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

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 reduces component costs, simplifies the setting process, and enhances compatibility by automatically determining connected units, enabling seamless integration of indoor units from different manufacturers.

Implementation Method 1

a heat source device for supplying a refrigerant; an intermediate heat exchanger for exchanging heat between the refrigerant, supplied from the heat source device, and a heat medium such as water or antifreeze liquid

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

a use-side heat exchanger for exchanging heat between the heat medium and a thermal load; each use-side heat exchanger is accommodated in a respective indoor unit

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 3

outlet temperature sensors that are provided for the respective branch ports and each detect an outlet temperature of the heat medium flowing out of the branch port to the corresponding use-side heat exchanger

Methodology Applied
Scientific EffectTemperature detection: Temperature Gradient

Implementation Method 4

inlet temperature sensors that are provided for the respective branch ports and each detect an inlet temperature of the heat medium flowing into the branch port from the corresponding use-side heat exchanger

Methodology Applied
Scientific EffectTemperature detection: Temperature Gradient

Implementation Method 5

the relay-unit controller makes the indoor units operate on a one-by-one basis and identifies which of the indoor units is connected to the respective branch port on the basis of a difference between the inlet temperature and the outlet temperature at the respective branch port

Methodology Applied
Scientific EffectTemperature difference detection: Temperature Gradient

Data Source

PatentEP2682686B1Refrigeration and air-conditioning device
Publication Date: 2019.11.06 MITSUBISHI ELECTRIC CORP
  • EP2682686B1 patent drawingFigure 1
  • EP2682686B1 patent drawingFigure 2
  • EP2682686B1 patent drawingFigure 3

AI summary

A refrigerating and air-conditioning apparatus that achieves reduced limitations with respect to the communication of indoor units and can identify which indoor unit is connected to each branch port is obtained. Indoor units 2 are made to operate on a one-by-one basis, and it is identified which indoor unit 2 is connected to each branch port 6 on the basis of the difference between an inlet temperature and an outlet temperature at the branch port 6 at that time.