Separate-Circuit Heat Medium Relay Unit for Refrigerant Isolation

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Solution Overview

Problem

Conventional air-conditioning systems face issues with refrigerant leakage into indoor spaces, high energy consumption due to long heat medium circulation paths, complex and costly configurations, and high failure rates of heat medium flow control devices, which affect safety and serviceability.

Innovation Solution

A heat medium relay unit with a heat exchanger, heat medium flow control devices, and flow switching devices that separate the refrigerant and heat medium circuits, allowing controlled heat medium circulation without refrigerant in indoor units, reducing energy consumption and improving ease of maintenance and safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If refrigerant is circulated to indoor units, then cooling and heating operations can be performed, but refrigerant leakage into indoor spaces occurs

Engineering Contradiction:

Improvecooling and heating operation capabilityVSAvoidrefrigerant leakage into indoor space

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The system is divided into two separate circulation circuits: a refrigerant circuit that remains confined to the outdoor unit, and a heat medium circuit that serves the indoor units. This segmentation isolates the refrigerant to a safe location while maintaining the cooling and heating functions through the heat medium in indoor units.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A heat medium (such as water or brine) is introduced as an intermediary substance that transfers thermal energy from the refrigerant in the outdoor unit to the indoor units without directly contacting the refrigerant. This intermediary eliminates the risk of refrigerant leakage into indoor spaces while preserving the desired cooling and heating effects.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If heat medium circulation path is extended to reach indoor units, then cooling and heating can be provided to indoor spaces, but energy consumption due to conveyance power increases

Engineering Contradiction:

Improveindoor space cooling and heating capabilityVSAvoidenergy consumption for heat medium conveyance

Core Design Contradiction:

Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

Multiple indoor units are connected to share a common heat medium circulation system rather than having separate circulation paths. This merging reduces the total length of circulation pipes and the number of pumps required, thereby lowering the energy consumption for heat medium conveyance while still providing cooling and heating to multiple indoor spaces.

Inventive Principle:

Principle #5Merging (Combining)

3Measurement precision

If heat medium flow control devices are disposed inside the structure, then control precision can be improved, but ease of maintenance deteriorates

Engineering Contradiction:

Improveheat medium flow control precisionVSAvoidmaintenance accessibility of flow control devices

Core Design Contradiction:

Measurement precisionVSEase of repair

Solution Approach 1:

The heat medium flow control devices are positioned at the boundary between the indoor and outdoor units, utilizing the outdoor unit's exterior surface as a mounting location. This dimensional placement allows the devices to be externally accessible for maintenance while still effectively controlling heat medium flow to indoor units through integrated connection points.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

4Ease of repair

If heat medium flow control devices are disposed outside the structure, then ease of maintenance can be improved, but control precision deteriorates

Engineering Contradiction:

Improvemaintenance accessibility of flow control devicesVSAvoidheat medium flow control precision

Core Design Contradiction:

Ease of repairVSMeasurement precision

Solution Approach 1:

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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

The solution enhances safety by preventing refrigerant leakage and reduces energy consumption by optimizing heat medium circulation, while improving serviceability through easier maintenance of heat medium flow control devices.

Implementation Method 1

a heat exchanger that exchanges heat between a refrigerant in a refrigerant circuit in which the refrigerant is circulated by being discharged from a compressor provided in an outdoor unit and a heat medium, which is different from the refrigerant, in a heat medium circuit

Methodology Applied

Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP2629022B1Heating medium relay unit

Publication Date: 2020.02.19 MITSUBISHI ELECTRIC CORP

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AI summary

Obtained is a heat medium relay unit capable of having improved serviceability and an air-conditioning apparatus equipped with the heat medium relay unit. Heat medium flow control devices 25 are each disposed below a corresponding one of the first heat medium flow switching devices 22. The heat medium flow control devices 25 are similarly disposed in a zigzag manner along with the zigzag arrangement of the first heat medium flow switching devices 22.