Building comprising an air conditioner

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Solution Overview

Problem

Conventional air-conditioning systems for buildings face challenges such as refrigerant leakage into indoor spaces, high energy consumption due to long circulation paths of heat media, complex and costly configurations, and the inability to use flammable refrigerants safely due to leakage risks.

Innovation Solution

An air-conditioning apparatus with a heat medium relay unit that exchanges heat between a flammable refrigerant and a different heat medium, located in a non-air conditioned space, reducing the number of pipings and allowing for the use of flammable refrigerants with low global warming potential, while preventing refrigerant leakage into indoor spaces through ventilation and controlled circulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a refrigerant is circulated to an indoor unit in a conventional air-conditioning apparatus, then cooling or heating can be provided to the air conditioned space, but the refrigerant may leak into the indoor space causing safety issues

Engineering Contradiction:
ImprovesafetyVSAvoidrefrigerant leakage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a heat medium relay unit that acts as an intermediary between the refrigerant circuit and the indoor units. The refrigerant exchanges heat with a heat medium (water or brine) in this relay unit, and the heat medium is then circulated to indoor units. This intermediary system prevents direct refrigerant circulation in indoor spaces, eliminating leakage risks while maintaining cooling and heating functions.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a heat medium such as water or brine is circulated from an outdoor unit to indoor units through long circulation paths, then cooling or heating can be provided, but energy consumption increases due to the long circulation path

Engineering Contradiction:
Improvecooling and heating functionVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent segments the heat transfer system into two distinct circuits: a refrigerant circuit confined to the outdoor unit and a heat medium circuit that serves indoor units. This segmentation allows the refrigerant to operate in a compact outdoor location while the heat medium handles the distribution function, optimizing each circuit's performance and reducing overall energy consumption.

Inventive Principle:
Principle #1Segmentation

3Reliability

If a non-flammable refrigerant is used to ensure safety, then refrigerant leakage does not pose fire hazards, but flammable refrigerants with low global warming potential cannot be used

Engineering Contradiction:
ImprovesafetyVSAvoidglobal warming potential
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The heat medium relay unit serves as a physical barrier and heat transfer intermediary that decouples the refrigerant selection from indoor space safety requirements. This allows the system to use environmentally friendly flammable refrigerants in the outdoor unit while the heat medium (water or brine) handles the indoor distribution, eliminating fire hazards in occupied spaces.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Adaptability or versatility

If four water pipings are arranged between the heat source unit and each indoor unit to allow simultaneous cooling and heating, then free selection of cooling and heating is enabled, but the system configuration becomes complex

Engineering Contradiction:
Improvecooling and heating selectionVSAvoidpiping configuration
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements a dual-piping heat medium relay unit that can simultaneously perform cooling and heating functions through a single relay unit. The relay unit contains separate heat exchangers for cooling and heating operations, allowing both functions to be achieved through two pipings instead of four, simplifying the overall system configuration while maintaining full operational versatility.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 into indoor spaces, reduces energy consumption by shortening circulation paths, and improves construction ease and energy efficiency, while allowing the use of flammable refrigerants that minimize environmental impact.

Implementation Method 1

a heat medium relay unit including a heat exchanger related to heat medium that exchanges heat between a flammable refrigerant and a heat medium different from the refrigerant

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

a housing having a vent hole allowing ventilation between a housing space and a space outside the housing space

Methodology Applied
Scientific EffectVentilation: Convection

Data Source

PatentEP2535651B1Building comprising an air conditioner
Publication Date: 2021.04.28 MITSUBISHI ELECTRIC CORP
  • EP2535651B1 patent drawingFigure 1~2
  • EP2535651B1 patent drawingFigure 3
  • EP2535651B1 patent drawingFigure 4

AI summary

To obtain an air-conditioning apparatus that is capable of insuring safety related to refrigerants while saving energy. The air-conditioning apparatus includes a heat medium relay unit 3 accommodating heat exchangers related to heat medium 15a and 15b exchanging heat between a flammable refrigerant and a heat medium different from the refrigerant and having a housing 50 having a vent hole 24 allowing ventilation between a housing space and a space outside the housing space, in which the heat medium relay unit 3 disposed in a space 8 in a structure 9 that is not an air conditioned space; a single or a plurality of outdoor units 1 connected to the heat medium relay unit 3 by piping and circulating the refrigerant therein, in which the single or the plurality of outdoor units 1 disposed in a space outside the structure 9 or a space inside the structure 9 that is not isolated completely from the space 6 outside the structure 9; and a single or a plurality of indoor units 2 connected to the heat medium relay unit 3 by piping to a different system to that of the one or the plurality of outdoor units 1, in which the single or the plurality of indoor units 2 circulates the heat medium therein to exchange heat with air related to the indoor space.