Air conditioner and air discharge method of air conditioner

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Solution Overview

Problem

Conventional air-conditioning apparatuses fail to effectively discharge both air parcels and air dissolved in the heat-medium cycle circuit, leading to potential corrosion and reduced pump lifetime due to air accumulation.

Innovation Solution

An air-conditioning apparatus with an intermediate heat exchanger, refrigerant and heat-medium cycle circuits, and a discharge mechanism, utilizing a controller to execute operation modes that dissolve and release air within the heat-medium cycle circuit, allowing for complete air discharge.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If air is discharged only by mechanical means (pump rotation) during heat medium charging, then air parcels can be partially removed, but dissolved air remains trapped in the heat-medium cycle circuit

Engineering Contradiction:
Improveair discharge completenessVSAvoiddischarge mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the physical parameters of the heat medium (temperature and pressure) to alter air solubility. By heating the heat medium in the heat source-side heat exchanger, dissolved air is released from the heat medium. The air separation mechanism then separates and discharges this released air, achieving complete air removal including both air parcels and dissolved air.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces an air separation mechanism as an intermediary component between the heat-medium cycle circuit and the external environment. This mechanism receives the heat medium containing released air, separates the air from the heat medium, and discharges the air externally, enabling effective removal of dissolved air without complicating the main pump system.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Duration of action of stationary object

If air remains inside the heat-medium cycle circuit, then the system structure remains simple, but corrosion accelerates and pump lifetime reduces

Engineering Contradiction:
Improvepump lifetimeVSAvoidcorrosion and air accumulation
Core Design Contradiction:
Duration of action of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The patent implements preliminary air discharge action during the heat medium charging process and initial operation phases. The air separation mechanism operates to remove air before it can cause significant corrosion or damage, extending pump lifetime by preventing harmful air accumulation in advance.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent converts the harmful effect of dissolved air (which causes corrosion when released) into a beneficial process by controlling its release. By heating the heat medium in a controlled manner and using the air separation mechanism, the previously harmful dissolved air is systematically removed and discharged, transforming a corrosion risk into an effective air purification process.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 apparatus effectively dissolves and discharges both air parcels and dissolved air from the heat-medium cycle circuit, preventing corrosion and extending pump life.

Implementation Method 1

with the heat source-side heat exchanger functioning as an evaporator... circulating the refrigerant in the refrigerant cycle circuit... circulating the heat medium in the heat-medium cycle circuit

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

The intermediate heat exchanger includes a first heat transfer unit in which refrigerant flows, and a second heat transfer unit in which a heat medium different from the refrigerant flows. The intermediate heat exchanger is configured to exchange heat between the first heat transfer unit and the second heat transfer unit

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP4116638B1Air conditioner and air discharge method of air conditioner
Publication Date: 2025.08.13 MITSUBISHI ELECTRIC CORP
  • EP4116638B1 patent drawingFigure 1
  • EP4116638B1 patent drawingFigure 2
  • EP4116638B1 patent drawingFigure 3

AI summary

An air-conditioning apparatus is configured to allow heat exchange in an intermediate heat exchanger between refrigerant that circulates in a refrigerant cycle circuit and a heat medium that circulates in a heat-medium cycle circuit. The heat-medium cycle circuit includes a discharge mechanism including a discharge valve, the discharge mechanism being configured to, when the discharge valve is open, discharge air present inside the heat-medium cycle circuit to the outside of the heat-medium cycle circuit. The air-conditioning apparatus is configured to execute an air discharge operation mode in which the air present inside the heat-medium cycle circuit is discharged to the outside of the heat-medium cycle circuit. The air discharge operation mode includes a first operation mode, and a second operation mode performed after the first operation mode. The first operation mode is an operation mode in which, with the discharge valve being closed, an operation similar to a cooling operation is performed. The second operation mode is an operation mode in which, with the discharge valve being open, an operation similar to a heating operation is performed.