Air-conditioning unit

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In top-blow type outdoor air conditioning units, uneven air velocity distribution and turbulence around the fan lead to increased noise and energy loss due to the presence of wall panels blocking air flow in areas without heat exchangers, making maintenance difficult.

Innovation Solution

The air-conditioning unit is designed with segmented heat exchanger sections, where the area without heat exchangers is larger farther away from the fan, reducing air velocity distribution unevenness by allowing air to flow through longer heat exchange sections closer to the fan, thus reducing noise and energy loss while facilitating maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the heat exchanger area at the lower level is extended in the rotation direction of the fan, then the unevenness in air velocity distribution is reduced, but maintenance work becomes more difficult

Engineering Contradiction:
Improveair velocity distribution uniformityVSAvoidmaintenance accessibility
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The heat exchanger is divided into multiple sections along the rotation direction of the fan, with each section having a different area. This segmentation allows the air velocity distribution to be optimized while maintaining access pathways for maintenance personnel to reach internal components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different sections of the heat exchanger are designed with locally optimized areas, where the area without heat exchanger varies along the rotation direction. This creates local variations in air flow resistance that balance the overall air velocity distribution without completely filling the housing space.

Inventive Principle:
Principle #3Local quality

2Strength

If wall panels are arranged in areas without heat exchangers to block air passage, then structural support is provided, but air flow turbulence and noise increase

Engineering Contradiction:
Improvestructural supportVSAvoidair flow turbulence and noise
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

Guide walls are introduced as intermediary structures between the wall panels and the air flow. These guide walls smoothly direct the air flow around the wall panels, preventing turbulence and noise generation while maintaining the structural support function of the wall panels.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Loss of energy

If the heat exchanger area is increased to improve heat exchange efficiency, then energy efficiency improves, but air flow resistance increases causing uneven velocity distribution

Engineering Contradiction:
Improveheat exchange efficiencyVSAvoidair velocity distribution uniformity
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The heat exchanger area is optimized locally at different positions along the rotation direction of the fan. By creating variations in heat exchanger area across different sections, the patent balances heat exchange efficiency with air flow resistance, preventing excessive velocity unevenness while maintaining effective heat transfer.

Inventive Principle:
Principle #3Local quality

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 design reduces air flow fluctuations and noise, improves energy efficiency, and provides easier access for maintenance by ensuring a larger area without heat exchangers farther from the fan.

Implementation Method 1

an air flow generated by rotation of a fan

Methodology Applied
Scientific EffectFan rotation: Fan

Implementation Method 2

heat exchange to occur between outside air and refrigerant

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP3141827B1Air-conditioning unit
Publication Date: 2020.09.16 MITSUBISHI ELECTRIC CORP
  • EP3141827B1 patent drawingFigure 1
  • EP3141827B1 patent drawingFigure 2
  • EP3141827B1 patent drawingFigure 3

AI summary

In an air-conditioning unit, a heat exchanger is arranged at a position shifted relative to a fan in an axial direction of the fan. Further, the heat exchanger is arranged on an imaginary setting plane surrounding the axis of the fan. Further, the heat exchanger is segmented into a plurality of heat exchange sections that are present respectively in a plurality of regions arrayed in the axial direction of the fan. Assuming that a direction along the imaginary setting plane on a plane perpendicular to the axis of the fan is a peripheral direction of the imaginary setting plane, among lengths of the plurality of heat exchange sections along the peripheral direction of the imaginary setting plane, a length of the heat exchange section that is present in a region closer to the fan is longer.