Indoor unit and air conditioning device provided with same

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In air conditioning apparatuses, the proximity of the bell mouth and filter increases airflow resistance, leading to higher noise levels and increased fan motor power consumption.

Innovation Solution

The indoor unit design includes a bell mouth with distinct sections, where the second section has a first flat portion and the third section has a second flat portion, with L1 < L2, ensuring a distance between the bell mouth and filter, thereby reducing airflow resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the bell mouth and filter are positioned close to each other, then the device complexity is reduced, but the airflow resistance increases

Engineering Contradiction:
Improvestructural complexityVSAvoidairflow resistance
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The bell mouth is divided into three distinct sections (first section with narrowing opening, second section with first flat portion, third section with second flat portion) to systematically manage airflow from the filter to the fan, reducing turbulence and resistance while maintaining a compact structure

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different sections of the bell mouth have different geometric properties tailored to specific airflow functions: the first section narrows to direct airflow, the second section provides a flat portion for flow stabilization, and the third section transitions to the drain pan, optimizing local airflow characteristics throughout the path

Inventive Principle:
Principle #3Local quality

2Device complexity

If the bell mouth and filter are positioned close to each other, then the device complexity is reduced, but the noise level increases

Engineering Contradiction:
Improvestructural complexityVSAvoidnoise
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The three-section bell mouth structure breaks down the airflow path into manageable segments, each designed to minimize turbulence and noise generation while maintaining compact dimensions

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The bell mouth opening narrows in a curved manner from the first section to the fan, creating smooth transitions that reduce airflow separation and turbulence, thereby minimizing noise generation in the compact configuration

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Device complexity

If the bell mouth and filter are positioned close to each other, then the device complexity is reduced, but the power consumption of fan motor increases

Engineering Contradiction:
Improvestructural complexityVSAvoidfan motor power consumption
Core Design Contradiction:
Device complexityVSUse of energy by moving object

Solution Approach 1:

The segmented bell mouth structure optimizes airflow delivery to the fan in three stages, reducing the work required by the fan motor to move air through the system while maintaining a compact design

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cross-sectional area and shape parameters of the bell mouth are systematically varied across the three sections to optimize airflow velocity and pressure distribution, reducing the power required by the fan motor while keeping the overall structure compact

Inventive Principle:
Principle #35Parameter changes

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 configuration reduces airflow resistance, leading to lower noise levels and decreased fan motor power consumption by ensuring a uniform air velocity distribution and minimizing circulating flows.

Implementation Method 1

The air taken in through the intake grill is directed to the fan by the bell mouth having an opening. The air directed to the fan is fed toward the surroundings of the fan and flows through the heat exchanger.

Methodology Applied
Scientific EffectFluid flow:

Implementation Method 2

As the air flows through the heat exchanger, heat exchange takes place between refrigerant and the air flowing through the heat exchanger.

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP4060246B1Indoor unit and air conditioning device provided with same
Publication Date: 2023.06.14 MITSUBISHI ELECTRIC CORP
  • EP4060246B1 patent drawingFigure 1
  • EP4060246B1 patent drawingFigure 2
  • EP4060246B1 patent drawingFigure 3~4

AI summary

In an indoor unit (5), a bell mouth (23) includes a first section (25), a second section (27) having a flat portion (27a), and a third section (29) having a flat portion (29a). L1&lt;L2 is satisfied, where L1 is a distance in an axial direction of a rotational shaft (CA) between the flat portion (27a) and the flat portion (29a), and L2 is a distance in the axial direction between the flat portion (27a) and an open end of the first section (25). The flat portion (27a) of the second section (27) is located between a second extension (49) of a drain pan (43) and a fan (35) in the axial direction.