Multi-Indoor Air Conditioning Control Using Weighted Shared Temperature

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Solution Overview

Problem

In air conditioning systems with multiple indoor units in the same indoor space, there are inefficiencies due to some units being in thermo-ON and others in thermo-OFF states, despite high individual unit efficiencies, leading to suboptimal overall system performance.

Innovation Solution

An air conditioning system that calculates a representative temperature value based on set temperatures of indoor units, using weighted averages that consider factors like rated capacity, air-conditioning capability, airflow volume, and occupant density to simultaneously switch units between thermo-ON and thermo-OFF, and adjusts airflow volumes and expansion mechanism settings to optimize performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a simple average temperature is used for control, then the control system remains simple, but it fails to account for differences in influence on thermal environment and occupant comfort among different indoor units

Engineering Contradiction:
Improvecontrol system complexityVSAvoidsystem performance optimization
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent applies local quality by assigning different weights to different indoor units based on their specific characteristics (rated capacity, air-conditioning capability, airflow volume, occupant density). This allows the control system to prioritize units with greater influence on thermal environment and occupant comfort, optimizing system performance while maintaining reasonable complexity through a structured weighting approach

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 approach improves the overall efficiency of the air conditioning system by ensuring all units operate in a synchronized manner, reducing efficiency losses and providing a more comfortable environment by prioritizing units with higher influence on thermal conditions and occupant comfort.

Implementation Method 1

a heat-source-side heat exchanger and usage-side heat exchanger for enabling the refrigerant to exchange heat

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP3054231B1Air conditioning system and control method for same
Publication Date: 2018.07.18 DAIKIN INDUSTRIES LTD
  • EP3054231B1 patent drawingFigure 1
  • EP3054231B1 patent drawingFigure 2
  • EP3054231B1 patent drawingFigure 3

AI summary

An air conditioning system having a plurality of indoor units disposed in the same indoor space, wherein the efficiency of the entire air conditioning system is improved. A plurality of indoor units are installed in a room (1) which is the same indoor space, the indoor units including respective indoor heat exchangers (42, 52, 62), and the indoor units being capable of setting set temperatures individually. An outdoor unit (20) includes an outdoor heat exchanger (23) for conducting heat exchange with refrigerant circulating through the indoor heat exchangers (42, 52, 62). Indoor-side control devices (47, 57, 67) are configured so as to calculate a shared representative temperature related value using the set temperatures of the indoor units, and to simultaneously switch the indoor units between thermo-ON and thermo-OFF on the basis of the representative temperature related value.