Multi-Indoor Air Conditioning Load Control via Temperature Feedback

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Solution Overview

Problem

Air-conditioning apparatuses with multiple indoor units connected to a single system struggle to respond effectively to varying loads, leading to insufficient temperature control in environments with intense load changes, requiring dedicated outdoor units and direct compressor capacity control based on suction or blow-out temperatures.

Innovation Solution

An air-conditioning apparatus with a compressor, temperature detection units in each indoor unit, and a controller that compares detected temperatures with set values to calculate required capacities across all units, controlling the compressor capacity based on these calculations to ensure responsive load management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the compressor capacity is controlled based on only the highest required capacity from utilization units, then the evaporating temperature of the heat exchanger can be kept constant, but the system cannot follow load changes in environments with intense load variations

Engineering Contradiction:
Improveevaporating temperature stabilityVSAvoidload change responsiveness
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The patent segments the load calculation by individually calculating required capacities for each indoor unit based on its specific temperature differential, then aggregating these segmented values to determine total compressor capacity control, allowing responsive adaptation to varying loads across multiple units

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically adjusts compressor capacity control by continuously monitoring temperature differentials in each indoor unit and recalculating required capacities in real-time, enabling the system to adapt to intense load variations while maintaining evaporating temperature stability through aggregated feedback from all units

Inventive Principle:
Principle #15Dynamics

2Device complexity

If multiple indoor units are connected to one system with a single outdoor unit, then system complexity is reduced, but the system cannot effectively respond to varying loads in each unit

Engineering Contradiction:
Improvesystem structure simplicityVSAvoidload following capability
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent implements feedback control by having each indoor unit's temperature detection unit continuously monitor its local conditions, calculate required capacity based on temperature differential from set temperature, and feed this information to the controller which aggregates requirements from all units to dynamically adjust compressor capacity, enabling effective load response despite single-system architecture

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The controller serves multiple functions simultaneously: it receives temperature data from all indoor units, calculates individual required capacities for each unit, aggregates these requirements, and controls compressor capacity based on the total load, making the single outdoor unit system universally adaptable to varying loads across multiple units

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

Data Source

PatentEP3919834B1Air conditioning device
Publication Date: 2022.11.16 MITSUBISHI ELECTRIC CORP
  • EP3919834B1 patent drawingFigure 1
  • EP3919834B1 patent drawingFigure 2
  • EP3919834B1 patent drawingFigure 3

AI summary

An air-conditioning apparatus includes a compressor, a temperature detection unit provided at each indoor unit and configured to detect a blow-out temperature or a suction temperature of the indoor unit, and a controller configured to control operations of an outdoor unit and indoor units. The controller is configured to acquire a required capacity by comparing a detected value detected by the temperature detection unit with the set temperature for each of the indoor units and control the capacity of the compressor at a frequency based on a value calculated based on the acquired required capacities.