Compressor Condensation Temperature Control for Low-Draft Heating

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Solution Overview

Problem

Existing air conditioner technologies face challenges in reducing compressor starts and stops while maintaining user comfort, often resulting in a 'cold draft' due to temperature settings that compromise energy efficiency.

Innovation Solution

The air conditioner controller adjusts the compressor revolutions based on decreasing air volume, setting a lower limit for condensation temperature that varies with air volume, and allows multiple lower limits for different settings to ensure comfort and energy savings, with the option to set these limits during installation or based on user preference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the number of compressor starts and stops is reduced to enhance energy saving, then energy efficiency is improved, but user comfort deteriorates due to cold draft

Engineering Contradiction:
Improveenergy efficiencyVSAvoidcold draft
Core Design Contradiction:
Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The patent dynamically adjusts the lower limit temperature (Tcs) parameter based on air volume settings. When air volume is reduced, the lower limit temperature is lowered accordingly, allowing the compressor to operate at lower temperatures without causing cold draft. This parameter adaptation resolves the contradiction by enabling energy-saving continuous operation while maintaining user comfort across different air volume conditions.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If a fixed lower limit temperature is used for compressor control, then control simplicity is maintained, but adaptability to different air volume settings deteriorates

Engineering Contradiction:
Improvecontrol simplicityVSAvoidadaptability to air volume settings
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent implements a dynamic control system where the lower limit temperature (Tcs) is no longer fixed but varies according to the selected air volume setting. The controller automatically selects appropriate Tcs values from a predetermined table based on the air volume, enabling the system to adapt to different operating conditions while maintaining straightforward control logic through automated parameter selection.

Inventive Principle:
Principle #15Dynamics

3Loss of energy

If the air outlet opening area is reduced to decrease air volume, then energy saving is improved, but user comfort deteriorates due to increased cold draft

Engineering Contradiction:
Improveenergy savingVSAvoidcold draft
Core Design Contradiction:
Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The patent coordinates the adjustment of lower limit temperature (Tcs) with air volume settings. When the air outlet opening area is reduced to decrease air volume for energy saving, the system simultaneously lowers the Tcs parameter to prevent the blown air from becoming too cold. This coordinated parameter change allows energy-saving operation at reduced air volumes while maintaining user comfort by preventing cold draft.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3208550B1Air conditioning apparatus
Publication Date: 2021.04.07 DAIKIN INDUSTRIES LTD
  • EP3208550B1 patent drawingFigure 1
  • EP3208550B1 patent drawingFigure 2
  • EP3208550B1 patent drawingFigure 3

AI summary

Disclosed herein is an air conditioner including: an indoor unit (12) configured to blow air (SA) into a room in varying volumes with settings; a refrigerant circuit (20) including a compressor (21) and filled with a refrigerant; and a controller (32) configured to control the number of revolutions of the compressor (21) while keeping a condensation temperature (Tc) of the refrigerant equal to or higher than a predetermined lower limit (Tcs) during a heating mode of operation. The controller (32) has a control mode in which the controller (32) controls the number of revolutions of the compressor (21) based on the lower limit (Tcs) that decreases as a volume of air corresponding to one of the settings decreases during the heating mode of operation.