Air-conditioning system

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Solution Overview

Problem

Air conditioning systems face issues when a power source is interrupted to one or more indoor units, potentially leading to compressor breakage or overflow of drain water due to limited power feeding capabilities.

Innovation Solution

An air conditioning system with a refrigerant cycle, power feed unit, controller, and determining unit that can assess the need to continue oil return or defrosting operations, deciding whether to stop the compressor based on refrigerant wetness and drain water levels, and manage indoor unit groups to optimize operations during power outages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the power feed unit feeds power from an auxiliary power source to the indoor unit during a power source interruption, then the indoor unit can continue operation, but the limited power feed capacity may cause compressor breakage or drain water overflow

Engineering Contradiction:
Improveair conditioning operation continuityVSAvoidcompressor breakage and drain water overflow
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The determining unit performs preliminary assessment before allowing compressor operation to continue during power interruption. It evaluates refrigerant wetness degree and drain water amount in advance to predict potential harmful effects, then makes a determination whether to stop or continue the compressor based on these preliminary findings, preventing damage before it occurs

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements feedback control by having the determining unit continuously monitor refrigerant wetness degree and drain water amount, then use this feedback information to make real-time decisions about compressor operation. The controller adjusts compressor operation based on the determination result, creating a closed-loop control system that prevents harmful effects while maintaining operation continuity

Inventive Principle:
Principle #23Feedback

2Duration of action of moving object

If the compressor continues operating during power source interruption, then oil return and defrosting operations can be completed, but the limited auxiliary power capacity may be exceeded causing system damage

Engineering Contradiction:
Improveoil return and defrosting operation completionVSAvoidauxiliary power source capacity
Core Design Contradiction:
Duration of action of moving objectVSPower

Solution Approach 1:

The determining unit performs preliminary assessment of power requirements for completing oil return and defrosting operations before the power interruption occurs or immediately after detection. It evaluates whether the auxiliary power source has sufficient capacity to complete these operations safely, and makes a determination in advance to stop or continue compressor operation accordingly

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system allows the compressor to operate partially (continue operation) only when the determining unit assesses that sufficient power capacity exists to complete the necessary oil return and defrosting operations. When power capacity is insufficient, the system stops the compressor entirely, avoiding the risk of power overload while maximizing operation continuity when safe

Inventive Principle:
Principle #16Partial or excessive action

3Object-affected harmful factors

If the system stops the compressor during power source interruption, then damage to the compressor is prevented, but the air conditioning operation is interrupted

Engineering Contradiction:
Improvecompressor protectionVSAvoidair conditioning operation continuity
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The determining unit performs preliminary assessment of the situation before making the stop/continue decision. It evaluates refrigerant wetness degree and drain water amount in advance to determine whether stopping the compressor is necessary to prevent damage, or whether the compressor can safely continue operating, thereby protecting the compressor only when truly necessary while maintaining operation continuity when safe

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from the determining unit's assessment of refrigerant wetness and drain water conditions to make intelligent decisions about compressor operation. The controller receives the determination result and adjusts compressor operation accordingly, creating a responsive control system that balances compressor protection with operation continuity based on real-time system conditions

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3978817B1Air-conditioning system
Publication Date: 2024.01.10 DAIKIN INDUSTRIES LTD
  • EP3978817B1 patent drawingFigure 1
  • EP3978817B1 patent drawingFigure 2~3
  • EP3978817B1 patent drawingFigure 4

AI summary

An air conditioning system (100) includes a refrigerant cycle (RC), a power feed unit (40), a controller (60), and a determining unit (90). The refrigerant cycle (RC) includes an outdoor unit (10) and a plurality of indoor units (30). The outdoor unit (10) includes a compressor (11). In a case where a power source for at least one indoor unit of the plurality of indoor units (30) is interrupted, the power feed unit (40) feeds power from an auxiliary power source to the at least one indoor unit. The controller (60) controls at least the compressor (11). In the case where the power source for the at least one indoor unit of the plurality of indoor units (10) is interrupted, the determining unit (90) makes one of a determination to stop the compressor (11) and a determination to cause the compressor (11) to continue operating. The determining unit (90) transmits to the controller (60) an instruction corresponding to the determination that has been made.