Air conditioner

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Solution Overview

Problem

Existing air conditioner systems face challenges in efficiently judging the adequacy of refrigerant quantity in the refrigerant circuit, often resulting in prolonged or unstable operations due to difficulties in maintaining constant pressure at the compressor's suction side, leading to ineffective refrigerant quantity judging operations.

Innovation Solution

The system introduces a stability judging mechanism that adjusts target control values, such as pressure and superheat degree, to stabilize the refrigerant quantity judging operation, allowing for continuous refinement until stability is achieved, thereby reducing operation time and ensuring completion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the pressure at the suction side of the compressor is controlled to be constant during the refrigerant quantity judging operation, then the refrigerant quantity judging operation can be performed accurately, but it becomes difficult to maintain constant pressure due to installation conditions and other factors, causing the operation to be performed in vain or finished prematurely

Engineering Contradiction:
Improverefrigerant quantity judging accuracyVSAvoidadaptability to installation conditions
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent applies dynamics by making the target control value adjustable rather than fixed. The stability judging mechanism continuously monitors whether the refrigerant quantity judging operation has stabilized, and the target control value is dynamically changed based on this stability judgment. This allows the system to adapt to different installation conditions and environmental factors, resolving the contradiction between maintaining constant pressure for accurate measurement and adapting to varying installation conditions.

Inventive Principle:
Principle #15Dynamics

2Device complexity

If the refrigerant quantity judging operation is performed with a fixed target control value, then the control system is simple, but the operation may continue for a long period without stabilizing or may be finished prematurely

Engineering Contradiction:
Improvecontrol system complexityVSAvoidoperation completion reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent implements feedback through the stability judging mechanism that continuously monitors the refrigerant quantity judging operation. The mechanism judges whether the operation has stabilized based on predetermined criteria, and this judgment feedback is used to determine whether to continue or terminate the operation. This feedback loop ensures reliable operation completion while maintaining relatively simple control logic, resolving the contradiction between system simplicity and operation reliability.

Inventive Principle:
Principle #23Feedback

3Productivity

If the target control value is changed when stability is not achieved, then the refrigerant quantity judging operation can be completed reliably and quickly, but the control system becomes more complex

Engineering Contradiction:
Improverefrigerant quantity judging efficiencyVSAvoidcontrol mechanism complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by modifying the target control value based on stability judgment results. When the stability judging mechanism determines that the refrigerant quantity judging operation has not stabilized, the target control value is changed to facilitate stabilization. This parameter adjustment approach improves productivity by ensuring reliable and timely operation completion while keeping the control mechanism relatively simple, as it only involves adjusting a single parameter (target control value) based on clear stability criteria.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP1970654B1Air conditioner
Publication Date: 2019.08.07 DAIKIN INDUSTRIES LTD
  • EP1970654B1 patent drawingFigure 1
  • EP1970654B1 patent drawingFigure 2
  • EP1970654B1 patent drawingFigure 3

AI summary

In an air conditioner having a function to judge the adequacy of the refrigerant quantity in a refrigerant circuit, a period of time for a refrigerant quantity judging operation is reduced and the refrigerant quantity judging operation is reliably completed. An air conditioner (1) includes a refrigerant circuit (10), operation controlling means, stability judging means, refrigerant quantity judging means, and condition changing means. The operation controlling means is capable of performing a refrigerant quantity judging operation to control constituent equipment to reach a predetermined target control value. The stability judging means judges whether or not the refrigerant quantity judging operation has stabilized. The refrigerant quantity judging means judges the adequacy of the refrigerant quantity in the refrigerant circuit (10) by using an operation state quantity of constituent equipment or refrigerant flowing in the refrigerant circuit (10) when it is judged that the refrigerant quantity judging operation has stabilized. The condition changing means changes the target control value in the refrigerant quantity judging operation when it is judged that the refrigerant quantity judging operation has not stabilized.