Air conditioner
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Solution Overview
Problem
Conventional air-conditioning apparatuses face challenges in accurately controlling compressor rotation speed, leading to frequent activation/deactivation and increased power consumption, especially in low air conditioning load scenarios like highly airtight and well-insulated buildings, where the compressor may operate at its lowest frequency inadequately.
Innovation Solution
An air-conditioning apparatus with an indoor air temperature sensor and a controller that adjusts the compressor's rotation speed based on detected temperature changes, decreasing the speed by a predetermined amount when the indoor air temperature change is minimal, and increasing it when changes are significant, to match the air conditioning load effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the compressor is controlled to operate at the lowest frequency to save energy, then power consumption is reduced, but the air conditioning load cannot be appropriately covered and the compressor turns on/off frequently
Solution Approach 1:
The patent applies dynamics by making the compressor's lower limit frequency adjustable rather than fixed. The control device dynamically changes the lower limit frequency based on detected air conditioning load characteristics, allowing the system to adapt between energy-saving mode (lower frequency) and adequate cooling mode (higher frequency) depending on building insulation, airtightness, and outdoor conditions.
Solution Approach 2:
The patent changes the parameter of compressor operating frequency by allowing the lower limit frequency to be adjusted according to detected air conditioning load. This parameter change enables the system to prevent frequent on/off cycling by raising the minimum operating frequency when the load requires it, while still allowing energy-saving operation at lower frequencies when appropriate.
2Reliability
If the compressor lower limit frequency is corrected to prevent frequent on/off cycling, then reliability is improved, but power consumption increases
Solution Approach 1:
The system dynamically adjusts the lower limit frequency based on real-time detection of air conditioning load characteristics rather than using a fixed correction. This allows the compressor to operate at the most energy-efficient frequency that still maintains reliable operation, avoiding unnecessary energy consumption while preventing frequent cycling.
Solution Approach 2:
The control device uses feedback from detecting air conditioning load characteristics (building insulation, airtightness, outdoor conditions) to determine the appropriate lower limit frequency. This feedback mechanism ensures the compressor operates reliably without excessive energy consumption by continuously optimizing the minimum frequency based on actual system conditions.
3Device complexity
If the compressor operates at a fixed lowest frequency, then device complexity is reduced, but adaptability to different air conditioning loads is poor
Solution Approach 1:
The system performs self-service by automatically detecting air conditioning load characteristics and autonomously determining the appropriate lower limit frequency without requiring complex external control or manual configuration. The control device uses built-in detection capabilities to adapt to different building types and outdoor conditions, maintaining simplicity while achieving high adaptability.
Solution Approach 2:
The patent changes the operating parameter (lower limit frequency) based on detected air conditioning load characteristics. This allows a single device to adapt to various building types (highly airtight vs. less airtight, well-insulated vs. poorly insulated) and outdoor conditions without requiring multiple hardware configurations or complex control algorithms.
Data Source
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AI summary
An air-conditioning apparatus includes a refrigeration cycle in which a compressor, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger are connected in a circuit and is provided with an indoor air temperature sensor configured to detect indoor air temperature in a space in which the air-conditioning apparatus is installed, and a controller configured to control a rotation speed of the compressor. The controller controls operation of the compressor based on an operation state of the compressor and a change amount of the indoor air temperature detected by the indoor air temperature sensor at a set time interval.