Refrigerant Supercooling Control for Variable-Condition Air Conditioners
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Solution Overview
Problem
Conventional air conditioner control methods cannot optimize the coefficient of performance (COP) under various conditions, particularly differing between cooling and heating operations, and are unable to adapt effectively to fluctuating usage and environmental conditions.
Innovation Solution
An air conditioner system that includes a refrigerant circuit, fluid feeding mechanism, condensing temperature sensing, fluid temperature sensing, and a control unit that adjusts the compressor, expansion mechanism, and fluid feeding mechanism based on calculated supercooling values, using temperature and pressure sensors to optimize COP by setting target values that account for condensing and fluid temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a constant target degree of supercooling is used for control, then the COP can be improved under specific conditions, but the COP cannot be optimized under various conditions including different cooling and heating operations
Solution Approach 1:
The patent applies dynamics by making the target degree of supercooling variable rather than constant. The control unit dynamically adjusts the target degree of supercooling based on detected refrigerant temperatures and calculated supercooling degrees, allowing the system to adapt to different operating conditions (cooling/heating modes, varying loads, ambient temperatures) while maintaining optimal COP performance across all scenarios
Solution Approach 2:
The patent implements feedback control by continuously detecting the actual degree of supercooling through temperature sensors, comparing it with the target value, and adjusting the expansion valve opening degree accordingly. This closed-loop feedback mechanism enables real-time optimization of COP under varying operational conditions, resolving the contradiction between energy efficiency and adaptability
2Loss of energy
If the target degree of supercooling is adjusted for different operations, then the COP can be optimized for specific modes, but the control complexity increases
Solution Approach 1:
The patent applies self-service by enabling the control unit to automatically calculate the appropriate target degree of supercooling based on detected temperature parameters and operational mode, without requiring external manual intervention or complex preset tables. The system serves itself by using real-time sensor data to determine optimal control parameters, simplifying the overall control architecture while maintaining high COP performance across different operations
3Adaptability or versatility
If conventional control methods are used, then the system structure remains simple, but the system cannot adapt effectively to fluctuating usage and environmental conditions
Solution Approach 1:
The patent applies parameter changes by dynamically modifying the target degree of supercooling parameter based on detected temperature conditions and operational mode. Rather than changing the physical structure or adding complex hardware, the system achieves adaptability to fluctuating conditions through intelligent adjustment of control parameters (target supercooling degree and expansion valve opening), maintaining system simplicity while enhancing responsiveness to environmental variations
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for improved COP even under fluctuating conditions, ensuring reliable performance during both cooling and heating operations by optimizing condensing temperatures and fluid temperatures, thereby enhancing energy efficiency and adaptability.
Implementation Method 1
a condensing temperature ascertaining means for sensing a physical quantity so as to derive a condensing temperature of the refrigerant
Implementation Method 2
a fluid temperature ascertaining means for sensing a physical quantity so as to derive a temperature of the fluid which exchanges heat with the refrigerant inside the condenser
Implementation Method 3
a condenser... in which the refrigerant and the fluid exchange heat
Data Source
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AI summary
The present invention provides an air conditioner that can optimize the COP even if usage conditions vary. A refrigerant circuit (10) comprises and connects a compressor (21), an outdoor heat exchanger (23), an indoor expansion valve (41, 51), and an indoor heat exchanger (42, 52) such that a refrigerant circulates therein. An outdoor fan (28) feeds a fluid toward the outdoor heat exchanger (23). A heat exchanging temperature sensor (33) senses a condensing temperature of the refrigerant. An outdoor temperature sensor (36) senses the temperature of the outdoor air, which exchanges heat with the refrigerant inside the outdoor heat exchanger (23). A control unit (8) controls at least one member selected from the group consisting of the compressor (21), the indoor expansion valve (41, 51), and the outdoor fan (28) using as a target value a value calculated by dividing a degree of supercooling of the refrigerant in the vicinity of an outlet of the outdoor heat exchanger (23) by the difference between the condensing temperature ascertained by the heat exchanging temperature sensor (33) and the outdoor temperature ascertained by the outdoor temperature sensor (36).