Expansion Valve Control for Higher Air Conditioner Outlet Temperature
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional air conditioners fail to sufficiently increase the temperature of hot air blown out during a heating operation, even when maximizing compressor frequency and reducing indoor fan rotations.
Innovation Solution
The air conditioner includes a refrigerant circuit with a control unit that adjusts the expansion valve to increase the temperature of refrigerant flowing through the utilization-side heat exchanger, and additional controls to manage subcooling, fan rotations, and refrigerant flow rates to enhance heat transfer and distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the operating frequency of the compressor is maximized and the number of rotations of the indoor-side fan is lowered, then the compressor capacity is increased, but the temperature of the hot air blown out is not sufficiently increased
Solution Approach 1:
The patent changes the control parameters of the expansion valve to increase the refrigerant temperature. Specifically, it adjusts the opening degree of the expansion valve to control the refrigerant flow rate and temperature, thereby increasing the temperature of the hot air blown out without compromising heating efficiency
Solution Approach 2:
The patent dynamically adjusts the expansion valve opening degree based on the requested air temperature. The control unit modifies the expansion valve control in real-time to optimize the refrigerant temperature, enabling the system to adapt to different heating demands while maintaining efficiency
2Temperature
If the expansion valve opening degree is increased to increase refrigerant flow rate, then more refrigerant flows through the heat exchanger, but the refrigerant temperature may not be sufficiently increased
Solution Approach 1:
The patent simultaneously adjusts multiple parameters including expansion valve opening degree, compressor frequency, and fan rotation speed to achieve the desired refrigerant temperature. This multi-parameter coordination ensures that increasing refrigerant flow rate does not compromise temperature increase
Solution Approach 2:
The control unit monitors the actual refrigerant temperature and adjusts the expansion valve opening degree accordingly. This feedback mechanism ensures that the refrigerant temperature is sufficiently increased while maintaining appropriate refrigerant flow rate through continuous optimization
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 solution effectively increases the temperature of hot air blown out, maintains efficient operation by distributing refrigerant appropriately, and allows for user-requested high-temperature settings without frequent heating operation state changes, ensuring comfort and efficient refrigerant management.
Implementation Method 1
a refrigerant circuit that has a first refrigerant path to which a compressor, a first utilization-side heat exchanger, a first expansion valve, and a heat source-side heat exchanger are connected in order
Implementation Method 2
the control unit changes control of the first expansion valve such that a temperature of a refrigerant that flows through the first utilization-side heat exchanger increases
Implementation Method 3
a compressor that compresses a refrigerant
Implementation Method 4
a first utilization-side heat exchanger through which the refrigerant flows, and an indoor fan that blows the indoor air through the first utilization-side heat exchanger
Data Source
AI summary
An air conditioner is provided with a refrigerant circuit that has a first refrigerant path to which a compressor, a first utilization-side heat exchanger, a first expansion valve, and a heat source-side heat exchanger are connected in order. A control unit controls the compressor and the first expansion valve. When the control unit receives a request for high-temperature air that temporarily increases the temperature of the hot air blown out through the first utilization-side heat exchanger, the control unit changes the control of the first expansion valve so that the temperature of a refrigerant that flows through the first utilization-side heat exchanger increases.