Air-conditioning apparatus
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Solution Overview
Problem
The distribution of refrigerant in air-conditioning systems is uneven relative to airflow through the heat exchanger, leading to suboptimal performance and reduced energy efficiency, particularly in top-flow arrangements where airflow is highest near the fan and decreases with distance.
Innovation Solution
The air-conditioning apparatus features a heat exchanger with heat transfer tubes spaced vertically and a header manifold with branch tubes inserted at varying lengths to match airflow distribution, with refrigerant flowing in an annular or churn pattern, ensuring optimal refrigerant distribution by concentrating liquid refrigerant flow where airflow is highest and lowest.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If branch tubes are inserted at equal lengths into the header manifold, then refrigerant distribution is improved, but the complexity of the device increases due to additional structural objects
Solution Approach 1:
The patent applies local quality by varying the insertion length of branch tubes into the header manifold based on their vertical position. Branch tubes at different heights have different insertion depths, creating non-uniform local characteristics that match the non-uniform airflow distribution in the heat exchanger. This resolves the contradiction by achieving improved refrigerant distribution without requiring additional structural objects, as the variation in insertion length alone creates the necessary flow optimization.
2Manufacturing precision
If refrigerant is uniformly distributed to the heat exchanger, then refrigerant distribution is improved, but heat exchanger performance deteriorates due to mismatch with non-uniform airflow
Solution Approach 1:
The patent creates non-uniform refrigerant distribution by varying branch tube insertion lengths, matching the local airflow characteristics at different vertical positions. This resolves the contradiction between uniform refrigerant distribution and heat exchanger performance by making the refrigerant distribution non-uniform in a controlled manner that corresponds to the airflow pattern, thereby optimizing heat transfer efficiency.
Solution Approach 2:
The patent changes the parameter of branch tube insertion length to optimize refrigerant flow distribution. By adjusting this geometric parameter based on vertical position, the system achieves better alignment between refrigerant distribution and airflow patterns, improving overall heat exchanger performance without changing other structural parameters.
3Manufacturing precision
If additional structural objects are provided inside the header manifold, then refrigerant distribution is improved, but manufacturing cost increases significantly
Solution Approach 1:
The patent achieves improved refrigerant distribution through local variation in branch tube insertion lengths rather than adding structural objects to the header manifold. This approach maintains manufacturing simplicity while achieving the desired flow distribution, as it only requires adjusting the insertion depth of existing branch tubes rather than adding partitions, eject ports, or other complex internal structures.
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 configuration enhances the performance of the heat exchanger by aligning refrigerant distribution with airflow patterns, improving energy efficiency and heat transfer efficiency.
Implementation Method 1
The refrigerant flows in the header manifold in an annular or churn flow pattern in which gas-phase refrigerant collects at the center of the header manifold and liquid-phase refrigerant collects on the wall surface of the header manifold
Implementation Method 2
The refrigerant circuit is a circuit to direct the refrigerant into the flow space such that the refrigerant flows upward in a two-phase gas-liquid state, and to cause the refrigerant to evaporate in the heat exchanger
Implementation Method 3
The axial fan includes a blade disposed around a boss that rotates, the blade having a rotational plane that faces the plurality of heat transfer tubes in the horizontal direction
Implementation Method 4
The heat exchanger includes a plurality of heat transfer tubes in which refrigerant flows
Implementation Method 5
The refrigerant circuit is a circuit to cause the refrigerant to evaporate in the heat exchanger
Data Source
AI summary
The air-conditioning apparatus includes a heat exchanger including a plurality of heat transfer tubes and a header manifold an axial fan and a refrigerant circuit. When the distance from the center of the flow space in the horizontal plane is represented on a scale of 0 to 100%, where 0% represents the center of the flow space and 100% is the position of the wall surface of the header manifold, among the plurality of branch tubes located within a height range that allows the blade to rotate, the majority of the branch tubes located at or below the height of the boss are connected to the header manifold such that their distal ends are positioned at 0 to 50% of the distance from the center, and the majority of the branch tubes located above the height of the boss are connected to the header manifold such that their distal ends are positioned at more than 50% of the distance from the center.