Cross-Fin Heat Exchanger Flow Layout for Balanced Heating and Cooling
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Solution Overview
Problem
Conventional heat exchangers for air conditioners face challenges in achieving a balance between heating and cooling performance, often compromising one performance to enhance the other, due to fixed refrigerant and air flow path configurations.
Innovation Solution
A cross-fin tube heat exchanger with a row structure featuring three or more rows of heat transfer tubes, including coexistent paths with both parallel and counter-flow portions, allowing for efficient heat exchange in both heating and cooling operations by optimizing refrigerant flow paths between upstream, intermediate, and downstream tube rows.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If orthogonal counter-flows are formed to improve cooling performance, then cooling performance is enhanced, but heating performance deteriorates
Solution Approach 1:
The heat exchanger dynamically switches between orthogonal counter-flow configuration for cooling operation and orthogonal parallel-flow configuration for heating operation. The refrigerant flow direction is reversed between the first and second heat exchangers based on operational mode, allowing optimal performance in both heating and cooling while maintaining high heat exchange efficiency in both directions
Solution Approach 2:
The heat exchanger system performs dual functions as both evaporator and condenser efficiently. By configuring two heat exchangers with interchangeable flow patterns (counter-flow when acting as evaporator, parallel-flow when acting as condenser), the system achieves universal applicability for both cooling and heating operations without sacrificing performance in either mode
2Power
If orthogonal parallel-flows are formed to improve heating performance, then heating performance is enhanced, but cooling performance deteriorates
Solution Approach 1:
The system dynamically adjusts the refrigerant flow configuration based on operational requirements. During heating operation, the refrigerant flows in orthogonal parallel-flow pattern through the heat exchangers to maximize heating efficiency. During cooling operation, the flow pattern switches to orthogonal counter-flow to maximize cooling efficiency, thus resolving the contradiction between heating and cooling performance
3Productivity
If heat exchanger rows are arranged to optimize one flow pattern, then performance in that pattern is improved, but performance in the other pattern deteriorates
Solution Approach 1:
The heat exchanger system is segmented into two distinct heat exchangers (first and second), each optimized for specific flow patterns. The first heat exchanger is optimized for counter-flow while the second is optimized for parallel-flow, allowing the system to maintain high efficiency in both operational modes by selecting the appropriate heat exchanger for each mode
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 design enhances the balance between heating and cooling performance by ensuring effective heat transfer in both modes, suppressing declines in either performance while emphasizing the other, through optimized refrigerant flow paths that maintain efficient heat exchange across varying operational conditions.
Implementation Method 1
Air which is sucked into a case of the air conditioner exchanges heat with a refrigerant which flows inside the heat transfer tubes
Implementation Method 2
Air which is sucked into a case of the air conditioner exchanges heat with a refrigerant which flows inside the heat transfer tubes, when the air passes through the gaps between the fins
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
A heat exchanger 11 has a plurality of paths P as refrigerant paths, and at least one of the plurality of paths P has a coexistent path P, in which both of a parallel flow portion R1 where refrigerant flows from a heat transfer tube 15 of one of the tube rows L to a heat transfer tube 15 of a tube row L which is on a downstream side of the one tube row L in terms of an air flow direction A, and a counter-flow portion R2 where refrigerant flows from a heat transfer tube 15 of one of the tube rows L to a heat transfer tube 15 of a tube row L which is on an upstream side of the one tube row L in terms of the air flow direction A, exist in use both as a condenser and as an evaporator.