Evaporator Split Flow Cores Reduce Pressure Drop
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Solution Overview
Problem
Existing evaporators in vehicle air-conditioning systems face issues with complete evaporation of the liquid refrigerant leading to superheating and increased flow resistance due to pressure differences, as well as high flow resistance through the conduits from inlet to outlet.
Innovation Solution
The evaporator design features a pair of adjacent heat exchanger cores with a split refrigerant flow configuration, where the initial refrigerant passes through the rear core and is split into parallel paths, ensuring even temperature distribution and preventing complete boiling off, thereby reducing pressure differences and flow resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If refrigerant flows through conventional evaporator conduits from inlet to outlet, then heat exchange function is provided, but flow resistance becomes relatively large and pressure difference increases
Solution Approach 1:
The evaporator is divided into multiple independent heat exchange cores (first core, second core, third core) arranged in parallel. Each core has its own inlet and outlet connections, allowing refrigerant to flow through multiple simultaneous paths rather than a single sequential path. This segmentation reduces the pressure difference across each individual core while maintaining overall heat exchange efficiency.
Solution Approach 2:
The patent transitions from a single-path sequential flow arrangement to a multi-path parallel flow arrangement by adding spatial dimensionality to the refrigerant flow paths. Multiple cores are positioned side-by-side with independent flow paths, effectively distributing the refrigerant flow across multiple dimensions rather than forcing it through a single linear path, thereby reducing flow resistance and pressure drop.
2Temperature
If refrigerant flows through evaporator conduits, then cooling function is provided, but liquid refrigerant may evaporate completely causing superheating and increased flow resistance
Solution Approach 1:
The evaporator is divided into multiple independent heat exchange cores (first core, second core, third core) arranged in parallel. Each core has its own inlet and outlet connections, allowing refrigerant to flow through multiple simultaneous paths rather than a single sequential path. This segmentation reduces the pressure difference across each individual core while maintaining overall heat exchange efficiency.
Solution Approach 2:
The patent transitions from a single-path sequential flow arrangement to a multi-path parallel flow arrangement by adding spatial dimensionality to the refrigerant flow paths. Multiple cores are positioned side-by-side with independent flow paths, effectively distributing the refrigerant flow across multiple dimensions rather than forcing it through a single linear path, thereby reducing flow resistance and pressure drop.
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 achieves improved thermal efficiency and performance by maintaining a lower pressure drop across the evaporator, ensuring even temperature distribution and preventing premature evaporation, thus enhancing the overall performance of the air-conditioning system.
Implementation Method 1
The air to be cooled is blown across refrigerant conduits or tubes in the evaporator, causing the remaining liquid part of the cold refrigerant mixture to evaporate, further lowering the temperature of the ambient air passing through the evaporator
Implementation Method 2
The pressure reduction results in flash evaporation of a part of the liquid refrigerant, lowering its temperature
Implementation Method 3
The refrigerant is cooled by ambient air flowing across condenser coils and is condensed into a liquid
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The invention relates to an evaporator (130; 230; 330; 430; 530) comprising a first core (331; 401; 501); and a second core (332; 402; 502), the first core (331; 401; 501) being arranged downstream of and overlapping the second core (332; 402; 502) in an air flow direction through the evaporator. Each core comprises an upper tank (503; 505) at a first end of the evaporator and a lower tank (504; 506) at a second end of the evaporator. Multiple conduits are arranged to allow fluid communication between the upper and lower tanks. Refrigerant supplied through the refrigerant inlet (410; 510) is directed from the first upper tank (503) to the first lower tank (504) a first path (P1). A split second path (P2, P2') is directed from the first lower tank (504) to the first upper tank (503) on either side of the first path (P1). Refrigerant is then directed from the second upper tank (505) to the second lower tank (506) in a split third path (P3, P3') on either side of a fourth path (P4). The fourth path (P4) is directed from the second lower tank (506) to an outlet (420; 520) at the second upper tank (505).