Evaporator coil insert
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Solution Overview
Problem
Refrigerant systems face environmental concerns due to ozone-depleting refrigerants, and there is a need to reduce refrigerant charge while maintaining system efficiency and compliance with legislation.
Innovation Solution
An insert for the evaporator coil that reduces refrigerant volume by up to 70% and changes the direction of refrigerant flow, increasing turbulence and efficiency, while being adaptable and cost-efficient to fit various coil sizes and materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If refrigerant charge is reduced to meet environmental regulations, then environmental compliance is improved, but system cooling capacity may deteriorate
Solution Approach 1:
The evaporator coil is segmented into multiple sections with inserts placed at specific locations (inlet, middle, outlet) to create localized flow disruption. This segmentation allows the refrigerant charge to be reduced while maintaining cooling capacity through distributed turbulence enhancement rather than requiring high overall charge levels.
Solution Approach 2:
Inserts with specific geometries (twisted tapes, helical structures) are placed at specific locations within the evaporator coil where they locally enhance heat transfer coefficients. This local quality enhancement compensates for reduced refrigerant charge by creating high-performance zones that maintain overall system capacity.
2Quantity of substance
If insert is added to evaporator coil to reduce refrigerant charge, then refrigerant volume is reduced, but device complexity increases
Solution Approach 1:
The insert is nested within the existing evaporator coil tubing, fitting inside the refrigerant flow path without replacing the coil structure. This nesting approach reduces refrigerant charge by occupying volume while maintaining the original coil geometry and manufacturing processes.
Solution Approach 2:
The inserts are manufactured from inexpensive materials such as aluminum or plastic with simple geometries that can be produced via extrusion or molding. These low-cost components are designed to be inserted during assembly and remain as permanent fixtures, providing ongoing refrigerant charge reduction without requiring expensive materials or complex fabrication.
3Productivity
If insert geometry is optimized for gas regions, then vapor flow efficiency is improved, but liquid flow regions may be adversely affected
Solution Approach 1:
The insert geometry transitions dynamically along the flow direction, with different sections having different characteristics. The inlet section features larger pitch or spacing to handle liquid-slug flow, while the outlet section has smaller pitch to enhance vapor-liquid mixing and heat transfer in the vapor-dominated region.
Solution Approach 2:
Different sections of the insert have locally optimized geometries matched to the local flow regime. Liquid-rich regions receive inserts with geometries that promote slug breakup and mixing, while vapor-rich regions receive inserts that enhance interfacial area and heat transfer coefficients appropriate for vapor-liquid contact.
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
The insert reduces refrigerant charge, improves oil return, and enhances system efficiency by increasing the Reynolds number, thereby addressing environmental concerns and compliance with refrigerant limits.
Implementation Method 1
causes refrigerant flowing through the evaporator coil to change direction... increase the Reynolds (Re) number... describes the degree of turbulent flow
Data Source
AI summary
In one embodiment, an apparatus includes an insert for an evaporator coil. The insert is located within the evaporator coil. The insert for the evaporator coil reduces refrigerant charge in the evaporator coil and causes refrigerant flowing through the evaporator coil to change direction. The insert for the evaporator coil includes a solid core and a plurality of support legs.