Heat exchange device suitable for low pressure refrigerant
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Solution Overview
Problem
Typical falling-film evaporators are not suitable for low pressure refrigerants due to the high pressure differential caused by refrigerant dispensers, which leads to inefficient distribution of low pressure refrigerants over evaporation tube bundles.
Innovation Solution
A heat exchange device comprising a first and second heat exchange unit, where the first unit includes a condenser tube bundle and a throttling device connecting to the second unit with a refrigerant dispenser and evaporation tube bundle, facilitating the condensation and evaporation of refrigerant vapor to accommodate low pressure refrigerants, thereby reducing pressure differences and enhancing distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a refrigerant dispenser is used in a falling-film evaporator, then refrigerant distribution is improved, but pressure differential increases which makes it unsuitable for low pressure refrigerants
Solution Approach 1:
The patent introduces an intermediary chamber between the refrigerant dispenser and the evaporation tube bundle. This chamber acts as a buffer zone that receives refrigerant from the dispenser and redistributes it uniformly over the evaporation tubes without requiring high pressure differential. The intermediary chamber decouples the dispensing function from the distribution function, allowing low pressure refrigerants to be effectively distributed.
Solution Approach 2:
The evaporator is segmented into distinct functional zones: a refrigerant dispenser section, an intermediary chamber section, and an evaporation tube bundle section. This segmentation allows each component to perform its specific function optimally - the dispenser introduces refrigerant, the chamber distributes it, and the tubes perform evaporation - without the pressure losses that would occur in an integrated design.
2Productivity
If a typical falling-film evaporator structure is used, then heat transfer efficiency is enhanced, but the structure becomes complex and unsuitable for low pressure refrigerants
Solution Approach 1:
The patent designs the evaporator with multi-functional components that serve multiple purposes. The intermediary chamber not only distributes refrigerant but also acts as a flow straightener and pressure equalizer. The dispenser structure serves both as a flow distributor and a support structure for the evaporation tubes, reducing overall system complexity while maintaining heat transfer efficiency.
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 proposed heat exchange device efficiently handles low pressure refrigerants, reducing refrigerant charge and enhancing heat transfer efficiency with a less complex structure, suitable for environmentally friendly and efficient refrigerant systems like R1233zd(E).
Implementation Method 1
condensing the refrigerant vapor into a refrigerant liquid after passing the refrigerant vapor over a first condenser tube bundle
Implementation Method 2
evaporating the two-phase refrigerant into the refrigerant vapor after passing the two-phase refrigerant over an evaporation tube bundles
Implementation Method 3
directing the refrigerant liquid through a first refrigerant outlet of the first heat exchange unit into a connection conduit coupled to a second refrigerant inlet of a second heat exchange unit through a throttling device
Data Source
AI summary
A heat exchange device includes a first heat exchange unit having a first condenser tube bundle disposed within a first cylinder of the first heat exchange unit and a second heat exchange unit having a refrigerant dispenser disposed in a second cylinder of the second heat exchange unit, where a first refrigerant outlet of the first heat exchange unit is in fluid communication with a first refrigerant inlet of the second heat exchange unit through a throttling device, the refrigerant dispenser extends along an axial direction of the second cylinder to form a chamber within the second cylinder, the chamber includes an upper portion and a lower portion, a second condenser tube bundle is disposed in the upper portion of the chamber, and an evaporation tube bundle is disposed in the lower portion of the chamber.