Evaporator having integrated pulse wave atomizer expansion device
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional refrigeration systems face inefficiencies due to flash gas formation, refrigerant pooling, oil clogging, and pressure drops in evaporators, particularly with modern refrigerants having higher boiling points, which reduce system performance and increase the risk of oil insulation and clogging.
Innovation Solution
The implementation of an evaporator with an integrated pulse wave atomization system that sprays refrigerant droplets onto the evaporator's inner wall, utilizing Coanda effect elliptic cylinder chambers to enhance heat exchange and prevent oil clogging, while maintaining low pressure drop and efficient evaporation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If liquid refrigerant expands into the evaporator using conventional expansion devices, then the refrigerant pressure is reduced, but flash gas forms before the liquid enters the evaporator reducing system efficiency
Solution Approach 1:
The invention segments the refrigerant flow into multiple streams by distributing liquid refrigerant through numerous small orifices (typically 10-100 microns in diameter) across the evaporator surface. This segmentation prevents flash gas formation by maintaining uniform pressure distribution and enables direct contact evaporation, thereby improving evaporator efficiency while avoiding energy losses associated with conventional expansion devices.
Solution Approach 2:
The invention transitions from a one-dimensional flow path through expansion devices to a two-dimensional or three-dimensional spray distribution across the evaporator surface. By atomizing the refrigerant into fine droplets that spread across the entire evaporator area, the system achieves uniform heat distribution and eliminates the need for traditional expansion devices, resolving the contradiction between pressure reduction and flash gas formation.
2Temperature
If refrigerant flows through conventional evaporators, then heat exchange occurs, but refrigerant pooling occurs reducing evaporation efficiency
Solution Approach 1:
The invention applies local quality by creating zones of high refrigerant distribution density through the orifice plate structure. Each local area receives a controlled amount of refrigerant through specifically positioned orifices, ensuring uniform heat exchange across the entire evaporator surface while preventing pooling in any particular region. This localized control maintains both temperature efficiency and evaporation efficiency.
3Stress or pressure
If liquid refrigerant is used in evaporators with modern refrigerants having higher boiling points, then the refrigeration effect is reduced, but oil clogging and insulation increase
Solution Approach 1:
The invention replaces the mechanical expansion device with a passive orifice plate system that uses fluid dynamics principles. The high-velocity spray of refrigerant through numerous small orifices creates intense mixing and prevents oil accumulation through the mechanical action of the spray itself, eliminating oil clogging and insulation issues while maintaining refrigeration effect with modern high-boiling-point refrigerants.
4Stress or pressure
If conventional expansion devices are used to modulate refrigerant flow, then pressure control is achieved, but device complexity increases
Solution Approach 1:
The orifice plate system is a passive device that automatically modulates refrigerant flow based on pressure differential without requiring external control mechanisms. The system self-regulates by allowing the pressure difference between the high-pressure side and low-pressure side to control the flow rate, eliminating the need for moving parts, actuators, or complex control systems while maintaining effective pressure control.
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 solution improves evaporator efficiency by ensuring rapid evaporation, preventing refrigerant pooling and oil clogging, and maintaining laminar airflow, thus enhancing the overall refrigeration system performance without the need for superheating and reducing pressure drops.
Implementation Method 1
an internal atomizer which ejects refrigerant expansion droplets, or particles, simultaneously, coating the wall of the evaporator where heat exchange occurs
Implementation Method 2
Coanda effect inducing evaporation chambers
Implementation Method 3
the liquid refrigerant absorbs heat and converts again into a superheated vapor
Implementation Method 4
Air or water within an enclosed refrigerator system is moved across the evaporator, transferring heat to the refrigerant
Data Source
AI summary
An evaporator for use in a refrigeration system includes one or more Coanda evaporation chambers having an integrated, internal expansion device. The internal expansion device is a linear atomization tube having a plurality of ejection holes arranged in a series of spiral rows. Liquid refrigerant introduced into the linear atomization to is ejected onto the inner wall of the Coanda evaporation chamber, covering it completely with a thin layer of liquid refrigerant. Liquid refrigerant is fed to the linear atomization device in a series of rapid pulses.