Fluidic Oscillating Nozzle Cooling to Disrupt Leidenfrost Vapor Layers

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Solution Overview

Problem

The high temperature difference between cryogenic liquids and objects to be cooled leads to the Leidenfrost effect, resulting in reduced heat transfer and inefficient cooling due to the insulating vapor layer formed, causing longer cooling times and less efficient use of cooling fluids.

Innovation Solution

A method using fluidic oscillating nozzles to generate a spatially oscillating jet of cryogenic cooling liquids, disrupting the vapor layer and enhancing heat transfer by maintaining a constant flow rate, which is simpler and less costly than generating pulsating jets.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a cryogenic liquid is used to cool an object, then the cooling effect is enhanced, but the Leidenfrost effect forms a vapor layer that reduces heat transfer efficiency

Engineering Contradiction:
Improvecooling effectVSAvoidheat transfer efficiency
Core Design Contradiction:
TemperatureVSLoss of energy

Solution Approach 1:

The patent employs periodic oscillation of the cryogenic liquid jet to disrupt the vapor layer formation. By oscillating the jet in a periodic manner, the vapor barrier that insulates the object from the cooling liquid is continuously broken, allowing efficient heat transfer to occur while maintaining the large temperature difference necessary for rapid cooling

Inventive Principle:
Principle #19Periodic action

2Object-affected harmful factors

If a vapor layer forms between the cryogenic liquid and object surface, then the Leidenfrost effect occurs, but heat transfer is reduced and cooling time increases

Engineering Contradiction:
ImproveLeidenfrost effectVSAvoidcooling time
Core Design Contradiction:
Object-affected harmful factorsVSLoss of time

Solution Approach 1:

The periodic oscillation of the cryogenic liquid jet prevents the vapor layer from establishing a stable insulating barrier. The oscillating motion periodically breaks the vapor layer, ensuring continuous contact between the cryogenic liquid and the object surface, thereby maintaining high heat transfer rates and reducing overall cooling time

Inventive Principle:
Principle #19Periodic action

3Object-generated harmful factors

If a vapor layer is formed, then the Leidenfrost phenomenon occurs, but the use of cooling fluid becomes less efficient

Engineering Contradiction:
Improvevapor layer formationVSAvoidcooling fluid efficiency
Core Design Contradiction:
Object-generated harmful factorsVSLoss of energy

Solution Approach 1:

By oscillating the cryogenic liquid jet periodically, the system prevents the vapor layer from forming a continuous insulating barrier. This ensures that the cryogenic liquid maintains effective thermal contact with the object surface, maximizing the utilization of the cooling fluid's thermal energy and preventing waste of the expensive cryogenic resource

Inventive Principle:
Principle #19Periodic action

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 method effectively increases heat transfer away from objects, leading to faster and more efficient cooling by disrupting the vapor layer, thus improving the cooling process with cryogenic fluids.

Implementation Method 1

said at least one fluidic oscillating nozzle is configured to generate a spatially oscillating jet of said cryogenic cooling liquid while maintaining a constant flow rate of the cryogenic cooling liquid through the nozzle

Methodology Applied
Scientific EffectFluidic oscillation:

Implementation Method 2

This extremely high temperature difference causes the so-called Leidenfrost effect, wherein a vapor layer is formed between the cryogenic liquid and the surface of the object or substance to be cooled

Methodology Applied
Scientific EffectLeidenfrost effect: Leidenfrost Effect

Implementation Method 3

the spatially oscillating jet of the cryogenic cooling liquid disturbs or even removes a vapor layer on the surface of the at least one object to be cooled so that the heat transfer away from the at least one object is increased

Methodology Applied
Scientific EffectHeat transfer enhancement:

Implementation Method 4

the heat distribution in a space around the at least one object (this space can be an internal space of an enclosure such as a chamber of a cabinet freezer or a tunnel of a tunnel freezer) takes place due to evaporation of the cryogenic cooling liquid in the oscillating jet

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP3318825B1Method and apparatus for cooling objects with a cryogenic liquid using fluidic oscillating nozzles
Publication Date: 2021.12.29 LINDE AG
  • EP3318825B1 patent drawingFigure 1
  • EP3318825B1 patent drawingFigure 2

AI summary

The invention relates to a method for cooling an object (O), comprising the steps of: providing at least one object (O) to be cooled, spatially distributing a cryogenic cooling liquid (L) using at least one nozzle (100) onto said at least one object (O) so that the at least one object (O) is cooled. According to the invention said at least one nozzle (100) is a fluidic oscillating nozzle (100). Furthermore, the invention relates to a corresponding apparatus (1).