Boiling Cooler Groove Structure to Prevent High-Heat-Flux Dryout
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing boiling coolers face issues with localized dryout due to reduced liquid-phase refrigerant supply to boiling surfaces, leading to decreased heat transfer efficiency, particularly under high heat flux conditions.
Innovation Solution
The boiling cooler incorporates grooves with irregularly protruding/recessed shapes on the boiling surface, formed by energy beam processing, which serve as nucleate boiling sites and allow for increased heat transfer area and smooth refrigerant supply, preventing localized dryout.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If holes with rough interior surfaces and annular ridges are formed on the boiling heat transfer surface, then the generation rate of bubbles is improved, but the liquid-phase refrigerant cannot easily flow into the openings due to surrounding annular ridges, leading to localized dryout
Solution Approach 1:
The invention introduces grooves with different structural characteristics at specific locations on the boiling heat transfer surface. The grooves have open structures that facilitate liquid supply while their internal geometry promotes bubble generation. This local structural differentiation allows different regions of the heat transfer surface to perform specialized functions: some areas optimize for liquid ingress while others optimize for bubble formation and departure.
Solution Approach 2:
The boiling heat transfer surface is segmented into multiple groove structures distributed across the surface. Each groove acts as an independent functional unit that contributes to overall heat transfer performance. The segmentation allows liquid to access multiple entry points rather than relying on a single opening, ensuring continuous liquid supply even when some grooves are temporarily filled with bubbles.
2Power
If the input heat per unit time (heat flux) is increased, then the cooling capacity is improved, but the interiors of the holes are likely to be continuously filled with bubbles and become dry (dryout)
Solution Approach 1:
The invention changes the geometric parameters of the surface structures from closed holes to open grooves. This parameter change fundamentally alters the fluid dynamics within the structures: the open groove geometry allows bubbles to escape more easily while maintaining liquid contact, enabling the system to sustain higher heat fluxes without transitioning to a dryout state. The groove depth, width, and spacing are optimized to maintain nucleate boiling across a wider range of heat flux conditions.
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 solution effectively increases the generation rate of bubbles while ensuring continuous refrigerant supply, thereby maintaining efficient heat transfer and preventing dryout, even under high heat flux conditions.
Implementation Method 1
a groove(s) that extends/extend in a line shape and has/have an irregularly protruding/recessed shape shaped by melting and solidification of a material by energy beam processing
Implementation Method 2
a boiler boiling a refrigerant by transferring heat from a heat source; the liquid-phase refrigerant is boiled and vaporized to a gaseous state in a part in contact with the boiling heat transfer surface
Implementation Method 3
a condenser condensing the refrigerant vaporized in the boiler and returning the condensed refrigerant to the boiler
Data Source
Figure 1~2
Figure 3~4
Figure 5~6B
AI summary
A boiling cooler (100) according to this invention includes a boiler (10) boiling a refrigerant (5) by transferring heat from a heat source (HS), and a condenser (20) condensing the refrigerant vaporized in the boiler and returning the condensed refrigerant to the boiler. The boiler includes a mounting surface (11a) on which the heat source is mounted, and a boiling surface part (13) on a surface (11b) that is opposite to the mounting surface and is in contact with the refrigerant. The boiling surface part includes a groove(s) (14) that extends/extend in a line shape and has/have an irregularly protruding/recessed shape shaped by melting and solidification of a material by energy beam processing.