Heat Pipe Thermal Modeling for Dryout and Pool Formation
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Solution Overview
Problem
Current methods for simulating heat pipe performance, such as 1D simplified models, fail to accurately predict dryout in the evaporator section and pool formation in the condenser section, leading to performance losses and errors, especially under high heat loads, and require excessive computational time for 2D and 3D comprehensive models.
Innovation Solution
A novel methodology that calculates pressure variation and edge angle along the heat pipe to determine liquid and vapor phase distribution, computes effective liquid flow length, and separates heat transfer via conduction and phase change, allowing for fast computation of thermal performance parameters like temperature distribution and vapor temperature, while detecting dryout and pool formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If 1D simplified models are used for heat pipe simulation, then computation time is reduced, but accuracy in predicting dryout and pool formation deteriorates
Solution Approach 1:
The patent changes the dimensional parameter from 1D to 2D/3D modeling to improve prediction accuracy of dryout and pool formation. By incorporating additional spatial dimensions, the model captures complex fluid flow patterns and thermal gradients that 1D models cannot represent, thereby resolving the accuracy issue while managing computational complexity through efficient numerical methods.
Solution Approach 2:
The heat pipe is divided into multiple control volumes or computational cells along its length, with separate treatment for evaporator, adiabatic, and condenser sections. This segmentation allows the model to locally resolve dryout conditions in the evaporator and pool formation in the condenser without requiring a fully resolved 3D mesh throughout the entire structure, thus balancing accuracy and computational cost.
2Measurement precision
If 2D and 3D comprehensive models are used for heat pipe simulation, then prediction accuracy improves, but computation time increases significantly
Solution Approach 1:
The patent applies high-resolution 2D/3D modeling only in critical regions where dryout and pool formation occur (evaporator and condenser sections), while using simplified 1D modeling in the adiabatic section. This localized application of complexity maintains prediction accuracy for the phenomena of interest while significantly reducing overall computational time compared to full 3D modeling.
Solution Approach 2:
The patent uses 1D model results as a preliminary copy or approximation to guide the 2D/3D simulation setup, initial conditions, and parameter ranges. This allows the comprehensive model to focus computational resources on resolving the critical phenomena without requiring exhaustive exploration of the entire parameter space, thereby reducing computation time while maintaining accuracy.
3Device complexity
If traditional cooling methods are used for electronic components, then system complexity is reduced, but thermal management performance deteriorates
Solution Approach 1:
The patent utilizes phase change (evaporation and condensation) of the working fluid within the heat pipe to achieve high heat transfer coefficients. The liquid evaporates in the evaporator section absorbing heat from hot electronic components, and the vapor condenses in the condenser section releasing heat to the cooling medium. This passive phase-change-based thermal management achieves superior temperature control without requiring complex active cooling systems.
Solution Approach 2:
The heat pipe operates as a passive thermal management device that automatically transports heat from hot spots to cooling regions without requiring external actuators such as pumps or fans. The phase change mechanism and capillary forces within the wick structure self-regulate the fluid flow, providing adaptive thermal management that responds automatically to changing heat generation conditions in electronic components.
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 approach enables fast and accurate computation of heat pipe performance parameters, similar to comprehensive 2D and 3D models, with significantly reduced computational time, effectively predicting dryout and pool formation, and designing heat pipes with varying input parameters.
Implementation Method 1
Heat pipes, which do not need any external actuator systems such as pumps, operate in a passive and closed loop and have high heat transfer capacity owing to the phase change of the working fluid
Implementation Method 2
specifically 1D simplified models were proposed in the literature... modeling the phase change together with momentum and energy transfer inside the heat pipe... evaporation, condensation, capillary fluid flow, and counter vapor flow
Implementation Method 3
evaporation, condensation, capillary fluid flow, and counter vapor flow
Implementation Method 4
modeling the phase change together with momentum and energy transfer inside the heat pipe... capillary fluid flow
Data Source
AI summary
A method for performance determination of a heat pipe with an arbitrary liquid flow area and prescribed geometric dimensions, an external and internal structure, a heat pipe material and a working fluid, heating and cooling surface areas, and condenser cooling conditions is provided to obtain operating and performance parameters, wherein the operating and performance parameters are temperature distribution within the heat pipe, a heat transferred via a phase change and a conduction, an axial variation of a radius of curvature of a liquid-vapor interface along the heat pipe, a vapor temperature and pressure of the working fluid, by simulating a flow and an energy transfer inside.