Non-Invasive Void Fraction Measurement in Heat Conduction Members
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional measurement methods are invasive and inadequate for determining the void fraction within heat conduction members like vapor chambers and heat pipes, which affects their cooling performance and risk of dryout conditions.
Innovation Solution
A system and method using electrode pads and an LCR meter to measure impedances, converting them into void fractions, allowing for non-invasive calculation of vapor-liquid distribution and safe heat flux operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional invasive measurement methods are used to determine void fraction, then measurement can be performed, but the sealed state of the heat conduction member is compromised and measurement precision is insufficient
Solution Approach 1:
The patent replaces conventional invasive mechanical measurement methods with an electrical measurement system. By applying AC voltage through electrode pads on the outer surface and measuring impedance changes, the system determines void fraction non-invasively through the heat conduction member wall, preserving the sealed state while achieving precise measurement
Solution Approach 2:
The patent uses the heat conduction member wall itself as an intermediary medium. The electrode pads attach to the outer surface, and the electrical signal passes through the wall to interact with the working fluid inside, enabling measurement without breaking the seal. The impedance change of the wall-fluid system reflects the void fraction internally
2Reliability
If the fill rate of working fluid is increased to prevent dryout, then dryout risk is reduced, but fluid flow is blocked and heat dissipation performance deteriorates
Solution Approach 1:
The patent implements a feedback mechanism by continuously monitoring impedance changes that correlate with void fraction. The system can detect the optimal fluid distribution state and alert operators or automatically adjust conditions to maintain peak heat dissipation performance while preventing dryout, balancing fill rate optimization
Solution Approach 2:
The patent changes the measurement parameter from direct fluid level or pressure measurement to impedance measurement. By monitoring the electrical impedance of the wall-fluid system, the system can infer void fraction and working fluid distribution, enabling optimization of fill rate for maximum heat dissipation while preventing dryout 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
Enables non-invasive measurement of void fractions, preventing dryout conditions and ensuring safe operation by visualizing the vapor-liquid distribution within heat conduction members.
Implementation Method 1
an LCR meter electrically connected to the at least one pair of the electrode pads for measuring impedances of the heat conduction member
Implementation Method 2
a heating device configured as a heat source to heat an evaporation end of the heat conduction member
Implementation Method 3
a cooling device configured for cooling a condensation end of the heat conduction member
Implementation Method 4
a cyclic process of evaporation and condensation of the working fluid sealed in a chamber
Implementation Method 5
a cyclic process of evaporation and condensation of the working fluid sealed in a chamber
Data Source
AI summary
A system and a method for measuring a void fraction of an inside of a heat conduction member are provided. The system is used to measure the heat conduction member and includes: a heating device configured as a heat source to heat an evaporation end of the heat conduction member; a cooling device configured for cooling a condensation end of the heat conduction member; at least one pair of electrode pads respectively attached to two opposite surfaces of the heat conduction member; and an LCR meter electrically connected to the at least one pair of the electrode pads for measuring impedances of the heat conduction member. Each of the impedances is converted into the void fraction that corresponds to a measured position of the heat conduction member.