Electrohydrodynamic Heat Transfer Device for Satellite Thermal Control
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Solution Overview
Problem
Geostationary satellites face variable thermal environments due to uneven solar radiation, leading to inefficient heat dissipation and excessive cooling, with existing heat pipes operating passively and bidirectionally without control, resulting in suboptimal equipment temperature management and power availability issues.
Innovation Solution
A heat transfer device with a sealed housing containing a dielectric liquid and an electrohydrodynamic mixer, allowing for controlled heat transfer between two objects via forced convection, switching between low and high thermal conductance states, enabling bidirectional heat transport and acting as a thermal switch.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If heat pipes are used for passive bidirectional heat transfer, then heat transfer reliability is improved, but heat transfer control capability deteriorates
Solution Approach 1:
The patent applies the dynamics principle by transforming the static, passive heat pipe system into a dynamic, controllable system. The electrohydrodynamic mixer actively pumps dielectric liquid between hot and cold reservoirs, enabling real-time control of heat transfer direction and magnitude through electrode activation, while maintaining reliability through active monitoring and control mechanisms.
Solution Approach 2:
The patent replaces the passive mechanical heat pipe system with an electrohydrodynamic system that uses electric fields to drive liquid circulation. The electrohydrodynamic mixer uses electrodes to generate electrostatic forces that pump the dielectric liquid, substituting the passive capillary action of heat pipes with an actively controllable electrostatic pumping mechanism.
2Temperature
If radiators are sized for worst case hot, then equipment temperature safety is improved, but energy efficiency deteriorates due to excessive cooling
Solution Approach 1:
The patent applies dynamics by making the heat transfer system adaptive and controllable. The electrohydrodynamic mixer can be activated or deactivated based on real-time thermal conditions, allowing the system to transfer heat only when necessary. This prevents excessive cooling during normal operation while ensuring temperature safety during peak thermal loads, significantly improving energy efficiency.
Solution Approach 2:
The patent changes the operational parameters of the heat transfer system by using variable electrode activation and adjustable liquid flow rates. The system can modulate the degree of heat transfer by controlling the electrohydrodynamic pumping intensity, allowing optimization between temperature safety and energy efficiency based on actual operational requirements.
3Use of energy by moving object
If active cooling is implemented to prevent excessive cooling, then energy consumption is reduced, but device complexity increases
Solution Approach 1:
The patent applies universality by designing the electrohydrodynamic mixer to perform multiple functions: it acts as both a heat pump and a thermal switch, can operate in bidirectional mode, and integrates sensing and control capabilities. This multi-functionality reduces the need for separate active cooling systems, thereby limiting the increase in device complexity while achieving energy savings.
Solution Approach 2:
The patent implements self-service through the electrohydrodynamic system's ability to automatically respond to thermal conditions. The system can detect temperature differentials and activate the electrostatic pumping mechanism as needed, eliminating the need for external control systems and reducing overall device complexity while minimizing energy consumption.
4Stability of the object's composition
If thermal insulation is applied to East and West faces, then thermal stability is improved, but heat dissipation capacity deteriorates
Solution Approach 1:
The patent applies segmentation by dividing the satellite's thermal management into independent, controllable zones. The electrohydrodynamic heat transfer system can selectively manage heat from different equipment modules and direct it to appropriate radiators, allowing thermal insulation on East and West faces while maintaining overall heat dissipation capacity through active heat routing.
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 device provides a lightweight, reliable, and energy-efficient means to manage heat transfer, allowing precise control over equipment temperatures and reducing power consumption, while maintaining compatibility with existing heat pipes and radiators.
Implementation Method 1
the mixer comprising at least two electrodes arranged with a spacing between one another and immersed in the dielectric liquid, the electrodes and the liquid forming an electrohydrodynamic system
Implementation Method 2
a second state in which the dielectric liquid is in motion and transfers heat by forced convection between the first main wall and the second main wall
Implementation Method 3
the first main wall being intended to be in direct thermal contact by conduction with said first object, the second main wall being intended to be in direct thermal contact by conduction with said second object
Data Source
AI summary
A heat transfer device is disclosed having a housing including a first main wall and a second main wall, the housing having a sealed internal cavity, a liquid contained in the internal cavity, and a mixer able to set the liquid in motion, the heat transfer device being able to be switched between a first state and a second state in which the liquid is in motion and transfers heat by convection between the first main wall and the second main wall, the thermal conductance between the first main wall and the second main wall in the first state being four times less than the thermal conductance between the first main wall and the second main wall in the second state.