Subambient Boiling Coolant for High-Flux Electronics Cooling
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Solution Overview
Problem
Existing cooling methods for high-power electronic components, such as phased array antennas and future computational circuits, are inadequate due to the large size, weight, and power consumption of refrigeration units, and fail to effectively remove high flux heat loads using conventional coolants like fluorinerts.
Innovation Solution
A method involving a coolant at subambient pressure, where pure water or methanol is used to boil and vaporize, absorbing heat from heat-generating structures, with a system that includes a subambient cooling system, a bath or flow of coolant, and a filtration process to maintain purity and prevent electrical shorts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If refrigeration units are used to cool high-power electronics, then cooling capacity is sufficient, but the units become large, heavy, and consume many kilowatts of power
Solution Approach 1:
The patent utilizes the phase transition of dielectric liquid from liquid to vapor state during boiling. The liquid dielectric absorbs latent heat of vaporization when transitioning to vapor, providing efficient cooling. The vapor is then condensed back to liquid in a heat exchanger, completing the cycle. This phase change mechanism enables high cooling capacity without requiring large refrigeration units
Solution Approach 2:
The patent changes the pressure parameter of the dielectric liquid to subambient levels, which lowers the boiling temperature to below the temperature of the heat-generating electronics. This parameter change enables the liquid to boil and absorb heat at operating temperatures, providing continuous cooling without requiring large temperature differentials that would necessitate bulky refrigeration equipment
2Temperature
If conventional coolants like fluorinerts are used, then cooling is provided, but heat transfer performance is inadequate for high flux heat loads
Solution Approach 1:
The patent employs two-phase flow of dielectric liquid and vapor, utilizing phase transitions to dramatically enhance heat transfer performance. The boiling process absorbs large amounts of latent heat, and the vigorous two-phase flow creates intense mixing and heat transfer at the liquid-electronics interface, enabling effective removal of high flux heat loads that single-phase coolants cannot handle
Solution Approach 2:
The patent uses dielectric liquid in a two-phase pneumatic-hydraulic system where liquid and vapor phases work together for heat transfer. The liquid provides cooling through boiling and the vapor facilitates heat removal through flow and condensation, creating an efficient heat transfer mechanism that outperforms conventional single-phase coolant systems
3Productivity
If densely-packed electronics are used to increase computational power, then processing capacity increases, but heat generation increases to 1000-10,000 watts per cubic centimeter
Solution Approach 1:
The patent uses the high latent heat of vaporization of dielectric liquid during phase change from liquid to vapor to remove the intense heat generated by densely-packed electronics. The boiling process absorbs large amounts of heat energy, enabling the system to handle heat fluxes of 1000-10,000 watts per cubic centimeter without requiring excessive cooling infrastructure that would compromise the compact design
Solution Approach 2:
The dielectric liquid acts as an intermediary between the heat-generating electronics and the external environment. It absorbs heat directly from the electronics through boiling, transports the heat energy in vapor form, and releases it externally through condensation, enabling the densely-packed electronics to operate at high computational capacity without thermal runaway
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 allows for efficient heat removal from densely-packed electronics, reducing the need for large refrigeration units and minimizing power consumption, while maintaining high electrical resistivity to prevent shorts, enabling more compact and efficient cooling systems.
Implementation Method 1
the coolant boils and vaporizes to thereby absorb heat from the heat-generating structure
Implementation Method 2
the coolant boils and vaporizes to thereby absorb heat from the heat-generating structure
Implementation Method 3
the coolant boils and vaporizes to thereby absorb heat from the heat-generating structure
Implementation Method 4
reducing a pressure of the coolant to a subambient pressure at which the coolant has a boiling temperature less than a temperature of the heat-generating structure
Implementation Method 5
The liquid dielectric has a high electrical resistivity such that the liquid dielectric does not form a short in the microelectronics
Data Source
AI summary
According to one embodiment of the invention, a method is provided for cooling heat-generating structure disposed in an environment having an ambient pressure. The heat-generating structure includes electronics. The method includes providing a coolant, reducing a pressure of the coolant to a subambient pressure at which the coolant has a boiling temperature less than a temperature of the heat-generating structure, and bringing the heat-generating structure and the coolant at the subambient pressure into contact with one another, so that the coolant boils and vaporizes to thereby absorb heat from the heat-generating structure. In a more particular embodiment the coolant is either pure water or pure methanol with an electrical resistivity level of greater than one million Ohms-cm. Further, in another particular embodiment the method includes filtering the coolant to maintain its purity above a particular level.