Accession Number : ADD012677

Title :   Dual Mode Heat Exchanger.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE AIR FORCE WASHINGTON DC

Personal Author(s) : Altoz,Frank E

Report Date : 13 Jan 1987

Pagination or Media Count : 6

Abstract : The invention comprises a compact, light weight, dual mode heat transfer device. The dual mode heat transfer devices provides for air cooling of heat dissipating electronic components at moderate aircraft speeds and when the available ambient air is below a preselected temperature. At elevated aircraft speeds and when the ambient air temperature is above the preselected temperature a coolant liquid is converted to steam or vapor in order to cool the heat dissipating components. A preferred embodiment of the invention includes a cold plate for conducting heat away from the heat dissipating components and radiator fins for dissipating cold plate heat to a cooling air flow. Additionally, a liquid coolant is provided in cavities formed in the cold plate immediately adjacent to the electronic components. This liquid coolant vaporizes at elevated temperatures, when the cooling air flow is unavailable, to cool the cold plate. The steam released by vaporization of the liquid coolant is exhausted from the dual mode heat transfer device through a hydrophobic filter membrane covering a portion of the cavities. The hydrophobic membrane is impervious to liquids but permeable to gas.

Descriptors :   *PATENTS, *LIQUID COOLING, AIR, AIR COOLED, AIR FLOW, AIRSPEED, ATMOSPHERIC TEMPERATURE, CONVERSION, COOLING, DUAL MODE, ELECTRONIC EQUIPMENT, FILTERS, HEAT, HEAT EXCHANGERS, HIGH TEMPERATURE, HYDROPHOBIC PROPERTIES, LIGHTWEIGHT, MEMBRANES, STEAM, VAPORIZATION, AIRCRAFT EQUIPMENT, AVIONICS

Subject Categories : Aircraft
      Air Condition, Heating, Lighting & Ventilating

Distribution Statement : APPROVED FOR PUBLIC RELEASE