Title

Heat transfer issues in a cryogenic radar power system

Abstract

A recent study sponsored by the US Air Force showed that a cryogenic radar system which offers 50% savings in mass and volume and more than 65% savings in fuel consumed is feasible in the immediate future. This paper presents an analysis of the thermal management issues associated with cryocooling the power conditioning equipment in the cryogenic radar system. The impetus for cryogenic operation of the power conditioning system arises from the fact that power MOSFETs (Metal Oxide Semiconductor Field-Effect Transistors) which operate at much higher efficiencies at lower temperatures can be used with passive high-temperature-superconducting elements to realize high-efficiency hybrid circuits. However, the thermal management of superconductor/semiconductor hybrid circuits at cryogenic temperatures poses a challenge due to the high levels of heat dissipation at the semiconductor devices when they are operated near their current carrying capacities. In this study, an analysis is presented to compare the performance of a commercially available power MOSFET at 77K and at 150K with two different cooling techniques, immersion cooling and spray cooling. It is seen that the internal thermal resistances of the device are much lower than the external case-fluid resistance. As a result, the choice of the cooling technique has a major impact on the maximum drain current of the device. Also, it is seen that even at cryogenic temperatures, the power dissipation can be quite large. Therefore, with compact packaging, a MOSFET operating at high drain currents will require high-flux cooling techniques.

Publication Date

12-1-1997

Publication Title

Proceedings of the International Conference on Thermodynamic Analysis and Improvement of Energy Systems, TAIES'97

Number of Pages

608-614

Document Type

Article; Proceedings Paper

Personal Identifier

scopus

Socpus ID

0031377082 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/0031377082

This document is currently not available here.

Share

COinS