Universal heat exchanger for air and evaporative cooling of electronics

Abstract

We present a heat exchanger design that was developed for low temperature cooling of medium power density electronics and, more specifically, for the particle detectors of the “forward” AFP and TOTEM experiments at the CERN Large Hadron Collider (LHC). The heat exchanger uses a metal foam to enhance internal heat transfer, it is galvanically insulated from the pipes of the cooling system and hermetically sealed. The notable advantage of this heat exchanger is that the same design can be used with air or evaporating refrigerant as the cooling fluid. This can be beneficial when the development and testing phases of the detectors take place in laboratories with limited cooling equipment, or for backup cooling solutions that move from a primary refrigerant system to air-cooling. Several prototypes have been built and tested, both in the laboratory and in direct application in the AFP experiment at the LHC. The temperature difference between the inlet air and the surface of the heat exchanger is 20 °C with a 20 W heat load, this difference drops to 10 °C when R-218 refrigerant is used instead of the air.