Vapor Cycle System for the F-22 Raptor

The F-22 Raptor is the first high performance tactical aircraft to use a variable speed vapor cycle refrigeration system to support liquid cooling of electronic heat loads. A compact Vapor Cycle System (VCS), comprised of a VCS pack and a VCS Controller (VCC), has been developed for this purpose. This system is preferred for operation on the F-22 aircraft because of its ability to operate in a variable-G environment, because it has a coefficient of performance greater than 1, and because of its compact design compared to conventional air cycle and fixed-speed vapor cycle systems. The compactness of the VCS was achieved by trading off size with technological complexity. The purpose of this paper is to describe at a functional level the VCS pack and VCC designed for the F-22 aircraft. The results to date of system testing of the VCS are discussed.