Development of Spacecraft Vuilleumier Cryogenic Refrigerators. Part I. Thermodynamic Design and Study of Life-Limiting Components

摘要

A preliminary thermodynamic configuration has been established for a Vuilleumier (VM) cycle cryogenic refrigerator suitable for space flight and designed for long unattended life and high efficiency. To achieve an operational life of 20,000 hours, four major design areas were investigated, viz., mechanical drive, regenerator seals, electric hot side heater, and working gas contamination. The refrigerator will be a triple-expansion unit; it will utilize an oil-lubricated rhombic drive, rolling diaphragm reciprocating shaft seals, and a dual-element heater for the hot side. Concepts were evolved for the design of the life-limiting components, and preliminary tests are being conducted on the mechanical drive and regenerator seals. An initial design, including weight, power input and reliability, is described.