R47 -- Cryogenics - (SI)

Cryogenics is a term normally associated with low temperatures. However, the location on the temperature scale at which refrigeration generally ends and cryogenics begins has never been well defined. Most scientists and engineers working in this field restrict cryogenics to a temperature below 235F (225R; 125 K),because the normal boiling points of most permanent gases (e.g., helium, hydrogen, neon, nitrogen, argon, oxygen, and air) occur below this temperature. In contrast, most common refrigerants have boiling points above this temperature. Cryogenic engineering therefore is involved with the design and development of low-temperature systems and components. In such activities the designer must be familiar with the properties of fluids used to achieve these low temperatures as well as the physical properties of components used to produce, maintain, and apply such temperatures.

Chapter Table of Contents

General Applications
Low-Temperature Properties
Refrigeration and Liquefaction
Cryocoolers
Separation and Purification of Gases
Equipment
Low-Temperature Insulations
Storage and Transfer Systems
Instrumentation
Hazards of Cryogenic Systems

Citation: 2010 ASHRAE Handbook -- Refrigeration: Chapter 47, Cryogenics



Product Code(s): D-R472010SI