DESIGN ISSUES ASSOCIATED WITH SECONDARY LOOP REFRIGERATION SYSTEMS FOR MULTI-TEMPERATURE ROAD TRANSPORTATION UNITS

摘要

Secondary loop refrigeration systems are increasingly being used in stationary refrigeration applications and recent research has shown that they may have certain advantages over comparable direct expansion systems. However, for the transport refrigeration sector, the use of direct expansion refrigeration has been the favoured choice to date. In this paper, issues associated with the use of secondary loop refrigeration systems in multi-temperature transport refrigeration units are examined. Topics considered include circuit design, capacity control strategies, defrost, choice of secondary refrigerant as well other design issues. The design of an experimental test rig to examine these issues is also outlined.