Multicompressor ammonia refrigeration system with low-capacity screw compressors

摘要

This article presents multicompressor refrigeration systems with low-capacity screw compressors (compressor output up to about 250 m{sup}3/hr) for ammonia as the refrigerant. The capacity ranges appropriate for air conditioning, normal-temperature refrigeration, and low-temperature applications are shown. The various compressor designs and the technical aspects which characterize the quality and operating economy of these compressors are shown. The descriptions of the other major components are based on the conceptual design. Special consideration is devoted to the various possibilities for heat recovery. Typical potential applications of multicompressor systems with screw compressors are described, using examples from readymade liquid chillers and refrigeration plants constructed on-site. The final comparison with single-compressor units consisting of large screw compressors considers viewpoints important for the operators. The particular advantage of multicompressor refrigeration systems is their higher operating reliability because the total capacity is distributed over several compressors. That is why this concept for the medium capacity range is of such interest for industrial refrigeration plants.