TECHNOLOGIES NEEDED TO ADVANCE THE POSITION OF MAJOR NATURAL REFRIGERANTS: HC, NH_3, AND CO_2

摘要

Hydrocarbons (ie. propane, isobutene, propene, ethane, etc.) ammonia, and carbon dioxide are the three major natural refrigerants that could be really strong contenders for dominant positions in certain applications throughout the world. Actually, a few of them have already achieved this position: ammonia in large industrial refrigeration mostly in the USA and Europe, isobutene in household refrigerators mostly in northern Europe, CO_2 in heat pumps for water heating in Japan. This paper discusses which technologies or improvements are needed to increase the number of successful applications. Major directions are: charge reduction for each candidate, hermetic ammonia compressors, use of less costly materials in ammonia systems, further improved compressors for CO_2 as well as better heat exchangers (HX) and work recovery options.