Design Point Performance Trends for Water Vapor Compressors

A design study of various water vapor compressor configurations — including single and multistage centrifugal compressors and multistage axial compressors — is used to determine geometry and performance trends as a function of design speed, compressor configuration, and intercooling method. The intercooled multistage centrifugal machines led to the lowest required power levels, though the large outer diameter of these machines and the addition of an intercooler may reduce their appeal. The non-intercooled multistage axial configurations offered high design point performance and a much smaller outer diameter than the centrifugal machines, though at the expense of large overall axial length and limited flow range. Ultimately, the selection of the right machine for a given application is a tradeoff between the performance and geometry trends illustrated in this paper, as well as the cost of the machine.