Influence of the new refrigerant thermodynamic properties on some refrigerating turbocompressor characteristics

A zero ODP replacement for R12 in a centrifugal compressor: an experimental study using R134a

“…In particular, studies are in progress to obtain blends of refrigerants with properties sufficiently close to R12 so that it is not necessary to change the impeller or the variation of the impeller speed (Pearson and Pearson, 1999). No problems are related to the sonic velocity because the sonic velocity of the R134a is similar to that of R12: 135 ms À1 for R12 and 143 ms À1 for R134a (Sarevski, 1996). The thermodynamic properties of R134a require larger compressor suction volume flow rate per unit refrigerating capacity.…”

Characteristics of water vapor turbocompressors applied in refrigeration and heat pump systems

“…The global environmental problems, connected with ozone depletion and global warming, have led to renewed interest in natural refrigerants (ammonia, carbon dioxide, water, air and hydro-carbons such as propane, butane). The idea of water turbocompressor refrigerating systems started at the end of 1980s and 1990s ( Sarevski, 1989( Sarevski, , 1996Koren and Ophir, 1996;Madsboll and Minds, 1996;Paul, 2007). The company IDE Technologies, Israel, has been the pioneer for centrifugal water vapor compressors back in 1960s, 1970s and 1980s (Koren and Ophir, 1996.…”

“…(Jantovski and Levin, 1989;Su si c et al, 1994;Sarevski and Sarevski, in press). The characteristics of R718 centrifugal compressor and thermocompression heat pumps/refrigerating systems have been analyzed by Sarevski and Sarevski (2011), where are given possibilities for application of the turbocompressors operating in that systems with water vapor, as natural working medium (refrigerant).…”

“…The theory of refrigerating machines is given by Cerepnalkovski (1991). The influence of the refrigerant thermodynamic properties on some refrigerating turbocompressor characteristics is presented by Sarevski (1996). The world-wide extent of the centrifugal refrigerating units working with various refrigerants is very large.…”

Predicting off-design range and performance of refrigeration cycle with two-stage centrifugal compressor and flash intercooler

“…The thermodynamic model was simple, and the operation of the compressor was not discussed. Sarevski (1996) has conducted a study of the influence of different refrigerants on the characteristics of centrifugal compressors. It was concluded that the main parameters of the centrifugal compressor were mostly dependent on the refrigerant molecular mass, the normal boiling temperature and the specific volumetric cooling capacity.…”