1043 KB24 KB199920252020Gojak, MilanRudonja, NedžadTodorović, RužicaZlatanović, Ivanštevilka:11letnik:66str. 677-683ISSN:0039-2480COBISSID_HOST:38179075URN:URN:NBN:SI:doc-WN3O4TJ2enZveza strojnih inženirjev in tehnikov Slovenije etc.Strojniški vestnikcascade heat pumpscoefficient of performancedelovni medijieksergijski izkoristekexergy efficiencygrelno številokaskadne toplotne črpalkeworking mediumsThermodynamic analysis of a cascade heat pump incorporated in high-temperature heating system|In this article is presented thermodynamic analysis of a cascade heat pump system designed for using in high-temperature heating systems. The own thermodynamic model was built by using properties of working fluids from the CoolProp base. The cascade heat pump was designed to use ambient air as heat source with temperature tsubamb= -20 °C and for heating water in the high-temperature heating system up to 70 °C. The projected heating capacity of the cascade heat pump was 100 kW. The coefficient of performance (COP) of the cascade heat pump system due to use of different working mediums combinations in cycles of the cascade heat pump was investigated. For the best combination of working fluids (mediums) sub-cooling, super-heating, pressure loss in compressor's suction line, as well as exergy efficiency of the heat pump were analysed as a function of the mean temperature of the cascade heat exchangerTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaUniverza v Ljubljani, Fakulteta za strojništvo