Experimental investigation of a direct driven radial compressor for domestic heat pumps
The presence of oil in domestic heat pumps is an obstacle toward higher efﬁciency, particularly for enhanced surface evaporators and for advanced concepts based on two- stage cycles. Very compact direct driven radial compressors supported on oil-free bearings represent a promising alternative. This paper presents the derivation of the speciﬁcations, the choice for an appropriate refrigerant ﬂuid and the design of a proof of concept proto-type with the various tradeoffs between the impeller characteristics to follow the seasonal heat demand, the bearing and rotordynamics for a stable operation. Heat pump simulation results, the design of the impeller as well as the layout of the experimental facility and ﬁrst experimental results are presented. An impeller with a tip diameter of 20 mm has been tested at rotational speeds of up to 210 krpm reaching pressure ratios in excess of 3.3 and efﬁciencies above 78%. The refrigerant chosen for this ﬁrst experimental approach is HFC 134a.
Keywords: Heat pump ; Domestic application ; Centrifugal compressor ; Design ; Compressor ; Simulation ; Performance ; Pompe à chaleur ; Application domestique ; Compresseur centrifuge ; R134a ; Conception ; Compresseur ; Simulation ; Performance
Record created on 2009-11-19, modified on 2016-08-08