000265661 001__ 265661
000265661 005__ 20190812204800.0
000265661 037__ $$aCONF
000265661 245__ $$aImpact of large tip clearance ratios on the performance of a centrifugal compressor
000265661 260__ $$c2019-04-08
000265661 269__ $$a2019-04-08
000265661 300__ $$a12
000265661 336__ $$aConference Papers
000265661 520__ $$aUltra-compact and fast spinning turbomachinery is a key technology to increase performance of domestic heating applications and to address decentralization of power and heat as a consequence of the rise of renewable energy sources. Recently, a heat pump using a reduced-scale centrifugal compressor with an impeller diameter of 20 mm supported on gas bearings was tested successfully and higher system performance compared to commonly used positive displacement compressors was achieved. Nonetheless, due to the small feature size as well as manufacturing tolerances, the performance of such compressor systems is deteriorated compared to large-scale systems. The tip gap necessary to ensure a free spinning of the rotor on gas bearings is relatively large compared to industrial compressors. Unfortunately, limited experience about centrifugal compressors running on relative large clearance exists. This paper investigates the impact of tip leakage on the performance of centrifugal compressor systems for relative clearance ratios, ranging from 3 up to 15 %. The tip leakage analysis is conducted numerically on an experimentally validated centrifugal compressor system operating with refrigerant R134a. In order to investigate the behavior of the compressor by altering its clearance ratio, impellers with different blade heights are used to adjust the tip gap. The change in efficiency is investigated and empirical correlations available in literature are assessed. A new method to predict change in efficiency as function of relative clearance ratio is provided, thus extending current correlations to much higher relative clearance ratios.
000265661 6531_ $$aREFRIGERATION
000265661 6531_ $$aTIP GAP VARIATION
000265661 700__ $$0248884$$aDiehl, Markus$$g253887
000265661 700__ $$0246993$$aSchiffmann, Jürg Alexander$$g103606
000265661 7112_ $$aEuro Turbo Conderence ETC13$$cLausanne, Switzerland$$dApril 8-12, 2019
000265661 8560_ $$fjulie.lenoblezwahlen@epfl.ch
000265661 8564_ $$uhttps://infoscience.epfl.ch/record/265661/files/Diehl_ETC13.pdf$$s890156
000265661 85641 $$yconference website$$uwww.euroturbo.eu
000265661 909C0 $$pLAMD$$mjulie.lenoblezwahlen@epfl.ch$$0252488$$zMarselli, Béatrice$$xU12652
000265661 909CO $$pconf$$pSTI$$ooai:infoscience.epfl.ch:265661
000265661 960__ $$ajulie.lenoblezwahlen@epfl.ch
000265661 961__ $$aalain.borel@epfl.ch
000265661 973__ $$aEPFL$$rREVIEWED
000265661 980__ $$aCONF
000265661 981__ $$aoverwrite