Selection and Conversion of Turbocharger as Turbo-Expander for Organic Rankine Cycle (ORC)

Turbo-expander is the most crucial and expensive component in Organic Rankine Cycle (ORC) power generation systems. The turbine engineering, design and research development process for ORC system is costly, time-consuming, and difficult for new-entrants in the ORC field. This paper investigates the re-design and retrofit of an off-the-shelf turbocharger for use in a 1 kW ORC system. The expander requirements were determined for the 1 kW Capstone Gas Turbine bottoming cycles from the ORC system design. A radial turbine was selected and an off-theshelf turbocharger from a small petrol-driven vehicle was acquired. The turbocharger was simulated to study the offdesign performance in an ORC system. The turbocharger was evaluated by expansion of compressed air at room temperature to assess the leakage of working fluid and the lubrication requirements. A preliminary design was developed to deal with leakage and lubrication issues. The conceptual design of an ORC turbine was presented including the casing design and selection of auxiliary components such as bearings, seals and lubrication systems.

[1]  S. L. Dixon.  Fluid Mechanics and Thermodynamics of Turbomachinery Seventh Edition , 2013 .

[2]  S. Gondo,et al.  Solubility of HFC134a in Lubricants and Its Influence on Tribological Performance , 2001 .

[3]  Robert Zanelli,et al.  Externally Pressurised and Hybrid Bearings Lubricated with R134a for Oil-Free Compressors , 1996 .

[4]  David Japikse,et al.  Introduction to Turbomachinery , 1994 .

[5]  Peter L Meitner,et al.  Computer code for off-design performance analysis of radial-inflow turbines with rotor blade sweep , 1983 .

[6]  A. J. Glassman,et al.  FORTRAN program for predicting off-design performance of radial-inflow turbines , 1975 .

[7]  Srithar Rajoo,et al.  Unsteady performance analysis of a twin-entry variable geometry turbocharger turbine , 2012 .

[8]  Nikola Stosic,et al.  COST EFFECTIVE SMALL SCALE ORC SYSTEMS FOR POWER RECOVERY FROM LOW GRADE HEAT SOURCES , 2006 .

[9]  Sunil Sarangi,et al.  Mathematical Analysis for Off-Design Performance of Cryogenic Turboexpander , 2011 .

[10]  Bruno Vanslambrouck,et al.  Organic Rankine cycle as efficient alternative to steam cycle for small scale power generation , 2011 .

[11]  N. Baines.  Axial and Radial Turbines , 2003 .

[12]  S. Quoilin,et al.  Expansion Machine and fluid selection for the Organic Rankine Cycle , 2010 .

[13]  Saffa Riffat,et al.  Expanders for micro-CHP systems with organic Rankine cycle , 2011 .

[14]  B. Nesmith.  Bearing development program for a 25 kWe solar-powered organic Rankine-cycle engine , 1985 .

[15]  Peter A. Jacobs,et al.  Preliminary Design and Performance Estimation of Radial Inflow Turbines: An Automated Approach , 2012 .

[16]  Francisco José Arnau,et al.  A model of turbocharger radial turbines appropriate to be used in zero- and one-dimensional gas dynamics codes for internal combustion engines modelling , 2008 .

[17]  Peter L Meitner,et al.  Off-Design Performance Loss Model for Radial Turbines with Pivoting, Variable-Area Stators. , 1980 .

[18]  R. E. Nece,et al.  Chamber Dimension Effects on Induced Flow and Frictional Resistance of Enclosed Rotating Disks , 1960 .

[19]  O. E. Baljé,et al.  Turbomachines—A Guide to Design Selection and Theory , 1981 .