Centrifugal compressor efficiency improvement and its environmental impact in waste water treatment

Energy costs typically dominate the life-cycle costs of centrifugal compressors used in various industrial and municipal processes, making the compressor an attractive target for energy efficiency improvements. This study considers the achievable energy savings of using three different diffuser types in a centrifugal compressor supporting a typical end-use process in a waste water treatment plant. The effect of the energy efficiency improvements on the annual energy use and the environmental impacts are demonstrated with energy calculations and life-cycle assessment considering the selected compressor task in the waste water aeration. Besides the achievable energy saving benefits in the wastewater aeration process, the presented study shows the influence of the additional material needed in the diffuser manufacturing on the total greenhouse gas emissions of the compressor life-cycle. According to the calculations and assessment results, the studied diffuser types have a significant effect on the compressor energy use and environmental impacts when the compressor is operated in the aeration task. The achievable annual energy savings in this case were 2.5–4.9% in comparison with the baseline scenario. Also, the influence of the additional material and energy use for manufacturing the diffuser are insignificant compared with the avoided greenhouse gas reduction potential.

[1]  Hans-Jürgen Dr. Klüppel,et al.  The Revision of ISO Standards 14040-3 - ISO 14040: Environmental management – Life cycle assessment – Principles and framework - ISO 14044: Environmental management – Life cycle assessment – Requirements and guidelines , 2005 .

[2]  R. C. Pampreen.  Small Turbomachinery Compressor and Fan Aerodynamics , 1973 .

[3]  A. Grönman,et al.  Experimental study of centrifugal compressor vaneless diffuser width , 2013 .

[4]  Naresh K. Amineni,et al.  A centrifugal compressor stage with wide flow range vaned diffusers and different inlet configurations , 2002 .

[5]  Anibal T. de Almeida,et al.  Market transformation of energy-efficient motor technologies in the EU , 2003 .

[6]  M. Huijbregts,et al.  Handbook on Life Cycle Assessment: Operational Guide to the ISO Standards , 2002 .

[7]  Siva T. Ch. Reddy,et al.  Experimental studies on the effect of impeller width on centrifugal compressor stage performance with low solidity vaned diffusers , 2007 .

[8]  Amit Kumar,et al.  Using Sankey diagrams to map energy flow from primary fuel to end use , 2015 .

[9]  G. Luderer.  Greenhouse gas emission trends and projections in Europe 2006 , 2007 .

[10]  Y Dai,et al.  Numerical study and experimental validation of the performance of two different volutes with the same compressor impeller , 2009 .

[11]  Rahman Saidur,et al.  A review on electrical motors energy use and energy savings , 2010 .

[12]  Food Security.  Agriculture Organization of the United Nations (FAO) , 2004 .

[13]  Marco Giachi,et al.  Parametric Performance of a Class of Standard Discharge Scrolls for Industrial Centrifugal Compressors , 2014 .

[14]  Saad Mekhilef,et al.  A review on energy saving strategies in industrial sector , 2011 .

[15]  Mukka Govardhan,et al.  Performance and wall static pressure measurements on centrifugal compressor diffusers , 2003 .

[16]  Helge Brattebø,et al.  Energy consumption, costs and environmental impacts for urban water cycle services: Case study of Os , 2011 .

[17]  M Molinos-Senante,et al.  Energy efficiency in Spanish wastewater treatment plants: a non-radial DEA approach. , 2011, The Science of the total environment.

[18]  Aki Grönman,et al.  Investigation of the Stage Performance and Flow Fields in a Centrifugal Compressor with a Vaneless Diffuser , 2014 .

[19]  System optimization through co-operation , 2013 .

[20]  G. Eisenlohr,et al.  Thermal Tip Clearance Control for Centrifugal Compressor of an APU Engine , 1993 .

[21]  William C. Hohlweg,et al.  Comparison of Conventional and Low Solidity Vaned Diffusers , 1993 .

[22]  S. Schneider,et al.  Climate Change 2007 Synthesis report , 2008 .

[23]  Kyu-Jung Chae,et al.  Estimating the energy independence of a municipal wastewater treatment plant incorporating green energy resources. , 2013 .

[24]  A Engeda.  The design and performance results of simple flat plate low solidity vaned diffusers , 2001 .

[25]  H. Hayami,et al.  Application of Low-Solidity Cascade Diffuser to Transonic Centrifugal Compressor , 1989 .

[26]  T Turunen-Saaresti,et al.  Effect of vaneless diffuser width on the overall performance of a centrifugal compressor , 2011 .

[27]  Walter Klöpffer,et al.  Life cycle assessment , 1997, Environmental science and pollution research international.

[28]  J. Backman A. Grönman,et al.  Review and collection of preliminary design rules for low solidity diffusers , 2013 .

[29]  Aie.  World Energy Outlook 2011 , 2001 .

[30]  Joerg R. Seume,et al.  Improved Diffuser/Volute Combinations for Centrifugal Compressors , 2008 .

[31]  Eric Johnson.  Handbook on Life Cycle Assessment Operational Guide to the ISO Standards , 2003 .

[32]  Daniel Favrat,et al.  Design, experimental investigation and multi-objective optimization of a small-scale radial compressor for heat pump applications , 2010 .

[33]  Teemu Turunen-Saaresti,et al.  Influence of the Different Design Parameters to the Centrifugal Compressor Tip Clearance Loss , 2011 .

[34]  Anibal T. de Almeida,et al.  Ecoanalysis of Variable-Speed Drives for Flow Regulation in Pumping Systems , 2011, IEEE Transactions on Industrial Electronics.

[35]  François Maréchal,et al.  Energy efficiency in waste water treatments plants: Optimization of activated sludge process coupled with anaerobic digestion , 2012 .

[36]  Koen Hillewaert,et al.  Experimental and numerical investigation of the flow in a centrifugal compressor volute , 1999 .

[37]  Y. Senoo,et al.  Application of a Low-Solidity Cascade Diffuser to Transonic Centrifugal Compressor , 1990 .

[38]  Naresh K. Amineni,et al.  Performance of Low Solidity and Conventional Diffuser Systems for Centrifugal Compressors , 1996 .

[39]  Nasrudin Abd Rahim,et al.  A review on compressed-air energy use and energy savings , 2010 .

[40]  Tomaz Kmecl,et al.  Optimization of a Vaned Diffuser Geometry for Radial Compressors: Part II — Optimization of a Diffuser Vane Profile in Low Solidity Diffusers , 1999 .

[41]  John H. Lienhard,et al.  Energy requirements for water production, treatment, end use, reclamation, and disposal , 2012 .

[42]  Jan Hofman,et al.  The potential of (waste)water as energy carrier , 2013 .

[43]  D. L. Palmer,et al.  Design and Development of an Advanced Two-Stage Centrifugal Compressor , 1994 .