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Low-grade waste heat recovery and repurposing to reduce the load on cooling towers

  • McLean, Shannon H. (School of Engineering, Laurentian University) ;
  • Chenier, Jeff (Sudbury Integrated Nickel Operations (a Glencore Company)) ;
  • Muinonen, Sari (Sudbury Integrated Nickel Operations (a Glencore Company)) ;
  • Laamanen, Corey A. (School of Engineering, Laurentian University) ;
  • Scott, John A. (School of Engineering, Laurentian University)
  • Received : 2020.04.13
  • Accepted : 2020.08.19
  • Published : 2020.06.25

Abstract

Industrial cooling towers are often ageing infrastructure that is expensive to maintain and operate. A novel approach is introduced in which a heat pump circuit is incorporated to reduce the load upon the towers by extracting low-grade energy from the stream sent to the towers and repurposing in on-site processing operations. To demonstrate the concept, a model was constructed, which uses industrial data on cooling towers linked to a smelter's sulphuric acid plant, to allow direct economic and environmental impact comparison between different heat recovery and repurposing scenarios. The model's results showed that implementing a heat pump system would significantly decrease annual operating costs and achieve a payback period of 3 years. In addition, overall CO2 emissions could be reduced by 42% (430,000 kg/year) and a 5% heat load reduction on the cooling towers achieved. The concept is significant as the outcomes introduce a new way for energy intensive industrial sectors, such as mineral processing, to reduce energy consumption and improve long-term sustainable performance.

Keywords

Acknowledgement

This work was supported by the Mitacs Accelerate program and the National Science and Research Council (NSERC).

References

  1. Afshari, F. and Dehghanpour, H. (2019), "A review study on cooling towers; types, performance and application", ALKU J. Sci., 1-10.
  2. Ahmad, S.N. and Prakasha, O. (2019), "Experimental exergy assessment of ground source heat pump system", Adv. Energy Res., 6(2), 161-172. https://doi.org/10.12989/eri.2019.6.2.161.
  3. Ammar, Y., Joyce, S., Norman, R., Wang, Y. and Roskilly, A.P. (2012), "Low grade thermal energy sources and uses from the process industry in the UK", Appl. Energy, 89(1), 3-20. https://doi.org/10.1016/j.apenergy.2011.06.003.
  4. Antwan, N.F. and Maree, I.E. (2010), "The efficiency of geothermal heat pumps with vertical ground heat exchangers: A simulation under Iraqi conditions", Proceedings of the ASME 2010 10th Biennial Conference on Engineering Systems Design and Analysis, ESDA 2010, Istanbul, Turkey, December.
  5. Ataei, A., Hemmatabady, H. and Nobakht, S.Y. (2016), "Hybrid thermal seasonal storage and solar assisted geothermal heat pump systems for greenhouses", Adv. Energy Res., 4(1), 87-106. https://doi.org/10.12989/eri.2016.4.1.087.
  6. Axair Fans (2018), Understanding the Basic Fan Laws; United Kingdom. https://www.axair-fans.co.uk/news/applications/understanding-basic-fan-laws.
  7. Bahtiar, E., Nugroho, N., Hermawan, D., Wirawan, W., Sari, R., Rahman, M. and Sidik, M. (2017), "Wood deterioration of cooling tower structure at geothermal power plant", Asian J. Appl. Sci., 10, 79-87. https://doi.org/10.3923/ajaps.2017.79.87.
  8. Baltimore Aircoil Company (n.d.), Strategies to Reduce Energy and Lower Operating Costs; BAC Technical Resource. http://www.baltimoreaircoil.com/english/resource-library/file/1684.
  9. Bansal, R.K. (2005), A Textbook of Fluid Mechanics, Firewall Media, India.
  10. CT/HX (2014), Cooling Tower Repair and Refurbishment. http://www.cthx.com/services/cooling-towers.
  11. Enexio (2020), Natural Draft Cooling Towers, Germany. https://www.enexio.com/cooling-solutions/wet-cooling-towers/natural-draft-cooling-towers.
  12. Gudjonsdottir, V., Infante Ferreira, C.A., Rexwinkel, G. and Kiss, A.A. (2017), "Enhanced performance of wet compression-resorption heat pumps by using NH 3 -CO 2 -H 2 O as working fluid", Energy, 124, 531-542. https://doi.org/10.1016/j.energy.2017.02.051.
  13. Gunson, A.J. (2013), "Quantifying, reducing and improving mine water use", Ph.D. Dissertation, University of British Columbia, Vancouver, Canada.
  14. Hawkeye Energy Solutions (2015), Energy Efficiency. https://www.hawkeye-es.com/energy-efficiency.
  15. He, S., Gurgenci, H., Guan, Z., Huang, X. and Lucas, M. (2015), "A review of wetted media with potential application in the pre-cooling of natural draft dry cooling towers", Renew. Sust. Energy Rev., 44, 407-422. https://doi.org/10.1016/j.rser.2014.12.037.
  16. Hoffman, H.W. (2019), Water Efficiency, Facilitiesnet, U.S.A. https://www.facilitiesnet.com/green/article/As-Water-Rates-Rise-Efficiency-More-Important-Especially-For-Cooling-Towers--16525.
  17. Hydro One (2019), Electricity Pricing and Costs, Canada. https://www.hydroone.com:443/rates-and-billing/rates-and-charges/electricity-pricing-and-costs.
  18. Jordan, S. (2013), Cooling Tower Fundamentals: The Evolution of Wooden Cooling Towers; Midwest Cooling Towers. https://midwesttowers.com/cooling-tower-fundamentals-the-evolution-of-wooden-cooling-towers.
  19. Kiijarvi, J. (2011), "Darcy friction factor formulae in turbulent pipe flow", Research Report No. 110727; Lunowa, Finland.
  20. Laamanen, C.A., Shang, H., Ross, G.M. and Scott, J.A. (2014), "A model for utilizing industrial off-gas to support microalgae cultivation for biodiesel in cold climates", Energ. Convers. Manage., 88, 476-483. https://doi.org/10.1016/j.enconman.2014.08.047.
  21. Lee, J. (1979), "Potential weather modification caused by waste heat release from large dry cooling towers", J. Heat Transfer, 101, 164. https://doi.org/10.1115/1.3450909.
  22. Lienhard, J.H. and Lienhard, J.H. IV (2013), A Heat Transfer Textbook, Third Edition, Courier Corporation, North Chelmsford, Massachusetts, U.S.A.
  23. MATLAB 2014b (2014), The MathWorks, Inc, Massachusetts, U.S.A.
  24. Mazzoni, S., Arreola, M.J. and Romangoli, A. (2017), "Innovative organic rankine arrangements for water savings in waste heat recovery applications", Energy Procedia, 143, 361-366. https://doi.org/10.1016/j.egypro.2017.12.697.
  25. Miah, J.H., Griffiths, A., McNeill, R., Poonaji, I., Martin, R., Leiser, A., Morse, S., Yang, A. and Sadhukhan, J. (2015), "Maximising the recovery of low grade heat: An integrated heat integration framework incorporating heat pump intervention for simple and complex factories", Appl. Energy, 160, 172-184. https://doi.org/10.1016/j.apenergy.2015.09.032.
  26. Munson, B., Okiishi, T., Huebsch, W. and Rothmayer, A. (2013), Fundamentals of Fluid Mechanics, 7th Edition, Wiley, U.S.A.
  27. Ning, T., Chong, D., Jia, M., Wang, J. and Yan, J. (2015), "Experimental investigation on the performance of wet cooling towers with defects in power plants", Appl. Therm. Eng., 78, 228-235. https://doi.org/10.1016/j.applthermaleng.2014.12.032.
  28. Nuclear Power (2019a), Prandtl Number Formula, https://www.nuclear-power.net/nuclear-engineering/heat-transfer/introduction-to-heat-transfer/characteristic-numbers/what-is-prandtl-number/prandtl-number-formula.
  29. Nuclear Power (2019b), Reynolds Number. https://www.nuclear-power.net/nuclear-engineering/fluid-dynamics/reynolds-number.
  30. Nuclear Power (2019c), What is Nusselt Number. https://www.nuclear-power.net/nuclear-engineering/heat-transfer/introduction-to-heat-transfer/characteristic-numbers/what-is-nusselt-number.
  31. Prosser, I., Wolf, L. and Littleboy, A. (2011), Water: Science and Solutions for Australia, CSIRO Publishing, Australia.
  32. Ross, I.M. (2016), "Employing heat pumps to recover low grade industrial thermal resources for space heating and cooling", M.A.Sc. Dissertaion, Laurentian University, Sudbury, Canada.
  33. Rubio-Castro, E., Serna-Gonzalez, M., Ponce-Ortega, J.M. and El-Halwagi, M.M. (2013), "Synthesis of cooling water systems with multiple cooling towers", Appl. Therm. Eng., 50, 957-974. https://doi.org/10.1016/j.applthermaleng.2012.06.015.
  34. Rubio, C.L., Garcia-Alcaraz, J.L., Martinez-Camara, E., Latorre-Biel, J.I., Jimenez-Macias, E. and Blanco-Fernandez, J. (2020), "Replacement of electric resistive space heating by a geothermal heat pump in a residential application-Environmental amortisation", Sust. Energy Technol. Assess., 37. https://doi.org/10.1016/j.seta.2019.100567.
  35. SPX (2016), What is a Cooling Tower, SPX Cooling Technologies. https://spxcooling.com/coolingtowers/ (accessed 1.15.20).
  36. Staffell, I., Brett, D., Brandon, N. and Hawkes, A. (2012), "A review of domestic heat pumps", Energy Environ. Sci., 5(11), 9291-9306. https://doi.org/10.1039/c2ee22653g.
  37. Sudbury INO (2017), Personal Communication, Ontario, Canada.
  38. Sukhatme, S.P. (2005), A Textbook on Heat Transfer, Fourth Edition, Universities Press, India.
  39. Tran, N.C., Toulemonde, C., Beaudouin, F., Meuwisse, C., Schmitt, N., El-Yazidi, A., Courtois, A., Genest, Y. and Moriceau, S. (2017), "Innovative methodology of ranking cooling towers based on structural safety margin", Proceedings of the 2017 25th International Conference on Nuclear Engineering, Shanghai, China, July.
  40. United States Environmental Protection Agency (2018), Greenhouse Gas Emissions. https://www.epa.gov/ghgemissions/sources-greenhouse-gas-emissions.
  41. Weather Atlas (2020), Monthly Weather Forecast and Climate, Sudbury, Canada. https://www.weather-ca.com/en/canada/sudbury-climate.
  42. Williams, M., Frankowski, C. and Allen, G. (2017), "Measuring up to global warming", Research Report No. 1602202, RWDI, Toronto, Canada.
  43. Woolley, E., Luo, Y. and Simeone, A. (2018), "Industrial waste heat recovery: A systematic approach", Sust. Energy Technol. Assess., 29, 50-59. https://doi.org/10.1016/j.seta.2018.07.001.
  44. Yang, S. and Lee, S.B. (2020), "Dynamic thermal analysis of a residential ground-source heat pump", Sust. Energy Technol. Assess., 37, 100608. https://doi.org/10.1016/j.seta.2019.100608.
  45. Young, D. (2018), "Cooling towers replacement at enercare centre", Research Report No. 8.10, W.S. Nicholls Construction Inc., Toronto, Canada.
  46. Zhang, J., Zhang, H.H., He, Y.L. and Tao, W.Q. (2016), "A comprehensive review on advances and applications of industrial heat pumps based on the practices in China", Appl. Energy, 178, 800-825. https://doi.org/10.1016/j.apenergy.2016.06.049.