Zeotropic mixture

Not to be confused with Zoetrope.

A zeotropic mixture, or non-azeotropic mixture, is a mixture with liquid components that have different boiling points.[1] For example, nitrogen, methane, ethane, propane, and isobutane constitute a zeotropic mixture.[2] Individual substances within the mixture do not evaporate or condense at the same temperature as one substance.[3] In other words, the mixture has a temperature glide, as the phase change occurs in a temperature range of about four to seven degrees Celsius, rather than at a constant temperature.[3] On temperature-composition graphs, this temperature glide can be seen as the temperature difference between the bubble point and dew point.[4] For zeotropic mixtures, the temperatures on the bubble (boiling) curve are between the individual component's boiling temperatures.[5] When a zeotropic mixture is boiled or condensed, the composition of the liquid and the vapor changes according to the mixtures's temperature-composition diagram.[5]

Zeotropic mixtures have different characteristics in nucleate and convective boiling, as well as in the organic Rankine cycle. Because zeotropic mixtures have different properties than pure fluids or azeotropic mixtures, zeotropic mixtures have many unique applications in industry, namely in distillation, refrigeration, and cleaning processes.

  1. ^ Gaspar; Pedro Dinis; da Silva; Pedro Dinho (2015). Handbook of Research on Advances and Applications in Refrigeration Systems and Technologies. IGI Global. p. 244. ISBN 978-1-4666-8398-3. Retrieved 23 January 2017.
  2. ^ Barraza, Rodrigo; Nellis, Gregory; Klein, Sanford; Reindl, Douglas (2016). "Measured and predicted heat transfer coefficients for boiling zeotropic mixed refrigerants in horizontal tubes". International Journal of Heat and Mass Transfer. 97: 683–695. doi:10.1016/j.ijheatmasstransfer.2016.02.030.
  3. ^ a b Mohanraj, M.; Muraleedharan, C.; Jayaraj, S. (2011-06-25). "A review on recent developments in new refrigerant mixtures for vapour compression-based refrigeration, air-conditioning and heat pump units". International Journal of Energy Research. 35 (8): 647–669. doi:10.1002/er.1736. ISSN 1099-114X.
  4. ^ Herold, Keith; Radermacher, Reinhard; Klein, Sanford (2016-04-07). Absorption Chillers and Heat Pumps, Second Edition. CRC Press. pp. 23–63. doi:10.1201/b19625-4. ISBN 9781498714341.
  5. ^ a b Sweeney, K.A.; Chato, J.C. (May 1996). "The Heat Transfer and Pressure Drop Behavior of a Zeotropic Refrigerant Mixture in a Microfinned Tube" (PDF). Air Conditioning and Refrigeration Center.