Nonazeotropic Mixtures
Nonazeotropic liquid mixture, consisting of several components of various volatile substances which, when used in refrigeration cycles changes in composition during evaporation (boiling) or condensation. Recently, nonazeotropic mixture were called zeotropic mixtures or mixtures. Application nonazeotropic blend of refrigerants in cooling systems was proposed in the early twentieth century. A large study of these systems nonazeotropic mixtures and their thermophysical properties done during this time.
Great interest was shown in nonazeotropic mixtures, especially for heat pumps because of their adaptation composition offers a new dimension in the planning and design vapour-compression systems. Much work has been done since the first proposal to use these liquids in heat pumps. Through the energy crisis of the 1970s, nonazeotropic mixtures has become more attractive in research and development on advanced vapor-compression heat pump systems.
They offered the following advantages:
- improving energy efficiency and conservation,
- performance management and
- adaptation of the hardware components on carrying capacity and limits of application
. In the past, studies have shown that commonly used refrigerants such as R-11, R-12, R-22 and R-114 became the most popular due to its clean components nonazeotropic mixtures. Although many nonazeotropic mixture (e.g., R-11 + R-12, R-12 + R-22, R-12 + R-114, R-13B1 + R-152a, R-22 and R-114, R-114 + R-152a and others) was well-known, ten years ago, research and development, mainly concentrated on three blends, R-12 + R-114, R-22 and R-114, R-13B1 + R-152a. It is clear that the heat transfer phenomena at phase transitions nonazeotropic mixtures are more complex than with one-component refrigerants.
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Refrigerants