What are mixed refrigerants?

Mixed refrigerants refer to blends of two or more refrigerants that are combined to achieve specific thermodynamic properties or performance characteristics. This blending allows for improved efficiency and effectiveness in various applications. For example, by mixing refrigerants, you can achieve a desired boiling point, pressure, or other desired thermal properties that suit specific cooling needs or environmental conditions.

Mixed refrigerants are commonly used in systems where a wide range of operating conditions exist or where improved performance is essential. Each component of the blend contributes unique properties, which can enhance the overall efficiency and effectiveness of the refrigeration cycle.

The other options do not accurately describe mixed refrigerants. While recycled refrigerants refer to previously used refrigerant that has been purified for reuse, that does not reflect the concept of combining multiple substances for enhanced properties. Temporary storage does not pertain to the blending of refrigerants, but rather to methods of refrigerant management. Lastly, single refrigerants with varying efficiency do not involve a blend; rather they focus on the performance characteristics of one particular refrigerant. Hence, the definition provided in the correct answer accurately captures the essence of mixed refrigerants.