What happens to the temperature of vaporizing refrigerant even if the pressure remains constant?

• A. It increases steadily
• B. It remains unchanged
• C. It increases then decreases
• D. Temperature glide occurs

Answer: (D)

The correct choice underscores an important concept in refrigeration systems known as temperature glide, which occurs when the refrigerant evaporates. Even if the pressure within the system is held constant, the temperature of the refrigerant can exhibit variations as it transitions from a liquid to a vapor.

Temperature glide is characteristic of azeotropic blends or refrigerants that do not perfectly behave like simple single-component refrigerants. During the phase change, the refrigerant absorbs heat and changes its physical state, and different components of the mixture can vaporize at different temperatures. Therefore, instead of maintaining a single temperature, the refrigerant displays a range of temperatures, or glide, as it moves through this phase change.

Understanding this phenomenon is crucial for technicians working with refrigeration systems, as it impacts system efficiency and the performance of the equipment. The temperature may not remain constant even when pressure is stable, emphasizing the complex behaviors of mixed refrigerants in practical applications.