Reading a pressure–enthalpy (p–h) diagram On a refrigerant p–h chart, which region corresponds to the superheated vapour state?

Introduction / Context:
The pressure–enthalpy (p–h) diagram is the principal tool for visualizing vapour-compression cycles. Correctly identifying the single-phase regions avoids errors in reading states, enthalpy differences, and compressor work.

Given Data / Assumptions:

• The two-phase region lies under the saturation dome bounded by the saturated liquid and saturated vapour lines.
• Single-phase liquid lies to the left of the saturated liquid line; single-phase vapour lies to the right of the saturated vapour line.
• Superheated vapour is single-phase vapour at temperatures above saturation for the given pressure.

Concept / Approach:
On the p–h chart, the saturated liquid line forms the left boundary of the dome and the saturated vapour line forms the right boundary. Any state to the right of the saturated vapour line is superheated vapour; any state between the lines is a liquid–vapour mixture; any state to the left of the saturated liquid line is subcooled (compressed) liquid.

Step-by-Step Solution:

Verification / Alternative check:
Cross-check with temperature–entropy (T–s) diagrams: superheat appears to the right of the saturated vapour line on T–s as well; both charts are consistent in topology.

Why Other Options Are Wrong:

Left of saturated liquid line: that is compressed liquid.Between the lines: two-phase mixture, not superheated.Exactly on the saturation lines: those are saturated states, not superheated.

Common Pitfalls:
Confusing superheat with subcooling; remember superheat applies to vapour above saturation, subcooling to liquid below saturation.

Final Answer:

To the right of the saturated vapour line