🔍 Key Concepts

• Refrigeration cycle flow shown in the illustration (compressor → condenser coil → receiver tank → thermostatic expansion valve → evaporator coil → back to compressor) • Where pressure drops suddenly in the system and how that affects liquid/vapor state (flash gas formation) • The legend in the drawing that shows high-pressure liquid, high-pressure vapor, low-pressure liquid, and low-pressure vapor

💭 Think About

• Follow the refrigerant along the arrows and note at which component the pressure changes from high to low most abruptly. What happens to a warm high‑pressure liquid when its pressure is suddenly reduced? • Look carefully at the shading in the piping just before and just after each component. At which component does the refrigerant change from all high‑pressure liquid to a mixture that includes low‑pressure vapor? • In normal operation, where do we want most of the boiling (change from liquid to vapor) to occur: before the evaporator, inside the evaporator, or after it? How does that relate to flash gas formation?

✅ Before You Answer

• Use the illustration legend to verify the pressure level and phase of the refrigerant entering and leaving each component • Confirm which component’s outlet line first shows any low-pressure vapor mixed with liquid, while its inlet is all high-pressure liquid • Make sure the component you choose is one where this liquid-to-vapor change is an intended, normal part of the refrigeration cycle, not a sign of a problem or inefficiency