Absorption refrigeration (aqua–ammonia): If rectification is incomplete, where does the carried-over water ultimately accumulate in the system?

Introduction / Context:
In aqua–ammonia absorption systems, the generator liberates ammonia vapour from the strong solution. A rectifier (dephlegmator) removes water vapour to ensure nearly pure ammonia reaches the condenser and evaporator. Incomplete rectification causes operational issues.

Given Data / Assumptions:

• Working pair: ammonia (refrigerant) and water (absorbent).
• Rectifier is not fully effective; some water vapour passes with ammonia.
• Standard component sequence: generator → rectifier → condenser → expansion → evaporator → absorber.

Concept / Approach:
If water passes beyond the rectifier, it condenses with ammonia in the condenser and is then throttled with it to the evaporator. At evaporator conditions, water has an extremely low vapour pressure and tends to remain liquid, progressively accumulating and impairing heat transfer and capacity.

Step-by-Step Solution:

Verification / Alternative check:
Check vapour pressure data: at evaporator temperatures, water's saturation pressure is too low to evaporate significantly, confirming accumulation.

Why Other Options Are Wrong:
Condenser drains to the expansion device; absorber receives vapour from evaporator, not liquid water from poor rectification; “none” ignores the described mechanism.

Common Pitfalls:
Neglecting rectifier performance; assuming any condensate is harmless—water contamination severely degrades refrigeration effect.

Final Answer:
Evaporator