Primary functions of a refrigerant compressor In a vapour-compression refrigeration system, what does the compressor accomplish?

Introduction / Context:
The compressor is the work-input device of a vapour-compression cycle. Recognizing all of its effects clarifies why condenser and expansion device conditions are what they are.

Given Data / Assumptions:

• Compression of superheated or saturated vapour from evaporator pressure to condenser pressure.
• Real compressors have isentropic efficiency < 1, so discharge temperature rises.

Concept / Approach:
By compressing the vapour, the compressor increases its pressure to the condensing level, simultaneously increasing temperature (due to compression work) and providing the driving force for circulation around the closed loop.

Step-by-Step Solution:
Pressure: suction (low) → discharge (high), enabling condensation at ambient conditions.Temperature: rises due to work input; crucial for superheat management and oil return.Circulation: the compressor draws vapour from the evaporator and pushes it through condenser and expansion device.

Verification / Alternative check:
Energy balance: W_in to the compressor equals the enthalpy rise across it (neglecting heat loss), explaining temperature increase.

Why Other Options Are Wrong:

• Any single-function choice is incomplete; the compressor performs all three.
• “Only maintains mass balance” ignores the required pressure rise and work.

Common Pitfalls:
Overlooking that discharge temperature depends on isentropic efficiency and suction superheat.

Final Answer:
All of the above