Absorbent in a Vapour Absorption Refrigerator System

In a vapor absorption refrigerator system, the absorbent plays a crucial role in separating from the refrigerant. The correct answer to the given question is option 'A', which states that the absorbent separates from the refrigerant only when it is sufficiently heated. Let's understand why this is the correct answer in detail.

1. Introduction to Vapour Absorption Refrigeration System:
- The vapor absorption refrigeration system is an alternative to the more commonly used vapor compression refrigeration system.
- It operates on the principle of using a heat source to generate refrigeration rather than using a mechanical compressor.
- The components of a vapor absorption refrigeration system include an absorbent, a refrigerant, a generator, a condenser, an evaporator, and a pump.

2. Role of Absorbent:
- The absorbent in a vapor absorption refrigeration system is a chemical substance that has the ability to absorb the refrigerant vapor.
- It helps in the separation of the refrigerant from the mixture of refrigerant vapor and absorbent solution.
- The absorbent absorbs the refrigerant vapor in the absorber and releases it in the generator when heated.
- The absorbent undergoes a cyclic process of absorption and desorption to facilitate the refrigeration cycle.

3. Absorbent Separation:
- The separation of the absorbent from the refrigerant occurs during the desorption phase in the generator.
- The generator is heated using a heat source, which causes the absorbent solution to boil.
- As the absorbent solution boils, the absorbent separates from the refrigerant vapor, leaving only the refrigerant vapor in the generator.
- The refrigerant vapor then condenses in the condenser and releases heat to the surroundings.
- After condensation, the refrigerant liquid flows back to the evaporator, where it absorbs heat and evaporates, thus completing the refrigeration cycle.

4. Significance of Absorbent Separation:
- The separation of the absorbent from the refrigerant is essential for the proper functioning of the vapor absorption refrigeration system.
- It ensures that only the refrigerant vapor enters the condenser and further stages of the refrigeration cycle.
- If the absorbent were to not separate from the refrigerant, it would lead to a decrease in the efficiency of the system and could potentially cause operational issues.

In conclusion, the absorbent in a vapor absorption refrigeration system separates from the refrigerant only when it is sufficiently heated. This separation occurs in the generator during the desorption phase of the absorbent cycle. It is crucial for the proper functioning and efficiency of the system.