Mechanical Engineering - Heat Transfer, Refrigeration and Air Conditioning - Discussion

The correct answer is: required pressure drop cannot be achieved.

Capillary tubes are commonly used as expansion devices in small to medium-capacity refrigeration systems, but they are not suitable for large-capacity systems because:

1. Pressure drop: Capillary tubes are designed to create a specific pressure drop, which is difficult to achieve in large systems with high refrigerant flow rates.
2. Refrigerant flow control: Capillary tubes have a fixed flow restriction, making it challenging to control refrigerant flow in large systems with varying cooling demands.
3. Size and scalability: Capillary tubes are typically small and not easily scalable for large systems.

The other options are not the primary reasons:

- Cost: While capillary tubes may be more expensive than other expansion devices, cost is not the main reason they're not used in large systems.
- Material: Capillary tubes are often made of copper, but material is not a limiting factor.
- Capacity control: While capacity control is a challenge, it's not the primary reason capillary tubes are not used in large systems.

In large-capacity refrigeration systems, other expansion devices like float valves, thermostatic expansion valves, or electronic expansion valves are typically used to provide better control and flexibility.

Right, I agree with you @Prashant.

What is the use of a capillary tube in a refrigeration system? Someone, please tell me.

The correct option should be D.