Which component helps maintain the quality of refrigerant by removing contaminants?

The correct choice is the filter dryer, as it plays a crucial role in maintaining the quality of the refrigerant within a refrigeration system. This component is designed to remove moisture and contaminants from the refrigerant. Moisture is particularly harmful because it can lead to the formation of ice, which can block refrigerant flow and cause system failures. Additionally, contaminants such as dirt, metal particles, and other debris can impair the functioning of the system and lead to increased wear and tear on mechanical parts.

By filtering out these unwanted substances and preventing moisture from entering the refrigerant system, the filter dryer ensures the refrigerant remains clean and effective in heat exchange processes. This cleanliness is essential for the optimal performance and longevity of the refrigeration system.

While other components like the suction accumulator and receiver have important functions, they do not specifically focus on cleaning or purifying the refrigerant. The suction accumulator helps manage the flow of refrigerant to the compressor, and the receiver stores excess refrigerant. The oil pressure switch monitors the oil system but does not play a role in filtering or maintaining refrigerant quality.