What is the purpose of the upper piston rings in a compressor?

The purpose of the upper piston rings in a compressor is primarily for compression. These rings create a seal between the piston and the cylinder wall, allowing the piston to effectively compress the refrigerant gas within the cylinder during the compression stroke. When the piston moves down, it draws in the gas, and as it moves back up, the upper rings ensure that the gas is compressed to the required pressure before being discharged.

This sealing action helps to maintain the efficiency of the compressor by minimizing gas leakage, ensuring that the maximum amount of refrigerant is compressed. The correct operation of the upper piston rings is crucial for the compressor to maintain its designed efficiency and performance in the refrigeration cycle. Without proper sealing and compression, the system would not operate effectively, leading to reduced cooling capacity and overall inefficiencies in the cooling process.