What is true about compression ratio in relation to volumetric efficiency?

The relationship between compression ratio and volumetric efficiency is indeed inversely proportional. As the compression ratio increases, the volumetric efficiency tends to decrease. This is primarily because a higher compression ratio can lead to less efficient filling and suction of the refrigerant into the compressor. In simpler terms, when a compressor operates at a high compression ratio, it has to work harder to compress the vapor, often resulting in a loss of the refrigerant's density and ultimately, a reduction in the amount of refrigerant that can be effectively drawn into the cylinder during the suction phase.

Volumetric efficiency is a measure of how effectively the compressor can fill its cylinder with refrigerant. Factors influencing this include the physical characteristics of the refrigerant, the design of the compressor, and how well the system is operating under varying conditions. Thus, as the compression ratio rises, the effective volume capacity of the compressor diminishes, leading to a decline in volumetric efficiency.

Understanding this relationship is crucial for technicians when diagnosing performance issues and optimizing refrigeration systems. It highlights the importance of considering both the compression ratio and volumetric efficiency when assessing compressor performance.