How is the compression ratio in an ammonia compression system defined?

The compression ratio in an ammonia compression system is defined as the ratio of absolute discharge pressure to absolute suction pressure. This is an essential parameter in the design and operation of refrigeration systems because it directly affects the efficiency and performance of the compressor.

In this context, "absolute pressure" refers to the total pressure measured relative to absolute vacuum, which provides an accurate representation of how much pressure is acting on the refrigerant at both the discharge and suction sides of the compressor. Using absolute pressures ensures that the compression ratio reflects the true conditions of the refrigerant, allowing for a more precise analysis of the compressor's behavior and performance in various operating conditions.

Understanding the compression ratio in this way helps in assessing the efficiency of the refrigeration cycle, as higher compression ratios can indicate higher temperature and pressure differences that the system must manage. Properly defining this ratio is crucial for optimizing system performance and ensuring effective heat exchange within the system.