The compression ratio is defined as the ratio of discharge pressure to suction pressure at saturated conditions, expressed in absolute terms, e.g. Pa or kPa.
where CR is compression ratio; Pd is saturated discharge pressure, kPa; and Ps is saturated suction pressure, kPa.
The performance of a compressor is influenced by a number factors, including (Pita, 1984):
• compressor speed,
• suction pressure,
• suction temperature,
• discharge pressure, and
• type of refrigerant.
