A stepped pressure cycle is proposed to improve the energy efficiency of refrigeration and heat pump cycles. By constructing multiple suction and discharge pressures

the refrigerant temperatures in the evaporators and condensers underwent step changes and approached the heat source temperatures. This helps to improve heat transfer efficiency and reduce the compression ratio. However

we found that the conclusion of energy savings for the stepped pressure cycle is conditional. Over 6.5% of the energy-saving potential is reduced because of inefficient heat exchangers or a small temperature glide of the heat transfer fluid. Moreover

an excessive subcooling degree will lead to a worse COP than a simple cycle. Finally

in this study

some application cases are summarized to demonstrate the energy-saving potential of the stepped pressure cycle.