Ejector Cycle - Denso

In 2003, DENSO introduced the world’s first refrigeration unit with an ejector cycle for mid- and large-sized trucks.
The newly developed ejector cycle is a high-efficiency refrigeration cycle with a significantly improved energy consumption efficiency, achieved by using a small injector called an ejector. The refrigeration units with the ejector cycle increase energy consumption efficiency by 50 percent compared to previous models.
The ejector cycle can be used, in principle, in the refrigeration cycle of car air conditioners, room air conditioners, and refrigerators. DENSO will continue to work on commercializing these new products.
How it works:
  • The ejector, used in the ejector cycle instead of a conventional expansion valve, expands high-pressure refrigerant by using energy which previously was lost.
  • A gas-liquid separator separates expanded refrigerant into gas and liquid so that gas refrigerant is directly drawn into the compressor at a higher pressure while liquid refrigerant flows into the evaporator to exchange heat with air.
Benefits and Features
  • Small compressor power consumption
    • The ejector uses energy, which is lost in a conventional expansion valve, to increase the pressure of refrigerant drawn into the compressor, resulting in compressor power consumption almost two-thirds smaller than the power consumption required in a conventional expansion valve cycle.
  • High evaporator performance
    • Only liquid refrigerant flows into the evaporator, reducing pressure loss and improving evaporator performance.
  • Small size and light weight
    • Compared to the expansion valve cycle with similar refrigeration capacity, the overall weight of the ejector cycle is reduced by 40 percent thanks to the remarkable minimization of the compressor, condenser and evaporator. The weight reduction also increases fuel efficiency by 60 percent.