| 摘要 |
A refrigerated merchandiser system (10) includes a compressor (20), a condenser (30), a display case (100) having an evaporator (40), an expansion device (50), and an evaporator pressure control device (60) connected in a closed refrigerant circuit via refrigerant lines (12, 14, 16 and 18). The evaporator pressure control device (60) operates to maintain the pressure in the evaporator at a set point pressure so as to maintain the temperature of the refrigerant expanding from a liquid to a vapor within the evaporator (40) at a desired temperature. A controller (90) operatively associated with the evaporator pressure control device (60) maintains the set point pressure at a first pressure for the refrigerant equivalent to a first refrigerant temperature during a first refrigeration mode and at a second pressure for the refrigerant equivalent to a second refrigerant temperature about 2 to about 12 degrees warmer than the first temperature during a second refrigerant mode. The controller (90) sequences operation between said first refrigeration mode and said second refrigeration mode.
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