Patent ID: 8397528

Claim:
A refrigerated transport system ( 20 ) comprising: a container ( 24 ) having an interior ( 26 ); a generator system ( 30 , 32 ); a refrigeration system ( 34 ), electrically coupled to the generator system to receive electric power and thermally coupled to the container and comprising: an electrically-powered compressor ( 120 ); a condenser ( 128 ) downstream of the compressor along a refrigerant flowpath; an expansion device ( 144 ) downstream of the compressor along the refrigerant flowpath; an evaporator ( 148 ) downstream of the expansion device along the refrigerant flowpath; and a controller ( 100 ) coupled to the expansion device to control operation of the expansion device, wherein the controller is configured: to operate the expansion device to control an evaporator superheat: to be relatively high for a set temperature (T S ) of a first value associated with non-frozen perishables; and to be relatively low for said set temperature of a second value associated with frozen goods, subject to maintenance of a minimum suction superheat; for said set temperature of said first value, control the expansion device to control the superheat toward a first target superheat (T 1 ); for said set temperature of said second value, lower than the first value, and a suction superheat above a threshold, control the expansion device to control the superheat toward a second target superheat (T 2 ) lower than the first target superheat; and for said set temperature of said second value, lower than the first value, and said suction superheat not above a threshold, control the expansion device to control the superheat toward a third target superheat higher than the second target superheat.