Patent ID: 11965688
Assignee: THEMRO KING LLC
Field: Thermal processes and apparatus (Mechanical engineering)
Classification: CPC F  B | IPC F

Claim 6:
7. A method of adapting a transport refrigeration unit and a portable refrigeration device, comprising:
providing a transport refrigeration unit comprising a refrigeration module defining an outer refrigeration cycle configured to transfer heat from an enclosed cargo space of the transport refrigeration unit exteriorly of the cargo space to cool the cargo space, the outer refrigeration cycle extending through a condenser positioned for rejecting heat to external air and an evaporator positioned for transferring heat from a controlled environment within the enclosed cargo space; and a first stage cycle of a cascade refrigeration cycle which is configured to reject heat exteriorly of the cargo space, the first stage cycle extending through the condenser positioned for rejecting heat to external air such that said condenser is in common between the outer refrigeration cycle and the first stage cycle;
providing a portable refrigeration device to be installed in the cargo space, the portable refrigeration device comprising:
a container;
an inner refrigeration cycle configured to transfer heat from an interior of the container exteriorly of the container, the inner refrigeration cycle extending through a condenser positioned for rejecting heat from the inner refrigeration cycle and an evaporator positioned for transferring heat from the interior of the container, the inner refrigeration cycle forming a second stage cycle of the cascade refrigeration cycle, with an inter-stage heat exchanger provided between the first stage cycle and the second stage cycle;

charging the portable refrigeration device with a low temperature refrigerant having a triple point at −70° or less;
configuring a controller of the portable refrigeration device to operate the inner refrigeration cycle to maintain one or more thermodynamic conditions including
a target interior temperature of the container of −70° C. or less;

installing the portable refrigeration device in the cargo space of the transport refrigeration unit.