Series loop intermodal container

1. A refrigerated transport system ( 20 ) comprising:

a body ( 22 ) enclosing a refrigerated compartment ( 69 ) and comprising:

a pair of side walls ( 22 C, 22 D);

a top ( 22 A);

a bottom ( 22 B); and

one or more doors ( 28 A, 28 B); and

a refrigeration system ( 30 ) comprising:

a vapor compression loop ( 31 ) having a first heat exchanger ( 38 ) positioned to reject heat to an external environment in a cooling mode;

a heat transfer loop ( 32 ) having a second heat exchanger ( 58 ) positioned to absorb heat from the refrigerated compartment in the cooling mode, wherein a heat transfer fluid of the heat transfer loop comprises at least 50% carbon dioxide, by weight; and

an inter-loop heat exchanger ( 44 ) having a first leg ( 42 ) along the vapor compression loop and a second leg ( 43 ) along the heat transfer loop in heat exchange relation with the first leg.

2. The refrigerated transport system of claim 1 , wherein:

the vapor compression loop sequentially comprises:

a compressor ( 36 );

said first heat exchanger;

an expansion device ( 40 ); and

said first leg; and

the heat transfer loop sequentially comprises:

a pump ( 56 );

said second heat exchanger; and

said second leg.

3. The refrigerated transport system of claim 2 , further comprising:

an electric fan ( 60 A, 60 B) positioned to drive a recirculating air flow from the refrigerated compartment across the second heat exchanger.

4. The refrigerated transport system of claim 2 , wherein:

the first heat exchanger is a refrigerant-air heat exchanger.

5. The refrigerated transport system claim 1 , wherein:

the inter-loop heat exchanger is a brazed plate heat exchanger.

6. The refrigerated transport system of claim 1 , further comprising:

a carbon dioxide detector.

7. The refrigerated transport system of claim 6 further comprising:

a ventilation fan ( 81 A, 60 A).

8. The refrigerated transport system of claim 1 , wherein:

a refrigerant charge of the vapor compression loop comprises at least 50% by weight propane.

9. The refrigerated transport system of claim 1 , wherein:

a refrigerant charge of the vapor compression loop comprises at least 90% by weight propane.

10. The refrigerated transport system of claim 1 , being an intermodal shipping container, wherein:

the one or more doors are at a first end ( 28 A, 28 B); and

the refrigeration system is mounted in an equipment module ( 26 ) at a second end of the body opposite the first end.

11. The refrigerated transport system of claim 10 , wherein:

a wall ( 67 ) of the equipment module divides the external environment from the refrigerated compartment;

the inter-loop heat exchanger is on the external environment side of the wall; and

the second heat exchanger is on the refrigerated compartment side of the wall.

12. The refrigerated transport system of claim 11 , wherein:

the vapor compression loop sequentially comprises:

a compressor ( 36 );

said first heat exchanger;

an expansion device ( 40 ); and

said first leg;

the heat transfer loop sequentially comprises:

a pump ( 56 );

said second heat exchanger; and

said second leg; and

the pump is on the refrigerated compartment side of the wall.

13. The refrigerated transport system of claim 10 , further comprising:

at least one flame arrestor across at least one opening of the equipment module.

14. The refrigerated transport system of claim 13 , wherein:

said at least one opening is along the front of the equipment module.

15. The refrigerated transport system of claim 13 , wherein:

the at least one flame arrestor comprises metallic wire mesh or perforated mesh.

16. A refrigerated transport system ( 20 ) comprising:

a body ( 22 ) enclosing a refrigerated compartment ( 69 ) and comprising:

a pair of side walls ( 22 C, 22 D);

a top ( 22 A);

a bottom ( 22 B); and

one or more doors ( 28 A, 28 B); and

a refrigeration system ( 30 ) comprising:

a vapor compression loop ( 31 ) having a first heat exchanger ( 38 ) positioned to reject heat to an external environment in a cooling mode wherein a refrigerant charge of the vapor compression loop comprises at least 50% by weight propane;

a heat transfer loop ( 32 ) having a second heat exchanger ( 58 ) positioned to absorb heat from the refrigerated compartment in the cooling mode; and

an inter-loop heat exchanger ( 44 ) having a first leg ( 42 ) along the vapor compression loop and a second leg ( 43 ) along the heat transfer loop in heat exchange relation with the first leg.

17. The refrigerated transport system of claim 16 , wherein:

a refrigerant charge of the vapor compression loop comprises at least 90% by weight propane.

18. An intermodal shipping container ( 20 ) comprising:

a body ( 22 ) enclosing a refrigerated compartment ( 69 ) and comprising:

a pair of side walls ( 22 C, 22 D);

a top ( 22 A);

a bottom ( 22 B); and

one or more doors ( 28 A, 28 B) at a first end of the body;

an equipment module ( 26 ) at a second end of the body opposite the first end with at least one flame arrestor across at least one opening of the equipment module; and

a refrigeration system ( 30 ) mounted in the equipment module and comprising:

a vapor compression loop ( 31 ) having a first heat exchanger ( 38 ) positioned to reject heat to an external environment in a cooling mode;

a heat transfer loop ( 32 ) having a second heat exchanger ( 58 ) positioned to absorb heat from the refrigerated compartment in the cooling mode; and

an inter-loop heat exchanger ( 44 ) having a first leg ( 42 ) along the vapor compression loop and a second leg ( 43 ) along the heat transfer loop in heat exchange relation with the first leg.

19. The intermodal shipping container of claim 18 , wherein:

said at least one opening is along the front of the equipment module.

20. The intermodal shipping container of claim 18 , wherein:

the at least one flame arrestor comprises metallic wire mesh or perforated mesh.