Refrigeration unit having a linear compressor

1. A refrigeration merchandiser comprising:

at least one surface at least partially defining an environmental space adapted to accommodate a commodity;

a free-piston linear compressor, a condenser, an expansion device, and an evaporator in fluid communication, the free-piston linear compressor including dual-opposing pistons, the evaporator being in thermal communication with the environmental space to influence the temperature of the environmental space;

a frame supporting the at least one surface, the linear compressor, the condenser, the expansion device, and the evaporator; and

a controller to control operation of the linear compressor and coupled to the linear compressor, wherein the linear compressor provides variable capacity control and the controller modulates refrigerant capacity in the linear compressor.

2. A merchandiser as set forth in claim 1 wherein the frame comprises the at least one surface.

3. A merchandiser as set forth in claim 1 wherein the merchandiser further comprises a display fixture comprising the at least one surface and defining the environmental space.

4. A merchandiser as set forth in claim 3 wherein the frame comprises the display fixture.

5. A merchandiser as set forth in claim 3 wherein the environmental space is a permanently open space.

6. A merchandiser as set forth in claim 3 wherein at least a portion of the at least one surface is translucent.

7. A merchandiser as set forth in claim 1 wherein the merchandiser further comprises a fluid-input line and a fluid-output line, both of which being supported by the frame, wherein the condenser comprises a fluid-cooled condenser, and wherein the fluid input line, the fluid-cooled condenser, and the fluid-output line are all in fluid communication.

8. A merchandiser as set forth in claim 7 , wherein the controller comprises a fluid-cooled controller, and wherein the fluid-input line, the fluid-cooled controller, and the fluid-output line are all in fluid communication.

9. A merchandiser as set forth in claim 7 , wherein the linear compressor comprises a fluid-cooled linear compressor, and wherein the fluid-input line, the fluid-cooled linear compressor, and the fluid-output line are all in fluid communication.

10. A merchandiser as set forth in claim 1 wherein the controller further controls the operation of the merchandiser including controlling the temperature of the environmental space.

11. A merchandiser as set forth in claim 1 wherein the controller comprises a sensor configured to sense a parameter representative of an operating condition associated with the merchandiser, and wherein the controller controls the linear compressor based at least in part on the sensed parameter.

12. A merchandiser as set forth in claim 11 wherein the controller is further operable to control the expansion device based at least in part on the sensed parameter.

13. A merchandiser as set forth in claim 11 wherein the sensor comprises a pressure sensor, and wherein the sensed parameter comprises a sensed pressure.

14. A merchandiser as set forth in claim 11 wherein the sensor comprises a temperature sensor, and wherein the sensed parameter comprises a sensed temperature.

15. A merchandiser as set forth in claim 11 wherein the controller controls the linear compressor by controlling the stroke of the pistons based at least in part on the sensed parameter.

16. A merchandiser as set forth in claim 11 wherein the controller controls the linear compressor by controlling the stroke of the pistons for varying the effective displaced volume of refrigerant based at least in part on the sensed parameter.

17. A stand-alone refrigeration merchandiser comprising:

a display fixture comprising at least one surface at least partially defining an environmental space, the display fixture being adapted to accommodate a commodity in the environmental space;

a free-piston linear compressor, a fluid-cooled condenser, an expansion device, and an evaporator in fluid communication, the free-piston linear compressor including dual-opposing pistons, the evaporator being in thermal communication with the environmental space to influence the temperature of the environmental space;

a controller to control operation of the linear compressor and coupled to the linear compressor, wherein the linear compressor provides variable capacity control and the controller modulates refrigerant capacity in the linear compressor;

a fluid input line and a fluid output line, both of which being in fluid communication with the fluid-cooled condenser; and

a frame supporting the display case, the fluid-input line, the fluid-output line, the free-piston linear compressor, the fluid-cooled condenser, the expansion device, and the evaporator.

18. A merchandiser as set forth in claim 17 wherein the frame comprises the display fixture.

19. A merchandiser as set forth in claim 17 wherein the controller comprises a fluid-cooled controller, and wherein the fluid-input line, the fluid-cooled controller, and the fluid-output line are all in fluid communication.

20. A merchandiser as set forth in claim 19 wherein the free-piston linear compressor comprises a fluid-cooled, free-piston linear compressor, and wherein the fluid-input line, the fluid-cooled, free-piston linear compressor, and the fluid-output line are all in fluid communication.

21. A merchandiser as set forth in claim 19 wherein the controller further controls the operation of the merchandiser including controlling the temperature of the environmental space.

22. A merchandiser as set forth in claim 17 wherein the free-piston linear compressor comprises a fluid-cooled, free-piston linear compressor, and wherein the fluid-input line, the fluid-cooled, free-piston linear compressor, and the fluid-output line are all in fluid communication.

23. A merchandiser as set forth in claim 17 wherein the controller comprises a sensor configured to sense a parameter representative of an operating condition associated with the merchandiser, and wherein the controller controls the free-piston linear compressor based at least in part on the sensed parameter.

24. A merchandiser as set forth in claim 23 wherein the controller is further operable to control the expansion device based at least in part on the sensed parameter.

25. A merchandiser as set forth in claim 23 wherein the sensor comprises a pressure sensor, and wherein the sensed parameter comprises a sensed pressure.

26. A merchandiser as set forth in claim 23 wherein the sensor comprises a temperature sensor, and wherein the sensed parameter comprises a sensed temperature.

27. A merchandiser as set forth in claim 23 wherein the controller controls the free-piston linear compressor by controlling the stroke of the pistons based at least in part on the sensed parameter.

28. A merchandiser as set forth in claim 23 wherein the controller controls the free-piston linear compressor by controlling the stroke of the pistons for varying the effective displaced volume of refrigerant based at least in part on the sensed parameter.

29. A refrigeration merchandiser comprising:

a display fixture comprising at least one surface at least partially defining an environmental space, the display fixture being adapted to accommodate a commodity in the environmental space;

a frame supporting the display fixture;

a free-piston linear compressor, a condenser, an expansion device, and an evaporator in fluid communication, the free-piston linear compressor including dual-opposing pistons, the evaporator being in thermal communication with the environmental space to influence the temperature of the environmental space, and at least the free-piston linear compressor and the evaporator being supported by the frame;

a controller to control operation of the linear compressor and coupled to the linear compressor, wherein the linear compressor provides variable capacity control and the controller modulates refrigerant capacity in the linear compressor.

30. A merchandiser as set forth in claim 29 wherein the frame further supports the condenser and the expansion device.

31. A merchandiser as set forth in claim 29 wherein the refrigeration system further comprises a fluid-input line and a fluid-output line, both of which being supported by the frame, wherein the condenser comprises a fluid-cooled condenser, and wherein the fluid-input line, fluid-cooled condenser, and fluid output line are all in fluid communication.

32. A merchandiser as set forth in claim 29 wherein the controller comprises a sensor configured to sense a parameter representative of an operating condition associated with the merchandiser, and wherein the controller controls the free-piston linear compressor based at least in part on the sensed parameter.

33. A merchandiser as set forth in claim 32 wherein the controller is further operable to control the expansion device based at least in part on the sensed parameter.

34. A merchandiser as set forth in claim 32 wherein the sensor comprises a pressure sensor, and wherein the sensed parameter comprises a sensed pressure.

35. A merchandiser as set forth in claim 32 wherein the sensor comprises a temperature sensor, and wherein the sensed parameter comprises a sensed temperature.

36. A merchandiser as set forth in claim 32 wherein the controller controls the linear compressor by controlling the stroke of the pistons based at least in part on the sensed parameter.

37. A merchandiser as set forth in claim 32 wherein the controller controls the free-piston linear compressor by controlling the stroke of the pistons for varying the effective displaced volume of refrigerant based at least in part on the sensed parameter.

38. A refrigeration unit comprising:

at least one surface at least partially defining an environmental space;

a free-piston linear compressor, a fluid-cooled condenser, an expansion device, and an evaporator in fluid communication, the free-piston linear compressor including dual-opposing pistons, the evaporator being in thermal communication with the environmental space to influence the temperature of the environmental space;

a controller to control operation of the linear compressor and coupled to the linear compressor, wherein the linear compressor provides variable capacity control and the controller modulates refrigerant capacity in the linear compressor;

a fluid-input line and a fluid-output line, both of which being in fluid communication with the fluid-cooled condenser; and

a frame supporting the at least one surface, the fluid-input line, the fluid-output line, the compressor, the fluid-cooled condenser, the expansion device, and the evaporator.

39. A refrigeration unit as set forth in claim 38 wherein the frame comprises the at least one surface.

40. A refrigeration unit as set forth in claim 38 wherein the controller comprises a fluid-cooled controller, and wherein the fluid-input line, the fluid-cooled controller, and the fluid-output line are all in fluid communication.

41. A refrigeration unit as set forth in claim 40 wherein the linear compressor comprises a fluid-cooled linear compressor, and wherein the fluid-input line, the fluid-cooled linear compressor, and the fluid-output line are all in fluid communication.

42. A refrigeration unit as set forth in claim 38 wherein the controller comprises a sensor configured to sense a parameter representative of an operating condition associated with the merchandiser, and wherein the controller controls the linear compressor based at least in part on the sensed parameter.

43. A refrigeration unit as set forth in claim 42 wherein the controller is further operable to control the expansion device based at least in part on the sensed parameter.

44. A refrigeration unit as set forth in claim 42 wherein the sensor comprises a pressure sensor, and wherein the sensed parameter comprises a sensed pressure.

45. A refrigeration unit as set forth in claim 42 wherein the sensor comprises a temperature sensor, and wherein the sensed parameter comprises a sensed temperature.

46. A refrigeration unit as set forth in claim 42 wherein the controller controls the linear compressor by controlling the stroke of the pistons based at least in part on the sensed parameter.

47. A refrigeration unit as set forth in claim 42 wherein the controller controls the linear compressor by controlling the stroke of the pistons for varying the effective displaced volume of refrigerant based at least in part on the sensed parameter.