초록 ▼

A system includes a scroll compressor having a first scroll member interleaved with a second scroll member to define at least two moving fluid pockets that decrease in size as they move from a radially outer position to a radially inner position. A valve in fluid communication with the compression c

A system includes a scroll compressor having a first scroll member interleaved with a second scroll member to define at least two moving fluid pockets that decrease in size as they move from a radially outer position to a radially inner position. A valve in fluid communication with the compression chamber is movable between an open state allowing fluid to the compression chamber and a closed state preventing fluid to the compression chamber. A controller continuously cycles the valve between the open state and the closed state at a rate that is faster than a thermal time constant of a load on the system.

대표청구항 ▼

We claim: 1. A system comprising: a compressor including a compression chamber; a first valve in fluid communication with said compression chamber and movable between an open state allowing fluid to said compression chamber and a closed state preventing fluid to said compression chamber; a second v

We claim: 1. A system comprising: a compressor including a compression chamber; a first valve in fluid communication with said compression chamber and movable between an open state allowing fluid to said compression chamber and a closed state preventing fluid to said compression chamber; a second valve in fluid communication with said compression chamber and movable between a first position allowing compressed fluid to leak from said compression chamber to unload said compressor and a second position sealing said compression chamber to load said compressor; and a controller providing first duty cycle signal to said first valve and a second duty cycle signal to said second valve to cycle said first valve and said second valve at a rate that is faster than a thermal time constant of a load on the system. 2. The system of claim 1, wherein said controller is operable to generate a pulse width modulated signal to control at least one of said first valve and said second valve. 3. The system of claim 2, wherein said pulse width modulated signal is a function of at least one of a physical property and a thermodynamic property of a refrigeration system. 4. The system of claim 3, wherein said physical property and said thermodynamic property include at least one of pressure and temperature. 5. The system of claim 1, wherein at least one of said first valve and said second valve is a solenoid valve. 6. The system of claim 1, wherein said rate is at least two times faster than said thermal time constant. 7. The system of claim 1, wherein said rate is at least four times faster than said thermal time constant. 8. The system of claim 1, further comprising a pressure sensor, said controller being responsive to said pressure sensor for providing a variable duty cycle control signal for modulating at least one of said first valve and said second valve. 9. The system of claim 1, further comprising a temperature sensor, said controller being responsive to said temperature sensor for providing a variable duty cycle control signal for modulating at least one of said first valve and said second valve. 10. The system of claim 1, further comprising a diagnostic module coupled to said controller for monitoring and comparing said rate with at least one predetermined fault value indicative of a system fault condition. 11. The system of claim 10, further comprising an alert module, said alert module responsive to said diagnostic module for issuing an alert signal when said rate bears a predetermined relationship to said fault value. 12. The system of claim 1, further comprising a shell housing said compression chamber. 13. The system of claim 12, further comprising a motor disposed in said shell for driving said compressor. 14. The system of claim 1, wherein said first valve is disposed in a suction line of said compression chamber. 15. The system of claim 1, wherein said first and second duty cycle signals cycle said first and second valves at the same rate. 16. The system of claim 1, wherein said first and second duty cycle signals cycle said first and second valves at different rates. 17. The system of claim 1 wherein at least one of said first and second duty cycle signals is a pulse width modulated signal. 18. A refrigeration system comprising: a condenser; an evaporator fluidly coupled to said condenser; a compressor including a compression chamber and fluidly coupled to said condenser and said evaporator and operable to circulate a fluid therebetween; a first valve disposed between said evaporator and said compressor and movable between an open state allowing fluid to said compressor and a closed state preventing fluid to said compressor; a second valve in fluid communication with said compression chamber and movable between a first position allowing compressed fluid to leak from said compression chamber to unload said compressor and a second position sealing said compression chamber to load said compressor; and a controller providing a first duty cycle signal to said first valve and a second duty cycle signal to said second valve to cycle said first valve and said second valve at a rate that is faster than a thermal time constant of a load on the system. 19. The refrigeration system of claim 18, wherein said controller is operable to generate a pulse width modulated signal to control at least one of said first valve and said second valve. 20. The refrigeration system of claim 19, wherein said pulse width modulated signal is a function of at least one of a physical property and a thermodynamic property of the refrigeration system. 21. The refrigeration system of claim 20, wherein said physical property and said thermodynamic property include at least one of pressure and temperature. 22. The refrigeration system of claim 18, wherein at least one of said first valve and said second valve is a solenoid valve. 23. The refrigeration system of claim 18, wherein said rate is at least two times faster than said thermal time constant. 24. The refrigeration system of claim 18, wherein said rate is at least four times faster than said thermal time constant. 25. The refrigeration system of claim 18, further comprising a pressure sensor, said controller being responsive to said pressure sensor for providing a variable duty cycle control signal for modulating at least one of said first valve and said second valve. 26. The refrigeration system of claim 18, further comprising a temperature sensor, said controller being responsive to said temperature sensor for providing a variable duty cycle control signal for modulating at least one of said first valve and said second valve. 27. The refrigeration system of claim 18, further comprising a diagnostic module coupled to said controller for monitoring and comparing said rate with at least one predetermined fault value indicative of a system fault condition. 28. The refrigeration system of claim 27, further comprising an alert module, said alert module responsive to said diagnostic module for issuing an alert signal when said rate bears a predetermined relationship to said fault value. 29. The refrigeration system of claim 18, wherein said compressor includes a shell. 30. The refrigeration system of claim 29, further comprising a motor disposed in said shell for driving said compressor. 31. The refrigeration system of claim 18, wherein said first valve is disposed in a suction line of said compressor. 32. The system of claim 18, wherein said first and second duty cycle signals cycle said first and second valves at the same rate. 33. The system of claim 18, wherein said first and second duty cycle signals cycle said first and second valves at different rates. 34. The system of claim 18, wherein at least one of said first and second duty cycle signals is a pulse width modulated signal.