Compressor with vapor injection system

1. A heat pump system comprising:

a compressor;

a first heat exchanger in fluid communication with said compressor;

a second heat exchanger in fluid communication with said first heat exchanger and said compressor;

a flash tank fluidly coupled to said first heat exchanger and said second heat exchanger;

a first conduit extending between said first heat exchanger and said second heat exchanger; and

a valve associated with said first conduit and operable in an open state to permit flow along said first conduit between said first heat exchanger and said second heat exchanger to at least partially bypass said flash tank and operable in a closed state to prevent flow along said first conduit between said first heat exchanger and said second heat exchanger to direct flow into said flash tank,

wherein the heat pump system is operable in a heating mode and a cooling mode; and

wherein said valve is in said open state when the heat pump system is operating in said heating mode and an outdoor ambient temperature is high and is in said closed state when the heat pump system is operating in said heating mode and said outdoor ambient temperature is low.

2. The heat pump system of claim 1 , wherein said valve is operable in said open state and said closed state when the heat pump system is in said heating mode or said cooling mode.

3. The heat pump system of claim 1 , wherein said valve is in said open state when the heat pump system is operating in said cooling mode and an outdoor ambient temperature is low and is in said closed sate when the heat pump system is operating in said cooling mode and said outdoor ambient temperature is high.

4. The heat pump system of claim 1 , further comprising a capillary tube disposed between said valve and an inlet of one of said first heat exchanger and said second heat exchanger.

5. The heat pump system of claim 1 , further comprising a second conduit extending between one of said first heat exchanger and said second heat exchanger and an inlet of said flash tank.

6. The heat pump system of claim 5 , wherein said second conduit fluidly couples an inlet of said flash tank to said first conduit to selectively deliver refrigerant to said flash tank from one of said first heat exchanger and said second heat exchanger.

7. The heat pump system of claim 6 , wherein all refrigerant from said one of said first heat exchanger and said second heat exchanger is delivered to said flash tank via said second conduit when said valve is in said closed state.

8. The heat pump system of claim 6 , wherein refrigerant flows into said flash tank via said second conduit and flows through said valve along said first conduit when said valve is in said open state.

9. In a heat pump system circulating refrigerant between a first heat exchanger and a second heat exchanger in a fluid circuit including a compressor, a vapor injection system comprising:

a flash tank;

a first conduit fluidly coupling an inlet of said flash tank to the first heat exchanger and the second heat exchanger and operable to deliver refrigerant to said flash tank from at least one of the first heat exchanger and the second heat exchanger;

a second conduit extending between the first heat exchanger and the second heat exchanger and operable to selectively deliver refrigerant from one of the first heat exchanger and the second heat exchanger to the other of the first heat exchanger and the second heat exchanger to at least partially bypass said flash tank; and

a valve associated with said second conduit and operable between a closed state preventing flow between the first heat exchanger and the second heat exchanger along said second conduit and an open state permitting flow between the first heat exchanger and the second heat exchanger along said second conduit;

wherein said valve is in said open state when the heat pump system is operating in a heating mode and an outdoor ambient temperature is high and is in said closed state when the heat pump system is operating in said heating mode and said outdoor ambient temperature is low.

10. The vapor injection system of claim 9 , further comprising a capillary tube disposed between said valve and an inlet of one of the first heat exchanger and the second heat exchanger.

11. The vapor injection system of claim 9 , wherein all refrigerant from one of the first heat exchanger and the second heat exchanger is delivered to said flash tank via said first conduit when said valve is in said closed state.

12. The vapor injection system of claim 9 , wherein said valve is in said open state when the heat pump system is operating in a cooling mode and an outdoor ambient temperature is low and is in said closed state when the heat pump system is operating in said cooling mode and said outdoor ambient temperature is high.

13. The vapor injection system of claim 9 , wherein said valve is operable in said open state and said closed state when the heat pump system is operating in a heating mode or in a cooling mode.

14. A heat pump system comprising:

a compressor;

a first heat exchanger in fluid communication with said compressor;

a second heat exchanger in fluid communication with said first heat exchanger and said compressor;

a flash tank fluidly coupled to said first heat exchanger and said second heat exchanger;

a first conduit extending between said first heat exchanger and said second heat exchanger; and

a valve associated with said first conduit and operable in an open state to permit flow along said first conduit between said first heat exchanger and said second heat exchanger to at least partially bypass said flash tank and operable in a closed state to prevent flow along said first conduit between said first heat exchanger and said second heat exchanger to direct flow into said flash tank,

wherein the heat pump system is operable in a heating mode and a cooling mode; and

wherein said valve is in said open state when the heat pump system if operating in said cooling mode and an outdoor ambient temperature is low and is in said closed sate when the heat pump system is operating in said cooling mode and said outdoor ambient temperature is high.

15. The heat pump system of claim 14 , further comprising a second conduit extending between one of said first heat exchanger and said second heat exchanger and an inlet of said flash tank.

16. The heat pump system of claim 15 , wherein said second conduit fluidly couples an inlet of said flash tank to said first conduit to selectively deliver refrigerant to said flash tank from one of said first heat exchanger and said second heat exchanger.

17. The heat pump system of claim 16 , wherein all refrigerant from said one of said first heat exchanger and said second heat exchanger is delivered to said flash tank via said second conduit when said valve is in said closed state.

18. The heat pump system of claim 16 , wherein refrigerant flows into said flash tank via said second conduit and flows through said valve along said first conduit when said valve is in said open state.

19. In a heat pump system circulating refrigerant between a first heat exchanger and a second heat exchanger in a fluid circuit including a compressor, a vapor injection system comprising:

a flash tank;

a first conduit fluidly coupling an inlet of said flash tank to the first heat exchanger and the second heat exchanger and operable to deliver refrigerant to said flash tank from at least one of the first heat exchanger and the second heat exchanger;

a second conduit extending between the first heat exchanger and the second heat exchanger and operable to selectively deliver refrigerant from one of the first heat exchanger and the second heat exchanger to the other of the first heat exchanger and the second heat exchanger to at least partially bypass said flash tank; and

a valve associated with said second conduit and operable between a closed state preventing flow between the first heat exchanger and the second heat exchanger along said second conduit and an open state permitting flow between the first heat exchanger and the second heat exchanger along said second conduit;

wherein said valve is in said open state when the heat pump system is operating in a cooling mode and an outdoor ambient temperature is low and is in said closed state when the heat pump system is operating in said cooling mode and said outdoor ambient temperature is high.

20. The vapor injection system of claim 19 , wherein all refrigerant from one of the first heat exchanger and the second heat exchanger is delivered to said flash tank via said first conduit when said valve is in said closed state.

21. The vapor injection system of claim 19 , wherein said valve is operable in said open state and said closed state when the heat pump system is operating in a heating mode or in a cooling mode.