CHARGE AIR SYSTEM AND CHARGE AIR OPERATION METHOD

• US 20110000469A1
• Filed: 06/26/2007
• Published: 01/06/2011
• Est. Priority Date: 06/26/2007
• Status: Active Grant

• Current Assignee: Volvo Lastvagnar AB (Volvo AB)
• Original Assignee: Volvo Lastvagnar AB (Volvo AB)
• Inventors: Lauberts, Peteris, Bertilsson, Bert-Inge
• Granted Patent: US 9,016,059 B2
• Time in Patent Office: Days
• US Class Current: 123/564
• CPC Class Codes: F02B 29/0412 Multiple heat exchangers arranged in parallel or in series
• CPC Class Codes: F02B 29/0418 the intake air cooler having a bypass or multiple flow paths within the heat exchanger to vary the effective heat transfer surface
• CPC Class Codes: F02B 29/0468 Water separation or drainage means
• CPC Class Codes: F02B 29/0493 Controlling the air charge temperature
• CPC Class Codes: F02B 37/004 with exhaust drives arranged in series
• CPC Class Codes: F02B 37/013 with exhaust-driven pumps arranged in series
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A charge air system for a combustion engine and an operation method are provided. The charge air system includes a first turbocharger stage for intake of combustion air supplied to the engine from a first pressure to a second pressure, a second turbocharger stage for compression of the compressed air to a third pressure, a first heat exchanger being arranged between the first and the second turbocharger stage for cooling the compressed air, a first intake air bypass for modulating the flow of the air through the first heat exchanger and/or a first mass flow control unit for controlling the flow of a cooling medium supplied to the first heat exchanger.

Claims

1. Charge air system for a combustion engine, comprising

a first boost system stage for compression of combustion air supplied to the engine from a first pressure to a second pressure,

a second boost system stage for compression of the compressed air to a third pressure,

a first heat exchanger being arranged between the first and the second turbocharger stage for cooling the compressed air, and

at least one of a first intake air bypass for modulating the flow of the air through the first heat exchanger a first mass flow control unit for controlling the flow of a cooling medium supplied to the first heat exchanger.

2. The charge air system according to claim 1, wherein a second heat exchanger is provided downstream of the second turbocharger stage between the second turbocharger stage and an intake manifold of the engine.

3. The charge air system according to claim 1, wherein a second intake air bypass is provided for modulating the flow of the air through the second heat exchanger.

4. The charge air system according to claim 3, wherein at least one of the first and the second intake air bypasses are provided for at least partially bypassing at least one of the first and second heat exchangers.

5. The charge air system according to claim 3, wherein at least one of the first and the second intake air bypasses are provided for fully bypassing at least one of the first and second heat exchangers.

6. The charge air system according to claim 1, wherein a second mass flow control unit is provided for controlling the flow of a cooling medium supplied to the second heat exchanger.

7. The charge air system according to claim 1, wherein an exhaust gas recirculation system is provided for recirculating exhaust gas from an exhaust manifold to the intake manifold of the engine.

8. The charge air system according to claim 7, wherein a first exhaust heat exchanger is provided in an exhaust line downstream of the engine for cooling the exhaust gas to a fourth temperature.

9. The charge air system according to claim 7, wherein a first exhaust bypass is provided for modulating the flow of the exhaust through the first exhaust heat exchanger by at least partially or fully bypassing the first exhaust heat exchanger.

10. The charge air system according to claim 7, wherein a third mass flow control unit is provided for controlling the flow of a cooling medium supplied to the first exhaust heat exchanger.

11. The charge air system according to one claim 7, wherein a second exhaust heat exchanger is provided in the exhaust line downstream of the engine for cooling the exhaust gas received from the first exhaust heat exchanger to a fifth temperature.

12. The charge air system according to claim 7, wherein a second exhaust bypass is provided for modulating the flow of the exhaust through the second heat exchanger by at least partially or fully bypassing the second exhaust heat exchanger.

13. The charge air system according to claim 7, wherein a fourth mass flow control unit is provided for controlling the flow of a cooling medium supplied to the second exhaust heat exchanger.

14. The charge air system according to claim 1, wherein a control unit is provided for controlling at least one of the amount of air which bypasses at least one of the first heat exchanger and the second heat exchanger, the amount of exhaust gas which bypasses at least one of the first exhaust heat exchanger and the second exhaust heat exchanger and the mass flow of a cooling medium through at least one of the first heat exchanger, second heat exchanger, first exhaust heat exchanger, and second exhaust heat exchanger.

15. The charge air system according to claim 1, wherein a sensor unit is provided at a discharge port of the first heat exchanger for estimating the dew point temperature of the air discharged from the heat exchanger.

16. The charge air system according to claim 1, wherein a sensor unit is provided at a discharge port of the second exhaust heat exchanger for estimating the dew point temperature of the exhaust discharged from the heat exchanger.

17. An operation method for a charge air system, comprising

compressing intake air from a first pressure to a second pressure in a first turbocharger stage,

compressing the compressed air to a third pressure in a second turbocharger stage,

estimating the amount of water in air taken in by the first turbocharger stage,

estimating a first dew-point temperature of the air discharged by a first heat exchanger arranged between the first and the second turbocharger stage,

comparing the first dew-point temperature to an estimated temperature of the air exiting the first heat exchanger,

activating at least one of an air bypass and a cooling-medium mass flow control unit for raising the second temperature above the first dew-point temperature if the second temperature is below the first dew-point temperature.

18. The method according to claim 17, wherein an air flow through at least one of the first and a second heat exchanger is modulated by at least partially bypassing at least one of the first and second heat exchangers.

19. The charge air system according to claim 17, wherein an air flow through at least one of the first and a second heat exchanger is modulated by fully bypassing at least one of the first and second heat exchangers.

20. The method according to claim 17, comprising estimating the amount of water in the air taken in based on an ambient first temperature, an ambient humidity and the first pressure.

21. The method according to claim 17, comprising

estimating a second dew-point temperature of the air discharged by the second heat exchanger,

comparing the dew-point temperature to an estimated third temperature of the air discharged by the second heat exchanger and

activating at least one of an air bypass and a cooling-medium mass flow control unit for raising the third temperature above the dew-point temperature if the second temperature is below the second dew-point temperature.

22. The method according to claim 17, wherein a delay function is applied for compensating a warm-up behaviour of the at least one of the first heat exchanger and the second heat exchanger at a cold start of the engine.

23. The method according to claim 17, comprising

estimating the amount of water in a recirculated exhaust gas downstream a second exhaust heat exchanger.

estimating a forth dew-point temperature depending on the amount of water in the exhaust gas fed back directly or indirectly to the intake manifold of the engine,

comparing the fourth dew-point temperature to an estimated temperature of the exhaust discharged from the second exhaust heat exchanger, and

activating at least one of an exhaust bypass and a cooling-medium mass flow control unit for raising the temperature above the fourth dew-point temperature if the estimated temperature is below the fourth dew-point temperature.

24. The method according to claim 17, comprising

providing an air-exhaust mixture to the first turbocharger stage, estimating the amount of water in the air-exhaust mixture,

estimating the first dew-point temperature upstream the first heat exchanger,

comparing the first dew-point temperature to the estimated temperature of the air-exhaust mixture discharged by the first heat exchanger,

activating at least one of the air bypass and the cooling-medium mass flow control unit for raising the second temperature above the first dew-point temperature if the second temperature is below the first dew-point temperature.

25. The method according to claim 23, comprising estimating the amount of water in the recirculated exhaust gas from an air/fuel ratio of the engine.

26. The method according to claim 17, measuring the second temperature with a sensor unit.

27. The method according to claim 17, comprising calculating the second temperature based on the first temperature, the first pressure and second pressure and a compressor isentropic entropy derived from the first turbocharger stage.

28. The method according to claim 17, comprising calculating pressures downstream at least one of the first and second air heat exchanger based on a rotational speed and the compressor isentropic entropy of the turbocharger stage.

29. The method according to claim 17, wherein a delay function is applied for compensating a warm-up behaviour of at least one of the first exhaust heat exchanger and a second exhaust heat exchanger at a cold start of the engine.