Turbocharger system

• US 20070144175A1
• Filed: 12/28/2006
• Published: 06/28/2007
• Est. Priority Date: 03/31/2005
• Status: Abandoned Application

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Sopko, Thomas, Casey, Kent, Vanderham, Michael, Kuras, Brian
• Application Number:
  US11/646,416
• Publication Number:
  US 20070144175A1
• Time in Patent Office: Days
• US Class Current: 60/605.100
• CPC Class Codes: F02B 2275/14 Direct injection into combustion chamber
• CPC Class Codes: F02B 29/0412 Multiple heat exchangers arranged in parallel or in series
• CPC Class Codes: F02B 39/10 electric
• CPC Class Codes: F02D 13/0226 changing valve lift or valve lift and timing
• CPC Class Codes: F02D 13/0269 Controlling the valves to perform a Miller-Atkinson cycle
• CPC Class Codes: F02D 15/04 by alteration of volume of compression space without changing piston stroke
• CPC Class Codes: F02D 2200/0406 Intake manifold pressure
• CPC Class Codes: F02D 23/02 the engines being of fuel-injection type
• CPC Class Codes: F02D 41/0007 for control of turbo-charged or super-charged engines control of the pumps per se F02B37/12
• CPC Class Codes: F02M 26/08 for engines having two or more intake charge compressors or exhaust gas turbines, e.g. a turbocharger combined with an additional compressor
• CPC Class Codes: F02M 26/23 Layout, e.g. schematics
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A system for controlling intake pressure of a combustion engine operably coupled to a power generation system includes at least one turbocharger operably coupled to the intake system of the combustion engine. The at least one turbocharger is configured to increase the intake pressure in the intake system of the combustion engine. A turbocharger controller is configured to compare actual and desired intake pressures and control operation of the at least one turbocharger based on the comparison such that the turbocharger supplies a desired intake pressure to the combustion engine.

Claims

1. A system for controlling intake pressure of a combustion engine operably coupled to a power generation system, the system comprising:

at least one turbocharger operably coupled to an intake system of the combustion engine, the at least one turbocharger being configured to increase the intake pressure in the intake system of the combustion engine; and

a turbocharger controller configured to compare actual and desired intake pressures and to control operation of the at least one turbocharger based on the comparison such that the at least one turbocharger supplies a desired intake pressure to the combustion engine.

2. The system of claim 1, wherein the turbocharger controller includes a comparator configured to output an intake pressure error based on a difference between the desired intake pressure and the actual intake system.

3. An engine comprising:

the system of claim 1;

a chamber with an intake port associated therewith;

a piston partially defining the chamber and being movable in a reciprocating manner within a cylinder through cycles, each cycle involving four strokes of the piston and two rotations of a crankshaft, the four strokes including an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke;

at least one cooler cooling air compressed by the at least one turbocharger and supplying the cooled, pressurized air to the intake port associated with the chamber; and

an intake valve movable to open and close the intake port;

wherein the engine is configured so that the intake valve opens the intake port,

allows cooled, pressurized air to flow through the intake port and into the chamber during the intake stroke,

maintains open the intake port during the intake stroke and beyond the end of the intake stroke and into the compression stroke and during a majority portion of the compression stroke, and

then closes the intake port during travel of the piston to capture in the chamber a cooled, compressed charge comprising the cooled pressurized air.

4. The engine of claim 3, further including a fuel delivery system delivering fuel into the chamber after the cooled compressed charge is captured in the chamber, wherein the engine ignites a mixture of the fuel and air within the chamber.

5. The engine of claim 4, wherein the fuel delivery system supplies pressurized fuel directly to the chamber during a portion of the compression stroke and during a portion of the expansion stroke.

6. The engine of claim 3, further including an exhaust gas recirculation system forming a mixture including air and recirculated exhaust gas, wherein the at least one turbocharger compresses the air and exhaust gas mixture and the at least one cooler cools the air and exhaust gas mixture before supplying the cooled, compressed mixture to the chamber via the intake port.

7. The engine of claim 6, wherein the exhaust gas recirculation system varies the proportion of exhaust gas and air in the mixture in response to at least one monitored condition and cools the recirculated exhaust gas prior to mixing the recirculated exhaust gas and the air.

8. The engine of claim 3, further including a variable intake valve closing system varying timing of the intake valve.

9. The engine of claim 8, wherein the variable intake valve closing system closes the intake valve at a first crank angle during one four stroke cycle of the piston and at a second crank angle during another four stroke cycle of the piston, the first crank angle being different from the second crank angle.

10. The engine of claim 3, wherein the intake port is maintained open for at least 65% of the compression stroke.

11. The engine of claim 3, wherein the intake port is maintained open for at least 80% of the compression stroke.

12. The engine of claim 3, wherein the at least one turbocharger provides a first stage of compression for air and the at least one cooler provides a first stage of cooling, and wherein the engine includes a second stage of compression and a second stage of cooling.

13. The engine of claim 3, wherein the air is compressed outside the chamber to at least 5 atmospheres, and then cooled to a temperature less than or equal to 200 degrees F.

14. The engine of claim 3, wherein the engine is a diesel-fueled, compression ignition engine.

15. The engine of claim 3, wherein the engine is either a gasoline-fueled engine or a natural gas-fueled engine, and wherein the engine is spark ignited.

16. The engine of claim 3, wherein the intake port is maintained open for a majority portion of the compression stroke during high load operation of the engine.

17. A method of maintaining a desired air-to-fuel ratio supplied to a combustion engine operably coupled to a power generation system, the method comprising:

determining a load on the power generation system;

controlling operation of at least one turbocharger via a turbocharger controller based on a comparison of actual and desired engine intake pressures and the load on the power generation system such that the desired air-to-fuel ratio supplied to the combustion engine is substantially maintained.

18. A method of operating a four-stroke, internal combustion engine including a chamber with an intake port associated therewith, and a piston partially defining the chamber and being movable in a reciprocating manner within a cylinder through cycles, each cycle involving four strokes of the piston and two rotations of a crankshaft, the four strokes including an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke, the method comprising:

maintaining a desired air-to-fuel ratio in accordance with claim 17;

compressing air outside the chamber via the at least one turbocharger;

cooling air outside the chamber;

supplying the cooled, pressurized air to the intake port associated with the chamber;

opening the intake port;

allowing cooled, pressurized air to flow through the intake port and into the chamber during the intake stroke;

maintaining open the intake port during the intake stroke and beyond the end of the intake stroke and into the compression stroke and during a majority portion of the compression stroke; and

after the maintaining, closing the intake port during travel of the piston to capture in the chamber a cooled, compressed charge comprising the cooled pressurized air.

19. The method of claim 18 further including delivering fuel into the chamber after the cooled compressed charge is captured in the chamber, and igniting a mixture of the fuel and air within the chamber.

20. The method of claim 19, further including supplying pressurized fuel directly to the chamber during a portion of the compression stroke and during a portion of the expansion stroke.

21. The method of claim 18, further including forming a mixture including air and recirculated exhaust gas, and compressing and cooling the air and exhaust gas mixture before supplying the cooled, compressed mixture to the chamber via the intake port.

22. The method of claim 21, further including varying the proportion of exhaust gas and air in the mixture in response to at least one monitored condition and cooling the recirculated exhaust gas prior to mixing the recirculated exhaust gas and the air.

23. The method of claim 18, further including varying timing of the intake valve.

24. The method of claim 23 wherein varying the timing includes closing the intake valve at a first crank angle during one four stroke cycle of the piston and at a second crank angle during another four stroke cycle of the piston, the first crank angle being different from the second crank angle.

25. The method of claim 18, wherein the intake port is maintained open for at least 65% of the compression stroke.

26. The method of claim 18, wherein the intake port is maintained open for at least 80% of the compression stroke.

27. The method of claim 18, wherein the compressing includes a first stage of pressurization and a second stage of pressurization, and wherein the cooling includes a first stage of cooling and a second stage of cooling.

28. The method of claim 18, wherein the air is compressed outside the chamber to at least 5 atmospheres, and then cooled to a temperature less than or equal to 200 degrees F.

29. The method of claim 18, wherein the engine is a diesel-fueled, compression ignition engine.

30. The method of claim 18, wherein the engine is either a gasoline-fueled engine or a natural gas-fueled engine, and wherein the engine is spark ignited.

31. The method of claim 18, wherein the intake port is maintained open for a majority portion of the compression stroke during high load operation of the engine.