Virtual compressor outlet temperature sensing for charge air cooler overheating protection

• US 7,143,580 B2
• Filed: 10/22/2004
• Issued: 12/05/2006
• Est. Priority Date: 10/22/2004
• Status: Expired due to Fees

• Current Assignee: Detroit Diesel Corporation (Daimler Truck Holding AG)
• Original Assignee: Detroit Diesel Corporation (Daimler Truck Holding AG)
• Inventors: Ge, Ping
• Primary Examiner(s): TRIEU, THAI BA
• Application Number:
  US10/971,469
• Publication Number:
  US 20060086089A1
• Time in Patent Office: 774 Days
• Field of Search: 606/051, 606/052, 606/11, 123/568.22, 123/563, 701104-112
• US Class Current: 60/605.1
• 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 29/0425 Air cooled heat exchangers
• CPC Class Codes: F02B 29/0493 Controlling the air charge temperature
• CPC Class Codes: F02B 37/22 by varying cross-section of exhaust passages or air passages , e.g. by throttling turbine inlets or outlets or by varying effective number of guide conduits F02B37/24 takes precedence
• CPC Class Codes: F02B 37/24 by using pumps or turbines with adjustable guide vanes
• CPC Class Codes: F02B 39/16 Other safety measures for, or other control of, pumps
• CPC Class Codes: F02D 2041/0067 Determining the EGR temperature
• CPC Class Codes: F02D 2041/0075 by using flow sensors
• CPC Class Codes: F02D 2200/0414 Air temperature
• 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: F02D 41/005 according to engine operating conditions
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: F02M 26/05 High pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust system upstream of the turbine and reintroduced into the intake system downstream of the compressor
• CPC Class Codes: F02M 26/10 having means to increase the pressure difference between the exhaust and intake system, e.g. venturis, variable geometry turbines, check valves using pressure pulsations or throttles in the air intake or exhaust system
• CPC Class Codes: F02M 26/16 with EGR valves located at or near the connection to the exhaust system
• CPC Class Codes: F02M 26/25 with coolers having bypasses
• CPC Class Codes: F02M 26/28 with liquid-cooled heat exchangers
• CPC Class Codes: F02M 26/47 the characteristics being temperatures, pressures or flow rates
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A system and method for controlling an internal combustion engine, having an exhaust recirculation (EGR) system and a charge air cooler, to prevent overheating the charge air cooler. The system calculates the output temperature of a turbocharger compressor as a function of ambient air temperature, air pressure, air mass flow rate, and turbo speed by processing an equation and controls the engine to modify charge air flow to reduce the output temperature of the turbocharger compressor if that temperature exceeds that of a determined crucial temperature above which charge air cooler damage could occur.

Claims

1. A method for controlling an internal combustion, compression-ignition engine, having an EGR circuit, a turbocharger compressor, and a charge air cooler, to avoid overheating the charge air cooler, the method comprising:

determining a crucial temperature above which damage to the charge air cooler could occur;

determining current ambient conditions;

determining current engine operating conditions;

processing an equation wherein a value of turbocharger compressor output temperature is predicted as a function of parameters representing the determined current ambient conditions and current engine operating conditions;

comparing the predicted turbocharger compressor output temperature with the determined crucial temperature; and

controlling the engine to prevent damage to the charge air cooler if the turbocharger compressor output temperature exceeds the determined crucial temperature.

2. The method as defined by claim 1, wherein the step of determining a crucial temperature comprises assigning a value from a memory or storage of data.

3. The method as defined by claim 1, wherein the step of determining current ambient conditions includes determining ambient air temperature and air pressure.

4. The method as defined by claim 1, wherein the step of determining current engine operating conditions includes determining air mass flow rate and turbocharger compressor speed.

5. The method as defined by claim 1, wherein the step of controlling the engine comprises reducing the temperature of the charge air cooler.

6. The method as defined by claim 5, wherein reducing the temperature of the charge air cooler comprises bypassing at least a portion of the charge air around the charge air cooler before said portion of the charge air around the charge air cooler is directed to an intake manifold of the engine.

7. The method as defined by claim 1, wherein the step of processing an equation comprises instructions for processing the following equation:

$\mathrm{TCO}=\frac{\mathrm{ATS}\times <br><br>\mathrm{CF}}{{\mathrm{\eta <br><br>}}_{\mathrm{TT}}}<br><br>\left(P_r^{\frac{\mathrm{\gamma <br><br>}-1}{\mathrm{\gamma <br><br>}}}-1+{\mathrm{\eta <br><br>}}_{\mathrm{TT}}\right)$

where;

ATS is the temperature of the turbocharger compressor inlet;

η

_TT is the compressor efficiency;

P_r is the compressor pressure ratio;

γ

is the ratio of specific heats; and

CF is the TCO sensor correction factor.

8. A computer-readable storage medium having stored data representing instructions executable by a computer to control an internal combustion, compression-ignition engine, having an EGR circuit, a charge air cooler, and a turbocharger compressor, to avoid overheating the charge air cooler, the computer-readable storage medium comprising:

instructions for determining a crucial temperature above which damage to the charge air cooler could occur;

instructions for determining current ambient conditions;

instructions for determining current engine operating conditions;

instructions for processing an equation wherein a value of turbocharger compressor output temperature is predicted as a function of parameters representing the determined current ambient conditions and current engine operating conditions;

instructions for comparing the predicted turbocharger compressor output temperature with the determined crucial temperature; and

instructions for controlling the engine to prevent damage to the charge air cooler if the turbocharger compressor output temperature exceeds the determined crucial temperature.

9. The computer-readable storage medium as defined by claim 8, wherein the instructions for determining a crucial temperature include instructions for assigning a value from a memory or storage of data.

10. The computer-readable storage medium as defined by claim 8, wherein the instructions for determining current ambient conditions include instructions for determining ambient air temperature and air pressure.

11. The computer-readable storage medium as defined by claim 8, wherein the instructions for determining current engine operating conditions include instructions for determining air mass flow rate and turbocharger compressor speed.

12. The computer-readable storage medium as defined by claim 8, wherein the instructions for controlling the engine comprise instructions for reducing the temperature of the charge air cooler.

13. The computer-readable storage medium as defined by claim 12, wherein the instructions for reducing the temperature of the charge cooler comprise instructions for bypassing at least a portion of the charge air around the charge air cooler before said portion of the charge air around the charge air cooler is directed to an intake manifold of the engine.

14. The computer-readable storage medium as defined by claim 8, wherein the instructions for processing an equation comprise instructions for processing the following equation:

$\mathrm{TCO}=\frac{\mathrm{ATS}\times <br><br>\mathrm{CF}}{{\mathrm{\eta <br><br>}}_{\mathrm{TT}}}<br><br>\left(P_r^{\frac{\mathrm{\gamma <br><br>}-1}{\mathrm{\gamma <br><br>}}}-1+{\mathrm{\eta <br><br>}}_{\mathrm{TT}}\right)$

where;

ATS is the temperature of the turbocharger compressor inlet;

η

_TT is the compressor efficiency;

P_r is the compressor pressure ratio;

γ

is the ratio of specific heats; and

CF is the TCO sensor correction factor.

15. A system for controlling an internal combustion, compression-ignition engine, having an EGR circuit, a turbocharger compressor, and a charge air cooler, to avoid overheating the charge air cooler, the system comprising:

a computer-readable storage medium storing a value of a crucial temperature above which damage to the charge air cooler could occur;

ambient condition sensors for determining current ambient conditions;

engine condition sensors for determining current engine operating conditions;

a charge air bypass valve for selectively bypassing at least a portion of charge air around the charge air cooler before it is combined with recirculated exhaust gas; and

a processor for calculating an equation wherein a value of turbocharger compressor output temperature is predicted as a function of parameters representing the determined current ambient air temperature, current air pressure, rotational speed of the turbocharger compressor, and air mass flow rate, the processor comparing the predicted turbocharger compressor output temperature with the determined crucial temperature, the charge air bypass valve being responsive to a processor command to bypass at least a portion of charge air around the charge air cooler if the predicted turbocharger compressor output temperature exceeds the determined crucial temperature.

16. The system as defined by claim 15, wherein the ambient condition sensors comprise:

a temperature sensor for determining current ambient air temperature; and

a pressure sensor for determining current air pressure.

17. The system as defined by claim 15, wherein the engine condition sensors comprise:

a turbo speed sensor for determining the rotational speed of the turbocharger compressor; and

an air mass flow rate sensor for determining air mass flow rate through the turbocharger compressor.

18. The system as defined by claim 15, wherein the equation calculated by the processor comprises the following:

$\mathrm{TCO}=\frac{\mathrm{ATS}\times <br><br>\mathrm{CF}}{{\mathrm{\eta <br><br>}}_{\mathrm{TT}}}<br><br>\left(P_r^{\frac{\mathrm{\gamma <br><br>}-1}{\mathrm{\gamma <br><br>}}}-1+{\mathrm{\eta <br><br>}}_{\mathrm{TT}}\right)$

where;

ATS is the temperature of the turbocharger compressor inlet;

η

_TT is the compressor efficiency;

P_r is the compressor pressure ratio;

γ

is the ratio of specific heats; and

CF is the TCO sensor correction factor.