METHOD AND SYSTEM FOR MONITORING PROCESS STATES OF AN INTERNAL COMBUSTION ENGINE

• US 20090281737A1
• Filed: 06/08/2009
• Published: 11/12/2009
• Est. Priority Date: 12/07/2006
• Status: Active Grant

• Current Assignee: ABB Research Ltd. (ABB Limited)
• Original Assignee: ABB Research Ltd. (ABB Limited)
• Inventors: Von Hoff, Thomas, Poncet, Andreas, STADLER, Konrad
• Granted Patent: US 8,280,647 B2
• Time in Patent Office: Days
• US Class Current: 702/34
• CPC Class Codes: F01D 17/08 responsive to condition of working-fluid, e.g. pressure
• CPC Class Codes: F02C 7/057 Control or regulation conjointly with fuel supply control F02C9/50, with nozzle area control F02K1/16
• CPC Class Codes: F02C 9/00 Controlling gas-turbine plants; Controlling fuel supply in air- breathing jet-propulsion plants controlling air intakes F02C7/057; controlling turbines F01D; controlling compressors F04D27/00; controlling in general G05
• CPC Class Codes: F02D 2200/1004 Estimation of the output torque
• 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 41/1445 the characteristics being related to the exhaust flow
• CPC Class Codes: F02D 41/1446 the characteristics being exhaust temperatures
• CPC Class Codes: F02D 41/1447 with determination means using an estimation
• CPC Class Codes: F02D 41/1497 With detection of the mechanical response of the engine
• CPC Class Codes: F02D 41/18 by measuring intake air flow
• CPC Class Codes: F05D 2260/80 Diagnostics
• CPC Class Codes: F05D 2270/303 Temperature
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

For monitoring (unmeasured) process states of a rotating machine having a combustion chamber (e.g. a gas turbine), compositions of educts entering the combustion chamber are measured. Based on the compositions of the educts, the composition of the product produced by the combustion chamber can be determined. Moreover, the mechanical power (P_mech) generated by the rotating machine can be determined. Based on the mechanical power (P_mech), the composition of the educts and product, and stoichiometric relationships of educts and product, the values of process states, such as the air mass flow (w_a) through the compressor leading into the combustion chamber and/or the gas mass flow (w_g), the composition and/or the temperature (T₃) of exhaust gas exiting the combustion chamber can be determined. Based on precise measurements of the educt (e.g. the composition of air and fuel in the combustion process), the product (i.e. the composition of the exhaust gas and its temperature) is derived and, without the need of an iterative or recursive method, the turbine inlet temperature (T₃) can be monitored and controlled.

Claims

1. A method of monitoring at least one process state of an internal combustion engine having a combustion chamber, the method comprising:

measuring compositions of educts (m_a, m_f) entering a combustion chamber;

determining, based on the compositions of the educts (m_a, m_f), a composition of a product produced by the combustion chamber;

determining mechanical power (P_mech) generated by the internal combustion engine; and

determining a value of at least one process state based on the mechanical power (P_mech), the composition of the educts (m_a, m_f) and product, and stoichiometric relationships of educts and product.

2. The method according to claim 1, wherein determining the value of the at least one process state includes:

determining at least one of an air mass flow (w_a) through a compressor leading into the combustion chamber, and a gas mass flow(w_g), a composition (m_g) and a temperature (T₃) of exhaust gas exiting the combustion chamber and/or entering a turbine.

3. The method according to claim 1, comprising:

measuring temperatures of the educts and product, and determining enthalpies for the educts and product using enthalpy functions associated with their respective compositions, wherein determining the enthalpies for educts and product is based on their respective temperatures, and wherein determining the value of the at least one process state is based on the enthalpies.

4. The method according to claim 1, comprising:

monitoring the process states of a gas turbine, wherein determining the value of the at least one process state includes;

determining an air mass flow (w_a) through a compressor leading into the combustion chamber;

determining a gas mass flow (w_g) of exhaust gas exiting the combustion chamber based on the air mass flow (w_a) and a fuel mass flow (w_f) into the combustion chamber;

determining a composition of the exhaust gas (m_g) based on the air mass flow (w_a) and the gas mass flow (w_g); and

determining a temperature (T₃) of the exhaust gas exiting the combustion chamber based on the air mass flow (w_a), the gas mass flow (w_g), and the composition of the exhaust gas (m_g), the temperature (T₃) of the exhaust gas exiting the combustion chamber being representative of an inlet temperature of the turbine driven by the exhaust gas exiting the combustion chamber.

5. The method according to claim 4, wherein determining the temperature (T₃) of the exhaust gas includes:

determining an inverted enthalpy function associated with the composition of the exhaust gas (m_g), and determining the temperature (T₃) of the exhaust gas exiting the combustion chamber based on the air mass flow (w_a) and the gas mass flow (w_g) using the inverted enthalpy function.

6. The method according to claim 4, comprising:

measuring temperatures (T₂, T_f) of air and fuel entering the combustion chamber;

measuring the temperature of the exhaust gas exiting the turbine; and

determining enthalpies (h_a, h_f, h_g) for air, fuel and exhaust gas based on their respective temperatures, wherein determining the value of the at least one process state is based on the enthalpies (h_a, h_f, h_g).

10. A method of monitoring at least one process state according to claim 1, comprising:

diagnosing the internal combustion system by determining the composition (m_g) of the exhaust gas as a process state;

measuring properties of specific exhaust gas components using sensors;

deriving, from the composition and the properties, information on a quality of combustion or a quality of fuel input, or information about a sensor failure.

11. The method according to claim 1, wherein the itnernal combustion engine is a rotating machine having the combustion chamber.

7. A system for monitoring at least one process state of an internal combustion engine having a combustion chamber, the system comprising:

means for measuring compositions of educts (m_a, m_f) entering the combustion chamber;

means for determining based on the compositions of the educts (m_a, m_f) a composition of a product produced by the combustion chamber;

means for determining mechanical power (P_mech) generated by the internal combustion engine; and

means for determining a value of at least one process state based on the mechanical power (P_mech), the composition of the educts (m_a, m_f) and product, and stoichiometric relationships of educts and product.

8. The system according to claim 7, wherein the internal combustion engine is a rotating machine configured as a gas turbine, and

wherein the at least one process state includes at least one of an air mass flow (w_a) through a compressor leading into the combustion chamber, and a gas mass flow (w_g), a composition (m_g) and a temperature (T₃) of exhaust gas exiting the combustion chamber, and

wherein the means for determining the value of the at least one process state are configured to determine the air mass flow (w_a) through the compressor leading into the combustion chamber, to determine the gas mass flow (w_g) of exhaust gas exiting the combustion chamber based on the air mass flow (w_a) and a fuel mass flow (w_f) into the combustion chamber, to determine a composition of the exhaust gas (m_g) based on the air mass flow (w_a) and the gas mass flow (w_g), and to determine a temperature (T₃) of the exhaust gas exiting the combustion chamber based on the air mass flow (w_a), the gas mass flow (w_g), and the composition of the exhaust gas (m_g), the temperature (T₃) of the exhaust gas exiting the combustion chamber being representative of an inlet temperature of the turbine driven by the exhaust gas exiting the combustion chamber.

9. The system according to claim 8, comprising:

means for measuring temperatures (T₂, T_f) of air and fuel entering the combustion chamber;

means for measuring the temperature of the exhaust gas exiting the turbine; and

means for determining enthalpies (h_a, h_f, h_g) for air, fuel and exhaust gas based on their respective temperatures, wherein the means for determining the value of the at least one process state are configured to determine the value of the at least one process state based on the enthalpies (h_a, h_f, h_g).