System and method for managing multiple exhaust gas recirculation coolers

Abstract

A system is provided. The system includes a controller communicatively coupled to an industrial combustion engine and an exhaust gas recirculation (EGR) system, wherein the EGR system is configured to direct exhaust gas generated by the industrial combustion engine from at least one exhaust system to at least one intake system, the EGR system includes a plurality of EGR loops, each of the plurality of EGR loops includes an EGR cooler unit, the EGR cooler unit includes at least two of a high temperature non-condensing cooler, a low temperature condensing cooler, an adiabatic gas / liquid separator, and a reheater. The controller includes a processor and a non-transitory memory encoding one or more processor executable routines, wherein the one or more routines, when executed by the processor, cause the controller to control the operation of both the industrial combustion engine and the EGR system.

Description

Technical Field

[0001] The subject matter disclosed herein relates to internal combustion engines, and more particularly to the management of multiple exhaust gas recirculation coolers for industrial internal combustion engines. Background Art

[0002] Exhaust gas recirculation (EGR) involves introducing a portion of the exhaust gas from an internal combustion engine into the combustion chamber of the internal combustion engine, such as one or more cylinders of the internal combustion engine. EGR can be used to reduce nitrogen oxides such as, for example, nitric oxide (NO) and nitrogen dioxide (NO2) (hereinafter collectively referred to as NO x ) formation. Exhaust gas is essentially inert. Therefore, introducing a portion of the exhaust gas into the combustion chamber of the internal combustion engine dilutes the mixture of fuel and air to be burned and thus reduces the peak combustion temperature and excess oxygen. As a result, the engine produces a reduced amount of NO x , because NO x EGR is therefore used to reduce or limit the NO generated during combustion in the engine. x The amount. Summary of the invention

[0003] The following summarizes certain embodiments that are commensurate in scope with the originally claimed subject matter. These embodiments are not intended to limit the scope of the claimed subject matter, but rather these embodiments are intended only to provide a brief overview of possible forms of the subject matter. In fact, the subject matter may include a variety of forms that are similar to or different from the embodiments set forth below.

[0004] In a first embodiment, a system is provided. The system includes an industrial combustion engine, the industrial combustion engine including at least one intake system and at least one exhaust system. The system also includes an exhaust gas recirculation (EGR) system, which is coupled to the industrial combustion engine and configured to direct exhaust gas generated by the industrial combustion engine from the at least one exhaust system to the at least one intake system. The EGR system includes a first EGR cooler unit for a first group of cylinders of an industrial combustion engine arranged along a first EGR loop. The EGR system also includes a second EGR cooler unit for a second group of cylinders of an industrial combustion engine arranged along a second EGR loop, wherein the first and second EGR cooler units each include at least two of a high temperature non-condensing cooler, a low temperature condensing cooler, an adiabatic gas / liquid separator, and a reheater. The first and second EGR cooler units are respectively coupled to first and second EGR valves, and the first and second EGR valves are configured to enable exhaust gas to flow from the first and second EGR loops to the industrial combustion engine, respectively. The system also includes a controller communicatively coupled to the industrial combustion engine and the EGR system, wherein the controller includes a processor and non-transitory memory encoding one or more processor-executable routines, wherein the one or more routines, when executed by the processor, cause the controller to manage flow of exhaust gas to the industrial combustion engine by modulating the first and second EGR valves via signals sent to the actuator.

[0005] In a second embodiment, a system is provided. The system includes a controller communicatively coupled to an industrial combustion engine and an exhaust gas recirculation (EGR) system, wherein the EGR system is configured to route exhaust gas generated by the industrial combustion engine from at least one exhaust system to at least one intake system, the EGR system includes a plurality of EGR loops, each of the plurality of EGR loops includes an EGR cooler unit, the EGR cooler unit includes at least two of a high temperature non-condensing cooler, a low temperature condensing cooler, an adiabatic gas / liquid separator, and a reheater. The controller includes a processor and a non-volatile memory encoding one or more processor-executable routines, wherein the one or more routines, when executed by the processor, cause the controller to manage the flow of exhaust gas to the industrial combustion engine via a control signal sent to an actuator by: fully opening the corresponding EGR valves arranged along the multiple EGR loops and modulating the shared EGR valve shared by the multiple EGR loops downstream of the corresponding EGR valve to adjust the flow of exhaust gas to the industrial combustion engine; fully opening the shared EGR valve and modulating the corresponding EGR valve to adjust the flow of exhaust gas to the industrial combustion engine; or partially opening the corresponding EGR valve and the shared EGR valve to adjust the flow of exhaust gas to the industrial combustion engine.

[0006] In a third embodiment, a method is provided. The method includes using a controller that is communicatively coupled to an industrial combustion engine and an exhaust gas recirculation (EGR) system and includes a non-transitory memory and a processor to: initially activate only one of a plurality of EGR loops of the EGR system via a control signal during a first cold start of the industrial combustion engine; and then subsequently activate each of the plurality of EGR loops when the controller detects that an operating parameter of the industrial combustion engine is approaching an outer limit of a specified range based on feedback received from a sensor. The method also includes: initially activating any of the plurality of EGR loops that were not activated during the first cold start of the industrial combustion engine via a control signal during a second cold start of the industrial combustion engine, and initially activating the EGR loop that was initially activated during the first cold start during a subsequent hot start of the industrial combustion engine, wherein the second cold start or the subsequent hot start is a next start after the first cold start, and wherein each of the plurality of EGR loops includes an EGR cooler unit that includes a plurality of functional sections. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] These and other features, aspects, and advantages of the present subject matter will become better understood when the following detailed description is read with reference to the accompanying drawings, in which like numerals refer to like parts throughout the drawings, and in which:

[0008] Figure 1 is a block diagram of an engine driven power generation system according to an embodiment;

[0009] Figure 2 is a schematic diagram of an engine control module (ECM) in an engine-driven power generation system according to an embodiment;

[0010] Figure 3 According to an embodiment, a low-pressure loop EGR system is used. Figure 1 A schematic diagram of an engine driven power generation system;

[0011] Figure 4 According to an embodiment, a low-pressure loop EGR system (e.g., a shared intake manifold) is used. Figure 1 A schematic diagram of an engine driven power generation system;

[0012] Figure 5 According to an embodiment, a low-pressure loop EGR system (eg, shared intake and exhaust manifolds) is used. Figure 1 A schematic diagram of an engine driven power generation system;

[0013] Figure 6 According to an embodiment, a high pressure loop EGR system is used. Figure 1A schematic diagram of an engine driven power generation system;

[0014] Figure 7 According to an embodiment, a high pressure loop EGR system (eg, shared intake manifold) is used. Figure 1 A schematic diagram of an engine driven power generation system;

[0015] Figure 8 According to an embodiment, a low-pressure loop EGR system (eg, shared intake and exhaust manifolds) is used. Figure 1 A schematic diagram of an engine driven power generation system;

[0016] Fig. 9 According to an embodiment, Figure 1 A flow chart of a method for utilizing an EGR system during sequential warm-up of an engine driven power generation system; and

[0017] Fig.10 According to the embodiment Figure 2 Schematic representation of the functional operation of the ECM. DETAILED DESCRIPTION

[0018] One or more specific embodiments of the present subject matter will be described below. In order to provide a concise description of these embodiments, all features of the actual implementation may not be described in the specification. It should be understood that in the development of any such actual implementation, as in any engineering or design project, many implementation-specific decisions must be made to achieve the developer's specific goals, such as meeting system-related and business-related constraints, which may vary from one implementation to another. In addition, it should be understood that such development efforts may be complex and time-consuming, but for ordinary technicians who benefit from this disclosure, this will be a routine task of design, processing and manufacturing.

[0019] When introducing elements of various embodiments of the present subject matter, the articles "a," "an," "the," and "said" are intended to mean that there are one or more of the elements. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0020] Embodiments of the present disclosure enable control or management of an exhaust gas recirculation (EGR) system for an industrial combustion engine (e.g., configured to generate 2 megawatts (MW) of power). As described in more detail below, the EGR system includes a plurality of EGR loops, each of which includes an EGR cooler unit that includes a plurality of functional sections. For example, each EGR cooler unit may include at least two of the following sections: a high temperature non-condensing cooler, a low temperature condensing cooler, an adiabatic gas / liquid separator, and a reheater. In addition, each EGR loop may include a thermostatically controlled bypass valve that, when opened, enables exhaust gas to bypass each cooler within the corresponding EGR cooler unit. A controller is communicatively coupled to both the industrial combustion engine and the EGR system, which enables control of the operation of both the industrial combustion engine and the EGR system. Management of multiple EGR loops (and EGR cooler units) provides redundancy and additional capacity as well as additional functionality. For example, as described in more detail below, multiple EGR cooler units enable in-line manipulation of EGR heat rejection, utilization of the engine when one EGR loop is derated (i.e., the engine is operated at less than maximum power) with another EGR loop disabled, EGR distribution management, sequential warm-up, and other functions.

[0021] exist Figure 1An example of an engine driven power generation system 10 is illustrated in FIG. It should be noted that the engine generates and outputs power, but the application of the power can be used for electrical power generation, gas compression, mechanical drive, cogeneration (sometimes also referred to as combined power generation) (e.g., combined heat and power), trigeneration (e.g., combined heat, power and industrial chemicals for greenhouse applications), or other applications. The system includes an engine 12 (e.g., a reciprocating internal combustion engine) coupled to an exhaust gas recirculation (EGR) system 14. The system 10 is suitable for use in stationary applications (e.g., an industrial power generation engine or a stationary reciprocating internal combustion engine). Although in some embodiments, the described technology can be used in mobile applications (e.g., ships or locomotives). In some embodiments, the system 10 can generate more than 2 megawatts (MW) of power. In other embodiments, the system 10 can generate less than 2 MW of power (e.g., between 1 MW and 2 MW, or even less than 1 MW of power). The system 10 may also operate the engine 12 at a stoichiometric air-fuel equivalence ratio (e.g., λ=1) while utilizing EGR as a diluent. Operating the engine 12 under stoichiometric conditions enables an exhaust aftertreatment system (e.g., a three-way catalyst) to be utilized by the system 10 to reduce emissions. It should be noted that in some operating modes, the λ setpoint may be rich (e.g., λ is less than 1.0). The primary determinant of the actual λ depends on the emissions output from the exhaust aftertreatment system, commonly referred to as "stack-out". In certain embodiments, operation may be directed to a specific λ value or to a jitter within a λ range at a specific frequency to achieve the desired "stack-out" emissions. It is typical to operate a stoichiometric / rich engine with a λ of 0.96 to 1.04, but this is primarily dependent on the specific exhaust aftertreatment system (e.g., precious metal loading, coating, temperature, etc.). Changes in λ have a dynamic impact on the EGR system 14 that is interpreted by the ECM 16. In certain embodiments, the system 10 may also operate the engine under lean burn conditions while also utilizing EGR as a diluent and an exhaust aftertreatment system such as a two-way oxidation catalytic converter (“Oxi-Cat”) and / or a selective catalytic reduction (SCR) that actively injects a reductant into the catalyst, such as, but not necessarily limited to, ammonia or urea.

[0022] As described in more detail below, due to heat removal requirements and EGR cooler physical size determination, the EGR system 14 may include multiple EGR loops, each of which includes an EGR cooler unit. Each EGR cooler unit may include multiple functional sections. The EGR system 14 may utilize a high-pressure loop EGR system (e.g., exhaust gas is turned from the upstream of the turbine of the turbocharger and reintroduced into the intake system after the compressor) or a low-pressure loop EGR system (e.g., exhaust gas is turned from the downstream of the turbine of the turbocharger and reintroduced into the intake system before the compressor of the turbocharger). The utilization of multiple EGR loops / cooler units by the EGR system 14 increases the freedom of the management system 14 to generate redundancy, additional capacity and additional functions. For example, multiple EGR cooler units can realize online manipulation of EGR heat removal, utilization of another EGR loop when the engine is derated when one EGR loop is disabled, EGR distribution management, sequential preheating and other functions.

[0023] The engine 12 may be a two-stroke engine, a four-stroke engine, or other types of engines 12. In a particular embodiment, the engine 12 is a four-stroke engine. The engine 12 may also include any number of combustion chambers, pistons, and associated cylinders (e.g., 1-24) in one (e.g., in-line) or multiple (e.g., left and right cylinder groups) cylinder groups of V-type, W-type, VR-type (also known as V-type in-line) or WR-type cylinder group structures. For example, in certain embodiments, the system 8 may include a large industrial reciprocating engine having 6, 8, 12, 16, 20, 24 or more pistons that reciprocate in the cylinder. In some such cases, the cylinder and / or piston may have a diameter between approximately 13.5 and 31 centimeters (cm). In certain embodiments, the cylinder and / or piston may have a diameter beyond the above range. The fuel utilized by engine 12 may be any suitable gaseous fuel, such as, for example, natural gas, associated petroleum gas, hydrogen (H2), propane (C3H8), biogas, sewage gas, landfill gas, coal mine gas, butane (C4H 10 ), ammonia (NH3). The fuel may also include various liquid fuels, such as gasoline, diesel, methanol or ethanol fuel. The fuel may be introduced through a high pressure (blowing) fuel supply system or a low pressure (suction) fuel supply system or direct injection. In some embodiments, the engine 12 may utilize spark ignition. In other embodiments, the engine 12 may utilize compression ignition.

[0024] The system 10 includes an engine control module (ECM) or engine control unit (ECU) 16 (e.g., a controller) operably coupled to communicate with the engine 12 and the EGR system 14. In addition, the ECM 16 is operably coupled to communicate with one or more sensors 18 and one or more actuators 20. The ECM 16 may be a single controller or multiple controllers housed in the same or separate housings. The sensors 18 may be coupled to one or more components of the engine 12, the EGR system 14, or other components of the engine system 10 and sense one or more operating characteristics of the engine 12, the EGR system 14, and / or the engine system 10 and output signals representative of the operating characteristics. Some examples of typical engine operating characteristics include: engine speed; torque indicating characteristics, such as intake manifold absolute pressure (IMAP) or intake manifold density (IMD); characteristics indicating the power output of the engine determined from inputs into the engine, such as brake mean effective pressure (BMEP) or indicated mean effective pressure (IMEP) or other estimates; characteristics indicating the air to fuel equivalence ratio of the engine, such as exhaust oxygen content; ambient and / or engine temperature; ambient pressure; ambient humidity; and others. Some examples of other characteristics that may be measured by sensor 18 include the power output of the engine from outputs of the engine, such as a generator driven by the engine, throughput and pressure of a compressor driven by the engine, engine load measured using a load cell, and others. Actuator 20 is adapted to control various engine system components (not specifically shown) used to control engine 12, EGR system 14, and other engine system components. Some examples of typical engine components include a throttle, a turbocharger, a turbocharger compressor bypass or wastegate, an air / fuel regulating device such as an adjustable fuel mixer, a fuel pressure regulator, a fuel injector, a carburetor, one or more EGR valves, and others. The ECM 16 may also be coupled to communicate with other components 22. Some examples of other components 22 may include a user interface that allows a user to query the ECM 16 or input data or instructions to the ECM 16, one or more external sensors that sense information other than operating characteristics of the engine or engine system, monitoring or diagnostic equipment to which the ECM 16 may transmit characteristics of the system, a load driven by the engine (e.g., a generator, a compressor, or other load), and others.

[0025] refer to Figure 2, the ECM 16 includes a processor 24 operably coupled to a non-transitory computer readable medium or memory 26. The computer readable medium 26 may be completely or partially removable from the ECM 16. The computer readable medium 26 contains instructions used by the processor 24 to perform one or more of the methods described herein. More specifically, the memory 26 may include volatile memory such as random access memory (RAM) and / or non-volatile memory such as read-only memory (ROM), an optical drive, a hard drive, or a solid-state drive. In addition, the processor 24 may include one or more application-specific integrated circuits (ASICs), one or more field-programmable gate arrays (FPGAs), one or more general-purpose processors, or any combination thereof. Furthermore, the term processor is not limited to those integrated circuits referred to as processors in the art, but rather refers broadly to computers, processors, microcontrollers, microcomputers, programmable logic controllers, application-specific integrated circuits, and other programmable circuits. The ECM 16 may receive one or more input signals (input 1 . . . input 22) such as from sensors 18, actuators 20, and other components 22. n ), and may output one or more output signals (output 1 . . . output 1 ) such as to sensors 18, actuators 20, and other components 22 n ).

[0026] The ECM 16 controls the engine 12 ( Figure 1 ) to a specified operating state, such as a specified speed, torque output, or other specified operating state, and maintain the engine in steady-state operation. To this end, the ECM 16 receives inputs from sensors 18, including engine state parameters, and determines and outputs one or more actuator control signals suitable for controlling actuators 20 to operate the engine 12. As described in more detail below, the ECM 16 also operates the EGR system 14 based on inputs from the sensors 18. The following are non-limiting examples of sources (e.g., sensors, techniques, etc.) that the ECM 16 may utilize when estimating or calculating the amount or rate of EGR flow: Coriolis flowmeter, hot wire anemometer, laminar flowmeter, ultrasonic flowmeter, vortex flowmeter, differential pressure (ΔP; across the engine, EGR loop, or separate components) and net difference method (fuel for power, air for λ, sum of velocity density). In certain embodiments, additional methods for estimating or calculating the amount or rate of EGR flow include estimating or calculating each chemical component from the intake system (e.g., CO2, CO, NO x, N2O, VOCs, HC, CH2O, NH3, etc.) and compare these to the additional flow streams that make up the intake system flow as part of the total engine flow (e.g., ambient air, fuel, closed crankcase ventilation (CCV), and EGR). Some of these chemical components come only from the exhaust (i.e., EGR). Therefore, if the intake system concentrations are measured, the percent volume EGR flow can be estimated because it will be proportional when the state characteristics of the flow stream are corrected. Fig.10 More specific non-limiting examples are provided for the ECM 16 .

[0027] Figures 3 to 8 Various embodiments of an engine driven power generation system 10 are described. Figure 3 A low-pressure loop EGR system (e.g., exhaust gas is diverted downstream of the turbine of a turbocharger (TC) and reintroduced into the intake system before the compressor of the turbocharger (TC)) is used. Figure 1 Schematic diagram of an engine driven power generation system 10. Although shown as multiple components, Figure 3 Various components of the system 10 illustrated in FIG. 1 may be shared across the engine cylinder groups, as indicated by asterisks. As depicted, the engine 12 includes multiple cylinder groups 28 (e.g., group A and group B, but typically referred to as left and right cylinder groups, respectively) and multiple EGR circuits 30. As depicted, the system 10 includes two EGR circuits 30 in parallel. The number of EGR circuits 30 may vary (e.g., 2, 3, 4 or more). In addition, in certain embodiments, the EGR circuits 30 may be arranged in series. Each combustion chamber 34 includes a corresponding cylinder head. Each cylinder head 32 includes multiple components, which include corresponding pistons disposed in corresponding cylinders (not shown). Fuel is provided to the combustion chamber 34 in each cylinder, while an oxidant (e.g., air) is provided to the combustion chamber 34 (where combustion occurs) via (multiple) intake valves 36, and (multiple) exhaust valves 38 control the discharge of exhaust gas from the engine 12. Each cylinder bank 28 includes an intake manifold 40 (or intake system), an exhaust manifold 42 (or exhaust system), and a throttle 44. The throttle 44, compressor bypass valve 58, and wastegate 56 are the primary power controls that limit the amount of oxidant / fuel delivered to the combustion chamber 34. In certain embodiments, other power controls may include variable turbine geometry or variable valve timing.

[0028] As shown, the system 10 also includes a turbocharger 46 and an intercooler 48 (e.g., a heat exchanger) associated with each EGR loop 30. In some embodiments, an electric compressor (e.g., an electric motor coupled to a compressor) may be used instead of the turbocharger 46. In some embodiments, a multi-stage turbocharging system may be used. Each turbocharger 46 includes a compressor 50 coupled to a turbine 52 (e.g., via a drive shaft (not shown)). Air (e.g., an oxidant) is provided via an intake port 54. In some embodiments, an air filter may be provided in the intake port 54. The turbine 52 is driven by exhaust gas to drive the compressor 50, which in turn compresses the intake air, fuel, and EGR flow so as to be introduced into the intake manifold 40 after being cooled by the intercooler 48. In addition, the fuel is supplied from a fuel supply system 53 downstream of the intake port 54 and upstream of the compressor 50. As depicted, the fuel supply system 53 is a low-pressure (suction) fuel supply system. In a low pressure (LP) fuel system, low gas pressure is utilized by mixing gas (fuel) with air at atmospheric pressure or slightly below atmospheric pressure before compressor 50. Then, the air-fuel mixture is sucked through compressor 50 and compressed. Since the fuel is mixed under ambient conditions, changes in these conditions will affect engine performance. Typical gas (fuel) pressure to the engine fuel regulator falls within the range of 0.5 to 5 psig. In certain embodiments, fuel supply system 53 may be a high pressure (HP) fuel supply system. For high pressure fuel systems, turbocharged engines require gas (fuel) supply pressure greater than the boost pressure generated by compressor 50. Since fuel is introduced into the air flow after air passes through compressor 50, the differential pressure (i.e., gas exceeds air pressure) allows proper mixing of fuel and air in the carburetor. Typical gas (fuel) pressure to the engine fuel regulator falls within the range of 12 to 90 psig. In certain embodiments, fuel supply system 53 may include a control device to adjust the air and fuel provided to engine 12.

[0029] A wastegate 56 (e.g., a wastegate valve) may be disposed between the exhaust manifold discharge and the exhaust system to regulate the turbocharger 46 by diverting exhaust energy from the turbine 52. The wastegate 46 functionally regulates the amount of engine exhaust provided to the turbine 52 of the turbocharger 46, and thus regulates the compressor discharge pressure generated by the compressor 50. The wastegate 56 may be an integral (e.g., with the turbine 52), an electronically controlled wastegate (electronic wastegate), or a pneumatic wastegate that senses pressure elsewhere within the system 10. The system 10 may also include a respective bypass valve 58 (e.g., a compressor bypass valve (CBV)) associated with each compressor 50 of each turbocharger 46 to control pressure by diverting a portion of the intake airflow to the engine 12. As depicted, the compressor bypass valve 58 is separate from the compressor 50. In certain embodiments, the compressor bypass valve 58 is integrated within the compressor 50.

[0030] Disposed downstream of each turbine 52 along the EGR loop 30 is an EGR cooler unit 60. In certain embodiments, each EGR cooler unit 60 includes a plurality of functional sections. As depicted, each EGR cooler unit 60 includes a high temperature non-condensing cooler 62, a low temperature condensing cooler 64, an adiabatic gas / liquid separator 66, and a reheater 68. The reheater 68 can utilize engine coolant (sometimes referred to as jacket water) to heat the EGR flow to a desired temperature. Each of the high temperature non-condensing cooler 62, the low temperature condensing cooler 64, and the reheater 68 can include a separate coolant line referred to as an auxiliary coolant loop, or can utilize jacket water. In addition, the high temperature non-condensing cooler 62, the low temperature condensing cooler 64, and the reheater 68 can be interconnected to a hydraulic integrated circuit 70, which can be part of an auxiliary facility (BOP). In certain embodiments, each EGR cooler unit 60 includes at least two of these functional sections. In certain embodiments, each EGR cooler unit 60 can include more than one of each functional section. The system 10 includes a bypass valve 72 (e.g., a thermostatically controlled bypass valve) disposed between the EGR loop 30 and the EGR cooler unit 60. The bypass valve 72 may be responsive to local temperature or controlled by the ECM 16 (e.g., via an actuator). The bypass valve 72 (e.g., when open) directs the EGR flow to the gas / liquid separator 66, thereby bypassing the coolers 62, 64.

[0031] Each EGR loop 30 of the EGR system 14 includes an EGR valve 74 disposed downstream of the exhaust manifold 42 and upstream of the compressor 50. In particular, the EGR valve 74 is located on the cold side of the corresponding EGR cooler unit 60 to keep it close to the ambient temperature. When opened, the EGR valve 74 allows the EGR flow to reach the compressor 50 and then reach the intake manifold 40 of the engine 12. As depicted, these EGR valves 74 are arranged in parallel with each other. As depicted, a shared or mixed EGR valve 76 is disposed downstream of the EGR valve 74. The EGR valve 76 enables modulation (and mixing) of the EGR flow from each of the EGR loops 30. The EGR valve 76 is disposed in series with each of the EGR valves 74. In certain embodiments, the EGR system 14 may not include the EGR valve 76, and the EGR flow may be provided directly upstream of the compressor 50.

[0032] While a portion of the exhaust in each loop 30 is diverted to the EGR cooler unit 60, the remainder of the exhaust is diverted to the exhaust aftertreatment system 78. In certain embodiments, the exhaust aftertreatment system 78 may include a three-way catalyst to reduce exhaust emissions (e.g., nitrogen oxides (NO X ), hydrocarbons (HC), carbon monoxide (CO) and other emissions).

[0033] Various components of the system 10, engine 12, and EGR system 14 (or actuators for such components) may communicate with the ECM 16. For example, the EGR valves 74, 76, throttle 44, compressor bypass valve 58, wastegate valve 56, bypass valve 72, and / or fuel supply system 53 (including air / fuel control devices) may be communicatively coupled to the ECM 16 to enable the ECM 16 to control such components.

[0034] As mentioned above, certain components of the system 10 may be shared (eg, across the cylinder bank 28 ). Figure 4 Is a low pressure loop EGR system (eg, shared intake manifold 40) Figure 1 Schematic diagram of an engine driven power generation system 10 . Figure 4 The system 10 depicted in Figure 3 , except that the following components are shared throughout the cylinder bank 28 to facilitate sharing the intake manifold 40 : intercooler 48 , intake manifold 40 , and throttle 44 . Figure 5 Is a low pressure loop EGR system (eg, shared intake manifold 40 and exhaust manifold 42) Figure 1 Schematic diagram of an engine driven power generation system 10 . Figure 5 The system 10 depicted in Figure 34, except that the following components are shared throughout the cylinder bank 28 to facilitate sharing the intake manifold 40 and the exhaust manifold 42: the intake port 54, the wastegate 56, the compressor bypass valve 58, the intercooler 48, the intake manifold 40, the throttle 44, the turbocharger 46 (including the compressor 50 and the turbine 52), the exhaust aftertreatment system 78, and the exhaust manifold 42. In these embodiments, other components may be shared.

[0035] Figure 6 Is a high pressure loop EGR system (i.e. exhaust gas is diverted upstream of the turbine and reintroduced into the intake manifold after the compressor) Figure 1 Schematic diagram of an engine driven power generation system 10. Although shown as multiple components, Figure 6 The various components of the system 10 illustrated in FIG. 1 may be shared throughout the engine block group, as indicated by the asterisks. Aside from some differences, Figure 6 System 10 and Figure 3 Same as described in. Figure 6 As depicted in FIG. 5 , the EGR cooler unit 60 of each EGR circuit is disposed downstream of the exhaust manifold 42 and upstream of the turbine 52. In addition, the EGR flow is introduced from the EGR cooler unit 60 downstream of the compressor 50 between the intercooler 48 and the intake manifold 40. In addition, the fuel is introduced into the air and exhaust gas between the intercooler 48 and the intake manifold 40. As depicted, the fuel supply system 53 is a high-pressure (blowing) fuel supply system. In certain embodiments, the high-pressure fuel supply system 53 may take the form of a separate gas mixing achieved by port injection (not shown). In certain embodiments, the fuel supply system 53 may be a low-pressure fuel supply system.

[0036] As mentioned above, certain components of the system 10 may be shared (eg, across the cylinder bank 28 ). Figure 7 Is a high pressure loop EGR system (eg, shared intake manifold 40) Figure 1 Schematic diagram of an engine driven power generation system 10 . Figure 7 The system 10 depicted in Figure 6 , except that the following components are shared throughout the cylinder bank 28 to facilitate sharing the intake manifold 40 : intercooler 48 , intake manifold 40 , and throttle 44 . Figure 8 Is a high pressure loop EGR system (eg, shared intake manifold 40 and exhaust manifold 42) Figure 1 Schematic diagram of an engine driven power generation system 10 . Figure 8 The system 10 depicted in Figure 64, except that the following components are shared throughout the cylinder bank 28 to facilitate sharing the intake manifold 40 and the exhaust manifold 42: the intake port 54, the wastegate 56, the compressor bypass valve 58, the intercooler 48, the intake manifold 40, the throttle 44, the turbocharger 46 (including the compressor 50 and the turbine 52), the exhaust aftertreatment system 78, and the exhaust manifold 42. In these embodiments, other components may be shared.

[0037] As described below, the management of multiple EGR loops 30 and EGR cooler units 60 provides increased functionality for the EGR system 14. For example, the EGR loops 30 and EGR cooler units 60 can be managed to reduce the thermal mass of the EGR system 14 via sequential preheating of the EGR system 12. Thermal mass is a property of a mass body that enables it to store heat and provide inertia against temperature fluctuations. Generally speaking, for a reciprocating internal combustion engine, it can be described as having two different temperatures it can experience: operating temperature and ambient temperature. The operating temperature can be described as the steady-state temperature of a fully functional engine or a key EGR flow component with the potential to produce condensate, which is capable of operating at rated power (speed and load) (which is often referred to as preheating). The operating temperature can also be a predefined constant value input. The ambient temperature can best be described as the current ambient temperature around the engine and the lowest temperature that the engine can reach (if allowed to equalize) or a predefined constant value input. In theory, the maximum temperature change that the engine can experience starts at ambient temperature and heats up until the operating temperature is reached. Similarly, any engine not producing power (potentially not needing EGR flow) and an engine at its maximum power (potentially needing maximum EGR flow) will continually increase EGR flow between these two extremes. The intention is to limit the thermal mass that needs to be heated, which interacts with the EGR flow and risks creating condensation by being cooler than the dew point of the fluid. The transition temperature can be defined manually. Alternatively, the transition temperature between these two temperatures can be defined in the following equation, where :

[0038] T 转变 =T 环境 +C(T 操作 -T 环境 ).

[0039] In some embodiments, C may be less than or equal to 1.0, 0.9, 0.8, 0.7, 0.6 or 0.5 or any number therebetween. For example, if C is less than or equal to 0.5, a simple average between the two conditions can be achieved.

[0040] Alternatively, the transition temperature may be defined independently of the operating temperature or the ambient temperature. For example, commercial quality natural gas (CQNG) burned with zero excess air at atmospheric pressure is approximately 57.2°C (135°F) while maintaining a certain margin from the condensing temperature (dew point) of the exhaust gas. Alternatively, the transition between hot and cold starts may replace the predefined time constant input, since time and temperature are directly related through heat transfer principles. At engine start (crankshaft rotation at minimum speed under the action of an external starting force), the transition temperature will be used as a threshold to define two states: First, if T <T 转变 , which will be defined as a cold start, and second, if T>T 转变 , which would be defined as a hot start. The purpose of the transition temperature is to establish a threshold that balances the thermal mass advantages of reusing hardware that is already above ambient temperature with mechanical wear and degradation due to cumulative damage from hot low cycle fatigue, fouling from deposits from the EGR fluid, and other issues.

[0041] An EGR usage objective function will also need to be defined. The purpose of this usage objective function is to quantify the mechanical wear or degradation of different components of the parallel and independently controllable EGR loops. The EGR usage objective function can be, but is not necessarily limited to, duty cycle (engine power and time), number of starts, total EGR volume flowing, total coolant volume flowing, sensor-based, user input override, or other factors. When cranking the shaft as a cold start begins, at least one of the multiple EGR parallel loops 30 will be used first according to the EGR usage objective function. This will occur until the EGR flow requirements based on engine operation require the use of more than one EGR parallel loop 30 at the same time. No two immediately subsequent cold start events will use the same one of the multiple EGR parallel loops 30 first. When cranking the shaft as a hot start begins, at least one of the multiple EGR parallel loops 30 will be used first (e.g., activated) according to the EGR usage objective function. This will occur until the EGR flow requirements based on engine operation require the use of more than one EGR parallel loop 30 at the same time. Any hot start event will use the last identified for the same of the multiple EGR parallel loops 30 used by the EGR usage objective function during a cold start.

[0042] During a cold restart, only one EGR loop 30 is initially utilized because there is only half the amount of mass that needs to be heated by the EGR loop 30 (or less than half if more than two EGR loops are present in parallel). Initially, during the start-up of the engine 12, in the first utilized EGR loop, the bypass valve 72 is fully open or opened to enable the EGR flow to flow to the separator 66 and bypass the thermal mass of the coolers 62, 64. As the EGR cooler unit 60, which is composed of the high temperature non-condensing cooler 62 and / or the low temperature condensing cooler 64, reaches its target temperature, the bypass valve 72 is gradually closed or turned off. In certain embodiments, the bypass can be used as a supplement to the reheater 68. Once the maximum amount of cooling possible has been achieved using the initial EGR loop 30, but more cooling is needed, utilization of the other EGR loop 30 begins in the same manner as the initial EGR loop 30 (e.g., initial utilization of the bypass valve 72). During a hot restart, the EGR loops 30 are utilized sequentially in the same manner, but utilization of the bypass is skipped.

[0043] Fig. 9 is used in Figure 1 Flowchart of a method 80 for utilizing an EGR system during a sequential warm-up of an engine-driven power generation system of an engine 16. In certain embodiments, all or some of the operations or steps illustrated in the method 80 may be performed by the processor 24 of the ECM 16. For example, the processor 24 may execute a program to execute data stored on the memory 26. The method 80 includes determining which EGR loop 30 (and EGR cooler unit 60) was first utilized (e.g., activated) at a most recent start event (e.g., a hot start or a cold start) (frame 82). The method 80 also includes: if the next start event is a cold start or a restart, starting the start or restart with the EGR loop 30 that was not first utilized at the most recent start or restart (frame 84). The method 80 also includes: if the next start is a hot start or a restart, starting the start or restart with the same EGR loop 30 that was first utilized at the most recent start or restart (frame 86). The method 80 even further includes subsequently utilizing the remaining EGR loops 30 (i.e., the EGR loops 30 that were not initially utilized in the current start or restart) when needed (i.e., when the controller detects based on feedback received from the sensors that the operating parameters of the industrial combustion engine are approaching the outer limits of the specified range) (block 88). As noted above, depending on the type of restart, the bypass valve 72 may or may not be utilized. The utilization of sequential preheating of the EGR loops 30 reduces the thermal mass of the EGR system 14.

[0044] Another function accomplished by multiple EGR circuits 30 in the EGR system 14 is EGR distribution management. Multiple EGR circuits 30 (e.g., parallel circuits) may differ in their fluid flow behavior. Such differences may exist during initial manufacturing or maintenance, or may manifest over time due to operation. Sources of different fluid flow behaviors may include, but are not necessarily limited to: variations in manufacturing tolerances, improper installation, improper maintenance, different maintenance stages, differences in flow losses (differences in circuit lengths, pipe elbows, constrictions, etc.), external heat sources (radiation, convection, conduction), accumulation of fouling caused by deposits, differences in secondary coolant flow temperature or flow rate, differences in applied back pressure (location of EGR extraction), differences in applied downstream pressure (location of EGR outlet), additional flow flow connections to the EGR circuit (closed crankcase ventilation (CCV) gases, supply or demand for EGR The EGR loop 30 is connected to the EGR system 12 and is connected to the EGR system 12. ...

[0045] Another function implemented by the multiple EGR circuits 30 in the EGR system 14 is a limp-home mode. The limp-home mode is a safety system designed to protect the engine 12 from damage during abnormal operation as detected by diagnostics. Once the limp-home mode is initiated, the engine 12 will only operate at a reduced speed, reduced load, or reduced power. The limp-home mode allows continued operation (albeit at a reduced rating) until a convenient time, when maintenance can be scheduled to repair the abnormal operating condition. For multiple EGR parallel circuits 30, if there should be a full or partial failure that will reduce the EGR capacity compared to the current engine demand for EGR, engine derating will occur until the level of EGR can be safely provided by the entire EGR system 14. In certain embodiments, engine derating may be accompanied by complete deactivation of an entire portion of one or more of the multiple EGR parallel circuits 30. In certain embodiments, all EGR flow is stopped and the engine 12 operates at the maximum power achievable without diluent (e.g., ~40% rated power). In certain embodiments, when one of the EGR loops 30 is disabled, the ECM 16 reduces the power of the engine 12 enough to enable utilization of the non-disabled one of the EGR loops 30 .

[0046] Yet another function accomplished by the multiple EGR loops 30 in the EGR system 14 is in-line manipulation of EGR heat rejection. The multiple EGR parallel loops 30 may each include a respective EGR cooler unit 60 having multiple functional sections as described above. When more than one parallel EGR loop 30 operates in coordination, each component of each respective EGR loop 30 (including the components of the EGR cooler unit 60) may be independently controlled to maintain the thermophysical state of the combined EGR fluid output from the parallel loops to the engine 12. The thermophysical state of the combined EGR fluid output may be determined by its temperature, pressure, liquid mass flow rate, gas mass flow rate, each chemical composition (CO2, CO, NO x, N2O, VOCs, HC, CH2O, NH3, etc.) volume concentrations. Liquid mass flow rate and gas mass flow rate can be expressed alternately as relative humidity values ​​or absolute humidity values. Different volume concentrations of each chemical component may occur due to the following reasons: misfire, flashback (intake deflagration), afterburning (exhaust deflagration), incomplete combustion, changes in air-fuel equivalence ratio, changes in dilution ratio, damage to components that interact with combustion, differences in ash or deposit accumulation in the cylinder body, and other problems. Independent control of each corresponding EGR loop 30 will affect the heat balance, heat loss or heat rejection from the engine 12 to the environment or auxiliary facilities (BoP). This heat rejection can be optimized (minimized or maximized) by application requirements. For example, in a combined heat and power (CHP) application where thermal energy can be effectively controlled and utilized, the heat loss to the BoP can be maximized. For example, in an application where thermal energy cannot be effectively controlled and utilized and is sent to the final heat sink (UHS) (typically the ambient environment), the heat loss to the BoP can be minimized and the capacity of the heat flow of the BoP can be limited. Common situations where heat rejection to the environment is limited are on hot, sunny, humid days, or when available utility or ambient water flow is limited. In one example, the ECM 16 can manipulate EGR heat rejection by maintaining the EGR flow from one of the EGR loops 30 at a cooler temperature than the EGR flow from the other EGR loops 30 (e.g., by shutting down the reheater 68 of the EGR cooler unit 60 for that EGR loop 30). Manipulation of EGR heat rejection can be performed via control of the primary fluid (EGR) or the secondary fluid (coolant) to the EGR loops 30.

[0047] Yet another function achieved by multiple EGR loops 30 in the EGR system 14 is ultra-fine EGR mass flow resolution control. For multiple EGR parallel loops 30, there may be at least two EGR flow control valves in a series / parallel configuration with each other, as described above in Figures 3 to 8As described in . For example, as described above, the EGR valves 74 of each parallel EGR loop are connected in parallel relative to each other, while the shared EGR valve 76 is arranged in series relative to each of the EGR valves 74. With two EGR valves in series (e.g., EGR valve 74 to EGR valve 76), there is the possibility of ultra-fine EGR mass flow resolution control functionality beyond what is normally possible. Valves typically have limitations on their functionality, such as deadband (e.g., if there is significant play in the valve actuator system, and there will be periods where the valve does not move), minimum positioning accuracy / resolution of the control actuator, dithering between two positions to pseudo-replicate impossible intermediate flow positions, turndown ratio (refers to the width of the operating range of the device, and is defined as the ratio of maximum capacity to minimum capacity), and other limitations. For two EGR valves in series, a strategy of coarse and fine adjustment of the EGR mass flow can be used. The combination of valve actuation has a finer flow control resolution than each of the EGR valves alone. Functionally, this is important for engines using EGR because the location of maximum efficiency is typically near the boundaries of the combustion operating range / window (e.g., knock boundaries, exhaust temperature limits, misfire limits, peak combustion pressure limits, etc.). This manipulation of the EGR valve enables the maximum efficiency of the engine to be maintained without allowing changes in EGR flow to cause the combustion to operate outside its designed combustion operating range / window (e.g., knock boundaries, exhaust temperature limits, misfire limits, peak combustion pressure limits, exhaust emission aftertreatment system operating windows, etc.), where the mechanical health or emissions compliance of the engine will be at risk. In some embodiments, the ECM 16 manages the EGR flow to the engine by fully opening the EGR valve 74 of the EGR circuit and modulating the shared EGR valve 76 to adjust the flow of the EGR flow to the engine. In another embodiment, the ECM 16 manages the EGR flow to the engine by fully opening the shared EGR valve 76 and modulating the EGR valve 74 to adjust the EGR flow to the engine. In yet another embodiment, the ECM manages EGR flow by partially opening the EGR valves 74 , 76 to adjust EGR flow to the engine.

[0048] In certain embodiments, when the EGR valves 74 and 76 are arranged in a series / parallel configuration as described above, EGR valve failure can be overcome. For example, in the case where two valves are connected in series, it is possible to continue EGR control even if one valve fails (stuck in a fully open position, stuck in a fully closed position, stuck in a partially open position) or its corresponding actuator fails. This can be achieved by compensating with other valves in a series / parallel configuration. For example, if a downstream valve (e.g., EGR valve 76) in a series flow configuration fails partially closed, the EGR flow quality can be partially restored by reducing the operating margin to increase the system pressure difference or gas flow rate. One method of controlling the pressure difference is by changing the hydraulic resistance, a variable geometry turbocharger, a variable valve timing, an EGR pump or a blower. In another example, if a downstream valve (e.g., EGR valve 76) in a series flow configuration fails fully open, full EGR flow control can be maintained via an upstream valve (e.g., EGR valve 74). In yet another example, if an upstream valve (e.g., EGR valve 74) in a series flow configuration fails fully closed or partially closed, the EGR flow quality may be partially restored by increasing the system pressure differential or gas flow rate by reducing the operating margin and increasing the flow through the other EGR parallel loops. In yet another example, if an upstream valve (e.g., EGR valve 74) in a series flow configuration fails fully open, full EGR flow control may be maintained via a downstream valve (e.g., EGR valve 76) and valves for other parallel EGR loops (e.g., EGR valve 74). The only situation that cannot be overcome is when a downstream valve (e.g., EGR valve 76) fails fully closed. If this occurs, the limp home mode function described above is utilized.

[0049] Yet another function achieved by the multiple EGR loops 30 in the EGR system 14 is to achieve gas / liquid separation efficiency by managing the EGR cooler unit 60 of the EGR loop 30. The goal is to supply controlled amounts of EGR and liquid mass flow. The reason is that both exhaust gas and water (in liquid or vapor state) are used as diluents for combustion. Controlling the liquid mass flow is important because excessive liquid mass flow can lead to erosion caused by high-speed droplets, which can reduce system efficiency and cause other complications (e.g., liquid in the intake manifold, intercooler, cylinder sleeve, spark plug shorting, etc.), or too small liquid mass flow can lead to combustion knock. Superheating is one way to do this, but once leaving the EGR heat exchanger, the exhaust gas will immediately lose heat and potentially condense as it travels throughout the system. When the gas components are cooled below their dew point, the formation of droplets with different diameters always occurs. Superheating can occur at approximately 25 to 30° C. above the dew point of the fluid. The condensing temperature (dew point) of the exhaust gas of commercial quality natural gas (CQNG) burned with zero excess air is approximately 57.2°C (135°F) at atmospheric pressure.

[0050] Another method of controlling the mass flow of liquid in EGR is to use a gas / liquid separator, which can be different in type and style (e.g., mesh, vane, cyclone, fiber bed, etc.). A gas / liquid separator is simply a device that retains droplets entrained by the gas flow. Gas / liquid separation operates through several mechanisms (e.g., inertia (gravity is a special case), direct interception, diffusion (Brownian motion), electrostatic attraction, etc.). Each mechanism will have its own separation efficiency, which is not constant over the entire application, operation, or service life. The overall gas / liquid separation efficiency is also not constant over the entire application, operation, or service life through all combined mechanisms. The efficiency of complete (i.e., 100%) separation of all droplets from the gas is unrealistic. Therefore, the overall gas / liquid separation efficiency is usually expressed as a definite integral between the limiting separation minimum droplet diameter and the maximum droplet diameter. The range of limiting separation droplet diameters should match the intended application. It is important to note that the limiting droplet diameter and therefore the overall gas / liquid separation efficiency are inverse functions of the gas velocity. The overall gas / liquid separation efficiency increases with increasing gas flow rate until the flooding limit is reached. The flooding limit is when the droplets that accumulate in the gas / liquid separator are large enough that the shear forces generated by the gas velocity can cause the droplets to disengage from the liquid surface (i.e., re-entrainment (liquid carryover)). Re-entrainment is an indication of operation where the gas flow rate or liquid mass is higher than the value that the system is designed to handle. The maximum gas flow rate corresponding to the flooding limit varies according to the system design. In general, the maximum gas flow rate for wire-based separators should be kept below 3 to 5 m / s, and the maximum gas flow rate for blade-based separators is kept below 10 m / s. It is not uncommon to use a wire-based separator and a blade-based separator in series to accumulate droplets in the first wire-based separation stage, the first wire-based separation stage purposefully operating at or above the flooding limit so that re-entrainment (liquid carryover) of larger coarse droplets occurs to be effectively separated by the second blade-based separator; resulting in a higher overall gas / liquid separation efficiency for a multi-stage system. It should be noted that directional changes and pressure differentials in the EGR system outside the gas / liquid separator may be the cause of re-entrainment at flow velocities as low as 10 m / s. Gas velocities in EGR systems typically do not exceed 30 m / s. If it should be desired to avoid this, the design velocity should be about 75% of the maximum gas flow velocity of the flooding-limited maximum gas velocity to provide an acceptable margin.

[0051] For gas / liquid separators, due to the transition of each mechanism with its own separation efficiency, it is typical to have a range in which a minimum in terms of overall separation efficiency is observed. It is generally believed that there are seven parameters in three categories that affect separation efficiency. These categories include: 1) geometric parameters, such as characteristic target separator size and droplet size, referring to their aerodynamic diameter; 2) flow parameters, such as gas velocity, pressure drop and stability or uniformity of flow; and 3) physical properties, such as droplet density, gas density, gas viscosity (all of which are functions of temperature and pressure). When the engine is online, only a limited number of operating variables can be manipulated and optimized to affect the overall gas / liquid separation efficiency (e.g., gas velocity, pressure drop and temperature). If a predetermined low temperature condensing cooler subcooling and reheater superheating are used, gas velocity and pressure drop are the only operating variables to be manipulated to optimize to affect the overall gas / liquid separation efficiency. Through the management of multiple EGR coolers 60, the engine diluent demand requirements can be balanced between multiple EGR coolers 60 to achieve a specific separation efficiency of the EGR system 14. In practice, the target separation efficiency is achieved by an EGR determiner in the ECM 16 based on inputs from performance sensor(s) (e.g., sensor 18) and other optional inputs related to the EGR system 14. The EGR transfer function may include constants, variables, fluid properties, empirical correlations, historically stored data, weighted objective functions, physical dimensions, formulas, or other mathematical operations, logic, or models. Thus, in certain embodiments, the ECM 16 (e.g., at low engine loads) may asynchronously modulate the EGR valves 74, 76 to achieve a target gas / liquid separation efficiency range for the EGR system 14 while maintaining a total EGR supply of both exhaust gas and water vapor (limiting liquid water mass flow) to achieve the engine diluent requirement by maintaining a higher gas velocity in one of the EGR loops 30, providing a majority of the exhaust gas to the engine as the separation efficiency increases with increasing gas flow velocity up to the flooding limit, while the remainder of the cooler meets the remainder of the engine diluent requirement at a lower velocity. For example, the ECM 16 may maintain a higher gas velocity for the biased EGR loop to remain within an optimal gas / liquid separation efficiency range for the gas-liquid separator(s) 66 because one or more EGR cooler modules in the restricted EGR loop 30 may completely restrict or disable their secondary fluid flow.

[0052] Fig.10 An illustrative ECM 16 is depicted for use in controlling an air / fuel mixture and an amount of EGR supplied to a combustion chamber of an industrial combustion engine 12 . Fig.10 is a non-limiting example of the ECM 16. In summary, the air / fuel mixture, EGR, and any other diluents supplied to the combustion chambers is referred to herein as an air charge. Fig.10The illustrative ECM 16 receives inputs of engine state parameters from sensors 18, which in this example may include torque indicating characteristic sensors 90 such as IMAP or IMD sensors, engine speed sensors 92, engine performance sensors 94, and diagnostic sensors 95, and outputs signals to actuators 20. The ECM 16 may also receive additional inputs 96 discussed in more detail below. Additional inputs 96 may include intake manifold pressure and fuel quality inputs. Additional, fewer, or different additional inputs may be used in other implementations. The actuator 20 includes at least an air / fuel control device 98, which is operable to control the ratio of air and fuel supplied to the engine 12. Examples of air / fuel control devices 98 include a fuel pressure regulator or an air bypass in an engine system that uses a fixed orifice area air / gas mixer, an adjustable orifice area air / gas mixer, one or more fuel injectors, or other air / fuel control devices or combinations of devices. The actuator 20 may also include one or more EGR control devices 100 (e.g., multiple EGR actuators, multiple EGR bypasses, etc.) for introducing a certain amount of EGR to the engine 12. Other examples of the EGR control device 100 include a vacuum regulator, a pressure regulator, a combined pressure and vacuum regulator, a servo-controlled valve, a combined servo-controlled valve and vacuum regulator, a variable area valve (e.g., a butterfly valve, a gate valve, and a ball valve), and a combined servo-controlled valve and pressure regulator or other regulators.

[0053] In one implementation, the ECM 16 may include a lambda set point determiner 102 that receives one or more engine state parameters and determines and outputs a lambda (λ) set point. The lambda set point is selected to substantially maintain engine operation at, for example, a steady state. Lambda is a term that generally refers to an air-fuel equivalence ratio, where a lambda value of 1 refers to a stoichiometric air / fuel mixture. Specifically, lambda is the actual air-fuel ratio divided by the stoichiometric air-fuel ratio. The lambda set point determiner 102 is used to determine an air / fuel actuator control signal operable to control the air / fuel control device 98. Although Fig.10An implementation in which a lambda set point is the only input to control the air / fuel control device 98 is illustrated, but additional or different inputs may be used to determine the air / fuel actuator control signal. For example, some implementations may use a fuel parameter used to compensate for differences in fuel quality or type or engine wear, damage or modification in conjunction with the lambda set point to determine the air / fuel actuator control signal. In determining the lambda set point, the illustrative ECM 16 uses the engine speed from the engine speed sensor 92, the torque indicating characteristic (e.g., IMAP or IMD) from the torque indicating characteristic sensor 90, and optionally other inputs 96. In some examples, the optional inputs 96 may include ambient temperature, intake air temperature (e.g., intake manifold pressure), and / or fuel parameters. According to some implementations, the torque indicating characteristic sensor 90 is operable to determine the expected or estimated torque output of the engine 12. In addition, the torque indicating characteristic sensor 90 may include any sensor, instrument, or device for sensing or otherwise determining the torque output or power output of the engine 12, because it is possible to convert between power output and torque output using known engineering relationships as discussed in detail below. The ECM 16 may use other sensors, such as mass air sensors, volumetric flow sensors, or other sensors (eg, diagnostic sensor 95 ), alternatively or in combination with those discussed above.

[0054] In certain implementations, the lambda set point determiner 102 may determine the lambda set point using a lookup table in a memory of the ECM 16 that includes at least values ​​indicative of engine speed and torque that indicate characteristics associated with a lambda set point determined to maintain a specified engine operating state, such as steady-state engine operation. Alternatively or in conjunction with the lookup table, the lambda set point determiner 102 may use a formula to determine the lambda set point as a function of inputs from one or more of the sensors 18 (e.g., engine speed and torque indicating characteristics). In either instance, the lambda set point is selected relative to the corresponding engine speed and torque indicating characteristic values ​​to provide a specified combustion mixture to the engine 12 to maintain a specified engine operating state, such as steady-state operation. Thus, different lambda set points may achieve different engine operating states.

[0055] The ECM 16 may also include a lambda set point error determiner 104 for determining an error or difference between a determined lambda set point and an input indicative of actual lambda. For example, an error may be determined when the engine 12 is in a transient condition, e.g., whenever an actual lambda condition of the engine does not correspond to, for example, a lambda set point. In certain implementations, the lambda set point error determiner 104 may determine a lambda adjustment 106, i.e., a signal indicating an amount by which to adjust the operation of the engine 12.

[0056] The lambda sensor 108 measures the actual lambda condition of the engine 12 at any given time by, for example, measuring the amount of oxygen remaining in the exhaust gas, and sends a corresponding signal to the lambda set point error determiner 104. The lambda set point error determiner 104 then compares the actual lambda condition with the lambda set point received from the lambda set point determiner 104. The lambda set point error determiner 104 then determines the amount by which the actual lambda condition should be adjusted (e.g., increased or decreased) to achieve the specified engine performance, and generates a lambda adjustment 106. That is, based on the comparison between the actual lambda condition and the lambda set point, if the comparison indicates a deviation between the two values, an adjustment may be determined. The lambda set point error determiner 104 then outputs the lambda adjustment 106 (e.g., a positive or negative value) to the actuator transfer function 109. The actuator transfer function 109 receives at least the lambda adjustment 106 and determines an air / fuel actuator control signal suitable for operating the air / fuel control device 98.

[0057] The ECM 16 also includes an EGR determiner 110 for determining an EGR flow rate for one or more EGR loops. In certain embodiments, the ECM 16 includes an EGR transfer function 112 that receives at least an EGR setpoint signal and determines an EGR actuator control signal suitable for operating one or more EGR control devices 100. The EGR transfer function 112 can determine the EGR actuator control signal by: using a lookup table that relates, for example, throttle position, lambda setpoint, fuel parameters, and any other inputs that affect the EGR actuator control signal; calculating as a function of the EGR setpoint and any other inputs; a combination of a lookup table and calculation; or by another method. According to one implementation, the EGR setpoint can be converted to a pre-signal using a lookup table and applying different parameters (such as fuel parameters) in the calculation to offset the pre-signal when determining the EGR actuator control signal. The amount of EGR introduced into engine 12 may depend on engine operating conditions (e.g., based on feedback from sensor 18), such as torque-indicating characteristics, engine speed, engine power output, input-based determination of engine power output, air / flow actuator control signals, and others, such as, for example, air / fuel mixture temperature. The EGR flow rate may also be determined as described above.

[0058] Technical effects of the disclosed embodiments include providing an engine driven power generation system including an EGR system having multiple EGR loops. These multiple EGR loops provide additional degrees of freedom in managing the EGR system. In particular, multiple EGR loops each having an EGR cooler unit enable in-line manipulation of EGR heat rejection, utilization of another EGR loop when the engine is derated with one EGR loop disabled, EGR distribution management, sequential preheating to reduce thermal mass, and other functions.

[0059] This written description uses examples to disclose the subject matter, including the best mode, and also enables any person skilled in the art to practice the subject matter, including making and using any device or system and performing any incorporated method. The patentable scope of the subject matter is defined by the claims and may include other examples that occur to those skilled in the art. These other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that have no substantial differences from the literal language of the claims.

[0060] The technology proposed and claimed herein is cited and applied to physical and specific examples of a practical nature that significantly improve the art and are therefore not abstract, intangible or purely theoretical. In addition, if any claim attached at the end of this specification contains one or more elements designated as "means for [performing] ... [function]" or "steps for [performing] ... [function]", it is intended that such elements be interpreted according to 35 USC 112 (f). However, for any claim that contains the designated elements in any other manner, it is intended that such elements should not be interpreted according to 35 USC 112 (f).

Claims

1. A system for managing an EGR system for an industrial internal combustion engine, comprising: An industrial combustion engine comprising at least one air intake system and at least one exhaust system; an EGR system coupled to the industrial combustion engine and configured to direct exhaust gas generated by the industrial combustion engine from the at least one exhaust system to the at least one intake system, wherein the EGR system comprises: a first EGR cooler unit for a first group of cylinders of said industrial combustion engine arranged along a first EGR loop; and a second EGR cooler unit for a second group of cylinders of the industrial combustion engine arranged along a second EGR loop, wherein the first EGR cooler unit and the second EGR cooler unit each include at least two of a high temperature non-condensing cooler, a low temperature condensing cooler, an adiabatic gas / liquid separator, and a reheater; wherein the first and second EGR cooler units are coupled to first and second EGR valves, respectively, the first and second EGR valves being configured to enable exhaust gas to flow from the first and second EGR loops, respectively, to the industrial combustion engine; and a controller communicatively coupled to the industrial combustion engine and the EGR system, wherein the controller includes a processor and non-transitory memory encoding one or more processor-executable routines, wherein the one or more routines, when executed by the processor, cause the controller to manage flow of the exhaust gas to the industrial combustion engine by modulating the first and second EGR valves via control signals sent to an actuator, wherein the first and second EGR loops each include a thermostatically controlled bypass valve that, when open, enables the exhaust gas to bypass each cooler within the first and second EGR cooler units, respectively, and wherein, when executed by the processor, the one or more routines cause the controller, via the control signal, to initially activate only one of the first EGR cooler unit or the second EGR cooler unit during a first cold start of the industrial combustion engine, and then subsequently activate both the first EGR cooler unit and the second EGR cooler unit when the controller detects, based on feedback received from a sensor, that an operating parameter of the industrial combustion engine is approaching an outer limit of a specified range.

2. The system according to claim 1, wherein: Both the first and second EGR cooler units are coupled to a third EGR valve downstream of both the first and second EGR valves, the third EGR valve being configured to enable the exhaust gas to flow to the industrial combustion engine.

3. The system according to claim 1, wherein: When executed by the processor, the one or more routines cause the controller via the control signal to initially activate either the first EGR cooler unit or the second EGR cooler unit that was not activated during the first cold start of the industrial combustion engine during a second cold start of the industrial combustion engine, wherein the second cold start is a next start after the first cold start.

4. The system according to claim 1, wherein: When executed by the processor, the one or more routines cause the controller via the control signal to initially activate the same EGR cooler unit of the first EGR cooler unit or the second EGR cooler unit that was activated during the first cold start of the industrial combustion engine during a subsequent hot start of the industrial combustion engine, wherein the subsequent hot start is a next start after the first cold start.

5. The system according to claim 1, wherein: When executed by the processor, the one or more routines cause the controller to asynchronously modulate the first and second EGR valves via the control signals sent to the actuators to achieve a target gas / liquid separation efficiency range for the EGR system to achieve engine dilution requirements.

6. The system according to claim 1, wherein: When executed by the processor, the one or more routines cause the controller via the control signal to adjust respective amounts of the exhaust gas utilized from the first and second EGR loops based on respective amounts of dirt detected by the controller in the first and second EGR loops based on feedback from a sensor.

7. The system according to claim 1, wherein: When executed by the processor, the one or more routines cause the controller, via the control signal, to manipulate EGR heat rejection by maintaining the exhaust gas from one of the first and second EGR loops at a cooler temperature than the exhaust gas from the other of the first and second EGR loops.

8. The system according to claim 1, wherein: When executed by the processor, the one or more routines cause the controller to send the control signal to the industrial combustion engine when one of the first EGR loop and the second EGR loop is disabled to reduce the power of the industrial combustion engine to a power level that can utilize a non-disabled EGR loop of the first EGR loop and the second EGR loop.

9. The system according to claim 1, wherein: The EGR system includes a high pressure loop EGR system.

10. The system according to claim 1, wherein: The EGR system includes a low-pressure loop EGR system.

11. A system for managing an EGR system for an industrial internal combustion engine, comprising: A controller communicatively coupled to an industrial combustion engine and an EGR system, wherein the EGR system is configured to route exhaust gas generated by the industrial combustion engine from at least one exhaust system to at least one intake system, the EGR system comprising a plurality of EGR loops, each of the plurality of EGR loops comprising an EGR cooler unit, the EGR cooler unit comprising at least two of a high temperature non-condensing cooler, a low temperature condensing cooler, an adiabatic gas / liquid separator, and a reheater, and wherein the controller comprises a processor and non-transitory memory encoding one or more processor executable routines, wherein the one or more routines are executed by the controller The processor, when executed, causes the controller to manage the flow of the exhaust gas to the industrial combustion engine via a control signal sent to an actuator by: fully opening the corresponding EGR valves arranged along the multiple EGR circuits and modulating a shared EGR valve shared by the multiple EGR circuits downstream of the corresponding EGR valve to adjust the flow of the exhaust gas to the industrial combustion engine; fully opening the shared EGR valve and modulating the corresponding EGR valve to adjust the flow of the exhaust gas to the industrial combustion engine; or partially opening the corresponding EGR valve and the shared EGR valve to adjust the flow of the exhaust gas to the industrial combustion engine, wherein the one or more routines, when executed by the processor, cause the controller, via the control signal, to initially activate only one of the plurality of EGR loops during a first cold start of the industrial combustion engine, and then subsequently activate each of the plurality of EGR loops when the controller detects, based on feedback received from a sensor, that an operating parameter of the industrial combustion engine is approaching an outer limit of a specified range.

12. The system according to claim 11, wherein: When executed by the processor, the one or more routines cause the controller, via the control signal, to initially activate any one of the plurality of EGR loops that was not activated during the first cold start of the industrial combustion engine during a second cold start of the industrial combustion engine, wherein the second cold start is a next start after the first cold start.

13. The system according to claim 11, wherein: When executed by the processor, the one or more routines cause the controller via the control signal to initially activate the EGR loop among the plurality of EGR loop units activated during the first cold start of the industrial combustion engine during a subsequent hot start of the industrial combustion engine, wherein the subsequent hot start is a next start after the first cold start.

14. The system according to claim 11, wherein: When executed by the processor, the one or more routines cause the controller, via the control signal, to asynchronously modulate the corresponding EGR valve to achieve a target gas / liquid separation efficiency range for the EGR system to achieve an engine dilution requirement.

15. The system according to claim 11, wherein: The one or more routines, when executed by the processor, cause the controller via the control signal to adjust respective amounts of the exhaust gas utilized from the plurality of EGR loops based on respective amounts of dirt in each of the plurality of EGR loops detected by the controller based on feedback from a sensor.

16. The system according to claim 11, wherein: When executed by the processor, the one or more routines cause the controller, via the control signal, to manipulate EGR heat rejection by maintaining the exhaust gas from one of the plurality of EGR loops at a cooler temperature than the exhaust gas from other of the plurality of EGR loops.

17. The system of claim 11, wherein: When executed by the processor, the one or more routines cause the controller to send the control signal to the industrial combustion engine when one of the multiple EGR loops is disabled to reduce the power of the industrial combustion engine to a power level that can utilize a non-disabled EGR loop of the multiple EGR loops.

18. A method for managing an EGR system for an industrial internal combustion engine, comprising: Utilizing a controller communicatively coupled to an industrial combustion engine and an EGR system and including a non-transitory memory and a processor to: initially activating only one of a plurality of EGR loops of the EGR system via a control signal during a first cold start of the industrial combustion engine, and then subsequently activating each of the plurality of EGR loops when the controller detects, based on feedback received from a sensor, that an operating parameter of the industrial combustion engine is approaching an outer limit of a specified range; and During a second cold start of the industrial combustion engine, any one of the plurality of EGR loops that was not activated during the first cold start of the industrial combustion engine is initially activated via the control signal, and during a subsequent hot start of the industrial combustion engine, the EGR loop that was initially activated during the first cold start is initially activated, wherein the second cold start or the subsequent hot start is a next start after the first cold start, and wherein each of the plurality of EGR loops includes an EGR cooler unit, the EGR cooler unit including a plurality of functional sections.

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