Application of Silicon Carbide Photodiode Flame Temperature Sensors in an Active Combustion Pattern Factor Control System

2009 ◽  
Author(s):  
Carl A. Palmer ◽  
Royce L. Abel ◽  
Peter Sandvik
Keyword(s):  
Silicon Carbide ◽  
Gas Turbines ◽  
Fault Tolerant ◽  
Flame Temperature ◽  
Diagnostic System ◽  
Open Loop ◽  
Bulk Temperature ◽  
Loop Control ◽  
Engine Model ◽  
Fuel Flow

This paper describes the development and initial application studies for an active combustion pattern factor controller (APFC) for gas turbines. The system is based around use of a novel silicon carbide (SiC) optical ultraviolet (UV) dual diode flame temperature sensor (FTS) developed by General Electric’s Global Research Center and GE Energy. The APFC system determines combustion flame temperatures, validates the values, and integrates an assessment of signal and combustion hardware health to determine how to trim the fuel flow to individual fuel nozzles. Key aspects of the system include: • Determination of each flame’s bulk temperature using the FTS. • Assessment of the reliability of the flame temperature data and physical combustion hardware health through analysis of the high frequency output of the sensor. • Validation of the flame temperature signal using a data-driven approach (model based validation - MBV). • Fusion of sensor ‘health indices’ into the APFC to alter the trim control signal based on the health (or ‘believability’) of each sensor and fuel nozzle/combustor. • Fault-tolerant peak/valley detection and control module that selects individual fuel valves to target for reducing pattern factor, while simultaneously balancing the overall fuel flow. The authors demonstrated feasibility of the approach by performing simulations using a quasi-2D T700 turbine engine model. Tests were run on the simulated platform with no faults, simulated sensor faults, and on a system with underlying combustion hardware issues. The final APFC system would be applicable for aviation, naval and land-based commercial gas turbines, and can be used in closed-loop control or adapted as an open-loop advisory / diagnostic system.

Application of Silicon Carbide Photodiode Flame Temperature Sensors in an Active Combustion Pattern Factor Control System

2010 ◽  
Vol 133 (1) ◽  
Author(s):  
Carl A. Palmer ◽  
Royce L. Abel ◽  
Peter Sandvik
Keyword(s):  
Silicon Carbide ◽  
Gas Turbines ◽  
Fault Tolerant ◽  
Flame Temperature ◽  
Diagnostic System ◽  
Open Loop ◽  
Bulk Temperature ◽  
Loop Control ◽  
Engine Model ◽  
Fuel Flow

This paper describes the development and initial application studies for an active combustion pattern factor controller (APFC) for gas turbines. The system is based around the use of a novel silicon carbide optical ultraviolet dual diode flame temperature sensor (FTS) developed by General Electric Co. The APFC system determines combustion flame temperatures, validates the values, and integrates an assessment of signal and combustion hardware health to determine how to trim the fuel flow to individual fuel nozzles. Key aspects of the system include the following: determination of each flame’s bulk temperature using the FTS, assessment of the reliability of the flame temperature data and physical combustion hardware health through analysis of the high-frequency output of the sensor, validation of the flame temperature signal using a data-driven approach, fusion of sensor “health indices” into the APFC to alter the trim control signal based on the health (or “believability”) of each sensor and fuel nozzle/combustor, fault-tolerant peak/valley detection and control module that selects individual fuel valves to target for reducing pattern factor while simultaneously balancing the overall fuel flow. The authors demonstrated feasibility of the approach by performing simulations using a quasi-2D T700 turbine engine model. Tests were run on the simulated platform with no faults, simulated sensor faults, and on a system with underlying combustion hardware issues. The final APFC system would be applicable for aviation, naval, and land-based commercial gas turbines, and can be used in closed-loop control or adapted as an open-loop advisory/diagnostic system.

Active Control of Combustion Instabilities in a Matrix Burner Using Primary and Pilot Fuel and Acoustic Forcing

2010 ◽  
Author(s):  
Dieter Bohn ◽  
Nils Ohlendorf ◽  
Frank Weidner ◽  
James F. Willie
Keyword(s):  
Heat Release ◽  
Mass Flow ◽  
Gas Turbines ◽  
Open Loop ◽  
Nox Emissions ◽  
Combustion Instabilities ◽  
Loop Control ◽  
First Case ◽  
Pilot Fuel ◽  
Acoustic Forcing

Lean premixed flames applied in modern gas turbines leads to reduce NOx emissions, but at the same time they are more susceptible to combustion instabilities than diffusion flames. These oscillations cause pressure fluctuations with high amplitudes and unacceptable noise as well as the risk of component or even engine failure. They can lead to pockets of fuel being formed in the mixing chamber and to bad mixing, which leads to increase in emissions. This paper reports the successful decoupling of the pressure and heat release inside the combustion chamber of a matrix burner using two actuation techniques. This led to the successful attenuation of the dominant instability modes occurring inside the combustor of the matrix burner. In the first case, acoustic forcing was used to decouple the pressure and the heat release inside the combustor. This was achieved by using a loudspeaker to modulate the primary air mass flow. This was followed by using acoustic forcing in CFD to decouple the pressure and heat release inside the combustor. For the action of the loudspeaker, sinusoidal forcing was used to mimic the modulation action of the diaphragm of the loudspeaker. In the second case, a fast gaseous “on-off” injector was used to modulate the primary fuel mass flow. After this, pilot fuel modulation was used to stabilize the flame. The control law governing the primary and pilot fuel modulation is discussed in details. The effect of open loop control on NOx emissions in the burner is also reported and discussed.

Optimal Performance of Cylinder-by-Cylinder and Fuel Bank Controllers for a CIDI Engine

2009 ◽  
Author(s):  
Ming Fang ◽  
Shawn Midlam-Mohler ◽  
Rajaram Maringanti ◽  
Fabio Chiara ◽  
Marcello Canova
Keyword(s):  
Closed Loop ◽  
Open Loop ◽  
Optimal Performance ◽  
Combustion Control ◽  
Open Loop Control ◽  
Loop Control ◽  
Engine Model ◽  
Engine Combustion ◽  
Performance Gains ◽  
Near Future

At present, Diesel engine combustion in most production engines is controlled via open-loop control. Increasing pressure from tightening emissions standards and on-board diagnosis requirements has made closed-loop combustion a possibility for production engines in the near future. For new combustion concepts, such as Homogeneous Charge Compression Ignition and other low NOx regimes, the need for closed-loop combustion control is very strong. In this work, the applicability of closed-loop combustion control for controlling the variability between cylinders in conventional Diesel combustion is explored through the use of a high-fidelity engine model. The problem is formulated such that the optimal performance of two different closed-loop control concepts can be evaluated through optimization rather than via control design. It is found that, for the types of disturbances occurring in a non-faulty engine, that control of individual cylinders leads to small performance gains compared to fuel bank control.

Fuel Flexibility Test Campaign on a 10 MW Class Gas Turbine Equipped With a Dry-Low-NOx Combustion System

2007 ◽  
Author(s):  
Stefano Cocchi ◽  
Michele Provenzale ◽  
Gianni Ceccherini
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Pressure Ratio ◽  
Flame Temperature ◽  
Nox Emission ◽  
Pollutant Emissions ◽  
Combustion System ◽  
Fuel Flow ◽  
Fuel Flexibility ◽  
Air Staging

An experimental test campaign, aimed to provide a preliminary assessment of the fuel flexibility of small power gas turbines equipped with Dry Low NOx (DLN) combustion systems, has been carried over a full-scale GE10 prototypical unit, located at the Nuovo-Pignone manufacturing site, in Florence. Such activity is a follow-up of a previous experimental campaign, performed on the same engine, but equipped with a diffusive combustion system. The engine is a single shaft, simple cycle gas turbine designed for power generation applications, rated for 11 MW electrical power and equipped with a DLN silos type combustor. One of the peculiar features of such combustion system is the presence of a device for primary combustion air staging, in order to control flame temperature. A variable composition gaseous fuel mixture has been obtained by mixing natural gas with CO2 up to about 30% vol. inerts concentration. Tests have been carried over without any modification of the default hardware configuration. Tests performed aimed to investigate both ignition limits and combustors’ performances, focusing on hot parts’ temperatures, pollutant emissions and combustion driven pressure oscillations. Results indicate that ignition is possible up to 20% vol. inerts concentration in the fuel, keeping the fuel flow during ignition at moderately low levels. Beyond 20% vol. inerts, ignition is still possible increasing fuel flow and adjusting primary air staging, but more tests are necessary to increase confidence in defining optimal and critical values. Speed ramps and load operation have been successfully tested up to 30% vol. inerts concentration. As far as speed ramps, the only issue evidenced has been risk of flameout, successfully abated by rescheduling combustion air staging. As far as load operation, the combustion system has proven to be almost insensitive to any inerts concentration tested (up to 30% vol.): the only parameter significantly affected by variation in CO2 concentration has been NOx emission. As a complementary activity, a simplified zero-dimensional model for predicting NOx emission has been developed, accounting for fuel dilution with CO2. The model is based on main turbine cycle and DLN combustion system controlling parameters (i.e., compressor pressure ratio, firing temperature, pilot fuel and primary air staging), and has been tuned achieving good agreement with data collected during the test campaign.

Dynamics Suppression in Liquid-Fueled Combustors Using Fuel Modulation

2012 ◽  
Author(s):  
Zekai Hong ◽  
Joel M. Haynes ◽  
John T. Herbon ◽  
Keith R. McManus
Keyword(s):  
Control Algorithm ◽  
Low Frequency ◽  
Control Valve ◽  
Open Loop ◽  
Instability Mode ◽  
Fuel Injector ◽  
Loop Control ◽  
Fuel Flow ◽  
Resonance Frequencies ◽  
Fuel Nozzle

In the present work, an atmospheric pressure combustor using a modern aviation gas turbine fuel nozzle was used to demonstrate active combustion control. The combustor exhibited a low-frequency dynamics mode under fuel-rich conditions. A fast-response fuel valve was adapted as an in-line valve upstream of the nozzle for fuel modulation. Large fuel modulation amplitudes were achieved with the combination of the valve and the engine nozzle at frequencies exceeding 200 Hz. Open-loop flame response to fuel modulation was first examined when the instability mode was absent; for a range of inlet air temperatures, fuel flow rates, and combustor pressure drops. Simple open-loop control at discrete off-resonance frequencies was found ineffective in suppressing the instability mode. An advanced, fast algorithm was developed to enable closed-loop control. In this scheme, the entire fuel supply to the combustor was modulated with the control valve and injected through the fuel nozzle. The control algorithm commanded the fuel injector to produce a steady fuel flow, when the combustion was stable, or to modulate the fuel when the level of pressure oscillations in the combustion chamber became unacceptable. With an optimized control algorithm, an 88% reduction in the amplitude of the low-frequency dynamics mode was achieved.

Open-loop control of compensation for optical propagation through a turbulent shear flow

1998 ◽  
Author(s):  
C. Truman ◽  
Lenore McMackin ◽  
Robert Pierson ◽  
Kenneth Bishop ◽  
Ellen Chen
Keyword(s):  
Shear Flow ◽  
Open Loop ◽  
Turbulent Shear ◽  
Turbulent Shear Flow ◽  
Open Loop Control ◽  
Loop Control ◽  
Optical Propagation

scholarly journals Sensuator: A Hybrid Sensor–Actuator Approach to Soft Robotic Proprioception Using Recurrent Neural Networks

Actuators ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 30
Author(s):  
Pornthep Preechayasomboon ◽  
Eric Rombokas
Keyword(s):  
Neural Networks ◽  
Recurrent Neural Networks ◽  
Linear Models ◽  
Open Loop ◽  
Proof Of Concept ◽  
State Estimator ◽  
Loop Control ◽  
Practical Applications ◽  
Soft Actuator ◽  
The Cost

Soft robotic actuators are now being used in practical applications; however, they are often limited to open-loop control that relies on the inherent compliance of the actuator. Achieving human-like manipulation and grasping with soft robotic actuators requires at least some form of sensing, which often comes at the cost of complex fabrication and purposefully built sensor structures. In this paper, we utilize the actuating fluid itself as a sensing medium to achieve high-fidelity proprioception in a soft actuator. As our sensors are somewhat unstructured, their readings are difficult to interpret using linear models. We therefore present a proof of concept of a method for deriving the pose of the soft actuator using recurrent neural networks. We present the experimental setup and our learned state estimator to show that our method is viable for achieving proprioception and is also robust to common sensor failures.

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