Open Loop and Closed Loop Performance of Solid Oxide Fuel Cell Turbine Hybrid Systems During Fuel Composition Changes

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Nor Farida Harun ◽  
David Tucker ◽  
Thomas A. Adams
Keyword(s):  
Control System ◽  
Fuel Cell ◽  
Closed Loop ◽  
Open Loop ◽  
Solid Oxide ◽  
Fuel Composition ◽  
Oxide Fuel ◽  
Thermal Effluent ◽  
Turbine Speed ◽  
Composition Changes

The dynamic behavior of a solid oxide fuel cell gas turbine hybrid system (SOFC/GT) from both open and closed loop transients in response to sudden changes in fuel composition was experimentally investigated. A pilot-scale (200–700 kW) hybrid facility available at the U.S. Department of Energy, National Energy Technology Laboratory was used to perform the experiments using a combination of numerical models and actual equipment. In the open loop configuration, the turbine speed was driven by the thermal effluent fed into the gas turbine system, where the thermal effluent was determined by the feedforward fuel cell control system. However, in the closed loop configuration, a load-based speed control system was used to maintain the turbine speed constant at 40,500 rpm by adjusting the load on the turbine, in addition to the implementation of the fuel cell system control. The open loop transient response showed that the impacts of fuel composition changes on key process variables, such as fuel cell thermal effluent, turbine speed, and cathode feed stream conditions, in the SOFC/GT systems were propagated over the course of the test, except for the cathode inlet temperature. The trajectories of the aforementioned variables are discussed in this paper to better understand the resulting mitigation/propagation behaviors. This will help lead to the development of novel control strategies to mitigate the negative impacts experienced during fuel composition transients of SOFC/GT systems.

Open Loop and Closed Loop Performance of Solid Oxide Fuel Cell Turbine Hybrid Systems During Fuel Composition Changes

2015 ◽  
Author(s):  
Nor Farida Harun ◽  
David Tucker ◽  
Thomas A. Adams
Keyword(s):  
Control System ◽  
Fuel Cell ◽  
Closed Loop ◽  
Open Loop ◽  
Solid Oxide ◽  
Fuel Composition ◽  
Oxide Fuel ◽  
Thermal Effluent ◽  
Turbine Speed ◽  
Composition Changes

The dynamic behavior of a solid oxide fuel cell gas turbine hybrid system (SOFC/GT) from both open and closed loop transients in response to sudden changes in fuel composition was experimentally investigated. A pilot-scale (200kW – 700kW) hybrid facility available at the U.S. Department of Energy, National Energy Technology Laboratory was used to perform the experiments using a combination of numerical models and actual equipment. In the open loop configuration, the turbine speed was driven by the thermal effluent fed into the gas turbine system, where the thermal effluent was determined by the feedforward fuel cell control system. However, in the closed loop configuration, a load-based speed control system was used to maintain the turbine speed constant at 40,500rpm by adjusting the load on the turbine, in addition to the implementation of the fuel cell system control. The open loop transient response showed that the impacts of fuel composition changes on key process variables, such as fuel cell thermal effluent, turbine speed and cathode feed stream conditions in the SOFC/GT systems were propagated over the course of the test, except for the cathode inlet temperature. The trajectories of the aforementioned variables are discussed in this paper to better understand the resulting mitigation/propagation behaviors. This will help lead to the development of novel control strategies to mitigate the negative impacts experienced during fuel composition transients of SOFC/GT systems.

Study on Fuel Composition for the Performance Enhancement of Solid Oxide Fuel Cell Operated with Biodiesel Fuel

2013 ◽  
Vol 57 (1) ◽  
pp. 3005-3011
Author(s):  
Q. T. Tran ◽  
Y. Shiratori ◽  
Y. Kakihara ◽  
T. Kitaoka ◽  
K. Sasaki
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Performance Enhancement ◽  
Solid Oxide ◽  
Biodiesel Fuel ◽  
Fuel Composition ◽  
Oxide Fuel

scholarly journals Control Design for a Bottoming Solid Oxide Fuel Cell Gas Turbine Hybrid System

2006 ◽  
Author(s):  
Fabian Mueller ◽  
Faryar Jabbari ◽  
Jacob Brouwer ◽  
Rory Roberts ◽  
Tobias Junker ◽  
...  
Keyword(s):  
Control System ◽  
Fuel Cell ◽  
Dynamic Model ◽  
Hybrid System ◽  
Solid Oxide ◽  
System Control ◽  
Oxide Fuel ◽  
Transient Load ◽  
Control Approach ◽  
Wide Range

A bottoming 275 kilowatt planar solid oxide fuel cell (SOFC) gas turbine (GT) hybrid system control approach has been conceptualized and designed. Based on previously published modeling techniques, a dynamic model is developed that captures the physics sufficient for dynamic simulation of all processes that affect the system with time scales greater than ten milliseconds. The dynamic model was used to make system design improvements to enable the system to operate dynamically over a wide range of power output (15 to 100% power). The wide range of operation was possible by burning supplementary fuel in the combustor and operating the turbine at variable speed for improved thermal management. The dynamic model was employed to design a control strategy for the system. Analyses of the relative gain array (RGA) of the system at several operating points gave insight into input/output (I/O) pairing for decentralized control. Particularly, the analyses indicate that for SOFC/GT hybrid plants that use voltage as a controlled variable it is beneficial to control system power by manipulating fuel cell current and to control fuel cell voltage by manipulating the anode fuel flowrate. To control the stack temperature during transient load changes, a cascade control structure is employed in which a fast inner loop that maintains the GT shaft speed receives its setpoint from a slower outer loop that maintains the stack temperature. Fuel can be added to the combustor to maintain the turbine inlet temperature for the lower operating power conditions. To maintain fuel utilization and to prevent fuel starvation in the fuel cell, fuel is supplied to the fuel cell proportionally to the stack current. In addition, voltage is used as an indicator of varying fuel concentrations allowing the fuel flow to be adjusted accordingly. Using voltage as a sensor is shown to be a potential solution to making SOFC systems robust to varying fuel compositions. The simulation tool proved effective for fuel cell/GT hybrid system control system development. The resulting SOFC/GT system control approach is shown to have transient load-following capability over a wide range of power, ambient temperature, and fuel concentration variations.

High Pressure Turbocharger for Solid Oxide Fuel Cells

2006 ◽  
Author(s):  
Steven G. Berenyi
Keyword(s):  
High Pressure ◽  
Control System ◽  
Fuel Cell ◽  
Basic Structure ◽  
Cell System ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Efficient System ◽  
Current Test ◽  
And Control

Rolls-Royce has designed, built, and continues to test a high pressure (HP) turbocharging system specifically designed for a hybrid solid oxide fuel cell system being developed by Rolls-Royce Fuel Cell Systems, Ltd. This turbocharger is comprised of a two-spool machine with a shaft speed motor/generator on the low speed spool. Each spool contains a centrifugal compressor driven by a radial inflow turbine. The two spools run independently, but are physically close coupled for a smaller, more efficient system. The spools are mounted into a basic structure to provide structural rigidity, as well as sound and heat isolation. In its current test rig form, the system runs on oil lubricated bearings; is equipped with a liquid fueled slave combustor; and is controlled with a digital control system. Although never intended to be a “stand alone” microturbine — it is simply a high pressure turbocharger; if one wanted to — with a proper fuel and control system installed, it is capable of operation in such a stand alone mode. However, without heat recovery it would be a highly inefficient microturbine and therefore, was not considered in this application. Multiple units have been built and continue developmental testing. Initial matching to a fuel cell stack is scheduled for operation later in 2006.

scholarly journals Multiloop and Prediction Based Controller Design for Sugarcane Crushing Mill Process

2015 ◽  
Vol 4 (4) ◽  
pp. 135
Author(s):  
Sandeep Kumar Sunori ◽  
Pradeep Kumar Juneja ◽  
Anamika Bhatia Jain
Keyword(s):  
Control System ◽  
Linear Model ◽  
Predictive Control ◽  
Closed Loop ◽  
Controller Design ◽  
Mimo System ◽  
Pi Controller ◽  
Open Loop ◽  
Turbine Speed ◽  
Mill Process

In the present work a sugarcane crushing mill is presented as a MIMO system with high multivariable interaction.A linear model of the plant is taken with flap position and turbine speed as manipulated variables and mill torque and buffer chute height as controlled variables.The multiloop PI controller has been designed for this plant by first investigating the RGA and the value of Niederlinski index of this plant.The decoupling of this system is done and the respective open loop and closed loop step responses are observed and compared with those of the composite MIMO system. Also the performance of multiloop controller is compared with controller designed using model predictive control system strategy for this plant.

Evaluation of Compressor Bleed Air Transients in a Fuel Cell Gas Turbine Hybrid System Using Hardware Simulation

2015 ◽  
Author(s):  
Nana Zhou ◽  
Chen Yang ◽  
David Tucker
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Gas Turbine ◽  
Thermal Management ◽  
Hybrid System ◽  
Solid Oxide ◽  
Sudden Increase ◽  
Oxide Fuel ◽  
Bypass Valve ◽  
Turbine Speed

Thermal management in the fuel cell component was a critical issue in the operation of a solid oxide fuel cell gas turbine (SOFC/GT) hybrid system. The effective management of fuel cell cathode air mass flow was thought to be a potential method to improve the thermal management during transients. The U.S. Department of Energy, National Energy Technology Laboratory (NETL) designed and built a hybrid performance (HyPer) facility by interfacing a real time solid oxide fuel cell system numerical model through hardware with a physical gas turbine system. Perturbations were accomplished by diverting part of the compressor discharge directly to atmosphere through the manipulation of a bleed-air bypass valve in open loop experiments using the HyPer facility. Two tests were performed: the fuel cell numerical simulation model was both decoupled and fully coupled with the gas turbine hardware component. The responses of both physical subsystem and virtual subsystem to the disturbances were evaluated in this paper. Distributed temperatures and current densities along the fuel cell were evaluated. Turbine speed and system pressures were analyzed. The application of bleed-air bypass valve was shown to have a minimal impact on cathode airflow, but a significant effect on turbine speed. Thus, the manipulation of compressor bleed was expected to be an effective means to mitigate the impact of a sudden increase in turbine speed, such as fuel cell load reductions or load trips.

scholarly journals Fuel composition influences on exergetic performance of a standalone internal reforming solid oxide fuel cell

2019 ◽  
Author(s):  
Mazlan Aabdul Wahid ◽  
Hasan Barzegaravval ◽  
Ahmad Dairobi Ghazali ◽  
Adam Kasani ◽  
Mohammad Amri Mazlan ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Solid Oxide ◽  
Fuel Composition ◽  
Oxide Fuel ◽  
Internal Reforming

Development of an Automated Control System Verification Platform for a Solid Oxide Fuel Cell

2006 ◽  
Author(s):  
John Absmeier ◽  
Tuhin Das ◽  
Swaminathan Gopalswamy ◽  
Ravi S. Paike
Keyword(s):  
Control System ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Rapid Development ◽  
Cell System ◽  
Solid Oxide ◽  
Verification And Validation ◽  
Oxide Fuel ◽  
Power Sources ◽  
System Verification

The fuel cell industry is currently undergoing rapid development, and applications of fuel cell based power sources are diversifying. The advent of new and more sophisticated application areas and the expanding market necessitates development of efficient and robust fuel cell based power supplies that are reliable in their performance. These demands are answered not only by improved plant designs and innovations, but also by developing high-quality control algorithms. Quality and reliability of the complete system are ensured through extensive and varied testing. To this end an automated Hardware-in-the-Loop based control code verification and validation platform for the Delphi Solid Oxide Fuel Cell plant and control system has been developed. Verification activities are managed using the System Verification Manager tool. This paper outlines the application of this platform for safety and diagnostics verification and validation for a Solid Oxide Fuel Cell system.

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