Simultaneous Turbine Speed Regulation and Fuel Cell Airflow Tracking of a SOFC/GT Hybrid Plant With the Use of Airflow Bypass Valves

2011 ◽  
Author(s):  
Alex Tsai ◽  
David Tucker ◽  
David Clippinger
Keyword(s):  
Fuel Cell ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Transfer Functions ◽  
Nonlinear Models ◽  
Cell Mass ◽  
Hybrid Plant ◽  
Simultaneous Control ◽  
Turbine Speed

This paper studies a novel control methodology aimed at regulating and tracking turbo machinery synchronous speed and fuel cell mass flow rate of a SOFC/GT hardware simulation facility with the sole use of airflow bypass valves. The hybrid facility under consideration consists of a 120kW auxiliary power unit gas turbine coupled to a 300kW SOFC hardware simulator. The hybrid simulator allows testing of a wide variety of fuel cell models under a Hardware-in-the-Loop configuration. Small changes in fuel cell cathode airflow have shown to have a large impact on system performance. Without simultaneous control of turbine speed via load or auxiliary fuel, fuel cell airflow tracking requires an alternate actuator methodology. The use of bypass valves to control mass flow rate and decouple turbine speed allows for a greater flexibility and feasibility of implementation at the larger scale, where synchronous speeds are required. This work utilizes empirically derived Transfer Functions (TF) as the system model and applies a Fuzzy Logic (FL) control algorithm that can be easily incorporated to nonlinear models of direct fired recuperated hybrid plants having similar configurations. This methodology is tested on a SIMULINK/MATLAB platform for various perturbations of turbine load and fuel cell heat exhaust.

Simultaneous Turbine Speed Regulation and Fuel Cell Airflow Tracking of a SOFC/GT Hybrid Plant With the Use of Airflow Bypass Valves

2011 ◽  
Vol 8 (6) ◽  
Author(s):  
Alex Tsai ◽  
David Tucker ◽  
David Clippinger
Keyword(s):  
Fuel Cell ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Transfer Functions ◽  
Nonlinear Models ◽  
Cell Mass ◽  
Hybrid Plant ◽  
Simultaneous Control ◽  
Turbine Speed

This paper studies a novel control methodology aimed at regulating and tracking turbo machinery synchronous speed and fuel cell mass flow rate of a SOFC/GT hardware simulation facility with the sole use of airflow bypass valves. The hybrid facility under consideration consists of a 120 kW auxiliary power unit gas turbine coupled to a 300 kW SOFC hardware simulator. The hybrid simulator allows testing of a wide variety of fuel cell models under a hardware-in-the-loop configuration. Small changes in fuel cell cathode airflow have shown to have a large impact on system performance. Without simultaneous control of turbine speed via load or auxiliary fuel, fuel cell airflow tracking requires an alternate actuator methodology. The use of bypass valves to control mass flow rate and decouple turbine speed allows for a greater flexibility and feasibility of implementation at the larger scale, where synchronous speeds are required. This work utilizes empirically derived transfer functions (TF) as the system model and applies a fuzzy logic (FL) control algorithm that can be easily incorporated to nonlinear models of direct fired recuperated hybrid plants having similar configurations. This methodology is tested on a SIMULINK/matlab platform for various perturbations of turbine load and fuel cell heat exhaust.

Decentralized PID Controller Design for SOFC-GT

2020 ◽  
Author(s):  
Tooran Emami ◽  
Alex Tsai ◽  
David Tucker
Keyword(s):  
Fuel Cell ◽  
Power Plant ◽  
Flow Rate ◽  
Pid Controller ◽  
Transfer Functions ◽  
Cell Mass ◽  
Electric Load ◽  
Cold Air ◽  
Air Valve ◽  
Turbine Speed

Abstract This paper presents a performance of a 300 kW Solid Oxide Fuel Cell Gas Turbine (SOFC-GT) pilot power plant simulator under an area of selection of the Proportional Integral Derivative (PID) controller coefficients that satisfies the stability, gain and phase margins. The performance of turbine speed and the fuel cell mass flow rate is controlled by the set of PID controller coefficients from this area. The input to the subsystems power plant are the electric load and cold air valve. The decentralized controllers are designed for each subsystems performance individually as a Single Input Single Output (SISO) system. Two of subsystem plants are the transfer functions of turbine speed over the electric load and the cold air valve. The other two subsystem plants are the transfer functions of fuel cell mass flow rate over the electric load and the cold air bypass valve. The flexibility to have an area to select PID controller coefficients is beneficial to SOFC-GT plant due to the wide range of operations and internal parameter interactions. Designing the PID controller for the specific phase and gain margins increase the reliability and robustness of the SOFC-GT with multiple uncertain parameters. The practical implementation of this methodology is presented through the software environment.

Uncertain Gain and Time-Delay Control of 300-kW SOFC-GT

2021 ◽  
Author(s):  
Tooran Emami ◽  
David Tucker ◽  
John Watkins
Keyword(s):  
Fuel Cell ◽  
Time Delay ◽  
Pid Controller ◽  
Transfer Functions ◽  
Cell Mass ◽  
Electric Load ◽  
Cold Air ◽  
Internal Gain ◽  
Air Valve ◽  
Turbine Speed

Abstract This paper presents a Proportional Integral Derivative (PID) controller design with the presence of an uncertain internal gain and additional time delay in the forward path of a 300 kW Solid Oxide Fuel Cell-Gas Turbine (SOFC-GT). The outputs of the system are turbine speed and the fuel cell mass flow rate. A fixed set of proportional controller coefficients are determined to graphically develop an area of selection for the integral and derivative coefficients of the PID controller. The inputs to the power plant are the electric load and cold air valve. The decentralized controllers are applied to four sub-systems as a Single Input Single Output (SISO). The PID controller coefficients are selected from a singular matrix solution that stabilizes the system and satisfies the internal gain and time delay uncertainties. Two sub-systems are the transfer functions of the turbine speed over the electric load and the cold air valve. The other two sub-systems are the transfer functions of the fuel cell mass flow rate over the electric load and the cold air bypass valve. Multiple options for selecting PID controller coefficients are beneficial to the SOFC-GT plant due to the wide range of operations and internal uncertainty interactions. The specific internal time delay and gain margins increase the reliability and robustness of the SOFC-GT with multiple uncertain parameters.

scholarly journals Thermodynamic Analysis of a Solid Oxide Fuel Cell Based Combined Cooling, Heating, and Power System Integrated with Biomass Gasification

Entropy ◽  
2021 ◽  
Vol 23 (8) ◽  
pp. 1029
Author(s):  
Zhiheng Cui ◽  
Jiangjiang Wang ◽  
Noam Lior
Keyword(s):  
Fuel Cell ◽  
Power System ◽  
Solid Oxide Fuel Cell ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Biomass Gasification ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Energy And Exergy

A novel cooling, heating, and power system integrated with a solid oxide fuel cell and biomass gasification was proposed and analyzed. The thermodynamic models of components and evaluation indicators were established to present energetic and exergetic analysis. After the validations of thermodynamic models, the system performances under design work conditions were evaluated. The proposed system's electrical, energy, and exergy efficiencies reached up to 52.6%, 68.0%, and 43.9%, respectively. The gasifier and fuel cell stack were the most significant components of exergy destruction in this system, accounting for 41.0% and 15.1%, respectively, which were primarily caused by the gasification and electrochemical reactions’ irreversibility. The influences of the key parameters of the ratio of steam to biomass mass flow rate (S/B), the biomass flow rate (Mbio), and the temperature and pressure of the fuel cell (Top and Psofc) on system energy performances were analyzed: doubling S/B (from 0.5 to 1.0) reduced the energy efficiency by 5.3%, while increasing the electrical efficiency by 4.6% (from 52.6% to 55.0%) and raising the biomass mass flow rate by 40% increased the energy and exergy efficiencies by 2.4% and 2.1%, respectively. When raising the SOFC operating temperature by 31.3%, the energy and exergy efficiencies rose by 61.2% (from 50.0% to 80.6%) and 45.1% (from 32.8% to 47.6%), respectively, but this likely would result in a higher operating cost. Increasing the SOFC pressure from 2 to 7 bar increased the electrical efficiency by 10.6%, but additional energy for pumping and compression was consumed.

The standard unit mass flow rate of gas-liquid mixtures

2020 ◽  
pp. 13-16
Author(s):  
V.N. Petrov ◽  
◽  
V.F. Sopin ◽  
L.A. Akhmetzyanova ◽  
Ya.S. Petrova ◽  
...  
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Liquid Mixtures ◽  
Unit Mass ◽  
Standard Unit

Prediction of Leakage Mass Flow Rate Through Gas Springs

1987 ◽  
Author(s):  
Roberto Bruno Bossio ◽  
Vincenzo Naso ◽  
Marian Cichy ◽  
Boleslaw Pleszewski
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate
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