Steady-State Simulation of a Gas Turbine Operating with Sewage Sludge Biogas

2018 ◽

Cited By ~ 1

Author(s):

Thomas Krummrein ◽

Martin Henke ◽

Peter Kutne

Keyword(s):

Steady State ◽

Gas Turbine ◽

Solution Process ◽

Simulation Tool ◽

Fast Computation ◽

Micro Gas Turbine ◽

Simulation Tools ◽

Complexity Result ◽

Combustion Technology ◽

Steady State Simulation

Steady state simulations are an important method to investigate thermodynamic processes. This is especially true for innovative micro gas turbine (MGT) based cycles as the complexity of such systems grows. Therefore, steady state simulation tools are required which ensure large flexibility and computation robustness. As the increased system complexity result often in more extensive parameter studies also a fast computation speed is required. While a number of steady state simulation tools for micro gas turbine based systems are described and applied in literature, the solving process of such tools is rarely explained. However, this solving process is crucial to achieve a robust and fast computation within a physically meaningful range. Therefore, a new solver routine for a steady state simulation tool developed at the DLR Institute of Combustion Technology is presented in detail in this paper. The solver routine is based on Broyden’s method. It considers boundaries during the solving process to maintain a physically and technically meaningful solution process. Supplementary methods are implemented and described which improve the computation robustness and speed. Furthermore, some features of the resulting steady state simulation tool are presented. Exemplary applications of a hybrid power plant, an inverted Brayton cycle and an aircraft auxiliary power unit show the capabilities of the presented solver routine and the steady state simulation tool. It is shown that the new solver routine is superior to the standard Simulink algebraic solver in terms of system evaluation and robustness for the given applications.

Download Full-text

A Highly Flexible Approach on the Steady-State Analysis of Innovative Micro Gas Turbine Cycles

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4040855 ◽

2018 ◽

Vol 140 (12) ◽

Cited By ~ 3

Author(s):

Thomas Krummrein ◽

Martin Henke ◽

Peter Kutne

Keyword(s):

Steady State ◽

Gas Turbine ◽

Solution Process ◽

Simulation Tool ◽

Fast Computation ◽

Micro Gas Turbine ◽

Simulation Tools ◽

Complexity Result ◽

Combustion Technology ◽

Steady State Simulation

Steady-state simulation is an important method to investigate thermodynamic processes. This is especially true for innovative micro gas turbine (MGT)-based cycles as the complexity of such systems grows. Therefore, steady-state simulation tools are required that ensure large flexibility and computation robustness. As the increased system complexity result often in more extensive parameter studies also a fast computation speed is required. While a number of steady-state simulation tools for MGT-based systems are described and applied in literature, the solving process of such tools is rarely explained. However, this solving process is crucial to achieve a robust and fast computation within a physically meaningful range. Therefore, a new solver routine for a steady-state simulation tool developed at the DLR Institute of Combustion Technology is presented in detail in this paper. The solver routine is based on Broyden's method. It considers boundaries during the solving process to maintain a physically and technically meaningful solution process. Supplementary methods are implemented and described which improve the computation robustness and speed. Furthermore, some features of the resulting steady-state simulation tool are presented. Exemplary applications of a hybrid power plant (HyPP), an inverted Brayton cycle (IBC), and an aircraft auxiliary power unit (APU) show the capabilities of the presented solver routine and the steady-state simulation tool. It is shown that the new solver routine is superior to the standard Simulink algebraic solver in terms of system evaluation and robustness for the given applications.

Download Full-text

A new simultaneous approach to the steady-state simulation of complex technological systems

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19773570 ◽

1977 ◽

Vol 42 (12) ◽

pp. 3570-3575

Author(s):

S. Ragheb Tewfik ◽

J. Vrba

Keyword(s):

Steady State ◽

Technological Systems ◽

Simultaneous Approach ◽

Steady State Simulation

Download Full-text

Cyclic Breathing Simulations in Large Scale Models of the Lung Airway From the Oronasal Opening to the Terminal Bronchioles

Volume 2: Biomedical and Biotechnology ◽

10.1115/imece2012-88901 ◽

2012 ◽

Author(s):

D. Keith Walters ◽

Greg W. Burgreen ◽

Robert L. Hester ◽

David S. Thompson ◽

David M. Lavallee ◽

...

Keyword(s):

Steady State ◽

Boundary Conditions ◽

Large Scale ◽

Whole Body ◽

Patient Specific ◽

Cfd Simulations ◽

Reduced Order ◽

Scale Models ◽

Steady State Simulation ◽

Conducting Zone

Computational fluid dynamics (CFD) simulations were performed for unsteady periodic breathing conditions, using large-scale models of the human lung airway. The computational domain included fully coupled representations of the orotracheal region and large conducting zone up to generation four (G4) obtained from patient-specific CT data, and the small conducting zone (to G16) obtained from a stochastically generated airway tree with statistically realistic geometrical characteristics. A reduced-order geometry was used, in which several airway branches in each generation were truncated, and only select flow paths were retained to G16. The inlet and outlet flow boundaries corresponded to the oronasal opening (superior), the inlet/outlet planes in terminal bronchioles (distal), and the unresolved airway boundaries arising from the truncation procedure (intermediate). The cyclic flow was specified according to the predicted ventilation patterns for a healthy adult male at three different activity levels, supplied by the whole-body modeling software HumMod. The CFD simulations were performed using Ansys FLUENT. The mass flow distribution at the distal boundaries was prescribed using a previously documented methodology, in which the percentage of the total flow for each boundary was first determined from a steady-state simulation with an applied flow rate equal to the average during the inhalation phase of the breathing cycle. The distal pressure boundary conditions for the steady-state simulation were set using a stochastic coupling procedure to ensure physiologically realistic flow conditions. The results show that: 1) physiologically realistic flow is obtained in the model, in terms of cyclic mass conservation and approximately uniform pressure distribution in the distal airways; 2) the predicted alveolar pressure is in good agreement with previously documented values; and 3) the use of reduced-order geometry modeling allows accurate and efficient simulation of large-scale breathing lung flow, provided care is taken to use a physiologically realistic geometry and to properly address the unsteady boundary conditions.

Download Full-text