Validation of a T100 Micro Gas Turbine Steady-State Simulation Tool

2015 ◽  
Author(s):  
Martin Henke ◽  
Nikolai Klempp ◽  
Martina Hohloch ◽  
Thomas Monz ◽  
Manfred Aigner
Keyword(s):  
Numerical Simulation ◽  
Steady State ◽  
Gas Turbines ◽  
Power Plants ◽  
Numerical Models ◽  
Measurement Data ◽  
Cycle Performance ◽  
Simulation Tool ◽  
Test Rig ◽  
Cycle Simulation

Micro gas turbines (MGT) provide a highly efficient, low-pollutant way to generate power and heat on-site. MGTs have also proven to be a versatile technology platform for recent developments like utilization of fuels with low specific heating values and solar thermal electricity generation. Moreover, they are the foundation to build novel cycles like the inverted Brayton cycle or fuel cell hybrid power plants. Numerical simulations of steady operation points are beneficial in various phases of MGT cycle development. They are used to determine and analyze the future potentials of innovative cycles for example by predicting the electrical efficiency and they support the thermodynamic design process (by providing mass flow, pressure and temperature data). Numerical Simulation allows to approximate off-design performance of known cycles e.g. power output at different ambient conditions. Additionally, numerical simulation is used to support cycle optimization efforts by analyzing the sensitivity of component performance on cycle performance. Numerical models of the MGT components have to be tuned and validated based on experimental data from MGT test rigs. At DLR institute of combustion technology a MGT steady-state cycle simulation tool has been used to analyze a variety of cycles and has been revised for several years. In this paper, the validation process is discussed in detail. Comparing simulation data with measurement data from the DLR Turbec T100 test rig has led to extensions of the numeric models, on the one hand, and to modifications of the test rig on the other. Newly implemented numerical models account for the generator heat release to the inlet air and the power electronic limitations. The test rig was modified to improve the temperature measurement at positions with uneven spatial temperature distribution such as the turbine outlet. Analyzing these temperature distributions also yields a possible explanation for the apparent strong recuperator efficiency drop at high load levels, which was also observed by other T100 users before.

scholarly journals Influence of Turbulence on the Dynamic Behaviour of Premixed Flames

1998 ◽  
Author(s):  
Uwe Krüger ◽  
Stefan Hoffmann ◽  
Werner Krebs ◽  
Hans Judith ◽  
Dieter Bohn ◽  
...  
Keyword(s):  
Steady State ◽  
Frequency Response ◽  
Gas Turbines ◽  
Power Plants ◽  
Dynamic Behaviour ◽  
Diffusion Flames ◽  
Premixed Flames ◽  
Combustion Process ◽  
Turbulent Premixed Flame ◽  
Improved Model

Environmental compatibility requires low emission burners for gas turbine power plants as well as for jet engines. In the past significant progress has been made developing low NOx and CO burners by introducing lean premixed techniques. Unfortunately these burners often have a more pronounced tendency than conventional burner designs to produce combustion driven oscillations. The oscillations may be excited to such an extent that strong pulsation may possibly occur; this is associated with a risk of engine failure and higher NOx emissions. In order to describe the acoustical behaviour of the complete burner system the determination of the transfer function of the flame itself is crucial. Using a new method which was presented by Bohn, Deutsch and Krüger (1996) and Bohn, Li, Krüger and Matousckek (1997), the dynamic flame behaviour can be predicted by means of a full Navier-Stokes-simulation of the complex combustion process for the steady-state as well as for the transient situation. This method has been successfully used by the authors to obtain the frequency response of turbulent diffusion flames and laminar premixed flames. For the application in modern gas turbines the influence of turbulence on the dynamic behaviour of premixed flames is of big interest. Therefore, this paper presents numerical studies of a turbulent premixed flame configuration for which experimental data is available in the literature. Two different combustion models have been used for the steady-state as well as for the transient calculations. With the improved model, which takes into account the chemical kinetics and the interaction between turbulence and kinetics, good agreement has been found for the steady-state results and for the frequency response of the flame.

scholarly journals Flow simulation in air intake system of gas turbine

2021 ◽  
Vol 23 (4) ◽  
pp. 66-83
Author(s):  
V. L. Blinov ◽  
I. S. Zubkov ◽  
Yu. M. Brodov ◽  
B. E. Murmanskij
Keyword(s):  
Numerical Simulation ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Numerical Models ◽  
Flow Simulation ◽  
Technical Condition ◽  
Model Parameters ◽  
Intake System ◽  
Performance Factors ◽  
Air Intake

THE PURPOSE. To study the issues of air intake system’s performance as the part of the gas turbines. To estimate the possibility of modeling different performance factors of air intake systems with numerical simulation methods. To develop the recommendations of setting up the grid and the numerical models for researches in air intake system’s performance and assessing the technical condition of elements of it. METHODS. The main method, which was used during the whole study, is computational fluid dynamics with usage of CAE-systems.RESULTS. During the study the recommendations for setting up the numerical model were developed. Such factors as grid model parameters, roughness scale, pressure drop in elements of air intake system and some more were investigated. The method for heat exchanger’s performance simulation were created for modeling the air temperature raising. CONCLUSION. The air intake system’s performance analysis becomes one of the actual topics for research because of the high demands of gas turbines to air, which is used in its annulus. The main part of these researches is in analysis of dangerous regimes of work (e.g. the icing process of annulus elements) or in assessing technical condition of air intake systems and its influence to the gas turbine as a whole. The developed method of numerical simulation allows to get the adequate results with low requirements for computational resources. Also this method allows to model the heat exchanger performance and study its defects’ influence to the performance of air intake system as a whole. 

Prediction and Mitigation Strategies for Compressor Instabilities due to Large Pressurized Volumes in Micro Gas Turbine Systems

2021 ◽  
Author(s):  
Thomas Krummrein ◽  
Martin Henke ◽  
Timo Lingstädt ◽  
Martina Hohloch ◽  
Peter Kutne
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Flow Instability ◽  
Measurement Data ◽  
Mitigation Strategies ◽  
Mathematical Explanation ◽  
Shaft Speed ◽  
Micro Gas Turbine ◽  
The Impact

Abstract Micro gas turbines are a versatile platform for advanced cycle concepts. In these novel cycles, basic micro gas turbine components — compressor, turbine, combustor and recuperator — are coupled with various other technologies to achieve higher efficiency and flexibility. Examples are hybrid power plants integrating pressurized fuel cells, solar receivers or thermal storages. Characteristically, such complex cycles contain vast pressurized gas volumes between compressor and turbine, many times larger than those contained in conventional micro gas turbines. In fast deceleration maneuvers the rotational speed of the compressor drops rapidly. However, the pressure decrease is delayed due to the large amount of gas contained in the volumes. Ultimately, this can lead to compressor flow instability or surge. To predict and mitigate such instabilities, not only the compressor surge limit must be known, but also the dynamic dependencies between shaft speed deceleration, pressure and flow changes within the system. Since appropriate experiments may damage the system, investigations with numerical simulations are crucial. The investigation begins with a mathematical explanation of the relevant mechanisms, based on a simplified analytical model. Subsequently, the DLR in-house simulation program TMTSyS (Transient Modular Turbo-System Simulator) is used to investigate the impact of transient maneuvers on a micro gas turbine test rig containing a large pressurized gas volume in detail. After the relevant aspects of the simulation model are validated against measurement data, it is shown that the occurrence of compressor instabilities induced by fast deceleration can be predicted with the simulator. It is also shown that the simulation tool enables these predictions using only measurement data of non-critical maneuvers. Hence, mitigation strategies are derived that allow to estimate save shaft speed deceleration rate limits based on non-critical performance measurements.

Micro Gas Turbine Cycle Humidification for Increased Flexibility: Numerical and Experimental Validation of Different Steam Injection Models

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Ward De Paepe ◽  
Massimiliano Renzi ◽  
Marina Montero Carrerro ◽  
Carlo Caligiuri ◽  
Francesco Contino
Keyword(s):  
Combustion Chamber ◽  
Gas Turbines ◽  
Numerical Models ◽  
Steam Injection ◽  
Power Production ◽  
Cycle Performance ◽  
Small Scale ◽  
Model Parameters ◽  
Complete Combustion ◽  
The Impact

With the current shift from centralized to more decentralized power production, new opportunities arise for small-scale combined heat and power (CHP) production units like micro gas turbines (mGTs). However, to fully embrace these opportunities, the current mGT technology has to become more flexible in terms of operation—decoupling the heat and power production in CHP mode—and in terms of fuel utilization—showing flexibility in the operation with different lower heating value (LHV) fuels. Cycle humidification, e.g., by performing steam injection, is a possible route to handle these problems. Current simulation models are able to correctly assess the impact of humidification on the cycle performance, but they fail to provide detailed information on the combustion process. To fully quantify the potential of cycle humidification, more advanced numerical models—preferably validated—are necessary. These models are not only capable of correctly predicting the cycle performance, but they can also handle the complex chemical kinetics in the combustion chamber. In this paper, we compared and validated such a model with a typical steady-state model of the steam injected mGT cycle based on the Turbec T100. The advanced one is an in-house MATLAB model, based on the NIST database for the characterization of the properties of the gaseous compounds with the combustion mechanisms embedded according to the Gri-MEch 3.0 library. The validation one was constructed using commercial software (Aspen Plus), using the more advance Redlich-Kwong-Soave (RKS)- Boston-Mathias(BM) property method and assuming complete combustion by using a Gibbs reactor. Both models were compared considering steam injection in the compressor outlet or in the combustion chamber, focusing only on the global cycle performance. Simulation results of the steam injection cycle fueled with natural gas and syngas showed some differences between the two presented models (e.g., 5.9% on average for the efficiency increase over the simulated steam injection rates at nominal power output for injection in the compressor outlet); however, the general trends that could be observed are consistent. Additionally, the numerical results of the injection in the compressor outlet were also validated with steam-injection experiments in a Turbec T100, indicating that the advanced MATLAB model overestimates the efficiency improvement by 25–45%. The results show the potential of simulating the humidified cycle using more advanced models; however, in future work, special attention should be paid to the experimental tuning of the model parameters in general and the recuperator performance in particular to allow correct assessment of the cycle performance.

Reconstruction of Temperature Distribution for a Turbulent Free Jet Using Background Oriented Schlieren

2021 ◽  
Author(s):  
Benjamin H. Wahls ◽  
Kishore Ranganath Ramakrishnan ◽  
Srinath Ekkad
Keyword(s):  
Steady State ◽  
Temperature Distribution ◽  
Gas Turbines ◽  
Numerical Models ◽  
Ideal Gas ◽  
Reactive Flows ◽  
Free Jet ◽  
Reconstructed Temperature ◽  
Background Oriented Schlieren ◽  
Nozzle Temperature

Abstract Background Oriented Schlieren (BOS) has been shown to be an excellent tool for qualitative flow visualization, and more recently, literature has shown that the technique can be expanded to yield quantitative measurements as well. In this study, a BOS setup was built to construct the temperature distribution of a heated turbulent free 12mm diameter jet near the nozzle. A 1080p DSLR camera was used to view a black and white speckled background plane through the heated free jet in question. Comparing images of the background with and without flow present using a cross correlation algorithm gave the apparent displacement of all points on the background viewed through the flow. Once this displacement field was obtained, a ray-tracing algorithm was implemented to reconstruct the refractive index of the center plane of the jet. Then, the Gladstone-Dale and ideal gas relations were combined and used to calculate the temperature of the center plane. Reynolds number, based on the jet diameter, was held constant at 6,000 for all cases, and steady state nozzle temperature was varied from 57°C to 135°C. Reconstructed temperature distributions were validated using K-type thermocouple measurements by allowing the system to reach steady state before acquiring data. Average agreement of 4–6% was observed between thermocouple and BOS measurements for axial locations of at least 30 mm downstream. Due to experimental error, accuracy decreases as axial location moves towards the nozzle, and as nozzle temperature increases. Improvements to the setup are being considered to improve the agreement in low accuracy regions. Further, this technique has the potential to be used to determine the temperatures in open and optically accessible closed reactive flows. Having information about near wall temperature in closed reactive flows will give insight into wall convective heat transfer characterization and will also help benchmark combustion based numerical models in applications such as gas turbines.

Influence of Ambient Conditions on an Aeroderivative Gas Turbine Based Cogeneration Plant — A Comparison of Numerical Simulation With Field Performance Data

2000 ◽  
Author(s):  
Carlo Carcasci ◽  
Bruno Facchini ◽  
Francesco Grillo
Keyword(s):  
Numerical Simulation ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Field Performance ◽  
Performance Data ◽  
Plant Performance ◽  
Air Cooling ◽  
Ambient Conditions ◽  
Compressor Inlet

Gas turbine performances are directly related to outside conditions. The use of gas turbines in combined gas-steam power plants, also applied to cogeneration, increases performance dependence by outside conditions, because plants boundary conditions become more complex. In recent years, inlet air cooling systems have been introduced to control air temperature and humidity at compressor inlet resulting in an increase in plant power and efficiency. In this paper, the dependence of outside conditions for an existing cogenerative plant, located in Tuscany (Italy), is studied. The plant is equipped with two GE-LM6000 aeroderivative gas-turbines coupled with a three pressure level heat recovery steam generator, cogenerative application being related to the industrial district. The ambient temperature has been found to be the most important factor affecting the plant performance, but relative air humidity variation also has considerable effects. The field performance data are compared with a numerical simulation. The simulation results show a good agreement with the field performance data. The simulation allows evaluation of design and off-design plant performance and can become a useful tool to study the outside condition influence on power plant performance.

Options to Maximize Power Output for Merchant Plants in Combined Cycle Applications

2001 ◽  
Author(s):  
Rattan Tawney ◽  
Cheryl Pearson ◽  
Mona Brown
Keyword(s):  
Power Output ◽  
Gas Turbines ◽  
Life Cycle Cost ◽  
Peak Power ◽  
Power Plants ◽  
High Reliability ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Plant Design ◽  
Capital Costs

Deregulation and growth in the power industry are causing dramatic changes in power production and distribution. The demand for peak power and potentially high revenues due to premium electricity rates has attracted independent developers to the concept of Merchant Power Plants (MPPs). Over 100,000 MW of greenfield capacity is currently being developed through approximately 200 merchant plants in North America. These MPPs will have no captive customers or long-term power purchase agreements, but will rely on selling electricity into a volatile electricity spot market. Because of this, MPPs need the capability to export as much power as possible on demand. MPPs must also have the capability to produce significant assets in order to compete in the marketplace, based on both technical and commercial operation factors such as value engineering, life-cycle cost management, and information technology. It is no surprise then, that almost all merchant project developers have specified combined cycle (CC) technology. The CC power plant offers the highest thermal efficiency of all electric generating systems commercially available today. It also exhibits low capital costs, low emissions, fuel and operating flexibility, low operation and maintenance costs, short installation schedule, and high reliability/availability. However, since gas turbines (GTs) are the basis for CC power plants, these plants experience power output reductions in the range of 10 to 15 percent during summer months, the period most associated with peak power demand. In order to regain this loss of output as well as to provide additional power to meet peak demands, the most common options are GT inlet fogging, GT steam injection, and heat recovery steam generator (HRSG) supplemental firing. This paper focuses on plant design, cycle performance, and the economics of plant configuration associated with these options. Guidelines are presented in this paper to assist the owner in selecting power enhancement options for the MPP that will maximize their Return on Equity (ROE).

Second Law Efficiency of the Rankine Bottoming Cycle of a Combined Cycle Power Plant

2008 ◽  
Author(s):  
S. Can Gulen ◽  
Raub W. Smith
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Power Output ◽  
Gas Turbines ◽  
Power Plants ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Second Law ◽  
Modeling Tools ◽  
Combined Cycle Power Plant

A significant portion of the new electrical generating capacity installed in the past decade has employed heavy-duty gas turbines operating in a combined cycle configuration with a steam turbine bottoming cycle. In these power plants approximately one third of the power is generated by the bottoming cycle. To ensure that the highest possible combined cycle efficiency is realized it is important to develop the combined cycle power plant as a system. Doing so requires a solid understanding of the efficiency entitlement of both, topping and bottoming, cycles separately and as a whole. This paper describes a simple but accurate method to estimate the Rankine bottoming cycle power output directly from the gas turbine exhaust exergy utilizing the second law of thermodynamics. The classical first law approach, i.e. the heat and mass balance method, requires lengthy calculations and complex computer-based modeling tools to evaluate Rankine bottoming cycle performance. In this paper, a rigorous application of the fundamental thermodynamic principles embodied by the second law to the major cycle components clearly demonstrates that the Rankine cycle performance can be accurately represented by several key parameters. The power of the second law approach lies in its ability to highlight the theoretical entitlement and state-of-the-art design performances simultaneously via simple, fundamental relationships. By considering economically and technologically feasible upper limits for the key parameters, the maximum achievable bottoming cycle power output is readily calculable for any given gas turbine from its exhaust exergy.

scholarly journals Application of RQL Coal Combustor Technology to Large Utility Gas Turbines

1993 ◽  
Author(s):  
C. Wilkes ◽  
R. A. Wenglarz ◽  
P. J. Hart ◽  
H. C. Mongia
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Heat Engine ◽  
Combined Cycle ◽  
Pulverized Coal ◽  
Department Of Energy ◽  
Cycle Performance ◽  
Proof Of Concept ◽  
Combustion System

This paper describes the application of Allison’s rich-quench-lean (RQL) coal combustor technology to large utility gas turbines in the 100 MWe+ class. The RQL coal combustor technology was first applied to coal derived fuels in the 1970s and has been under development since 1986 as part of a Department of Energy (DOE)-sponsored heat engine program aimed at proof of concept testing of coal-fired gas turbine technology. The 5 MWe proof of concept engine/coal combustion system was first tested on coal water slurry (CWS); it is now being prepared for testing on dry pulverized coal. A design concept to adapt the RQL coal combustor technology developed under the DOE program to large utility-sized gas turbines has been proposed for a Clean Coal V program. The engine and combustion system modifications required for application to coal-fueled combined cycle power plants using 100 MWe+ gas turbines are described. Estimates for emissions and cycle performance are given. Included are comparisons with a conventional pulverized coal plant that illustrates the advantages of incorporating a gas turbine on cycle efficiency and emission rate.

scholarly journals Gas Turbine Arekret-Cycle Simulation Modeling for Training and Educational Purposes

2019 ◽  
Vol 5 (4) ◽  
Author(s):  
Emmanuel O. Osigwe ◽  
Pericles Pilidis ◽  
Theoklis Nikolaidis ◽  
Suresh Sampath
Keyword(s):  
Steady State ◽  
Gas Turbine ◽  
Case Studies ◽  
Cycle Performance ◽  
Closed Cycle ◽  
Design Point ◽  
Modeling Approach ◽  
Cycle Simulation ◽  
Component Design ◽  
And Performance

This paper presents the modeling approach of a multipurpose simulation tool called gas turbine Arekret-cycle simulation (GT-ACYSS); which can be utilized for the simulation of steady-state and pseudo transient performance of closed-cycle gas turbine plants. The tool analyzes the design point performance as a function of component design and performance map characteristics predicted based on multifluid map scaling technique. The off-design point is analyzed as a function of design point performance, plant control settings, and a wide array of other off-design conditions. GT-ACYSS can be a useful educational tool since it allows the student to monitor gas path properties throughout the cycle without laborious calculations. It allows the user to have flexibility in the selection of four different working fluids, and the ability to simulate various single-shaft closed-cycle configurations, as well as the ability to carry out preliminary component sizing of the plant. The modeling approach described in this paper has been verified with case studies and the trends shown appeared to be reasonable when compared with reference data in the open literature, hence, can be utilized to perform independent analyses of any referenced single-shaft closed-cycle gas turbine plants. The results of case studies presented herein demonstrated that the multifluid scaling method of components and the algorithm of the steady-state analysis were in good agreement for predicting cycle performance parameters (such as efficiency and output power) with mean deviations from referenced plant data ranging between 0.1% and 1% over wide array of operations.

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