The CFD Design and Optimisation of a 100 kW Hydrogen Fuelled mGT

2020 ◽  
Author(s):  
Cedric Devriese ◽  
Gijs Penninx ◽  
Guido de Ruiter ◽  
Rob Bastiaans ◽  
Ward De Paepe
Keyword(s):  
Combustion Chamber ◽  
Power Plants ◽  
Internal Combustion Engines ◽  
Cone Angle ◽  
Electricity Production ◽  
Design Parameters ◽  
Inlet Temperature ◽  
Large Power ◽  
Power Sources ◽  
The Impact

Abstract Against the background of a growing deployment of renewable electricity production, like wind and solar, the demand for energy storage will only increase. One of the most promising ways to cover the medium to long-term storage is to use the excess electricity to produce hydrogen via electrolysis. In a modern energy grid, filled with intermittent power sources and ever-increasing problems to construct large power plants in densely populated areas, a network of Decentralised Energy Systems (DES) seems more logical. Therefore, the importance of research into the design of a small to medium-sized hydrogen fuelled micro Gas Turbine (mGT) unit for efficient, local heat and electricity production becomes apparent. To be able to compete with Reciprocating Internal Combustion Engines (RICEs), the mGT needs to reach 40% electrical efficiency. To do so, there are two main challenges; the design of an ultra-low NOX hydrogen combustor and a high Turbine Inlet Temperature (TIT) radial turbine. In this paper, we report on the progress of our work towards that goal. First, an improvement of the initial single-nozzle swirler (swozzle) combustor geometry was abandoned in favour of a full CFD (steady RANS) design and optimisation of a micromix type combustion chamber, due to its advantages towards NOx-emission reduction. Second, a full CFD design and optimisation of the compressor and turbine is performed. The improved micromix combustor geometry resulted in a NOx level reduction of more than 1 order of magnitude compared to our previous swozzle design (from 1400 ppm to 250 ppm). Moreover, several design parameters, such as the position and diameter of the hydrogen injection nozzle and the Air Guiding Panel (AGP) height, have been optimized to improve the flow patterns. Next to the combustion chamber, CFD simulations of the compressor and turbine matched the 1D performance calculations and reached the desired performance goals. A CFD analysis of the impact of the tip gap and exhaust diffuser cone angle led to a choice of these parameters that improved the compressor and turbine performance with a limited loss in efficiency.

scholarly journals Trends in OMI NO<sub>2</sub> observations over the United States: effects of emission control technology and the economic recession

2012 ◽  
Vol 12 (24) ◽  
pp. 12197-12209 ◽  
Author(s):  
A. R. Russell ◽  
L. C. Valin ◽  
R. C. Cohen
Keyword(s):  
United States ◽  
Power Plants ◽  
Economic Recession ◽  
The United States ◽  
Retrieval Algorithm ◽  
Vertical Column ◽  
Large Power ◽  
Mobile Sources ◽  
Light Duty Vehicle ◽  
The Impact

Abstract. Observations of tropospheric NO2 vertical column densities over the United States (US) for 2005–2011 are evaluated using the OMI Berkeley High Resolution (BEHR) retrieval algorithm. We assess changes in NO2 on day-of-week and interannual timescales to assess the impact of changes in emissions from mobile and non-mobile sources on the observed trends. We observe consistent decreases in cities across the US, with an average total reduction of 32 ± 7% across the 7 yr. Changes for large power plants have been more variable (−26 ± 12%) due to regionally-specific regulation policies. An increasing trend of 10–20% in background NO2 columns in the northwestern US is observed. We examine the impact of the economic recession on emissions and find that decreases in NO2 column densities over cities were moderate prior to the recession (−6 ± 5% yr−1), larger during the recession (−8 ± 5% yr−1), and then smaller after the recession (−3 ± 4% yr−1). Differences in the trends observed on weekdays and weekends indicate that prior to the economic recession, NO2 reductions were dominated by technological improvements to the light-duty vehicle fleet but that a decrease in diesel truck activity has contributed to emission reductions since the recession. We use the satellite observations to estimate a 34% decrease in NO2 from mobile sources in cities for 2005–2011 and use that value to infer changes in non-mobile sources. We find that reductions in NO2 from non-mobile sources in cities have been both more modest and more variable than NO2 reductions from mobile sources (−10 ± 13%).

Conceptual Design Using Generic Object Inheritance

2008 ◽  
Author(s):  
Olof Johansson ◽  
Henric Andersson ◽  
Petter Krus
Keyword(s):  
Conceptual Design ◽  
Power Plants ◽  
Design Parameters ◽  
Product Model ◽  
Complex Products ◽  
Business Jet ◽  
Product Models ◽  
Multiple Copies ◽  
The Impact

Conceptual design for complex products like aircraft and power plants requires a considerable effort since the product models become very large if they are to cover all important aspects for different stakeholders. To cope with this overall effort, designers have to rely on legacy designs and reuse, and improve the product concepts incrementally between product generations. This paper describes a generalized inheritance mechanism we call generic object inheritance that enables quick reuse and modification of conceptual product models at any level in their hierarchical break down structures. By facilitating reuse of conceptual models of previously well studied products, more time can be spent on developing the parts that contain the edge of a new product generation. This enables keeping the modified concepts in context of a complete analyzable product model where the impact of changes can be studied without having to maintain multiple copies of the same object structures. The paper describes how generic object inheritance is used for developing the next version of a conceptual product model of a small business jet, while reusing the essential parts of the previous version with minor modifications to design parameters and substructures. The design and core mechanisms of generic object inheritance are briefly described, and illustrated with examples from the case study.

Thermodynamic Modeling and Optimization of Cogeneration Heat and Power System Using Evolutionary Algorithm (Genetic Algorithm)

2010 ◽  
Author(s):  
P. Ebrahimi ◽  
H. Karrabi ◽  
S. Ghadami ◽  
H. Barzegar ◽  
S. Rasoulipour ◽  
...  
Keyword(s):  
Genetic Algorithm ◽  
Combustion Chamber ◽  
Objective Function ◽  
Evolutionary Algorithm ◽  
Gas Turbine ◽  
Saturated Steam ◽  
Design Parameters ◽  
Inlet Temperature ◽  
Decision Variables ◽  
Isentropic Efficiency

A gas-turbine cogeneration system with a regenerative air preheater and a single-pressure exhaust gas boiler serves as an example for application of CHP Plant. This CHP plant which can provide 30 MW of electric power and 14kg/s saturated steam at 20 bars. The plant is comprised of a gas turbine, air compressor, combustion chamber, and air pre-heater as well as a heat recovery steam generator (HRSG). The design Parameters of the plant, were chosen as: compressor pressure ratio (rc), compressor isentropic efficiency (ηac), gas turbine isentropic efficiency (ηgt), combustion chamber inlet temperature (T3), and turbine inlet temperature (T4). In order to optimally find the design parameters a thermoeconomic approach has been followed. An objective function, representing the total cost of the plant in terms of dollar per second, was defined as the sum of the operating cost, related to the fuel consumption. Subsequently, different pars of objective function have been expressed in terms of decision variables. Finally, the optimal values of decision variables were obtained by minimizing the objective function using Evolutionary algorithm such as Genetic Algorithm. The influence of changes in the demanded power on the design parameters has been also studied for 30, 40 MW of net power output.

scholarly journals The Economic Effect of the Pandemic in the Energy Sector on the Example of Listed Energy Companies

Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 158
Author(s):  
Edyta Rutkowska-Tomaszewska ◽  
Aleksandra Łakomiak ◽  
Marta Stanisławska
Keyword(s):  
Power Plants ◽  
Stock Exchange ◽  
Research Question ◽  
Economic Effect ◽  
Financial Statements ◽  
Energy Sector ◽  
Electricity Production ◽  
Warsaw Stock Exchange ◽  
Energy Companies ◽  
The Impact

The study posed a research question: did the situation caused by COVID-19 affect the economic position of energy companies? The aim of the study is to investigate the impact of the situation of the epidemic state introduced in 2020 on the activities of the efficiency of energy sector companies. The subject of the research will be the ten largest Polish power plants in terms of electricity production, including four capital groups to which they belong. Financial data from 2014 to 2020 will be used for the research. To test the effectiveness, the tools of the ratio analysis will be used. The analysis of the financial statements in terms of investments in manufacturing activities confirms the hypothesis that companies investing in new solutions and technologies will be best prepared for an exceptional situation. The results of the research show that those capital groups which in the period preceding the outbreak of the epidemic made the largest investment outlays and at the same time their financial ratios and market valuation on the Warsaw Stock Exchange were the highest, they also achieved the highest financial results during the pandemic—they had the most favorable economic situation.

CCPP Operational Flexibility Extension Below 30% Load Using Reheat Burner Switch-Off Concept

2015 ◽  
Author(s):  
Dirk Therkorn ◽  
Martin Gassner ◽  
Vincent Lonneux ◽  
Mengbin Zhang ◽  
Stefano Bernero
Keyword(s):  
Gas Turbine ◽  
Power Plants ◽  
Fast Response ◽  
Combined Cycle ◽  
Pollutant Emissions ◽  
Inlet Temperature ◽  
Operational Flexibility ◽  
Part Load ◽  
Combustion Technology ◽  
The Impact

Highly competitive and volatile energy markets are currently observed, as resulting from the increased use of intermittent renewable sources. Gas turbine combined cycle power plants (CCPP) owners therefore require reliable, flexible capacity with fast response time to the grid, while being compliant with environmental limitations. In response to these requirements, a new operation concept was developed to extend the operational flexibility by reducing the achievable Minimum Environmental Load (MEL), usually limited by increasing pollutant emissions. The developed concept exploits the unique feature of the GT24/26 sequential combustion architecture, where low part load operation is only limited by CO emissions produced by the reheat (SEV) burners. A significant reduction of CO below the legal limits in the Low Part Load (LPL) range is thereby achieved by individually switching the SEV burners with a new operation concept that allows to reduce load without needing to significantly reduce both local hot gas temperatures and CCPP efficiency. Comprehensive assessments of the impact on operation, emissions and lifetime were performed and accompanied by extensive testing with additional validation instrumentation. This has confirmed moderate temperature spreads in the downstream components, which is a benefit of sequential combustion technology due to the high inlet temperature into the SEV combustor. The following commercial implementation in the field has proven a reduction of MEL down to 26% plant load, corresponding to 18% gas turbine load. The extended operation range is emission compliant and provides frequency response capability at high plant efficiency. The experience accumulated over more than one year of successful commercial operation confirms the potential and reliability of the concept, which the customers are exploiting by regularly operating in the LPL range.

Computational and Experimental Analysis of Direct CNG Injection and Mixture Formation in a Spark Ignition Research Engine

2010 ◽  
Author(s):  
Mirko Baratta ◽  
Andrea E. Catania ◽  
Francesco C. Pesce
Keyword(s):  
Numerical Model ◽  
Combustion Chamber ◽  
Cone Angle ◽  
Combustion Process ◽  
Laser Induced Fluorescence ◽  
Operating Conditions ◽  
Design Parameters ◽  
Experimental Investigations ◽  
Injection Timing ◽  
Mixture Formation

Direct injection (DI) of compressed natural gas (CNG) under high pressure conditions is a topic of great interest, owing to its potential for improving SI engine performance and fuel consumption. However, relevant technical difficulties have yet to be resolved in order to stabilize combustion process, especially for stratified engine operating conditions. The present paper is focused on experimental and numerical investigations of the jet formation and fuel-air mixing process in a research optical-access single-cylinder engine. The engine is based on the multi-cylinder engine under development within the European Community (EC) VII Framework Program (FP) InGAS Integrated Project, and features a centrally mounted poppet-valve injector on a pent-roof combustion chamber with a bowl in piston. Experimental investigations were made by means of the planar laser-induced fluorescence technique, and revealed a cycle-to-cycle jet shape variability. In particular, for specific cylinder pressure values at the start of injection, the jet can adhere to chamber walls for a relevant number of cycles, leading to an ‘umbrella-like’ shape. This can change the mixing capabilities of the combustion chamber and cause instabilities in the combustion process. The mentioned behaviour is strongly dependent not only on the injection and cylinder pressures, but also on important design parameters, such as needle cone angle and in-chamber injector protrusion. For this reason, in order to obtain a deep insight into the injected gas behaviour on an average cycle basis, the experimental investigation was supported by a numerical analysis. Simulations were carried out by an optimized variable-density finite-volume numerical model which was built within the Star-CD environment. A previously developed and validated ‘virtual injector’ model was implemented. The outcomes of the numerical model were compared to laser-induced fluorescence images, for both stratified- and homogeneous-charge engine operating conditions and a good agreement was obtained, substantiating the reliability of the applied computational model. Then, the effects of the injector protrusion in the combustion chamber and of injection timing were analyzed, and their impact on jet stability and mixture-formation process was analyzed.

Second Law Based Optimization of Micro Gas Turbine (MGT) Cycle for Residental Application Using a Genetic Algorithm

2010 ◽  
Author(s):  
N. Enadi ◽  
P. Ahmadi ◽  
F. Atabi ◽  
M. R. Heibati
Keyword(s):  
Genetic Algorithm ◽  
Combustion Chamber ◽  
Objective Function ◽  
Gas Turbine ◽  
Operating Cost ◽  
Saturated Steam ◽  
Design Parameters ◽  
Inlet Temperature ◽  
Decision Variables ◽  
Isentropic Efficiency

Exergoeconomic analysis helps designers to find ways to improve the performance of a system in a cost effective way. Most of the conventional exergoeconomic optimization methods are iterative in nature and require the interpretation of the designer at each iteration. In this work, a cogeneration system that produces 50MW of electricity and 33.3 kg/s of saturated steam at 13 bars is optimized using exergoeconomic principles and evolutionary programming such as Genetic algorithm. The optimization program is developed in Matlab Software programming. The plant is comprised of a gas turbine, air compressor, combustion chamber, and air pre-heater as well as a heat recovery steam generator (HRSG).The design Parameters of the plant, were chosen as: compressor pressure ratio (rc), compressor isentropic efficiency (ηac), gas turbine isentropic efficiency (ηgt), combustion chamber inlet temperature (T3), and turbine inlet temperature (T4). In order to optimally find the design parameters a thermoeconomic approach has been followed. An objective function, representing the total cost of the plant in terms of dollar per second, was defined as the sum of the operating cost, related to the fuel consumption. Subsequently, different pars of objective function have been expressed in terms of decision variables. Finally, the optimal values of decision variables were obtained by minimizing the objective function using Evolutionary algorithm such as Genetic Algorithm. The influence of changes in the demanded power on the design parameters has been also studied for 50, 60, 70 MW of net power output.

Thermoeconomic Optimization of Gas Turbine Combined Heat and Power System in a Paper Mill

2007 ◽  
Author(s):  
Sepehr Sanaye ◽  
Maziar Ghazinejad
Keyword(s):  
Combustion Chamber ◽  
Objective Function ◽  
Gas Turbine ◽  
Paper Mill ◽  
Combined Heat And Power ◽  
Saturated Steam ◽  
Design Parameters ◽  
Inlet Temperature ◽  
Decision Variables ◽  
Isentropic Efficiency

Located in the South of Iran, Jiroft Paper Mill Company requires an integrated combined heat and power plant, which can provide 50 MW of electric power and 100 ton/hr saturated steam at 13 bars, to produce paper from an adjacent eucalyptus forest. The plant is comprised of a gas turbine, air compressor, combustion chamber, and air preheater as well as a heat recovery steam generator (HRSG). The design Parameters of the plant were chosen as: compressor pressure ratio (rc), compressor isentropic efficiency (ηAC), gas turbine isentropic efficiency (ηT), combustion chamber inlet temperature (T3), and turbine inlet temperature (T4). In order to optimally find the design parameters a thermoeconomic approach has been followed. An objective function representing the total cost of the plant in terms of dollar per second, was defined as the sum of the operating cost related to the fuel consumption, and the capital investment which stands for equipment purchase and maintenance costs and the cost, corresponding to the exergy destruction in various components. Subsequently, different parts of the objective function have been expressed in terms of decision variables. Finally, the optimal values of decision variables were obtained by minimizing the objective function using sequential quadratic programming (SQP). The influence of changes in the demanded power and steam on the design parameters have been also studied for 40, 50, 60, and 70 MW of net power output, and 100, 120, 150, ton/hr of saturated steam mass flow rate.

Exergy, Exergoeconomic and Exergoenvironomic Analyses of Selected Gas Turbine Power Plants in Nigeria

2014 ◽  
Author(s):  
Richard Olayiwola Fagbenle ◽  
Sunday Sam Adefila ◽  
Sunday Oyedepo ◽  
Moradeyo Odunfa
Keyword(s):  
Environmental Impact ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Co2 Emissions ◽  
Thermodynamic Analysis ◽  
Power Plants ◽  
Energy Systems ◽  
Energy Utilization ◽  
Inlet Temperature ◽  
Exergy Destruction

Energy supply trends as well as environmental regulations and climate change issues have made it necessary to closely scrutinize the way energy is utilized. Efficient energy utilization thus requires paying more attention to accurate and advanced thermodynamic analysis of thermal systems. Hence, methods aimed at evaluating the performances of energy systems take into account the Energy, Environment and Economics. Therefore, the first and second law of thermodynamics combined with economics and environmental impact represents a very powerful tool for the systematic study and optimization of energy systems. In this study, a thermodynamic analysis of eleven selected gas turbine power plants in Nigeria was carried out using the first and second laws of thermodynamics, economic and environmental impact concepts. Exergetic, exergo-economic and exergo-environmental analyses were conducted using operating data obtained from the power plants to determine the exergy destruction and exergy efficiency of each major component of the gas turbine in each power plant. The exergy analysis confirmed that the combustion chamber is the most exergy destructive component compared to other cycle components as expected. The percentage exergy destruction in combustion chamber varied between 86.05 and 94.6%. Increasing the gas turbine inlet temperature (GTIT), the exergy destruction of this component can be reduced. Exergo-economic analysis showed that the cost of exergy destruction is high in the combustion chamber and by increasing the GTIT effectively decreases this cost. The exergy costing analysis revealed that the unit cost of electricity produced in the plants ranged from cents 1.88/kWh (₦2.99/kWh) to cents 5.65/kWh (₦8.98/kWh). Exergo-environmental analysis showed that the CO2 emissions varied between 100.18 to 408.78 kgCO2/MWh while cost rate of environmental impact varied from 40.18 $/h (N6, 388.62/h) to 276.97 $/h (N44, 038.23/h). The results further showed that CO2 emissions and cost of environmental impact decrease with increasing GTIT.

Thermal and Economic Analysis of Besat Steam Power Plant Repowering

2006 ◽  
Author(s):  
Sepehr Sanaye ◽  
Younes Hamzeie ◽  
Mohammad Reza Malekian ◽  
Mohammad Reza Sohrabi
Keyword(s):  
Power Generation ◽  
Power Plant ◽  
Gas Turbine ◽  
Capital Investment ◽  
Power Plants ◽  
Design Parameters ◽  
Inlet Temperature ◽  
Steam Power ◽  
Total Cost ◽  
Steam Power Plants

There is a rapid growth of electricity consumption in the world. This problem needs enough resources for capital investment for construction of new power plants and/or making all efforts to increase the thermal efficiency of existing power generation cycles. Therefore this situation has lead power generation industries to repower and modify the existing steam power plants which are constructed in the recent three or four decades. In this paper an important method for repowering of old steam power plants which uses a gas turbine is analyzed. Hot Wind Box (HWB) repowering method was technically and economically evaluated to repower the Besat steam power plant. This power plant was constructed and exploited in 1967 in Tehran. The optimum design parameters such as gas turbine power output, compressor and turbine isentropic efficiency, pressure ratio, and the ratio of turbine inlet temperature to compressor inlet temperature were found by defining an objective function the total cost per unit of repowered plant power output and using numerical search optimization technique for its minimizing. The objective function, the total cost, included initial or capital investment, operation and maintenance costs during plant life cycle. The numerical values of optimum design parameters and the results of the sensitivity analysis are reported.

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