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Hoseyn Sayyaadi - One of the best experts on this subject based on the ideXlab platform.
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heat and mass recirculations strategies for improving the thermal efficiency and environmental emission of a Gas turbine Cycle
Applied Thermal Engineering, 2017Co-Authors: Mohammad Tahmasebzadehbaie, Hoseyn Sayyaadi, Ali Sohani, Mona Zamani PedramAbstract:Abstract Thermal efficiency and emission of a Gas-turbine Cycle were improved through consideration of heat and mass recirculations. In this regard, three potential scenarios were investigated: using lone mass circulation, only heat recirculation, and both types of recirculation at the same time. In each scenario, the maximum potential improvement was found by multi-objective optimization. Furthermore, in the case of only heat circulation scenario, the best heat recirculator was chosen by comparing a tubular with a plate-fin heat exchanger (PFHE) a well-known decision-making method which is called analytical hierarchy process (AHP). Finally, AHP method was employed again to select the superior scenario for improving the Gas Cycle. According to the results, the best scenario was the scenario in which heat recirculation with PFHE was used in the absence of mass recirculation. In this scenario, thermal efficiency and NOx emission were improved 4.20 and 17.94%, respectively. The payback time of the investment of the modification was also about 62 days. Moreover, due to the shortage of power in the case of mass recirculation, this scenario was found to be desirable when there is extra capacity in power generation, and the goal is reducing emissions as much as possible.
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A conceptual design of a dual hydrogen-power generation plant based on the integration of the Gas-turbine Cycle and copper chlorine thermochemical plant
International Journal of Hydrogen Energy, 2017Co-Authors: Hoseyn SayyaadiAbstract:Abstract The Cu Cl hydrogen production plants are one of the promising hydrogen production plants that have a higher conversion efficiency compared to water electrolyzing system. However, these plant requires a high-temperature source of thermal energy in the order of 530–560 °C. Such high-temperature source of thermal energy is aimed to be provided from the fourth-generation nuclear reactor. Due to a shortage in the technology of the fourth-generation nuclear reactors in developing countries, one alternative to provide such high temperature of thermal energy is the exhaust Gasses of Gas-turbine stations. In this paper, a conceptual design for dual production Cycle of power and hydrogen-based on the integration of Gas Cycles into the Cu Cl thermochemical hydrogen plant was examined. The main product of the Cycle was supposed to be 130,000 kg per day. However, the Gas Cycle is the upper Cycle of the dual production plant; the electric power was considered as the byproduct of this plant. The aim was to present a conceptual design of the combined plant with the lowest cost of produced hydrogen and highest conversion efficiency, on the one hand, and the highest and cheapest cost of electric power, on the other hand. In this regard, the concept of pinch analysis and multi-objective optimization was conducted. Moreover, a decision-making tool was employed to find the best combination of Gas turbines for the configuration of the upstream Cycle. Different configurations of the upper Gas Cycle were examined by 39 types of commercial Gas turbine. The final design of the combined plant could generate hydrogen with 51.3% thermal efficiency, 55.2% exergetic efficiency, and the cost of 4.02 $ kg−1. This plant used four Gas turbine's model Mitsubishi HI 501 F with 735 MW capacity of electric power generation at the cost of 0.10 $ kWh−1.
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efficiency enhancement and nox emission reduction of a turbo compressor Gas engine by mass and heat recirculations of flue Gases
Applied Thermal Engineering, 2016Co-Authors: Mohammad Tahmasebzadehbaie, Hoseyn SayyaadiAbstract:Abstract A simple Turbo-Compressor model-GE MS 6001B PLTG-PLN-Sektor Tello Makassar with 30 MW power generation, 27.71% thermal efficiency and 26.07 exergy efficiency (at ISO condition) was considered for the efficiency enhancement and emission reduction. A cross flow plate-fin heat exchanger (PFHE) as an air pre-heater (heat recirculation) along with direct recirculation of a part of flue Gases into the combustion chamber (mass recirculation) were considered as modifications of original turbo-compressor Gas engine to increase thermal efficiency and reduce NO x emission. In a multi-objective optimization process, geometric and thermal specifications of the plate-fin heat exchanger as well as the percentage of the recirculated flue Gas were obtained. The payback time for the capital investment of the heat exchanger and NO x emission were minimized simultaneously while the exergetic efficiency of the Gas Cycle was maximized and a frontier of optimal solution called as the Pareto frontier was obtained in objective space. The final optimal solution was selected from the Pareto frontier using three different decision-making methods, including the fuzzy Bellman-Zadeh, TOPSIS and LINMAP methods. It was shown that the best results in comparison to the simple Cycle led to 34.7% reduction in NO x emission and 5.8% improvement in exergy efficiency (as difference).
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efficiency enhancement of a Gas turbine Cycle using an optimized tubular recuperative heat exchanger
Energy, 2012Co-Authors: Hoseyn Sayyaadi, Reza MehrabipourAbstract:A simple Gas turbine Cycle namely as the Kraftwerk Union AG unit including a Siemens Gas turbine model V93.1 with 60 MW nominal power and 26.0% thermal efficiency utilized in the Fars power plant located is considered for the efficiency enhancement. A typical tubular vertical recuperative heat exchanger is designed in order to integrate into the Cycle as an air pre-heater for thermal efficiency improvement. Thermal and geometric specifications of the recuperative heat exchanger are obtained in a multi-objective optimization process. The exergetic efficiency of the Gas Cycle is maximized while the payback time for the capital investment of the recuperator is minimized. Combination of these objectives and decision variables with suitable engineering and physical constraints makes a set of the MINLP optimization problem. Optimization programming is performed using the NSGA-II algorithm and Pareto optimal frontiers are obtained in three cases including the minimum, average and maximum ambient air temperatures. In each case, the final optimal solution has been selected using three decision-making approaches including the fuzzy Bellman-Zadeh, LINMAP and TOPSIS methods. It has been shown that the TOPSIS and LINMAP decision-makers when applied on the Pareto frontier which is obtained at average ambient air temperature yields best results in comparison to other cases.
Bernhard Hoffschmidt - One of the best experts on this subject based on the ideXlab platform.
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Choice of solar share of a hybrid power plant of a central receiver system and a bioGas plant in dependency of the geographical latitude
Proceedings of the World Renewable Energy Congress – Sweden 8–13 May 2011 Linköping Sweden, 2011Co-Authors: Spiros Alexopoulos, Christoph Rau, Bernhard Hoffschmidt, Joost SattlerAbstract:The potential of renewable energies varies significantly from North to South Europe. Southern Europe has a high solar potential and is ideal for the implementation of solar concentrated power plants. To this group of solar thermal power systems belong the solar tower, parabolic trough, solar dish and linear Fresnel systems. North European countries, especially the Scandinavian countries, have a high biomass and hydropower potential. This paper focuses on calculation of the power production for hybrid systems of solar tower with Gas turbine in Southern Europe and bioGas-only operation in Northern Europe. The solar tower system consists of a heliostat field, which concentrates direct solar irradiation on an open volumetric central receiver. The receiver heats up ambient air to temperatures of around 700°C. The hot air's heat energy is transferred to a steam Rankine Cycle in a heat recovery steam generator (HRSG). The steam drives a steam turbine, which in turn drives a generator for producing electricity. In order to increase the operational hours of a solar tower power plant, a heat storage system and/ or hybridization may be considered. The advantage of solar-fossil hybrid power plants, compared to solar-only systems, lies in low additional investment costs due to an adaptable solar share and reduced technical and economical risks. On sunny days the hybrid system operates in a solar-only mode with the central receiver and on cloudy days and at night with the Gas turbine only. As an alternative to methane Gas, environmentally neutral bioGas can be used for operating the Gas turbine. Hence, the hybrid system is operated to 100% from renewable energy sources. An advanced software tool library has been developed for modelling such solar hybrid power plants. This library includes the components of the solar-heated hot Gas Cycle and the steam Cycle. Moreover, a choice of different Gas turbine and duct burner components is given. When developing a simulation model for the calculation of a small hybrid power plant, components from the library are inserted into the model. The software tool features the possibility of either calculating the energy output of individual operating points or of time intervals in the range of days up to an entire year. With this simulation tool, hybrid solar tower systems are calculated for various locations with high solar potential within Europe. In addition, locations in North Scandinavian countries with high biomass potential are investigated and power plants with bioGas as fuel without solar input are calculated.
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Simulation and control of solar thermal power plants
Renewable energy & power quality journal, 2010Co-Authors: Jan Gall, Dirk Abel, Nils Ahlbrink, Robert Pitz-paal, Joel Andersson, Moritz Diehl, Christiano Boura, Mark Schmitz, Bernhard HoffschmidtAbstract:In this paper, first the overall modeling approach for an optimized control of a hot-Gas Cycle for solar thermal power plants in the Modelica language is pointed out. The emphasis of the modeling work lies on the development of dynamic component models to be used in control systems. Depending on the control task, the discretization of the models has to be adapted. Main components of the hot-Gas Cycle are the solar thermal receiver and the storage system. The steam Cycle is preliminarily only included as heat sink. Second, for control purposes a linear model-based controller (MPC) was implemented in Modelica based on an external state-of-the-art QP solver linked to the Modelica model. The performance of the MPC is compared with a basic automation scheme based on classical PID controllers.
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Optimized Control of Hot-Gas Cycle for Solar Thermal Power Plants
Proceedings of the 7 International Modelica Conference Como Italy, 2009Co-Authors: Jan Gall, Dirk Abel, Nils Ahlbrink, Robert Pitz-paal, Joel Andersson, Moritz Diehl, Christiano Boura, Mark Schmitz, Bernhard HoffschmidtAbstract:In this paper, the overall modeling approach for an optimized control of a hot-Gas Cycle with its different components for solar thermal power plants is pointed out. For control purposes a linear model-based controller (MPC) was implemented in Modelica based on an external state-of-the-art QP solver linked to the Modelica model.
James Wadsley - One of the best experts on this subject based on the ideXlab platform.
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in n out the Gas Cycle from dwarfs to spiral galaxies
The Astrophysical Journal, 2016Co-Authors: Charlotte Christensen, Romeel Dave, Fabio Governato, Andrew Pontzen, Alyson Brooks, Ferah Munshi, Thomas R Quinn, James WadsleyAbstract:We examine the scalings of galactic outflows with halo mass across a suite of 20 high-resolution cosmological zoom galaxy simulations covering halo masses in the range 10^9.5-10^12\M. These simulations self-consistently generate outflows from the available supernova energy in a manner that successfully reproduces key galaxy observables, including the stellar mass–halo mass, Tully–Fisher, and mass–metallicity relations. We quantify the importance of ejective feedback to setting the stellar mass relative to the efficiency of Gas accretion and star formation. Ejective feedback is increasingly important as galaxy mass decreases; we find an effective mass loading factor that scales as v-circ-2.2, with an amplitude and shape that are invariant with redshift. These scalings are consistent with analytic models for energy-driven wind, based solely on the halo potential. Recycling is common: about half of the outflow mass across all galaxy masses is later reaccreted. The recycling timescale is typically ~1 Gyr, virtually independent of halo mass. ReCycled material is reaccreted farther out in the disk and with typically ~2–3 times more angular momentum. These results elucidate and quantify how the baryon Cycle plausibly regulates star formation and alters the angular momentum distribution of disk material across the halo mass range where most cosmic star formation occurs.
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in n out the Gas Cycle from dwarfs to spiral galaxies
arXiv: Astrophysics of Galaxies, 2015Co-Authors: Charlotte Christensen, Romeel Dave, Fabio Governato, Andrew Pontzen, Alyson Brooks, Ferah Munshi, Thomas R Quinn, James WadsleyAbstract:We examine the scalings of galactic outflows with halo mass across a suite of twenty high-resolution cosmological zoom galaxy simulations covering halo masses from 10^9.5 - 10^12 M_sun. These simulations self-consistently generate outflows from the available supernova energy in a manner that successfully reproduces key galaxy observables including the stellar mass-halo mass, Tully-Fisher, and mass-metallicity relations. We quantify the importance of ejective feedback to setting the stellar mass relative to the efficiency of Gas accretion and star formation. Ejective feedback is increasingly important as galaxy mass decreases; we find an effective mass loading factor that scales as v_circ^(-2.2), with an amplitude and shape that is invariant with redshift. These scalings are consistent with analytic models for energy-driven wind, based solely on the halo potential. Recycling is common: about half the outflow mass across all galaxy masses is later re-accreted. The recycling timescale is typically about 1 Gyr, virtually independent of halo mass. ReCycled material is re-accreted farther out in the disk and with typically about 2-3 times more angular momentum. These results elucidate and quantify how the baryon Cycle plausibly regulates star formation and alters the angular momentum distribution of disk material across the halo mass range where most of cosmic star formation occurs.
L. A. Ogurechnikov - One of the best experts on this subject based on the ideXlab platform.
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Thermodynamic substantiation of power generation using a steam-Gas mixture with a variable composition of components
Thermal Engineering, 2013Co-Authors: V. E. Nakoryakov, L. A. OgurechnikovAbstract:In incomplete conditions of initial information for the calculation of thermodynamic parameters of the steam-Gas Cycle, the ideal Gas approximation is accepted. In order to increase the efficiency of using the energy of the steam-Gas flow, the possibility of using a binary thermal power Cycle is considered.
Romeel Dave - One of the best experts on this subject based on the ideXlab platform.
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in n out the Gas Cycle from dwarfs to spiral galaxies
The Astrophysical Journal, 2016Co-Authors: Charlotte Christensen, Romeel Dave, Fabio Governato, Andrew Pontzen, Alyson Brooks, Ferah Munshi, Thomas R Quinn, James WadsleyAbstract:We examine the scalings of galactic outflows with halo mass across a suite of 20 high-resolution cosmological zoom galaxy simulations covering halo masses in the range 10^9.5-10^12\M. These simulations self-consistently generate outflows from the available supernova energy in a manner that successfully reproduces key galaxy observables, including the stellar mass–halo mass, Tully–Fisher, and mass–metallicity relations. We quantify the importance of ejective feedback to setting the stellar mass relative to the efficiency of Gas accretion and star formation. Ejective feedback is increasingly important as galaxy mass decreases; we find an effective mass loading factor that scales as v-circ-2.2, with an amplitude and shape that are invariant with redshift. These scalings are consistent with analytic models for energy-driven wind, based solely on the halo potential. Recycling is common: about half of the outflow mass across all galaxy masses is later reaccreted. The recycling timescale is typically ~1 Gyr, virtually independent of halo mass. ReCycled material is reaccreted farther out in the disk and with typically ~2–3 times more angular momentum. These results elucidate and quantify how the baryon Cycle plausibly regulates star formation and alters the angular momentum distribution of disk material across the halo mass range where most cosmic star formation occurs.
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in n out the Gas Cycle from dwarfs to spiral galaxies
arXiv: Astrophysics of Galaxies, 2015Co-Authors: Charlotte Christensen, Romeel Dave, Fabio Governato, Andrew Pontzen, Alyson Brooks, Ferah Munshi, Thomas R Quinn, James WadsleyAbstract:We examine the scalings of galactic outflows with halo mass across a suite of twenty high-resolution cosmological zoom galaxy simulations covering halo masses from 10^9.5 - 10^12 M_sun. These simulations self-consistently generate outflows from the available supernova energy in a manner that successfully reproduces key galaxy observables including the stellar mass-halo mass, Tully-Fisher, and mass-metallicity relations. We quantify the importance of ejective feedback to setting the stellar mass relative to the efficiency of Gas accretion and star formation. Ejective feedback is increasingly important as galaxy mass decreases; we find an effective mass loading factor that scales as v_circ^(-2.2), with an amplitude and shape that is invariant with redshift. These scalings are consistent with analytic models for energy-driven wind, based solely on the halo potential. Recycling is common: about half the outflow mass across all galaxy masses is later re-accreted. The recycling timescale is typically about 1 Gyr, virtually independent of halo mass. ReCycled material is re-accreted farther out in the disk and with typically about 2-3 times more angular momentum. These results elucidate and quantify how the baryon Cycle plausibly regulates star formation and alters the angular momentum distribution of disk material across the halo mass range where most of cosmic star formation occurs.
