The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
Mariusz Adamski - One of the best experts on this subject based on the ideXlab platform.
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Ventilation system with spiral recuperator
Energy and Buildings, 2010Co-Authors: Mariusz AdamskiAbstract:A new kind of longitudinal flow spiral recuperator for the heat recovery in ventilation systems of buildings was studied experimentally and analytically. The aim of this work is to analyze the possibility of using air handling units with new type of spiral recuperator in order to recover heat in ventilation systems of buildings. For the reason that the air flows are parallel to the symmetry axis of the longitudinal flow spiral recuperator, in this unit pressure drops are smaller than in commonly known spiral exchangers. Because of the counter flow, a greater value of thermal effectiveness ɛ is reached for the same value of the number of transfer units in comparison to cross-flow Recuperators. The exploitation of the new type of spiral recuperator in winter periods brings significant savings. The results obtained from computations are very encouraging for a widespread use of these devices.
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heat transfer correlations and ntu number for the longitudinal flow spiral Recuperators
Applied Thermal Engineering, 2009Co-Authors: Mariusz AdamskiAbstract:This paper reports experimental data for heat transfer in a longitudinal flow spiral recuperator. The primary measurements include flow rates as well as the inlet and outlet fluid temperature values for each fluid stream. The results of the experimental study are presented in a dimensionless form. The problem of determining correlations for average heat transfer coefficients is formulated as a parameter estimation problem, by selecting the functional form for the Nusselt number. The non-linear problem is solved using the least-squares estimation method. The results presented in this paper provide data for the longitudinal flow spiral Recuperators application design.
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longitudinal flow spiral Recuperators in building ventilation systems
Energy and Buildings, 2008Co-Authors: Mariusz AdamskiAbstract:Abstract Capital expenditure and exploitation costs of ventilation systems with longitudinal counterflow spiral Recuperators are minimized taking into consideration the results of measurements and calculations together with the well-known effectiveness–NTU method. It was estimated that ventilation system with longitudinal flow spiral Recuperators refunds the capital expenditure within 2 or 3 years. Due to their advantages, spiral Recuperators with the longitudinal counter current flow should be widely utilized for ventilation systems in winter and cool recuperation in summer.
Peyman Maghsoudi - One of the best experts on this subject based on the ideXlab platform.
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a multi factor methodology for evaluation and optimization of plate fin Recuperators for micro gas turbine applications considering payback period as universal objective function
International Journal of Numerical Methods for Heat & Fluid Flow, 2019Co-Authors: Peyman Maghsoudi, Sadegh Sadeghi, Qingang Xiong, S M AminossadatiAbstract:Purpose: Because of the appreciable application of heat recovery systems for the increment of overall efficiency of micro gas turbines, promising evaluation and optimization are crucial. This paper aims to propose a multi-factor theoretical methodology for analysis, optimization and comparison of potential plate-fin Recuperators incorporated into micro gas turbines. Energetic, exergetic, economic and environmental factors are covered. Design/methodology/approach: To demonstrate applicability and reliability of the methodology, detailed thermo-hydraulic analysis, sensitivity analysis and optimization are conducted on the Recuperators with louver and offset-strip fins using a genetic algorithm. To assess the relationship between investment cost and profit for the recuperated systems, payback period (PBP), which incorporates all the factors is used as the universal objective function. To compare the performance of the recuperated and non-recuperated systems, exergy efficiency, exergy destruction and corresponding cost rate, fuel consumption and environmental damage cost rates, capital and operational cost rates and acquired profit rates are determined. Findings: Based on the results, optimal PBP of the louvered-fin recuperator (147 days) is slightly lower than that with offset-strip fins (153 days). The highest profit rate is acquired by reduction of exergy destruction cost rate and corresponding decrements for louver and offset-strip fins are 2.3 and 3.9 times compared to simple cycle, respectively. Originality/value: This mathematical study, for the first time, focuses on introducing a reliable methodology, which covers energetic, exergetic, economic and environmental points of view beneficial for design and selection of efficient plate-fin Recuperators for micro gas turbine applications.
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a comprehensive thermo economic analysis optimization and ranking of different microturbine plate fin Recuperators designs employing similar and dissimilar fins on hot and cold sides with nsga ii algorithm and dea model
Applied Thermal Engineering, 2018Co-Authors: Peyman Maghsoudi, Sadegh Sadeghi, Hossein Khanjarpanah, Hamid Haghshenas GorganiAbstract:Abstract This study aims to perform a comprehensive thermo-economic analysis, optimization and ranking of cross and counter-flow plate-fin Recuperators employing rectangular, triangular, offset strip and louver fins. The analysis is mainly conducted for two recuperator structures: (i) fins’ configurations on both hot and cold sides are the same; (ii) fins on hot side and cold side are dissimilar in configuration. Considering effective practical optimization constraints and design parameters, Non-dominated Sorting Genetic Algorithm (NSGA-II) is used to maximize the recuperator effectiveness and minimize its total cost, simultaneously. Pareto-optimal fronts are presented to specify the desirable recuperator designs satisfying the constraints. Afterwards, in order to accurately and reliably rank the optimal designs based on significant factors including recuperator effectiveness, total cost, volume, mass and pressure drop, Data Envelopment Analysis (DEA) model is utilized. According to the ranking results achieved from the DEA model, the counter-flow recuperator employing louver fins on the cold side and rectangular fins on the hot side has the best performance among the investigated recuperator structures for which the values of effectiveness, cost, pressure drop, volume and mass are equal to 0.814359, 326688.3 $, 0.716857 kPa, 0.40834 m3, 419.3277 kg, respectively.
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comparative study and multi objective optimization of plate fin Recuperators applied in 200 kw microturbines based on non dominated sorting and normalization method considering recuperator effectiveness exergy efficiency and total cost
International Journal of Thermal Sciences, 2018Co-Authors: Peyman Maghsoudi, Sadegh Sadeghi, Hamid Haghshenas GorganiAbstract:Abstract The current study aims to simultaneously and comprehensively investigate the performance of four types of recuperative heat exchangers applied in 200 kW microturbines by using numerical method. Different fin configurations including rectangular, triangular, louver and offset strip fins are employed in the Recuperators to enhance the heat transfer rate. Additionally, the calculations are separately undertaken for both counter and cross-flow arrangements. To achieve the best performance, a three-objective optimization problem is solved using Non-dominated Sorting Genetic Algorithm (NSGA-II). Recuperator effectiveness and exergy efficiency and total cost are considered as the objective functions. The recuperator effectiveness and exergy efficiency are maximized and the recuperator total cost is minimized, simultaneously. The results of each optimization are delineated by a set of designs using three dimensional Pareto-optimal fronts. Maximum cycle thermal and exergy efficiencies and NPV occur in the counter-flow recuperator employing offset strip fin and the values are found to be 39.1275%, 36.7431% and 3088164 $, respectively. A sensitivity analysis of variation in recuperator effectiveness and exergy efficiency and total cost with changes in design parameters of the plate-fin Recuperators employing louver and offset strip fins with counter-flow arrangement is performed. Finally, all the optimal designs obtained from the Pareto diagrams are compared to determine the optimum designs using normalization method and non-dominated sorting concept. According to the comparisons, offset strip fin and louver fin with counter flow arrangement show better performance.
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Thermoeconomic Optimization and Comparison of Plate-Fin Heat Exchangers Using Louver, Offset Strip, Triangular and Rectangular Fins Applied in 200 kW Microturbines
Journal of Heat Transfer, 2017Co-Authors: Peyman Maghsoudi, Somayeh Sadeghi, Payam HanafizadehAbstract:Copyright © 2017 by ASME. In this paper, four types of plate-fin heat exchangers applied in 200 kW microturbines are investigated. Multi-objective optimization algorithm, NSGA-II (nondominated sorting genetic algorithm (GA)), is employed to maximize the efficiency of the recuperator and minimize its total cost, simultaneously. Feasible ranges of pressure drop, Reynolds number, and recuperator efficiency are obtained according to a penalty function. The optimizations are conducted for rectangular fin, triangular fin, louver fin, and offset strip fin Recuperators with cross and counter flow arrangements. The results of each optimization problem are presented as a set of designs, called "Pareto-optimal solutions." Afterward, for the designs, cycle efficiency and net present value (NPV) are compared based on technical and economic criteria, respectively. Maximum cycle efficiency occurring in a recuperator with louver fin and counter flow arrangement is found to be 38.17%. Finally, the optimum designs are compared based on nondominated sorting concept leading to the optimal solutions.
Hamid Haghshenas Gorgani - One of the best experts on this subject based on the ideXlab platform.
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a comprehensive thermo economic analysis optimization and ranking of different microturbine plate fin Recuperators designs employing similar and dissimilar fins on hot and cold sides with nsga ii algorithm and dea model
Applied Thermal Engineering, 2018Co-Authors: Peyman Maghsoudi, Sadegh Sadeghi, Hossein Khanjarpanah, Hamid Haghshenas GorganiAbstract:Abstract This study aims to perform a comprehensive thermo-economic analysis, optimization and ranking of cross and counter-flow plate-fin Recuperators employing rectangular, triangular, offset strip and louver fins. The analysis is mainly conducted for two recuperator structures: (i) fins’ configurations on both hot and cold sides are the same; (ii) fins on hot side and cold side are dissimilar in configuration. Considering effective practical optimization constraints and design parameters, Non-dominated Sorting Genetic Algorithm (NSGA-II) is used to maximize the recuperator effectiveness and minimize its total cost, simultaneously. Pareto-optimal fronts are presented to specify the desirable recuperator designs satisfying the constraints. Afterwards, in order to accurately and reliably rank the optimal designs based on significant factors including recuperator effectiveness, total cost, volume, mass and pressure drop, Data Envelopment Analysis (DEA) model is utilized. According to the ranking results achieved from the DEA model, the counter-flow recuperator employing louver fins on the cold side and rectangular fins on the hot side has the best performance among the investigated recuperator structures for which the values of effectiveness, cost, pressure drop, volume and mass are equal to 0.814359, 326688.3 $, 0.716857 kPa, 0.40834 m3, 419.3277 kg, respectively.
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comparative study and multi objective optimization of plate fin Recuperators applied in 200 kw microturbines based on non dominated sorting and normalization method considering recuperator effectiveness exergy efficiency and total cost
International Journal of Thermal Sciences, 2018Co-Authors: Peyman Maghsoudi, Sadegh Sadeghi, Hamid Haghshenas GorganiAbstract:Abstract The current study aims to simultaneously and comprehensively investigate the performance of four types of recuperative heat exchangers applied in 200 kW microturbines by using numerical method. Different fin configurations including rectangular, triangular, louver and offset strip fins are employed in the Recuperators to enhance the heat transfer rate. Additionally, the calculations are separately undertaken for both counter and cross-flow arrangements. To achieve the best performance, a three-objective optimization problem is solved using Non-dominated Sorting Genetic Algorithm (NSGA-II). Recuperator effectiveness and exergy efficiency and total cost are considered as the objective functions. The recuperator effectiveness and exergy efficiency are maximized and the recuperator total cost is minimized, simultaneously. The results of each optimization are delineated by a set of designs using three dimensional Pareto-optimal fronts. Maximum cycle thermal and exergy efficiencies and NPV occur in the counter-flow recuperator employing offset strip fin and the values are found to be 39.1275%, 36.7431% and 3088164 $, respectively. A sensitivity analysis of variation in recuperator effectiveness and exergy efficiency and total cost with changes in design parameters of the plate-fin Recuperators employing louver and offset strip fins with counter-flow arrangement is performed. Finally, all the optimal designs obtained from the Pareto diagrams are compared to determine the optimum designs using normalization method and non-dominated sorting concept. According to the comparisons, offset strip fin and louver fin with counter flow arrangement show better performance.
Alberto Traverso - One of the best experts on this subject based on the ideXlab platform.
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analysis of uncertainties in compact plate fin Recuperators for microturbines
Applied Thermal Engineering, 2019Co-Authors: Andrea Giugno, Alessandra Cuneo, Alberto TraversoAbstract:Abstract The current study aims to perform a stochastic analysis on microturbine compact Recuperators to evaluate the impact of uncertainties in design parameters on their cost and volume, by using two different probabilistic approaches: Monte Carlo (MC) and Response Sensitivity Analysis (RSA). These two methods have been developed in Matlab® and then coupled with CHEOPE (Compact Heat Exchanger Optimisation and Performance Evaluation) software, which allows to analyze two different types of Recuperators, used in microturbine applications: the furnace-brazed plate-fin type and the welded primary surface type. This paper focuses on an analysis of plate-fin type Recuperators, for which the cost function adopted was tuned and verified in a previous study. Three main parameters of the recuperator have been considered as uncertain: effectiveness, hot side and cold side pressure drops. The uncertainties associated with these three parameters are based on industrial knowledge. The aforementioned stochastic methods have been used to propagate such uncertainties on the relevant outputs, such as cost and volume, allowing us to evaluate the least expensive and the most compact recuperator among those analysed.
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experimental analysis of flow unbalance in two parallel counter flow Recuperators
ASME Turbo Expo 2013: Turbine Technical Conference and Exposition, 2013Co-Authors: Alessio Martini, Alberto Traverso, David Tucker, John VanosdolAbstract:The aim of this study was to provide a characterization of non-symmetrical operation in two counter-flow primary surface exhaust gas Recuperators installed in parallel flow loops. The hybrid system emulator test rig and facility designed and operated by the Department of Energy, National Energy Technology Laboratory located at the West Virginia (USA) campus was used for the study. Various tests from the past years often resulted in non-symmetrical operation, indicated by significantly variant temperature measurements at the outlets of the Recuperators.Some specific tests have been carried out in order to identify the possible cause of this flow unbalance. The isolated effects of bleed air, cold air and hot air valve on the heat exchangers flow unbalance have been studied. Also, the impact of load bank changes on flow distribution has been considered in this study. Each test has been carried out in close loop fuel valve speed control. The influence of each independent variable in the study on parallel recuperator flow distribution has been quantitatively characterized using temperatures and a heat balance. Both the bleed and the cold air compressor bypass valves showed an appreciable impact on the heat exchangers flow unbalance, while hot air valve and load bank changes had minimal effect.Copyright © 2013 by ASME
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optimal design of compact Recuperators for microturbine application
Applied Thermal Engineering, 2005Co-Authors: Alberto Traverso, Aristide F MassardoAbstract:Abstract This paper presents a new approach for the optimization of microturbine Recuperators from the technical and economic standpoints. The procedure proposed has been implemented in the software called CHEOPE (compact heat exchanger optimization and performance evaluation), which considers two types of recuperator concept, which have proved to be the most promising for microturbine applications: the furnace-brazed plate-fin type and the welded primary surface type. The general design rules for performance evaluation of gas–gas heat exchangers are summarized and specifically applied to these two types of recuperator. Moreover, the cost equation, employed to estimate the capital cost of these types of heat exchanger, is discussed. With regard to the sizing procedure, a special optimization procedure of the recuperator matrix has been developed, which takes into account several targets in a single multi-objective function: the compactness, the pressure drops and the expected cost of the device. The tests performed for the validation are presented, and three case studies are illustrated for three different microturbine sizes, for a 50 kW, 100 kW and 500 kW machine, respectively.
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cheope a tool for the optimal design of compact Recuperators
ASME Turbo Expo 2004: Power for Land Sea and Air, 2004Co-Authors: Alberto Traverso, Federico Zanzarsi, Aristide F MassardoAbstract:This paper presents the organization, theoretical background and application of a new software tool for the optimization of the technical and economical design of microturbine Recuperators. The code called CHEOPE (Compact Heat Exchanger Optimization and Performance Evaluation) considered two types of recuperator concept, which proved to be the most promising for microturbine applications: the furnace-brazed plate-fin type and the welded primary surface type. The general design rules for performance evaluation of gas-gas heat exchangers are summarized and specifically applied to these two types of recuperator. Moreover, the cost equation, employed to estimate the capital cost of these types of heat exchanger, is discussed. CHEOPE can be used both for solving the sizing problem and the rating problem. With regard to the former, the code is capable of a special optimization of the recuperator matrix, which takes into account the compactness, the pressure drops and the expected cost of the device. The objective function can be customized according to the designer’s priorities. The tests performed for the validation are presented, and three case studies are illustrated for three different microturbine sizes, for a 50kW, a 100kW and a 500kW machine.Copyright © 2004 by ASME
Philip J. Maziasz - One of the best experts on this subject based on the ideXlab platform.
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evaluation of alumina forming austenitic foil for advanced Recuperators
Journal of Engineering for Gas Turbines and Power-transactions of The Asme, 2011Co-Authors: Bruce A Pint, Philip J. Maziasz, Michael P Brady, Yukinori Yamamoto, Michael L Santella, Wendy J MatthewsAbstract:A corrosion- and creep-resistant austenitic stainless steel has been developed for advanced recuperator applications. By optimizing the Al and Cr contents, the alloy is fully austenitic for creep strength while allowing the formation of a chemically stable external alumina scale at temperatures up to 900 C. An alumina scale eliminates long-term problems with the formation of volatile Cr oxy-hydroxides in the presence of water vapor in exhaust gas. As a first step in producing foil for primary surface Recuperators, three commercially cast heats have been rolled to 100 m thick foil in the laboratory to evaluate performance in creep and oxidation testing. Results from initial creep testing are presented at 675 C and 750 C, showing excellent creep strength compared with other candidate foil materials. Laboratory exposures in humid air at 650 800 C have shown acceptable oxidation resistance. A similar oxidation behavior was observed for sheet specimens of these alloys exposed in a modified 65 kW microturbine for 2871 h. One composition that showed superior creep and oxidation resistance has been selected for the preparation of a commercial batch of foil. DOI: 10.1115/1.4002827
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evaluation of alumina forming austenitic foil for advanced Recuperators
Volume 5: Industrial and Cogeneration; Microturbines and Small Turbomachinery; Oil and Gas Applications; Wind Turbine Technology, 2010Co-Authors: Bruce A Pint, Philip J. Maziasz, Michael P Brady, Yukinori Yamamoto, Michael L Santella, Wendy J MatthewsAbstract:A corrosion- and creep-resistant austenitic stainless steel has been developed for advanced recuperator applications. By optimizing the Al and Cr contents, the alloy is fully austenitic for creep strength while allowing the formation of a chemically-stable external alumina scale at temperatures up to 900°C. An alumina scale eliminates long-term problems with the formation of volatile Cr oxy-hydroxides in the presence of water vapor in exhaust gas. As a first step in producing foil for primary surface Recuperators, three commercially cast heats have been rolled to ∼100μm thick foil in the laboratory to evaluate performance in creep and oxidation testing. Results from initial creep testing are presented at 675° and 750°C showing excellent creep strength compared to other candidate foil materials. Laboratory exposures in humid air at 650°-800°C have shown acceptable oxidation resistance. Similar oxidation behavior was observed for sheet specimens of these alloys exposed in a modified 65kW microturbine for 2,871h. One composition that showed superior creep and oxidation resistance has been selected for preparation of a commercial batch of foil.Copyright © 2010 by ASME
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development of alumina forming austenitic alloys for advanced Recuperators
Volume 5: Microturbines and Small Turbomachinery; Oil and Gas Applications, 2009Co-Authors: Bruce A Pint, Michael P Brady, Yukinori Yamamoto, Rosa M Trejo, Michael L Santella, Jane Y Howe, Philip J. MaziaszAbstract:A new class of corrosion- and creep-resistant austenitic stainless steels has been developed for advanced recuperator applications. The Al and Cr contents have been optimized to maintain a fully austenitic composition for creep strength while allowing the formation of a highly-protective external alumina scale at temperatures up to 900°C in the presence of water vapor. Strengthening was achieved via the formation of stable nano-scale MC type carbides and creep properties were comparable to commercially available advanced austenitic stainless steel alloys. These properties are particularly well-suited for thin-walled Recuperators for both small and large gas turbines and fuel cells. By forming an alumina scale, long-term problems with Cr evaporation in the presence of water vapor in the exhaust gas are eliminated. Laboratory data are presented from humid air and microturbine exhaust gas to illustrate the oxidation resistance of this class of alloys at 650°–900°C and compared to results for some current commercial alloys. Alloy development is continuing in order to determine the effect of composition on performance over this temperature range.Copyright © 2009 by ASME
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austenitic stainless steels and alloys with improved high temperature performance for advanced microturbine Recuperators
ASME Turbo Expo 2004: Power for Land Sea and Air, 2004Co-Authors: Philip J. Maziasz, Bruce A Pint, John P Shingledecker, Karren L More, N D Evans, Edgar LaracurzioAbstract:Compact Recuperators/heat-exchangers increase the efficiency of both microturbines and smaller industrial gas turbines. Most Recuperators today are made from 347 stainless steel and operate well below 700°C. Larger engine sizes, higher exhaust temperatures and alternate fuels all demand recuperator materials with greater performance (creep strength, corrosion resistance) and reliability than 347 steel, especially for temperatures of 700–750°C. The Department of Energy (DOE) sponsors programs at the Oak Ridge National Laboratory (ORNL) to produce and evaluate cost-effective high-temperature recuperator alloys. This paper summarizes the latest high-temperature creep and corrosion data for a commercial 347 steel with modified processing for better creep resistanc, and for advanced commercial alloys with significantly better creep and corrosion resistance, including alloys NF709, HR120. Similar data are also provided on small lab heats of several new ORNL modified stainless steels.Copyright © 2004 by ASME
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screening and evaluation of materials for microturbine Recuperators
ASME Turbo Expo 2004: Power for Land Sea and Air, 2004Co-Authors: Edgar Laracurzio, Philip J. Maziasz, Karren L More, Rosa M Trejo, Bruce A PintAbstract:The effects of stress, temperature and exposure to microturbine exhaust gases on the mechanical properties and corrosion resistance of candidate materials for microturbine Recuperators were investigated. Results are presented for 347 stainless steel metallic foils after 500-hr exposure to temperatures between 620°C and 760°C at a tensile stress of 50 MPa. It was found that the material experienced accelerated attack at the highest temperature and that the corrosion products consisted of mixed oxides of iron and chromium. It was also found that exposure at the highest temperatures resulted in significant decrease in both tensile strength and ductility. ORNL’s microturbine recuperator test facility, where the exposures were carried out, is also described.Copyright © 2004 by ASME
