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Fredrik Haglind - One of the best experts on this subject based on the ideXlab platform.
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a comparison of organic and Steam Rankine Cycle power systems for waste heat recovery on large ships
Energies, 2017Co-Authors: Jesper Graa Andreasen, Andrea Meroni, Fredrik HaglindAbstract:This paper presents a comparison of the conventional dual pressure Steam Rankine Cycle process and the organic Rankine Cycle process for marine engine waste heat recovery. The comparison was based on a container vessel, and results are presented for a high-sulfur (3 wt %) and low-sulfur (0.5 wt %) fuel case. The processes were compared based on their off-design performance for diesel engine loads in the range between 25% and 100%. The fluids considered in the organic Rankine Cycle process were MM(hexamethyldisiloxane), toluene, n-pentane, i-pentane and c-pentane. The results of the comparison indicate that the net power output of the Steam Rankine Cycle process is higher at high engine loads, while the performance of the organic Rankine Cycle units is higher at lower loads. Preliminary turbine design considerations suggest that higher turbine efficiencies can be obtained for the ORC unit turbines compared to the Steam turbines. When the efficiency of the c-pentane turbine was allowed to be 10% points larger than the Steam turbine efficiency, the organic Rankine Cycle unit reaches higher net power outputs than the Steam Rankine Cycle unit at all engine loads for the low-sulfur fuel case. The net power production from the waste heat recovery units is generally higher for the low-sulfur fuel case. The Steam Rankine Cycle unit produces 18% more power at design compared to the high-sulfur fuel case, while the organic Rankine Cycle unit using MM produces 33% more power.
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thermoeconomic optimization of a kalina Cycle for a central receiver concentrating solar power plant
Energy Conversion and Management, 2016Co-Authors: Anish Modi, Martin Ryhl Kae, Jesper Graa Andrease, Fredrik HaglindAbstract:Abstract Concentrating solar power plants use a number of reflecting mirrors to focus and convert the incident solar energy to heat, and a power Cycle to convert this heat into electricity. This paper evaluates the use of a high temperature Kalina Cycle for a central receiver concentrating solar power plant with direct vapour generation and without storage. The use of the ammonia-water mixture as the power Cycle working fluid with non-isothermal evaporation and condensation presents the potential to improve the overall performance of the plant. This however comes at a price of requiring larger heat exchangers because of lower thermal pinch and heat transfer degradation for mixtures as compared with using a pure fluid in a conventional Steam Rankine Cycle, and the necessity to use a complex Cycle arrangement. Most of the previous studies on the Kalina Cycle focused solely on the thermodynamic aspects of the Cycle, thereby comparing Cycles which require different investment costs. In this study, the economic aspect and the part-load performance are also considered for a thorough evaluation of the Kalina Cycle. A thermoeconomic optimization was performed by minimizing the levelized cost of electricity. The different Kalina Cycle simulations resulted in the levelized costs of electricity between 212.2 $ MWh −1 and 218.9 $ MWh −1 . For a plant of same rated capacity, the state-of-the-art Steam Rankine Cycle has a levelized cost of electricity of 181.0 $ MWh −1 . Therefore, when considering both the thermodynamic and the economic perspectives, the results suggest that it is not beneficial to use the Kalina Cycle for high temperature concentrating solar power plants.
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Part-load performance of a high temperature Kalina Cycle
Energy Conversion and Management, 2015Co-Authors: Anish Modi, Jesper Graa Andreasen, Martin Ryhl Kærn, Fredrik HaglindAbstract:Abstract The Kalina Cycle has recently seen increased interest as an alternative to the conventional Steam Rankine Cycle. The Cycle has been studied for use with both low and high temperature applications such as geothermal power plants, ocean thermal energy conversion, waste heat recovery, gas turbine bottoming Cycle, and solar power plants. The high temperature Cycle layouts are inherently more complex than the low temperature layouts due to the presence of a distillation-condensation subsystem, three pressure levels, and several heat exchangers. This paper presents a detailed approach to solve the Kalina Cycle in part-load operating conditions for high temperature (a turbine inlet temperature of 500 °C) and high pressure (100 bar) applications. A central receiver concentrating solar power plant with direct vapour generation is considered as a case study where the part-load conditions are simulated by changing the solar heat input to the receiver. Compared with the Steam Rankine Cycle, the Kalina Cycle has an additional degree of freedom in terms of the ammonia mass fraction which can be varied in order to maximize the part-load efficiency of the Cycle. The results include the part-load curves for various turbine inlet ammonia mass fractions and the fitted equations for these curves.
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Waste heat recovery technologies for offshore platforms
Applied Energy, 2014Co-Authors: Leonardo Pierobon, Fredrik Haglind, Alberto Benato, Enrica Scolari, Anna StoppatoAbstract:This article aims at finding the most suitable waste heat recovery technology for existing and future offshore facilities. The technologies considered in this work are the Steam Rankine Cycle, the air bottoming Cycle and the organic Rankine Cycle.
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Technologies for Waste Heat Recovery in Off-Shore Applications
Volume 6A: Energy, 2013Co-Authors: Leonardo Pierobon, Fredrik Haglind, Rambabu Kandepu, Alessandro Fermi, Nicola RossettiAbstract:In off-shore oil and gas platforms the selection of the gas turbine to support the electrical and mechanical demand on site is often a compromise between reliability, efficiency, compactness, low weight and fuel flexibility. Therefore, recovering the waste heat in off-shore platforms presents both technological and economic challenges that need to be overcome. However, onshore established technologies such as the Steam Rankine Cycle, the air bottoming Cycle and the organic Rankine Cycle can be tailored to recover the exhaust heat off-shore. In the present paper, benefits and challenges of these three different technologies are presented, considering the Draugen platform in the North Sea as a base case. The Turboden 65-HRS unit is considered as representative of the organic Rankine Cycle technology. Air bottoming Cycles are analyzed and optimal design pressure ratios are selected. We also study a one pressure level Steam Rankine Cycle employing the once-through heat recovery Steam generator without bypass stack. We compare the three technologies considering the combined Cycle thermal efficiency, the weight, the net present value, the profitability index and payback time. Both incomes related to CO2 taxes and natural gas savings are considered. The results indicate that the Turboden 65-HRS unit is the optimal technology, resulting in a combined Cycle thermal efficiency of 41.5% and a net present value of around 15 M$, corresponding to a payback time of approximately 4.5 years. The total weight of the unit is expected to be around 250 ton. The air bottoming Cycle without intercooling is also a possible alternative due to its low weight (76 ton) and low investment cost (8.8 M$). However, Cycle performance and profitability index are poorer, 12.1% and 0.75. Furthermore, the results suggest that the once-trough single pressure Steam Cycle has a combined Cycle thermal efficiency of 40.8% and net present value of 13.5 M$. The total weight of the Steam Rankine Cycle is estimated to be around 170 ton.Copyright © 2013 by ASME
Santanu Bandyopadhyay - One of the best experts on this subject based on the ideXlab platform.
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thermo economic analysis and selection of working fluid for solar organic Rankine Cycle
Applied Thermal Engineering, 2016Co-Authors: Nishith B Desai, Santanu BandyopadhyayAbstract:Abstract Organic Rankine Cycle (ORC), powered by line-focusing concentrating solar collectors (parabolic trough collector and linear Fresnel reflector), is a promising option for modular scale. ORC based power block, with dry working fluids, offers higher design and part-load efficiencies compared to Steam Rankine Cycle (SRC) in small-medium scale, with temperature sources up to 400 °C. However, the cost of ORC power block is higher compared to the SRC power block. Similarly, parabolic trough collector (PTC) system has higher optical efficiency and higher cost compared to linear Fresnel reflector (LFR) system. The thermodynamic efficiencies and power block costs also vary with working fluids of the Rankine Cycle. In this paper, thermo-economic comparisons of organic Rankine and Steam Rankine Cycles powered by line-focusing concentrating solar collectors are reported. A simple selection methodology, based on thermo-economic analysis, and a comparison diagram for working fluids of power generating Cycles are also proposed. Concentrating solar power plants with any collector technology and any power generating Cycle can be compared using the proposed methodology.
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Thermo-economic comparisons between solar Steam Rankine and organic Rankine Cycles
Applied Thermal Engineering, 2016Co-Authors: Nishith B Desai, Santanu BandyopadhyayAbstract:Among all concentrated solar power technologies, plants with parabolic trough collector and Steam Rankine Cycle are the most matured and established technology. Organic Rankine Cycle is a promising option for modular scale power plants with low temperature heat sources. The decision of selection between Steam Rankine and organic Rankine Cycles is influenced by solar collector field characteristics and cost, Steam Rankine Cycle efficiency, and power block cost. In this paper, based on the condition of equality of the levelized cost of energy, a methodology for selecting working fluid through a novel graphical representation, called working fluid selection diagram, is proposed. The proposed methodology also includes selection between parabolic trough and linear Fresnel collector based plant, for a given working fluid of the Rankine Cycle. Most of the methods, proposed in literature, require multiple simulations for selecting various design parameters and optimum configuration of the plant. The proposed working fluid and solar collector field selection diagrams can be used for quick suggestion about optimal configuration of a concentrated solar power plant, without any detailed simulations. Based on the thermodynamic and economic parameters, R113 and isohexane achieves levelized cost of energy close to the parabolic trough collector based plant with Steam Rankine Cycle. Effects of different parameters on selection of optimal configuration of a concentrating solar power plant are also studied. The analytical procedures developed for selecting solar collector field and working fluid of the power generating Cycle are important during conceptual design of a concentrated solar power plant. These methodologies can be applied at the initial design stage to compare the alternative configurations and to reduce the search space related to various design parameters.
Mahmoud M Elhalwagi - One of the best experts on this subject based on the ideXlab platform.
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optimal design and integration of solar thermal collection storage and dispatch with process cogeneration systems
Chemical Engineering Science, 2015Co-Authors: Faissal Abdelhady, Mahmoud M Elhalwagi, Hisham S Bamufleh, Jose Maria PonceortegaAbstract:Abstract This paper introduces an optimization approach to the design of process combined heat and power systems that integrate the thermal profile of the process, an external fossil fuel, and solar energy. A hierarchical design approach is proposed to stage the implementation of steady-state and dynamic calculations. Initially, energy integration is used to identify minimum heating and cooling utility targets. Next, a genetic algorithm approach is employed to optimize the external heating load and generated power of the cogeneration system that includes a Steam Rankine Cycle. An outer loop is used to optimize the flowrate, temperature, and pressure of the Steam entering and exiting the turbine. A multiperiod optimization approach is developed to account for the diurnal variability of solar energy. Direct usage of collected solar energy is considered along with the option of thermal storage and dispatch. The solution of this mixed integer nonlinear program determines the optimal mix of energy throughout the year. A case study for a petrochemical plant in Jeddah, Saudi Arabia was solved to illustrate the applicability of the devised approach.
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sustainable integration of trigeneration systems with heat exchanger networks
Industrial & Engineering Chemistry Research, 2014Co-Authors: Luis Fernando Lirabarragan, Jose Maria Ponceortega, Medardo Sernagonzalez, Mahmoud M ElhalwagiAbstract:A novel superstructure-based approach for synthesizing sustainable trigeneration systems (i.e., heating, cooling, and power generation Cycles) integrated with heat exchanger networks is presented in this paper. The trigeneration system accounts for Steam and organic Rankine Cycles and an absorption refrigeration Cycle. The Steam Rankine Cycle can be driven by multiple primary energy sources (i.e., solar, biofuels, and fossil fuels) for sustainable generation of power and process heating. The waste energy from the Steam Rankine Cycle and/or the excess of process heat can be used to drive both the organic Rankine Cycle and the absorption refrigeration Cycle to produce power and process cooling below the ambient temperature, respectively. The synthesis problem is formulated as a multiobjective mixed-integer nonlinear programming problem for the simultaneous consideration of the economic, environmental, and social dimensions of sustainability. Two example problems are presented to show the applicability of th...
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multiobjective design of interplant trigeneration systems
Aiche Journal, 2014Co-Authors: Brigido Jesus Hipolitovalencia, Luis Fernando Lirabarragan, Jose Maria Ponceortega, Medardo Sernagonzalez, Mahmoud M ElhalwagiAbstract:A systematic approach for heat integration into an eco-industrial park through an integrated trigeneration system is presented. The approach is based on a new superstructure formulated as a multiobjective mixed-integer nonlinear programming model, where intraplant and interplant heat exchange for the process streams is allowed, in addition to the energy integration into the utility system that is constituted by a Steam Rankine Cycle (to produce electric power and hot utility), an organic Rankine Cycle (to recover waste heat and produce electric power), and an absorption refrigeration Cycle (to recover waste heat and provide refrigeration). To run the utility system, several external heat sources (solar, fossil fuels, and biofuels) are considered, which impact the economic, environmental, and social objectives considered in the model. A systematic approach to tradeoff the objectives considered is presented. Two examples are presented, where the advantages of the integrated eco-industrial park are shown. © 2013 American Institute of Chemical Engineers AIChE J, 60: 213–236, 2014
Gang Pei - One of the best experts on this subject based on the ideXlab platform.
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Performance investigation of solar tower system using cascade supercritical carbon dioxide Brayton-Steam Rankine Cycle
Energy Conversion and Management, 2020Co-Authors: Honglun Yang, Li Jing, Qiliang Wang, M.r. Rodríguez-sánchez, Domingo Santana, Gang PeiAbstract:Abstract A novel solar power tower system that integrates with the cascade supercritical carbon dioxide Brayton-Steam Rankine Cycle is proposed to tackle the challenges of a simple supercritical carbon dioxide system in solar power systems. It provides a large storage capacity and can react to the fluctuation of solar radiation by adjusting the mass flow rate of molten salts in the receiver and heat exchanger. The fundamental is illustrated and comprehensive mathematical models are built. Energy and exergy analysis in the heat collection and power conversion processes is conducted. A comparison between the novel system and simple supercritical carbon dioxide system is made at a design plant output of 10 MW. Results indicated that: (1) the cascade system has a lower receiver inlet temperature, wider temperature difference across the receiver, higher specific work of the thermal energy storage system and lower mass flow rate of the working fluids. The solar-thermal conversion efficiency of the receiver is improved significantly. The heat gain of the tower receiver of the novel system is 53.4 MWh, which is about 7.1 MWh more than that of the simple system. The electricity production of the cascade system is improved by 9.5% at design point; (2) The novel system can generate constant electricity in a wide range of solar radiation and offer flexible control strategy for heat collection and storage. It is a promising option for central solar tower technology with a high efficiency, large storage capacity and short payback period.
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Examination of the expander leaving loss in variable organic Rankine Cycle operation
Energy Conversion and Management, 2013Co-Authors: Gang Pei, Dongyue WangAbstract:Abstract The organic Rankine Cycle (ORC) favorably operates at low temperature. It differs significantly from the Steam Rankine Cycle in fluid enthalpy drop during expansion and reaction to change in condensation temperature. In current method for ORC-based energy conversion the expander leaving loss is generally neglected. Shortcomings of this method are outlined in this paper. Theoretical analysis of the expander leaving loss varying with the condensation temperature, evaporation temperature, and inlet pressure is first performed. Experimental test is subsequently carried out. The results indicate that unlike in the Steam Rankine Cycle, the leaving loss in the ORC on using R123 or R245fa increases by about 10 times as the condensation temperature changes from 30 to 0 °C, and is comparable with the enthalpy drop. With an inlet temperature of about 97 °C and a deviation of about 20 °C from the design condensation temperature, the ratio of the leaving loss to the enthalpy drop is about 10.4%. Besides, variation in the leaving loss may lead to expansion wave or shock wave inside the expander. The leaving loss becomes an important factor and should be included to determine the ORC year-round performance.
Nishith B Desai - One of the best experts on this subject based on the ideXlab platform.
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thermo economic analysis and selection of working fluid for solar organic Rankine Cycle
Applied Thermal Engineering, 2016Co-Authors: Nishith B Desai, Santanu BandyopadhyayAbstract:Abstract Organic Rankine Cycle (ORC), powered by line-focusing concentrating solar collectors (parabolic trough collector and linear Fresnel reflector), is a promising option for modular scale. ORC based power block, with dry working fluids, offers higher design and part-load efficiencies compared to Steam Rankine Cycle (SRC) in small-medium scale, with temperature sources up to 400 °C. However, the cost of ORC power block is higher compared to the SRC power block. Similarly, parabolic trough collector (PTC) system has higher optical efficiency and higher cost compared to linear Fresnel reflector (LFR) system. The thermodynamic efficiencies and power block costs also vary with working fluids of the Rankine Cycle. In this paper, thermo-economic comparisons of organic Rankine and Steam Rankine Cycles powered by line-focusing concentrating solar collectors are reported. A simple selection methodology, based on thermo-economic analysis, and a comparison diagram for working fluids of power generating Cycles are also proposed. Concentrating solar power plants with any collector technology and any power generating Cycle can be compared using the proposed methodology.
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Thermo-economic comparisons between solar Steam Rankine and organic Rankine Cycles
Applied Thermal Engineering, 2016Co-Authors: Nishith B Desai, Santanu BandyopadhyayAbstract:Among all concentrated solar power technologies, plants with parabolic trough collector and Steam Rankine Cycle are the most matured and established technology. Organic Rankine Cycle is a promising option for modular scale power plants with low temperature heat sources. The decision of selection between Steam Rankine and organic Rankine Cycles is influenced by solar collector field characteristics and cost, Steam Rankine Cycle efficiency, and power block cost. In this paper, based on the condition of equality of the levelized cost of energy, a methodology for selecting working fluid through a novel graphical representation, called working fluid selection diagram, is proposed. The proposed methodology also includes selection between parabolic trough and linear Fresnel collector based plant, for a given working fluid of the Rankine Cycle. Most of the methods, proposed in literature, require multiple simulations for selecting various design parameters and optimum configuration of the plant. The proposed working fluid and solar collector field selection diagrams can be used for quick suggestion about optimal configuration of a concentrated solar power plant, without any detailed simulations. Based on the thermodynamic and economic parameters, R113 and isohexane achieves levelized cost of energy close to the parabolic trough collector based plant with Steam Rankine Cycle. Effects of different parameters on selection of optimal configuration of a concentrating solar power plant are also studied. The analytical procedures developed for selecting solar collector field and working fluid of the power generating Cycle are important during conceptual design of a concentrated solar power plant. These methodologies can be applied at the initial design stage to compare the alternative configurations and to reduce the search space related to various design parameters.