The Experts below are selected from a list of 1932 Experts worldwide ranked by ideXlab platform
Johannes L. Van Niekerk - One of the best experts on this subject based on the ideXlab platform.
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Thermodynamic Modelling of Thermal Energy Storage Systems
Energy Procedia, 2016Co-Authors: Sameer Hameer, Johannes L. Van NiekerkAbstract:This paper presents a novel methodology for comparing thermal energy storage to electrochemical, chemical, and mechanical energy storage technologies. The underlying physics of this model is hinged on the development of a Round Trip Efficiency formulation for these systems. The charging and discharging processes of compressed air energy storage, flywheel energy storage, fuel cells, and batteries are well understood and defined from a physics standpoint in the context of comparing these systems. However, the challenge lays in comparing the charging process of these systems with the charging process of thermal energy storage systems for concentrating solar power plants (CSP). The Round Trip Efficiency and the levelized cost of energy (LCOE) are the metrics used for comparison purposes. The thermal energy storage system is specifically compared to vanadium redox, sodium sulphur, and compressed air energy storage (CAES) systems from a large scale storage perspective of 100's of MWh. The rationale behind this analysis was to develop an electrical storage Efficiency for molten salt thermal energy storage systems, such that it can be compared to battery energy storage technologies in the context of comparing CSP with thermal energy storage to solar photovoltaic with battery storage from a utility scale perspective. The results from the modelling using Andasol 3 CSP plant as a case study yield a storage Efficiency of 86% and LCOE of $216/MWh. The results of this modelling will facilitate the future generation of a thermal energy storage roadmap.
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A THERMODYNAMIC MODEL FOR COMPARING THERMAL ENERGY STORAGE SYSTEM TO ELECTROCHEMICAL, CHEMICAL, AND MECHANICAL ENERGY STORAGE TECHNOLOGIES
2015Co-Authors: Sameer Hameer, Johannes L. Van NiekerkAbstract:This paper presents a novel methodology for comparing thermal energy storage to electrochemical, chemical, and mechanical energy storage technologies. The machination of this model is hinged on the development of a Round Trip Efficiency formulation for these systems. The charging and discharging processes of compressed air energy storage, flywheel energy storage, fuel cells, and batteries are well understood and defined from a physics standpoint in the context of comparing these systems. However, the challenge lays in comparing the charging process of these systems with the charging process of thermal energy storage systems for concentrating solar power plants (CSP). The source of energy for all these systems is electrical energy except for the CSP plant where the input is thermal energy. In essence, the Round Trip Efficiency for all these systems should be in the form of the ratio of electrical output to electrical input. This paper also presents the thermodynamic modelling equations including the estimation of losses for a CSP plant specifically in terms of the receiver, heat exchanger, storage system, and power block. The Round Trip Efficiency and the levelized cost of energy (LCOE) are the metrics used for comparison purposes. The results from the modelling are compared with solar power plants in operation and literature. The crux of this modelling can be regarded as a platform for the generation of a thermal energy storage roadmap cocooned in a comprehensive energy storage roadmap from a system of systems perspective.
Hiroko Ohmori - One of the best experts on this subject based on the ideXlab platform.
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numerical prediction of system Round Trip Efficiency and feasible operating conditions of small scale solid oxide iron air battery
Journal of Power Sources, 2016Co-Authors: Hiroko Ohmori, Hiroshi Iwai, Kotaro Itakura, Motohiro Saito, Hideo YoshidaAbstract:Abstract A simulation model of a small-scale solid oxide iron–air battery system was developed to clarify its fundamental characteristics and feasibility from the view point of energy Efficiency. The energy flow in one cycle of charge/discharge operations was evaluated under a quasi-state assumption with 0-dimensional models of the system components, i.e., a solid oxide electrochemical cell, an iron (Fe) box and heat exchangers. Special care was taken when considering thermal aspects; not only a simple system but also a more complicated system with thermal recirculation by three heat exchangers was investigated. It was found that the system Round-Trip Efficiency reaches 61% under the base conditions in this study. The results also show that several limitations exist for the operation parameters and conditions in view of practical applications. In particular, higher and lower limits exist for the fuel and air utilization factors under which the system operates effectively because of constraints such as the maximum allowable fuel-blower temperature and no heat input during the discharge operation.
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Numerical prediction of system Round-Trip Efficiency and feasible operating conditions of small-scale solid oxide iron–air battery
Journal of Power Sources, 2016Co-Authors: Hiroko Ohmori, Hiroshi Iwai, Kotaro Itakura, Motohiro Saito, Hideo YoshidaAbstract:Abstract A simulation model of a small-scale solid oxide iron–air battery system was developed to clarify its fundamental characteristics and feasibility from the view point of energy Efficiency. The energy flow in one cycle of charge/discharge operations was evaluated under a quasi-state assumption with 0-dimensional models of the system components, i.e., a solid oxide electrochemical cell, an iron (Fe) box and heat exchangers. Special care was taken when considering thermal aspects; not only a simple system but also a more complicated system with thermal recirculation by three heat exchangers was investigated. It was found that the system Round-Trip Efficiency reaches 61% under the base conditions in this study. The results also show that several limitations exist for the operation parameters and conditions in view of practical applications. In particular, higher and lower limits exist for the fuel and air utilization factors under which the system operates effectively because of constraints such as the maximum allowable fuel-blower temperature and no heat input during the discharge operation.
Haisheng Chen - One of the best experts on this subject based on the ideXlab platform.
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Cyclic transient behavior of the Joule–Brayton based pumped heat electricity storage: Modeling and analysis
Renewable & Sustainable Energy Reviews, 2019Co-Authors: Liang Wang, Lei Chai, Long Peng, Dong Yu, Haisheng ChenAbstract:Abstract Pumped heat electricity storage (PHES) has the advantages of a high energy density and high Efficiency and is especially suitable for large-scale energy storage. The performance of PHES has attracted much attention which has been studied mostly based on steady thermodynamics, whereas the transient characteristic of the real energy storage process of PHES cannot be presented. In this paper, a transient analysis method for the PHES system coupling dynamics, heat transfer, and thermodynamics is proposed. Judging with the Round Trip Efficiency and the stability of delivery power, the energy storage behavior of a 10 MW/4 h PHES system is studied with argon and helium as the working gas. The influencing factors such as the pressure ratio, polytropic Efficiency, particle diameters, structure of thermal energy storage reservoirs are also analyzed. The results obtained indicate that, mainly owing to a small resistance loss, helium with a Round-Trip Efficiency of 56.9% has an overwhelming advantage over argon with an Efficiency of 39.3%. Furthermore, the increases in the pressure ratio and isentropic efficiencies improve the energy storage performance considerably. There also exit optimal values of the delivery compression ratio, particle sizes, length-to-diameter ratios of the reservoirs, and discharging durations corresponding to the maximum Round-Trip Efficiency and preferable discharging power stability. The above can provide a basis for the optimal design and operation of the Joule–Brayton based PHES.
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Unbalanced mass flow rate of packed bed thermal energy storage and its influence on the Joule-Brayton based Pumped Thermal Electricity Storage
Energy Conversion and Management, 2019Co-Authors: Liang Wang, Lei Chai, Long Peng, Dong Yu, Haisheng ChenAbstract:Abstract As the most suitable thermal energy storage manner for the Joule-Brayton based Pumped Thermal Electricity Storage (PTES), packed beds thermal energy storage has the natural feature that a steep thermal front propagates with great difference of temperature and density, which lead to an unbalanced mass flow rate of packed bed reservoirs and the PTES close loop. In this paper, the expression of thermal front propagation and unbalanced mass flow rates between the inflow and the outflow of packed beds is developed and validated experimentally. The result indicates that there are 0.62%, 0.26% and 0.36% unbalanced mass flow for the hot reservoir, the cold reservoir and the PTES close loop respectively. The sensitivities of the factors such as pressure ratio, heat capacity of TES material and porosity on the unbalanced mass flow rate and the Round–Trip Efficiency of PTES system considering mass flow rate is discussed. Furthermore, a feasible and self-balancing PTES system without buffer vessel is proposed, with a Round-Trip Efficiency 0.12% higher than the buffer vessel balancing PTES system.
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thermodynamic analysis of the cascaded packed bed cryogenic storage based supercritical air energy storage system
Energy Procedia, 2019Co-Authors: Liang Wang, Guoyue Li, Haisheng ChenAbstract:Abstract This paper presents a thermodynamic analysis of a novel stand-alone supercritical air energy storage (SAES) system, based on cascaded packed bed cryogenic storage. This system has the advantages of low cost, high Efficiency and safety thanks to the different grade cryogenic energy be transferred and stored in two cascaded packed beds. Thermodynamic analysis results show that the discharge pressure and RoundTrip Efficiency are influenced by component efficiencies, charge pressure and middle temperature, and the optimized charge pressure and middle temperature are 120.0 bar and -70°C, respectively, no matter how component efficiencies changes. The increasing liquid air storage pressure reduces the exergy loss in evaporator and condenser and improves the Round Trip Efficiency. Results show that a high Round Trip Efficiency, which is up to 65% could be obtained in this novel supercritical air energy storage system.
Sameer Hameer - One of the best experts on this subject based on the ideXlab platform.
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Thermodynamic Modelling of Thermal Energy Storage Systems
Energy Procedia, 2016Co-Authors: Sameer Hameer, Johannes L. Van NiekerkAbstract:This paper presents a novel methodology for comparing thermal energy storage to electrochemical, chemical, and mechanical energy storage technologies. The underlying physics of this model is hinged on the development of a Round Trip Efficiency formulation for these systems. The charging and discharging processes of compressed air energy storage, flywheel energy storage, fuel cells, and batteries are well understood and defined from a physics standpoint in the context of comparing these systems. However, the challenge lays in comparing the charging process of these systems with the charging process of thermal energy storage systems for concentrating solar power plants (CSP). The Round Trip Efficiency and the levelized cost of energy (LCOE) are the metrics used for comparison purposes. The thermal energy storage system is specifically compared to vanadium redox, sodium sulphur, and compressed air energy storage (CAES) systems from a large scale storage perspective of 100's of MWh. The rationale behind this analysis was to develop an electrical storage Efficiency for molten salt thermal energy storage systems, such that it can be compared to battery energy storage technologies in the context of comparing CSP with thermal energy storage to solar photovoltaic with battery storage from a utility scale perspective. The results from the modelling using Andasol 3 CSP plant as a case study yield a storage Efficiency of 86% and LCOE of $216/MWh. The results of this modelling will facilitate the future generation of a thermal energy storage roadmap.
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A THERMODYNAMIC MODEL FOR COMPARING THERMAL ENERGY STORAGE SYSTEM TO ELECTROCHEMICAL, CHEMICAL, AND MECHANICAL ENERGY STORAGE TECHNOLOGIES
2015Co-Authors: Sameer Hameer, Johannes L. Van NiekerkAbstract:This paper presents a novel methodology for comparing thermal energy storage to electrochemical, chemical, and mechanical energy storage technologies. The machination of this model is hinged on the development of a Round Trip Efficiency formulation for these systems. The charging and discharging processes of compressed air energy storage, flywheel energy storage, fuel cells, and batteries are well understood and defined from a physics standpoint in the context of comparing these systems. However, the challenge lays in comparing the charging process of these systems with the charging process of thermal energy storage systems for concentrating solar power plants (CSP). The source of energy for all these systems is electrical energy except for the CSP plant where the input is thermal energy. In essence, the Round Trip Efficiency for all these systems should be in the form of the ratio of electrical output to electrical input. This paper also presents the thermodynamic modelling equations including the estimation of losses for a CSP plant specifically in terms of the receiver, heat exchanger, storage system, and power block. The Round Trip Efficiency and the levelized cost of energy (LCOE) are the metrics used for comparison purposes. The results from the modelling are compared with solar power plants in operation and literature. The crux of this modelling can be regarded as a platform for the generation of a thermal energy storage roadmap cocooned in a comprehensive energy storage roadmap from a system of systems perspective.
Hideo Yoshida - One of the best experts on this subject based on the ideXlab platform.
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numerical prediction of system Round Trip Efficiency and feasible operating conditions of small scale solid oxide iron air battery
Journal of Power Sources, 2016Co-Authors: Hiroko Ohmori, Hiroshi Iwai, Kotaro Itakura, Motohiro Saito, Hideo YoshidaAbstract:Abstract A simulation model of a small-scale solid oxide iron–air battery system was developed to clarify its fundamental characteristics and feasibility from the view point of energy Efficiency. The energy flow in one cycle of charge/discharge operations was evaluated under a quasi-state assumption with 0-dimensional models of the system components, i.e., a solid oxide electrochemical cell, an iron (Fe) box and heat exchangers. Special care was taken when considering thermal aspects; not only a simple system but also a more complicated system with thermal recirculation by three heat exchangers was investigated. It was found that the system Round-Trip Efficiency reaches 61% under the base conditions in this study. The results also show that several limitations exist for the operation parameters and conditions in view of practical applications. In particular, higher and lower limits exist for the fuel and air utilization factors under which the system operates effectively because of constraints such as the maximum allowable fuel-blower temperature and no heat input during the discharge operation.
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Numerical prediction of system Round-Trip Efficiency and feasible operating conditions of small-scale solid oxide iron–air battery
Journal of Power Sources, 2016Co-Authors: Hiroko Ohmori, Hiroshi Iwai, Kotaro Itakura, Motohiro Saito, Hideo YoshidaAbstract:Abstract A simulation model of a small-scale solid oxide iron–air battery system was developed to clarify its fundamental characteristics and feasibility from the view point of energy Efficiency. The energy flow in one cycle of charge/discharge operations was evaluated under a quasi-state assumption with 0-dimensional models of the system components, i.e., a solid oxide electrochemical cell, an iron (Fe) box and heat exchangers. Special care was taken when considering thermal aspects; not only a simple system but also a more complicated system with thermal recirculation by three heat exchangers was investigated. It was found that the system Round-Trip Efficiency reaches 61% under the base conditions in this study. The results also show that several limitations exist for the operation parameters and conditions in view of practical applications. In particular, higher and lower limits exist for the fuel and air utilization factors under which the system operates effectively because of constraints such as the maximum allowable fuel-blower temperature and no heat input during the discharge operation.
