The Experts below are selected from a list of 295380 Experts worldwide ranked by ideXlab platform
Claudia Toro - One of the best experts on this subject based on the ideXlab platform.
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Thermodynamic analysis of a Rankine dual loop waste thermal energy Recovery System
Energy Conversion and Management, 2016Co-Authors: Enrico Sciubba, Lorenzo Tocci, Claudia ToroAbstract:Waste thermal energy Recovery Systems have assumed an important role in the last decade as an effective way to improve fuel utilization in thermal engines, since they provide an opportunity to produce eco-friendly electrical power from an otherwise wasted energy source, leading to a reduction of the pollution and an increase of the overall System efficiency. In this scenario, the Rankine cycle technology based on simple or Organic Rankine cycle, earned a promising market position, since it allows for the production of additional electric power from relatively low-temperature heat sources (350-650 K); this feature makes these cycles a very suitable solution to recover thermal energy from Internal Combustion Engines, geothermal sources, solar thermal modules and micro-gas turbines. This paper presents the comparison between a single loop and a dual loop waste energy Recovery System specifically designed as a bottomer to marine engines of different power range. The particular application considered shows several advantages for the installation of a waste energy Recovery System; in particular, the basically infinite availability of the cooling medium represented by the seawater substantially facilitates the condenser design. R 245fa and R600 have been implemented in the second Recovery loop and their performance has been addressed. The paper shows how adding a second Recovery loop based on organic Rankine cycle to the steam Rankine cycle loop improves the System performance both in terms of recovered electric power (up to 8.11% and 2.67% respectively in small and large application size) and heat source utilization rate, since the heat source temperature could reach values as low as 343.15 K when considering a sulfur free fuel. In addition, R 245fa is to be preferred over the R 600 since it allows for the production of the same power considering lower values for the cycle top pressures.
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feasibility analysis of a small scale orc energy Recovery System for vehicular application
Energy Conversion and Management, 2014Co-Authors: Roberto Capata, Claudia ToroAbstract:Abstract This paper analyses the feasibility of an “on-board” innovative and patented ORC Recovery System. The vehicle thermal source can be either a typical diesel engine (1400 cc) or a small gas turbine set (15–30 kW). The sensible heat recovered from the exhaust gases feeds the energy Recovery System that can produce sufficient extra power to sustain the conditioning System and other auxiliaries. The concept is suitable for all types of thermally propelled vehicles, but it is studied here for automotive applications. The characteristics of the organic cycle-based Recovery System are discussed, and a preliminary design of the main components, such as the heat Recovery exchanger, the evaporator and the pre-heater is presented. The main challenge are the imposed size and weight limitations that require a particular design for this compact Recovery System. A possible System layout is analyzed and the requirements for a prototypal application are investigated.
Fengyi Zhang - One of the best experts on this subject based on the ideXlab platform.
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4e analysis and multiple objective optimizations of a cascade waste heat Recovery System for waste to energy plant
Energy Conversion and Management, 2021Co-Authors: Mingzhang Pan, Yan Zhu, Jiwen Yin, You Liao, Chengzheng Tong, Fengyi ZhangAbstract:Abstract Owning to its advantage in waste reuse, waste-to-energy technology, has become the most popular way to deal with the increasingly municipal solid waste. However, the energy efficiency of waste-to-energy plant is limited because of the huge heat loss. In this study, a novel waste heat Recovery System, consisting of a supercritical CO2 cycle, an organic Rankine cycle, and an absorption refrigeration cycle, is proposed to improve both the thermal efficiency and economic performance of the waste-to-energy plant. A comprehensive thermodynamic analysis is performed to study the energy and exergy efficiency of the System by establishing a reliable mathematical model. Net present value analysis is carried out to study the final net profit and dynamic investment payback period. Besides, the levelized cost of electricity and ecological efficiency of the waste-to-energy plant are investigated. Based on the results of parameter sensitivity analysis of the System, multiple objective optimizations is carried out by using non-dominated sorting genetic algorithm-II. The results show that the combined System obtains the highest economic benefit in winter. The energy efficiency of the waste-to-energy plant can be up to 75.07% after adding the waste heat Recovery System, with an increment of 54.58%. And the maximum net present value and minimum dynamic payback period are 23.22 M$ and 4.11 years, separately. Compared with the original waste-to-energy plant, the levelized cost of electricity and ecological efficiency are decreased by 68% and increased by 16%, respectively. From the results of sensitivity analysis, the isentropic efficiency of turbine of supercritical CO2 cycle, the evaporator pressure of organic Rankine cycle, and the generator temperature of absorption refrigeration cycle are the most sensitive factors for the thermal efficiency and economic performance of the System. The exergy destruction analysis shows that the exergy destruction rate of the boiler declines to 48.41% after adding the waste heat Recovery System, but the condensers need further improvement for their lowest exergy efficiency. In conclusion, the waste-to-energy plant can provide electricity, heating and cooling simultaneously after adding the waste heat Recovery System and the proposed System is theoretically feasible from the results of thermodynamic, economic and environmental analysis.
Roberto Capata - One of the best experts on this subject based on the ideXlab platform.
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feasibility analysis of a small scale orc energy Recovery System for vehicular application
Energy Conversion and Management, 2014Co-Authors: Roberto Capata, Claudia ToroAbstract:Abstract This paper analyses the feasibility of an “on-board” innovative and patented ORC Recovery System. The vehicle thermal source can be either a typical diesel engine (1400 cc) or a small gas turbine set (15–30 kW). The sensible heat recovered from the exhaust gases feeds the energy Recovery System that can produce sufficient extra power to sustain the conditioning System and other auxiliaries. The concept is suitable for all types of thermally propelled vehicles, but it is studied here for automotive applications. The characteristics of the organic cycle-based Recovery System are discussed, and a preliminary design of the main components, such as the heat Recovery exchanger, the evaporator and the pre-heater is presented. The main challenge are the imposed size and weight limitations that require a particular design for this compact Recovery System. A possible System layout is analyzed and the requirements for a prototypal application are investigated.
K J Chua - One of the best experts on this subject based on the ideXlab platform.
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multi objective optimization of a cryogenic cold energy Recovery System for lng regasification
Energy Conversion and Management, 2021Co-Authors: Y L Shao, K Y Soh, Yangda Wan, Zhifeng Huang, M R Islam, K J ChuaAbstract:Abstract Regasification of LNG for combustion in power plants typically employ seawater as a heat carrier in Open-Rack Vaporizers (ORV), causing much of the cold energy to be lost to the ambient. A comprehensive literature review shows that, thus far, no studies have been conducted to simultaneously consider the impacts of the exergy, economy and environment in the optimal design of a hybrid LNG Recovery System. This paper aims to address this knowledge gap by establishing a multi-objective optimization model for a novel cascading quad-generation cold energy LNG Recovery System. Single- and multi-objective optimizations based on Fuzzy method and Pareto optimal method are carried out on the proposed System to obtain the optimal operating parameters and component sizing, as well as the corresponding performances for each condition. The optimal sizing for each stage is computed for the maximizing of exergy efficiency and CO2 savings rate, and the minimizing of capital cost. The exergy efficiency obtained from the triple-objective optimization yields 12.3% improvement compared to the best result from the single-objective optimization with a 5 kg/s LNG mass flow rate. In addition, when the LNG mass flow is larger than 1 kg/s, the maximized exergy efficiency remains constant (around 0.13) with increasing LNG mass flow rate while the maximized CO2 emission reduction rate and minimized total cost per year increase linearly with the LNG mass flow rate. It has been demonstrated in this work that the System is able to maintain consistency in performance for the optimal design conditions over a wide range of LNG demands and hence good scalability for possible industrial and commercial settings.
Jae Suk Park - One of the best experts on this subject based on the ideXlab platform.
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Effects of secondary combustion on efficiencies and emission reduction in the diesel engine exhaust heat Recovery System
Applied Energy, 2010Co-Authors: Dae Hee Lee, Jun-sik Lee, Jae Suk ParkAbstract:An experimental study on the effects of secondary combustion on efficiencies and emission reduction in the diesel engine exhaust heat Recovery System has been undertaken. The co-generation concept is utilized in that the electric power is produced by the generator connected to the diesel engine, and heat is recovered from both combustion exhaust gases and the engine by the fin-and-tube and shell-and-tube heat exchangers, respectively. A specially designed secondary combustor is installed at the engine outlet in order to reburn the unburned fuel from the diesel engine, thereby improving the System's efficiency as well as reducing air pollution caused by exhaust gases. The main components of the secondary combustor are coiled Nichrome wires heated by the electric current and diesel oxidation catalyst (DOC) housed inside a well insulated stainless steel shell. The performance tests were conducted at four water flow rates of 5, 10, 15 and 20Â L/min and five electric power outputs of 3, 5, 7, 9 and 11Â kW. The results show that at a water flow of 20Â L/min and a power generation of 9Â kW, the total efficiency (thermal efficiency plus electric power generation efficiency) of this System reaches a maximum 94.4% which is approximately 15-20% higher than that of the typical diesel engine exhaust heat Recovery System. Besides, the use of the secondary combustor and heat exchangers results in 80%, 35% and 90% reduction of carbon monoxide (CO), nitrogen oxide (NOx) and particulate matter (PM), respectively.
