检索结果-南通市图书馆

exergy analysis of Charge and Discharge Processes of Thermal Energy Storage System with Various Phase Change Materials:A Comprehensive Comparison

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2024年第2期33卷 509-521页

作者： Mojtaba TAHERI Fathollah POURFAYAZ Roghayeh HABIBI Akbar MALEKI Department of Renewable Energies and Environment Faculty of New Sciences and TechnologiesUniversity of TehranTehran***Iran Faculty of Mechanical Engineering Shahrood University of TechnologyShahrood***Iran

Thermal energy storage(TES) is of great importance in solving the mismatch between energy production and *** this regard,choosing type of Phase Change Materials(PCMs) which are widely used to control heat in latent thermal energy storage systems,plays a vital role as a means of TES ***,this field suffers from lack of a comprehensive investigation on the impact of various PCMs in terms of *** address this issue,in this study,in addition to indicating the melting temperature and latent heat of various PCMs,the exergy destruction and exergy efficiency of each material are estimated and compared with each ***,in the present work the impact of PCMs mass and ambient temperature on the exergy efficiency is *** results proved that higher latent heat does not necessarily lead to higher exergy ***,to obtain a suitable exergy efficiency,the specific heat capacity and melting temperature of the PCMs must also be *** to the results,LiF-CaF_(2)(80.5%:19.5%,mass ratio) mixture led to better performance with satisfactory exergy efficiency(98.84%) and notably lower required mass compared to other ***,the highest and lowest exergy destruction are belonged to GR25 and LiF-CaF_(2)(80.5:19.5) mixture,respectively.

关键词： exergy analysis phase change materials thermal energy storage exergy efficiency

exergy analysis of Photo-Thermal Interaction Process between Solar Radiation Energy and Solar Receiver

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2021年第5期30卷 1541-1547页

作者： WANG Gang WANG Cheng CHEN Zeshao School of Energy and Power Engineering Northeast Electric Power UniversityJilin132012China School of Engineering Science University of Science and Technology of ChinaHefei230027China

A unified theory of non-equilibrium radiation thermodynamics is always in search as it is meaningful for solar energy *** exergy analysis of photo-thermal interaction process between the solar radiation energy and solar receiver is conducted in this *** non-equilibrium radiation thermodynamic system is *** thermodynamic process of photo-thermal interaction between the solar radiation and solar receiver is ***,exergy and entropy equations for the photo-thermal process are *** for calculating the optimum receiving temperatures of the solar receiver under both non-concentration and solar concentration conditions are presented.A simple solar receiver is chosen as the calculation example to launch the exergy analysis under non-concentration ***,the effect analysis of solar concentration on the thermodynamic performance of the solar receiver for solar thermal utilization is carried *** analysis results demonstrate that both the output exergy flux and efficiency of the solar receiver can be improved by increasing the solar concentration ratio during the solar thermal utilization *** formulas and results provided in this paper may be used as a theoretical reference for the further studies of non-equilibrium radiation thermodynamic theory and solar thermal utilization.

关键词： non-equilibrium radiation thermodynamics solar energy exergy analysis optimum receiving temperature solar thermal utilization

exergy analysis of Organic Rankine Cycles with Zeotropic Working Fluids

在线全文

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2023年第3期19卷 593-601页

作者： Antonio Mariani Davide Laiso Biagio Morrone Andrea Unich Department of Engineering DI Universitàdella Campania“Luigi Vanvitelli”Aversa(CE)Caserta81031Italy

Waste heat recovery is one of the possible solutions to improve the efficiency of internal combustion *** of wasting the exhaust stream of an energy conversion system into the environment,its residual energy content can be usefully recovered,for example in Organic Rankine Cycles(ORC).This technology has been largely consolidated in stationary power plants but not yet for mobile applications,such as road transport,due to the limitations in the layout and to the constraints on the size and weight of the ORC *** ORC system installed on the exhaust line of a bus powered by a natural gas spark ignition engine has been *** thermal power available at engine exhaust has been evaluated by measuring gas temperature and mass flow rate during real driving *** waste thermal power has been considered as heat input for the ORC plant simulation.A detailed heat exchanger model has been developed because it is a crucial component for the ORC *** exergy analysis of the ORC was performed comparing different working fluids:R601,R1233zd(E)and two zeotropic blends of the two organic pure *** model allowed the evaluation of the ORC produced energy over the driving cycle and the potential benefit on the engine efficiency.

关键词： Organic Rankine Cycle zeotropic mixtures exergy analysis waste heat recovery engine efficiency internal combustion engine

exergy analysis and Optimization of Ladle Furnace Refining Process

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2010年第11期17卷 24-28页

作者： MIN Yi JIANG Mao-fa School ofMaterials and Metallurgy Northeastern University Shenyang 110819 Liaoning China

To decrease energy consumption of ladle furnace, exergy analysis and optimization were conducted based on the ladle furnace refining process of modern clean steelmaking. exergy analysis results showed that exergy loss induced by unavailable electric energy is the largest, and the electric energy efficiency is 46.20%. To cut down the unavailable electric energy, industrial experiments of submerged arc heating were carried out combined with slag composition modification. Results showed that submerged arc heating can be achieved within most heating period, average heating rate increased by 0. 5 ℃/min, unavailable electric energy decreased by 21. 730 MJ per ton steel, and electric energy efficiency was enhanced by 14.84 %. As the refining cycle was shortened, the exergy loss induced by heat elimination decreased from 19. 455 MJ per ton steel to 11. 066 MJ per ton steel.

关键词： LF exergy analysis exergy loss submerged arc heating

exergy analysis of Direct-Expansion Solar-Assisted Heat Pump Based on Experimental Data

在线全文

学校读者我要写书评

暂无评论

Journal of Shanghai Jiaotong university(Science) 2021年第2期26卷 138-145页

作者： KONG Xianggiang CUI Fulin LI Jianbo ZHANG Maoyuan College of Mechanical and Electronic Engineering.Shandong University of Science and Technology Oinedao 266590ShandongChina

The purpose of this research is to reveal the exergy variation of each component in a direct-expansion solar-assisted heat pump(DX-SAHP)*** analysis of the DX-SAHP system with R134a is *** the performance evaluation is *** proposed system is mainly composed of a bare plate solar collec-tor/evaporator,a hermetic variable-frequency rotary-type compressor,a micro-channel condenser and an electronic expansion *** experimental data include the exergy loss *** rates and exergy loss ratios of all components and the infuences of ambient temperature on these *** analysis results show that the average irreversibility rate of the compressor is 204.8 W at an ambient temperature of 16℃,and 149.9 W atan ambient temperature of 27℃.The highest irreversibility rate occurs in the compression process,followed by the throttling *** evaporation process and the condensation process.

关键词： exergy analysis heat pump solar energy direct expansion

Process Study and exergy analysis of a Novel Air Separation Process Cooled by LNG Cold Energy

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Thermal Science 2014年第1期23卷 77-84页

作者： XU Wendong DUAN Jiao MAO Wenjun Key Laboratory of Enhanced Heat Transfer & Energy Conservation of the Ministry of Education School of Chemistry and Chemical EngineeringSouth China University of Technology Zhongshan ling niao Gas Co.Ltd.

In order to resolve the problems of the current air separation process such as the complex process, cumbersome operation and high operating costs, a novel air separation process cooled by LNG cold energy is proposed in this paper, which is based on high-efficiency heat exchanger network and chemical packing separation technology. The operating temperature range of LNG cold energy is widened from 133K-203K to l13K-283K by high- efficiency heat exchanger network and air separation pressure is declined from 0.5MPa to about 0.35MPa due to packing separation technology, thereby greatly improve the energy efficiency. Both the traditional and novel air separation processes are simulated with air handling capacity of 20t＇h-1. Comparing with the traditional process, the LNG consumption is reduced by 44.2%, power consumption decrease is 211.5 kWh per hour, which means the annual benefit will be up to 1.218 million CNY. And the exergy efficiency is also improved by 42.5%.

关键词： LNGs air separation cold energy exergy analysis heat exchanger.

Energy and exergy analysis of a Novel Efficient Combined Process by Hydrothermal Degradation and Superheated Steam Drying of Degradable Organic Wastes

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2006年第3期15卷 274-280页

作者： Shuqing GUO Yunhan XIAO Wendong TIAN Zhedian ZHANG Zhongyuan University of Technology Zhengzhou City Henan Province 450007 China Institute of Engineering Thermophysics Chinese Academy of Sciences Beijing 100080 China

This paper considers the combination of hydrothermal degradation （HTD） and superheated steam （SHS） drying in disposal and processing of degradable organic wastes in municipal solid wastes （MSW）. In SHS drying, a fraction of dryer thermal energy input can be recovered and used to satisfy the heat requirement in maintaining the HTD operating temperature. Both energy and exergy analysis are applied to the combined process. The analysis covers ranges of dryer inlet temperatures of 202.38-234.19~C and feed water content of 32.5-65%. Thermal energy analysis shows that the combination of HTD and SHS drying can achieve thermal energy self-sufficiency （TES） by manipulating process variables. The exergy analysis indicates the location, type, and magnitude of the exergy losses during the whole process by applying the second law of thermodynamics.

关键词： hydrothermal degradation superheated steam drying energy analysis exergy analysis

Synthesis of indirect work exchange networks considering both isothermal and adiabatic process together with exergy analysis

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2018年第8期26卷 1644-1652页

作者： Yu Zhuang Linlin Liu Lei Zhang Jian Du Institute of Chemical Process Systems Engineering School of Chemical Engineering Dalian University of Technology

In this paper, an efficient methodology for synthesizing the indirect work exchange networks(WEN) considering isothermal process and adiabatic process respectively based on transshipment model is first proposed. In contrast with superstructure method, the transshipment model is easier to obtain the minimum utility consumption taken as the objective function and more convenient for us to attain the optimal network configuration for further minimizing the number of units. Different from division of temperature intervals in heat exchange networks,different pressure intervals are gained according to the maximum compression/expansion ratio in consideration of operating principles of indirect work exchangers and the characteristics of no pressure constraints for stream matches. The presented approach for WEN synthesis is a linear programming model applied to the isothermal process, but for indirect work exchange networks with adiabatic process, a nonlinear programming model needs establishing. Additionally, temperatures should be regarded as decision variables limited to the range between inlet and outlet temperatures in each sub-network. The constructed transshipment model can be solved first to get the minimum utility consumption and further to determine the minimum number of units by merging the adjacent pressure intervals on the basis of the proposed merging methods, which is proved to be effective through exergy analysis at the level of units structures. Finally, two cases are calculated to confirm it is dramatically feasible and effective that the optimal WEN configuration can be gained by the proposed method.

关键词： Work exchange networks Transshipment model Adiabatic process exergy analysis Isothermal process Work cascade

Energy and exergy analysis of a 20-MW grid-connected PV plant operating under harsh climatic conditions

在线全文

学校读者我要写书评

暂无评论

Clean Energy 2024年第1期8卷 281-296页

作者： Nouar Aoun Unitéde Recherche en Energies Renouvelables en Milieu Saharien URERMSCentre de Développement des Energies RenouvelablesCDER01000 AdrarAlgeria

Large grid-connected photovoltaic(PV)plants are increasingly being installed around the world,including in harsh desert *** their performance can help improve the design and operation of PV *** study performed an energy and exergy analysis of a 20-MW grid-connected PV plant under desert climatic conditions in southern Algeria over a period of 1 *** PV plant was divided into two 10-MW *** analysis was performed using actual irradiation,power output,wind speed and ambient temperature *** annual average energy efficiency of the plant and subsystems was 10.82%,10.95%and 10.69%,*** radiation had the most significant impact(80%determination coefficient)on thermal exergy *** exergy efficiency of the plant was lower than the literature values,likely due to the harsh desert *** comprehensive energy and exergy analysis provides insights into the performance of large-scale PV plants in desert *** results can help guide the system design and operation improvements for such *** cleaning and cooling could improve performance.

关键词： photovoltaic grid-connected energy exergy analysis efficiency