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thermodynamic optimization of DyCl_3-NaCl System

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Journal of Shanghai University(English Edition) 2005年第3期9卷 279-282页

作者：叶信宇孙益民张静谈君君 College of Chemistry and Materials Science Anhui Normal University Wuhu 241000 P. R. China

In this paper, the phase diagram of the DyCl_3-NaCl system is optimized and calculated with CALPHAD (calculation of phase diagram) technology. A set of thermodynamic functions of compounds Na_3DyCl_6, NaDyCl_4, and NaDy_2Cl_7 have been optimized and calculated based on an interactive computer-assisted analysis. The optimized thermodynamic parameters, calculated phase diagram and experimental phase diagram are thermodynamically self-consistent.

关键词： thermodynamic optimization DyCl_3-NaCl system thermodynamic properties.

Performance Improvement of Combined Cycle Power Plant Based on the optimization of the Bottom Cycle and Heat Recuperation

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Journal of Thermal Science 2007年第1期16卷 84-89页

作者： Wenguo XIANG Yingying CHEN Education Ministry Key Laboratory of Clean Coal Power Generation and Combustion Technology Southeast University Nanjing 210096 China

Many F class gas turbine combined cycle （GTCC） power plants are built in China at present because of less emission and high efficiency. It is of great interest to investigate the efficiency improvement of GTCC plant. A combined cycle with three-pressure reheat heat recovery steam generator （HRSG） is selected for study in this paper. In order to maximize the GTCC efficiency, the optimization of the HRSG operating parameters is performed. The operating parameters are determined by means of a thermodynamic analysis, i.e. the minimization of exergy losses. The influence of HRSG inlet gas temperature on the steam bottoming cycle efficiency is discussed. The result shows that increasing the HRSG inlet temperature has less improvement to steam cycle efficiency when it is over 590℃. Partial gas to gas recuperation in the topping cycle is studied. Joining HRSG optimization with the use of gas to gas heat recuperation, the combined plant efficiency can rise up to 59.05% at base load. In addition, the part load performance of the GTCC power plant gets much better. The efficiency is increased by 2.11% at 75% load and by 4.17% at 50% load.

关键词： Heat Recovery Steam Generators (HRSG) thermodynamic optimization Exergy analysis Combined cycle power plant Efficiency Heat rate

Performance optimization of Irreversible Air Heat Pumps Considering Size Effect

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Journal of Thermal Science 2018年第3期27卷 223-229页

作者： BI Yuehong CHEN Lingen DING Zemin SUN Fengrui Institute of Civil & Architectural Engineering Beijing University of Technology Beijing 100124 China Beijing Key Laboratory of Green Built Environment and Energy Efficient Technology Beijing 100124 China Institute of Thermal Science and Power Engineering Naval University of Engineering Wuhan 430033 China

Considering the size of an irreversible air heat pump （AHP）, heating load density （HLD） is taken as thermodynamic opt/mization objective by using finite-time thermodynamics. Based on an irreversible AHP with infinite reservoir thermal-capacitance rate model, the expression of HLD of AHP is put forward. The HLD opti-mization processes are studied analytically and numerically, which consist of two aspects：（1） to choose pressure ratio; （2） to distribute heat-exchanger inventory. Heat reservoir temperatures, heat transfer performance of heat exchangers as well as irreversibility during compression and expansion processes are important factors influenc-ing on the performance of an irreversible AHP, which are characterized with temperature ratio, heat exchanger inventory as well as isentropic efficiencies, respectively. Those impacts of parameters on the maximum HLD are thoroughly studied. The research results show that HLD optimization can make the size of the AHP system smaller and improve the compactness of system.

关键词： Irreversible Air Heat Pump thermodynamic optimization Heating Load Density Size Effect Finite Time thermodynamics

A novel cryogenic insulation system of hollow glass microspheres and self-evaporation vapor-cooled shield for liquid hydrogen storage

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Frontiers in Energy 2020年第3期14卷 570-577页

作者： Jianpeng ZHENG Liubiao CHEN Ping WANG Jingjie ZHANG Junjie WANG Yuan ZHOU Chinese Academy of Sciences Key Laboratory of Cryogenics Technical Institute of Physics and ChemistryBeijing 100190China University of Chinese Academy of Sciences Beijing 100190China Chinese Academy of Sciences State Key Laboratory of Technologies in Space Cryogenic Propellants Technical Institute of Physics and ChemistryBeijing 100190China

Liquid hydrogen(LH2)attracts widespread attention because of its highest energy storage ***,evaporation loss is a serious problem in LH2 storage due to the low boiling point(20 K).Efficient insulation technology is an important issue in the study of LH2 *** glass microspheres(HGMs)is a potential promising thermal insulation material because of its low apparent thermal conductivity,fast installation(Compared with multi-layer insulation,it can be injected in a short time.),and easy maintenance.A novel cryogenic insulation system consisting of HGMs and a selfevaporating vapor-cooled shield(VCS)is proposed for storage of LH2.A thermodynamic model has been established to analyze the coupled heat transfer characteristics of HGMs and VCS in the composite insulation *** results show that the combination of HGMs and VCS can effectively reduce heat flux into the LH2 *** the increase of VCS number from 1 to 3,the minimum heat flux through HGMs decreases by 57.36%,65.29%,and 68.21%,*** significant advantage of HGMs is that their thermal insulation properties are not sensitive to ambient vacuum *** ambient vacuum rises from 10^-3 Pa to 1 Pa,the heat flux into the LH2 tank increases by approximately 20%.When the vacuum rises from 10^-3 Pa to 100 Pa,the combination of VCS and HGMs reduces the heat flux into the tank by 58.08%-69.84% compared with pure HGMs.

关键词： liquid hydrogen storage hollow glass microspheres(HGMs) self-evaporation vapor-cooled shield(VCS) thermodynamic optimization

一种基于“最优捕集窗口”设计的全球化空气取水系统

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Science Bulletin 2024年第10期69卷 1437-1447页

作者：李乾邵昭邹启宏潘权稳赵曜冯耀辉王雯雯王如竹葛天舒 Institute of Refrigeration and Cryogenics Shanghai Jiao Tong UniversityShanghai 200240China

Atmospheric water harvesting(AWH)is a promising solution to the water shortage *** sorption-based AWH(SAWH)systems seldom obtain both wide climatic adaptability and high energy efficiency due to the lack of thermodynamic *** achieve the ideal harvesting circulation in SAWH systems,the“optimal harvesting window”(OHW)design based on thermodynamic analysis was first proposed and validated by our ***“OHW”theory indicates the water production rate and energy efficiency could be improved by properly reducing the adsorption *** the humidity increases,the optimal adsorption temperature should be closer to the dew point of the *** results revealed that,loaded with 3 kg widely adopted silica gel,the daily water production could reach 5.76-17.64 L/d with ultrahigh energy efficiency of 0.46-1.5 L/*** prototype could also achieve optimal performance in wide climatic conditions in terms of 13-35℃and 18%-72%***,the performance of photovoltaic(PV)-driven SAWH was *** showed that a 1 m^(2)PV panel could generate 0.66-2 L water per day in Shanghai throughout the year,the highest in opening ***,this work introduces a promising concept that can help achieve large-scale,ultra-fast,energyefficient AWH worldwide.

关键词： Atmospheric water harvesting thermodynamic optimization Optimal harvesting window Large-scale and worldwide water production