双效复叠吸附式制冷循环的研究

为克服吸附式制冷能量利用效率不高的缺点，采用硅胶－水、分子筛－水分别作为两级循环的工作对以及两级循环中都用分子筛－水为工作对，构造了两种双效复叠式制冷循环．该循环可有效利用第二级循环的吸附热、析出蒸汽的显热，能有效提高热力完善度。建立了计算机模型，对系统和影响性能的一些参数进行了分析讨论。     

一个带喷射器的两级吸收式制冷循环

提出一种带喷射器的两级吸收式制冷循环,部分低压发生器出口的制冷剂蒸气被高压发生器出口的制冷剂蒸气直接引射到冷凝压力。相比传统的两级吸收式制冷循环,由于部分制冷剂无需被高压溶液循环吸收和发生,因此新循环拥有更高的性能系数。以水-溴化锂作为工质的模拟结果显示,在部分工况下,新循环相对传统两级吸收式制冷循环的COP可提高20%以上。     

渔船发动机废热驱动的两级复叠吸收制冷循环性能分析

针对传统吸收式制冷无法达到较低温度以及自复叠吸收制冷在制得较低温度时系统性能系数过小的缺点,提出发动机废热驱动的两级复叠式吸收制冷循环用于捕获海产品的速冻保鲜。首先采用SRK方程获得了该循环高、低温级工质对R134a/DMF和R23/DMF的热力学性质参数,进而对循环进行了建模分析。通过直接搜索法得到了在不同工况下的最优高温级发生温度。发现在当吸收温度为30℃,冷凝温度为35℃,制冷温度在-40℃以上时,循环最佳蒸发冷凝温度和高、低温级发生温度分别为-3℃、106℃和140℃,此时循环COPint 可达到0.143。但该循环性能受吸收、冷凝温度影响较大,因此不太适合在海水温度过高的海域使用。     

CO2-[emim][Tf2N]喷射-吸收冷热电联供循环㶲效率分析

针对传统吸收式冷热电联供循环存在制冷量和制冷效率低等缺陷,提出了一种新型低品位热驱动CO2-[emim][Tf2N]喷射-吸收冷热电联供循环.通过构建新型喷射-吸收冷热电联供循环理论模型及理论模拟计算,分析新循环的关键性参数对其性能的影响.结果表明:提高循环冷却水进口温度及冷冻水进口温度均可有效提高循环性能,冷却水进口...     

低品位热驱动的混合工质喷射制冷循环研究

提出一种低品位热驱动的混合工质喷射制冷循环,将沸点相差较大的非共沸混合工质引入喷射制冷循环,采用两级分凝分离降低该新循环压比,实现在喷射制冷循环中获得较低的制冷温度和较高制冷效率。建立组成循环各部件热力学数学模型,在系统稳定运行的条件下,分析喷射器压比、冷凝温度和混合工质组分配比对新循环工作性能的影响。研究表明:采用混合工质R600/R290的喷射制冷循环可获得低于-20℃的制冷温度。     

热阻、热漏和内不可逆性对两级吸收式制冷循环性能的影响

建立考虑工质与外部热源间的传热损失、内不可逆性损失及外部热源热漏损失的不可逆两级吸收式制冷循环模型,给出制冷系数和制冷率的一般关系。在6个换热器总热导率一定时,对循环性能进行优化,导出循环制冷率和制冷系数的基本优化关系,并得到制冷率和制冷系数的极值。通过数值算例,分析热阻、热漏和内不可逆性损失对循环性能的影响规律。     

太阳能海洋热能驱动的冷电联供循环热力分析

基于南海地区渔业冷库的实际需求,结合海洋温差能综合利用技术,提出一种利用太阳能辅热的吸收式双级引射增压OTEC动力-制冷混合循环。该混合循环以太阳集热器加热的表层温海水作为循环热源,同时以深层冷海水作为循环冷源,可兼顾渔业冷库制冷与发电。建立该动力-制冷混合循环模型,并对该循环进行热力学分析。结果表明:混合循环冷库温度可达到-30℃以下,混合循环有效效率为7.82%;与OTEC制冷动力复合循环相比,采用压缩制冷的混合循环制冷量可增加70.5%,制冷温度降低12℃;提高太阳集热器出口温度有助于提升混合循环热力性能,而过高的发生器压力则会降低混合循环热力性能。     

烧结型沸石分子筛(1 3X)-水有效导热系数之测定

研究了一种新型吸附式制冷单元管－烧结型13X沸石分子筛单元管的传热性能，指出：沸石层的传热性能是制约吸附式制冷（热）循环效率的主要因素。本文提出了一种测定含水沸石层工作过程有效导热系数的方法，并进行了实验测定。     

可利用低品位热源的Einstein循环初始运行参数确定

Einstein制冷循环通过制冷剂(正丁烷)、压力平衡剂(氨气)和吸收剂(水)协同作用,在三工质连续的扩散-吸收循环过程中产生制冷效应.制冷装置的驱动力可由太阳能等低品位能源提供.使用状态方程法(EOS),选用适合描述强极性工质汽液两相物性的Patel-Teja(PT)立方型方程,结合Reid-Panagiotopolos混合规则对Einstein制冷循环中NH3/C4H10和NH3/H2O混合工质的相平衡性质进行了预测,得出几组不同压力条件下的相平衡数据.利用校核计算后所绘相图,结合制冷循环的经济实用性,完成了Einstein制冷循环初始运行状态参数的确定,为该制冷循环的热力设计计算创造了条件.     

太阳能溴化锂吸收式制冷技术的研究进展

介绍了太阳能澳化锂吸收式制冷循环的工作原理和系统构成,具体阐述了该制冷循环的几种典型结构,包括单效、双效、两级以及三效涣化锂吸收式制冷循环,分析了各种制冷循环的优缺点以及目前研究进展;进一步讨论了太阳能澳化锂吸收式制冷机组的性能特点受冷媒水出口温度、冷却水进口温度、加热蒸汽温度、污垢系数及不凝性气体等诸多因素的影响;提出了太阳能溴化锂吸收式制冷技术现存问题,最后指出,随着科学技术的发展和绿色建筑的兴起,太阳能溴化锂吸收式制冷将会有非常大的发展前景。     

Trace metal chemistry and silicification of microorganisms in geothermal sinter, Taupo Volcanic Zone, New Zealand

As part of a pilot study investigating the role of microorganisms in the immobilisation of As, Sb, B, Tl and Hg, the inorganic geochemistry of seven different active sinter deposits and their contact fluids were characterised. A comprehensive series of sequential extractions for a suite of trace elements was carried out on siliceous sinter and a mixed silica-carbonate sinter. The extractions showed whether metals were loosely exchangeable or bound to carbonate, oxide, organic or crystalline fractions. Hyperthermophilic microbial communities associated with sinters deposited from high temperature (92–94°C) fluids at a variety of geothermal sources were investigated using SEM. The rapidity and style of silicification of the hyperthermophiles can be correlated with the dissolved silica content of the fluid. Although high concentrations of Hg and Tl were found associated with the organic fraction of the sinters, there was no evidence to suggest that any of the heavy metals were associated preferentially with the hyperthermophiles at the high temperature (92–94°C) ends of the terrestrial thermal spring ecosystems studied.     

尿素喷射计量试验控制系统的硬件开发与测试

尿素喷射计量试验是完成车载尿素喷射计量装置的功能开发和性能考核的重要环节,而该试验内容离不开尿素喷射计量试验控制系统(UCDS)的开发,本文基于尿素喷射计量系统(UDS)的组成,开发出了试验所需的控制系统的硬件平台,用模块化的设计思想对UDCS控制器进行了方案设计,测试结果与设计目标一致,达到了尿素喷射计量试验的要求.     

Characterization and prediction of biomass pyrolysis products

In this study some literature data on the pyrolysis characteristics of biomass under inert atmosphere were structured and analyzed, constituting a guide to the conversion behavior of a fuel particle within the temperature range of 200-1000 °C. Data is presented for both pyrolytic product distribution (yields of char, total liquids, water, total gas and individual gas species) and properties (elemental composition and heating value) showing clear dependencies on peak temperature. Empirical relationships are derived from the collected data, over a wide range of pyrolysis conditions and considering a variety of fuels, including relations between the yields of gas-phase volatiles and thermochemical properties of char, tar and gas. An empirical model for the stoichiometry of biomass pyrolysis is presented, where empirical parameters are introduced to close the conservation equations describing the process. The composition of pyrolytic volatiles is described by means of a relevant number of species: H₂O, tar, CO₂, CO, H₂, CH₄ and other light hydrocarbons. The model is here primarily used as a tool in the analysis of the general trends of biomass pyrolysis, enabling also to verify the consistency of the collected data. Comparison of model results with the literature data shows that the information on product properties is well correlated with the one on product distribution. The prediction capability of the model is briefly addressed, with the results showing that the yields of volatiles released from a specific biomass are predicted with a reasonable accuracy. Particle models of the type presented in this study can be useful as a submodel in comprehensive reactor models simulating pyrolysis, gasification or combustion processes.     

Economic viability assessment of sustainable hydrogen production,storage, and utilisation technologies integrated into on- and off-grid micro-grids: A performance comparison of different meta-heuristics

In recent years, there has been considerable interest in the development of zero-emissions, sustainable energy systems utilising the potential of hydrogen energy technologies. However, the improper long-term economic assessment of costs and consequences of such hydrogen-based renewable energy systems has hindered the transition to the so-called hydrogen economy in many cases. One of the main reasons for this is the inefficiency of the optimization techniques employed to estimate the whole-life costs of such systems. Owing to the highly nonlinear and non-convex nature of the life-cycle cost optimization problems of sustainable energy systems using hydrogen as an energy carrier, meta-heuristic optimization techniques must be utilised to solve them. To this end, using a specifically developed artificial intelligence-based micro-grid capacity planning method, this paper examines the performances of twenty meta-heuristics in solving the optimal design problems of three conceptualised hydrogen-based micro-grids, as test-case systems. Accordingly, the obtained numeric simulation results using MATLAB indicate that some of the newly introduced meta-heuristics can play a key role in facilitating the successful, cost-effective development and implementation of hydrogen supply chain models. Notably, the moth-flame optimization algorithm is found capable of reducing the life-cycle costs of micro-grids by up to 6.5% as compared to the dragonfly algorithm.     

The oxidation of hydrogen cyanide and related chemistry

For modeling the formation of nitrogen oxides in combustion via both the prompt-NO and the fuel-NO mechanisms, as well as for modeling the reduction of nitrogen oxides via reburning, a good knowledge of the kinetics of oxidation of hydrogen cyanide (HCN) is required. The formation routes to HCN and the thermochemistry of HCN-related species are reviewed. The available kinetic data for the oxidation of HCN are presented and a comprehensive detailed chemical kinetic reaction mechanism for the oxidation of HCN is proposed and discussed.     

Wind power for pumping: The development of the ITP windpump

Water pumping has been one of the main applications for wind power in the past and despite the spread of mains-electric pumps, more than a million windpumps remain in regular use. This paper reviews the general technical and economic requirements for pumping water using wind energy and by way of example gives an overview of the development of the new ITP wind-pump. It then considers the future prospects for this kind of technology.     

静电除尘器和湿法烟气脱硫装置对烟气汞形态的影响与控制

利用安大略标准方法和在线汞监测技术对6套典型燃煤电站锅炉静电除尘器(ESP)和湿法烟气脱硫(WFGD)装置前后烟气汞的浓度及形态进行了测试,并研究了2种装置对烟气汞形态转化的影响及其汞控制能力.结果表明:ESP对飞灰的捕获直接降低了烟气中颗粒汞的比例,从已测试的典型燃煤锅炉来看,ESP前的燃煤烟气中颗粒汞的平均比例在30%左右,经ESP后颗粒汞所占比例降至5%左右;经WFGD装置洗涤后,烟气中汞的形态发生了较大的改变,二价汞基本被捕获,进入WFGD装置的烟气中二价汞的比例越高,WFGD装置对烟气汞的脱除效率也越高.配置有选择性催化还原(SCR)脱硝装置+ESP+WFGD尾部烟气处理装置的燃煤电厂,能够很好地控制燃煤烟气汞的排放.     

Qualitative Properties of Foliations on Closed Surfaces

The paper contains a survey of the author's results obtained at last ten years on a research of foliations with singularities on closed surfaces. The following problems of the qualitative theory of foliations are considered.(1) Generalization of the Poincaré–Bendixon theory.(2) Kneser problem and estimation of the number of quasiminimal sets.(3) Anosov problem about interrelation between geodesics and asymptotic behavior of leaves of foliations.(4) Topological classification of supertransitive foliations.     

车用汽油机HC排放分布规律研究

根据大量ＨＣ排放实测数据，运用数理统计手段，研究确定国产主要车型货车和轿车汽油机ＨＣ排放分布规律及分布参数，进而建立了相应国车用汽油机的ＨＣ排放分布计算模型。它对准确对计算车用汽油机ＨＣ排放分布数值和评价车用汽油机ＨＣ排放对大气环境的影响等，具有十分重要的作用。     

The recent European biofuel debate as a case study in the politics of renewable energy

This study outlines a number of issues of a political nature, associated with the implementation of renewables, with the primary emphasis on the recent European push for the production of liquid biofuels. In recent years biofuels have been gaining increasing attention as a potential alternative to conventional automotive fuels. This potential has recently become an issue in the European Union (EU) with surplus agricultural land being considered for the production of energy crops. In this paper political issues at stake in the promotion of biofuel crops in the EU are examined. A critical analysis is made of the environmental claims put forward in defence of the promotion of these fuel crops and comparisons made with alternate woody biomass fuels. Contrasts are drawn between this case study and other examples of the implementation of renewables including the development of PV in the US and wind power in the UK. Conclusions are made regarding the impact of the issues thrown up on the future development of renewables.