A Compound Cycle for Power Generation by Utilizing Residual Heat of Flue Gas in Electric Steelmaking Process

Electric furnace short process steelmaking is one of the most important steelmaking methods in the world today, and the waste heat recovery potential of electric furnace flue gas is huge.?The research on the recovery of electric furnace flue gas waste heat is of great significance. In order to make better use of this part of the heat,?in this paper, a compound cycle of nitrogen Brayton cycle as a first-order cycle and toluene transcritical Rankine cycle as a second-order cycle is proposed to recover waste heat from furnace flue gas in steelmaking process for power generation. A mathematical model was established with the net output power as the objective function and the initial expansion pressure, the final expansion pressure, the initial expansion temperature and the initial pressure of the second cycle as the independent variables. The effect of multivariate on the net output power of the waste heat power generation cycle is studied, and then, the optimal parameters of the compound cycle are determined. The results show that under the general electric furnace steelmaking process, the power generation efficiency of this new cycle can be increased by 21.02% compared with the conventional cycle.

Power Generation from Municipal Solid Waste Plastics

Generation of electrical energy from imported fossil fuels is subject to the price fluctuations of the global marketplace and, thus, constitutes a major expense in its distribution to the end users. Even with the current low prices of fuel, residents and businesses in the United States pay a significant price for their utilities, if not higher than most other countries in the world. Emissions from the evaporation and combustion of these traditional fossil fuels contribute to a range of environmental and health problems, causing poor air quality, and emitting greenhouse gases that contribute to global warming. Alternative fuel created from domestic sources has been proposed as a solution to these problems and much alternative energy are being developed based on solar, wind, biomass, hydropower, fuel cell, geothermal, etc. A new alternative hydrocarbon fuel which is produced from waste plastics can be used with compatble power plants and generators appliances to produce electricity that can be supplied into homes, businesses, power grids and other sectors.

Integration of Low-level Waste Heat Recovery and Liquefied Nature Gas Cold Energy Utilization

Two novel thermal cycles based on Brayton cycle and Rankine cycle are proposed, respectively, which integrate the recovery of low-level waste heat and Liquefied Nature Gas （LNG） cold energy utilization for power generation. Cascade utilization of energy is realized in the two thermal cycles, where low-level waste heat,low-temperature exergy and pressure exergy of LNG are utilized efficiently through the system synthesis. The simulations are carried out using the commercial Aspen Plus 10.2, and the results are analyzed. Compared with the conventional Brayton cycle and Rankine cycle, the two novel cycles bring 60.94% and 60% in exergy efficiency, respectively and 53.08% and 52.31% in thermal efficiency, respectively.

Generation of Electric Power from Domestic Cooking System

This study work related with floating of an idea about conversion of reclaimed thermal energy from domestic cooking system into the electrical power. There were different techniques in use worldwide for harnessing the energy into the appropriate useful work and also to create efficient system for the energy conversion process. The ignorance in this regard might be due to the reason that this wastage did not cost too much for a single home on per day or per month basis, but it could be a ample amount of cost if integrated this loss for a whole city or on yearly bases for a single home. The idea in this work depended upon the recovery of waste heat from Pressure Cookers used in the houses for the domestic cooking purposes, and optimized the reclaimed thermal energy for the conversion into electric power. This research work related with losses of energy discussed and analyzed on the basis of thermo dynamically regarding (a) the wastage of thermal energy escaped through the system due to the spreading of exhaust vapors and taking away significant amount of thermal energy;(b) losses of enthalpy through the dissipate steam;(c) heat losses in the tubing from the Pressure Cooker to the turbine;(d) electric power produces from the system. In this work, new methods were advised, in order to reduce the losses of thermal energy from the system. It would open the venue for researchers to promote this new idea in near future.

Analysis and Economic Evaluation of Hourly Operation Strategy Based on MSW Classification and LNG Multi-Generation System

In this study,a model of combined cooling,heating and power system with municipal solid waste(MSW)and liquefied natural gas(LNG)as energy sources was proposed and developed based on the energy demand of a large community,andMSW was classified and utilized.The systemoperated by determining power by heating load,and measures were taken to reduce operating costs by purchasing and selling LNG,natural gas(NG),cooling,heating,and power.Based on this system model,three operation strategies were proposed based on whether MSW was classified and the length of kitchen waste fermentation time,and each strategy was simulated hourly throughout the year.The results showed that the strategy of MSW classified and centralized fermentation of kitchen waste in summer(i.e.,strategy 3)required the least total amount of LNG for the whole year,which was 47701.77 t.In terms of total annual cost expenditure,strategy 3 had the best overall economy,with the lowest total annual expenditure of 2.7730×108 RMB at LNG and NG unit prices of 4 and 4.2 RMB/kg,respectively.The lower heating value of biogas produced by fermentation of kitchen waste from MSW being classified was higher than that of MSW before being classified,so the average annual thermal economy of the operating strategy of MSW being classified was better than that of MSW not being classified.Among the strategies in which MSW was classified and utilized,strategy 3 could better meet the load demand of users in the corresponding season,and thus this strategy had better thermal economy than the strategy of year-round fermentation of kitchen waste(i.e.,strategy 2).The hourly analysis data showed that the net electrical efficiency of the system varies in the same trend as the cooling,heating and power loads in all seasons,while the relationship between the energy utilization efficiency and load varied from season to season.This study can provide guidance for the practical application of MSW being classified in the system.

考虑光热电站和柔性负荷的电氢热综合能源系统联合优化运行

为解决现有综合能源系统运行灵活性差及风、光消纳难的问题,同时充分利用氢能实现碳减排目标,本文提出一种考虑光热电站和柔性负荷的电氢热综合能源系统联合优化运行方法。首先,基于光热电站和含电转氢余热利用的氢能系统模型构建电氢热综合能源系统。其次,考虑需求侧电氢热柔性负荷的特征和调节价值,构建含可平移、可转移、可削减负荷的电氢热柔性负荷模型。然后,进一步构建考虑电氢热柔性负荷调节特性的电氢热综合能源系统联合优化运行模型。最后,通过算例仿真验证所提方法能够兼顾经济运行与低碳效果,不仅可以提高光热电站与氢能系统的联合运行能力,而且能够有效提升系统运行的经济性和低碳性,电、氢、热负荷峰谷差分别降低6.68%、11.95%、8.35%,系统运行总成本降低24.4%。

基于能量流分析的低温能耗研究

为研究低温环境下导致电耗恶化的主要因素,文章通过整车能量流分析方法,测试了常温(23℃)和低温(-7℃)环境下中国乘用车行驶工况(CLTC-P)各个部件能量消耗。测试结果表明,低温和常温的主要能耗差异部件为电驱、压缩机、低压风扇、鼓风机、水泵等。其中压缩机和电驱消耗增加占比较大,所以重点剖析低温电驱恶化的原因,理论分析电驱低温能耗恶化的原因为低温底盘阻力恶化、低温电驱润滑油粘度增加、电机效率恶化等。为了验证润滑油温对电驱电耗的影响,通过电驱水泵流量控制电驱油温,在不同油温下进行低温CLTC-P工况电耗测试。为了验证低温电驱余热通热泵系统和自加热电驱油温这两个方案的能耗差异,实验过程中同时记录电驱电耗和压缩机电耗以及电驱油温,实验结果表明电驱余热自加热油温总电耗更优。

Diesel generator exhaust heat recovery fully-coupled with intake air heating for off-grid mining operations:An experimental,numerical,and analytical evaluation

The customarily discarded exhaust from the fossil fuel-based power plants of the off-grid mines holds the thermal potential to fulfill the heating requirement of the underground operation.This present research fills in an important research gap by investigating the coupling effect between a diesel exhaust heat recovery and an intake air heating system employed in a remote mine.An integrative approach comprising analytical,numerical,and experimental assessment has been adapted.The novel analytical model developed here establishes the reliability of the proposed mine heating system by providing comparative analysis between a coupled and a decoupled system.The effect of working fluid variation has been examined by the numerical analysis and the possible improvement has been identified.Experimental investigations present a demonstration of the successful lab-scale implementation of the concept and validate the numerical and analytical models developed.Successful deployment of the fully coupled mine heating system proposed here will assist the mining industry on its journey towards energy-efficient,and sustainable mining practices through nearly 70%reduction in fossil fuel consumption for heating intentions.

Technical Analysis: Generation of Electricity by Pyrolysis of Plastics in a Canadian Environment

The study takes motivation from provincial and national issues regarding waste management and electricity production in Canada.Most sources include previous research relating pyrolysis’applications in different parts of the world.The research included 2-3 weeks of extensive reading of previous research and understanding the theory relating polymers.Research has been conducted to understand why polymers have the properties that they do.Thorough analysis about the chemical reactions relating polymers on a small and large scale is conducted.More research was conducted relating to socio-economic conditions of Canada and Singapore for application purposes.Findings of the research point to an addition the Canadian government can uphold i.e.,build more plastic pyrolysis plants in different regions for waste management.Our findings also suggest that the short term spending on such projects can yield long term benefits.This research is important because it will solve Canada’s non-recyclable waste problems,it will help bring in a new source of electricity and it will help increase the budget of municipalities in the long run.This paper is not just informative on polymers,but also will help readers understand issues regarding Canadian waste management and propose possible solutions.

基于能量梯级利用的高效灵活供热系统性能研究

为兼顾供热节能和负荷调节灵活性,构建低品位余热与抽汽耦合的高效灵活供热系统,确定评价供热和调峰的性能指标,并利用Ebsilon软件进行热力建模;针对案例地区研究系统设计工况和变工况热力性能,得到不同供热负荷下的电负荷可调范围,研究同时满足热、电需求下的系统灵活运行调控策略及能耗特性。结果表明:系统通过能质匹配,降低比当量电耗,实现了低能耗供热,设计工况供热煤耗率为13.3kg/GJ;调峰容量比最大为48.1%,比抽背模式提高24.3%;电热负荷变化时,背-抽-切方式间切换,供热煤耗率区间为8~14.7kg/GJ;供热煤耗率随电负荷率降低而增加;系统充分发挥低品位余热供热的节能优势,且在一定范围内热电解耦,兼顾了“节能”与“灵活”运行。

基于Stackelberg博弈的钢铁企业余热余压发电的上网电价策略

研究钢铁行业余热余压发电与传统火力发电组成的电力市场,分析钢铁企业余热余压发电上网电价策略.建立了有关钢铁企业、传统化石燃料发电企业和地方政府三方的斯坦克尔伯格博弈(Stackelberg)模型,比较余热余压发电技术上网电价的三种定价策略(固定价格、固定溢价和可变溢价),并进行了数值模拟分析市场规模、余热余压发电成本系数和钢铁企业环境成本对最优规制价格、最优钢铁企业利润和最优社会总福利的影响.结果表明:三种定价策略下最优规制价格、最优钢铁企业利润和最优社会总福利差异非常大.不同偏好的政策制定者会从不同的风险性和补贴选择不同的定价策略.其中,风险性大和补贴高是最优规则价格中的可变溢价策略、最优钢铁企业利润中的固定溢价策略和最优社会总福利中的可变溢价策略;风险性低和补贴低是最优规则价格中的固定价格策略、最优钢铁企业利润中的固定价格策略和最优社会总福利中的固定溢价策略;其他情形的风险性和补贴位于这两种情况之间.

钢铁烧结余热发电控制系统的设计与应用分析

针对目前钢铁企业烧结废热发电的电力控制系统在实际开发和施工中存在的多种问题,基于余热发电电气控制系统的功能特点,从烧结废热发电控制系统结构、烧结余热锅炉DCS系统结构、控制组态软件选型、人机界面软件选型四个方面总体设计了烧结废热发电控制方案,并将其在实际生产中予以应用。应用表明,该系统可使余热资源得到充分利用,实现节能降耗。

基于水泥厂电能计量系统的新能源发电接入点的选择

水泥工厂引入新能源发电技术后,如何合理设置电能计量点及新能源发电接入点,关系到水泥工厂电力系统的安全性、稳定性和经济性。阐述了某水泥生产线电能计量与分析系统的布置方案,基于该电能计量系统布置、并网电压等级、容量要求,提出了光伏发电、风力发电和余热发电三种新能源发电方式接入点方案的选择。通过合理规划水泥厂电能计量系统布置和新能源发电接入点,可实时、全面地收录水泥厂电力系统运行数据,优化电能管理,进一步实现节能降耗。

Nanofluidic osmotic power generation from CO_(2) with cellulose membranes

The diffusion of chemical species down concentration gradient is a ubiquitous phenomenon that releases Gibbs free energy.Nanofluidic materials have shown great promise in harvesting the energy from ionic diffusion via the reverse electrodialysis process.In principle,any chemicals that can be converted to ions can be used for nanofluidic power generation.In this work,we demonstrate the power generation from the diffusion of CO_(2) into air using nanofluidic cellulose membranes.By dissolving CO_(2) in water,a power density of 87 mW/m^(2) can be achieved.Using monoethanolamine solutions to dissolve CO_(2),the power density can be increased to 2.6 W/m^(2).We further demonstrate that the waste heat released in industrial and carbon capture processes,can be simultaneously harvested with our nanofluidic membranes,increasing the power density up to 16 W/m^(2) under a temperature difference of 30°C.Therefore,our work should expand the application scope of nanofluidic osmotic power generation and contribute to carbon utilization and capture technologies.

热动领域的化学技术对电力系统的影响与应用

文章以余热锅炉和航改型燃机为重点,介绍了热动领域化学技术的原理和应用,概述了电力系统的基本概念、组成和运行机制,分析了化学技术对电力系统相关方面的影响,阐述了余热锅炉和航改型燃机工作原理及其在电力系统中的作用,并介绍了利用热动力化学技术提高其效率的方法和技术,展望了热动力化学技术在电力系统中的应用前景与挑战,并提出了解决策略和建议。

热管在核电工程中的应用

概述了热管在空间核电源、核废料冷却、事故条件下安全壳的保护等方面的应用情况，并提出了将热管应用于核电工程中的蒸汽发生器。介绍了国内外针对这些应用所进行的开发研究工作。已有的研究工作表明：根据不同的温度范围选择适当的热管壳体材料、工作介质和吸液芯结构，经过仔细的设计、必要的实验和精良的制作。

电炉烟气余热发电系统的优化设计

本文分析了电炉烟气余热回收的难度和研究现状,针对电炉烟气的特性,提出了中压过热蒸汽余热发电系统,分析了其需要解决的关键技术问题,并对100 t电炉余热发电系统的经济效益进行了分析,结果表明该系统具有良好的经济和社会效益,对各企业开展余热发电具有重要的参考价值。

考虑广义电热需求响应的含碳捕集电厂综合能源系统低碳经济调度

构建综合能源系统(integrated energy system,IES),并对燃煤机组进行低碳化改造,同时辅以广义需求响应资源,是实现碳达峰、碳中和的重要途径。该文提出了考虑广义电热需求响应的源-荷协调IES低碳经济调度模型,结合有机朗肯循环余热发电和电热综合需求响应能增加源荷两侧灵活性的特点,改善了火电机组低碳化改造过程中存在的峰荷时段碳捕集水平不足问题。首先,在IES中引入余热回收装置,解耦热电联产(combined heat and power,CHP)机组“以热定电”约束,灵活CHP机组电出力。其次,考虑基于分时电价和供热舒适度模糊性的电热综合需求响应,与余热回收的热电负荷调节效应相协同,构建广义电热需求响应模型,并挖掘其源-荷协调低碳调度机理。最后,以系统运行总成本最优为目标制定机组出力方案,并采用CPLEX求解器对所构建模型进行求解。仿真算例表明:该方法有效提高了碳捕集电厂捕碳水平,兼顾了系统的经济性与低碳性,可为含碳捕集电厂的IES低碳经济调度提供参考。

钢铁企业余热余能转换或替代电能的途径

钢铁企业是用能大户,利用余热余能技术发电或替代耗电设备可有效降低电能消耗,减少企业外购电能。余热余能转换成电能的主要途径有可燃废气通过燃烧发电,燃气—蒸汽联合循环发电,烧结余热发电,转炉轧钢加热炉发电等。替代电能的主要途径有汽轮机拖动风机旋转等。这些措施为钢铁企业实现节能降耗提供了有效途径。

混合动力发动机与动力电池冷却余热双向循环预热

为了提高并联式混合动力汽车发动机和动力电池低温生存能力,探索发动机与电池冷却余热资源的利用新途径,提出了一种基于余热再利用的发动机和动力电池双向循环低温预热的新方法。建立发动机和动力电池余热数值模型,定量分析和研究余热系统的温升特点与温度分布状况,揭示了发动机与动力电池余热的传热规律,设计了基于相变材料的自动双向热控装置并进行了低温试验。结果表明:该方法实现了发动机与动力电池吸热冷却和发热加热的一体化应用,可将发动机冷却余热经热换器预热动力电池并使电池内部温度保持在29℃,又将动力电池冷却余热反向循环传输至发动机机体,使发动机内部冷却液温度预热至51℃,能够明显提高发动机和动力电池低温运行能力,节约了能量,验证了所提方法的优越性。