Analysis and Prospect of Waste Heat Utilization from Blast Furnace Slag Flushing

Estimating the residual heat of blast furnace slag flushing in China,classifying and introducing the current proposed methods of slag flushing waste heat utilization,and listing existing cases.In order to better save energy and water in the slag flushing process of blast furnaces,an ideal comprehensive cascade utilization system scheme for annual recovery of waste heat is proposed.Based on the measured waste heat data of a steel plant,design calculations are carried out to further analyze the economic feasibility of the new scheme and provide reference for its promotion and application.

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

分别地，二个新奇热周期基于 Brayton 周期和 Rankine 被建议它集成低级废热和液化性质气体(LNG ) 的恢复为发电的冷精力利用。在低级废热，低温度的 exergy 和 LNG 的压力 exergy 通过系统合成高效地被利用的地方，精力的串联利用在二个热周期被认识到。模拟加 10.2 用商业白杨被执行，并且结果被分析。与常规 Brayton 周期和 Rankine 相比，二个新奇周期在 exergy 效率带 60.94% 和 60% ，分别地并且 53.08% 和 52.31% 在热效率分别地。

Technical and Economic Aspects and Experience from 6 Years of Operating the Technology Using the Waste Heat from the Exhaust Gases of Heat Sources and 3 Years of Operating a Heating Plant in an Autonomous, Island Regime

This article is focused on technical and economic evaluation of more than 6-years experiences of operating the Waste Heat Recovery technology—the manner and system of flue gas processing generated in the combustion process in heat & power plants, cogeneration units, etc., which burn the gaseous fuel, primarily natural gas, or methane, biogas, geothermal gas, or other gaseous mixtures containing hydrogen. The solution proposes a more effective and non-traditional use of gaseous fuel for heating, the flue gases of which are processed in order to extract additional utilisable heat, with potential elimination of CO2 from them. Deploying of the heating plant in an island regime (OFF-GRID) enables definition of the benefits brought by the 3 years of operational experience and presents visions for the future offering the possibility to utilise the support energy services at the municipal as well as regional level.

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.

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.

Thermodynamics of Cascaded Waste Heat Utilization from Flue Gas and Circulating Cooling Water

A detailed thermal power plant model was developed to evaluate power plant waste heat usage in terms of the operating parameters,energy consumption,water consumption,and pollutant emissions.This model was used to analyze the bypass flue gas energy cascade utilization design which provides excellent energy savings and emission reductions.This paper then presents a design to use the low-temperature waste heat and to extract water from the flue gas.The low-grade heat can be recovered from a coal-fired unit using absorption heat pumps to increase the air preheating.This method significantly reduces the turbine steam extraction in the low pressure stages which increases the turbine power and reduces the coal consumption.This design has a small heat transfer temperature difference between the air preheater and the air warmer,resulting in a smaller exergy loss.The power output of the present design was 1024.28 MW with a coal consumption savings of 3.69 g·(kWh)^(−1).In addition,the present design extracts moisture out of the flue gas to produce 46.48 t·h^(−1)of water.The main goal of this work is to provide a theoretical analysis for studying complex thermal power plant systems and various energy conservation and CO_(2)reduction options for conventional power plants.

余热余压空气梯级利用的双涡流管有机朗肯循环综合性能分析与优化

为充分利用工业生产中的余热余压空气能量,同时降低ORC系统冷凝热损失,该文提出一种双涡流管ORC系统(ORC coupled with double vortex tubes,DVT-ORC)。利用热源涡流管将放热后的余热余压空气分离成冷、热空气,冷空气用于工质冷却,热空气作为二级蒸发器的热源且换热后其余压用于驱动气动增压泵;利用工质涡流管将透平乏气分离成冷、热气流,热气流经气动增压泵升压再循环,冷气流进入空气冷却器冷却。以150℃、0.6 MPa的空气为初始热源,R245fa为工质,建立热力与经济的多目标优化模型,分析双涡流管冷流比和透平排气压力对系统综合性能的影响;采用遗传算法进行优化,确定系统最优工况。结果表明:当热源涡流管冷流比大于0.3时,DVT-ORC输出功大于基本ORC输出功,工质涡流管与空气冷却器的㶲损失之和较基本ORC系统冷凝器的㶲损失最大可减小1240.32 kW,单位电力生产成本较低,DVT-ORC系统热力性与经济性提升。系统最佳运行工况在透平排气压力为0.3007 MPa、工质涡流管冷流比为0.8738、热源涡流管冷流比为0.8942时,对应的净输出功为173.94 kW、热效率为13.57%、单位电力生产成本为0.415元/(kW·h)。

集成碳捕集的1000 MW超超临界燃煤机组热力系统优化与性能研究

为降低CO_(2)的能耗并且提高发电效率,以超超临界二次再热-碳捕集系统为参考系统,提出了耦合太阳和ORC系统的二次再热-碳捕集优化方案。利用Ebsilon软件构建了优化系统模型,并进行了热力性能、经济性和运行性能分析。结果表明:与参考系统相比,优化系统热效率提高了4.78%,热耗降低了1005 kJ/(kW·h),煤耗降低了36.50 g/(kW·h);太阳能辅助系统年运行时间占比为60%,均省煤量可达到2.0×10^(4)t。优化方案具有更好的热经济性并且减少了发电耗煤量,为CO_(2)捕集和减排提供优化思路。

A Distributed Energy System with Advanced Utilization of Internal Combustion Engine Waste Heat

New trigeneration system consists of an internal combustion engine,a power and cooling cogeneration system and an absorption heat transformer system.The exhaust gas is recovered by the power and cooling cogeneration subsystem producing the cooling and power.The jacket water is recovered by the absorption heat transformer subsystem producing lowpressure steam.The exergy performance and the energy saving performance which is evaluated by the primary energy saving ratio of the new distributed energy system are analyzed.The effects of the ratio of the output power and cooling of the power and cooling cogeneration subsystem and the generator outlet temperature of the absorption heat transformer subsystem to the primary energy saving ratio are considered.The contributions of the subsystems to the primary energy saving ratio are quantified.The maximum primary energy saving ratio of the new distributed energy system is 15.8%,which is 3.9 percentage points higher than that of the conventional distributed energy system due to the cascade utilization of the waste heat from the internal combustion engine.

某调度通信楼空调系统节能减碳改造设计实践

重点介绍了某调度通信楼空调系统的节能减碳改造设计,通过综合运用余热回收、可再生能源、固体蓄热、高效制冷机房等多项技术,构建了安全可靠、绿色低碳、高效节能的空调系统。采用HDY-SMAD空调负荷计算及分析软件模拟了建筑物全年的空调能耗,并对优化前后空调系统的运行能耗和碳排放进行了测算。结果显示,优化方案空调系统全年节约电量100万kW·h,全年碳减排573 t,节能减碳效果显著。

生物质好氧发酵热生产与回收利用研究进展

好氧发酵是目前有机固体废弃物处理的一种有效手段。人们对于好氧发酵的研究主要集中在高效有机肥的获取上,但发酵过程产生的热能不容忽视。发酵热作为一种“零碳”能源,可代替传统化石能源应用于加温供暖、生物干化等领域,助力实现“碳达峰、碳中和”。为将生物质能高效转化为热能利用,人们对发酵热回收利用进行了研究,但是没有将热生产、热回收和热利用三个阶段进行系统联系,导致热回收工艺效率不高。该文主要阐述了好氧发酵产热原理,并从菌剂、原料理化性质和发酵工艺三个方面对发酵热生产的影响进行了探讨,总结了现有热回收利用系统,最后对生物质好氧发酵热生产与回收利用系统的发展方向进行展望,以期为生物质发酵热能利用提供支持。

基于相变材料的蒸汽卡诺电池热力学循环设计

为了研究工业园区综合能源系统的多能互补新路线,提出基于高低温相变材料的新型蒸汽卡诺电池.建立计及设备性能与质量流量的热力学循环计算模型,分析设计参数、多级压缩结构对系统热泵系数、循环效率、储电损失与供热(火用)效率的影响.通过探究发现,低温相变材料的相变温度和高温相变材料的相变温度是影响蒸汽卡诺电池性能的主要因素,得到蒸汽卡诺电池的高循环性能区.优化蒸汽卡诺电池的参数与结构,结果表明,循环效率可达56.96%,热泵系数可达2.55,供热(火用)效率可达68.74%.

海上平台烟气余热利用分析与工艺优化

依托南海某在建钻采平台,从工艺原理、工艺流程、有机工质的选择、安全性、能源节约及降低二氧化碳排放等方面进行分析,论证有机朗肯循环(Organic Rankine Cycle,ORC)技术在海上平台应用的可行性。根据能量梯级利用原则,设计一套优化的烟气-导热油-热用户系统,利用透平废热实现ORC发电、生产系统加热及溴化锂制冷的热电冷联产系统。

基于太阳能和双有机朗肯循环的液态空气储能系统特性研究

为了解决传统太阳能蓄热式液态空气储能系统(LAES-S)余热利用不完全的问题,进一步提高系统的往返效率,文章在LAES-S系统基础上,构建了一个耦合太阳能蓄热和双有机朗肯循环的液态空气储能系统(LAES-S-O),并建立了耦合系统的热力学模型,分析了关键参数对系统性能的影响。结果表明:典型工况下,子系统ORC1和ORC2的净输出功分别为1296 kW和6695.83 kW;新系统的往返效率可达117.63%,火用效率为38.97%,能量效率为28.88%,与参考系统相比,分别提升了12.58%,2.35%,1.21%。此外,该系统还为用户提供了温度为364.15 K的生活热水,实现了热电联产功效。对关键参数的敏感性分析显示,当液化压力(末级压缩机出口压力)从15 MPa升高到18 MPa,液化温度(节流阀入口空气温度)从93.15 K上升到113.15 K时,空气液化率、往返效率、火用效率随液化压力的增大而降低,液化压力和温度的提高不利于系统性能的提升;但当排气压力从5.3 MPa升高至7.7 MPa时,往返效率、火用效率均随之升高。研究结果可为液态空气耦合太阳能系统提供一定的理论支持。

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%。

耦合余热回收下电站锅炉尾部烟气热能高效梯级利用系统设计

针对电站锅炉尾部烟气热能利用效率较低,梯级利用数值模拟过程与全尺度数据分析过程偏差较大的问题,设计了一种耦合余热回收下的电站锅炉尾部烟气热能高效梯级利用系统。实验结果表明,系统的最佳烟气热能高效梯级节点利用情况和热能梯级置换情况整体都保持在60%以上,采用热能阶梯式温差电站后,系统整体效率提高了约22%,证明了所设计系统的使用优越性。

多热网联动提高石化企业余热利用率研究

针对大中型城市供热能力不足、能源消耗量大、能源利用效率低、污染物排放量大的问题,提出了提高余热利用率以实现清洁能源替代、环境保护、节能增效的有效手段。石化企业作为耗能大户,低温余热排放量大,将其低温余热回收用于供热可以节能减排。为了解决常规余热提取技术存在的余热利用率低的问题,本文提出了多热网联动余热提取技术。实际案例分析表明,与单热网余热提取技术相比,多热网联动余热提取技术节能效果和环保效益更为突出。

煤电升级改造背景下烟气余热利用节能效益对比评估

对火电企业进行节能减排改造,能够降低火电供电煤耗,进而有效减少二氧化碳排放量的增长,对实现碳达峰、碳中和目标具有重要意义。以某630 MW机组为例,对比4种余热利用方案(低温省煤器方案、二级低温省煤器方案、旁路烟道方案和机炉耦合方案)的系统机组,进行了关键技术参数与节电效果比较分析,结果表明:排烟温度降为90℃,供电煤耗率低温省煤器方案降低1.88 g/(kW·h),二级低温省煤器方案降低2.16 g/(kW·h),旁路烟道方案降低2.29 g/(kW·h),而机炉耦合方案降低2.66 g/(kW·h),节能效果最为显著。

某浓香型白酒污水厂污泥处置设计案例

为研究适宜的浓香型白酒污水厂污泥处置方案,满足节能降碳、高效用能的项目需求,提出通过能耗分析比对主流污泥处置工艺的设计思路。结果表明,离心脱水和污泥低温干化工艺不需要消耗沼气和额外补充能源,满足能源利用的要求,适宜在浓香型白酒污水厂污泥处置中使用。经过投资分析,该方案10年费用为1.28亿元,同期板框脱水方案为1.56亿元,具有成本优势。研究对浓香型白酒污水厂污泥处置设计有一定的指导和借鉴意义。

精细化工厂余热回收利用方案设计及应用

结合一精细化工厂节能技改实例,简要介绍了工业余热资源特点,着重分析研究了该工厂余热回收利用系统方案设计及应用效果,重点介绍了技术工艺设备及突出特点,阐述了企业因地制宜回收利用余热资源能够取得良好的经济效益和社会效益。