5000t_d级水泥窑低温余热利用方式对比研究

为了更有效利用低温余热以降低水泥窑能耗,对5 000t/d级新型干法水泥窑低温余热发电的利用方式进行探讨.以生产过程中从窑头冷却机和窑尾预热器抽出的废气为热源,建立单压、双压、闪蒸循环系统模型,采用遗传算法优化出各循环的热力特性参数,改进双压系统结构,并对单压、双压与闪蒸系统各自的优缺点进行比较,分析结果表明:改进双压循环系统输出功率最高,但闪蒸循环系统,结构简单、运行方式灵活,两者都有广泛应用价值.     

纯低温双压余热发电系统性能分析及参数优化

针对新型干法水泥窑纯低温双压余热发电系统,进一步完善了性能评价方法,以 5 000t/d水泥生产过程为实例分析了窑头AQC、窑尾SP余热锅炉废气参数、高压段、低压段蒸汽参数、公共省煤器出口水温对余热发电系统性能的影响以及各参数之间的耦合关系.结果表明:在确定的水泥窑废气参数下,通过对纯低温双压余热发电系统热力参数的优化,能够进一步提高余热发电量.     

5000t_d干法水泥线余热发电热工参数的计算分析

针对某5 000 t/d新型干法水泥窑系统设计了纯低温余热双压发电系统,对系统各个参数进行了理论计算分析,得到了双压系统中主蒸汽温度和压力、给水温度、高压节点温差和接近点温差、低压蒸汽温度和压力、低压节点温差和接近点温差、系统给水温度对系统发电功率的影响规律.计算结果表明:影响水泥窑余热系统发电功率的因素较多,在进行余热发电系统设计时,应对系统发电功率和经济性进行综合考虑,以选取优化参数.在计算的各工况中,当窑尾余热锅炉主蒸汽温度为300 ℃、主蒸汽绝对压力为1.6 MPa、给水温度为170 ℃、高压低压节点温差为15 ℃、高压低压接近点温差为11 ℃;窑头余热锅炉低压蒸汽温度为180 ℃、低压蒸汽绝对压力为0.25 MPa、系统给水温度为50 ℃,汽轮机背压为8 kPa时,系统发电功率是最大的,达到13 791.878 kW.     

一种新型水泥工业余热与生物质能互补发电系统

本文提出一种新型水泥工业余热与生物质能互补发电系统,该系统采用水泥窑低温余热和生物质补燃有机结合的方式大幅提高水泥窑余热发电蒸汽参数与系统效率。来自水泥生产线窑头和窑尾的低温余热烟气全部用来加热工质水产生饱和蒸汽,饱和蒸汽进入生物质补燃系统中进行过热后送入汽轮发电机组中做功发电,补燃燃料为生物质气化燃气。本研究建立了单压和双压2种互补发电系统,分析了其热力学性能,结果表明:单压互补发电系统与传统单压纯低温发电系统相比,系统循环热效率和系统发电效率分别提高了1.63和1.92个百分点。双压互补发电系统与传统双压纯低温发电系统相比,系统循环热效率和系统发电效率分别提高了1.05和1.53个百分点。     

1000t/d石灰窑余热发电系统分析及优化

针对1000t/d石灰窑生产线余热发电系统进行建模分析及优化。计算结果表明:采用传统朗肯循环发电系统,实际发电功率低于900k W,进汽轮机蒸汽最佳压力范围为0.35~0.5MPa,最佳温度范围为190~220℃;采用双工质有机朗肯循环发电系统发电功率大幅度提高,以R123作为有机工质为例,进汽轮机蒸汽最佳压力3.0MPa、蒸汽温度173.3℃,理论最大输出功率1391k W。同时对有机朗肯循环系统中广泛采用的有机工质ORC循环系统进行了对比分析,为活性石灰低温余热的高效利用提供了理论基础。     

中低温余热发电技术及其在水泥生产中的应用

介绍常用的中低温余热发电技术及其特点,并给出了水泥窑中低温余热发电系统的实例,对不同的余热利用方案进行了对比分析。结果表明,在相同条件下,混合工质循环具有比双压朗肯循环更高的余热利用效率。     

基于固体氧化物燃料电池的有机工质余热发电联合系统特性的理论研究

针对有机朗肯循环对低温余热回收的显著优势,提出了一种基于固体氧化物燃料电池(SOFC)的有机工质余热发电联合系统.该系统包含内重整SOFC、后燃室、燃气轮机、压气机、预热器和有机朗肯循环,实现了能量的梯级利用,有效地提高了系统的总发电效率.在稳态数学模型的基础上,建立了基于SOFC的有机工质余热发电联合系统的热力仿真分析平台,研究了关键参数对系统性能的影响.结果表明:在设计工况下,系统的总发电效率可达65%以上;随着燃料摩尔流量的增加,系统的净输出功增加,但系统的总发电效率有所下降;在一定范围内,增大压气机压比可以提高系统净输出功和总发电效率;随着蒸汽与碳物质的量比的增大,系统的净输出功减小,总发电效率下降.     

海上油气平台余热朗肯循环发电系统热力学分析

海上油气平台存在大量的燃气轮机余热。通过建立海上平台余热朗肯循环发电系统仿真模型,开展平台余热发电热力学及热经济性分析。选取工质泵功率、发电机输出功率、系统热效率、换热面积和单位面积发电量等参数作为优化目标,研究不同冷凝温度下优化目标函数随蒸发器烟气进出口温差的变化规律。结果表明:随着蒸发器烟气进出口温差的增加,工质泵功率、发电机输出功率和系统APR先增大后减小。冷凝温度越高,工质泵功率越大,发电机输出功率和系统热效率越小。当冷凝温度为65℃时,系统APR最大。受透平出口蒸汽干度的限制,所研究工况下,系统发电机最大输出功率为7 496 kW,系统最大热效率和APR分别为14.16%和5 kW·m~(-2)。研究结果可为撬装化、集成化海上油气平台余热发电系统研制提供理论参考。     

基于BP神经网络低温余热发电系统建模

通过设计低温余热发电系统的模拟实验,研究基于有机朗肯循环的余热发电系统的性能以及主要影响因素。通过对实验数据的研究分析,发现涡轮机转速与工质蒸发压力相匹配,能够使系统达到最大功率输出。为研究这一问题构建BP神经网络,并用实验数据对BP网络进行训练,建立基于BP神经网络的系统模型。     

水泥窑双压系统纯低温余热发电的应用

介绍了9 MW双压系统纯低温余热发电技术在水泥厂的工程应用,探讨了双压系统的节能和环境保护意义。通过对双压系统技术特点的分析表明:双压系统纯低温余热发电技术能提高余热发电量,可适用于中、低温余热发电,具有利废、环保、节能三重效果。     

水泥余热发电窑头取热技术研究及工程应用

在干法水泥熟料生产线余热发电中,如何在不影响二次风、三次风以及水泥生产其他用风的情况下,使窑头篦冷机余热得到最大利用,是目前本行业的难点之一。本文针对水泥熟料生产线余热发电窑头篦冷机取热问题,应用流体力学商用软件对篦冷机内部压力场和温度场进行了数值模拟。研究了余热发电中篦冷机余热抽气口位置以及抽风量的变化对余热用风和水泥生产线用风的影响,研究结果成功用于了工程实际中。     

Thermo-economic analysis of using an organic Rankine cycle for heat recovery from both the cell stack and reformer in a PEMFC for power generation

Distributed power generation is gaining attention as a solution for the transmission loss and site selection in centralized power generation. Polymer-electrolyte membrane fuel cells (PEMFCs) are suitable as a distributed power source for residential areas because of their high efficiency and low environmental impact. This study proposes a combined power generation system for recovering waste heat from both the cell stack and the reformer of a PEMFC by applying an organic Rankine cycle (ORC). The best working fluid with the highest ORC power output (i.e., the highest combined system efficiency) was identified through a parametric study of different working fluids. An economic analysis was also performed for different working fluids, waste heat sources, and types of system operation. The results show that the installation cost of the ORC can be recovered within the fuel cell's lifetime in all design cases. Greater cumulative profit can be generated by maintaining the same power output as the stand-alone PEMFC system for greater efficiency than when increasing the power output to sell surplus power. The results demonstrate that the optimal heat recovery from the PEMFC system is both thermodynamically and economically beneficial.     

低温废热高效回收系统及其_评价

通过一定的设备系统将大量放散的具有一定品位的热能回收发电 ,是废热回收的高价值方法。而对于原本品位不高的低温废热 ,如何有效地提高其回收率 ,则是低温废热回收中值得研究的课题。本文介绍一种多次闪蒸—混汽发电的废热回收发电系统 ,并采用火用方法对其热经济性做出了评价。     

A waste heat recovery system development and analysis using ORC for the energy efficiency improvement in aluminium electrolysis cells

The present work investigates an active waste heat recovery system for the side walls of the aluminium electrolysis cells, enabling utilization of the extracted heat in power generation. This will potentially lead to energy efficiency improvement in the primary aluminium production industry and an enhanced aluminium production rate. An experimentally validated loop thermosyphon heat pipe model was used for heat extraction from the cell side wall. Boosting system thermal efficiency through waste heat recovery, by means of a heat utilization system, and increasing the level of control, as well as thermal equilibrium, stand as the main addressed objectives of the current study, which consequently result in an increased aluminium production rate. An organic Rankine cycle is incorporated into the system, and its performance is evaluated, taking into consideration the operating situations in terms of available temperature and thermal power range.     

基于有机朗肯循环的APU余热回收系统性能分析

为有效利用飞机辅助动力装置（Auxitlary Power Unit , APU）排气余热,基于有机朗肯循环（Organic Rankine Cycle, ORC）发电系统,构建了APU余热回收系统。系统以APU排气余热为输入,驱动ORC做功,输出电能,为机载设备提供二次能源。结合工程热力学原理,建立系统热力学模型,并通过Matlab编程对余热回收系统进行了仿真计算及性能分析。仿真结果表明,系统功率及效率随飞行马赫数增加而降低;APU余热回收系统在飞机低音速飞行时有良好的性能;马赫数小于1时,系统功率在12 kW以上,效率在11%以上,耗气率低于0.0262 kg/kJ。     

A new concept for integrating a thermal air power tube with solar energy and alternative, waste heat energy sources and large natural or man-made, geo-physical phenomenon

A method for power generation combining a solar concentration system and a pneumatic power tube system in a large open pit is described. Solar energy is concentrated by a plurality of heliostat mirrors placed along the embankment of the pit, which tends to be spherical in contour. The pneumatic tubes recover waste heat energy from the solar Rankine power cycle system and from a variety of sources that originate from or are in close proximity to the very deep, man-made open-pit mine or from other naturally occurring geo-physical chasms. The man-made or naturally formed chasms provide structural support for the pneumatic power tubes. The air in the tubes is heated by the recovered waste energy, and in so doing, its density is sufficiently reduced so as to produce air drafts from which mechanical power can be recovered from wind turbines and converted into electrical power by suitable electric generators. The deep chasms can be from a man-made phenomenon such as commissioned, open-pit mines or from naturally occurring fissures in the earth. The waste heat can be from solar energy, ground source energy or products of combustion from waste products that are to be mitigated or destroyed. The concept is novel in its integration of a solar powered heat engine with recoverable waste heat via the proposed pneumatic power tube as well as in the means of structural support that the geo-physical phenomenon provides and the modularity (for ease in manufacturing and installation) that makes the pneumatic power tube economically viable. The complete system uses state-of-the art wind turbine power recovery, solar reflective surfaces for solar energy collection, heat pipe arrays for ground source heat recovery, and air diffuser subsystems for enhanced wind turbine efficiency.     

Theoretical analysis of a thermodynamic cycle for power and heat production using supercritical carbon dioxide

A numerical study of a thermodynamic cycle is described: solar energy powered Rankine cycle using supercritical carbon dioxide as the working fluid for combined power and heat production. A model is developed to predict the cycle performance. Experimental data is used to verify the numerical formulation. Of interest in the present study is the thermodynamic cycle of 0.3–1.0 kW power generation and 1.0–3.0 kW heat output. The effects of the governing parameters on the performance are investigated numerically. The results show that the cycle has a power generation efficiency of somewhat above 20.0% and heat recovery efficiency of 68.0%, respectively. It is seen that the cycle performance is strongly dependent on the governing parameters and they can be optimized to provide maximum power, maximum heat recovery or a combination of both. The power generation and heat recovery are found to be increased with solar collector efficient area. The power generation is also increased with water temperature of the heat recovery system, but decreased with heat exchanging area. It is also seen that the effect of the water flow rate in the heat recovery system on the cycle performance is negligible.