火电厂热力系统炯分析计算研究

在对电厂各设备的运行性能和炯计算方法分析的基础上,寻求共通性构造出合理程序模型,开发编制了详尽的电厂热力系统分析计算软件以适用于机组性能在线计算.实例计算验证了方法的有效性,同时对结果进行了分析.表4参16     

火电厂热力系统Yong分析计算研究

在对电厂各设备的运行性能和Yong计算方法分析的基础上，寻求共通性构造出合理程序模型，开发编制了详尽的电厂热力系统分析计算软件以适用于机组性能在线计算。实例计算验证了方法的有效性，同时对结果进行了分析。表4参16     

电厂热力系统工质流量分配计算方法

文中提出了一组热力系统工质流量分配因子的计算公式,这组公式可以简化电厂热力性能的计算方法,这种计算是运用热力学第二定律分析电厂热力系统的基础。     

基于单元炯分析模型回热系统节能诊断

电厂运行的经济性已经日显重要。回热系统作为电厂热力系统中的主要系统之一,它对全厂的经济运行产生着很大影响,因此,回热系统经济性分析是电厂节能工作中的重要部分。以某热电厂机组的回热系统为研究对象,给出了系统的单元划分方法和通用的单元炯分析控制体模型,导出了通用的性能评价指标计算式,以实际计算说明了基于单元炯分析模型的节能潜力诊断方法。该方法可以找出系统能量损失的关键部位,为电厂热力系统节能分析提供一条依据。     

基于单元(火用)分析模型回热系统节能诊断

电厂运行的经济性已经日显重要。回热系统作为电厂热力系统中的主要系统之一,它对全厂的经济运行产生着很大影响,因此,回热系统经济性分析是电厂节能工作中的重要部分。以某热电厂机组的回热系统为研究对象,给出了系统的单元划分方法和通用的单元分析控制体模型,导出了通用的性能评价指标计算式,以实际计算说明了基于单元分析模型的节能潜力诊断方法。该方法可以找出系统能量损失的关键部位,为电厂热力系统节能分析提供一条依据。     

回热加热器变工况计算方法研究北大核心

目的是通过公式推导,研究出一套更加简洁、准确的回热系统计算模型,进而用于对电厂回热系统的性能监测及经济性分析。它通过对回热系统换热特性进行深入、系统性的分析,基于能量守恒方程、传热方程和传热学原理的理论支撑,借鉴美国传热学会公式,通过对加热器管侧传热系数、壳侧传热系数及总体传热系数简化、推导,提出了求解回热加热器传热系数的新方法,得到了新的回热加热器的计算模型,使计算模型更加简便,提高了计算精度,适用于各类回热加热器的变工况计算,进而确定了加热器端差的基准值计算方法,解决了电厂变工况端差不准确的缺点,其准确性和实用性在实践中得到了证明,在提高电厂变工况运行经济性的同时还可以在事故处理中进行指导,可以对电厂运行人员进行技术支持。     

广州珠江电厂汽轮机组热经济性分析

通过性能试验得出的数据,对珠江电厂1号机组的热耗进行了具体的计算;同时,结合电厂实际,对影响机组热耗的各种因素进行了具体分析,并在此基础上,提出了相应的解决方法。     

回热加热器变工况计算方法研究

目的是通过公式推导,研究出一套更加简洁、准确的回热系统计算模型,进而用于对电厂回热系统的性能监测及经济性分析。它通过对回热系统换热特性进行深入、系统性的分析,基于能量守恒方程、传热方程和传热学原理的理论支撑,借鉴美国传热学会公式,通过对加热器管侧传热系数、壳侧传热系数及总体传热系数简化、推导,提出了求解回热加热器传热系数的新方法,得到了新的回热加热器的计算模型,使计算模型更加简便,提高了计算精度,适用于各类回热加热器的变工况计算,进而确定了加热器端差的基准值计算方法,解决了电厂变工况端差不准确的缺点,其准确性和实用性在实践中得到了证明,在提高电厂变工况运行经济性的同时还可以在事故处理中进行指导,可以对电厂运行人员进行技术支持。     

一种燃气内燃机-蒸汽轮机联合循环电厂基准热耗计算方法

燃气内燃机-蒸汽轮机联合循环电厂内燃机数量多、内燃机和汽轮机的组合运行方式多,全厂基准热耗计算及性能评估困难。介绍了一种能正确计算燃气内燃机-蒸汽轮机联合循环全厂基准热耗的方法,通过电厂的实际应用表明该方法真实的反映了电厂的基准热耗水平,保证了电厂与电网PPA协议的有效执行和电费的准确结算。     

300MW机组凝汽器改造后的性能测试分析

介绍了凝汽器热力性能测试的原理和计算方法,并给出了凝汽器压力和端差的修正方法。同时针对某电厂300MW机组的凝汽器改造,列举了该计算方法在其改造后的性能测试实例。通过计算分析表明,改造后凝汽器的冷却性能达到了设计保证值。     

基于_分析的发电厂改造方法研究

根据分析理论,把锅炉、汽轮机及发电厂热力系统作为一个整体,通过对发电厂各环节进行分析找到具体损失环节并对具体位置提出改造方案,是发电厂改造的一种新方法。以某超超临界机组为例,运用分析理论找到损失环节,找到二次风温及给水温度对锅炉系统及电厂热力系统影响的关系,通过增加一级高压加热器提高给水温度,同时在保证锅炉排烟温度不变的前提下适当地提高二次风温,分析在给水温度及二次风温的双重作用下,锅炉乃至整个机组性能的变化。结果表明,当给水温度由299.5℃升高至322℃时,二次风温由327.8℃升高至360℃,锅炉系统传热损失由3 443 kJ/kg降低至3 254 kJ/kg,燃烧环节损失由6 204 kJ/kg降低至6 158 kJ/kg,锅炉效率由54.15%升高至54.45%,机组目的效率由42%升高至46.7%。     

Exergy analysis of a coal‐based 210 MW thermal power plant

In the present work, exergy analysis of a coal‐based thermal power plant is done using the design data from a 210 MW thermal power plant under operation in India. The entire plant cycle is split up into three zones for the analysis: (1) only the turbo‐generator with its inlets and outlets, (2) turbo‐generator, condenser, feed pumps and the regenerative heaters, (3) the entire cycle with boiler, turbo‐generator, condenser, feed pumps, regenerative heaters and the plant auxiliaries. It helps to find out the contributions of different parts of the plant towards exergy destruction. The exergy efficiency is calculated using the operating data from the plant at different conditions, viz. at different loads, different condenser pressures, with and without regenerative heaters and with different settings of the turbine governing. The load variation is studied with the data at 100, 75, 60 and 40% of full load. Effects of two different condenser pressures, i.e. 76 and 89 mmHg (abs.), are studied. Effect of regeneration on exergy efficiency is studied by successively removing the high pressure regenerative heaters out of operation. The turbine governing system has been kept at constant pressure and sliding pressure modes to study their effects. It is observed that the major source of irreversibility in the power cycle is the boiler, which contributes to an exergy destruction of the order of 60%. Part load operation increases the irreversibilities in the cycle and the effect is more pronounced with the reduction of the load. Increase in the condenser back pressure decreases the exergy efficiency. Successive withdrawal of the high pressure heaters show a gradual increment in the exergy efficiency for the control volume excluding the boiler, while a decrease in exergy efficiency when the whole plant including the boiler is considered. Keeping the main steam pressure before the turbine control valves in sliding mode improves the exergy efficiencies in case of part load operation. Copyright © 2006 John Wiley & Sons, Ltd.     

火电机组的热经济性分析

为进行整个火电机组的能量系统热经济性分析及考察其组元变化的影响，提出了以热经济学和边际成本概念为基础的热经济性分析方法。对复杂能量系统主要以功能划分后形成的组元，考察其组元的输出炯流变化引起整个系统的能耗变化，可以通过边际炯成本、单位炯成本和组元产品的函数来表达，来衡量整个系统所有组元的输出炯流变化对系统外部输入燃料的影响，便于火电机组的运行经济状态动态评估。通过300MW机组主蒸汽参数变化的计算表明：参数变化时将引起系统的煤耗增加，降低了经济性，因而从本质上进行了热经济性的全面综合分析，以优化机组运行，进行性能诊断。图1表2参10     

On the improvement of annual performance of solar thermal power plants through exergy management

Advancing in the learning curve of solar thermal power plants (STPP) requires detailed analysis for reducing exergy losses in the energy conversion chain. This requirement should be applied to any configuration proposed for the solar field and the power block. The aim of this work is to perform this type of analysis for two ways of structuring the power plant. The first plant structure consists of a subdivision of the solar collector field into specialized sectors with specific goals conveying different requirements in temperature. The second plant structure is based on a dual thermal energy storage system with a defined hierarchy in the storage temperature. The subdivision of the solar field into different sectors reduces the exergy losses in the heating process of the working fluid. Moreover, the average temperature of the heat transfer fluid in the solar field decreases when it is compared to the conventional solar field, reducing this way the exergy losses in the collectors. The dual thermal energy storage system is devised for keeping the exergy input to the power block at its nominal level for long periods of time, including post‐sunset hours. One of the storage systems gathers a fluid heated up to temperatures above the nominal value and the second one is the classical one. The combination of both allows the manager of the plant to keep the nominal operation of the plant for longer periods than in the case of classical system. Numerical simulations performed with validated models are the basis of the exergy analyses. The configurations are compared to a reference STPP in order to evaluate their worth. Furthermore, the behaviour of the configurations is analysed to study the irreversibility of the included devices. Special attention is paid to the storage systems, as they are a key issue in both plant structures. Copyright © 2013 John Wiley & Sons, Ltd.     

Energy–exergy analysis and modernization suggestions for a combined‐cycle power plant

Energy and exergy analysis were carried out for a combined‐cycle power plant by using the data taken from its units in operation to analyse a complex energy system more thoroughly and to identify the potential for improving efficiency of the system. In this context, energy and exergy fluxes at the inlet and the exit of the devices in one of the power plant main units as well as the energy and exergy losses were determined. The results show that combustion chambers, gas turbines and heat recovery steam generators (HRSG) are the main sources of irreversibilities representing more than 85% of the overall exergy losses. Some constructive and thermal suggestions for these devices have been made to improve the efficiency of the system. Copyright © 2005 John Wiley & Sons, Ltd.     

火电机组热力系统成本分布通用矩阵方程

基于成本理论建立了热力系统局部成本分析通用模型及火电机组热力系统成本分布的通用矩阵方程,并对某600MW机组的热力系统进行实例计算与分析,得到了额定工况下独立流的单位成本.结果表明：该方程构造规范,适用于各种不同的热力系统,可以用于分析热力系统中存在的共性规律;对于具体的热力系统,通过将一些必要的矩阵元素代入方程中,可得到独立流的单位成本和单位成本的分布规律,为机组的节能降耗提供指导;如果对方程进行进一步的微分运算分析,还可求出一些因素变化对单位成本影响的敏感度.     

闭式内可逆回热布雷顿热电冷联产装置(火用)分析

应用有限时间热力学理论和方法建立了闭式内可逆回热布雷顿热电冷联产装置模型,导出了装置无量纲(火用)输出率和效率的解析式。通过数值计算分析了回热器热导率对(火用)输出率和(火用)效率的影响,发现存在临界压比,同时优化了压比,研究了热电比、制冷和供热温度等设计参数对最优(火用)输出率和(火用)效率以及相应最佳压比的影响,发现最优(火用)输出率时的设计压比要大于最优(火用)效率时的设计压比,最优(火用)输出率和(火用)效率均随冷用户温度的升高而减小,分别存在最佳的热用户温度使(火用)输出率和(火用)效率取得最大值,热用户温度对装置最优(火用)性能的影响比冷用户温度更为明显。     

SECOND LAW ANALYSIS OF A SOLAR THERMAL POWER SYSTEM

This communication presents second law analysis based on exergy concept for a solar thermal power system. Basic energy and exergy analysis for the system components (viz. parabolic trough collector/receiver and Rankine heat engine etc.) are carried out for evaluating the energy and exergy losses as well as exergetic efficiency for typical solar thermal power system under given operating conditions. Relevant energy flow and exergy flow diagrams are drawn to show the various thermodynamic and thermal losses. It is found that the main energy loss takes place at the condenser of the heat engine part whereas the exergy analysis shows that the collector-receiver assembly is the part where the losses are maximum. The analysis and results can be used for evaluating the component irreversibilities which can also explain the deviation between the actual efficiency and ideal efficiency of solar thermal power system.     

开式回热燃气轮机热电冷联产装置性能优化

建立了考虑压降的开式回热燃气轮机热电冷联产装置的有限时间热力学模型,导出了各个部件的相对压降和各个热流率与压气机进口相对压降的关系式,以第一定律效率、[火用]输出率、[火用]效率和利润率为目标,在无燃料消耗和装置尺寸约束下,通过数值计算发现分别存在最佳的压气机进口相对压降使[火用]输出率和利润率取得最优值,进一步优化压比,得到了最大[火用]输出率和利润率,分别存在最佳的供热温度使最大[火用]输出率和利润率取得双重最大值,以利润率为设计目标能够减小装置的尺寸.在燃料消耗和装置尺寸约束下,优化了压气机进口相对压降,得到了最优效率,同时各部件流通面积分配也得到了优化.回热能够增大装置的利润率和效率.