Power Generation Systems Using Continuous Blowdown Waste Heat from Drum Boilers Driving an Organic Rankine Cycle

提出了一种利用汽包锅炉排污系统余热的有机朗肯循环发电系统,有机工质回收扩容器疏水的热量,并通过气轮机发电。建立了系统的热力性能分析模型,并对R227ea、RC318、R236ea、R245fa、R245ca、R123和R113等7种工质的热力性能进行了优化。结果表明,临界温度高的工质,其o2循环的最佳主气温度（蒸发温度）反而低；亚临界循环采用干流体时,过热不利于余热的利用；超临界循环可以改善热源与工质间的温度匹配,有利于增大系统输出功,但是其运行压力高、大比热区的传热恶化等问题是实际运行和设计需要考虑的因素；R236ea的热力性能优于其余6种工质。

An inverse method for online stress monitoring and fatigue life analysis of boiler drums

A method based on solution of the inverse heat conduction problem was presented for online stress monitoring and fatigue life analysis of boiler drums. The mathematical model of the drum temperature distribution is based on the assumptions that the difference of temperature along the longitudinal axis of the boiler drum is negligible with changes only in the radial direction and the circumferential direction, and that the outer surface of drum is thermaUy insulated. Combining this model with the control-volume method provides temperatures at different points on a cross-section of the drum. With the temperature data, the stresses and the life expectancy of the boiler drum are derived according to the ASME code. Applying this method to the cold start-up process of a 300 MW boiler demonstrated the absence of errors caused by the boundary condition assumptions on the inner surface of the drum and testified that the method is an applicable technique for the online stress monitoring and fatigue life analysis of boiler drums.

A Simple Approach to Determine Noise Frequency of Boiler Drum Level

This paper proposed a simple approach to determine noise frequency of boiler drum level in order to improve control performance. Based on analysis of uncertainty of drum level, the redundant oscillation component of signal, noise is ascribed to the surface wave of drum water. According to the characteristic of surface wave, a new method was proposed to determine noise’s frequency band. By gradually removing the lowest frequency component of signal, the variance of remained component is calculated and observed. An apparent turning point was found and the corresponding critical frequcncy was determined. With this result a low-pass filter was designed to separate noise component. Finally validation is conducted by comparing the proposed method and conventional ones. Results show the accuracy and simpleness of the proposed method.

Digital Control Design for the Boiler Drum BDT921

A boiler drum BDT921 that is installed in the Control Laboratory, Department of Mechatronics and Robotics Engineering, Faculty of Electric and Electronic Engineering, Universiti Tun Hussein Onn Malaysia （UTHM） is being used as a model plant to achieve the digital control system since its analog. Implementing a digital system to boiler quite a though work. This paper covers analysis from the experiment done to match with digital design that will be implemented to the real system. The digital control design will come up with the mathematical model and will be analyzed with MATLAB and SIMULINK software named as ＂Discrete Analysis ofBDT921 Simulation＂. A proportional integral and derivative （PID） controller is being chosen as the control element in discrete form as the real system is using the same control element. The output responses behave as the second order system with a bit difference in rise times and peak times compared with data obtained from experiment. With regarding to the analysis done, the digital control can be implemented and for further viewing, to be controlled digitally with computer in the control room.

Prediction of Boiler Drum Pressure and Steam Flow Rate Using Artificial Neural Network

Numerical simulation of complex systems and components by computers is a fundamental phase of any modern engineering activity. The traditional methods of simulation typically entail long, iterative processes which lead to large simulation times, often exceeding transient real time. Artificial neural networks （ANNs） may be advantageous in this context, the main advantage being the speed of computation, the capability of generalizing from the few examples, robustness to noisy and partially incomplete data and the capability of performing empirical input-output mapping without complete knowledge of underlying physics. In this paper, the simulation of steam generator is considered as an example to show the potentialities of this tool. The data required for training and testing the ANN is taken from the steam generator at Abott Power Plant, Champaign （USA）. The total number of samples is 9600 which are taken at a sampling time of three seconds. The performance of boiler （drum pressure, steam flow rate） has been verified and tested using ANN, under the changes in fuel flow rate, air flow rate and load disturbance. Using ANN, input-output mapping is done and it is observed that ANN allows a good reproduction of non-linear behaviors of inputs and outputs.

自然循环锅炉壁温控制的研究与应用

自然循环锅炉是一种简单、经济的锅炉形式,采用自然对流的方式实现热量传递。在自然循环锅炉中,壁温控制是一个重要环节。正确的壁温控制可以保证锅炉的安全运行,延长锅炉的使用寿命,提高锅炉的热效率。现有的自然循环锅炉壁温控制方法主要有两种,一种是基于传统PID控制的方法,另一种是基于智能算法的方法。传统PID控制方法需要根据锅炉的特点和工作条件手动调节PID参数,工作量大,调节时间长,且控制效果有限。而基于智能算法的方法,比如神经网络、模糊控制、遗传算法等,可以快速学习和适应锅炉的工作条件,提高控制精度和稳定性。

提高330 MW汽包炉的燃烧效率策略研究

锅炉燃烧效率指锅炉在燃烧过程中,有效利用燃料所含能量的比例。其是衡量锅炉能量利用效率和运行经济性的重要指标之一。为提高330MW汽包炉的锅炉燃烧效率,文章提出优化燃料供应、改进燃烧技术、提高炉膛温度、加强锅炉维护和检修等策略。

炼油装置锅炉汽包液位测量若干问题分析

在炼油装置中,为确保锅炉安全稳定运行,需要加强对汽包液位的测量和控制及保护,以保证炼油装置可安全生产。这就需要采取有效方式对锅炉汽包液位进行精准测量,避免发生液位超限情况。基于此,文章分析了电容液位计、平衡容器式差压液位计在锅炉汽包液位测量中的具体应用,以确保炼油装置可正常发挥作用。

汽包水位全程控制在工业锅炉中的应用

汽包水位全程控制在锅炉生产中起到了十分重要的作用,充分反映了锅炉蒸汽流量与给水量之间的关系,只有两者处于平衡状态,才能保证锅炉的安全,避免安全事故发生。文章以工业锅炉作为背景,介绍了汽包水位异常危害,以及汽包水位全程控制优势,明确了汽包水位全程控制在工业锅炉中的应用方式以及应用注意事项,对汽包水位全程控制应用方案进行了研究,目的是通过汽包水位全程控制,确保工业锅炉可安全、稳定运行,减少安全隐患,充分展现出汽包水位全程控制系统自身优势。

Development and Theoretic Validation of Model of Drum Level Sloshing

In order to develop a feasible model of drum level sloshing, the mechanism of drum level sloshing was analyzed, and the model of drum level sloshing was developed on the Easy5 software flat. The thermodynamic property of the model was validated by using the reference model, which was set up by using the method of lump parameter. The results indicate that the model can precisely reflect the phenomena of thermodynamic property inside drum, and the numeric error is within 1%. And the hydraulic property of the model was validated by the analytical theory of liquid sloshing, and the results indicate that the hydraulic property inside drum can also be correctly reflected by the model, and the sloshing period error is within 5%. The important work was done for exploring modeling for drum level sloshing, research of drum level sloshing and precision controlling of drum level.

抽汽再热循环的热力性能分析

为了提高特殊汽轮机组的整体经济性水平,以55 MW级垃圾焚烧发电汽轮机组为研究对象,采用提高主汽压力和抽汽再热循环的措施,定性研究了不同再热汽源抽汽点的位置、再热温度和再热压力对机组经济性的影响,计算了不同方案下的热力性能。结果表明:提高主汽压力并采用抽汽再热循环可大幅提高机组的经济性水平;在相同锅炉吸热量下,方案3和方案4的机组出力比方案1分别高5.46%和6.61%,方案4的机组出力比方案3高1.15%。

垃圾发电机组采用炉外抽汽再热特性

为有效提高垃圾发电机组的整体经济性水平,解决垃圾焚烧烟气对锅炉管道的腐蚀作用造成主蒸汽温度受限且不宜采用中间再热的难题,可采用炉外再热并提高主汽压力的措施。以55 MW级垃圾焚烧发电汽轮机组为研究对象,针对常规参数配置(方案一)循环效率低的问题,采用提高主汽压力和炉外再热措施,定性研究了不同再热汽源抽汽点的位置、再热温度和再热压力对机组经济性的影响。在理论分析基础上,提出了汽包抽汽再热循环(方案三)、汽机抽汽再热循环(方案四)方案。定量计算结果表明:(1)提高主汽压力和炉外再热可大幅提高机组经济性水平,且方案四最优;(2)方案四存在最佳再热压力,再热压力增大或减小,循环效率均降低;(3)相同锅炉吸热量下的机组功率,方案三比方案一大5.46%,方案四比方案一大6.61%。研究结果对解决主蒸汽温度受限且不宜采用中间再热的汽轮机组提高经济性具有重要的指导意义。

用于一次调频分析的汽包锅炉模型及参数在线确定方法

火电机组的一次调频性能与锅炉蓄热能力密切相关,为准确反映不同工况下亚临界汽包炉机组的一次调频特性,该文建立了汽包锅炉分布式参数动态模型。模型采用动态热量流法分析换热特性,同时考虑工质变物性,重点描述工质的换热、相变及流动过程。模型参数可基于机组分布式控制系统的监测数据在线计算,能够准确反映机组调频能力随运行工况的变化。以包头电厂600MW机组为例进行模型验证与仿真分析,结果显示,在-0.1Hz频差阶跃扰动下,加入该文所建锅炉模型后,调频功率仿真曲线和实测曲线在30s时的相对误差从38.74%有效减小至-2.16%(90%工况),该文所建模型能够较为准确地描述汽包锅炉主蒸汽压力等关键参数在一次调频期间的动态响应特性。

余热锅炉汽包壁温差控制策略

阐述燃气-蒸汽联合循环启停操作过程中汽包壁温差大的现象,从余热锅炉汽包结构特点和启停过程传热特性入手,详细剖析余热锅炉汽包壁温差超限的原因,找到余热锅炉负荷变动中汽包壁温差大的末端影响因素。机组实际运行中优化操作包括提高余热锅炉汽包上水初温、改变汽包升温升压速率、加快余热锅炉水循环等等,防止机组启停过程中汽包上、下壁温差大,对于优化余热锅炉启停操作和限制汽包上、下壁温差的燃气轮机电厂有借鉴意义。

汽包锅炉炉水品质及自动化排污控制技术研究

汽包锅炉在化工生产过程中主要用于供应蒸汽,其炉水品质直接影响设备的运行效率与安全。为了科学有效地控制炉水品质,实现锅炉排污自动化,本文采用化学成分在线测控模块计算炉水二氧化硅、磷酸根、电导率、PH值,将炉水指标控制至某一平稳值中,同时借助排污流量测量与控制模块工具,解决了气液两相状态下锅炉水“测不准”的问题,在分布式控制系统下控制炉水指标,实现了根据炉水溶解固形物的量来设定锅炉排污量的目标,提高了精准排污能力和自动化程度。实践证明,锅炉排污量每增加1%,循环水损失1%,燃料消耗增加0.12%~0.18%。本系统有效解决了锅炉排污量不准确和自动化程度低的问题,提高了汽包锅炉运行的安全性和经济性,且为设备的数字量化管理提供了科学的支撑。

基于灰狼优化算法的自抗扰控制在汽包水位中的应用

针对余热锅炉汽包水位控制系统具有非线性、大滞后、强干扰、大惯性等特点,采用自抗扰(ADRC)控制器来改善其控制效果,提高汽包水位控制系统的控制精度及鲁棒性。针对控制器参数过多,引入灰狼算法(GWO)对控制器参数进行整定。利用SIMULINK构建汽包水位控制系统,用灰狼算法调节ADRC-PI控制器与PID-PI控制器参数,对比不同控制器对汽包水位控制的效果。结果表明:GWO-ADRC-PI控制效果具有超调量小、鲁棒性强和抗干扰能力强等优点。

高性能特殊容器钢板的开发生产

根据锅炉汽包用高性能容器钢板的制造要求,采用低碳、高锰、微铌+中镍、钼、铬的成分体系设计,严格控制有害元素及夹杂物含量,结合正火+回火工艺,成功开发出13MnNiMoR高性能特殊容器钢板;该钢板组织均匀,以贝氏体为主,具有较高的强韧性和抗层状撕裂性能的基础上,具备较好的断后伸长率≥22%,并拥有良好低温韧性,0℃冲击功可达150 J以上,力学性能均达到或超过GB 713—2014《锅炉和压力容器用钢板》标准要求。

Water Level Deviation Analysis of Levels Between Two Sides of the Boiler Drum

It is always quite difficult to accurately measure boiler drum water level in power plant. Though the effect of false measurement of water level can be reduced with some devices, the effect of deviation of boiler drum water level to the monitoring and alarm system, even to the control of drum water level, and so on, cannot be surmounted. Because of these reasons, the accurate water level alarm signal cannot be provided and the water level control measures cannot be applied. In order to solve this problem, a water level deviation analysis method is presented for analyzing boiler drum water level. Based on the analysis of boiler drum water level related running parameters, the relational model of water level deviation under different working conditions and its parameters is constructed. By analyzing this model, the specific impacts of the main factors can be fixed. Thus the drum water level deviation can be reduced by adjusting running parameters without changing unit load. And then the measurement of drum water level can be more accurate only if power plants have accurate measuring devices. Therefore, the boiler drum water level can be more accurately monitored and controlled. So, this innovation is important in ensuring the safe running of power plant.

Design and application of a novel coal-fired drum boiler using saline water in heavy oil recovery

In this paper,the design and operation of a novel coal-fired circulating fluidized bed(CFB)drum boiler that can generate superheated steam using saline water were introduced.The natural circulation water dynamics with a drum was adopted instead of the traditional once-through steam generator(OTSG)design,so that superheated steam can be generated for the better performance of the steam assisted gravity drainage(SAGD)technology in heavy oil recovery.The optimized staged evaporation method was proposed to further decrease the salinity of water in the clean water section of the boiler.The evaporating pipes of the salted water section were rearranged in the back pass of the boiler,where the heat load is low,to further improve the heat transfer safety.A CFB combustion technology was used for coal firing to achieve a uniform heat transfer condition with low heat flux.Pollutant control technologies were adopted to reduce pollutant emissions.Based on the field test,the recommended water standard for the coal-fired CFB drum boilers was determined.With the present technology,the treated recovery wastewater can be reused in steam-injection boilers to generate superheated steam.The engineering applications show that the boiler efficiency is higher than 90%,the blowdown rate is limited within 5.5%,and the superheat of steam can reach up to 30 K.Besides,the heavy oil recovery efficiency is significantly improved.Moreover,the pollutant emissions of SO2,NOV and dust are controlled within the ranges of 20-90 mg/(N·m^(3)),30-90 mg/(N·m^(3))and 2-10 mg/(N·m^(3))respectively.

基于DeltaV系统的PID控制算法的实时性能优化

以DeltaV系统中的比例积分微分(Proportional-Integral-Derivative,PID)控制算法为研究对象,以锅炉汽包液位调节为例,针对当前算法的实时性能进行评估与改进。提出了一种改进方法,包括参数优化和控制策略调整。通过提高控制器的响应速度和精度,旨在更好地满足锅炉汽包液位调节的实时要求。实验结果表明,改进后的PID控制算法在锅炉汽包液位调节中具有更好的实时性能,能够更准确地控制液位,提高系统的稳定性和可靠性。