高压给水加热器泄漏的动态仿真与故障特征提取

通过对高压加热器的动态数值仿真计算,分析了高压加热器泄漏时对其运行参数,如给水出口温度、抽汽管道压损、疏水温度以及疏水水位的影响,并由此提取了表征高压加热器泄漏时的故障特征量,为完善建立高压加热器故障知识库并对其进行泄漏故障的早期诊断奠定了基础。     

回热系统运行状况对机组热经济性影响的定量分析

基于机组热平衡图和改进弗留格尔公式,建立了汽轮机定功率变工况计算模型.以某超临界620MW机组为研究对象,75％THA工况和50％THA工况下典型参数的计算结果与设计值相比误差均小于1％.运用所建立的定功率变工况计算模型研究了THA、75％THA和50％THA工况下加热器端差、抽气管道压损、加热器旁路泄漏量以及加热器事...     

阀门泄漏故障状态与声发射信号特征之间定量关系实验研究

设计搭建了阀门泄漏故障模拟实验台以及阀门泄漏声发射信号检测系统;通过实验研究了不同泄漏工况下,阀门泄漏状态与泄漏所产生的声发射信号特征参数之间的定量关系。基于最小二乘法对实验数据进行分析处理,得到了泄漏声发射信号的振铃计数、能量、幅值、均方根值和中心频率随阀门类型、阀门尺寸、进口压力和漏孔尺寸的变化规律,建立了基于声发射信号特征的阀门泄漏故障诊断规则,找到了表征阀门泄漏故障状态的最佳声发射信号特征参数。     

高压加热器管束泄漏的原因

高压加热器属压力容器，是利用汽轮机不同段位抽出的蒸汽对给水进行加热，最终达到锅炉所要求的给水温度和品质，使蒸汽热量得到了充分的利用，提高了整个循环的热效率。高压给水加热器（简称高加）由于工作在高温高压的环境下，所以比较容易发生管束泄漏故障。高压加热器运行中常见的加热器管系泄漏，换热管、管子与管板的泄漏是存在的普遍问题。本文对产生高加泄漏的原因进行了分析，并根据实际运行情况提出了预防和解决的措施。     

数字化高压加热器故障率自适应推算方法

高压加热器在给水回热系统中起到重要作用,其运行的可靠性影响着机组的安全稳定输出。因此,提出数字化高压加热器故障率自适应推算方法。构建数字化高压加热器的动态数学模型,分析高压加热器在工作状态下的运行特点,以此为依据建立高压加热器故障模型,提取导致高压加热器出现故障的主要参数。采用Elman神经网络构建高压加热器故障率推算模型,将上述提取的故障参数输入模型中,完成数字化高压加热器故障率的自适应推算。实验结果表明,所提方法可准确地检测数字化高压加热器的疏水温度、给水出口温度、给水压力和给水流量,具有较高的推算精度。     

斯特林发动机管式加热器内振荡流动的换热特性实验研究

模拟管式加热器在斯特林发动机中的工作状态,研究加热器管内工作气体振荡流动的换热特性,得到气体压力、振荡频率等对换热的影响规律,进一步得到工作气体与管壁间的平均换热系数,并将结果转化为无量纲参数,比较稳定流动换热关联式计算结果与实验结果的偏差。实验结果可对斯特林发动机管式加热器设计、优化和换热性能预测提供参考。     

火力发电厂加热器端差应达值的确定

通过对火电厂加热器的结构组成及换热过程的分析,提出了计算加热器端差数学方法并建立数学模型。利用N600-16.67/537/537机组100%、75%和50%THA设计工况及75%、50%THA试验工况的相关参数,根据所提供的计算方法,对加热器的应达值进行了计算。结果表明,由该方法计算所得到的值,在3种设计工况下,与设计端差基本相符;与两试验工况下的端差值也基本相符;加热器设计端差与其端差应达值并不是同一个值,端差应达值随加热器工况变化而变;端差应达值对故障加热器能够进行判别,也是加热器换热性价是否最佳的判据。     

电站加热器泄漏故障能损分析

以高压加热器小泄漏为例,利用等效焓降局部简化算法导出了能损关系式。对某300MW机组加热器发生泄漏故障时进行了定量能损分析,与高加不投运时机组效率相比后,为运行人员确定是否切除高加提供了直接的决策依据。     

基于LSTM深度学习模型的锅炉加热器故障诊断方法

为实时排查锅炉加热器故障，降低人力维护成本的同时确保其稳定运行，提出一种基于LSTM(Long Short-Term Memory,长短期记忆网络)深度学习模型的锅炉加热器故障诊断方法。将单数据包动态分配到不同节点，优化信息素更新模式，引入信息素负载调节因子，使用蚁群优化算法采集锅炉加热器运行数据；利用时间序列分析明确异常值特征并创建异常组合模型，使用迭代检验法实现锅炉加热器数据清洗，保证故障诊断结果可靠性；通过LSTM深度学习模型筛选强、弱关联数据，划分锅炉加热器典型故障征兆，标准化处理数据训练集，计算实际值和评估值的差异损失，完成故障诊断目标。实验结果表明，所提方法故障诊断精准度高、时效性强，具有优秀的鲁棒性，可为快速诊断锅炉加热器故障提供参考。     

基于运行参数的加热器疏水端差简易计算模型

传统的加热器疏水端差应达值计算是在具备详细结构参数和运行参数的基础上通过理论计算得出,而实际计算中不同加热器结构参数的搜集比较困难。对于结构参数一定的加热器,通过计算加热器各运行参数对疏水端差的影响,建立了一种新的只考虑运行参数的加热器疏水端差计算模型。利用660MW和300MW机组卧式加热器运行参数验证结果表明,该模型精确度高,计算简单,有利于快速计算加热器疏水端差应达值。     

应用液压胀管技术提高高压给水加热器胀管质量

本文对近几年哈锅公司在高压给水加热器产品制造中应用液压胀管技术的试验与实践予以了阐述。并和其他胀接技术-机械胀管做了比较,得出了在目前高压给水加热器产品制造中液压胀管技术优于其他胀接技术的结论。     

1000MW超超临界高压加热器的研制

本文通过1000MW超超临界高压加热器的研制,阐述了制造过程中的管系、外壳、总装等关键工序和制造难点控制,解决了管板组装及管系与外壳套装等工艺难题。     

Cost optimization of a conical electric heater

Electric heaters are used extensively in many industrial applications including air conditioning, water heating, and drying of crop and other materials. There are several interacting parameters that affect heater performance and contribute to its operating and manufacturing costs. The design parameters of interest included coil length, coil diameter, helix diameter, coil pitch, number of turns, coil emissivity, heater wall emissivity, applied voltage, air flow rate, air temperature at the heater outlet, insulation thickness, and the heater dimensions. An objective function for the heater cost was defined in terms of the total annual costs for energy usage and manufacturing. The manufacturing cost included the material cost of the heater, the cost of coating the heater coil, and the cost of insulating the heater. A detailed model describing the performance of a conical heater was utilized to evaluate and minimize the objective function. The optimization problem was completely defined by introducing fourteen inequality constraints, three equality constraints, and ten design variables. The univariate search was used to reduce the number of inequality constraints. The direct search and variable metric methods were used to optimize the objective function at different values of the applied power and air temperature at the heater outlet, leading to the same results. The optimization results indicate that the optimum heater design was found at the minimum values of the coil diameter, conical angle, coil emissivity, and the maximum value of coil temperature. The maximum operating temperature of the optimum heater design (a heater with a silver coated coil) is substantially lower than the maximum normal operating temperature so that longer life for the heating element is expected. The effect of varying the applied power on the objective function showed that as the applied power increases the objective function may increase or decrease, depending on the combined effect of increasing the coil length and heater efficiency and decreasing the insulation thickness. The effect of varying the air temperature at the heater outlet on the objective function indicated that as the air temperature increases the objective function increases. Copyright © 2005 John Wiley & Sons, Ltd.     

高压加热器保护系统的配置

高加系统能否安全运行,将直接影响到机组的效率,这就需要有一套齐备安全的保护系统附件.本文简要介绍高压加热器保护系统的配置,以供参考.     

回转式空气预热器密封形式的改进

分析回转式空气预热器的漏风因素及现行密封形式的优缺点,提出回转式空气预热器“单密封”的“双密封”形式改进的理论依据及可行性研究,通过几个发电厂实际改进效果表明,此项改进是改善回转式空气预热器漏风大的有效方法。     

The performance of a cylindrical solar water heater

A cylindrical solar water heater is designed and manufactured in the Department of Mechanical Engineering, University of Bahrain. It consists of a cylindrical tube made from high quality glass having a length of 0.8, 0.14 m outer diameter and a thickness of 6 mm. A copper coil tube in the shape of spiral rings, with the tube inner diameter of 2 mm and outer diameter of 3.175 mm, painted black, serves as a collector to the incident solar energy on the cylinder wall. The thermal performance was evaluated extensively throughout the months of March and April 2002; a maximum temperature difference of 27.8 °C between inlet and outlet of the solar water heater at a mass flow rate of 9 kg/h was achieved. The efficiency of the cylindrical solar water heater was calculated. The maximum value during the experimental period was found to be 41.8%. This reveals a good capability of the system to convert solar energy to heat which can be used for heating water. An economic analysis has reveals that the cylindrical solar water heater compared with the flat plate collector is cost effective.     

大柳塔热电厂高压加热器的运行经济性分析

高压加热器由于泄漏不能正常投运，对机组的安全经济运行带来严重影响，通过定量分析、对高压加热器进行改造，提高了高压加热器的投入率，为机组的安全运行提供了保障，降低了发电成本，提高了全厂的热经济效率。