汽轮机热耗在线分析及管理系统结构设计

对热耗进行在线监测和实时故障分析已成为当今先进汽轮发电机组发展的必然趋势之一。该文根据电厂不同的运动状况，提出了热耗在线分析和管理系统的结构设计，实践表明，所提出的设计思路能成功地对电厂机组经济性进行在线管理。采用该诃提高机组运行的可靠性，经济性，延长机组的运行寿命。     

基于遗传算法的多机型多热源复杂热电负荷优化分配方法

热电联产机组因同时能生产热负荷和电负荷而得到了广泛应用.机组在不同热、电负荷下的热耗不同,不同机组在相同热、电负荷下的热耗也不相同.因此,为达到节约能源的目的 ,对其进行热电负荷优化分配成为至关重要的问题.针对某电厂的多机型、多热源的复杂机组,提出了一种改进的遗传算法,对该机组进行负荷优化分配.结果 表明,优化后的热耗...     

计及容积效应的汽轮机热耗率修正数学模型

目前电厂常用的热耗率计算方法忽略了汽轮机的容积效应,使得机组处于动态过程中时计算出的热耗率存在不合理的波动,无法反映机组真实运行水平。针对这一问题,从容积效应机理出发,推导出动态过程中热耗率修正数学模型,并利用仿真数据对热耗率修正模型进行了验证。结果表明,提出的修正模型可有效减小动态过程中机组热耗率的不合理波动,提高热耗率实时计算的准确性和稳定性。     

2×1000 MW机组循环水系统一机双塔改造热耗变化研究

针对某电厂2×1 000 MW机组单机运行工况较长,夏季机组背压高于设计值的现状,拟通过对原单元制供水系统进行一机双塔改造,降低单机运行时凝汽器循环水进水温度。提出了一种一机双塔改造热耗变化分析方法:在利用PIPENET软件对改造后一机双塔水力分析的基础上,分别对冷却塔、凝汽器进行热力分析,确定凝汽器背压变化情况;进而利用机组"背压—热耗曲线",得出改造后机组热耗降低值。     

注水对燃气轮机联合循环机组性能试验研究

为了对比研究某机组注水脱硝系统对燃机出力及热耗率等的影响,对某燃气轮机联合循环机组进行性能试验。试验共分3个试验工况:相同基础负荷注水前后性能试验及注水后机组最大出力工况,计算了不同工况下机组出力及热耗率,计算了注水脱硝系统投运后NOx减排量和增加的度电成本,最后分析了注水对机组运行的影响,试验结果表明注水能够提高燃气轮机出力,增加热耗,降低热效率,注水可以大幅降低燃气轮机NOx排放量。注水会增加度电成本,降低电厂经济性。     

定量分析凝汽器冷却水管结垢对机组经济性的影响

以热力学第一定律为基础,应用传热学原理,定量分析了凝汽器冷却水管结垢对凝汽器真空、机组功率以及机组热耗率的影响。研究成果对提高电厂机组运行的经济性有着重要的现实意义。     

考虑环境温度的负荷经济调度

随着发电成本的不断上升,负荷经济调度被给予了高度的重视。将环境温度作为电厂负荷经济调度的影响因素,比只考虑总负荷的研究具有更强的工况适应性。文中介绍粒子群算法在负荷经济调度中的应用。结合2台典型机组的实际运行数据对考虑环境温度与不考虑环境温度的负荷经济调度进行对比分析。分析结果表明:考虑环境温度和不考虑环境温度的结果都是机组热耗率随着总负荷的上升而下降,随着温度的上升而上升。考虑环境温度的机组热耗率始终低于不考虑环境温度的机组热耗率。并且随着温度的下降,二者的差值越来越大。分析结论对当前的电厂负荷经济调度有一定的参考意义。     

某350MW热电联产机组低压缸零出力改造热电特性分析

以某电厂350MW热电联产机组为例,介绍了低压缸零出力改造方式,结合试验数据对比分析了低压缸零出力改造前后供热能力和调峰能力,并从热耗率和调峰收益量方面对机组运行经济性进行分析计算.     

基于BP和RBF神经网络的机组能耗特性研究

火电机组在运行过程中不仅产生大量的历史数据,同时这些边界参数还与热耗率之间存在复杂的非线性关系。针对某电厂的实时数据,首先利用敏感性分析,从大量的机组运行参数中筛选出对机组能耗影响较大的重要参数:负荷、循环水入口温度、主蒸汽温度、再热蒸汽温度、主蒸汽压力、循环水流量。然后,对BP和RBF神经网络在热耗率与机组边界参数的应用进行了对比分析。训练和预测结果表明,BP和RBF神经网络都能对此进行分析研究,但RBF比BP神经网络的训练和预测的相对误差较小些,可以更准确地对机组热耗进行预测。为今后的可控参数优化提供了有效的模型,具有一定指导意义。     

基于遗传算法的抽汽供热机组间的热电负荷分配优化研究

目前,随着电网中新能源电力的规模接入,缺乏全局优化指导的传统调度模式使得电网整体运行效率低下,火电厂的节能减排日趋重要。本文针对电厂中200 MW及600 MW供热抽汽机组间热电负荷的分配优化问题进行了相关研究,通过理论计算和现场实验相结合的方法,建立了不同热、电负荷下每台机组的热耗曲线,在考虑冷凝器背压的情况下,利用热耗曲线以及机组的耗差信号,通过遗传优化算法,实现了热电负荷分配优化,达到了节能降耗的目的。这对我国供热机组占绝大多数的北方电厂的节能优化具有一定借鉴意义。     

Heat pump dryer Part 1: Simulation of the models

Heat pump dryer is a complex system because of the interaction of heat and mass transfer of the working fluids. Since the system cannot be completely close, ambient conditions (temperature and humidity) influence the performance of the system. To investigate the performance of the heat pump dryer thoroughly, simulation models of heat pump dryer components have been developed. The finite-difference method was employed in the simulation to examine the state of the working fluids and heat and mass transfer. The simulation of each component can be used to construct different system configurations the results of which are reported in Part 2.     

On the steady‐state modelling of a two‐stage evaporator system

We develop and validate against experimental measurements a steady‐state two‐stage flooded refrigerant evaporator model for a heat pump drying system. A prototype two‐stage heat pump dryer test facility was designed, built and instrumented to provide the required measurements for the validation of the model. Repeatability and data quality tests were conducted to evaluate the accuracy of measurements. Experimental data could be reproduced to within ±6.5 per cent of replicated air and refrigerant side measurements for the same evaporator's air inlet conditions while the discrepancy of energy balance at the air‐side and refrigerant‐side was observed to be within ±8.9 per cent. The two‐stage evaporator model predicted the air‐side total heat and latent heat transfer of the two‐stage evaporator to within (?6.3 per cent, 7.6 per cent) and (?11.5 per cent, 9.5 per cent), respectively. On the refrigerant‐side, the model enabled the calculation of the degree of superheat to within (?10.6 per cent, 1.7 per cent). The model has shown that there is significant improvement in the heat recovered from a two‐stage evaporator system compared to a single evaporator system. In addition, the model demonstrated that the improvement in total heat recovery could be as high as 40 per cent over its base‐value when the latent to total load at the two‐stage evaporator is increased. Copyright © 2001 John Wiley & Sons, Ltd.     

Quantification of the European industrial heat demand by branch and temperature level

We present the first comprehensive estimate of the final energy demand for heat in all EU28 member states for the reference year 2012, differentiated by temperature levels, comparing two different approaches. Two different calculation approaches based on different data sets yielded estimates of the total final energy demand for heat in the EU28 of 8150 PJ and 8518 PJ in 2012, respectively. Approach 1 distinguishes between three different process heat (PH) temperature levels and results in final energy demand for heat <100°C: 2077 PJ, 100–400°C: 2214 PJ and >400°C: 3859 PJ. The second approach distinguishes between low temperature space heat and hot water (<100°C: 1161 PJ) and four different PH temperature levels with a resulting energy demand of <100°C: 1027 PJ, 100–500°C: 1785 PJ, 500–1000°C: 1679 PJ and >1000°C: 2865 PJ. The high share of high‐temperature heat illustrates the limits to the potential decarbonisation of industrial thermal processes with renewable energy sources such as (non‐concentrating) solar thermal, geothermal or environmental heat. Therefore specific information on required temperature levels is of the essence. This, in turn, points out the relevance of renewable electricity and synthetic fuels based on renewable power for a significant reduction of CO₂ emissions from the industry sector in Europe. Considering current data quality, it is recommended to develop a consistent, comprehensive methodology to significantly improve the data basis on industrial heat demand. Copyright © 2015 John Wiley & Sons, Ltd.     

LDV散热器传热特性的分析研究

散热器是发动机是重要部件总成。本文对上海汽车商用车技术中心LDV车用散热器的传热性能进行风洞试验,由实测试验数据,将管外横掠管簇的对流换热系数从传热系数中分离出来,整理成无量纲准则式,为散热器的优化设计提供参考依据。另外,对一些未做过性能试验的散热器的设计计算也能提供帮助。     

地源热泵的分类及其若干问题的看法

针对地源热泵的分类和名称不很统一的现状，提出了按低温热源的来源统一分类的看法，并据此对目前常用的各种土壤源、水源热泵进一步分类；并提出目前把水环热泵当作水源热泵是不合适的，应该作为空气源热泵的一种。     

热网管道保温与热化发电之间的相互关系分析

热网管道的保温设计，尤其是长距离热风管道的保温设计，对热网管道设计成功与否显得十分重要。而热电厂供热参数的高低不仅与经济发电相关，更主要的是跟热网的保温、散热损失有关。一般热能工程设计手册中，仅有经济厚度等计算方法介绍，而没有考虑保温散热损失对热化发电的影响。这对集中供热来说是合理的，但对于热电联产来说，似乎有点欠缺。本文试图通过实例分析计算，来说明保温厚度、散热损失、热化发电的相互关系。以期重视热网管道的保温设计、施工，正确处理经济厚度与热化发电的联系，进一步降低消耗，节约能源。     

地源热泵竖直埋管的有限长线热源模型

对地热换热器竖直埋管的非稳态传热模型进行了分析讨论。采用虚拟热源和格林函数法给出了半无限大介质中有限长线热源产生的非稳态温度场的解析解表达式。与稳态温度场的解进行比较,讨论了温度场达到名义上的“稳态”所需的时间,同时对于达到稳态时的温度场也进行了分析,指出了现行教科书中关于该问题的错误,提出了稳态时两个地热换热器孔壁代表性温度的定义,并对两者进行了比较,进而给出了可供工程应用的简化计算公式,并对两者进行了比较,进而给出了可供工程应用的简化计算公式。基于以上分析,进一步讨论了全年冷热负荷不平衡对地热换热器长期性能的影响。     

热管技术在高架原油罐上的应用探讨

热管是一种高效的传热元件,在传热和节能方面的应用越来越多.对目前高架原油罐加热的主要方法进行了简单的分析,提出了一种利用热管对高架原油罐原油进行升温降黏的方法并简单介绍了其热力学方面的计算,有一定的应用价值.     

振荡热管换热器用于染整加工中余热回收的分析研究

叙述了振荡热管换热器用于染整加工中定型机余热回收,比传统热管换热器在能量回收上的经济性,指出,振荡热管换热器不仅每小时回收的能量大于传统热管换热器,且投资收益较高,维护费用低.     

The heat transfer and pressure loss characteristics of a heat exchanger for recovering latent heat (the heat transfer and pressure loss characteristics of the heat exchanger with wing fin)

In recent years the requirement for reduction of energy consumption has been increasing to solve the problems of global warming and the shortage of petroleum resources. A latent heat recovery type heat exchanger is one of the effective methods of improving thermal efficiency by recovering latent heat. This paper described the heat transfer and pressure loss characteristics of a latent heat recovery type heat exchanger having a wing fin (fin pitch: 4 mm, fin length: 65 mm). These were clarified by measuring the exchange heat quantity, the pressure loss of heat exchanger, and the heat transfer coefficient between outer fin surface and gas. The effects of condensate behavior in the fins on heat transfer and pressure loss characteristics were clarified. Furthermore, the equations for predicting the heat transfer coefficient and pressure loss which are necessary in the design of the heat exchanger were proposed. ©2007 Wiley Periodicals, Inc. Heat Trans Asian Res, 36(4): 215–229, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20154