立式余热锅炉简介

本文主要就介绍燃气-蒸汽联合循环电厂余热锅炉的特点，阐述余热锅炉设计原则，并对两种余热锅炉作了比较，着重说明了立式余热锅炉的优点．     

联合循环中的余热锅炉及其设计参数选择

介绍了燃气-蒸汽联合循环的基本原理、余热锅炉结构及其汽水系统,分别讨论了余热锅炉节点和接近点温差的选择、余热锅炉设计参数的选择以及余热锅炉变工况运行技术.文章可以为燃气-蒸汽联合循环中余热锅炉的设计、运行和改造提供依据.     

余热锅炉最小温差和接近点温差的选择

本文通过数值计算，研究了最小温差和接近点温差以及烟气侧阻力对余热锅炉传热面积和余热锅炉效率的影响，从而在燃气－蒸汽联合循环用余热锅炉设计中，为合理选择余热锅炉的最小温差和接近点温差这两个重要设计参数，提供了理论依据．     

保证燃气-蒸汽联合循环余热锅炉性能的措施

从燃气-蒸汽联合循环余热锅炉的设计出发,根据影响余热锅炉性能的各种因素,简要分析说明了保证余热锅炉性能的一系列措施;余热锅炉的性能优劣直接影响到燃气-蒸汽联合循环机组的整体运行,是燃气-蒸汽联合循环机组高参数、大型化发展的重要因素。     

联合循环发电技术及其余热锅炉

燃气-蒸汽联合循环发电技术可实现化学能梯级利用,具有很高的效率。余热锅炉处于燃气轮机和蒸汽轮机之间,对联合循环系统效率产生重要影响。本文概述了燃气-蒸汽联合循环发电技术的原理和组成,重点介绍了余热锅炉的结构和热力性能等方面的特点,并对影响余热锅炉性能的有关因素进行了阐述。最后,对余热锅炉的研究方向进行了讨论。     

联合循环余热锅炉蒸汽参数的优化分析

对双压再热余热锅炉的蒸汽参数进行了优化研究，计算归纳了最优化的蒸汽压力、蒸汽流量以及Yong回收量随余热锅炉进口燃气参数的变化规律。其结果对联合循环余热锅炉优化设计具有理论意义和价值。     

余热锅炉热力性能的正确评估

以某燃机联合循环机组中的余热锅炉测试数据为依据,重点分析了余热锅炉的热力性能与名义效率的差别;在燃气轮机联合循环机组性能考核中,按惯例用名义效率考核三压余热锅炉热力性能,仅反映了其所利用余热量的多少,未客观真实体现蒸汽品质的高低,而余热锅炉蒸汽品质决定了有效做功能力;因此,为真实、完整地体现联合循环机组主机及其三压余热锅炉的热力性能,三压蒸汽有效做功能力的计算分析是关键。     

蒸汽吹灰器在燃气——蒸汽联合循环电厂余热锅炉中的应用

本文针对燃气－－蒸汽联合循环电厂余热锅炉的积灰问题,提出了几种解决办法,并重点介绍了蒸汽吹灰器用于燃气－－蒸汽联合循环余热锅炉除灰的成功经验。     

饱和蒸汽减温在燃机余热锅炉的应用

介绍了燃气－蒸汽联合循环电站余热锅炉过热蒸汽调温的一种方法－自身饱和蒸汽减温。对余热锅炉自身饱和蒸汽减温系统的设计进行了分析,指出了实际应用中应该注意的问题。     

燃气-蒸汽联合循环余热锅炉方案简介

本文根据大型燃气-蒸汽联合循环余热锅炉的技术特点,简要介绍某电厂匹配GE 9FB型燃气轮机的余热锅炉方案,并分析说明了燃气-蒸汽联合循环余热锅炉快速启动的一系列措施。     

稠油地面蒸汽管线热力参数影响及保温厚度优化

提高蒸汽注汽品质和优化保温层厚度是改善地面蒸汽管线热力输运、实现稠油高效开采的关键。建立了油田地面蒸汽管线热力参数计算模型和保温层厚度经济性分析模型,基于分段微元方法求解沿程蒸汽干度、热损等特性参数,分析了锅炉出口蒸汽参数和注汽流量的影响规律,并结合经济厚度法的计算原理优化了保温层厚度。结果表明：提高锅炉出口蒸汽温度和压力,沿程蒸汽干度降低速度变快,沿程热损增加变快,与锅炉出口蒸汽温度313 oC,压力10.2 MPa相比,其热损最大增加11.15%;增加注汽流量,蒸汽干度提升且随管线沿程降幅缩小,等梯度注汽流量差下,高注汽流量时蒸汽干度降幅较小,其降幅为3.58%;经济厚度为0.33m时,其热损费用同比原有厚度可降低68.22%。     

余热锅炉动态特性的数值计算

本文对单压余热锅炉的动态特性进行了数值计算。分析了当燃气轮机排烟温度和流量发生扰动时,余热锅炉出口参数随时间的变化规律。研究结果为联合循环余热锅炉控制系统的设计提供了理论依据。     

一种太阳能吸热器过热蒸汽温度控制系统

介绍了一种应用于塔式太阳能热发电系统的水/蒸汽吸热器过热蒸汽温度控制系统。受到太阳辐射能间歇性和不确定性的影响,吸热器产生的过热蒸汽温度难于控制。控制系统根据吸热器在蒸汽流量变化、光功率变化和减温水流量变化等3种主要扰动下的过热汽温度动态响应特性,以减温水流量作为控制量,光功率和蒸汽负荷作为前馈信号,设计和研制了两段式过热蒸汽温度控制系统,使吸热器过热区出口汽温维持在允许的范围内。     

Experiments on hydrogen production from methanol steam reforming in fluidized bed reactor

A novel approach for the hydrogen production which integrated methanol steam reforming and fluidized bed reactor (FBR) was proposed. The reaction was carried out over Cu/ZnO/Al₂O₃ catalysts. The critical fluidized velocities under different catalyst particle sizes and masses were obtained. The influences of the operating parameters, including that of H₂O-to-CH₃OH molar ratio, feed flow rate, reaction temperature, and catalyst mass on the performance of methanol steam reforming were investigated in FBR to obtain the optimum experimental conditions. More uniform temperature distribution, larger surface volume ratio and longer contacting time can be achieved in FBR than that in fixed bed reactor. The results indicate that the methanol conversion rate in FBR can be as high as 91.95% while the reaction temperatures is 330 °C, steam-to-carbon molar ratio is 1.3, and feed flow rate is 540 ml/h under the present experiments, which is much higher than that in the fixed bed.     

Experimental study on stable steam condensation in a quenching tank

Experimental study on direct contact condensation (DCC) of a stable steam discharging into a quenching tank with sub‐cooled water has been performed for five different sizes of horizontal nozzles over a wide range of steam mass flux and pool temperature conditions. Two different steam jet shapes (conical and ellipsoidal) were typically observed, depending on the steam mass flux and the pool temperature. The steam jet expansion ratios, the dimensionless steam jet lengths, and the average heat transfer coefficients were determined and the effects of steam mass flux, pool temperature, and nozzle diameter on these parameters were discussed. Empirical correlations for the dimensionless steam jet length and the average heat transfer coefficient as a function of steam mass flux and condensation driving potential were established. The axial and radial temperature distributions in the steam jet and in the surrounding pool water were measured and the effects of steam mass flux, pool temperature, and nozzle diameter on these parameters were also discussed. Copyright © 2001 John Wiley & Sons, Ltd.     

Analysis of the superheated steam cycle of a PWR secondary system

The impacts of variations of turbine exhaust steam wetness, live steam parameters, and the turbine sectional pressure ratio on the thermodynamic efficiency of the saturated steam cycle in a PWR secondary system are analyzed. The effects of live steam parameters and turbine sectional pressure ratio on the thermodynamic efficiency and the turbine exhaust steam wetness for the superheated steam cycle are also investigated. The optimum ranges of operating parameters are proposed based on the comparison of the performance of the superheated steam cycle with that of the saturated steam cycle. © 2001 Scripta Technica, Heat Trans Asian Res, 30(3): 185–194, 2001     

Effects of particle sizes on performances of the multi-zone steam generator using waste heat in a bio-oil steam reforming hydrogen production system

Hydrogen production by bio-oil steam reforming is an advanced production technology. It is a good method of coupling waste heat utilization with bio-oil steam reforming to produce hydrogen, which increases the cleaning ability of the bio-oil steam reforming system. A multi-zone steam generator using waste heat has been proposed, which can produce the heat source and steam source of the hydrogen system. The DEM model of the multi-zone steam generator was set up. The model has been used to investigate the effects of particle sizes (40 mm–80 mm). With increasing particle size, the flow index and the flow uniformity gradually decrease, the vertical velocity gradient increases in the area on both side with the zone steam generator, and the vertical velocity fluctuation amplitude gradually increases. So, the hydrogen production decreases from the particle size increasing.     

Performance prediction of steam gasification of wood using an ASPEN PLUS thermodynamic equilibrium model

In this article, an equilibrium model based on Gibbs free energy minimisation is presented for steam gasification of biomass in process simulator ASPEN PLUS. Carbon is assumed as fully converted into product gases and no tar content is assumed to be present in gaseous product. The objective is to arrive at the optimum process conditions of gasification. An analysis on the sensitivity of producer gas composition, lower heating value, combustible gas yield, and first and second law efficiencies on gasification process variables including reactor temperature, pressure and steam to biomass mass ratio is also envisaged. Simulations are performed with wood as the biomass material, based on real gas behaviour for product gases and gasifying medium. The predicted results of the model are compared with another Gibbs free energy model formulated using simulated annealing minimisation algorithm. The present ASPEN PLUS model is validated with published experimental results on steam gasification on a fluidised bed gasifier.     

三喷头蒸汽水下喷注噪声试验研究

蒸汽在过冷水下喷注过程中,由于汽泡溃灭及喷注射流扰动会产生强烈的噪声.通过试验研究了不同结构的三喷头蒸汽水下喷注在不同的水温及蒸汽流量下的噪声规律.试验结果表明:三喷头喷注A声压级噪声主要受水温、蒸汽流量及喷头结构的影响,其中水温对喷注噪声的影响最大;喷注噪声随着蒸汽流量的增加而增大;在试验范围内,减小喷头的孔径或相对孔间距,可以减小喷注噪声.