中,小型凝汽式汽轮机组改造为供热机组的方法研究

国家计委、国家经贸委、电力工业部、建设部于1998年2月17日联合发布的《关于发展热电联产的若干规定》第八条明确规定,“发展热电联产应优先安排现有中、小型凝汽机组改造为供热机组”.目前我国许多中小电厂安装有为数不少的中、小型凝汽式汽轮发电机组.这些机组由于煤耗高、热效率低,有的已停止运行,有的即将停止运行.因此,将其改造成供热机组,实行热电联产,是改造中小电厂的唯一     

凝汽式汽轮机高背压循环水供热改造技术研究

文章通过对汽轮机低压通流及凝汽器改造,充分利用汽轮机排汽中的低位能供热,极大提高了能源利用.文章研究了汽轮机高背压供热改造对轴系静动特性、机组热膨胀的影响,总结了本体结构及设备保温设计特点,探讨了保证机组安全运行的末端冷却手段及安全保护值设定.     

节能环保新举措──浅谈小型凝汽式汽轮发电机组低真空供热

本文着重讨论了小型凝汽式汽轮发电机组低真空供热的几个问题。实践证明,利用小型发电厂低真空供热运行方式采暖,是一个节约用水、节约用电、节约用煤的节能环保新举措,具有很高的经济效益和环境效益。     

N600MW纯凝汽机组改造为供热机组的可行性研究

小热电联产机组关闭后形成的供热负荷,将由中、大型凝汽机组改造为供热机组实现。对N600MW亚临界纯凝发电机组提出两种改造方案,并进行了技术经济分析。     

100MW背压式抽汽凝汽式机组经济效益的探讨

１００ＭＷ背压式抽汽凝汽机组非常适合于北方集中供热采暖。冬天,北方采暖时间长达３￣５个月,机组这时按背压方式运行供热,全年（７０００小时）的其余时间机组按纯凝汽方式运行,热电厂全年总热效率和热电比就会比国家规定的４５％和５０％的要求高得多。     

供热初末期50MW机组低真空循环水供热的可行性

对供热机组运行现状及其存在问题进行分析,探讨50MW机组在供热初末期改变运行方式,进行低真空运行循环水供热的可行性;该项目对于提高电厂经济效益、节约能源等方面,具有重要的参考价值与指导意义。     

大容量抽汽供热机组的设计开发

主要介绍了上海汽轮机有限公司与美国西星公司联合开发的我国首台大容量抽汽供热机组的设计特点和所采用的最新技术。     

小火电凝汽机组采用循环水供热势在必行

小火电凝汽机组采用循环水供热势在必行赵念平最近，我国国民经济和社会发展＂九五＂计划和２０１０年远景目标纲要再一次提出＂能源工业应坚持节约与开发并举，把节约放在首位＂的能源利用政策。可以预见，这一政策必将推动我国各项节能工作向更快更深的方向发展，从而使...     

大型凝汽机组改造成供热机组的最佳途径

在电力工业“上大压小”节能减排的政策指导下,一些小热电厂关停,部分大型凝汽机组开始承担供热任务。由于大型凝汽式机组没有合适的抽汽口来实现供热,必须进行改造。     

齐鲁石化丙烯腈厂废水焚烧炉余热锅炉改造方案研究

简述了原有火管式废水焚烧炉余热锅炉的结渣原因 ,提出了改造方案 ,介绍了改造方案的结渣周期计算和技术经济分析 ,证明其在理论上有效可行 ,节能和经济效益显著.     

Characteristics of heat transfer inside a tube during sodium‐water reaction in a FBR steam generator

Sodium reacts chemically with water in the case of an unexpected tube failure of a steam generator (SG) in a fast breeder reactor (FBR). In order to predict the event with high accuracy, it is very important to understand the characteristics of heat transfer inside the tube in detail during the tube failure due to the sodium–water reaction. Experiments were performed by using purified water under the following conditions: initial pressure of 11.2–13.4 MPa, initial water temperature of 200 °C, and water mass flux of 45.7 to 3630 kg/(m²s). The test tube was heated rapidly by high‐frequency induction current. The time averaged heat flux was estimated by using an inverse solution from the measured temperatures at two points on three different locations along the tube. It was confirmed that the derived values agreed with the measured heat fluxes on the outer surface within 20% accuracy. It was found that the characteristics of the heat transfer strongly depend on the flow rate. The heat transfer on the wall changed from nucleate boiling to transient‐film boiling during increasing the heat flux and returned to the nucleate boiling during decreasing the heat flux. A counterclockwise cycle always appeared in the transition boiling region, where the nucleate and film boiling coexisted and the area ratio of these varied with time. The adequacy of heat transfer correlations to evaluate tube overheating was confirmed. © 2010 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/htj.20320     

Applying different optimization approaches to achieve optimal configuration of a dual pressure heat recovery steam generator

The optimal design for heat recovery steam generator (HRSG) should be chosen based on technical and economic considerations. Therefore, parameters that are related to thermodynamic and economic aspects should be considered in optimization approaches. It is worth mentioning that one of the significant issues in the HRSG design is the diversity of arrangements between various components (economizer, evaporator, and superheater), which absolutely affect the HRSG performance. According to these facts, in the present article, different arrangements of a dual pressure HRSG are analyzed, and the economizer at the high‐pressure level is divided into two parts; these arrangements are optimized by applying different optimization approaches to achieve the optimal configuration. These approaches include the reduction of gas pressure drop, the reduction of generated steam cost and the consideration of both approaches as the third approach. These three approaches are also considered to perform economic and thermodynamic optimization. With regard to the limitations of optimization such as the pinch and approach point, seven different configurations are considered. First, a comprehensive model is developed for calculating thermodynamic, heat transfer, and pressure loss. To perform a thorough optimization, both thermodynamic and geometric variables as well as diversity of various arrangements is considered using genetic algorithm. The results of the optimization study show that the best arrangement is not unique, and each arrangement has different characteristics. Hence, the best arrangement for the HRSG is chosen according to the importance of the objective functions. Copyright © 2012 John Wiley & Sons, Ltd.     

Optimization of heat recovery steam generator through exergy analysis for combined cycle gas turbine power plants

This paper proposes a new approach to finding the optimum design parameters of the heat recovery steam generator (HRSG) system to maximize the efficiency of the steam turbine (bottom) cycle of the combined cycle power plant (CCPP), but without performing the bottom cycle analysis. This could be achieved by minimizing the unavailable exergy (the sum of the destroyed and the lost exergies) resulted from the heat transfer process of the HRSG system. The present approach is relatively simple and straightforward because the process of the trial-and-error method, typical in performing the bottom cycle analysis for the system optimization, could be avoided. To demonstrate the usefulness of the present method, a single-stage HRSG system was chosen, and the optimum evaporation temperature was obtained corresponding to maximum useful work for given conditions of water and gas temperatures at the inlets of the HRSG system. Results show that the optimum evaporation temperature obtained based on the present exergy analysis appears similar to that based on the bottom cycle analysis. Also shown is the dependency of number of transfer unit (NTU) on the evaporation temperature, which is another important factor in determining the optimum condition when the construction cost is taken into account in addition to the operating cost. The present approach turned out to be a powerful tool for optimization of the single-stage HRSG systems and can easily be extended to multi-stage systems. Copyright © 2008 John Wiley & Sons, Ltd.     

A review of integration strategies for solid oxide fuel cells

Due to increasing oil and gas demand, the depletion of fossil resources, serious global warming, efficient energy systems and new energy conversion processes are urgently needed. Fuel cells and hybrid systems have emerged as advanced thermodynamic systems with great promise in achieving high energy/power efficiency with reduced environmental loads. In particular, due to the synergistic effect of using integrated solid oxide fuel cell (SOFC) and classical thermodynamic cycle technologies, the efficiency of the integrated system can be significantly improved. This paper reviews different concepts/strategies for SOFC-based integration systems, which are timely transformational energy-related technologies available to overcome the threats posed by climate change and energy security.