300MW机组高背压供热改造方案及试验分析

针对某300MW供热机组的汽轮机特性以及其所在热电厂的供热背景,分析了高背压改造存在的关键技术问题,提出了汽轮机本体及主要辅机的改造方案,并通过改造后的热力性能试验分析了高背压改造对机组性能的影响。分析得出,所采用的改造方案是可行性的,改造后机组节能降耗效果显著。机组供电煤耗由改造前的289. 48g/(k W·h)降至151. 04g/(k W·h),降低了47. 82%。     

300MW供热机组高背压供热改造方案分析

高背压供热机组是近年为适应北方采暖供热而出现的改造型机组,大都是由纯凝或抽凝式机组经改造而成。为进一步提高机组的供热能力和供热经济性,某300 MW供热机组进行了高背压供热改造技术方案分析研究。针对汽轮机特性以及其所在热电厂的供热背景,提出了3种汽轮机本体改造方案。通过分析3种改造方案的技术特征与改造内容,得到了3种改造方案对汽轮机及机组供热经济性的影响,并据此确定了最优改造方案。     

350MW超临界机组高背压供热改造研究及性能分析

针对大连开发区热电厂当前供热存在的问题,提出回收汽轮机排汽余热用于供热,以提高机组的供热能力,满足日益增加的供热需求。对大连开发区热电厂1#机组汽轮机进行了高背压供热改造,改造后机组的供热能力显著提高,能耗降低,同时污染物排放减少,经济效益显著。     

集中供暖换热站扩容供热方式的选择

通过对某换热站新增区域的供热方式与原采暖用户进行系统分析,建议新增区采用间接连接和混水直接连接两种方案,并对两种方案给出详细的设计说明;通过对两种方案进行整体比较分析,综合得出混水直供换热方式运行经济,供热效果良好,尤其是区域供热新增区或新建区采暖用户的供热选择方式。     

吸收式热泵耦合大型抽凝机组供热的经济性分析

针对供热需求与供热能力之间的矛盾和电站低品位冷凝热利用不充分的问题,以300MW抽凝供热机组为实例制定了吸收式热泵耦合抽凝机组供热方案。结合耦合供热方案提出供热面积扩容率的概念,通过对耦合供热与传统热电联产供热两种供热方式的定流量热力计算,以供热面积扩容率、能源综合利用率和热电总收益三个经济性指标为比较标准,进行了经济性指标对比分析。结果表明:耦合供热方式在机组不增容的前提下能够扩大供热面积,提高能源利用率,并增加热电厂的经济收益。     

热电厂供电供热煤耗指标核算数据的校验

针对目前热电厂供电、供热煤耗核算存在的问题,通过对热电厂实际生产数据核算、分析及校验,提出合理实用的供电供热煤耗简便校验方法,准确地核算热电厂煤耗指标,为政府节能主管部门和企业能源管理部门对热电厂发电、供电指标考核提供准确的参考依据。     

新疆风城油田特1联合站供热系统节能改造技术

针对新疆油田特1联合站供热系统节能改造工程,从供热现状、存在问题、改造目的、改造方案、改造结果等方面进行了论述,提出用其他热源取代蒸汽来满足采暖需求,通过对3种不同方案比较,得出方案一符合项目改造需要,对同类项目实施节能改造具有一定的参考价值。     

利用吸收式循环对热电机组供热首站改造的经济性分析

利用吸收式换热原理对郑州市某热电厂进行集中供热系统热网首站进行改造,依次进行方案设计,供热机组最小抽汽量优化,经济、环境效益分析计算。研究结果表明,利用吸收式换热机组对郑州市某热电厂进行供热首站改造,在有效回收凉水塔废热、显著提升热电厂供热能力的同时,可大量减少燃煤和供热抽汽量,其经济效益和环境效益显著,有效缓解城市供热热源紧张的现状。     

基于热力学第二定律的热电厂低真空供热能耗分析

基于热力学定律与单耗分析理论,推导热电厂低真空供热的能耗分析方法,并进行能耗分析。结果表明:热电厂的总能耗水平由好到差依次为:抽汽+低真空供热工况、抽汽供热工况、纯凝工况;各子系统的火用效率和附加单耗由好到差的顺序依次为:低真空供热子系统、抽汽供热子系统、电能生产子系统;热电厂低真空供热时,背压、端差的取值存在一个最佳值,可由实例计算得到,且背压取值的乏汽温度为65℃,端差取值为3℃;热电厂利用低真空取代抽汽供热时,抽汽量也存在一个最佳值,实例计算最小抽汽量为283.96 t/h。可见,在电厂具有热用户的前提下,进行抽汽供热以及低真空供热改造是十分必要的。     

背压机技术在供热优化改造中应用研究

针对300MW亚临界纯凝机组高压供热改造问题,提出了5种背压机解决方案。借助EBSILON软件,通过变工况分析方法对各方案进行分析,结果表明:方案2、方案3和方案4经济性相同,但由于采用减压技术,比方案1系统效率降低了约35. 93%。方案5经济性虽高,但存在改造范围大和高中压供热耦合性大等问题。综合考虑方案的经济性和灵活性,方案1是解决此类问题的首选方案。同时,还提出了采用汽-汽换热器系统,解决高压供热温度偏低的问题。     

300 MW湿冷汽轮机双转子互换高背压供热改造应用

随着用户需求增加及国家节能减排政策要求,对亚临界300 MW湿冷汽轮机组进行高背压供热改造成为火力发电厂满足对外供热需求和提高机组效率的重要措施之一,而汽轮机在供热期和非供热期双低压转子互换是实现高背压供热改造一个行之有效的手段.以某电厂2号机300 MW机组采用双低压转子互换技术进行高背压循环水供热改造为例,简述了汽轮机在改造过程中需要考虑的主要问题及相应的改造方案.     

Solar multi-mode heating system based on latent heat thermal energy storage and its application

为克服太阳能间断性和不稳定性的缺点进而实现太阳能集热与采暖的能量供需调节和全天候连续供热,提出了基于相变储热的太阳能多模式采暖方法（太阳能集热直接采暖、太阳能集热采暖+相变储热、太阳能相变储热采暖）,并在西藏林芝市某建筑搭建了太阳能与相变储热相结合的采暖系统,该系统可根据太阳能集热温度和外界供热需求实现太阳能多模式采暖的自动控制和自动运行。实验研究表明：在西藏地区采用真空管太阳能集热器可以和中低温相变储热器很好地结合,白天储热器在储热过程中平均储热功率为10.63 kW,储热量达到92.67 kW·h,相变平台明显;晚上储热器在放热过程中供热量达85.23 kW·h,放热功率和放热温度平稳,储放热效率达92%,其储热密度是传统水箱的3.6倍,可连续供热时间长达10 h,从而实现了基于相变储热的太阳能全天候连续供热,相关研究结果对我国西藏地区实施太阳能采暖具有一定的指导作用。     

300MW机组凝结水泵变频改造方案及应用分析

通过比较四种变频改造的技术方案,分析某电厂4号机组凝结水泵变频改造后的节能效果与运行情况。采用高压变频技术对凝结水泵进行调速改造后,降低了母管压力,实现了"软启停",延长了系统寿命,经济分析表明凝结水泵采用变频控制具有较好的经济效益。     

Combined heat and power plant integrated with mobilized thermal energy storage (M-TES) system

Energy consumption for space and tap water heating in residential and service sectors accounts for one third of the total energy utilization in Sweden. District heating (DH) is used to supply heat to areas with high energy demand. However, there are still detached houses and sparse areas that are not connected to a DH network. In such areas, electrical heating or oil/pellet boilers are used to meet the heat demand. Extending the existing DH network to those spare areas is not economically feasible because of the small heat demand and the large investment required for the expansion. The mobilized thermal energy storage (M-TES) system is an alternative source of heat for detached buildings or sparse areas using industrial heat. In this paper, the integration of a combined heat and power (CHP) plant and an M-TES system is analyzed. Furthermore, the impacts of four options of the integrated system are discussed, including the power and heat output in the CHP plant. The performance of the M-TES system is likewise discussed.     

Cost effectiveness of decentralized energy supply systems taking solar and wind utilization plants into account

In this article, results are presented of annual simulations of a decentralized (regional) plant for the power and heat supply of a residential complex. This complex consists of four houses with 40 flats all in all. The annual power consumption of the complex is 157 MWh and the heat requirement is 325 MWh. The concrete dynamics of the energy demands over the year is taken into consideration. The energy supply system is composed of a power-controlled combined heat and power (CHP) plant (55 kW), a photovoltaic plant (PV array or PV plant) array for power generation as well as a field of solar thermal collectors with a short-term accumulator for water heating and a long-term accumulator for supplying heat for domestic heating purposes. Simulation results demonstrate that synergetic effects result from the combination of a CHP plant with wind power and PV plants of varying sizes, which have an effect on the cost effectiveness of the plant as a whole with the different dynamics of energy sources (wind and solar energies) and of the consumption of power and heat being the decisive factors. The power deficits of wind power and PV plants are compensated through the application of a natural gas-operated CHP plant. In almost all variants, the demand for fossil energy carriers is distinctly less than in conventional energy supply plants.     

Energy consumption minimization in an innovative hybrid power production station by employing PV and evacuated tube collector solar thermal systems

Combination of a grid connected photovoltaic (PV) plant with a compressed air energy storage system (CAES) and a city gate station (CGS) has been proposed and investigated recently, leading to satisfactory performance results. The only deficiency of this system is the huge amount of fuel required to provide its heating demand. In this work, feasibility of employing evacuated tube solar thermal systems to supply the heating demand of the hybrid power plant is studied. After presenting detailed mathematical modeling, the solar heating units and other components of the power plant are properly sized. The results of simulations demonstrate that a total of 7000 evacuated tube collectors are required in the system, leading to elimination of the air heater from the CAES system completely and 17.2% fuel saving at the CGS. The total annual solar heat of 17.5 GWh is supplied for the system, 214 GWh power could directly be sold to the grid, 9.7 GWh power slumps is recovered and 53.5 GWh power is produced at nights. In the end, internal rate of return (IRR) method is used to compare economically the proposed system with similar systems proposed previously, outperforming all of the other candidates with an IRR of 11.1%.     

基于燃煤机组供热改造方案技术经济性研究

  目的  为了解决目前燃煤机组面临的电负荷与热负荷矛盾突出的问题,保障机组冬季热源供给,有必要进行破除其热电耦合关系的供热改造方案的研究。  方法  对某类型300 MW燃煤机组的两种供热改造方式进行模型分析,比较机组改造前后的供热量等数据,研究符合生产条件的热电解耦供热改造方案。总结出了热电联产机组供热改造的经济效果。  结果  通过文中供热模型分析可知,燃煤机组仅靠抽汽进行供热,受电负荷制约很大,高电负荷时供热量为低电负荷时的2～3倍。当电负荷受限严重时,其供热量无法满足冬季供热需求。但机组经过高背压改造、切缸改造后,调峰能力增强,相同电负荷下其供热量增加到原来的3～4倍,有效解决了这一问题。  结论  文章研究成果对今后相同类型的燃煤机组供热改造具有借鉴意义。     

A comprehensive thermodynamic analysis of load‐flexible CHP plants using district heating network

Because of the rapid expansion of intermittent renewable energy, conventional coal‐fired power plants, including combined heat and power (CHP) plants, are required to improve the quick‐response ability to respond the changing demand of the grid. However, the flexibility of CHP plants is not easy to be improved because of the restriction of traditional load variation mechanism. This work presents a comprehensive thermodynamic analysis on the flexibility‐improving scheme using the thermal energy storage (TES) capacity of district heating (DH) network. A typical CHP plant and related DH network were selected as a case study. The flexibility demand under the context of renewables accommodation in the short timescale (counted by minutes) and the operational characteristics of CHP plants were analyzed on the basis of experimental data and thermodynamics. Besides, the influence of heat supply adjustment on heat users' indoor temperature was quantified with a dynamic model, and the thermal inertia of the DH network is discussed. Moreover, a thermodynamic model for the load variation processes simplified with operational characteristics was established to analyze the response ability improvement of CHP plants. Results of the case study show, the scheme can shorten approximately 34% of the response time while almost have no influence on the indoor temperature of heat users.     

60MW机组凝汽器余热利用技术改造

阐述了齐鲁石化公司热电厂1号汽轮机组凝汽器余热利用改造方案，实现冬季凝汽器半侧循环水切换为工业水，与乏汽换热后作为化学水制水原水。改造后节能效果明显，经济效益显著。