背压式供热机组热力系统优化探讨

火力电厂的凝汽式汽轮机组为了提高循环热效率,全部采用了抽汽回热系统,利用抽汽加热凝结水和给水,回收热量,减少排汽损失.背压机组没有回热抽汽,机组做功能力增加,汽轮机排汽量增大也使对外供热量提高.通过经济性对比分析得出结论,取消背压式汽轮机组回热加热器,仍能保证机组的循环热效率,同时提高了供热机组的经济效益.     

太阳能与谷电互补供热系统设计

利用太阳能辅以低谷电加热,采用两个储热罐进行交替轮流集热、供热。当正常集热或低温预热时,两个储热罐的水温低者优先集热循环运行;若两储热罐水温相同,则设定储热罐优先集热循环运行。当正常供热、夜间防冻循环和低温维持运行时,太阳能集热系统优先于低谷电循环运行给储热罐加热。当假日集热或低温保温供热时,同时给两储热罐集热循环运行。供热循环水泵和用热循环水泵的启动运行,以供热时优先,其停止运行以用热系统的回水温度大于或等于取暖温度的最大设定值者优先。以可编程控制器和组态软件技术,实现了系统集热、供热时段的定温、定时、定温差。此互补供热系统可以取代传统的高耗能锅炉,节能率达30%以上。     

汽轮机低压回热系统的改善

《Теглознергетнка》2008年12月号报道,汽轮机回热系统包含低压加热器、除氧器、高压加热器、循环水泵和给水泵。大量技术一经济性计算表明,具有7～9级加热是合理的。这时,回热度可能达到95％。由于采用回热系统,在经济性提高的总份额中,低压加热器的贡献达到50％～55％,保证其高效的工作是最重要的任务。分析了提高汽轮机装置低压回热系统经济性的问题。     

600MW超临界机组热网循环水泵驱动方式分析

不同的纯凝机组改造为供热机组时,有多种供热方案可供选择,通过比较分析不同供热方案的优缺点和适用范围,确定了某600MW超临界纯凝机组采用中低压连通管抽汽供热的实施方案。在此基础上,对比分析了热网循环水泵不同驱动方式的特点,并采用年费用分析方法,重点分析了工业汽轮机驱动方式和变频调速电机驱动方式的经济性,认为采用工业汽轮机驱动热网循环泵,可明显降低厂用电率,提高整个电厂的经济效益,在发电量相同的情况下前者的经济效益更好。     

利用小汽机驱动热网循环泵的供热经济性分析

从供热的角度,对采用工业小汽机驱动热网循环水泵的方式进行经济性分析,并以某300MW亚临界供热机组为例,进行数据计算和论证。结果指出,在一个供热周期,通过采用汽泵驱动的方式,可节约运行成本207.36万元、可降低机组供电煤耗1.8g/(kW·h),体现了非常好的经济性和降耗水平。     

分布式循环水泵供热系统的设计实例

介绍分布式循环水泵供热系统的基本构造和设计方法,主要包括循环水泵的设计、系统水压图的绘制及节能分析。给出分布式循环水泵供热系统的节能率计算公式和方法,结合工程实例,对分布式循环水泵供热系统的节能效率进行分析。     

新型减阻剂将会降低管网输配费用

<正> 新型减阻剂,有些已接近商业化,将会给区域供热供冷工业带来巨大的经济效益。减阻剂可以抑制水流中的湍流,减少摩擦阻力,因此水泵、管道以及输配系统的其它设备和部件的尺寸可以缩小,显著地降低整套装置的造价。另一方面,如果不超过系统的压力限制,减阻剂能够显著增大现有输配系统的流量,降低水泵运行能耗。     

基于超音速激波升压装置的回热系统的热经济性分析

本文通过超音速激波升压装置替代常规的加热器，建立了超音速激波升压回热系统。在此替代基础上，用等效热降理论分析了替代机组的热经济性变化情况，建立了替代机组热经济性变化的通用计算数学公式。实例计算结果表明通过超音速激波升压装置替代常规加热器，可以在较大程度上提高火电厂的热经济性。     

国内首台回热背压式汽动引风机组调试

某电厂660MW超超临界火力发电机组引风机是国内首次采用回热背压式汽轮机驱动,其汽机排汽经低压加热器对凝结水加热回收热能,冷凝水至疏水箱通过疏水泵升压后回到主机凝结水系统,既回收工质又减少了排汽的冷源损失,提高了电厂运行的经济性;文中介绍了汽动引风机组的调试程序、调试关注要点及调试中发生的主要问题处理情况,以期在今后电力工程建设中提供借鉴。     

多级串联乏汽余热回收系统在直接空冷机组中的应用

针对某热电联产机组基于Co-ah循环的多级串联乏汽余热回收供热扩能改造工程,分析了该系统存在的优势,并对其运行数据进行了详细的计算及分析。通过对某热电厂两台135MW空冷机组多级串联乏汽余热回收系统的运行数据进行统计,该热电厂供热期内总共回收1号、2号汽轮机排汽余热1 739 400GJ,供热期内可节约76 100t标准煤,满足市区3 368 500m2的供热需求,经济效益显著。     

Rough sets-based prediction model for increasing safety of thermal power plants

This paper presents a model based on the rough sets theory for the prediction of a feed pump failure on a steam block of thermal power plant. There are many parameters that can cause pump failure, and this model enables extraction of the most significant ones. Model creation is based on the empirical data collected during the operation of thermal power plant, which is a part of the largest system for electricity production in Serbia. The model provided an insight into the parameters that have the greatest influence on the operation of the feed pump, and can be applied to other elements of the thermal power plant and affect the overall increase in the safety of thermal power plant operation. The goal of implementation of a new model is to increase system reliability by reducing the number of failures, thus increasing operational safety of thermal power plants. This is in accordance with the provision of energy security by applying measures of Directive 2005/89/EU. According to the directive, it is necessary to ensure: a reliable, safe, efficient and quality power supply.     

Optimization Potentials for the Waste Heat Recovery of a Gas-Steam Combined Cycle Power Plant Based on Absorption Heat Pump

A new waste heat recovery system is presented to recover exhausted steam waste heat from the steam turbine by absorption heat pump(AHP) in a gas-steam combined cycle(GSCC) power plant. The system can decrease energy consumption and further improve the energy utilization. The performance evaluation criteria are calculated, and exergy analysis for key components are implemented in terms of the energy and exergy analysis theory. Besides, the change of these criteria is also revealed before and after modification. The net power output approximately increases by 21738 kW, and equivalent coal consumption decreases by 5.58 g/kWh. A 1.81% and 1.92% increase in the thermal and exergy efficiency is respectively obtained in the new integrated system as the heating load is 401095 kJ at 100% condition. Meanwhile, the appropriate extraction parameters for heating have been also analyzed in the two systems. The proposed scheme can not only save energy consumption but also reduce emission and gain great economic benefit, which is proven to be a huge potential for practical application.     

Targeting the optimum steam system for power generation with increased flexibility in the steam power island design

The importance of the steam cycle design to maximize power generation is demonstrated using pinch analysis targeting techniques is demonstrated. Fixed steam headers, such as assumed in total site analysis, give no allowance for reheating before turbine expansion, which can be valuable to consider when optimizing the steam system for certain plant configurations. Additionally, previous work optimizes the steam pressure level based on its saturation temperature alone. The present work examines the effect of including both sensible and latent heating of steam in the balanced composite curve. It is shown that including sensible heating allows for better thermal matching between the process and steam system which results in improving the overall efficiency while minimizing cost. A case study using an IGCC plant with CCS is analyzed to assess changes in steam cycle design on the plant efficiency and cost.     

电厂循环水吸收式热泵利用系统分析

热电厂的循环水所具有的热量一般是通过冷却塔释放给大气环境,为对这部分余热回收利用,进行了水源热泵能量系统的分析研究。将热泵系统供给的热量扣除消耗的驱动蒸汽热量,再考虑导致新增的驱动电耗,及以凝汽器真空下降引起发电的热耗增加作为修正,可确定最终节能量。通过对实际热电厂4台200 MW供热机组的循环水源吸收式热泵系统进行计算,可获知年节约标准煤9 985.7 t,该方案实现了比较理想的工程节能效果。     

吸收式热泵在热电厂利用的节能效果

一方面为了降低化石燃料持续走高的价格并由此带来的环境污染问题;另一方面为了解决热电厂目前普遍存在的供热能力严重不足的矛盾,本文通过对某热电厂供热机组的循环水侧的局部系统改造,利用吸收式热泵技术对循环水余热回收,在热泵系数COP、热泵净回收量、节约煤炭量、节约用水量及减排量几个指标方面得到结果,最后得到热电厂的日常维护成本明显下降,达到了节能环保的目的,也解决了冬季供热能力不足的问题。     

背压汽轮机组增设后置机的研究

[目的]为了解决机组对外供热由工业供热改为采暖供热的问题,以某热电厂为对象开展技术可行性研究.[方法]对调节阀组、双缸汽轮机、全厂共用的后置背压汽轮机、单元制带发电机的汽动给水泵组等四种方案进行了比对分析.[结果]考虑方案的特点和工程实际,最终选择了全厂共用的后置背压汽轮机方案.[结论]该方案基于能级梯级利用原则,运行...     

一种海洋能及风能联合发电装置

文章提出了一种利用海洋温差能和风能联合发电的方法及装置。利用海洋表层的热海水加热低沸点工质,使之蒸发．送入汽轮机推动汽轮发电机组做功发电,汽轮机排出的工质乏气用海洋深层的冷海水冷凝为液态,再用热海水加热,送入汽轮机,使之蒸发,推动汽轮机发电机组做功发电,如此循环,持续发电;并且利用洋面风力发电,并用该电力驱动热泵装置．由热泵装置的媒质将工质的温度进一步提高．增大工质体积膨胀率;由热泵装置的媒质将冷海水的温度进一步降低．再用该低温海水去冷凝工质乏气,增强对工质乏汽的冷凝效果。该装置既需要用到小型透平,又需要用到风力发电装置．十分适合公司发展。     

Exergetic analysis of solar concentrator aided natural gas fired combined cycle power plant

This article deals with comparative energy and exergetic analysis for evaluation of natural gas fired combined cycle power plant and solar concentrator aided (feed water heating and low pressure steam generation options) natural gas fired combined cycle power plant. Heat Transfer analysis of Linear Fresnel reflecting solar concentrator (LFRSC) is used to predict the effect of focal distance and width of reflector upon the reflecting surface area. Performance analysis of LFRSC with energetic and exergetic methods and the effect, of concentration ratio and inlet temperature of the fluid is carried out to determine, overall heat loss coefficient of the circular evacuated tube absorber at different receiver temperatures. An instantaneous increase in power generation capacity of about 10% is observed by substituting solar thermal energy for feed water heater and low pressure steam generation. It is observed that the utilization of solar energy for feed water heating and low pressure steam generation is more effective based on exergetic analysis rather than energetic analysis. Furthermore, for a solar aided feed water heating and low pressure steam generation, it is found that the land area requirement is 7 ha/MW for large scale solar thermal storage system to run the plant for 24 h.     

压水堆核电厂二回路系统管道热效率的影响因素分析

在压水堆核电厂热经济性分析中,管道热效率的分析往往不被研究者所重视。首先从管道热效率的定义出发,给出了管道热效率的计算表达式,以及各种管道损失的计算方法。然后针对某些影响管道热效率的因素,同时也对蒸汽动力转换系统循环热效率产生影响的问题,分析了影响管道热效率的因素变化对蒸汽动力转换系统循环热效率和压水堆核电厂全厂热效率的影响。最后,以某990MW核电机组为例,通过计算分析了如主蒸汽管道疏水门泄漏蒸汽、厂用蒸汽、主蒸汽管道散热、蒸汽发生器排污等对管道热效率、蒸汽动力转换系统循环热效率及全厂热效率的影响。结果表明,上述因素变化均导致管道热效率降低和全厂热效率的降低,但不同因素变化对全厂热效率的影响机理却存在较大的差别。     

热电厂汽动给水泵节能分析

汽动给水泵是热电厂利用富裕蒸汽 ,节能降耗的有效措施之一。它投资少、见效快 ,综合经济效益显著