火电厂凝汽式汽轮机冷端运行优化研究

针对目前国内凝汽式汽轮机冷端系统运行优化存在的问题,从电厂汽轮机冷端系统实际出发,在确定凝汽器的最佳真空和最佳冷却水量时,除考虑了传统的因素外,还考虑水资源使用费用和冷却水热污染的环保费用,使冷端系统运行优化更加贴合实际。研究过程中,并以国产600MW凝汽式机组为例,对汽轮机冷端系统进行了运行优化分析和计算,收到了满意的效果。     

汽轮机冷端优化运行和最佳背压的研究与应用

根据对电厂330MW汽轮机组冷端系统的试验结果,结合机组微增功率和背压关系曲线以及凝汽器变工况特性,经过认真研究和分析,建立了冷端优化数学模型,并结合循环水泵运行优化调整试验,提出了机组在不同运行负荷和冷却水进口温度下冷端循环水泵的最佳运行方式,从而确定了凝汽器最佳运行背压。研究结果应用于某电厂,在夏季工况时取得了较好的经济效益,验证了该方法具有较强的实践意义。     

汽轮机冷端系统运行优化及故障诊断系统

针对汽轮机冷端系统运行中存在的问题,通过在线监测其运行状态,利用适当的优化方法,对冷端系统的有关设备的运行方式进行优化,并利用BP网络对凝汽器低真空原因进行分析诊断,给出故障处理对策和运行操作指导。通过优化操作,减少损失,提高机组的经济性,保证机组在最佳状态下运行。     

某F级燃气轮机发电机组冷端优化策略研究

在能源结构调整及“双碳”背景下，电力行业的压力增大，电厂冷端系统具有巨大节能潜力，且由于气 电与煤电机组冷端性能差异明显，需开展专项研究。首先针对某F级燃气轮机发电机组凝汽器进行了清洁 度评估，然后通过电厂热力边界及运行参数建立了仿真模型，基于凝汽器、循环水泵、机力通风塔风机开展了 运行策略研究，分析了循环水流量、循环水温度及辅机功率等因素与凝汽器背压的敏感度关系，提出了机组 不同环境温度和机组负荷下冷端系统最佳运行方案，为燃气机组经济可靠运行提供了技术支持。     

基于实时稳态模型的汽轮机冷端系统闭环优化控制

汽轮机冷端系统是火电机组的重要辅助系统,其运行状态的好坏直接关系到机组的安全、经济运行。分析汽轮机冷端系统的换热机理,通过对汽轮机末级变工况计算模型、凝汽器换热变工况计算模型以及变频循环水泵变工况特性分析,建立汽轮机冷端系统最佳真空稳态计算模型。分析了机组在不同边界条件下的最佳运行真空,进而利用稳态计算模型构建最佳真空闭环优化实时控制系统,实现对机组循环冷却水流量的连续调节,提高了机组的运行经济性。     

某600MW机组冷端系统优化及应用研究

介绍了一种冷端系统改造技术,并对该技术在国内某600MW机组投入运行后的经济性进行了分析,得出以下结论:冷端系统改造技术可大幅降低凝汽器运行压力,相比于改造前,凝汽器运行压力降低0.99kPa;该冷端系统改造技术投入运行后,机组年平均标煤耗降低2.48g/(kW·h),按机组年运行5500h、标煤单价600元/t计算,节能效益为515.6万元/年。     

直接空冷机组冷端传热特性研究

以直接空冷机组冷端系统传热特性为研究对象,充分考虑排汽管道压损、水蒸气压差对排汽压力的影响,建立直接空冷机组冷端换热数学模型,并对影响空冷凝汽器传热的因素进行研究分析。研究结果对直接空冷机组冷端系统保持最佳运行状态,保障凝汽器的安全和经济运行具有重要的指导作用。     

海勒式空冷系统变工况热经济性分析计算模型

在详尽分析海勒式空冷系统凝汽器压力变工况计算模型基础上,通过严谨的理论推演,导出了海勒式空冷系统冷端各运行参数对机组运行热经济性影响的分析计算模型,为空冷机组冷端系统的优化运行提供了理论依据和指导。     

海勒式空冷系统变工况热经济性分析计算

在详尽分析海勒式空冷系统凝汽器压力变工况计算模型基础上,通过严谨的理论推演,导出了海勒式空冷系统冷端各运行参数对机组运行热经济性影响的分析计算模型,为空冷机组冷端系统的优化运行提供了理论依据.     

600MW机组冷端优化节能潜力分析

首先介绍了电厂汽轮机冷端优化的必要性,从冷端系统的基本构成和原理出发,阐述了双背压凝汽器优化的节能降耗的能力。最后,针对某机组凝汽器面积明显小于同地区同类型机组,背压明显偏高,严重影响机组经济性的问题,应用冷端优化技术后节能效果显著做了详细阐述。提出的节能方法可为其它同类机组借鉴。     

Optimization of cold end system of steam turbine

An optimization of the movement characteristic of the cold end system of the steam turbine was conducted from an overall consideration of the condenser and the circulation water pump. An analysis method based on thermodynamics theory that fixes coupling characteristic between the best vacuum and the best circulation discharge of water was proposed. The proposed method was applied to the optimized analysis of the operating mode of the cold end system of a 300 MW unit in a power plant. __________ Translated from Thermal Turbine, 2007, 36(1): 19–23 [译自: 热力透平]     

寒区水源热泵及调峰供暖运行机制的优化分析

首先介绍了适用于寒区供暖的水源热泵及调峰供暖系统,指出该供暖系统的运行机制影响着运行的经济性。在不改变末端原有散热器的前提下,分析了该供暖系统主要运行参变量之间的关系。以系统运行费用为目标函数,推导出了系统运行时的优化模型。以哈尔滨某一小区从原有传统供暖方式改造为水源热泵及调峰供暖为例,对其进行了优化分析,得出了最优的系统方案及其运行情况,说明水源热泵及调峰供暖具有明显环保和经济效益。     

考虑凝汽器压力的火电厂循泵出口阀启闭规律优化

当火电厂循环冷却水系统中发生水力瞬变时,凝汽器可能出现冷却水失水现象,这将导致凝汽器压力增高,从而影响汽轮机组运行的稳定性及安全性。循泵出口阀启闭规律的优化设定对凝汽器最大失水量能起到一定的控制作用。本文提出水力过渡过程计算结合凝汽器变工况计算的方法来优化设定阀门规律。经应用于300MW汽轮机组实例表明,采用该法确定的最优规律,凝汽器最小过流量从1.991m3/s增加到2.271m3/s,凝汽器最大压力从22.111kPa降低为16.911kPa。这样既能保证循环水系统的水力安全,又考虑了瞬变过程中凝汽器的动态特性,有利于汽轮机组的安全稳定运行。     

Thermosiphon circulation in solar water heaters incorporating evacuated tubular collectors and a novel water-in-glass manifold

A study is reported of thermosiphon circulation in solar water heaters incorporating glass tubular evacuated collectors and a water-in-glass manifold of extremely simple design. The manifold is characterised by the absence of partitioning of the inner volumes of the absorber tubes into inlet/outlet channels and buoyancy effects are utilised to convey heat to a header pipe at the open end of the tubes. Solar energy input to the tubes has been simulated by electric heating. The thermosiphon system design is unusual in that there are no risers within the collector tubes, thus, the pressure head responsible for thermosiphon flow originates entirely from relatively short pipe runs between manifold and storage tank. Thermosiphon flow has been measured for a number of system designs and a wide range of operating conditions. The relative impedances of the system components has been evaluated allowing optimization of the system design. An investigation of the effect of withdrawal of hot water from the storage tank, with associated injection of cold water to the bottom of the tank, has illustrated that the self-regulating nature of the thermosiphoning system results in a large proportion of heat stored in the wate filled collector tubes being effieciently transferred to the storage tank, providing some water is drawn off intermittently.     

A “once-through” solar water heating system

In China, solar water heater is being popularized and most existing solar water heaters are the natural circulation system. Due to some shortcomings of the natural circulation system, a “once-through” system is proposed. In a once-through system, the storage tank can be placed below the collector, therefore, the load on the roof will be cut down significantly. This system also has the advantages of no mixing of hot and cold water, no reverse flow and being able to provide hot water earlier, etc. Both theoretical and experimental investigations have been conducted to compare the collector efficiences between the once-through and natural circulation systems and they coincide with each other very well. The once-through system performs worse in the morning but better in the afternoon than the natural circulation system and the difference of daily collector efficiency between these two systems is negligible.     

Chemical and light-stable isotope characteristics of waters from the raft river geothermal area and environs, cassia county, idaho; box elder county, Utah

Chemical and light-stable isotope data are presented for water samples from the Raft River geothermal area and environs. On the basis of chemical character, as defined by a trilinear plot of per cent milliequivalents, and light-stable isotope data, the waters in the geothermal area can be divided into waters that have and have not mixed with cold water. The non-mixed waters have essentially a constant value of light-stable isotopes but show a large variation in chloride content. The variation of chloride composition is not the usual pattern for deep geothermal waters, where it is normally assumed that the deep water has a single chloride composition. Different mixed waters also have hot-water sources of varying chloride composition. Plots of chloride values on cross-sections show that water circulation patterns are confused, with non-mixed waters having different chloride concentrations located in close proximity. Three models can explain the characteristics of the deep geothermal water: (1) in addition to near-surface mixing of cold and hot water, there is deep mixing of two hot waters with the same enthalpy and isotopic composition but differing chloride concentrations to produce the range of chloride concentrations found in the deep geothermal water; (2) there is a single deep hot water, and the range of chloride concentrations is produced by the water passing through a zone of highly soluble materials (most likely in the sedimentary section above the basement) in which waters have different residence times or slightly different circulation paths; (3) the varying chloride concentrations in space have been caused by varying chloride concentrations in the deep feed water through time. Some of this older water has not been flushed from the system by the natural discharge. Although one model may seem more plausible than the others, the available data do not rule out any of them. Data for water samples from the Raft River and Jim Sage Mountains show that water from these areas is probably the source for the cold mixing water determined from end-members on mixing lines. Data for water samples in the Upper Raft River Valley show that the thermal anomaly found at Almo 1 is probably not related to the Raft River geothermal area. The water is different in type as shown by its placement on a trilinear plot, and the isotopes are different enough to show that it is probably a different water. Isotopic compositions of samples from a wide area around the Raft River geothermal system indicate that the likely source of the recharge water is the southern Albion Mountains and western Raft River Mountains. The recharge area is at one end of the Narrows zone, and the geothermal area is along the Narrows zone; thus it is likely that the Narrows zone defines the circulation path.     

Transient analysis of parallel plate forced circulation solar water heating system

In this paper, a transient analysis of a forced circulation solar water heating system with and without heat exchangers in the collector loop and storage tank has been presented for a parallel flat plate collector. The effect of various water heating system parameters on its performance have been studied. Numerical calculations have been made for a typical cold day viz. 26 January 1980 in Delhi.     

发电厂冷端系统最优运行方式的研究

根据"能量价值分析"原理,对发电厂冷端系统的最优运行方式进行了详细的分析,克服了传统分析方法的缺陷,提出了以综合成本煤耗率为判据的优化新方法,找到了在市场经济条件下发电厂冷端系统最优运行方式的判断方法。     

高速柴油机高增压试验研究

本文介绍在一台普通柴油机上进行的高增压试验研究。通过采用二级增压、MPC系统、旁通增流系统、预热循环系统等，达到提高Pme、优化部分负荷性能、保证低压缩比下冷起动等目标。     

Transient analysis of closed loop solar water heating system (effect of heat exchangers)

This paper presents a general and more realistic model of the transient behaviour of a forced circulation solar water heating system with and without heat exchangers in the collector loop and storage tank. The analysis has been presented for a constant flow mode. The effects of heat exchanger length and various water heating system parameters on its performance have been studied. Numerical calculations have been made for a typical cold day (26 January 1980) at Delhi.