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准确而快速地评价加热器端差引起的机组热经济性变化,对热力系统的设计、运行和检修具有十分重要的意义.以热力系统热平衡方程、锅炉输入燃料(火用)方程、锅炉吸热量方程、汽轮机输入热(火用)量(火用)方程和汽轮机功率方程为基础,根据小扰动理论和微分理论,得各抽汽量、锅炉输入燃料炯、锅炉吸热量、汽轮机输入热量(火用)和汽轮机功率对端差的变化率.在锅炉(火用)效率、机组炯效率和发电煤耗率概念的基础上,由微分理论推导端差对(火用)经济性指标的影响.以N 1000 - 25/600/600机组为例,计算加热器端差对机组(火用)经济性指标的影响. 相似文献
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热电联合生产机组的发电成本、供热成本、发电煤耗和供电煤耗的计算是一个有争议的问题。本文提出统计修正法,按照机组所在地区的平均发电成本、供热锅炉平均供热成本、平均发电煤耗和供热锅炉平均供热煤耗的数据什算供热发电机组的成本和煤耗。 相似文献
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抽汽压损是一种不明显的热力损失,它使蒸汽的做功能力下降,热经济性降低.加热器抽汽压损的变化将影响火电机组的发电煤耗率,因此定量计算分析抽汽压损变化对火电机组发电煤耗率的影响对节能降耗具有重要的现实意义.文中提出了一种计算抽汽压损变化对煤耗率影响的新方法,该方法以火电机组热经济性分析的统一物理模型和数学模型为基础,建立了基于强度矩阵的抽汽压损变化对煤耗率影响的通用计算模型.本模型不必建立热力系统能量平衡方程与质量平衡方程,且推导简单、计算量小、精度高和通用性强,为研究抽汽压损改变对机组热经济性的影响提供了一种新方法. 相似文献
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以某600MW超临界凝汽式机组为例建立仿真模型,在VWO工况、THA工况、75%THA工况和50%THA工况下模型的计算值与设计值的相对误差小于0.08%。运用模型进行了不同工况下加热器效率、加热器切除、除氧器排汽连续运行、给水泵汽轮机汽源变化4种回热系统变工况对机组发电煤耗影响的定量分析。结果表明,不同负荷工况下,2号高压加热器效率对机组发电煤耗影响更大,其次是1号高加、3号高加、5号低加至8号低加;高压加热器切除对机组发电煤耗影响最大,5号低加至8号低加切除对发电煤耗的影响逐渐减小;除氧器排汽量相同时,机组发电功率越低,对机组发电煤增量的影响越大;给水泵汽轮机采用辅助联箱蒸汽作为汽源时,机组发电功率越高,对机组发电煤耗增量的影响越大。 相似文献
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电厂运行机组节能经济性评估的方法 总被引:1,自引:0,他引:1
以外高桥电厂设计计算煤耗为基础进行经济性分析,综合考虑实际运行中的不可避免损失及当年不可控偏差,得出了电厂机组当前运行条件下可能达到的基准煤耗和当年达标煤耗,并提出了一种运行机组经济性综合评估的技术思路,据此可以了解机组目前的经济性能状况、节能潜力,同时为机组达到经济运行目标提出改进方向。 相似文献
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热电联产机组热经济性代表了热电厂能量利用水平、热功转换技术的先进水平和运行的经济水平,因而准确地分析热电联产机组热经济性显得尤为重要.等价煤耗法是把电厂实际发电效益和供热效益通过热、电等价转换,得到等价发电量,进而得到等价煤耗率.结合300 MW机组,首先分别用热量法、实际焓降法和等价煤耗法对热电联产机组煤耗率进行计算,并通过分析比较,证明了等价煤耗法在评价热电联产机组方面的可行性和准确性;其次比较了同一热电联产机组在供热期和非供热期的煤耗率——供热期煤耗率比非供热期煤耗率低,从而证明了热电联产机组在节能方面优于纯凝机组. 相似文献
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电厂运行过程中氧量是一个重要的参数.运行氧量的变化对机组的效率及安全性有很大的影响.使用两种不同方法对氧量变化和供电煤耗率的关系进行分析,并使用数据进行了计算.通过分析得出了氧量对煤耗影响的精确计算方法. 相似文献
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Usama Al-mulali Che Normee Binti Che Sab 《Energy Sources, Part B: Economics, Planning, and Policy》2018,13(4):218-223
This study examined the long-run and the causal relationship between total coal consumption, CO2 emission, and GDP growth in China, the United States, India, Germany, Russia, South Africa, Japan, Australia, Poland, and South Korea. The panel model was employed during the period 1992–2009. The results showed that total coal consumption and CO2 emission have a long-run relationship with the GDP growth. In addition, there was a short-run positive bidirectional causal relationship between total coal consumption and CO2 emission. However, total coal consumption and CO2 emission have no short-run or long-run causal relationship with GDP growth. Thus energy conservation policies on total coal consumption such as rationing energy consumption and controlling CO2 emissions are likely to have no negative impact on the real output growth of the investigated countries. 相似文献
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Michael B. Morrison 《Energy Policy》1985,13(3):243-252
Unit train rates for coal shipments in the USA are set in a bargaining process between railroads and electric utilities. If either party is dissatisfied with the outcome then the Interstate Commerce Commission may be asked to intervene. However, recent legislation has limited ICC participation in the rate-setting process to cases where competition is proven to be very limited. This article uses a model to estimate unit train rates for coal shipments and the ICC is seen to have been relatively ineffective even in these circumstances. Without competition from other transport modes, in particular slurry pipelines, and with the imposition of increasingly stricter sulphur-emission regulations on utilities, further real increases in unit train rates for western coal shipments could be expected in the future. 相似文献
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Emilio Congregado Antonio A. Golpe Mónica Carmona 《Renewable & Sustainable Energy Reviews》2012,16(5):3339-3343
This paper estimates an unobserved components model to explore coal consumption in the USA. We ask whether coal consumption exhibits hysteresis, defined as a dynamic structure in which the cyclical component of coal consumption has permanent effects on the natural component. In contrast to previous analysis, we provide evidence in favor of hysteresis in coal consumption, by using the nonlinear framework proposed recently by Pérez-Alonso and Di Sanzo [13], in which threshold type nonlinearities are introduced by allowing past cyclical consumption to have a different impact on the natural component depending on the regime. The article discusses implications of the findings for energy conservation policies. 相似文献
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供电标煤耗是评价热电联产企业综合竞争能力的重要指标之一。文中根据某企业供电标煤耗与热电比、汽轮机效率、锅炉效率的对应数据资料,将供电标煤耗与三者之间的变动关系加以模型化,找出并检验回归方程,尝试用回归分析的方法对供电标煤耗进行预测,为热电联产企业降低煤耗,提高市场竞争能力提供依据。 相似文献
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ARIMA模型在煤炭消费预测中的应用分析 总被引:3,自引:0,他引:3
煤炭属于重要的民用能源,对其消费量进行预测,可为合理安排煤炭生产提供依据,优化社会资源的配置。采用Box和Jenkins的ARIMA模型,对1953年以来我国煤炭消费量的年度数据进行分析。与结构性因果模型、自回归(AR)、移动平均(MA)、自回归移动平均(ARMA)模型等相比较,ARIMA模型不但适合于我国煤炭消费量的非平稳时间序列的特点,并且预测效果比较理想。结果表明,ARIMA(3,1,3)模型的预测效果良好,2002年~2005年平均预测误差仅为3.981%,可用于未来我国煤炭消费量的预测。 相似文献
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In the push towards greener ICT, there is a need to examine the energy savings possible in the design of network infrastructure and each network component. The focus of this paper is to evaluate the impact of routing algorithms on the power consumption of network routers. In a comparison of the power consumption of a number of routers implementing different routing protocols on the open source NetFPGA board, our results show the Bloom filter-based zFilter forwarding node is the greenest router. The rate control protocol (RCP) router and the precision time protocol (PTP) router consume almost identical power, which is about 1.1–1.6% higher than that of the reference router. This higher power consumption of RCP and PTP routers is attributed to the 3.6%–4.7% higher power consumption in the 3.3-V power component of the total power consumption, which is due to the higher router design complexity. Furthermore, we examined the impact of scaling down the core operational clock frequency to demonstrate the merits of energy proportional routing in each of the routers. The zFilter, operating at 62.5 MHz, outperforms the RCP, PTP, and the reference routers operating at 125 MHz, in terms of both packet loss and throughput. In addition, the zFilter operating at 62.5 MHz consumes around 10.9–11.2% less power than the reference router operating at 125 MHz. We analyze the architecture of each router to further explain these results. 相似文献
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《Energy Policy》2016
Although China owns large coal reserves, it now faces the problem of depletion of its coal resources in advance. The coal-based energy mix in China will not change in the short term, and a means of delaying the coal resources depletion is therefore urgently required. The residual coal was exploited first with a lower recovery percentage and was evaluated as commercially valuable damaged coal. This approach is in comparison to past evaluations when the residual coal was allocated as exploitation losses. Coal recovery rates, the calculation method of residual coal reserves and statistics of its mines in China were given. On this basis, a discussion concerning the impacts on the delay of China's coal depletion, development of coal exploitation and sustainable developments, as well as technologies and relevant policies, were presented. It is considered that the exploitation of residual coal can effectively delay China's coal depletion, inhibit the construction of new mines, redress the imbalance between supply and demand of coal in eastern China, improve the mining area environment and guarantee social stability. The Chinese government supports the exploitation technologies of residual coal. Hence, exploiting residual coal is of considerable importance in sustainable development of the coal industry in China. 相似文献
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M Santamouris N Papanikolaou I Livada I Koronakis C Georgakis A Argiriou D.N Assimakopoulos 《Solar Energy》2001,70(3):201
Climatic measurements from almost 30 urban and suburban stations as well as specific measurements performed in 10 urban canyons in Athens, Greece, have been used to assess the impact of the urban climate on the energy consumption of buildings. It is found that for the city of Athens, where the mean heat island intensity exceeds 10°C, the cooling load of urban buildings may be doubled, the peak electricity load for cooling purposes may be tripled especially for higher set point temperatures, while the minimum COP value of air conditioners may be decreased up to 25% because of the higher ambient temperatures. During the winter period, the heating load of centrally located urban buildings is found to be reduced up to 30%. Regarding the potential of natural ventilation techniques when applied to buildings located in urban canyons, it is found that, mainly during the day, this is seriously reduced because of the important decrease of the wind speed inside the canyon. Air flow reduction may be up to 10 times the flow that corresponds to undisturbed ambient wind conditions. 相似文献