300MW 汽轮机组不同运行方式比较

针对300MW机组编写了汽轮机定压运行和滑压运行的变工况热力计算程序,利用程序计算出了在定压运行和滑压运行方式下调节阀门压损、高压缸排汽温度、调节级相对内效率、给水泵耗功、热耗率、理想循环效率等各项指标。通过对上述各项指标的分析比较,得到了机组滑压运行的最佳运行方式,进而确定了机组滑压运行的负荷区域,并分析了滑压运行对机组安全性的影响。     

联合循环中余热锅炉与汽轮机的滑压运行

本文首先叙述了联合循环中蒸汽侧采用滑压运行的原因,接着对余热锅炉、汽轮机的滑压运行和联合循环的变工况性能进行了计算,论述了运行参数变化的特点,并与定压运行作了比较,从而说明采用滑压运行的合理性。     

汽轮机经济运行方式的比较研究

汽轮机长期低负荷运行,在变负荷运行时可采用定压运行和滑压运行2种运行方式.定性地分析并比较了2种运行方式对机组热经济性及安全性的影响,提出了定量研究方向.     

火电厂冷端系统性能分析与优化研究

在对火电厂冷端系统运行特性分析计算的基础上,深入探讨了影响冷端性能的主要因素;针对冷端系统的运行特点,分析了冷端系统最优化运行原理,建立了冷端系统优化运行的数学模型,开发了优化软件;实例分析了冷端系统优化运行方案及其效益,验证了模型与软件的精确性与实用性。结果表明,所开发的软件对火电厂的优化运行及节能具有重要意义和价值。     

辽河油田特石超稠油管线优化运行研究

为降低能耗,减少运行成本,对辽河油田特石超稠油输送管道进行了优化运行研究。建立了辽河油田特石超稠油管道优化运行的数学模型,并确定了求解方法。实例计算结果表明,特石超稠油管道的运行参数经过优化之后,总的运行费用显著下降。     

400t/h燃油锅炉的调峰运行

论述了黄埔发电厂的 40 0t/h燃油锅炉的调峰运行 ,指出了调峰运行的要点、设备改造、优化运行以及调峰运行锅炉的前景     

蓄热式高温带压蒸汽发生器检测与控制

介绍了自制蓄热式高温带压蒸汽发生器的工作原理及运行过程,根据运行特性,相应地提出了运行控制方案和参数检测方式。经过冷热态运行表明,系统运行状态稳定、参数检测可靠,为进一步的研究工作提供了可靠的基础和保障。     

负荷对电站锅炉运行参数影响特性分析及应达值的确定

运行参数对锅炉经济性的影响普遍采用偏差分析法进行分析,对锅炉各种运行参数的应达值而言其性质是不同的,在确定了应达值的基础上才能分析运行参数的偏差对锅炉经济性的影响。在分析了锅炉运行参数的静态特性后,对各类锅炉运行参数进行了分类,并分析了各类应达值的确定方法,为分析和提高电厂运行经济性提供了依据。     

东海海上风电场的运行管理实践与成果

介绍了上海东海大桥风电场的运行管理的制度建设和运行实践以及取得的成果,分析了海上风电场运行管理的重点和难点,为海上风电场的运行管理做了有益的探索。     

流化床机组与孤网运行

对孤网运行作了概述,并对循环流化床锅炉适应孤网运行的特点作了描述,分析了循环流化床锅炉参与孤网运行的若干问题,总结了流化床锅炉参与孤网运行的优越性,提出了一些建议。     

热油泄漏对土壤温度场影响的模拟分析

借助CFD(Computational Fluid Dynamics)软件建立土壤多孔介质中流固耦合的相变数学模型,对埋地管道上部泄漏热油在冬夏季不同土壤中渗透扩散时,大地温度场的变化进行模拟分析。模拟结果表明:泄漏前,热油管道冬夏季长期运行所形成的径向稳态温度场等温线分布呈近似的对称状态;泄漏发生后,热油凝点以上的液相热影响区域冬夏季等温线分布相似,均是以扇形区域逐步向四周扩张,固液两相区外围的热影响区冬季冻土中的温度梯度大于夏季泄漏工况;热油在冬季冻土中的扩散速率比夏季低约3%。     

Explosion hazard of hydrogen–air mixtures in the large volumes

The report deals with the investigation of non-stationary combustion of hydrogen–air mixtures extremely relevant to the issues of safety. Considered are the conditions of its formation and development in the tubes, in the conic element and in the spherical 12-m diameter chamber. The report shows that at the formation of non-stationary combustion in the conic element, in its top the pressure can develop exceeding 100 MPa. It is also shown that in large closed volumes non-stationary combustion can develop from a small energy source, in contrast to detonation for its stimulation in large volumes of significant power influences are required. Simultaneously, in the large closed volume a pressure can be formed by far exceeding the Chapman–Jouguet pressure in the front of stationary detonation.     

亚澳地区油气形势及对我国的影响

亚澳地区天然气的资源潜力大于石油。石油储、产量分别仅占世界的0.9%和3.8%,且近年来呈下降趋势;石油消费量占世界的4.9%,且呈上升趋势。而天然气储、产量分别占世界的4.4%和4.8%。曾是重要石油输出国的印尼、澳大利亚已成为原油净进口国,曾大量输出原油的越南也将变成原油进口国,区内总体的原油进口量将日趋增大。新加坡是区内最大的原油进口国,但同时出口大量油品,出口对象是区内其他国家和东北亚。亚澳地区天然气的出口以LNG方式为主,澳大利亚、印尼、马来西亚、文莱是主要出口国,其出口量将大幅增长,主要输往东北亚的日、韩、中国大陆和台湾省以及区内其他国家。中国与这一邻区有着非常密切的经济关系,亚澳地区油气形势的变化对我国油气进出口将产生相当大的影响。中国从亚澳地区进口的原油将进一步减少,但油品互补贸易仍将居重要地位,LNG的进口会有大幅增长。     

Comparison of two different flow types on CO removal along a two-stage hydrogen permselective membrane reactor for methanol synthesis

Carbon monoxide (CO) is a gaseous pollutant with adverse effects on human health and the environment. Industrial chemical processes contribute significantly to CO accumulation in the atmosphere. One of the most important processes for controlling carbon monoxide emissions is the conversion of CO to methanol by catalytic hydrogenation. In this study, the effects of two different flow types on the rate of CO removal along a two-stage hydrogen permselective membrane reactor have been investigated. In the first configuration, fresh synthesis gas flows in the tube side of the membrane reactor co-currently with reacting material in the shell side, so that more hydrogen is provided in the first sections of the reactor. In the second configuration, fresh synthesis gas flows in the tube side of the membrane reactor counter-currently with reacting material in the shell side, so that more hydrogen is provided in the last sections of the reactor. For this membrane system, a one-dimensional dynamic plug flow model in the presence of catalyst deactivation was developed. Comparison between co-current and counter-current configurations shows that the reactor operates with higher conversion of CO and hydrogen permeation rate in the counter-current mode whereas; longer catalyst life is achieved in the co-current configuration. Enhancement of CO removal in the counter-current mode versus the co-current configuration results in an ultimate reduction in CO emissions into the atmosphere.     

The impact of the European Union emission trading scheme on the electricity-generation sector

In order to comply with their commitments under the Kyoto Protocol, France and Germany participate in the European Union Emission Trading Scheme (EU ETS) which predominantly concerns the electricity-generation sectors. In this paper we ask whether the EU ETS provides the appropriate economic incentives to produce an efficient system in line with the Kyoto commitments. If so, electricity producers in the countries concerned should include the price of carbon in their cost functions. After identifying different sub-periods of the EU ETS during its pilot phase (2005–2007), we model the prices of various electricity contracts in France and Germany and look at the volatility of electricity prices around their fundamentals while evaluating the correlation between electricity prices in the two countries. We find that electricity producers in both countries were constrained to include the carbon price in their cost functions during the first two years of the EU ETS. Over this period, German electricity producers were more constrained than their French counterparts, and the inclusion of the carbon price in the electricity-generation cost function was much more stable in Germany than in France. We also find evidence of fuel switching in electricity generation in Germany after the collapse of the carbon market. Furthermore, the European market for emission allowances has greatly contributed to the partial alignment of the wholesale price of electricity in France to that in Germany.     

基于相对湿润度指数的贵州省近十年干旱特征分析

为分析贵州省干旱分布特征,基于贵州省均匀分布的30个气象站点2010~2019年的逐日气象数据,以相对湿润度指数为干旱监测指标,利用反距离权重插值分析及相关分析研究贵州省近10年的干旱特征。结果表明,贵州省不同月份的干旱强度和干旱发生范围有所不同,且总体上呈干旱等级越高,干旱范围越小的态势。不同时间尺度的干旱强度和干旱范围在空间上有所差异,月尺度的干旱强度大于年尺度的干旱强度和季尺度的干旱强度,而季尺度的干旱表现为西高东低,年尺度的干旱表现为北高南低的趋势。按照年尺度和季尺度的平均水平来看,贵州省近十年无干旱发生。研究区干旱的发生受气候因子影响较大,且受降雨影响最大。     

我国发展异戊二烯橡胶前景分析

介绍了异戊二烯橡胶的基本概念和特点,并分别对世界和国内异戊二烯橡胶的供应和消费情况进行分析。通过对国内异戊二烯橡胶市场情况和近年来异戊二烯橡胶进口数据的分析,预测出国内异戊二烯橡胶的需求量;并结合国内天然橡胶大量依赖进口和其销售价格一路攀升的现象、国内市场对异戊二烯橡胶的强烈需求、生产异戊二烯橡胶的原料供应和国内合成异戊二烯橡胶的技术进展情况等,分析了国内异戊二烯橡胶的发展前景。同时,通过研究国内天然橡胶的发展趋势、杜仲胶的发展以及国内相关异戊二烯橡胶装置的实际建设情况,分析了当前投资异戊二烯橡胶项目的潜在风险。通过分析,提出我国异戊二烯橡胶工业正处在有资源、有市场、有技术的较低风险期,在现有装置基础上再建设万吨级以上的异戊二烯橡胶装置是可行的;同时,建议尽快新增10×104～15×104t/a规模的异戊二烯橡胶生产装置,以满足国内需求,提高我国合成橡胶产业的综合实力。     

A case study on the effects of the wind catcher and Taiko-shoji in Japanese environment-friendly house

Recently, people around the world have actively made efforts to conserve energy in residential homes as a countermeasure against global warming. The awareness of the importance of energy saving has continued to grow in Japan since the Great East Japan Earthquake in March 2011. The interest in cross-ventilation for air conditioning energy saving in summer is especially increasing. Japan's climate features high temperatures and humidity, and it is a country in which people used cross-ventilation in their homes during summer and the middle season earlier. However, due to changes in modern society, including the progress in air-conditioning facilities, the focus on an environmentally conscious house design was lost. Therefore, studies about cross-ventilation have not been conducted in recent years. This study reconsidered the value of Japanese traditional houses and evaluated the effect of the planar-shaped house in cross-ventilation. It also surveyed the heat-insulating effect of a Taiko-shoji that was developed from an ordinary shoji screen used in Japanese traditional houses. The results show that a skylight opening increased the cross-ventilation air volume and that the shape worked effectively as a wind catcher without any special equipment. Moreover, the study found that the installment of a Taiko-shoji had a significant effect on heat insulation in summer and winter.     

Why did the energy intensity fall in China's industrial sector in the 1990s? The relative importance of structural change and intensity change

There have been a variety of studies investigating the relative importance of structural change and real intensity change to the change in China's energy consumption in the 1980s. However, no detailed analysis to date has been done to examine whether or not the increased energy efficiency trend in the 1980s still prevailed in the 1990s. This article has filled this gap by investigating the change in energy consumption in China's industrial sector in the 1990s, based on the data sets of value added and end-use energy consumption for the 29 industrial subsectors and using the newly proposed decomposition method of giving no residual. Our results clearly show that the overwhelming contributor to the decline in industrial energy use in the 1990s was the decline in real energy intensity, indicating that the trend of real energy intensity declines in the 1980s at the 2-digit level was still maintained in the 1990s. This conclusion still holds even if we lower the growth rate dramatically in line with the belief that the growth rate of China's GDP may be overestimated.     

Flame structure changes resulting from hydrogen-enrichment and pressurization for low-swirl premixed methane–air flames

With the current focus on alternate and renewable fuels, fuel flexibility has become a driving factor in the design of new turbines. Flame stability is heavily impacted by the presence of hydrogen in the fuel stream (as is common in many alternative fuels). This study examines how the flame dynamics change in response to the systematic addition of hydrogen in a low-swirl lean premixed methane–air burner. Stability maps for these test cases show that adding hydrogen broadens the blow-off limits, with 20% hydrogen resulting in a 7% change while 40% hydrogen results in a 35% larger stable region. The most dramatic manifestation of hydrogen addition is the greatly decreased radius of curvature of the local flame surface, which is visible from the increased wrinkling of the flame front. Increases in both pressure and hydrogen enrichment result in higher means and variances of flame front curvatures. The flame surface density is in agreement with the aforementioned flame front curvature PDFs in that increasing the pressure and hydrogen concentration leads to an increase in the maximum flame surface density.