Could on-site fuel storage economically reduce power plant-gas grid dependence in pipeline constrained areas like New England?

In the Northeastern United States, natural gas supply constraints have led to periods when gas shortages have caused up to a quarter of all unscheduled power plant outages. Dual fuel oil/gas generators or local gas storage might mitigate gas supply shortages. We use historical power plant operational and availability data to develop a supply curve of the costs required for generators to mitigate fuel shortage failures in New England. Based on 2012–2018 data, we find that the historical fuel shortages at approximately 2 GW worth of gas-fired capacity could be mitigated using on-site fuel storage. For comparison, New England’s average reserve margin was 1.7–2.8 GW over our sample period. Oil dual fuel plants would recoup their investment if compensated with a reliability adder of $3−7/MWh during their normal operations, while $7−16/MWh would incentivize using on-site, compressed natural gas storage. We estimate that the capital expenses associated with the fuel storage options would be less expensive than installing battery backup for resource adequacy at current battery prices.     

冷热电气多能互补的微能源网鲁棒优化调度

随着能源结构调整,集成风/光等可再生能源输入、冷热电气等多种能源互补输出的微能源网得到了逐步发展,如何协调调度微能源网内冷热电气源网荷成为当前研究热点。建立了冷热电气多能互补的微能源网在孤岛/并网模式下的协调调度模型,并利用供热/供冷系统的热惯性和热/冷负荷的柔性,发挥供热/供冷系统的“储能”功能,以电转气(P2G)装置实现电-气网络双向互通。模型采用鲁棒线性优化理论将随机优化模型进行确定性转化,取得经济性和鲁棒性的适当折中。算例仿真验证了温度负荷储能特性对微能源网灵活调度的优化作用和鲁棒性指标对优化结果的协调作用。     

Energy Crisis ?Fact or Fiction

SOME political pundits suggest that the energy crisis is a political conspiracy to cover up the other difficulties confronting the administration. Others suggest that it is a business conspiracy to drive up prices. There are still others who believe it to be the natural evolution of our affluent society. With headlines screaming of gasoline shortages natural gas restrictions, and heating oil allocations, is there any doubt that an energy crisis exists?     

面向绿色生态乡镇的综合能源系统关键问题及展望

乡镇作为经济社会发展的重要一环,相比于城市,在自然资源禀赋、用能特性及能源设施基础条件等方面都具有自身独特特征。通过总结绿色生态乡镇的特征以及目前存在的问题,综合考虑乡镇清洁能源资源及冷、热、电用能需求,为实现电、气、冷、热多能互补,源、网、荷互动优化,从乡镇综合能源系统的多能源协同规划、运行优化、综合评价3个方面提出面向绿色生态乡镇的综合能源系统关键问题,对乡镇综合能源系统的未来发展方向进行了展望。     

Probability techniques application for economic operation of powercables

High costs and shortages of many raw materials have necessitated renewed analysis of utilization of many engineering material and products. Also, substantial increases in costs to manufacture high quality engineering products have motivated the engineering community to seek more sophisticated techniques to analyze problems. These techniques are designed to render solutions which account for a variety of contingencies in a realistic way. In particular, the tremendous capital investment in electric power systems is motivated to maximize the utilization of all power system components. This paper focuses on the efficient use of insulated power cables for reliable transmission and distribution of electrical energy. Typically, power cables are subject to loading in a manner which is only partially predictable. Both the conductor voltage to ground and loading current may be viewed as stochastic in nature. It is desirable to study cable loading in stochastic terms in order to realistically establish a rating for the conductor. Such a study would lead to more economic cable use     

Impact of Energy End Use and Customer Interruption Cost on Optimal Allocation of Switchgear in Constrained Distribution Networks

The introduction of new energy carriers, such as natural gas and district heating, to energy systems dominated by electrical power will certainly relieve stress on the power system. Some of the end uses initially served by the power system will be gradually decoupled and served by alternative energy carriers. As a result, the specific customer interruption costs and load profiles will change. In this paper, we analyze how the optimal level of switchgear in electric power distribution systems is affected by such changes. The proposed optimization method is based on a genetic algorithm and takes into account the constrained network capacity.     

冷热电联供系统多目标优化研究

在研究冷热电联供系统发展现状与运行原理的基础上,以冷热电联供系统相对于分供系统节约的能源消耗和二氧化碳排放作为约束条件,以联供系统和分供系统的投资差值为目标函数,构建了一个惩罚函数,并以某地区为实例研究冷热电联供系统与分供系统在满足节能减排效果的条件下,达到最优经济效果的状态。研究结果表明,在文中所给定的系统状运行态下,联供系统的节能减排效果优于分供系统,在电气价格比大于0.13时,联供系统投资小于分供系统。     

Aligning gas regulation with climate goals: A road map for state regulators

Reduction in the usage of natural gas is critical to mitigate climate change. When combusted, natural gas usages can vary from home heating and cooking to large industrial processes to fuel for electric generation. While many states have adopted greenhouse gas (GHG) emissions targets and are conducting long-term planning for the transition away from natural gas, retail gas utilities and their regulators have generally continued to operate in a business-as-usual framework assuming static or increased natural gas usage. In most states, there is a lack of reconciliation between these two policy objectives. This paper presents recommendations for State Public Utilities Commissions (Commissions) and other regulators to align decision making regarding gas utility operations, rates and infrastructure with climate goals to drive reductions in GHG emissions. While this paper primarily focuses on states that have enacted climate laws, the recommendations are equally relevant for states without such laws, as they ultimately serve to improve regulatory oversight, protect customers from unnecessary costs, and support continued provision of safe, reliable and affordable service in an evolving industry.     

计及温控厌氧发酵和阶梯碳交易的农村综合能源低碳经济调度

针对北方农村地区冬季清洁取暖造成局部供电、供气紧张的问题,提出一种计及温控厌氧发酵和阶梯碳交易的农村综合能源低碳经济调度模型。首先,基于沼气厌氧发酵池的热力学模型和温度与产气率的关系,构建沼气发酵的温控模型。然后,采用变压吸附设备提纯分离沼气中的甲烷和二氧化碳,引入电转气消纳其中的二氧化碳,产生甲烷回馈系统。同时考虑农村用户参与碳市场,采用阶梯碳价,分析碳交易基价和价格增长率对农村用能成本和碳排放的影响。最后,以系统运行成本最低为目标函数进行优化求解。仿真分析表明,所提模型可实现系统碳排量降低157.27 kg,运行成本降低11.57%。     

天然气分布式能源分阶段补贴机制

当前中国天然气分布式能源补贴政策较为欠缺,仅少数省市出台了相关政策,且补贴模式仍存在不足,亟须制定补贴指导性标准。首先结合特定项目分类方式和项目实际发展阶段规律,提出了天然气分布式能源分阶段补贴机制,同时提出了能源项目发展阶段界定办法。其次建立了基于内部收益率法的天然气分布式能源补贴测算模型,定量分析了补贴额度与能源项目内部收益率之间的关系。最后分析了上海市分阶段补贴算例,为各省市天然气分布式能源补贴政策的制定提供了参考。     

基于混合模式的气表质检系统的设计与实现

随着我国能源结构的升级,天然气越来越受到人们的欢迎.围绕燃气而来的技术与设备也经历着新一轮的革新.智能燃气无线表正是技术革新下的产物.当该类智能仪表在大规模采用的过程中,必然要保证所使用仪表的质量.为了使此类智能仪表检测工作可以高效而准确地进行,在融合B/S和C/S两种模式优点的基础上,又结合业务特点提出开发一套既灵活高效又稳定准确的全新的仪表检测系统.将以先整体结构、后局部板块的顺序进行系统设计与实现的探讨,并通过系统测试这一环节对结论进行最终的验证.     

石灰石—石膏湿法烟气脱硫装置优化改造

某火电厂2×300 MW机组烟气脱硫装置各子系统设计冗余、繁杂,运行能耗偏高,设备维护成本高;系统工质腐蚀性、磨损性极强,频发泄漏现象,既影响设备投运率,又造成环境污染。为此,充分利用主机附属系统、设备资源对工艺水、滤液水等子系统进行优化改造;采取喷淋区内、外壁加强处理、脱硫系统室外管道加装暖通伴热系统改造等措施,解决吸收塔喷淋区频发冲蚀穿孔及冻结等问题改造后,在相同工况下,机组脱硫单耗下降6 kWh/t,并节约石灰石耗量3500t/a,同时降低了设备维护费用,效益显著。     

内置式气气换热器在SCR烟气脱硝尿素热解系统中的应用

采用内置式气气换热器的尿素热解过程具有系统简单、能耗低等优点。在详细分析内置式气气换热器技术特点的基础上,提出了采用内置式气气换热器的尿素热解方案并应用于某300MW机组的脱硝系统,将原天然气加热热解工艺改造为内置式气气换热器。改造后运行结果表明,内置式气气换热器每年可减少天然气消耗约360 000 m³（标准状态）,减少运行费用90余万元,产生了良好的经济效益。     

Assessing the limitations of just-in-time energy delivery in the ERCOT interconnection

In February of 2021, an atypical continental weather pattern imposed lower-than-average temperatures on the southern U.S. Prolonged subfreezing temperatures in turn put substantial strain on Texas’s energy systems. The electric grid of Texas, operated by the Electric Reliability Council of Texas (ERCOT), was crippled by a number of technical and operational difficulties initiated by the extreme weather. Freeze-offs on natural gas equipment and wind shortages resulted in significant under-generation, at times approaching 50% of load forecasts. Blackouts and prolonged rolling outages were the result. These rolling outages, necessary to retain broader stability and grid synchronism, proved effective in providing necessary grid stabilization. However, such actions left millions of Texas residents without power, heat, water, and other life sustaining resources during several of coldest days in recent memory, causing hundreds of fatalities. Analysis of the event indicates that the lack of both sufficient baseload and dispatchable generating capacity is the result of a number of interweaved operational constraints placed on grid operators by alterations in the interconnection’s fuel resource availability. Fuel supplies are no longer readily stored on-hand in sufficient quantity, and just-in-time delivery creates dependence on suppliers who are themselves subject to the forces of extreme weather.     

Fearing electricity: overhead wire panic in New York City

Many historians have portrayed the late nineteenth century as a period of great technological utopianism or enthusiasm. Closely intertwined with this technological enthusiasm, however, was also a strong strand of technological pessimism. Americans of this period desired innovations like electric lighting and communication, rapid transit, and gas cooking and heating, but they also feared the physical hazards created by these innovations. They believed that new technology would improve society, but at the same time worried that they had no control over the pace and direction of this change. An early example of the technological pessimism of this period was the electric wire panic that took place in New York City in the 1880s. At this time, the streets of the city were darkened by dangerous, overhead electric wires. The failure of the city to bury these wires, along with debate over electrical safety, generated great fear of electricity. This fear reached its height in 1889 when a series of horrible electrical accidents terrorized the city. Despite their fears, most New Yorkers found it impossible to give up electrical technology. The tension between technological enthusiasm and pessimism created a profound anxiety about electricity and the new urban world it was creating     

基于碳交易机制的电—气互联综合能源系统低碳经济运行

燃气轮机等发电技术为低碳电力提供了一条有效途径,"能源互联网"的提出也使得天然气网络与电力网络的联系更加紧密。文中提出了一种电—气互联综合能源系统的联合经济运行模型,并引入碳交易机制,以综合能源系统发电能源成本与碳交易成本之和最小为目标函数,综合考虑了天然气网络和电力网络的安全约束。采用修改的IEEE 30节点电力网络与比利时20节点天然气网络进行算例分析,通过燃气轮机建立两个网络之间的耦合,分析比较了基于碳交易机制的电—气互联综合能源系统和单纯火电机组电力系统低碳经济模型下的运行状态,验证了所提出模型的有效性。最后,分析了碳交易价格、天然气价格及天然气网络约束对系统运行的影响。     

富氧气氛下受热面改造的经济性分析

富氧气氛下由于烟气量的减少以及锅炉热效率提高所带来的燃料量的减少使得烟气中的粉尘量得到一定的降低,为电站锅炉水平烟道烟气流速的提高带来了可能.增加烟气流速虽然强化了传热,但同时也增大了风机的电耗.采用基于初投资分摊费用和经营成本的动态费用分析法对不同烟气流速下对流受热面的换热进行经济性分析.计算结果表明,最佳工况比空气燃烧方式下的烟道更加紧凑,但是流速超过一定范围之后带来的引风机耗电量的增加超过了流速增加所带来的强化换热的收益,因此是不经济的.采用动态费用法为富氧燃烧方式下对流受热面最佳流速的选择提供依据,对新型富氧燃烧锅炉换热器的设计具有一定的指导意义.     

IGCC电站燃气轮机启动燃料的替换研究

当整体煤气化联合循环(integratedgasification combined cycle,IGCC)电站低热值合成气燃气轮机的启动燃料为柴油时,启动成本高,污染物难以控制。为了解决该问题,一个较适用的方法是将燃气轮机的启动燃料由柴油替换为天然气。但由于2种燃料的燃烧特性的不同,需要对燃机在两种不同燃料下的动态特性进行深入的研究,从而提出相应的改造和运行策略。基于天津IGCC低热值燃气轮机的结构及实际运行数据,建立燃气轮机热力学计算模型,对比分析了燃气轮机启动过程中,柴油量、天然气量随燃气轮机负荷的变化情况;其次计算了燃烧器燃烧天然气时的火焰稳定速度范围和优化燃烧器当量直径的范围;并对该燃气轮机燃烧室内的燃烧过程进行了数值模拟研究。最后提出了燃烧器的改造方案和运行策略,在尽量小的范围内进行改造来实现对柴油的替代而且保证燃机的稳定、安全和清洁启动。     

考虑电-气耦合综合能源需求响应的电网调度决策方法研究

随着天然气发电的迅速发展,天然气网络与电力网络愈发耦合。天然气存储运营商作为天然气市场的参与主体之一,拥有存储、释放天然气的能力,在综合能源系统中可以实现对电网的跨网支持。然而,目前尚缺乏考虑电-气耦合综合能源需求响应的电网调度决策方法。建立了一种考虑电-气耦合综合能源需求响应参与电网运行的调度模型,该模型分别以电气双网连接点燃气机组最大出力可减少量以及跨网响应资源成本最优为目标函数,计及电网负荷平衡、储气成本等约束,为电气双网跨网资源的调度提出了一种新的机制与方法。