基于省级截面数据的分布式光伏发电补贴政策实证分析

分布式光伏发电作为电能生产的重要组成部分,对优化能源结构、改善生态环境具有十分重要的意义。国家和地方出台了一系列鼓励分布式光伏发电的政策,但由于缺乏参照,补贴政策多种多样,实际效果并不明显。针对此问题,文章通过收集2014~2015年各省份分布式光伏发电的新增装机容量、财政补贴等数据,建立了基于省级截面数据的分布式光伏发电补贴政策实证模型,分析影响分布式光伏发电发展的主要因素以及财政补贴政策对分布式光伏发电发展的影响程度。研究结果表明,各省份分布式光伏发电的发展一方面决定于当地经济发展水平和资源条件,另一方面,补贴政策对分布式光伏发电的发展具有明显的激励效果。省级层面在制定分布式光伏发电支持政策时,应充分考虑当地的经济发展水平和资源条件,评估补贴政策对分布式光伏发电发展的促进效果以及给地方政府带来的财政负担,并对地市层面分布式光伏发电的发展配套一些鼓励性和约束性政策。     

基于动态负荷特性的家用光伏发电系统经济性评价

以家用光伏发电系统为研究对象,基于用户侧动态负荷特性与供给侧光伏发电出力特性的耦合解析,根据分布式光伏系统"自用为主、余电上网"的应用原则,构建家用分布式光伏发电系统经济性评价模型。应用该模型,以上海某家用光伏发电系统为例,分析其运行特性、经济性能及其影响因素。研究结果表明,现行政策下家用光伏发电系统的动态投资回收年限为12.4 a;在中国,促进光伏产业发展最实际、最有效的政策是提高上网电价。     

第三批光伏发电“领跑者”项目的技术分析

针对第三批光伏发电"领跑者"项目大量采用"双面双玻光伏组件+单轴跟踪"技术方案的特点,进行了技术性、经济性的研究,通过分析得出,该技术方案使未来光伏发电系统平价上网、脱离政府补贴成为可能。     

基于优化LCOE的光伏平价上网可行性分析

平准化度电成本(LCOE)是国际上通用评价发电技术的主要经济性指标。在原有LCOE评估模型基础上,增加了考虑折旧抵税后的税收成本和损耗带来的额外成本,进一步优化成本模型,并考虑清洁发展机制(CDM)的收入因素,提出更准确、更完整的优化LCOE模型,并结合其他投资指标提出适应我国现状的光伏发电效益模型。以南京某3 MW分布式光伏电站项目为例进行敏感性分析,进一步探讨未来光伏平价上网的可行性,提出提高光伏系统单位造价和提高发电量是实现平价上网的主要途径。     

分布式光伏发电项目的投资影响因素研究

为应对全球气候变化,中国提出了碳达峰、碳中和的战略目标。作为中国实现该目标的重要途径之一,分布式光伏发电不仅能够减少和替代化石能源消费,而且有利于构建安全、高效的局域微电网,近年来在政策的影响下得到快速发展。目前,分布式光伏发电项目的投资竞争已经进入白热化阶段,优质的项目资源越来越少,同时又面临产业链上游环节原材料价格的波动和补贴退坡等问题,分布式光伏发电项目的投资决策越发困难。首先对分布式光伏发电系统的优势进行了分析,然后从补贴政策、产业链价格传导、售电收入的不确定性这3个方面对新能源投资企业在分布式光伏发电项目投资决策中需要考虑的几个关键影响因素进行了分析。研究结果可为日后在更加严峻的投资环境中的项目投资决策提供借鉴和参考。     

内蒙古偏远牧区户用光伏发电系统的经济性与环境效益分析

离网光伏发电系统的经济性,主要体现在系统成本与投资收益的对比关系上。通过在内蒙古某偏远牧区安装小型家用离网光伏发电系统进行监测及数据采集,从投资成本、系统收益及环保贡献方面对离网光伏发电系统经济性的影响进行分析。结果表明:离网光伏发电系统的投资收益并不明显,但针对偏远地区用电不便的问题,却有很大帮助及改善,并且在节能减排方面也有很大贡献。而且从长远看,系统成本的降低对其经济性的提高有很大的影响。所以希望通过政策补贴等的方式,提高离网系统在发展初期的投资收益,并为在内蒙古地区推广离网光伏发电系统提供积极的示范作用。     

中国南方部分地区分布式光伏发电项目的经济性对比

在碳达峰、碳中和目标背景下,“十四五”期间中国的分布式光伏发电将持续高速发展。为向装机容量为250 kW及以下的分布式光伏发电项目的建设提供经验,对某成品油管道公司在中国南方4个地区的分布式光伏发电项目在2018—2021年的运行数据进行了统计,并以日有效利用小时数和日电费收益这2个指标对此类光伏电站的发电能力和经济性进行了分析。结果显示：云南省的日有效利用小时数平均值最大,是实现碳中和目标的重点发展地域;广东省的分布式光伏发电项目最具有经济性优势。     

太阳照在谁家屋顶上

截至目前,国家电网公司累计受理光伏并网相关咨询业务5741件,报装业务352户。然而,个人发电并网用户多是能源专家、科技发烧友和光伏设备企业的员工,真正的普通人申请光伏发电并网的寥寥无几。无论是从目前实际的项目情况,还是从将出台的电价补贴政策看,个人分布式光伏项目并不具备经济性。     

国家能源局就关于申报分布式光伏发电规模化应用示范区发出通知

通知指出：根据全国可再生能源发展＂十二五＂规划和太阳能发电发展＂十二五＂规划,各省（区、市）提出分布式光伏发电规模化应用示范区的建设方案;示范区的分布式光伏发电项目应具备长期稳定的用电负荷需求和安装条件,所发电量主要满足自发自用;鼓励采用先进技术并创新管理模式;国家对示范区的光伏发电项目实行单位电量定额补贴政策,国家对自发自用电量和多余上网电量实行统一补贴标准;     

新能源上网电价补贴政策

<正>上网电价补贴(也称为可再生能源回购电价、保护性分类电价制度或者政府电力收购制度)是一项旨在推进可再生能源广泛应用的政策。政府与使用可再生能源发电的个人或公司签订一份长期合约,期间发电者每向公共电网输送1kW·h电,就可获得相应的电价补贴。这种补贴的金额由政府公布,一般取决于当时此种能源发电设施的造价及安装费用,因此造价高的能源补贴也高,比如,对风能的补贴相对于光伏太阳能和潮汐能来说就要少一些。上网电价补贴的金额通常随     

Ash-forming elements in four Scandinavian wood species. Part 1: Summer harvest

Woody biomass in Finland and Sweden comprises mainly four wood species: spruce, pine, birch and aspen. To study the ash, which may cause problems for the combustion device, one tree of each species were cut down and prepared for comparisons with fuel samples. Well-defined samples of wood, bark and foliage were analyzed on 11 ash-forming elements: Si, Al, Fe, Ca, Mg, Mn, Na, K, P, S and Cl. The ash content in the wood tissues (0.2–0.7%) was low compared to the ash content in the bark tissues (1.9–6.4%) and the foliage (2.4–7.7%). The woods’ content of ash-forming elements was consequently low; the highest contents were of Ca (410–1340 ppm) and K (200–1310), followed by Mg (70–290), Mn (15–240) and P (0–350). Present in the wood was also Si (50–190), S (50–200) and Cl (30–110). The bark tissues showed much higher element contents; Ca (4800–19,100 ppm) and K (1600–6400) were the dominating elements, followed by Mg (210–2400), P (210–1200), Mn (110–1100) and S (310–750), but the Cl contents (40–330) were only moderately higher in the bark than in the wood. The young foliage (shoots and deciduous leaves) had the highest K (7100–25,000 ppm), P (1600–5300) and S (1100–2600) contents of all tissues, while the shoots of spruce had the highest Cl contents (820–1360) and its needles the highest Si content (5000–11,300). This paper presented a new approach in fuel characterization: the method excludes the presence of impurities, and focus on different categories of plant tissues. This made it possible to discuss the contents of ash element in a wide spectrum of fuel-types, which are of large importance for the energy production in Finland and Sweden.     

NEXT GENERATION ENGINEERED MATERIALS FOR ULTRA SUPERCRITICAL STEAM TURBINES

正1 ABSTRACT To reduce the effect of global warming on our climate,the levels of CO2emissions should be reduced.One way to do this is to increase the efficiency of electricity production from fossil fuels.This will in turn reduce the amount of CO2emissions for a given power output.Using US practice for efficiency calculations,then a move from a typical US plant running at 37%efficiency to a 760℃/38.5 MPa(1 400/5 580 psi)plant running at 48%efficiency would reduce CO2emissions by 170kg/MW.hr or 25%.     

Contents in Volume 23,2014

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Aerodynamic performance effects of leading-edge geometry in gas-turbine blades

The purpose of this paper is to illustrate the advantages of the direct surface-curvature distribution blade-design method, originally proposed by Korakianitis, for the leading-edge design of turbine blades, and by extension for other types of airfoil shapes. The leading edge shape is critical in the blade design process, and it is quite difficult to completely control with inverse, semi-inverse or other direct-design methods. The blade-design method is briefly reviewed, and then the effort is concentrated on smoothly blending the leading edge shape (circle or ellipse, etc.) with the main part of the blade surface, in a manner that avoids leading-edge flow-disturbance and flow-separation regions. Specifically in the leading edge region we return to the second-order (parabolic) construction line coupled with a revised smoothing equation between the leading-edge shape and the main part of the blade. The Hodson–Dominy blade has been used as an example to show the ability of this blade-design method to remove leading-edge separation bubbles in gas turbine blades and other airfoil shapes that have very sharp changes in curvature near the leading edge. An additional gas turbine blade example has been used to illustrate the ability of this method to design leading edge shapes that avoid leading-edge separation bubbles at off-design conditions. This gas turbine blade example has inlet flow angle 0°, outlet flow angle −64.3°, and tangential lift coefficient 1.045, in a region of parameters where the leading edge shape is critical for the overall blade performance. Computed results at incidences of −10°,   −5°,   +5°,   +10° are used to illustrate the complete removal of leading edge flow-disturbance regions, thus minimizing the possibility of leading-edge separation bubbles, while concurrently minimizing the stagnation pressure drop from inlet to outlet. These results using two difficult example cases of leading edge geometries illustrate the superiority and utility of this blade-design method when compared with other direct or inverse blade-design methods.     

Hydrogen production by steam-gasification of carbonaceous materials using concentrated solar energy – V. Reactor modeling,optimization, and scale-up

A chemical reactor for the steam-gasification of carbonaceous particles (e.g. coal, coke) is considered for using concentrated solar radiation as the energy source of high-temperature process heat. A two-phase reactor model that couples radiative, convective, and conductive heat transfer to the chemical kinetics is applied to optimize the reactor geometrical configuration and operational parameters (feedstock's initial particle size, feeding rates, and solar power input) for maximum reaction extent and solar-to-chemical energy conversion efficiency of a 5 kW prototype reactor and its scale-up to 300 kW. For the 300 kW reactor, complete reaction extent is predicted for an initial feedstock particle size up to 35 μm at residence times of less than 10 s and peak temperatures of 1818 K, yielding high-quality syngas with a calorific content that has been solar-upgraded by 19% over that of the petcoke gasified.     

汽轮机数字电液调节系统挂闸异常的技术完善

分析了200MW汽轮机数字电液调节系统在运行中存在的挂闸异常问题,采取了相应的技术处理措施,且运行实践效果良好。     

新型高压共轨ECU升压模块的数字化开发与优化

为了提高喷油器电磁阀的响应速率,提出了一种基于CPLD(复杂可编程逻辑器件)应用于高压共轨ECU的数字升压模块。鉴于该升压电路结构参数多,其升压电压的恢复响应要求高等特征,基于Pspice建立了升压电路的仿真模型,研究了不同电路参数下升压模块的输出特性,全面优化了该升压模块的性能。结果显示,该升压模块的最大转换效率可以达90%以上。在柴油发动机上对ECU的试验表明,升压电压最大波动不超过10%,其恢复时间仅为1.3ms,功率管最大温升仅为41℃,满足整机运行范围内ECU的需求。     

Trace metal chemistry and silicification of microorganisms in geothermal sinter, Taupo Volcanic Zone, New Zealand

As part of a pilot study investigating the role of microorganisms in the immobilisation of As, Sb, B, Tl and Hg, the inorganic geochemistry of seven different active sinter deposits and their contact fluids were characterised. A comprehensive series of sequential extractions for a suite of trace elements was carried out on siliceous sinter and a mixed silica-carbonate sinter. The extractions showed whether metals were loosely exchangeable or bound to carbonate, oxide, organic or crystalline fractions. Hyperthermophilic microbial communities associated with sinters deposited from high temperature (92–94°C) fluids at a variety of geothermal sources were investigated using SEM. The rapidity and style of silicification of the hyperthermophiles can be correlated with the dissolved silica content of the fluid. Although high concentrations of Hg and Tl were found associated with the organic fraction of the sinters, there was no evidence to suggest that any of the heavy metals were associated preferentially with the hyperthermophiles at the high temperature (92–94°C) ends of the terrestrial thermal spring ecosystems studied.     

Assessment methods of material ageing using Sdobyrev''s creep rupture model

The physical aspects of the activation energy, in higher and high temperatures, of the metal creep process were examined. The research results of creep-rupture in a uniaxial stress state and the criterion of creep-rupture in biaxial stress states, at two temperatures, are then presented. For these studies creep-rupture, taking case iron as an example the energy and pseudoenergy activation was determined. For complex stress states the criterion of creep-rupture was taken to be Sdobyrev's, i.e. σ_red = σ₁ β + (1 − β)σ_i, where: σ₁-maximal principal stress, σ_i-stress intensity, β-material constant (at variable temperature β = β(T)). The methods of assessment of the material ageing grade are given in percentages of ageing of new material in the following mechanical properties: 1) creep strength in uniaxial stress state, 2) activation energy in uniaxial stress state, 3) criterion creep strength in complex stress states, 4) activation pseudoenergy in complex stress states. The methods 1) and 3) are the relatively simplest because they result from experimental investigations only at nominal temperature of the structure work, however, for methods 2) and 4) it is necessary to perform the experimental investigations at least at two temperatures.     

Production of hydrogen from sewage biosolids in a continuously fed bioreactor: Effect of hydraulic retention time and sparging

Hydrogen was produced from primary sewage biosolids via mesophilic anaerobic fermentation in a continuously fed bioreactor. Prior to fermentation the sewage biosolids were heated to 70 °C for 1 h to inactivate methanogens and during fermentation a cellulose degrading enzyme was added to improve substrate availability. Hydraulic retention times (HRT) of 18, 24, 36 and 48 h were evaluated for the duration of hydrogen production. Without sparging a hydraulic retention time of 24 h resulted in the longest period of hydrogen production (3 days), during which a hydrogen yield of 21.9 L H₂ kg⁻¹ VS added to the bioreactor was achieved. Methods of preventing the decline of hydrogen production during continuous fermentation were evaluated. Of the techniques evaluated using nitrogen gas to sparge the bioreactor contents proved to be more effective than flushing just the headspace of the bioreactor. Sparging at 0.06 L L min⁻¹ successfully prevented a decline in hydrogen production and resulted in a yield of 27.0  L H₂ kg⁻¹ VS added, over a period of greater than 12 days or 12 HRT. The use of sparging also delayed the build up of acetic acid in the bioreactor, suggesting that it serves to inhibit homoacetogenesis and thus maintain hydrogen production.