某炼厂升级改造总流程方案研究及设计优化

以某炼厂升级改造工程的总流程方案研究及设计优化过程为例,说明加工渤海海上混合原油的炼厂升级改造工程的总流程方案配置。通过对渤海海上混合原油的主要性质分析,特别是密度、硫含量及酸值等性质分析,阐述主要设计原则、产品方案、总加工流程及主要工艺技术方案。在关键技术方案研究中,对比了常规减压蒸馏和减压深拔对经济效益的影响,以及延迟焦化装置、催化裂化装置、汽(柴)油加氢精制装置及柴油加氢改质装置改造方案的确定及改造后的装置规模、优化工艺,重整汽油中C6及以上组分加工方案等内容,并对全厂环保、安全操作及企业未来的发展方向进行了考虑。最终确定的全厂总流程能够使企业获得较好的技术和经济效益,生产的汽(柴)油产品全部满足国Ⅴ标准。项目实施后,年均净利润为41098万元,税后财务内部收益率为14.51%,税后投资回收期为7.39a。     

热集成技术在常减压装置上的应用

茂名分公司炼油分部3号常减压装置由于换热终温较低（为255.4℃）,应用热集成技术对工艺过程用能进行分析,提出了同步优化分馏塔和换热网络的方案,包括操作优化和改造优化两个方面。其中,操作优化是通过改变操作工况,最终达到提高换热终温、降低燃料消耗的目的。实施后,分馏塔实现零回流控制,原油各流股温差缩小,混合[火用]损减少,原油换热终温提高到262.4℃,节省能耗0.568kg标油/t,产生经济效益476.5万元/a。改造优化是通过改造换热设备以达到增加换热量、提高换热终温、节能能耗的目的。具体措施为交换换热器换7-3与换5-3AB的位置,回收常压塔顶冷凝负荷,用来加热电脱盐水,可使其注水温度由60℃提高到127℃,原油换热终温可提高4.1℃。     

实现效益最大化的一体化生产运行优化与组织

茂名石化是中国首家炼油加工能力达千万吨级、乙烯生产能力达百万吨级的炼化一体化企业,其生产系统由炼油、化工、动力、港口、铁路运输五大板块构成,原油由湛江-茂名长输管线和300kt单点系泊通过北山岭-茂名长输管线输送到炼油厂,成品油通过10Mt/a西南成品油管线、12Mt/a珠三角成品油管线,或火车、汽车,输送到广西、贵州和云南及珠三角等地区,化工产品主要由汽车及火车外运到附近及珠三角等地区。2007年以来,利用大炼油、大化工的有利条件,深化炼化一体化生产运行优化与组织,2007～2009年,连续获得炼化企业效益排头兵称号,2009年成为中国首家利润突破60亿元的炼化企业。所谓实现效益最大化的一体化生产运行优化与组织,主要实施以下方案:优化原油结构和原油接卸转输与一次加工排产方案;优化一体化生产及产品方案;优化一体化资源配置方案;优化一体化库存及流程方案。提出未来一体化生产运行优化与组织的思路及对策:接近安全和效益的临界点,优化原油结构;深化原油混输混炼工作,提高原油性价比;提高装置原料多元化、性质复杂化的适应性;加强炼化一体化生产运行优化与组织;提高氢气、干气等一体化资源的利用水平;适应原油劣质化趋势,深化产业结构调整;加大决策软件、分析、调控等基础及信息工具的升级力度。     

600MW超临界汽轮机机组冷端的优化改造

对某发电公司1号超临界机组（600 MW）汽轮机冷端设备老化和双背压凝汽器抽空气系统不合理进行了分析并提出改造和优化方案.通过该机组冷端改造和优化方案的实施,该机组全年真空约提高0.816kPa,降低发电煤耗1.67 g/（kW·h）,节约标煤6 346 t,节约资金561.621万元.通过全年的运行经验表明,该项改造取得了显著的经济效益.     

300MW汽轮机采用最新通流技术改造的结构分析

介绍了上海汽轮机厂对上世纪80年代引进美国西屋公司的300 MW亚临界汽轮机进行通流部分改造的方案.改造后机组采用先进的AIBT通流技术,结构部件进行了较大的优化,如调节级逆流改为顺流的优化、高压蒸汽室的优化,整体高压内缸的全新设计优化等.机组投运后表明,改造对提升机组性能有明显的效果,机组运行稳定、灵活,热经济性得到提高.     

炼油企业蒸汽动力系统的节能改造探析

本文介绍了一炼油企业的蒸汽动力系统合理用能,节能的一些优化改造措施,论述了从机组的优化配置到蒸汽的梯级利用改造方案,从对改造方案的技术经济评价中见,改造后节约了能源并显著提高了经济效益。     

四种原油评价与可行性加工方案探讨

对巴士拉原油、龙卡多原油、梵高原油、邦加原油的一般性质、直馏产品收率、产品性质进行比较和数据分析,结合大连石化现状,对原油加工方案进行探讨.结论认为,巴士拉原油各直馏馏分的收率比例适中,硫含量高,需要与其他硫含量低的原油混炼;龙卡多原油各直馏馏分的收率比例适中,但是硫含量高,酸值达到0.5mgKOH/g,需要与其他硫含量低、酸值低的原油混炼;邦加原油除减压塔底油收率稍低外,其他各直馏馏分的收率比例适中,但酸值高达0.5mgKOH/g,需要与其他酸值含量低的原油混炼;梵高原油为偏重原油,重整原料、航煤和柴油馏分收率小,大部分为减压馏分和渣油馏分,酸值超过1.0mgKOH/g,加工时会严重腐蚀常减压装置,应根据需要掺炼其他酸值低的原油,后续加工可通过催化裂化或加氢裂化等深度加工工艺,生产出高价值的轻馏分油.原油评价为生产计划系统、生产调度排产系统和原油优化调合系统提供数据支持,并为选择效益最优的原油采购方案,确保生产装置平稳运行,保证原油加工效益最大化提供技术支持.     

对优化加工劣质原油前期设计的探讨

炼油行业根据原油的一般性质,把原油大致分为优质、中质和劣质三大类.劣质原油除了(.)API值小、硫含量大、总酸值高外,还呈现如下特点:常压拔出率低,常压重油产率(或减压渣油产率)高,黏度大,且杂质含量高,主要表现为硫含量、重金属(Ni+V)含量高,残炭值高.以加工能力为20Mt/a Merey-16原油的燃料型炼油厂为例,阐明优化加工劣质原油前期设计的全过程,即在建立LP模型基础上,利用相关软件对全厂总加工流程进行优化.因为原油性质太差,需要在其公用工程、特别是公用工程岛的优化-评价后,才能得出最终结果.当利用石油焦作为IGCC原料时,只有选用热回收方案,才能实现余热回收量、超高压水蒸气产量、酸性气回收量最大化,从而实现水蒸气能量的全过程、逐级优化利用;实现硫磺、CO2高回收率;在保障本装置低碳化的同时,使全炼油厂最大限度地节能减排.     

利用放空天然气作加热炉燃气的节能改造

简要介绍了吐哈油田鄯善采油厂原油稳定装置,利用原油缓冲罐V-1的放空天然气代替中压天然气作为原油加热炉燃气的改造过程,改造后的系统在满足原油稳定装置加热炉的热要求及其它工艺要求的同时也减少了系统中天然气的燃烧量,是一项值得借鉴的节能改造技术。     

全厂空压机系统优化节能技术改造

对国电福州发电有限公司全厂空压机系统的布局形式和运行特点进行科学合理分析,提出具体的系统节能优化改造方案.通过系统优化升级改造,不仅取得了可观的节能经济效益,而且大大提升了空压机系统的安全稳定性.通过实例说明发电企业可以通过自身内部挖潜降耗等经营管理手段来缓解企业经营压力,实现可持续发展.     

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。     

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.     

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.