Opposed multi-burner gasification technology:Recent process of fundamental research and industrial application

Opposed multi-burner(OMB)gasification technology is the first large-scale gasification technology developed in China with completely independent intellectual property rights.It has been widely used around the world,involving synthetic ammonia,methanol,ethylene glycol,coal liquefaction,hydrogen production and other fields.This paper summarizes the research and development process of OMB gasification technology from the perspective of the cold model experiment and process simulation,pilotscale study and industrial demonstration.The latest progress of fundamental research in nozzle atomization and dispersion,mixing enhancement of impinging flow,multiscale reaction of different carbonaceous feedstocks,spectral characteristic of impinging flame and particle characteristics inside gasifier,and comprehensive gasification model are reviewed.The latest industrial application progress of ultralarge-scale OMB gasifier and radiant syngas cooler(RSC)combined with quenching chamber OMB gasifier are introduced,and the prospects for the future technical development are proposed as well.

Design on Tool Profile for Machining Cone Screw with Opposed Conical High Pressure Seawater Hydraulic Pump

In order to meet the requirements of the machining process of cone screw of the Opposed Conical High Pressure Seawater Hydraulic Pump,this work describes the design process to determine the theoretical profile of the tool,starting from the surface equation of the cone screw. Along with the expression of the theoretical tool profile,the equation of the contact line between the cone screw and the tool is established based on the coordinate transformation theory and the space meshing theory,as well as the surface equation and the position relationship between the screw and the tool during processing. By solving the contact condition based on the method of numerical discretization analysis via MATLAB,the contact line trajectory and theoretical tool profile curve are derived.The feasibility of the proposed method is verified by an example of tool profile design for machining the screw.

Two Opposed Ideas As Immature Ambivalence In The Great Gatsby

The Great Gatsby narrates a symbolist tragedy in a transitional era.It’s ambivalent characterizationand themes find justifications in the writer’s own ideology of two opposed ideas ,and in his efforts to define andjudge subjects of social problems.The ambivalent characterization concerns the writer’s dual response to theprotagonist’s corruption and innocence respectively.Ultimately the writer is convinced that both the corruptionand innocence are justifiable in the morality of his protagonist.Whereas the ambivalent themes dealing withthe American dream attach importance to the social class perspectives and the vision of history,undoubtedlythe writer slides into a compromise with his themes:repudation and approval.Because of the equally strong in-terplay of two opposed ideas,the writer fails to locate a definite position and scale,which results in his imma-ture control in the art of the work.The writer’s characteristic code and achievement are significant becausethey genuinely reveal human being’s fundamental dilemma in social life.

Matching analysis of combined charging of an opposed-piston two-stroke engine

To experimentally match performance and structural features of an opposed-piston two- stroke engine （ OPTSE ）, two calculation models, a one-dimensional （ 1-D ） model and a three-di- mensional （3-D） model, of the combined charging matching simulation of an OPTSE was established by using the GT-Power software. To test and verify the one dimensional model, the three-dimension- al computational fluid dynamics simulation model was established using AVL FIRE software. Cylinder pressure curves in these two models match perfectly, showing that it is reasonable to use the one-di- mensional model to simulate the work process of an OPTSE. Moreover, the effects of delivery ratio, nozzle ring diameter and exhaust back pressure on brake specific fuel consumption （ BSFC ） were studied.

Design of Synchronous Drive Mechanism of Opposed-Piston Hydraulic-Output Engine

In order to improve the thermal power conversion capacity of the internal combustion engine,combined with existing opposed-piston two-stroke engine（ OP2S） and hydraulic free piston engine（HFPE）,the integral structure for a newtype of opposed-piston hydraulic-output（ OPHO） engine has been designed,an operating principle has been introduced,the composition of its synchronous drive mechanism has been carefully analyzed,and a mathematical model has been built. In addition,the kinematics models of both the mechanism and the conventional crank-link mechanism have been established by utilizing MATLAB,and the movement rules of the pivotal moving components have been obtained. According to the simulation results,the piston movement of this newtype of opposed-piston hydraulic-output engine reveals a prominent asymmetry compared to the conventional crank-link engine. Under a fixed engine revolving speed,the compression time of the opposedpiston hydraulic-output engine is shortened while the expanding time is lengthened,thus the gas turbulence intensity is strengthened around the top dead center（ TDC） position. Meanwhile,the piston obtains a longer isometric process compared to conventional engines,which could be benefitial to enhance the combustion efficiency.

Frequency compensation control method for opposedpiston two-stroke folded-cranktrain engine's common rail system by loop-shaping theory

A frequency compensation control method for the opposed-piston two-stroke folded-cranktrain（ OPFC） diesel engine＇s common rail system is presented as a result of the study of the loop-shaping theory. A common rail working process and the classical frequency control theory are combined to construct a frequency restriction of common rail pressure. A frequency compensator is utilized to improve the robustness of multiplicative perturbations and disturbance. The loop-shaping method has been applied to design the common rail pressure controller of the OPFC diesel engine. Simulation and bench test results show that in the condition of perturbation that comes from the effect of injection,multi-injection,fuel pumping of a pre-cylinder,and instantaneous pressure fluctuation,the controller indicates high precision. Compared with the original controller,this method improves the control precision by 67. 3%.

Mixture formation analysis of an opposed-piston two-stroke gasoline-direct-injection engine

The effects of different flow forms on an opposed-piston two-stroke（OPTS）gasoline-directinjection（GDI）engine was studied by analyzing the mixture formation and combustion.Swirl was broken and dissipated gradually and the turbulence kinetic energy（TKE）was small in the compression process;however,tumble was strengthened and the TKE was strong in the compression process.For swirl around X axis（the axis of cylinder）and tumble around Y axis（the vertical direction of injector）,droplets were attached to the cylinder liner by the centrifugal force and the mixture distribution was poor.For tumble around Zaxis（the direction of injector）,the wall film in cylinder liner was thin and mixture distribution was homogeneous.Results showed that since the injector were installed on the wall of the cylinder liner in the OPTS-GDI engine,the spray angle was small and the mixture formation time was short.The 45° oblique axis tumble ratio of 1 was reasonable for the mixture formation and combustion for an OPTS-GDI engine.

逆向射流对高超声速升力体构型的减阻特性研究

在高超声速飞行过程中,飞行器往往会面临巨大的阻力,严重限制了其飞行性能,并增加了飞行器表面的热负荷和材料应力。针对这一问题,通过数值模拟系统地分析了射流孔数量、位置和攻角对升力体减阻性能的影响。研究结果表明,随着射流孔数量的增加,整体减阻率显著提高,有效降低了升力体头部的高压区域,但也导致四周流场的不稳定性增强。射流孔位置对激波脱体距离和“气膜”厚度具有重要影响。此外,增大攻角会导致整体减阻率下降,但对局部减阻率影响较小,同时会增加上下壁面之间的压差。进一步比较研究发现,在20 km和55 km高空条件下,这3种因素对减阻性能的影响规律保持一致。研究结果为设计高效减阻方案提供了重要参考。

OP2S双燃料发动机气口匹配特性研究

对置活塞二冲程(OP2S)发动机是一种结构可调性较高的动力系统,采用等效二冲程方法建立并校验了OP2S柴油机的一维仿真模型,研究了不同甲醇含量下进排气口高度冲程比对OP2S柴油机动力性能、燃油经济性、换气性能和排放性能的影响。结果表明:OP2S柴油机具有换气性能和排放性能的双“trade-off”关系。甲醇含量增加会促进经济性能的提高和动力性能的降低,也会促进扫气效率的增加和捕获率的降低。进排气口的匹配设计是提升OP2S柴油机性能的关键之一。进气口通过增加新鲜空气主动促进燃烧,而排气口通过减少能量和新鲜充量损失被动改善换气性能。随着气口高度的增加,OP2S柴油机的性能曲线具有双转捩点。将性能曲线分为3个区域,其中第2区域为最佳性能区,该区域对应的进/排气口高冲程比分别为0.056~0.122和0.078~0.100。

330 MW旋流对冲锅炉低负荷运行的低NO_(x)燃烧优化

以某热电厂一台330 MW旋流对冲燃煤锅炉为研究对象,通过数值模拟分析了锅炉在150 MW低负荷运行、不同配风比下炉内的流动、传热及NO_(x)排放情况。结果表明,当二次风配比和燃尽风率增大时,NO_(x)的生成趋势并不呈线性变化,而是存在一个最低点,可得到一个NO_(x)排放值最低的最佳配风方式。为了验证该最佳工况的优化效果及实际运行的可行性,又将数值研究中的3个典型工况进行了现场实验。实验结果表明:与原运行工况相比,采用最佳配风方式的实际炉膛出口NO_(x)浓度下降20%,锅炉效率提高0.41%。该配风优化方案经济可行,为同类型工程问题提供了优化思路。

通督调神针刺联合阴阳平衡透穴巨刺法治疗卒中后偏瘫疗效观察

目的:观察通督调神针刺联合阴阳平衡透穴巨刺法治疗卒中后偏瘫的临床疗效。方法:选取60例卒中后偏瘫患者,随机将其分成对照组与治疗组,每组30例。对照组患者根据缺血性和出血性脑卒中相关指南予以基础治疗,结合普通针刺治疗;治疗组患者基础治疗与对照组相同,结合通督调神针刺联合阴阳平衡透穴巨刺法。两组治疗2周后,观察指标为临床疗效有效率、美国国立卫生院卒中量表(NIHSS)评分、改良后日常生活活动能力评分(MBI)表(改良Barthel指数)评分、卒中患者运动功能评估量表(MAS)评分、功能独立性评定(FIM)量表运动功能部分评分。结果:两组方法治疗后治疗组与对照组临床疗效明显,分别对评分表进行比较,显示NIHSS量表分值降低,MBI量表、MAS量表、FIM量表评分的分值都有升高,两组治疗方法均有疗效,两组方法组内比较疗效均优于治疗前(P<0.05);两组间进行比较,经对比两种治疗方法效果差异明显,具有统计学意义(P<0.05)。结论:通督调神针刺联合阴阳平衡透穴巨刺法治疗卒中后偏瘫疗效确切,值得在临床应用。

压燃式二冲程对置活塞转盘发动机一维性能仿真

二冲程对置活塞转盘(2S-OPCP)发动机是一种新型发动机.该发动机使用凸轮转盘机构替代了传统发动机中的曲柄连杆机构,这种特殊的结构使转盘发动机具有功率密度高、体积小和结构简单等优点.发动机两侧的凸轮转盘存在相对转角,通过改变凸轮相对转角θ可以改变发动机的有效压缩比及换气正时,从而影响发动机的性能.根据转盘发动机的结构特点及工作过程搭建了一维热力学仿真模型,并使用试验数据对模型的缸内压力曲线进行了标定.随着θ改变,发动机的扫气过程及性能表现都会发生变化.当θ在0°~10°内变化时,发动机的换气过程有所改善,给气比在θ=7°时最高,提升了3.5%.同时,在θ达到4°后,指示燃油消耗率(ISFC)开始逐渐增加,ISFC最高增加了3.5%(θ=10°);而平均有效压力(IMEP)最高增加了3.3%(θ=4°),之后随着θ的上升,IMEP开始降低.

中国共产党“厉行节约、反对浪费”理念的实践探索、基本蕴涵与赓续发展

中国共产党“厉行节约、反对浪费”理念随着时代的发展和社会的进步而不断丰富充实。新民主主义革命时期,艰苦奋斗是共产党的优良作风;社会主义革命和建设时期,把“勤俭建国”和“勤俭美德”相统一;社会主义改革开放时期,“厉行节约,反对浪费”是践行执政新风的重要内容;中国特色社会主义新时代,“厉行节约、反对浪费”更为制度化、规范化、程序化,其核心要义是合理地利用人力、物力和财力,以资源的节约发展经济和改善人民生活。在全面建设社会主义现代化国家新的历史起点上,赓续“厉行节约、反对浪费”优良传统,要始终坚持以人民为中心的立场、推动党风廉政建设、注重制度建设和倡导简约适度的美好生活。

俄罗斯古代文人文学的抗暴叙事

在俄罗斯古代文人文学中即形成了反抗暴政的叙事基调,这种基调主要受到东正教文化中圣愚文化和民间文学狂欢化精神的影响。其表现形式一是对世俗权力的反抗,二是对教会威权的否定。前者的代表性文本是库尔勃斯基给伊凡四世的书信,后者的代表性文本是阿瓦库姆的《行传》。这些文本从价值立场和诗学形态上都为19世纪俄罗斯经典文学提供了宝贵的叙事资源。

基于等值反磁通装置频率域电磁法研究

人工源近区频率域电磁法具有轻便、分辨率高及抗干扰能力强等优点,但提取地质体二次场响应难题困扰了该方法推广应用。基于等值反磁通原理提取二次场响应,首先,推导出了基于等值反磁通原理的频率域近场垂直磁场响应的表达式;然后,采用层状介质与均匀半空间介质的垂向磁场同相分量的比值定义视电阻率,并计算了典型层状介质垂直磁场的频率响应;最后,通过试验对比时间域与频率域方法对浅埋藏铝板的异常响应。研究结果表明:基于等值反磁通原理能够有效提取近场频率域二次场信号,近场垂向磁场的同相分量与大地电导率的二次方成正比;垂向磁场同相分量的比值定义视电阻率能够清晰反映A型、Q型、H型及K型地电断面的特征。

燃气锅炉振动问题探究

本文对燃气锅炉运行期间存在的振动问题进行了研究。对于对冲燃气燃烧器的典型锅炉,在50%负荷以上,前墙单只燃烧器的燃气开度为后墙燃气开度的一半时,振动明显减弱。

探究燃尽风对墙式对冲锅炉主再热汽温的影响

本文探究了燃尽风对墙式对冲燃烧锅炉主再热汽温的影响。关小燃尽风燃烧器拉杆,可以提高该区域的整体壁温,反之亦然。利用这一规律,可以有效调节主汽温度和再热汽温。

粉量分布不均对1000 MW机组对冲锅炉的影响及调整

针对1000 MW机组对冲锅炉存在的偏烧问题进行了试验研究,结果发现粉量不均是偏烧的主要原因。粉量分布、煤粉细度分布均呈现典型的间隔分布趋势,且两者分布呈正相关。粉量分布不均、煤粉细度的偏差以及二次风箱风量分配特性等因素共同造成了炉内偏烧。为缓解炉内偏烧,从煤粉细度、燃烧器配风、燃尽风摆角和贴壁风开度等方面进行了调整。试验发现,燃尽风开度和摆角调整对于炉内偏烧的影响最为明显。燃尽风开度减小、燃尽风摆角由中间向两侧摆动有助于缓解偏烧。通过调整,屏过出口汽温偏差由40℃降低到10℃以内,省煤器出口氧量最低点由调整前的低于1%提高到调整后不低于2%;CO浓度最高点由调整前的5000μL/L以上降低到调整后的500μL/L以下,使该机组偏烧问题得到大幅度缓解。

基于NACS-PSO算法的光伏系统MPPT控制研究

对于局部遮阴下的光伏阵列,传统的最大功率点跟踪算法收敛速度慢、精度差、功率波动大且容易陷入局部最优。为此,提出一种基于新型自适应布谷鸟算法与粒子群算法相结合的复合算法。该方法在布谷鸟算法中引入自适应发现概率和自适应莱维飞行步长控制因子,同时加入对立种群策略,以提高算法收敛速度和全局寻优能力。在算法前期,用粒子群算法全局搜索快速找到全局最大功率点附近,后期用新型自适应布谷鸟算法在局部范围内精准寻优,以快速、准确和稳定地跟踪到全局最大功率点。仿真结果表明,本文提出的算法在四种光照模式下的收敛时间和跟踪误差分别为0.106s和0.012%、0.108s和0.034%、0.110s和0.059%、0.106s和0.031%,均优于其他算法,验证了本文算法在六种对比算法中,收敛速度最快、跟踪精度最高、功率波动最小、陷入局部最优的可能性最小。

反向射流作用下可回收火箭升阻特性

可回收火箭动力减速过程中反向射流将大幅改变箭体气动特性,为获得反向射流对箭体气动特性的影响,利用数值模拟方法获得箭体升阻力系数,分析升阻特性变化规律并提出升阻特性表征参数。首先,对反向射流钝体构型进行数值模拟,将得到的结果与已公开的实验数据进行对比,验证了数值模拟方法的有效性。其次,采用RANS方法模拟了单喷管构型火箭多种典型飞行状态,得到箭体升阻力系数随迎角变化曲线以及升阻特性变化规律,通过对回流区内流动状态进行分析得到升阻特性改变的机理。最后,由反向射流对箭体气动特性影响程度提出表征参数。结果表明:反向射流会对箭体形成遮挡作用并影响箭体升阻力特性。有射流时升阻力特性受飞行高度影响较大,受飞行马赫数影响较小,与无射流时的规律恰好相反。大部分飞行工况下阻力系数小于0.1,部分高空飞行工况将出现负阻力。本研究提出以反向射流与箭体宽度比作为气动特性表征参数,可以较好地反映反向射流对箭体的遮挡作用并表征箭体在反向射流作用下的气动特性变化规律。