Large Units, Large Plants -Major Thermal Power Sources

China’s electric power industry as a basic industry, plays an important role in the longterm, sustained and healthy development of the whole national economy. China’s electric power industry attained great achievement in technology and economical results during the past eight years from 1987-1995. The total national installed generating capacity increased from 102.897 GW in 1987 to more than 200 GW in March, 1995.

Xiangfan Coal-fired Power Plant - a matched large power plant for Three Gorges Project starts to construct

Xiangfan Coal-fired Power Plant, a key energy construction project matched with Three Gorges Project, approved by the State Council. formally started to build in the suburb of Xiangfan City, Hubei Province on November 29, 1996.

Development of Key Technologies of Large Hydro Unit in HEC

Introduction to HEC Harbin Electric Machinery Company Limited (HEC) is a pivotal company that produces large electric machinery and accessorial control equipment in China. The hydro units made by HEC have

Abdominal compartment syndrome:Often overlooked conditions in medical intensive care units

Intra-abdominal hypertension(IAH)and abdominal compartment syndrome are well recognized entities among surgical patients.Nevertheless,a number of prospective and retrospective observational studies have shown that IAH is prevalent in about half of the critically ill patients in the medical intensive care units(ICU)and has been widely recognized as an independent risk factor for mortality.It is alarming to note that many members of the critical care team in medical ICU are not aware of the consequences of untreated IAH and the delay in making the diagnosis leads to increased morbidity and mortality.Frequently it is underdiagnosed and undertreated in this patient population.Elevated intraabdominal pressure decreases the blood flow to the kidneys and other abdominal viscera and also results in reduced cardiac output and difficulties in ventilating the patient because of increased intrathoracic pressure.When intraabdominal hypertension is not promptly recognized and treated,it leads to abdominal compartment syndrome,multiorgan dysfunction syndrome and death.Large volume fluid resuscitation is very common in medical ICU patients presenting with sepsis,shock and other inflammatory conditions like pancreatitis and it is one of the major risk factors for the development of intra-abdominal hypertension.This article presents an overview of the epidemiology,definitions,risk factors,pathophysiology and management of IAH and abdominal compartment syndrome in critically ill medical ICU patients.

A novel carbon trap sampling system for coal-fired flue gas mercury measurement

A novel carbon trap sampling system for gas-phase mercury measurement in flue gas is developed, including the high efficient sorbents made of modified biomass cokes and high precision sorbent traps for measuring particle-bound and total vapor-phase mercury in flue gas. A dedusting device is installed to collect fine fly ash for reducing the measurement errors. The thorough comparison test of mercury concentration in flue gas is conducted between the novel sampling system and the Ontario hydro method （OHM） in a 6 kW circulating fluidized bed combustor. Mercury mass balance rates of the OHM range from 95.47% to 104.72%. The mercury breakthrough rates for the second section of the sorbent trap are all below 2%. The relative deviations in the two test cases are in the range of 15. 96% to 17. 56% under different conditions. The verified data suggest that this novel carbon trap sampling system can meet the standards of quality assurance and quality control required by EPA Method 30B and can be applied to the coal-fired flue gas mercury sampling system.

A GPU-Based Parallel Algorithm for 2D Large Deformation Contact Problems Using the Finite Particle Method

Large deformation contact problems generally involve highly nonlinear behaviors,which are very time-consuming and may lead to convergence issues.The finite particle method(FPM)effectively separates pure deformation from total motion in large deformation problems.In addition,the decoupled procedures of the FPM make it suitable for parallel computing,which may provide an approach to solve time-consuming issues.In this study,a graphics processing unit(GPU)-based parallel algorithm is proposed for two-dimensional large deformation contact problems.The fundamentals of the FPM for planar solids are first briefly introduced,including the equations of motion of particles and the internal forces of quadrilateral elements.Subsequently,a linked-list data structure suitable for parallel processing is built,and parallel global and local search algorithms are presented for contact detection.The contact forces are then derived and directly exerted on particles.The proposed method is implemented with main solution procedures executed in parallel on a GPU.Two verification problems comprising large deformation frictional contacts are presented,and the accuracy of the proposed algorithm is validated.Furthermore,the algorithm’s performance is investigated via a large-scale contact problem,and the maximum speedups of total computational time and contact calculation reach 28.5 and 77.4,respectively,relative to commercial finite element software Abaqus/Explicit running on a single-core central processing unit(CPU).The contact calculation time percentage of the total calculation time is only 18%with the FPM,much smaller than that(50%)with Abaqus/Explicit,demonstrating the efficiency of the proposed method.

Tempospacial energy-saving effect-based diagnosis in large coal-fired power units:Energy-saving benchmark state

The energy-saving analytics of coal-fired power units in China is confronting new challenges especially with even more complicated system structure, higher working medium parameters, time-dependent varying operation conditions and boundaries such as load rate, coal quality, ambient temperature and humidity. Compared with the traditional optimization of specific operating parameters, the idea of the energy-consumption benchmark state was proposed. The equivalent specific fuel consumption(ESFC) analytics was introduced to determine the energy-consumption benchmark state, with the minimum ESFC under varying operation boundaries. Models for the energy-consumption benchmark state were established, and the endogenous additional specific consumption(ASFC) and exogenous ASFC were calculated. By comparing the benchmark state with the actual state, the energy-saving tempospacial effect can be quantified. As a case study, the energy consumption model of a 1000 MW ultra supercritical power unit was built. The results show that system energy consumption can be mainly reduced by improving the performance of turbine subsystem. This nearly doubles the resultant by improving the boiler system. The energy saving effect of each component increases with the decrease of load and has a greater influence under a lower load rate. The heat and mass transfer process takes priority in energy saving diagnosis of related components and processes. This makes great reference for the design and operation optimization of coal-fired power units.

Distribution and exploration direction of medium-and large-sized marine carbonate gas fields in Sichuan Basin, SW China

Based on the analysis of the basic characteristics of medium-and large-sized marine gas fields in Sichuan Basin, combined with the division of major reservoir forming geological units in the marine craton stage and their control on key hydrocarbon accumulation factors, the distribution law of medium-and large-sized marine carbonate gas fields in the basin was examined and the exploration direction was pointed out. Through the analysis of the periodic stretching-uplifting background, it is concluded that five large scale paleo-rifts, three large scale paleo-uplifts, five large scale paleo erosion surfaces were formed in the marine craton stage of Sichuan Basin, and these geological units control the key reservoir forming factors of medium and large sized gas fields:(1) Large-scale paleo-rifts control the distribution of high-quality hydrocarbon generation centers.(2) The margin of large-scale paleo-rifts, high position of paleo-uplifts and paleo erosion surfaces control the distribution of high-quality reservoirs.(3) Large-scale paleo-rifts, paleo-uplifts, paleo erosion surfaces and present tectonic setting jointly control the formation of many types of large and medium-sized traps.(4) Natural gas accumulation is controlled by the inheritance evolution of traps in large geological units. Based on the comparative analysis of the distribution characteristics of medium-and large-sized gas fields and large geological units, it is proposed that the superimposition relationship between single or multiple geological units and the present structure controls the distribution of medium-and large-sized gas fields, and the "three paleo" superimposed area is the most advantageous. According to the above rules, the main exploration fields and directions of medium-and large-sized marine carbonate gas fields in Sichuan Basin include periphery of Deyang-Anyue paleo-rift, eastern margin of Longmenshan paleo-rift, margins of Kaijiang-Liangping oceanic trough and Chengkou-western Hubei oceanic trough, the high part of the subaqueous paleo-uplifts around Central Sichuan, paleo erosion surfaces of the top boundary of Maokou Formation in eastern and southern Sichuan Basin, paleo erosion surfaces of the top boundary of the Leikoupo Formation in central and western Sichuan Basin.

The Effects of SO_3 in Flue Gas on the Operation of Coalfired Units and Countermeasures

There exists a certain amount of SO_3 in flue gas discharged from coal-fired power plants. With the operation of the selective catalystic reduction( SCR) denitrification system,SO_3 concentration in the flue gas increases,which will lead to fouling,erosion and plugging of downstream equipment. In this study,the main effects of SO_3 on the safety,stability and efficiency of units were analyzed,and measures to control SO_3 were proposed.

全视角学习理论视域下单元教学实践探索——以呼伦贝尔“群落及其演替”大单元教学为例

根据全视角学习理论,从“动机”“内容”和“互动”三个维度进行教学设计框架的搭建,以呼伦贝尔“群落及其演替”大单元教学为例,帮助学生构建“生物学大概念”,加深学生对国家“生态文明”政策制定的理解,实现课程思政与教学内容的融合,匹配单元教学目标与多维度的评价体系,培养学生终身可持续的“学习能力”。

智慧教育环境下五年级篮球大单元精准化教学研究

随着科技的不断进步和教育理念的更新,智慧教育在提升教学质量、推动个性化学习与优化教学管理等方面发挥着至关重要的作用。以五年级篮球教学为例,在智慧教育环境下,通过分析技术动作的构成,建立相对完善的大单元教学体系。在教学过程中,充分利用多媒体教学资源、数据分析辅助教学、在线互动学习环境以及个性化辅导等多种手段,着重把体育核心素养的培养转化为实际行动,旨在提高学生的运动能力、培养学生的健康行为并塑造其体育品德。教学实施流程包括课前以学定教、课中精准施教以及课后有效追踪三个关键阶段,同时运用信息技术工具优化教学策略,以达到提高教学效果、促进学生全面发展的目的。

地方特色文化内容融入中学化学大单元教学——以南疆地区文化为例

分析地方特色文化内容融入化学教学的优势,整理南疆地区文化涉及的化学知识。以南疆地区的地方特色文化内容基础,探究将地方特色内容融入中学大单元教学的模式。以哈萨克族服饰和石榴酒为例,通过化学视角看待地方特色文化内容。根据石榴酒中的化学知识进行教学设计,为促进地方特色内容更好融入化学教学提供参考,并进一步培养学生核心素养。

全位置自动焊技术在国际大型石油化工装置中的应用

石油化工装置中的各类介质大部分为易燃、易爆、高温、高压介质,若工程质量出现问题则极易导致安全事故,因此保证石油化工装置建设工程质量对装置的平稳运行至关重要。而保证输送各类介质的工艺管道焊接质量是其中重要的一环。如何提高工艺管道焊接生产效率和焊接质量是亟待解决的技术难题。文章结合某国际工程项目880万吨/年渣油加氢装置工艺管道采用全位置自动焊新技术提高焊接质量和效率的应用实例,从全位置自动焊技术现状调研、焊接设备开发、不同材质性能试验、操作工艺要点、质量要求、功效对比、工程应用情况等方面,全面阐述了全位置自动焊的关键工艺要点。该技术不仅在国际工程得到很好应用,而且在国内多个工程项目推广应用,有效推动了工艺管道焊接技术创新发展。

多功能浮动港应用研究

自20世纪20年代以来,不断有对海上大型浮体的概念设想以及具体的开发建设实践,在总结归纳现有多功能浮动港开发应用实例基础上,分析多功能浮动港的应用场景和主要需求,包括解决城市空间矛盾、助力岛礁开发和保护、为海洋资源开采提供支撑、为水上活动提供服务等。总结多功能浮动港主要特征,提出按水平投影面积将浮动港分为6个规模等级,以便在建设开发中进行归类管控,按功能将浮动港划分为商业型、公共服务型、居住型、生产服务型、特殊服务型等5种类型。经过技术、政策、经济方面初步适应性分析,结构单元模块的介绍,以及主要技术问题的分析,认为在我国应用尚处于起步阶段的浮动港契合未来海洋经济的发展需求,具备较为广阔的应用前景。

Energy conservation in China's coal-fired power industry by installing advanced units and organized phasing out backward production

Coal-fired power is the main power source and the biggest contributor to energy conservation in the past several decades in China.It is generally believed that advanced technology should be counted on for energy conservation.However,a review of the decline in the national average net coal consumption rate(NCCR)of China's coal-fired power industry along with its development over the past few decades indicates that the upgradation of the national unit capacity structure(including installing advanced production and phasing out backward production)plays a more important role.A quantitative study on the effect of the unit capacity structure upgradation on the decline in the national average NCCR suggests that phasing out backward production is the leading factor for the decline in the NCCR in the past decade,followed by the new installation,whose sum contributes to approximately 80%of the decline in the national average NCCR.The new installation has an effective affecting period of about 8 years,during which it would gradually decline from a relatively high value.Since the effect of phasing out backward production may remain at a certain degree given a continual action of phasing out backward capacity,it is suggested that the organized action of phasing out backward production should be insisted on.

Multi-relaxation-time lattice Boltzmann simulations of lid driven flows using graphics processing unit

Large eddy simulation （LES） using the Smagorinsky eddy viscosity model is added to the two-dimensional nine velocity components （D2Q9） lattice Boltzmann equation （LBE） with multi-relaxation-time （MRT） to simulate incompressible turbulent cavity flows with the Reynolds numbers up to 1 × 10^7. To improve the computation efficiency of LBM on the numerical simulations of turbulent flows, the massively parallel computing power from a graphic processing unit （GPU） with a computing unified device architecture （CUDA） is introduced into the MRT-LBE-LES model. The model performs well, compared with the results from others, with an increase of 76 times in computation efficiency. It appears that the higher the Reynolds numbers is, the smaller the Smagorinsky constant should be, if the lattice number is fixed. Also, for a selected high Reynolds number and a selected proper Smagorinsky constant, there is a minimum requirement for the lattice number so that the Smagorinsky eddy viscosity will not be excessively large.

大单元视阈下体育与健康教学模式的经验汲取与应用策略

核心素养导向的体育与健康大单元教学亟需从专家的理念引领转化为教师的课堂实践。体育与健康大单元教学组织形式与教学模式均顺应教学专业化的要求,试图找寻能够指导基层课堂教学的规律、原理,教学模式着眼于结构程序与操作框架,教学组织形式立足于作用机制与环境特征。围绕体育与健康大单元教学的关键内核:多课时的教学单位是大单元教学整体规划的载体;结构化的教学设计是大单元教学内容整合的抓手;运动项目完整的体验与理解是大单元教学情境设计的依据,研究汲取了运动教育模式、领会教学模式、个人与社会责任教学模式等的教学组织经验,提出大单元视阈下体育与健康教学模式的应用策略:基于学习体验、任务拆解规划教学单元;围绕学习主题、概念原理整合教学内容;依循认知规律、活动架构创设学习情境。

从学习进阶到内容重构:基于情境链的体育与健康课程大单元的内部构建

情境链是体育与健康课程大单元教学内容重构的重要支撑,能有效解决中小学体育教学实践中的教学内容低级重复、情境创设连贯性较弱和延展性不够等问题。基于情境链的体育与健康课程大单元教学重视链式整合的课程样态,依托递进的情境进行专项运动技能的有效学练,通过情境链串联目标、任务、内容等课程元素,整体规划体育与健康课程大单元的学习路径。情境认知理论、境脉学习理论与学习进阶理论为情境链的深入理解提供了理论基石与实操框架。结合三大理论的基本要素探讨基于情境链的体育与健康课程大单元的构建流程,聚焦核心素养的整体性,通过水平二“篮球保护和控制球能力的提升”大单元主题案例,从“精准分析学情,确立大单元学习目标”“提取关键概念,规划大单元学习路径”“串联进阶元素,重构大单元学习内容”“基于真实情境,评价学生的学习表现”展现完整的情境链研究。