露天煤矿开采工艺发展探究

对露天开采的概念进行了叙述并简单介绍了中国露天开采的发展历程,对露天开采工艺划分进行了总结.随后对中国露天开采工艺的发展进行了较为详细的介绍,并对其未来发展趋势做出了展望.     

DF11型机车柴油机隔振系统改进

对戚墅堰机车车辆厂DF11型机车柴油机隔振系统进行了改进研究,对改进前原有隔振系统进行了测试,提出了隔振器改进设计的思路和方法,并对改装6WN-8500型隔振器后进行了装车测试,对结果进行分析比较,证实了隔振器改进项目是成功的。     

汽轮机末叶片叶根强度分析与优化

针对某"215mm"汽轮机封口末叶片,应用有限元方法对其强度进行分析,对有限元计算的结果进行了验证,结合分析结果,对其结构进行了优化,并对不同的优化方案进行了对比,提出了结构优化的最佳方案。     

电控柴油机ECU系统选型与设计论证及系统开发研究

本文对电子控制燃油喷射柴油机的电控单元ＥＣＵ进行了功能分析和系统结构设计,对其内核即单片机进行了选型,并对ＥＣＵ软件部分进行了概要设计,对系统开发计划进行了初步的探讨。     

太阳能集热器热性能动态测试方法研究

对太阳能集热器热性能动态测试方法进行了介绍,并对该方法的数学模型进行了分析;探讨了各项参数在方程中的作用、可以忽略的条件等;分析了稳态测试方法严格规定试验条件的必要性及原因,并对方程的数值求解进行了分析与推导。对同一台太阳能集热器分别进行动态和稳态测试方法的试验数据进行了不确定度分析,对试验结果进行了分析和对比,并分析了太阳能集热器效率曲线截距的差异以及在不同归一化温差处集热器瞬时效率曲线差异的深层次原因。     

CRH5型动车组充电机技术研究

对CRH5型动车组充电机的主电路结构及原理进行了描述,对控制电路功能进行了分析,并对软件结构及功能、蓄电池充电策略进行了详细介绍。     

燃油滤清器清洁度试验新方法初探

本文对目前国内外广泛采用的燃油滤清器清洁度试验方法进行了介绍,对采用在线粒子计数系统对燃油滤清器清洁度进行检测这一新方法进行了分析,对新方法的特点进行了概述。     

HXD2型电力机车自动换端控制研究与实现

介绍了HXD2型电力机车自动换端控制技术,对相关控制原理进行了系统阐述.首先对自动换端功能进行了概述,然后对自动换端升弓原理进行了逻辑分析,最后对机车外重联模式下的自动换端控制进行了详细说明.     

国有煤炭企业环境保护的新思路

首先对国有煤炭企业环境保护工作的意义进行了说明,并对煤炭工业发展状况进行了分析,之后着重对国有煤炭企业环境保护策略进行了深入研究,从而帮助加快环境保护工作的进程。     

太阳能电热联用系统研究进展

首先对太阳能电热联用系统的基本组成形式进行了简要介绍,并对不同的电热联用集热器、热能利用 方式进行了对比分析,接着对电热联用的研究方法和发展现状进行了详细说明,并列举了一些电热联用产品和 示范工程,最后指出了电热联用发展中应解决的问题,并对其发展前景进行了展望。     

VLES Modelling with the Renormalization Group

In a Very-Large-Eddy Simulation (VLES), the filterwidth-wavenumber can be outside the inertial range, and simple subgrid models have to be replaced by more complicated ('RANS-like') models which can describe the transport of the biggest eddies. One could approach this by using a RANS model in these regions, and modify the lengthscale in the model for the LES-regions[1-3]. The problem with these approaches is that these models are specifically calibrated for RANS computations, and therefore not suitable to describe inertial range quantities. We investigated the construction of subgrid viscosity and transport equations without any calibrated constants, but these are calculated directly form the Navier-Stokes equation by means of a Renormalization Group (RG) procedure. This leads to filterwidth dependent transport equations and effective viscosity with the right limiting behaviour (DNS and RANS limits).     

Variable-speed generation with the series-resonant converter

Results of study and measurements are presented for a variable-speed generation (VSG) system that uses a series-resonant converter to excite the rotor windings of a doubly-fed generator. The capabilities of this system include maximum-efficiency operation and limited converter rating for a speed range from stand-still (zero RPM) to well beyond synchronous speed, as well as flexibility for line-voltage control, reactive power generation, and synchronization at zero RPM. Measurements of the harmonic distortion are provided showing the superiority of this converter as compared with a VSG system using a conventional cycloconverter or a DC-link converter. A convenient tool for analyzing the operating modes of the system is discussed that can be developed under varying resource conditions     

用秸秆块取代煤碳做燃料

农田秸秆经粉碎加工,掺混7%左右的(Na、Ca)0.33(Al、Mg)2(SiO)10·(OH)2·nH2O拌匀,进入成形机———9KWH-20型机中成形,加工出的秸秆块:压缩比1:20、质量0.8～1kg/dm3、截面32mm×34mm的方体,可取代煤碳做燃料,其发热量达20934～30982kJ/kg。     

Lattice Boltzmann Method Combined with the Smoothed Profile Method for the Simulation of Particulate Flows with Heat Transfer

In this work, a hybrid method based on the lattice Boltzmann method (LBM) combined with smoothed profile method (SPM) is proposed for simulating the fluid flow and heat transfer in particulate systems. LBM is used to evaluate the flow field, while the temperature distribution is computed by a finite difference method. The no-slip and constant temperature boundary conditions on particle surfaces are treated with SPM. The following benchmarking studies are considered to validate the accuracy and robustness of the proposed method: natural convection in a square cavity with a heated circular cylinder, natural convection in a concentric annulus, and the sedimentation of single and two circular particles in a long narrow container. In all the studies, the results obtained from the present technique based on hybrid method show good agreement with the previously published results and those given by LBM combined with SPM based on the double-population model. After evaluating the central processing unit time taken by the two methods, it was found that the proposed method is about 50% more computationally efficient than the method based on double-population model in all the simulation cases considered in this work.     

电阻炉和燃料炉的比较分析

根据电阻炉和燃料炉(以火焰炉为例)的特点,从其热量产生装置、控制方式、投资成本、运行成本及环境保护等方面进行比较分析,并给出比较分析的结论.     

用节约理念指导政府机构节能工作——访清华大学教授,中国工程院院士江亿

政府机构节能是构建和谐社会,缓解资源和环境压力,实现国民经济可持续发展的必然选择,也是引导和推进全社会节约能源,建设节约型社会的有效途径。在国家发展和改革委员会发布的《节能中长期专项规划》中,政府机构节能被列为十项重大节能工作之一。无论是国家机关,还是各省、市政府机关对这项工作都非常重视,出台了各自的政府机构节能计划。如何使这项工作能够顺利地开展,我们采访了建筑节能的资深专家,清华大学教授、中国工程院院士江亿。     

Obtaining aluminum by the electrolysis with the solar radiation using

The aluminum production is one of the most energy-intensive processes of modern industry. The paper describes an attempt to obtain aluminum by electrolysis according to the Hall-Herout’s process without utilization of the industrial electric power but due to the cheap renewable environmentally friendly solar energy using. In this version, the electrolysis cell heating is performed by a concentrator of solar radiation while the electrolysis process is carried out with the direct electric current from a solar battery. It is shown that the Hall-Heroult’s process can be carried out by the solar energy exclusively. The proposed approach is a some contribution to development of alternative energy industry, in particular in its using in the classical metallurgy processes.     

浅谈我国太阳热水器与建筑的结合

这个问题是近年来的热门话题，事实上，也是太阳能界与建筑业界２０多年来共同的热切希望，也是广大人民群众呼声日益高涨的迫切需要。常年能够利用热水作为生活用水，可以说是生活质量获得显著改善和提高的一项重要标志。但是在过去的１／４个世纪中，由于思想观念、设计水平和生产技术等诸多原因，太阳能界和建筑业界之间存在着相当明显的差异，主要表现在以下几个方面。１思想观念：太阳能界从事热利用的人员对于建筑业界的常规要求不大了解，总局限于认为只要尽量改进热水器的类型和材质选取、生产技术、工艺水平并提高实际有效的得热量…     

一种带过热器的SZS型锅炉结构设计

简述了SZS型燃气水管锅炉的结构特点,针对其过热器的结构布置进行了分析比较,并介绍了一种新型过热器布置方案及特点.     

Exceeding the Betz limit with tidal turbines

The Betz limit sets a theoretical upper limit for the power production by turbines expressed as a maximum power coefficient of 16/27. While power production by wind turbines falls short of the Betz limit, tidal turbines in a channel can theoretically have a power coefficient several times larger than 16/27. However, power extraction by turbines in large tidal farms also reduces the flow along the channel, limiting their maximum output. Despite this flow reduction, turbines in tidal farms can produce enough power to meet a stricter definition of what it means to exceed the Betz limit, one where the maximum power output of a turbine at the reduced flow exceeds the maximum output from a single Betz turbine operating in the unreduced flow. While having a power coefficient >16/27 is easily achieved by turbines in a channel, generating enough power to meet this stricter definition of exceedance is much more difficult. Whether turbines meet this stricter definition depends on their number, how they are arranged and tuned, and the dynamical balance of the channel. Arranging a tidal turbine farm so that the turbines within it exceed the stricter Betz limit would give tidal turbine farms an economic advantage over similarly sized wind farms. However, exceeding the stricter limit comes at a cost of both higher structural loads on the tidal turbines and the need to produce power from weaker flows. Farms in a channel loosely based on the Pentland Firth are used to discuss exceedance and structural loads.