微型计算机在内燃机中的应用

在先进国家,微型计算机在内燃机设计与制造中的应用已相当普及。本文介绍微机在内燃机行业中三个方面的应用情况:在过程控制中的应用;在计算和优化方面的应用;CAD方面的应用。     

高温燃烧技术在周期式炉上应用的新途径

介绍了高温燃烧技术在周期式炉上应用的背景和意义,并对传统燃烧技术进行分析和总结,提出了高温燃烧技术在周期式炉上应用的新途径,同时详细介绍了高温燃烧技术在周期式炉上应用的新型技术特点及应用的前景。     

硅酸铝纤维的性能误区分析和在工业炉中的应用技术

具有优良隔热,保温性能的硅酸铝纤维材料,已在工业炉上逐步推广应用,但我国对硅酸铝纤维材料的性能研究和应用技术研究还未互位,在应用中对纤维性能产生的误区和应用技术的不当,阻碍了推广应用顺利进行,根据多年从事工业炉技术工作的经验和体会,对纤维性能容易产生的几点误区和应用技术中的几点体会进行分析。     

3S技术在我国西部国土空间开发中的应用初探

就3S集成技术在我国西部国土空间开发中一些领域的基本应用进行探讨,包括3S技术在城市规划中的应用,3S技术在土地资源调查中的应用,3S技术在自然环境保护和生态文明建设中的应用。     

节能工程的价值分析初探

价值工程分析是一门技术与经济相结合的新兴学科,它主要研究以最低的成本实现最合适的功能,以提高产品的价值.目前,价值工程分析在产品开发中应用较广,在工程项目和节能工程项目中应用很少,但由于工程项目和节能工程项目一次性投资大,应用价值工程分析的意义很大.本文以在某节能工程中应用价值工程分析为例,初步探讨了价值工程分析在节能工程中的应用.     

数字插装式水轮机调速器应用研究

数字插装式调速器作为水轮机调速器控制的一个新方向,已在工程实践中得到了较好的应用,但相关理论和工程应用研究偏少。因此,采用理论和工程应用相结合的方式,论述了数字插装式水轮机调速器在工程应用中重点关注的闭环功率调节、孤网运行、贯流式机组甩负荷低频灭磁和过速等方面的控制策略和规律,总结了数字插装式调速器的工程应用情况,对于解决调速器工程应用中的相关问题有较好借鉴意义。     

分布式状态估计技术在智能变电站的应用

分析了智能电网研究和建设中的关键问题和需求,结合分布式状态估计技术在苏州智能变电站的实际应用情况,详细阐述实现方案和关键技术,从调度和变电站两端总结分布式状态估计技术在智能电网中的应用价值。结果表明,分布式状态估计技术在智能变电站的应用,提升了变电站基础数据的可靠性、准确性,加快了二次信息缺陷的处理,提高了变电站智能化水平,对变电站的高级智能应用有积极意义。     

新材料与新技术在电力接地系统中的应用

以铜镀钢接地棒、放热焊接技术等为主介绍了新接地材料和工艺在接地系统中的应用,并以英国ER I-CO公司的一个案例简单介绍了在实际接地系统中的应用以及工艺流程;同时,通过实际应用案例中技术和经济上的比较,论证了新型接地材料以及放热焊接等工艺在接地系统应用中的经济性、有效性和可靠性。     

Flowmaster2在空调水系统中的应用

通过对流体分析软件Flowmaster2功能和特点的分析研究,并结合了一工程算例,论述了该软件在空调水系统管网运行工况诊断分析和技术改造中的建模方法和应用,表明该软件在空调水系统中的应用具有重要意义和较好的应用前景.     

苹果iOS技术在发电企业中的应用和研究

苹果iOS系统因其封闭性的沙盘(Sand Box)结构,在开发、发布、部署、应用过程中,有着天然的安全性和稳定性,iOS与桌面应用之间又存在很大差异,在开发工具的选择、显示图形的优化、安全机制的应用上都需要重新设计和开发,才能获得优异的操控性和体验性.随着云计算的推广和云端应用的普及,基于iOS技术的产品在企业移动办公...     

The concept of the gas turbine‐based hybrid vehicle: system,design and configuration issues

The object of this study is a theoretical and experimental analysis of a new hybrid propulsion system for a passenger sedan in which the thermal engine is a small gas turbine set. Some preliminary results on the possibility of replacing the conventional ICE of a hybrid ‘series’ configuration by a turbogas were presented and discussed in previous papers by the same authors: several possible designs were examined under both a thermodynamic and an operative point of view. This paper presents a summary of the project and constitutes an attempt to put things in a proper engineering perspective: the technical feasibility of the project is assessed via a calculation of the required mission loads, a preliminary design of the most important elements of the propulsive system, the choice of the mission control strategy and the implementation of a numerical system simulator. The experiments that provided a verification for the assumed component efficiencies were carried out, in cooperation with the Research Centre of ENEA‐Casaccia, on an ELLIOTT TA‐45 group. Our results, though only preliminary, allow for a direct comparison between a GT‐hybrid vehicle and a modern diesel car, and indicate that the GT‐hybrid may be actually a competitor for the FC‐powered vehicle concept. Our ‘optimal’ configuration is a combination of a 100 kg battery pack and two turbogas set of 5 and 16 kW, respectively. Copyright © 2005 John Wiley & Sons, Ltd.     

Design and analysis of a new wave energy converter based on a point absorber and a hydraulic system harvesting energy from waves near the shore in calm seas

The aim of this paper is to illustrate the design of a new wave energy converter, composed of a point absorber and a hydraulic system (power take off) and sized for recovering energy in calm seas from waves near the shore. The point absorber is consisting of a rectangular shaped buoy integrating a piston pump. The set buoy‐pump oscillates under the waves action and moves natural water in a closed circuit hydraulic system (power take off) composed of a piping connecting the piston pump itself, a pressurized reservoir, a hydraulic turbine and a discharge tank. The methodology adopted for designing the main constituents involves a 1D mathematical model, settled for understanding the motion of the buoy under the hypothesis of regular waves and fully developed sea, and a sizing procedure applied for the design of all the components of the hydraulic system. The project related to the Calabrian site of Cetraro (Mediterranean Sea—south Italy) led to designing a system with a 4 m large buoy, associated with a small 13 cm diameter micro Pelton turbine, so that more than 22 000 kWh could be recovered in a year.     

基于非线性模型的燃气轮机热参数故障诊断及仿真

燃气轮机气动部件故障的发生会导致机组性能参数的变化,且为复杂的非线性变化。在建立燃气轮机标准模型的基础上,研究了系统的故障性能参数的变化及建立了系统的故障模型。首先通过标准模型仿真数据和机组故障运行数据的对比分析,初步定位机组的故障部件,进而提出了修正部件特征性能参数的方法,通过模块实现机组故障的非线性表达,在EASY5仿真平台上建立了燃气轮机系统的故障模型。利用该模型可通过机组非线性模型定量表达部件性能参数的变化,准确地实现机组的故障定位和仿真。以某联合循环机组的燃气轮机为例对此方法进行了验证,实现了机组故障工况的重现,为机组性能特性研究、故障诊断和故障分析奠定了一定的基础。     

叶型探针对跨声压气机性能影响的数值模拟

为揭示叶型探针对跨声压气机气动性能影响的物理机理,采用三维数值模拟方法,通过构建带多点实体探头的1.5级压气机计算模型,详细研究了设计转速下压气机在安装探头前后性能特性与内部流场的变化规律。结果表明:级间局部静叶安装探头后,压气机下堵点流量减小0.1%,最高效率降低0.4%,失速点流量增大0.15%;由压气机工作点改变所引起的静叶攻角变化是影响叶片表面两侧探头绕流尺度的重要因素,并且探头绕流影响程度与静叶气动负荷存在较高的关联度;探头大尺度绕流加剧下游转子叶背根部附面层径向迁移与分离是导致该型压气机气动失稳提前的主要原因。     

Analysis and synthesis of the variability of irradiance and PV power time series with the wavelet transform

The irradiance fluctuations and the subsequent variability of the power output of a PV system are analysed with some mathematical tools based on the wavelet transform. It can be shown that the irradiance and power time series are nonstationary process whose behaviour resembles that of a long memory process. Besides, the long memory spectral exponent α is a useful indicator of the fluctuation level of a irradiance time series. On the other side, a time series of global irradiance on the horizontal plane can be simulated by means of the wavestrapping technique on the clearness index and the fluctuation behaviour of this simulated time series correctly resembles the original series. Moreover, a time series of global irradiance on the inclined plane can be simulated with the wavestrapping procedure applied over a signal previously detrended by a partial reconstruction with a wavelet multiresolution analysis, and, once again, the fluctuation behaviour of this simulated time series is correct. This procedure is a suitable tool for the simulation of irradiance incident over a group of distant PV plants. Finally, a wavelet variance analysis and the long memory spectral exponent show that a PV plant behaves as a low-pass filter.     

The effect of ambient pressure on the evaporation of a single droplet and a spray

The effect of ambient pressure on the evaporation of a droplet and a spray of n-heptane was investigated using a model for evaporation at high pressure. This model considered phase equilibrium using the fugacities of the liquid and gas phases for the behavior of a gas being real, and its importance in the calculation of the evaporation of a droplet or spray at high pressures was demonstrated. For the evaporation of a single droplet, the fact that the droplet's lifetime increased with pressure at a low ambient temperature, but decreased at high temperatures, was explained with pressure and the droplet's temperature determining phase equilibrium. In this study, it was also found that the evaporation of a spray can be explained in terms of multiplex dependencies of the atomization and evaporation of a single droplet. The evaporation of a spray was enhanced by increasing the ambient pressure and this effect was more dominant at higher ambient temperatures.     

Transcritical CO2 refrigerator and sub‐critical R134a refrigerator: A comparison of the experimental results

This paper describes experiments comparing a commercial available R134a refrigeration plant subjected to a cold store and a prototype R744 (carbon dioxide) system working as a classical ‘split‐systems’ to cool air in residential applications in a transcritical cycle. Both plants are able to develope a refrigeration power equal to 3000 W. The R744 system utilizes aluminium heat exchangers, a semi‐hermetic compressor, a back‐pressure valve and a thermostatic expansion valve. The R134a refrigeration plant operates using a semi‐hermetic reciprocating compressor, an air condenser followed by a liquid receiver, a manifold with two expansion valves, a thermostatic one and a manual one mounted in parallel, and an air cooling evaporator inside the cold store. System performances are compared for two evaporation temperatures varying the temperature of the external air running over the gas‐cooler and over the condenser. The refrigeration load in the cold store is simulated by means of some electrical resistances, whereas the air evaporator of the R744 plant is placed in a very large ambient. The results of the comparison are discussed in terms of temperature of the refrigerants at the compressor discharge line, of refrigerants mass flow rate and of coefficient of performance (COP). The performances measured in terms of COPs show a decrease with respect to the R134a plant working at the same external and internal conditions. Further improvements regarding the components of the cycle are necessary to use in a large‐scale ‘split‐systems’ working with the carbon dioxide. Copyright © 2009 John Wiley & Sons, Ltd.     

某船用汽轮机短座阀流量与提升力特性数值模拟计算

由于汽轮机内部空间的限制及船用汽轮机多工况的要求,部分船用汽轮机采用了短座阀。因扩压段长度的大幅减小．阀门的气动性能及强度振动特性产生较大变化,对汽轮机总体性能有较大的影响。本文对某短座阀在试验研究的基础上进行了数值计算分析：通过气动试验,得到某船用汽轮机短座阀的流量系数与提升力系数曲线簇;基于可压缩,N-S方程,利用S-A湍流模型及有限积分法,采用四面体非结构性网格．对此阀门进行了数值模拟计算。通过对该阀门的数值计算得到在不同相对开度及不同压比下的计算结果与试验结果吻合良好;得到对各种短座阀广泛适用的计算方法．为船用调节阀、旁通阀的设计和性能分析提供了重要依据。     

燃用超低热值燃料的燃气轮机及其热力分析

提出一种基于催化燃烧方式利用超低热值燃料的方法,介绍超低热值燃料催化燃烧燃气轮机的结构组成和原理并分析技术关键点,实验验证超低热值燃料稳定催化燃烧的可行性;并以百千瓦级功率为例进行燃气轮机热力循环计算和分析,验证燃用超低热值燃料燃气轮机装置可以实现,且可以发出有效功,为燃用超低热值燃料燃气轮机系统的研制开发提供切实可行的方法和依据。