船用主汽轮机组测速泵改进的试验研究

通过理论计算片式和浮动式两种密封结构测速泵的漏油量,比较两种结构的漏油量受密封间隙变化的影响程度,提出改进方案。对浮动式密封结构的测速泵进行试验并得出结论,为船用主机组超速保护装置的改造提供理论和试验依据。     

用计算机计算汽轮机效率的方法

本文为设计阶段精确估算汽轮机汽耗提供了可用资料、过程要求、透平特性和计算程序。     

汽轮机危急超速最高飞升转速的试验计算方法

危急超速最高飞升转速的验收,考核方法,在国外的行业标准中都有具体的规定,我国在现有的规程中尚未见有明确的要求,所以该项工作未能得到广泛地开展。为此,本文提出了工程中较为实用的计算,试验方法,列举了应用实例,并进行了讨论,为估算危急超速最高飞升转速提供了方法,为制定适用于我国的行业标准提供了依据。     

汽轮机性能试验高精度修正曲线计算方法研究

标准GB/T 8117.1-2008/IEC 60953-1:1990对汽轮机性能试验结果的修正提出了两种修正方法:用热平衡计算修正和用制造厂提供的修正曲线修正。综合分析近年研究成果,优选高精度等效热降模型,并对加热器端差、抽汽压损定量分析模型进行了完善,给出了编制修正曲线的计算公式,并就N600-24.2/566/566型600MW超临界机组及类似热力循环的机组给出了修正计算公式及修正计算结果。     

适用于多种型号汽轮机组热耗率试验计算程序的开发

针对汽轮机机组型号多、热力系统复杂给机组热力性能试验带来的困难,根据ASME规程推导出汽轮机组试验使用的计算关系式,并编辑了通用计算程序。经过同汽轮机设计热力特性参数比较,展示了良好的计算精度。     

某1240MW机组汽轮机性能试验汽门阻塞修正计算方法

针对1 240 MW容量机组汽轮机性能试验中出现的汽门阻塞问题,提出了一种采用汽门压损增量修正计算及主蒸汽流量偏差修正计算的方式来代替停机检修重做试验,这能够节省大量时间和经济成本。采用相关模拟计算进行推算分析的方法获得修正曲线,修正计算后,汽轮机热耗率为7 252.59 kJ/(kW·h),与修正计算前相比降低了45.77 kJ/(kW·h),出力为1 308 178.32 kW,增加了28 792.56 kW,达到考核要求。研究成果可为汽轮机性能考核试验结果的修正计算提供参考。     

活塞裙部润滑油膜厚度的计算及试验研究

对活塞裙部润滑油膜厚度进行了仿真计算和试验研究。建立了活塞裙部混合润滑模型,进行了润滑油膜厚度的计算,并介绍了试验方法和试验过程。通过理论计算和试验结果的对比分析。证明了模型的适用性,发现了裙部润滑油膜的一些特点。     

汽轮机叶片结垢厚度的理论计算

采用热力计算法对汽轮机叶片结垢厚度与监视段压力的关系进行了研究，并结合实例进行了汽轮机通流部分结垢故障的诊断。     

再热汽轮机性能试验系统修正方法研究

依据《ASME PTC6—1996汽轮机性能试验规程》,深入研究了再热汽轮机性能试验系统修正计算的两种方法,给出了两种计算方法的实现过程,分析了两种计算方法的差别。通过一个算例考察了两种计算方法对计算结果的影响,在此基础上推荐了一种修正计算方法。     

风力提水与风力发电提水技术

风力提水作为风能利用的主要方式之一，在解决农牧业灌排、边远地区的人畜饮水以及沿海养鱼、制盐等方面都不失为一种简单、可靠、有效的实用技术。开发和应用风力提水技术对于节省常规能源、解决广大农牧区的动力短缺、改善我国的生态环境都有重要的现实意义。通过对风力提水和风力发电提水技术的特点与应用现状的分析，预测了风力提水的市场需求，并对今后我国风力提水技术产业的发展提出了建议。     

Analysis of off-grid hybrid wind turbine/solar PV water pumping systems

While many remote water pumping systems exist (e.g. mechanical windmills, solar photovoltaic, wind-electric, diesel powered), few combine both the wind and solar energy resources to possibly improve the reliability and the performance of the system. In this paper, off-grid wind turbine (WT) and solar photovoltaic (PV) array water pumping systems were analyzed individually and combined as a hybrid system. The objectives were to determine: (1) advantages or disadvantages of using a hybrid system over using a WT or a solar PV array alone; (2) if the WT or solar PV array interfered with the output of the other; and (3) which hybrid system was the most efficient for the location. The WT used in the analysis was rated at 900 W alternating current (AC). There were three different solar PV arrays analyzed, and they were rated at 320, 480, and 640 W direct current (DC). A rectifier converted the 3-phase variable voltage AC output from the WT to DC before combining it with the solar PV array DC output. The combined renewable energies powered a single helical pump. The independent variable used in the hybrid WT/PV array analysis was in units of W/m². The peak pump efficiency of the hybrid systems at Bushland, TX occurred for the 900 W WT combined with the 640 W PV array. The peak pump efficiencies at a 75 m pumping depth of the hybrid systems were: 47% (WT/320 W PV array), 51% (WT/480 W PV array), and 55% (WT/640 W PV array). Interference occurred between the WT and the different PV arrays (likely due to voltage mismatch between WT and PV array), but the least interference occurred for the WT/320 W PV array. This hybrid system pumped 28% more water during the greatest water demand month than the WT and PV systems would have pumped individually. An additional controller with a buck/boost converter is discussed at end of paper for improvement of the hybrid WT/PV array water pumping system.     

Theory of wind-electric water pumping

A proper understanding of the electrical and mechanical behavior of the system and its components is essential for the successful operation of a wind-electric pumping system. In the present article we present a formal theory of such a system, developing a framework for the determination of the steady-state operating point, as well as the study of its transient behavior, particularly at start-up. It is shown that the sufficient accumulation of kinetic energy in the wind turbine before connecting it to its load is critical for a successful start-up, even when the system has been designed to function at optimal steady-state conditions. A detailed discussion of the start-up process in terms of stored kinetic energy in the braking power provided by both the pump and the electrical system losses is given. The results of this analysis are believed to be useful both for the steady-state design of wind-electric pumping systems, as well as the optimization of control schemes and energy capture.     

Direct coupling of photovoltaic power source to water pumping system

Direct coupling between a photovoltaic (PV) solar panel and a water pumping system driven by a permanent magnet dc motor is analyzed theoretically. The analysis is based on the simulated performance of a pumping system which consists of a Jacuzzi general purpose pump and a permanent magnet dc motor with selected characteristics. Hourly insolation data obtained from typical meteorological year SOLMET data are used in the simulation. A comparison between systems with and without a PV peak-power point tracker shows that a PV pumping system with peak-power tracker is more desirable because of its higher efficiency.     

A study of action point correction factor for L‐type flanges of wind turbine towers

A correction factor accounting for the effect of elastic deformation of flange is proposed for the ultimate strength analysis of L‐type flanges used for wind turbine towers. It is derived based on systematic analyses and explicitly expressed as a function of flange dimensions. The proposed factor is simple and suitable for the engineering applications, comparing with the conventional formula for the ultimate strength analysis of flange connections.     

Performance of PV water pumping systems

The aim of this work is to analyse the performance of different photovoltaic water pumping systems. The Typical Meteorological Year (TMY) data from four distinct Algerian climatic sites are used: Algiers, Bechar, Oran and Tamanrasset. The study has been carried out for three different profiles, three tank capacities, two PV modules types, two PV array configurations and several pumping heads, applied to two centrifugal pumps. To predict the photovoltaic pumping system performance, it is necessary to use a simulation program, because it takes into account the different parameters of the system and its geographic location. The determination of the best couple generator configuration-pump for a given installation site and a daily load profile is easily obtained by the simulation program.     

Performance testing and comparison of turbine ventilators

A turbine ventilator is a device having a combined function of wind turbine and extract fan. Turbine ventilators are attractive replacements for electrical ventilation fans in terms of using wind energy. They are commonly used in attic, loft and rooftop spaces to facilitate ventilation in buildings at both domestic and industrial level. This study presents measurement of flow rates of four commercial turbine ventilators on a specifically designed experimental system. The ventilation flow rates and rotational speeds are taken at different wind speeds and compared with a simple open column and two standard vent hats. Use of a DC motor to power the ventilators in the absence of wind is described and power consumption against flow rate is given.     

风力提水泵站的设计

近年来出现和发展的风力提水泵站,在工程设计中还存在着很多的缺陷.一些风力提水工程运行效率低,有些不能很好地发挥作用.根据多年风力提水泵站的建设和设计经验,从工程的选址、机型的选择、参数的确定和蓄水及输水问题等方面,介绍了风力提水泵站的设计方法和步骤.     

Validation of a hybrid modeling approach to floating wind turbine basin testing

Hybrid modeling combining physical tests and numerical simulations in real time opens new opportunities in floating wind turbine research. Wave basin testing is an important validation step for floating support structure design, but current methods are limited by scaling problems in the aerodynamic loadings. Applying wind turbine loads with an actuation system controlled by a simulation that responds to the basin test offers a way to avoid scaling problems and reduce cost barriers for floating wind turbine design validation in realistic coupled conditions. In this work, a cable‐based hybrid coupling approach is developed and implemented for 1:50‐scale wave basin tests with the DeepCwind semisubmersible floating wind turbine. Tests are run with thrust loads provided by a numerical wind turbine model. Matching tests are run with physical wind loads using an above‐basin wind maker. When the numerical submodel is set to match the aerodynamic performance of the physical scaled wind turbine, the results show good agreement with purely physical wind‐wave tests, validating the hybrid model approach. Further hybrid model tests with simulated true‐to‐scale dynamic thrust loads and wind turbulence show noticeable differences and demonstrate the value of a hybrid model approach for improving the true‐to‐scale realism of floating wind turbine basin tests.