CO_2掺混比对甲烷HCCI燃烧特性的影响

基于微型均质充量压燃(HCCI)自由活塞动力装置内自由活塞单次冲击过程,通过试验与数值模拟的方法,对比分析了甲烷掺混不同比例的CO_2时,混合气着火时刻、微燃烧室内的温度、压力以及装置做功能力的变化.结果表明:在初始当量比为0.5时,甲烷中CO_2的掺混使混合气着火时刻延迟、燃烧速率变慢,微燃烧室内的压力与温度峰值后移且降低,混合气体的爆燃现象得到改善.随着甲烷中CO_2掺混比的增加,混合气的着火与燃烧不断恶化,装置的做功能力不断减弱,同时装置所需的启动能量不断增加;当CO_2掺混比达到40%时,自由活塞的速度增量减少2.67 m/s,平均有效指示压力减少0.584 MPa,同时装置所需的启动能量增加至0.182 4 J.当CO_2掺混比达到58%时,混合气无法被压燃,微动力装置不对外做功.在保证装置做功能力的基础上,甲烷掺混一定比例的CO_2,微燃烧室内平均温度能够降低30～100 K,微动力装置可以降低对微燃烧室材料的依赖,实现低温燃烧.     

船舶动力装置及系统的技术特点与应用研究

介绍了船舶动力装置组成及分类,船舶动力装置一般按主机类型可分为:柴油机动力装置、汽轮机动力装置、燃气轮机动力装置、核动力装置等几种基本型式,据此分别介绍了其技术特点及应用。作为船舶前行的重要能量来源,动力装置依然起着举足轻重的作用,基于船舶动力装置而进行的技术研究及工程试验依然有着重大而深远的意义。     

用于海船的大功率动力装置的展望

正据《Судостроение》2015年9~10月刊报道,以С.О.Макаров海军上将命名的俄罗斯国立海洋和内河船队大学的专家分析了用于海船大功率动力装置的发展远景。一些类型的海船都装有大功率的动力装置。大量的集装箱船、海洋破冰船、液化天然气运输船和油船均属于这种船舶。例如,现代集装箱船动力装置的功率达到90 MW,破冰船的功率达到30~55 MW,核动力破冰船的功率达到70 MW,大型液化气运输船的功率达到21~40 MW。对在这些船舶上使用柴油机装置、汽轮机装置和核动力装置进行了性能分析和比较。指出,现有的用于     

动力装置与液力传动装置共同工作点匹配计算及液力传动内燃机车牵引计算程序开发探讨

介绍了动力装置与液力传动装置共同工作点匹配计算及液力传动内燃机车牵引计算程序开发的基本思路和程序段的主要组成.     

液压力偶矩动力装置

液压力偶矩动力装置将液压力对称地作用在一个装置上，产生的力偶矩使装置旋转．其特点是；与传统的动力装置相比．它增加了力偶臂．并且动力装置越大．力偶臂越长．越省力．与汽轮机相比最大的不同就是将高温高压的气体喷射改为液压力．同时液压力有将力放大的功能．这种...     

基于模糊综合评判的水面舰艇主动力装置选型论证

介绍了模糊综合评判法的基本原理,建立了主动力装置选型论证的数学模型,以某型舰为例,通过模糊综合评判,得出了主动力装置选型论证的评判指标.评判结果说明,根据模糊综合评判模型,可把模糊性很强的主动力装置选型论证量化,为动力装置方案设计提供依据.     

新型二冲程微型摆式内燃机中心摆的柔性动力学分析

在新型二冲程微型摆式内燃机的设计和完善过程中,动力学分析占有重要地位.中心摆是该动力装置中唯一的运动件,起能量转化和传递扭矩的作用.在工作过程中,受交变的高温燃气压力作用,中心摆将会产生较大的弹性变形,并将影响动力装置的工作可靠性和寿命.因此针对中心摆弹性变形对其运动精度和整个装置工作可靠性的影响,有必要对中心摆进行柔性体动力学分析.     

3820kW内燃机车的研制

介绍了3820kW客、货运内燃机车的设计思想、总体布置、主要技术特性、动力装置、结构特点等.3820kW机车采用了12V280ZJ型柴油机,该柴油机安装了电子喷射装置.     

舰用蒸汽动力装置再热循环及性能评估

在船舶蒸汽动力装置中应用再热循环的研究的基础上,对舰用蒸汽动力装置采用再热循环及其评价方法进行了探讨,通过对不同方案热平衡计算的比较,证明再热循环的应用改善了装置的经济性和舰艇的续航力。     

复杂循环燃气轮机装置在舰船中的应用

叙述了ＷＲ－２１中间冷却回热式燃气同和基于燃气轮机的燃蒸联合循环动力装置的研制和应用情况。简要介绍了前苏联,美国和英国在这方面所做的工作。指出,作为两种高效节能的动力装置,ＷＲ－２１和ＣＯ－ＧＡＳ装置具有一系列的优点,它们是应用于军舰和商船的较为理想的动力装置。     

Intelligent power management in a vehicular system with multiple power sources

This paper presents an optimal online power management strategy applied to a vehicular power system that contains multiple power sources and deals with largely fluctuated load requests. The optimal online power management strategy is developed using machine learning and fuzzy logic. A machine learning algorithm has been developed to learn the knowledge about minimizing power loss in a Multiple Power Sources and Loads (M_PS&LD) system. The algorithm exploits the fact that different power sources used to deliver a load request have different power losses under different vehicle states. The machine learning algorithm is developed to train an intelligent power controller, an online fuzzy power controller, FPC_MPS, that has the capability of finding combinations of power sources that minimize power losses while satisfying a given set of system and component constraints during a drive cycle. The FPC_MPS was implemented in two simulated systems, a power system of four power sources, and a vehicle system of three power sources. Experimental results show that the proposed machine learning approach combined with fuzzy control is a promising technology for intelligent vehicle power management in a M_PS&LD power system.     

Power management system for a 2.5 W remote sensor powered by a sediment microbial fuel cell

One of the challenges in using wireless sensors that require high power to monitor the environment is finding a renewable power source that can produce enough power. Sediment microbial fuel cells (SMFCs) are considered an alternative renewable power source for remote monitoring, but current research on SMFCs has demonstrated that they can only produce several to tens of mW of continuous power. This limits the use of SMFCs as an alternative renewable remote power source to mW-level power. Such low power is only enough to operate a low-power sensors. However, there are many remote sensors that require higher power, on the order of watts. Current technology using a SMFC to power a remote sensor requiring watts-level intermittent power is limited because of limitations of power management technology. Our goal was to develop a power management system (PMS) that enables a SMFC to operate a remote sensor consuming 2.5 W of power. We designed a custom PMS to store microbial energy in capacitors and use the stored energy in short bursts. Our results demonstrate that SMFCs can be a viable alternative renewable power source for remote sensors requiring high power.     

Analysis of the damping contribution of power system stabilizers driving wind power plants

Recently, the concept of wind power plant has been introduced as a result of the increment of wind power penetration in power systems. A wind power plant can be defined as a wind farm, which is expected to behave similar to a conventional power plant in terms of power generation, control and ancillary services. Transmission system operators are requiring wind power generation to help to power system with some ancillary services such as fault ride through or power system stabilizer capability. Therefore, it is important to study the power system stabilizer capability of wind power plants. In this paper, a comparison of various power system stabilizer schemes is presented. The effect of the distance from the tie line to the wind farm on the controller response and the influence of wind power plants proximity to synchronous generators are also evaluated. These studies show that wind power plants have promising power system stabilizer capability even using local input signals. However, the location of the wind power plant on the power system is a critical factor. Copyright © 2012 John Wiley & Sons, Ltd.     

国外风电并网特点及对我国的启示

国外风电发达国家已有风电场大多装机规模较小,主要是分散接入配电网就地消纳。风电大规模并网依赖于坚强电网的支撑,同时也需要其他电源的支持和协调发展。如丹麦东部电网通过交流输电线路与挪威、瑞典、芬兰等国组成北欧电网,西部电网则通过德国电网与欧洲大陆互联电网相联,北欧电网中的大量水电为丹麦风电提供了足够的调峰支持;而美国大量具有灵活调节能力的燃气电站为风电快速发展提供了保障。国外针对未来风电大规模开发,规划通过高电压等级线路接入电网,远距离输送至负荷中心地区,并且扩展输电网以扩大风电消纳范围和规模。风电发达国家都制定了严格的并网导则且强制执行,风电收购政策根据风电发展的不同阶段不断调整,同时广泛开展了风电功率预测工作,并对风电进行有效调控。我国风电在持续快速发展中暴露出一些问题,如风电开发缺乏统一规划,配套电网建设难度较大;系统调峰能力不足;电网建设滞后于电源建设,尤其是跨大区电网的互联规模不足;风电技术和运行水平较低,相关政策有待完善等。建议我国应努力优化电源结构,增加电源装机中调峰电源和灵活调节电源的比重;建设坚强智能电网,解决风电大规模接入和输送问题;完善相关法律和政策支持体系。     

The power regulation of a PWM type superconducting magnetic energystorage unit

This paper presents an analysis of the power regulation of a SMES unit under PWM switching control. The criteria for executing a power limit scheme to maintain power flows of the SMES unit within a controllable range are described. A general technique for design of power controllers based on the power limit scheme is developed. Two illustrative examples, being separate active and reactive power compensations of a model power system, are presented. The study indicates that active power priority control plays a dominant role in the power regulation of a SMES unit. Experimental results for two examples are also presented     

Agent-based power sharing scheme for active hybrid power sources

The active hybridization technique provides an effective approach to combining the best properties of a heterogeneous set of power sources to achieve higher energy density, power density and fuel efficiency. Active hybrid power sources can be used to power hybrid electric vehicles with selected combinations of internal combustion engines, fuel cells, batteries, and/or supercapacitors. They can be deployed in all-electric ships to build a distributed electric power system. They can also be used in a bulk power system to construct an autonomous distributed energy system. An important aspect in designing an active hybrid power source is to find a suitable control strategy that can manage the active power sharing and take advantage of the inherent scalability and robustness benefits of the hybrid system. This paper presents an agent-based power sharing scheme for active hybrid power sources. To demonstrate the effectiveness of the proposed agent-based power sharing scheme, simulation studies are performed for a hybrid power source that can be used in a solar car as the main propulsion power module. Simulation results clearly indicate that the agent-based control framework is effective to coordinate the various energy sources and manage the power/voltage profiles.     

基于遗传算法优化粗糙决策模型的光伏电站发电量的影响因素研究

通常光伏电站设计时要考虑2个主要目标,一个是使光伏电站的发电量最大,另一个是使光伏电站的度电成本最低.影响光伏电站发电量的因素众多,不同因素之间的相互影响及其交互影响极其复杂.在粗糙决策模型的基础上,引入遗传算法来寻找光伏电站发电量的主要影响因素.以光伏电站发电量作为决策属性,选取8个参数作为条件属性,建立了光伏电站发...     

计及集电线路和内部损耗的风电场模型分析比较

风电的接入会改变电网原有的潮流分布而对电网电压稳定性产生影响。潮流计算作为风电接入系统研究的基础,为得到其计算结果的准确性而建立风电场稳态模型具有重要的意义。以往的风电场系统潮流计算都是把整个风电场等效为一个风机处理,并没有详细讨论风电场内部的电网结构,潮流计算无法深入到风电场内部。在DigSILENT/PowerFactory中建立了改进的潮流计算模型,充分考虑了由双馈异步发电机组成的大型风电场的集电系统以及风电机组间电缆的功率损耗对稳态潮流计算的影响。     

AC/DC power conversion interface for self-excited induction generator

A new AC/DC power conversion interface for the self-excited induction generator (SEIG) is proposed here. The proposed AC/DC conversion interface includes an excitation systemand a diode rectifier connected in parallel.The variable frequency AC power generated by the SEIG is converted into DC power by the diode rectifier.The DC power of the diode rectifier can charge a battery set and supply DC loads or be further converted into fixed-frequency AC power by an inverter for AC loads.The DC voltage is expected to be regulated in the above applications.The excitation system supplies an exciting reactive current to maintain the amplitude of the SEIG output voltage to be a constant value. Moreover, it can also serve as an active power filter to suppress the harmonic current generated by the diode rectifier. The excitation system is composed of an AC power capacitor and a power converter connected in series. The AC power capacitor is adapted to provide a basic reactive power, and it can also reduce the voltage rating and the capacity of the power converter. The salient point of the proposed AC/DC power conversion interface is that the capacity of the power converter in the AC/DC power conversion interface can be minimised, and the power loss of the AC/DC power conversion interface can also be reduced. A prototype is developed and tested to verify the performance of the proposed AC/DC power conversion interface.     

我国风电大规模外送协同运行方式研究

由于风力发电具有随机性、间歇性和不可控性等特点,大规模接入后对电网运行将会产生较大影响,目前风电与电网的适应性和配套问题已成为限制风电发展和使用的瓶颈。基于风电出力特性,结合大规模风电外送时存在的问题,研究分析了风电外送协同运行方式,提出了风电大规模外送协同运行方式结构框架,并结合实例进行了应用分析。结果表明,在送端配置相应配套电源及调整风电并网容量等措施后,可有效解决风电外送电力瞬变、随机间隔等问题,并能促使风电外送电力过程相对平稳,降低风电弃风率、增加输送有效容量、提高输变电利用小时数。