采用锅炉火用平衡数学模型,对大型循环流化床(CFB)锅炉的各项火用损失和火用效率进行了分析,并以某亚临界300MW机组CFB锅炉为对象,进行了实例计算,并对不同参数等级CFB锅炉进行了火用效率分析.结果表明:CFB锅炉的燃烧和传热损失之和占燃料化学火用的45%以上,是锅炉的主要损失;提高机组容量和蒸汽参数,可以提高炉水平吸热温度,从而有效降低锅炉传热火用损失;锅炉排烟火用损失率在1%左右,比排烟热损失率小很多;CFB锅炉的可燃气体未完全燃烧火用损失率、散热火用损失率均可忽略不计;固体未完全燃烧火用损失由于损失的是未燃尽碳的化学火用,其热能品位较高,因此应重点采取措施减小该项损失;CFB锅炉炉渣占煤中灰分比例较高,降低炉渣物理火用损失对于提高锅炉效率具有重要意义。

关键词：CFB锅炉；火用效率；火用损失；节能；锅炉效率；热能品位

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在自行搭建的冷态流化床实验台的基础上,分别利用Kolmogorov熵、关联维以及Lyapunov指数对气固流化床床内气泡运动的复杂性进行了混沌特性分析,从定性、定量两个方面分析了鼓泡床、节涌床、湍动床和快速流化床的流动特性.结果表明:在流化床风帽入口P0处所测得的压力信号能够传达与侧墙压力测点P1-P10相同的信息;流化床气固两相流动具有混沌特性;鼓泡床压力脉动信号的Kolmogorov熵为0.11~0.15,其混沌程度最大,而节涌床、湍动床和快速流化床的Kolmogorov熵分别在0.08~0.09,0.09~0.11和0.11~0.13之间,混沌特性较弱;利用Kolmogorov熵、关联维以及Lyapunov指数的理论方法能够很好地辨别流化床的流化状态,有助于理解流化床的流动机理。

关键词：流化床；气固两相流；压力脉动；混沌分析；Kolmogorov熵；关联维；Lyapunov指数

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Actually, variable speed wind turbines are continuously increasing their market share, since it is possible to track the changes in wind speed by adapting shaft speed, and thus maintaining optimal power generation. The more variable speed wind turbines are investigated, the more it becomes obvious that their behavior is significantly affected by the used control strategy. Typically, they use aerodynamic controls in combination with power electronics to regulate torque, speed, and power. The aerodynamic control systems, usually variable-pitch blades or trailing-edge devices, are expensive and complex, especially for larger turbines. This situation provides a motivation to consider alternative control approaches. This chapter deals, therefore, with high-order sliding mode control of doubly-fed induction generator-based wind turbines. This kind of control strategy presents attractive features such as chattering-free behavior (no extra mechanical stress), finite reaching time, and robustness with respect to external disturbances (grid faults) and unmodeled dynamics (generator and turbine). High-sliding mode control appropriateness will be highlighted in terms of sensorless control and enhanced fault-ride through capabilities. Simulations using the NREL FAST code will be shown for validation purposes.

关键词：风力发电机组；双馈感应发电机；高阶滑模

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Owing to industrial and social requirements, but also to technical and scientific progress, the food processing industry is facing new challenges: a wide diversification of processing equipment and the emergence of new food matrices which are more and more complex. In the meantime, the choice of technologies and processes should achieve the following goals: (ⅰ) to ensure the microbiological security of a given product up to a date limit; (ⅱ) to improve product quality through better control and understanding of the process and (ⅲ) to enhance the competitiveness and reliability of the process.

关键词：能源效率；欧姆加热过程；控制器

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Two different operating modes can be clearly identified in wind turbine control systems. In low wind speeds, the main control objective is the energy capture maximization, whereas in high wind speeds it is desired to regulate turbine power and speed at their rated values. The fulfillment of these different control objectives implies the transition through low controllability operating conditions that impose severe constraints on the achievable performance. The control task is usually tackled using two separate controllers, one for each operating mode, and a switching logic. Although satisfactory control solutions have been developed for low and high wind speeds, controller design needs refinement in order to improve performance in the transition zone. This chapter overviews a control scheme covering the entire operating range with focus on the transition zone. H_∞ and advanced anti-windup techniques are exploited to design a high performance control solution for both operating modes with optimum performance in the transition zone.

关键词：抗饱和；增益调度控制；H_∞最优控制

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Increased demands for cleaner burning energy, coupled with the relatively recent technological advances in accessing unconventional hydrocarbon-rich geologic formations, have led to an intense effort to find and extract natural gas from various underground sources around the country. One of these sources, the Marcellus Shale, located in the Allegheny Plateau, is currently undergoing extensive drilling and production. The technology used to extract gas in the Marcellus Shale is known as hydraulic fracturing and has garnered much attention because of its use of large amounts of fresh water, its use of proprietary fluids for the hydraulic-fracturing process, its potential to release contaminants into the environment, and its potential effect on water resources. Nonetheless, development of natural gas extraction wells in the Marcellus Shale is only part of the overall natural gas story in this area of Pennsylvania. Conventional natural gas wells, which sometimes use the same technique, are commonly located in the same general area as the Marcellus Shale and are frequently developed in clusters across the landscape. The combined effects of these two natural gas extraction methods create potentially serious patterns of disturbance on the landscape. This document quantifies the landscape changes and consequences of natural gas extraction for Somerset County and Westmoreland County in Pennsylvania between 2004 and 2010. Patterns of landscape disturbance related to natural gas extraction activities were collected and digitized using National Agriculture Imagery Program (NAIP) imagery for 2004, 2005/2006, 2008, and 2010. The disturbance patterns were then used to measure changes in land cover and land use using the National Land Cover Database (NLCD) of 2001. A series of landscape metrics is also used to quantify these changes and is included in this publication.

关键词：大气；天然气开采；能源利用

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This chapter presents a control scheme of a variable-speed wind turbine with a permanent-magnet synchronous-generator (PMSG) and full-scale back-to-back voltage source converter. A comprehensive dynamical model of the PMSG wind turbine and its control scheme is presented. The control scheme comprises both the wind-turbine control itself and the power-converter control. In addition, since the PMSG wind turbine is able to support actively the grid due to its capability to control independently active and reactive power production to the imposed set-values with taking into account its operating state and limits, this chapter presents the supervisory reactive-power control scheme in order to regulate/contribute the voltage at a remote location. The ability of the control scheme is assessed and discussed by means of simulations, based on a candidate site of the offshore wind farm in Jeju, Korea.

关键词：永磁同步发电机；风力发电机组；风电场

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报告从主要发电企业集团动态、电力产业环境、国内电网动态、电力设备行业信息、港台电力行业信息、国际动态等几个方面进行了分析评论。

关键词：电力；集团动态；产业环境；电网动态；行业信息；国际动态

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This chapter illustrates how to set up an inexpensive but effective Hardware-in-the-Loop (HIL) platform for the test of wind turbine (WT) controllers. The dynamics of the WT are simulated on the open-source National Renewable Energy Laboratory WT simulator called FAST (Fatigue, Aerodynamics, Structures, and Turbulence), which emulates all required input signals of the controller and reacts to the controller commands (almost) like an onshore real turbine of 5 MW. The dynamic torque control system runs on an open hardware Arduino microcontroller board, which is connected to the virtual WT via USB. In particular, the power generation control in the full load region for variable-speed; variable-pitch wind turbines is considered through torque and pitch control. The HIL proposed platform is used to characterize the behavior of the WT in normal operation as well as in fault operation. In particular, a stuck/unstuck fault is modeled and the behavior of a proposed chattering torque controller is analyzed in comparison to a baseline torque controller.

关键词：硬件在中环；Arduino；控制

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This chapter studies the control problems in grid integration of wind energy conversion systems. Sliding-mode control technique will be used to optimize the control of wind energy conversion systems. The maximum power point tracking control algorithms for variable-speed wind energy conversion systems are presented. The grid integration of wind energy conversion systems can be optimized in terms of power delivered to the grid and providing the voltage support ancillary service at the point of common coupling. The control objective for the grid integration of wind energy conversion systems is to keep the DC-link voltage in a desirable value and the input or output power factors staying unitary. The high-order terminal sliding-mode voltage and current regulators are designed, respectively, to control the DC-link voltage and the current rapidly and exactly. The numerical simulations will be carried out to evaluate the control schemes.

关键词：双馈型风力发电系统；电压定向控制（VOC）；电网侧PWM变换器

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