Recent Developments in Integrated Solar Combined Cycle Power Plants

Global concern for depleting fossil fuel reserves have been compelling for evolving power generation options using renewable energy sources. The solar energy happens to be a potential source for running the power plants among renewable energy sources. Integrated Solar Combined Cycle(ISCC) power plants have gained popularity among the thermal power plants. Traditional ISCC power plants use Direct Steam Generation(DSG) approach. However, with the DSG method, the ISCC plant’s overall thermal effici...     

Morphological study of silver corrosion in highly aggressive sulfur environments

A silicone coated power module, having silver conducting lines, showed severe corrosion, after prolonged use as part of an electronic device in a pig farm environment, where sulfur containing corrosive gasses are known to exist in high amounts. Permeation of sulfur gasses and humidity through the silicone coating to the interface has resulted in three corrosion types namely: uniform corrosion, conductive anodic filament type of Ag2S growth, and silver migration with subsequent formation of sulfur compounds. Detailed morphological investigation of new and corroded power modules was carried out, and possible theoretical explanation for various corrosion mechanisms has been attempted.     

Hilbert-Huang变换发展历程及其应用

Hilbert-huang(希尔伯特黄)变换是20世纪90年代末兴起的一种重要的非平稳信号处理方法,其中的经验模态分解(EMD)算法更是近年来的研究的热点之一。回顾了EMD算法近十余年来的发展历程,介绍了EMD算法的改进算法及其在工程领域中的运用,包括目前最新的演化算法BEMD、EEMD、CEEMD、MEMD、DEMD等,并结合作者的相关研究介绍了该算法在去噪及盲分离中的一些运用。讨论了EMD算法存在的不足和需要进一步研究的工作。     

Concept study of wind power utilizing direct thermal energy conversion and thermal energy storage

Present wind power is intermittent and cannot be used as the baseload energy source. Concept study of wind power utilizing direct thermal energy conversion and thermal energy storage named Wind powered Thermal Energy System (WTES) is conducted. The thermal energy is generated from the rotating energy directly at the top of the tower by the heat generator, which is a kind of simple and light electric brake. The rest of the system is the same as the tower type concentrated solar power (CSP). The cost estimation suggests that the energy cost of WTES is less than that of the conventional wind power, which must be supported by the backup thermal plants and grid enhancement. The light heat generator reduces some issues of wind power such as noise and vibration.     

基于JTAG的矢量生成型边界扫描架构设计与实现

在结合IEEE1149.1标准的基础上,利用半跳变(Half Transition,HT)模型的基本思想,提出新的HTF模型新的矢量施加方式,在此基础上构建了实现基于JTAG的矢量生成型边界扫描架构.该架构的设计思路为:在兼容1149.1的基础上,通过自定义SI测试指令,实现JTAG对信号完整性测试的支持,拓展了边界扫描的应用范围.     

Heat transfer enhancement of the latent heat storage system using different encapsulating materials with and without fins

This study is aimed at analysing the heat transfer characteristics of different encapsulating materials and the fins on the overall heat transfer in the latent heat storage system (LHSS). Experimentation is done with different phase change materials (PCMs) (d-mannitol, d-sorbitol and paraffin wax) using different encapsulating materials, i.e. copper, aluminium and brass, with and without fins. During the charging process, there is an average 15% heat loss of copper encapsulations without using fins as compared with using fins. The heat losses in aluminium and brass encapsulations are 10% and 15%, respectively. In the discharging process, 23% of heat extraction loss is seen in copper encapsulations, 5% and 18% in aluminium and brass encapsulations, respectively. The results showed that the usage of fins is an effective technique to increase the heat stored and recovered in a LHSS. The most cost-effective encapsulation is aluminium balls with fins as it has the lowest cost/kJ as compared with other two.     

Thermal performance of latent heat storage for free cooling of buildings in a dry and hot climate: An experimental study

Experimental studies on the Phase Change Material (PCM) storage unit for building ventilation in dry and hot climates were conducted to determine its thermal performance. The PCM unit stored the night time coolness and used it for cooling the hot ambient air during day time. The influence of air flow rate and the inlet air temperature on cold accumulation in PCM during charging process and cold extraction from the PCM during discharging process were analyzed. The air temperatures used for charging of PCM were 20^oC, 22^oC and 24^oC, while during the discharging process, it was at 36^oC, 38^oC and 40^oC. The air flow rates considered for charging of PCM were 4 and 5 m³/hr/kg of PCM. Experimental observations showed that solidification of PCM was more sensitive to the charging air temperature compared to the air flow rate. When the charging air temperature was reduced from 22^oC to 20^oC, ∼33% less time was needed to completely solidify the PCM. Moreover, when the charging temperature was increased from 22^oC to 24^oC, ∼52% more time was required by the PCM to complete the solidification process. Changing the air flow rate from 4 m³/hr to 5 m³/hr reduced the solidification time period up to ∼16%.     

空气热源式气化技术在大型LNG接收终端的应用

近年来,空气热源式气化设备和技术（Ambient air based heating vaporization,AHV）因其具有环境友好、节约能源、可持续利用等优势而在其他国家的新建LNG项目中不断得到实践验证和推行。为此,介绍了AHV的技术特点、分类及其在世界各地的最新应用情况,并与常规气化技术进行了对比,进而提出了该类技术的应用条件,分析了该技术方案的优缺点。结果认为：①LNG接收终端所处位置具体环境的气象条件（年最低环境温度、湿度、风向和风速、持续时间等）是选择合适的AHV技术的关键因素;②设计空气热源气化系统需要确定它的最低环境温度以及备用热源系统需要热机备用的工况条件;③相对于浸没燃烧式气化器,AHV系统的优势明显,且燃气（电）价格比率越高,其优势越显著;④在不适合采用海水开架式气化技术的条件下,AHV可作为优选方案;⑤在免费海水使用受限、天然气燃烧制热成本高昂的情况下,以空气热源作为气化系统基荷热源是最为便利和直接的选择。为中国规划和设计新建LNG接收终端提供了更为经济和环保的气化技术选项     

Thermal performances of the active and passive water heating systems based on annual operation

In this paper, the year round thermal performance evaluation of active and passive solar water heating systems for rural/urban area have been studied. Two types experiments are the normalized draw-off temperature profile and the normalized draw-off mixing profile conducted in the months of April 2003–March 2004. Effect of morning, mid-afternoon, evening draw-off and effect of water mixing in the morning and evening are also studied during the experiments. Thermal efficiency for the system and collection efficiency for the collectors were calculated during the experiments. The values of F_R · (τα) of the collectors used in active and passive water heating systems were found 0.69 and 0.61 respectively. Ethylene glycol has a 50/50 glycol-to-water ratio used as a heat transfer fluid (HTF) in the systems due to the cold climate in South Korea.