巴基斯坦SAIF发电厂燃机小岛运行试验分析

由于燃机具备启动快速的特点,故比较适合作为电网事故情况下黑启动电源,此时燃机能够运行在小岛模式显得尤为重要.介绍了巴基斯坦SAIF发电厂燃机小岛运行试验的情况,主要分析了GE公司燃机小岛运行逻辑的设计思想,并对试验的过程及试验过程中出现的问题及解决方法进行了总结.试验证明,GE公司的燃机具备比较优良的小岛运行能力.     

9FA燃机DLN2.0+燃烧系统故障分析及处理

统计表明,DLN 2.0+燃烧系统故障是9FA燃机运行中最频率的故障。介绍 了GE公司9FA燃机DLN 2.0+燃烧系统的结构及其设备在机组启动、运行和停机过程中的动作时序,列举了出现在该系统的燃气泄漏试验失败、辅助关断阀(FSV)故障、速比阀(SRV)故障、清吹故障的原因分析及处理过程,并提出了改进措施。实际应用表明,采用改进措施后,故障率明显降低。     

喷流床气化技术选择对IGCC系统能量利用效率的影响

气化炉是整体煤气化联合循环(integrated gasificationcombined cycle,IGCC)中的核心设备之一,气化技术的选择会对系统发电效率产生重要影响。文中采用GT Pro软件,分别对以壳牌(Shell)炉、德士古(GE/Texaco)炉(分激冷流程和废锅流程)和三菱(MHI)空气气化炉为合成气气源的4种IGCC系统进行流程模拟,并在此基础上探讨气化技术对IGCC系统能量利用效率的影响和内在机制。计算结果表明,整体系统的能量转化和分配受气化岛的进料形式、氧化剂选择和合成气显热回收方式等因素的影响。在采用Shell气化炉的IGCC系统中,煤炭能量更多地转化为合成气的化学能,易获得较高的系统效率;而采用GE废锅流程和空气气化炉,煤炭能量中转化为合成气物理显热的比例增加,并以蒸汽形式回收利用。     

Analysis of GSM/GPRS Cell with Multiple Data Service Classes

This paper is concerned with the performance modelling and evaluationof a General Packet Radio Service (GPRS) for a wireless Global System forMobile telecommunication (GSM) cellinvolving both voice and multiple class data services under a completepartitioning scheme (CPS). The GPRS is modelled as a system ofaccess and transfer queues in tandem having an external multiple classcompound Poisson bursty traffic with geometrically distributedbatches under first-come-first-served (FCFS) and generalised processor-sharing(PS) scheduling disciplines, respectively. The proposed queueing model isvalid for both uplink and downlink connections and provides multiple classdata services with different arrival rates, interarrival-time squaredcoefficients of variation (SCVs), file (burst) sizes and different PSdiscrimination service levels.Based on the principle of maximum entropy (ME), a product formapproximation is characterised for the two queues in tandem, subject to queueing theoretic mean value constraints. The MEsolution implies a decomposition of the system into individual singleserver building block queues, each of which can be analysed inisolation. Consequently, ME closed form expressions and simulation resultsfor the aggregate state probability together with the marginal mean queuelength and blocking probability are divised to assess the credibility of theME solution and also to study the effect of external GPRS bursty traffic uponthe performance of the wireless cell.     

Effect of corrosion potential on the corrosion fatigue crack growth behaviour of low-alloy steels in high-temperature water

The low-frequency corrosion fatigue (CF) crack growth behaviour of different low-alloy reactor pressure vessel steels was characterized under simulated boiling water reactor conditions by cyclic fatigue tests with pre-cracked fracture mechanics specimens. The experiments were performed in the temperature range of 240-288 °C with different loading parameters at different electrochemical corrosion potentials (ECPs). Modern high-temperature water loops, on-line crack growth monitoring (DCPD) and fractographical analysis by SEM were used to quantify the cracking response. In this paper the effect of ECP on the CF crack growth behaviour is discussed and compared with the crack growth model of General Electric (GE). The ECP mainly affected the transition from fast (‘high-sulphur’) to slow (‘low-sulphur’) CF crack growth, which appeared as critical frequencies ν_crit = f(ΔK, R, ECP) and ΔK-thresholds ΔK_EAC = f(ν, R, ECP) in the cycle-based form and as a critical air fatigue crack growth rate da/dt_Air,crit in the time-domain form. The critical crack growth rates, frequencies, and ΔK_EAC-thresholds were shifted to lower values with increasing ECP. The CF crack growth rates of all materials were conservatively covered by the ‘high-sulphur’ CF line of the GE-model for all investigated temperatures and frequencies. Under most system conditions, the model seems to reasonably well predict the experimentally observed parameter trends. Only under highly oxidizing conditions (ECP ? 0 mV_SHE) and slow strain rates/low loading frequencies the GE-model does not conservatively cover the experimentally gathered crack growth rate data. Based on the GE-model and the observed cracking behaviour a simple time-domain superposition-model could be used to develop improved reference CF crack growth curves for codes.     

GE300 铸钢件性能及焊补

介绍钢铁产品一种新牌号——GE300,并详细说明它的化学成分与机械性能及铸造缺陷焊补操作过程。同时为同类牌号的产品提供一种可行的焊接方法。实践证明这种牌号的产品综合性能优良,可应用于更多铸件产品。     

基于GE的热能回收装置

本文介绍了基于GE PLC的全自动热能回收装置,包括人机界面的含义、PLC的设计和创新点,该设备能广泛适用于印染企业的热能回收。     

行业英语背景下高职公共英语教学改革若干问题探讨

当前在我国新一轮高等职业教育改革与发展的背景下,公共英语教学面临着新的转折点.行业英语融入公共英语课程教学是新一轮高职公共英语教学改革的关键所在.分析了行业英语教学课程出现的背景,并结合实际探讨了公共英语教学从"通用型"到"融入型"的改革过程中应注意的若干问题,强调了行业英语教学应把握好目的性原则、实用性原则和主体性原则.     

煤质对Texaco（GE）气化装置运行的影响及其选择

文中介绍了水煤浆加压气化适宜的煤种和Texaco煤气化工艺对煤质的要求及其选择适应性,分析了煤质对Texaco煤气化装置运行的影响。     

GE气化工艺高压黑水管线改造探讨

针对GE水煤浆气化普遍存在的激冷室至高压闪蒸罐,洗涤塔至高压闪蒸罐等高压管线的堵塞问题,分析原因,提出改进措施.