600MW超临界W型火焰锅炉水冷壁开裂原因初探及对策

作为燃烧劣质煤、无烟煤发电的高参数、大容量炉型,600MW超临界W型火焰锅炉近几年在国内得到大力推广。受炉型固有特性及安装、调试、运行过程中对该炉型特性不熟悉等因素影响,目前国内几大锅炉制造厂家生产的该类型锅炉,在多个项目上出现水冷壁扁钢开裂现象,甚至引起水冷壁管泄漏。本文从炉型特点、安装、调试、运行等几方面,初步分析探索引起水冷壁扁钢开裂的原因及预防对策。     

600 MW汽轮机润滑油压力低的分析与处理

介绍了田集发电厂2台600 MW超临界机组N600-24.2/566/566型汽轮机的润滑油系统设备情况,阐述了对机组启动调试过程中出现汽轮机润滑油压力低问题的检查、分析及相应的处理过程,指出每次处理和改进后的效果。     

600 MW机组协调控制策略优化

针对大同发电有限责任公司2台600 MW机组主汽压力和负荷相互适应能力差、协调不稳定、投入发电机自动控制系统(AGC)后负荷升降速度慢等问题,制定了相应的优化措施,使机组对负荷指令的响应速度大大提高,保证了AGC投入的可靠性。     

Initiation of SCC in nickel base alloys in primary PWR environment: studies at Studsvik since mid 1980s

Abstract

Investigations on initiation of primary water stress corrosion cracking (PWSCC) in alloys 600 and 690 in simulated primary pressurised water reactor (PWR) environments, carried out since 1985, are reviewed. A large number of tests, mostly on reverse U bend specimens, some from steam generator tubes from operating PWRs, have been conducted for periods up to 33 000 h (4 years). Most exposures were at 365 or 330°C in either high purity water with hydrogen addition or simulated primary water (representing beginning of cycle conditions). Parameters investigated include: material (composition, heat treatment (mill annealed or thermally treated), carbide distribution, yield strength, grain size, etc.), environmental (hydrogen content, boron–lithium–pH, zinc) and experimental environment control techniques. Although the PWSCC mechanism has yet to be fully explained, these studies provide an overview of important parameters for crack initiation. The present review aims to survey the evidence for PWSCC initiation in nickel base alloys. It is concluded that, within the normal range for operating PWRs, the influence of dissolved hydrogen on initiation is small. However, a weak maximum in crack growth rate is observed at 15–25 ml H₂/kg H₂O; a corresponding minimum in crack initiation time has not been confirmed but cannot be excluded. It is concluded that hydrogen must be reduced to well below 10 ml H₂/kg H₂O to achieve significant benefits. Increasing the Li content from 2–2·5 to 3·5 ppm is shown to reduce crack initiation time by 30–50%. Lithium in the range 2·2–7·5 ppm has little effect on crack growth rate at ～1200 ppm B. Boron appears to have little influence on crack initiation or growth.     

树脂对大豆异黄酮吸附与洗脱性能的研究

利用HPD-600大孔吸附树脂对大豆异黄酮的吸附与洗脱性能进行了研究.测定其静态吸附率为53.30%,静态解吸率为95.36%.吸附时间2 h时,吸附基本达到最大,解吸时间为2.4h时,解吸基本达到最大.上样量45mL时,吸附效果最佳.经吸附-解吸和干燥后,产品纯度达到39.7%.     

Ti-600合金蠕变性能及硅对其蠕变性能的影响

研究了Ti-600合金在3种温度(550、600、650℃)、5种应力(150、200、250、300、350 MPa)下的蠕变性能,并分析了硅化物对合金蠕变性能的影响。研究结果表明,Ti-600合金具有较小的稳态蠕变速率及较大的蠕变激活能,反映出该合金具有较好的蠕变抗力。当温度升高、应力增大时,Ti-600合金的稳态蠕变速率增大。600℃下,当蠕变应力高达350 MPa时,Ti-600合金的稳态蠕变速率低至3.72×10-7s-1。Ti-600合金的蠕变激活能最高可达574.6kJ·mol-1,最低为332.7 kJ·mol-1。在蠕变过程中,Ti-600合金内析出了S2型(TiZr)6Si3硅化物,能够钉扎位错、阻碍位错滑移,提高合金的蠕变抗力。     

Performance of NiB inhibitor for PbSCC of alloy 600 in Pb-contaminated water and caustic solutions

Nickel-based iron-chromium alloys are used as steam generator (SG) tubing materials in nuclear power plants (NPPs) but experience intergranular stress corrosion cracking (IGSCC) and lead stress corrosion cracking (PbSCC) due to the harsh operating conditions of NPPs. In order to improve the integrity of SGs, many studies have sought suitable inhibitors for IGSCC, while those for PbSCC have been sought to a limited extent. In this study, the performance of nickel boride (NiB) as an inhibitor for PbSCC was evaluated. Nickel boride has been shown to be a good inhibitor for IGSCC of Alloy (or Inconel) 600 in a caustic aqueous solution containing no lead (Pb). No significant SCC was observed to occur in Alloy 600 tested in pure water under the slow strain rate test (SSRT) condition in this study. A mixed mode of IGSCC and TGSCC, however, occurred relatively easily in Alloy 600 tested in pure water containing lead oxide (PbO) at 315 °C. The susceptibility of Alloy 600 to SCC decreased with the addition of NiB, implying that NiB can be used as an inhibitor for PbSCC in Pb-contaminated water.     

600MW超临界一号机组整套试运分析

对贵州首台超临界机组分部试整套试运完成情况进行了的总结和分析。     

CAWS600系列自动气象站故障分析及排除方法

根据CWAS600系列自动气象站的系统结构和工作原理,将其故障分为：通信、电源供电系统、传感器、采集器四类故障。文章列举了几个典型故障的分析和处理方法。重点介绍了＂测量法＂,通过测量关键点的电信号,将故障进行分级判断和定位。熟悉这些典型故障的处理方法,可以大大提高自动气象站故障排除的时效性。     

600MW机组锅炉屏式过热器壁温测试及三维计算

大型锅炉过热器爆管是造成机组强迫停机的重要因素之一,而大多数的爆管都是由管壁超温引起的。因此,为了准确了解锅炉屏式过热器(屏过)的壁温分布情况,在大别山电厂超临界600 MW机组锅炉屏式过热器上进行了炉内外壁温测试,实时采集了炉内壁温及炉外壁温的变化数据,找出了屏式过热器炉内外壁温的关系,并用最小二乘法拟合出二者的关联模型,并进行了三维壁温分布计算分析。利用所拟合的屏式过热器炉内外壁温的关联模型及炉外可长久保留的测点测量出的温度t0,可以预测发生超温管段的炉内温度。此外,利用该模型还可验证屏式过热器三维管壁温度计算程序结果的可靠性。