Optimization of High Pressure Feedwater Heater

At the beginning of 1980’s, the power equipment manufacturing industry in China introduced patent technology on designing and manufacturing the turbine, generator, boiler and their auxiliaries from USA owing to the policy of opening and reformation. In the meantime, our works also imported the patent technology on designing

Characterization of diamond MWCNTs composite fiber synthesized under high pressure and high temperature

A regrown composite fiber was synthesized during the sintering of diamond under high pressure 5.8 GPa and high temperature 1500℃for 1 min,using 3wt%MWCNTs as additive.SEM observation of the fiber after alkali and acid treatment revealed that the outer layer of the fiber is composed of nano-polycrystalline diamond.EDS,XPS,XRD and Raman spectrum analysis further identified that the fiber is composed of MWCNTs in the inner part and nano-polycrystalline diamond in the out layer.It is proposed that the untransformed MWCNTs may act as a template for the regrown outer layer of nano diamond fiber under high pressure and high temperature.

Study on doping effect of interface binding state in the system of PCD and PDC at superhigh pressure

Experimental and theoretical researches on the doping effect of interface binding state with homologous and heterogeneous dopants(d) in the system of PCD etc,as well as the action of intermediate layers between D /d at superhigh pressure and high temperature(HP-HT) are reported in this paper.

Producing ultra-high-speed nitrogen jets by arc heating in a low-pressure chamber

Pure nitrogen gas was heated with direct current arc, at input powers from several hundred Watt to over 5 kW, and then injected through a nozzle into a chamber at 1 or 10 Pa pressure, with the purpose of accelerating the gas to very high speed around 7 km/s. Various structures of the arc generator and gas expansion nozzle were examined. Results show that bypass exhausting of the boundary layer before it enters the nozzle divergent section can greatly increase flow speed of the jet, thus it might be possible to use nitrogen as a working gas in high speed gas dynamic test facilities.

碳纤维复合材料高压树脂传递模塑(HP-RTM)成型工艺

RTM是指低黏度树脂在密闭模腔中流动、浸润的增强复合材料,在一定温度下固化成型的一种复合材料成型工艺,属于复合材料的半液体成型或织物液体成型技术。其具体方法是在设计好的模具中,预先放入经详细设计、剪裁或经机械化预成型的增强纤维材料,模具周边配备密封件和紧固件,在模具内需达到树脂流动顺畅,合模后注入所需树脂,待树脂充分浸润固化后,即可得到所需产品。RTM工艺起始于20世纪50年代,目前,RTM成型工艺己广泛应用于建筑、交通、电信、卫生、航天航空等领域。2015年以后,碳纤维成本的降低及快速固化环氧树脂的出现,加上针对热固性复合材料快速制造开发的HP-RTM工艺和热塑性复合材料层板热成型自动化设备的研发,到2020年,碳纤维复合材料的综合性价比优于金属,并取代金属材料,用于量产车的底盘制造,并涵盖大多数高端车型和少量中级车。高压树脂传递模塑(HPRTM)是传统树脂传递模塑(RTM)的大规模工业化量产的解决方案,也是使用快速固化的化学原料,文中主要介绍用于医疗器械、新能源汽车、数码电子产品的碳纤维复合材料RTM成型工艺,以及国内外目前RTM成型工艺近况和应用。

Late-Stage Ductile Deformation in Xiongdian-Suhe HP Metamorphic Unit, North-Western Dabie Shan, Central China

New structural and petrological data unveil a very complicated ductile deformation history of the Xiongdian-Suhe HP metamorphic unit, north-western Dabie Shan, central China. The fine-grained symplectic amphibolite-facies assemblage and coronal structure enveloping eclogite-facies garnet, omphacite and phengite etc., representing strain-free decompression and retrogressive metamorphism, are considered as the main criteria to distinguish between the early-stage deformation under HP metamorphic conditions related to the continental deep subduction and collision, and the late-stage deformation under amphibolite to greenschist-facies conditions occurred in the post-eclogite exhumation processes. Two late-stages of widely developed, sequential ductile deformations D 3 and D 4, are recognized on the basis of penetrative fabrics and mineral aggregates in the Xiongdian-Suhe HP metamorphic unit, which shows clear, regionally, consistent overprinting relationships. D 3 fabrics are best preserved in the Suhe tract of low post-D 3 deformation intensity and characterized by steeply dipping layered mylonitic amphibolites associated with doubly vergent folds. They are attributed to a phase of tectonism linked to the initial exhumation of the HP rocks and involved crustal shortening with the development of upright structures and the widespread emplacement of garnet-bearing granites and felsic dikes. D 4 structures are attributed to the main episode of ductile extension (D 1 4) with a gently dipping foliation to the north and common intrafolial, recumbent folds in the Xiongdian tract, followed by normal sense top-to-the north ductile shearing (D 2 4) along an important tectonic boundary, the so-called Majiawa-Hexiwan fault (MHF), the westward continuation of the Balifan-Mozitan-Xiaotian fault (BMXF) of the northern Dabie Shan. It is indicated that the two stages of ductile deformation observed in the Xiongdian-Suhe HP metamorphic unit, reflecting the post-eclogite compressional or extrusion wedge formation, the subhorizontal ductile extension and crustal thinning as well as the top-to-the north shearing along the high-angle ductile shear zones responsible for exhumation of the HP unit as a coherent slab, are consistent with those recognized in the Dabie-Sulu UHP and HP metamorphic belts, suggesting that they were closely associated in time and space. The Xiongdian-Suhe HP metamorphic unit thus forms part of the Triassic (250-230 Ma) collision orogenic belt, and can not connect with the South Altun-North Qaidam-North Qinling UHP metamorphic belt formed during the Early Paleozoic (500-400 Ma).

A double-layer heating method to generate high temperature in a two-stage multi-anvil apparatus

A new heating method is proposed to increase the cell temperature of the 6-8 type multi-anvil apparatus without reducing the volume of the sample chamber. The double-layer heater assembly (DHA) has two layers of heaters connected in parallel. The temperature of the cell was able to reach 2500 ℃ by using 0.025 mm rhenium foils, and the temperature limit was increased by 25% compared with that of the traditional single-layer assembly. The power-temperature relationships for these two assemblies with different sizes were calibrated by using W/Re thermocouple at 20 GPa. When the volume of samples was the same, the DHA not only attained higher temperature, but also kept the holding time longer, compared to the traditional assembly. The results of more than ten experiments showed that the new 10/4 DHA with a relatively large sample size (2 mm in diameter and 4 mm in height) can work stably with the center temperature of the sample cavity exceeding 2300 ℃ under the pressure of 20 GPa.

Photosynthetic Performance and Potency of <i>Cannabis sativa</i>L. Grown under LED and HPS Illumination

Light-emitting diodes (LEDs) can be used as an energy efficient alternative to high-pressure sodium (HPS), which have historically been the standard for supplemental lighting in cannabis cultivation. However, there is a lack of scientific understanding in the cannabis industry regarding plant physiology, which has resulted in the adoption of cannabis cultivation methods based on hearsay rather than scientific research. The goals of this study were to 1) compare LED lighting options that are commonly used in the cannabis industry and 2) compare the top performing LED light with an industry standard HPS light. Specifically, three LED lights were compared (California Light Works ((SolarSystem 1100), BIOS Lighting (Icarus Gi2), and Fluence Bioengineering (now Fluence by Osram) (SPYDR xPLUS)), based on light distribution, leaf temperature, and photosynthetic performance indices. The LED versus HPS comparison was based on light response curves measured at photosynthetic photon flux densities (PPFD) of (0, 100, 200, 300, 400, 500, 750, 1000, 1250, 1500, 1750 and 2000 μmol∙m−2∙s−1), carbon assimilation rates (A) μmol CO2 m−2∙s−1 using a LiCor-6800 and resulting cannabinoid potency (THCA). The SPYDR xPLUS-Fluence by Osram had the highest performing LED light used in the LED comparison. At the suggested distance from bulb to canopy in the HPS versus LED comparison (6 inches for LEDs and 4 ft for HPS), carbon assimilation rates displayed a 142% percent increase in plants grown under LED vs. HPS with average photon flux densities of 795 and 298 μmol∙m−2∙s−1 for LED and HPS, respectively. All cultivars of Cannabis sativa L. showed increased cannabinoid potency when grown under LED illumination. The results of this study provide further insight regarding the selection of supplemental light to achieve maximum productivity of Cannabis sativa L.

浅谈2MX2AHP高压加热器液位测量改造的可行性

针对秦山核电一期工程方家山核电项目常规岛2MX2AHP高压加热器运行状况,对液位测量差压变送器测量液位过程中所遇到的假液位、液位波动、启机时液位正压室无液等问题进行技术分析,建议采用导波雷达液位计替代差压变送器来进行测量。

12Cr2Mo1VR在电站辅机产品中的应用及制造工艺优化

本文主要介绍采用12Cr2Mo1VR材料短筒身的高压加热器,在制造过程中出现裂纹问题,针对此材料进行研究并采取措施,包括优化工艺、改进设计结构等,从而规避风险,保证产品质量。

HP-Indigo技术及其照片应用

HP-Indigo数字印刷机应用了基于电子油墨(ElectroInk~?)和热转印橡皮布的液体电子照相技术。通过多束激光扫描单元使光电导体充电后产生潜影,然后再通过多色显影站,使潜影产生油墨显影。利用电场将油墨转移至橡皮布,油墨载体溶剂在橡皮布上蒸发,生成热熔性油墨薄膜,凭借压力和粘性转移至承印物。端到端的工作流程和整理解决方案也由HP-Indigo通过合作网络伙伴提供。工作流程解决方案包括创建软件、自动图像增强服务器、拼版、高速图像处理(rips)和颜色转换。裁切解决方案包括在线层压、在线液体涂布、切割、堆叠、书籍装订等。

适用于多种一次调频技术及工况变化的抽汽凝汽式汽轮机数学模型

火电机组是目前电力系统中重要的调频资源,其一次调频能力与汽轮机动态密切相关,但现有汽轮机动态数学模型无法准确反映火电机组在多种一次调频技术以及工况变化情况下的一次调频能力。为准确描述火电机组真实的一次调频动态,该文对汽轮机本体、回热抽汽管道及回热加热器的动态耦合特性进行机理分析,建立适用于主汽阀调节、凝结水节流和高加给水旁路调频技术的汽轮机动态模型;基于机组结构数据及分布式控制系统实测数据,提出跟随工况变化的模型参数在线确定方法;最后,以实际600MW机组为例进行模型验证与仿真分析。结果表明,汽轮机输出功率会受到汽轮机本体和回热系统动态耦合特性的重要影响,且不同工况下机组一次调频能力存在明显差异。该文模型能更准确地描述不同一次调频技术方案及不同运行工况下汽轮机的动态响应特性。

BIM技术在1000MW大型火力发电工程中的应用

随着我国电力建设技术的快速发展,目前1000MW机组工程成为了主流,为保证工程顺利施工,需要借助数字化手段,赋能过程管理。本文介绍了将BIM技术应用于火力发电项目建设过程,辅助进行方案交底,特别是解决重大技术方案不直观、交底不透彻的问题,提升技术交底质量,从而减少返工和成本,产生良好的经济效益。重点介绍一种采用井字架吊具转换吊装高加设备的方法,在吊装施工前进行施工模拟重点技术工艺分析,开展建模内容分析和建模软件选择,进而建模和开展施工模拟,并以其中3个具有代表性的技术工艺模拟优化过程为例,阐述了BIM技术在项目立式高加安装中的应用。通过经济性分析,该施工方案经济效益明显,证明BIM技术的三维化、优化性、模拟性等优点,对于保障危重大施工方案的安全、顺利实施可以发挥十分重要的作用。

高加危疏阀泄漏对汽轮机性能试验热耗率的影响

针对某电厂2号机组性能试验中3号高加危疏阀无法测量泄漏量导致计算热耗率比实际值虚高的情况,基于ASME PTC6标准,以凝结水流量为基准进行推导分析,认为高加危疏阀存在泄漏但又无法测量泄漏量,会对给水流量和热耗率的计算产生严重干扰。通过建模仿真计算了不同高加危疏阀泄漏量对汽轮机热耗率的真实影响、特性关系及泄漏未被考虑时对热耗率的影响,进而建议性能试验前特别关注高加危疏阀的隔离效果,确保高加危疏阀不存在泄漏,以保证试验结果的客观性。

燃煤机组高压加热器水侧泄漏影响因素分析

为及时发现燃煤机组高压加热器泄漏,对某燃煤机组3号高压加热器水侧泄漏对运行参数的影响进行分析。基于高压加热器泄漏案例,通过建立回热系统分析模型,定量分析3号高压加热器水侧泄漏对正常疏水调节阀开度、给水流量偏差及给水泵汽轮机转速等参数的影响,并进行影响因素敏感性分析。采用定量分析方式明确高压加热器水侧泄漏判断依据,并对各判断依据进行优化组合,确定泄漏预警的最终触发条件,据此开发高压加热器水侧泄漏预警装置。结果表明,高压加热器水侧泄漏预警装置比人为判断提前7天时间,可以有效避免因高压加热器泄漏引发的安全事故。

某电厂高压加热器电动门跳闸保护逻辑优化

针对某电厂5号、6号机组高压加热器电动门保护逻辑存在的安全隐患,提出“3取2”的动作逻辑条件,设计安装电动门阀位确认装置,优化逻辑并进行试验。结果表明,改进后的逻辑可有效防止高压加热器电动门误动导致的高压加热器受损事故,延长其使用寿命,保证机组安全稳定运行。

火电厂外置蒸汽冷却器技术经济性分析

介绍了汽轮发电机组3号高压加热器外置蒸汽冷却器的设计原理和其在某1000 MW机组中的实际运行情况,并对其热经济性进行了分析。对该机组蒸汽冷却器分流系数、温升情况等进行了研究,对比了机组性能试验数据与设计值的差异,从设计角度和设备故障角度分析了该差异产生的原因。

核电厂高加水位异常分析及应对措施

秦山地区近年来发生多起高加疏水故障引起的降功率或功率波动事件,高压加热器的正常、稳定运行对机组的安全和效率有重要影响。本文对秦山第二核电厂60万千瓦级压水堆机组高压加热器近年来运行中的水位异常现象进行分析总结,提出相应的应对措施,以减少高加水位异常事件的发生,并在瞬态发生时以便运行人员能够及时、准确干预,防止事故扩大化。

超高压处理对牡蛎超微结构、组分及蛋白质变性的影响

研究了超高压处理对牡蛎超微结构、组分及蛋白质变性的影响。研究结果表明,由于蛋白质发生了显著的变性,牡蛎闭壳肌表面的肌纤维结构逐渐消失,表面致密;超高压处理对于牡蛎成分也有一定的影响,主要表现在牡蛎组织中的某些盐溶性蛋白质和灰分在高压的作用下溶出;超高压还可提高牡蛎中蛋白质水解酶的活性,使得牡蛎蛋白质水解程度增加,牡蛎流失液中游离氨基酸的含量随着压力的升高而大幅增加;经过较高超高压(600 MPa)处理后,牡蛎中蛋白质发生了明显的变性。

苏北高压变质带绿片岩中石榴石内文石包裹体的发现

苏北高压变质带位于苏鲁超高压变质带东南缘,露头多为绿片岩相的中—晚元古代云台岩群,典型的蓝片岩仅见于灌云县杨集的钻孔岩心中。本文通过拉曼光谱研究,在连云港地区的绿片岩内石榴石中发现文石(CaCO3)包裹体。文石呈细小包裹体残留于细粒半自形石榴石斑晶中。这些石榴石作为低扩散的刚性矿物,经历了多期变质变形作用,变质反应证据保存在石榴石的成分环带及包体矿物组合中。文石包裹体的存在证明苏北高压变质带北部的、即本区出露的这套岩系是早期经历了高压变质作用、晚期又叠加了绿片岩相变质作用的高压变质地体。