Yang T.,Nanjing Southeast University |
Xu J.,Nanjing Southeast University |
Zhou K.,Nanjing Southeast University |
Shi Y.,China HuaDian Electrical Research Institute
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2014
A mathematical model of three-section heater for varying condition was established based on dimensional analysis. The operation characteristic of low liquid level was modelled with the calculation of heat transfer coefficient of drain cooler mixed with steam. Taking #1 high pressure feedwater heater of a 330 MW steam turbine for example, the model was used to calculate the terminal temperature difference of regular liquid level, the heat transfer condition of drain cooler and the terminal temperature difference of low liquid level. The calculation results were verified by the experimental data. The influence of liquid level and power load on terminal temperature difference was also quantitativly analyzed, and the security level and economic level were reseted. The research provides a reference for analyzing the operation characteristic of low liquid level and adjusting liquid level timely. © 2014 Chin. Soc. for Elec. Eng.
Zhang N.-N.,China Huadian Electrical Research Institute |
Zhang N.-N.,Hohai University |
Chen Z.-J.,Hohai University |
Chen Y.-J.,Hohai University
Zhendong yu Chongji/Journal of Vibration and Shock | Year: 2012
Frequently monitoring data for the cable-tower anchorage zone of Sutong Bridge showed that in the various noises leading to data distortion, tall structures, such as, cable towers are obviously affected by temperature and backward-sunflower phenomena appear. In order to find the deformation of cable-tower caused by temperature and accurately evaluate the safety of cable-tower, combining the real-time meteorological date and the construction schedule, adopting the wavelet multi-scale denoising method at regular time intervals, the excursion of cable tower caused by temperature was extracted step by step. The deformation features of cable-tower anchorage zone brought by construction condition were extracted. Reliable calculation and analysis basis for mechanical behavior of anchorage zone and construction control were provided.
Wei Y.,Chubu University |
Li H.,Anhui University of Science and Technology |
Wang Q.,China HuaDian Electrical Research Institute |
Honma K.,Taiheiyo Cement Corporation |
And 2 more authors.
Fuel | Year: 2014
During coal gasification, the resulting slag varies in the mineral compositions and amount due to the ambient gas in gasifier. In this study, the microstructure and leaching behavior of typical slag were investigated under simulated mildly/strongly reducing gasification conditions with different H 2S concentration. XRF, XRD and SEM-EDX were used to study the properties of slag. And ICP-AES was used to determine the metallic ions in acid-digested slag samples. The results indicate that iron phase was separated from molten slag phase in melting process under a strongly reducing condition. In the strongly reducing condition with H2S, FeSx(x < 1) was formed below about 1200°C and it decomposed to iron liquid when the temperature is above about 1200°C while it takes a long time to reach equilibrium. In the strongly reducing condition, heavy metals, such as Cr, Cu, Ni, Co easily form an interstitial compound in iron phase. Adding of H 2S causes heavy metals enrichment in the iron phase, where it has a significant impact on Ni and Cu. On the other hand, addition of H2S has negligible effect on slag properties under mildly reducing condition. © 2013 Elsevier Ltd. All rights reserved.
Jiang F.-Q.,China HuaDian Electrical Research Institute |
Chen E.-H.,CAS Zhengzhou Research Institute |
Xi J.-F.,China HuaDian Electrical Research Institute |
Zhao J.,CAS Zhengzhou Research Institute
Jingangshi yu Moliao Moju Gongcheng/Diamond and Abrasives Engineering | Year: 2014
Diamond coatings present the perfect cutting performance of tools for machining titanium and its alloys. However, the influence of this coating on the wear mechanism has not been elucidated yet. In this test, on-disc wear tests against Ti-2Al-1.5Mn (TC1) balls had been performed to characterize the wear performance of a polycrystalline diamond (PCD) coating on tungsten carbide (WC-Co) produced by hot filament chemical vapor deposition (HFCVD). The PCD coating exhibited lower friction coefficient and high wear resistance than those of the WC-Co under same testing condition. For WC-Co, abrasive wear was the main wear mechanism. In contrast to that, the PCD coating was worn by microcuts in the on-disc test. Compact oxidized TC1 debris also had a great effect on its wear mechanism.
Wang M.,Xi'an Jiaotong University |
Wang J.,Xi'an Jiaotong University |
Zhao Y.,China HuaDian Electrical Research Institute |
Zhao P.,Xi'an Jiaotong University |
Dai Y.,Xi'an Jiaotong University
Applied Thermal Engineering | Year: 2013
This paper presents a regenerative organic Rankine cycle (ORC) to utilize the solar energy over a low temperature range. Flat-plate solar collectors are used to collect the solar radiation for their low costs. A thermal storage system is employed to store the collected solar energy and provide continuous power output when solar radiation is insufficient. A daily average efficiency is defined to evaluate the system performance exactly instead of instantaneous efficiency. By establishing mathematical models to simulate the system under steady-state conditions, parametric analysis is conducted to examine the effects of some thermodynamic parameters on the system performance using different working fluids. The system is also optimized with the daily average efficiency as its objective function by means of genetic algorithm under the given conditions. The results indicate that under the actual constraints, increasing turbine inlet pressure and temperature or lowering the turbine back pressure could improve the system performance. The parametric optimization also implies that a higher turbine inlet temperature with saturated vapor state could obtain the better system performance. Compared with other working fluids, R245fa and R123 are the most suitable working fluids for the system due to their high system performance and low operation pressure. © 2012 Elsevier Ltd. All rights reserved.
Wang Y.,China University of Mining and Technology |
Wang Q.,China Huadian Electrical Research Institute |
Fu X.,China University of Mining and Technology
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2012
Two kinds of typical low-rank coal were burned in a drop tube furnace under different atmosphere. The produced particulate matters (PM) were collected by the cyclone and low pressure impactor (LPI). Transmission electron microscopy (TEM) and scanning electron microscope (SEM) were used to identify the morphology of the super-micron and submicron PM. SEM with an energy dispersive X-ray (SEM-EDX), TEM with an energy dispersive X-ray spectroscopy (TEM-EDS) and computer-controlled scanning electron microcopy (CCSEM) were applied to analyze the chemical composition in the ash. It has been confirmed that compared with air atmosphere, O2/CO2 atmosphere changes the generated fine ash particle size distribution and the concentration of the chemical composition, but the formation mechanisms are same for different atmosphere. For the case of the lignite with more amount of organic-associated minerals, O2/CO2 atmosphere increase the vaporization degree of Fe, Na/K sulfates, Al and Si, and thus increase the concentration of sub-micron particles. Also Fe is found to be a key element in the lignite. Oxy-fuel-combustion increases the attachment of vaporized Fe element to other particle. © 2012 China. Soc. for Elec. Eng.
Jiang F.,China HuaDian Electrical Research Institute |
Hu W.,China HuaDian Electrical Research Institute |
Xi J.,China HuaDian Electrical Research Institute
Jinshu Rechuli/Heat Treatment of Metals | Year: 2015
A 600 MW subcritical boiler final-stage reheater tube made of 12Cr1MoV steel cracked after running 51 020 h. The burst reheater tube was analyzed through macroscopical examination, oxidation layer measuring, microstructure and energy spectrum analysis by using optical microscope (OM) and scanning electron microscopy (SEM). The results show that the burst exhibited a long term overheat characteristics, a thicker oxidation film forms on the fire-facing side of the burst reheater tube, and serious spheroidization of pearlite appears in microstructure. Many creep cavities and intergranular cracks are observed in the fire-facing side of the burst wall. And the cracks, extending along the grain boundaries are full filled with oxide. The results of the energy spectrum analysis show that the alloying elements are depleted in the matrix, which causing the deterioration of tube microstructure. In conclusion, deterioration of the microstructure caused by long term overheat is the main reason lead to the failure of the 12Cr1MoV hot stage reheater tube, and the creep cracking lead to a burst. ©, 2015, Chinese Mechanical Engineering Society of Heat Treatment. All right reserved.
Hu W.,China Huadian Electrical Research Institute |
Jiang F.,China Huadian Electrical Research Institute |
Xi J.,China Huadian Electrical Research Institute
Jinshu Rechuli/Heat Treatment of Metals | Year: 2015
State and life assessment of final-stage reheater 12Cr1MoV steel tube which was running more than 50000 h were carried out by optical microscope (OM), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The results show that room temperature tensile properties of some sample tubes are below standard requirement,and spheroidization of fire-facing side of samples tube is above 4 grade,and depleted phenomenon of alloy element appeares in the matrix. All these show obviously aging trend. Life assessment shows equivalent temperature of the sample tubes don't exceed ceiling temperature of 12Cr1MoV steel and remaining life of sample tubes are above 28000 h. The foregoing shows that sample tubes are in mid and late life. ©, 2015, Chinese Mechanical Engineering Society of Heat Treatment. All right reserved.
Chen D.W.,China Huadian Electrical Research Institute |
Li Z.,China Huadian Electrical Research Institute |
Lu K.,China Huadian Electrical Research Institute
Advanced Materials Research | Year: 2014
In order to solve the domestic sub and super-critical unit import the high cost of procurement of high parameters of valves and valve operation in the common issues such as defects, and introduces the new valve of the Sino-ROK cooperative project--the labyrinth of high parameter control valve. First elaborates its structure characteristics, the core technology and application, and introduces concrete application for the settlement of condensate water pump recirculation valve defect. And we can see the labyrinth of high parameter control valve important role and development prospects in the future power plant. © (2014) Trans Tech Publications, Switzerland.
Zhang D.,China Huadian Corporation |
Wang J.,China Huadian Electrical Research Institute |
Fan W.,China Huadian Electrical Research Institute |
Wang L.,China Huadian Electrical Research Institute
Dianli Zidonghua Shebei/Electric Power Automation Equipment | Year: 2012
A midterm maximum peak load regulation model of hydropower stations is proposed from the perspective of coordinative operation of thermal and hydraulic power generation. The exponential penalty function is used to convert the minimax problem into the unconstrained programming problem to be solved directly, and the parallel computing advantage of multi-population genetic algorithm is integrated in the coarse-grained parallel genetic algorithm to increase the calculation efficiency and accuracy. The computative results for 8 hydropower stations in Wujiang river basin show that the proposed model mitigates the effect of system load change on the start-up and shut-down of thermal power plants while ensures the peak load regulation of hydropower stations. The coarse-grained parallel genetic algorithm improves the calculation efficiency significantly.