Power Equipment

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  • 2019 Volume 33 Issue 3
    Published: 15 May 2019
      
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  • Experimental Research of Lean Iron Ore Oxygen Carrier Modified by Plant Ash Aqueous Solution
    Wang Haitao, Hu Xiaoyu, Wang Xudong
    2019, 33(3): 149-154.
    Abstract ( )   Knowledge map   Save
    Taking the lean iron ore modified by plant ash aqueous solution as the oxygen carrier, and the CO as the reducing gas, a series of short-duration multi-cycle chemical-looping combustion (CLC) tests were conducted in a fixed bed to analyze the effects of K+ load ratio on the activity of the modified oxygen carrier. Results show that the higher the K+ load ratio is, the better the activity of the modified oxygen carrier will be. The modified oxygen carrier exhibits strong cyclic stability in the fixed bed for 100 cycles. With the rise of cyclic number, the modified oxygen carrier gets pulverized, and the higher the K+ load ratio is, the more serious the pulverizing phenomenon will be.
  • Cold Test and Numerical Simulation on Dynamic Field of a Swirl Burner with Deep Air Staging
    Ma Qilei
    2019, 33(3): 155-159.
    Abstract ( )   Knowledge map   Save
    Cold test and numerical simulation were conducted on a swirl burner to study the influence of multi-layer auxiliary air design on the dynamic field in the nozzle area and furnace region, and to analyze the effects of swirl intensity on the attenuation of axial wind speed, the distribution of nozzle wind speed and the law of air flow diffusion. Results show that with the increase of swirl angle, the axial speed of tertiary air and quaternary air drops, the axial speed attenuation of primary air accelerates, and the recirculation area gets enlarged and obvious. It is suggested that in daily operation, the straight-flow secondary air should be kept in full open position, while the swirl secondary air kept at the opening of 50%~70%, and the swirl angle at 45°.
  • Application Research of Molten Salt Energy Storage Technology in Gas-Steam Combined Cycle Systems
    Fan Lingping, Liu Keliang
    2019, 33(3): 160-163.
    Abstract ( )   Knowledge map   Save
    A gas-steam combined cycle system adopting molten salt energy storage technology was proposed, and its operation parameters and economy were studied after application of the technology. Results show that the scheme proposed, with molten salt storing energy under valley-energy requirements and releasing energy under peak-energy requirements, is proved to be practicable, which helps to improve the gas turbine efficiency by at least 18%, resulting in increased benefit and enhanced energy utilization of the power plant.
  • Influence of Concentrator Surface Roughness on the Specular Reflectance in a Solar Power Generation System
    Yuan Yuhao, Zuo Jie
    2019, 33(3): 164-167.
    Abstract ( )   Knowledge map   Save
    Taking the trough concentrator as an example, statistical analysis was carried out on the measured data before and after hot bending of the concentrator based on non-parametric test and normality test, so as to obtain the distribution function model of the surface roughness and to analyze its influence on the specular reflectance. Results show that using the non-contact mirror manufacturing process, the surface roughness before and after hot bending of the concentrator only changes from 10.3 nm to 12.3 nm, which is in accordance with the normal distribution; besides, the smaller the surface roughness, the wider the wavelength range of the light that could be specularly reflected.
  • Comparative Analysis of Domestic Biomass Power Generation Technologies
    Gong Shishang, Zhang Bo, Liu Hongpeng, Chen Lu, Zhao Jianming
    2019, 33(3): 168-172.
    Abstract ( )   Knowledge map   Save
    A comparative analysis was conducted on four biomass power generation technologies and four pre-feeding systems. Results show that the direct combustion biomass/coal co-firing technology is proved to be mature with least investment; the technology of "front bunker + secondary feeding" in the biomass power feeding system has strong fuel adaptability, where fuel blockage does not easily occur; the technology of "co-firing with burners" has little impact on the original combustion system with a high degree of co-firing effect, which is suitable for large-scale power generation systems.
  • Experimental Study on Scale Inhibition in Wet Desulfurization Process Based on Response Surface Analysis
    Zhu Dongqi, Chen Hongwei, Cheng Kai, Jia Jiandong, Zhu Lou
    2019, 33(3): 173-177.
    Abstract ( )   Knowledge map   Save
    An introduction was presented to the scale inhibition mechanism of ethylene diamine tetraacetic acid (EDTA) in desulphurization slurry, while the effects of following factors on the amount of accumulated scale were researched based on response surface analysis, such as the EDTA mass concentration, stirring speed, reaction temperature and reaction time, etc. Results show that EDTA has a certain buffer effect on scale inhibition in CaCO3 slurry and Ca(OH)2 slurry, but the EDTA mass concentrations achieving the best buffer effect are different for the two slurries. With the increase of EDTA mass concentration, the amount of accumulated scale on the surface of sheet metal drops rapidly, which tends to be stable when the EDTA mass concentration reaches 3.0 g/L; with the increase of stirring speed, the amount of accumulated scale on the surface of sheet metal reduces in a certain extent, and tends to be stable when the stirring speed gets up to 200 r/min.
  • Optimization and Retrofit of an SCR Denitrification System Based on CFD Simulation
    Tao Zhengxin, Wei Hongqi, Li Wenxia, Zhou Shiqi
    2019, 33(3): 178-181.
    Abstract ( )   Knowledge map   Save
    To solve the problem of low gas velocity near the front wall and high gas velocity near the rear wall of the catalyst layer in a selective catalytic reduction (SCR) denitrification system of a 600 MW unit, simulation analyses were conducted on the internal flow field, after which the simulation results were verified by on-site cold-state experiments, and subsequently an optimization scheme was proposed. Results show that the problem could be solved by optimizing the internal flow field through reasonably arranging the guide plates and adjusting the structure of rectifier grilles.
  • Experimental Research on Coal Pretreatment Technology by Biological Enzyme for a 660 MW Supercritical Boiler
    Liu Zhongxuan, Ning Xinyu, Zhang Qingfu, Shang Xianyao
    2019, 33(3): 182-185.
    Abstract ( )   Knowledge map   Save
    Experimental tests were conducted on a 660 MW supercritical boiler burning the coal pretreated by biological enzyme to study the effects of coal treatment technology on the boiler efficiency, NOx generation and SO2 generation, etc., during large-scale industrial application of the technology. Results show that this technology has no effect on the improvement of boiler efficiency, but has a certain effect on the reduction of NOx generation and SO2 generation.
  • Experimental Research on Treatment and Utilization of the Condensate from Wet Flue Gas Desulphurization
    Li Jian
    2019, 33(3): 186-188.
    Abstract ( )   Knowledge map   Save
    Experimental studies were conducted on the condensate collected from wet flue gas desulphurization. Results show that the condensate, collected from the flue gas having been cooled down for 5~10 K, could be directly taken as the flushing water of demister; it could also be used as industrial make-up water after being added with sodium hydroxide; when the pH value of circulating cooling water is relatively high, the condensate could be taken as the make-up water for cooling tower to reduce the pH value of circulating cooling water instead of sulfuric acid.
  • Influence of Shot Peening on Steam Oxidation Resistance of 18-8 Type Austenitic Heat-resistant Steels
    Yang Shouen, Yang Huachun, Liu Shengbo
    2019, 33(3): 189-192.
    Abstract ( )   Knowledge map   Save
    Characteristic analysis was conducted on the oxide layers covering the surface of austenitic heat-resistant steel tubes with and without shot peening experiencing different periods of service or after steam oxidation tests at 650℃ and 27 MPa. Results show that the steam oxidation resistance of both shot-peened TP347H and shot-peened S30432 is better than TP347HFG, and that of shot-peened S30432 is better than TP347HFG under ultra supercritical conditions, indicating that shot peening is the most effective way to create excellent steam oxidation resistance for 18-8 type austenitic heat-resistant steels.
  • Corrosion Behavior of Austenitic Heat-resistant Steel Sanicro25 in Flue Gas with Different SO2 Concentrations
    Yu Mingming, Liu Guangming, Yang Huachun
    2019, 33(3): 193-196.
    Abstract ( )   Knowledge map   Save
    To study the corrosion behavior of new austenitic heat-resistant steel Sanicro25 for ultra-supercritical boilers under the combined action of simulated flue gas and coal ash with different SO2 concentrations at 700℃, an analysis was conducted on the effects of SO2 concentration in flue gas on the corrosion behavior of the material. Results show that Sanicro25 shows good corrosion resistance in simulated flue gas without SO2, due to the protective oxide layer formed on the surface of the material. However, in the flue gas with SO2, hot corrosion appears in the steel, with internal oxidation and sulfidation in the base metal; micro-cracks form in the corrosion layer and corrosion products peel off from the surface when the SO2 volume fraction reaching 0.5%.
  • Analysis on Piping Design for the Drain and Vent System of High-pressure Heaters
    Zhou Hua, Shen Qinfeng
    2019, 33(3): 197-200.
    Abstract ( )   Knowledge map   Save
    Fallible problems existing in piping design for the drain and vent system of high-pressure heaters were summarized from the aspects of parameter setting, piping layout and the design of supports and hangers. Taking the No.2 high-pressure heater of a certain engineering project as an example, the parameters of related drain pipe were calculated and determined, with some measures proposed to optimize the layout of piping system and the design of supports and hangers.
  • Vibration Diagnosis and Treatment of the Vertical Long Shaft Pump Motor in a Nuclear Power Plant
    Fu Jangyong, Liu Mingli, Wang Hongyan
    2019, 33(3): 201-204.
    Abstract ( )   Knowledge map   Save
    To solve the problem of structural resonance existing in the auxiliary motor matching the service pump of a nuclear power plant, a fault diagnosis was conducted based on spectrum analysis and natural frequency analysis, so as to analyze the variation law of vibration amplitude with excitation force and system stiffness, and the relationship between system stiffness and natural frequency. By changing the joint stiffness of the system, the vibration has been reduced effectively with good results obtained.
  • Discussion on Test Method for Self-aligning Ability of Elliptical Radial Bearings for Steam Turbines
    Wei Yingqiang
    2019, 33(3): 205-208.
    Abstract ( )   Knowledge map   Save
    A method was proposed for testing the self-aligning ability of elliptic radial bearings, together with an introduction to the measurement steps. To solve the problem existing in spherical surface fit of some steam turbines that the moment of force is out of tolerance, corresponding countermeasures were put forward based on an analysis of relevant operation conditions. Actual measurement results show that the out-of-tolerance problem has been solved. This may serve as a reference for assembly improvement of elliptical radial bearings with similar structures.
  • Research and Application of the Localization of Cooling Blowers for PG9171E Gas Turbine Exhaust Frames
    Hong Yaguang, Yin Chunhong, Chen Sitong
    2019, 33(3): 209-212.
    Abstract ( )   Knowledge map   Save
    For the PG9171E gas turbine exhaust frames, only two blowers with respective 50% capacity were equipped and no spare blower was prepared, this may bring great risk to normal operation of the unit. To solve this problem, a domestic blower with 50% capacity was newly added. Based on simulation results, the domestic blower was reasonably placed to realize switching operation among the three blowers with an introduction of Mark Ⅵe control system, which helps to eliminate hidden troubles and secure safety operation of the unit.
  • Slagging Analysis and Retrofit for a 330 MW Boiler
    Chen Wei
    2019, 33(3): 213-216.
    Abstract ( )   Knowledge map   Save
    To solve the problem of severe slagging in a power plant boiler, an analysis was conducted on the causes, following which, corresponding countermeasures were put forward. Results show that the used coal has a strong slagging tendency. The problem could finally be solved by replacing part of the coal, burning blended coal,increasing the primary air flow rate and improving the fineness of the pulverized coal.
  • Retrofit of an IP Cylinder Exhaust Heat-supply System in a 350 MW Steam Turbine Unit
    Dai Jiangang
    2019, 33(3): 217-219,222.
    Abstract ( )   Knowledge map   Save
    An introduction is presented to the arrangement and control logics for the thermal system of a steam turbine unit in the retrofit of its IP cylinder exhaust heat-supply system, including adding a three-direction link between the IP and LP cylinder, designing the control logics required by the retrofit, which help to ensure the safety operation of the power generation and heat supply facilities, achieving the retrofit objective for the IP cylinder exhaust heat-supply system of the steam turbine.
  • Effectiveness Analysis on the Addition of a Low-temperature Economizer to a 150 MW Unit
    Wang Cao, Peng Yilin, Tian Xinming
    2019, 33(3): 220-222.
    Abstract ( )   Knowledge map   Save
    To reduce the energy consumption of a 150MW power unit, a retrofit was conducted by installing a low-temperature economizer to the unit. The operation parameters of related low-temperature economizer and electrostatic precipitator (ESP) were then analyzed after the retrofit. Results show that under full load conditions after retrofit, the operation parameters of the low-temperature economizer can basically meet the design requirements; the standard coal consumption and the mean dust concentration at ESP outlet could be reduced by 2.39 g/(kW·h) and 45% accordingly, indicating high economic benefits.