600 MW机组锅炉掺烧劣质煤技术经济性研究

为了减少炉膛结渣,优化劣质煤掺烧和提高电厂收益,通过劣质煤掺烧比例、磨煤机组合方式、炉膛火焰温度、还原气体分布、SO₂质量浓度、结渣行为等现场试验,研究了600 MW亚临界机组锅炉掺烧劣质煤技术经济性。结果表明：机组可采用3台磨煤机掺烧中高硫分煤的方式安全运行,最大掺烧比例为37%,锅炉未出现明显的结渣现象;在最大掺烧比例时,烟气SO₂质量浓度明显上升,但脱硫系统仍有较大裕度;经济性评价表明尽管掺烧小幅增加了供电煤耗,但劣质煤价格低廉使发电成本明显降低。现场试验和经济性评价方面的研究,为同类型机组优化掺烧劣质煤提供了思路和参考。     

基于主成分分析法的不同地区煤储层瓦斯吸附量差异性研究

为了准确有效地预测煤储层瓦斯吸附量,以我国沁水盆地和鄂尔多斯盆地东缘的典型煤层气区块为研究对象,采用主成分分析法确定煤储层瓦斯吸附量影响因素的主成分,进而利用主成分建立煤储层瓦斯吸附量模型.结果表明:从8个影响煤储层瓦斯吸附量因素的指标中提取出4个主成分,这4个主成分对原指标系统的信息解释达到了86.804％;不同区块...     

用于降低接触热阻的复合黏结材料的制备优化

基于提高吸附床的导热性能,研制一种可涂于吸附床与吸附剂之间降低接触热阻的耐高温耐腐蚀的高导热复合黏结材料。通过稳态试验研究导热填料、稀释剂与偶联剂等因素对复合黏结材料热导率的影响,采用正交试验方法优化复合黏结材料的配制方案。研究结果表明:复合黏结材料的导热性能随着Al₂O₃导热填料的质量分数的增加而提高,采用10 μm Al₂O₃导热填料粒子的导热性能略高于采用35 μm Al₂O₃导热填料粒子的复合黏结材料,10 μm Al₂O₃导热填料粒子用质量分数8%的偶联剂处理,复合黏结材料的热导率最高。采用适当配比的导热填料、稀释剂与偶联剂能显著提高复合黏结材料的热导率。     

1000MW燃煤机组工业废水零排放改造中脱水机的调试优化运行研究

以华能某2×1000 MW燃煤机组为例,对全厂原有工业废水处理系统进行升级改造,从而实现工业废水系统持续稳定运行.改造的重点在于脱水机的调试运行,实现脱水机在满足工业废水系统出力要求的基础上,连续稳定地产出合格的回用水和污泥.     

基于ANSYS/LS-DYNA高速弹头冲击仿真

高速弹头的侵彻问题是军工防护等领域研究的一个重要课题;采用有限元仿真软件ANSYS/LS-DYNA为平台对高速弹头侵彻靶板的过程进行了数值模拟;选取Johnson-Cook本构模型来描述侵彻过程,得到了速度为1 300 m/s的子弹侵彻6 mm靶板的速度、加速度、能量变化曲线和VonMises应力云图,从而直观地显示靶板的变形情况和动态响应,有助于分析高速弹头的撞击过程;验证了ANSYS/LS-DYNA有限元仿真在分析侵彻问题中的可行性和优越性,对改进弹头和防护材料设计具有重要意义;并为防护材料设计进行高速冲击实验的研究提供了新的途径和思路。     

Theoretical and Experimental Studies for the Transient Response of Cavity

During the transient state of aero-engine, cavity has evidently transient characteristics in the secondary air system. To investigate transient characteristics, theoretical and experimental studies were implemented for both static and rotating cavities. First of all, the typical transient response phenomena in secondary air system were investigated based on the basic concepts of the dynamic process. According to the basic theory of gas dynamics, the causes of transient phenomena were analyzed in...     

硫黄硫化体系对天然橡胶性能的影响研究

以促进剂CBS用量作为变量,研究硫黄硫化体系对天然橡胶（NR）性能的影响。结果表明：促进剂CBS用量增大,混炼胶的F _max和F _max－F_L 增大, t₁₀和t₉₀缩短,硫化胶的压缩生热最低,压缩变形较小;促进剂CBS用量为2.5份的有效硫黄硫化体系硫化胶的拉伸性能最好,促进剂CBS用量为3份的有效硫黄硫化体系硫化胶的tan δ 峰值最小;在90 ℃以上,促进剂CBS用量为2和2.5份的半有效硫黄硫化体系硫化胶的热导率较高。     

Phase equilibria and crystal structure of ternary compounds in Al-rich corner of Al-Er-Y system at 673 and 873 K

Phase equilibria in the Al-rich corner of the Al-Er-Y ternary system from 65 at.% to 100 at.% Al at 673 and873 K were investigated,and the two isothermal sections were established by X-ray diffraction(XRD),scanning electron microscope(SEM) and electron probe micro analysis(EPMA).Three ternary-phase regions are observed and the phase relations are similar at both isothermal sections.There are two ternary compounds,and a complete crystal structures and composition ranges of the two ternary compounds are determined as τ₁(Al_75-76Er_15-22Y_2-10,R-3 m) and τ₂(Al_75-76Er_11-17Y_7-14,P6₃/mmc) via XRD,focused ion beam coupled with transmission electron microscope(FIB-TEM) and EPMA.Meanwhile,the solubilities of the third element in the binary compounds at both temperatures are measured.The solubility of Er inβ-Al₃ Y phase reaches to 6.6 at.% and that of Y in Al₃ Er phase reaches to 1.5 at.% after annealing at 873 K.The temperature effect is not obvious for the phase equilibria at 673 and 873 K,but it increases the solubility of Er in β-Al₃ Y,while it is not obvious for both the solubility of Y in Al₃ Er and that of Er and Y in(Al).The phase equilibria of the Al-Er-Y ternary system determined by the present work have provided new phase diagram data for a future thermodynamic assessment of this system.     

带束层角度对电动汽车轮胎性能的影响

采用有限元技术研究带束层角度对205/55R16电动汽车轮胎接地印痕、侧偏刚度和回正刚度的影响。结果表明：随着带束层角度的增大,轮胎接地印痕由方形逐渐变成偏圆形,接地印痕短轴长度变小,接地印痕长轴长度增大,接地印痕面积增大;在相同负荷、不同充气压力和相同充气压力、不同负荷下,随着带束层角度的增大,轮胎侧偏刚度均减小,回正刚度均增大。     

Research on HTML5 application cache poison attack

HTML5 application cache (AppCache) allowed Web browser to access Web offline.But it also brought a new method of cache poisoning attack that was more persisting.As for websites which used the AppCache,a novel poisoning method RFTM (replace file twice method),in which the attacker replaced the manifest file twice to poison the client’s AppCache,was proposed.Compared with the original attack,the legal server would not receive abnormal HTTP requests from the client in the attack.Therefore,changing the server configuration could not prevent the client from the RFTM AppCache poisoning.To avoid the attack mentioned above,a lightweight signature defense scheme Sec-Cache in application layer was designed.Furthermore,experiments show that it has good performance and compatibility.