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为了研究煤粉在O_2/H_2O气氛下SO_2的生成特性,选取3种特定含硫量和Ca/S摩尔比的煤粉,在沉降炉燃烧系统上对其在O_2/N_2、O_2/CO_2和O_2/H_2O 3种不同气氛下SO_2生成与煤灰自固硫特性进行研究。结果表明:神华煤SO_2排放质量浓度分别为120、125和129 mg/m~3、自固硫效率为26%、26.01%和25.29%,霍林河煤为153、145和160 mg/m~3以及35.65%、36.18%和35.43%,平顶山煤为1 007、1 071和1 064 mg/m~3以及18.54%、19.69%和19.6%,煤燃烧产生的SO_2以及煤灰的自固硫特性与燃烧气氛基本无关,与煤中硫的质量分数有关;含硫量越高的煤,SO_2排放越多;煤灰的自固硫作用并不随Ca/S摩尔比的增加而增加。 相似文献
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Fe2O3—Cr2O3选择性吸收涂层的研究 总被引:1,自引:0,他引:1
研究了Fe2O3-Cr2O3有机硅改性丙烯酸选择性吸收涂层及其与TiO2-SiO2选择性透过膜复合涂层的性能,讨论了影响涂层光学性能的因素。当黑色颜料用量为40-50%、粒径0.05-0.5μm、掺铝箔20%左右、涂层厚度的2μm时,涂层光学性能较佳。该涂层还有较好的力学、耐腐蚀及耐老化等性能。涂敷TiO2-SiO2薄膜后其光学性能、硬度和耐蚀性等均得到改善。 相似文献
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简述了汽车排放污染物的种类、危害及各种相应的减排控制措施,针对CO2这一温室气体提出了通过Na2O2吸收的解决方案,并给出了CO2吸收器的基本构造和反应机理,同时也指出了这一方案在实际运行中存在的问题。 相似文献
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UV-TiO2-H2O悬浮体系光催化降解聚乙烯醇 总被引:4,自引:0,他引:4
在自制的圆柱状夹套光化反应器中,以6W(Emax=365nm)紫外光灯为光源,研究了聚乙烯醇(PVA)的光催化降解行为,探讨了催化剂用量、pH及外加氧化剂等因素对PVA的光催化降解效率的影响。结果表明,催化剂用量与pH是影响PVA光解的重要因素,在酸性和碱性条件下PVA更易于光催化降解。另外,外加分子氧与过氧化氢可以有效地提高PVA的光解速率。PVA与降解60min后样品的红外光谱(IR)分析表明,PVA光催化氧化降解过程中羟基氧化形成羰基,碳-碳键的剪切形成短链化合物,实现了长链的断裂。 相似文献
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This study investigates the influence of the thermal physics of nanofluids on the critical heat flux (CHF) of nanofluids. Thermal physics tests of nanoparticle concentrations ranged from 0 to 1 g/L. Pool boiling experiments were performed using electrically heated NiCr metal wire under atmospheric pressure. The results show that there was no obvious change for viscosity and a maximum enhancement of about 5 to 7% for thermal conductivity and surface tension with the addition of nanoparticles into pure water. Consistently with other nanofluid studies, this study found that a significant enhancement in CHF could be achieved at modest nanoparticle concentrations (<0.1 g/L by Al2O3 nanoparticle concentration). Compared to the CHF of pure water, an enhancement of 113% over that of nanofluids was found. Scanning electron microscope photos showed there was a nanoparticle layer formed on the heating surface for nanofluid boiling. The bubble growth was photographed by a camera. The coating layer makes the nucleation of vapor bubbles easily formed. Thus, the addition of nanoparticles has active effects on the CHF. 相似文献
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La2O3改进Ni/γ-Al2O3催化剂上沼气重整制氢 总被引:1,自引:0,他引:1
为了寻求制备氢气的可再生资源及减少沼气的排放量,用浸渍法制备了不同La2O3含量的Ni/La2O3/γ Al2O3催化剂,用CH4/CO2体积比为1的混合气体模拟沼气,考察了还原温度、反应温度、空速等操作条件对该催化剂上沼气重整制氢性能的影响.并运用H2-TPR、TEM、TG-DSC等对催化剂进行了表征.结果表明:La2O3含量为6%的催化剂具有较好的综合性能;载体中掺杂适量La2O3能增加金属Ni的分散性,提高催化剂的可还原性及载体对CO2的吸附能力,从而改善了催化剂的活性及抗积炭性,使催化剂具有较好的稳定性.在100h的稳定性实验中,CH4及CO2转化率、H2及CO的选择性、H2/CO比平均值分别约为87.4%、88.8%、87.3%、93.8%及0.92.催化剂表面积炭速率非常低,仅为0.7279mg/(gcat·h). 相似文献
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In this study, the cooling performance of Al2O3–H2O nanofluid was experimentally investigated as a much better developed alternative for the conventional coolant. For this purpose the nanofluid was passed through the custom-made copper minichannel heat sink which is normally attached with the electronic heat source. The thermal performance of the Al2O3–H2O nanofluid was evaluated at different volume fraction of the nanoparticle as well as at different volume flow rate of the nanofluid. The volume fraction of the nanoparticle varied from 0.05 vol.% to 0.2 vol.% whereas the volume flow rate was increased from 0.50 L/min to 1.25 L/min. The experimental results showed that the nanofluid successfully has minimized the heat sink temperature compared to the conventional coolant. It was noticed also that the thermal entropy generation rate was reduced via using nanofluid instead of the normal water. Among the other functions of the nanofluid are to increase the frictional entropy generation rate and to drop the pressure which are insignificant compared to the normal coolant. Given the improved performance of the nanofluid, especially for high heat transportation capacity and low thermal entropy generation rate, it could be used as a better alternative coolant for the electronic cooling system instead of conventional pure water. 相似文献
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《Journal of power sources》2004,128(2):165-172
A series of ceramic glazes based on the SiO2–CaO–B2O3–Al2O3 system as sealant for intermediate temperature solid oxide fuel cell (ITSOFC) were investigated. Different ratios of B2O3/SiO2 and Al2O3/CaO were investigated to control softening process, phase separation, and crystallization. When B2O3/SiO2 ratio was in the range of 0.14–0.27, the glazes showed good wetting and bonding behavior with both 8 mol% yttria-stabilized zirconia (8YSZ) electrolyte and stainless steel interconnect which could satisfy the sealing demand at 850 °C. And the dimension stability can be kept for over 100 h by introducing ceramic felt and controlling the glazes viscosity in the range of 104 to 106 Pa s. By means of controlling Al2O3/CaO ratio in the range of 0.4–0.68, phase separation and crystallization were restrained effectively. After holding at 850 °C for 100 h, non-crystalline network in the glazes could be found, and a suitable viscous flow could well relax thermal stress. The sealing was effective even after 10 thermal cycles. Element analysis showed a good chemical stability at the ceramic glazes/stainless steel interconnect and ceramic glazes/8YSZ electrolyte interfaces. 相似文献
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《Journal of power sources》1996,63(1):141-144
The results from measurements of the d.c. electrical conductivity of the Na2ONaFB2O3Tl2O glass system and the transference number are reported. Electrochemical cells with the configuration Na/(30Na2O60B2O310Tl2O)/(graphite + iodine + electrolyte) have been fabricated and the discharge characteristics examined. The open-circuit voltage and the short-circuit current (maximum) are 2.27 V and 2.19 mA, respectively. Several other cell parameters are reported. 相似文献
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研究以并流共沉淀法制备Cu/La2 O3 /Al2 O3 系列催化剂催化甲醇水蒸气重整制氢反应过程 ,考察了La2 O3含量、反应温度、水醇比、液体空速 (WHSV)等因素对催化剂活性的影响。结果表明 :催化剂表现出较好的低温活性、高氢气选择性和稳定性。La2 O3 质量分数为 15 % ,在 2 5 0℃反应时 ,催化剂活性表现最佳 ,甲醇摩尔转化率为94 .5 % ,氢气选择性为 10 0 % ,CO摩尔分数为 1.0 5× 10 -7。 相似文献
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为了提高余热回收效率,强化沸腾换热。在池内沸腾强化换热实验中运用Al_2O_3-H_2O纳米流体,研究了Al_2O_3纳米流体浓度、工件壁厚、热流密度对强化率的影响及最优强化条件。单因素分析结果显示,随着Al_2O_3纳米流体浓度、热流密度增大,强化率先增大后减小;随着工件壁厚增大,强化率逐渐减小。在单因素分析结果上,采用响应曲面法中Box-Behnken Design(BBD)模型对池内沸腾传热条件优化,得出三个因素对强化率的影响大小为:Al_2O_3纳米流体浓度工件壁厚热流密度。并且Al_2O_3纳米流体浓度与热流密度交互作用对强化率最为显著。通过曲面响应拟合最佳实验条件为:质量浓度1.2 wt%、热流密度83 543 W/m~2、壁厚0.45 mm,模拟结果强化率为107%,实验测得最优条件下强化率为106%,与预测接近。 相似文献