Removal of adhesive dusts from flue gas using corona discharges with spraying water

Effective removal of adhesive and fine dusts from flue gas is very difficult. A new method of electrostatic precipitation of the corona discharges with spraying water(CDSW) was introduced. A new electrode configuration and the circulation spraying of water were employed in the method. The efficient electrostatic precipitation for adhesive and fine dusts can be accomplished without any drain water during a long operating period. The fundamental structure, discharge characteristics, mechanism of spraying and precipitation principle of the electrostatic precipitation using CDSW were described and analyzed. The V I characteristics, spraying state, supplying water quantity, influence of temperature and clean of the electrodes were researched in series experiments. The treating effects of circulating spraying using the corona plasma at the same time of electrostatic precipitation were investigated. The fundamental theories and experimental data were proposed, in order to effectively remove the adhesive dusts from flue gas using CDSW in practice.

Experiment on Gas Hydrates Formation by Water Spraying

An experimental investigation of natural gas hydrate formation has been conducted in a high-pressure water spraying reactor,which is cooled by the circulation water through an external cooling jacket.The results show that the morphology of hydrates formed by water spraying is like ice-slurry,which depends on the initial pressure and temperature.At a certain reaction pressure,the rate of hydrate formation is increasing with lower temperature.And also,the induction time of hydrate formation can be greatly shortened by water spraying compared to a quiescent system.Solution with appropriate surfactant sodium dodecyl sulfate (SDS) is found to improve the formation rate obviously.

Controlled Cooling of Hot Rolled Steel Channels by Water Spraying on the Final Cooling Bed

The objective of this research is to design an effective and relatively simple method for controlled cooling of hot rolled steel channels by water spraying on the final cooling bed after continuous cast steel billets passing through reheating furnace and sequential rolls to form channels. The need for this research arose as the channels were being cooled by forced air draft and natural convection which brought the temperature of the channels to about 270°C (518°F) at the shear stand. Steel at this temperature is too hot for convenient handling by the operators. Additional cooling by water spraying would be an acceptable solution but such cooling should be designed to enable an acceptable microstructure to be developed in the channel, as the microstructure of steel is strongly affected by nonequilibrium cooling through the eutectoid range: the mechanical properties of steel are a consequence of the microstructure. The approach followed in this investigation was first to develop a finite element method (FEM) to determine the temperature profiles in the channel subjected to cooling by water spraying and natural convection and arrive at suitable water spray rates to bring the temperature of the channel at the shear stand to levels suitable for convenient handling. PATRAN was used for preprocessing and ABAQUS for processing and post processing. Next, laboratory experiments were conducted to determine the microstructure and hardness of channels at the spray rates found suitable through FEM, to suggest the water spray rate most suitable for providing a temperature convenient for handling and for developing a desirable microstructure.

Effect of Hydration Aging and Water Binder Ratio on Microstructure and Mechanical Properties of Sprayed Concrete

In order to study the durability of sprayed concrete （shotcrete）, effects of different hydration aging and water-binder ratio （w/b） on the microstructure of cement paste and basic mechanical properties of test specimens were investigated. The phase composition, mass percentage of ettringite and portland in hydration production and microstructure were characterized by X-ray diffraction （XRD）, thermo gravimetry-differential scanning calorimetry （TG-DSC） and scanning electron microscopy （SEM）, respectively. The experimental results showed that changes in phase composition was more significant than those of water-binder ratio. With hydration aging and water-binder ratio increased, the mass percentage of ettringite and portland was decreased from 4.42%, 1.49% to 3.31%, 1.35%, respectively and the microstructure of paste was significantly compacted. Likewise, the mechanical properties including cubic compressive strength and splitting tensile strength were rised obviously.

The mechanics and deformation of high temperature steel frame rapidly cooled by spray water in fire fighting

A finite element is established for analyzing the dynamical mechanics and deformation of steel frame at high temperature when it is rapidly cooled down by spray water in fire fighting, The simulation result shows that remarkable mechanical coupling effects are produced in the process, and the sectional stress in rapid cooling down is found considerably larger than that in heating-up. Meanwhile, the stress and deformation of a beam mainly related to cooling rate and location are much larger than those of a column in rapid cooling, In fire fighting, the structure on the first or second floor was more dangerous than those on other floors in rapid cooling, These results could provide a theoretical reference for the design of steel structure and fire fighting.

Tribological Behavior of Thermally Sprayed WC Coatings under Water Lubrication

Thermally sprayed coatings have been used in various fields of industry for enhancing surface characteristics of materials and extending their service life. The contact surface of some mechanical equipment such as the fine pulverization equipment which is used in the woody biomass production process is required to have wear resistance in the water environment. Thermally sprayed coatings would be a good candidate to improve surface wear resistance under water lubrication. The objective of this study was to evaluate the tribological performance of thermally sprayed coatings under water lubrication. Thermally sprayed coatings which were classified into WC, WB and Ni spraying of three categories were compared with water-lubricated sliding test at a sliding velocity of 0.02 m/s and mean pressure of p0 = 10 MPa with a ring-on-disk apparatus. Thermally sprayed coatings showed comparatively high friction coefficient and well wear resistance under water lubrication. WC contained coatings showed better wear resistance than WB and Ni coatings. Thermally sprayed coatings showed obviously different mechanical properties and tribological behaviors, and the effect of wettability and hardness on tribological characteristics was discussed under water lubrication. Friction coefficient increased as the surface contact angle of thermally sprayed coatings increased. The wear rate decreased as the surface hardness of thermally sprayed coatings increased. Wear resistance of thermally sprayed coatings was excellent under water lubrication. WC contained coatings showed lower wear rate than WB and Ni coatings. WC-14CoCr coating showed the lowest wear rate.

STUDY OF THE HEAT AND HUMIDITY TRANSFER PROCESSES BETWEEN AIR AND WATER IN THE AIR WASHER

The processes of heat and humidity transfer between air and water are what to be studied mainly in the paper, we put forward some main factors which influence the processes of heat and humidity transfer in the air washer. We come to the conclusion that we can change these main factors to achieve different heat and humidity transfer processes and decide processes of heat and humidity transfer of air and water with the initial temperature of spraying water in the air washer. All these results can make things convenient for the air conditioning management.

Transient Heat Transfer Study of Direct Contact Condensation of Steam in Spray Cooling Water

We conducted a transient experimental investigation of steam–water direct contact condensation in the absence of noncondensible gas in a laboratory-scale column with the inner diameter of 325 mm and the height of 1045 mm. We applied a new analysis method for the steam state equation to analyze the molar quantity change in steam over the course of the experiment and determined the transient steam variation. We also investigated the influence of flow rates and temperatures ofcooling water on the efficiency ofsteam condensation. Our experimental results show that appropriate increasing of the cooling water flow rate can significantly accelerate the steam condensation. We achieved a rapid increase in the total volumetric heat transfer coefficient by increasing the flow rate of cooling water, which indicated a higher thermal convection between the steam and the cooling water with higher flow rates. We found that the temperature ofcooling water did not play an important role on steam condensation. This method was confirmed to be effective for rapid recovering ofsteam.

Water Content Effect on Oxides Yield in Gas and Liquid Phase Using DBD Arrays in Mist Spray

Electric discharge in and in contact with water can accompany ultraviolet（UV）radiation and electron impact, which can generate a large number of active species such as hydroxyl radicals（OH）, oxygen radical（O）, ozone（O_3） and hydrogen peroxide（H_2O_2）. In this paper, a nonthermal plasma processing system was established by means of dielectric barrier discharge（DBD）arrays in water mist spray. The relationship between droplet size and water content was examined,and the effects of the concentrations of oxides in both treated water and gas were investigated under different water content and discharge time. The relative intensity of UV spectra from DBD in water mist was a function of water content. The concentrations of both O_3 and nitrogen dioxide（NO_2） in DBD room decreased with increasing water content. Moreover, the concentrations of H_2O_2, O_3 and nitrogen oxides（NOx） in treated water decreased with increasing water content,and all the ones enhanced after discharge. The experimental results were further analyzed by chemical reaction equations and commented by physical principles as much as possible. At last,the water containing phenol was tested in this system for the concentration from 100 mg/L to9.8 mg/L in a period of 35 min.

有限元仿真模拟在超声喷水无损检测用水套设计中的应用

水套在超声喷水穿透检测中具有重要作用,为设计出具有良好耦合效果的水套,减少水流紊流对声波耦合的影响,本文通过构建探头套几何模型、物理建模、数值求解的有限元仿真方法对探头水套进行流体动力学仿真。结果表明,在无整流装置下,从入水口射入的水流撞击探头套内壁,产生严重紊流,进入出水管后,紊流状态仍然保持,水流流线方向杂乱。增加整流装置后,探头套内紊流得到很好的抑制,使得进入出水管的水流流线方向趋向一致,这种现象随着整流片增多而效果越加明显。本文为后续模拟水流经过出水口后的水柱状态,特别是随着初始水流速度加大后的水柱状态,以及利用有限元多物理场模拟功能,在加入声场后,模拟紊流状况下声场的变化打下了基础。

水喷雾对隧道遮挡火灭火性能及顶棚温度的影响

水喷雾系统作为一种有效的火灾扑救设施,被广泛应用于隧道等场所中。本研究基于1:8的缩尺寸双层隧道火灾试验平台(36 m长、单层隧道净高0.58 m),在该模型的下层隧道空间内开展了水喷雾试验,探究了水喷雾系统工作压力、开启时间、喷淋区段和开启组数等因素对火灾控制效果的影响。研究结果表明,水雾与火焰作用过程中火焰强化和燃烧抑制作用共同存在,燃烧抑制作用随着水喷雾压力的增加而增强,喷水压强超过0.30 MPa后燃烧抑制起主导作用;火源熄灭时间随着水喷雾区段的增加而缩短;越早启动水喷雾系统,越能迅速有效地将火场温度控制在较低水平,较晚开启水喷雾,高温汽化产生大量水蒸气,对燃烧产生阻隔作用,减弱火势的增长,同时水喷雾区段作用范围对隧道火灾烟气温度分布具有显著影响。

玄武岩纤维再生混凝土高温水冷损伤试验研究

为研究消防喷水灭火对纤维再生混凝土力学特性的影响,以玄武岩纤维(BF)体积掺量和历经最高温度为变化参数,共设计90个玄武岩纤维再生混凝土(BFRC)标准立方体试块,进行高温喷水冷却和抗压强度—声发射(AE)试验,探讨BF体积掺量和历经最高温度对BFRC力学性能的影响。结果表明,当温度升到1 000℃,试块表面脱落,骨料全部露出,试块的完整性遭到严重破坏;试块的剩余抗压强度在温度为200~400℃时下降趋缓,抵抗高温的效果明显;BFRC的高温喷水冷却受压损伤过程可分为初期压密与裂纹萌生阶段、裂纹扩展汇集阶段和峰后破坏阶段,各阶段的声发射振铃累计计数具有明显差异;拟合得到消防喷水灭火后BFRC抗压强度计算公式,可为评估不同BF体积掺量及历经最高温度对BFRC抗压强度的影响提供参考。

南京定淮门长江隧道新增自动灭火系统设计探讨

南京定淮门长江隧道为国内已通车的最长水下双管双层盾构隧道,鉴于定淮门长江隧道内现状无自动灭火系统,从隧道运营安全及防灾救援的角度考虑,拟在隧道内增设自动灭火系统。通过对国内水下隧道自动灭火系统设计的研究现状进行分析后,对隧道新增泡沫/水喷雾系统设计的重难点进行了分析,详细介绍了其针对性的设计解决方案及系统中的重要设备设施,包括:隧道专用泡沫喷头的选型、隧道泡沫/水喷雾系统分区设计、新增消防泵房及消防水池选址、消防管道设置、水力计算、系统控制要求及运行控制系统的设计等,总结了设计中的创新点并进行了展望。

高燃压中型运载火箭发射地面低高度排导技术

综合高燃压中型运载火箭高密度发射燃气流地面排导需求及烧蚀风险分析,提出基于地面双面导流装置与高位挡流墙结合的地面低高度排导技术方案。利用火箭发射燃气动力学研究总结的燃气流膨胀特性以及导流型面设计方法,解决了地面低高度排导技术涉及的地面导流装置导流型面气动设计以及尺度控制两个关键问题。地面低高度排导技术方案设计与燃气流场瞬态仿真多轮叠代,实现了燃气流排导烧蚀范围合理控制,避免了燃气流低高度排导烧蚀反溅影响箭体。地面低高度排导技术采用专利支撑的喷水冷却防护方案实现高燃压中型运载火箭发射燃气流强烧蚀环境发射系统、发射设施综合防护。基于喷流缩比试验相似性控制方法研制了1∶10比例喷流缩比试验系统,通过喷流缩比试验验证确认高燃压中型运载火箭发射燃气流能够实现地面低高度安全、顺畅排导,同时与发射台、导流装置结构融合的阵列喷水方案能够行之有效解决高燃压中型运载火箭地面低高度排导强烧蚀难题。

气压及水压对超声雾化喷雾粒径的影响研究

为了研究气压和水压对超声雾化喷雾粒径参数的影响;设计了实验平台,选用了阴离子型表面活性剂快渗T配置成浓度为0.07%的溶液进行实验;分析在不同气压和水压的组合之下超声雾化喷雾粒径参数的变化情况。实验结果表明:粒径参数D10、D50、D90、VAD、SMD、NAD随着气压的增加而减小,减小幅度受到水压影响;同时,以上粒径参数也随着水压的增加而增大,增大幅度也会受到气压影响,气压对雾滴粒径变化的影响程度大于水压;当压力改变时,粒径参数D10和NAD的变化趋势呈现高度一致,D50、VAD、SMD粒径增加量呈现高度一致,总体上D90变化幅度最大,D10变化幅度最小。

淋浴器水效检测试验装置的研究与实现

为了有效评价淋浴器的节水性能,推进水效标识制度的顺利实施和全面落实,该文致力于研制一种用于淋浴器水效检测的标准试验装置,可实现淋浴器喷射流量、喷射力以及流量均匀性的测量。该文通过理论分析和结构设计论证了方案的科学性和可行性,研制完成后用符合国家标准要求的淋浴器进行了实验验证,检测结果可靠。

基于5G通信技术农作物喷洒浇灌行走机器人的设计

结合农业灌溉和喷洒技术现状,设计了一种集灌溉功能和喷洒功能于一体的基于5G通信技术的作物喷灌行走机器人。该机具有体积小、适应性强、技术要求低、操作方便、成本低等特点,既能精准浇灌,又能立体、全方位地喷洒农药,减少水资源浪费,具有一定的推广应用价值。

通风喷雾对热应激肉牛生长性能、营养物质表观消化率、瘤胃发酵参数及血清指标的影响

本试验旨在研究通风喷雾对热应激肉牛生长性能、营养物质表观消化率、瘤胃发酵参数及血清指标的影响。选取12月龄左右、体重(420.22±46.67)kg的西门塔尔杂交公牛32头,随机分为2组,即对照组和通风喷雾组,每组16个重复,每个重复1头牛。试验期间2组肉牛大部分时间处于轻度或中度热应激环境中,试验组牛舍安装风机和喷雾装置,对照组牛舍不做任何处理。试验期共45 d,其中预试期15 d,正试期30 d。结果显示:1)与对照组相比,通风喷雾组肉牛的呼吸频率(RR)和直肠温度(RT)极显著降低(P<0.01)。2)与对照组相比,通风喷雾组肉牛的生长性能和营养物质表观消化率无显著变化(P>0.05),但平均日增重(P=0.089)和干物质采食量(P=0.075)均有显著升高的趋势。3)与对照组相比,通风喷雾组的肉牛瘤胃液pH极显著升高(P<0.01),丁酸浓度和乙酸/丙酸(A/P)比值显著升高(P<0.05)。4)与对照组相比,通风喷雾组肉牛血清中总胆固醇(TCHO)、皮质酮(CORT)含量及谷丙转氨酶(ALT)活性极显著降低(P<0.01),甘油三酯(TG)含量显著降低(P<0.05),高密度脂蛋白(HDL)含量显著提高(P<0.05)。5)与对照组相比,通风喷雾组肉牛血清中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性及总抗氧化能力(T-AOC)极显著提高(P<0.01),丙二醛(MDA)含量极显著降低(P<0.01)。6)与对照组相比,通风喷雾组肉牛血清中肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)和白细胞介素-6(IL-6)含量极显著降低(P<0.01),免疫球蛋白A(IgA)含量极显著升高(P<0.01),免疫球蛋白G(IgG)含量显著升高(P<0.05)。综上所述,在热应激条件下对牛舍进行通风喷雾能够降低肉牛直肠温度和呼吸频率,提高肉牛血清中免疫球蛋白含量和抗氧化水平,减少体内自由基累积,从而有效缓解热应激对肉牛生理和免疫功能以及抗氧化能力造成的负面影响。

基于传感器技术和水封效应协同的VOCs废气处理系统火灾监测及阻隔装置设计

为了预防和控制有机废气处理设施在运行过程中发生火灾事故,研究设计并制作了一种基于传感器技术和水封效应协同的VOCs废气处理系统火灾监测及阻隔装置。通过多种类型的传感器实时监测关键设备状态参数,早期发现火灾隐患,利用水喷淋阻火装置有效切断火焰在VOCs废气处理系统各区域及生产车间之间的传播路径,依靠逻辑控制程序实现各设备之间的安全联锁,保障VOCs废气处理系统的稳定运行,对当前企业废气处理设施的安全生产研究与探索具有一定的现实价值和意义。

某电厂锅炉水冷壁管及表面电弧喷涂NiCr涂层高温腐蚀行为机理分析

在低氮氧燃烧技术及深度调峰技术广泛应用的背景下,锅炉水冷壁管在服役过程中的高温腐蚀失效更为严重。对比研究了取自某电厂锅炉水冷壁管及高速电弧喷涂PS45涂层管的高温腐蚀行为特征,利用SEM、EDS、XRD等手段对腐蚀表面形貌特征、腐蚀产物组成及腐蚀截面特征进行了系统分析。结果表明:高速电弧喷涂PS45涂层可有效提高水冷壁管的抗高温腐蚀性能,其表面腐蚀层厚度较小;在高温服役过程中,PS45涂层因其高Cr、Ni元素而表现出更好的抗腐蚀性能,其表面腐蚀产物层较薄,但涂层粒子间的微观孔隙会导致高温腐蚀反应的侵入,甚至导致涂层/基材界面处水冷壁管的直接腐蚀。