热定型工艺对斜纹涤纶机织滤布透气性能的影响

通过改变热定型温度、时间等工艺条件测试了织物热定型前后的透气性的变化,探讨了热定型工艺参数对涤纶机织滤布透气性的影响规律;采用二次回归正交设计得出斜纹涤纶机织滤布透气性与定型工艺的非线性关系,建立了热定型工艺与织物透气性影响规律的二次回归非线性经验方程.在定型温度为212℃、定型时间为143 s时涤纶机织滤布的透气量达...     

Progress and recent trend in MILD combustion

Moderate or intense low oxygen dilution(MILD)combustion plays a significant role in the mitigation of combustion-generated pollutants and greenhouse gases whilst meeting thermal efficiency needs.However,due to the lack of the fundamental knowledge on this combustion,there is a misconception that MILD combustion should be established by high preheating of the air,which has limited its application.Our research and development on this combustion has been performed for several years. We have found that the requ...     

住宅辐射-送风末端冷负荷分担率研究——从热舒适及室内空气品质角度

以住宅建筑为研究对象,针对低、中、高负荷3种不同住宅负荷工况,对不同冷负荷条件下不同负荷分担率下的室内热环境进行了数值模拟,分别分析比较不同冷负荷分担率匹配时室内热舒适性水平及室内空气品质情况,从舒适和健康的角度,分析适宜的冷负荷分担率范围。研究结果表明辐射供冷末端承担的显热负荷分担率ωc〈0．7时,可将工作区人体热舒适性指标控制在舒适性标准允许范围内。从避免局部不舒适度方面讲,ωc宜取0．4～1。从室内空气品质角度讲,定风量模式低中负荷工况,ωc宜取0．5～0．9,高负荷工况,叫。宜取0．35～0．6;变风量模式,ωc值越小,室内空气品质越好。     

三相流管道输送技术研究

通过模型试验的方法研究了管道输送加气减阻的机理,分析了影响减阻效果的因素,进行了延长排距的计算,利用模型试验研究的结果进行了实船试验。研究表明,在绞吸式挖泥船的排泥管中加入适当压力和一定体积分数的气体,可以降低管道输送阻力和延长排距。     

Operation of a catalytic reverse flow reactor for the purification of air contaminated with volatile organic compounds

Catalytic oxidation in a reverse flow reactor is an attractive process for the decontamination of air polluted with volatile organic compounds (VOCs). In this paper several aspects of operating this type of reactor for air purification under strongly varying conditions will be discussed. For a successfit operation of such reactor a minimum amount of combustibles is required, and a simple theory is developed to predict this minimum value. This minimum amount is strongly influenced by the reaction kinetics, the heat transport in the packed bed and the adiabaticity of the reactor. To cope with a too low temperature level in the reactor for a complete conversion, an electrical heating device should be installed in the centre of the reactor bed to increase locally the temperature rapidly and efficiently. To control the maximum temperature in case of too high concentrations, extra air should be added to the feed.     

变风量空调系统恒温解耦控制优化

在室内恒温控制问题的研究中,变风量空调系统的房间送风量、冷冻水流量和风机转速三个输入变量与房间温度、送风温度和静压三个输出变量之间存在着不同程度的耦合关系,每个房间的温度控制会受到不同程度的干扰,严重时会影响到整个系统的稳定性.为解决上述问题,根据变风量空调系统的房间、表冷器、风机等各个子系统模型,通过寻找一个合适的开环传递函数矩阵,实现对系统的解耦控制,通过使解耦矩阵的对角元素为1,得到简化的解耦矩阵.比通常利用对角化方法和状态反馈矩阵方法直接求得的解耦矩阵要简单.运行空调实验结果表明控制回路之间干扰不明显,解耦控制效果良好.     

超视距空战飞行轨迹建模及仿真

超视距多目标攻击逻辑决策和空战态势评估是超视距空战研究的主要方面,但对空战战术影响较大的战机飞行轨迹和飞行参数的研究较少.通过对超视距空战和视距内空战的比较,分析了超视距空战的空战过程.根据超视距空战迎头攻击战术的特点,建立了相应飞行轨迹的数学模型,并求解了载机速度、载机发射导弹速度、转弯速度、载机转弯半径、目标机速度、载机飞行时间、转弯时间和导弹飞行时间之间的关系.通过仿真分析了飞行参数对飞行轨迹的影响,并根据载机性能约束条件,求解了飞行参数的最优解.仿真结果表明,飞行轨迹模型和最优飞行参数设计的合理性和可信性,可为超视距空战战术、战法决策等作战应用提供重要参考.     

Relationship of structure to properties of surfactants. 16. Linear decyldiphenylether sulfonates

The properties of some well-characterized sodium linear decyldiphenylether (C₁₀DPE)sulfonates have been studied. Among the properties investigated are dynamic and equilibrium surface tension, critical micelle concentration (CMC), area per molecule at the aqueous solution/air interface, wetting time by the Draves technique, foaming by the Ross-Miles method, solubilization, and hydrotropy. The decyldiphenylether moiety appears to be equivalent to a terminally substituted straight alkyl chain of 16 carbon atoms. The trialkyl- and dialkyl-mono-sulfonates have solubilities of < 0.01 g/dm³ in water, but are readily soluble in hexane. The didecyldiphenyl ether disulfonate (DADS) has a very low CMC value (1.0 × 10⁻⁵ mol dm⁻³) in aqueous 0.1 N Na⁺ solution (NaCl), characteristic of surfactants with two hydrophilic and two hydrophobic groups. It also has a much larger area per molecule at the aqueous solution/air interface than the monodecyldiphenyl-ether monosulfonate (MAMS) and a much higher surface tension at the CMC. MAMS has a much lower surface tension at a surface age of 1 second (γ_1s) than either DADS or the monodecyldiphenylether disulfonate (MADS). In agreement with γ_1s and γ_eq values, wetting times increase in the order: MAMS < DADS < MADS and initial foam heights decrease in the order: MAMS > DADS > MADS. Solubilization for three water-insoluble surfactants decreases in the order: DADS > MAMS > MADS, while hydrotropy is most pronounced with the disulfonates.     

500kV断路器因空气压力低告警导致断路器控制保护回路断线分析

针对天生桥换流站500kV三菱断路器因空气压力低告警导致断路器控制保护回路断线这一情况,根据工作站中出现的信号,结合断路器的控制、保护二次回路,对信号及其出现的缘由进行分析,评估断路器控制保护回路断线时,可能出现的安全生产风险,发现目前存在的问题,并对这些问题提出解决方案。     

调节阀“三断”保位方案在焦化厂的应用

根据厂区所使用的调节阀自身具备的功能以及生产工艺需求,选择合适的（三断）保位方案,分析了所选择方案的工作原理及优、缺点及适用条件.