饮食业后堂噪声综合控制技术研究

分析了饮食业后堂噪声的频率特性,采取隔声、吸声、消声控制技术和防油雾措施,并独创设计了一种排油烟通风复合消声器,解决了同时排油烟和降噪的难题,得出了饮食业后堂噪声综合控制的有效工艺。经2年的实际应用证明,降噪能力强,可满足60dB(A)的区域环境标准的要求,效果稳定,是一项值得推广的技术。特别是排油烟通风复合消声器、通风消声窗及“声闸”的设计参数,可在同类噪声控制中推广应用。     

湖南耐寒桉树优良单株组培研究

本研究以湖南省林业技术推广总站在湖南选育的17个耐寒桉树优良单株为试验材料,进行组培繁殖,有14个优良单株成功地诱导出了愈伤组织或芽。结果表明,以一年生扦插苗的当年生嫩枝作为外植体来源,污染率低且愈伤组织和芽的诱导率高;0.25％氯化汞消毒15—20分钟,可将污染率控制在70％以下,且对外植体的损害最小;按树最佳的诱导培养基为:1/2MS+BA_(1.0)+IBA_(0.25),最佳的继代培基为:MS+BA_(1.0)+KT_(1.0)+VB2_(10)。     

多能场协同紫外光催化降解甲基橙的实验研究

以甲基橙为模拟废水,负载型纳米TiO2为光催化剂,在自制的多能场组合反应器中,初步研究了电场和超声场协同紫外光催化降解水中甲基橙的特点和规律。结果表明,在偏置电场电压为20 v,超声场声频为21.33 kHz、声强为0.375 W/cm2,紫外光波长为366 nm,功耗为O.25 W/mL,TiO2催化降解负荷为1.25 mL/cm2的条件下,对浓度为4 mg/L的甲基橙溶液分别处理30 min和90 min,脱色率分别可达91.67％和95.36％;比单一紫外光催化降解脱色率分别提高86.59％和86.79％。     

不同曲率弯曲巷道爆炸冲击波传播特性数值模拟研究

为研究爆炸冲击波在不同曲率弯曲巷道内的传播规律,采用数值模拟手段建立了不同曲率弯曲巷道爆炸模型,分析了爆炸冲击波在巷道内的传播特性及其变化规律, 并结合冲击波超压对人体的伤害程度分类,研究了不同曲率弯曲巷道内爆炸破坏效应分区。模拟结果表明,弯曲角度改变了巷道内冲击波超压分布,随着巷道弯曲角度的不断增大,壁面反射对冲击波超压峰值分布起主要作用,随着传播距离的增加,冲击波超压峰值衰减显著,体现了超压峰值变化的距离效应。此外,巷道弯曲角度的增加整体减小了爆炸损伤严重程度。研究结果可实现对不同曲率弯曲巷道内冲击波超压分布的预测,并为巷道内爆炸事故预防及应急救援提供借鉴。     

浅谈提高爆炸容器使用安全性的技术措施

针对爆炸容器工作时 ,产生的爆炸冲击波、破片、有害气体、振动及噪声等危害因素 ,简述了国内外使用爆炸容器时 ,采取的一些相关安全技术措施 ;提出了将结构健康监测技术应用于爆炸容器寿命安全评估的构想     

爆炸冲击环境下内凹蜂窝型梯度结构响应特性研究*

为提升应急救援人员防护服抗爆能力,减少爆炸事故中人员伤亡数量,以内凹蜂窝型梯度结构为研究对象,采用爆炸冲击实验与数值有限元法相结合的研究手段,通过改变胞元尺寸与胞元凹角对梯度蜂窝结构进行优化,分析梯度结构在爆炸冲击环境下冲击波衰减效率和力学响应规律。结果表明:同等质量条件下,内凹蜂窝结构尺寸梯度为2.58 mm-3.40 mm-2.58 mm、角度梯度30°-22.5°-30°时对冲击波的衰减效应最佳,衰减效率分别为85.44%,82.29%。研究结果可为同时满足轻质、高强抗爆要求的防护服结构设计提供技术支撑。     

Fracture criterion and control plan on CO2 pipelines: Theory analysis and full-bore rupture (FBR) experimental study

Pressurized pipelines are the most reliable and cost-effective option for the long-distance transportation of CO₂ from an emitter to an onshore storage site. Propagating or unstable factures are considered catastrophic pipeline failures, resulting in a massive escape of inventory within a short period of time. The decompression curve for CO₂ exhibits a large drop in decompression wave speed at the phase transition pressure, leading to a higher driving force for crack propagation. The study of fracture control plans is very important for assessing the possibility of fracture propagation and preventing unstable fracturing along CO₂ pipelines. Three full-bore rupture (FBR) experiments were performed using an industrial-scale (258 m long, 233 mm inner diameter) CO2 pipeline with initial CO2 states of gaseous, dense and supercritical phases, respectively. The relation between the decompression velocity and the pipeline fracture propagation velocity was analyzed during the process of buried CO2 pipeline release. A fracture propagation criterion was established for the buried CO₂ pipeline. For the gaseous CO₂ leakage, the pressure plateau corresponding to the decompression wave velocity only appeared near the closed end of the pipeline. For the dense CO₂ leakage, the pressure plateau corresponding to the decompression wave velocity was observed near the saturation pressure after rapid decompression. For the supercritical CO₂ leakage, the pressure plateau corresponding to the decompression wave velocity was observed in the stage when the supercritical CO₂ transformed into the two phases of gas and liquid. Compared with the gaseous and dense CO₂, for the supercritical CO_2, the initial decompression wave velocity was the smallest, and the requirement of the pipeline safety factor was the highest.     

压力脉冲波法天然气管道堵塞检测研究

为快速检测出天然气管道堵塞位置、长度及堵塞程度,解决天然气输运管道中堵塞定位难题,探讨压力脉冲波法管道堵塞检测的可行性与效果.搭建长220 m的压力脉冲波堵塞检测实验系统,进行多组连续性长堵塞检测实验和水堵检测实验.结果表明:连续性长堵塞检测实验中堵塞前沿反射信号为负压波,堵塞后沿信号为正压波,且波形清晰可辩,其多组实...     

除尘管道内木粉尘爆炸压力传播规律研究

为了探明除尘管道中粉尘爆炸压力的传播规律,利用自制通风除尘管道爆炸特性测试装置进行试验。研究结果表明:整个管道中粉尘爆炸压力波的传播过程可以分为自由传播阶段、管壁反射阶段和一维传播阶段;压力波在传递过程中处于边移动边生长的状态,具有压力累积效应;除尘管道中粉尘爆炸压力波幅及平均升压速率均与粒径呈负相关关系,二者随浓度变化呈现先上升后下降的趋势;利用Matlab分析了浓度、粒径对压力波的交互效应,表明二者交互作用显著。     

Influence of the elastic behaviour of liquids on transient flow from pressurised containments

Release of liquids from vessels and pipelines is a very important scenario in consequence assessment. When the operating pressure is significant, its evolution and the corresponding discharge rate are affected by the elastic behaviour of the liquid. Bulk modulus is the key-driver of the related fluid-dynamics and is expected to govern the elastic-to-atmospheric pressure transition. Despite the well known physical background, the availability of release models relevant to the elastic phase is rather poor, compared to those relevant to vapours, gases and atmospheric liquids. On the other hand, if the operating pressure is high, release times and dynamics are expected to be strongly affected by the elastic behaviour and prediction of release time and flow rate is fundamental. This article carries outs a general analysis of the elastic behaviour of liquids, including water and hydrocarbons. Lumped (vessel-type) and distributed (pipeline) parameters systems have been modelled with the aim to characterize the pressure evolution during the elastic phase and to evaluate the significance of the associated duration. The findings have shown that, depending on pressure and geometric features, the importance of the elastic phase is high and that the availability of reliable and relatively simple models could be beneficial in consequence assessment. The approach is strictly valid for non-boiling liquid, but accounting for vaporisation of flashing or boiling liquids such as LPG and LNG would not imply significant complications.