烟囱高度合理性论证技术方法研究

通过研究有关烟囱高度合理性的国家标准、规定和方法,指出影响污染物落地浓度的主要影响因子,结合一些烟囱高度合理性设计的实例,总结出了一套论证烟囱高度合理性的方案,并从气象和环境空气影响角度对不同高度烟囱合理性进行了检验.分析结果表明,烟囱高度要以适合当地气象和环境空气质量实际情况为原则,最大限度地减轻污染物落地浓度对当地造成的不利影响.这对减轻污染和减少厂家经费投入以及对于指导大气环境影响评价工作具有重要的现实意义.     

电厂烟囱高度确定的技术方法

烟囱不仅是电厂生产工艺上为获得一定抽力的排气筒,更重要的是控制大气污染保护环境的重要设施.通过研究有关电厂烟囱高度合理性方法,指出影响污染物落地浓度的主要影响因素,并从气象和环境空气影响角度对不同高度烟囱合理性进行检验.本文实例分析结果表明,烟囱高度要以适合当地气象和环境空气质量实际情况为原则,最大限度地减轻污染物落地浓度对当地造成的不利影响,并从技术、经济的合理性方面进行分析和论证,这对减轻污染和减少资金投入以及对于指导环境空气影响评价工作具有重要意义.     

大气扩散浓度估算在锅炉房烟囱高度计算中的应用

锅炉房的烟囱已从单纯的排气装置发展成为控制污染、保护环境的设备。因此烟囱高度的正确估算对于环境影响评价工作、建设单位都至关重要。结合唐山某城区集中供热锅炉房环境影响评价案例,利用大气扩散浓度公式估算锅炉房烟囱高度。在计算过程中,考虑了烟气流速及当地常年风向、风速、稳定度等污染气象特征,由正态分布模式导出的简化公式导出最大着地浓度与烟囱有效高度的平方成反比,从而计算出烟囱高度。另外还总结烟囱设计中应注意的一些问题,为建有锅炉房的建设项目环境影响评价工作提供参考。     

A Methodology for Assessing Blast Protection in Explosive Ordnance Disposal Bomb Suits

To reduce human casualties associated with explosive ordnance disposal, a wide range of protective wear has been designed to shield against the blast effects of improvised explosive devices and munitions. In this study, 4 commercially available bomb suits, representing a range of materials and armor masses, were evaluated against 0.227 and 0.567 kg of spherical C-4 explosives to determine the level of protection offered to the head, neck, and thorax.

A Hybrid III dummy, an instrumented human surrogate [1], was tested with and without protection from the 4 commercially available bomb suits. 20 tests with the dummy torso mounted to simulate a kneeling position were performed to confirm repeatability and robustness of the dummies, as well as to evaluate the 4 suits. Correlations between injury risk assessments based on past human or animal injury model data and various parameters such as bomb suit mass, projected area, and dummy coverage area were drawn.     

基于CFD方法的燃煤电厂烟气排放数值模拟

为研究燃煤电厂的烟气扩散,采用计算流体力学（computational fluid dynamics,CFD）方法对燃煤电厂烟气排放中污染物（包含气态污染物和固态颗粒物）的扩散形态进行模拟.燃煤电厂的排烟方式主要有烟塔合一和烟囱两种,根据几何参数建立烟塔合一及烟囱的数值模型,采用纳维-斯托克斯方程（Navier-Stokes equations,N-S equations）求解流场及气态污染物浓度场,采用离散相模型（Discrete Phase Model,DPM）计算固态颗粒污染物运动轨迹.结果表明:对于气态污染物,由于冷却塔下游漩涡的卷吸作用,采用烟塔合一排放的烟气最大浓度和超标范围随环境风速的增加逐渐增大,不利于烟气扩散.但随着环境风速的增加,空气的对流作用逐渐增强,从而加速了烟气的扩散.在漩涡和环境风的综合作用下,烟气的最大浓度和超标范围在环境风速为6 m/s时达到最大值,随后随着环境风速增加而减小.采用烟囱排放的烟气由于漩涡作用很小,因此其最大浓度及超标范围随风速的增加呈递减趋势.得益于烟气在冷却塔内的预扩散,采用烟塔合一排放的烟气最大浓度比采用烟囱排放的烟气最大浓度低将近1个数量级,但这种优势会随着环境风速的增加而减小.对于固态污染物,冷却塔后方的漩涡会加速颗粒物的扩散,因此采用烟塔合一排放的颗粒物的扩散状态远优于采用烟囱排放的颗粒物的扩散状态.      

垂直发射装置排气道极限承压性能分析

目的研究导弹在意外点火时排气道的力学性能及导弹发射的安全性,对排气道的极限承压性能进行研究。方法建立排气道的极限承压的仿真模型,通过水压试验及发射试验,获取排气道不同种试验方式下的极限承压数据。结果排气道在导弹正常发射时承压设计值为0.3 MPa。极限承压仿真试验过程中,排气道在受到0.5 MPa压强时,所受应力超过材料最大抗拉极限。水压试验过程中,排气道受0.58 MPa压强时,其结构发生破坏。意外点火试验过程中,排气道所受最大压强值为0.24 MPa。结论排气道的极限承压能力可以满足正常发射及意外点火的发射要求,排气道的设计裕量充足。     

The Influence of Enhanced Side Impact Protection on Kinematics and Injury Measures of Far- or Center-Seated Children in Forward-Facing Child Restraints

Objective: To evaluate the influence of forward-facing child restraint systems’ (FFCRSs) side impact structure, such as side wings, on the head kinematics and response of a restrained, far- or center-seated 3-year-old anthropomorphic test device (ATD) in oblique sled tests.

Methods: Sled tests were conducted utilizing an FFCRS with large side wings and with the side wings removed. The CRS were attached via LATCH on 2 different vehicle seat fixtures—a small SUV rear bench seat and minivan rear bucket seat—secured to the sled carriage at 20° from lateral. Four tests were conducted on each vehicle seat fixture, 2 for each FFCRS configuration. A Q3s dummy was positioned in FFCRS according to the CRS owner's manual and FMVSS 213 procedures. The tests were conducted using the proposed FMVSS 213 side impact pulse. Three-dimensional motion cameras collected head excursion data. Relevant data collected during testing included the ATD head excursions, head accelerations, LATCH belt loads, and neck loads.

Results: Results indicate that side wings have little influence on head excursions and ATD response. The median lateral head excursion was 435 mm with side wings and 443 mm without side wings. The primary differences in head response were observed between the 2 vehicle seat fixtures due to the vehicle seat head restraint design. The bench seat integrated head restraint forced a tether routing path over the head restraint. Due to the lateral crash forces, the tether moved laterally off the head restraint reducing tension and increasing head excursion (477 mm median). In contrast, when the tether was routed through the bucket seat's adjustable head restraint, it maintained a tight attachment and helped control head excursion (393 mm median).

Conclusion: This testing illustrated relevant side impact crash circumstances where side wings do not provide the desired head containment for a 3-year-old ATD seated far-side or center in FFCRS. The head appears to roll out of the FFCRS even in the presence of side wings, which may expose the occupant to potential head impact injuries. We postulate that in a center or far-side seating configuration, the absence of door structure immediately adjacent to the CRS facilitates the rotation and tipping of the FFCRS toward the impact side and the roll-out of the head around the side wing structure. Results suggest that other prevention measures, in the form of alternative side impact structure design, FFCRS vehicle attachment, or shared protection between the FFCRS and the vehicle, may be necessary to protect children in oblique side impact crashes.     

不同排放标准下的燃煤电厂烟囱高度与落地浓度关系研究

燃煤电厂全面实施超低排放后,烟气污染物排放浓度及落地浓度得到较大程度降低,是否仍需采用高烟囱排放已引起各方关注.以西北某电厂为例,采用SCREEN3估算模式,对烟气污染物执行超低排放、特别排放及一般排放限值时,不同烟囱高度对应的最大落地浓度及落地距离进行预测.结果表明,执行超低排放限值后,SO2、NO2和PM10的最大落地浓度均显著降低,落地距离不发生变化;最大落地浓度受烟囱高度的影响较小,通过增加烟囱高度降低污染物落地浓度的效益不显著.     

宁夏地区餐厨废弃物管理现状及发展对策——以银川保绿特生物技术有限公司为例

为进一步探索宁夏地区餐厨废弃物管理模式,解决管理过程中存在的政策倾斜不足、产业链缺失、人才短缺等问题,在宁夏地区开展了餐厨废弃物产生现状及管理方式调研。以银川保绿特生物技术有限公司为例,讨论宁夏地区餐厨废弃物回收处置企业发展瓶颈,提出了建立健全长效机制、引导餐厨废弃物处置端口前移、引进全产业链回收利用项目及增加科研经费投入等方式,以改善宁夏地区餐厨废弃物收运、处置及资源化利用管理模式。     

关于焦化厂焦炉烟囱二氧化硫排放分析

论文通过介绍焦化厂的工艺流程,分析焦化厂硫的来源及去向,通过数据比对,分析焦炉烟囱SO2满足达标要求时,入炉煤中含硫量以及相应的脱硫效率之间的关系,得出焦炉烟囱SO2排放浓度达标所需的条件。