外循环式UASB反应器处理槟榔废水

在中温（35±2℃）条件下,利用外循环式UASB反应器处理中高有机浓度的槟榔加工废水,并着重探讨了水力停留时间（HRT）对厌氧消化的影响。研究表明,当反应器稳定运行,水力停留时间为1 d,进水COD浓度5 000 mg/L左右,容积负荷在2.53-5.25 kg COD/（m3·d）时,COD去除率在38%以上,出水COD〈3 000 mg/L,平均产气率为0.41 m3/kg COD;若水力停留时间延长至4 d,容积负荷为1.26-1.30 kg COD/（m3·d）,COD去除率可以达到79%,出水COD〈1 200 mg/L,出水可生化性下降,BOD5/COD平均为0.28,实验取得了良好的处理效果,为利用厌氧技术处理槟榔加工废水提供了设计依据。     

中国省域物流作业的CO2排放量测评及低碳化对策研究

物流活动是主要碳排放源之一,是温室气体减排、缓解气候变化的重要领域,从省域层面对我国物流作业的碳排放量进行核算和比较分析,对于从宏观上掌控各省域物流作业碳排放量及省域物流作业节能减排目标确定具有重要的意义.本文首先给出了省域物流作业CO2排放量测量模型,测算了不同能源的CO2排放因子及排放系数.然后,以物流作业直接能耗法核算我国各省域2008年物流作业的CO2排放指标,包括各省域的CO2排放量和单位货物周转CO2排放置,对比分析发现:我国省域之间物流活动产生的CO2排放量存在着地域不平衡性,CO2排放量中东部大部分省域要高于西部省域,而单位货物周转CO2排放置西部大部分省域要高于中东部省域.最后,根据物流作业的特点,分别从发展低碳运输、探索物流作业的技术性减碳方法、实行精细化物流作业管理、建立完善的节能减排考核与激励约束机制、制定低碳物流作业标准与打造低碳物流示范企业等五个主要的方面,阐述了我国物流作业的低碳化对策,以期促进我国低碳物流的发展.     

高速高架复合道路交通噪声的分析和预测

以济青高速公路中青岛市郊一段典型高架结构公路为例,分析了高架复合道路交通噪声与各有关因素的关系,提出了高速高架复合道路交通噪声的预测数学模型,其理论计算值与模拟实测结果基本相符。     

常用金属材料表面积冰仿真分析及试验验证

目的 通过实验室模拟不同环境条件的降雨试验,研究金属材料表面的积冰行为。方法 基于数值仿真分析,选择适合积冰的放置方法,针对金属材料开展降雨环境模拟试验。以水温、环境温度、试件温度、喷淋高度、试件厚度为基本参数,分析实验室模拟降雨环境下不同金属材料表面的积冰程度。结果 仿真分析可以得到理想状态的理论分析结果。当水温为5℃,环境温度为–1.5、–3℃时,在高度3、4 m喷淋30 min后,除10 mm厚度7075铝合金外,被试材料积冰均难以达到6 mm。当水温不变,环境温度为–6℃时,在高度3、4 m喷淋30 min后,部分被试材料达到6 mm积冰。当试验环境温度不变而水温降低时,水温与积冰呈较明显的递增趋势。在其他试验条件相同的情况下,环境温度为–9℃时,所有被试材料积冰均达到6 mm以上。结论 调整各项试验环境参数可控制金属材料表面的积冰程度。在相同水温、喷淋高度和材料厚度的条件下,随着环境温度的降低,积冰增加,4 m喷淋高度的积冰优于3 m喷淋高度。可将试验数据与理论分析数据相融合,使用理论分析结果进行方向预测,利用环境模拟试验数据对其进行修正。     

组合式通风打磨台风量对粉尘控制效果的影响

打磨作业过程中,利用组合式通风打磨台进行通风除尘已得到广泛应用,但大多根据经验设置通风参数。以数值模拟为研究手段,采用CFD-DPM风流-粉尘耦合数值模拟方法,研究粉尘最大浓度和呼吸带粉尘浓度与风量分配和总排风量的关系,对组合式通风打磨台进行通风除尘系统参数优化,为金属打磨粉尘治理提供依据。研究结果表明:当组合式通风打磨台总排风量为1 850 m3·h-1、台面与壁面的配风比K=1.67时,粉尘质量浓度较低,防尘效果最好。     

苏州火车站地下环形车道通风安全及火灾烟控技术研究

以苏州火车站地下环形车道的营运通风方案为对象,对正常运营和火灾时的需风量进行计算和分析,并采用计算流体力学方法对车道火灾模式下排烟的有效性进行了模拟研究,确定该车道采用竖井送排式加射流风机进行通风,竖井设在车道的西北和东南两个对角处,有效面积分别为10.2 m2和11.7 m2,为地下空间运营通风方案选择和计算提供参考依据。     

CO2 transportation for carbon capture and storage: Sublimation of carbon dioxide from a dry ice bank

Climate change is being caused by greenhouse gases such as carbon dioxide (CO₂). Carbon capture and storage (CCS) is of interest to the scientific community as one way of achieving significant global reductions of atmospheric CO₂ emissions in the medium term. CO₂ would be captured from large stationary sources such as power plants and transported via pipelines under high pressure conditions to underground storage. If a downward leakage from a surface transportation system module occurs, the CO₂ would undergo a large temperature reduction and form a bank of “dry ice” on the ground surface; the sublimation of the gas from this bank represents an area source term for subsequent atmospheric dispersion, with an emission rate dependent on the energy balance at the bank surface. Gaseous CO₂ is denser than air and tends to remain close to the surface; it is an asphyxiant, a cerebral vasodilator and at high concentrations causes rapid circulatory insufficiency leading to coma and death. Hence a subliming bank of dry ice represents safety hazard. A model is presented for evaluating the energy balance and sublimation rate at the surface of a solid frozen CO₂ bank under different environmental conditions. The results suggest that subliming gas behaves as a proper dense gas (i.e. it remains close to the ground surface) only for low ambient wind speeds.     

Comparison of constant volume balloons, model trajectories and tracer transport during ETEX

In the field phases of the European Tracer EXperiment (ETEX), an inert tracer was released for 12 h into the atmosphere and samples taken at several locations downwind. During the same time, several Constant Volume Balloons (CVB) (10 and 6 for ETEX first and second release, respectively) were launched into different altitudes and followed as far as 21–188 km, to indicate the initial dispersion directions of the tracer puff. A model simulating the CVB behaviour in hydrostatic meso-scale model forecasts is applied to ETEX data to demonstrate its capability to predict the tracer puff mean axis over long distances (−2000 km). CVB model results are first compared to air parcels trajectories and 2D (i.e. isentropic, isobaric and isodensity) trajectories. Then they are compared to the measured CVB trajectories and finally to the tracer puff trajectories. As expected, the CVB model and isodensity model trajectories are found to be identical. The 16 CVBs calculated trajectories nearly overlap the real ones over 21–188 km with mean absolute horizontal transport deviations less than 20 km (average value of 8.2 km). The corresponding relative transport deviations are less than 45% with an average value of 20.6%. Better predictions are obtained for the ETEX second release. During the 60 h following ETEX’s first release start, the simulated CVBs are mainly found in the area of the maximum surface concentrations of the released tracer, up to 2000 km. Up to 36 h after ETEX second tracer release start, the simulated CVB trajectories predict well the mean axis of the tracer puff, but failed later.     

考虑流固耦合的桥墩地震反应方法

跨海桥梁地震反应中,作用于桥墩上的动水压力具有明显的流固耦合特征。依据张量理论,推导时变区域散度变换关系及微分形式的几何守恒律;基于任意拉格朗日-欧拉描述,从采用欧拉描述的流体运动Navier-Stokes方程出发,推导时变区域的流体运动控制方程;给出流固耦合问题中的结构计算模型、耦合面接触条件、耦合场计算方法以及流场网格运动控制方法。以某跨海大桥为例说明桥墩地震反应方法,重点突出地震动输入、流场初始条件模拟等问题。计算结果表明:流固耦合理论能够模拟桥梁墩台地震反应中的流场和结构特性;流场初始条件的正确模拟可保证计算稳定性,并减少运算量;横向地震动激励下,桥墩基底剪力较大,纵向地震动激励下,结构运动剧烈;流固耦合系统中的线弹性结构在地震反应中具有明显的非线性特征。     

深井高温矿山热害控制新技术

阐述了对深井高温进行治理的技术措施。重点研讨了冰冷却技术．包括冰的制备、输送和融化技术等。作为一种新型深井降温技术．冰冷却系统由于其具有无静水压力、运行成本低、制冷效率高等突出优点,将在深井热害控制领域有着良好的应用前景。