汽车尾气CO浓度分布理论研究意义及应用前景展望

阐述了汽车尾气CO浓度分布理论在汽车排放控制研究中的意义及应用前景，并综述了国内外汽车排放控制理论研究的概况。提出了用气固两项流场微分方程研究汽车排放CO浓度分布理论的研究方法，并用来确定我国轿车排放CO气体浓度梯度变化的数学规律和分析人员在与轿车不同距离下对人体危害定量标准的确定理论，研究分布对大气污染的程度的定量分析。该研究为其它车型和其它排放污染物的研究奠定理论基础，也为研制控制排放污染装置提供理论依据。     

耐久试验中不同测试循环下排放规律研究

采用标准台架循环(SBC)和标准道路循环(SRC)两种方式,分别对催化器进行耐久试验,并在不同耐久里程时分别进行排放试验。采用SBC方式时,随耐久里程增加,CO排放无明显变化,NO_x明显增大,THC有小幅增大;CO瞬态曲线由单峰态变为双峰态,双峰态峰值小于单峰态峰值;NO_x为双峰态,第1个峰值总体上呈增大趋势,第2个峰值无明显规律;THC为明显的单峰态,峰值总体上呈增大趋势。采用SRC方式时,随耐久里程增加,CO排放明显增大,NO_x也呈增大趋势,THC先增大后减小;CO瞬态曲线始终为单峰态,峰值呈增大趋势;NO_x为双峰态,第1个峰值与第2个峰值总体上均呈增大趋势;THC为明显的单峰态,峰值先增大后减小。     

Characteristics of gaseous and particulate pollutants exhaust from logistics transportation vehicle on real-world conditions

On-road vehicle tests of three heavy duty diesel trucks were conducted by a portable emission measurement system (PEMS) in Chengdu, China. SEMTECH-ECOSTAR provided by Sensors Inc. was employed to detect gaseous emissions and MI2, an emissions measuring instrument powered by the Pegasor Particulate Sensor (PPS) was used to detect particulate emissions during the tests. The impacts of speed, acceleration and engine load on emissions were analyzed. The average nitrogen oxides (NOx) emission factors of the heavy duty diesel truck (HDDT), medium-duty diesel truck (MDDT), light duty diesel truck (LDDT) were 7.29, 5.29 and 5.53 g/km. The particulate emission factors were 0.60, 0.30 and 0.14 g/km respectively, higher than the similar reported in the previous studies. Both gaseous and particulate emission exhibit significant correlations with the change in vehicle speed, acceleration and power demand. The highest emission was generally in high VSPs and higher loads. High engine load caused by aggressive driving was the main factor of high emissions for the vehicles on real-world conditions.     

Modeling the effects of vehicle emission taxes on residential location choices of different-income households

Taxing vehicle emissions has been advocated as an effective measure to solve the smog and haze problems in China. This paper investigates the effects of vehicle emission taxes on residential segregation in a model of a monocentric city with two income classes. The proposed model explicitly considers the interactions among three types of stakeholders, namely the authority, property developers and heterogeneous households in terms of income level. The properties of the proposed model are analytically explored and the optimal vehicle emission taxes that maximize the social welfare of the urban system are determined. The conditions under which either the rich or the poor lives in the urban central area while the other class in the suburb are identified. The findings show that (i) a high emission tax can drive the low-income households to migrate from suburbs to urban central areas, and the high-income households to migrate from urban central areas to suburbs; (ii) the implementation of the vehicle emission taxes can effectively reduce the air pollution cost and increase the total social welfare of the urban system; and (iii) the emission tax policy may incur inequity issue in terms of change in utility levels of different income classes before and after introducing the vehicle emission taxes.     

A two-stage optimization approach for sulphur emission regulation compliance

In this paper, we present a two-stage optimization model for the machinery system selection problem. The objective is to minimize total cost, while aggregated power requirement and emission regulations are constraining the problem. Future fuel prices are considered to be uncertain. From a set of alternatives, the machinery configuration providing the lowest total cost is found. Also design flexibility in terms of future reconfiguration possibilities is taken into account. The machinery selection for a 2000 TEU container vessel is used as an illustrative case. Five initial machinery concepts are considered: diesel machinery, diesel machinery with a scrubber system, dual fuel (DF) machinery, pure gas engines, and a DF ready machinery. There is also a set of reconfiguration possibilities available for each alternative. From solving the case study, DF machinery is found optimal, while pure gas machinery is close to equally good. By solving the problem with deterministic fuel prices, the value of flexibility is not properly accounted for, resulting in an unreasonably high total cost for the flexible machinery alternatives. This demonstrates the need for a decision support approach that explicitly handles future uncertainty, as the two-stage stochastic model presented in this paper does.     

Integrated data-driven modeling to estimate PM2.5 pollution from heavy-duty truck transportation activity over metropolitan area

Based on the national emission inventory data from different countries, heavy-duty trucks are the highest on-road PM_2.5 emitters and their representation is estimated disproportionately using current modeling methods. This study expands current understanding of the impact of heavy-duty truck movement on the overall PM_2.5 pollution in urban areas through an integrated data-driven modeling methodology that could more closely represent the truck transportation activities. A detailed integrated modeling methodology is presented in the paper to estimate urban truck related PM_2.5 pollution by using a robust spatial regression-based truck activity model, the mobile source emission and Gaussian dispersion models. In this research, finely resolved spatial–temporal emissions were calculated using bottom-up approach, where hourly truck activity and detailed truck-class specific emissions rates are used as inputs. To validate the proposed methodology, the Cincinnati urban area was selected as a case study site and the proposed truck model was used with U.S. EPA’s MOVES and AERMOD models. The heavy-duty truck released PM_2.5 pollution is estimated using observed concentrations at the urban air quality monitoring stations. The monthly air quality trend estimated using our methodology matches very well with the observed trend at two different continuous monitoring stations with Spearman’s rank correlation coefficient of 0.885. Based on emission model results, it is found that 71 percent of the urban mobile-source PM_2.5 emissions are caused by trucks and also 21 percent of the urban overall ambient PM_2.5 concentrations can be attributed to trucks in Cincinnati urban area.     

Integrating a simplified emission estimation model and mesoscopic dynamic traffic simulator to efficiently evaluate emission impacts of traffic management strategies

This paper presents a computationally efficient and theoretically rigorous dynamic traffic assignment (DTA) model and its solution algorithm for a number of emerging emissions and fuel consumption related applications that require both effective microscopic and macroscopic traffic stream representations. The proposed model embeds a consistent cross-resolution traffic state representation based on Newell’s simplified kinematic wave and linear car following models. Tightly coupled with a computationally efficient emission estimation package MOVES Lite, a mesoscopic simulation-based dynamic network loading framework DTALite is adapted to evaluate traffic dynamics and vehicle emission/fuel consumption impact of different traffic management strategies.     

某型高速动车组开关侧门故障分析及解决措施

高速动车组的空调通风系统会对车内外产生一定的压力差,而塞拉门的开启与关闭需在一定的压力范围内才能正常工作。针对无法开关塞拉侧门的故障进行了分析,主要是由于车内外的压力差引起,从而对空调通风系统进行了一定的改进和优化,以保证侧门的正常开闭。     

船舶废气清洗系统SCHEME A方案设计及验证研究

为了降低船舶尾气造成的环境污染,同时也为满足MARPOL 73/78 ANNEX VI修正案的相关规定,越来越多的船舶已通过加装废气清洗(EGC)系统来减少船舶尾气硫化物的排放。文中以某型采取SCHEME A认证方案的船为例,从系统设计、试验与达标要求等,进行废气清洗系统SCHEME A认证方案的研究。研究结果表明:方案设计及验证结果满足规范要求,该废气清洗系统可用于同等设计的船舶而免于测试。     

Determination of wholesome elements and heavy metals in safflower （Carthamus tinctorius I.. ） from Xinjiang and Henan by

An inductively coupled plasma mass spectrometry （ICP-MS） or inductively coupled plasma atomic emission spectrometry （ICP-AES） was developed to determine 19 elements in safflower, a traditional Chinese medicinal herb from Xinjiang Autonomous Region and Hen