Real World Driving Emission Characteristics and Mechanism of Heavy Duty Liquefied Natural Gas Vehicles
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摘要: 为掌握重型天然气车在实际道路行驶过程中的排放特性,使用便携式车载排放测试系统(PEMS)对2辆国Ⅴ重型天然气车(简称“国Ⅴ车辆”)和2辆国Ⅵ重型天然气车(简称“国Ⅵ车辆”)进行实际道路排放测试,分析了CO和NOx的排放特征和不同工况下的排放因子. 结果表明:①国Ⅴ车辆在3种代表性道路类型(市区路、市郊路、高速路)下CO和NOx的高排放区主要分布在中低速区域的加速阶段,而国Ⅵ车辆CO和NOx的高排放区在市区和市郊路上主要集中在速度大于30 km/h区间,在高速路两种污染物的高排放区分布较为零散. ②根据MOVES模型划分机动车比功率区间(VSP Bin)后发现,国Ⅵ车辆在Bin 11~Bin 18区间,CO和NOx排放速率基本稳定且处于较低水平;在Bin 21~Bin 28区间,CO和NOx排放速率均随VSP的增加而逐渐升高. ③国Ⅴ车辆综合工况下CO和NOx排放因子分别为国Ⅵ车辆的1.1~3.9和3.3~8.2倍,其中,在市区路分别为3.0~25.0和11.3~30.2倍. ④国Ⅴ车辆的NO2/NOx(浓度比,下同)远高于国Ⅵ车辆,且在高速路国Ⅴ和国Ⅵ车辆的NO2/NOx均最低. 此外,对比不同研究的测试结果发现,本研究国Ⅵ车辆的CO和NOx排放因子高于其他研究中国Ⅵ重型柴油车. 研究显示,国Ⅵ车辆的CO和NOx排放因子均低于国Ⅴ车辆,且在市区路下与国Ⅴ车辆差距更明显,因此,推广使用国Ⅵ天然气车,逐步淘汰采用稀薄燃烧技术的天然气车,能有效减少NOx的排放.Abstract: In order to investigate the emission characteristics of heavy-duty liquefied natural gas vehicle on real-world roads, real-world driving emission tests were performed on two China Ⅴ and two China Ⅵ heavy-duty vehicles using a portable emission measurement system (PEMS). The CO and NOx emission characteristics were analyzed. The results show that the high emission areas of CO and NOx for China Ⅴ vehicles on three types of roads (urban, rural, motorway) are mainly distributed under acceleration conditions of the low and medium speed. While high CO and NOx emission areas under urban and rural conditions of China Ⅵ vehicles are mainly distributed in the range of speeds greater than 30 km/h, and high CO and NOx emission areas under motorway conditions are discretely distributed. Notably, there are high NOx emission areas under deceleration conditions with high speed. After dividing the vehicle specific power (VSP) bin according to the MOVES model, it is found that when driving condition bins in Bin11-18, CO and NOx emission rates of China Ⅵ vehicles are stable and maintained at a low level. In Bin21-28, with the increase of VSP, CO and NOx emission rates of China Ⅵ gradually increase. Comprehensive emission factors of CO and NOx of China V vehicles are 1.1-3.9 and 3.3-8.2 times higher than those of China Ⅵ vehicles, respectively, and emission factors of CO and NOx under urban conditions are 3.0-25.0 and 11.3-30.2 times higher than those of China Ⅵ vehicles. NO2/NOx ratios of China Ⅴ vehicles are much higher than those of China Ⅵ vehicles. But NO2/NOx ratios under motorway conditions are lower than those under other road type conditions. Compared with the results of other studies, it was found that the CO and NOx emission factors of China Ⅵ heavy-duty vehicles were higher than those of China Ⅵ heavy-duty diesel vehicles. The study shows that CO and NOx emission factors of China Ⅵ vehicles are lower than those of China Ⅴ vehicles, and the difference is more obvious in urban roads.
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表 1 测试车辆技术参数信息
Table 1. Technical specifications of the test vehicle
项目 1号车 2号车 3号车 4号车 生产日期 2017年9月 2017年9月 2020年6月 2019年12月 排放阶段 国Ⅴ 国Ⅴ 国Ⅵ 国Ⅵ 燃料类型 天然气 天然气 天然气 天然气 技术类型 稀薄燃烧+OC 稀薄燃烧+OC 化学计量比燃烧+EGR+TWC 化学计量比燃烧+EGR+TWC 最大牵引质量/t 25 25 40 40 额定功率/kW 272 272 333 333 行驶里程/km 114 642 113 397 1 800 175 800 表 2 基于速度、加速度和VSP的工况区间划分
Table 2. Definition of driving condition bins based on velocity, acceleration and VSP
VSP/(kW/t) 速度(v)/(km/h) v<1.6 1.6≤v<40 40≤v<80 VSP<−4 Bin 0(a<−0.89 m/s2,
减速工况)、Bin 1
(怠速工况)Bin 11 Bin 21 −4≤VSP<−2 Bin 12 Bin 22 −2≤VSP<0 Bin 13 Bin 23 0≤VSP<2 Bin 14 Bin 24 2≤VSP<4 Bin 15 Bin 25 4≤VSP<6 Bin 16 Bin 26 6≤VSP<8 Bin 17 Bin 27 VSP≥8 Bin 18 Bin 28 -
[1] ZHANG Q J,WU L,YANG Z W,et al.Characteristics of gaseous and particulate pollutants exhaust from logistics transportation vehicle on real-world conditions[J].Transportation Research Part D:Transport and Environment,2016,43:40-48. doi: 10.1016/j.trd.2015.09.005 [2] SHAHBAZI H,HASSANI A,HOSSEINI V.Evaluation of Tehran clean air action plan using emission inventory approach[J].Urban Climate,2019,27:446-456. doi: 10.1016/j.uclim.2019.01.002 [3] 周成,李少洛,孙友敏,等.基于CMAQ空气质量模型研究机动车对济南市空气质量的影响[J].环境科学研究,2019,32(12):2031-2039.ZHOU C,LI S L,SUN Y M,et al.Influence of motor vehicles on air quality in urban areas based on the CMAQ model[J].Research of Environmental Sciences,2019,32(12):2031-2039. [4] LUO Z Y,WANG Y,LV Z F,et al.Impacts of vehicle emission on air quality and human health in China[J].Science of the Total Environment,2022,813:152655. doi: 10.1016/j.scitotenv.2021.152655 [5] 王燕军,何巍楠,宋国华,等.北京市2017年典型日机动车动态排放特征研究[J].环境科学研究,2021,34(1):141-148.WANG Y J,HE W N,SONG G H,et al.Vehicular dynamic emission characteristics of typical days in Beijing in 2017[J].Research of Environmental Sciences,2021,34(1):141-148. [6] LIU H,HUANG F F,DENG F Y,et al.Road freight emission in China:from supply chain perspective[J].Environmental Pollution,2021,285:117511. doi: 10.1016/j.envpol.2021.117511 [7] 黄志辉,纪亮,尹洁,等.中国道路交通二氧化碳排放达峰路径研究[J].环境科学研究,2022,35(2):385-393.HUANG Z H,JI L,YIN J,et al.Peak pathway of China's road traffic carbon emissions[J].Research of Environmental Sciences,2022,35(2):385-393. [8] LI M,LIU H,GENG G N,et al.Anthropogenic emission inventories in China:a review[J].National Science Review,2017,4(6):834-866. doi: 10.1093/nsr/nwx150 [9] DENG F,LV Z,QI L,et al.A big data approach to improving the vehicle emission inventory in China[J].Nature Communications,2020,11(1):2801. doi: 10.1038/s41467-020-16579-w [10] SONG H Q,OU X M,YUAN J H,et al.Energy consumption and greenhouse gas emissions of diesel/LNG heavy-duty vehicle fleets in China based on a bottom-up model analysis[J].Energy,2017,140:966-978. doi: 10.1016/j.energy.2017.09.011 [11] LAJEVARDI S M,AXSEN J,CRAWFORD C.Examining the role of natural gas and advanced vehicle technologies in mitigating CO2 emissions of heavy-duty trucks:modeling prototypical British Columbia routes with road grades[J].Transportation Research Part D:Transport and Environment,2018,62:186-211. doi: 10.1016/j.trd.2018.02.011 [12] MAC K M,ZHU S P,CERVANTES A,et al.Benefits of near-zero freight:the air quality and health impacts of low-NOx compressed natural gas trucks[J].Journal of the Air & Waste Management Association,2021,71(11):1428-1444. [13] MCCAFFERY C,ZHU H W,TANG T B,et al.Real-world NOx emissions from heavy-duty diesel,natural gas,and diesel hybrid electric vehicles of different vocations on California roadways[J].Science of the Total Environment,2021,784:147224. doi: 10.1016/j.scitotenv.2021.147224 [14] 胡明禹.天然气在交通领域的发展现状及立法建议[J].能源研究与利用,2020(5):36-40. doi: 10.3969/j.issn.1001-5523.2020.05.012 [15] LV L Q,GE Y S,JI Z,et al.Regulated emission characteristics of in-use LNG and diesel semi-trailer towing vehicles under real driving conditions using PEMS[J].Journal of Environmental Sciences,2020,88:155-164. doi: 10.1016/j.jes.2019.07.020 [16] THIRUVENGADAM A,BESCH M,PADMANABAN V,et al.Natural gas vehicles in heavy-duty transportation:a review[J].Energy Policy,2018,122:253-259. doi: 10.1016/j.enpol.2018.07.052 [17] 解淑霞,胡京南,鲍晓峰,等.天然气-汽油双燃料车实际道路排放特性研究[J].环境科学学报,2011,31(11):2347-2353.XIE S X,HU J N,BAO X F,et al.Real-world emission characteristics of natural gas-gasoline bi-fuel vehicles[J].Acta Scientiae Circumstantiae,2011,31(11):2347-2353. [18] THIRUVENGADAM A,BESCH M C,THIRUVENGADAM P,et al.Emission rates of regulated pollutants from current technology heavy-duty diesel and natural gas goods movement vehicles[J].Environmental Science & Technology,2015,49(8):5236-5244. [19] ZHU H W,MCCAFFERY C,YANG J C,et al.Characterizing emission rates of regulated and unregulated pollutants from two ultra-low NOx CNG heavy-duty vehicles[J].Fuel,2020,277:118192. doi: 10.1016/j.fuel.2020.118192 [20] MCTAGGART-COWAN G P,REYNOLDS C C O,BUSHE W K.Natural gas fuelling for heavy-duty on-road use:current trends and future direction[J].International Journal of Environmental Studies,2006,63(4):421-440. doi: 10.1080/00207230600802056 [21] WANG T Y,QUIROS D C,THIRUVENGADAM A,et al.Total particle number emissions from modern diesel,natural gas,and hybrid heavy-duty vehicles during on-road operation[J].Environmental Science & Technology,2017,51(12):6990-6998. [22] KARAVALAKIS G,HAJBABAEI M,JIANG Y,et al.Regulated,greenhouse gas,and particulate emissions from lean-burn and stoichiometric natural gas heavy-duty vehicles on different fuel compositions[J].Fuel,2016,175:146-156. doi: 10.1016/j.fuel.2016.02.034 [23] 吴岳.清洁能源公交车实际道路排放特性研究[D].北京:北京理工大学,2016.47-59 [24] WANG J G,GUI H Q,YANG Z W,et al.Real-world gaseous emission characteristics of natural gas heavy-duty sanitation trucks[J].Journal of Environmental Sciences,2022,115:319-329. doi: 10.1016/j.jes.2021.06.023 [25] 刘颖帅,葛蕴珊,谭建伟.基于国Ⅵ标准的重型柴油车气态污染物排放控制技术[J].环境工程学报,2019,13(7):1703-1710. doi: 10.12030/j.cjee.201903060LIU Y S,GE Y S,TAN J W.Gaseous pollutants emission control technology for heavy diesel vehicles based on China Ⅵ standard[J].Chinese Journal of Environmental Engineering,2019,13(7):1703-1710. doi: 10.12030/j.cjee.201903060 [26] LIU H,HE K B,LENTS J M,et al.Characteristics of diesel truck emission in China based on portable emissions measurement systems[J].Environmental Science & Technology,2009,43(24):9507-9511. [27] HE L Q,ZHANG S J,HU J N,et al.On-road emission measurements of reactive nitrogen compounds from heavy-duty diesel trucks in China[J].Environmental Pollution,2020,262:114280. doi: 10.1016/j.envpol.2020.114280 [28] 束嘉威.基于实际道路工况的重型柴油车排放规律研究[D].北京:清华大学,2013.26-41 [29] RAŠIĆ D,RODMAN O S,SELJAK T,et al.RDE-based assessment of a factory bi-fuel CNG/gasoline light-duty vehicle[J].Atmospheric Environment,2017,167:523-541. doi: 10.1016/j.atmosenv.2017.08.055 [30] MERA Z,FONSECA N,CASANOVA J,et al.Influence of exhaust gas temperature and air-fuel ratio on NOx aftertreatment performance of five large passenger cars[J].Atmospheric Environment,2021,244:117878. doi: 10.1016/j.atmosenv.2020.117878 [31] 闫博文.基于当量燃烧的天然气发动机燃烧系统开发研究[D].天津:天津大学,2017.37-58 [32] GETSOIAN A B,THEIS J R,LAMBERT C K.Sensitivity of three-way catalyst light-off temperature to air-fuel ratio[J].Emission Control Science and Technology,2018,4(3):136-142. doi: 10.1007/s40825-018-0089-3 [33] 周松,肖友洪,朱元清.内燃机排放与污染控制[M].北京:航空航天大学出版社,2010. [34] MISRA C,RUEHL C,COLLINS J,et al.In-use NOx emissions from diesel and liquefied natural gas refuse trucks equipped with SCR and TWC,respectively[J].Environmental Science & Technology,2017,51(12):6981-6989. [35] MILLER R,DAVIS G,LAVOIE G,et al.A super-extended Zel'dovich mechanism for NOx modeling and engine calibration[J].SAE transactions,1998,107(3):1090-1100. [36] OLSEN D B,KOHLS M,ARNEY G.Impact of oxidation catalysts on exhaust NO2/NOx ratio from lean-burn natural gas engines[J].Journal of the Air & Waste Management Association,2010,60(7):867-874. [37] BOERSMA K F,JACOB D J,BUCSELA E J,et al.Validation of OMI tropospheric NO2 observations during INTEX-B and application to constrain NOx emissions over the eastern United States and Mexico[J].Atmospheric Environment,2008,42(19):4480-4497. doi: 10.1016/j.atmosenv.2008.02.004 [38] 孙银川,严晓瑜,缑晓辉,等.中国典型城市O3与前体物变化特征及相关性研究[J].环境科学研究,2020,33(1):44-53.SUN Y C,YAN X Y,HOU X H,et al.Characteristics and correlation of ozone and its precursors in typical cities in China[J].Research of Environmental Sciences,2020,33(1):44-53. [39] 马国霞,於方,张衍燊,等.《大气污染防治行动计划》实施效果评估及其对我国人均预期寿命的影响[J].环境科学研究,2019,32(12):1966-1972.MA G X,YU F,ZHANG Y D,et al.Effect of implementation of the Action Plan on Prevention and Control of Air Pollution and its impact on life expectancy in China[J].Research of Environmental Sciences,2019,32(12):1966-1972. [40] LI X Y,AI Y,GE Y S,et al.Integrated effects of SCR,velocity,and air-fuel ratio on gaseous pollutants and CO2 emissions from China Ⅴ and Ⅵ heavy-duty diesel vehicles[J].Science of the Total Environment,2022,811:152311. doi: 10.1016/j.scitotenv.2021.152311