LPG & CNG 한성대학교안전과학기술연구소 윤재건
목차 1. CNG Bus vs. LPG Bus 2. 부천 LPG 충전소사고
Current Status of Air Pollution(Seoul ) 78 78 PM( μg / m3 ) 72 68 Avg.. year 57 0.032 0.032 0.033 0.032 0.030 O 3 (ppm) 0.014 0.013 0.015 0.016 0.017 NOx(ppm) 94 95 96 97 98 Urban Smog become a major concern due to the increased emission O 3 precursor and PM Eight Cities including Seoul exceed the Ozone ambient air quality standard
Estimated shares of air pollution sources ( Seoul, 1997 ) Industrial use & Electricity Generation (17 thousand ton) Total emission 388 thousand ton Automobile (331 thousand ton) Heating (40 thousand ton) Major source of air pollution in metropolitan area is motor vehicles(seoul, 85.3%) For seven major cities, motor vehicles are responsible for 64.3% of total emission
Motor Vehicles Mix and Current status of pollutant emission( Seoul, 1997 ) number of vehicle(thousand) emission(thousand ton) 1,736 165 113 450 53 61 승용차 중소형경유차 Light Duty Diesel 대형경유차 (SUV, Van, Light duty truck) Passenger Car (Gasoline/LPG) Heavy Duty Diesel (Bus & Truck) Heavy duty diesel including city buses are responsible for 34% of total Motor pollutant emission
Air Quality Improvement Goal for Major Cities Motor Vehicle Emission Reduction Goal Motor Vehicle Emission (thousand ton) 1,794 1,794 2,182 2,455 1,451 1,466 Air quality improvement PM ( μg / m3 ) O 3 (ppm) 68 0.016 57 0.014 50 0.013 Current(the end of '97) 2002(World Cup hosting) 2005 22% reduction of air pollutants emission by year 2002 Enhancement of air quality to provide pleasant environment for World Cup 2002
Counter Measures for urban motor vehicle pollution Replace diesel city buses with CNG Introduction of clean fuel vehicles Low emission diesel production Strengthening in-use vehicle program Replace van and Light duty truck with LPG/Gasoline fueled vehicles Fleet operation of hybrid electrical vehicles (plan to use a World Cup official vehicle) Applying diesel emission standards equivalent to US or EU s Engine improvement and/or emission control devices are required to install Shorten periodic emission testing interval and adopt advanced in-service test method Strengthening gasoline and diesel fuel standards
CNG City Bus Promotion Goal Replaced old City-Buses within World Cup 2002 hosting cities 8 World Cup host cities with air quality problem (Seoul, 6 Major city and Suwon city) By 2002, introduce 5,000 CNG buses. By 2007 replaced total city bus fleet with CNG(Total number of city Buses : 20,000) Priority Replacement City Buses vehicles with high emission and vehicles operated within refuelling station service range
Test Running of CNG City Bus Seoul Vicinity Area : Inchon City - 2 City Buses Ansan City - 1 City Bus, 1 Commuter Bus Seoul : 15 City Buses, 3 refuelling stations will be in service in 1999 No visible emission and No mal-odor comparing to current Diesel buses NOx & HC are reduced by 60~70% Less pass-by Noise by 2dB
인천광역시삼환교통 ( 주 ) 에서 '98.7 월부터 운행중인천연가스시내버스
Results of CNG City-Bus Running 85 100 100 100 100 85 1 40 30 PM NOx HC CO2 No visible smoke and sharp Ozone precursor emission reduction Viable CO 2 reduction option
Problems for CNG Bus promotion Vehicle price is higher than diesel-powered vehicle Current Diesel bus price(42 thousand US$) CNG Bus(63 thousand US$) Need more CNG refuelling stations 580 thousand US $ /station ( 100 vehicle/day refuelling capacity) Need to provide economic incentives for CNG bus and refuelling station owners Difficult to secure 20m safety distance requirement between refuelling station and neighboring buildings
1994 30,000 NGV NGV : Zero death / 278.3 x 10 6 vehicle miles Gasoline : 2.2 death / 100 x 10 6 vehicle miles Fire of NGV 2.9 fire / 100 x 10 6 vehicle miles
DAF, MAN LPG buses LPG 버스현황 1994 년부터소개 (DAF) ; LPI 장착, LPG 버스와 CNG 버스용가스엔진생산 (MAN) 70% emissions 감소, 60% 소음감소 ( 경유버스대비 ) LPG 버스유럽주요도시운행중 (1000여대) : 네덜란드 (400), 덴마크 (300), 프랑스 (100), 이태리 (20), 벨기에, 스위스, 스페인, 이태리, 포르투갈, 그리스, 독일, 오스트리아등
TNO LPG Multi-Point Injection Engine
버스용가스 (LPG/CNG) 엔진비교 Engine Spec. Fuel CR Charge exchange A/F ratio Emission Max Power (PS) Max Torque (kg-m) Application MAN G engine 128/155 12 liter LPG 9.5 : 1 N.A. (mixer) λ = 1.0 TWC 240 90 Bus DAF R engine 118/132 8.6 liter LPG 9 : 1 Turbo (liquid injection) λ = 1.0 TWC 231 96 Bus MAN E engine 128/155 12 liter CNG 11 : 1 N.A. (mixer) λ = 1.0 TWC 240 88 Bus A C engine 130/140 11 liter CNG 11.5 : 1 Turbo (mixer) λ = 1.0 270 100 Bus
버스용 LPG, CNG, Diesel Emission Regulated emissions of stoichiometric and lean burn HD engines compare with Diesel (1990 1997) 13-Mode Urban Use Fuel Type of engine HC g/kwh CO g/kwh NOx g/kwh PM g/kwh Effi % Energy MJ/kWh LP Gas CNG SI stoich. + 3 way cat. SI stoich. + 3 way cat. 0.2 0.6 0.8 0.8 0.8 0.8 <0.02 <0.02 25.8 26.9 14.0 13.4 LP Gas CNG CNG SI lean burn with cat SI lean burn with cat SI lean burn w/o cat 0.2 0.6 2.5 0.2 0.2 2.0 2.5 2.5 2.5 <0.02 <0.02 <0.02 27.7 29.0 29.0 13.0 12.4 12.4 Diesel 93 Diesel 96 Turbo-aftcooled Euro I Turbo-aftcooled Euro II 0.4 0.4 1.5 1.5 7.8 6.8 0.15 0.12 34.4 34.4 10.5 10.5
세계 LPG 자동차보급현황 LPG 차량운행현황 (`97) 38 개국 4 백만대운행중 국가별 Automotive LPG 소비량 (`97) Country Consumption (ton) No. of vehicles South Korea Japan Australia Italy U.S.A. Netherlands 1,786,000 1,693,000 1,240,000 1,198,000 1,198,000 733,000 401,000 300,000 490,000 1,100,000 271,000 362,000 Total World 10,265,000 4,072,000
Automotive LPG Vehicles ( 97) Country Taxis LD cars LD Fleets HD Buses HD Trucks South Korea Japan Australia Italy U.S.A. Netherlands Canada Mexico Soviet Union Poland +++ +++ ++ + + + + + + ++ +++ +++ + + +++ + + +++ +++ + + + + + + + ++
LPG 연료의 emissions - 가솔린, 디젤과비교 -
국내외 LPG 자동차기술 ( 소형 ) 국내차량의유해배기가스배출량 ( 국립환경연구원자동차공해연구소 ) 외국 LPG 차량의유해배기가스배출량
국내외 LPG 자동차기술 ( 대형 ) 국내경유버스와외국 LPG 버스의배출가스비교 LPG 버스자료는 TNO 에서 1996 년 DAF 버스로서 13mode test 결과임배출허용기준 : 한국 2001.12.31 까지, EUROIII 2000 년이후
LP 가스엔진의연료공급시스템 LP 가스엔진으로의변환시가장중요한 System Automotive LP Gas Fuel System 의변천사 1 st generation carburation system, open loop control 2 nd generation ( 국내기술수준 ) feed back mixer, closed loop lambda control 3 rd generation ( 유럽기술수준 ) gas/liquid injection system, closed loop lambda control
LPG 연료주요성분조성 한국겨울철 ( 서울 ) 프로판 25%, 부탄 75% 여름철 ( 서울 ) 프로판 0%, 부탄 100% 유럽프로판 60%, 부탄 40% 북미지역프로판 100%, 부탄 0%
CNG Bus vs. LPG Bus 경제성 안전성 Infra structure
LPG 충전소사고사례분석 탱크로리와저장탱크와의이 충전시가스누설에의한사고. 충전소설비의검사, 수리, 유지보수작업시에의한사고. LPG 차량오발진에의한충전호스및충전기파손사고.
[LPG 충전소사고사례분포 ]
1985-1994, 6, 41 6, 22 0.35 % 0.04 % LPG 1991-1996, 9 7 1, 20 0.25 %
부천 LPG 충전소사고개요 부탄탱크로리로부터저장탱크로의작업개시직후많은량의가스누출이발생하여지표에잠시체류후미상의점화원에의해화재가발생한후충전소내에정차하여하역작업중이던 2 대의탱크로리에 BLEVE 현상으로발전한사고이다.
부천대성에너지충전소
Height of Flame H : 화재의가시적높이 (m) b r : LPG 의연소속도 (kg/m 2 s) g : 중력가속도 (m/s 2 ) D : 화염의바닥직경 (m)
시간에따른연소량 W : 연소량 (kg) D : 화염의바닥직경 (m) s : 연소시간 (sec)
화염높이, 직경의변화와연소시간에따른부탄의연소량 (kg) 20 m 8.00 m 5 1,570 10 3,140 15 m 5.29 m 5 690 10 1,370 10 m 2.95 m 5 210 10 430
LPG 의질량누출속도 계산결과 (kg/s) 2 2 S(12.5mm) 2.31 0.91 0.21 1.37 0..99 0.09 M(25mm) 9.23 3.63 0.86 5.50 3.96 0.35 L(50mm) 36.93 14.53 3.43 21.98 15.86 1.42
일반적으로 LPG 누출화재사고는 Pool 화재의형태로발전하지않는다고알려져있다. 그것은 LPG 가대기중에누출할경우급속한증발로인하여액상의유지시간이짧다고보기때문이다. 그러나부탄의경우부천의 LPG 충전소사고와같은 Pool 화염이발생한다. 이는부탄의잠열이커서일반의추측과달리급격한기화가일어나지않기때문이다.
funnel cock pressure gage measure Injection tank C 4 H 10 solenoid valve air tank nozzle
0 1 2 3 4 5 6 7 8 cm
0 1 2 3 4 5 g 6 7 8 cm
6 5 nozzle diameter=0.40mm nozzle diameter=0.52mm Liquid length [cm] 4 3 2 1 0 0 5 10 15 20 25 Jet Velocity [m/s]
1.8 1.6 pressure difference, ΔP[atm] 1.4 1.2 1.0 0.8 0.6 0.4 nozzle diameter=0.40mm(water) 0.2 nozzle diameter=0.52mm(water) Butane 0.0 0.0 0.4 0.8 1.2 1.6 2.0 2.4 2.8 3.2 3.6 4.0 flow rate, Q[cc/s]
맺음말 1) 상온, 상압의대기중으로의액체부탄분출제트는상당한거리를진행할때까지액체상태를유지한다. 대기와의낮은온도차이와부탄의낮은증기압이급격한상변화를유발하지않는다. 따라서액체부탄이누출할경우액상만의제트가가능하다. 이렇게액상만으로누출될경우부탄에의한풀화재의가능성은충분하다. 2) 액체부탄의누출량을유량의검정을통하여물과의상대적인값을구해보았다. 본실험조건 ( 압력차 2 기압미만 ) 에서액체부탄의누출량이물에비해 25 내지 40% 정도많았다.
,. - 유홍준의나의문화유산답사기에서