Petroleum Gas Vehicles Research Articles

Thermodynamic Analysis of Air Conditioning System for a Passenger Vehicle with Suction Line Heat Exchanger Using HFO-1234yf

In this study, the experimental thermodynamic performance and environmental impacts of a vehicle air conditioner using HFO-1234yf with a suction line heat exchanger are studied and compared with HFC-134a results. The influences of air flow rate and air temperature at the evaporator inlet, condenser side air face velocity, and the compressor speeds on the thermodynamic performance of the system are investigated. The results showed that HFO-1234yf has a 12% improved coefficient of performance with 8% higher exergy efficiency than HFC-134a. However, HFO-1234yf has marginally poor performance at higher compressor speeds due to more irreversibilities occurred in the compressor and evaporator. The average SLHX effectiveness was observed to be 45% for HFC-134a, while it was 41% for HFO-1234yf. The HFO-1234yf has a 33.9% and 29.4% and 45.1% lower total equivalent warming impact than HFC-134a for petrol, diesel, and liquefied petroleum gas vehicles, respectively. This study paves a way to promote the use of HFO-1234yf instead of HFC-134a without major modifications in the vehicle air conditioner unit.

The contributions of non-methane hydrocarbon emissions by different fuel type on-road vehicles based on tests in a heavily trafficked urban tunnel

Automobile exhaust is a major source of volatile organic compounds (VOCs) in metropolitan areas, yet it is difficult to accurately determine the contributions of different types of on-road vehicles. Tunnel tests are an effective way to measure real-world vehicle emissions, and the data collected are also suitable for receptor modeling to analyze the contributions of non-methane hydrocarbons (NMHCs) from different types of vehicles, as the closed environment ensures good mixing and minimal aging. In this study, tunnel tests were conducted inside a heavily trafficked city tunnel in Guangzhou in south China, and the positive matrix factorization (PMF) model was applied to the inlet-outlet incremental NMHC data. The results revealed that gasoline vehicles (GVs), Liquefied Petroleum Gas vehicles (LPGVs), and diesel vehicles (DVs) were responsible for 39 %, 45 % and 16 % of NMHCs, and 52 %, 23 %, and 24 % of the ozone formation potentials, respectively. LPGVs were the largest contributor of (56 %) alkanes, and GVs were the largest contributor of aromatics (61 %) and C2-C4 alkenes (55 %). With the video-recorded traffic counts the emissions of different fuel types are further compared on a per-vehicle-per-kilometer basis, and the results reveal that LPGVs and GVs were comparable in the OFPs of NMHCs emitted per kilometer, while on average a DV emitted 2.0 times more NMHCs than a GV with 2.4 times more OFPs. This study highlights substantial contribution of reactive alkenes and aromatics by DVs and the benefits of strengthening diesel exhaust control in terms of preventing ozone pollution.

Forecasting the Reduction in Urban Air Pollution by Expansion of Market Shares of Eco-Friendly Vehicles: A Focus on Seoul, Korea.

Due to global climate change, various countries have agreed upon the use of conventions. In this study, the eco-friendly vehicular policy on carbon neutrality implemented in Seoul, Korea, was examined. To this end, various policy-based scenarios were set, and the changes in automotive exhaust gas emissions were evaluated and compared. The evaluation method combined macroscopic and microscopic emission models as its analysis framework. Micro-traffic data available in Korea were used for analyses, and the results for all autonomous districts were derived to cover the entire area of Seoul. The findings confirmed that the most effective measure is the initial replacement of old, mid-size, or large diesel passenger cars with eco-friendly vehicles (Middle-sized: Scenario 2-1 5.52%, Scenario 2-2 6.86%, Scenario 3-1 80.93%, and Scenario 3-2 83.98%). The replacement of old vehicles exhibited the highest effect in all tested scenarios, while the initial replacement of diesel vehicles was more effective than the replacement of gasoline and liquified petroleum gas vehicles (Diesel: Scenario2-1 6.64%, Scenario 2-2 8.21%, Scenario3-1 86.23%, and Scenario 3-2 90.51%). Among the autonomous districts of Seoul, the Gangnam-gu area exhibited the largest emission-reduced effect among all the tested scenarios (Gangnam-gu: Scenario 2-1 5.80%, Scenario 2-2 6.74%, Scenario 3-1 80.44%, and Scenario 3-2 82.62%). Overall, it was demonstrated that the findings of this study may have significant policy implications in terms of urban emission changes pertaining to transportation.

Adsorption Isotherms and Isosteric Heat of Adsorption of Metal Organic Frameworks as Gas Storage for Liquefied Petroleum Gas Vehicle in Iraq

This research provides a novel technique for using metal organic frameworks (HKUST-1) as a gas storage system for liquefied petroleum gas (LPG) in Iraqi vehicles to avoid the drawbacks of the currently employed method of LPG gas storage. A low-cost adsorbent called HKUST-1 was prepared and characterized in this research to investigate its ability for propane storage at different temperatures (25, 30, 35, and 40 oC) and pressures of (1-7) bar. HKUST-1 was made using a hydrothermal method and characterized using powder X-ray diffraction, BET surface area, scanning electron microscopic (SEM), and Fourier Transforms infrared spectroscopy (FTIR). The HKUST-1 was produced using a hydrothermal technique and possesses a high crystallinity of up to 97%, surface area 3400 m2/g, and pore volume 0.7 cm3/g. The prepared adsorbent (HKUST-1) tested using volumetric method, the maximum adsorption capacity of propane was (10.499 mmol/g) at a temperature of 298K and a pressure of 7 bar. Furthermore, adsorption isotherm study was conducted to understand the system equilibrium (i.e., the fitting with one of the known models Langmuir, Freundlich, and Temkin isotherm models). It was observed that the Freundlich isotherm model fitted well the experimental data. The Clausius-Clapeyron equation was used to determine the heat of adsorption, and the results revealed that the heat of adsorption increased as the propane adsorption capacity increased. The prepared HKUST-1, which has a large surface area and a high adsorption capacity, can be used as a major solution for gas storage for liquefied petroleum gas (LPG) in Iraqi vehicles.

Emissions and light absorption of PM2.5-bound nitrated aromatic compounds from on-road vehicle fleets

Vehicle emissions are an important source of nitrated aromatic compounds (NACs) in particulate size smaller 2.5 μm (PM2.5), which adversely affect human health and biodiversity, especially in urban areas. In this study, filter-based PM2.5 samples were collected during October 14–19, 2019, in a busy urban tunnel (approximately 35,000 vehicles per day) in south China to identify PM2.5-bound NACs. Among them, 2,8-dinitrodibenzothiophene, 3-nitrodibenzofuran and 2-nitrodibenzothiophene were the most abundant nitrated polycyclic aromatic hydrocarbons (NPAHs), while 2-methyl-4-nitrophenol, 2,4-dinitrophenol, 3-methyl-4-nitrophenol and 4-nitrophenol were the most abundant nitrophenols (NPs). The observed mean fleet emission factors (EFs) of NPAHs and NPs were 2.2 ± 2.1 and 7.7 ± 4.1 μg km−1, and were 2.9 ± 2.7 and 10.2 ± 5.4 μg km−1 if excluding electric and liquefied petroleum gas vehicles, respectively. Regression analysis revealed that diesel vehicles (DVs) had NPAH-EFs (55.3 ± 5.3 μg km−1) approximately 180 times higher than gasoline vehicles (GVs) (0.3 ± 0.2 μg km−1), and NP-EFs (120.6 ± 25.8 μg km−1) approximately 30 times higher than GVs (4.1 ± 0.2 μg km−1), and thus 89% NPAH emissions and 56% NP emissions from the onroad fleets were contributed by DVs although DVs only accounted for 3.3% in the fleets. Methanol solution-based light absorption measurements demonstrated that the mean incremental light absorption for methanol-soluble brown carbon at 365 nm was 6.8 ± 2.2 Mm−1, of which the 44 detected NACs only contributed about 1%. The mean EF of the 7 toxic NACs was approximately 3% that of the 16 priority PAHs; However, their benzo(a)pyrene toxic equivalence quotients (TEQBaP) could reach over 25% that of the PAHs. Moreover, 6-nitrochrysene mainly from DVs contributed 93% of the total TEQBaP of the NACs. This study demonstrated that enhancing DV emission control in urban areas could benefit the reduction of exposure to air toxins such as 6-nitrochrysene.

Microstructural analysis of liquefied petroleum gas vehicle emissions, one of the anthropogenic environmental pollutants

Microstructural analysis of liquefied petroleum gas vehicle emissions, one of the anthropogenic environmental pollutants

Real-world emissions of carbonyls from vehicles in an urban tunnel in south China

Carbonyls play a vital role in atmospheric photochemistry. Vehicle emission is among most important primary emission sources of carbonyls in urban areas, yet knowledge is quite scarce about real-world emissions of carbonyls with the changing on-road vehicle fleets. In this study, emissions of carbonyls were characterized based on tests in a busy urban tunnel in south China. Emission factor (EF) of carbonyls was measured to be 9.89 ± 0.65 mg km−1 on average, in which formaldehyde alone shared 53.1% with an EF of 5.25 ± 0.35 mg km−1, followed by acetaldehyde with an EF of 1.47 ± 0.13 mg km−1. Glyoxal and methylglyoxal showed identical EFs of 0.18 ± 0.02 mg km−1. Multiple linear regression retrieved total carbonyl EFs of 5.68, 47.71 and 35.09 mg km−1 and ozone formation potentials (OFPs) of 38.4, 329.3, and 242.4 mg km−1 for gasoline, diesel and liquefied petroleum gas vehicles (LPGVs), respectively. The unexpectedly high carbonyl emissions from LPGVs were largely attributed to the lack of after-treatment systems or the inefficiency of the after-treatment systems. Among vehicle-emitted non-methane hydrocarbons and carbonyls, carbonyls could contribute ~20% of the total OFPs while they only accounted for 7.1% of the total mass.

Can liquefied petroleum gas vehicles join the fleet of alternative fuel vehicles? Implications of transportation policy based on market forecast and environmental impact

Given the growing severity of particulate matter (PM) and greenhouse gas pollution, the Korean government recently began supporting the use of eco-friendly vehicles, such as electric vehicles and hydrogen fuel cell vehicles. However, the uptake of these vehicles has been slower than anticipated because of the high purchase price and lack of infrastructure. Therefore, the Korean government has eased restrictions on liquefied petroleum gas (LPG) vehicles to encourage the vast majority of consumers to purchase LPG vehicles, expecting that they will serve as a stepping stone to switch from internal combustion engine vehicles to their eco-friendly counterparts. However, there have been only a few studies on consumer preferences for LPG vehicles in consideration of this amendment. To analyze consumer preferences for all fuel types, including LPG, this study used a discrete choice experiment combined with a reference-dependent model. The results showed a loss aversion tendency and asymmetric preferences among consumers with regard to vehicle choice. Based on these results, a simulation analysis was conducted to predict the future market share and PM pollution level. The findings indicated that the government's LPG vehicle deregulation policy could achieve positive PM reduction effects in the short term but none in the long term.

Emission factors of ammonia for on-road vehicles in urban areas from a tunnel study in south China with laser-absorption based measurements.

Vehicle emission is an important source of ammonia (NH3) in urban areas. To better address the role of vehicle emission in urban NH3 sources, the emission factor of NH3 (NH3-EF) from vehicles running on roads under real-world conditions (on-road vehicles) needs to update accordingly with the increasingly tightened vehicle emission standards. In this study, laser-absorption based measurements of NH3 were conducted during a six-day campaign in 2019at a busy urban tunnel with a daily traffic flow of nearly 40,000 vehicles in south China's Pearl River Delta (PRD) region. The NH3-EF was measured to be 16.6±6.3mgkm-1 for the on-road vehicle fleets and 19.0±7.2mgkm-1 for non-electric vehicles, with an NH3 to CO2 ratio of 0.27±0.09ppbv ppmv-1. Multiple linear regression revealed that the average NH3-EFs for gasoline vehicles (GVs), liquefied petroleum gas vehicles, and heavy-duty diesel vehicles (HDVs) were 18.8, 15.6, and 44.2mgkm-1, respectively. While NH3 emissions from GVs were greatly reduced with enhanced performance of engines and catalytic devices to meet stricter emission standards, the application of urea selective catalytic reduction (SCR) in HDVs makes their NH3 emission an emerging concern. Based on results from this study, HDVs may contribute over 11% of the vehicular NH3 emissions, although they only share ∼4% by vehicle numbers in China. With the updated NH3-EFs, NH3 emission from on-road vehicles was estimated to be 9Ggyr-1 in the PRD region in 2019, contributing only 5% of total NH3 emissions in the region, but still might be a dominant NH3 source in the urban centers with little agricultural activity.

Insight into the Variability of the Nitrogen Isotope Composition of Vehicular NOx in China.

Nitrogen isotope (δ15N) monitoring is a potentially powerful tool in tracing atmospheric nitrogen oxides (NOx); however, the isotopic fingerprint of vehicle exhaust remains poorly interpreted. This deficiency limits our understanding of the origin of atmospheric haze pollution, especially in China. In this study, we systemically explored the δ15N-NOx fingerprints of various vehicle exhausts (n = 137) in China. The δ15N-NOx values of vehicle exhausts ranged from -18.8‰ to +6.4‰, presenting a significant correlation with NOx concentrations (p < 0.01). The highest δ15N-NOx values were observed for liquefied petroleum gas vehicles (-0.1 ± 1.8‰), followed by gasoline vehicles (-7.0 ± 4.8‰) and diesel vehicles (-12.7 ± 3.4‰), all of which displayed a rising trend as emissions standards were continuously updated. The δ15N-NOx values under working conditions followed the trend warm start (-5.9 ± 5.0‰) > driving (-7.3 ± 5.9‰) > cold start (-9.2 ± 2.7‰). By establishing a suitable model for assessing representative δ15N-NOx values, the δ15N-NOx values of various vehicles, including different fuel types with different emission standards, were evaluated. A model of δ15N-NOx associated with motor vehicle data was developed, which estimated the national δ15N-NOx value of vehicle emissions to be -12.6 ± 2.2‰, but there was considerable variation among different target areas in China.

Methane emissions from on-road vehicles in China: a case study in an urban tunnel

Reducing emissions of methane (CH4) in developed regions and urban areas is a practical way to curb the unexpected surge in global CH4 levels in recent decades. Traffic emissions are among the important anthropogenic CH4 emission sources in megacities, yet CH4 emissions from on-road vehicles are less characterized and not well addressed. Based on tunnel tests in an urban tunnel in south China, a real-world emission factor (EF) of CH4 was measured to be 0.26 ± 0.03 g·km−1 (mean ±95% C.I.) for on-road vehicle fleet which including gasoline vehicles, diesel vehicles, and liquefied petroleum gas vehicles, with an average CH4/CO2 mass ratio of 40.6E-5 g·g−1, and CH4 could account for 1.3% of vehicle CO2-equivalent emissions. Using the measured CH4/CO2 ratio and available automobile CO2 emission estimates, traffic CH4 emissions in 2014 could have reached 333 Gg and represented 0.6% of total anthropogenic CH4 emissions in China, approximately four times the previous reported value of 79 Gg. Our results indicate that improving energy efficiency would have co-benefits for reducing traffic emissions of CH4, as observed EFs of CH4 are positively correlated with that of CO2, and over 90% of traffic CH4 emissions in China could be avoided if the traffic CH4/CO2 ratio can be an order of magnitude lower as previously observed in a tunnel in Switzerland.

The Tax Incentives in the IVTM and “Eco-Friendly Cars”: The Spanish Case

This article describes research that was carried out regarding the tax incentives in Spain associated with the “eco-friendly car,” which are reflected in its share of taxes on motor-driven vehicles. The study focused on the electric vehicle, the hybrid, and the liquefied petroleum gas vehicle. First, the current regulatory framework was addressed. The maximum bonus limits were considered, as well as how each of 68 cities examined the incentives. The qualitative and quantitative differences among the Spanish cities were discussed. Next, the annual tax savings on the Tax on motor vehicles (IVTM) quota were calculated, and the differences in the tax savings depending on the municipality and type of vehicle were noted, as well as the temporal duration of the bonus. Finally, the average tax savings were calculated based on the type of vehicle, power and municipality. It is clear that, although the tax incentives are positive, they must be complemented by other measures if the public authorities in Spain want to achieve a change in mentality and an increase in the acquisition of “eco-friendly cars” that eliminate pollutants (powered by the combustion of gasoline or diesel).

A stochastic multi-objective optimization decision model for energy facility allocation: a case of liquefied petroleum gas station

To mitigate air pollution problem, the government has been planning to build more liquefied petroleum gas stations to motivate drivers to use liquefied petroleum gas vehicles in Taiwan. Such facility allocation problem is a multi-objective optimization process considering spatial variation in the need of refueling. This study presents a stochastic multi-objective optimization model for liquefied petroleum gas station allocation (SMOMLSA) that integrates a nondominated sorting genetic algorithm II with a Monte Carlo simulation to optimally allocate liquefied petroleum gas stations according to three trade-off objectives, including investment performance, energy conversion, and business opportunity. Monte Carlo simulation procedure generates the starting location of a taxicab car in need of refueling in the spatial grid based on a probability distribution. Nondominated sorting genetic algorithm II resolves the station location problem with these multi-objectives. The SMOMLSA was validated by conducting a real-world case study. Result depicts that the SMOMLSA can provide information on the optimal allocation of liquefied petroleum gas stations for minimizing construction costs, minimizing average refueling distance for vehicles, and maximizing potential customers.

Evaluation of the effectiveness of air pollution control measures in Hong Kong

From 2005 to 2013, volatile organic compounds (VOCs) and other trace gases were continuously measured at a suburban site in Hong Kong. The measurement data showed that the concentrations of most air pollutants decreased during these years. However, ozone (O3) and total non-methane hydrocarbon levels increased with the rate of 0.23 ± 0.03 and 0.34 ± 0.02 ppbv/year, respectively, pointing to the increasing severity of photochemical pollution in Hong Kong. The Hong Kong government has ongoing programs to improve air quality in Hong Kong, including a solvent program implemented during 2007–2011, and a diesel commercial vehicle (DCV) program since 2007. From before to after the solvent program, the sum of toluene, ethylbenzene and xylene isomers decreased continuously with an average rate of −99.1 ± 6.9 pptv/year, whereas the sum of ethene and propene increased by 48.2 ± 2.0 pptv/year from before to during the DCV program. Despite this, source apportionment results showed that VOCs emitted from diesel exhaust decreased at a rate of −304.5 ± 17.7 pptv/year, while solvent related VOCs decreased at a rate of −204.7 ± 39.7 pptv/year. The gasoline and liquefied petroleum gas vehicle emissions elevated by 1086 ± 34 pptv/year, and were responsible for the increases of ethene and propene. Overall, the simulated O3 rate of increase was lowered from 0.39 ± 0.03 to 0.16 ± 0.05 ppbv/year by the solvent and DCV programs, because O3 produced by solvent usage and diesel exhaust related VOCs decreased (p < 0.05) by 0.16 ± 0.01 and 0.05 ± 0.01 ppbv/year between 2005 and 2013, respectively. However, enhanced VOC emissions from gasoline and LPG vehicles accounted for most of the O3 increment (0.09 ± 0.01 out of 0.16 ± 0.05 ppbv/year) in these years. To maintain a zero O3 increment in 2020 relative to 2010, the lowest reduction ratio of VOCs/NOx was ∼1.5 under the NOx reduction of 20–30% which was based on the emission reduction plan for Pearl River Delta region in 2020.

Emission factors of fine particles, carbonaceous aerosols and traces gases from road vehicles: Recent tests in an urban tunnel in the Pearl River Delta, China

Motor vehicles contribute primarily and secondarily to air quality problems due to fine particle (PM2.5) and ozone (O3) pollution in China's megacities. Characterizing vehicle emission with the rapid change of vehicle numbers and fleet compositions is vital for both bottom-up emission survey and top–down source apportioning. To obtain emission factors (EFs) of PM2.5, carbonaceous aerosols and trace gases for road vehicles, in urban Guangzhou we conducted a field campaign in 2014 in the Zhujiang Tunnel, a heavily burdened tunnel with about 40,000 motor vehicles passing through each of its two separated bores per day. PM2.5 and volatile organic compounds (VOCs) were sampled for offline analysis while trace gases including SO2, NOx and CO were measured online and in situ. An eddy covariance system with an integrated 3-D sonic anemometer was also adopted to measure CO2 and winds inside the tunnel. We recorded an average fleet composition of 61% light-duty gasoline vehicles (LDVs) + 12% heavy-duty diesel vehicles (HDVs) + 27% liquefied petroleum gas vehicles (LPGVs), and EFs of 82.7 ± 28.3, 19.3 ± 4.7 and 13.3 ± 3.3 mg veh−1 km−1, respectively, for PM2.5, organic carbon (OC) and elemental carbon (EC). These EFs were respectively 23.4%, 18.3% and 72.3% lower when compared to that measured in the same tunnel in 2004. EFs of PM2.5, OC and EC were higher at night time (148 ± 126, 29 ± 24 and 21 ± 18 mg veh−1 km−1, respectively) due to significantly elevated fractions of HDVs in the traffic fleets. An average ratio of OC to EC 1.45 from this tunnel study was much higher than that of ∼0.5 in previous tunnel studies. The EFs of SO2, NOx, CO, CO2 and NMHCs for road traffic were also obtained from our tunnel tests, and they were 20.7 ± 2.9, (1.29 ± 0.2)E+03, (3.10 ± 0.68)E+03, (3.90 ± 0.49)E+05, and 448 ± 39 mg veh−1 km−1, respectively.

Effects of the sulfur content of liquefied petroleum gas on regulated and unregulated emissions from liquefied petroleum gas vehicle

A more stringent standard for sulfur in liquefied petroleum gas (LPG) is currently being considered by the Ministry of Environment of Korea. Therefore, we investigated the characteristics of exhaust emissions from liquid phase LPG injection passenger car depending on the sulfur content of the LPG. Using a chassis dynamometer test with exhaust gas analyzers and Fourier-transform infrared spectroscopy, regulated emissions of carbon monoxide, non-methane hydrocarbons, and nitrates were investigated, as well as unregulated emissions of CH4, N2O, NH3, and SO2. Vehicle tests were carried out using Federal Test Procedure 75 (FTP-75) and Highway Fuel Economy Test (HWFET) cycles and time-resolved exhaust emissions and mass emissions were analyzed. The concentrations of regulated and unregulated time-resolved emissions increased during the cold start phase (Phase 1) of the FTP-75 cycle, in which the catalyst does not reach the light-off temperature. In the FTP-75 and HWFET cycles, most of the regulated and unregulated mass emissions increased as the sulfur content of the LPG increased. The SO2 concentration in the emissions increased in proportion to the sulfur content in the LPG, particularly in the high-speed portion of the FTP-75 cycle.

LPi 시스템 자동차의 인젝터, 공회전 액추에이터 및 개스킷 고장사례 연구

이 논문의 목적은 LPG 자동차의 액상 분사시스템에 관련된 고장사례를 연구하는 것이다. LPi 분사시스템인 인젝터를 점검한 결과, 인젝터에 카본이 누적되어 운전 중에 간헐적으로 연료를 분사하는 인젝터의 미세한 홀을 막아 연비를 5% 정도 떨어뜨리는 것으로 확인되었다. 엔진의 공회전을 조절하는 시스템인 공회전 조절장치 부품과 엔진에 공기를 공급하는 시스템인 스로틀 보디에 카본이 퇴적되어 공기의 흐름을 간섭함으로써 연비가 7% 악화된 것을 확인되었다. 엔진의 흡기 매니폴드 개스킷의 일부가 찢어져, 실린더 헤드와 실린더 블록의 밀착성이 약화되어 흡기행정에서 외부의 공기가 이 틈새로 간헐적으로 유입되면서 증가된 공기량만큼 연료량의 증가를 가져와 엔진의 회전수가 증가하여 부조화 현상이 발생되어 정상적인 상태보다 연비가 3% 정도 악화된 것으로 확인되었다. 이러한 고장사례는 운전중에 엔진의 출력 성능을 떨어뜨리고, 자동차의 연비를 악화시키는 요인이 된다. 따라서 품질확보에 철저하게 대처하여 고장현상을 최소화 하여야 할 것으로 판단된다. The purpose of this paper studies the failure cases including with system of liquefied phase injection in liquified petroleum gas vehicle. The first case, resulting with inspection the injector of LPG, it occasionally certified the injection damage phenomenon that the fuel efficiency(km/l) was decreased to 5% by carbon deposit with injector hole when the driver operates the vehicle. The second case, it certified the interference phenomenon of air flow with carbon deposit in ISA system control for idle speed of engine and throttle body suppling air into engine. As a result, the fuel efficiency was decreased 7%. The third case, the outer air during intake stroke was intermittently flowed in this gasket gap because of weaken adhesion power phenomenon for cylinder block by intake manifold gasket tearing. Consequentially, it certified the decrease for fuel efficiency to 3% by risen the amount of fuel injection as the air inflow quantity. These failure examples reduced the power performance of engine and the fuel efficiency of vehicle. It have to minimize of failure phenomenon preparing through quality management.

액화석유가스 자동차 엔진의 전자제어 컴퓨터의 고장사례 연구

The purpose of this paper analyzes and studies to improve the failure cases on the computer that one of electronic control elements for engine in liquified petroleum gas vehicle. The first case, it certified the non-starting phenomenon of engine that it`s electronic control unit didn`t control the fuel for idle speed actuator because of no given action signal in slow-cut solenoid valve. The second case, it knew the bad condition phenomenon of engine and back-fire by the wire melting of ignition coil and firing of transistor being inside ECU. The third case, it certified the action stoping phenomenon of engine and malfunctioning signal for engine ECU because of leakage of current and an excess current by moisture inflowing inside ECU curcuit plate. Therefore, it is thought that will elevate the durability and reliability of engine computer throughout procure of quality.

LPG 자동차 엔진의 솔레노이드밸브, 릴레이, 공회전조절장치의 고장사례 연구

이 논문의 목적은 LPG 자동차의 전자제어에 대한 요소의 하나인 액추에이터에 대한 고장사례를 찾아 분석하고 연구하는 것이다. 차량의 연료를 저장하는 봄 내부의 LPG 긴급 차단 솔레노이드 밸브의 필터가 막혀 연료의 공급이 간헐적으로 차단되는 현상이 발생되어 엔진이 작동하는 동안 엔진의 초기시동불량이나 가속이 되지 않는 것을 확인하였다. 엔진 컨트럴 릴레이 부위의 접점부가 가공불량이나 조립불량에 의해 완전한 면접촉이 되지않아 접촉저항이 발생되어 초기 시동을 걸었을 때 시동이 걸렸으나 재시동을 걸 때 시동이 걸리지 않는 현상을 확인하였다. 공회전 조절장치의 내부에 카본이 퇴적되어 액추에이터가 고착되어 흡입공기의 공급이 감소되어 자동차의 시동이 걸려 공회전 상태일 때 엔진의 회전수가 규정 범위를 벗어나 상승과 하락을 반복하는 불안정 상태를 확인하였다. The purpose of this paper analyzes and studies to seek the failure examples of electronic control actuators for engine in liquified petroleum gas vehicle. The first, it was verified phenomenon for intial starting damage and no-acceleration of engine because of occasionally fuel feeding interception by clogged of emergency cutting solenoid valve filter. The second, the contact resistance produced in the connecting part of engine control relay because of no fully surface contacting by processes and assembly badness. It was displayed phenomenon of re-starting badness. The actuator that idle speed control system was sticked inside because of intake-air decreasing by carbon deposit. As a result, it was verified the phenomenon of disharmony that repeated up and down the engine revolution.

Making markets for hydrogen vehicles: Lessons from LPG

The adoption of liquefied petroleum gas vehicles is strongly linked to the break-even distance at which they have the same costs as conventional cars, with very limited market penetration at break-even distances above 40,000 km. Hydrogen vehicles are predicted to have costs by 2030 that should give them a break-even distance of less than this critical level. It will be necessary to ensure that there are sufficient refuelling stations for hydrogen to be a convenient choice for drivers. While additional LPG stations have led to increases in vehicle numbers, and increases in vehicles have been followed by greater numbers of refuelling stations, these effects are too small to give self-sustaining growth. Supportive policies for both vehicles and refuelling stations will be required.