Non-road Diesel Engine Research Articles

Measuring non-road diesel emissions in the construction industry: a synopsis of the literature

Non-road diesel engines (NRDE) emissions are unregulated in several countries including Australia and there is an absence of data for construction sites in rapidly growing metropolitan Sydney. Secondary data from the NSW Environmental Protection Authority in Australia indicate that construction sites form a surprisingly high contribution to nitrogen oxides, particulate matter and greenhouse gas emissions given the small ratio of NRDE to total vehicles. Moreover, diesel consumption by the NRDE sector is projected to rise substantially in the construction industry over the next two decades. Thus, the objectives of this paper are to analyze the current literature on construction site emission monitoring, to identify the methods employed, and to propose an innovative way of overcoming deficiencies in existing measurement approaches. The contribution of the paper has been firstly, to classify the construction emissions literature into distinctive categories, not previously done and drawing attention to the almost complete absence of air quality data for construction sites in Australia. Categorizing the literature has revealed a significant gap in researchers’ ability to provide accurate emissions data on construction sites, while the third consequential contribution is the proposal to develop and test a web-based emissions system for accurate and long-term monitoring.

Experimental investigation of iso-butanol/diesel reactivity controlled compression ignition combustion in a non-road diesel engine

As non-road engine emission control programs are developed largely in number of countries around the world, adopting a high efficiency and low emission combustion techniques has become essential. Flexible fuel operation using in-cylinder blending technique is a primary option for using higher octane fuel in a non-road diesel engine to mitigate emissions and fossil fuel dependency. In the present study, iso-butanol/diesel dual fuel reactivity controlled compression ignition concept is preferred considering the benefits of iso-butanol over other alcohol fuels and better combustion control over other low temperature combustion concepts. An experimental investigation is performed on a suitably modified single cylinder non-road diesel engine for the entire load range (0–100% engine full load) focusing on the effect of operating parameters (iso-butanol mass fraction, diesel injection timing, diesel injection pressure, diesel mass in split injection, and intake air temperature) on the dual fuel combustion, performance and emission characteristics. The reactivity controlled compression ignition combustion is analyzed at each load condition and the best operating points are selected based on brake thermal efficiency and emissions. The results indicated that increase in iso-butanol mass fraction with advanced start of injection of direct injected diesel fuel showed a 99% reduction in oxides of nitrogen and a 91% reduction in smoke emissions with 4.5% increase in brake thermal efficiency. Further the drawback in dual fuel combustion, hydrocarbon emission is reduced by 65% with an increase of intake air temperature from 303 K to 338 K. Also, both hydrocarbon and carbon monoxide emissions are reduced with increase in diesel injection pressure and mass of diesel fuel injected in first injection due to the enhanced mixture formation.

NO, NO2 and N2O emissions over a SCR using DOC and DPF systems with Pt reduction

A Pt-reduced diesel oxidation catalyst (DOC) and diesel particulate filter (DPF) combination was used to evaluate the influences of Pt reduction on the oxidation performance in a nonroad diesel engine. For the Pt-reduced combination, a mass fraction of 1.5% Pt in the DOC was lower than a DOC of a non-reduction combination. These DOCs were composed of Pt only. The DPF in the Pt-reduced combination was composed of Pt and Pd with a 2:1 ratio, i.e., Pd was substituted for Pt. Whereas the DPF in the non-reduction combination was Pt only. The oxidation performance in the DOC and DPF systems of the Pt-reduced combination was relatively consistent with the non-reduction combination. The behavior of the undesirable oxidation of nitric oxide (NO) to nitrogen dioxide (NO2) occurred in both combinations. The selective catalytic reduction (SCR) system was also installed for NO and NO2 abatement, and NO and NO2 were evaluated based on the conversion efficiency. The fast SCR reaction, which involves both NO and NO2, was dominantly activated at the SCR inlet temperature of 380 °C because the NO2/NOX ratio is approximately 60%. The fast SCR reaction competed with the standard SCR reaction above 380 °C, and then the standard SCR reaction became the prevailing reaction as the temperatures increased. Nitrous oxide (N2O), which has 298 times more global warming potential than carbon dioxide, was also investigated mainly over the SCR. N2O has increased dozens of times over the SCR, and a lower ratio of N2O emission after the SCR to the NOX at the SCR inlet was obtained in the Pt-reduced combination than in the non-reduction combination.

Effects of different diesel particulate filter on emission characteristics of in-use diesel vehicles

ABSTRACTWith the increasingly stringent emission regulations, retrofitting in-use vehicles with matched diesel particulate filter (DPF) becomes a cost-effective measure to meet the regulations emission limit. Forty in-use heavy-duty diesel vehicles and 15 non-road diesel engines were retrofitted with DPF and the effects of DPF on the emission characteristics were investigated in this work. A high-efficiency matching method to select DPFs for different retrofitting applications has been presented in this paper. The results also verified that the particle number (PN) of all the diesel vehicles decreased over 95% after suitable matching of DPFs. It indicated that this method could be used for reference in other retrofitting projects.

Effects of insulation on exhaust temperature and subsequent SCR efficiency of a heavy-duty diesel engine

Ammonia/urea selective catalytic reduction (SCR) is an efficient technology to control NOx emission from diesel engines. One of the critical challenges of SCR systems is its lack of catalytic activities in low temperature conditions such as cold start or warm-up periods. In this study, the effect of pipe insulation on the reduction of exhaust temperature drop was experimentally investigated based on dynamometer tests with a heavy-duty non-road diesel engine. The temperature drop of exhaust gas was measured with and without applying pipe insulation. Measurement results revealed that the effect of insulation on the mitigation of temperature loss becomes significant as engine brake power decreases. Thus, it is expected that the need for pipe insulation would be increased to keep SCR deNOx efficiency high, especially at low temperature conditions. Also, this study carried out numerical simulations to quantify the impact of pipe insulation on NOx conversion efficiency of a commercial SCR catalyst over a scheduled non-road transient cycle (NRTC) mode. Under the current heavy-duty non-road engine and SCR conditions, the application of pipe insulation would reduce 19.5 % of total cumulative tail-out NOx emission over NRTC hot mode. These results led to the cycle-averaged SCR efficiency of 98.2 % for ‘with insulation’, while it was predicted to be lowered to 97.6 % for ‘without insulation’.

Experimental investigation on a 3000 bar fuel injection system for a SCR-free non-road diesel engine

The upcoming Stage V emissions regulation for Non-Road Heavy Duty Diesel Engines will force OEMs to adopt Diesel Particulate Filters, adding a further degree of complexity to the aftertreatment system, which in several cases already includes specific devices for NOx reduction. Since complex aftertreatment systems can rise packaging problems as well as reliability issues, the authors evaluated the performance of a Stage V compliant engine layout which can avoid dedicated aftertreatment devices for NOx. This engine features a low pressure exhaust gas recirculation system, a two-stage turbocharger and a 3000 bar injection pressure-capable fuel injection system. This paper focus on the experimental assessment of the performance of the fuel injection system, demonstrating how increasing the rail pressure from 2000 to 3000 bar can dramatically improve the NOx-Soot and NOx-Particulate Number trade-off, together with the engine efficiency, without adversely affecting the emission of nanoparticles. In particular, extremely high injection pressures in conjunction with the use of after injection as a soot reduction technique, was found to be capable of achieving a 50% smoke reduction with a more than acceptable engine efficiency degradation.

Emerging investigator series: oxidative potential of diesel exhaust particles: role of fuel, engine load, and emissions control.

Exposure to diesel exhaust particles (DEP) has been linked to adverse human health outcomes. DEPs are reactive and can directly or indirectly lead to oxidative stress, which promotes inflammation in the body. The oxidative potential (OP) of DEPs is not well understood, particularly for combustion with alternative fuels, under different engine loads, and in combination with modern emissions control devices. In this study, we measured the OP of DEPs using a dithiothreitol assay (OP-DTT) from a modern-day non-road diesel engine for two different fuels (conventional diesel and soy-based biodiesel), two different engine loads (idle and 50% load), and with and without an emissions control system. The OP-DTT of DEPs was sensitive to the fuel used and the presence of an emissions control system but not to the engine load. On average, the use of biodiesel resulted in factor of ∼6 reduction in OP-DTT normalized to the DEP mass and a factor of ∼12 reduction in OP-DTT normalized to the fuel consumed. The use of the emissions control, on average, resulted in a factor of ∼6 reduction in OP-DTT normalized to the DEP mass and a three order of magnitude decrease in OP-DTT normalized to the fuel consumed. When studied in conjunction with the DEP composition, the OP-DTT seemed to correlate most strongly with elemental carbon (EC), followed by semi-volatile organic vapors. Assays performed on DEPs where EC was deliberately filtered out suggested that the species responsible for the OP-DTT might be correlated with EC but would need to be water soluble (e.g., quinones). The semi-volatile organic vapors accounted for more than a quarter of the OP-DTT of DEPs collected on the quartz filters. Finally, sensitivity studies performed with a different filter membrane (i.e., Teflon®) and solvent (i.e., dichloromethane) tended to increase the OP-DTT value. OP-DTT is emerging as an important metric for studying the adverse effects of DEPs and PM2.5 on human health; results of this work help define the sources and components of diesel PM2.5 that contribute to OP-DTT.

Using renewable n-octanol in a non-road diesel engine with some modifications

ABSTRACTn-Octanol is a promising biofuel synthesized from biomass with several properties closer to diesel than the more popularly researched n-butanol. This study investigates the effects of injection timing (2°CA advance & retard), EGR (up to 30%) and Oct30 (30% by vol. of n-octanol in diesel) on combustion, performance, and emissions of a DI diesel engine. Results in comparison with diesel indicated Oct30 blend presented an enhanced premixed combustion phasing with higher peaks of pressure and HRR. BSFC was found to be slightly higher for Oct30 blend at all EGR rates. Further, when the injection timing is advanced, the blend produced better BSFC. Oct30 delivered better BTE at all injection timings. NOx and smoke emissions are lower for Oct30 at all conditions. Oct30 could overcome the trade-off between smoke and NOx emissions at a combination of certain EGR and injection timings. It was found that at advanced injection, the reduction in NOx and smoke density was 19.02% and 57.14%, respectively, while BTE increased by 4.6% and BSFC increased by 1.3%. At late injection, a reduction of 50.87% in NOx emissions and 15.87% in smoke density was achieved with a slight drop in BTE by 3.5% and an increase in BSFC by 9.7%.

Gas-phase and semivolatile organic emissions from a modern nonroad diesel engine equipped with advanced aftertreatment

ABSTRACTU.S. Tier 4 Final and Euro Stage IV and V regulations for nonroad compression-ignition engines have led to the development of exhaust aftertreatment technologies optimized for nonroad engines and duty cycles. In this study, several aftertreatment configurations consisting of state-of-the-art diesel oxidation catalysts (DOCs), diesel particulate filters (DPFs), copper (Cu) zeolite– and vanadium-based selective catalytic reduction (SCR) catalysts, and ammonia oxidation (AMOX) catalysts are evaluated using both nonroad transient (NRTC) and steady (8-mode NRSC) cycles in order to understand both component- and system-level effects of diesel aftertreatment on gas-phase, semivolatile, and particle-phase and particle-bound unregulated organic emissions. Organic emissions reported in this work include total hydrocarbon (THC), n-alkanes, branched alkanes, saturated cycloalkanes, aromatics, aldehydes, ketones, hopanes, steranes, and soluble organic fraction (SOF). Brake-specific emissions are reported for four configurations, including engine-out, DOC+CuZ-SCR+AMOX, V-SCR+AMOX, and DOC+DPF+CuZ-SCR+AMOX, and conversion of engine-out emissions is reported for the three aftertreatment configurations. Mechanisms responsible for the reduction of organic species are discussed in detail. This summary of emissions from a current nonroad diesel engine equipped with advanced aftertreatment can be used to more accurately model the impact of anthropogenic emissions on the atmosphere with tools such as the U.S. Environmental Protection Agency’s Motor Vehicle Emissions Simulator (MOVES2014a) model.Implications: Anthropogenic emissions are a source of significant human health and environmental risk. This study, focused on the treatment of exhaust emissions from a modern nonroad diesel engine with a variety of aftertreatment configurations, examines the impact that human industrial activity can have on air pollution. In particular, we focus on the remediation of gas-phase and semivolatile organic emissions by emission reduction technologies. This detailed summary of emissions from a current nonroad diesel engine equipped with advanced aftertreatment can be used to more accurately model the impact of anthropogenic emissions on the atmosphere with tools such as the U.S. Environmental Protection Agency’s MOVES2014a model.

Gas emissions and particulate matter of non-road diesel engine fueled with F-T diesel with EGR

ABSTRACTThe gas emissions and particulate matter of non-road diesel engine fueled with Fischer–Tropsch diesel fuel were investigated. The test was carried out on a four-stroke, water-cooled, single-cylinder engine under different the exhaust gas recirculation (EGR) rates such as 0%, 15%, and 30% at 2,700 rpm, 25%, 50%, and 75% load. The test results showed that when the EGR rate is less than 15%, nitrogen oxides (NOx) are reduced significantly, while hydrocarbon (HC) and carbon monoxide (CO) are increased less than 5%. However, when the EGR rate was 30%, HC and CO were maximally increased to 13.2% and 13.3%, respectively. Additionally, the Field Emission Scanning Electronic Microscope test and Energy Dispersive Spectrometer test were conducted. With increase of EGR rates, the micromorphology of particles was mainly showed as chain-like status and the growth of number concentration of particle was mainly contributed by the nuclear particle when the engine was at 25% load. In contrast, the micromorphology of particles was principally showed as clustered-like status, and the aggregated particles were dominating growth at 50% and 75% load. Moreover, as EGR rates increased, the degree of agglomeration and carbon content were gradually decreased at 25% load. The test also showed the opposite tendency at 50% and 75% load.

Ventilation Requirements for Today's Mechanized Underground Metal Mines

Ventilation is a basic part of all underground mine operations. The main objective of underground mine ventilation is to provide sufficient quantities of air to all the working areas. Today, in modern mechanized underground metal mines, diesel-powered mobile equipment is extensively used for high production rates. Ore can be extracted from many production stopes due to the production rate in a mine. Amount of airflow required for an underground mine depends on several factors, including daily production capacity, number of diesel equipment, ambient temperature, mining method, mining depth and airway type. After implementation of Stage IV Emission Standards for nonroad diesel engines, it is getting more complex to determine airflow quantities required for underground mines wherefore reduced diesel emissions. Required amount of airflow for a mine is obtained by ventilation fans and the largest cost aspect in mine ventilation is the power costs of running the ventilation fans which can reach as high as 50 percent of a mine’s entire electrical power cost. The cost of electrical power has increased significantly in recent years and is likely to continue increasing in the future. That is why it is getting more important to determine proper ventilation design for underground metal mines.

Effect of compression ratio, nozzle opening pressure, engine load, and butanol addition on nanoparticle emissions from a non-road diesel engine.

Currently, diesel engines are more preferred over gasoline engines due to their higher torque output and fuel economy. However, diesel engines confront major challenge of meeting the future stringent emission norms (especially soot particle emissions) while maintaining the same fuel economy. In this study, nanosize range soot particle emission characteristics of a stationary (non-road) diesel engine have been experimentally investigated. Experiments are conducted at a constant speed of 1500rpm for three compression ratios and nozzle opening pressures at different engine loads. In-cylinder pressure history for 2000 consecutive engine cycles is recorded and averaged data is used for analysis of combustion characteristics. An electrical mobility-based fast particle sizer is used for analyzing particle size and mass distributions of engine exhaust particles at different test conditions. Soot particle distribution from 5 to 1000nm was recorded. Results show that total particle concentration decreases with an increase in engine operating loads. Moreover, the addition of butanol in the diesel fuel leads to the reduction in soot particle concentration. Regression analysis was also conducted to derive a correlation between combustion parameters and particle number emissions for different compression ratios. Regression analysis shows a strong correlation between cylinder pressure-based combustion parameters and particle number emission.

Optimization of engine operating conditions and investigation of nano-particle emissions from a non-road engine fuelled with butanol/diesel blends

ABSTRACTThis study presents the experimental investigation of performance and emission characteristics (including nano-particle emissions) of a non-road diesel engine fuelled with neat diesel and butanol/diesel blends. Experiments were performed at optimal engine operating conditions for a constant engine speed of 1500 rpm. To find the optimal engine operating conditions, first experiments were conducted using diesel fuel. Engine operating parameters were optimized for higher brake thermal efficiency and lower exhaust emissions (i.e. gaseous as well as nano-particle emissions). Taguchi's design of experiment was used to optimize the compression ratio, injection pressure and engine operating load. To investigate the effect of butanol blends on the performance and emissions characteristics, experiments were conducted at three different butanol/diesel blend ratios (i.e. 10, 20 and 30% of butanol by volume) at optimum engine operating conditions. Results indicate that butanol/diesel blends have the potential to reduce CO, NO and particle emissions. The results also revealed that the concentration of ultrafine particle number reduces with diesel/butanol blends for all tested load conditions. The highest reductions in total particle number concentration for all butanol blends were found at 25% and 50% engine load conditions, as compared to neat diesel.

Effects of a Diesel Particulate Filter on Emission Characteristics of a China II Non-road Diesel Engine

The emission standard of China’s non-road diesel engines is experiencing the transition period from China II to China III, and the relative non-road diesel engine emission issues need to be urgently solved. As a kind of effective after-treatment technology, a diesel particulate filter (DPF) has become increasingly important in non-road diesel engine emission research. To evaluate the emission characteristics of a non-road diesel engine retrofitted with a DPF, particulate matter (PM) and gaseous emissions emitted from a China II non-road diesel engine loaded with a DPF were investigated on the engine bench. The mass (specific emissions) and number concentrations of PM emissions were obtained by a DLS7200 mass collection system and matter CU-2 number instrument with and without a DPF, respectively. Additionally, gaseous emissions [NOx, CO, and hydrocarbon (HC)] were quantitatively analyzed with and without a DPF by a MEXA-7100EGR emission analysis chamber. Results showed that a DPF could lower the mass and ...

EGR 적용 비도로 엔진의 쿨러 열화에 따른 질소산화물 배출특성

EGR 적용 비도로 엔진의 쿨러 열화에 따른 질소산화물 배출특성

Polycyclic aromatic hydrocarbon emissions of non-road diesel engine treated with non-thermal plasma technology

Non-road diesel engines are important polycyclic aromatic hydrocarbon (PAH) sources in the environment due to their high emission concentration compared to on-road diesel engines. Particle- and gas-phase PAH concentrations of a non-road diesel engine were investigated. Non-thermal plasma (NTP) as an effective after-treatment technology was used to reduce PAH emissions. The results showed that particle-phase PAH concentrations were 329.7 µg/m3, 3,206.7 µg/m3, and 1,185.7 µg/m3 without the action of NTP at three different engine loads respectively. Relatively low concentrations were measured for gas-phase PAHs. Excellent linearity was shown for particle-phase with total PAH concentrations both with, and without, NTP. The gas-phase PAH concentrations linearly increased with engine load without NTP. The five most abundant compounds of PAHs were among low molecular weight (LMW) and medium molecular weight (MMW) compounds. Total PAH cleaning efficiency was beyond 50% when treated with NTP at the three different engine loads. We hypothesized that naphthalene (Nap) concentrations increased greatly at 60% and 80% engine loads because it was produced within the plasma zone by decomposition of high molecular weight (HMW) PAHs. The PAHs content of particulate matter (PM) aggregation at 60% load was approximately three times higher than at 40% and 80% loads. High correlation values were observed for MMW PAHs with total PAH concentrations. Correlations of PAH concentration reduction could be important to clarify the PAH reduction mechanism with NTP technology.

Design of combustion bowl geometry to meet final Tier 4 of 11 L non-road heavy-duty diesel engine with multi-dimensional combustion simulation

To comply with the new non-road emission standards, final Tier 4, two big strategies have been applied to the 11 L heavy-duty diesel engine. The first strategy is to apply Exhaust gas recirculation and selectivity catalytic reduction system to meet the NOx limitation. The other one is to apply low swirl ratio (for higher volumetric efficiency) and multi-hole nozzle, a high pressure direct injection, and an optimized combustion system in order to reduce PM emission. Both strategies put a focus on the optimization of combustion system. In this study, a ULPC bowl concept applied in the previous works has been successfully verified in 11 L heavy-duty diesel engine with wellvalidated 3D combustion simulation, and the ULPC bowl shape has been geometrically optimized. A rough 0D calculation is used to calculate the fuel split ratio of the various ULPC bowl shapes. In the rated-power operating condition of the final Tier 4 engine which is deduced by 1D cyclic simulation, the optimal fuel split ratio of the injected fuel has been verified. Also, additional geometric optimization has been achieved without changing the optimal fuel split ratio. From these results, soot has been reduced by about 30% with ULPC optimum bowl shape against the Tier 3 re-entrant bowl shape.

Simulation study on improving the selective catalytic reduction efficiency by using the temperature rise in a non-road transient cycle

In this study, the transient nitrogen oxide reduction performance of a urea selective catalytic reduction system installed on a non-road diesel engine was tested on an engine dynamometer bench over a scheduled non-road transient cycle mode. Based on the measurement results, the characteristics of the transient selective catalytic reduction behaviours of nitrogen oxide reduction were evaluated. Also, in this study, the effects of several thermal management strategies for improving the selective catalytic reduction efficiency was investigated by transient selective catalytic reduction simulations. The kinetic parameters of the current simulation code for selective catalytic reduction were calibrated and validated by comparison with the measurement data. As a result of this study, it was found that a thermal management strategy utilizing a partial temperature rise in the transient time domain can be an efficient approach for improving the transient selective catalytic reduction efficiency, in comparison with the temperature rise over the entire cycle period. Furthermore, this study can provide some guideline data for the magnitude and the duration of the temperature rise required to obtain the target selective catalytic reduction efficiency over the non-road transient cycle mode. In the last part of this study, the impact of the variation in the space velocity on the transient selective catalytic reduction efficiency was assessed using transient selective catalytic reduction simulations.

Effects of wood-based renewable diesel fuel blends on the performance and emissions of a non-road diesel engine

Renewable fuels form an essential means to reduce greenhouse gas (GHG) emissions emitted by vehicles and non-road machines. Due to the limited production so far, different blends of renewable fuels in fossil fuels are a realistic way to implement the increasing use of renewable fuels. In addition to significant GHG emissions reduction, further benefits can be achieved when high quality renewable fuels are utilized as blending components since the pollutant exhaust emissions, such as unburned hydrocarbons (HC), carbon monoxide (CO), particulate matter mass (PM) and particle number (PN), may also decrease. A global Finnish forestry company has developed an innovative production process from crude tall oil (CTO), a wood-based residue of pulp making process, to renewable diesel. The fuel properties correspond to those of the traditional fossil fuels but the GHG emissions are reduced significantly.

Particle- and gas-phase PAHs toxicity equivalency quantity emitted by a non-road diesel engine with non-thermal plasma technology.

Polycyclic aromatic hydrocarbon (PAH) toxicity equivalency quantity (TEQ, denoted by benzo(a)pyrene equivalent (BaPeq) concentration) is more meaningful when evaluating the influence of non-road diesel engines PAH toxicity on environment. Particle- and gas-phase PAH BaPeq concentrations were calculated based on gas chromatography-mass spectrometer (GC-MS) results and toxic equivalency factors. A non-thermal plasma (NTP) reactor was applied to a non-road diesel engine to decrease PAH TEQ content. Only the gas-phase Nap BaPeq concentration increased slightly with the action of NTP at three different generator power outputs. BaP dominated the BaPeq concentration for 15 samples with, and without NTP except in the gas-phase at 4kW. Almost all medium molecular weight (MMW) and high molecular weight (HMW) PAH TEQs increased for particle- and gas-phases at 3kW power output compared to 2kW without the use of NTP. Particle-phase Nap, Acp, and AcPy (low molecular weight, LMW) TEQ were under detection at 3 and 4kW, while gas-phase BkF, IND, DBA, and BghiP (HMW) concentrations were below the limits of detection. The most abundant PAH TEQ compounds were MMW and HMW PAHs for gas- and particle-phase while they were BaA, CHR, BbF, BaP, and IND for PM aggregation. The total BaPeq emission factors were 15.1, 141.4, and 46.5μgm(-3) at three engine loads, respectively. Significant BaPeq concentration percentage reduction was obtained (more than 80 and 60%) with the use of NTP for particle- and gas-phases. A high TEQ content was observed for PM aggregation (38.8, 98.4, and 50.0μgkg(-1)) which may have caused secondary PAH toxicity emissions. With the action of NTP, the breakup of MMW and HMW into LMW PAHs led to reduction of some PAH concentrations.