scholarly journals Tests of urban bus specific emissions in terms of currently applicable heavy vehicles operating emission regulations

2017 ◽  
Vol 168 (1) ◽  
pp. 21-26
Author(s):  
Jerzy MERKISZ ◽  
Łukasz RYMANIAK

The article presents a study of a city bus in real operating conditions (RDE) from the perspective of the latest regulations for the assessment of specific emissions compliance for heavy-duty vehicles (Euro VI standard). The object of the research was a serial configuration hybrid drive vehicle. Measurements were made in the real driving conditions in Poznan agglomeration. The latest mobile equipment PEMS was used for the measurements. This article presents the details of the EU 582/2011 Procedure in operational conformity assessment, the methodology of the study was discussed, and the obtained results were presented, both in terms of vehicle operating conditions and engine operation, as well as specific emissions evaluation.

2019 ◽  
Vol 294 ◽  
pp. 02002
Author(s):  
Andrzej Ziolkowski ◽  
Pawel Daszkiewicz ◽  
Lukasz Rymaniak ◽  
Paweł Fuc ◽  
Pawel Ukleja

The introduction of the Euro 6c emission norm in 2017 resulted in a change of the type approval procedures. The most important of these was the replacement of the NEDC test with WLTC test with different procedures. In addition, the research was extended to include emission tests in real operating conditions (RDE). Such tests are enforced for heavy vehicles since 2014. PEMS apparatus was used for the measurements, which has been used by many research and development centers to carry out exhaust emissions measurements long before the applicable procedures were introduced. The article presents the methodology of conducting RDE measurements in accordance with the requirements defined by the Euro 6c norm. The focus in this case was primarily on the selection of the test route in the Poznań agglomeration. After determining its course, RDE measurements were made for a vehicle with a hybrid drive. The test route parameters have complied with the applicable requirements. All requirements were met and it was possible to analyze the exhaust emissions. The main focus being the determination of exhaust emissions from the entire test and in accordance with the EMROAD method. The CF (Comformity Factor) coefficients were also determined for both methods and compared with the applicable legal values. An analysis of the hybrid drive system operation was carried out, defining the degree of hybridization, which is the portion of the vehicle travel using only the electric motor of the drive system throughout the whole test. All analyzes were carried out in individual sections of the test: urban, rural and motorway.


2014 ◽  
Vol 518 ◽  
pp. 108-113 ◽  
Author(s):  
Maciej Bajerlein ◽  
Lukasz Rymaniak ◽  
Piotr Swiatek ◽  
Andrzej Ziolkowski ◽  
Pawel Daszkiewicz ◽  
...  

In this paper the authors present the methodology and results of exhaust emissions and energy consumption tests of an 18-meter city bus fitted with a serial hybrid drive. During the tests, parameters of the engine operation, capacitor charging level and exhaust emissions were recorded. The tests were performed under actual conditions of the bus operation in city traffic on a regular bus route. The testing cycles were conducted twice on the same vehicle. The first cycle was performed on the bus with the original configuration and the second one - on the optimized engine and drivetrain. The paper presents the results of the conducted investigations and a comparison that tells us whether the optimization changes have a positive influence on the vehicle reducing its energy consumption and exhaust emissions.


2006 ◽  
Vol 56 (1) ◽  
pp. 1-43
Author(s):  
Sándor Richter

The order and modalities of cross-member state redistribution as well as the net financial position of the member states are one of the most widely discussed aspects of European integration. The paper addresses selected issues in the current debate on the EU budget for the period 2007 to 2013 and introduces four scenarios. The first is identical to the European Commission's proposal; the second is based on reducing the budget to 1% of the EU's GNI, as proposed by the six net-payer countries, while maintaining the expenditure structure of the Commission's proposal. The next two scenarios represent radical reforms: one of them also features a '1% EU GNI'; however, the expenditures for providing 'EU-wide value-added' are left unchanged and it is envisaged that the requisite cuts will be made in the expenditures earmarked for cohesion. The other reform scenario is different from the former one in that the cohesion-related expenditures are left unchanged and the expenditures for providing 'EU-wide value-added' are reduced. After the comparison of the various scenarios, the allocation of transfers to the new member states in terms of the conditions prevailing in the different scenarios is analysed.


1992 ◽  
Vol 26 (5-6) ◽  
pp. 1355-1363 ◽  
Author(s):  
C-W. Kim ◽  
H. Spanjers ◽  
A. Klapwijk

An on-line respiration meter is presented to monitor three types of respiration rates of activated sludge and to calculate effluent and influent short term biochemical oxygen demand (BODst) in the continuous activated sludge process. This work is to verify if the calculated BODst is reliable and the assumptions made in the course of developing the proposed procedure were acceptable. A mathematical model and a dynamic simulation program are written for an activated sludge model plant along with the respiration meter based on mass balances of BODst and DO. The simulation results show that the three types of respiration rate reach steady state within 15 minutes under reasonable operating conditions. As long as the respiration rate reaches steady state the proposed procedure calculates the respiration rate that is equal to the simulated. Under constant and dynamic BODst loading, the proposed procedure is capable of calculating the effluent and influent BODst with reasonable accuracy.


Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4136
Author(s):  
Clemens Gößnitzer ◽  
Shawn Givler

Cycle-to-cycle variations (CCV) in spark-ignited (SI) engines impose performance limitations and in the extreme limit can lead to very strong, potentially damaging cycles. Thus, CCV force sub-optimal engine operating conditions. A deeper understanding of CCV is key to enabling control strategies, improving engine design and reducing the negative impact of CCV on engine operation. This paper presents a new simulation strategy which allows investigation of the impact of individual physical quantities (e.g., flow field or turbulence quantities) on CCV separately. As a first step, multi-cycle unsteady Reynolds-averaged Navier–Stokes (uRANS) computational fluid dynamics (CFD) simulations of a spark-ignited natural gas engine are performed. For each cycle, simulation results just prior to each spark timing are taken. Next, simulation results from different cycles are combined: one quantity, e.g., the flow field, is extracted from a snapshot of one given cycle, and all other quantities are taken from a snapshot from a different cycle. Such a combination yields a new snapshot. With the combined snapshot, the simulation is continued until the end of combustion. The results obtained with combined snapshots show that the velocity field seems to have the highest impact on CCV. Turbulence intensity, quantified by the turbulent kinetic energy and turbulent kinetic energy dissipation rate, has a similar value for all snapshots. Thus, their impact on CCV is small compared to the flow field. This novel methodology is very flexible and allows investigation of the sources of CCV which have been difficult to investigate in the past.


2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
A Cremona ◽  
J Garlasco ◽  
I Gintoli ◽  
A D'Ambrosio ◽  
F Quattrocolo ◽  
...  

Abstract Background Antibiotics (AB) are administered for medical prophylaxis (MP) to prevent infectious complications. The second national point prevalence survey (PPS) of healthcare-associated infections and AB use was conducted in Italy in 2016-2017. The survey found MP accounted for nearly 25% of all registered ABs, more than twice the EU/EEA proportion. The aim of this study was to evaluate how many ABs were administered for MP and how frequently general indications were followed. Methods Data from the PPS were used to evaluate the prevalence of indications for MP over the total number of ABs, the proportion - among these indications - of those justified by a motivation in the patients' charts, and the prevalence of ABs considered appropriate for MP. The evaluation was made in 12 hospitals out of 14 participating in the PPS in Piedmont, chosen on the basis of patient traceability. According to national guidelines, the indications for MP that were considered appropriate in this study were: Trimethoprim/sulfamethoxazole for P. carinii pneumonia, Rifaximin for diverticulitis, Penicillin for Streptococcal infections and for splenectomized patients, and Rifampin for TB infections. Results 1844 AB prescriptions were registered among 1334 traceable inpatients in Piedmont. The prevalence of indications for MP was 16.2% and 253 ABs (84.6%) were prescribed with a motivation. Only 3% of ABs registered as MP were appropriate for this indication: Bactrim 2%, Rifaximin 0.3%, Penicillin 0.2% and Rifampin 0.4%. Conclusions This study found an extremely high rate of inappropriate ABs for MP, that will be further investigated through qualitative analysis of medical records to evaluate whether a misunderstanding of the PPS protocol occurred and empirical therapy was confused with MP. Nevertheless, this study highlighted the need for interventions to improve prescribing appropriateness for MP. Key messages This study found that only 2.98% of ABs registered as MP among traceable patients in Piedmont were appropriate for this indication. 15.38% of prescriptions for MP were not justified by a motivation. Interventions to improve prescribing appropriateness for MP could lead to a considerable reduction in inappropriate use of ABs, which is crucial in a country facing hyperendemic levels of AMR.


Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3966
Author(s):  
Jarosław Mamala ◽  
Michał Śmieja ◽  
Krzysztof Prażnowski

The market demand for vehicles with reduced energy consumption, as well as increasingly stringent standards limiting CO2 emissions, are the focus of a large number of research works undertaken in the analysis of the energy consumption of cars in real operating conditions. Taking into account the growing share of hybrid drive units on the automotive market, the aim of the article is to analyse the total unit energy consumption of a car operating in real road conditions, equipped with an advanced hybrid drive system of the PHEV (plug-in hybrid electric vehicles) type. In this paper, special attention has been paid to the total unit energy consumption of a car resulting from the cooperation of the two independent power units, internal combustion and electric. The results obtained for the individual drive units were presented in the form of a new unit index of the car, which allows us to compare the consumption of energy obtained from fuel with the use of electricity supported from the car’s batteries, during journeys in real road conditions. The presented research results indicate a several-fold increase in the total unit energy consumption of a car powered by an internal combustion engine compared to an electric car. The values of the total unit energy consumption of the car in real road conditions for the internal combustion drive are within the range 1.25–2.95 (J/(kg · m)) in relation to the electric drive 0.27–1.1 (J/(kg · m)) in terms of instantaneous values. In terms of average values, the appropriate values for only the combustion engine are 1.54 (J/(kg · m)) and for the electric drive only are 0.45 (J/(kg · m)) which results in the internal combustion engine values being 3.4 times higher than the electric values. It is the combustion of fuel that causes the greatest increase in energy supplied from the drive unit to the car’s propulsion system in the TTW (tank to wheels) system. At the same time this component is responsible for energy losses and CO2 emissions to the environment. The results were analysed to identify the differences between the actual life cycle energy consumption of the hybrid powertrain and the WLTP (Worldwide Harmonized Light-Duty Test Procedure) homologation cycle.


2021 ◽  
Vol 167 ◽  
pp. 112350
Author(s):  
Ilenia Catanzaro ◽  
Pietro Arena ◽  
Salvatore Basile ◽  
Gaetano Bongiovì ◽  
Pierluigi Chiovaro ◽  
...  

2019 ◽  
Vol 141 (11) ◽  
Author(s):  
Jinlong Liu ◽  
Hemanth Kumar Bommisetty ◽  
Cosmin Emil Dumitrescu

Heavy-duty compression-ignition (CI) engines converted to natural gas (NG) operation can reduce the dependence on petroleum-based fuels and curtail greenhouse gas emissions. Such an engine was converted to premixed NG spark-ignition (SI) operation through the addition of a gas injector in the intake manifold and of a spark plug in place of the diesel injector. Engine performance and combustion characteristics were investigated at several lean-burn operating conditions that changed fuel composition, spark timing, equivalence ratio, and engine speed. While the engine operation was stable, the reentrant bowl-in-piston (a characteristic of a CI engine) influenced the combustion event such as producing a significant late combustion, particularly for advanced spark timing. This was due to an important fraction of the fuel burning late in the squish region, which affected the end of combustion, the combustion duration, and the cycle-to-cycle variation. However, the lower cycle-to-cycle variation, stable combustion event, and the lack of knocking suggest a successful conversion of conventional diesel engines to NG SI operation using the approach described here.


Author(s):  
Bruce D. Hockaday

Detection of airfoil time of arrival with optical probes has been evolving since the 1980s. Time of arrival data are used to infer airfoil stresses caused by vibration through a sequence of manipulations. The data conversion begins by converting arrival time to blade position, so blade deflection can be determined from the expected non-vibrating position. Various methods are used in the industry to convert deflection data to frequency, amplitude, and stress, which is beyond the scope of this paper. Regardless of the analytical approach used, producing accurate stress information relies on the precise detection and measurement of time of arrival, which equates to blade position. Recent improvements have been made in time of arrival system accuracy by running faster clocks to increase temporal resolution of the measurement. Greater timing resolution, afforded by clock speed, will have diminishing returns when probe and blade-tip interactions begin producing dominant errors. In the case of optical probes, the blade-tip needs to be treated as a curved reflector in the optical system that is capable of introducing dynamic errors. In engine operation the blade-tip moves axially under the probe from untwist, static deflection, and vibration, causing the light to reflect from different parts of the blade-tip. This relative movement between the probe and blade-tip cause the arrival time to change dynamically. Neglecting the dynamic arrival errors caused by the blade-tip’s optical properties will result in blade deflection-errors that propagate into the stress information. This paper presents a laboratory study that quantifies time of arrival errors due to optical interaction with tip radii. The study reports measured arrival position error as a function of location and optical signal power levels. The work is presented in terms of arrival position, producing information that is independent of rotational speed, and vibratory mode.


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