scholarly journals Experimental research made during a city cycle on the feasibility of electrically charged SI engines

2014 ◽  
Vol 4 (2) ◽  
Author(s):  
Levente Kocsis ◽  
Nicolae Burnete

AbstractThe paper presents experimental research on performance improvements in a city cycle (operating mostly transient) of a compact class vehicle equipped with a turbocharged SI engine which had attached an electric charger, to improve engine response at low operational speeds. During tests, functional parameters, energy consumption of the electric charger and vehicle performances were measured while driving in two operating conditions: with active and inactive electric charger. The tests were carried out on a well-defined path, in the same driving style, by the same driver.

Author(s):  
Brian T. Reese ◽  
Yann G. Guezennec ◽  
Miodrag Oljaca

A novel fuel atomization device (Nanomiser™) was evaluated under laboratory conditions with respect to its ability to reduce SI engine cold-start hydrocarbon emissions. First, comparisons between the level of atomization using the conventional, pintle-type fuel injector and the novel atomizer were carried out using flow visualization in a spray chamber and particle size distribution. The novel atomizer is capable of producing sub-micron fuel droplets, which form an ultra-fine mist with outstanding non-wetting characteristics. To capitalize on these atomization characteristics, this device was compared to a conventional fuel injector in a small, two-cylinder, SI engine under a number of operating conditions. Results show a slightly enhanced combustion quality and lean limit under warm operating conditions and a dramatic reduction in unburned HC emission under cold operating conditions, with cold emissions with the Nanomiser™ matching those with a conventional injector under fully warm conditions.


Author(s):  
K. von Rueden ◽  
H. Pucher ◽  
J. Nickel

Abstract In result of the permanent endeavor to reduce fuel consumption of vehicle engines, nowadays the implementation of downsizing concepts is being enforced. Thereby the desired nominal engine power can be produced by an engine with lower displacement operating with correspondingly higher charging pressure. Mechanical supercharging as well as turbocharging can be considered as a suitable supercharging method. This paper reports on experimental and simulation results regarding the stationary and transient operation of a four-stroke cycle SI passenger car engine supercharged by a new type of screw-type supercharger. In this manner the load control of the SI engine is performed by a supercharger internal slide valve system. Thus not only the throttling losses will be reduced noticeably, but also expansion work can be regained by this supercharger under certain operating conditions. The results obtained will be compared with those of the turbocharged reference engine.


2019 ◽  
pp. 116-122
Author(s):  
V. V. Stepanov ◽  
A. D. Kashtanov ◽  
S. U. Shchutsky ◽  
A. N. Agrinsky ◽  
N. I. Simonov

We consider the results of studies on the choice of material of the lower radial bearing of the pump, designed to circulate the coolant lead – bismuth. The circulation of the liquid coolant is provided by a vertical axial pump having a “long” shaft. In this design it is necessary to provide for the lower bearing the lubrication carried out with lead – bismuth coolant. Having analyzed the operating conditions of the axial pump, we decided to carry out the lower bearing in accordance with the scheme of a hydrodynamic sliding bearing. The materials of friction pairs in such a bearing must withstand the stresses arising from the operation of the pump, as well as the aggressive conditions of the coolant. Non-metallic materials – ceramics and carbon-based composite materials – were selected basing on the study of literature data for experimental research on the corrosion and heat resistance in the lead-bismuth environment. 


2020 ◽  
Vol 5 (1) ◽  
pp. 563-572
Author(s):  
Iman Golpour ◽  
Mohammad Kaveh ◽  
Reza Amiri Chayjan ◽  
Raquel P. F. Guiné

AbstractThis research work focused on the evaluation of energy and exergy in the convective drying of potato slices. Experiments were conducted at four air temperatures (40, 50, 60 and 70°C) and three air velocities (0.5, 1.0 and 1.5 m/s) in a convective dryer, with circulating heated air. Freshly harvested potatoes with initial moisture content (MC) of 79.9% wet basis were used in this research. The influence of temperature and air velocity was investigated in terms of energy and exergy (energy utilization [EU], energy utilization ratio [EUR], exergy losses and exergy efficiency). The calculations for energy and exergy were based on the first and second laws of thermodynamics. Results indicated that EU, EUR and exergy losses decreased along drying time, while exergy efficiency increased. The specific energy consumption (SEC) varied from 1.94 × 105 to 3.14 × 105 kJ/kg. The exergy loss varied in the range of 0.006 to 0.036 kJ/s and the maximum exergy efficiency obtained was 85.85% at 70°C and 0.5 m/s, while minimum exergy efficiency was 57.07% at 40°C and 1.5 m/s. Moreover, the values of exergetic improvement potential (IP) rate changed between 0.0016 and 0.0046 kJ/s and the highest value occurred for drying at 70°C and 1.5 m/s, whereas the lowest value was for 70°C and 0.5 m/s. As a result, this knowledge will allow the optimization of convective dryers, when operating for the drying of this food product or others, as well as choosing the most appropriate operating conditions that cause the reduction of energy consumption, irreversibilities and losses in the industrial convective drying processes.


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.


Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 607
Author(s):  
Tommy R. Powell ◽  
James P. Szybist ◽  
Flavio Dal Forno Chuahy ◽  
Scott J. Curran ◽  
John Mengwasser ◽  
...  

Modern boosted spark-ignition (SI) engines and emerging advanced compression ignition (ACI) engines operate under conditions that deviate substantially from the conditions of conventional autoignition metrics, namely the research and motor octane numbers (RON and MON). The octane index (OI) is an emerging autoignition metric based on RON and MON which was developed to better describe fuel knock resistance over a broader range of engine conditions. Prior research at Oak Ridge National Laboratory (ORNL) identified that OI performs reasonably well under stoichiometric boosted conditions, but inconsistencies exist in the ability of OI to predict autoignition behavior under ACI strategies. Instead, the autoignition behavior under ACI operation was found to correlate more closely to fuel composition, suggesting fuel chemistry differences that are insensitive to the conditions of the RON and MON tests may become the dominant factor under these high efficiency operating conditions. This investigation builds on earlier work to study autoignition behavior over six pressure-temperature (PT) trajectories that correspond to a wide range of operating conditions, including boosted SI operation, partial fuel stratification (PFS), and spark-assisted compression ignition (SACI). A total of 12 different fuels were investigated, including the Co-Optima core fuels and five fuels that represent refinery-relevant blending streams. It was found that, for the ACI operating modes investigated here, the low temperature reactions dominate reactivity, similar to boosted SI operating conditions because their PT trajectories lay close to the RON trajectory. Additionally, the OI metric was found to adequately predict autoignition resistance over the PT domain, for the ACI conditions investigated here, and for fuels from different chemical families. This finding is in contrast with the prior study using a different type of ACI operation with different thermodynamic conditions, specifically a significantly higher temperature at the start of compression, illustrating that fuel response depends highly on the ACI strategy being used.


Author(s):  
Robson L. Silva ◽  
Bruno V. Sant′Ana ◽  
José R. Patelli ◽  
Marcelo M. Vieira

This paper aims to identify performance improvements in cooker-top gas burners for changes in its original geometry, with aspect ratios (ARs) ranging from 0.25 to 0.56 and from 0.28 to 0.64. It operates on liquefied petroleum gas (LPG) and five thermal power (TP) levels. Considering the large number of cooker-top burners currently being used, even slight improvements in thermal performance resulting from a better design and recommended operating condition will lead to a significant reduction of energy consumption and costs. Appropriate instrumentation was used to carry out the measurements and methodology applied was based on regulations from INMETRO (CONPET program for energy conversion efficiency in cook top and kilns), ABNT (Brazilian Technical Standards Normative) and ANP—National Agency of Petroleum, Natural Gas (NG) and Biofuels. The results allow subsidizing recommendations to minimum energy performance standards (MEPS) for residential use, providing also higher energy conversion efficiency and/or lower fuel consumption. Main conclusions are: (i) Smaller aspect ratios result in the same heating capacity and higher efficiency; (ii) higher aspect ratios (original burners) are fuel consuming and inefficient; (iii) operating conditions set on intermediate are lower fuel consumption without significant differences in temperature increases; (iv) Reynolds number lower than 500 provides higher efficiencies.


Author(s):  
M. Z. Haq ◽  
M. R. Mohiuddin

The paper presents a thermodynamic analysis of a single cylinder four-stroke spark-ignition (SI) engine fuelled by four fuels namely iso-octane, methane, methanol and hydrogen. In SI engines, due to phenomena like ignition delay and finite flame speed manifested by the fuels, the heat addition process is not instantaneous, and hence ‘Weibe function’ is used to address the realistic heat release scenario of the engine. Empirical correlations are used to predict the heat loss from the engine cylinder. Physical states and chemical properties of gaseous species present inside the cylinder are determined using first and second law of thermodynamics, chemical kinetics, JANAF thermodynamic data-base and NASA polynomials. The model is implemented in FORTRAN 95 using standard numerical routines and some simulation results are validated against data available in literature. The second law of thermodynamics is applied to estimate the change of exergy i.e. the work potential or quality of the in-cylinder mixture undergoing various phases to complete the cycle. Results indicate that, around 4 to 24% of exergy initially possessed by the in-cylinder mixture is reduced during combustion and about 26 to 42% is left unused and exhausted to the atmosphere.


Agronomy ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 72
Author(s):  
Vilma Naujokienė ◽  
Daiva Rimkuvienė ◽  
Egidijus Šarauskis

Different bio-impacts affect the various properties and composition of soil, plant residues, harvests, and technological processes, as well as the interactions between different parts of the soil, working machine tools, energy consumption and environmental pollution with harmful gases. To summarize the wide-coverage investigations of various aspects of different bio-impact parameters, a multicriteria evaluation was conducted. Experimental research shows that different bioeffects such as those of agricultural practices can be oriented towards a reduction in fuel consumption, followed by reductions in CO2 emissions from machinery and changes in soil properties, dynamics of composition, yield and other parameters. A multicriteria assessment of the essential parameters would give farmers new opportunities to choose one optimal decision for reducing fuel consumption and increasing agricultural production, thereby reducing the negative environmental impact of soil cultivation processes, increasing yields and improving soil. Of all the properties investigated, from a practical point of view, the selection of the most important of all the essential links, such as reducing energy and expenditure, reducing environmental pollution, improving soil, and increasing yields and productivity, is reasonable. The evaluation of the bio-impact effects in agriculture by accounting for many criteria from several aspects was the main objective of the multicriteria assessment using the analytic hierarchy process. Based on the results of a multivariable research of fuel consumption—C1, C2, yield—C3, CO2 from soil—C4, density—C5, total porosity—C6, humus—C7, soil stability—C8, and soil moisture content—C9, the evaluation used experimental research data and the Simple Additive Weighting (SAW) mathematical method to find the best-case scenario. Multicriteria effectiveness was most pronounced after the first and third soil bio-impacts by using a solution of essential oils of plants, 40 species of various herbs extracts, marine algae extracts, mineral oils, Azospirillum sp. (N), Frateuria aurentia (K), Bacillus megaterium (P), seaweed extract. The most important goal was to achieve the best soil bio-impact effectiveness—minimized energy consumption from ploughing and disc harrowing operations, parallelly minimized harmful emissions from agricultural machinery, minimized CO2 from soil, soil density, maximized soil total porosity, soil humus, soil stability, yield and optimized soil moisture.


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