Diesel engine

This paper presents a study carried out to investigate the economics of wind turbine as an energy fuel saver. The load and the wind data is taken from a remote agricultural research station in Oman. Presently, the station is provided with electricity from diesel-engine generating units. The annual peak load and minimum load recorded at the site is 130 kW and 28 kW respectively. The annual average wind speed at the site is 5.7 m/s. A 50-kW wind turbine is selected to demonstrate the economic feasibility of the turbine as a fuel saver. The results show that wind energy utilization is an attractive option with total specific cost of the selected wind turbine ranges between 7.4 and 8.45 ¢/kWh at 7.55% discount rate comparing to diesel generation operating cost of 14.3 ¢/kWh, considering the capital cost of diesel units as sunk. The simple payback period of the turbine is between 5.1 and 5.4 years and discounted payback between 6.7 and 8.0 years.

This paper investigates typical behaviors like damped oscillations in fractional order (FO) dynamical systems. Such response occurs due to the presence of, what is conceived as, pseudo-damping and meta-damping in some special class of FO systems. Here, approximation of such damped oscillation in FO systems with the conventional notion of integer order damping and time constant has been carried out using Genetic Algorithm (GA). Next, a multilayer feed-forward Artificial Neural Network (ANN) has been trained using the GA based results to predict the optimal pseudo and meta-damping from knowledge of the maximum order or number of terms in the FO dynamical system.

Nowadays, environmental issues are greatly concerned. Conventional solutions that use lead acid batteries and diesel engines as sources of energy for both uninterruptible power supply (UPS) and isolated power generation systems are facing an increasing opposition due to environmental and economical concerns. The aim of the paper is to evaluate the technical feasibility and aspects related to the use of fuel cells instead of traditional electrochemical batteries in the UPS. The proposed system is named FCB-UPS (Fuel Cell Based UPS). However, the quality of UPS output voltage is important when it supports the sensitive loads. So, in this paper a new configuration of UPS based on flying capacitor multicell (FCM) converter is proposed to produce the multilevel output voltage to support the sensitive load with sinusoidal voltage. The main properties of FCM converter, which causes increase in the number of output voltage levels, are transformer-less operation and natural self-balancing of flying capacitors voltages. The proposed configuration is simulated using PSCAD/EMTDC software and simulation results are presented to validate its effectiveness.

The autoignition and combustion of hydrogen were investigated in a constant-volume combustion vessel under simulated direct-injection (DI) diesel engine conditions. The parameters varied in the investigation included: the injection pressure and temperature, the orifice diameter, and the ambient gas pressure, temperature and composition. The results show that the ignition delay of hydrogen under DI diesel conditions has a strong, Arrhenius dependence on temperature; however, the dependence on the other parameters examined is small. For gas densities typical of top-dead-center (TDC) in diesel engines, ignition delays of less than 1.0 ms were obtained for gas-temperatures greater than 1120 K with oxygen concentrations as low as 5\% (by volume). These data confirm that compression ignition of hydrogen is possible in a diesel engine at reasonable TDC conditions. In addition, the results show that DI hydrogen combustion rates are insensitive to reduced oxygen concentrations. The insensitivity of ignition delay and combustion rate to reduced oxygen concentration is significant because it offers the potential for a dramatic reduction in the emission of nitric oxides from a compression-ignited DI hydrogen engine through use of exhaust-gas-recirculation. (C) 1998 International Association for Hydrogen Energy.

The selective catalytic reduction (SCR) of NO by NH3 has been studied over vanadia/ titania catalysts prepared by selective immobilization of vanadyl alkoxide species on two structurally different titania supports. The loading of vanadia was varied from 1.8 to 7.5 μ,mol V5+ per m2 surface area. Comparative kinetic measurements at 150 °C show that the NO turnover frequencies increase by more than an order of magnitude when the vanadia loading is increased from 1.8 to ≈ 3 μmol V5+/m2. In the region of lower SCR activity, i.e. at lower coverages (≈ 2 μmol V5+/m2), small clusters and ribbons of vanadia are detected in the Raman spectra, whereas at loadings where maximum NO turnovers are achieved (≈ 3 μmol V5+/m2) the prevalent vanadia species are well-developed two-dimensional vanadia layers bound to titania.

We present an industrial case study in automotive control of significant complexity: the new common rail fuel injection system for Diesel engines, currently under production by Magneti Marelli Powertrain. In this system, a flow–rate valve, introduced before the High Pressure (HP) pump, regulates the fuel flow that supplies the common rail according to the engine operating point. The standard approach followed in automotive control is to use a mean–value model for the plant and to develop a controller based on this model. In this particular case, this approach does not provide a satisfactory solution as the discrete–continuous interactions in the fuel injection system, due to the slow time–varying frequency of the HP pump cycles and the fast sampling frequency of sensing and actuation, play a fundamental role. We present a design approach based on a hybrid model of the Magneti Marelli Powertrain common–rail fuel–injection system for four-cylinder multi–jet engines and a hybrid approach to the design of a rail pressure controller. The hybrid controller is compared with a classical mean–value based approach to automotive control design whereby the quality of the hybrid solution is demonstrated.

This study was set out to characterize particulate emissions from a mid-sized diesel engine in terms of metals, benzene soluble fraction, elemental and organic carbon. For this study, the exhaust particulates from Mahindra direct injection transportation diesel engine (40 hp) were collected at four different engine operating conditions, namely idle, 40%, 70% and full load for the above parameters. It was found that as the load increased from idling to full load, the metal content in particulates gradually decreased. The metal content in exhaust particulates was correlated with that of metal content in diesel. Benzene soluble fraction, which is a marker for carcinogenicity, also showed decrease in its level with increasing load. It was found that at idling, 67% of mass was soluble in benzene while at full load it was only about 24%. Elemental carbon content increased with increase in load showing a maximum of 48% at 70% load and a minimum of 25% at idling. The trend of organic carbon was quite opposite; it showed 35% organic carbon at idling, which decreased gradually with increase in load. This research has suggested that composition of diesel exhaust particles varies significantly with varying engine load conditions.

Vegetable oil derived fuels for diesel engines are becoming important as alternative to petroleum diesel fuels due to their environmental friendliness and availability. Ignition quality in compression ignition (CI) engines is influenced by thermal characteristics and fuel properties. In this study, the effects of vegetable oil transesterification and vegetable oil–1-butanol-diesel blends on fuel properties, cetane number (CN) and thermal characteristics were experimentally investigated. Methyl esters (biodiesel) and 10% vegetable oil–10% 1-butanol–80% diesel blends were prepared from croton oil (CRO), coconut oil (COO) and jatropha oil (JAO). CN was measured in a CFR F-5 engine, and a thermogravimetric analysis (TG), as well as the determination of fuel properties of vegetable oils, biodiesels and blends was carried out. It can be observed for vegetable oils that they possess low volatility characteristics, low CN and high viscosity different from those of biodiesels, blends and diesel fuel. It was observed that biodiesels and blends exhibit similarities with diesel in the fuel characteristics, CN and TG curves.

Recent environmental trends, including (1) an expansion of existing command and control directives, (2) the introduction of market-based policy instruments, and (3) the adoption of extended producer responsibility, have created a need for new tools to help managerial decision-making. To address this need, we develop a nonlinear mathematical programming model from a profit-maximizing firm's perspective, which can be tailored as a decision-support tool for firms facing environmental goals and constraints. We typify our approach using the specific context of diesel engine manufacturing and remanufacturing. Our model constructs are based on detailed interviews with top managers from two leading competitors in the medium and heavy-duty diesel engine industry. The approach allows the incorporation of traditional operations-planning considerations—in particular, capacity, production, and inventory—together with environmental considerations that range from product design through production to product end of life. A current hurdle to implementing such a model is the availability of input data. We therefore highlight the need not only to involve all departments within businesses but also for industrial ecologists and business managers to work together to implement meaningful decision models that are based on accurate and timely data and can have positive economic and environmental impact.

Total Suspended Particulate Matter (TSPM) samples were collected at Nunhai Agra from April to September 2006. The concentrations of 16 PAHs in aerosols were quantified. The dominated predominant PAHs in TSPM include high molecular weight (HMW) congeners BghiP, DbA, IP and BaP. Nap and Acy were not detected in any of the samples. The sum of 14 priority PAHs ranged from 150 to 480 ng m−3 with a mean value of 269 ± 121 ng m−3. The Results indicated that PAH concentrations at Nunhai were higher than in other industrial sites, but are comparable to those measured in several urban Chinese cities, however, and less than the industrial locations of China. Higher HMW PAH concentration were attributable to higher rates of emissions as well as or greater scavenging and adsorption of vapor phase PAH on available TSPM. Potential sources of PAHs in aerosols were identified using the diagnostic ratios between PAHs. Vehicular emissions were the main contributors of particulate-associated PAHs, with minor contribution from stationary combustion sources may also contribute to the particulate PAHs. PAHs in aerosols were predominantly from gasoline and diesel engines.