Z. A. Abdul Karim

Current Trends in Water-in-Diesel Emulsion as a Fuel

Water-in-diesel emulsion (WiDE) is an alternative fuel for CI engines that can be employed with the existing engine setup with no additional engine retrofitting. It has benefits of simultaneous reduction of both NOx and particulate matters in addition to its impact in the combustion efficiency improvement, although this needs further investigation. This review paper addresses the type of emulsion, the microexplosion phenomenon, emulsion stability and physiochemical improvement, and effect of water content on the combustion and emissions of WiDE fuel. The review also covers the recent experimental methodologies used in the investigation of WiDE for both transport and stationary engine applications. In this review, the fuel injection pump and spray nozzle arrangement has been found to be the most critical components as far as the secondary atomization is concerned and further investigation of the effect of these components in the microexplosion of the emulsion is suggested to be center of focus.

Puffing and Microexplosion Behavior of Water in Pure Diesel Emulsion Droplets During Leidenfrost Effect

ABSTRACT The microexplosion evolution phenomenon of single droplets of water in pure diesel emulsion under Leidenfrost effect has been studied. The tested emulsions were stabilized with a blend of commercial surfactants with three different water contents of 9%, 12%, and 15%. A high speed camera synchronized with backlight technique was used to capture the evolution of microexplosion and puffing. Three different droplet diameters of approximately 2.6 mm, 2 mm, and 0.2 mm were analyzed. It was found that the tendency of microexplosion and puffing frequency was influenced by the droplet diameter. Coalescence was the dominating factor in inducing microexplosion in bigger droplets. It was observed that the child droplets ejected from the parent droplet undergoes further puffing processes. The size of the secondary droplets after microexplosion were also found to be slightly influenced by the parent droplet size.The waiting time for microexplosion and puffing were compared for different droplets size.

Methodology for short-term performance prognostic of gas turbine using recurrent neural network

The issue of performance prognosis has been a topic of considerable interest in industrial condition monitoring applications. An innovative data driven prognostic methodology has been introduced in the current study by utilizing artificial recurrent neural network (RNN) approach which intends to improve the capability of equipment performance prediction within a specified short time bound even with limited available data. The ability of the approach is demonstrated using condition monitoring parameters collected from a 20 MW industrial gas turbine. An appropriate selection and fusion of measured variables has been employed to feed RNN with the most influential performance information. The analysis demonstrated that the developed prognostic approach has a great potential to provide an accurate short term forecast of equipment performance which can be invaluable for maintenance strategy and planning.

Experimental Study on Influence of Surfactant Dosage on Micro Explosion Occurrence in Water in Diesel Emulsion

An experimental investigation has been carried out to study the effect of surfactant dosage on micro explosion phenomenon. Three water in diesel emulsion with 20% water by volume was prepared using mechanical stirring at 17000rpm for 100s.The emulsions were stabilised by a were stabilized by a single surfactant with three different doses. Water in diesel emulsion droplet was suspended on a thermocouple and the evolution of micro explosion was recorded with a high speed camera synchronized with temperature data logger. Secondary atomization of emulsion droplet was observed under Leiden frost regime using a hot plate as the heat source. The results show that the occurrences of micro explosion are affected by the volume of added surfactant by influencing the exploding temperature and waiting time. Physical properties like density, viscosity and surface tension were also found to be influenced by the amount of surfactant used.

Time series method for machine performance prediction using condition monitoring data

Accurate machine performance prediction is crucial to an effective maintenance strategy for improved reliability and to reduce total maintenance cost. In this study, a time series neural network based approach is introduced to achieve more accurate and reliable performance prediction of machine using condition monitoring data source. The proposed time series model utilizes the various measured condition monitoring data at the current and previous inspection marks as the inputs, and the machine output performance as the targets for the model. To validate the model, it considers a two-shaft industrial gas turbine as a case study. The collected condition monitoring data are used to train and validate the proposed model. Results showed that the proposed time series method could predict the performance of the gas turbine power output with more accuracy and better results.

A Technique for Localized Rapid Soot Oxidation Using Metal Aided Microwave Radiation

The regeneration of soot filter using microwave heating has several drawbacks, which include non-uniform regeneration, ineffective on very small soot thickness, and could lead to excessive heating, which damages the filter that is loaded with high layer of soot. This paper proposes a novel technique for localized rapid heating and oxidation of any thickness of solid soot, and saving of the consumed microwave energy. This technique was applied by inserting a metal in the accumulated soot, located inside a closed multi-mode microwave cavity, attached to a mono-mode waveguide, connected with a magnetron with a capacity of 2.45 GHz and 800 W. The electric field, generated heat, and temperature variation with time till the attaining of the oxidation temperature of the soot during microwave heating were simulated. The simulation methodology is based on the concept of electromagnetic-thermal energy conversion by coupling Maxwell with heat transfer equations. Finite element method was used with frequency domain for electromagnetic analysis and time domain for thermal analysis. In agreement with experimental results, the predicted microwave heating time to attaining the soot ignition/oxidation temperature was reduced from 8.5 to 0.3 seconds. Based on the presented technique, metallic electrodes can be inserted on the soot filter surfaces as local heating electrodes to enhance the microwave heating of the soot filter regeneration.

Optimizing electro-thermo Helds for soot oxidation using microwave heating and metal

Soot is produced by incomplete combustion of various carbon-containing compounds. Soot is one of the main environmental pollutants and has become an important environmental and specific objective. To reduce soot from exhaust emission of diesel engine, a new technique is proposed and implemented by using metal inserted in the soot exposed to electromagnetic radiation. This paper presents a simulation to obtain optimum metal length and shape that give optimum electric field for attaining temperature enough for soot oxidation using microwave heating and a thin metal rod. Four cases were numerically examined to investigate the electric field and temperature distributions in a mono-mode TE10 microwave cavity having closed surfaces of perfect electric conductors. The operating frequency is 2.45 GHz, and power supply is 1500 W. The simulation methodology is coupling the absorbed electromagnetic energy with heat transfer energy. The absorbed electromagnetic energy is found from the electric field within the soot. The simulation was run using ANSYS based on finite element method. The results of the four simulation cases show that the optimum simulation is represented by case 2 where the value of electric field is 39000 V/m and heating time to arrive at the oxidation temperature (873 K) is 35 s using cylindrical metal rod of 8 mm length. It is revealed that the concept of achieving high temperature for soot oxidation by using thin metal rod inside a microwave cavity can be applied.

Water-in-Diesel Emulsions—Fuel Characteristics

The characteristics of water-in-diesel emulsion is strongly related to the amount of water added to the fuel, type and amount of surfactant used, and the emulsification technique. The characteristics include the emulsified fuel stability, density, kinematic viscosity and water droplet sizes. These characteristics on the other hand, affect the occurance of microexplosion during fuel atomization process which has a beneficial effect on the formation of emissions. This chapter provides an example of how the emulsified fuel was produced and the characteristics of various water-in-diesel emulsion blends, as compared to diesel fuel.