• Energy Research

Abstract In this paper the work deals with the Experimental analysis of the early direct injected HCCI. The computational analysis of the engine was carried out using CHEMKIN-PRO Software. The computational analysis was carried out using the auto ignition chemistry by means of reduced chemical kinetics. For these investigations, the neat diesel and bio ethanol - diesel blend (E20) fuels were used as fuel and the pressure, combustion and emission characteristics were studied in the equivalence ratio of 0.6 (ɸ = 0.6). The injection timing was advanced to 18° rather than the normal 23° before top dead centre (BTDC) as specified engine conditions. Since pressure and temperature profiles plays a vital role in reaction path at certain operating conditions, an effort has been made here to present a comprehensive reaction path analysis on the formation/destruction of chemical species at peak temperature and pressure conditions.

Abstract In this paper the work deals with the Experimental analysis of the early direct injected PCCI. For this investigations, the neat diesel and bio ethanol - diesel blend (E20) fuels were used as fuel and the pressure, combustion and emission characteristics were studied in the equivalence ratio of 0.6 (ɸ = 0.6). The injection timing was advanced to 18° rather than the normal 23° before top dead centre (BTDC) as specified engine conditions. For the Experimental analysis the partial homogeneity of the charge was achieved by injecting the fuel in the pre chamber which consists of a heater unit. The fuel injection timing was controlled with respective to the crank angle timing with the help of an ECU unit. In the pre chamber the fuel was vaporised and the partial homogeneous charge was fed in to the engine during the suction stroke. The injection timing was advanced by removing shim from the cam shaft rocker arm mechanism of the engine. The results of the neat diesel and bio ethanol diesel (E20) blends were compared and oxides of Nitrogen were reduced to very lower levels when compared to neat diesel operations.

AbstractFor the past one hundred years, lots of easily accessible petroleum fuel has been burned out by humankind in inefficient engines. In this regard, present-day engine researchers face a formidable challenge to achieve the goal of significant improvements in both thermal efficiency and fuel economy. Although the direction to reach this target is critical, homogenous charge compression ignition (HCCI) is just another combustion concept to achieve this target. By the way, this work investigates the combustion phenomena of the HCCI engine by external mixture formation technique. In a nut-shell, an endeavor has been made in this work to prepare homogeneous mixture outside the combustion chamber using a fuel vaporizer system to form a uniform fuel–air mixture. The fundamental research experiments were carried out with vaporized diesel and vaporized e-diesel blends (10% and 20% ethanol substitution by volume), and the results were compared with conventional diesel engine operation. In HCCI mode, the maximum rate of pressure rises and the maximum rate of heat-release significantly reduced with increase of ethanol concentration in diesel. The experimental outcomes exposed that when HCCI engine is operated with e-diesel blend, smooth engine operation is apparent.

Abstract In this research, work is focused on the performance and emission characteristics of the CI engine fuelled with algae oil diesel blend B20 with variable injection timing. Algae based bio-diesel is receiving increased attention in the recent years because of its low emission characteristics. Algae oil methyl ester is obtained from micro algae. The oil has been converted into bio-diesel with the help of transesterification process. The experiment is conducted both by advancing and retarding the injection timing with various load conditions. The retarded injection timing of 21°bTDC and 19°b TDCis selected for this study. For advanced injection timing 25°b TDC and 27°b TDCis adopted. The experimental results reveals that the brake thermal efficiency (BTE) increased by 5.70% in the advanced injection timing of 270bTDC with a massive reduction of CO by 81.25% and HC emission is reduced by 30%. The smoke intensityis reduced by 26.39% at high load conditions. The retardation test showed significant decrease in NOx by 28% at high load condition. The exhaust gas temperature is also reduced by 7.8% by advancing the injection timing at high load condition.

The solar photovoltaic (PV) cell is a prominent energy harvesting device that reduces the strain in the conventional energy generation approach and endorses the prospectiveness of renewable energy. Thus, the exploration in this ever-green field is worth the effort. From the power conversion efficiency standpoint of view, PVs are consistently improving, and when analyzing the potential areas that can be advanced, more and more exciting challenges are encountered. One such crucial challenge is to increase the photon availability for PV conversion. This challenge is solved using two ways. First, by suppressing the reflection at the interface of the solar cell, and the other way is to enhance the optical pathlength inside the cell for adequate absorption of the photons. Our review addresses this challenge by emphasizing the various strategies that aid in trapping the light in the solar cells. These strategies include the usage of antireflection coatings (ARCs) and light-trapping structures. The primary focus of this study is to review the ARCs from a PV application perspective based on various materials, and it highlights the development of ARCs from more than the past three decades covering the structure, fabrication techniques, optical performance, features, and research potential of ARCs reported. More importantly, various ARCs researched with different classes of PV cells, and their impact on its efficiency is given a special attention. To enhance the optical pathlength, and thus the absorption in solar PV devices, an insight about the advanced light-trapping techniques that deals with the concept of plasmonics, spectral modification, and other prevailing innovative light-trapping structures approaching the Yablonovitch limit is discussed. An extensive collection of information is presented as tables under each core review section. Further, we take a step forward to brief the effects of ageing on ARCs and their influence on the device performance. Finally, we summarize the review of ARCs on the basis of structures, materials, optical performance, multifunctionality, stability, and cost-effectiveness along with a master table comparing the selected high-performance ARCs with perfect AR coatings. Also, from the discussed significant challenges faced by ARCs and future outlook; this work directs the researchers to identify the area of expertise where further research analysis is needed in near future.