Khaliq A.,Jamia Millia Islamia University |
Trivedi S.K.,Directorate of Training and Technical Education |
Dincer I.,University of Ontario Institute of Technology
Applied Thermal Engineering | Year: 2011
In this paper, a conceptual wet ethanol operated homogeneous charge compression ignition (HCCI) engine is proposed to shift the energy balance in favor of ethanol. The investigated option, HCCI engine is a relatively new type of engine that has some fundamental differences with respect to other prime movers. Combined first and second law of thermodynamic approach is applied for a HCCI engine operating on wet ethanol and computational analysis is performed to investigate the effects of turbocharger compressor ratio, ambient temperature, and compressor adiabatic efficiency on first law efficiency, second law efficiency, and exergy destruction in each component. First law and second law efficiencies are found to be an increasing function of the turbocharger pressure ratio, while they are found to be a decreasing function of the ambient temperature. The effect of turbocharger pressure ratio on exergy destruction is found to be more significant than compressor efficiency and ambient temperature. Exergy analysis indicates that maximum exergy is destroyed in HCCI engine which represents about 90.09% of the total exergy destruction in the overall system. Around 4.39% exergy is destroyed by the process of heat transfer in fuel vaporizer and heat exchanger. Catalytic converter contributes about 4.08% of the total exergy destruction. This will provide some original information on the role of operating variables and will be quite useful in obtaining the optimum design of ethanol fuelled HCCI engines. © 2011 Elsevier Ltd. All rights reserved.
Khaliq A.,Jamia Millia Islamia University |
Trivedi S.K.,Directorate of Training and Technical Education
Journal of Energy Resources Technology, Transactions of the ASME | Year: 2012
In this study, first and second law analyses of a new combined power cycle based on wet ethanol fuelled homogeneous charge compression ignition (HCCI) engine and an organic Rankine cycle are presented. A computational analysis is performed to evaluate first and second law efficiencies, with the latter providing good guidance for performance improvement. The effect of changing turbocharger pressure ratio, organic Rankine cycle (ORC) evaporator pinch point temperature, turbocharger compressor efficiency, and ambient temperature have been observed on cycle's first law efficiency, second law efficiency, and exergy destruction in each of its component. A first law efficiency of 41.5% and second law efficiency of 36.9% were obtained for the operating conditions (T 0 300 K, r p 3, T 80%). The first law efficiency and second law efficiency of the combined power cycle significantly vary with the change in the turbocharger pressure ratio, but the change in pinch point temperature, turbocharger efficiency, and ambient temperature shows small variations in these efficiencies. Second law analysis demonstrates well how the fuel exergy is used, lost, and reused in all of the cycle components. It was found that 78.9% of the total input exergy is lost: 2.0% to the environment in the flue and 76.9% due to irreversibilities in the components. The biggest exergy loss occurs in the HCCI engine which is 68.7%, and the second largest exergy loss occurs in catalytic converter, i.e., nearly 3.13%. Results clearly show that performance evaluation based on first law analysis alone is not adequate, and hence more meaningful evaluation must include second law analysis. © 2012 American Society of Mechanical Engineers.
Grover M.,National Bureau of Plant Genetic Resources |
Grover R.,Directorate of Training and Technical Education
Proceedings of the National Academy of Sciences India Section B - Biological Sciences | Year: 2012
Systems biology is not new but in recent years it has begun to receive renewed attention. Properties of biological systems such as robustness and fragility emerge as central issues which can be well understood by application of principles of engineering to the biological systems. Besides this automatic control has played a vital role in the advance of engineering and science. Advances in control theory provide the means for obtaining efficient performance of the dynamic systems and improving productivity. In this context some of the recent and important applications of engineering principles particularly control theory in biology are discussed in this review. © 2012 The National Academy of Sciences, India.
Singh M.,Directorate of Training and Technical Education |
Mittal A.K.,Indian Institute of Technology Delhi |
Upadhyay V.,Indian Institute of Technology Delhi
Water Science and Technology: Water Supply | Year: 2014
A number of international initiatives have been undertaken in recent years to develop benchmarking frameworks. Performance indicator system and data envelopment analysis are the two most widely used methods for performance assessment as is evident from the established literature on benchmarking. This paper demonstrates two benchmarking approaches using these two methods for the selected 12 Indian urban water utilities (municipal bodies) of Maharashtra state/province. Both the methodologies have been compared and analysed. The outcomes from both the methods are largely found to be consistent and mutually complementary. The proposed benchmarking techniques would serve as an important tool to assess the performance, induce competitive environment and encourage efficient practices by the urban water utilities. © IWA Publishing 2014