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Mohapatra A.K.,Nalanda Institute of Technology | Sanjay,National Institute of Technology Jamshedpur
Journal of the Energy Institute | Year: 2015

The current article is focused on assessing the comparison of two different means of inlet air cooling (evaporative cooing and vapor compression cooling) integrated to a cooled gas turbine power plant. Air film cooling has been adopted as the cooling technique for gas turbine buckets. A parametric study of the effect of pressure ratio (rp,c), compressor inlet temperature (CIT), turbine inlet temperature (TIT), inlet temperature ratio (rIT), ambient relative humidity and ambient temperature on performance parameters of plant has been carried out. It has been observed that the integration of the inlet air cooling system to the gas turbine cycle improves the overall performance, the improvement being higher at higher ambient temperature and ambient relative humidity. At a TIT = 1700 K, rp,c = 23, RHa = 0.2 and Ta = 313 K, vapor compression inlet air cooling has been observed to improve the plant specific work by 18.4% and efficiency by 4.18%, compared to 10.48% and 4.6% respectively for evaporative cooling. In geographical regions having low ambient relative humidity and low ambient temperature however, evaporative inlet air cooling should be preferred over vapor compression cooling in terms of higher plant efficiency.. The adoption of higher turbine inlet temperature has a more pronounced effect on vapor compression cooled gas turbine in terms of enhancement in plant performance parameters as compared to evaporative cooling. The work ratio increases with increase in value of rIT upto5.6 after which it decreases. © 2014 Energy Institute. Published by Elsevier Ltd. All rights reserved. Source


This paper is focused on accessing the benefits of incorporating an air humidifier with a cooled gas turbine cycle. Air transpiration cooling has been adopted as the cooling technique for gas turbine blades. A parametric study of the effect of compressor pressure ratio (rp,c), compressor inlet temperature (CIT), turbine inlet temperature (TIT), inlet temperature ratio (rIT), ambient relative humidity, and ambient temperature on performance parameters of plant has been carried out. Evaporative inlet air cooling has been observed to improve the plant efficiency of a transpiration cooled gas turbine plant by 4.84% and plant specific work by 9.68% at an ambient temperature of 313 K and ambient relative humidity of 0.2. The effects of variation of ambient parameters on cycle performance are found to be more pronounced at higher turbine inlet temperature and higher compression ratio (rp,c). The work ratio increases with an increase in the value of rIT up to 5.6 after which it decreases. There exists an optimum rIT at any rp,c with reference to the maximum work ratio. The heat rate increases with an increase in rIT and a decrease in rp,c. For all values of TIT there exists an optimum rp,c at which plant efficiency is at its maximum. © 2014 American Society of Civil Engineers. Source


Gudavalli M.,Vignans Nirula Institute of Technology and Science for Women | Viswanadha Raju S.,Jawaharlal Nehru Technological University | Vinaya Babu A.,JNTUH College of Engineering | Srinivasa Kumar D.,Nalanda Institute of Technology
Proceedings - 2012 International Symposium on Biometrics and Security Technologies, ISBAST 2012 | Year: 2012

Biometrics is the science and technology of measuring and analyzing biological data of human body, extracting a feature set from the acquired data, and comparing this set against to the template set in the database. The increasing demand of enhanced security systems has led to an unprecedented interest in biometric based person authentication system. Biometric systems based on single source of information are called Unimodal systems. Although some Unimodal systems have got considerable improvement in reliability and accuracy, they often suffer from enrollment problems due to non-universal biometrics traits, susceptibility to biometric spoofing or insufficient accuracy caused by noisy data. Hence, single biometric may not be able to achieve the desired performance requirement in real world applications. One of the methods to overcome these problems is to make use of multimodal biometric authentication systems, which combine information from multiple modalities to arrive at a decision. Multimodal biometric systems are those which utilize, or capability of utilizing, more than one physiological or behavioral characteristic for enrollment, verification, or identification. Studies have demonstrated that multimodal biometric systems can achieve better performance compared with Unimodal systems. We discuss here different multimodal sources, multimodal architectures different fusion techniques used in multimodal biometric systems. © 2012 IEEE. Source


Mohapatra A.K.,Nalanda Institute of Technology | Sanjay,National Institute of Technology Jamshedpur | Prasad L.,National Institute of Technology Jamshedpur
Journal of the Energy Institute | Year: 2012

The paper investigates the effect of compressor pressure ratio, turbine inlet temperature, ambient relative humidity (RH) and ambient temperature on the performance parameters of a gas turbine cycle with evaporative cooling of inlet air and different means of blade cooling. The cooling techniques include film, transpiration and internal convection cooling (ICC). The mass of coolant required for turbine blade cooling is found to decrease with a decrease in ambient temperature and ambient RH. The coolant mass required for turbine blade cooling is lowest for transpiration cooling (TC) followed by film and ICC. However, the highest reduction in coolant mass and the highest enhancement in plant efficiency and work (due to the decrease in ambient RH and ambient temperature) are observed in case of ICC followed by film cooling and TC. The increase in performance parameters due to the addition of inlet cooling system is also found to be maximum for ICC. The inlet cooling improves the plant efficiency by 11·3% and specific work by 19·7% for ICC against 4·2 and 9·8% respectively for TC. Finally, the optimum value of T IT and r p,c is suggested for best plant efficiency and plant specific work. © 2012 Energy Institute. Source


Srinivasa Krishna T.,Nalanda Institute of Technology | Gowri Sankar M.,Acharya Nagarjuna University | Govardhan Rao S.,St Marys Group Of Institutions | Munibhadrayya B.,Sri Venkateswara College of Engineering
Journal of Molecular Liquids | Year: 2015

This paper reports measurements of densities (ρ), and speeds of sound (u) for the binary systems of an ionic liquid and an alkanediol at T = (298.15 to 323.15) K. The ionic liquid is 1-butyl-3-methylimidazolium tetrafluoroborate [bmim(BF4)] and alkanediols are 1,2-propanediol or 1,3-propanediol. The excess molar volumes and the excess molar isentropic compressibility for the above systems were calculated from experimental densities and the speeds of sound, respectively. Redlich-Kister polynomial equation was used to fit the excess molar volume and excess isentropic compressibility data. A qualitative analysis of intermolecular interactions and structural effects between [bmim(BF4)] and alkanediols are analyzed in terms of declustering and breaking of H-bonds in alkanediols, new hydrogen bonding, and ion-dipole interactions at all temperatures. © 2015 Published by Elsevier B.V. Source

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