The Experts below are selected from a list of 86421 Experts worldwide ranked by ideXlab platform
Abdul Khaliq - One of the best experts on this subject based on the ideXlab platform.
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Exergy analysis of the regenerative gas turbine cycle using absorption inlet cooling and evaporative aftercooling
Journal of The Energy Institute, 2009Co-Authors: Abdul Khaliq, K. ChoudharyAbstract:AbstractThis paper provides an exergy analysis to investigate the effects of pressure ratio, turbine inlet temperature, compressor inlet temperature and ambient relative humidity on the thermodynamic performance of a regenerative gas turbine cycle using absorption inlet cooling and evaporative aftercooling. Combined first and second Law analysis indicates that the exergy destruction in various components of the gas turbine cycle is significantly affected by compressor pressure ratio and turbine inlet temperature, and slightly varies with the compressor inlet temperature and ambient relative humidity. It also indicates that the maximum exergy destroyed in the combustion chamber; which represents over 60% of the total exergy destruction in the overall system. The net work output, first Law Efficiency, and second Law Efficiency of the cycle significantly varies with the change in the pressure ratio, turbine inlet temperature, compressor inlet temperature and ambient relative humidity.
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exergy analysis of gas turbine trigeneration system for combined production of power heat and refrigeration
International Journal of Refrigeration-revue Internationale Du Froid, 2009Co-Authors: Abdul KhaliqAbstract:A conceptual trigeneration system is proposed based on the conventional gas turbine cycle for the high temperature heat addition while adopting the heat recovery steam generator for process heat and vapor absorption refrigeration for the cold production. Combined first and second Law approach is applied and computational analysis is performed to investigate the effects of overall pressure ratio, turbine inlet temperature, pressure drop in combustor and heat recovery steam generator, and evaporator temperature on the exergy destruction in each component, first Law Efficiency, electrical to thermal energy ratio, and second Law Efficiency of the system. Thermodynamic analysis indicates that exergy destruction in combustion chamber and HRSG is significantly affected by the pressure ratio and turbine inlet temperature, and not at all affected by pressure drop and evaporator temperature. The process heat pressure and evaporator temperature causes significant exergy destruction in various components of vapor absorption refrigeration cycle and HRSG. It also indicates that maximum exergy is destroyed during the combustion and steam generation process; which represents over 80% of the total exergy destruction in the overall system. The first Law Efficiency, electrical to thermal energy ratio and second Law Efficiency of the trigeneration, cogeneration, and gas turbine cycle significantly varies with the change in overall pressure ratio and turbine inlet temperature, but the change in pressure drop, process heat pressure, and evaporator temperature shows small variations in these parameters. Decision makers should find the methodology contained in this paper useful in the comparison and selection of advanced heat recovery systems.
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energy and exergy analyses of compressor inlet air cooled gas turbines using the joule brayton refrigeration cycle
Proceedings of the Institution of Mechanical Engineers Part A: Journal of Power and Energy, 2009Co-Authors: Abdul Khaliq, K. Choudhary, I DincerAbstract:AbstractIn this article, a novel method of inlet air cooling is proposed to enhance the performance of a gas turbine operating in hot climates. The intake air at the compressor bell-mouth is cooled by an air Brayton refrigerator driven by the gas turbine, and the refrigerator uses air as the working fluid. Introducing the air refrigeration cycle provides the advantage of quite low temperatures close to 0 °C and even lower. This is not possible with other methods of intake air cooling, namely evaporative cooling or use of waste heat-driven absorption machines. A thermodynamic analysis through energy and exergy is employed, and a comprehensive parametric study is performed to investigate the effects of extraction pressure ratio, extracted mass rate, turbine inlet temperature (TIT), and ambient relative humidity (RH) on increase in net work output, first Law Efficiency, and second Law Efficiency of a compressor inlet air-cooled gas turbine cycle using a Joule—Brayton refrigerator. The analysis of the results...
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Thermodynamic Performance Assessment of Gas Turbine Trigeneration System for Combined Heat Cold and Power Production
Journal of Engineering for Gas Turbines and Power, 2008Co-Authors: Abdul Khaliq, Rajesh KumarAbstract:The thermodynamic performance of the combustion gas turbine trigeneration system has been studied based on first Law as well as second Law analysis. The effects of overall pressure ratio and process heat pressure on fuel utilization Efficiency, electrical to thermal energy ratio, second Law Efficiency, and exergy destruction in each component are examined. Results for gas turbine cycle, cogeneration cycle, and trigeneration cycle are compared. Thermodynamic analysis indicates that maximum exergy is destroyed during the combustion and steam generation process, which represents over 80% of the total exergy destruction in the overall system. The first Law Efficiency, electrical to thermal energy ratio, and second Law Efficiency of trigeneration system, cogeneration system, and gas turbine cycle significantly varies with the change in overall pressure ratio but the change in process heat pressure shows small variations in these parameters. Results clearly show that performance evaluation of the trigeneration system based on first Law analysis alone is not adequate and hence more meaningful evaluation must include second Law analysis.
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combined first and second Law analysis of gas turbine cogeneration system with inlet air cooling and evaporative aftercooling of the compressor discharge
Journal of Engineering for Gas Turbines and Power-transactions of The Asme, 2007Co-Authors: Abdul Khaliq, K. ChoudharyAbstract:A conceptual gas turbine based cogeneration cycle with compressor inlet air cooling and evaporative aftercooling of the compressor discharge is proposed to increase the cycle performance significantly and render it practically insensitive to seasonal temperature fluctuations. Combined first and second-Law approach is applied for a cogeneration system having intercooled reheat regeneration in a gas turbine as well as inlet air cooling and evaporative aftercooling of the compressor discharge. Computational analysis is performed to investigate the effects of the overall pressure ratio r P , turbine inlet temperature (TIT), and ambient relative humidity φ on the exergy destruction in each component, first-Law Efficiency, power-to-heat ratio, and second-Law Efficiency of the cycle. Thermodynamic analysis indicates that exergy destruction in various components of the cogeneration cycle is significantly affected by overall pressure ratio and turbine inlet temperature, and not at all affected by the ambient relative humidity. It also indicates that the maximum exergy is destroyed during the combustion process, which represents over 60% of the total exergy destruction in the overall system. The first-Law Efficiency, power-to-heat ratio, and second-Law Efficiency of the cycle significantly vary with the change in the overall pressure ratio and turbine inlet temperature, but the change in relative humidity shows small variations in these parameters. 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. Decision makers should find the methodology contained in this paper useful in the comparison and selection of advanced combined heat and power systems.
S C Kaushik - One of the best experts on this subject based on the ideXlab platform.
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multi objective thermodynamic optimization of solar parabolic dish stirling heat engine with regenerative losses using nsga ii and decision making
Applied Solar Energy, 2016Co-Authors: Rajesh Arora, S C Kaushik, Raj KumarAbstract:The proposed work investigates optimal values of various decision variables that simultaneously optimize power output, net-work output and second Law Efficiency of solar driven Stirling heat engine with regenerative heat losses, conducting thermal bridging losses using evolutionary algorithm based on NSGA-II in Matlab simulink environment. Effects of design parameters as absorber temperature, concentrating ratio, radiative and convective heat transfers are included in the analysis. Pareto frontier is obtained for triple and dual objectives and the best optimal value is selected through four different decision making techniques viz. Fuzzy, Shannon entropy, LINMAP and TOPSIS. Triple objective evolutionary approach applied to the proposed model gives power output, net-work output and second Law Efficiency as (38.87 kW, 1.24 kJ, 0.3156) which are 18.19, 16.78 and 31.51% lower in comparison with reversible system. With the objective of error investigation, the average and maximum error of the obtained results are figured at last.
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THE SECOND Law ANALYSIS OF AN UNBALANCED CONSTRUCTAL HEAT EXCHANGER
International Journal of Green Energy, 2013Co-Authors: K. Manjunath, S C KaushikAbstract:Based on constructal theory, entropy generation minimization, and second Law Efficiency, equations are formulated for tree-shaped counterflow-imbalanced heat exchanger for fully developed laminar and turbulent fluid flow. Entropy generation number, rational Efficiency, and effectiveness behavior with respect to changes in number of pairing levels and different tube length-to-diameter ratios of constructal heat exchanger are analyzed analytically. Different values of capacity ratio and Reynolds number for fully developed laminar and turbulent fluid flow are considered to study the influence of pressure drop and flow imbalance irreversibilities of constructal heat exchanger. Values of tube length-to-diameter ratio and number of pairing levels of constructal heat exchanger can be obtained for lower entropy generation number and higher second Law Efficiency which includes both irreversibilities due heat transfer and pressure drop. The analysis reveals the improvements in the performance of constructal heat ex...
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Exergetic analysis of closed Brayton thermal power cycle with reheater, regenerator and intercooler
International journal of ambient energy, 2013Co-Authors: H. Chandra, S C KaushikAbstract:Energy and exergy analysis of a Brayton cycle gas turbine power plant with regenerator, reheater and intercooler is carried out in this work. It has been found that the effects of the regenerator, intercooler and reheater are significant. Although, the energy analysis shows that the first Law Efficiency is more effective than the second Law Efficiency and there are significant losses in these components which cannot be neglected, and hence proper care should be taken for the size and operating conditions of these components. Efficiency of some components is 100% especially when energy balance is applied, while it is not 100% in the case of energy consuming/conversion systems like compressor, turbine, etc. The energy loss in reheater is zero while there is a small amount of exergy loss. The intrercooler has both energy and exery losses, so proper care should be taken in intercooler.
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second Law based thermodynamic analysis of brayton rankine combined power cycle with reheat
Applied Energy, 2004Co-Authors: Abdul Khaliq, S C KaushikAbstract:Abstract The aim of the present paper is to use the second-Law approach for the thermodynamic analysis of the reheat combined Brayton/Rankine power cycle. Expressions involving the variables for specific power-output, thermal Efficiency, exergy destruction in components of the combined cycle, second-Law Efficiency of each process of the gas-turbine cycle, and second-Law Efficiency of the steam power cycle have been derived. The standard approximation for air with constant properties is used for simplicity. The effects of pressure ratio, cycle temperature- ratio, number of reheats and cycle pressure-drop on the combined cycle performance parameters have been investigated. It is found that the exergy destruction in the combustion chamber represents over 50% of the total exergy destruction in the overall cycle. The combined cycle Efficiency and its power output were maximized at an intermediate pressure-ratio, and increased sharply up to two reheat-stages and more slowly thereafter.
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Thermodynamic performance evaluation of combustion gas turbine cogeneration system with reheat
Applied Thermal Engineering, 2004Co-Authors: Abdul Khaliq, S C KaushikAbstract:This communication presents thermodynamic methodology for the performance evaluation of combustion gas turbine cogeneration system with reheat. The energetic and exergetic efficiencies have been defined. The effects of process steam pressure and pinch point temperature used in the design of heat recovery steam generator, and reheat on energetic and exergetic efficiencies have been investigated. From the results obtained in graphs it is observed that the power to heat ratio increases with an increase in pinch point, but the first-Law Efficiency and second-Law Efficiency decreases with an increase in pinch point. The power to heat ratio and second-Law Efficiency increases significantly with increase in process steam pressure, but the first-Law Efficiency decreases with the same. Results also show that inclusion of reheat, provide significant improvement in electrical power output, process heat production, fuel-utilization (energetic) Efficiency and second-Law (exergetic) Efficiency. This methodology may be quite useful in the selection and comparison of combined energy production systems from thermodynamic performance point of view.
Atit Koonsrisuk - One of the best experts on this subject based on the ideXlab platform.
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Comparison of conventional solar chimney power plants and sloped solar chimney power plants using second Law analysis
Solar Energy, 2013Co-Authors: Atit KoonsrisukAbstract:Abstract In the present paper the performance of solar chimney power plants based on second Law analysis is investigated for various configurations. A comparison is made between the conventional solar chimney power plant (CSCPP) and the sloped solar chimney power plant (SSCPP). The appropriate entropy generation number and second-Law Efficiency for solar chimney power plants are proposed in this study. Results show that there is the optimum collector size that provides the minimum entropy generation and the maximum second-Law Efficiency. The second-Law Efficiency of both systems increases with the increasing of the system height. The study reveals the influence of various effects that change pressure and temperature of the systems. It was found that SSCPP is thermodynamically better than CSCPP for some configurations. The results obtained here are expected to provide information that will assist in improving the overall Efficiency of the solar chimney power plant.
Rajesh Kumar - One of the best experts on this subject based on the ideXlab platform.
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First and second Law analysis of solar operated combined Rankine and ejector refrigeration cycle
Applied Solar Energy, 2014Co-Authors: Devendra Kumar Gupta, Rajesh Kumar, Naveen KumarAbstract:A combined Rankine and ejector refrigeration cycle is proposed for the production of power and refrigeration output using duratherm 600 oil as the heat transfer fluid. Thermodynamic analysis has been done to observe the effect of parameters on the performance of the combined cycle. The effect of various parameters asthe turbine inlet pressure, evaporator temperature, condenser temperature, extraction ratio and direct normal radiation per unit area on the performance of the cycle have significant effects on the net power output, refrigeration output, first Law Efficiency and second Law Efficiency. It is also observed that the maximum irreversibility occurs in central receiver as 52.5% followed by 25% in the heliostat, 5.3% in the heat recovery vapor generator, 2.6% in the ejector, and 1.6% in the turbine and around 1.1% in the other components of the cycle. The second Law Efficiency of the solar operated combined Rankine and ejector refrigeration cycle is 11.90% which is much lower than its first Law Efficiency of 14.81%.
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Thermodynamic Performance Assessment of Gas Turbine Trigeneration System for Combined Heat Cold and Power Production
Journal of Engineering for Gas Turbines and Power, 2008Co-Authors: Abdul Khaliq, Rajesh KumarAbstract:The thermodynamic performance of the combustion gas turbine trigeneration system has been studied based on first Law as well as second Law analysis. The effects of overall pressure ratio and process heat pressure on fuel utilization Efficiency, electrical to thermal energy ratio, second Law Efficiency, and exergy destruction in each component are examined. Results for gas turbine cycle, cogeneration cycle, and trigeneration cycle are compared. Thermodynamic analysis indicates that maximum exergy is destroyed during the combustion and steam generation process, which represents over 80% of the total exergy destruction in the overall system. The first Law Efficiency, electrical to thermal energy ratio, and second Law Efficiency of trigeneration system, cogeneration system, and gas turbine cycle significantly varies with the change in overall pressure ratio but the change in process heat pressure shows small variations in these parameters. Results clearly show that performance evaluation of the trigeneration system based on first Law analysis alone is not adequate and hence more meaningful evaluation must include second Law analysis.
Damola S. Adelekan - One of the best experts on this subject based on the ideXlab platform.
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energetic and exergetic analysis of a domestic refrigerator system with lpg as a replacement for r134a refrigerant using poe lubricant and mineral oil based tio2 sio2 and al2o3 lubricants
International Journal of Refrigeration-revue Internationale Du Froid, 2018Co-Authors: Jatinder Gill, Olayinka S. Ohunakin, Jagdev Singh, Damola S. AdelekanAbstract:Abstract This paper experimentally investigated energetic and exergetic performance analysis of a domestic refrigerator using R134a and LPG refrigerants with different lubricants (polyol-ester (POE), mineral oil (MO), and TiO2, SiO2, Al2O3 nanoparticles dispersed in mineral oil).The energetic and exergetic performance analysis of the domestic refrigerator were investigated with test parameters including compressor power consumption, cooling capacity, coefficient of performance (COP), discharge temperature, irreversibility in the components, total irreversibility and second Law Efficiency. Findings showed that the lowest compressor power consumption and total irreversibility were observed in refrigerator with 40 g charge of LPG/TiO2-MO lubricant (0.2 g/L of TiO2); these values of compressor power consumption and total irreversibility were 15.87% and 31.69%, respectively, lower than for R134a/POE lubricant. In addition, the domestic refrigerator using LPG refrigerant at 40 g charge with TiO2-MO (0.2 g/L TiO2) lubricant, had the highest COP and second Law Efficiency among the selected nano-lubricants. These values of COP and second Law Efficiency were 56.32% and 47.06%, respectively, higher than that of R134a/POE. Futhermore, compressor discharge temperature of the domestic refrigerator with 40 g charge of LPG/TiO2-MO lubricant (0.2 g/L of TiO2) was found to be lower than that of R134a/POE. Hence, extended compressor life may be expected with the adoption of TiO2-Mineral oil lubricant. It can be concluded that based on energetic and exergetic performance analysis, the domestic refrigerator using the 40 g charge of LPG/TiO2-MO (0.2 g/L TiO2) performed better than R134a/POE.
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artificial neural network approach for irreversibility performance analysis of domestic refrigerator by utilizing lpg with tio2 lubricant as replacement of r134a
International Journal of Refrigeration-revue Internationale Du Froid, 2018Co-Authors: Jatinder Gill, Olayinka S. Ohunakin, Jagdev Singh, Damola S. AdelekanAbstract:Abstract This paper experimentally investigated irreversibility performance analysis of domestic refrigerator using 40 g, 50 g, 60 g and 70 g of LPG refrigerant with varying concentration of TiO2 nanoparticles dispersed in a mineral oil lubricant as replacement of R134a. The irreversibility performance analysis of the domestic refrigerator investigated with test parameters including irreversibility in the components, total irreversibility, and second Law Efficiency. Findings showed that under similar operating conditions irreversibilities in condenser, capillary tube, evaporator and compressor of the domestic refrigerator using LPG refrigerant with lubricant TiO2–mineral oil found lower than R134a by 6.05–48.10%, 17.83–46.98%, 2.51–33.17% and 2.21–23.29% respectively. Additionally, total irreversibility and second Law Efficiency in the domestic refrigerator using LPG refrigerant with TiO2, nanoparticles dispersed in a mineral oil lubricant found lower and higher than R134a by around 0.65–35.97% and 6.23–54.74% respectively. All in all 0.4 g L−1 of TiO2 and 40 g of LPG charge were the attained optimal values of nanoparticle concentration and LPG charge respectively in the domestic refrigerator utilizing LPG as replacement of R134a. Artificial Neural Networks (ANN) approach to delineate total irreversibility and second Law Efficiency of the domestic refrigerator was additionally applied to develop the models. It found that ANN models predictions concurred well with experimental results and brought out an absolute fraction of variance of (0.989–0.990), root mean square error of (0.831–1.061) and mean absolute percentage error of (1.734–2.056%) respectively with experimental results.
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Artificial neural network approach for irreversibility performance analysis of domestic refrigerator by utilizing LPG with TiO2–lubricant as replacement of R134a
International Journal of Refrigeration-revue Internationale Du Froid, 2018Co-Authors: Jatinder Gill, Olayinka S. Ohunakin, Jagdev Singh, Damola S. AdelekanAbstract:Abstract This paper experimentally investigated irreversibility performance analysis of domestic refrigerator using 40 g, 50 g, 60 g and 70 g of LPG refrigerant with varying concentration of TiO2 nanoparticles dispersed in a mineral oil lubricant as replacement of R134a. The irreversibility performance analysis of the domestic refrigerator investigated with test parameters including irreversibility in the components, total irreversibility, and second Law Efficiency. Findings showed that under similar operating conditions irreversibilities in condenser, capillary tube, evaporator and compressor of the domestic refrigerator using LPG refrigerant with lubricant TiO2–mineral oil found lower than R134a by 6.05–48.10%, 17.83–46.98%, 2.51–33.17% and 2.21–23.29% respectively. Additionally, total irreversibility and second Law Efficiency in the domestic refrigerator using LPG refrigerant with TiO2, nanoparticles dispersed in a mineral oil lubricant found lower and higher than R134a by around 0.65–35.97% and 6.23–54.74% respectively. All in all 0.4 g L−1 of TiO2 and 40 g of LPG charge were the attained optimal values of nanoparticle concentration and LPG charge respectively in the domestic refrigerator utilizing LPG as replacement of R134a. Artificial Neural Networks (ANN) approach to delineate total irreversibility and second Law Efficiency of the domestic refrigerator was additionally applied to develop the models. It found that ANN models predictions concurred well with experimental results and brought out an absolute fraction of variance of (0.989–0.990), root mean square error of (0.831–1.061) and mean absolute percentage error of (1.734–2.056%) respectively with experimental results.
