The Experts below are selected from a list of 9174 Experts worldwide ranked by ideXlab platform
W. Zhang - One of the best experts on this subject based on the ideXlab platform.
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turbine. Part 2: Performance optimization
2016Co-Authors: Linge Che, W. ZhangAbstract:The power and efficiency of the open regenerative cycle of an externally fired micro gas turbine power plant without blade cooling with pressure drop irreversibilities are optimized based on the model established using thermodynamic optimization theory in Part 1 of this article by adjusting the mass flow rate (or the distribution of pressure losses along the flow path). It is shown that there are optimal air mass flow rates (or the distribution of pressure losses along the flow path) which maximize the net power output, and the maximum has an additional maximum with respect to the Compressor pressure ratio. When the optimization is performed with the constraints of the fixed fuel flow and the plant size, the net power output and the thermal conversion efficiency of the cycle can be maximized again by properly allocating the fixed flow area among the Compressor Inlet and the power turbine outlet. The numerical examples show the effects of the design parameters on the power output and heat conversion efficienc
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turbine. Part 2: Performance optimization
2016Co-Authors: Linge Che, W. ZhangAbstract:The power and efficiency of the open regenerative cycle of an externally fired micro gas turbine power plant without blade cooling with pressure drop irreversibilities are optimized based on the model established using thermodynamic optimization theory in Part 1 of this article by adjusting the mass flow rate (or the distribution of pressure losses along the flow path). It is shown that there are optimal air mass flow rates (or the distribution of pressure losses along the flow path) which maximize the net power output, and the maximum has an additional maximum with respect to the Compressor pressure ratio. When the optimization is performed with the constraints of the fixed fuel flow and the plant size, the net power output and the thermal conversion efficiency of the cycle can be maximized again by properly allocating the fixed flow area among the Compressor Inlet and the power turbine outlet. The numerical examples show the effects of the design parameters on the power output and heat conversio
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thermodynamic optimisation for open regenerated inverse brayton cycle refrigeration heat pump cycle part 2 performance optimisation
Journal of The Energy Institute, 2016Co-Authors: W. ZhangAbstract:The thermodynamic performances for the model established in Part 1 of this paper are optimised by adjusting the mass flowrate. When the optimisation is performed with the constraints of the fixed power input and the plant size, the coefficient of performance can be maximised again by properly allocating the fixed flow area among the Compressor Inlet and the expander outlet. The coefficient of performance of refrigeration can be maximised again by properly allocating the fixed heat conductance inventory among the hot and cold side exchangers and the regenerator. The obtained maxima reach its maxima at optimal Compressor pressure ratio. When the heat conductance distribution of the regenerator is fixed for the heat pump, the coefficient of performance can be maximised again by properly allocating the fixed heat conductance inventory between the hot and cold side exchangers. The obtained maxima reach its maxima at optimal Compressor pressure ratio.
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thermodynamic optimization principle for open inverse brayton cycle refrigeration heat pump cycle
Scientia Iranica, 2012Co-Authors: W. ZhangAbstract:Abstract A thermodynamic model for an open inverse Brayton cycle (refrigeration or heat pump cycle) with pressure drop irreversibilities is established. There are seven flow resistances (or pressure drops) encountered by the working fluid stream for the inverse Brayton cycle. Two of these, the friction through the blades and vanes of the Compressor and the expander, are related to the isentropic efficiencies. The remaining flow resistances are always present because of the changes in flow cross-section at the Compressor Inlet and outlet, heat exchanger Inlets and outlets and expander Inlet and outlet. The analytical formulae about the cooling load of refrigeration cycle, the heating load of heat pump cycle and other coefficients are derived, which indicate that the thermodynamic performance for open inverse Brayton cycle can be optimized by adjusting the mass flow rate (or the distribution of pressure losses along the flow path). It is shown that there are optimal air mass flow rates (or the distribution of pressure losses along the flow path) which maximize the cooling load of refrigeration cycle, and the optimal air mass flow rates are smaller than the one at the maximum power output of the direct Brayton cycle.
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thermodynamic optimisation for open regenerated inverse brayton cycle refrigeration heat pump cycle
Journal of The Energy Institute, 2012Co-Authors: W. ZhangAbstract:A thermodynamic model for an open regenerated inverse Brayton cycle with pressure drop irreversibilities is established using finite time thermodynamics considering the size constraints of real plant in Part 1 of this paper. The analytical formulae about the cooling load and coefficient of performance of refrigeration cycle, the heating load and coefficient of performance of heat pump cycle are derived, which indicate that the thermodynamic performance for open regenerated inverse Brayton cycle can be optimised by adjusting the mass flowrate. It is shown that the cooling load, heating load and the power input increase with the increase in the Compressor Inlet relative pressure drops, the coefficient of performance reaches its maximum at the optimal Compressor ratio and the exhaust temperature is higher than that of the ambient, which is lower than that of the ambient only at small effectiveness of the regenerator.
Onkar Singh - One of the best experts on this subject based on the ideXlab platform.
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performance evaluation of steam injected gas turbine based power plant with Inlet evaporative cooling
Applied Thermal Engineering, 2016Co-Authors: A. K. Shukla, Onkar SinghAbstract:Abstract Present paper deals with the study for performance evaluation of steam-injected gas turbine (STIG) based power plant with Inlet evaporative cooling. It investigates the combined effect of Inlet evaporative cooling (IEC), steam injection (SI) and film cooling (FC) on the power augmentation of simple gas turbine cycle. Thermodynamic modeling has been carried out and presented along with results showing the influence of Inlet evaporative cooling on various performance parameters of STIG based power plant. Results show that there occurs increment of 3.2% in cycle thermal efficiency due to lowering of the Compressor Inlet temperature from 318 K to 282 K at 5% steam to air ratio (SAR). At 1850 K turbine Inlet temperature and cycle pressure ratio of 24 there occurs increase in thermal efficiency of the GT cycle with IEC, SI and FC as compared to the simple GT cycle. Injection of steam in the combustion chamber enhances the specific expansion work in the gas turbine, which increases at rate of 2.95% for every increase in SAR by 2%. The study shows that gas turbine cycle configuration with Inlet evaporative cooling (IEC), steam injection and film cooling is the best combination for obtaining more efficiency and power.
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Thermodynamic analysis of steam-injected gas turbine cycle power plant with Inlet air cooling
International Journal of Ambient Energy, 2016Co-Authors: A. K. Shukla, Onkar SinghAbstract:© 2016 Taylor & Francis Steam-injected gas turbine cycle is the modified arrangement of simple gas turbine (GT) cycle, wherein part of steam generated in a heat recovery steam generator is injected into the combustion chamber to increase power output and the efficiency. This paper studies the effect of integration of Inlet air cooling, steam injection (SI) and film cooling (FC) on the performance of GT cycle. Two different methods for cooling the Inlet air, namely Inlet fogging and evaporative cooling, are considered for analysis here. Results show that the Inlet fogging is better than evaporative cooling to achieve the lowest temperature at the Compressor Inlet. Thermodynamic performance of simple GT cycle is also compared with SI in GT cycle. The present study shows that GT cycle with integration of Inlet fogging, SI and FC is a better configuration for achieving higher performance.
Gary E Rochau - One of the best experts on this subject based on the ideXlab platform.
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Dry-Cooled Supercritical CO2 Power for Advanced Nuclear Reactors
Journal of Engineering for Gas Turbines and Power, 2014Co-Authors: Thomas M. Conboy, Matthew D. Carlson, Gary E RochauAbstract:Currently, waste heat rejection from electrical power systems accounts for the largest fraction of water withdrawals from the U.S. fresh water table. Siting of nuclear power plants is limited to areas with access to a large natural supply of fresh or sea water. Due to a rise in energy needs and increased concern over environmental impact, dry air cooling systems are poised to play a large role in the future energy economy. In practice, the implementation of dry air-cooled condensing systems at steam plants has proven to be capital-intensive and requires the power cycle to take a significant efficiency penalty. These shortcomings are fundamental to dry-air steam condensation, which must occur at a fixed temperature. Closed-cycle gas turbines are an alternative to the conventional steam Rankine plant that allows for much improved dry heat rejection compatibility. Recent research into advanced nuclear energy systems has identified the supercritical CO2 (s-CO2) Brayton cycle in particular as a viable candidate for many proposed reactor types. The s-CO2 Brayton cycle can maintain superior thermal efficiency over a wide range of ambient temperatures, making these power systems ideally suited for dry air cooling, even in warm climates. For a sodium fast reactor (SFR) operating at 550 °C, thermal efficiency is calculated to be 43% with a 50 °C Compressor Inlet temperature. This is achieved by raising CO2 Compressor Inlet pressure in response to rising ambient temperatures. Preliminary design studies have shown that s-CO2 power cycle hardware will be compact and therefore well-matched to near-term and advanced integral small modular reactor (SMR) designs. These advantages also extend to the cooling plant, where it is estimated that dry cooling towers for an SFR-coupled s-CO2 power cycle will be similar in cost and scale to the evaporative cooling tower for a light-water reactor (LWR). The projected benefits of the s-CO2 power cycle coupled to dry air heat rejection may enable the long-awaited rise of next-generation nuclear energy systems, while redrawing the map for siting of small and large nuclear energy systems.
Engin Gedik - One of the best experts on this subject based on the ideXlab platform.
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Performance analysis of open cycle gas turbines
International Journal of Energy Research, 2009Co-Authors: Hüseyin Kurt, Ziyaddin Recebli, Engin GedikAbstract:In this study, the performance of ideal open cycle gas turbine system was examined based on its thermodynamic analysis. The effects of some parameters, such as Compressor Inlet temperature (CIT), pressure ratio (PR) and the turbine Inlet temperature (TIT), on the performance parameters of open cycle gas turbine were discussed. The turbine net power output, the thermal efficiency and the fuel consumption of the turbine were taken as the performance parameters. The values of these parameters were calculated using some basic cycle equations and variables values of thermodynamic properties. Other variables such as lower heating value, combustion efficiency and isentropic efficiencies of Compressor and turbine were assumed to be constant. The result showed that the net power output and the thermal efficiency increased by a decrease in the CIT and increase in the TIT and PR values. If it is aimed to have a high net power output and the thermal efficiency for the turbine, the CIT should be chosen as low as possible and the TIT should be chosen as high as possible. Copyright © 2008 John Wiley & Sons, Ltd.
A. K. Shukla - One of the best experts on this subject based on the ideXlab platform.
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performance evaluation of steam injected gas turbine based power plant with Inlet evaporative cooling
Applied Thermal Engineering, 2016Co-Authors: A. K. Shukla, Onkar SinghAbstract:Abstract Present paper deals with the study for performance evaluation of steam-injected gas turbine (STIG) based power plant with Inlet evaporative cooling. It investigates the combined effect of Inlet evaporative cooling (IEC), steam injection (SI) and film cooling (FC) on the power augmentation of simple gas turbine cycle. Thermodynamic modeling has been carried out and presented along with results showing the influence of Inlet evaporative cooling on various performance parameters of STIG based power plant. Results show that there occurs increment of 3.2% in cycle thermal efficiency due to lowering of the Compressor Inlet temperature from 318 K to 282 K at 5% steam to air ratio (SAR). At 1850 K turbine Inlet temperature and cycle pressure ratio of 24 there occurs increase in thermal efficiency of the GT cycle with IEC, SI and FC as compared to the simple GT cycle. Injection of steam in the combustion chamber enhances the specific expansion work in the gas turbine, which increases at rate of 2.95% for every increase in SAR by 2%. The study shows that gas turbine cycle configuration with Inlet evaporative cooling (IEC), steam injection and film cooling is the best combination for obtaining more efficiency and power.
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Thermodynamic analysis of steam-injected gas turbine cycle power plant with Inlet air cooling
International Journal of Ambient Energy, 2016Co-Authors: A. K. Shukla, Onkar SinghAbstract:© 2016 Taylor & Francis Steam-injected gas turbine cycle is the modified arrangement of simple gas turbine (GT) cycle, wherein part of steam generated in a heat recovery steam generator is injected into the combustion chamber to increase power output and the efficiency. This paper studies the effect of integration of Inlet air cooling, steam injection (SI) and film cooling (FC) on the performance of GT cycle. Two different methods for cooling the Inlet air, namely Inlet fogging and evaporative cooling, are considered for analysis here. Results show that the Inlet fogging is better than evaporative cooling to achieve the lowest temperature at the Compressor Inlet. Thermodynamic performance of simple GT cycle is also compared with SI in GT cycle. The present study shows that GT cycle with integration of Inlet fogging, SI and FC is a better configuration for achieving higher performance.