Optimization of Air-Cooled Condensers

1987 ◽  
Vol 109 (2) ◽  
pp. 90-95 ◽  
Author(s):  
S. C. Lau ◽  
K. Annamalai ◽  
S. V. Shelton
Keyword(s):  
Rankine Cycle ◽  
Design Parameters ◽  
Power Cycle ◽  
Optimum Configuration ◽  
Air Cooled Condensers ◽  
Condenser Temperature ◽  
Exit Temperature ◽  
Cooling Air ◽  
Cycle Efficiency ◽  
Minimum Heat

The essential design parameters for determining the optimum configuration of an air-cooled condenser are identified in this paper. For a power plant operating on a Rankine cycle, expressions for (i) the minimum frontal area, (ii) the minimum heat transfer area, and for (iii) the maximum net cycle efficiency, with respect to the condenser temperature and the cooling air velocity are derived. The analyses are carried out with the assumption that the exit temperature of the cooling air is equal to the condenser temperature. All resulting equations are presented in dimensionless form so that they are applicable to any power cycle with a gas-cooled condenser.

Brayton Cycle As an Alternate Power Conversion Option for Sodium Cooled Fast Reactor

2019 ◽  
Author(s):  
Jofred Joseph ◽  
Satish Kumar ◽  
Tanmay Vasal ◽  
N. Theivarajan
Keyword(s):  
Power Conversion ◽  
Rankine Cycle ◽  
Inlet Temperature ◽  
Brayton Cycle ◽  
Generation System ◽  
Fast Reactors ◽  
Turbine Inlet Temperature ◽  
Power Cycle ◽  
Power Generation System ◽  
Cycle Efficiency

Abstract Enhancing the safety and economic competitiveness are major objectives in the development of advanced reactor designs with emphasis on the design of systems or components of the nuclear systems. Innovative power cycle development is another potential option to achieve these objectives. Sodium cooled fast reactor (SFR) is one among the six reactor design concepts identified by the Gen IV International Forum for development to meet the technology goals for new nuclear energy system. Similar to the power cycle used in conventional fossil fuel based thermal power plants, sodium-cooled fast reactors have adopted the Rankine cycle based power conversion system. However, the possibility of sodium water reaction is a major concern and it becomes necessary to adopt means of early detection of leaks and isolation of the affected SG module for mitigating any adverse impact of sodium water reaction. The high exothermic nature of the reaction calls for introducing an intermediate sodium heat transport loop, leading to high overall plant cost hindering commercialization of sodium fast reactors. The Indian Prototype Fast Breeder Reactor (PFBR) also uses Rankine cycle in the power generation system. The superheated steam temperature has been set at 490 degree Celsius based on optimisation studies and material limitations. Additional Fast Breeder reactors are planned in near future and further work is being done to develop more advanced sodium cooled fast reactors. The closed Brayton cycle is a promising alternative to conventional Rankine cycle. By selecting an inert gas or a gas with milder reaction with sodium, the vigorous sodium water reaction can be avoided and significant cost savings in the turbine island can be achieved as gas turbine power conversion systems are of much smaller size than comparable steam turbine systems due to their higher power density. In the study, various Brayton cycle designs on different working gases have been explored. Supercritical-CO2 (s-CO2), helium and nitrogen cycle designs are analyzed and compared in terms of cycle efficiency, component performance and physical size. The thermal efficiencies at the turbine inlet temperature of Indian PFBR have been compared for Rankine cycle and Brayton cycle based on different working fluids. Also binary mixtures of different gases are investigated to develop a more safe and efficient power generation system. Helium does not interact with sodium and other structural materials even at very high temperatures but its thermal performance is low when compared to other fluids. Nitrogen being an inert gas does not react with sodium and can serve to utilise existing turbomachinery because of the similarity with atmospheric air. The supercritical CO2 based cycle has shown best thermodynamic performance and efficiency when compared to other Brayton cycles for the turbine inlet temperature of Indian PFBR. CO2 also reacts with sodium but the reaction is mild compared to sodium water reaction. The cycle efficiency of the s-CO2 cycle can be further improved by adopting multiple reheating, inter cooling and recuperation.

Parametric Study of an Ideal Rankine Cycle with a Reheat

2011 ◽  
Vol 110-116 ◽  
pp. 4166-4170
Author(s):  
Amir Vosough ◽  
Samaneh Keshavarzi
Keyword(s):  
Parametric Study ◽  
Rankine Cycle ◽  
Exergy Destruction ◽  
Power Cycle ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis ◽  
Cycle Efficiency ◽  
Percentage Ratio ◽  
Stack Gas ◽  
Plant Efficiency

In this study, the energy and exergy analysis of an ideal Rankine cycle with reheat is presented. The percentage ratio of the exergy destruction to the total exergy destruction was found to be maximum in the boiler system 86.27% and then condenser and stack gas 13.73%. In addition, the calculated thermal efficiency was 38.39 % while the exergy efficiency of the power cycle was 45.85%. For improvement the power plant efficiency, parametric study has been done and the effect of boiler and reheat pressure and condenser pressure on the cycle efficiency calculated.

The Combined Reheat Gas Turbine/Steam Turbine Cycle: Part II—The LM 5000 Gas Generator Applied to the Combined Reheat Gas Turbine/Steam Turbine Cycle

1980 ◽  
Vol 102 (1) ◽  
pp. 42-49 ◽  
Author(s):  
I. G. Rice
Keyword(s):  
Steam Turbine ◽  
Gas Turbine ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Heat Recovery Boiler ◽  
Gas Generator ◽  
Reheat Steam ◽  
Cycle Efficiency ◽  
Minimum Heat ◽  
Steam Heat

Part I presented an analysis of the simple and reheat gas turbine cycles and related these cycles to the combined gas turbine Rankine cycle. Part II uses the data developed in Part I and applies the second generation LM5000 to a combined cycle using a steam cycle with 1250 psig 900 FTT (8.62MPa and 482°C) steam conditions; then the reheat gas turbine is combined with a reheat steam turbine with steam conditions of 2400 psig and 1000/1000 FTT (16.55 MPa and 538/538° C). A unique arrangement of the superheater is discussed whereby part of the steam heat load is shifted to the reheat gas turbine to obtain a minimum heat recovery boiler stack temperature and a maximum cycle efficiency. This proposed power plant is projected to have a net cycle efficiency of 50 percent LHV when burning distillate fuel.

A Novel Absorption Regeneration-Thermodynamic Heat Engine Cycle

1978 ◽  
Vol 100 (4) ◽  
pp. 566-570 ◽  
Author(s):  
B. Nimmo ◽  
R. Evans
Keyword(s):  
Electrical Power ◽  
Research Work ◽  
Heat Engine ◽  
Rankine Cycle ◽  
Design Parameters ◽  
Plant Design ◽  
Power Cycle ◽  
First Order ◽  
Important Design ◽  
Heat Engine Cycle

This paper introduces and provides a first order thermal cycle analysis of a new power plant design, the absorption-regeneration power cycle. Preliminary analysis indicates that this new cycle may have potential for increased operating efficiencies compared to the modified Rankine cycle presently in use for most stationary electrical power production. Graphs are presented to illustrate calculated efficiencies as well as some important design parameters of the cycle. Research work on extending presently available thermo-chemical data required to improve the model analysis is suggested.

scholarly journals Design analysis of ORC micro-turbines making use of thermal energy of oceans

2013 ◽  
Vol 20 (2) ◽  
pp. 48-60 ◽  
Author(s):  
Marian Piwowarski
Keyword(s):  
Energy Conversion ◽  
Thermal Energy ◽  
Power Plants ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Design Parameters ◽  
Thermal Energy Conversion ◽  
Working Medium ◽  
Ocean Thermal Energy ◽  
Cycle Efficiency

Abstract The article presents the results of the analysis of energy conversion cycles making use of thermal energy of oceans. The objects of analysis were two cases of closed Organic Rankine Cycle (ORC) power plants, which were: the cycle in which the vapour of the working medium was produced by warm oceanic water in the circum-equatorial zone, and the so-called “arctic” cycle in which this vapour was produced by non-frozen water in the circumpolar zone. Between ten and twenty low-boiling media were examined for which operating parameters were optimised to obtain the highest cycle efficiency. A preliminary design of an ORC turbine which was obtained by optimising basic design parameters is included. It has been proved that realisation of the Ocean Thermal Energy Conversion (OTEC) cycle is possible both in the warm and permanently frozen regions. The results of the calculations have also revealed that the efficiency of the OTEC cycle is higher in the circumpolar zone. Selecting a low-boiling medium and designing a highly efficient turbine operating in both abovementioned regimes is technically realisable.

Waste Heat Produces Electrical Power System, Using Organic Rankine Cycle (ORC) from Steelworks

2012 ◽  
Vol 512-515 ◽  
pp. 1338-1342
Author(s):  
Song Xiao ◽  
Shu Ying Wu ◽  
Dong Sheng Zheng
Keyword(s):  
Mathematical Model ◽  
Power System ◽  
Waste Heat ◽  
Electrical Power ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Design Parameters ◽  
Electrical Power System ◽  
Condenser Temperature ◽  
Energetic Performance

This study presents an energetic performance analysis for a waste heat produces electrical power system which is use organic Rankine cycle (ORC) from steelworks. In order to simulate the system under steady-state conditions, a mathematical model is developed. The developed model is used to determine the potential effects caused by the changes of the design parameters on the energetic performance of the system. As design parameters, turbine inlet pressure, condenser temperature, are taken into account. In this regard, the electrical power is estimated by parametrical analysis and discussed comprehensively.

Effect of Reducing the Blade Cooling Air Temperature and Mass Flow on Blade Life and Cycle Efficiency

1984 ◽  
Vol 198 (3) ◽  
pp. 225-230 ◽  
Author(s):  
N Hay ◽  
J H Taylor
Keyword(s):  
Mass Flow ◽  
Engine Performance ◽  
Specific Work ◽  
Cooling Device ◽  
Blade Cooling ◽  
Cent Increase ◽  
Exit Temperature ◽  
Cooling Air ◽  
Cycle Efficiency ◽  
Further Development

Reduction of the temperature of the air used for blade cooling to below the compressor exit temperature would allow the required mass flow to be reduced and might be expected to result in an improvement in engine performance. This is demonstrated and quantified in this paper. Improvements in both blade life and cycle efficiency are shown to be possible. For example by cooling the coolant by 50°C a reduction in coolant flow of 40 per cent is possible as well as an improvement of 20 per cent in blade life. Additionally a marginal increase in cycle efficiency is obtained and a 1.4 per cent increase in specific work output. A concept for an integrated cooling device for producing the required reduction in temperature of the blade cooling air is described and appraised. As envisaged at present, the device would be too bulky for airborne applications. However, with further development a feasible design might be evolved.

Supercritical Carbon Dioxide and Its Application to Rankine Cycle

2017 ◽  
pp. 335-368 ◽  
Author(s):  
Hiroshi Yamaguchi
Keyword(s):  
Heat Transfer ◽  
Supercritical Co2 ◽  
Rankine Cycle ◽  
Heat Energy ◽  
Working Fluid ◽  
Supercritical State ◽  
Power Cycle ◽  
Cycle System ◽  
Main Components ◽  
Cycle Efficiency

Supercritical CO2 has been given much attention to be a working fluid in a power cycle due to its unique properties. The supercritical CO2 solar Rankine cycle system was designed and developed by using the benefit of supercritical state of CO2 to generate electric power and supply heat energy in environmentally friendly manner. The development of main components in the system are introduced and discussed particularly by focusing on the properties of CO2 for obtaining higher performance. The properties of CO2 in near critical region are also discussed in this chapter. Operating the power cycle in the supercritical region of CO2 enhances the heat transfer in energy exchanging process and improves the cycle efficiency.

Supercritical Carbon Dioxide Fluid and Its Application to Rankine Cycle

2021 ◽  
pp. 533-565
Author(s):  
Hiroshi Yamaguchi
Keyword(s):  
Heat Transfer ◽  
Supercritical Co2 ◽  
Rankine Cycle ◽  
Heat Energy ◽  
Working Fluid ◽  
Supercritical State ◽  
Power Cycle ◽  
Cycle System ◽  
Main Components ◽  
Cycle Efficiency

Supercritical CO2 has been given much attention to be a working fluid in a power cycle due to its unique properties. The supercritical CO2 solar Rankine cycle system was designed and developed by using the benefit of supercritical state of CO2 to generate electric power and supply heat energy in environmentally friendly manner. The development of main components in the system are introduced and discussed particularly by focusing on the properties of CO2 for obtaining higher performance. The properties of CO2 in near critical region are also discussed in this chapter. Operating the power cycle in the supercritical region of CO2 enhances the heat transfer in energy exchanging process and improves the cycle efficiency.

Thermodynamic Modeling and Comparative Analysis of Supercritical Carbon Dioxide Brayton Cycle

2017 ◽  
Author(s):  
Apostolos A. Gkountas ◽  
Anastassios M. Stamatelos ◽  
Anestis I. Kalfas
Keyword(s):  
Comparative Analysis ◽  
Supercritical Co2 ◽  
Design Parameters ◽  
Simulation Tools ◽  
Power Cycle ◽  
Iterative Model ◽  
Modeling Software ◽  
Commercial Process ◽  
Cycle Efficiency ◽  
Recompression Cycle

Supercritical CO2 cycles is a promising technology for the next generation power conversion cycles. Supercritical CO2 Brayton cycles offer equivalent or higher cycle efficiency when compared with steam cycles at similar temperatures. This paper presents an investigation of the sCO2 recompression cycle, where recompressing a fraction of the flow without heat rejection, results in an increase in thermal efficiency. A thermodynamic analysis of a 600 MWth power cycle has been carried out, in order to study the effect of the most significant design parameters on the components performance and cycle efficiency, using two different simulation tools to model the recompression system. An iterative model using basic thermodynamic equations describing the system’s components was employed in this direction. The system was also modeled by means of commercial process modeling software for comparison. Hence, useful results regarding the operating pressures and temperatures of the cycle and how they affect the recuperators, the compressor and the turbine performance have been derived. Finally, a comparative analysis of the results of the two simulation tools and those of a reference cycle from the bibliography is carried out, showing deviations in the range of 2.8 to 4%.

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