scholarly journals Numerical analysis and field study of time dependent exergy-energy of a gas-steam combined cycle

2012 ◽  
Vol 77 (7) ◽  
pp. 945-957
Author(s):  
Bamdad Barari ◽  
Abbasian Shirazi ◽  
Mohsen Keshavarzi ◽  
Iman Rostamsowlat
Keyword(s):  
Power Plant ◽  
Exergy Analysis ◽  
Combined Cycle ◽  
Time Dependent ◽  
Fars Province ◽  
Exergy Destruction ◽  
Time Duration ◽  
Aging Rate ◽  
Lost Work ◽  
Gas Turbine Cycle

In this study, time dependent exergy analysis of the Fars Combined Power Plant Cycle has been investigated. Exergy analysis has been used for investigating each part of actual combined cycle by considering irreversibility from Apr 2006 to Oct 2010. Performance analysis has been done for each part by evaluating exergy destruction in each month. By using of exergy analysis, aging of each part has been evaluated respect to time duration. In addition, the rate of lost work for each month has been calculated and variation of this parameter has been considered as a function of aging rate. Finally, effects of exergy destruction of each part have been investigated on exergy destruction of whole cycle. Entire analysis has been done for Unit 3 and 4 of gas turbine cycle which combined by Unit B of steam cycle in Fars Combined Power Plant Cycle located in Fars province in Iran.

scholarly journals ANALISIS TERMOEKONOMI SIKLUS KOMBINASI TURBIN GAS DAN UAP UNIT PLTGU GRATI

2021 ◽  
Author(s):  
Putri Sundari
Keyword(s):  
Power Plant ◽  
System Performance ◽  
Fossil Fuels ◽  
Exergy Analysis ◽  
Combined Cycle ◽  
Plant Performance ◽  
Combine Cycle Power Plant ◽  
Exergy Destruction ◽  
Combine Cycle ◽  
Research Analysis

The increasing of electricity needs and the crisis of fossil fuels have been requiring an improvement of power plant performance, including combined cycle power plant which has important role as a provider of national electricity nowadays. Thermoeconomic analysis is one of new concept that combine exergy analysis with cost approachment to improve a system performance. In this research, analysis applied in combine cycle power plant of PT. Indonesia Power Grati. The result shows that combustion chamber is the greatest irreversibility source with an exergy destruction was found 53,81%. Where as an economic analysis obtains a different result, LP steam turbine is the component which has a huge exergoeconomic loss was found Rp 33.655.386,46/hour. Based on this result, the efforts that we can do to get an optimal performance of combine cycle power plant are preheating a combustion air to reach a perfect combustion and cleaning all the components continually.

Comparison of Combined Cycle and Conventional Steam Power Plant Through Energy Level and Thermoeconomic Analysis

2008 ◽  
Author(s):  
Mohammad Hasan Khoshgoftar Manesh ◽  
Majid Amidpour ◽  
Hasan Khodaei Jalal Abadi
Keyword(s):  
Power Plant ◽  
Computer Program ◽  
Exergy Analysis ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Plant Performance ◽  
Exergy Destruction ◽  
Steam Power ◽  
Steam Power Plant ◽  
Exergoeconomic Analysis

Exergy, exergoeconomic and combined pinch and exergy analysis are beneficial methods that can be applied for design or performance evaluation of process systems or thermal power plants; however, these methods are usually applied individually. In this paper, these methods have been applied for 423 MW NEKA combined cycle power plant located in NEKA at north of Iran and 315-MW RAMIN steam power plant located in Ahvaz at south of Iran as real cases to evaluation and comparison of performance of each component in different load conditions simultaneously. To perform these analysis for both plants, a computer program is developed from thermodynamic modeling of the plant as simulator. With the thermodynamic properties of the most significant mass and energy flow stream being obtained from the plant, the simulator can reproduce the cycle behavior for different operating conditions with relative errors less than 4.2%. The models of computer program are refined using data from designed performance test in these plants. After thermodynamic simulation, this program can calculate exergy of the flows. In addition, it can perform exergoeconomic analysis using thermoeconomic model of both plants that are defined based on the functionally of each component by the fuel-product definition. The costs of all flows in production structure can be calculated by solving a set equation including thermoeconomic modeling of each plant. Furthermore, it is helpful to display the system information graphically for one to visualize the performance of system in different conditions by applying combined pinch-exergy analysis. Meanwhile, due to importance of exergy destruction cost and better understanding plant performance, the new variables have been defined as Exergy Destruction Level (EDL) and Exergy Cost Destruction Level (ECDL). In this respect, new graphical representation has been developed for showing performance of each component based on exergoeconomic analysis. In this regard, this computer program can generate improved combined pinch-exergy and EDL/ ECDL representation.

EFFECT OF AMBIENT TEMPERATURE ON THE PERFORMANCE OF A COMBINED CYCLE POWER PLANT

2013 ◽  
Vol 37 (4) ◽  
pp. 1177-1188 ◽  
Author(s):  
Arvind Kumar Tiwari ◽  
Mohd. Muzaffarul Hasan ◽  
Mohd. Islam
Keyword(s):  
Power Plant ◽  
Ambient Temperature ◽  
Thermal Power ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Exergy Destruction ◽  
Combined Cycle Power Plant ◽  
Combined Cycle Plant ◽  
Gas Turbine Cycle ◽  
Cycle Efficiency

The aim of the present paper is to examine the effect of ambient temperature on the performance of a combined cycle power plant. For this work, the combined cycle plant chosen is NTPC (National Thermal Power Corporation) Dadri, India where a gas unit of 817 MW is installed. The effect of ambient temperature on combined cycle efficiency, gas turbine cycle efficiency, exergy destruction in different components, exergy loss via exhaust and air fuel ratio at lower and higher turbine inlet temperature are reported. The results show that the net decrease in combined cycle efficiency is 0.04% and the variation in exergy destruction of different plant components is up to 0.35% for every °C rise in ambient temperature.

Transient Exergy Analysis of the Dynamic Operation of a Combined Cycle Power Plant

2021 ◽  
Author(s):  
Raphael Wittenburg ◽  
Moritz Hübel ◽  
Dorian Holtz ◽  
Karsten Müller
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Exergy Analysis ◽  
Measurement Data ◽  
Combined Cycle ◽  
Exergy Destruction ◽  
Transient Operation ◽  
State Equations ◽  
Component Level ◽  
Combined Cycle Power Plant

Abstract The increasing share of fluctuating electricity feed-in from wind energy and photovoltaic systems has a significant impact on the operating regime of conventional power plants. Since frequent load changes were not the focus of optimization in the past, there is still potential for improving the transient operating behavior. Exergy analyses are increasingly used to determine optimization potentials in energy conversion processes, but are mostly limited to stationary conditions. In order to perform an exergy analysis of the transient operation of a combined cycle power plant on component level, detailed information on the state and process variables of the individual components is required. These are not completely accessible via measurement data alone. For this reason, a comprehensive dynamic simulation model was developed, which includes the process components and the power plant control system. With the help of the implemented exergetic balance and state equations, the desired exergy quantities can be determined. The simulation results are used to evaluate the transient operating behaviour at different load change gradients and control actions on the basis of exergetic parameters. The exergy analysis results in an improved understanding of the causes of exergy destruction in the system, which can be used for optimization approaches. As expected, the main causes of exergy destruction are combustion processes and increased temperature gradients during transient operation. Overall, however, only moderately increased exergy destruction can be determined for the transient operation of the investigated plant compared to the steady state.

scholarly journals How to Construct a Combined S-CO2 Cycle for Coal Fired Power Plant?

Entropy ◽  
2018 ◽  
Vol 21 (1) ◽  
pp. 19 ◽  
Author(s):  
Enhui Sun ◽  
Han Hu ◽  
Hangning Li ◽  
Chao Liu ◽  
Jinliang Xu
Keyword(s):  
Power Plant ◽  
Flue Gas ◽  
Heat Recovery ◽  
Water Cycle ◽  
Combined Cycle ◽  
Exergy Destruction ◽  
Generation Efficiency ◽  
Air Preheater ◽  
Recompression Cycle ◽  
Residual Heat

It is difficult to recover the residual heat from flue gas when supercritical carbon dioxide (S-CO2) cycle is used for a coal fired power plant, due to the higher CO2 temperature in tail flue and the limited air temperature in air preheater. The combined cycle is helpful for residual heat recovery. Thus, it is important to build an efficient bottom cycle. In this paper, we proposed a novel exergy destruction control strategy during residual heat recovery to equal and minimize the exergy destruction for different bottom cycles. Five bottom cycles are analyzed to identify their differences in thermal efficiencies (ηth,b), and the CO2 temperature entering the bottom cycle heater (T4b) etc. We show that the exergy destruction can be minimized by a suitable pinch temperature between flue gas and CO2 in the heater via adjusting T4b. Among the five bottom cycles, either the recompression cycle (RC) or the partial cooling cycle (PACC) exhibits good performance. The power generation efficiency is 47.04% when the vapor parameters of CO2 are 620/30 MPa, with the double-reheating-recompression cycle as the top cycle, and RC as the bottom cycle. Such efficiency is higher than that of the supercritical water cycle power plant.

scholarly journals A STUDY OF FIELD GEOTHERMAL POWER POTENTIAL & THERMODYNAMIC CONCEPTS OF PROSPECTIVE BINARY POWER CYCLE BASED GEOTHERMAL POWER PLANT FOR TATAPANI GEOTHERMAL FIELD.

2020 ◽  
Vol 9 (12) ◽  
pp. 90-104
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Exergy Analysis ◽  
Geothermal Field ◽  
Flow Diagram ◽  
Exergy Destruction ◽  
Geothermal Power Plant ◽  
Power Cycle ◽  
Geothermal Fields ◽  
Geothermal Power

Tatapani Geothermal field is one of the most promising low-enthalpy geothermal fields in central India, located on Son-Narmada lineament in the state of Chhattisgarh, India. The Tatapani geothermal field geological, geo-chemical & reservoir data has been compiled and analysed for evaluating true power potential & better understanding of the field. The low enthalpy geothermal reservoirs can be utilized for power production using Organic Rankine Cycle (ORC) or binary power cycle. Based on previous research works done, the Tatapani geothermal field has been found to be very prospective and has got huge potential for power generation. The binary power cycle has been studied in detail along with thermodynamic concepts. In addition, similar low enthalpy geothermal power plants (conceptual & existing both) have been thoroughly studied in order to understand the concepts and methodology to perform technical feasibility based on thermodynamic and exergy analysis. The literature review covers the previous works done on Tatapani geothermal field including works on other geothermal fields in India along with previous research works for Thermodynamic & Exergy Analysis carried-out for binary geothermal power plants across the world for similar low enthalpy prospects. The methods of performing thermodynamic and exergy analysis for a potential geothermal power plant has been studied and compared. Exergy analysis highlights the areas of primary exergy destruction at various plant components and can be illustrated in the form of exergy flow diagram. The loss of exergy indicates the potential reasons for the inefficiencies within a process and exergic efficiency as conversion of input heat energy from the brine in to useful work output. The exergic efficiencies can be calculated for each component along with exergy destruction. The detailed study has been conducted in order to gather the knowledge regarding conducting the feasibility of setting up binary geothermal power plant at Tatapani from technical point of view using thermodynamic concepts.

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