Computer -Aided Evaluation of Steam Power Plants Performance Based on Energy and Exergy Analysis (original) (raw)
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Energy and exergy analysis of Montazeri Steam Power Plant in Iran
ScienceDirect, 2016
This paper aims at investigating steam cycle of Shahid Montazeri Power Plant of Isfahan with individual unit capacity of 200 MW. Using mass, energy, and exergy balance equations, all cycle equipment have been analyzed individually and energy efficiency, exergy efficiency, and irreversibility has been calculated for each of them as required. EES (Engineering Equation Solver) software is used for performing analyses. Values and ratios regarding heat drop and exergy loss have been presented for each equipment in individual tables. The results from the energy analysis show that 69.8% of the total lost energy in the cycle occurs in the condenser as the main equipment wasting energy, while exergy analysis introduces the boiler as the main equipment wasting exergy where 85.66% of the total exergy entering the cycle is lost.
Energy and Exergy Analysis of a 348.5 MW Steam Power Plant
Energy Sources, Part A: Recovery, Utilization, And Environmental Effects, 2010
In the present work, the energy and exergy analysis of Kostolac power plant in Serbia is presented. The primary objectives of this article are to analyze the system components separately and to identify and quantify the sites having the largest energy and exergy losses. The energy and exergy efficiency is calculated using the plant operating data from the plant at different loads. The load variation is studied with the data at 100% and 60% of full load. Moreover, the effects of the load variations are calculated in order to obtain a good insight into this analysis. The performance of the plant is estimated by a component-wise modeling, and a detailed break-up of energy and exergy losses for the considered plant has been presented. The results show that energy losses have mainly occurred in the condenser where 421 MW is lost to the environment while only 105.78 MW has been lost from the boiler. Nevertheless, the irreversibility rate of the boiler is higher than the irreversibility rates of the other components. The percentage ratio of the exergy destruction to the total exergy destruction was found to be maximum in the boiler system (88.2%) followed by the turbines (9.5%), and then the forced draft fan condenser (0.5%). In addition, the calculated thermal efficiency based on the lower heating value of fuel was 39% while the exergy efficiency of the power cycle was 35.77%.
Energy and exergy analysis of a steam power plant in Jordan
In this study, the energy and exergy analysis of Al-Hussein power plant in Jordan is presented. The primary objectives of this paper are to analyze the system components separately and to identify and quantify the sites having largest energy and exergy losses. In addition, the effect of varying the reference environment state on this analysis will also be presented. The performance of the plant was estimated by a componentwise modeling and a detailed break-up of energy and exergy losses for the considered plant has been presented. Energy losses mainly occurred in the condenser where 134 MW is lost to the environment while only 13 MW was lost from the boiler system. The percentage ratio of the exergy destruction to the total exergy destruction was found to be maximum in the boiler system (77%) followed by the turbine (13%), and then the forced draft fan condenser (9%). In addition, the calculated thermal efficiency based on the lower heating value of fuel was 26% while the exergy efficiency of the power cycle was 25%. For a moderate change in the reference environment state temperature, no drastic change was noticed in the performance of major components and the main conclusion remained the same; the boiler is the major source of irreversibilities in the power plant. Chemical reaction is the most significant source of exergy destruction in a boiler system which can be reduced by preheating the combustion air and reducing the air-fuel ratio.
Energy and Exergy Analysis of a Steam Power Plant in Sudan
African Journal of Engineering and Technology, 2021
In this study, the energy and exergy analysis of Garri 4 power plant in Sudan is presented. The primary objective of this paper is to identify the major source of irreversibilities in the cycle. The equipment of the power plant has been analyzed individually. Values regarding heat loss and exergy destruction have been presented for each equipment. The results confirmed that the condenser was the main source for energy loss (about 67%), while exergy analysis revealed that the boiler contributed to the largest percentage of exergy destruction (about 84.36%) which can be reduced by preheating the inlet water to a sufficient temperature and controlling air to fuel ratio.
Investigating The Performance of A Steam Power Plant
ABSTRACT: The performance analysis of Shobra El-Khima power plant in Cairo, Egypt is presented based on energy and exergy analysis to determine the causes , the sites with high exergy destruction , losses and the possibilities of improving the plant performance. The performance of the plant was evaluated at different loads (Full, 75% and, 50 %). The calculated thermal efficiency based on the heat added to the steam was found to be 41.9 %, 41.7 %, 43.9% , while the exergetic efficiency of the power cycle was found to be 44.8%, 45.5% and 48.8% at max, 75% and, 50 % load respectively. The condenser was found to have the largest energy losses where (54.3%, 55.1% and 56.3% at max, 75% and, 50 % load respectively) of the added energy to the steam is lost to the environment. The maximum exergy destruction was found to be in the turbine where the percentage of the exergy destruction was found to be (42%, 59% and 46.1% at max, 75% and, 50 % load respectively). The pump was found to have the minimum exergy destruction. It was also found that the exergy destruction in feed water heaters and in the condenser together represents the maximum exergy destruction in the plant (about 52%). This means that the irreversibilities in the heat transfer devices in the plant have a significant role on the exergy destruction. So, it is thought that the improvement in the power plant will be limited due to the heat transfer devices.
مجلة أكاديمية الجبل للعلوم الأساسية والتطبيقية
In this study, an energy and exergy analysis of the Derna steam power plant in Libya is presented. This study aims to identify the components with high energy and exergy losses which are leading to a decrease in the performance of the power plant. The largest place losses can be figured out hence to subsequently ensure where the greatest margin for improvement would be incurred. The influence of different parameters, such as temperatures and pressure values, on this analysis, is also conducted via the so-called Engineering Equation Solver software (EES). In terms of energy, the condenser is found to majorly have the highest energy losses of approximately 103MW which is received by the environment whilst the boiler losses are recorded to be about 24MW. As far as exergy is concerned, the boiler system is found to have the highest percentage ratio of exergy destruction to overall exergy destruction of 88 %, followed by the turbine of 8% and then the condenser of 3%. In addition, the th...
Energy and Exergy Analysis of a Steam Power Plant at Part Load Conditions
Port-Said Engineering Research Journal, 2017
A steam power plant can run at off-design due to change of ambient conditions or load demand. This needs to study how part-load affects the power plant performance. In this paper, the results of energy and exergy analysis carried out on a 65 MW Derna steam power plant in Libya at part load conditions are presented. The article aims to identify the magnitude, location and source of thermodynamic inefficiencies in the steam power plant at part loads. The performance of the plant was estimated by a component-wise modeling and a detailed break-up of energy and exergy losses for the considered power plant. The required outputs (power, heat and exergy destruction) of the various components and for the whole plant were assessed and calculated using mass, energy and exergy balance equations of the developed model. Based on this model, a computer program was written and used to investigate the performance of the power plant. According to the results, for full and part loads, the largest amount of energy loss occurs in the condenser and the least occurs in the boiler. In terms of exergy, the major exergy destruction was found to be maximum in the boiler, followed by the turbine, and then the condenser. The results revealed remarkable dependency of overall energy and exergy efficiencies, total exergy destruction ratio, heat rate and specific fuel consumption on the change in the load of the power plant. In conclusion, the results show how energy and exergy have been used to locate places of inefficiencies in the power plant operating at different loads.
THERMOECONOMIC ANALYSIS OF ALKHOMS STEAM POWER PLANT AT DIFFERENT OPERATING LOADS
Journal of Engineering Research, 2021
Exergoeconomic (thermoeconomic) analysis is performed on Alkhoms steam power plant. The nominal power of the plant is 120 MW. The analysis is based on real-time data and performed for three different loads. The main factor of load variation is the variation of the steam mass flow rate. These loads are 120 MW (full load), 60 MW (part load), and 100 MW (real-time operation). It is worth to mention that high-pressure heaters are out of service these days. A systematic and general methodology for defining and calculating exergetic efficiencies, exergy destruction, and exergy related to costs in thermal systems is presented. The methodology is based on the Specific Exergy Costing (SPECO) method. Results of the exergy analysis showed the exergetic efficiency (effectiveness) increases from 34.74% at the real-time operation to 40.96% at full operating load, and hence the ratio of the total exergy destruction to fuel input exergy decreases from 64.46% at a real-time operation to 59.6 at part load up to 57.88% at full operating load. The exergoeconomic analysis results the average specific cost is 0.177 /kWhatreal−timeoperationand0.113/kWh at real-time operation and 0.113 /kWhatreal−timeoperationand0.113/kWh at part load, and 0.102 /kWhatfulloperatingloadtakingintoconsiderationtheescalationoffuelprice(levelizedfuelcost).Itisfoundthatthecostofexergydestructioninthesteamgeneratorpresentsthemaincontributiontothetotalcostofexergyloss;itsvaluevariesinthesteamgeneratorfrom8296/kWh at full operating load taking into consideration the escalation of fuel price (levelized fuel cost). It is found that the cost of exergy destruction in the steam generator presents the main contribution to the total cost of exergy loss; its value varies in the steam generator from 8296 /kWhatfulloperatingloadtakingintoconsiderationtheescalationoffuelprice(levelizedfuelcost).Itisfoundthatthecostofexergydestructioninthesteamgeneratorpresentsthemaincontributiontothetotalcostofexergyloss;itsvaluevariesinthesteamgeneratorfrom8296/h at the real-time operation to 6560 /hatfulloperatingload,whileexergydestructioncostatpartloadisatanotablevalueof3495/h at full operating load, while exergy destruction cost at part load is at a notable value of 3495 /hatfulloperatingload,whileexergydestructioncostatpartloadisatanotablevalueof3495/h due to low fuel consumption. The contributions and the variation of exergy destruction cost with load are lower for the other components.