Performance Of Steam Power Plant Research Articles

Enhancing conventional steam power plant performance through feed water heating repowering

ABSTRACT Repowering of old steam power plants is a viable solution to increase power and improve efficiency. This study investigates the feasibility of feed water heating repowering for the Neka steam power plant by considering the influences of steam mass flow rate on the condenser performance and the heat rate of the new cycle. Energy and exergy analyses were conducted using the first and second laws of thermodynamics and heat transfer relations in each scheme. The effect of increasing the steam mass flow rate on the performance of the condenser and the cycle was also investigated. The repowered cycle was simulated using Thermoflow software, and the results were validated with small errors. The results showed that replacing low and high-pressure heaters with new heat exchangers increased the power of the steam unit and the repowered cycle, energy, and exergy efficiencies by 15.7%, 49.3%, 5.93%, and 2.17%, respectively. Although the condenser pressure increased by 19 millibars, leading to a 0.63% increase in the heat rate, the total heat rate of the repowered cycle improved by 4.62%. Overall, the findings demonstrate that feed water heating repowering can be an effective strategy to increase the efficiency and power of conventional steam power plants.

Improving the Performance of Steam Power Plant by Applying Energy and Exergy Analysis at Altering Operating Parameters

This study presents the energy and exergy analysis for unit three of the Al-Mosyab thermal power plant, which has a capacity of 225 MW. The energy losses, exergy destruction and second law efficiency, are computed. The objective is to obtain a comprehensive prediction of improvement that will happen in the performance. Results showed that the second law efficiency of the cycle is 34.91%, and the maximum exergy destruction was at the boiler by 86%. The plant's second law efficiency improves successfully to 37.65%, and 0.67 kg/s of the fuel mass flow rate can be saved. As well as, the total exergy destruction decreased by 10.8% at increasing the feedwater temperature to 230 °C. The second law efficiency has enhanced to 35.74% and 1.32% of the exergy destruction drops when reducing the mass flow rate of the desuperheater spray water of the main steam. The second law efficiency increased by 2.27%, and 1.25% of the total exergy destruction was reduced when the hot reheat pressure increased. Moreover, the analysis reveals that the plant's second law efficiency has grown by 6.45% and that the total exergy destruction has fallen by 3.31% when cold reheat steam temperature is reduced.

Simulation of Effects Off Service Closed Feedwater Heater on Steam Power Plant Performance Using Cycle Tempo 5.0

Steam power plant needs three important things in its operation, they are safety, reliability, and efficiency. Steam power plant efficiency can be elevated by installing regenerative feedwater heater. Feedwater heater is used to increase the temperature of water needed for combustion process in the boiler, therefore minimizing the fuel used in boiler. Case study is taken from PT. PJB UP Muara Karang Steam Power Plant unit 4 and 5. HPH 4 off service in August 2018 caused thermal efficiency drop about 1.86 % from the previous month. The same case was found in January 2019, in which HPH F off service caused 0.68 % from the previous month. This study’s aim is to find out the effect of off service closed feedwater heater to steam power plant performance using Cycle Tempo 5.0. Steam power plant unit 5 with 172 MW load is modelled on Cycle Tempo. Validation is done by comparing some parameter of simulation result to performance test result with 5% error tolerance. Few variation off service feedwater heater conditions are done by regulating valve for line bypass in order to set feedwater flow into tubes as well as drain flow. NPHR analysis is done by gathering net power and heat needed in boiler for each variation. The result obtained from this study shows that off service feedwater heater cause NPHR enhancement. The highest NPHR increase is achieved when HPH F is on off service condition, with value about 30.58 kCal/kWh. Off service HPH has bigger effect on NPHR increase than LPH on the same condition. Steam power plant efficiency increase continuously with the greater amount of operating feedwater heater. 3 LPH and 2 HPH usage on steam power plant with 172 MW load is assessed as adequate efficient, with all feedwater heater operating at 33.39 %.

Steam Power Plant Performance Operating at High Temperature and Pressure Conditions

Steam Power Plant Performance Operating at High Temperature and Pressure Conditions

Modelling the power output from a steam power plant in Nigeria

Adequate supply of electricity at a competitive price is pivotal to sustainable development. More often than not, the generation of electricity which drives modern growth and development is currently powered by limited fossil fuels in many nations. Electricity generation and megawatt demand are also usually fluctuating due to several pertinent factors. In a bid to articulate the impact of inherent variations in process parameters on the performance of steam power plant at different loads, this paper presents an investigation into the efficacy of two validation strategies in predicting the net power output from the plant using GMDH Shell software. Using the combinatorial algorithm, the k-fold cross-validation strategy and the training/testing validation technique were applied to empirical data of a power plant in Nigeria. The performance of the models returned from the two validation strategies was evaluated using maximum negative error, maximum positive error, mean absolute percentage error (MAPE), root mean square percentage error (RMSPE), residual sum, the standard deviation of residuals, coefficient of determination (R2) and correlation. For the number of folds and the training/testing split percentage considered in this study, results show that both models obtained were quite competitive, with the k-fold model having a slight edge over the other model. It is expected that the outcome of the study will be handy in researches for providing knowledge base information on choosing and setting optimum operating conditions at various load demand.

ANALISIS KENAIKAN PLANT HEAT RATE PLTU SEBELUM PERBAIKAN BERKALA TERHADAP KONDISI TESTING KOMISIONING (Studi Kasus : PLTU XX)

Steam power plant is a power plant which use coal as fuel to heating the water into superheated steam . The standard of efficient or not for a power plant can be seen from the value of plant heat rate. Plant heat rate is amount of energy required to generate one kWh electricity. The smallest of that is the best power plant . In general, the value of plant heat rate has increased than commisioning test after the power plant operated continously . The method used in the calculation of the steam power plant is energy balance method. Energy balance calculation method used by the standard of the American Society of Engineers Mechanichal Performance Test Code (ASME PTC). The value of plant heat rate is influenced by the value of turbine heat rate and boiler efficiency from steam power plant . Turbine heat rate is the required energy turbines obtained from heat transfer process to generate one kWh electricity, while boiler efficiency is an indicator from boiler performance of steam power plant by comparing the outputs and inputs. After calculation of plant heat rate at actual condition, the value of plant heat rate has increased than commisioning. The increrase of plant heat rate value is due to more losses which result degradation performance on the main components of the unis, such as : turbine, boiler, air heater and condenser. Therefore necessary corrective maintenance when first year inspection, so that the steam power plant can be re-optimal performance as at commisioning test.

Adaptive Control Using NARMA-L2 Model and Electric Circuit for Condenser of Thermal Power Plant

Design and implantation electric circuit for enhancement performance of steam power plant and artificial neural networks technique used to control of condenser. Artificial neural network has been applied to control of the important variables of condenser in Al–Dura power plant in Baghdad such as pressure, temperature. in this study, applied Simulink model in Matlab program (v 2014 a) by using artificial neural network toolbox. the model of condenser of neural network by using NARMA to generated data and train network and using back propagation algorithm for training neural network. The method of control by ANN is off line. the electric circuit of pressure sensor and temperature sensor consist of transformer, dc bridge and voltage regulator. Experimental data of actual power plant obtained from al-dura power plant. comparing results of modelling neural network and electric circuit with experimental data of actual power plant. the results shown the maximum deviation between the ANN and electric circuit with experimental data is less than 4%. artificial neural network can be used in many industrial and engineering application.

Solar-assisted steam power plant retrofitted with regenerative system using Parabolic Trough Solar Collectors

This work investigates the performance of a conventional steam power plant retrofitted with a solar-assisted regenerative system using Parabolic Trough Solar Collectors (PTC). The solar collectors were used to compensate for the effect of removing Low-Pressure (LP) turbine extractions without changing other elements of a 300 MW power plant unit during peak load operations. The steam power plant, located in Kuwait, receives high levels of solar irradiation. Modeling of the solar-assisted regenerative system using PTC is simulated for Kuwait’s weather conditions. Results of the system analysis show that removing the LP turbine extractions enhanced the performance of the steam power plant by 9.8 MW, with an optimum PTC aperture area equal to 25,850 m2. A techno-economic analysis was used to estimate the Levelized Cost of Energy (LCOE). Compared to an equivalent photovoltaic solar plant, the optimum aperture area and LCOE for the PTC solar plant were found to be less by 45% and 44%, respectively. When compared to an equivalent conventional steam turbine, the solar-assisted steam power plant decreased cost by 56% over the lifecycle of 25-years.

SOCIETY COMMUNICATION ON THE PERFORMANCE OF STEAM POWER PLANT (PLTU) : A Case Study On the Society Who Lived On Sub-District of Tawaeli Palu City

The waste produced by Steam Power Plant (PLTU) in Taweli Sub-district has negative impact on public health because the disposal process is not performed properly, causing Society communication such as demonstration. This research aims to describe and analyze the communication behavior of people in Taweli Sub-district in relation to the performance of Steam Power Plant (PLTU). This study used a qualitative approach with a case study method. The research results are divided into three indicators, namely (a) The initial information obtained by the Taweli Subdistrict Society related to the construction and performance of the Steam Power Plant (PLTU) was positively welcomed (b) Information on waste disposal by the Steam Power Plant (PLTU) was made into the society as a negative, and (c) The response given by the Taweli Sub-district Society and the people of Palu City was by conducting a demonstration.

Comparison between PID controller and fuzzy sliding mode control (FSMC) on super heater system

Super heater, a component in a boiler, is an important component in a steam power plant system. It serves to transform the heat into superheated steam to spin a turbine. The steam temperature must be carefully controlled, to ensure good quality of steam. For the best performance of steam power plant (PLTU) 3-4 PJB UP Gresik, Indonesia, the temperature of superheated steam must be achieve 814 K. In this paper was designed PID controller super heater system and analysis of the performance of the system by comparing PID and FSMC. PID Controller can generate steam temperature stable at 814 K. While the FSMC controller generate steam temperature stable at 814.097 K. Thus, it was concluded that PID controller can generates more accurate steam temperature than FSMC. However when the system get a disturbance, FSMC can handle it better than PID controller.

Utilizing exergy analysis in studying the performance of steam power plant at two different operation mode

This paper presents the exergy analysis for a 650 MW thermal power plant. The relationship between power plant exergy and thermal efficiencies is being presented for two different loads. Moreover, the effect of the decreasing condenser pressure, IPT inlet pressure and increasing S/H steam temperature inlet to both HPT and IPT is studied. The exergy analysis shows that the maximum source of exergy destruction is the boiler, followed by the turbine, then the condenser. Also, it is found that 0.5725% of the power can be saved at full load and by 0.5878% at half load if the condenser pressure is decreased from 0.067 bar to 0.049. Decreasing IPT inlet pressure by 4.5 bar will save power by 0.709% at full load and 1.394% at half load. When S/H steam temperature inlets to HPT are increased by 45 °C. The power is saved by 10.383% and 8.906% at full load and half load respectively. Also, increasing S/H steam temperature inlets to IPT by 45 °C will save power by 7.285% at full load, compared with 6.736% at half load. Moreover, increasing both inlets to HPT and IPT by 45 °C will save power by 17.67% and 15.64% at full and half loads.

Enhancement of Performance for Steam Turbine in Thermal Power Plants Using Artificial Neural Network and Electric Circuit Design

Design and implantation of electric circuit for enhanced performance of steam power plant and artificial neural networks technique are used to control turbine. Artificial neural networks technique is used to control a lot of industrial models practically. Artificial neural network has been applied to control the important variables of turbine in AL–Dura power plant in Baghdad such as pressure, temperature, speed, and humidity. In this study Simulink model was applied in MATLAB program (v 2014 a) by using artificial neural network (ANN). The method of controlling model is by using NARMA to generate data and train network. ANN is offline. ANN requires data to obtain results and for comparison with actual power plant. The values of the input variables have a large effect on the number of nodes and epochs and in hidden layer of the artificial neural network they also affect performance of ANN. The electric circuit of sensors consists of transformer, DC bridge, and voltage regulator. Comparing the results from modeling by ANN and electric circuit with experimental data reveals a good agreement and the maximum deviation between the experimental data and predicted results from ANN and circuit design is less than 1%. The novelty in this paper is applying NARMA controller for the purpose of enhancement of turbine performance.

Effects of Oxy-Fuel Combustion on Performance of Heat Recovery Steam Generators

The performance of steam power plants, utilizing recovered waste heat from air-fuel and oxy-fuel combustion, are compared. Temperature profiles in the heat recovery steam generator (HRSG), steam production rate, net-work output and energy efficiency are simulated for different conditions. Investigations are made into the effect of varying pinch point on HRSG performance, net-work and energy efficiency for power generation utilizing oxy-fuel combustion. It is found that with increased pinch point there is an associated decrease in HRSG and steam plant efficiencies. Exhaust gas composition influences the energy efficiency of the power plant. When air-fuel and oxy-fuel combustion are compared there is a reduced amount of nitrogen in the oxidant stream in the latter case. When comparing air-fuel and oxy-fuel combustion, a considerable deviation in HRSG and steam power plant performance is exhibited, with oxy-fuel combustion offering benefits in system efficiency and plant output. The exhaust gas composition at the HRSG inlet contributes significantly the performance characteristics of the system. Raising the HRSG inlet temperature also increases power generation and system efficiency. The results provide insights into the use of oxy-fuel combustion for systems utilizing HRSG for power generation while demonstrating the influence of gas composition, pinch point, and exhaust gas temperature on system performance, and suggest that oxy-fuel combustion can help enhance the contribution to sustainable development of some energy systems.

Effect of Low Pressure End Conditions on Steam Power Plant Performance

Most of the electricity produced throughout the world today is from steam power plants and improving the performance of power plants is crucial to minimize the greenhouse gas emissions and fuel consumption. Energy efficiency of a thermal power plant strongly depends on its boiler-condenser operating conditions. The low pressure end conditions of a condenser have influence on the power output, steam consumption and efficiency of a plant. Hence, the objective this paper is to study the effect of the low pressure end conditions on a steam power plant performance. For the study each component was modelled thermodynamically. Simulation was done and the results showed that performance of the condenser is highly a function of its pressure which in turn depends on the flow rate and temperature of the cooling water. Furthermore, when the condenser pressure increases both net power output and plant efficiency decrease whereas the steam consumption increases. The results can be used to run a steam power cycle at optimum conditions.

Derivation of correlations to evaluate the impact of retrofitted post-combustion CO 2 capture processes on steam power plant performance

When integrating a post-combustion CO 2 capture process and CO 2 compression into a steam power plant, the three interface quantities heat, electricity and cooling duty must be satisfied by the power plant, leading to a loss in net efficiency. The heat duty shows to be the largest contributor to the overall net efficiency penalty of the power plant. Additional energy penalty results from the cooling and electric power duty of the capture and compression units. In this work, the dependency of the energy penalty on the quantity and quality of the heat duty is analyzed and quantified for a state-of-the-art hard coal fired power plant. Furthermore, the energy penalty attributed to the additional cooling and power duty is quantified. As a result correlations are provided which enable to predict the impact of the heat, cooling and electricity duty of post-combustion CO 2 capture processes on the net output of a steam power plant in a holistic approach.

Derivation of power loss factors to evaluate the impact of postcombustion CO2 capture processes on steam power plant performance

Abstract When integrating a post-combustion CO 2 capture process and a CO 2 compressor into a steam power plant, the heat duty for the regeneration of the solvent (and the corresponding steam extraction) shows to be the largest contributor to the overall net efficiency penalty of the power plant. One parameter which varies from plant to plant and which significantly affects the impact of steam extraction from the steam turbine on the power plant efficiency is the pressure in the IP/LP crossover. In this work, the dependency of the energy penalty on the quantity and quality of the heat duty is analysed and quantified for three state-of-the-art hard coal fired power plant configurations with different pressure levels in the IP/LP crossover.

Use of Cooling Thermal Storage as a Heat Sink for Steam Power Plant

In the present paper, a system is proposed for improving the performance of steam power plant with air-cooled condenser during peak loads. In this system, the power plant comprises two steam turbines, and the air-cooled condenser is replaced by two condensers. The first one is air-cooled (dry) and used for condensing the exhaust steam of the first turbine, while the second is water-cooled and serves to condense the steam outlet of the second turbine. The warm cooling water exiting the wet condenser is pumped to a cooling storage container, where it is cooled and re-circulated to the wet condenser. Cooling is produced by a refrigeration machine driven by the extra electric power generated by the two turbines during the time of the off-peak-loads (low electricity rates). Simple energy analyses have been developed to predict the energy characteristics of this system. The results of this paper showed that the proposed system leads to improving the plant power output at peak-loads. About 6, 16, 24 and 33% increase in generated plant power can be achieved at peak-loads (high electricity rates) when the ambient temperature is 20, 30, 40 and 50°C respectively, and the whole steam exiting both turbines is cooled in a wet condenser to a design temperature of 20°C. The results showed also that choice of the capacity of each turbine is essentially affected by the quality of the refrigeration machine and ambient temperature.

Evaluation of a process simulator for modelling and analysis of Rankine cycle steam power plants

Applicability of the HYSYS process simulation package to thermodynamic modelling and analysis of Rankine cycle steam power plants, using first and second law analyses, has been evaluated. Theoretical Rankine cycles, and more realistic cycles based on power plants modelled in other studies, were simulated. Energy, exergy and efficiency values determined from the simulations were compared to those obtained from theory or reported in literature. Discrepancies of <1% were observed for theoretical cycles, while more realistic cycles were modelled to within 8% of reported values. Results suggest HYSYS is appropriate for use in thermodynamic assessments of steam power plant performance.

Essential statistics for general comparison of steam power plant performance

This paper briefly outlines a method for preparing statistical reports relating to power generation in steam power plants, whereby fairly close comparisons can be made of the efficiencies between different plants, without going into a detailed study of the thermal characteristics of the plants, or the intricate subject of power costs. The essential items of steam power plant performance that should be recorded and a uniform method of expressing them, are given in tabular form, followed by an illustration demonstrating the advantage of the proposed method.

Essential Statistics for General Comparison of Steam Power Plant Performance

This paper briefly outlines a method for preparing statistical reports relating to power generation in steam power plants, whereby fairly close comparisons can be made of the efficiencies between different plants, without going into a detailed study of the thermal characteristics of the plants, or the intricate subject of power costs. The essential items of steam power plant performance that should be recorded and a uniform method of expressing them, are given in tabular form, followed by an illustration demonstrating the advantage of the proposed method.