Power Plant Unit Research Articles

Effect of Turbine and Compressor Inlet Temperatures and Air Bleeding on the Comparative Performance of Simple and Combined Gas Turbine Unit

The proper utilization of all the available forms of energy resources has become imminent to meet the power requirement and energy demand in both the developed and developing countries of the world. Even though the emphasis is given to the renewable resources in most parts of the world, but fossil fuels will still remain the main resources of energy as these can meet both normal and peak demands. Saudi Arab has number of power plant based on natural gas and fuel that are spread in all its regions. These power plants have aeroderivative gas turbine units supplied by General Electric Company as main power producing units. These units work on dual fuel systems. These units work as simple gas turbine units to meat peak demands and as part of combined cycle otherwise. The subject matter of this study is the performance of one of the units of a power plant situated near Riyadh city of Saudi Arab. This unit also works both as simple gas turbine unit and as a part of combined cycle power plant unit. A parametric based performance evaluation of the unit has been carried out to study both energetic and exergetic performance of the unit for both simple and combined cycle operation. Effect of compressor inlet temperature, turbine inlet temperature, pressure ratio of the compressor, the stage from which bleed off air have been taken and percentage of bleed off air from the compressor on the energetic and exergetic performance of the unit have been studied. The study reveals that all these parameters effect the performance of the unit in both modes of operation.

New Method for Synchronous Generator Parameters Estimation Using Load Rejection Tests Data Considering Operational Limitations

Load rejection (LR) test, recommended by different standards including IEEE Std.115., is considered as one of the most popular methods for parameter estimation of the synchronous generator (SG). However, parameter identification using this method has demonstrated no acceptable results for experimental data. Therefore, the present study aims to analyze common LR test operational limitations and to suggest a new method for parameter estimation based on LR test results which overcome the shortcomings of the previous method. To this end, a new approach is proposed for SG parameter estimation using LR test data. Using the proposed method, parameter estimation covers both salient pole and round rotor SGs. In both d and q axes, the effects of limitations are considered, and finally, parameters are estimated by fitting curve to experimental data based on the non-linear least square method and the genetic algorithm (GA). The proposed method is applied to the 200 MVA gas unit of a combined cycle power plant, and the results are discussed accordingly.

Reliability enhancement of LNG fuel gas supply system in combined-cycle power plant

This article aims to present a technique to enhance reliability of liquefied natural gas (LNG) fuel gas supply system (FGSS) of gas turbine unit in a combined-cycle power plant. In order to prevent unplanned plant shutdowns, the proposed technique is based on the use of failure modes, effects, and diagnostic analysis (FMEDA) to identify and evaluate the effects of possible failure modes, to determine what could minimize the chance of failures, and to design a new safety interlock. The studied FGSS consists of gas analytical system (GAS) in 2-out-of-2 voting scheme, shutdown valve system (SDV) in 1-out-of-2 voting scheme, fuel gas controller (FGC), and engineering/operator workstations. Two automatic GAS subsystems with different measurement methods are installed in the GAS. One of two GAS subsystems uses three gas chromatography analyzers in 2-out-of-3 voting scheme. The gas chromatography results and diagnostic alarm historian are utilized to consider the failure behavior. The reliability models for the GAS subsystem using gas chromatography and the overall FGSS are also included to confirm the effectiveness of utilizing diagnostic information from the gas analyzers. Based on the FMEDA results, the new safety interlock with no additional software and hardware costs can be achieved. The workability of the proposed safety interlock is demonstrated by test results.

Оценка температурного состояния и методические вопросы газодинамических испытаний образцов высокотемпературной керамики

Material selection for aerospace structural and power plant units subjected to thermal stresses is based on thorough investigation of their physical, mechanical and optical properties in a wide range of temperatures up to 2500--3000 K, which are in practice the highest possible. However, it is exceptionally difficult and expensive to obtain the whole extent of data on the properties of structural and refractive materials currently in development that is required to analytically estimate the thermal state and performance of the structures designed to be subjected to thermal stresses. Moreover, the theoretical thermal state models in use are most often based on a number of assumptions, which means that they will need to be validated against experimental investigation data. As a result, integral methods of estimating material performance under intended real-world thermal and force loads become highly important. Ground-based development testing using simulation installations will solve this problem. While testing, it is important to ensure that the simulated thermal modes of the object being tested match its real-world thermal modes. The paper considers these issues regarding estimating refractory ceramics performance subjected to a high-temperature gas flow

THE RESEARCH OF CIRCULATION WATER SUPPLY SYSTEM OF POWER UNIT OF THERMAL POWER PLANT WITH HELLER COOLING TOWER

Analytical hydraulic researches of the circulating water cooling system of the power unit of a thermal power plant with Heller cooling tower have been performed. Analytical studies were performed on the basis of experimental data obtained during the start-up tests of the circulating water cooling system of the “Hrazdan-5” power unit with a capacity of 300 MW. Studies of the circulating water cooling system were carried out at an electric power of the power unit of 200 - 299 MW, with a thermal load of 320 - 396 Gcal/hr. By circulating pumps (CP), water mixed with condensate is fed to the cooling tower, from where it is returned through the turbine for spraying by nozzles in the turbine steam condenser. An attempt to increase the water supply to the condenser by increasing the size of the nozzles did not give the expected results. The amount of the water supply to the circulating pumping station depends on the pressure loss in the circulating water cooling system. The highest pressure losses are in hydro turbines (HT), which are part of the circulating pumping station. Therefore, by adjusting the load of the hydro turbine, with a decrease in water pressure losses, you can increase the water supply by circulating pumps to the condenser. Experimental data and theoretical dependences were used to calculate the changed hydraulic characteristics of the circulating water cooling system. As a result of reducing the pressure losses in the section of the hydro turbine from 1.04 to 0.15 kgf/cm2, the dictating point for the pressure of circulating pumping station will be the turbine steam condenser. The thermal power plant cooling tower is designed to service two power units. Activation of the peak cooler sectors of the cooling tower gives a reduction of the cooled water temperature by 2-4 °С only with the spraying system.

Experimental and Numerical Analysis of 60-Year-Old Sluice Gate Affected by Long-Term Operation.

Technological units of water reservoirs and power plants include sluice gates which are designed to completely seal the inflow or outflow of water in supply or discharge channels. This article describes the issue of technical assessment of a sluice gate made in the 1950s. Such structures are characterised by states of significant corrosive wear, permanent deformations of contact and sealing surfaces as well as increased levels of residual stresses. In such cases, it is difficult to determine service life using only numerical modelling methods, mainly due to problematic definition of material properties and boundary conditions. Therefore, for safety assessment, it is necessary to verify these facts experimentally. This article presents the procedure for assessing safe operation of the sluice gate on which places with permanent deformation and a broken part of the guide wheel flange were identified. By means of numerical modelling, we identified critical stress values at the locations of reinforcing elements, which were modified, and the stress values were reduced by about 15%. The results of numerical modelling were verified at select locations by experimental measurements during operation using strain gauges. The maximum values of operational normal stresses in the assessed places reached about 27 MPa. Based on the comparison of obtained results and taking into account values of residual stresses reaching up to 190 MPa made by shielded metal arc welding, it can be stated that, for safe operation of the sluice gate, it is necessary to follow the proposed procedure during its lowering and to modify the reinforcing elements structurally.

The Description of the Application of Healthy Workplaces at PT PJB Power Plant Unit Gresik

Introduction: Healthy workplaces is a concept where everyone in the work environment works together to achieve the vision of the health and welfare of workers and the surrounding community. PT PJB UP Gresik is a supplier of electrical energy since 14th June 1996, and has received top management awards in 2018 with zero accidents in 2018 and 2019. This study aimed to describe the working environment of PT PJB UP Gresik using Healthy Workplaces Theory. Methods: The study was conducted in February-August 2019 through descriptive of quantitative method. The population involved was 325 workers selected using simple random sampling, divided into two groups of 22 managements, and 76 staffs. Research tool used was in the form of WHO questionnaire. The study passed the ethical review of the Faculty of Dentistry, Universitas Airlangga in June 2019 number 324/HRECC.FODM/VI/2019. Result: As much as 97% of the management and 76% of staff agreed that the company had health-oriented regulations. It also obtained that 100% management, and 92% staff agreed that the company's psychosocial environment was healthy. As much as 96% of each respondent group agreed that the work environment was safe. About 63% management and 64% staff agreed that the company supported changes in healthy lifestyles. Around 60% management and 64% staff agreed that the company's health service units were available and implemented well. The statement of company being a good effect has been approved by 89% of the management. Conclusion: PT PJB UP Gresik has a healthy work environment and can be improved if it pays more attention to the lifestyle and the functions of health service.Keywords: heat radiation, noise, ship production

Why sulfur dioxide emissions decline significantly from coal-fired power plants in China? Evidence from the desulfurated electricity pricing premium program

Sulfur dioxide (SO2) emissions from coal-fired power plants in China have declined significantly since an incentive-based policy named as the desulfurated electricity pricing premium program (DEPPP) was implemented for all coal-fired power plants in 2006. Using industrial pollution panel data from 350 prefectures in China and difference-in-differences models, we estimate causal effects of the DEPPP on the coal-fired power plants. We find that the DEPPP provided the coal-fired power plants strong incentives to invest in capital-intensive flue gas desulfurization (FGD) equipment and to operate the installed FGD at a higher rate, and thus contributed to significant reductions in total SO2 emissions in China. Our results suggest that the DEPPP reduced uncertainty faced by the coal-fired power plants when making large capital investments in SO2 abatement techniques such as FGD to comply with stringent environmental regulations. However, the DEPPP may not be cost-effective in reducing SO2 emissions given heterogeneous marginal costs for operating FGD units in different coal-fired power plants. Furthermore, the effectiveness of the DEPPP also depends on strengthened environmental regulatory capacities to enforce coal-fired power plants to comply with the operating rate requirement for the installed FGD.

Optimization of a 660 MWe Supercritical Power Plant Performance—A Case of Industry 4.0 in the Data-Driven Operational Management Part 1. Thermal Efficiency

This paper presents a comprehensive step-wise methodology for implementing industry 4.0 in a functional coal power plant. The overall efficiency of a 660 MWe supercritical coal-fired plant using real operational data is considered in the study. Conventional and advanced AI-based techniques are used to present comprehensive data visualization. Monte-Carlo experimentation on artificial neural network (ANN) and least square support vector machine (LSSVM) process models and interval adjoint significance analysis (IASA) are performed to eliminate insignificant control variables. Effective and validated ANN and LSSVM process models are developed and comprehensively compared. The ANN process model proved to be significantly more effective; especially, in terms of the capacity to be deployed as a robust and reliable AI model for industrial data analysis and decision making. A detailed investigation of efficient power generation is presented under 50%, 75%, and 100% power plant unit load. Up to 7.20%, 6.85%, and 8.60% savings in heat input values are identified at 50%, 75%, and 100% unit load, respectively, without compromising the power plant’s overall thermal efficiency.

Technological methods for processing non-rigid finned shells of power plants

The paper provides information on the new processes designed and adopted for implementation on the combined surface treatment of loaded parts and assembly units of advanced power plants and special technological equipment, the original means of technological equipment are described, and the prospects for further expansion of their technological capabilities and impact on improving the manufacturing processability of products are given.

Incorporating Health Cobenefits in Decision-Making for the Decommissioning of Coal-Fired Power Plants in China.

China's coal-fired power industry urgently needs deep decarbonization to meet the challenge of climate change. Regional air quality improvement and the health benefits can motivate efforts to achieve low-carbon goals. However, the health cobenefit per amount of carbon reduction may vary drastically across power plant units. The strategy of targeting more health cobenefits has been considered in designing an efficient carbon mitigation pathway, whereas this issue has not been analyzed at the unit level. In this study, an indicator called health benefit by carbon reduction (H/C) was constructed for each power unit to assess the relative potential of obtaining health cobenefits. The results reveal that the distribution of H/C values among units is extremely uneven: the first 1, 5, and 20% of the total carbon emission contributed to nearly 20, 40, and 70%, respectively, of the total health effects. The additional health benefits from H/C optimization were evaluated, and the decommissioning pathway of China's coal-fired power industry for achieving more health benefits was explored.

Low-Frequency Pressure Pulsations in the Penstocks of Hydroelectric Power Plants and Swing of the Generator Rotor

Full-scale data on the pulsations of pressure and the oscillations of the real power in units of hydraulic power plants are analyzed. The relationships among the low-frequency pressure pulsations, oscillations in the turbine torque, and oscillations in the real power of the generator are established.

Prediction of Carbon Content in Fly Ash in Ultra Supercritical Generation Unit with Long Short-term Memory Neural Network

The accurate measurement of carbon content in fly ash is the basis of improving the thermal conversion efficiency of boiler and reducing the coal consumption of power generation. Based on the operation data of 1000MW Ultra-supercritical Unit in a thermal power plant, the input parameters of the model were selected by correlation analysis. The Long Short-Term Memory neural network (LSTM) was used to establish a prediction model with the boiler operation parameters as the input and the carbon content of the boiler fly ash as the output. According to the actual operation data of the unit, the prediction performance of the model was trained and tested. The simulation results show that the average prediction error of the LSTM model is 2.8136%, and 86% of the total samples are data with error less than 4.5%, which means it has high accuracy and strong generalization ability.

Deliberateness and Representativeness of Public Deliberation Process: Focusing on the Public Deliberation Process of the Singori Nuclear Power Plant Units 5 and 6

이 연구는 ‘공론화의 숙의성과 대표성이 얼마나 확보되어 있는지’를 논의하기 위해 우리 사회에서 공론화 확산의 계기가 되었던 신고리원전 5･6호기 공론화 과정의 숙의성과 대표성을 분석하 였다. 분석 결과는 성공적 평가에도 불구하고 공론화의 숙의성과 대표성 논란의 여지도 남겨 두었음을 보여주고 있다. 약 1개월에 걸친 숙의과정이 짧지는 않았지만, 높은 전문성을 필요로 하는 원전 문제를 다룸에도 불구하고 시민참여단에 대한 정보제공과 자료 검토의 기회는 충분하지 않았다. 또한 집중성 높은 숙의과정이 진행되었으나, 분임토의 참여자 간 편중된 발언 기회, 감정적 호소에 의존한 발표, 전문성의 불균형 문제들도 나타났다. 숙의 전후 시점을 기준으로 분석한 숙의 효과는 판단을 유보했던 시민참여단의 최종 선호 변화에서 크게 나타났고, 건설중단 입장을 표명했던 시민참여단에게도 크게 나타났다. 한편, 공론화 주제가 특정 집단에 편향된 주제가 아니었으며, 시민참여단의 정치적 평등이 확보되어 참여자의 포괄성도 높았으나, 표본 추출방식의 한계, 비통제변수의 영향 가능성으로 인해 표본의 설명력이 낮을 수 있다는 문제도 내재되어 있었다. 연구 결과는 숙의성은 참여자에게 학습을 위한 충분한 정보제공과 검토 기회가 제공되고, 참여자 간 계서화됨 없이 정치적 평등 관계가 유지되어야 확보될 수 있음을 시사 한다. 마지막으로, 공론화는 쟁점이 다양하고 복잡하거나 높은 전문성을 필요로 하는 의제를 다룰 경우 그 적용의 실효성이 낮다.This study analyzed the deliberateness and representativeness of the public deliberation process of Singori Nuclear Power Plant Units 5 and 6, which was the trigger for the dissemination of public debate, in order to discuss how secure the deliberateness and representativeness of public deliberation is in our society . The results show that despite the successful evaluation, the deliberation and representativeness of public deliberation remained controversial. The schedule for deliberation over a month and the deliberation of the Citizen Participation Group for three days were not short, but the opportunity for information and data review for the Citizen Participation Group was not sufficient. In addition, although the intensive deliberation process was conducted, there was a problem of unbalanced opportunities for speech among participants in a small group discussion, presentations that depended on emotional appeals, and unbalanced professionalism. The effect of deliberation, analyzed based on the pre- and post-deliberation period, was large in the final preference change of the Citizens Participation Group, which had retained the judgment pending, and also in the Citizen Participants, who expressed their cessation of construction. On the other hand, the topic of public deliberation was not a topic biased to a specific group, and the political equality of the Citizens Participation Group secured the inclusiveness of the participants, but due to the limitations of the sampling method and the possibility of influence of non-controlled variables such as job and education level, there was also a problem that the sample s explanatory power could be low. The study show that deliberateness can be guaranteed only if it provides participants with sufficient information and review opportunities for learning, and political equality without being accounted for among participants is maintained. Lastly, public deliberation is less effective when dealing with agendas that are complex or require high expertise.

Development and Validation of a New Domestic Software for Dose Assessment during Normal and Accident Conditions in Nuclear Power Plants (NPPS).

In this research, a comprehensive code called KIANA is developed based on the Gaussian plume model to simulate and predict the radiological consequences received through all the possible, reasonable, probable, and standard exposure pathways for NPPs and chemical facilities. To validate the KIANA code, a case study is modeled for Bushehr Nuclear Power Plant Unit One (BNPP-1), and the KIANA code results are compared with the results of the Final Safety Analysis Report (FSAR-2017) data of BNPP-1. To assess the performance of the KIANA code, the total dose due to the airborne pathway in accident conditions including small break LOCA (SBLOCA), large break LOCA (LBLOCA), and equivalent exposure dose for the thyroid gland of a group of infants and children age 1 to 8 y at BNPP-1, are investigated. The KIANA code results show that the total effective doses do not exceed the regulatory limit of 5 mSv for external and internal exposures and the regulatory limit of 50 mSv for thyroid equivalent dose. The KIANA code results indicate good agreement with the results of FSAR-2017.

FPGA application for wireless monitoring in power plant

The process of automation and monitoring in industrial control system involves the use of many types of sensors. A programmable logic controller plays an important role in the automation of the different processes in the power plant system. The major control units are boiler for temperature and pressure, turbine for speed of motor, generator for voltage, conveyer belt for fuel. The power plant units are controlled using microcontrollers and PLCs, but FPGA can be the feasible solution. The paper focused on the design and simulation of hardware chip to monitor boiler, turbine, generator and conveyer belt. The hardware chip of the plant is designed in Xilinx Vivado Simulator 17.4 software using VHDL programming. The methodology includes VHDL code design, simulation, verification and testing on Virtex-5 FPGA hardware. The system has four independent buzzers used to indicate the status of the boiler, generator, turbine motor and conveyer belt in on/off conditions respectively. The GSM is used to display corresponding message on the mobile to know the status of the device in on/off condition. The system is very much helpful for the industries working on plant automation with FPGA hardware integration.

Pinch and exergy evaluation of Kalina/Rankine/gas/steam combined power cycles for tri-generation of power, cooling and hot water using liquefied natural gas regasification

Today, due to the increasing trend of energy demand in the world, the use of energy types with the approach of maximizing the efficiency of energy systems is inevitable. In this paper, an integrated power generation system consisting of low-temperature organic Rankine cycle, gas and steam combined power plant and Kalina power generation unit is developed and analyzed. Liquefied natural gas regasification is employed to supply the cooling for the hybrid system. This integrated system generates 158.5 MW power, 9.498 MW cooling, and 46.02 kg/s hot water. The total electrical, thermal, and exergy efficiencies of the integrated system are 48.62%, 55.18% and 67.74%, respectively. System exergy analysis shows that reactors and heat exchangers accounted for the largest share of total exergy destruction, each accounting for 59.91% and 15.76% of total energy destruction, respectively, indicating that these two parts have more than 75% of the destruction occurred. The pinch method was used to extract the heat exchanger network related to the multi-stream heat exchanger of the integrated system. In the parametric analysis, the effect of air/fuel molar ratio (input to the combustion chamber) on system performance has been investigated. One of the most important results is the increase in the total thermal efficiency of the system to 56.15% if the inlet air into the combustion chamber is reduced to 250.0 kg/s. The parametric analysis results also show that in addition to increasing the efficiency of the system due to the decrease in the amount of incoming air, the ratio of power production as the main product to byproducts (hot water and cooling) increases.

Design and development of a comprehensive program for the assessment and analysis of environmental effects due to the release of radioactive materials from the stack of nuclear installations: A case study in Bushehr nuclear power plant

The current investigation presents a comprehensive program called KIANA to assess and analyze the environmental effects due to the release of radioactive materials from the stack of nuclear installations. Bushehr Nuclear Power Plant Unit One (BNPP-1) is modeled using the KIANA software and the release of radioactive materials from the BNPP-1 stack on the members of the public through the airborne pathway is evaluated during normal operation as well as in the accident conditions including Design Basis Accidents (DBA) and Beyond Design Basis Accidents (BDBA). To verify and validate the KIANA software, the results of the KIANA are compared with the results of DOZA_M, ESTE, PC-CREAM 98, RECASS Express, and the values of the total effective dose monitored by the local detectors of BNPP-1. The KIANA is developed based on the Gaussian diffusion model written using C# programming language. In the current research, the total effective dose received by a member of the public due to the radioactive plume passage through the airborne pathway is calculated in the normal condition of BNPP-1. Moreover, the total effective dose in the case of the primary-to-secondary leakage inside the steam generators, the total effective dose in the case of Large Break Loss of Coolant Accident (LBLOCA) and Small Break Loss of Coolant Accident (SBLOCA), and the equivalent dose of the thyroid gland tissue for an infant group (1–8 years old) in the case of LBLOCA in DBA conditions are evaluated. Finally, the absorbed dose of the whole body of adults at the initial stage after a BDBA, absorbed dose of the thyroid gland tissue for an infant group (1–8 years old) at the initial stage after a BDBA, and the total effective dose in the first year after the accident in the case of a BDBA are assessed. The results of the KIANA software indicate a good agreement with the results of the DOZA_M, ESTE, PC-CREAM 98, RECASS Express computer programs, and the values of the total effective dose monitored by the local detectors of BNPP-1. The developed software has the potential of calculations of concentration and radionuclide dose received through all the exposure pathways such as airborne, foodstuff, marine, soil, animals, and vegetation without any restriction in normal and accident conditions, simultaneously.

Optimal operating strategy of high-temperature heat and power storage system coupled with a wind farm in energy market

Due to the fluctuating nature of solar and wind power plants, they are mostly accompanied by energy storage units to be able to offer dispatchable energy output. One of the main challenges of energy storage units in renewable power plants, however, is determining an efficient and optimal energy trading strategy as the majority of the electricity should be traded in the day-ahead market. As a result, the plants are imposed on huge penalties due to less- or over-supply compared to that bided on the day before. This work presents a novel model to optimize the bidding strategy of a wind farm coupled with a high-temperature heat and power energy storage system (based on different designs) in the energy market. This novel storage technology is highly efficient and offers cogeneration of heat and electricity. The proposed problem determines the best bidding value to maximize the total profit of energy sales from a monthly perspective. The case study includes a real wind farm and Danish energy market. The results reveal the importance of having a precise model of marketing for such plants and the effect of small deviation from the optimal marketing strategy on the net annual revenue of the power plant.

ANALISIS KEBUTUHAN UDARA PEMBAKARAN UNTUK MENGOPTIMALKAN PROSES PEMBAKARAN BOILER PT. PLN (PERSERO) SEKTOR PEMBANGKITAN ASAM ASAM UNIT 3 & UNIT 4

The performance of a power plant unit is strongly influenced by various aspects, one of which is very determined by how the combustion process occurs in the combustion chamber, because it can affect the efficiency of the power plant itself, especially in the efficiency aspects of the boiler combustion process. To find out the efficient operation of the boiler, the operator as the holder of the power plant must understand what the combustion process is like in it. Good combustion will always require the right combination of fuel and air (oxygen). From the results of the research that has been done, it can be seen that if the actual amount of air flow needed for the combustion process is closer to the ideal air flow value it will indirectly increase the combustion efficiency value of the boiler.