System Of Thermal Power Plant Research Articles

Markov-based performance evaluation and availability optimization of the boiler–furnace system in coal-fired thermal power plant using PSO

The appropriate maintenance strategy is essential for maintaining the thermal power plant highly reliable. The thermal power plant is a complex system that consists of various subsystems connected either in series or parallel configuration. The boiler–furnace (BF) system is one of the most critical subsystems of the thermal power plant. This paper presents availability based simulation modeling of the boiler–furnace system of thermal power plant with capacity (500MW). The Markov based simulation model of the system is developed for performance analysis. The differential equations are derived from a transition diagram representing various states with full working capacity, reduced capacity, and failed state. The normalizing condition is used for solving the differential equations. Furthermore, the performance of the system is analyzed for a possible combination of failure rate and repair rate, which revealed that failure of the boiler drum affects the system availability at most, and the failure of reheater affects the availability at least. Based on the criticality ranking, the maintenance priority has been provided for the system.The availability of the boiler–furnace system is optimized using particle swarm optimization method by varying the number of particles. The study results revealed that the maximum system availability level of 99.9845% is obtained. In addition, the optimized failure rate and repair rate parameters of the subsystem are used for suggesting an appropriate maintenance strategy for the boiler–furnace​ system of the plant. The finding of the study assisted the decision-makers in planning the maintenance activity as per the criticality level of subsystems for allocating the resources.

Cooling performance evaluation for double-layer configuration of air-cooled heat exchanger

For large-scale natural draft dry cooling system in thermal power plants, the double-layer air-cooled heat exchanger is recommended thanks to its lower water flow resistance, while the cooling performance is rarely reported so far. Based on the typical natural draft dry cooling system with double-layer air-cooled heat exchanger, the numerical modeling and solution apporaches are developed, by which the representative variable fields and overall cooling performance are obtained and compared with the conventional system. The results show that at the wind speeds of 4 m/s and 8 m/s, the frontal and middle sectors of lower layer show better heat transfer performances than upper layer, especially for the middle sector. At high wind speeds, the frontal sector of upper layer presents a better performance than that of lower layer, but the cooling performances of the middle sectors for both layers get worse with the lower layer showing a slight recovery. The rear sector of lower layer has a much superior cooling performance to upper layer. With increased wind speed, the cooling performance difference of both layers varies little for the middle front sector. As for the middle and middle rear sectors, the performance gap between two layers increases greatly from 4 m/s to 8 m/s, but changes little at high wind speeds. For the rear sector, the difference between both layers stands always prominent at all wind speeds. Compared with the conventional system, the cooling performance gets improved in the absence of winds and at the wind speeds of 4 m/s and 8 m/s, but deteriorated a little at high wind speeds, so this innovative system could be recommended for power plants in arid places with weak wind all year round.

Cooling performance of natural draft hybrid system with parallel air path

The flexibility of the dry cooling system in thermal power plant needs to be improved to suit the load undulation caused by the increased renewable energy power. For overcoming the weakness of conventional cooling system, a natural draft hybrid (dry/wet) cooling system (NDHCS) is proposed to fully take advantage of dry and wet cooling technologies, which comprises the wet and dry cooling sections with parallel air flow path. The three-dimensional numerical models are developed to investigate the thermal-flow performances of the NDHCS under various environment and operation conditions, by which the flow fields near the NDHCS as well as the heat and mass transfer between circulating water and cooling air are obtained. The results show that both the dry and wet cooling sections dominate the cooling capacity of the hybrid system but the performance of the former is inferior to the latter in most of the cases. Low ambient humidity, large spraying water flow ratio in the wet cooling section and small wind speed are of benefit to the thermal performance of hybrid cooling system. For the dry and wet cooling sections themselves, the cooling performance can be improved thanks to the ambient wind under specific conditions. Besides, NDHCS can effectively avoid visible plume especially under windy conditions.

Energy efficient strategies for anti-freezing of air-cooled heat exchanger

In cold winter, the air-cooled heat exchanger of natural draft dry cooling system in thermal power plants is easy to freeze, so the turbine back pressure is generally lifted to avoid freezing at the cost of reduced energy efficiency of power generating unit in practical engineering. In this paper, the energy-efficient strategies for the anti-freezing of air-cooled heat exchanger are proposed with matching the water and air side heat capabilities. By applying the macro heat exchanger model to air-cooled heat exchanger, the thermo-flow behaviors of circulating water, cooling air and exhaust steam in a representative 600 MW power generating unit are synchronously modeled and resolved. The results show that, at a low temperature, the air cooing capability should be fully utilized firstly by adjusting the water flow rate alone. But the air-side cooling capacity becomes conspicuously large as the ambient temperature decreases further, and the louvers of cooling deltas should be turned down in priority so as to match the maximum water-side heat load. Moreover, from −5 °C to −10 °C of ambient temperature, the anti-freezing turbine back pressure drops at all wind speeds, while it keeps at the chocking back pressure if the ambient temperature further decreases, so that the optimal energy efficiency of cold end system can be achieved.

Uncertainty Research of Particles Concentration Measurement in Continuous Emission Monitoring System of Thermal Power Plants

In order to monitor the reliability of the CEMS operation data of a thermal power plant in Hangzhou, the data of its operation process were collected. The components of uncertainty influencing on the particles concentration measurement, including zero drift, range drift, relative accuracy and measuring repeatability, were analyzed in the system. The confidence interval (2.80%) and the allowable interval (8.94%) were introduced to ensure the reliability of the system data. The result of evalution shows that the related expanded uncertainty of particles concentration measurement is 9.26% when coverage factor is k=2 and level of confidence is 95%. Measuring repeatability is the main factor affecting the uncertainty.

Research on Faults and Maintenance Methods of Steam Turbine in Thermal Power Plant

The steam turbine is one of the most critical equipment in the power generation system of thermal power plants, its daily operation condition and maintenance work will directly affect whether the power generation system can operate safely and stably. Therefore, it is necessary to strengthen the management of the steam turbine, ensure the continuous and full operation of the steam turbine unit, and ensure the power transmission of the power grid. However, some faults unavoidably appear in the steam turbine in the long-term operation, if these faults are not handled in time and effectively, the influence scope of the fault will be expanded, which causes the turbine to fail to operate normally and affect the normal work of thermal power plants. This paper analyses the common faults of steam turbine in thermal power plants, and further studies the maintenance methods for common faults of steam turbine in thermal power plants.

Reliability Analysis of External Optimized Control System for Thermal Power Unit

With the construction of intelligent power plants and the development of clean energy, the application of external optimized control system of thermal power plant will be more and more common, and its reliability will be more and more important. The mainstream external optimized control systems were investigated, and the reliability of three typical systems were analyzed which including an import system, a redevelop system and a domestic system. Based on the analysis, some technical measures were put forward to improve the reliability of external optimized control system for thermal power unit, which including hardware configuration, communication mode, the way in which signals work, software design, check and test. It has meaningful reference for the selection and optimization of external optimized control system.

Development of a new multi-layer perceptron based soft sensor for SO2 emissions in power plant

In the paper, a multi-layer perceptron (MLP) based soft sensor for SO2 emission in desulfurization process of thermal power plants is proposed. Firstly, the production process and variables involved in the desulfurization system of thermal power plants are analyzed. Secondly, the MLP network and its input variable selection algorithm with nonnegative garrote (NNG) and extremal optimization (EO) are studied. The proposed algorithm employs MLP to model the complex desulfurization process, and then conducts shrinkage on input weights of MLP by NNG. After that, further local variable selection is performed by EO and the final model is presented. Thirdly, the simulation on actual production data of a power plant and comparisons with other state-of-art soft sensors are made to demonstrate the performance of the proposed algorithm. The simulation results show that the proposed algorithm can accurately predict the target variable and has superior performance to other algorithms. Moreover, the variable importance analysis with our approaches are consistent with the field operating experience and can provide reference for the further optimization of the control system of desulfurization process.

Experimental investigation of conveyor idlers operational characteristics

The efficiency of thermal power plants significantly depends on the efficiency of belt conveyor systems. Conveyor idlers, as key parts of belt conveyors, are often the main cause of bulk material transportation systems failures. Testing the operational characteristics of conveyor idlers in laboratory and exploitation conditions is a prerequisite for any progress in the field of increasing energy efficiency of conveyor systems. This paper describes an analysis and discussion of testing results for different types of conveyor idlers, in terms of their performances under the act of predefined radial load. Tests were conducted on a new conveyor idler’s testing machine developed at the University of Belgrade - Faculty of Mechanical Engineering. The presented tests are performed in order to determine the quality of carrying and return conveyor idlers. The obtained results will help in solving the key problems in the critical areas of conveyor systems and will increase their energy efficiency. Finally, the expected results can potentially reduce the financial and energy losses which conveyor idlers cause in belt conveyor systems, as well as in the whole system of thermal power plants.

While all Eyes Are Set on Delhi, Kolkata Sitting on Ticking Time Bomb of Air Pollution

The metropolitan city of Kolkata today is facing challenges of air pollution like never before. With high population density and relatively lower green cover the city is at the verge of being a gas chamber with its AQI ranging between very poor to poor in winter months. Though the problem of air pollution is multifactorial in the city, major source is automobiles. Despite laws vehicles older than 15 years and diesel run vehicles ply uninhibitedly in the city. Also, the energy generation through conventional thermal power plant systems, use of bio fuels by the residents, rapid urbanisation leading to continuous construction activities and constant decrease in number of trees have made the situation further worse. The measures taken by government are slow in pace and insufficient. Though the capital city of India is facing all burnt at the centre stage of pollution, air pollution in Kolkata is less talked about and a relatively neglected issue. Another worrisome fact is that the city has high level of PM 2.5 which can easily enter the blood through lungs. The resulting health issues from such high levels of pollution are rampant and worrisome. Not only that the city has been nicknamed as lung cancer capital of India because of rising number of cancer patients for which air pollution is a major contributor. If timely swift actions are not taken; it will be too late to control the genocide in making.

EXERGY ANALYSIS ON THERMAL POWER PLANT PT. MAKASSAR TENE USING CYCLE-TEMPO 5

Analyzing exergy on the power plant generating system specially at PLTU, efficient utilization of energy resources can be obtained particularly since it leads efforts to reduce energy waste that already exists.The purposes of this research are to get the Thermal Power Plant system modeling of PT. Makassar Tene, to get the value of modeled exergy power plant system, to get exergy losses, to get the amount exergy efficiency and to get the cost of exergy losses.The research method was firstly, designing the Power Plant generating systems PT. Makassar Tene using Cycle-Tempo 5 as thermodynamic analysis tool. Results of calculations were then used to calculate the exergy profile.Exergy values analyzed on a system modeled Power Plant consists of turbine components, condensers and pump. Boilers are not included in the analysis because of the input device is not contained and the mass flow rate of the boiler occurs steady state in which the state of the same process with the state of the environment so that there is no exergy difference that can be utilized.The highest exergy losses based on the modelling was on the turbine components that was 10201.50 kW. This was due to the change in the vapor phase into the liquid phase contained in the component before and after leaving the turbine components. While the lowest exergy losses was on the pump component, that was 437.18 kW.The higher the efficiency value of a component, the better its performance is. The highest efficiency value of exergy that was 51.43% contained on the turbine components. While the lowest efficiency value of exergy was 0%.

THE POSSIBILITIES OF MEETING ENERGY DEMANDS IN SYSTEM THERMAL POWER PLANTS BY USING LOCAL SOLID BIOMASS

What is of crucial importance in local conditions as concerns the heat power industry is the use of local biomass, especially waste biomass, as an energy raw material in the existing system of thermal power plants. The purpose of the present study is to assess the possibility of replacing hard coal as an energy raw material with solid biomass. Solid biomass is constituted by: surpluses of cereal straw and rape straw, as well as hay from unused meadows, from the upkeep of roadside trees and from energy crop plantations. The research was conducted on the example of thermal power plants associated in the “Together Warmer” Cluster. This cluster is formed by 10 thermal power plants in small towns in the Warmińsko-Mazurskie Province and the city of Biała Podlaska (Lubelskie Province). All of these are located in north-east Poland. Considering the high transport costs of biomass, a biomass technical potential was accepted within a radius of 30 km from the thermal power plant. The solid biomass potential for each of the ten thermal power plants demonstrates that most of the thermal power plants from the Cluster under examination are able to meet their energy needs with solid biomass from the nearest neighbourhood (replace hard coal). However, when taking a decision on replacing hard coal with local biomass, it is necessary to adequately handle logistics and replace boilers in thermal power plants with special boilers for the combustion of solid biomass.

A DBN based reactive maintenance model for a complex system in thermal power plants

Thermal power plants consist of several complex systems having many interacting hidden components. Any unexpected failure may lead to prolonged downtime and serious lost profits. Therefore, implementing an effective maintenance policy is crucial for this sector. Although preventive maintenance has become a more popular strategy, it does not completely prevent the need for corrective maintenance. Our aim in this study is to tackle the corrective maintenance implementation problem of a multi-component partially observable dynamic system based on a regenerative air heater in a thermal power plant. We propose eight methods having different efficiency measures with respect to time, effect and probability criteria to minimize the total number of maintenance activities in a given planning horizon. Performances of these methods are evaluated under corrective maintenance strategy using dynamic Bayesian networks. The results show that fault effect methods with best working state probability measure perform better than the others considering both the total amount of maintenance activities and also the solution time. We also point out how the methods can be implemented in real-life and how the results can be used for requirements planning. Furthermore, the proposed methods can be used for the corrective maintenance of all systems having hidden interacting components.

Improving the Operational Reliability Model of the “Nikola Tesla-Block A” Thermal Power Plant System by Applying an Integrated Maintenance Model

Improving the Operational Reliability Model of the “Nikola Tesla-Block A” Thermal Power Plant System by Applying an Integrated Maintenance Model

Research on Improved Auto-Tuning of a PID Controller Based on Phase Angle Margin

In order to realize fast and efficient tuning of the proportional-integral-derivative (PID) controller parameters in thermal power plants, this paper thoroughly analyzes the problems existing in the relay characteristic method based on the phase angle margin auto-tuning method (PM method), and proposes an improved PM auto-tuning method for the most common first order plus dead time (FOPDT) model in practical engineering applications. The improved algorithm proposes the design of the target phase angle margin and the method of plant identification. Then, the optimization algorithm is used to calculate the correction coefficient of the setting formula to obtain the PID controller parameters that minimize the integrated time absolute error (ITAE) index of the control system. Finally, through the auto-tuning experiment on the generalized control model of the main steam temperature system in thermal power plants, it is verified that the improved algorithm is superior to the traditional PM method and Ziegler–Nichols method (Z-N method), and can obtain a fast and stable control performance.

Performance of Large-Scale Grounding Systems in Thermal Power Plants Against Lightning Strikes to Nearby Transmission Towers

In spite of the contemporary interest in renewable power plants, thermal power plants are still inevitable. Various electric equipment and apparatus are grounded via a large-scale grounding system in thermal power plants. In this paper, the three-dimensional finite-difference time-domain method has been employed to study the performance of such a large-scale grounding system against a lightning strike to a nearby transmission tower. The study has emphasized how a nearby sea, which is utilized for cooling purposes in thermal power plants, influences the ground potential rise on the large-scale grounding system considering soil ionization. The results show that the distribution of the ground potential rise on the large-scale grounding system is quite dependent on the alignment of sea with the large-scale grounding system. In addition, the extent that soil ionization affects the ground potential rise is dependent on the distance between the struck tower and the large-scale grounding system.

Study on the scale and corrosion inhibitor of urban reclaimed water reused in circulating cooling water of power plant

A new type of composite scale and corrosion inhibitor was developed for the thermal power plant circulating cooling water system using urban reclaimed water as supplementary water. Based on the main process parameters of the circulating cooling water system in thermal power plant, a dynamic simulation system is established under laboratory conditions.The new composite scale and corrosion inhibitor and the traditional phosphorus scale and corrosion inhibitor are tested.The results show that the new composite scale and corrosion inhibitor is superior to the traditional phosphorus scale and corrosion inhibitor in scale inhibition and corrosion inhibition.

Development and Research of Equipment Information Management System of Thermal Power Plant

By using the information of equipment management department of thermal power plant, we analyze the functional requirements detailedly.In function analysis, the system fun ction is divided into several modules which include equipment management, operation mana gement, inspection/giving grease management, two ticket management, plan management,secu rity management, technology management, staff management, material management and OA system.It is based on C/S architecture for system development and construction and it uses Mysql database development. PC client and server development adopted efficient C# progr amming language, and mobile phone client adopted Android language.

Methodical approach to assessing the effectiveness of the management system of thermal power plants in Russia

Physical deterioration of thermal power plants based on hydrocarbon fuels leads to technological violations (TV) in their work. Low rates of renewal of thermal generation predetermines the further exploitation of old capacities. In this regard, the activity of the management of energy holdings (EH) is more focused on maintaining the equipment in working condition. The methods, approaches and tools underlying decision-making by the management of energy holding companies are different, respectively, the results of the functioning of the organized management systems (MS) of each company are also different. To assess the effectiveness of the management system it is proposed to use such a generalized indicator as the number of technological violations per year per 1 GW of installed capacity.

MOGUĆNOST KORIŠĆENJA SOLARNE ENERGIJE ZA NAPAJANJE SISTEMA ZA ODLAGANJE PEPELA I ŠLJAKE U TE KOSTOLAC

U ovom radu prikazano je idejno rešenje fotonaponske (FN) elektrane na deponiji pepela i šljake “Ćirikovac” termoelektrane Kostolac B, kao alter­nativa konvencionalnom sistemu za odlaganje pepela i šljake, koji se napaja iz sopstvene potrošnje termoelek­trane. Opisan je način funkcionisanja ovog sistema, kao i njegova ukupna potrošnja. U sklopu idejnog rešenja obrađeni su svi ključni elementi FN elektrane. Obrađena je godišnja proizvodnja električne energije čitavog sis­tema i upoređeno sa zadatom potrošnjom. Na kraju je urađena je procena isplativosti gradnje FN elektrane.