Operation Of Thermal Power Plants Research Articles

Research on Financial Business Integration and Financial Management Function Transformation Based on Thermal Power Plants

The traditional financial management mode is challenging in the operation and management of modern thermal power plants facing the acceleration of informational process. It is necessary to seize the footsteps of informational to accelerate the integration of financial business and realize the transformation of financial management intelligence. Infiltrating information technology into financial management, the financial management work is no longer out of touch, enabling various businesses to achieve centralized and integrated management on the information management platform. The paper revolves around the investigation of thermal power generation thermal power plants, and summarizes the integration of financial information business and the transformation of financial management functions. It is expected to provide new ideas for reshaping the work structure and functional transformation of the financial management work of thermal power plants.

Rough sets-based prediction model for increasing safety of thermal power plants

ABSTRACTThis paper presents a model based on the rough sets theory for the prediction of a feed pump failure on a steam block of thermal power plant. There are many parameters that can cause pump failure, and this model enables extraction of the most significant ones. Model creation is based on the empirical data collected during the operation of thermal power plant, which is a part of the largest system for electricity production in Serbia. The model provided an insight into the parameters that have the greatest influence on the operation of the feed pump, and can be applied to other elements of the thermal power plant and affect the overall increase in the safety of thermal power plant operation. The goal of implementation of a new model is to increase system reliability by reducing the number of failures, thus increasing operational safety of thermal power plants. This is in accordance with the provision of energy security by applying measures of Directive 2005/89/EU. According to the directive, it is necessary to ensure: a reliable, safe, efficient and quality power supply.

Hydro storage reduces electricity costs and keep wind and solar unpolluted

New energy policy is caused by narrow range of operation of Thermal Power Plants, potential risks of Nuclear Power Plants, limited resources of oil, gas and coal, and new trends in ecology. Taking into account that renewable energy, solar and wind power particularly are very dependent on the climate, Hydro Power takes a new role in energy systems. Electricity conversion and storage in periods of lower consumption or available excess production, and electricity production from the stored energy in periods of higher demand or reduced production, are crucial for the maintenance of stable and efficient electrical system. This requirement has especially strengthened nowadays in the world due to the expansion of integration of new wind and solar plants. These renewable sources are characterized with inherent intermittent production both in daily periods and periods of several days, weeks or even months.A number of technologies might be considered for the electricity conversion and storage, but the only nature and high capacity available technology is based on the pumped-hydro storage plants. This article studies the potential of the pumped storage plants as the effective and economically competitive technology for the storage of wind, solar, run-of-river and other environmentally friendly energies, as well as energy from other conventional thermal plants including nuclear. Nuclear and coal fired plants can change power output to achieve demand but only at the price of extremely high maintenance cost. In addition, natural gas generators contribute to climate change and pollution only slightly less than coal. The pumped storage method is the most common storage system in the electricity sector. It is traditionally dependent on natural conditions, usually making use of rivers or lakes. However, some innovative methods have emerged in recent years, such as the use of the sea as the lower reservoir, or a proposal to use a surface reservoir as the upper reservoir and an underground reservoir as the lower. Analyses indicate that there is a strong economic incentive for further investment in pumped-storage installations when other hydro storages and sites are not available.

Dynamic Modeling and Simulation of a Hybrid Solar Thermal Power Plant

A solar thermal power plant presents an environmentally friendly process for producing power. However, due to diurnal and seasonal variations in the availability of solar radiation, as well as uncertainty caused by factors such as cloud cover, efficient operation of a solar thermal power plant is a challenging task. Availability of a dynamic model which represents the process behavior in face of these inevitable variations is a prerequisite for efficiently operating the plant. In this work, we develop a dynamic model for a hybrid solar thermal power plant operating in India. The plant uses two different technologies for solar power collection, namely, a Parabolic Trough Collector (PTC) for heating oil and a Linear Fresnel Reflector (LFR) for generating direct steam. Superheated steam, generated using heat exchangers, drives the turbine-generator block to generate electricity. The dynamic model is based on first-principles models of various components in the plant, such as PTC, LFR, heat exchangers, and storage tanks, and captures the integrated nature of plant. The model also incorporates heat losses to quantify night time cooling. A preliminary validation of the developed plant model is also presented using routine field data. The model is then used to simulate the dynamic operation of the plant for two case studies: (i) a two day simulation with field solar insolation profiles corresponding to summer days and (ii) a single day case study with cloud cover. The performances of the PTC and LFR fields as well as the overall plant were quantified and compared using various metrics. The case studies involved cold and warm startup scenarios and highlighted the impact of these initial conditions on the plant performance. The proposed dynamic model can be used for designing optimal operation and advanced control strategies.

Corrosion behaviour study of heat-resistant steel under oxidation and reduction atmosphere

High-temperature corrosion is one of the main problems that plague the safe operation of thermal power plants. Especially for units burning high-sulfur coal, the probability of high-temperature corrosion is much greater than that of units burning low-sulfur coal. In this paper, the 12Cr1MoV steel used in power plants is selected as the research object, the experiment studied the corrosion behavior of H2S, SO2 and air in the temperature range of 400-500°C. We found that 12Cr1MoV has the highest corrosion rate in the H2S atmosphere, the second in the air, and the slowest in the SO2 atmosphere.

Integrated Energy Supply Schemes on Basis of Cogeneration Plants and Wind Power Plants

Abstract The paper presents innovative technological concepts of integrated energy supply schemes based on joint operation of thermal and wind power plants. The main advantage of these systems lies in the improving the efficiency, reliability and environmental friendliness of energy supply (electricity and heat). This is a result of fuel saving and reduction in CO2 emissions from thermal power plants, which becomes possible when part of fuel is replaced with electric power generated by wind turbines. The technological advantages of the proposed schemes are considered. These advantages expand the range of applications for the technologies both in small-scale and large-scale energy systems. A patent protects the proposed technologies.

Management of complex human-machine systems with an extended intellectual component during the operation of thermal power plants under conditions of non-linear dynamics of the effects of unaccounted factors leading to emergency disturbances

Management of complex human-machine systems with an extended intellectual component during the operation of thermal power plants under conditions of non-linear dynamics of the effects of unaccounted factors leading to emergency disturbances

Managing the risk of emergency situations caused by staff at thermal power plants

Optimization of power plant operation in start and stop modes is an important task aimed at increasing the reliability and efficiency of its operation. The purpose of development of the new organizational mechanism is reduction of losses connected with incorrect actions of personnel during launching and shutdown operations of Steam-Gas furnaces of thermal power stations. The work is done on the example of one of the power plants of a large generating company. Implementation has confirmed the high efficiency of innovation. Total cost of project implementation at one station is estimated at the rate of 1.4 million rubles and the economic effect of the pilot project implementation in two years was estimated at 5.6 million rubles. It is also noted that further research is required to perform economic calculations for clarification as to which one of the new methodological approaches should be developed in the future. Conclusion was made that, first, regulation and control of personnel actions at the workplace is actually the first example of the distribution of the well-known Kaizen system and its modifications to a new specific area – energy generation. Second, the presented development can be a technological platform for further increase of the level of automation of operation of steam-gas and steam-power plants in non-stationary modes, up to full digitalization of control operation of thermal power plants.

Efficiency of using heat pumps with various refrigerants in real steam turbine power units with PT-80 and T-250 turbines

Prospects for increasing the efficiency of heat and electric energy-generation and heat-and-power supply at thermal power plants obviously draw attention to such modern and innovative technologies as heat pumps. Heat pumps allow efficient redistribution of energy flows. The abundance of low-potential heat carriers and heat sources in the cycle arrangement of the thermal power plants operation requires modernization of production and increase of the fuel heat utilization factor, therefore, reduction of specific fuel consumption for the production of heat and electricity. This paper analyzes the influence and practicability of introducing heat pumps into the heating circuit of the return water of the heat network of power units with PT-80 and T-250 turbines. Heat pumps of various configurations provide invariant energy conversion factor and efficiency. To assess energy and economic efficiency, modeling of the operation of power units and calculation of heat pump circuits for various refrigerants are performed. The economic effect is represented in quarterly cash savings of operating costs.

Thermodynamic and economic analysis of performance evaluation of all the thermal power plants: A review

AbstractSurging in energy demand makes it necessary to improve performance of plant equipment and optimize operation of thermal power plants. Inasmuch as thermal power plants depend on fossil fuels, their optimization can be challenging due to the environmental issues which must be considered. Nowadays, the vast majority of power plants are designed based on energetic performance obtained from first law of thermodynamic. In some cases, energy balance of a system is not appropriate tool to diagnose malfunctions of the system. Exergy analysis is a powerful method for determining the losses existing in a system. Since exergy analysis can evaluate quality of the energy, it enables designers to make intricate thermodynamic systems operates more efficiently. These days, power plant optimization based on economic criteria is a critical problem because of their complex structure. In this study, a comprehensive analysis including energy, exergy, economic (3‐E) analyses, and their applications related to various thermal power plants are reviewed and scrutinized.

Study on Condition Monitoring and Evaluation of Auxiliary Engine of Steam Turbine Based on Matter-element Theory

As an important equipment in thermal production process of thermal power unit, auxiliary equipment of steam turbine, such as feed-water pump, whether it can operate safely and economically is very important for normal operation of thermal power plant. Considering that the auxiliary machine on the side of the steam turbine of a power plant has the characteristics of high failure rate, a state monitoring and evaluation method based on the matter-element theory is proposed. Based on the establishment of the monitoring index and evaluation model of the auxiliary engine on the side of the steam turbine, the correlation degree between the main operating parameters of the auxiliary engine and the monitoring model is determined. According to the value of correlation degree, the operating condition of auxiliary machine is judged to be excellent, good, qualified or malfunction. Finally, a 300MW steam feed pump is taken as an example to prove that this method has certain engineering application value.

Treatment of the Equations of Metal Oxidation Rates at Nuclear Power Plants and Thermal Power Plants in Terms of Thermodynamics

The results of the thermodynamic analysis of experimental data and the kinetics equations of hightemperature steam oxidation of iron-based alloys (in the process of a thermal power plant operation) and of zirconium and iron alloys applied in manufacturing of fuel element cladding (at loss-of-coolant accident (LOCA)) are presented. The method of sorting data on the Arrhenius equation parameters and criteria of their reliability are proposed. The dependence of the Arrhenius equation parameter variance depends on the alloy composition and concentration of oxidants (oxygen, steam). The results of isothermal tests in one medium allow relating the activation energy of alloy oxidation to their chemical composition in order to study the process of their oxidation. The algorithm for calculation of oxidation rates and the thermodynamic model of alloy steam oxidation dependence on their composition are developed. The simulation engages the exponential dependence of the molecule collision frequency factor on the entropy of reaction activation in the Arrhenius equation for reactions proceeding on the surfaces of different alloys according to a uniform mechanism and the notion of pseudobinarity of alloys when all dopes in the alloy behave as a single second alloy component, each with its own stoichiometrical coefficient. The verification of the model is accomplished using the plausible experimental data, and the kinetics of steam oxidation is determined (the temperature interval is 1073–1473 K) for zirconium alloys E110opt, E635 on the sponge base, and comparison with the kinetics of M5 alloy oxidation is carried out. For iron–chrome alloys with different contents of the latter, the results of calculations by the proposed model are compared to the data of the experiment on oxidation of alternative cladding alloys. The established laws can be used as a basis to develop the calculation code module for changing the physical state of iron–zirconium alloy fuel element cladding during the failure. The changes can be caused by such phenomena as oxidation, creep strain, and rupture of cladding.

Experience of operating a solar parabolic trough direct steam generation power plant with superheating

TSE1 is the first solar thermal power plant operating in Southeast Asia. It was planned by Solarlite GmbH with support of Tiede- & Niemann GmbH, both German based. It is the first power plant with direct steam generation (DSG) concept and superheating in parabolic troughs. The solar field has a nominal power of 19 MWth driving a 5 MWel turbine by superheated steam at 30 bar and 330 °C. During 2010/2011 Solarlite built the solar field, while the later owner and operator Thai Solar Energy (TSE) from Bangkok built the power block, in Kanchanaburi, Thailand. TSE1 is being operated by TSE since January 2012 (Krüger et al., 2012).This publication is based on a study within the KanDis project, funded by the German Federal Ministry for Economic Affairs and Energy, in which an extensive database of records of almost 500 sensors installed in the power plant (solar field and power block) has been investigated. The data have been provided by Solarlite with a time resolution of about 1 min.Within the KanDis project, a stable operation could be demonstrated (Khenissi et al., 2015; Krüger et al., 2016). Even under the fluctuating irradiance conditions in the rainy season of Thailand, the turbine could be operated well and generate electricity. Evaluation of the operation data has helped to learn more about DSG behaviour. The TSE1 layout and the implemented control strategies were evaluated and strategies for improvement of TSE1 are suggested within this paper. From the experiences with the TSE1 power plant, conclusions could be drawn to improve the layout and control of future DSG plants.

Integrated Computational Materials Engineering in Solar Plants: The Virtual Materials Design Project

The high temperatures required for efficient operation of solar thermal power plants constitutes one of the major challenges of this technology. Gaining insight into materials behavior at very high temperatures is critical to improve their techno-economic feasibility. Standard material characterization approaches become inefficient, as extensive testing campaigns are required. We propose a multiscale–multiphysical approach that accounts for materials composition to (1) predict the behavior of both Inconel 625 and new solar salts, and (2) assess the thermomechanical performance of key components. We carried out a complete thermoelastic multiscale analysis that spans six time and length scales in a single simulation platform, combining discrete and continuum tools (from quantum to continuum mechanics). These applications show the substantial economic benefits that may be achieved by an ICME approach in the energy sector, reducing the cost of prototypes while decreasing development times and maintenance costs due to a better understanding of materials behavior.

The modeling of the formation of technogenic thermal pollution zones in large reservoirs

Thermal pollution of water bodies is an unavoidable consequence of thermal or nuclear power plant operation. To minimize the detrimental effects of these plants, one should assess the nature of dangerous zones. The most effective approach to solving these problems is the computational experiment. This paper presents the results of a numerical study of thermal pollution in one of the largest thermal power plants of Europe - Permskaya TPP, using the Kama Reservoir as a natural cooling system. Such problems are traditionally solved in 2D formulation using the “shallow water” approximation. However, with this approach it is impossible to take into account the vertical inhomogeneity of the temperature field. On the other hand, 3D models, which can take into account the effect of density stratification, require very large computational resources. In this work, a combined approach, based on a combination of computational models in the 1D, 2D and 3D formulations, is applied.

Experimental results of transient testing at the amine plant at Technology Centre Mongstad: Open-loop responses and performance of decentralized control structures for load changes

Flexible operation of combined cycle thermal power plants with chemical absorption post combustion CO2 capture is a key aspect for the development of the technology. Several studies have assessed the performance of decentralized control structures applied to the post combustion CO2 capture process via dynamic process simulation, however there is a lack of published data from demonstration or pilot plants. In this work, experiments on transient testing were conducted at the amine plant at Technology Centre Mongstad, for flue gas from a combined cycle combined heat and power plant (3.7–4.1 CO2 vol%). The experiments include six tests on open-loop responses and eight tests on transient performance of decentralized control structures for fast power plant load change scenarios.The transient response of key process variables to changes in flue gas volumetric flow rate, solvent flow rate and reboiler duty were analyzed. In general the process stabilizes within 1 h for 20% step changes in process inputs, being the absorber column absorption rates the slowest process variable to stabilize to changes in reboiler duty and solvent flow rate. Tests on fast load changes (10%/min) in flue gas flow rate representing realistic load changes in an upstream power plant showed that decentralized control structures could be employed in order to bring the process to desired off-design steady-state operating conditions within (<60 min). However, oscillations and instabilities in absorption and desorption rates driven by interactions of the capture rate and stripper temperature feedback control loops can occur when the rich solvent flow rate is changed significantly and fast as a control action to reject the flue gas volumetric flow rate disturbance and keeping liquid to gas ratio or capture rate constant.

Numerical Study of Discharged Heat Water Effect on Aquatic Environment From Coastal Thermal Power Plant by Using Two Water Discharged Pipes

The article presents a numerical study of the thermal load on the aquatic environment by using two water discharge pipes under various operational capacities of thermal power plant. It is solved by the Navier-Stokes and temperature transport equations for an incompressible fluid in a stratified medium. The aim of this article is to improve the existing water discharge system for reduce the heat load on the reservoir-cooler of the thermal power plants operation (Ekibastuz SDPP-1). In this article, thermal pollution using only two water discharge pipes, using the existing one and building only one additional in the eastern part of the reservoir-cooler is numerically simulated. The numerical method is based on the projection method, which was approximated by the finite volume method. The obtained numerical results of three-dimensional stratified turbulent flow for two water discharge pipes under various operational capacities of the thermal power plant were compared with experimental data and with the numerical results for one water discharge pipe.

A dynamic heat transfer model to estimate the flue gas temperature in the horizontal flue of the coal-fired utility boiler

The flue gas temperature is an important parameter for safe and economic operation of thermal power plants. However, in high temperature areas, it is difficult to measure the temperature directly because the sensors are subject to flying ash erosion. This paper establishes a dynamic heat transfer model for the furnace and the semi-radiative heat exchangers, and proposes an estimation approach of the flue gas temperature in the boiler’s horizontal flue. The boiler-side heat absorption models, which cover the heat exchangers, the metal wall and the heat losses are established to calculate the heat absorption rate of the working fluid in the boiler. By solving the optimization problems which are developed based on the dynamic heat transfer models, the flue gas temperature at the outlet of the furnace and the semi-radiative heat exchangers are obtained. Pseudo-online simulations are performed with the history data of an ultra-supercritical unit to verify the approach. The relative errors between the calculated and the designed flue gas temperature with both designed and calibrated feed coal are found less than 3.5%. Additionally, the proportion of the convective heat in the total heat absorption for each semi-radiative heat exchanger is obtainable with the same approach.

Peak shaving operational optimization of supercritical coal-fired power plants by revising control strategy for water-fuel ratio

Electricity generated from renewable energy source fluctuates heavily and can hardly be predicted. The peak shaving (or load cycling) operation of conventional thermal power plants is an effective means to mitigate the mismatch between electricity demands and supplies. Therefore, determining how thermal power plants can operate in a flexible and effective mode is an urgent issue that should be addressed. For thermal power plants, new methods and strategies need to be proposed to face the challenge of the integrating flexibility and energy saving into transient processes. Dynamic performances of thermal power plants during load cycling processes are affected by the coupling of the thermal system and the control system. Feasible approaches from optimizing the coordinated control system (CCS) may radically enhance the peak shaving capacity of thermal power plants. The heat storage in a coal-fired power plant, including heating surface metals and work media, varies with the load rate of the plant. During cycling load operations, the real-time heat storage value of one unit differs from that of the corresponding steady state load command rate. This difference hinders the flexibility of one unit and affects its economic performances during cycling processes. In this paper, a revised water fuel ratio (WFR) control strategy based on heat storage difference was proposed and tested on established coal-fired power plant models. Results show that the accumulation deviations of load rate command and real-time load rate are considerably reduced during load cycling processes when the proposed WFR control strategy is introduced. The revised WFR control strategy diminishes the difference between the target and the actual total power output. When the load cycling rate varies from 10 to 30 MW min−1 between 50% and 100% THA, the standard coal consumption variation rate (Δbs) decreases by 0.31–1.01 g kW−1 h−1 during loading up processes, and decreases by 0.26–1.69 g kW−1 h−1 during loading down processes.

Exergy efficiency analysis of lignite-fired steam generator

The operation of steam generators and thermal power plants is commonly evaluated on a basis of energy analysis. However, the real useful energy loss cannot be completely justified only by the First law of thermodynamics, since it does not differentiate between the quality and amount of energy. The present work aims to give a contribution towards identification of the sources and magnitude of thermodynamic inefficiencies in utility steam generators. The work deals with a parallel analysis of the energy and exergy balances of a coal-fired steam generator that belongs to a 315 MWe power generation unit. The steam generator is de-signed for operation on low grade coal - lignite with net calorific value 6280 to 9211 kJ/kg, in a cycle at 545?C/177.4 bar, with feed water temperature 251?C, combustion air preheated to 272?C and outlet flue gas temperature 160?C. Since the largest exergy dissipation in the thermal power plant cycle occurs in the steam generator, energy, and exergy balances of the furnace and heat exchanging surfaces are established in order to identify the main sources of inefficiency. On a basis of the analysis, optimization of the combustion and heat transfer processes can be achieved through a set of measures, including retrofitting option of lignite pre-drying with flue gas and air preheating with dryer exhaust gases.