Power Plant Unit Research Articles

Investigation of Radionuclide Migration at Sites Adjacent to the 30-km Exclusion Zone of the Chernobyl Nuclear Power Plant.

This paper reports the study of the vertical migration of radionuclides in soils at test sites adjacent to the 30-km Chernobyl Exclusion Zone. The results of this effort demonstrate that the migration processes for studied pollution occur similarly to the fuel fallout behavior at the vicinity of the Chernobyl Nuclear Power Plant (ChNPP) Unit 4. It was also observed that the main fallout component, 137Cs, originated from aerosol fallout and was bound in the surface layer. The authors determined a significant increase of 60Co, 94Nb, and 241Am radionuclide concentrations in soils near the ChNPP Unit 4 and suggested their appearance due to the installation of the New Safe Confinement. Niobium-94 activity is proposed as a marker for monitoring the "fresh" fallout in the Chernobyl Exclusion Zone.

Influence of Dry Sorbent Injection System on Emission Characteristics of Condensable Particulate Matter in Coal-fired Power Plant

To study the effect of dry sorbent injection (DSI) system on the emission characteristics of condensable particulate matter (CPM) in a 600MW unit of an ultra-low emission coal-fired power plant in China, the EPA Method 202A is used to sample the flue gas from its total exhaust. Through sample analysis, the CPM emission concentration and water-soluble ion composition corresponding to the two unit loads and whether the DSI is running are obtained. The results show that the use of DSI system reduces CPM emissions at 600MW and 300MW unit loads, and the CPM emission concentration is reduced by 32% and 9.7%, respectively. For the CPM reduction caused by DSI system under these two loads, SO4 2- and Cl− together contributed 65.7% and 87.3%, respectively. The DSI system achieves the removal of CPM mainly by removing the SO3 and HCl, which are gaseous precursors of SO4 2- and Cl− in CPM. At the same time, water-soluble ions are the main component of CPM. The analysis of its composition shows that the masses of NH4 +, Cl− and SO42- ions are relatively large, and they together account for 95.8%-96.8% of all water-soluble ions mass.

Numerical Study of the Erosion Process and Transport of Pulverized Coal–Air Mixture in the Mill-Duct System

One of the main causes of damage to the elements of coal-fired boilers installations, leading to breakdowns and, consequently, a shutdown of the block, are erosive processes. Unfortunately, there is not much research conducted on dust erosion of the dust ducts supplying the air–dust mixture to the burners. The problem of erosion of the dust ducts supplying the pulverized coal–air mixture to the burners was presented in this paper. This study was performed for the preliminary feasibility design. The destruction of the material of the dust ducts results in a failure due to erosion, resulting in the mill being shut down from an operation, which in turn may lead to the shutdown of the power plant unit. Therefore, it is important to identify places exposed to pulverized coal erosion. In order to perform calculations, numerical modeling in the commercial program Ansys.Fluent (Ansys Fluent, Computational Fluid Dynamics, Ansys Inc., Pittsburgh, PA, USA) was used. The parameters obtained as a result of laboratory tests were used in the erosion model. The places where erosion is expected are indicated. The highest erosive wear occurred for the M3 mill dust ducts for the case coal 1 and amounted to 45.6 mm/5200 h. On the other hand, the lowest erosive wear occurred for the M2 mill dust ducts powered by coal 3 and amounted to 20.9 mm/5200 h. The identification of places where erosion is expected can be used to protect these places from erosion adequately. Nevertheless, a dispersion threshold should also be placed where there is a high concentration of pulverized coal contributing to increased erosion. The numerical calculations provided information on the velocity of the medium and the behavior of the dust in the dust duct. The numerical calculations also provided information on where dust lacing has occurred. It was shown that coal dust particles with a diameter greater than 100 µm largely erode the dust duct’s wall. A model is presented for the calculation of the erosion process to be used in the dust ducts of the power plant.

Performance Analysis of a Waste-to-Energy System Integrated with the Steam–Water Cycle and Urea Hydrolysis Process of a Coal-Fired Power Unit

An innovative hybrid energy system consisting of a waste-to-energy unit and a coal-fired power unit is designed to enhance the energy recovery of waste and decrease the investment costs of waste-to-energy unit. In this integrated design, partial cold reheat steam of the coal-fired unit is heated by the waste-to-energy boiler’s superheater. The heat required for partial preheated air of waste-to-energy unit and its feedwater are supplied by the feedwater of CFPU. In addition, an additional evaporator is deployed in the waste-to-energy boiler, of which the outlet stream is utilized to provide the heat source for the urea hydrolysis unit of coal-fired power plant. The stand-alone and proposed designs are analyzed and compared through thermodynamic and economic methods. Results indicate that the net total energy efficiency increases from 41.84% to 42.12%, and the net total exergy efficiency rises from 41.19% to 41.46% after system integration. Moreover, the energy efficiency and exergy efficiency of waste-to-energy system are enhanced by 10.48% and 9.92%, respectively. The dynamic payback period of new waste-to-energy system is cut down from 11.39 years to 5.48 years, and an additional net present value of $14.42 million is got than before.

Study of Generator Set Overload Protection System in Power Generation Units

The need for electrical energy in an industry is very important for the production process to run. To meet the demand for electrical energy, one can use a power source from PLN or use an independent power source by establishing a power plant. The Power Plant Unit is a unit that functions to provide electrical energy needs for the production process at PPSDM Migas. Electricity generation in the Power Plant Unit, namely Pembangkit Listrik Tenaga Diesel (PLTD) using a generator set that uses diesel fuel. A generator set or generator is a generator that has been equipped with a prime mover. Gensets that work continuously are certainly inseparable from disturbances such as the occurrence of overloads. Overload disturbance occurs because the amount of load power supplied by the generator is greater than the capacity of the working generator. Air Circuit Breaker (ACB) is one of the protective equipment used to protect generator sets. Inside the ACB there is Over Current Trip equipment that will work if there is an overload on the generator. The capacity of the generator used is 1000kVA/400V with a nominal generator current of 1443.38 A. Under normal load conditions, the installed load power is 354.5 kW with a load current of 639.6 A. Then at peak load conditions, the installed load power is 510,3 kW with a load current of 920.7 A. In both conditions, the load current does not exceed the nominal current of the generator so Over Current Trip does not instruct ACB to trip. However, it is possible for overload disturbances to occur if there is no coordination between the operator at the power plant and the load operator (refinery & utilities) so that the operation of the load is not controlled.

INTERVAL MODELS OF TEMPERATURE CHARACTERISTICS OF SUPERHEATER SEPARATORS IN NUCLEAR POWER PLANT UNITS WITH THE CAPACITY OF 1000 MW

The analysis of the influence of changes in the parameters of steam superheater separators SHS-1000 of nuclear power plant units with the capacity of 1000 MW on the efficiency and safety of their operation, including the temperature characteristics at the nominal and partial operating modes of power units, has been carried out. Based on the experimental data of the thermal tests of the power unit, the temperature characteristic of the second stage of the SHS-1000 has been constructed in the form of the dependence of the temperature change of the heated steam at the second stage of the SHS on the change in the operating mode of the power unit. To create a correct mathematical model of this dependence, taking into account the limited amount of experimental data and the uncertainty of information about the structure and the probabilistic nature of measurement error during testing, the use of numerical methods of interval analysis has been proposed. Interval analysis has allowed to obtain an interval model that describes the receiver, which contains all possible values of the dependence of temperature change of the heated steam at the second stage of SHS on the unit operating mode (the electrical load). It has been shown that in conditions of limited initial data and uncertainty of information about it, numerical methods of interval analysis allow to create interval models of operational (energy) characteristics technological processes and equipment of NPP units with the maximum possible correspondence to real processes and objects, which is important to ensure high efficiency and safe operation of power units.

Вплив накопичуваної пошкоджуваності на експлуатаційний ресурс барабана котлоагрегата теплоелектростанції

Goal of the work is to develop a methodology for researching the possibility of further exploitation of drums of boiler units of thermal power plants after exhausting their park resource. Significance. During long-term operation of the drums of boiler units of TPP power units, which work under the action of high pressure, elevated temperature, repeatedly changing cyclic loads, the influence of a corrosive-active working environment, a water-steam mixture, the stressed metal of the drums degrades, various kinds of defects are formed in the vicinity of the stress concentrators and damage that can lead to failure and even large-scale catastrophic destruction. The proposed method makes it possible to establish the residual operational resource of the drums and outline the ways of their more economical operation. Method. The method of computer modeling of the processes of deformation of the drum of a high-pressure boiler under different modes of its operation is built on the basis of spatial-three-dimensional thermoelasticity ratios using the finite element method. Results. The developed technique makes it possible to establish the total value of the parameter of the accumulated damage of the metal of the drum and its residual operational resource. Scientific novelty. A methodology for researching the condition of drums of boiler units of thermal power plants according to the level of accumulated metal damage has been developed, taking into account the determined maximum stresses under different modes of their industrial operation. Practical significance. The proposed modeling technique will make it possible to establish the remaining operational resource of the drums of boiler units of thermal power plants and outline the ways of their more economical operation.

Металофізичні проблеми надійності зварювальних з’єднань корпусів реакторів ВВЕР

The prospects and possibilities of replacing the capacities of nuclear power units of Ukrainian nuclear power plants, which are currently almost completely depleting their operational life, as well as the possibility of extending the guaranteed service life are analyzed and generalized. Based on the study of reactor construction trends and proposals on the world market, a basic promising modern model of a high-capacity 3+ AP1000 nuclear water reactor manufactured by Westinghouse El. Corp. was selected and recommended as a basic promising for use in Ukraine. The results of new studies on the dynamics of strength loss of reactor steels of WWER reactors and their welding joints under the action of radiation are considered. The main attention is paid to the presence and processes of migration and segregation in the crystal structure of reactor steels of harmful impurities, in particular phosphorus and nickel. It is concluded that there are significant advantages of new foreign metallurgical technologies, the use of which in vessel steels provides reliability and increased guaranteed life of safe operation of PWR reactors, in particular, AP1000 type made in the USA. The urgent problems of commissioning additional shunting capacities in the National Unified Energy System of Ukraine were assessed and the conclusion was made that they can be solved by improving the shunting characteristics of existing high-capacity nuclear power units and (mainly) by accelerating construction and commissioning of small modular reactors with high shunting characteristics, in particular the SMR-160 model manufactured by SMR LLC (USA).

Potential of biomass and coal co-firing power plants in Indonesia: a PESTEL analysis

Biomass co-firing technology for coal power plants has been widely applied in developed countries. The government of Indonesia is currently encouraging the implementation of biomass co-firing to achieve the target of 23% new and renewable energy (NRE) share in the national energy mix by 2025. Although only a few technical issues are left on the implementation of biomass co-firing in coal power plants, the challenges for the large-scale application and the long-term sustainability of the technology still need to be investigated. To identify and overcome these challenges, this paper applies the Political, Economic, Social, Technological, Environmental, and Legal (PESTEL) framework to analyze the business prospects for biomass co-firing for coal power plants. There is potential for biomass co-firing in 114 units of coal power plants with a total capacity of 18.1 GW spread across various locations in Indonesia. As a consequence, it requires around 9 million tons of biomass per year. This huge potential market of biomass opens opportunities for people to participate in supplying the raw materials. The biomass market as co-firing fuels will push agricultural and industrial waste management to be used more efficiently. The biomass supply chain needs to be well developed so that the biomass supply can be sustainable at an economically feasible price, to ensure that electricity prices generated from utilities are affordable for the public. The technical specifications for biomass need to be standardized. The 10% co-firing acceleration of the total coal power plant capacity, or equivalent to around 1.81 GW, can directly contribute to the achievement of the NRE target for the electricity sector and simultaneously reduce greenhouse gas emissions. The government needs to prepare related supporting instruments such as technical regulations, technological and economic aspects, and policy support.

Modelling of Solar-Diesel Hybrid Power Plant

The article highlights the problems of distributed energy generation and focuses on solar-diesel hybrid power plant modelling and optimization. Designing power systems based on renewable energy sources includes a very relevant task of building mathematical models of such systems and their elements. The article presents an approach and definition of mathematical models describing photovoltaic-diesel (PV-D) hybrid power system elements used in decision making processes as a part of PV-D operation control. An overview of PV module output power, performance and temperature models is given. Along with the analysis of the specific fuel consumption dependencies on the operating power of the diesel generator, an example of diesel power plant unit commitment is shown.

МЕЖДУНАРОДНО-ПРАВОВОЕ РЕГУЛИРОВАНИЕ СОТРУДНИЧЕСТВА РОССИИ И ИНДИИ В ОБЛАСТИ МИРНОГО ИСПОЛЬЗОВАНИЯ АТОМНОЙ ЭНЕРГИИ

This article explores a framework for cooperation between Russia and India in the peaceful uses of nuclear energy with a view to providing a comprehensive analysis of the international legal acts in this field. The scientific novelty of the research is a reflection of the fact that it is the study in which international legal framework concerning cooperation between Russia and India in the field of nuclear energy are summarized, systematized and analyzed. It is mentioned that the Moscow-New Delhi relationship is based upon mutual needs: Indian energy needs and Russian strategic economic needs. The main agreements for cooperation in the field of peaceful uses of nuclear energy are the Kudankulam nuclear agreement (1988) and the intergovernmental agreement on cooperation in the uses of atomic energy for peaceful purposes (2010). The legal acts on cooperation in the construction of additional nuclear power plant units at Kudankulam site are of special importance. The article finds, moreover, that the increasing of the number of reactors in the Kudankulam Nuclear Power Plant has been expanding the India-Russian long-term partnership. India continues to view the expansion of its civilian nuclear sector as a critical element in the field of industry and decarbonization. In this regard, developing alternate nuclear fuel resources and civil nuclear cooperation agreements between Russia and India should be concluded.

Evaluation of operation regulation ability of a power plant unit in heating season

In order to further improve the operation level of thermal power units directly regulated by the power grid, the regulation capacity of a power plant unit is comprehensively analyzed and evaluated from the aspects of heating capacity, minimum startup mode of the whole plant, heating state and load capacity, etc., to provide support for the accurate dispatching of the unit.

Estimation of long-term ex-vessel debris cooling behavior in Fukushima Daiichi Nuclear Power Plant unit 3

Estimation of long-term ex-vessel debris cooling behavior in Fukushima Daiichi Nuclear Power Plant unit 3

Застосування методу досліджень кутового розподілу інтенсивності гамма-випромінювання

The paper presents the results of the application and verification results of the effectiveness of the method of studying the angular distribution of gamma radiation intensity using a dosimeter MKS-07 “Poshuk” with a remote detector in the collimator (DC-R). The purpose of this work is to verify the effectiveness of the method using the DС-R device on pre-known sources and to obtain an array of data in one area from different points. Before the start of the study, an analysis of available data on the radiation situation was performed. This allowed determining a sufficient number of measurements of angular distributions to verify the effectiveness of the method and the location of measurement points. As a result of the analysis of the initial data from the radiation state, it was decided to investigate the area of the Shelter object from the west to the east. Known source in the blockages of the central hall of of the Chornobyl Nuclear Power Plant Unit 4 of the Shelter object are located in this zone. The obtained measurements results of the quantitative characteristics of the angular distribution of gamma radiation intensity are presented graphically. As a result of the study of the angular distribution of gamma radiation intensity using the DC-R device, the high efficiency of source recognition was proved even in conditions of high gamma fields. After processing the obtained results and their analysis, the following conclusions were formulated: 1. The effectiveness of this method in the study of the angular distribution of gamma radiation intensity has been confirmed. This is seen when comparing points K1 and K3. 2. A hitherto unrecorded source of ionizing radiation was found, which forms a radiation state at the study site, which corresponds to point K2. 3. It is confirmed that in high fields of ionizing radiation this method is inappropriate in connection with the receipt of personnel of high dose loads during research. 4. Background values were recorded in the directions with no radiation sources, so they are not reflected on the cartograms. This is due to the fixation of gamma rays by the detector passing through the lead walls of the collimator. This proves the effectiveness of shielding the detector from powerful sources and allows it to be used in high fields.

The Demonstrator of Structural Health Monitoring System of Helicopter Composite Blades

The health and usage monitoring systems are widely used for the monitoring of vibrations of power plant units on helicopters. At the same time critical helicopter structures like main and tail rotors or tail boom are still out of permanent monitoring. Practically all non-destructive techniques (NDT), like ultrasound, eddy current, X-ray and others make the inspection of structural components available on the ground only, during the maintenance check or overhaul. The article considers the promising technique for structural health monitoring (SHM) of a helicopter in flight, inter alia, of rotating blades. Actively developing methods of modal analysis, especially “operational” one, open the new opportunity for structural monitoring and its attendant issues. The Operational Modal Analysis (OMA) techniques and the methods of its data application are the basis of the novel concept of “modal passport” for monitoring of helicopter’s blades. There is brief description of basic principles of the modal passport and its trial application. The paper discusses the problems associated with practical application of modal passport to rotating helicopter blades and ways to overcome it. The light coaxial helicopter Ka-26 became the operating platform for experimental study of OMA application and works as the demonstrator of advance SHM techniques. Brief description of measurement system, including equipment and transducers on the blades is presented. The discussed research stage aims to demonstrate the potential of OMA techniques for monitoring of rotating blades, applying the seeded faults to estimate sensitivity of the SHM system. The paper discusses analytical and experimental study of the blade, including FE modelling and comparative analysis with the experimental data. The conclusions of the paper summarize the results of the research stage, outline the novelties and its practical application. The tasks of further works for SHM research stages using the demonstrator are formulated.

Основні вимоги до сучасних систем діагностики потужних турбогенераторів

A turbogenerators design complication and the use of new auxiliary systems for the cooling intensification with increasing power unit lead to the decrease of their reliability. Therefore, the system and methods of control and diagnostics of generators main component parts to compensate this decrease of turdogenerators reliability were developed. In the paper, a system analysis for the reliability of nuclear power stations turbogenerators was carried out, and the main damaging elements and components, that were determined. It was found that almost half of the damages are stator and rotor, a third of which — stator core and winding bars defects. Modern diagnostic methods of technical condition for stator and rotor elements of powerful generators as well as their advantages and drawback are considered. All this allowed us to formulate the basic principles of diagnostic system construction for nuclear power stations powerful turbogenerators, which are based on the continuous control of the data on their most important parameters and defects, and deviations identification occurring in the most of operation cases as well as preventing further work of equipment. The economic effect owing to the introduction of monitoring and diagnostic modern systems is ensured by increasing the reliability of electric power equipment operation, reduction downtime due to emergency shutdowns of generators, decrease unplanned electricity underproduction, reducing in time and cost of repair and restoration work, the number of consumable spare parts and materials, as well as economic losses due to unplanned downtime of nuclear power plant unit.

Analysis of Status Fourteen Hours after All Power Loss at the Fukushima Daiichi Nuclear Power Plant Unit 1

Analysis of Status Fourteen Hours after All Power Loss at the Fukushima Daiichi Nuclear Power Plant Unit 1

Principal Modernization Solutions for a 300 MW Power Unit to be Converted to Operate at Ultra-Supercritical Steam Parameters

This paper analyses the state of power engineering in Ukraine and the main trends in the development of the world market in the field of converting high-capacity powerful power units of thermal power plants into ultra-supercritical (USC) ones. It is shown that the energy sector of Ukraine requires special attention and the introduction of new modern technical solutions. Worldwide trends indicate that the emphasis is now on increasing the steam parameters before a turbine to ultra-supercritical ones. This allows one both to increase the efficiency of power units and to reduce thermal emissions, fighting the global environmental problem of climate warming. The implementation of this approach is proposed taking into account the realities of the Ukrainian economy and the available technical capabilities of the power engineering industry. This paper presents the results of variational computational studies of the thermal scheme of the 300 MW power unit of the K-300-23.5 turbine to be converted into a USC one. The problem was solved under the condition of maximizing the preservation of the thermal scheme, increasing the efficiency of the power unit and minimizing capital investments during the modernization of the turbine. It was chosen to preserve the regeneration system, as well as the medium-pressure (MP) and low-pressure (LP) cylinders. Considered and calculated were variants with the addition to the existing turbine of a USC cylinder and the creation of a new high-pressure cylinder (HPC) with insignificant changes in its overall characteristics. The results of computational studies showed that the most rational variant for modernizing the 300 MW turbine plant is the creation of a new HPC designed for operation at USC steam parameters as well as the addition to the IPC of a new cylinder with the purpose of increasing the reheat steam parameters while preserving the regeneration system.

Centralized Control Operation Technology Management of Thermal Power Plant Units

Centralized Control Operation Technology Management of Thermal Power Plant Units

BOILER PLANTS AND THE ENVIRONMENT PROTECTION FROM INDUSTRY HARMFUL EFFECTS

Abstract. At present, environmental problems have become aggravated. The production process has a negative impact on the natural environment. It accumulates these harmful secondary effects. The degree of their harmful effects is increasing rapidly. The natural environment, taking into account its self-healing, undergoes dangerous, irreversible changes in its state. Now it is possible to talk only about slowing down this process. The ability to slow down and then stop the increase in the harmful impact on the natural environment is the essence of the nature conservation activities of humanity. It is necessary to move from a strategy of using the natural environment to a strategy of parity interaction with it. The problem was discussed at the Kyoto and Paris conferences of global importance. Among the branches of production, the most dangerous for the natural environment is energy. Its harmful effect is complex. Defending against it is a complex environmental issue. The adopted energy saving program actively contributes to solving the problem of saving the natural environment from degradation and death. The most environmentally aggressive element of power plants is solid fuel boiler plants. Reducing the intensity of their impact is the main direction of activities to protect the natural environment. The most difficult technical object is considered the power unit of a large thermal power plant. The most difficult part is the boiler plant. The most difficult element is the steam boiler. The level of environmental friendliness of the boiler is highly dependent on the degree of its wear. The problem of updating the fleet of boilers is of current importance. The general line of improving the environmental friendliness of production should be considered an increase in the level of environmental friendliness of power plants, especially those using fossil fuels, and a decrease in their emissions of carbon dioxide and heat. It is necessary to improve boiler installations, to increase their efficiency level, and the quality of their management. It is important to ensure the modernization of worn-out boiler installations based on their complete or partial renewal. In the formation of the power engineering of the future, the socio-psychological position of humanity must be radically changed.