Power Plant Equipment Research Articles

Evaluation of the Comparative Efficiency of CCGT in Variable Modes

The purpose of the research is to select the priorities for the development of various types of power plants and to substantiate the structure of generating capacities. An improved method has been developed for the selection of priorities for the development of various types of power plants, taking into account the service life and economic performance of the main equipment of power plants in variable modes based on equivalent operating hours. The influence of variable modes of combined-cycle gas installations on the service life of the main equipment (steam and gas turbines) is studied. The comparative efficiency of CCGT-450 in variable modes is calculated, taking into account the wear of the main equipment. As a result of calculations, it was found that with the minimum forecast prices for natural gas, the most efficient power plant (among those considered) is combined cycle power plant, which provides the lowest prime cost of electricity when operating in the base mode and the least increase in the prime cost of electricity when operating in an alternating mode.

A comparative analysis of the characteristics of the water removal processes in preparation for incineration of typical wood waste and forest combustible materials

The article presents the results of the experimental studies of the processes of removing moisture from fairly typical and widespread forest combustible materials, and woodworking waste under conditions of their thermal preparation for combustion. Based on the results of the experiments, the main regularities of the drying processes of woody biomass under conditions of radiation-convective heating have been established. The integral characteristics (characteristic times) of the drying process of forest biomass under typical (for this technology) heating conditions have been determined. The experiments were carried out on equipment that provides a low level of error (less than 3.3%) for determining the main characteristics of the biomass dehydration process. The values of the mass rates of moisture removal (Weva) of four promising (for modern and future power engineering) and fairly common types of biomass have been established in the ambient temperature range from 333 to 393 K, which corresponds to the operating modes of the drying equipment of power plants. According to the results of the experiments, it was shown that at relatively moderate ambient temperatures (333≤ Tg ≤ 353 K), the type of wood has a rather significant effect on the characteristics and conditions of the dehumidification process. At the same time, the process of drying wood chips is much faster compared to other types of biomass. As the ambient temperature rises (at 373≤Tg ≤ 393 K), the influence of the type of biomass decreases. As a result of the experiments, a physical model of the process of removing moisture from the bulk layer of biomass was formulated. According to the results of the experiments, it was found that before burning forest biomass in boilers of thermal power plants, it is most advantageous to carry out drying in conditions of relatively moderate (at 333≤Tg ≤ 353 K) ambient temperatures. The studies carried out provide grounds for justifying the use of forest combustible material as fuel (or one of the components of the fuel mixture) at thermal power plants currently operating on coal.

Reliability Analysis and Economic Life Calculation for Asset Management Optimization (Case Study in Steam Power Generation Unit at XYZCompany)

In a competitive market driven industry at a power generation business, requires The electricity producers to provide electricity with a low cost of supply. On the other hand, the large number of equipment assets managed by the power plant companies requires an appropriate asset management process, in order to reduce the increased maintenance and investment costs of equipment which which can cause an increase in the cost of supply. XYZ Company as a company that manages assets of more than Rp 174 trillion has challenges in the process of optimizing its company's asset management. The decreasing amount of maintenance and investment budget in the company each year and the equipment conditions that have been operated for more than 20 years, requires an asset management method that can provide a comprehensive understanding of the technical and economic conditions of each equipment, so it can be provide appropriate information to support the decision making process that is expected to reduce cost of supply.In this study, the authors conducted an analysis of asset conditions at XYZ Company by combining the method of reliability analysis and calculation of the economic life of the equipment. Case study was conducted at one of the units at XYZ Company precisely in Steam Turbine Unit 2.0. The purpose of this study is to obtain comprehensive information including the value of reliability and economic life of each equipment in the unit to facilitate management in the decision making process for the selection of maintenance strategies and asset replacement.Reliability analyzes were performed using RBD, RGA, and Weibull software. Reliability calculation will be done by looking at the amount and time between damages. Economic life calculation is done by calculating the annual equivalent cost. The analysis was performed on each equipment in the Steam Turbine Unit 2.0. From this analysis, it’s resulted the procedure for the classification of power plant equipment for the replacement process in accordance with the limits of the parameters of the reliability index and economic lifereliability and economic life conditon. Moreover, It’s resulted the mapping of Steam Turbine critical quipment. This mapping illustrates the amount of equipment that must be replaced immediately, still maintained, and the maintenance strategy needs to be evaluated immediately. This information is used by management in deciding the evaluation of equipment maintenance strategies and replacement strategies to reduce the power plant cost of supply.

Seismic capacity re-evaluation of the 480V motor control center of South Korea NPPs using earthquake experience and experiment data

The recent seismic events that occurred in South Korea have increased the interest in the re-evaluation of the seismic capacity of nuclear power plant (NPP) equipment, which is often conservatively estimated. To date, various approaches—including the Bayesian method proposed by the United States (US) Electric Power Research Institute —have been developed to quantify the seismic capacity of NPP equipment. Among these, the Bayesian approach has advantages in accounting for both prior knowledge and new information to update the probabilistic distribution of seismic capacity. However, data availability and region-specific issues exist in applying this Bayesian approach to Korean NPP equipment. Therefore, this paper proposes to construct an earthquake experience database by combining available earthquake records at Korean NPP sites and the general location of equipment within NPPs. Also, for the better representation of the seismic demand of Korean earthquake datasets, which have distinct seismic characteristics from those of the US at a high-frequency range, a broadband frequency range optimization is suggested. The proposed data construction and seismic demand optimization method for seismic capacity re-evaluation are demonstrated and tested on a 480 V motor control center of a South Korea NPP.

Дистанционный лабораторный комплекс «АСУ ТП тепломеханическим оборудованием электростанций» А. В. Трофимов,

Most industrial automation and control systems are remotely operated and monitored. We present the novel remote complex developed for educational purposes – to train engineering students in operating IACS intended for thermal mechanical equipment of power plants. Development of this remote training complex had multiple goals such as displaying all IACS components, operating real industrial equipment, simplicity, portability, and remote access. The typical structure of the automated process control system has been described. We have built a training stand in accordance with this structure, including all technology parts and connection of all sensors and equipment.

Model of Emergency Conditions’ Early Detection in Power Plant Equipment Based on the Least Potentials Method

Model of Emergency Conditions’ Early Detection in Power Plant Equipment Based on the Least Potentials Method

Generation Method of Target Power Spectral Density for Seismic Design of Nuclear Power Plant Equipment

The input ground motion for the seismic design of nuclear power plant (NPP) equipment is required to envelop both the required response spectrum (RRS) and target power spectral density (PSD). However, no unified algorithm exists to generate the target PSD, whether at home or abroad. Based on the generation methodology for target PSD suggested in Section 3.7.1 of the Standard Review Plan (SRP) of U.S. Nuclear Regulatory Commission, this paper proposes an improved method for target PSD synthesis with the original iteration process optimized. The proposed method is applied successfully to the two RRS cases for nuclear equipment. The result shows that the improved method for target PSD generation is highly compatible with RRS and provides simple and rapid calculation, while its convergence accuracy is similar to the calculations by random vibration theory (RVT). This method is considered as the target PSD test basis for the input artificial ground motion (AGM) for the seismic design of NPP equipment.

Analysis on Maintenance and Management of Electrical Equipment in Power Plant

Analysis on Maintenance and Management of Electrical Equipment in Power Plant

Comprehensive methodology for identifying tariff zones of efficiency of hydrogen-thermal accumulation system at the NPP

In countries with developed nuclear energy, there are problems associated with non-uniformity of the daily electricity load, due to the economically justified need to load nuclear power plants with a maximum installed capacity utilization factor. This is due to the cheapness of nuclear fuel compared to organic and, at the same time, high investment compared to thermal power plants, as well as the presence of technological limitations on maneuverability. Most organic fuel thermal power plants are switched to half-peak mode, which negatively affects their efficiency and reliability.In addition, the ever-increasing requires on the level of safety negatively affect the economic competitiveness of nuclear power plants. Improving safety through the introduction of passive heat removal systems of the reactor core is provided for in new NPP projects. These systems have several disadvantages: maintenance costs; a significant increase in capital investment; emergency cooling mode.To solve these problems, the authors developed a system of hydrogen-thermal accumulation, which, when combined with a nuclear power plant, allows one to accumulate cheap energy during the hours of a decrease in load in the power system due to electrolysis of water to produce hydrogen and oxygen, and thermal accumulation of hot water in heat-insulating tanks. Thanks to the use of hot water tanks, investment in the accumulation system is significantly reduced. Thanks to the use of a hydrogen-oxygen steam generator, the opportunity to generate an additional main steam and to use it in the additional steam turbine unit appears, which will allow to avoid costly modernization of the main equipment of the nuclear power plant and reducing its lifetime. The presence of a low-power steam turbine unit as part of the accumulation system ensures uninterrupted autonomous power supply to consumers of the NPP own needs due to the possibility of using the energy of the reactor residual heat, when the station is completely blackout. The method of combining the hydrogen complex with thermal accumulators is completely new and has no analogues.The economic efficiency of the developed energy complex has been investigated. The accumulated net present value was determined depending on the off-peak electricity tariff for the three options of the half-peak electricity tariff, taking into account possibility to refuse expensive heat exchangers of the passive heat removal systems. It is shown that the use of the proposed scheme is advisable in regions with off-peak electricity tariffs in the range 0–0.32 cents/kW·h, 0–0.8 cents/kW·h and 0–1.25 cents/kW·h, respectively, depending on the forecast dynamics of the half-peak electricity tariff. The average payback period of the accumulation system for given conditions is equal to 3–15 years.

Influence of Mass Transfer and Physicochemical Processes in the Working Fluid on Erosion–Corrosion of Equipment and Pipelines in Nuclear Power Plants

Influence of Mass Transfer and Physicochemical Processes in the Working Fluid on Erosion–Corrosion of Equipment and Pipelines in Nuclear Power Plants

Discussion on Maintenance Methods of Electric Secondary Equipment in Power Plant

Discussion on Maintenance Methods of Electric Secondary Equipment in Power Plant

An Adaptive Early Fault Detection Model of Induced Draft Fans Based on Multivariate State Estimation Technique

The induced draft (ID) fan is an important piece of auxiliary equipment in coal-fired power plants. Early fault detection of the ID fan can provide predictive maintenance and reduce unscheduled shutdowns, thus improving the reliability of the power generation. In this study, an adaptive model was developed to achieve the early fault detection of ID fans. First, a non-parametric monitoring model was constructed to describe the normal operating characteristics with the multivariate state estimation technique (MSET). A similarity index representing operation status was defined according to the prediction deviations to produce warnings of early faults. To deal with the model accuracy degradation because of variant condition operation of the ID fan, an adaptive strategy was proposed by using the samples with a high data quality index (DQI) to manage the memory matrix and update the MSET model, thereby improving the fault detection results. The proposed method was applied to a 300 MW coal-fired power plant to achieve the early fault detection of an ID fan. In addition, fault detection by using the model without an update was also compared. Results show that the update strategy can greatly improve the MSET model accuracy when predicting normal operations of the ID fan; accordingly, the fault can be detected more than 4 h earlier by using the strategy with the adaptive update when compared to the model without an update.

Life-cycle cost model and evaluation system for power grid assets based on fuzzy membership degree

Life-cycle cost (LCC) theory can be effectively applied to improve the efficiency and quality of power plant equipment and asset management. However, specific aspects of the LCC calculation and evaluation model require further research for practical application. This paper proposes an LCC assessment model for the management of electric power plant equipment during its service life. A membership function method based on fuzzy logic is used to improve the allocation of modernization and overhaul projects to multiple equipment assets. An LCC assessment model and evaluation system for power equipment are proposed and successfully applied to the equipment and project management of a Guangzhou power plant in the China Southern Power Grid, providing a decision-making mechanism that facilitates efficient operation and optimal utilization of power plant equipment and assets.

Power Plant Small-diameter Tube Phased Array Inspection Verification and Inspection Technology

In this paper, the phased array inspection is carried out on the small diameter pipes with artificial groove defects and natural defects, and then the conventional ultrasonic inspection and the penetration inspection after cutting and dissection are carried out respectively. The ultrasonic phased array inspection results are compared with the conventional ultrasonic and compared with the results obtained from penetrant testing, the reliability of ultrasonic phased array testing technology in the application of small-diameter pipe testing is analyzed. Then, taking the detection of the small pipe socket of the high-temperature superheater header of Huadian Weifang Power Plant as an example, it is verified that the ultrasonic phased array detection is feasible in the detection of small diameter pipe welded joints. Finally, the ultrasonic phased array testing process and testing technology of power station boiler small-diameter pipes are summarized, and the development direction of phased array testing application in power plant equipment inspection is prospected.

Development of a throttle and dampening device for the nuclear power plant of icebreaker LK-60

In the course of developing designs for mixing heat exchangers that operate on the principle of throttling the working medium on perforated grids, special attention is paid to ensuring the reliability of structures subject to erosive wear when subjected to dripping moisture and temperature stresses.JSC “NPO CKTI” has years of experience in the development of contact-type heat exchangers and was directly involved in the design of separate power plant equipment for LK-60, including a throttle and dampening device (TDD).It provides a description of the functional purpose of the TDD as part of the LK-60 nuclear power plant, the principle of operation and significant differences of the new design from those previously used. It is noted that while in previous designs the TDD included four columns connected in pairs, on LK-60 there are two columns located on top of the condenser. The TDD for LK-60 is designed to receive 132.5 t / h of steam of higher parameters than the previous generation designs intended to receive about 50 t / h of steam.The main technical solutions in the development of the design of the TDD are presented. The design provides access to the throttling lattices for diagnostics and their replacement if necessary which ensures a high degree of maintainability and reliability of the device. Perforation of the lattices arranged in series in the direction of the steam flow is made in such a way that the openings of the previous lattice, if possible, are not located opposite the openings of the subsequent lattice. The distance between the throttling lattices was taken from the conditions for ensuring the design course of the steam throttling process.Results are given of thermal and hydraulic calculations of the TDD. The calculation consists of two main parts. The first part includes thermal and hydraulic calculations with the determination of the degree of perforation of the lattices, the distribution of temperature and vapor pressure over the cross-sections of the TDD, etc. The second part contains the calculation of the cooling condensate injection nozzles.In the course of design studies, strength calculations were performed for all versions of TDD and individual parts. In addition, the nozzles underwent a full test cycle (determination of flow characteristics, water spray quality) in accordance with the test program.

The visualization of 3D nuclear radiation dose field

The nuclear energy is widely used as a new energy source due to the increasing depletion of fossil fuels. In the development of nuclear energy and technology, people are paying more and more attention to the issue of nuclear radiation protection. As a result, advanced computer technology has become a new way to solve nuclear radiation safety issues. This paper proposes to utilize CUDA-based ray-casting volume rendering to build an interactive nuclear radiation visualization system to solve the nuclear radiation safety problems, such as the judgment of radiation dose leakage and the planning of construction path. The system includes three modules, which are the overall dose rate distribution display of multiple power plants, the dose view of a specific equipment in power plants, and the dynamic evolution of nuclear radiation leakage. The analysis and user feedbacks of the experimental results show that this interactive visualization system can present the nuclear dose distribution of power plant in real time and from different granularities. This system utilizes the color mapping schema that as the dose density increases, the color changes from green to red, which is in line with human visual perception. Meanwhile, the dynamic radiation leakage scenario view is assistant to the design of nuclear radiation protection.

Probabilistic Seismic Demand Model and Seismic Fragility Analysis of NPP Equipment Subjected to High- and Low-Frequency Earthquakes

This study presents the Probabilistic Seismic Demand Model (PSDM) and explores optimal intensity measures (IMs) for nuclear power plant (NPP) equipment when subjected to ground motions having high-frequency (HF) and low-frequency (LF) contents. To this end, the PSDM is first constructed in terms of the IM and the corresponding engineering demand parameter, and its outcomes are utilized to select the optimum IMs based on the satisfaction of certain essential properties (i.e., efficiency, practicality, and proficiency). Regarding earthquake excitation, different IMs (i.e., structure-independent and structure-dependent IMs) are studied. The results show that the most appropriate IMs for the seismic performance of the cabinet are velocity spectrum intensity and spectral accelerations for the structure-independent IMs and the structure-dependent IMs, respectively. Moreover, fragility analysis is performed to assess the vulnerability of NPP equipment. The outcomes indicate that the cabinet is highly vulnerable to HF earthquakes as a consequence of response amplification. In addition, the selection of the earthquake IM has an important influence on the collapse capacity of the cabinet, and the fragility curves obtained from structure-dependent IMs are more reliable in comparison to those of structure-independent IMs.

Editorial: Nuclear Power Plant Equipment Prognostics and Health Management Based on Data-Driven Methods

Editorial: Nuclear Power Plant Equipment Prognostics and Health Management Based on Data-Driven Methods

Deep‐learning‐based nuclear power plant fault detection using remote light‐emitting diode array data transmission

AbstractThis paper proposes a deep‐learning‐based wireless sensor system that uses an embedded two‐dimensional (2D) light‐emitting diode (LED) array to display measured sensor data and remote data transmission to detect nuclear power plant (NPP) equipment defects. The frequent use of electromagnetic waves often interferes with the operation of NPP. Therefore, we devised a wireless image transmission network using a 2D LED array panel that includes a sensor module and a camera to capture LED array images. Based on the experimental results, the proposed method adopting deep‐learning‐based LED array data extraction produces reliable digital data restoration performance in terms of classification accuracy, even in a complex noise environment.

Design of flyback power supply of DC equipment in PV power plant

In photovoltaic (PV) grid-connected power generation systems, the needs of low-voltage DC power supply for equipment in PV power plant areas are common. This article provides a design of wide-range high-input voltage flyback power supply. Firstly, the needs of the input voltage range are analysed, and the power supply indexes are defined. Then, the design of the power supply and the transformer circuit are given. The prototype trial results are also given at the last. The results show that the designed power supply meets the requirements of equipment in PV power plant.