Quick Maintenance Research Articles

Skills and Techniques of Machine Repair Fitters

In this important understanding of machining, mechanical maintenance fitter occupies an important position. Machine repair fitters are mainly responsible for the processing and maintenance of various mechanical equipment, and use scientific control methods to restore mechanical properties. Therefore, we can see that the faults in machine maintenance need quick maintenance by fitters to solve various problems that often occur in machine maintenance. In this case, the fitter must master basic machine maintenance skills and use excellent information technology to assist in the installation of various machines. Therefore, this article gives a brief introduction to the machine fitters used for machine maintenance and shows how to increase their repair capacity to make machine maintenance more efficient. With the progress of scientific and the rapid increase in productivity, competition between enterprises is more and more intense. If enterprises want to maintain a high competitiveness and advantages, they need to focus on the research and development of core technology of their companies and improve core competitiveness. So in such a large background, many companies choose to focus on the development of their core business, and then they need other enterprises to complete their own non-core business resources. In such a development process, the logistics industry will gradually separated and then the third-party logistic enterprises show up.

The Ways to Improve the Skills and Techniques of Machine Repair Fitters

In this important understanding of machining, mechanical maintenance fitter occupies an important position. Machine repair fitters are mainly responsible for the processing and maintenance of various mechanical equipment, and use scientific control methods to restore mechanical properties. Therefore, we can see that the faults in machine maintenance need quick maintenance by fitters to solve various problems that often occur in machine maintenance. In this case, the fitter must master basic machine maintenance skills and use excellent information technology to assist in the installation of various machines. Therefore, this article gives a brief introduction to the machine fitters used for machine maintenance and shows how to increase their repair capacity to make machine maintenance more efficient. With the progress of scientific and the rapid increase in productivity, competition between enterprises is more and more intense. If enterprises want to maintain a high competitiveness and advantages, they need to focus on the research and development of core technology of their companies and improve core competitiveness. So in such a large background, many companies choose to focus on the development of their core business, and then they need other enterprises to complete their own non-core business resources. In such a development process, the logistics industry will gradually separated and then the third-party logistic enterprises show up.

Two-stage UHV GIL Fault Location Based on Ultrasonic Sensor Network

The failure of a long-distance Ultra-high voltage (UHV) Gas Insulated Transmission Line (GIL) during operation will cause great security risks to power transportation. How to locate GIL faults quickly and accurately and further carry out related operation and maintenance work is of great significance to the stable operation of the power grid. Based on this, this paper proposes a two-stage fault location method for UHV GIL based on an ultrasonic sensor network. In this method, ultrasonic sensors are configured in the shell of GIL to form an ultrasonic sensor network and internal faults are located by analyzing the signals collected from the network. The method is divided into two stages: 1) according to the collected signal data, the two sensors closest to the fault point are preliminarily identified, and then the fault point is roughly located, and obtain the data collected by the sensors; 2) we analyze sensor signal data, train and establish a network model based on recurrent neural network RNN for accurate fault location. The verification experiment shows that this method has fast location speed and high location accuracy, and can be effectively applied for quick maintenance, safe operation, and maintenance of GIL.

Research on Fault Diagnosis of Wind Turbine Gearbox with Snowflake Graph and Deep Learning Algorithm

Wind power generation is one of the important development projects for renewable energy worldwide. As wind turbines operate in harsh environments, failure of the wind turbines often occurs, thus leading to lower power generation efficiency and high maintenance cost. Earlier detection of the fault type can reduce the maintenance cost. This study proposed a hybrid recognition algorithm based on the symmetrized dot pattern (SDP) and convolutional neural network (CNN) for wind turbine gearbox fault diagnoses. In addition to a fault-free type, four fault types were discussed in this paper, including gear rustiness, broken tooth, wear, and aging. A vibration sensor was used for measurement. The original vibration signals of the gearbox were captured by a NI-9234 high-speed data acquisition card, filtered by a fast Fourier transform, and imported into the SDP to create the snowflake image features. Afterward, CNN diagnosed the gearbox fault type. There were 1500 test data in this study. A total of 200 data items for each fault type were used as training samples, and 100 data of each type were used as test samples. The test result shows that the training accuracy was 98.8%. The proposed method can diagnose the fault condition of the gearbox effectively and identify the fault type of the gearbox accurately. This is favorable for the quick maintenance of wind turbines.

A Portable Surface Plasmons Resonance Sensor Based on Single-Board Computer

The development of portable surface plasmons resonance (SPRs) are recently boosted by the use of instrumentation based on small-size single-board computer (SBC) platforms. The SPR and SBC combination is ideal for advances in direction of miniaturization and portability, however many scientific and engineering solutions yet required a computer connection for operation, and reported portable sensors in which hardware and software resources are misused. Here a standalone portable SPR based on an SBC is presented. The sensor operates without the need for another device, computer, or connection. Designed to work with thicker (3 mm thick) or thin (1.5 mm) biochips to support surface plasmons (SPs) and avoid rotational parts, a set of special structures was designed to encapsulate all electronics and optical elements. Composed of modular parts manufactured in a 3-D printer, the proposed arrangement enables quick maintenance and repair actions, eventually required for field applications. The chassis piece enclosure the components and fit the touchscreen. A replaced top cover piece enables the exchange of the thicker- and thin- biochips. And a back lid gives access to the internal components, where moving parts are designed and included to improve mechanical alignment. The sensor was optimized to Raspberry Pi SBC. The Python-based embedded software implements algorithms for acquiring, processing, displaying, storing, and delivering the SPR responses. To demonstrate the solution feasibility a Raspberry pi 3 model B was used. The well knows biochips PPBIO (Prism BIOchip) (thicker) and diffractive optical coupling element (DOCE) (thin) were attached to the proposed SBC-SPR Sensor. Those biochips dismissed index-matching gels and rotate parts, which benefits the sensing labor cost. Experiments of aqueous solutions were performed with a sensor operating in the so-called angular interrogation mode (AI mode). The results indicate the capability of phenomena excitation and sensor arrangement. The sensitivity figure-of-merit (FOM) was achieved in the order of 160°/RIU, similar to the performance of traditional set-up for those biochips.

Analysis of the kinetic energy recovery behind a tidal stream turbine for various submergence levels

Tidal turbines are commonly deployed at sea sites with water depths of up to 50 m to ease their deployment and quick maintenance operations. In these relatively shallow water depth conditions, the vertical expansion of tidal stream turbine wakes is restricted by the proximity of the rotor blades to the bottom bed and free-surface layer. These physical constrains can lead to changes in the flow mechanisms that drive momentum recovery behind the turbines, e.g. limiting the vertical fluxes of velocity. Understanding how the wake recovers depending on the submergence ratio is of utmost importance to designing the future multi-row tidal turbine arrays. Here, we adopt high-fidelity Large-Eddy Simulations (LES) with an Actuator Line Method (ALM) to represent the turbine's rotor to analyse the mean flow and transport equation for mean kinetic energy (MKE) behind a single bottom-fixed tidal turbine for four water depth values. Our results show that the close proximity of the turbine blade tip to the free-surface can notably constrain the wake expansion, with very shallow conditions leading to a limited contribution to the MKE replenishment of the turbulent momentum exchange over the vertical direction. Conversely, under such shallow conditions, the horizontal flux of MKE is enhanced over the lateral boundaries of the downstream wake. Our study evidences that the ratio of water depth to turbine diameter plays a relevant role in future tidal arrays and needs to be correctly accounted for in numerical models to provide reliable results.

A Novel Cold-Mixed Epoxy Concrete and Its Comparison with Hot-Mixed Epoxy Asphalt Concrete

A novel cold-mix epoxy (CME) concrete was developed to meet the urgent demand of quick maintenance in long-span steel deck pavement. Considering that the CME is a thermosetting resin, a differential scanning calorimeter (DSC) was employed to evaluate the curing behavior of the CME binder. Dynamic mechanical analysis (DMA) was used to investigate the viscoelasticity of the CME binder. The semicircular bending test and the three-point bending test were used to evaluate the crack resistance of CME concrete. Long-term performance was investigated by comparing the fatigue behavior of the CME concrete and hot-mixed epoxy asphalt (HMEA) concrete. The results showed that the curing reaction order of CME is similar to that of HME (hot-mixed epoxy) and the activation energy of CME is slightly higher than that of HME which means that the reactivity of the latter is higher. The bimodality that occurs in tanδ curve means that there are two phases existing in the CME and HMEA microstructure, while the secondary phase ensures that the CME and HMEA have good damping behavior. CME concrete has a better crack resistance than HMEA concrete at low temperature, and a similar crack resistance compared with HMEA concrete at high temperature. From the residual ratio of flexural stiffness after 1 million load cycles, the CME concrete shows better fatigue resistance than the HMEA concrete.

Экспертная диагностика интенсивности процессов шлакования и надёжности работы поверхностей нагрева пылеугольных паровых котлов

The article is devoted to the development of a system for the technical diagnostics of slagging processes and contamination of the heating surfaces of coal-fired steam boilers, which operates online based on the interpretation of the standard information of ACS TP and scientifically proved algorithms for processing balanced equations to evaluate the thermal efficiency of radiation, semi-radiation and convective heating surfaces. The system is implemented at the level of algorithmic data and software in the programming language C #, which is built into the current system of the automatic control system of the boiler unit. The project aims to increase the reliability, efficiency and economy of steam boilers by quick maintenance of heating surfaces in an operational clean state, ensuring optimal performance characteristics of the main technological equipment. This system is at the trial operation stage at the BKZ-500-140 boiler unit, station No. 6 of JSC Krasnoyarsk CHP-2. The expected effect of the introduction of this boiler due to the reduction of the blowing cycles and the decrease in the slagging intensity will amount up to 2.175 million roubles annually per one boiler unit.

Environmentally-efficient approaches to oil and gas producing sites

We have offered the investigations aimed at the design of eco-efficient technologies during oil and gas producing sites life cycle. The authors have conducted the analysis of conditions causing environmentally hazardous situations at oil and gas producing sites. We have established the necessity of quick maintenance of operation during emergencies that makes it possible to reduce material costs and environmental pollution. The increase of environmental safety in the process of winding up oil and gas wells emergencies that took place as a result of catching drilling string or some other pipe is crucial. We have analyzed different ways and various structural designs of the devices for pipe unscrewing from caught strings. We have established the ways of negative environmental impact reduction in the winding up emergencies at operating as well at stack oil and gas rigs. The recommendations regarding the structural design of the device are given. The device design is patented and the prototype model of the device is designed and manufactured. The device functions as the transformer of clockwise drilling string rotation into anticlockwise rotation of fishing tools. We have highlighted the positive effects after the implementation of the given device. We have noted the importance of innovative technologies design as well as the importance of forming adequate response skills during emergencies when wellsites are being constructed. The technical solutions and recommendations we have introduced make it possible to prevent negative environmental impact and reduce resource flows at different stages of wellsite life cycle.

Expert diagnostics of slagging of heating surfaces of coal-fired boilers

The article is devoted to the development of a system for the technical diagnostics of slagging processes and contamination of the heating surfaces of coal-fired steam boilers, which operates online based on the interpretation of the standard information of ACS TP and scientifically proved algorithms for processing balanced equations to evaluate the thermal efficiency of radiation, semi-radiation and convective heating surfaces. The system is implemented at the level of algorithmic data and software in the programming language C #, which is built into the current system of the automatic control system of the boiler unit. The project aims to increase the reliability, efficiency and economy of steam boilers by quick maintenance of heating surfaces in an operational clean state, ensuring optimal performance characteristics of the main technological equipment. This system is at the trial operation stage at the BKZ-500-140 boiler unit, station No. 6 of JSC Krasnoyarsk CHP-2. The expected effect of the introduction of this boiler due to the reduction of the blowing cycles and the decrease in the slagging intensity will amount up to 2.175 million rubles annually per one boiler unit.

Espécies vegetais utilizadas em áreas degradadas pela mineração

As atividades de explotação mineral são de grande importância e contribuição para a economia brasileira. A exigência do PRAD e cuidados ambientais durante o fechamento de minas, conforme descritos nos processos de EIA/RIMA, são garantias de que o ambiente será devolvido com qualidade e biodiversidade semelhante ao que foi previamente encontrado no início do empreendimento. Transposição do solo, banco de sementes, transposição de galharias, poleiros naturais e artificiais, nucleação e o plantio de mudas são técnicas ambientais comumente utilizadas visando à restauração ambiental. Esta pesquisa busca apresentar as espécies e famílias vegetais mais utilizadas na recuperação de áreas degradadas nas atividades de explotação de minério de ferro. Foi utilizada uma revisão bibliográfica em artigos científicos, teses de doutorados e pesquisa em sites e plataformas científicas digitais com a utilização das palavras chaves: mineração, revegetação, sucessão vegetal, fechamento de mina e espécies arbóreas nos últimos 10 anos. Após análise dos documentos, as espécies arbustivas mais citadas pelos autores foram: M. calodendron, L. pinaster e S. glabra, encontradas em áreas de recuperação ambiental inicial, e Lychnophora pinaster, Symphyopappus brasiliensis, Baccharis serrulata, Chromolaena sp., Trichogonia sp. e Trixis vauthieri, árvores de recuperação intermediária. Pelos artigos recentemente publicados, nota-se que as famílias Asteraceae, Podaceae e Orchidaceae são as que possuem maior número de representantes em áreas de recuperação após a explotação mineral, devido às facilidades de adaptação ao solo exposto ou com baixo recurso nutricional. A maioria dos autores ainda cita o feijão-guandu, capim-gordura, pau-brasil e eucalipto como espécies chaves no reestabelecimento de áreas degradadas. Faz-se necessário a elaboração de um banco de sementes rico e uma catalogação das espécies ambientais das regiões antes da atividade degradadora, garantindo o sucesso da recuperação e manutenção de espécies próprias regionais.

Wide regulated series hybrid excitation alternator

Parallel hybrid excitation alternators (PHEAs) are large in size but offers wide flux regulation capability. Series hybrid excitation alternator has limited flux regulation capability but compact compared to PHEAs. A new rotor excitation topology has been proposed for a series hybrid rotor excitation alternator (SHREA). The proposed machine is not only small in size but also have wide flux regulation capability. The proposed machine can be classified as a series hybrid machine as permanent magnets and field windings are arranged in a single rotor ensuring series addition of permanent magnet flux and field winding flux. In this study, one more rotor configuration for quick maintenance SHREA is also proposed. As the name suggests, for any fault in excitation winding, they can be easily replaced. Two 1.3 kW prototypes with such designs have been validated with finite-element method simulation and hardware testing.

Cloud-Based Augmented Reality Remote Maintenance Through Shop-Floor Monitoring: A Product-Service System Approach

Maintenance and its cost continue, over the years, drawing the attention of production management, since the unplanned failures decrease the reliability of the system and the return of investments. Maintenance services of manufactured products are among the most common services in the industry; they account for more than half of the total costs and influence the environmental impact of the product. In order for manufacturers to increase their productivity, by performing accurate and quick maintenance, advanced monitoring systems should be considered in order to easily detect machine tool failures before they occur. Toward that end, a cloud-based platform for condition-based preventive maintenance, supported by a shop-floor monitoring service and an augmented reality (AR) application, is proposed as a product-service system (CARM2-PSS). The proposed AR maintenance service consists of algorithms of automated generation of assembly sequences, part movement scripts, and improved interface that aim to maximize existing knowledge usage while creating vivid AR service instructions. Moreover, the proposed monitoring system is supported by a wireless sensor network (WSN), and is deployed on a Cloud environment together with the AR tool. The monitoring system monitors the status of the machine tools, calculates their remaining operating time between failures (ROTBF), and identifies the available windows of the machine tools in order to perform the AR remote maintenance. In order to validate the proposed methodology and calculate its impact, it is applied in a real-life case study of a white-goods industry.

Investigation of Part Feeding Problems in Manual Assembly Line

In a manual assembly line where different parts are consecutively assembled by workers along the conveyor line, line efficiency is dependent upon efficiency of part replenishment to the assembly line. If all parts can be served to the line on time, delay due to part interruption will not happen and jeopardize line efficiency. To avoid this adverse effect situation, a careful planning of feeding mechanism is a must and cannot overlook in a planning process. An optimum number of manpower, remaining buffer size, accurate feeding schedule, good logistic management, quick equipment maintenance and so on must be taken into account. Thus, this paper demonstrates a determination of optimum number of feeding worker, and feeding schedule based on different remaining buffer size. The equations formulated in this research and example of calculation will be delineated in details through a case study.

A Novel Excitation Assistance Switched Reluctance Wind Power Generator

The high inductance of a general switched reluctance generator (SRG) may prevent the excitation of the magnetic field from being quickly established enough, which may further limit the output power of the SRG. A novel excitation assistance SRG (EASRG) for wind power generation is proposed in this paper to solve the above problem. C-shape stator cores are employed in a modular design concept for quick maintenance or replacement, and a ring-shape excitation assistant coil is sandwiched in the space between the modular stator cores. The magnetization and torque characteristics are simulated by 3-D finite element analysis. The prototype of the proposed EASRG is built and the preliminary measurement of the inductance was done. The relative big difference between the measured and calculated result of the maximum inductance may be caused by the machining error of the air-gap. The prototype would be further examined and tested to prove the feasibility of the design.

An approach to enhance availability of repairable systems: a case study of SPMs

Purpose – The purpose of this paper is to demonstrate a tactical approach to cope with the issues related to low availability of repairable machines or systems because of their poor reliability and maintainability. It not only explores the significance of availability, but also embarks upon a step-by-step procedure to earmark a relevant replenishment plan to check the mean time between failure (MTBF) and the mean time to repair (MTTR) efficiently. Design/methodology/approach – The literature review identifies the extent to which availability depends on reliability and maintainability, and highlights the diversified challenges appearing among repairable systems. Different improvement initiatives have been suggested to avoid downtime, after analyzing the failure and repair time data graphically. Relevant plots and growth curves captured the historical deviations and trends along with the time, which further helps to create more robust action plans to enrich the respective reliability and maintainability of machines. During the case study, the proposed methodology has been tested on four SPMs and successfully validated the claims after achieving around a 98 percent availability at the end. Findings – Graphical analysis is the key to developing suitable action plans to enhance the corresponding reliability and maintainability of a machine or system. By increasing the MTBF, the reliability level can be improved and similarly quick maintenance activities can help to restore the prospect of maintainability. Both of these actions ultimately reduce the downtime or increase the associated availability exponentially. Research limitations/implications – The work revolves around the availability of SPMs. Moreover, SPMs have been divided only into series sub-systems. The testability and supportability aspects have not been considered thoroughly during the fabrication of the approach. Originality/value – The work focusses on the availability of systems and proposed frameworks that helps to reduce downtime or its associated expenditure, which is generally being ignored. As a case study-based work especially on SPMs in the auto sector this paper is quite rare and will motivate affiliated engineers and practitioners to achieve future breakthroughs.

An Ultracapacitor-Based No-Break System for Microcomputers

This work aims at presenting a no-break system for microcomputers using ultracapacitors in replacement of the conventional chemical batteries. We analyzed the most relevant data about average power consumption of microcomputers, electrical and mechanical characteristics of ultracapacitors and operation of no-break power circuits, to propose a configuration capable of working properly with a microcomputer switching mode power supply. Our solution was a sixteen-component ultracapacitor bank, with a total capacitance of 350 F and voltage of 10.8 V, adequate to integrate a low-capacity no-break system, capable of feeding a load of 180 Wh, during 75 s. Our proposed no-break increases the reliability of microcomputers by reducing the probability of user data losses, in case of a power grid failure, offering, so, a high benefit–cost ratio. The replacement of the battery by ultracapacitors allows a quick no-break recharge and low maintenance costs, since these modern components have a lifetime longer than the batteries. Moreover, this solution reduces the environmental impact and eliminates the constant recharge of the energy storage device.

8200호대 전기기관차 추진시스템 모델링을 이용한 응답특성분석

Conventional power conversion unit that is a major part of the propulsion system has applied GTO thyristor as a switching semiconductor device of main circuit since introduction of the 8200 electric locomotive. But problem that quick maintenance is difficult and its cost is increasing occurs because major components of the power conversion unit are slowly discontinued. To solve these, in this paper, it was analyzed the response characteristic of the propulsion system modeling of the 8200 electric locomotive using IGBT which is applied recently to ensure propulsion control technology. As results of response for a Propulsion system modeling, it show that a power conversion unit is controlled by PLL(Phase-locked loop) and SVPWM(Space Voltage PWM) respectively.

Research on Application of Precast-Assemble Technology to Road Maintenance Engineering

Through research on precast assembling structural design and construction technology in cement concrete pavement maintenance engineering, this paper brings forward reasonable size for precast assembling slab in cement concrete pavement maintenance engineering to improve original precast assembling construction technology and brings forward effective improvement measures for original construction technical difficulties. And simultaneously, through making a comparison of socioeconomic benefits among precast assembling maintenance mode, cast-in-place ordinary concrete maintenance mode , cast-in-place early-strength concrete maintenance mode and cast-in-place reinforced concrete, uses that precast assembling maintenance technology is a cement concrete pavement quick maintenance technology with extremely high performance price ratio.

Expert System of Fault Diagnosis for Gear Box in Wind Turbine

Gear box is one of the key components in wind turbine. To make timely and accurate diagnosis for gear box, an expert system based on fault tree analysis is developed in this paper. Firstly, a fault tree model is established in accordance with the structural features of wind turbine gearbox. On basis of the fault tree model, qualitative analysis and quantitative analysis of the gearbox faults are carried out afterwards. Finally, a Web-oriented expert system is developed by C# on the .NET platform which will save the fault diagnosis time significantly and make the expert solution for the fault of gear box to achieve the precise and quick maintenance more effectively.