System Analysis Model Research Articles

Sustainable energy system analysis modeling environment: Analyzing life cycle emissions of the energy transition

One of the global community’s most significant contemporary challenges is the need to satisfy growing energy demand, while simultaneously achieving very significant reductions in the greenhouse gas (GHG) emissions associated with the production, delivery, and consumption of energy. The energy sector is transforming via the convergence of power, transportation, and industrial sectors and inter-sectoral integration. To assess the level of decarbonization achieved through this change, one needs to study the carbon footprint of the energy system as a whole. Here, we present a novel, system-scale energy analysis tool, the Sustainable Energy System Analysis Modelling Environment (SESAME), to assess the pathway- and system-level GHG emissions of today’s changing energy system. The underlying analytic tool constitutes more than a thousand individual energy pathways. SESAME provides a consistent platform to estimate life cycle GHG emissions of all stages of the energy sector. Furthermore, the system representation is embedded into the tool for power and transportation sectors. The developed novel architecture, and implications of energy choices for example scenarios (vehicle fleet projections for US and generator-level hourly power generation) are presented to demonstrate SESAME’s high-resolution analysis capabilities. Impact of operational variations such as partial loading of power generation units and technology choices, such as treatment of the same crude oil in different refinery configurations, is explored.

A study on measurement system analysis in the presence of indeterminacy

A study on the neutrosophic measurement system analysis model (NMSAM) is introduced in the paper. The proposed NMSAM helps the industrial engineers to see the capability of gauge in measuring the product in an uncertain environment. Various gauge capability evaluation criteria in the presence of indeterminacy is also discussed. The efficiency of the proposed NMSAM is given with the help of an industrial example. From the study, it is concluded that the proposed NMSAM performs better than the existing measurement system analysis model (MSAM).

RETRACTED: Research on the innovation of college English teaching based on curriculum thinking

In order to realize the quantitative evaluation and analysis of the effect of college English teaching innovation reform, this paper puts forward the evaluation model of college English teaching innovation reform based on curriculum thinking, establishes the big data analysis model of college English teaching innovation reform effect, analyzes the constraint parameters of college English teaching innovation reform effect evaluation by means of statistical quantitative analysis, and abstracts the entropy characteristic quantity of big data, which is the effect of college English teaching innovation reform. The methods of spatial game equilibrium control and fuzzy decision are used to optimize and evaluate the effect evaluation of college English teaching innovation reform, the expert system analysis model of college English teaching innovation reform effect evaluation is established, and the hierarchical grey relational analysis method is used to carry out adaptive optimization and decision control for the evaluation of college English teaching innovation reform effect. The curriculum ideological and political model is used to optimize the reform of college English teaching innovation, and the quantitative analysis of the effect of college English teaching innovation reform is realized. The test results show that this method can effectively realize the evaluation decision of college English teaching innovation reform, with high reliability and strong innovative learning ability.

Identification of automatic systems for acoustic emission diagnostics

The difficulties of automation control, which are connected with variability of input parameters and complexity of mathematical description of internal dynamic processes in the controlled object, are noted. The features of categorical concepts of automation of control of acoustic-emission diagnostics control are formulated and marked: control object, control system, control functions. The mathematical formalism of modeling the energy spectrum of acoustic emission signals is presented. A discrete and continuous approach to describing the oscillatory properties of the internal structure of a material under load is used. The structural model of the basic stages of management is offered, which includes multidimensional input of diagnostics information, ensuring the controllability of products, informatization of diagnostic parameters, direct measurements, identification of the current state of the object. Functional purposes of the acoustic emission diagnostics system have been determined. On the basis of generalization of information on experimental studies of the effect of stresses under uniaxial loading and four-point bending on the parameters of acoustic emission signals, data on the influence of deformation processes on the information parameters of AE steels and composite materials were investigated and systematized. Areas of their application and rational use are established. It is noted that most of the experimental works in domestic and foreign practice are devoted to the influence on the material of one type of deformation measurements of the structure of materials, while during the operation of structures the material is subjected to a complex effect of complex loads. An algorithm for identification of systems for automatic control of acoustic emission diagnostics has been developed, which differs taking into account the variety of factors affecting the initial variables, the complexity of their interactions and estimates using expert evaluation, system analysis and simulation modeling.

Semi-Analytical Model for Design and Analysis of On-Orbit Servicing Architecture

Robotic on-orbit servicing (OOS) is expected to be a key technology and concept for future sustainable space exploration. This paper develops a novel semi-analytical model for OOS system analysis, responding to the growing needs and ongoing trend of robotic OOS. An OOS infrastructure system is considered whose goal is to provide responsive services to the random failures of a set of customer modular satellites distributed in space (e.g., at the geosynchronous orbit). The considered OOS architecture comprises a servicer that travels and provides module-replacement services to the customer satellites, an on-orbit depot to store the spares, and a series of launch vehicles to replenish the depot. The OOS system performance is analyzed by evaluating the mean waiting time before service completion for a given failure and its relationship with the depot capacity. By uniquely leveraging queueing theory and inventory management methods, the developed semi-analytical model is capable of analyzing the OOS system performance without relying on computationally costly simulations. The effectiveness of the proposed model is demonstrated using a case study compared with simulation results. This paper is expected to provide a critical step to push the research frontier of analytical/semi-analytical model development for complex space systems design.

Study on weak link of energy utilization in oil transfer station system: Insights from energy level analysis method

In this paper, an energy level analysis model of oil transfer station system is established, which is divided into oil transfer station subsystem and pipeline network subsystem. From the perspective of the level of energy, the system is evaluated and optimized by virtue of using energy level analysis method and combining with the ”three box” analysis model. Moreover, the energy level evaluation indexes of import and export, energy level difference and energy level balance coefficient, are calculated in terms of the calculation results. Then the energy utilization diagrams (EUD) are drawn, it can be seen that more than 95% of the supply energy in the oil transfer station subsystem is provided by gas. The energy level difference of the heating furnace is the largest, which can be seen intuitively that the heating furnace is the weak link of energy utilization in the whole system. Based on the influencing factors, the corresponding energy saving and consumption reduction measures are preliminarily proposed.

Energy projection of the seawater battery desalination system using the reverse osmosis system analysis model

Water-stressed countries have been shifting their sources of clean water from inland freshwater to seawater. This led to a comprehensive exploration of seawater desalination processes to address water scarcity; however, membrane processes have expensive operational costs and high energy consumption. In this regard, this study presented a novel energy self-sufficient desalination system design that incorporates rechargeable seawater batteries as an additional energy storage system. Experimental data were projected using the reverse osmosis system analysis model to determine the configuration that achieved the lowest energy consumption and highest charging rate. The results show that the seawater battery achieved a satisfactory desalination performance with >90% and 74%−82% removal of sodium and chloride ions from actual water samples, respectively. Among the configurations, using ultrafiltration as pretreatment and applying 1.8 mA as initial current yielded the lowest energy consumption (1.35 kWh/m3) and the highest energy charging rate (1.01). Compared to the conventional reverse osmosis desalination plants (2.83 kWh/m3), the seawater battery-desalination system has a huge potential in addressing the major disadvantages of current desalination technologies.

A Generalized Unit Commitment and Economic Dispatch Approach for Analysing the Polish Power System under High Renewable Penetration

The achievement of carbon neutrality requires a deep transformation of the Polish power sector. This paper analyses the impact of increased electricity generation from wind and solar technologies envisaged in the newest version of the Energy Policy of Poland until 2040 on the operation of dispatchable generators in 2030. The analysis was carried out using the Model of Economic Dispatch and Unit commitment for System Analysis (MEDUSA) model, which solves a mixed integer problem related to unit commitment and economic dispatch in electrical power production. At first, the model was validated based on the real operation data from 2018. Next, five scenarios were built to analyse the operation of the system in 2030. The overall result of the study is that the safest solution from the point of view of power system stability is to extend the decommissioning of coal units of 200 and 300 MW classes, to invest in renewable energy sources (RES) according to the energy policy, to build new gas power plants with the total capacity of ca. 4 GW, and to enforce Demand Side Management (DSM) programs for shifting the electrical load. The proposed framework for the optimization of power system planning helps to avoid wrong investment decisions that would have a negative impact on energy prices.

Design and modeling of a novel electromechanical optical micro-scanner

This article presents a design principle of a novel small-sized compliant optical micro-scanner with two translational (X, Y) and a rotational (θz) degree of freedoms (3-DOFs). A novel normal-stress electromagnetic actuator system is proposed to provide 3-DOFs actuating forces with the working strokes of hundreds of microns for the optical micro-scanner within a very compact structural envelope. The electromagnetic actuator system can not only generate high actuating force density which is similar to solenoid, but also has linear force-current relations along three actuating axes by adopting magnetic configuration design strategy. The theoretical analysis model of the actuator system is derived by using equivalent magnetic circuit method and the actuating force is analyzed through energy store method. Permanent magnet flux leakage and magnetic saturation of stator core in excitation situation are taken into consideration to improve the modelling accuracy. Finite element analysis (FEA) software is utilized to investigate the critical characteristics of the micro-scanner. By FEA comparison, both the theoretical and FEA results show that the actuating force generated by the designed electromagnetic actuator system has a linear relationship with the excitation current. Compare with the normal optical micro-scanner actuated by voice coil motors (VCMs) or piezoelectric (PZT) actuators, the normal-stress based micro-scanner can not only offer movements with three degrees of freedom within a very compact structural envelope, but also achieve high actuating forces which are over 6 times higher than the same sized VCM-actuated micro-scanners. The workspace of this scanner is more than 800 × 800 μm2, which is more than 8 times larger than that of PZT-actuated scanner. The volume of this stage is 60 * 60 * 14 mm3, resulting in a high area-ratio of 1.2%. The cross-axis coupling motion is less than 24 μm at the full primary motion. The resonant frequencies of the two working axes are about 184 Hz.

Метод рационального распределения учебных дисциплин в системе высшего учебного заведения

One of the tasks of the management of the educational institution is the development of measures aimed at improving the training of their graduates. The purpose of this article is to improve the system of planning the workload between disciplines at the university. To achieve this, an optimization model was built on the basis of system analysis and mathematical modeling. As a result, the introduction of this model in the management of the educational process will make it possible to distribute the load within the framework of one direction in such a way as to make it easier for students to master the educational material.

Risk Assessment of Ship Navigation Collision in Inland Waterway Transportation System Based on Bayesian Method

Due to the high risk and uncertainty of ship navigation, the identification, early warning and control of ship navigation risks have always been studied by scholars. In recent years, water traffic accidents have occurred frequently, resulting in an incalculable number of casualties and property losses, which makes ship navigation risk management more and more a research hotspot. Ship navigation risk is a complex system consisting of a number of risk factors. The assessment of it is a systematic project aimed at clarifying the risk factors that need to be controlled. The purpose of this paper is to use Bayesian methods to assess the risk of navigational collisions in inland waterway transport systems. In this paper, the Bayesian network and the inland waterway transportation system ship navigation collision risk simulation are combined, and the concept of the ship navigation collision risk analysis model of the Bayesian network inland waterway transportation system is proposed. This method essentially utilizes three important characteristics of Bayesian network itself—complex relation representation ability, probability uncertainty representation ability and causal reasoning ability. Through the expert experience and ship navigation collision risk simulation of inland waterway transportation system the data is learned, the knowledge contained therein is mined, and the ship navigation collision risk analysis model of the inland waterway transportation system is established, and the risk assessment analysis is carried out based on the model. Through a large number of experiments, the proposed method can better model the navigation state of the ship, quantify the navigation risk of the ship, and identify the navigation anomaly data.

АНАЛИЗ ЭФФЕКТИВНОСТИ ПРОМЕЖУТОЧНОГО ПЕРЕГРЕВА ПАРА В КОТЛЕ-УТИЛИЗАТОРЕ ГТ-НАДСТРОЙКИ ТЕПЛОФИКАЦИОННОГО ЭНЕРГОБЛОКА

Актуальность. Модернизация существующего теплоэнергетического оборудования является одним из приоритетных направлений развития энергетики. Внедрение газотурбинной установки в тепловую схему паросилового энергоблока с сохранением инфраструктуры станции может быть менее затратным вариантом по сравнению с сооружением новых энергоблоков парогазовых установок. Одним из малозатратных вариантов интеграции газотурбинных установок в тепловую схему паротурбинных энергоблоков является использование тепловой мощности котла-утилизатора для промежуточного перегрева отработавшего в паровой турбине рабочего тела с утилизацией оставшейся теплоты для нагрева питательной воды и основного конденсата. По сравнению с наиболее распространенными схемами с вытеснением регенерации в котел-утилизатор предложенный альтернативный вариант позволяет повысить тепловую экономичность паротурбинного контура. Такая схема уступает в тепловой экономичности схеме с параллельной генерацией пара в котле-утилизаторе, однако не требует испарительного контура, что упрощает проектирование котла-утилизатора. Проведенный анализ энергетических характеристик газотурбинных установок показал необходимость исследования схемы и параметров промежуточного перегрева для теплофикационных энергоблоков с учетом режимов работы паровой турбины. Объект: паротурбинный энергоблок Т–165/210–130 с газотурбинной надстройкой (ГТ-надстройкой) для промежуточного перегрева отработавшего в паровой турбине рабочего тела с утилизацией оставшейся теплоты для нагрева питательной воды и основного конденсата. Цель: выбор схемы и расчет оптимальных параметров промежуточного перегрева применительно к паротурбинному энергоблоку Т–165/210–130 с ГТ-надстройкой, анализ его основных показателей при работе по тепловому графику при изменении температуры промежуточного перегрева в котле-утилизаторе. Методы: системный анализ и математическое моделирование. Результаты. Разработана математическая модель и программа расчета предложенной схемы. Выполнен анализ особенностей, связанных с организацией промежуточного перегрева в котле-утилизаторе ГТ-надстройки. Показано, что эффективность работы теплофикационного энергоблока с промежуточным перегревом может быть повышена путем организации промежуточного перегрева в котле-утилизаторе ГТ-надстройки. Определено, что в этом случае наивысшая экономичность паротурбинного энергоблока с ГТ-надстройкой при работе в расчетном теплофикационном режиме достигается при температуре промежуточного перегрева ниже номинального значения.

Decomposition and Aggregation-Based Real-Time Analysis of Assembly Systems With Geometric Machines and Small Batch-Based Production Tasks

Steady-state analysis on production systems, especially serial lines with rigid production mode, have been carried out in a large amount of research literature. With the development of the advanced manufacturing technologies, as well as the national strategies, for example, Made in China 2025, real-time performance evaluation, prediction, production management, and efficient control of systems with flexible production mode are gradually becoming important issues. Under the assumption of assembly systems with small batch-based production tasks, we develop a mathematical model for the real-time performance analysis of such systems with the geometric machine reliability model, which is applicable in many manufacturing environments. The formulas for real-time performance analysis are derived first using the Markovian approach for three-machine assembly systems. Then, based on the idea of decomposition and aggregation, an algorithm with high accuracy and efficiency for system real-time performance approximation is proposed. Finally, the decomposition and aggregation-based real-time analysis approach is extended to the generalized assembly systems. <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Note to Practitioners</i> —As the concept of manufacturing intelligence being proposed and promoted, system flexibility appears frequently in production in recent years. A flexible production refers to the implementation of small batch-based production with multitype of products on the same production line, by quick setup or machine adjustments. The steady-state analysis method that is traditionally used might be not applicable in this case since most of the production process is in transient state. An approximation-based analytical method, for real-time performance evaluation of assembly systems with small batch-based production tasks and with machines having the geometric reliability model, is proposed. The algorithm developed in this article can be utilized by production managers and engineers, with which the real-time performance of the systems can be predicted with high accuracy. It can also provide assistance for decision-making on activities of production control.

Systemic Economic Problems and Effective Mechanisms for Achieving Financial Productivity

At present, when changes in all areas are accelerated, the effective innovative development of the national economy requires the use of innovative mechanisms for managing the economies of industries and regions that contribute to an increase in the rate of economic growth. It is important to understand and use the mutual influence of industries on each other and on overall development in order to create an integrated mechanism for ensuring the productivity of the economy, limiting the growth of prices and the interest of industries in reducing costs and prices for their products. A necessary condition for the stability of the economy is financial productivity, i.e. the exclusion of price increases, since even their growth in products of at least one sector of the economy (especially systemically important), causes an avalanche-like, uncontrolled rise in prices in other sectors. The objectives of this article were to consider precisely these issues and reflect the results of scientific research in this direction. The methods of system analysis, economic and mathematical modeling, the concept of managing the financial productivity of the economy based on research and analysis of inter-industry relations are used. The article examines the systemic problems of a developing economy (raw material orientation), analyzes the state and potential of the regional economies, their contribution to the development of the national economy, examines and analyzes the model of financial productivity using the two-sector model of Kazakhstan's intersectoral balance, proposes control mechanisms for achieving financial productivity: cost-effective mechanisms pricing and taxation; It is shown that their use leads to the interest of industries in lowering costs and prices for products of industries. Recommendations on the use of the considered models are formulated.

Comparative life cycle assessment of geothermal power generation systems in China

This study concerns the assessment of the environmental impacts of geothermal power generation systems using life cycle assessment approach. Particularly, four types of typical geothermal power generation systems in China based on different technologies (double flash, single flash, binary and enhanced geothermal system) are involved in the case study, and critical environmental impacts of acidification potential, global warming potential and eutrophication potential are evaluated for the above geothermal power generation systems based on their energy system analysis models. Analytical results reveal that environmental impacts of geothermal power generation systems are significantly affected by well drilling process. In general, construction process contributes more than 60 % of acidification potential while running process is the major source of eutrophication potential. Environmental impacts vary for each geothermal power generation system due to their different configurations as well as reservoir conditions (namely geothermal gradient). Acidification potential, global warming potential and eutrophication potential of the cases are among 30.43∼250.05 mgSO2/kWh, 3.88∼80.49 gCO2/kWh, 4.78∼32.50 mgPO43−/kWh. In particular, environmental impacts of geothermal power generation systems can be largely reduced with a larger geothermal gradient, and it’s the reason that South West double Flash geothermal power generation system is with the lowest environmental impacts.

Generalized oscillator model for nonlinear vibration analysis using quasi-static cubication method

A generalized oscillator model for nonlinear vibration analysis of various mechanical systems was proposed and solved using the quasi-static cubication method. The proposed generalized oscillator model is useful for introducing and discussing the nonlinear vibration models of several oscillatory systems. To establish the accuracy of the quasi-static cubication method for the generalized oscillator model, a number of simulations were carried out for the nonlinear vibration models of common mechanical systems derived from the generalized oscillator model. The results obtained were found to be in good agreement with exact solutions and other approximate solutions found in the literature. Furthermore, the quasi-static cubication method was found to be accurate for a wide range of oscillation amplitudes. A significant feature of the quasi-static cubication method is its simplicity and accuracy; hence, it is considered an efficient technique for nonlinear vibration analysis in undergraduate and post-graduate courses on dynamics.

Modelling of Electro-mechanical Servo System Based on the Planetary Roller Screw Mechanism

Taking the electro-mechanical servo system as the research object, considering the contact stiffness, friction and clearance of the main components in the electro-mechanical servo system, the analysis model of the electro-mechanical servo system based on Planetary roller screw mechanism (PRSM) is established by using AMESim software. The results showed that the response speed of the system slowed down when the friction of PRSM was taken into account. The larger the clearance or the smaller the stiffness, the greater the fluctuation amplitude of the system response. After the controller was adjusted, the steady-state error of the system caused by the load force can be reduced quickly.

Identifiability analysis of load model by estimating parameters' confidential intervals

The identification of load model parameters from practical measurement data has become an essential method to build load models for power system simulation, analysis and control. In practical situations, the accuracy of load model parameters identification results is impacted by data quality and measurement accuracy, 1 which leads to the problem of identifiability. In this paper, an identifiability analysis methodology of load model parameters by estimating the confidential intervals (CIs) of the parameters is proposed. The load model structure and the combined optimization and regression method to identify the parameters are introduced first. Then, the definition and analysis method of identifiability are discussed. The CIs of the parameters are estimated through the profile likelihood method, based on which a practical identifiability index (PII) is defined to evaluate identifiability quantitatively. Finally, the effectiveness of the proposed analysis approach is validated by the case study results in a practical provincial power grid. The results have shown that the impact of various disturbance magnitudes, measurement errors and data length can all be reflected by the proposed PII. Furthermore, the proposed PII can provide guidance in data length selection in practical load model identification situations.

Economic Benefit Evaluation of Waste Heat Recovery in Coal-fired CHP System Based on Exergoeconomic Analysis

As one of the main energy-saving measures and an important part of the power industry, CHP (combined heat and power) has achieved rapid development in recent years, which have the advantages of low heat loss, flexible operation mode, and cascade utilization of energy compared with heating boilers and traditional power plants. However, there is a lack of reasonable evaluation of CHP systems, due to the difference in energy quality of heat and electricity. It is urgent to establish considerable and reasonable evaluation indexes of CHP systems. In addition, in the actual operation of CHP plant, a large amount of waste heat is released into the environment, and there is still room for further improvement in the waste heat utilization. In this paper, an exergoeconomic analysis model of CHP system with circulating fluidized bed boiler is established, and the economic benefits of waste heat recovery in CHP systems are studied. After the application of waste heat recovery, the system exergy efficiency increased from 32.94% to 34.14%. The unit exergoeconomic cost of electricity and process steam did not change much, but the unit exergoeconomic cost of heating decreased by 17.1%, which indicates the economic benefits of waste heat recovery.

Steady State Energy Flow Analysis for Energy Internet Planning

The planning and design of energy Internet is an important work. The basis of this work is energy flow analysis of the design network. In this paper, the energy flow analysis model of typical gas-electricity interconnection system is established. The mismatch equations and iterative algorithm for energy flow solution are given. The effectiveness of the algorithm is verified by a typical gas-electric interconnection example.