The potential absorption of solar energy in photovoltaic thermal (PVT) hybrid solar collectors at different tilt angles was compared in the present study. The optimal tilt angles were tested in three variants: during 1 day, 1 year and a period of 30 years. Simulations were performed based on actual weather data for 30 years, including average hourly total radiation, insolation and air temperature. The apparent movement of the Sun across the sky, solar radiation properties, and the electrical and thermal efficiency of a PVT collector were also taken into account in the simulation model. The optimal orientation of the absorber surface was determined by solving an optimization task. The results of the study indicate that in the long-term perspective, the collector’s performance is maximized when the absorber is positioned toward the south at an elevation angle of 34.1°.

In this paper, a simulations model of a seasonal thermal energy storage (TES) reactor integrated into a house heating system is presented. The water vapour chemisorbing reactor contains a composite material composed of silica gel and hydrated magnesium carbonate (nesquehonite, MgCO3·3H2O) that can be produced by a carbon capture and storage by mineralisation process. The performance of the TES to supply winter heat instead of electrical resistance heat is analysed. Dividing the reactor into a few units (connected in series) for better heat output and storage capacity as developed by the authors is compared to one unit or parallel unit solutions. The heating system components are an exhaust air heat pump, solar collectors and a heat recovery ventilation unit (HRV). The TES is used as heat source during colder periods, which implies improved efficiency and coefficient of performance (COP). Around 70% of electrical resistance heat, assisting an exhaust air heat pump during cold periods, c... [more]

Electric vehicle (EV) charging stations have become prominent in electricity grids in the past few years. Their increased penetration introduces both challenges and opportunities; they contribute to increased load, but also offer flexibility potential, e.g., in deferring the load in time. To analyze such scenarios, realistic EV data are required, which are hard to come by. Therefore, in this article we define a synthetic data generator (SDG) for EV charging sessions based on a large real-world dataset. Arrival times of EVs are modeled assuming that the inter-arrival times of EVs follow an exponential distribution. Connection time for EVs is dependent on the arrival time of EV, and can be described using a conditional probability distribution. This distribution is estimated using Gaussian mixture models, and departure times can calculated by sampling connection times for EV arrivals from this distribution. Our SDG is based on a novel method for the temporal modeling of EV sessions, and... [more]

The targets of global CO2 reduction outline the importance of decarbonizing the heating and cooling sector, which consume half of the final energy in the European Union (EU). Consequently, heating network operators must adapt to growing requirements for carbon neutrality. Energy system modeling allows the simulation of individual network compositions and regulations, while considering electricity market signals for a more efficient plant operation. The district heating model, programmed for this work, covers a measured heat demand with peak load boiler, biomass-fired combined heat and power (CHP) plant, and biomass heating plant supply. The CHP plant reacts to electricity prices of the European Power Exchange market and uses a long-term heat storage to decouple heat and electricity production. This paper presents the results of three annual simulation scenarios aimed at carbon neutrality for the analyzed heating network. Two scenarios achieve a climate-neutral system by replacing the p... [more]

Increasing energy demand in buildings with a 40% global share and 30% greenhouse gas emissions has accounted for climate change and a consequent crisis encouraging improvement of building energy efficiency to achieve the combined benefit of energy, economy, and environment. For an efficient system, the optimization of different design control strategies such as building space load, occupancy, lighting, and HVAC becomes inevitable. Therefore, interdisciplinary teamwork of developers, designers, architects, and consumers to deliver a high-performance building becomes essential. This review aims to endorse the importance of Building Performance Simulation in the pre-design phase along with the challenges faced during its adaptation to implementation. A morphology chart is structured to showcase the improvement in Building Energy Efficiency by implementing Building Performance Simulation for different building energy systems and by implementing various energy efficiency strategies to achie... [more]

The research is aimed at comparing residential building windows’ thermal performance with and without thermal shutters, and at examining thermal shutters’ performance upon being insulated with various types of insulation, glares, outside temperatures, and solar radiation. As an example, one case study based out of the UAE is chosen, covering the status of the housing typology and traits of building energy consumption. The study uses the primary tool of computer simulation software “DesignBuilder” to examine the impact of window shutters design on energy consumption and environmental impact. It was found that the usage of conventional insulating materials within the shutters is sufficient for the house to attain a reduction in heat gain of up to 50%. Furthermore, the application of the rolling shutters with analyzed control strategies recorded a potential reduction in equivalent CO2 emissions level, up to 15%, which would decrease the environmental burden on a national level. The simula... [more]

The 2D P colonies is a version of the P colonies with a two-dimensional environment designed for observing the behavior of the community of very simple agents living in the shared environment. Each agent is equipped with a set of programs consisting of a small number of simple rules. These programs allow the agent to act and move in the environment. The 2D P colonies have been shown to be suitable for the simulations of various (not only) multi-agent systems, and natural phenomena, like flash floods. The Grey wolf algorithm is the optimization-based algorithm inspired by social dynamics found in packs of grey wolves and by their ability to create hierarchies, in which every member has a clearly defined role, dynamically. In our previous papers, we extended the 2D P colony by the universal communication device, the blackboard. The blackboard allows for the agents to share various information, e.g., their position or the information about their surroundings. In this paper, we follow our... [more]

In a semiconductor fab, wafer lots are processed in complex sequences with re-entrants and parallel machines. It is necessary to ensure smooth wafer lot flows by detecting potential disturbances in a real-time fashion to satisfy the wafer lots’ demands. This study aims to identify production factors that significantly affect the system’s throughput level and find the best prediction model. The contributions of this study are as follows: (1) this is the first study that applies machine learning techniques to identify important real-time factors that influence throughput in a semiconductor fab; (2) this study develops a test bed in the Anylogic software environment, based on the Intel minifab layout; and (3) this study proposes a data collection scheme for the production control mechanism. As a result, four models (adaptive boosting, gradient boosting, random forest, decision tree) with the best accuracies are selected, and a scheme to reduce the input data types considered in the models... [more]

The paper deals with the modeling of a slip-ring induction motor. Induction motors are very often used in industry and their suitable model is needed to reduce control and operating costs. The identification process of self and mutual inductances of the stator and rotor, and mutual inductances between them in the function of the rotor rotation angle is presented. The dependence of each inductance on the rotor rotation angle is determined experimentally. The inductance matrix is then formulated. Taking the magnetic energy of the inductances and kinetic energy of the rotor into account, the Lagrange function is defined. Next, the motor motion equations are obtained. After making some algebraic transformations and using the dimensionless variables, the motion equations of electric circuits and of the mechanical equation are written separately in the forms facilitating their solution. The solution was obtained using the Simulink model for the stator and rotor currents in the form of vector... [more]

The electrification of the mobility and heating sectors will significantly change the electrical behavior of households in the future. To investigate this behavior, it is important to include the heating and mobility sectors in load profile models. Existing models do not sufficiently consider these sectors. Therefore, this work aims to develop an integrated, consistent model for the electrical and thermal load of private households and their mobility behavior. The model needs to generate regionally distinct profiles depending on the building, household and resident type and should be valid for Germany. Based on a bottom-up approach, a model consisting of four components is developed. In an activity model based on a modified Markov chain process, persons are assigned to activities. The activities are then allocated to devices in the electrical and thermal models. A mobility model assigns distances to the journey activities. The results of the simulation to validate the model shows an av... [more]

The effect of ventilation bars on the porosity of a sinter bed charged on a sinter machine was investigated. The behavior of the sinter feed was calculated by discrete element method (DEM) simulation. By taking into account the adhesion force, the sinter feed in the wet state was represented and the simulation parameters were determined to reproduce the experimental values of the angle of repose. The porosity of the sinter bed was calculated, and the mechanism of the formation of the packing structure and the cause of the distribution of porosity in each region were clarified. As a result, it is shown that in the case of shear flow, the higher the powder pressure during flow, the higher the porosity.

City bus transport electrification has a strong potential of improving city air quality, reducing noise pollution and increasing passenger satisfaction. Since the city bus operation is rather deterministic and intermittent, the driving range- and charging-related concerns may be effectively overcome by means of fast charging at end stations and/or slow charging in depot. In order to support decision making processes, a simulation tool for planning of city bus transport electrification has been developed and it is presented in this paper. The tool is designed to use real/recorded driving cycles and techno-economic data, in order to calculate the optimal type and number of e-buses and chargers, and predict the total cost of ownership including investment and exploitation cost. The paper focuses on computationally efficient e-bus fleet simulation including powertrain control and charging management aspects, which is illustrated through main results of a pilot study of bus transport electr... [more]

This manuscript presents the simulation tests of an aerospace penetrator conducted to check the device’s validity and functionality. For this work, the numerical model was created on the basis of engineering data, the laboratory model of the tube reluctance actuator was created on the basis of the numerical model, and a set of simulations were executed on the basis of both presented. Moreover, the mathematical model was supplemented by precise boundary conditions. The main goal was the analysis of the introduced device’s properties by comparing them to experimental values. Three different variants were taken into account to check the construction functionality and to study the most important parameters, e.g., the hammer displacement, hammer velocity, eddy currents and overall electromagnetic properties of the penetrator’s hammer displacement. The high-end values of the applied components were derived on the basis of the results and are presented in the summary of the concluded work. An... [more]

Torrefied empty fruit bunch (EFB) co-firing is a promising technology to reduce emissions from coal-fired power plants. However, co-firing can influence the combustion and heat transfer characteristics in a coal boiler. In order to study the feasibility of co-firing application of torrefied EFB (T-EFB) in boilers, the combustion characteristics, gas emissions and heat flux distribution were analyzed, respectively. First, the kinetic parameters of T-EFB devolatilization and char oxidation were obtained by experimental analysis. Second, the computational fluid dynamics (CFD) analysis was applied to the actual 500 MWe boiler simulation to further evaluate the differences in the co-firing performance parameters (combustion characteristics and emissions) of the T-EFB and the heat transfer characteristics within the boiler. Numerical results show that T-EFB co-firing can improve the ignition characteristics of pulverized coal, reduce the formation of unburned particles. When the blending rat... [more]

The paper presents the study of an anti-lock braking system (ABS) that has been complemented by a fuzzy controller. The fuzzy controller was used to improve the braking performance of the vehicle, particularly in critical situations, for example, when braking a vehicle on wet road. The controller for the ABS was designed in the MATLAB/Simulink program. The designed controller was simulated on a medium-size vehicle model. During testing, three braking systems were simulated on the vehicle model. We compared the performance of a braking system without an ABS, a system with a threshold-based conventional ABS, and a braking system with the proposed ABS with a fuzzy controller. These three braking systems were simulation tested during braking the vehicle on a dry straight road and on a road with combined road adhesion. A maneuverability test was conducted, where the vehicle had to avoid an obstacle while braking. The results of each test are provided at the end of the paper.

The building sector contributes approximately one third of the total energy consumption worldwide. A large part of this energy is used for the heating and cooling of buildings, which can be drastically reduced by use of energy-efficient glazing. In this study, we performed building energy simulations on a prototypical residential building, and compared commercially available static (low-e, solar IR blocking) to newly developed adaptive thermochromic glazing systems for various climate regions. The modeling results show that static energy-efficient glazing is mainly optimized for either hot climates, where low solar heat gain can reduce cooling demands drastically, or cold climates, where low-e properties have a huge influence on heating demands. For intermediate climates, we demonstrate that adaptive thermochromic glazing in combination with a low-e coating is perfectly suited. The newly developed thermochromic glazing can lead to annual energy consumption improvement of up to 22% in c... [more]

Air quality and energy consumption are among the top ten environmental priorities in seaports as stated by the European Sea Ports Organization. Globally, it is estimated that 15% of energy consumption can be attributed to refrigeration and air conditioning systems in fishing activities. There is a real need to understand energy usage in fishery ports to help identify areas of improvements, with a view to optimize energy usage and minimize carbon emissions. In this study, we elaborate on ways in which a simulation capability can be developed at the community level with a fishery port, using a real-world case study seaport in Milford Heaven (Wales, UK). This simulation-based strategy is used to investigate the potential of renewable energy, including local solar farms, to meet the local power demand. This has informed the development of a simulation-based optimization strategy meant to explore how smart energy communities can be formed at the port level by integrating the smart grid with... [more]

Volatility in energy markets has made the purchase of battery electric vehicles (BEV) or hybrid vehicles (HEVs) attractive versus internal combustion engine vehicles (ICEVs). However, the total cost of ownership (TCO) and true environmental effects, are difficult to assess. This study provides a publicly available, user-driven simulation that estimates the consumer and environmental costs for various vehicle purchase options, supporting policymaker, producer, and consumer information requirements. It appears to be the first to provide a publicly available, user interactive simulation that compares two purchase options simultaneously. It is likely that the first paper to simulate the effects of solar recharging of electric vehicles (EV) on both cost-benefit for the consumer and environmental benefit (e.g., carbon dioxide, oxides of nitrogen, non-methane organic gasses, particulate matter, and formaldehyde) simultaneously, demonstrating how, as an example, solar-based charging of BEVs an... [more]

In this study, the performance evaluation of an adsorption chiller (AD) system with three different adsorbents—silica-gel, aluminum fumarate, and FAM-Z01—was conducted to investigate the effects of adsorption isotherms and physical properties on the system’s performance. In addition, the performance evaluation of the AD system for a low inlet hot-water temperature of 60 °C was performed to estimate the performance of the system when operated by low quality waste heat or sustainable energy sources. For the simulation work, a two-bed type AD system is considered, and silica-gel, metal organic frameworks (MOFs), and ferro-aluminophosphate (FAPO, FAM-Z01) were employed as adsorbents. The simulation results were well matched with the laboratory-scale experimental results and the maximum coefficient of performance (COP) difference was 7%. The cooling capacity and COP of the AD system were investigated at different operating conditions to discuss the influences of the adsorbents on the system... [more]

Currently, the oil industry deals with the challenge of produced-water proper disposal, and the membrane-separation technology appears as an important tool on the treatment of these waters. In this sense, this work developed a mathematical model for simulating the oil/water separation by a ceramic membrane. The aim was to investigate the thermal aspects of the separation process via computational fluid dynamic, using the Ansys CFX® 15 software (15, Ansys, Inc., Canonsburg, PA, USA). Oil concentration, pressure, and velocity distributions, as well as permeation velocity, are presented and analyzed. It was verified that the mathematical model was capable of accurately representing the studied phenomena and that temperature strongly influences the flow behavior.

This paper aims at the optimal designing of a stand-alone microgrid (PV/wind/battery/diesel) system, which can be utilized to meet the demand load requirements of a small residential area in Kasuga City, Fukuoka. The simulation part is developed to estimate the electrical power generated by each component, taking into account the variation of the weather parameters, such as wind, solar irradiation, and ambient temperature. The optimal system design is then based on the Particle Swarm Optimization (PSO) method to find the optimal configuration of the proposed system, using the least-cost perspective approach.

In recent decades, many EU and national regulations have been issued in order to increase the energy efficiency in different sectors and, consequently, to reduce environmental pollution. In the building sector, energy efficiency interventions are usually based on the use of innovative insulated materials and on the installation of cogeneration and tri-generation units, as well as solar technologies. New and retrofitted buildings are more and more commonly being called “smart buildings”, since they are characterized by the installation of electric and thermal power generation units, energy storage systems, and flexible loads; the presence of such technologies determines the necessity of installing Building Energy Management Systems (BEMSs), which are used to optimally manage their operation. The present paper proposes a BEMS for a smart building, equipped with plants based on renewables (photovoltaics, solar thermal panels, and geothermal heat pump), where the heating and cooling demand... [more]

This contribution is focused on the fuel economy improvement of the Miller cycle under part-load characteristics on a supercharged DI (Direct Injection) gasoline engine. Firstly, based on the engine bench test, the effects with the Miller cycle application under 3000 rpm were studied. The results show that the Miller cycle has different extents of improvement on pumping loss, combustion and friction loss. For low, medium and high loads, the brake thermal efficiency of the baseline engine is increased by 2.8%, 2.5% and 2.6%, respectively. Besides, the baseline variable valve timing (VVT) is optimized by the test. Subsequently, the 1D CFD (Computational Fluid Dynamics) model of the Miller cycle engine after the test optimization at the working condition of 3000 rpm and BMEP (Brake Mean Effective Pressure) = 10 bar was established, and the influence of the combined change of intake and exhaust valve timing on Miller cycle was studied by simulation. The results show that as the effect of t... [more]

Characterizing the mechanical behavior of rocks plays a crucial role to optimize the fracturing process in unconventional reservoirs. However, due to the intrinsic anisotropy and heterogeneity in unconventional resources, fracture process prediction remains the most significant challenge for sustainable and economic hydrocarbon production. During the deformation tracking under compression, deploying conventional methods (strain gauge, extensometer, etc.) is insufficient to measure the deformation since the physical attachment of the device is restricted to the size of the sample, monitoring limited point-wise deformation, producing difficulties in data retrieval, and a tendency to lose track in failure points, etc. Where conventional methods are limited, the application of digital image correlation (DIC) provides detailed and additional information of strain evolution and fracture patterns under loading. DIC is an image-based optical method that records an object with a camera and moni... [more]

Decarbonization of energy-intensive systems (e.g., heat and power generation, iron, and steel production, petrochemical processes, cement production, etc.) is an important task for the development of a low carbon economy. In this respect, carbon capture technologies will play an important role in the decarbonization of fossil-based industrial processes. The most significant techno-economic and environmental performance indicators of various fossil-based industrial applications decarbonized by two reactive gas-liquid (chemical scrubbing) and gas-solid CO2 capture systems are calculated, compared, and discussed in the present work. As decarbonization technologies, the gas-liquid chemical absorption and more innovative calcium looping systems were employed. The integrated assessment uses various elements, e.g., conceptual design of decarbonized plants, computer-aided tools for process design and integration, evaluation of main plant performance indexes based on industrial and simulation r... [more]