Energy Point Of View Research Articles

An Integrated Energy Data Analytics Approach for Machine Tools

Efficiency and the reduction of energy consumption in the manufacturing industry are crucial issues for green and sustainable manufacturing. In particular, the machine tool field, which is a representative resources of the manufacturing industry and consumes a large amount of energy, requires the development of a technology capable of monitoring and analyzing data from an energy point of view in addition to existing manufacturing indicators such as productivity improvement and processing quality; however, existing studies have focused on one-dimensional areas such as monitoring energy consumption or developing predictive models in an experimental environment. Therefore, it is necessary to establish a practical and integrated environment by developing more systematic methodologies and supporting systems. In this paper, an integrated approach to the energy consumption of machine tools based on a data analysis is introduced. During the development of the approach, the real-time data processing methods of various sources, such as sensors and computer numerical control interfaces were investigated in a real environment, and the energy consumption models of the target machine’s tools and feeds were defined. An energy data-based comparative analysis method for diagnosing an abnormal state was also developed. In addition, practicality was confirmed through the implementation of the developed approach and the actual application process. Through the results of this paper, a more efficient energy data management and consumption plan can be established, and the convergence of advanced information communication technology can be expected to be the basis for green and sustainable manufacturing.

Vertical green to improve the energy efficiency of buildings

Buildings in Europe consume 40% of total energy consumption and not less than 65% of the total electricity consumption. This work reports the first results of a research developed at the ENEA Casaccia Center, under the Electricity System Research Program (RDS), funded by the Ministry of Economic Development. The experiments were carried out on a demonstration building on which the necessary structures for research activities were built. Among the cultivated vegetable essences, the best results have been obtained with the Parthenocissus varieties, which have reached a leaf coverage of over 3.5 m2 and with the Vitis vinifera varieties with a leaf surface of over 3 m2. From an energy point of view, the data collected, although still preliminary and not definitive, the collected data showed a significant reduction in the surface temperature of the greened facade by over 14°C compared to the non-vegetated areas of the demonstration building. Taking into account the fact that the plant systems are an increasingly important element to improve energy efficiency and environmental sustainability of buildings, further research and experiments are necessary for a more detailed assessment of the biological and agronomic parameters that characterize plant systems when grown on the building to define their influence on the surface temperature of the vegetated facades of buildings and on the energy flows entering the building.

Leading agritourism facilities along Nearly Zero Energy paths: proposal of an easy-to-use evaluation method

The tourist sector, despite the present severe constraints imposed by the sanitary emergence, can be considered as an important component of almost all countries’ economies. In Italy agriturism, in particular, has been experiences a continuously rising trend in recent years. Clearly, such great interest towards these businesses also calls for a deep attention by an energy point of view, in sight of an energy efficiency improvement, hence a lowering of the pressure that such facilities exert to the natural environment. On the other hand, the European Union has been engaged, for a long time, in awarding the tourist accommodations environmental excellence brands, like the EU Ecolabel. Unfortunately, the achievement of such excellence brands requires the capability of managing complex energy and environmental data, which is often not the prerogative of people running such facilities. In order of contributing to overcome this difficulty, and with the aim of helping the addressing of agritourism towards a Nearly Zero Energy path, we propose here a simple approach that does not require the modelling and simulation of the energy behaviour of an agritourism, being essentially based on the application of easy-to-use ARERA (Italian Regulatory Authority for Energy Networks and Environment) datasheets scheme. On purpose, an application of the method, involving two typical Sicilian agritourism, is presented. The obtained results showed the viability of the proposed methodology, although the need of an update and/or replacement of some technical datasheets arose.

Impact of Orientation on the Thermal Performances in Vernacular Buildings in Hot Arid Climate

Morocco faces enormous climatic constraints. A large part of the national territory has a hot and dry climate, hence the importance of the climate aspect in the choice of an energy saving strategy. The use of reinterpreted, decontextualized, totally or partially vernacular architectural techniques and/or forms is visible at different levels in the Maghreb countries. The large-scale integration of this aspect seems to be ignored by the designers. The objective of this research is to evaluate the impact of the building orientation and vernacular architecture towards the occupant comfort, in order to meet its energy and comfort needs at a lower cost on one hand, and on the other hand, to design more efficient collective buildings from a thermal and energy point of view. The proposed methodology allows examining the thermal performances of a traditional building under the climatic conditions of the city of Rissani in order to naturally control comfort summer and winter, in addition to ensure a good thermal comfort without using any heating or cooling system. Finally, the simulations carried out lead to the identification of the optimal orientation that demonstrates an effective reduction in indoor temperatures and a decrease in the large daily fluctuations in these temperatures. The research focuses on the influence of the orientation of a building's facades in relation to the solar radiation and on providing the necessary thermal comfort.

Experimental investigation on the influence of internal heat exchanger in a transcritical CO2 heat pump water heater

In this paper, a transcritical CO2 heat pump water heater prototype was experimentally investigated to research the influence of internal heat exchanger (IHX). In addition, the exergy analysis was carried out based on the experimental data. The results showed that the optimal discharge pressure reduced with the application of IHX, and this reduction could be amplified by the decrease of the ambient temperature, the increase of the water inlet temperature and the increase of the water outlet temperature. From the energy point of view, under the optimal discharge pressure, the coefficient of performance (COP) increased by up to 6.65% and the total power consumption decreased by up to 6.22% via using IHX. Then the influence of IHX on the heat pump cycle was discussed. The results of the exergy analysis showed that the exergy destruction of compressor, gas cooler and evaporator increased, and the exergy destruction of expansion valve decreased with the application of IHX. Furthermore, the product exergy and the total exergy destruction increased, and the exergy efficiency of system decreased in all working conditions. In conclusion, the application of IHX enhanced the energy performance and impaired the exergy efficiency in this research.

Preemphasis Control in Switched-Mode Power Converter for Energy-Efficient Wide Bandwidth Visible Light Communication

Visible light communication (VLC) shows up as a trend for short-range wireless networks. However, from the energy point of view, there is still a lack of light-emitting diode (LED) drivers that support considerable data rates with high efficiency. Common solutions would include switched-mode power converters (SMPCs), which are efficient, but they still face challenges regarding the modulation bandwidth (BW) for VLC. Thus, this article presents an analysis of a preemphasis (PE) technique to overcome the low BW constraint of the SMPC. The PE filter is used to render the frequency response of the circuit to provide a wider BW for communications. It operates on the duty cycle of the converter, and it dictates the average output signal value over a switching period. Finally, the technique is presented in a theoretical approach with the aligned experimental results in a 21.5-W buck-converter-based LED driver switched at 1 MHz, with 89% efficiency and an increased modulation BW from 8.12 to 450 kHz (55 times).

Exploring the “resistance change per energy unit” as universal performance parameter for resistive switching devices

Resistive switching (RS) device (memristor) technology is continuously maturing towards industrial establishment. There are RS devices that demonstrate an “incremental” (analog) switching behavior, whereas others change their state in a binary form. The final achieved resistance is generally a function of the applied pulse characteristics, i.e. amplitude and duration. However, variability —both from device to device but also from cycle to cycle— and the stochastic nature of internal RS phenomena, still hold back any universal tuning approach based solely on these two magnitudes, making also difficult the qualitative comparison between devices with different material compounds owing to the required SET/RESET voltages being dependent on the biasing conditions. In this work we demonstrate experimentally using commercial RS devices from Knowm Inc. that the switching energy is very insensitive to the biasing conditions. We explored experimentally the SET-RESET behavior of bipolar RS devices from the energy point of view. We figured out the quantitative effect of the injected energy to the resistive state of the devices, and proposed an analytical model to explain our observations in the energy consumed by the device during the switching process. Our results lay the foundations for the definition of “resistance change per energy unit” as a performance parameter for this emerging device technology.

Mechanical properties and energy development characteristics of impact-prone coal specimens under uniaxial cyclic loading

Energy is the intrinsic driving factor of rock dynamic failure. In this paper, the mechanical properties and energy development characteristics of impact-prone coal are studied. The stress and strain data and the acoustic emission (AE) signals of the impact-prone coal specimens are obtained by conducting cyclic loading-unloading tests. The elastic modulus deterioration rate is defined to describe the deterioration of the mechanical properties of the specimens during the loading process. The calculation results show that the elastic modulus deterioration rate of the impact-prone coal specimens during the cyclic loading process is as low as 3%. The AE monitoring results show that the AE signal is rare in the loading-unloading cycle before failure, and a large number of AE signals are generated at the failure moment. The stress-strain data are used to analyze the energy storage and distribution law of the loading process of impact-prone coal specimens. The results show that the input energy density increases nonlinearly with the increase of the load, and the input energy is mostly stored in the rock as elastic strain energy. The dissipative energy density is linear with the axial load. The impact-prone coal specimens have a strong ability to store elastic energy, and the precursor of damage and failure is not obvious. The study in this paper reveals the cause of the impact-prone coal easily induced to coal bursts from the energy point of view.

Supporting tool for multi-scale energy planning through procedures of data enrichment

Considering the challenge of evaluation of the urban environment from the energy point of view, there is plenty of room to improve the resources currently managed by users, enterprises and public institutions. The goal is to create a tool that supports in the decision making in the energy planning process in specific areas by automatically estimating the energy demand and consumption of buildings using public data and representing the results in a geo-referenced way. The tool will provide a better understanding of what the current status of the buildings is, providing these stakeholders with a larger quantity of useful data about the city environment, including not only the geometric information present in cadastre repositories, but also the data collected from the Energy Performance Certificates (EPCs). In this case, the data from the cadastre repository are combined with the EPCs for each province, with data about the demanded and consumed energy. The objective is to generate a set of buildings typologies for each province with estimated values for the demand and consumption for each building type. These typologies could be used to generate a map with the energetic values for any municipality of this province. These results can be injected into GIS (Geographic Information Systems) tools that could show these data in order to evaluate the energy demand/consumption of the municipality easing the energy planning decision-making process, or even into databases for further uses.

Bioenergetic efficiency of cultivation of watermelon depending on agricultural practices

RelevanceThe relevance of the bioenergy assessment follows from the requirements of modern production: energy saving per unit of output.MethodsThe article presents the data of bioenergy evaluation of the use of table predecessors, types of fertilizers and growth regulators in the technology of watermelon cultivation.ResultsThe results of studies have shown that from the energy point of view, the proposed methods of cultivation of watermelon, are effective, because the coefficient of energy efficiency in all the studied variants is more than one. Studies have revealed the advantage of a layer of perennial grasses as a precursor to watermelon: CEE – 2.55 at its values according to the predecessor of winter rye – 1.70. The use of mineral fertilizers dose N60P90K60 in rain conditions leads to a significant increase in energy consumption of commercial products, 1.7 times more in the formation of perennial grasses and 1.3 times more than the predecessor of winter rye. A decrease in the CEE and an increase in the cost of total energy and energy intensity of 1 ton of products using manure 27 t / ha in relation to mineral fertilizers. Comparative energy analysis showed high efficiency of using water-soluble fertilizers and growth regulators for soaking seeds and processing of vegetating plants in watermelon cultivation. The use of these agricultural practices can reduce the energy costs of total energy by 70-79% compared with the introduction of mineral fertilizers dose N60P90K60, with an increase in the energy efficiency coefficient from 1.54 to 2.68-2.77. As shown by calculations from the energy point of view, the best was the reception of cultivation of watermelon table using for seed soaking and processing plants in vegetation water-soluble fertilizer master special with the addition of growth regulator megapol, the value of the EPS was amounted to 2.99, which is 7.9% and 11.5% more in comparison with potassium Humate and Ribav-extra, respectively.

Energy analysis of a 10 kW-class power-to-gas system based on a solid oxide electrolyzer (SOE)

This article presents a conceptual power-to-gas system based on a high temperature electrolysis unit. The solid oxide electrolyzer (SOE) delivers highly efficient conversion of intermittent electricity from wind and solar into hydrogen, which can then be directly injected into the gas grid or used to synthesize methane in a Sabatier reactor. Due to the unpredictable character of these sources, the grid experiences imbalances, which destabilize the energy system. The solution, in the form of a high temperature electrolyzer, mitigates the problem by coupling the electric and gas grids.The advantages of solid oxide electrolysis over conventional electrolyzers are as follows: (i) SOEC offers outstanding efficiency, exceeding 70–80%, (ii) no noble metals are needed for catalytic reactions – the ceramic materials of electrodes and the high temperature substitute noble metal loading, (iii) SOEC mode can be switched to SOFC and the interchange supports the unique self-healing of the cells, (iv) modular design makes it easy to scale up the system based on the SOEC stack, (v) absence of any liquid electrolyte that has to be replaced on a regular basis. The 10 kW-class power-to-gas system is presented and the efficiency of the system assessed and discussed from an energy point of view. Accepting the current assumptions related to the performance of cells making up the electrolysis unit, the system can achieve efficiency in excess of 74%. The modeling approach is given and the performance map of the system is analyzed with respect to the variation of voltage and steam utilization in the electrolyzer.

Toward an Efficient and Sustainable Use of Energy in Industries and Cities

Several countries have recently realized that the present development paradigm is not sustainable from an environmental and energy point of view. The growing awareness of the population regarding environmental issues is pushing governments worldwide more and more to promote policies aiming at limiting harmful effects of human development. In particular, the rapid increase of the global temperature, especially in the polar regions, and the management of human wastes, mainly plastic in seas, are some of the main points to be addressed by these novel policies. Several actions must be implemented in order to limit such issues. Unfortunately, the recent COP 24 Conference was not successful, but hopefully an agreement will be established in 2020 at the COP 26 Conference. The effort performed by policymakers must be mandatorily supported by the scientific community. In this framework, this paper aims at showing that countries worldwide are trying to negotiate an agreement to increase energy efficiency and reduce greenhouse gas (GHG) emissions. In addition, in this paper all the researchers reported can provide quantitative measures of the actions to be implemented in order to address a sustainable and efficient use of energy. Here, innovations in terms of novel efficient and environmentally friendly technologies mainly based on renewable energy sources have been also investigated. The study also highlights different sectors that have been involved for this aim, such as energy conversion systems, urban areas, mobility, sustainability, water management, social aspects, etc. In this framework, specific conferences are periodically organized in order to provide a forum for discussion regarding these topics. In this area the Sustainable Development of Energy, Water and Environment Systems (SDEWES) conference is the most ordinary conference. The 13th Sustainable Development of Energy, Water and Environment Systems Conference was held in Palermo, Italy in 2018. The current Special Issue of Energies, precisely dedicated to the 13th SDEWES Conference, is based on three main topics: energy policy and energy efficiency in urban areas, energy efficiency in industry and biomass and other miscellaneous energy systems.

Maturity-based approach for the improvement of energy efficiency in industrial compressed air production and use systems

Compressed Air Systems (CASs) are one of the most critical utilities from an energy point of view, as their overall efficiency can be as low as 10–15% and their incidence is about 10% of the total energy consumption in manufacturing companies, and up to 25% in process industry. Therefore, improving their energy efficiency is crucial to achieve cleaner production objectives. Nevertheless, basing the search for efficiency improvements only on new technological solutions might not be sufficient in the long term to trigger continuous improvement mechanisms. The creation and diffusion of a Compressed Air Systems Energy Efficiency Maturity Model (CASEEMM) can help guiding companies in an improvement path that includes managerial and organizational enhancements. This paper presents the design of an effective CASEEMM, as well as the definition of a self-assessment tool. The presented CASEEMM is validated through implementation in three different industrial cases. Such cases have been chosen in order to test the tool in three different industrial sectors and with three different maturity levels, in order to evaluate both its effectiveness and general validity. The CASEEMM showed good potential in providing a clear and unbiased picture of industrial energy behavior.

Technological Advancement in the Production of Peat Pellets by Extrusion

The effect of extrusion conditions on the properties of peat briquettes was experimentally studied with the use of an industrial crank press with an open matrix. Regression equations were obtained for determining the density, mechanical strength in axial compression, hardness, and water absorption of fuel peat as functions of compacting pressure and feed moisture content. The dependences of the density, mechanical compression strength, and hardness of briquettes on the compacting pressure have a threshold behavior, which is responsible for their maximally accessible values at a specified level of humidity. Conditions for the production of fuel were optimized to be consistent with the most effective regimes of extrusion from an energy point of view.

Metal Surface Texture Research on the Influence of Friction

In this paper, the influence of texture on wear and temperature rise is studied by comparing experiments at the normal temperature. Firstly, the preparation of experimental samples and the design of experimental methods are introduced. Secondly, based on the observation and analysis of two groups of experiment, the effects of surface texture on friction coefficient, temperature rise and wear are discussed respectively. The main reasons of surface texture on temperature rise are analyzed from the energy point of view, which lays a foundation for quantitative analysis of temperature rise mechanism.

Quantitative Energy-Based Evaluation of the Intensity of Mining-Induced Seismic Activity in a Fractured Rock Mass

To elucidate the mechanism of seismic activity taking place away from extracted stopes in underground mines, this study focuses on the influence of a fracture network on the intensity of seismic activity from an energy point of view. Four seismically active regions with local geological structures and one non-active region were identified on 3880 level in the 100 and 900 Orebody areas at Copper Cliff Mine. Subsequently, cube-shaped discrete element method (DEM) models with fracture networks of the regions were generated. The stress analysis for two regions out of the four revealed that the elastic strain energy related to tensile failure quantitatively agrees well with the cumulative radiated seismic energy of the microseismic database. For the other two regions, the computed tensile failure-related strain energy was smaller than the radiated energy, leading to the postulation that the seismicity in the region was caused by violent shear rupture. The postulation was verified by quantitatively computing energy released by brittle shear failure. Then, for the seismically inactive region, the DEM analysis yielded quite small tensile failure-related strain energy. Considering these results, it was concluded that strain energy stored within rock mass with tensile failure potential can be used as an indicator for the intensity of seismicity taking place away from extracted stopes. Also, the seismic energy calculation methodology can give a reasonable estimation of seismic energy released by shear rupture taking place in geologically abnormal regions. These findings should lay a foundation for the further development of a guideline and/or simple formulation to evaluate the risk for mining-induced seismicity.

Briquetting characteristics of bean straw-maize cob blend

Bean straw briquettes exhibited high quality in terms of density, impact resistance and compressive strength. The impact resistance was above 96% for a particle size up to 4 mm and pressures as low as 100 MPa at a compacting temperature of 80 °C. Reducing the compacting temperature required higher pressure and smaller particles to obtain similar quality briquettes. There were strong interactions between briquetting parameters with the pressure × temperature interaction significantly affecting both density, impact resistance and compressive strength. Adding bean straw significantly improved the mechanical properties of maize cob briquettes produced at low pressure and from larger particle size. From a practical and energy point of view, a temperature of 80 °C should be used for briquetting to reduce energy inputs (pressure and grinding) as this low temperature could be obtained directly from industrial waste heat.

Biorefineries productive alternatives optimization in the brazilian sugar and alcohol industry

A technical, economic and environmental analysis of different biorefinery configurations is carried out, considering the integration of different biomass technologies with sugar and ethanol plants. Biochemical routes for the production of lignocellulosic ethanol and biobutanol from ABE (Acetone-Butanol-Ethanol) fermentation were considered as alternatives for conversion, also a thermochemical process for the production of syngas. Second-generation ethanol favors better land use, and biobutanol is an important input for the chemical industry, as well as producing acetone and ethanol as co-products. Syngas from the thermochemical process is very versatile raw material, which can be used to manufacture various products. Syngas was considered for Diesel production through Fischer-Tropsch synthesis process, and also for electricity production. To verify biomass distribution in biorefinery processes, that allows reaching best results from a techno-economic, and environmental point of view, a computational experiment was carried on, using the Kriging method for plant optimization. Solving problems using mathematical modeling as an alternative to traditional methods of optimization can be simplified without loss of generality, precision or need of computer over time. Results show that, from an energy point of view, thermochemical routes perform better, in addition to being able to avoid large amounts of CO2eq emissions. From an economic point of view, biochemical routes prove to be only feasible when all available bagasse is destined for these alternatives. Finally, the process of lignocellulosic ethanol presents a superior performance, having the best combination of analyzed indicators, resulting in a more sustainable process. A Brazilian sugar and alcohol factory was taken as a case study; its results can be extended to any similar installation that uses biomass as a raw material.

Experimental investigation of the chemical degradation of lubricating grease from an energy point of view

Abstract The chemical degradation/oxidation of lubricating grease is investigated experimentally from an energy point of view. A Pressure Differential Scanning Calorimeter (PDSC) is used to measure the activation energies of two lithium-complex greases and to monitor their chemical degradation through induction time. For this purpose, an experimental setup consisting of a heating chamber, a temperature controller and an energy meter is designed, built, and calibrated to heat up grease samples and measure pure energy absorption during the chemical degradation at different test temperatures. A relationship between the energy absorption of the grease and its chemical degradation is established that is independent of the testing time and temperature. It is shown that the energy absorption of the grease approaches to an identical maximum value in a shorter time in high temperatures and a longer time in low temperatures. The maximum energy absorption depends on the grease type and experimental results reveal that it can be used to estimate the grease chemical life. A roller tester rig is used to measure and compare the lubrication ability of two chemically degraded grease samples and to validate the results of the research. To gain further insight, experimental results are presented to examine the flow characteristics of a chemically degraded grease in an elastohydrodynamic (EHL) line contact with a comparison to that of the fresh grease.

Енергетична ефективність виробництва свинини на комплексах

Introduction. Historically, pig production in Ukraine is an important and traditional branch of livestock breeding. Compared to other types of farm animals, pigs have valuable beneficial features that guarantee them a greater advantage in the production of meat. Pigs have such biological features as multiplicity, fastness, viscidity, and high energy of growth. Industrial pig production is one of the most energy-intensive branches of agricultural production. Therefore, finding of ways to increase energy efficiency of production is important for large pork farms. Analysis of recent researches and publications . Modern production in complexes and farms requires a large amount of energy resources for pork production and includes the main stages of production: breeding young animals, reproduction of fattening stock, fattening pigs, fodder production, slaughter of animals and carcass processing. The analysis of the researches shows that the existing method of bioenergy evaluation of poultry production and livestock production (EI Bazarov, AA Kiva, VM Rubtstina, DA Tikhomirov, AN Vasiliev, Chmel A.I.) needs to be improved. Purpose. Development of a method for calculating the energy efficiency of production at pig farms. Methods. In order to optimize the energy flows in the complex, the energy balance is used, which includes the system of indicators and reflects the complete quantitative equality between the energy consumed and received in the products and waste in the same units. In order to effectively take into account all the components of energy consumption in the complex it is expedient to use a balanced energy expenditure model. We will show energy expenditures as the sum of all the components of energy inputs, both bioenergy and technical expenditures spent on production. The use of systematic bioenergy analysis enables to overcome the feasibility of feasibility studies for identifying non-renewable energy reserves. Therefore, this approach allows us to take into account not only the direct costs of fuel and energy, but also the costs of living labor of workers and employees. The use of systematic bioenergy analysis enables to overcome the feasibility of feasibility studies for identifying non-renewable energy reserves. Results. Using the bioenergy assessment of energy efficiency on the one hand allows us to state the state of energy balance, and on the other to determine the most energy-intensive links in the complex. From the energy point of view, pig production complexes in the process of production, depending on both the quantity and quality of products, serve as an evaluation criterion for the coefficient of bioenergy efficiency which is not a constant value. In order to effectively take into account all the components of energy consumption in the complex it is expedient to use a balanced energy expenditure model. We will show energy expenditures as the sum of all the components of energy consumption, both bioenergy and technical, spent on production. Discussion. he method of calculating the energy efficiency of production at pig farms is developed. Utilizing the bioenergy assessment of energy efficiency of pig production, the most energy-intensive links in the complex were found. Based on the analysis of the energy balance, we have found that, depending on the size of the complex, the efficiency of cultivating the product varies, namely, when the size increases, the energy efficiency coefficient increases and reaches its maximum value with the size of the complex 54 thousand head.