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Building information modelling (BIM) is trying to overcome the issue of interoperability by promoting the collaboration between different professions, which enables Building Performance Assessments (BPA) to take place earlier in the design process. Nevertheless, the interoperability is rarely perfect and information is lost during translation from BIM authoring tool to simulation software or the interoperability is limited to the translation of the geometry. The discrepancies in data translations from BIM authoring tool to specific Calculation Virtual Environments (CVE) for energy and acoustic evaluation are considered. For the energy performance evaluation two software tools are tested in the present research paper, namely the Design Builder and IES VE , using IFC and gbXML as data exchange formats. Furthermore, a solution is proposed for overcoming the interoperability issue about acoustic evaluation by adapting programming language in Dynamo Graphical Interface for calculation of acoustic parameters, namely the Reverberation time and Schroeder’s frequency, which allow room quality evaluation to take place earlier in the design process as they are crucial for educational and other facility usage buildings.

In this work optimization of the parabolic trough (PT) based concentrated solar power (CSP) system is analyzed for solar energy export from Saudi Arabia to European and Asian countries based on their peak load hours. Initially, Al-Ahsa, in east, and Tabuk, in the west, are compared for a PT based CSP plant for electrical energy generation as these locations are used to export solar energy from Saudi Arabia to Pakistan, India, and China in east and Greece, Germany and UK in the west. The analysis is performed to sell electrical energy generated by the CSP plant to the customers in their peak load hours to reduce their load factor and keep the capital cost minimum. A high voltage direct current (HVDC) transmission system is employed for this study as an undersea cable for Asian or European countries. The feasibility of 2 GW solar energy export by PT based CSP system transmitted by 2 GW bipolar 660 kV HVDC transmission line is based on the net present value of the project (NPV), real levelized cost of energy (LCOE), and the payback period of the project where Karachi, Pakistan has the highest NPV of 1866 MUSD with LCOE of 10.76 cents/kWh and a payback period of 12.7 years.

In the past decade, compressed air vehicles have attracted much attention because of their zero pollution, high efficiency, environmental friendliness and relative maturity. To further explore the potential of compressed air technology in vehicles, three-stage and four-stage compressed air engine systems are optimized in present study by analyzing the energy and exergy distribution from a technological viewpoint. Their characteristics are compared in terms of shaft work, coolth, overall efficiency, and exergy distribution. Stage expansion ratios differ under maximum work output. The shaft work and coolth of both systems are increased with the increase of working pressure, turbine inlet temperature, or stage efficiency. Three-stage compressed air engine systems have a lower work output and coolth than four-stage compressed air engine systems at given operation condition. The overall efficiencies of these two systems are comparable to those of conventional diesel engines and fuel cell vehicles. Exergy losses of the two systems are composed by the exergy loss in the turbines, heat exchangers, and exits. The analyses suggest that increasing the number of stages, improving stage efficiency, and utilizing coolth to reduce the exergy loss in heat exchangers are effective ways to decrease the total exergy loss and improve the work output and overall efficiency of the compressed air engine systems.

This paper proposes the dissipation of the energy analysis approach for vehicle plane motion stability analysis. The vehicle uses a three-degree-of-freedom vehicle model, and a unified tire-sidesli...

An energy analysis study carried out on a vapor compression refrigeration cycle using refrigerants with low global warming potential (GWP) of the Hydro-Fluoro-Olefin (HFO) type, in particular R1234yf and R1234ze fluids to replace HFC refrigerants . Computer code was developed using software for solving engineering equations to calculate performance parameters; for this, three HFC type fluids (R134a, R404A and R410A) were selected for a comparative study. The results showed that R1234ze is the best refrigerant among those selected for the mechanical vapor compression refrigeration cycle. The thermodynamic analysis showed the effect of the evaporator temperature (-22 °C to 10 °C) and the condenser temperature (30 °C to 50 °C) on the steam cycle performance. Compression refrigeration, including the coefficient of performance. The results showed that the HFO-R1234ze with low GWP gives the best coefficient of performance of 3.14 close to that of the R134a fluid (3.17). In addition, R1234ze is considered an alternative fluid to R134a for their ecological properties.

In the paper an economic, ecological and energy analysis of a home photovoltaic on grid installation was presented. The increase in ecological awareness of the Polish society contributes to the continuous growth of interest in green energy. However, many people haven’t been aware of the ecological, economic and energy benefits of photovoltaic installations yet, so the following analysis is made. The analysis concerns a photovoltaic installation with a capacity of 3.96 kWp located in Ościęciny near Włocławek. The photovoltaic installation consists of 11 monocrystalline panels with a power of 360 Wp, a 4 KTLM Sofar Solar inverter and other necessary components. The first part presents basic issues related to photovoltaic installations. Parameters related to the proper functioning of the photo-voltaic installation were replaced. The analysis of the literature will help to understand the essence of the proper functioning of the photovoltaic installation. In the practical part, an analysis of a selected home photovoltaic installation was carried out. Based on the available data, it has been calculated that the installation will have a payback period of over 9 years. The photovoltaic installation will produce approximately 3 582.61 kWh of electricity and will contribute to the reduction of 70 tons of carbon dioxide during the entire operation.

Stenter machines are used widely in textile dyeing and printing houses for drying and heat setting of fabric. This is one of the most thermal energy-consuming equipment in the textile process. In t...

Building Information Modeling (BIM) can store information of building elements and provide a computational platform for physical analyses for building systems. BIM can resolve several problems throughout various phases of design (as well as construction and operation). While use-cases such as daylight or energy analysis widely take advantage of this computational power, there is no integrated acoustical analysis tool or any external programs with acceptable interoperability within the BIM ecosystem. This study investigates the possibility of developing a BIM-based calculation method based on the most widely used design authoring tool in North America, i.e., Autodesk Revit, to estimate the acoustical properties of buildings with acceptable accuracy and details. A novel algorithm is designed to calculate reverberation time (RT), one of the most critical acoustic indicators of building spaces. The algorithm extracts geometric information from the BIM (i.e., the model); matches it with the physical properties provided by an open-source library; performs the analysis; visualizes the results on the model. The tool is tested over several case studies, and the results have been verified and validated using other existing methods. In the paper, we have studied the acoustical properties of an educational building using the designed tool under various scenarios.

Industrial and building sectors demand efficient smart energy strategies, techniques of optimization, and efficient management for reducing global energy consumption due to the increasing world population. Nowadays, various artificial intelligence (AI) based methods are utilized to perform optimal energy forecasting, different simulation tools, and engineering methods to predict future demand based on historical data. Nevertheless, nonlinear energy demand modeling is still unfledged for a better solution to handle short-term and long-term dependencies and avoid static nature because it is purely on historical data-driven. In this paper, we propose an ensemble deep learning-based approach to predict and forecast energy demand and consumption by using chronological dependencies. Our system initially processes the data, cleaning, normalization, and transformation to ensure the model performance. Furthermore, the preprocess data is fed to proposed ensemble model to extract hybrid discriminative features by using convolution neural network (CNN), stacked, and bi-directional long-short term memory (LSTM) architectures. We trained our proposed system on the historical data to forecast the energy demand and consumption with a different time interval. In the proposed technique, we utilized the concept of active learning based on moving windows to ensure and improve the prediction performance of the system. The proposed system could be applicable to employ energy consumption in industrial and building sectors to demonstrate their significance and effectiveness. We evaluated the proposed system by using benchmark, residential UCI, and local Korean commercial building datasets. We conducted different extensive experimentation to show the error rate and used various kinds of evaluation matrices, which indicate the lower error rate of the proposed system.

A walking beam type reheating furnace with advanced control technology has been evaluated by combined energy and exergy analysis. In order to gain insight into the performance of the present furnace, the results of energy analysis are compared with those in published papers and the irreversibility of the furnace is analyzed via exergy destruction calculation. The results show that slabs preheated before charged into the furnace can save fuel and improve energy utilization. The structure and material of the wall and roof show good thermal insulation. However, the oxidized scale is a little more and the temperature of flue gas is high in the present reheating furnace. The energy efficiency of the furnace is 71.01%, while exergy efficiency is 51.41%, indicating a potential for energy-saving improvements of the present furnace. The exergy destruction of the furnace accounts for 28.36% of total exergy input which is mainly caused by heat transfer through a finite temperature difference (14.71%), fuel combustion (11.66%) and scale formation (1.99%).

PurposeThis paper aims to further the discussion on Building Information Modelling (BIM) legal requirements, providing a framework with key energy parameters capable of supporting the Appointing Party in the definition of the Exchange Information Requirements (EIR) for a BIM project appointment. The EIR is described in ISO-19650–1:2018 as a fundamental step in the information delivery cycle.Design/methodology/approachA literature review on the topic of BIM energy analysis was completed to identify current knowledge gaps and support the need for the proposed framework. Afterwards, the framework was established based on the review findings and the authors’ domain knowledge. The applicability of the proposed framework was assessed through a case study, where several energy simulations were performed in three different design stages of the same BIM model.FindingsThis study identified a lack of standards and legislation capable of supporting the Appointing Party in the definition of energy-related BIM requirements. To this end, a new framework is proposed to mediate existing practices, linking prior knowledge with BIM’s new reality. The study showcases the applicability of the framework, identifying that the performance of different energy studies involves distinct Level of Development (LOD) requirements, which in turn have an impact on the modelling time and cost.Originality/valueA BIM framework for the specification of information requirements in energy-related projects was developed to support the Appointing Party. The framework presents appropriate parameters for energy analysis in each design stage, as well as the suitable LOD for the BIM model.

Geothermal energy is a kind of green and non-polluting renewable energy. Medium and low-temperature geothermal energy below 150 °C is usually used directly for heating, industrial and agricultural heating, bathing, etc., and the utilization rate is low. Organic Rankine cycle (ORC) system can be used in a low-temperature geothermal power generation systems. Thermodynamic analysis of the thermal cycle system is carried out in this paper. Based on the principle of exergy analysis, the cycle parameters such as evaporation temperature, condensation temperature, superheating temperature, and supercooling temperature are analyzed. The results show that the exergy efficiency and system output power can improve by increasing evaporation temperature and the exergy loss can decrease in the evaporator. Increasing superheating temperature enhances the output power of the expander and the exergy loss in the condenser, decreases the exergy efficiency simultaneously. Increasing condensation temperature decreases the exergy efficiency of the system and the output power of the expander, and increases the exergy loss of the system. Although the output power of the expander will not be affected by supercooling temperature, the rise of supercooling temperature will reduce the exergy efficiency of the system and increase the exergy loss of the evaporator.

The article presents an energy analysis of a real suction-pressure unit of a high-efficiency radial piston pump. This pump can be used in small hydropower plants, where, together with a variable displacement hydraulic motor, it would form a hydrostatic transmission. The main advantage of this solution is the possibility of a stepless, automatic change of gear ratio during its operation, which allows an increase of the efficiency of power generation in a hydropower plant. Mathematical models of friction and resistance of flow through self-acting and geometrical deformations of chambers and piston under stress field are presented. In addition, mass, volume, and energy balance calculations were computed for the ideal unit and pressure losses were determined. Derived indicator diagrams for each chamber of the ideal suction-pressure unit served to analyze the technical work of occurring processes. The paper also presents the formulation of total efficiency of the unit. Lastly, the experimental procedure is presented, according to which it is possible to register the most important parameters of the proposed model.

Objective:To conduct a systematic review of studies for the validation of semiquantitative FFQ (SFFQ) that assess food intake in adults.Design:The authors conducted a systematic search in PubMed for articles published as late as January 2020 in Spanish, English, French and Portuguese. Individual searches (twelve in total) paired three hyphenated and non-hyphenated variations of ‘semiquantitative food frequency questionnaire’ with both ‘validity’ and ‘validation’ using the ‘all fields’ and the ‘title/abstract’ retrieval categories. Independent extraction of articles was performed by four authors using predefined data fields.Setting:We searched for original SFFQ validation studies that analysed general diet composition (nutrients with or without food groups or energy analysis) in healthy adults, in any setting, and that also reported correlation coefficients.Participants:Healthy adults.Results:Sixty articles were included. The preferred comparison standard for validation was food records (n37). The main correlation coefficients used were Pearson’s (n41), and validity coefficients varied from −0·45 to 1. Most correlation coefficients were adjusted by energy (twelve studies presented only crude values). The elements mentioned most frequently were energy, macronutrients, cholesterol, SFA, PUFA, fibre, vitamin C, Ca and Fe.Conclusions:Although all these SFFQ are reported as validated, coefficients may vary across groups of foods and nutrients. Based on our findings, we suggest researchers to consult our revision before choosing a SFFQ and to review important issues about them, such as their validation, number of items, number of participants, etc. Systematic Review Registration: PROSPERO number CRD42017064716. Available at:http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42017064716.

This Letter reports a method to obtain fine-grained energy consumption analysis of programs running on the low-power internet of things (IoT) devices. In the energy estimation domain, most state-of-the-art solutions focus on the coarse-grained approach to monitor the energy consumption of a device or an application. However, few solutions addressed energy monitoring to analyse fine-grained energy consumption of a program, especially for IoT appliances. Therefore, the authors present a fine-grained gem5-based energy profiling tool to help developers to evaluate the energy efficiency of hot spots in their programs. The authors demonstrate its usability by applying it to profiling garbage collection and property lookup in Jerryscript, a JavaScript engine specifically designed for resource-constrained IoT devices, and discover that these two operations are consuming, as they account for 17.67 and 12.26% of total energy, respectively. Therefore, this tool can aid the developers to gain insight into the energy efficiency of their software.

This work is an energy study of an organic Rankine cycle (ORC) for the recovery of thermal energy by comparing three organic fluids. This cycle is considered to be a promising cycle for the conversion of heat into mechanical energy suitable for low temperature heat sources; it uses more volatile organic fluids than water, which generally has high molecular weights, thus allowing operating pressures at temperatures lower than those of the traditional Rankine cycle. A thermodynamic model was developed using the Engineering Equation Solver (EES) software to determine its performance using different working fluids (toluene, R245fa and R123) under the same operating conditions, taking into account the effect of certain operating parameters and the selection of organic fluids on cycle performance. The results obtained show that the toluene organic fluid has the best thermal efficiency of the cycle compared to the other fluids; 14.38% for toluene, 13.68% for R123 and 13.19 for R245fa.

The failure patterns and energy evolution of three types of shaft lining concrete subjected to static and dynamic loading were reported. The energy and damage characteristics of concrete were determined by means of a uniaxial hydraulic servo machine, acoustic emission (AE) equipment, a split Hopkinson pressure bar (SHPB) and an ultrasonic wave analyser. The experimental results indicate that the confluence of multiple cracks forms a penetrating cross section in normal high-strength concrete (NHSC) under the condition of static loading, while the elastic energy that surges out at failure can cause tremendous damage when subjected to dynamic loading. A single crack was split into multiple propagation directions due to the presence of fibres in steel fibre-reinforced concrete (SFRC); adding fibre to concrete should be an effective way to dissipate energy. The non-steam-cured reactive powder concrete (NSC-RPC) designed in this paper can store and dissipate more energy than normal concrete, as NSC-RPC exhibits a strong ability to resist impact. Applying NSC-RPC to the long-service material of a shaft lining structure in deep underground engineering is quite effective.

Over the last few years, countries such as Brazil, the United States, Germany, and China have been receiving significant investments to advance the use of renewable energy sources, such as solar energy, biomass and wind. This has been due to the growing demand for electricity due to population increase and the evolution of industrial activities. Solar energy can be enjoyed by using solar concentrators that are commonly used in solar thermal systems where the working fluid reaches higher temperatures than can be obtained from other collectors. These concentrators are responsible for providing the thermal energy supply. This research analyzed the energy influence of Parabolic Solar Concentrator technology aided by a solar tracking system, taking into account its energy balance and thermal efficiency calculation. The concentrator had an optical efficiency of 81 % and was able to achieve average thermal efficiency values between 21.8 % and 24.7 % under maximum solar radiation conditions between 900 W/m² and 990 W/m². The temperature of the absorber tube used to receive the concentration of sunlight reached temperatures between 80 °C and 98.6 °C, allowing the system working fluid a temperature to reach values above 100 °C. These results show the ability of this type of solar collector to provide power for thermal applications such as heating water for industrial or domestic processes, food dehydration, and drying, refrigeration, thermal desalination and microgeneration of electricity. Besides, the thermal efficiency (between 21.8 % and 24.7 %) was satisfactory when considering the type of concentrator, which also validates the electronic tracking system as it was able to track the relative movement of the sun and favor the increase of thermal efficiency of the system.

The present work focusses on comparison of several low Global warming potential (GWP) refrigerants in search of possible alternatives to a refrigerant HFC-134a of a home refrigerator without any mo...

Our aim in this work is to improve the design and model of real-life applications. We put forward a standard based on m-polar fuzzy soft set decision-making criterion to examine the optimal alternative for the suitability of S-boxes to image encryption applications. The proposed standard studies the results of correlation analysis, entropy analysis, contrast analysis, homogeneity analysis, energy analysis, and mean of absolute deviation analysis. These analyses are applied to well-known substitution boxes. The algorithm of outcomes of these analyses is additional observed and a m-polar fuzzy soft set decision-making criterion is used to decide the optimal alternative for suitability of S-box to image encryption applications. All results taken by using the reality values for all S-boxes and experimental problems with reality values are discussed to show the validity of the optimal alternative for the suitability of S-box to image encryption.

In this study, hybrid solar drying of coffee beans was performed, and energy analysis was carried out, to assess the system’s performance, in terms of energy efficiency, compared to solar drying and the open sun drying method. The dryer has three compartments: solar collector for collecting solar radiation, drying chamber, and a Liquid Petroleum Gas burner, which acted as an auxiliary heater to assist the thermal energy. The drying chamber has four trays for placing the dried product. The initial moisture content of coffee beans was 54.23% w.b and was reduced to the final moisture content between 11-12% w.b. The coffee beans dried faster when subjected to the solar hybrid drying method, compared to other methods, with the dryer temperature of 40°C, 50°C, and 60°C. Results indicated that the coffee beans’ drying times varied from 10 to 14 hours. However, at temperature 50°C and 60°C for the 1st tray, the water content was reduced more rapidly compared to the other tray. From the results of this study, we can see the different efficiency of solar collector that shows of 54.15% at variable temperature 60°C for drying time 12:00 to 14:00 p.m for hybrid solar drying and for the solar drying process is 50.07% at the range of drying time 12:00 to 14:00 p.m. Mathematical modelling shows that Page model is the most suitable for describing the coffee beans’ drying behaviour using a hybrid solar dryer. The effective diffusivity values found in this experiment are all in the acceptable range for most agricultural products. ©2020. CBIORE-IJRED. All rights reserved

The Irish Seafood agency reports that 15% of global energy is consumed by operations related to refrigeration and air conditioning in the fish industry which stresses the importance of integration with clean renewables and adoption of smart energy management solutions. While fish processing industries have high energy costs with continuous refrigeration, air conditioning and ice making processes, there is a real need to analyse and model energy use in fish ports to understand environmental impacts in terms of CO2 emissions while exploring the potential for integrating renewable energy sources.In this paper, we conduct energy modelling and optimization for the Milford Haven fish processing port in South Wales. We explain how a simulation capability can be developed at the fish industry port level and propose a simulation-based optimization strategy to determine optimized schedules for appliances. The results show that energy consumption can be reduced with the use of optimized appliance schedules developed in relation to the total energy demand as well as a wide range of optimization constraints. Keywords: Energy analysis, Energy modelling, Simulation, Optimization, Renewable energy, Scheduling appliances

Limited by its low energy capacity, small UAVs have short flight time. Therefore, it is of great significance to improve the endurance performance of small UAVs by applying solar energy technology and dynamic soaring technology which can obtain external energy. This paper analyzes the energy exchange principle of small UAVs using solar energy technology and dynamic soaring technology, and works out the strategy of maximum energy gain. Small UAV flight dynamics model combined with solar power-energy system was built, choosing surround flight path at twilight moment for simulation validation. The advantages of small solar UAV using dynamic soaring technology in energy acquisition in hovering flight and pure dynamic gliding flight are verified, compared with traditional solar vehicle. The significance of combining the two energy acquisition technologies to improve the endurance of small UAV is proved, which provides a basis for further study of all-weather uninterrupted flight in the future.

In this communication, the performance evaluation has been discussed for various kinds of photovoltaic (PV) technologies which has integrated to solar air collector with drying system. Mathematical modelling has been carried out for photovoltaic thermal air collector (PVTAC) with dryer. On the basis of mathematical model, energy analysis has been carried out for different types of partially covered PV technologies (namely, c-Si, p-Si, a-Si, CdTe and CIGS) air collector. CIGS has been found to be the best PV technology for large systems in terms of minimum embodied energy and payback period.

The environmental impact of buildings has stimulated efforts to promote sustainable development in the construction sector. Technological development aims to provide an effective framework for the design, construction, and management of buildings through the use of tools such as Building Information Modeling (BIM). This paper critically assesses the use of BIM technology in vernacular design and analysis through the case study of a Greek vernacular museumbuilding. Based on software application as well as in-situ observation and interviews, accurate energy analysis and safety were proved to be important advantages achieved through BIM technology. On the contrary, the inability to capture tacit knowledge and the lack of adaptability to local specificities appear to be the main weaknesses of BIM technology. Certain measures to enhance the use of BIM technology for the design and analysis of vernacular buildings are proposed

In this study, the effects of malfunctions and problems occurring in the system components of air handling units, which are the main elements of the air conditioning system, on the energy consumption were investigated. Investigations were carried out in 10 air handling units located in 5 different shopping centers of Turkey. The malfunctions and problems that may occur in operation of air handling units were determined and the problems causing the decrease in the efficiency prescribed by the design characteristics were determined. For this purpose, rod-type anemometer measuring the airflow in the air handling unit ducts, propeller-type anemometer, and thermal camera were used to measure air tightness and heat losses in the body structure. Also, the tension control of the belt of the fan motors, which is one of the main components of the energy consumption unit, and the pollution control of the air filter have also been carried out. The flow rate of water circulating in air handling units was determined, and losses were detected by energy and exergy analyses with thermodynamic parameters for summer and winter periods. As a result of the calculations, it was determined that the energy efficiency of the air handling units in the cooling period was 63.7% and the exergy efficiency was 59.6%. The energy loss is 471 kW and the exergy loss is 27 kW in the cooling period. The energy loss is 957 kW and the exergy loss is 127 kW in the heating period. The energy efficiency and the exergy efficiency during the heating period was calculated to be 75% and 41.7%, respectively. WOS:000557881000002 2-s2.0-85087968080

The advent of the Internet-of-Things (IoT) has led to a rapid growth in data generation. The amount of computation resources required to process the massive data generated by IoT devices, along with the new intelligent use and applications of IoT data such as smart city that can be computation intensive and delay sensitive, have caused an increase in demand for locally available resources at network edge for computation offloading. To address this issue, we have proposed the concept of opportunistic fog radio access network (OF-RAN), which extends the computation capacity of existing fog-RAN (F-RAN) by establishing virtual fog access points (v-FAP) opportunistically using resourceful user devices that participate as service nodes. In this article, we develop an analytical model to evaluate the offloading performance of three RAN architectures: the traditional cloud radio access network (C-RAN), the existing F-RAN, and the proposed OF-RAN. The performances are analyzed in terms of their energy consumption, completion delay, and failure rate, under the effect of varying scenarios.

Mining of the coal seam adjacent to the extracted coal panel is widely practiced in China to improve coal resource recovery rates, but the energy change associated with longwall mining may present a new risk to ground stability and gateroad failure. To understand the energy change effectively, a meticulously validated numerical model, built using FLAC3D software, incorporating a double‐yield model for the gob materials and a strain‐softening model for the coal/rock masses, was developed to investigate the energy redistribution in coal seams and barrier pillars during the process of mining the coal seam adjacent to the extracted coal panel. The model results showed that the closer the region was to the LW 5301 gob, the higher the location and magnitude of the peak strain energy density. Consequently, the risk of rockburst in coal seams was greater than that in barrier pillars. Along the coal seam strike, with increasing advancing distance from the setup room, the magnitude of the peak strain energy density gradually increased to 1.88‐2.78 times the premining energy level. In addition, along the coal seam dip, the maximum distance from the peak strain energy density to the edge of the coal seam was approximately 16‐28 m, which is greater than that in the barrier pillar. The proposed numerical simulation procedure and calibrated method could be a viable alternative approach to evaluate longwall mining‐induced energy changes.

An attempt was made to estimate the value of the deformation energy of a metal specimen and the research system during impact strength tests on pendulum hammers. In the experimental research it was found that the rectangular metal specimens of the same cross-sectional area demonstrate different impact strength, depending on the direction of the load (bending stiffness) whereas the destruction work of such samples exposed to static bending is comparable. The article presents the results of the experimental research, completed with numerical calculations carried out to assess the value of the deformation energy during the impact tests. By performing numerical calculations, the authors estimated the deformation energies of specimens characterised by elastoplastic properties with a reinforcement (bilinear) under destructive loads. The energy of the elastic deformation of the hammer arm was estimated analytically. Based on the research, it was found that in the impact strength test, a large part of the recorded energy is connected with the deformation of the test device, in particular, the pendulum which undergoes bending. Also the recorded impact strength of the material is not proportional to its actual impact strength.

Cassava is a commodity that has great importance in food security in many developing countries. The main product in Brazil produced from cassava is the flour, representing approximately 60% of the cassava final destination. As a by-product of this process, we have a wastewater called manipueira. This effluent is highly toxic because it contains cyanidric acid. The manipueira has great potential for biogas production, adding values to the cassava production chain and, also, reducing the content of cyanidric during the methanation process. This study analyzes the energy and economic efficiency of the biogas production from the manipueira produced in a large power plant, using it as an energy source in the feeding of a cogeneration system composed of a gas microturbine and a heat recovery system, whose purpose is to generate electric and thermal energy. The use of themicroturbine systeminstead of other conversion technology is based on the power it presents when it is used for cogeneration, increasing the systemefficiency. The study showed that from the economic feasibility calculation, it was possible to determine the cost of producing electricity of US$ 0.16/kWh and of thermal energy of US$ 0.04/kWh with an amortization period of 1.3 years. The results obtained from these analyzes showed that the use of this biofuel is a good choice for energy generation. info:eu-repo/semantics/publishedVersion

The COVID-19 pandemic has focused renewed attention on the ways in which building HVAC systems may be operated to mitigate the risk of airborne disease transmission. The most common suggestion is to increase outdoor-air ventilation rates so as to dilute the concentrations of infectious aerosol particles indoors. Although this strategy does reduce the likelihood of disease spread, it is often much more costly than other strategies that provide equivalent particle removal or deactivation. To address this tradeoff and arrive at practical recommendations, we explain how different mitigation strategies can be expressed in terms of equivalent outdoor air (EOA) to provide a common basis for energy analysis. We then show the effects of each strategy on EOA delivery and energy cost in simulations of realistic buildings in a variety of climates. Key findings are that in-duct filtration is often the most efficient mitigation strategy, while significant risk reduction generally requires increasing total airflow to the system, either through adjusted HVAC setpoints or standalone disinfection devices.

Using BIM technology, the parameter modeling of the prefabricated building of new rural residential houses was carried out. Through DeST software algorithm, the difference of key energy consumption index between AAC energy-saving materials and the brick-concrete structure used in traditional rural residential houses was compared. Compared with the traditional brick-concrete buildings, the new rural residential buildings using AAC components have obvious advantages in terms of cooling and heating load index of equipment system and room cooling and heating load. From the aspect of building energy consumption, the data verified the excellent performance of AAC materials in building energy conservation, and the possibility and importance of applying AAC materials in the new rural residential buildings under the background of rural revitalization, which played a positive role in promoting the practice and exploration of new residential green buildings in the process of rural revitalization.

Many buildings have considerable thermal bridges at the junction of balcony slabs with walls. To achieve the new EU directive targets related to energy efficiency, greater attention should be paid to such design details. This study analyzes the efficiency of traditional balcony slab modernization methods, the use of modern insulation materials and a new alternative system: an added self-supporting light balcony system (LKBD) in retrofitted large-panel buildings. The main objective was to capture cost-effective renovation methods from both the heat loss reduction perspectives and risk of surface condensation. The analyses, carried out in four buildings, have shown that at current costs, the thermal modernization of balconies is not economically efficient (SPBT&gt, 98.4 years). However, it is necessary because leaving the balcony slabs without insulation or only insulating them from the bottom carries the risk of surface condensation. The most cost-effective renovation method is to insulate the balcony slabs from below and above with the thickest possible XPS layer (SPBT = 98.4 years, 107.4 years). Replacing XPS with modern material increases SPBT by almost 50%, for the LKBD system, SPBT = 269.2–281.5 years. More favorable energy and economic effects related to the reduction of balcony thermal bridges were achieved in the wall with lower insulation.

Geothermal heat pumps have a widespread diffusion as they are able to deliver relatively higher energy output than other systems for building air-conditioning. The exploitation of low-enthalpy geothermal energy, however, presents crucial sustainability issues. This review investigates the primary forms of the environmental impact of geothermal heat pumps and the strategies for their mitigation. As life-cycle analyses shows that the highest impacts arise from installation and operation stages, most optimization studies focus on system thermodynamics, aiming at maximizing the energy performance via the optimization in the design of the different components interacting with the ground and serviced building. There are environmental studies of great relevance that investigate how the climate and ground properties affect the system sustainability and map the most suitable location for geothermal exploitation. Based on this review, ground-source heat pumps are a promising technology for the decarbonization of the building sector. However, a sustainable design of such systems is more complex than conventional air-conditioning systems, and it needs a holistic and multi-disciplinary approach to include the broad environmental boundaries to fully understand the environmental consequences of their operation.

The urgent need to make buildings more performant in energy and environmental terms has led to the increasing study of recycled and natural materials as viable solutions. In this context, the present study aims at comparing the energy performance of innovative wall-sample solutions (with recycled polyethylene-terephthalate panels or durum-wheat straw bales) with a basic one. Energy evaluations were performed in Piazza Armerina (a city of Sicily–Italy), where the chosen material is widespread, by applying two calculation methods: a monthly average-energy-calculation approach, mandatory by Italian regulations (UNI TS 11300), and an hourly energy-calculation procedure (EN 52016). The results documented that: (i) the new innovative wall-sample allows for significantly reducing heat loss (heating of 4–10% and cooling of 40–50%) (ii) a lower primary-energy demand was obtained by adopting the new calculation procedure of EN 52016 (energy decreasing of 20–24%); (iii) significant differences in terms of heat-loss (of 10–36%) and heat-gain (up to 75%) calculations were found for the two calculation methods. This puts emphasis upon the importance of properly selecting a calculation method by accounting for all of those key variables and features that are representative of the energy system being investigated.

Graphical abstract, In this article, an abstract framework for annual averaged wind power output generation prediction of wind turbines is presented which is heavily based on large wind speed data sets and power curve data of wind turbines due to the rising interest in wind energy as one main future renewable energy source. As combinations of arbitrary power curve modeling techniques and arbitrary wind speed distributions based on wind speed data are seldom combined, the abstract combination of these two aspects in wind power output generation prediction in one pipeline is thoroughly described here. Conclusively, one detailed example wind speed data set from a weather station situation in Bremen, Germany illustrates applicability of the presented framework.

Given the large demand nowadays for domestic hot water, and its impact on modern building energy consumption, air source transcritical CO2 heat pumps have been extensively adopted for hot water production. Since their system efficiency is limited by significant irreversibility, a CO2-based mixture could offer a promising drop-in technology to overcome this deficiency without increasing system complexity. Although many CO2 blends have been studied in previously published literature, little has been presented about the CO2/R32 mixture. Therefore, a proposed mixture for use in transcritical CO2 heat pumps was analyzed using energy and exergy analysis. Results showed that the coefficient of performance and exergy efficiency variation displayed an “M” shape trend, and the optimal CO2/R32 mixture concentration was determined as 0.9/0.1 with regard to flammability and efficiency. The irreversibility of the throttling valve was reduced from 0.031 to 0.009 kW⋅kW−1 and the total irreversibility reduction was more notable with ambient temperature variation. A case study was also conducted to examine domestic hot water demand during the year. Pure CO2 and the proposed CO2 blend were compared with regard to annual performance factor and annual exergy efficiency, and the findings could provide guidance for practical applications in the future.

Buildings are responsible for several negative impacts on the environment, most of them related to nonrenewable energy consumption, increasing the concern regarding buildings energy efficiency. In this context, computer software has been used to estimate the energy needs of the built environment, and the Building Information Modelling (BIM) methodology can be used to simplify this process. This study aims to validate a BIM-based framework to streamline the energy analysis of Portuguese buildings, based on the method of the national regulation for the thermal performance of residential buildings. Currently, designers need to spend considerable time assessing all the building characteristics and performing the mandatory calculations for energy performance analysis. It is also intended to link the results of the energy simulation with a Building Sustainability Assessment method—SBToolPT-H. The purpose is to demonstrate how it is possible to benefit from this approach to simultaneously improve building sustainability during the design stage. To do so, different case studies were modelled in Autodesk Revit and exported to a BIM energy tool to perform energy simulation analysis. The results were validated against the official assessment method of the Portuguese thermal regulation and were successfully used to assess the SBToolPT-H energy efficiency category. The research outcomes provide design teams with a reliable BIM-based framework to improve building energy performance and to develop thermal projects while enhancing building sustainability. It also increases the knowledge about the integration of sustainability assessment in the BIM environment, providing new insights for complete integration., This research was funded by the Portuguese Foundation for Science and Technology through the Regional Operation Programme of North (grant number SFRH/BD/145735/2019).

The development of agriculture is linked to energy resources. Consequently, energy analysis in agroecosystems could be a useful tool for monitoring some measures in the agricultural sector to mitigate greenhouse gas emissions. The objectives of this study were to (a) evaluate differences of energy indices in orange and kiwi orchards, and (b) point out whether inputs, outputs, efficiency, productivity, and carbon footprint can play a key role in crop replacement. Proportional stratified random sampling was used to select 26 orchards (10 oranges, 16 kiwis) from the Prefecture of Arta, western Greece, during 2015 and 2016. Univariate statistical methods were combined with multivariate ones. Nitrogen, Mg, Zn, herbicides, insecticides, fungicides, renewable energy inputs, fruit production, total outputs, and energy efficiency and productivity were statistically significantly high in the orange orchards. Phosphorus, Ca, irrigation, machinery, total inputs, intensity, non-renewable energy consumption, and carbon footprint were statistically significantly high in the kiwi orchards. The most important energy inputs for both fruit crops were fertilizers, fuels, irrigation, machinery, and herbicides. The orange orchards seem to be more friendly to the environment than the kiwi orchards by having low total energy inputs 32,210.3 MJ ha-1, intensity 1.4, consumption of non-renewable energy 0.7 MJ kg-1 and CO2 equivalent/fruit production 0.08 kg kg-1, and high energy outputs 105,120.0 MJ ha-1 and fruit production 53,648.0 kg ha-1. The findings of the present study show a relation between climate change and the production of farming systems, which can be a tool for decision makers. The correlation of the abovementioned parameters ensure higher profits and could help in achieving the best possible sustainable management of the agricultural ecosystems.

BIPV (Building Integrated Photovoltaic) system is a building envelope technology that generates energy by converting solar energy into electricity. However, after producing electrical energy, the remaining solar energy is transferred as heat, raising the temperature at the rear of the BIPV module, and reducing electrical efficiency. On the other hand, a PVT (Photovoltaic Thermal) collector is a device that generates electricity from a PV module and at the same time uses the heat transferred to the air layer inside the collector. In general, the performance of air-type PVT collectors is based on energy analysis using the first law of thermodynamics. Since this performance does not take into account the loss amount, it is not the actual amount of power generation and preheat of the collector that can be used. Therefore, an exergy analysis based on the second law of thermodynamics considering the amount of energy loss must be performed. In this paper, an air-type PVT collector to which perforated baffles were applied was tested through outdoor experiments based on ISO 9806 standard. The total energy (thermal and electrical characteristics) and exergy according to the flow rate (100, 150, and 200 m3/h), solar radiation, and rear temperature of the PV module of the air-type PVT collector were analyzed. As a result, the total exergy efficiency of the air-type PVT collector with perforated baffles was 24.8–30.5% when the total energy efficiency was 44.1–63.3%.

In this work, computational intelligence is used to calculate the energy and exergy analysis of lithium bromide–water (LiBr-H2O)-operated vapour absorption refrigeration system. An artificial neura...

CO2-EOR is a recognized effective technology to enhance oil recovery by injecting CO2 into the reservoir to increase layer pressure. With the exploitation of oil, the overflow of large amount of CO2 has caused great difficulties to gas treatment and transportation, even affects the climate if it is discharged directly. CO2 capture from extraction gas plays an increasingly important role in oilfield due to these problems. Compared with other methods, cryogenic fractionation is an ideal method for large extraction gas volume and high CO2 content. In the presented work, Aspen HYSYS was used to simulate the cryogenic fractionation separation process with 100,000 Nm3/d extraction gas and 81.4% CO2 content. Meanwhile, the main factors including pressure of fractionating tower, condensation temperature, reboiling temperature, and CO2 content in raw gas which effect system cooling consumption are also analyzed. The simulation results show that the CO2 purity and recovery can reach over 95% and 90% respectively for high CO2 concentration. The effect of these parameters on system overall cooling consumption is significant and the reasonable parameters are obtained in this work. The results will provide some improvements for scale-up application of cryogenic fractionation in extraction gas CO2 capture.

A full-scale techno-economic analysis of a novel chemical looping based process using dynamically operated packed bed reactors has been carried out for the large-scale production of hydrogen (up to 30,000 Nm3/h) and methanol (up to 10,000 tons per day) with inherently integrated CO2 capture. The complete process is carried out in three main reactors, in which the reactions occurring are the dry and steam reforming of natural gas with H2O and CO2, the oxidation of the oxygen carrier (OC) with air and the reduction with a low-grade fuel such as plant off-gases. The thermal balance of the process is achieved by combining the endothermic reforming reaction with the exothermic chemical looping combustion. The chemical looping based process is fully integrated with the separation and synthesis units as well as the power and heat utilities of the two large scale production plants. The two plants are compared with state-of-the-art technologies, including the benchmarks for hydrogen and methanol production from natural gas through steam reforming and auto-thermal reforming. Compared to a conventional H2 production plant (without CO2 capture), the reforming efficiency is 3% higher, while the required primary energy consumption to separate CO2 is 0.47 MJLHV/kgCO2 which is significantly lower than that of an amine-based plant (>1.35 MJLHV/kgCO2) and the cost of hydrogen production with the proposed process is 2.19 $/kg with a CO2 avoidance cost of 58.7 $/tonCO2 (compared to > 70.6 $/tonCO2 for solvent based plant). In case of methanol production, the carbon conversion is comparable with the best available processes even though CO2 purification and separation (98% capture with >96% purity) units are included due to the improved energy recovery. By using chemical looping the cost of methanol production decreases overall by 17% compared to the benchmark plant due to the lower investment cost and higher electricity generation resulting overall in a negative CO2 avoidance cost (-303 $/tonCO2).