Energy Efficiency Parameters Research Articles

Envelope Life Cycle Costing of Energy-Efficient Buildings in Ukraine

The article describes main points and characteristics of the building envelope design considering life-cycle cost and compliance with the codes for energy efficiency parameters in Ukraine. This article contains of the problem analysis of the requirements development for the energy-efficient buildings parameters in Ukraine considering life-cycle cost in the walling design. The structural concepts for the thermal insulation of building exterior walls and roof coatings and their impact on energy efficiency are considered. Designing rational structural concepts for thermal insulating envelope of energy-efficient buildings. The role of the life cycle cost criterion in making decisions on the choice of building envelope is clarified. Analysis of activities, publications and regulatory documents in Ukraine and the EU-countries for the design of rational thermal insulating building envelope considering life-cycle cost to reducing energy consumption. The requirements of regulatory documents on the design of energy-efficient buildings in Ukraine are systematized. The variants of construction solutions for building envelope are considered in terms of the life-cycle cost and energy saving requirements. The tasks of choosing optimal solutions for enclosing structures of external walls and building coatings are multicriteria of a cardinal choice of alternatives with different important measures from a finite set of feasible solutions when considering a weakly structured problem with clearly defined separated parameters. Thermal insulating building envelope using modern insulation systems should be used in all types of buildings.

Прогнозування попиту на паливно-енергетичні ресурси для енергоємних видів продукції з урахуванням потенціалу енергозбереження до 2040 р.

This paper uses the direct account method to predict energy consumption at two hierarchical levels: the upper level corresponds to the country, and the lower to industrial production, social sphere, and population. When forecasting at the upper level, we applied the parameters of GDP energy intensity and the GDP forecast with estimation of the energy-saving potential from structural and technological changes. At the lower level, the parameters of energy efficiency were applied according to each group: industrial production – specific consumptions of energy resources and production forecast, social sector – specific consumptions of fuel and energy resources for municipal and other economic services, and forecast of the volume of services provided, population – demographic forecast and predicted volume of heated housing. For the prediction of energy consumption in industrial production, from 51 types of industrial products, 26 most energy-intensive ones were selected, which, in total, consume at least 70% of energy resources and have high specific consumptions of energy resources for at least one type of them. For each of 26 types of products, we chose measures of energy savings and estimated the potential for energy savings up to 2040. We calculated the forecasts for fuel, heat, and electricity consumption by 26 types of products, the forecasts of consumption of total fuel and energy resources up to 2040 for energy-intensive products, population, and social sphere. A comparison of the correspondence between obtained forecasts at the upper and lower levels for certain types of energy resources is made. We conclude that it is necessary to combine several methods in forecasting energy consumption for different types of energy resources, for example, normative and direct account.

Energy-efficient association mechanism designed for uplink CDMA-based HCNs

ABSTRACTTo reduce the energy consumption and prolong the battery lifetimes of mobile terminals, the design of energy-efficient association scheme is necessary and meaningful. To this end, we design a type of association mechanism (scheme) to maximize the whole energy efficiency (WEE) for uplink code-division-multiple-access (CDMA)-based heterogeneous cellular networks (HCNs), and formulate it as a WEE maximization problem with users’ SINR (signal-to-interference-plus-noise ratio) constraints. Considering that the finally formulated problem is in a fractional mixed-integer form and hard to tackle, we introduce an energy efficiency (EE) parameter to convert it into a parametric subtractive form. At last, we design two two-layer iterative algorithms for the formulated problem, whose primary difference lies in the treatment of SINR constraints. In general, the outer loop utilizes a bisection method to search the optimal EE parameter, and the inner loop alternately optimizes the association index and transmit power. At last, we give the corresponding convergence analyses for some subalgorithms, and also give some detailed complexity analyses for the whole algorithm. In the simulation, we introduce an existing energy-efficient association mechanism for comparison, and finally investigate the impacts of different network parameters on the association performance.

High temperature electrolysis of hydrogen bromide gas for hydrogen production using solid oxide membrane electrolyzer

Using solid oxide membrane, this paper presents the theoretical modeling of the high temperature electrolysis of hydrogen bromide gas for hydrogen production. The electrolysis of hydrogen halides such as hydrogen bromide is an attractive process, which can be coupled to hybrid thermochemical cycles. The high temperature electrolyzer model developed in the present study includes concentration, ohmic, and activation losses. Exergy efficiency, as well as energy efficiency parameters, are used to express the thermodynamic performance of the electrolyzer. Moreover, a detailed parametric study is performed to observe the effects of various parameters such as current density and operating temperature on the overall system behavior. The results show that in order to produce 1 mol of hydrogen, 1.1 V of the applied potential is required, which is approximately 0.8 V less compared to high temperature steam electrolysis under same conditions (current density of 1000 A/m2 and temperature of 1073 K). Furthermore, it is found that with the use of the presented electrolyzer, one can achieve energy and exergy efficiencies of about 56.7% and 53.8%, respectively. The results presented in this study suggest that, by employing the proposed electrolyzer, two-step thermochemical cycle for hydrogen production may become more attractive especially for nuclear- and concentrated solar-to-hydrogen conversion applications.

Reconciling Energy and Heritage: Retrofit of Heritage Buildings in Contexts of Energy Vulnerability

Chile is a resilient country which has been struck by a series of natural disasters, affecting heritage areas whose inhabitants live under a great economic and energy vulnerability. Although there are some advances that have been made in the country to recover its heritage, these do not include energy efficiency parameters. In this context, intervention in heritage properties requires a specific, complementary treatment above and beyond what is currently applied. Consequently, this research aims to develop a methodology that balances heritage and energy in energy vulnerability contexts. The proposed methodology analyzes heritage and energy aspects separately through attribute matrices, as well as the building pathologies, to later integrate the results in a final matrix which allows defining an energy-heritage intervention plan. In this way, it includes the systematic identification of elements that require intervention because of pathological issues, as well as the type of intervention that would be acceptable given its heritage significance and whether they mean a possibility to optimize the energy performance. The methodology, for its validation, was applied in a heritage residential building inhabited by low-income occupants. The case study presents physical damages and is located in the city of Lota, an area with an outstanding cultural heritage from the mining era.

Energy Efficiency of Briquettes Derived from Three Agricultural Waste’s Charcoal Using Two Organic Binders

Waste management could contribute significantly to reducing environmental degradation. Studies showed that briquetting provides with or without binder helps to manage wastes as energy fuels. However, the properties of many binders are not investigated extensively. This work investigated the effect of two organic binders’ low rate on energy efficiency of Briquettes produced from charcoals of Tender Coconut Husks (TCH), Palm Kernel Shells (PKS) and Corn Cobs (CC). Bombax Costatum calyx (B) and Cissus Repens barks (C) were used separately as binders to elaborate briquettes. The briquettes were compared based on their energy efficiency parameters with wood charcoal as control. Energy efficiency parameters such as water boiling time (WBT), mass of biomass used (MB), burning rate (BR), temperature rise rate (TR) and maximum temperature in the furnace (Tmax) were measured from each biomass charcoal briquette and wood charcoal combustion. Water boiling test was applied to determine briquettes thermal properties. The results of WBT, BR, TR and Tmax were respectively within the ranges 3.4 - 12.3 min, 2.90 - 7.71 g/min, 4.63°C/s - 16.10°C/s and 623°C - 900°C. Corn Cobs charcoal briquettes with Bombax binder took the shortest time to boil water and also presented a high temperature rise rate and the highest maximum temperature. The lowest burning rates were obtained for Tender coconut husks charcoal briquettes with Cissus binder. They showed good material conservation for bombax bound briquettes. The results of our investigations showed that binders content increasing enhanced the thermomechanical stability and affected negatively the energy efficiency parameters of the studied briquettes.

Analysis of energy consumption improvements of a zero-energy building in a humid mountainous area

The most significant basis for sustainable development, as well as one of the most critical concerns of today's human societies, is energy and how it is consumed. In Iran, about 40% of energy is consumed in residential, commercial, and office buildings. Considering the importance of energy for sustainable development, buildings with zero energy consumption have found a lot of supporters. In the present paper, buildings with zero energy consumption in the north of Iran (Qa'emshahr city) were studied, and the feasibility study for constructing such buildings in this humid mountainous area was done. In this regard, a residential building with a conventional condition was considered as a sample, and energy efficiency parameters were investigated; using different methods, energy consumption of the building was reduced to zero. The research method in this study was based on two principles. At first, using scientific resources, new methods for reducing energy consumption in buildings and how they are managed were researched; in the second step, which is the main part of this paper, using DesignBuilder Software, the energy consumption of the building was determined. In the final step, the power generation capacity and panel area and economic considerations in the payback period were calculated per month. For this purpose, an average of 63 m2 of the solar panel was considered to be the electrical power of the building, which was able to fully produce the building's electricity requirement in 8 months. According to the results, with activities, the amount of electrical energy used for air conditioning in the building has been released by 80% and has been detracted from 34 MW to 7 MW. In the case of return on investment (R0I), to supply the required power generation for the building, it would be possible to receive about 15 000 $per year from the Iranian Ministry of Energy.

Comparison between calculated and billed building energy consumption values of schools and daycare centers

In many countries, building regulations set requirements for energy efficiency, which must be fulfilled in order to have a building permit. Because the actual building does not yet exist, the calculations are done in the early design phase with approximate input data. This paper presents results from dynamic whole-building simulations and compares the results to monthly calculation results, billed energy consumption and to a small number of central building energy efficiency parameters. According to the results, using a more sophisticated calculation tool does not necessarily improve the accuracy of the calculation results, if the capabilities of the tool are not properly utilised. Although there was a clear difference between the calculated and billed values, lower calculated energy consumption did correlate with lower billed values. Besides the need for extra effort to ensure accurate input data in general, input values related to infiltration and ventilation should be evaluated especially carefully.

Monitoring the technical condition of autonomous electrical systems with electric drive

The article discusses the structure of autonomous electrical systems with an electric drive and an electric energy generation system. An approach is described for assessing the overall efficiency of technological cycle equipment with specification of parameters that must be considered when calculating it. The necessity of taking into account energy efficiency and operability indicators of autonomous electric complexes is substantiated. The effectiveness of the use of autonomous systems decreases throughout the entire life cycle due to wear and tear. As the operability of electromechanical equipment, an indicator of the residual resource is selected. The calculation of the residual resource, with the definition of its boundary values and recommendations for further use. Nominal energy efficiency parameters of autonomous electrotechnical complexes with electric drive deteriorate during operation, which also needs to be taken into account. To simplify the assessment of the operational state of electromechanical equipment, a state diagram is presented that allows you to track the dynamics of degradation of individual nodes. Taking into account the described indicators and means of control, it is possible to increase the efficiency of using autonomous complexes.

Facade Structures for Energy-efficient Buildings

In recent years, there is a growing interest in energy-efficient building all over the world. This paper presents an analysis of the link between the upgrading of the building structures and overall sustainability of a building in the case of facade structures. This research combines such important aspects in design and construction as installation time of façades, energy efficiency and also flexibility of the architectural appearance of a building. The comparative analysis of different facade structures has been conducted in terms of energy efficiency, operation and installation time. The energy efficiency parameters of a facade structure are determined by thermo technical characteristics. The installation and labor costs are analyzed considering factory-assembled panels that are most frequently used in hard-to-reach regions with extreme weather conditions. The additional options for facade structures are also reviewed in the paper, that include microclimate control systems and ventilation facilities. Based on this study, the new type of the façade panel was created. This type of panel combines benefits of the studied facades. The paper presents the description of constructive solutions and thermo technical characteristics.

Energy efficiency of winter wheat in a long-term tillage experiment under Pannonian climate conditions

Abstract One goal in sustainable agriculture is to use fossil energy more efficiently in crop production. Information on energy consumption and efficiency of different soil tillage systems for developing energy-efficient farming systems with reduced impact on climate change is missing for the Pannonian Basin. This 12-year study on a silt loam chernozem investigated the energy efficiency of four tillage systems (mouldboard plough (MP), deep conservation tillage (CTd), shallow conservation tillage (CTs), no-tillage (NT)) in rotations taking thereby into account diesel fuel consumption, total energy input (made up of both direct and indirect inputs), grain yield, energy output, net-energy output, energy intensity and energy output/input-ratio. Input rates of fertilizer, herbicides and seeds remained constant, while values of diesel fuel consumption were measured for all tillage operations. Total diesel fuel consumption for winter wheat (Triticum aestivum L.) production was 59.8 L ha−1, 60.6 L ha−1, 48.5 ha−1 and 36.0 L ha−1 for MP, CTd, CTs and NT, respectively. Between 73% and 83% of total energy input was required by indirect energy (seeds, fertilizer, herbicides, machinery). MP and CTd each required a total energy input of about 9.3 GJ ha−1; the total energy input for CTs and NT was lower by 4.8% for both. Direct energy input (diesel and lubricant oil) was much lower with no-tillage (with 1.5 GJ ha−1) than with mouldboard plough (with 2.4 GJ ha−1), deep conservation tillage (with 2.5 GJ ha−1) and shallow conservation tillage (with 2.0 GJ ha−1). Grain yield and thus energy output were mainly influenced by year. The year effect on yield and energy efficiency parameters was larger than the tillage effect. Especially in dry years, ploughless tillage systems tended to respond with competitive yields. This resulted in an increase of energy efficiency parameters. Over all twelve years, winter wheat produced in the CTs tillage system reached the highest net-energy and output/input-ratio with the lowest energy intensity.

Prospects of establishment of east-west transit transport corridor deploying magnetic levitation technology

According to economist Klaus Schwab, the today’s community is at the threshold of the Fourth Industrial Revolution which will influence transport branch especially. Today, we see a fundamental change of assessment of the place and role of transport in the world progress. At the governmental level the tasks of realisation of large-scale projects have been determined, which will be able to strengthen Russia’s positions at the world freight transport market, namely container transport, increase Russia’s transit potential, speed, quality of passenger service and freight transport.
 The authors suggest options to solve the set tasks building on the idea of implementation of innovative magnetic levitation technology while establishing East-West Transport Transit Corridor.
 Magnetic levitation technology is competitive with the existing modes of transport in key speed, sustainability, energy efficiency and safety parameters, namely ecological safety. The main purpose of establishment of a transit transport corridor is to introduce a new transport service with a unique number of properties. Accordingly, transport and technology tasks are solved which are associated with construction and modernisation of transport lines, terminals, information systems, etc. The project of transport transit corridor in question is suggested to undertake in three stages. The assessment of Russian container transport market and comparison study of maglev and conventional railway transport parameters confirm efficiency of the project. To deliver this project, the decision should be made at the governmental level.

Cooling Performance Characteristics of 20 Ah Lithium-Ion Pouch Cell with Cold Plates along Both Surfaces

Temperature control of the lithium-ion pouch cells is crucial for smooth operation, longevity and enhanced safety in the battery-operated electric vehicles. Investigating the thermal behavior of lithium-ion pouch cells and optimizing the cooling performance are required to accomplish better performance, long life, and enhanced safety. In the present study, the cooling performance characteristics of 20 Ah lithium-ion pouch cell with cold plates along both surfaces are investigated by varying the inlet coolant mass flow rates and the inlet coolant temperatures. The inlet coolant mass flow rate is varied from 0.000833 kg/s to 0.003333 kg/s, and the inlet coolant temperature is varied from 5 °C to 35 °C. In addition, the effects of the cold plate geometry parameter on cooling performance of 20 Ah lithium-ion pouch cell are studied by varying the number of the channels from 4 to 10. The maximum temperature and difference between the maximum and the minimum temperatures are considered as important criteria for cooling performance evaluation of the 20 Ah lithium-ion pouch cell with cold plates along both surfaces. The cooling energy efficiency parameter (β) and the pressure drop for 20 Ah lithium-ion pouch cell with cold plates along both surfaces are also reported. The study shows that enhanced cooling energy efficiency is accompanied with low inlet coolant temperature, low inlet coolant mass flow rate, and a high number of the cooling channels. As a result, the temperature distribution, the pressure drop, and the cooling energy efficiency parameter (β) of the 20 Ah lithium-ion pouch cell with cold plates along both surfaces are provided, and could be applied for optimizing the cooling performances of the thermal management system for lithium-ion batteries in electric vehicles.

Energy Efficient Power Allocation for Carrier Aggregation in Heterogeneous Networks: Partial Feedback and Circuit Power Consumption

The energy-efficient power allocation for carrier aggregation (CA) in heterogeneous networks (HetNets) is studied in this paper. We assume that multiple component carriers belong to HetNets and, thus, inter-band CA is considered, where both full and partial feedback scenarios are investigated. For the latter, we consider quantized channel state information at the transmitter and the corresponding power allocation policies are derived. Next, we derive energy-efficient optimal power allocation policies by assuming circuit power consumption for the transmitter that account for the multiple radio frequency (RF) chains required to support massive inter-band CA. The resulting algorithms are then used in order to investigate the relation between optimal energy efficiency (EE) and design parameters such as the number of frequency bands, antennas and feedback allocation through controlling the quantized information. A greedy optimization algorithm is also introduced to jointly optimize the aforementioned parameters. By carrying out simulations, it is observed that the achievable EE gains for massive CA in HetNets is further limited by either the number of feedback bits or the increase in RF circuits power consumption.

The Issues of Energy Efficiency of Buildings for Agricultural Purposes

The current problem of ensuring energy saving and improving the energy efficiency of buildings and structures for agricultural purposes is identified. The geopolitical situation, import substitution programs and agricultural development programs set the task of developing domestic vegetable production, which in its turn requires the construction of new vegetable store buildings, as in most regions of Russia the harvest is collected once a year. In this regard, the current task is to ensure the energy conservation and achieve high energy efficiency of the vegetable store buildings. Energy saving is the basic technology for creating effective agriculture. The purpose of the study is to analyse the requirements for insulation materials for buildings and vegetable store facilities, taking into account energy efficiency and life cycle cost. The authors analysed the criteria for choosing a heater for the vegetable stores: low coefficient of thermal conductivity, water absorption, sorption humidity, frost resistance, biostability, lack of cold bridges, long service life. It is proposed to supplement the criteria for choosing a building insulation with the characteristics of the life cycle cost and the service life. Design and construction of agricultural buildings is proposed to be implemented using the concepts of BLC and BIM, the use of which gives an opportunity to design buildings with optimal energy efficiency parameters and take into account the cost of the life cycle. The cost of the buildings life cycle is the main of all the performance indicators when comparing alternative design options that differ by the application of advanced technologies and material resources and the contractors' offers when concluding contracts not only for purchase, but for servicing the subject of trades during its service life. The conclusions are made about the advantages of using foamed polyethylene foam for warming vegetable store buildings, as well as the conclusion about the expediency of adding criteria determining the sustainable development of the human environment, namely life cycle cost, service life, recycling ability. The formula for calculating the cost of the buildings life cycle, adapted to the specificity of buildings for agricultural purposes, is given.

EEC-FM: Energy Efficient Clustering based on Firefly and Midpoint Algorithms in Wireless Sensor Network

Wireless sensor networks (WSNs) consist of set of sensor nodes. These sensor nodes are deployed in unattended area which are able to sense, process and transmit data to the base station (BS). One of the primary issues of WSN is energy efficiency. In many existing clustering approaches, initial centroids of cluster heads (CHs) are chosen randomly and they form unbalanced clusters, results more energy consumption. In this paper, an energy efficient clustering protocol to prevent unbalanced clusters based on firefly and midpoint algorithms called EEC-FM has been proposed, where midpoint algorithm is used for initial centroid of CHs selection and firefly is used for cluster formation. Using residual energy and Euclidean distance as the parameters for appropriate cluster formation of the proposed approach produces balanced clusters to eventually balance the load of CHs and improve the network lifetime. Simulation result shows that the proposed method outperforms LEACH-B, BPK-means, Park’s approach, Mk-means, and EECPK-means with respect to balancing of clusters, energy efficiency and network lifetime parameters. Simulation result also demonstrate that the proposed approach, EEC-FM protocol is 45% better than LEACH-B, 17.8% better than BPK-means protocol, 12.5% better than Park’s approach, 9.1% better than Mk-means, and 5.8% better than EECPK-means protocol with respect to the parameter half energy consumption (HEC).

Assessment of the ventilation efficiency in the breathing zone during sleep through computational fluid dynamics techniques

In developed countries, presence at home varies between 60% and 90% of the day, sleeping supposes 30%. Therefore, it is essential to ensure good indoor air quality that enhances health and benefits rest and recovery. In this context, it is necessary to achieve a balance between energy efficiency and air distribution parameters; thus, the influence exerted by the furniture of a bedroom on the air exchange efficiency, in the breathing zone during sleep, is assessed in this study. Computational fluid dynamics techniques, experimentally validated by the tracer gas (SF6) concentration decay method, are used to analyze 52 case studies corresponding to the same space, but varying both the number and the arrangement of the furniture inside. It is concluded that, in order to achieve a significant improvement in the air exchange efficiency, the number of elements included in the bedroom is not relevant, but the position of them. The highest increase in the ventilation efficiency in breathing zone is observed when the furniture is located avoiding the airflow obstruction in the area near the inlet and creating an unfilled volume of air in the area close to the outlet.

BIM-based process management model for building design and refurbishment

A conceptual model of BIM-based design and refurbishment, based on pre-built indicators and allowing the assessment of the building energy demand and eco-building parameters, is presented. The new approach presented in this model creates a knowledge-based decision-making environment for refurbishment strategies and quality control, in this way creating the preconditions to bridge the gap between expected and actual energy performance. The model with integration of new BIM-based optimization subsystems enables energy management and optimization processes. For a comprehensive evaluation of refurbishment measures, it is suggested to include energy efficiency, eco-efficiency, and economic parameters.

TO THE QUESTION OF VIBRO-EXCITER’S ENERGY EFFICIENCY INCREASING FOR VIBRATING COMPACTORS IN THE SPHERE OF ROAD CONCTRUCTION

Introduction. The article considers the relevance of the subject of using vibratory compactors in the road construction field. Moreover, the shortcomings of existing unbalance exciters are revealed. In order to eliminate the drawbacks, we propose a new design of a crank-rod type vibration exciter. Therefore, the design is a new step in the development of directional oscillators, the use of which in road engineering would increase its productivity and efficiency. The main provisions, which allow to calculate energy efficiency and vibration parameters of a new exciter, are considered. The results of calculations and the dependence of the power exponent for the entire period of oscillatory motion are presented. The article proposes a new principle of designing periodic generators of directed force action. The scheme of the construction and its kinematic scheme are presented. The result of the research is to increase the energy efficiency of using vibrating compactors in road construction. Material and methods. A new design of a vibration exciter is presented, the dependence character of the direction of the driving force on time relative to the treated surface is revealed. Results. Increase energy efficiency of the building materials’ processing by vibrating road rollers are given. Discussion and conclusion. As can be seen, the proposed technical solution is a new step in the development of oscillators of directional action and their usage in road engineering, which would improve its productivity and efficiency of processing road building materials.

Optimization Parameters for Energy Efficiency in End milling

One way to manage the modern challenges of global resource depletion and climate change is to reduce energy consumption. The use stage of machines in manufacturing operations consumes the majority of energy and brings serious emissions over a machine's life cycle. With this in mind, a multi-objective cutting parameter optimization model is proposed, focusing on minimizing the process time and energy consumption per unit of removed material. Constraint conditions, such as the processing capacity of the machine tool, the tool life, the surface roughness of the part, and wasted ploughing energy are considered. A genetic algorithm is used to solve the optimization model and the effects of the parameters on the energy consumption of the machine are discussed. To verify the proposed method, experiments were designed for an end milling operation, using Taguchi design principles.