Energy Efficiency Requirements Research Articles

Theoretical essentials for designing viscous liquid pumping systems in the conditions of the Arctic region

The purpose is the creation of a scientifically based solution for the design of hermetic electromechanical converters adapted to existing pipelines, as well as those under construction and development. These pipelines meet the energy efficiency requirements and operate in the conditions of the Arctic region. Methods: methods of mathematical analysis, numerical methods, and methods of mathematical programming were used as the main mathematical means. The CFD design package of Ansys Maxwell was used. Research results: we showed that an increase of the efficiency of the system of technological transportation of petroleum products at low temperatures is possible through the use of electromechanical devices that combine the functions of heating and pumping the working liquid. We solved the field problem based on the analytical calculations carried out by a computer. This allowed us to determine the distribution of eddy current density in the structural elements of these devices responsible for creating pressure and heating the pumped petroleum products. The importance of the electrical parameters of the secondary windings has been confirmed numerically and experimentally. The hydraulic characteristics, mechanical losses, volumetric losses and efficiency are determined. Taking into account the outcomes of theoretical studies the experimental sample of the sealed electromechanical converter with the specified physical and chemical characteristics was created at Emperor Alexander I St. Petersburg State Transport University. Practical relevance: the obtained analytical formulas can be used at the development of the systems for pumping viscous liquids at low temperatures using the sealed electromechanical converters which helps to reduce the installed power of energy equipment without degrading the values of technological indicators.

NOx reduction system selection and energy efficiency impact evaluation for ships sailing in restricted areas

The worldwide shipping provides 90 percent of the goods carriage and in the last 20 years their absolute volume is constantly increasing. However, carriers need to maintain service levels and reduce exploitation costs, and at the same time must ensure higher sustainability in all operations. The growth in number of ships in service inevitably leads to much more harmful emissions released by vessels in to the atmosphere. In the same time, more stringent environmental requirements and laws continue to regulate the maritime transport sector. Progress was made by International Maritime Organization (IMO) towards the ambition on reduction of greenhouse gas (GHG) emissions from ships. That is why IMO based International Convention for the Prevention of Pollution from Ships (MARPOL Convention) and its regulations continuously sets higher thresholds for environment protection expressed by Nitrous Oxides (NOx), Sulphur Oxides (SOx) and Carbone Dioxides (CO2) limitations. The new higher ecological requirements put on the table new technical and economic challenges for the shipowners and ship designers.In the current paper Selective Catalytic Reduction (SCR) and Exhaust Gas Bypass (EGR) NOx emissions reduction systems and their affect on the fuel consumption are under consideration. The application of each system depends on the ship’s type, installed propulsion system and its main engines and operational modes.The numerical study is carried based on 31800 DWT vessel for bulk loads, operating in restricted areas of the Great Lakes of North America. In the course of the research the fulfilment of the following objectives are being leaned: the ship must be capable for operation in Nitrogen Emission Control Areas (NECA’s), as well as its Energy Efficiency Design Index (EEDI) must be in compliance with Required Energy Efficiency Design Index (REEDI) Phase 3 coming in force in 2025.

To PiM or Not to PiM

As artificial intelligence becomes a pervasive tool for the billions of IoT (Internet of things) devices at the edge, the data movement bottleneck imposes severe limitations on the performance and autonomy of these systems. PiM (processing-in-memory) is emerging as a way of mitigating the data movement bottleneck while satisfying the stringent performance, energy efficiency, and accuracy requirements of edge imaging applications that rely on CNNs (convolutional neural networks).

Analysis of the compliance of windows with up to day energy efficiency requirements

Due to the consequences of the energy and environmental crises, reducing energy consumption in buildings is an urgent task, both globally and nationally. It is this goal that causes a constant increase in the requirements for resistance to heat transfer of the external enclosing structures of buildings in climatic conditions, where the design temperature of the outside air is at the level of -20ºС. Increasing the resistance of non-transparent enclosing structures is achieved by available means that allow guaranteed achievement of the designated resistance to heat transfer. Increasing the heat transfer resistance of transparent (or translucent) enclosing structures has limitations that limit the maximum values. The analysis of window designs that are offered on the construction market of Ukraine in the context of the requirements of DBN V.2.6.31-2021 "Thermal insulation and energy efficiency of buildings" was carried out. To increase the resistance to heat transfer of windows, the manufacturer has (today) three constructive means - an increase in the number of chambers, the use of selective coatings and filling the chambers with an inert gas argon. It should also be taken into account that the production of windows is a multicriteria task, in which the achievement of a certain level of resistance to heat transfer is one of the factors among others, no less important. The results of the analysis show that the fulfillment of the requirement Rqmin≥0.9 m2•ºС/W for the first temperature zone of Ukraine requires the use of all technical means available from manufacturers. A sample of eighty-two window designs that are actually offered on the Ukrainian construction market was analyzed. Compliance with the requirements for the second temperature zone was achieved for forty-three percent of window designs. Compliance with the requirements for the first temperature zone was achieved for seventeen percent of window designs. The complexity and increased cost of such structures may necessitate additional control measures at the completion of construction and during the operation of buildings.

COMPREHENSIVE METHOD OF ENERGY-EFFICIENT WORKLOAD PROCESSING IN THE INFORMATION AND COMMUNICATION NETWORK

Background. Peculiarities of the workload in a modern information and communication network (ICN) determine specific requirements for energy efficiency, performance and availability of its processing system. Existing approaches to increase energy efficiency and performance of workload processing do not take into account the possibility of dynamic changes in ICN workload arrival rate and individual energy consumption characteristics of computing nodes of the system.
 Objective. The purpose of the paper is to increase the energy efficiency and performance of ICN workload processing while meeting the requirements for the availability of the processing system, taking into account dynamic changes in the input workload arrival rate and the individual characteristics of the computing nodes’ energy consumption.
 Methods. A mathematical model of the workload processing system was built using the queueing theory methods, and an ontological model of this system was built using intelligent data analysis methods, which made it possible to quantitatively and qualitatively describe the complex relationships between system parameters and workload processing efficiency indicators. On the basis of the built models, a comprehensive method of energy-efficient workload processing was proposed, which differs from the known ones by the use of individual energy consumption models of computing nodes, combining the advantages of horizontal scaling and energy-efficient scheduling taking into account dynamic changes in workload arrival rate.
 Results. The efficiency of ICN workload processing is increased by 15.722% according to the efficiency criterion, which includes energy efficiency and performance indicators, compared to the known energy-efficient Backfill approach while meeting the requirements for the availability of the processing system.
 Conclusions. The energy efficiency, performance and availability of the ICN workload processing system can be improved by combining horizontal scaling and energy-efficient scheduling approaches using individual energy consumption models of computing nodes and taking into account dynamic changes in the input workload arrival rate.

Improving concurrency and memory usage in distributed operating systems for lightweight manycores via cooperative time-sharing lightweight tasks

Lightweight manycore processors arise to reconcile performance, energy efficiency, and scalability requirements on a single chip. Operating Systems (OSes) for these processors feature a distributed design, where isolated OS instances cooperate to mitigate programmability and portability issues coming from their architectural intricacies. Currently, OS services often resort to traditional execution flow abstractions (processes or threads) to implement small, periodic, or asynchronous functionalities. Although these abstractions considerably simplify the system design, they have a non-negotiable impact on the limited on-chip memories. Due to the memory restrictions, we argue that OS-level abstractions can be reshaped to reduce the OS memory footprint without introducing considerable overhead. In this context, we propose a complementary OS-level execution engine that supports cooperative time-sharing lightweight tasks that share a unique execution stack and features task synchronization via control flow and dependency graphs. This solution is orthogonal to the underlying execution support and provides numerous OS-level execution flows with reduced memory consumption. We implemented our engine in a distributed OS and executed experiments on a lightweight manycore. Our results show that it has the following advantages when compared to the classical thread abstraction: (i) it provides 63.2× more execution flows per MB of memory; (ii) it features less overhead to manage execution flows and system calls; (iii) it improves core utilization; and (iv) it exhibits competitive results on real-world applications.

Numerical analysis of energy recovery system for turbocharged internal combustion engines via a parallel compounding turbine

Increasing energy efficiency requirements mandatory ask for optimizing energy utilization in many devices, which include internal combustion engines. One of the most investigated subjects is the energy recovery from the exhaust, such as turbo-compound systems, which usually consist in a secondary turbine located afterward the turbocharger. Here an alternative arrangement is proposed and analysed via a numerical model. The recovery turbine works in parallel to the main turbine and uses the gasses which would be otherwise wasted through the waste-gate valve, once the set-point boost pressure is reached. The reference case analysed is a 12.4L turbocharged diesel engine, commonly used in marine, road and light railroad applications, with a nominal power of 380kW. The results showed that an overall 8% of power can be gained, without nor increasing the fuel mass flow rate, neither requiring significant modifications to the baseline engine. Moreover, in the case of the recovery system failure, the operation of the engine is not affected, thus resulting in no engine availability reduction. This work also shows a feasible way to convert the mechanical energy delivered by the recovery turbine into electrical energy, by making use of a high-speed electrical generator.

Optimization of biogas-reforming conditions considering carbon formation, hydrogen production, and energy efficiencies

Hydrogen production from biogas requires energy efficiency. This study systemically compared pure biogas reforming, CO2-free biogas steam reforming, and biogas steam reforming. A comprehensive evaluation combining thermodynamic analysis, energy efficiency evaluation, and experimental validation was performed to compare the reaction types. Biogas steam reforming is the most attractive reforming reaction because it has the lowest SEC. In addition, the main parameters for the reaction conditions were investigated to optimize hydrogen production from biogas. The optimal conditions for the biogas steam reforming were determined as 750 °C and an H2O/CH4 ratio of 1.5. Finally, the previously developed Ni–MgO–CeZrO2 catalyst was tested under the optimized reaction conditions. Consequently, the catalyst showed high catalytic performance and was maintained for 30 h, even at a high GHSV of 36 000 h−1. This result implies that the optimized reaction condition derived by comparing the various indicators such as conversion of reactants, yield of products, energy consumption, and thermal efficiency is suitable for hydrogen production from biogas.

Blast enhanced façade design by means of an optimal balance between security and sustainability

The major objective of this paper is to show that glazed curtain wall has a surprising potential for blast enhancement. However, often this potential is partially lost because of inaccurate and only presumed safe side approach. Indeed, in curtain wall it is much important to assess properly the beneficial effect of the deformable supports, framing and possibly brackets, on the glazing response under blast wave effects. Only in this way a true balanced design approach can be carried out and the protective requirement can be integrated into the façade design by preserving the architectural requirements, comfort, classical energy efficiency requirements and novel demand for sustainability. On the other side the large variability of materials and component behaviour under nonlinear range and the uncertainties related to the blast threat recommend a flexible calculation tool, which must be coupled with a sensitivity analysis on the most relevant inputs. For this reason, a Multi Degree of Freedom approach shows several advantages with respect to the Explicit Dynamic Finite Element Analysis, considering also the large number of geometry, component design and blast load variations are existing in a typical application of the protection on a high rise building. The impact of the calculation method is demonstrated by means of a comparative exercise and by means of real case applications.

The impact of building energy codes evolution on the residential thermal demand

The building stock decarbonization by 2050 requires the implementation of an energy transition strategy. Building energy codes must be considered to minimize the energy consumption of the residential sector. This paper aims to evaluate the evolution of the building energy codes of Spain based on energy simulation. A quantitative assessment of the residential thermal demand according to the new energy efficiency requirements introduced in national regulations over the years was performed. Heating, cooling, and domestic hot water demands were assessed for 60 cases modeled in DesignBuilder, combining different building geometric typologies, energy codes, and climate zones. Heating presented the largest contribution to the total energy demand reaching up to 75%. The codes’ evolution led to a significant reduction in heating and a slighter decrease in cooling. The results showed an average energy demand improvement of 50% from the first regulatory release to the latest one.

A biophilic wellbeing framework for positive indoor-outdoor connections in energy-efficient Arctic buildings

This paper develops a biophilic wellbeing framework for positive indoor-outdoor connections in Arctic buildings to respond to occupants’ wellbeing and energy-efficiency requirements. Extreme cold weather and drastic photoperiods of Arctic climates could have adverse impacts on wellbeing and reduce connections with nature, i.e., identified as biophilia. Characteristics of positive relationships with extreme Arctic climatic stressors have not yet been comprehensively studied in terms of integrated wellbeing needs and energy efficiency requirements. This paper aims to articulate a fundamental wellbeing framework integrating thermal and photobiological needs with biophilic recommendations to characterize positive connections with Arctic climates for energy-efficient buildings. A scoping literature review is conducted to discuss occupants' thermal and photobiological needs in relation to biophilic recommendations and Arctic climatic conditions. As a case study, shortcomings of existing building practices in Cambridge Bay, Nunavut, Canada, are studied regarding wellbeing, indoor-outdoor connections, and energy-efficiency needs. The proposed wellbeing framework for positive indoor-outdoor connections in Arctic buildings integrates (i) thermal and (ii) photobiological indicators based on biophilic recommendations. The integrated wellbeing framework enables characterizing thermal and (photobiological) lighting adaptation scenarios responding to Arctic weather, daylighting, and photoperiods as well as energy efficiency. Intermediate spaces are also proposed as a prosing architectural solution to address the integrated wellbeing framework energy efficiency in arctic buildings. Overall, the proposed framework could help architects, building designers, and stakeholders to develop further architectural solutions for positive, energy-efficient indoor-outdoor connections for Arctic buildings and occupants.

Perspective on oxide-based three-terminal artificial synapses in physical neural networks

The physical implementation of artificial neural networks, also known as “neuromorphic engineering” as advocated by Carver Mead in the late 1980s, has become urgent because of the increasing demand on massive and unstructured data processing. complementary metal-oxide-semiconductor-based hardware suffers from high power consumption due to the von Neumann bottleneck; therefore, alternative hardware architectures and devices meeting the energy efficiency requirements are being extensively investigated for neuromorphic computing. Among the emerging neuromorphic electronics, oxide-based three-terminal artificial synapses merit the features of scalability and compatibility with the silicon technology as well as the concurrent signal transmitting-and-learning. In this Perspective, we survey four types of three-terminal artificial synapses classified by their operation mechanisms, including the oxide electrolyte-gated transistor, ion-doped oxide electrolyte-gated transistor, ferroelectric-gated transistor, and charge trapping-gated transistor. The synaptic functions mimicked by these devices are analyzed based on the tunability of the channel conductance correlated with the charge relocation and polarization in gate dielectrics. Finally, the opportunities and challenges of implementing oxide-based three-terminal artificial synapses in physical neural networks are delineated for future prospects.

Energy-Efficient Offloading Based on Efficient Cognitive Energy Management Scheme in Edge Computing Device with Energy Optimization

Edge devices and their associated computing techniques require energy efficiency to improve sustainability over time. The operating edge devices are timed to swap between different states to achieve stabilized energy efficiency. This article introduces a Cognitive Energy Management Scheme (CEMS) by considering the offloading and computational states for energy efficacy. The proposed scheme employs state learning for swapping the computing intervals for scheduling or offloading depending on the load. The edge devices are distributed at the time of scheduling and organized for first come, first serve for offloading features. In state learning, the reward is allocated for successful scheduling over offloading to prevent device exhaustion. The computation is therefore swapped for energy-reserved scheduling or offloading based on the previous computed reward. This cognitive management induces device allocation based on energy availability and computing time to prevent energy convergence. Cognitive management is limited in recent works due to non-linear swapping and missing features. The proposed CEMS addresses this issue through precise scheduling and earlier device exhaustion identification. The convergence issue is addressed using rewards assigned to post the state transitions. In the transition process, multiple device energy levels are considered. This consideration prevents early detection of exhaustive devices, unlike conventional wireless networks. The proposed scheme’s performance is compared using the metrics computing rate and time, energy efficacy, offloading ratio, and scheduling failures. The experimental results show that this scheme improves the computing rate and energy efficacy by 7.2% and 9.32%, respectively, for the varying edge devices. It reduces the offloading ratio, scheduling failures, and computing time by 14.97%, 7.27%, and 14.48%, respectively.

Evaluation of the Quality of the Housing Environment Using Multi-Criteria Analysis That Includes Energy Efficiency: A Review

The quality of the housing environment (HE) is an important issue that has a direct impact on the life of inhabitants. Aiming for quality in residential architecture begins with a well-designed HE, with the designing process being a value that is difficult to evaluate. Nowadays, a well-designed HE takes into account the energy efficiency of a building. An appropriate degree of thermal comfort, which is required by inhabitants, needs to be considered at the design stage. Designers can use building certification programs and multi-criteria analysis to motivate investors to construct buildings in accordance with energy efficiency requirements. These systems respond to the needs of energy efficiency, thermal comfort, sustainable heating, and ventilation. Defining ways and methods to evaluate quality in architectural projects will allow the value of the HE to be improved. For this purpose, a multi-criteria analysis of five systems that can be used to evaluate HE quality and energy efficiency in a temperate climate was conducted: (1) Building For Life 12, (2) Home Quality Mark, (3) Housing Quality Indicators, (4) Système D’évaluation De Logements (Sel), and (5) NF Habitat-NF Habitat HQE. This analysis concerned information about the systems, their applicability in practice, and the applied assessment measures. The article shows that the quality of the HE consists of specific factors that can be distinguished and indicated by evaluation systems. As a result of the carried out assessment of the housing environment, 13 original categories of building assessment criteria were defined. The results of the conducted analysis indicated that it is possible to: (i) identify factors for the improvement of HE quality; (ii) prepare objective systems for the measurement of the HE; and (iii) use such systems in practice, e.g., in the design industry, real estates, and public administration. Moreover, the systems can be used in legal regulations for updating urban policies.

A Resource Efficient CNN Accelerator for Sensor Signal Processing Based on FPGA

With the use of Convolutional Neural Network (CNN) in the application of sensor signal processing system, it usually faces the urgent requirements of system integration, high throughput, hardware resource and energy efficiency. This paper introduces a resource efficient accelerator with general two-dimensional multiply-add array operator to focus on the characteristic of sensor signal processing, which can be applied to standard CNN, depth-wise CNN, Fully Connected (FC) layer for varied networks. Meanwhile, resource estimation model is also constructed to provide the exploration of parallel parameters for computing efficiency. Finally, a board-level verification is implemented to demonstrate the efficiency of proposed accelerator with common scene of LeNet and complex scene of MobileNetV1. Experimental results show that the Inferences Per Second (IPS) of 332225 and 1498 is realized with 100[Formula: see text]MHz frequency. The corresponding efficiency is 88.84% and 61.09%, which outperforms other related works about CNN accelerator design in terms of signal processing. This paper is also applicable and scalable to other fields about effective acceleration research.

A Comparative Analysis of Various Spatial Modulation Techniques

Abstract: Spatial modulation (SM) is an emerging digital modulation technology that fulfills the requirement of higher Spectra efficiency and high energy efficiency and has a very wide range of applications. The concept used in Spatial Modulation can further be extended to other domains such as frequency, time, angle or even across multiple domains. The basic idea behind SM is to convey extra information with the ON/OFF states of transmitting antennas. In single RF Spatial Modulation, only one antenna is activated at a time. Therefore, it requires only one RF chain which reduces the cost as compared to MIMO [1] system.

Is slow steaming a viable option to meet the novel energy efficiency requirements for containerships?

The Marine Environment Protection Committee has introduced the Energy Efficiency Existing Ship Index, which will enter into force in 2023, to reduce emissions from existing ships. Since many existing ships do not comply with the Energy Efficiency Existing Ship Index requirements, certain mitigation measures must be applied to reduce carbon dioxide emissions. In this study, an analysis of slow steaming for fulfilling these requirements is carried out using the example of containerships built until 2016 employing the analytic model. The required speed reduction for ships which do not meet the Energy Efficiency Existing Ship Index requirements is quantified, and the potential problems related to long-term sailing with reduced speed are highlighted. The relationship between ship speed and fuel consumption for Post Panamax, Post Panamax Plus, and Very Large Containership fleets is analysed. The obtained results highlight the significance of potential implementation issues of each mitigation measure to achieve sustainable growth of the maritime transport industry.

Energy Efficiency Engagement Training in SMEs: A Case Study in the Automotive Sector

Energy efficiency requirements in Europe are set by the Energy Efficiency Directive, considering energy audits as a systematic procedure to determine the savings in energy costs. These kinds of tools provide useful information for companies to identify opportunities for the improvement of their energy performance. However, the regulation is only applied for non-SMEs in Europe, which make up only 0.2% of the total number of European companies. Compared in terms of the value added or the number of employees, these companies are still at a lower percentage than small and medium enterprises. The wide versatility of small companies, however, makes it difficult to determine a regulation that promotes the objective of the Directive in a uniform way. For this reason, one aspect that is being worked on with small companies is raising awareness and training in energy aspects, encouraging them to carry out activities to improve their energy performance based on their own initiative. In this regard, within the framework of an H2020 research project based on the automotive sector, the E2DRIVER project, a collaborative–cooperative training methodology has been designed to motivate and empower the key actors within a company. This paper describes the methodology and its implementation in different companies in European countries, providing some representative results.

5G Edge Computing Access Node Selection Algorithm Based on Energy Efficiency and Delay

In order to address the dissipation of energy efficiency in 5G edge computing, and the problem of network delay, better improve the quality of user service, considering the data aggregation delay while improving the network energy efficiency. The author proposes a 5G edge computing access node selection algorithm based on energy efficiency and delay; through the energy efficiency and delay balanced data collection mechanism (EEDBDG), a new dynamic tree is used to organize the network topology, eliminating the hot zone problem; nodes dynamically choose routes and take turns acting as the root of the tree, which collects data and communicates directly with the base station. At the same time, three data collection strategies are proposed for different latency and energy efficiency requirements: delay optimal algorithm (EEDBDG-D), energy efficiency optimal algorithm (EEDBDG-E), and energy efficiency delay balance algorithm (EEDBDG-M). Experimental results show that, when the communication radius of nodes is limited, EEDBDG balances the energy consumption of nodes, prolongs the network life time, and shows outstanding performance in energy saving and time saving. Compared with GSEN, in the best case, the network lifetime of EEDBDG-E is increased by 72%, and the convergence delay of EEDBDG-D is reduced by 74%. Conclusion. The algorithm can effectively reduce the energy dissipation and delay of edge computing.

Sound Insulation of Façade Element with Triple IGU

Sound insulation design for structural glazed façade is an important task in environmental noise control, as increased continuously repeated noise is a significant factor impacting on people’s well-being and is associated with a negative impact on their health. For façades, in addition to sound insulation, requirements for safe use and high energy efficiency are also usually raised, which partly determine the composition of the glazing: triple insulating glass unit (IGU) with inner safety laminated glass sheet. Therefore, the aim of the research was to investigate the structural sealed façade structure with triple IGU and to determine the effect of the thickness of ordinary and laminated glasses, their position in the IGU, the thickness of the gas cavities, and the mass of the structural frame on the sound insulation level of structural glazing. Experimental measurements of the sound insulation index of the investigated façade elements with IGU of various constructions were performed in an acoustic reverberation chamber according to standard procedures. The result of the study indicated that the use of the second laminated glass in a triple IGU is inefficient, the highest sound insulation indicators are achieved by increasing the thicknesses of the external glass sheet and the gas cavity; increasing the mass of the frame also has only little effect on the sound insulation of the structural glazing.