Concept Of Energy Conservation Research Articles

Energy-conserving neural network for turbulence closure modeling

In turbulence modeling, we are concerned with finding closure models that represent the effect of the subgrid scales on the resolved scales. Recent approaches gravitate towards machine learning techniques to construct such models. However, the stability of machine-learned closure models and their abidance by physical structure (e.g. symmetries, conservation laws) are still open problems. To tackle both issues, we take the ‘discretize first, filter next’ approach. In this approach we apply a spatial averaging filter to existing fine-grid discretizations. The main novelty is that we introduce an additional set of equations which dynamically model the energy of the subgrid scales. Having an estimate of the energy of the subgrid scales, we can use the concept of energy conservation to derive stability. The subgrid energy containing variables is determined via a data-driven technique. The closure model is used to model the interaction between the filtered quantities and the subgrid energy. Therefore the total energy should be conserved. Abiding by this conservation law yields guaranteed stability of the system. In this work, we propose a novel skew-symmetric convolutional neural network architecture that satisfies this law. The result is that stability is guaranteed, independent of the weights and biases of the network. Importantly, as our framework allows for energy exchange between resolved and subgrid scales it can model backscatter. To model dissipative systems (e.g. viscous flows), the framework is extended with a diffusive component. The introduced neural network architecture is constructed such that it also satisfies momentum conservation. We apply the new methodology to both the viscous Burgers' equation and the Korteweg-De Vries equation in 1D. The novel architecture displays superior stability properties when compared to a vanilla convolutional neural network.

Laboratory short-term aging of crumb rubber modified asphalt: RTFOT temperature optimization and performance investigation

Improper disposal of substantial scrap tires can result in significant environmental issues, such as air pollution, water resources, and soil contamination. The scrap tires can be turned into valuable materials by preparing tire rubber powder into Crumb rubber modified asphalt (CRMA). This method can effectively reduce environmental pollution and achieve the concept of energy conservation, environmental protection, and low-carbon. However, during the production process of CRMA mixtures, the elevated construction temperature may induce more severe short-term aging of the mixtures. The standard laboratory short-term aging scheme of asphalt binders, the Rolling Thin Film Oven Test (RTFOT), cannot simulate the short-term aging of CRMA due to the increase in construction temperature. Besides, the determination methods and indices of RTFOT aging temperature are still unclear and inconsistent. In this study, three CRMA binders were treated by RTFOT with five temperatures, and the short-term oven aging (STOA) protocol was conducted on CRMA mixtures with three types of gradations. Firstly, the chemical and rheological performance of CRMA binders and mixtures were investigated by conducting Gel permeation chromatography (GPC), Fourier transformation infrared spectroscopy (FTIR), Dynamic shear rheology (DSR) tests, and Bending beam rheometer (BBR) test. Then, the equivalent aging temperatures were determined to optimize RTFOT temperatures by comparing the chemical indicators of binders and mixtures. Finally, the correlations of chemical and rheological indices were established, and the rheological properties of aged asphalt in mixtures were predicted. The analysis results indicate that suitable RTFOT temperature is not only related to the technical routes and viscosity of CRMA binders, but also relevant to the mixture gradations. Binders with higher viscosity need elevated RTFOT temperatures from 173 °C to 193 °C, especially simulating short-term aging of mixtures with higher air voids. The swelling and degradation of crumb rubber contribute to the enhancement of the anti-aging performance. The aging index (AI) can reflect the anti-aging performance of CRMA binders, and the variation of AI can validate the rationality of the optimized RTFOT temperatures.

Thermal Comfort Analysis on the Residential Buildings in Sarawak

Thermal comfort is a subjective response that reflects the contentment between one’s state of mind and the current environment. The energy consumption of the building sector has rapidly increased due to improved living standards and rising expectations of residents regarding thermal comfort. Mechanical ventilation, especially air conditioning systems, is essential for hot and humid countries aiming to achieve an ideal indoor comfort condition. However, such cooling systems often consume a significant amount of electricity, which contradicts the concept of energy conservation. Therefore, thermal comfort assessment is a method that can be employed to address this issue. Evaluating the thermal perception of occupants can subsequently facilitate more efficient electricity usage, aligning with the goal of energy conservation. In this study, a thermal comfort analysis was conducted on free-running residential buildings in Sarawak. These buildings were naturally ventilated with minimal use of mechanical ventilation systems. Physical measurements and subjective assessments were employed to evaluate the thermal responses of the residents based on various sensation and comfort scales, including the ASHRAE scale, Bedford scale, thermal acceptability scale, and thermal preference scale. Additionally, the widely used PMV model was utilized to predict the thermal sensation experienced by the residents. The results of the study indicated that the Bedford scale exhibited the highest percentage of acceptable responses, followed by the ASHRAE scale, thermal acceptability scale, and thermal preference scale. The PMV model was observed to overpredict the residents’ thermal responses. The comfort temperatures derived from the study were 27.5 ∘C, 28.1 ∘C, and 26.2 ∘C according to the ASHRAE scale, Bedford scale, and PMV model, respectively. Based on the actual percentage of dissatisfaction that ensures 80% satisfaction, the acceptable indoor temperature range was found to be 27.3 ∘C to 29.6 ∘C. Similarly, the acceptable range for relative humidity was 74.0% to 92.0%, and for air velocity, it was 0.18 m/s to 0.66 m/s.
 Keywords: thermal comfort, thermal perception, sensation, comfort scales

Study on Energy Efficiency Improvement Strategies of Photovoltaic-Hybrid Energy Storage DC Microgrids under the Concept of Green Energy Conservation

Abstract To improve the energy efficiency of a PV-hybrid energy storage DC microgrid, a series of management strategies are proposed in this paper. According to the working principle of photovoltaic cells, the variable step conductance increment method is used to track and control the output power of photovoltaic cells, and the time constant of the low-pass filter is dynamically adjusted according to the output characteristics of supercapacitors in different SOC intervals, so as to put forward a limit management strategy based on the supercapacitor’s SOC partitioning. An energy management strategy for PV DC microgrid based on hybrid energy storage is proposed to address the impact of internal power fluctuation on DC microgrid operation stability. Based on the voltage deviation range, the system is divided into five operation modes to achieve efficient distribution of system power. Through simulation verification, the charging state difference of the battery bank is reduced by 0.00537 after a charging process of 20 s under the withdrawal and addition of PV power, and the charging power ratio is 5.00:8.14:6.82 at steady state under the withdrawal and addition of the hybrid energy storage unit, U dc = 405.4V. This paper’s strategy makes the DC microgrid effective in improving energy efficiency and smoothing out power fluctuations in all operating modes.

Study on quantitative estimation method of energy saving and emission reduction of renewable energy system based on fuzzy matter-element method

The quantitative estimation method of energy saving and emission reduction of renewable energy system based on fuzzy matter-element method is studied, which provides reliable basis for the popularization and use of renewable energy system in practical work. Through quantitative estimation, a scientific evaluation index system and evaluation model can be established, transforming abstract and subjective concepts of energy conservation and emission reduction into concrete and objective numerical indicators. These indicators can reflect the energy-saving and emission reduction effects of renewable energy systems, making the evaluation results scientific, comparable, and traceable. The quantitative estimation index system of energy saving and emission reduction of renewable energy system and the index judgment standard are constructed, which are mainly composed of resource utilization, energy consumption and environmental pollution. On this basis, the fuzzy matter-element quantitative estimation model of energy saving and emission reduction of renewable energy system is established based on fuzzy matter-element and entropy weight theory, and the weight of energy saving and emission reduction index of renewable energy system is determined based on information entropy, and the energy saving and emission reduction effect of renewable energy system is comprehensively and quantitatively estimated with closeness as a reliable basis and reference. The experimental results show that this method can quantitatively evaluate the energy-saving and emission reduction effects of renewable energy systems, and it is feasible to comprehensively and quantitatively evaluate the energy-saving and emission reduction effects of renewable energy systems, with a maximum emission reduction of 99%. It can provide reliable reference for the energy-saving and emission reduction of renewable energy systems.

Impact dynamics of granular debris flows based on a small-scale physical model

AbstractThe peak pressure of a granular debris flow at low Froude conditions can be calculated with knowledge of the stress anisotropy and the bulk density as well as the run-up height at impact. Based on a small-scale physical model, measurements of stress anisotropy and flow density values at impact are presented and applied to existing run-up prediction models, and further compared with back-calculated run-up coefficients from measured maximum impact pressures. For this purpose, we conducted 17 experiments with impact measurements and six experiments without impact measurements at Froude numbers, ranging from 0.84 to 2.41. Our results indicate that run-up heights are best reproduced by predictive models, either based on energy or mass and moment conservation, when anisotropic stress conditions, found in this study to range from 1.2 to 5.0, and bulk density variations due to impact, ranging in this study from 0.8 to 2.3, are considered. The influence of stress anisotropy and density variation on the run-up prediction differs, depending on the modelling approach. For the calculation of run-up heights based on the energy conservation concept, the influence of stress anisotropy becomes more significant with increasing Froude number, whereas for models based on mass and momentum conservation, bulk density variations have a greater influence on the estimation of the potential run-up.

Challenges and countermeasures of the ‘Maritime Silk Road’ in the context of green development

In the context of green development and implementation of the strategies of carbon neutrality and carbon peaking, the concept of energy conservation, and the environmental protection advocated by the construction of the Maritime Silk Road is in line with global development planning and layout. Over the years, China’s national rejuvenation has presented struggles, and the construction of the Maritime Silk Road lasted for a long time. In this paper, we discuss the dilemmas and difficulties associated with the construction of the Maritime Silk Road based on the background of green development and provide corresponding solution strategies by combining the development conditions at home and abroad. These strategies can further deepen China’s reform and opening up strategy and strengthen its relationship with the world. They can also strengthen the connection between China and the world, stand at the head of the times, and lead worldwide development. This paper initially focuses on the theoretical basis of the development of maritime silk governance, that is, the concept of green development, analyzes the necessity and feasibility of the Maritime Silk Road strategy proposed, and proposes means of coping with the Maritime Silk Road’s difficulties by analyzing the challenges and deep-seated causes it encounters in the context of green development. To date, China’s reform and opening up presents an inconvenience, and the domestic and international situations show increasing complexity. Against the background of unprecedented changes in the past hundred years, the construction of the Maritime Silk Road can further realize the effective cooperation between countries and countries and between regions and regions. Moreover, by building a community of humans, we can jointly deal with development problems, which have a vital role in the rejuvenation of the Chinese nation. In the context of carbon neutrality and carbon peaking, green development has become the key direction of development for all countries worldwide. In addition, the concepts of environmental protection and energy saving are gradually being put into practice, which is extremely important to protect the natural environment and build a better home for mankind. In the context of green development, the construction of the Maritime Silk Road will further realize economic linkage between countries and jointly promote sustainable development. Scholars can assess the challenges that impede its construction at various levels and explore strategies for resolving these dilemmas based on changing domestic and foreign situations by analyzing the importance of the Maritime Silk Road strategy and the favorable conditions for its implementation, in order to truly promote the development of the Maritime Silk Road and provide assistance in creating a favorable environment for international relations and trade.

Cobalt Polyoxometalates Anchored on Nife‐LDH Nanoplates as Highly Active and Stable Bifunctional Catalysts for Overall Water Splitting

AbstractDesigning efficient and bifunctional electrocatalysts for water splitting conforms to the concept of energy conservation and emission reduction but remains challenging now. Herein, the fabrication of a heterostructure by anchoring cobalt‐polyoxometalates (Co‐POM) on NiFe layered double hydroxide (NiFe‐LDH) nanoplates in situ on nickel foam (NF) is first reported (Co‐POM@LDH/NF). The surface area, electron transfer ability, and stability of the heterostructure are increased due to the synergistic effect between Co‐POM and NiFe‐LDH. Particularly, Co‐POM@LDH/NF can deliver a current density of 100 mA cm−2 with an overpotential of only 220 mV for hydrogen evolution reaction (HER) and 226 mV for oxygen evolution reaction (OER) in 1.0 m KOH electrolytes. Impressively, the outstanding stability of Co‐POMs in heterostructures is verified by the experimental observations after electrolysis, indicating the successful construction of stable POMs‐based heterogeneous electrocatalysts. More attractively, the electrolyzer composed by Co‐POM@LDH/NF as anode and cathode shows a much lower operating voltage of 1.51 V at the current density of 10 mA cm−2 for overall water splitting. This study provides a feasible and extensible idea for the design of the POM‐based heterostructures.

Study on mechanical and thermal properties of alkali-excited fly ash aerogel foam concrete

With increasing focus on low-carbon energy conservation and environmental protection, there is a need to consider all aspects of life in future developments. To meet the concept and requirements of energy conservation and environmental protection in the building industry, we have developed alkali-excited aerogel-foamed concrete that exhibits excellent thermal insulation performance and mechanical strength. The variables involved in its production include fly ash, foam, aerogels, and polypropylene fibres. In this study, the microstructure and mechanical and thermal properties of alkali-excited fly ash aerogel foam concrete was analysed. The results indicated that fly ash can replace a portion of the cement, resulting in a reduction in the thermal conductivity of the concrete. The addition of aerogels and foams to the concrete can significantly decrease its thermal conductivity. Specifically, when the aerogel content reaches 12 % and the foam content reaches 75 %, the thermal conductivity of the concrete decreases from 0.498 W/m·K to 0.183 W/m·K and 0.19 W/m·K, respectively. However, this decrease in thermal conductivity comes at a cost of approximately 50 % reduction in the flexural and compressive strengths of the concrete. The findings reveal that the aerogel has excellent thermal insulation performance similar to that of the foam, but it has little influence on the mechanical properties of the concrete. Additionally, an increase in the polypropylene fibre content significantly improves the mechanical properties of alkali-excited fly ash aerogel concrete, but the thermal properties of the concrete remain mostly unaffected.

How to Promote Green Building Design in the City: Taking the Green Building of Shanghai Museum of Natural History as an Example

At present, China is still in the primary stage of socialist development. With the change of the current global development situation and the concept of "sustainable development" put forward in the 1980s, this concept began to become more and more popular. In the process of urban development, the environment will be damaged to a certain extent, and the sustainable development of the city is inevitable. Green building design can save resources and has become one of the hallmarks of modern cities. But green building is not widespread in China. Low-carbon life is very necessary, therefore, we should pay attention to the reasons why green building design has not been paid attention to and how to increase efforts to promote green building design. Green building should be the development direction of current construction industry. Adhering to the concept of ecology, energy conservation and sustainable development, green buildings will bring great changes to China's urban development. The development of green architecture in our country is still in its infancy, the green building design has failed to scale to thousands, its purpose is to promote people highly harmonious and unified, architecture, natural, economic and environmental benefits, social benefits fully coordinated, prompting the harmonious development of national economy and social environment, ecological environment quickly and well.

Recycling of tobacco waste: Development of reconstituted tobacco sheet with suitable strength and low-toxicity

Tobacco industry produces a large amount of tobacco waste every year, and the disposal of tobacco waste become a puzzling problem. Recycling of tobacco waste to reconstituted tobacco sheet (RTS) with suitable strength and low-toxicity was prepared in this paper. RTS with 1wt% compound adhesive that content sodium carboxymethyl cellulose and guar gum has a tensile strength (0.548 kN/m) which meet the requirements of industrial production. Strength enhancement was attributed to the synergistic effect of hydrogen bonding and physical cross-linking network through FTIR and SEM characterization. GC–MS was used to analyze the pyrolysis of RTS. The nicotine release of RTS was lower than commercial cigarettes, which significantly reduces the harmful substance. This work has been preliminarily applied to the industrial production. The production process of RTS is simple, with low water consumption and reuse of tobacco waste. Conforming to the concept of environmental protection, energy conservation, and tobacco resource recycling.

Design of Intelligent Street Lamp Control System

Design of Intelligent Street Lamp Control System

A METHOD FOR ASSESSING ENERGY EFFICIENCY OF LIGHT-DUTY VEHICLES TAKING INTO ACCOUNT CHANGES IN THEIR DESIGN PARAMETERS

The present stage of development of the world market of vehicles, in particular, light-duty vehicles (LDVs) is marked by an increasing variety of types and designs. Therefore, while validating or renewing fleet vehicle of an enterprise, carriers are faced with the choice of cars setting conditions they can assess using existing fragmentary and cost-effective approaches. However, the latter ones do not meet the concepts of saving energy and resources. Therefore, the task of choosing an efficient car is complex requiring a science-based formation of demands and their satisfaction. Existing approaches to the selection and validation of LDVs are simplified and imperfect in terms of transport technology. They do not take into account a) resource and technical properties of LDVs as a means of transport; b) main design and technical characteristics of LDVs; c) parameters of its operation (running surface, traffic density, length of the driving cycle, etc.). This article considers a method for assessing energy efficiency of light-duty vehicles, which is based on the scheme of the vehicle operation as a dynamic tool. To develop this method, the provisions of the energy and resource efficiency theory of a car have been used, namely the calculation schemes of transport operations based on models of reference prototypes and test operations. These models are able to ensure the reasonable use of the vehicle fleet with design novelty under the given operating conditions. In order to analyse changes in the parameters of new vehicles and improve the parameters of transport technology, a universal design of a light-duty vehicle of a generic type has been developed and considered. This structural pattern covers all options of the vehicle’s design basis. New options for the vehicle design are created by changing the number of design modules and their parameters. The method proposed for consideration ensures the technical and technological properties of light-duty vehicles in accordance with the concept of energy and resource conservation in the transport system. The paper develops methods for comprehensive improvement of transport energy efficiency and formation of requirements for transportation projects of LDVs taking into account technical and technological factors within their life cycle.

Research on the Development of HVAC Technology and Building Energy Conservation in China

Under the influence of the concept of energy conservation and environmental protection, more and more people begin to pay attention to the energy-saving design of HVAC. In building structure, central air conditioning is an important system to adjust indoor temperature and humidity. Because the system will consume a lot of energy in the actual operation process, the design of central air conditioning system has also become an important link affecting energy consumption. At present, China has also put forward the strategy of carbon neutrality and environmental protection, which also puts forward new requirements for HVAC system design. In order to achieve this goal, this paper analyzes the development of HVAC technology and building energy saving in depth, hoping to provide effective reference for relevant personnel.

Introducing the concept of energy conservation for elementary students through the Eduwisata program

Knowledge of energy conservation for elementary students is one of the education efforts to familiarize them with utilizing energy wisely at an early age. Therefore, this community service program is aimed to give knowledge to Elementary students on the use of energy through the Eduwisata program of Taman Rekreasi Sengkaling Universitas Muhammadiyah Malang (UMM). In conducting the community service program, the team observed the activities of the Eduwisata program to know the problems faced by the team of the program. The result of observation is used to plan the material and module as the solutions to the problems. The interview is also conducted with the manager of Taman Rekreasi Sengkaling UMM to find out the potential problems. The result of this community service program is the students more interactively participate in the Eduwisata program when the team of the community service program guided them in learning the energy and its utilization. The well-prepared preparation of the guides for materials and modules during the explanation is the factor.

Evaluation of the Social Effects of Enterprise Carbon Accounts Based on Variable Weight CFPR Fuzzy VIKOR

The carbon account is a digital path for an enterprise to achieve low-carbon transformation and high-quality sustainable development under the 'dual carbon' strategy. The carbon account has a good social effect while generating economic benefits. An evaluation index system of the social effects of enterprise carbon accounts has been established, including the concepts of energy conservation and carbon reduction, contributions, technological innovation, and customer trust. In view of the difficulty of quantifying the evaluation indicators of the social effects of enterprise carbon accounts and the requirement of effect equalization, a variable-weight CFPR fuzzy VIKOR evaluation model was constructed. Compared with the traditional fuzzy VIKOR model, the variable-weight CFPR fuzzy VIKOR model can solve the problem of quantifying indicators and realize the balance between indicators. This method can better compare and analyze the social effects of each enterprise's carbon accounts and provides a basis for overall carbon account construction and digging improvement space.

QoS-Aware Energy-Efficient MicroBase Station Deployment for 5G-Enabled HetNets

The increasing energy consumption is a legacy of the fast improvement of ICT (Information and Communication Technology). It is also contrary to the current energy conservation and emission reduction concept. There are several reasons for high energy consumption. Among them, we find that the increase in base station density of the 5G heterogeneous network (5G HetNets) is prominent. We present a micro base station deployment strategy in 5G HetNets for obtaining high energy efficiency. It optimizes target values as are trade-offs at different user distribution probabilities to improve adaptation to different user distribution scenarios. An energy deployment algorithm based on high efficiency for micro base stations is considered as jointly optimizing micro base station’s number, deployment location, and power configuration. Simulation results show that the proposed combinatorial optimization strategy effectively improves the system energy efficiency compared to the deployment method, regardless of the power factor. Moreover, it verifies that the micro base station power affects the energy efficiency in HetNets.

The Characteristic Differences between Ecological Culture and Low-carbon Tourism Cognition under the Vision of Carbon Neutrality

Ecological culture has a low-carbon attribute, which coincides with the concepts of energy conservation and emission reduction in low-carbon tourism. Analyzing the differences in the public perception of the two is of great significance for achieving the carbon neutral goal of tourism. Firstly, the views of nature, equality and ecology in ecological culture, as well as the cognition and participation willingness for low-carbon tourism were identified by using the principal component analysis method. Secondly, all samples were divided into four types of ecological culture cognition: sufficient, relatively sufficient, general and poorer, by the K-means clustering method. Thirdly, significant differences in the low-carbon tourism cognition among different types were revealed by using the ANOVA method. Finally, the influences of the main demographic characteristics on the low-carbon tourism cognition were analyzed. This analysis showed that gender, age, education level and income level had significant differences in some aspects of low-carbon tourism cognition and participation willingness, especially education level. On this basis, several corresponding strategies were put forward for managing the cognitive differences of the different types, which could contribute to the realization of the carbon neutral vision of tourism.

A Re-evaluation of the mechanism of microwave absorption in film – Part 1: Energy conservation

Energy conservation for a film with or without metal-back, or an interface provides the theoretical basis for understanding the mechanism of microwave absorption by the film. Film and material have been confused in the past and reflection loss defined for film has been used to characterize material. Such practices have lasted for many years, which has caused many problems in microwave absorption material research. Microwave absorption for film can be defined by considering energy conservation, which provides irrefutable evidence that film and material are different. Some difficult issues, such as that for an interface the voltage of the transmitted beam may be larger than that of the incident beam, and that for a film with a certain thickness, the voltage of the beam reflected from the interface with metal-back can exceed that of the incident beam, have been successfully explained. It is proved using complex variable functions that energy conservation concepts are different for film and interface related to material that absorbs microwaves. For films that absorb microwaves, it is shown that the absolute value of the reflected energy from an interface represented by RM2 can be greater than 1 and the real part of RM2 can be negative, especially at resonance.

Comparative Analysis of the Effect of the Evolution of Energy Saving Regulations on the Indoor Summer Comfort of Five Homes on the Coast of the Basque Country

In the last decade, several European directives have been established to contribute to the 2020, 2030 and 2050 energy saving targets and impose energy efficiency requirements for new construction, existing buildings and building renovation operations. One of the ways to achieve said objectives is to rely on the most demanding energy efficiency labels existing in Europe, such as Passivhaus, and to implement similar concepts into the national energy regulations of European countries based on a high-performance thermal envelope (high insulation and high-performance windows), high airtightness and high-performance heat-recovery ventilation systems, and solar heat harvesting. This energy conservation concept has shown to be effective for houses with low-density occupation in cold climates, but may cause severe overheating problems in denser collective housing in temperate and hot climates with higher solar radiation. To assess this impact, five flats in three developments from different periods that range from no insulation at all to a nZEB, Passivhaus-certified high-rise are compared in this paper, using data from a monitoring campaign during the summer of 2020. The results show and quantify the strong impact the evolution of the energy saving regulatory trend has had on summer indoor comfort, which may in some cases lead to previously unnecessary air conditioning for cooling and, ultimately, be counterproductive towards the end goals of reducing energy consumption and greenhouse-effect gas emissions and mitigating climate change.