Energy Efficiency Indicators Research Articles

Research on a TOPSIS energy efficiency evaluation system for crude oil gathering and transportation systems based on a GA-BP neural network

As the main link of ground engineering, crude oil gathering and transportation systems require huge energy consumption and complex structures. It is necessary to establish an energy efficiency evaluation system for crude oil gathering and transportation systems and identify the energy efficiency gaps. In this paper, the energy efficiency evaluation system of the crude oil gathering and transportation system in an oilfield in western China is established. Combined with the big data analysis method, the GA-BP neural network is used to establish the energy efficiency index prediction model for crude oil gathering and transportation systems. The comprehensive energy consumption, gas consumption, power consumption, energy utilization rate, heat utilization rate, and power utilization rate of crude oil gathering and transportation systems are predicted. Considering the efficiency and unit consumption index of the crude oil gathering and transportation system, the energy efficiency evaluation system of the crude oil gathering and transportation system is established based on a game theory combined weighting method and TOPSIS evaluation method, and the subjective weight is determined by the triangular fuzzy analytic hierarchy process. The entropy weight method determines the objective weight, and the combined weight of game theory combines subjectivity with objectivity to comprehensively evaluate the comprehensive energy efficiency of crude oil gathering and transportation systems and their subsystems. Finally, the weak links in energy utilization are identified, and energy conservation and consumption reduction are improved. The above research provides technical support for the green, efficient and intelligent development of crude oil gathering and transportation systems.

Ecological and economic determinants of energy efficiency in European countries

Since economic development is often associated with an increase in greenhouse gas emissions, it is especially important to answer the question of whether it is possible to achieve sustainable economic development and improve energy efficiency at the same time, which implies a reduction in greenhouse gas emissions. The purpose of this study was to build models that can help find the environmental and economic determinants of energy efficiency in European countries. An ecological and economic determinants of energy efficiency indicators of 38 European countries were found based on panel regression models. The models were built based on statistical data characterizing the level of their economic development and consumption of diverse types of energy for 1995-2021. To obtain the necessary approximations of energy efficiency indicators, one of three types of models was used: the random effects method, the fixed effects method, or the pooled model. For this, appropriate statistical tests were used. As a result, it was found that the factors that have a statistically significant impact on the energy intensity of GDP in European countries include the intensity of carbon dioxide emissions, unemployment rate, primary energy consumption per capita, and gross electricity production per capita. The findings showed that determinants of primary energy consumption were domestic consumption of solid fossil fuels per capita, domestic natural gas consumption per capita, and primary energy consumption per capita. The study results generally confirm the modern-day thesis that economic development can be achieved while reducing greenhouse gas emissions. The monitoring of factors that have a statistically significant impact on the indicators under consideration can become an essential element of the modern energy efficiency management system of the national economies of European countries

Energy Efficiency Indicator of Pumping Equipment Usage

The rational choice of pumping units and the effective usage of the corresponding pumping equipment are urgent problems in terms of ensuring the energy efficiency of up-to-date enterprises. The research aims to develop an energy efficiency indicator for torque flow pump usage to improve the decision-making procedure for choosing the corresponding pumping equipment for specific production conditions. Based on a study of the requirements of international standards for energy efficiency, a methodology for evaluating torque flow pumps according to the energy efficiency indicators is proposed, as the ratio between the values of the average compensated network power and the reference pump inlet power can determine the degree of reduced energy equipment operation efficiency in terms of the energy efficiency of pumping liquids. It was proposed to apply the base point method to determine the so-called compromise point of energy consumption for liquid pumping. This is a point for which another point, by the Pareto compromise, is likely to have a more significant (worse) value for energy consumption than the rest of the set of possible values.

Dynamic risk connectedness of crude oil price and sustainable investment in the United States: evidence from DCC-GARCH.

Sustainable investment is widely regarded as an important market-based approach to achieving inclusive green growth. To achieve the inclusive green growth objective, companies providing sustainable products must be profitable enough to attract private capital. Oil price changes can however affect the profitability of such companies. This study assesses volatility transmission between crude oil prices and sustainable investment in the USA. Using the dynamic conditional correlation-generalized autoregressive conditional heteroskedasticity (DCC-GARCH) method, daily data from September 28, 2012, to October 19, 2022, is analyzed. There are several key findings from this analysis. The risk connectedness of crude oil and sustainable investment is found to vary with time. Results further show that the risk connectedness increases in periods of important economic and geopolitical events. The greatest risk connectedness of crude oil and sustainable investment is observed during the outbreak of coronavirus disease (COVID-19). Moreover, the result shows that crude oil is the main risk transmitter, whereas, both the energy efficiency and pollution mitigation indices (i.e., sustainable investment) are risk receivers, and crude oil is constantly dominating sustainable investment. The study findings provide valuable insights for investors and policymakers alike.

Methodological aspects of optimization of energy consump-tion costs of low-rise buildings with a built-in air heat pump

Objective. The rational use of fuel and energy resources is one of the urgent problems. One of the promising ways to solve this problem is the use of environmentally friendly energy-saving air source heat pumps based on the use of non-traditional energy sources. The use of such innovative energy-saving technologies requires not only modern architectural and planning, design and engineering solutions, but also sound methodological recommendations for as-sessing their energy efficiency and feasibility. The article presents a methodology for calculating the consumed electrical energy and heat generation, as well as the seasonal indicator of energy efficiency in the operation of an air source heat pump.Method. The technique takes into account, as input data, experimental data from tests of high-voltage heat pumps in terms of heat output depending on the change in the temperature of the source of low-grade heat and the temperature regime of the coolant.Result. The need to develop a methodology is due to the shortcomings in the regulatory documents of the methodological basis for optimizing energy costs and heat generation by heat pumps. The accuracy of calculating the operating costs that will occur during the heating period of the air source heat pump (AHP) depends on the correct accounting of the required heat load of a low-rise building and the consumption of electricity to ensure it.Conclusion. This technique can be applied not only to calculate the annual operating costs of using a heat pump and determine the structure of energy consumption (thermal and electrical), but also to optimize the energy parameters of HHP with an assessment of the energy efficiency of different options for their configurations.

Study of the Efficiency of Heat-Supply Systems with Steam Turbine CHP Plants, Taking into Account Changes in the Temperature of the Delivery Water during Transportation

The aim of the work is to study the efficiency of steam turbine CHPPs in heat-supply systems, taking into account changes in the temperature of delivery water during transportation for various initial and extended heating regulation schedules. To achieve this goal, the following tasks were solved: calculation of the dependences of the delivery water cooling in the supply and return pipelines on the air temperature, construction of temperature and flow rate schedules of delivery water adjusted for heat losses during transportation, calculation of energy efficiency indicators for the operation of a model CHPP with various options for correcting schedules of delivery water. The most significant results are the following. Firstly, for the first time the method of the degree-by-degree calculation of heat losses during transportation and their distribution between pipelines of heating networks was used. Secondly, the dependences of the delivery water cooling in these pipelines on the outside air temperature are calculated. Thirdly, it has been established that the specific reference fuel consumption for electricity supply significantly decreases when switching to more efficient temperature schedules for heating regulation, but changes slightly when switching from natural regulation by flow rate to regulation by the temperature of the delivery water. The significance of the obtained results lies in the possibility of their use for an accurate assessment of the efficiency of heat supply systems with different heating control schedules and for determining the feasibility of correcting temperature schedules in order to take into account the cooling of delivery water during transportation.

ПОКАЗНИКИ ЕНЕРГОЕФЕКТИВНОСТІ ГРОМАДСЬКОЇ БУДІВЛІ

The relevance of paying attention to the energy efficiency of buildings, which will reduce the consumption of fossil fuels and electricity and reduce harmful emissions into the environment, is shown. The energy efficiency indicators of the public building were analyzed, namely the thermal resistance of the enclosing structures, the specific energy demand for heating, cooling and hot water supply, the specific energy consumption of the building for heating and cooling, the specific consumption of primary energy and the specific emissions of greenhouse gases.The effect of increasing the normative thermal resistance of the outer wall of the building on the required thickness of the insulation was evaluated. It is indicated that under the conditions of a large facade glazing ratio and compliance with the regulatory thermal resistance of the fences, the building does not meet the requirements for specific energy consumption for heating, cooling and hot water supply.The influence of the heat source for heating the building on its specific energy consumption, energy efficiency class, specific consumption of primary energy and specific emissions of greenhouse gases was studied. Considered options for using a gas boiler, a condensing gas boiler, electric heaters, a biomass pellet boiler and connection to a centralized heat supply system. The effectiveness of the implementation of reversible heat pump equipment for heating and cooling of buildings is substantiated

Double-Circuit Adaptive System of Fuzzy Phase-Autonomous and Energy-Efficient Control of Arc Furnace Electric Modes

The article provides an overview of the existing structures of fuzzy model systems for arc length control and optimal control of arc steel-melting furnaces (ASFs) electrical mode. The analysis of known adaptive optimal control strategies of alternating current steel-melting arc furnaces modes according to complex criteria of energy efficiency, energy saving and reliability was performed. Expedient system engineering solutions are proposed for the comprehensive improvement of energy efficiency and electromagnetic compatibility of arc furnaces and the power grid, which are implemented by improving automatic power and arc length control systems. Control principles, indicators of arc length control dynamics, energy efficiency and electromagnetic compatibility of various systems are analyzed. The expediency of using fuzzy control models for comprehensive improvement of dynamics, energy efficiency and electromagnetic compatibility indicators is substantiated. The expediency of implementing simultaneous phase-independent control of arc lengths and fast-acting arc currents control is substantiated. A variant of the double-circuit structure of fuzzy arc lengths control system and implementation of the multi-criteria optimal control strategy of electrical modes (EM) is proposed. The design of fuzzy inference systems for the synthesis of the electrode movement control signal was carried out in order to improve the dynamic accuracy of the ASF electrical mode coordinates stabilization. A computer Simulink model of the developed double-circuit system was created, and studies of the dynamics and energy efficiency indicators when handling deterministic and random perturbations were performed. The obtained results of model studies showed an improvement of the control dynamics quality indicators under the influence of deterministic and random perturbations and an increase in the energy efficiency of ASF EM at various technological stages of melting. The expediency of the practical use of the proposed solutions for operating arc furnaces is substantiated.

Innovative valorization of biomass waste through integration of pyrolysis and gasification: Process design, optimization, and multi-scenario sustainability analysis

An innovative valorization process for biomass waste treatment has been developed in this study. The basic simulation process developed considering experimental studies, and it has been optimized by application of a pattern search algorithm to obtain the optimum output of energy efficiency, economic performance, and process safety index (PSI). Mainly, three different scenarios have been analyzed based on the sustainability index (SI). These SI has been determined through energy, economy, safety, and electric power potential. According to the results of the SI, the optimized processes are more sustainable (SI = 0.517 to 0.563) in all scenarios as compared to the basic process (SI = 0.503). Similarly, the economic analysis in terms of internal rate of return (%) of the basic process varies from 37 to 2% when the process efficiency dropped from 100 to 80%, and it varies from 44 to 6% for the optimized process without any subsidy. The optimized process has a potential of 2788–4044 kW of electric power generation from thermal energy of the process while it is only 2302 kW for basic scenario. Therefore, the optimized process has better energy, economic, electric power, and safety performances, thus it is more sustainable as compared with the basic process.

Energy efficiency of the Process Planning Design in the scope of Industry 4.0

In this paper we present an experimental investigation in the scope of Industry 4.0 that provide an answer to the question of whether and to what extent operation sequencing during machining affects the output parameters of process planning design: main production time (MPT) and total energy consumption (TEC). Main production time is the basic indicator of productivity, while total energy consumption is an indicator of energy efficiency of the process. After experimental research, a relation was established between the variants of operation sequencing during machning, on the one hand, and main production time and total energy consumption, on the other hand.

Thermomodernization as a Mechanism for Improving Energy Efficiency and Reducing Emissions of Pollutants into the Atmosphere in a Public Utility Building

Improving energy efficiency indicators and reasonable use of energy resources in the context of the increasing demand for energy are sectors that must definitely be paid attention to. The fight against climate change must start in the construction sector, as buildings are the main consumers of energy. Saving energy through the rational use of energy sources and good thermal insulation of buildings allows you to reduce the amount of heating and/or cooling bills as well as to care for the environment by reducing emissions. This article presents aspects of improving the energy efficiency of a health clinic building in Mszana Dolna through the use of comprehensive thermal modernization of the external envelope. Thermal modernization of the most energy-intensive and leaky external partitions in the building, i.e., the external walls below and above the ground and the ventilated flat roof, managed to save 53% of the building’s thermal energy, which directly translates into lowering the building’s operating costs. We managed to achieve an improvement in energy efficiency ratios from 37% to almost 60%, and a reduction in CO2 emissions at a level of nearly 50%.

MODELING THE INTERRELATION BETWEEN ENERGY EFFICIENCY AND SHIP SAFETY BASED ON MULTIPLE LINEAR REGRESSION

Energy efficiency and ship safety are two important aspects of maritime transportation that are essential for economic efficiency, the environment and maritime safety. Ship safety ensures the protection of crew, cargo and the environment. Energy-efficient technologies in shipping contribute to economic efficiency and lower fuel costs, as well as reduce greenhouse gas emissions and, most importantly, increase ship maneuverability, reducing the likelihood of getting into accidents, while the choice of energy-efficient materials and optimization of the structure and hull increase the ship's resistance to adverse conditions. This article explores the relationship between energy efficiency and ship safety. The main objective of the study is to assess the impact of ship energy efficiency on safety in the context of operation. The study applies a methodology to establish the relationship between independent variables, such as energy efficiency, ship's technical condition and crew training, and the dependent variable, ship's operational safety. The article presents the results of the analysis of the company's fleet data, where energy efficiency and safety indicators evaluate each vessel. Using a multiple linear regression model, the coefficients of influence of each independent variable on ship safety were determined. These regression coefficients allow us to assess the contribution of each factor to the overall safety of the ship and identify the most significant factors. The results of the study indicate a significant impact of ship energy efficiency on operational safety. Vessels with higher energy efficiency indicators have a high level of operational safety. This allows shipowners and ship operators to take measures to improve the energy efficiency of their fleet in order to increase safety and efficiency of operation. The results of this study can be useful for ship owners, ship operators, as well as for representatives of maritime organizations and regulatory authorities involved in shipping safety.

A Mathematical Model for Layout Design of Linear Induction Motors

The designing of induction motors is considered as a two-stage process of synthesizing an electromechanical system. At the first stage, the device layout is designed, during which the electric motor main dimensions and electromagnetic loads are determined based on empirical data. At the second stage, the device detailed design is developed. The models and methods applied at the stages of layout and detailed designing of rotating and linear induction motors (LIM) differ radically from each other. The following requirements are imposed on the LIM design models. First, the LIM model should allow the designer to calculate the intensity and spatial distribution pattern of the electromagnetic field and secondary current for each speed value. Second, the LIM model should be able not only to link the main dimensions with electromagnetic loads, but also explicitly produce the numerical indicators of electric motor energy efficiency and thermal load. A design model is proposed that satisfies the above-mentioned requirements and describes the LIM electromechanical, energy and thermal states. The model input parameters are the main dimensions and electromagnetic loads of the device. The controlled parameters are the electromagnetic force, efficiency and temperature of the inductor winding. The system layout is designed by evaluating the values of controlled parameters with variations of input parameters in technically feasible ranges. The article presents the results of designing a LIM according to the proposed model with an electromagnetic force of up to 1000 N, motion speed up to 12 m/s, working stroke up to 2.16 m, and efficiency up to 46%. The results of the thermal calculation testify that the electric motor can operate in short-term and intermittent modes. The results of calculating the performance of an electric motor with the same dimensions and a reduced current density in the inductor winding are also presented. An electric motor with insulation class F and natural air cooling develops an electromagnetic force of up to 116 N and can operate continuously over the entire speed range.

항적 데이터에 기반한 하이브리드 추진 연료전지 선박의 효율 평가

Efforts have been made to reduce the greenhouse gas emissions from ships by limiting the energy efficiency index, and net zero CO2 emission was proposed recently. The most ideal measure to achieve zero emission ship is electrification, and fuel cells are considered as a practical power source of the electrified propulsion system. The electric efficiency in the electrochemical reaction of fuel cells can be achieved up to 60% practically. The remaining energy is converted to heat energy but most of them are dissipated by cooling. In the author’s previous research, a hybrid propulsion system utilizing not only electricity but also heat was introduced by combining electric motor and steam turbine. In this article, long term efficiency is evaluated for the introduced hybrid propulsion system by considering a virtual 24,000 TEU class container carrier model. To reflect a more practical operating condition, the actual navigation data of a similar real ship in the real world were collected from automatic identification system data and applied. From the result, the overall efficiency of the hybrid propulsion system is expected to be higher than a conventional electric propulsion fuel cell ship by 30%.

Multi-objective carbon neutrality optimization and G1-EW-TOPSIS assessment for renewable energy transition

Successful low-carbon energy systems rely on good economic, environmental and energy efficiency indicators. Yet, the current energy structure has shortcomings in these aspects, hence the need to develop the renewable energy transition. This study proposes a three-phase dynamic energy planning framework based on multi-objective optimization, assessment and analysis. The optimization phase utilizes the NSGA-II to determine the optimal allocation of multiple energy sources by considering various variables and constraints. A comprehensive assessment system combining the G1 method and the entropy weight method is proposed, and the TOPSIS method is used to evaluate the rationality and superiority of the energy structure. The relative trends in electricity consumption and renewable energy penetration are also analyzed in order to predict CO2 emissions. The dynamic framework and comprehensive assessment are applicable to Guangdong Province. Results reveal that Guangdong province should prioritize the development of offshore wind power, ensure the stability of the power grid by steadily developing hydropower and nuclear power, and vigorously develop solar power at the end of the planning period. Guangdong Province can reach carbon peaking around 2028 and net zero carbon emissions by 2060, leading to carbon neutrality. The optimized dynamic energy planning framework can provide effective decision support to promote the transformation of regional energy structures.

A serious gaming approach for optimization of energy allocation in CubeSats

Energy consumption remains an open challenge in aerial systems such as CubeSats and therefore optimization of its allocation is a top priority for maximizing operational capacity. Our research review reveals a plethora of approaches for optimization of energy allocation and all achieving varying degrees of success and not without any compromises. In this paper, we exploit the use of serious gaming in a novel energy allocation algorithm that aims at minimizing energy consumption to maximize the utilities of both CubeSats and terrestrial sensors. To demonstrate this, we use Stackelberg for serious gaming and standalone topology for CubeSat configuration. The experimental results show that the use of a Stackelberg game approach for optimization has led to reduction in the required transmission energy in sensors, an improved link performance between the CubeSat and ground sensors, and an increase in network lifetime and performance without resorting into sensor power enhancements or other external power sources. The overall average operational capacity improvement predictions range between 22 to 27% across all performance indicators of energy efficiency across RF chains of link budgets.

Current State and Prospects of River Passenger Transportation in the Volga Basin

The analysis of trends in the development of passenger transportation in Russia over the past decades has been carried out. A significant decrease in the volume of river transport was noted and the reasons for this phenomenon are given. The analysis of the current state of river passenger transportation in the Volga basin is carried out. The main carriers and operating passenger lines served by high-speed and displacement vessels are presented. It has been revealed that regular lines operate where river routes can significantly reduce the distance of transportation. The comparison of the energy efficiency indicators of river passenger vessels compared to bus service is carried out. The necessity of state support for socially significant transportation was noted. Based on the results of the analysis, proposals are formulated for the development of industry solutions in the field of river passenger transportation.

Design and optimization of a zero carbon emission system integrated with the utilization of marine engine waste heat and LNG cold energy for LNG-powered ships

Aiming at promoting LNG-powered ships to achieve zero carbon emission, this paper presents an efficient energy utilization system, which can fully recover the marine engine waste heat and LNG cold energy while realizing zero carbon emission. A combination of transcritical CO2 and organic Rankine cycles is adopted to replace the original ship's waste heat generation system. Based on balancing the ship's application constraints and energy efficiency indicators, the existing land air separation system is modified to recycle the products' cold energy and the oxygen-enriched combustion of the main engine is constructed. Then, through a sensible energy gradient design and adjusting the circulating flue gas parameters, the design goals are achieved while meeting the host power. The feasibility of the system's application is assessed through thermodynamic and economic analysis, and the optimal technical parameters are determined after working fluids matching and optimization of sensitive parameters based on the genetic algorithm. The results indicate that the system's CO2 capturing purity, exergy efficiency, net output power and annual net profit are 97.09%, 51.78%, 318.36 kW, US$485,165, respectively, demonstrating significant features such as high effective energy conservation and zero carbon emission.

Methodological platform for determining energy efficiency indicators of a complex system

The correct determination of the energy efficiency (EE) of a complex system is a problematic task that requires the use of specialized methods and approaches. Most often, EE is considered as an indicator of the quality-of-service provision, which most fully corresponds to the technical and economic essence of this indicator. The structural and functional organization of the system of such indicators is carried out either on a bottom-up approach or a top-down approach, gradually deploying macroeconomic indicators defined at the system levels. This paper considers the tensor form of organization of the system of such indicators, which allows combining within a single model not only their organizational levels (economy as a whole, economic sectors, enterprises, technologies and equipment), but also the types of activities that reflect these indicators (energy, financial, economic, institutional, environmental, social, etc.), and the factors of changes in energy use (structural, technological, resource, managerial, regulatory, etc.). The paper presents the mapping of this model on the plane of structural and functional factors in the form of classification tables (matrices) of these factors (system elements). The paper describes the procedure for optimizing indicators, which can be carried out for each of these factors separately, their aggregate at each level and for the system as a whole, taking into account the need to implement iterative procedures for coordinating the global (system-wide) goal and local objective functions. Given the use of optimization variables measured in energy and monetary units, this problem is formalized within the framework of the set-theoretic approach. For the purpose of comparing the results, the paper examines the relevant provisions of the International Energy Agency methodology, which uses the direct method of three-factor Laspeyres decomposition analysis, and the Sectoral Methodology for Calculating Harmful Emissions of the Ministry for Communities and Territories Development of Ukraine. Keywords: Energy efficiency, energy efficiency indicators, system analysis, tensor approach.

Агрегована модель енергозабезпечення за структурою даних продуктового енергетичного балансу

An economic-mathematical model of the production type was developed, intended for forecasting the country's energy supply by calculating the balanced supply of carbon-containing fuels, electricity and heat from fossil fuel and renewable energy sources. The model was built on the basis of open data sources according to the specific structure of technological methods by L.V. Kantorovich, which, unlike the known ones, uses subsystems for the production of abstract products that correspond to the range of outputs and inputs of the product energy balance, and also uses procedures for their selective aggregation to build various forms of inter-product balance matrices. This allowed us to obtain a tool for forecasting and assessing energy balances that is resistant to the growing limitations of information support, which is distinguished by a new system of conditions for a production-type model for the expanded range of the International Energy Agency's product energy balance, as well as a set of technological methods proposed for the first time by L.V. Kantorovich, which together determined the structure of output, costs and product links of individual producers of the energy supply system within the framework of a mutually agreed multi-product balance. The proposed model provides opportunities for using statistical and technological approaches to determining output and cost coefficients in solving forecasting problems, applying inherent means of analyzing retrospective balances to identify unaccounted volumes of FER, as well as volumes of their consumption and transformation in the country's energy sector with significant changes in the structure of electricity and heat generation capacities. The forecasted volumes of supply of the main types of energy resources obtained in the calculations using the developed energy supply model allowed us to assert that, given the indicators of energy efficiency achieved in 2020, the country's energy supply system is able to meet the country's needs mainly through the development of domestic fuel bases. Keywords: energy supply, product energy balance, production type model.