Comparison Of Energy Consumption Research Articles

CHAMBER FURNACE FOR SIMULATION OF CARBON MATERIALS HEAT TREATMENT IN ELECTROTHERMAL FLUIDIZED BED

Existing laboratory furnaces for high-temperature heat treatment of materials at around 3000°C, which have graphite heaters, allow samples to be heated at a rate two orders of magnitude lower than in electrothermal fluidized bed furnaces. This makes it impossible to use them in the research into the heat treatment of carbon materials because they do not meet the conditions of shock heating and do not allow to keep accurate residence time. The paper presents the research into the use of low-density composite carbon materials as heaters. Based on the results obtained, a high-temperature chamber furnace was designed, studied, and the temperature field in the heater was simulated. As a result, a high-temperature laboratory furnace was created with a sample heating rate of 20 °C/s - 100 °C/s, which made it possible to use it to simulate the heating process in the electrothermal fluidized bed furnace. Comparison of energy consumption in the furnace with a traditional graphite heater and a low-density carbon composite heater showed that heat loss in the furnace is reduced by 1.7 to 1.8 times.

Absorption Chiller Efficiency Increasing at Waste Heat Recovery of Cogen-eration Plants using a Vapor Compression Chiller as a Backup Cold Source

Cooling efficiency in a trigeneration cycles is one of the most frequently problems. A single-stage hot water absorption chiller is a universal solution for the gas engine waste heat utilization. How-ever, trigeneration centers exploitation experience shows the need for a more detailed technical and economic analysis to achieve maximum efficiency of the three-generation cycle. The purpose of this article is to substantiate the use of two-stage absorption cycles increasing the utilization rate of waste gas heat. The study presents the results of assessing the efficiency of using energy resources on the example of a three-generation center with more than 14 years of exploitation experience, including two single-stage absorption chillers (Q0= 0.65 MW each) and a chiller with a screw compressor (Q0= 0.8 MW). A comparison of actual energy consumption with designed indicators was carried out. The influ-ence of external and internal factors on the efficiency of heat recovery from a gas engine in single-stage absorption refrigeration machines with a water-heated generator is considered. The dependence of the change in the average annual cooling coefficient during the calendar year was obtained. Based on the study, proposals were formulated to improve the energy efficiency of refrigeration supply, giving an increase in refrigeration capacity of 6.1% with a commensurate reduction in the load on the screw chiller. The option of using a combined two-stage cycle chiller (type 2) under similar operating conditions showed a COP=1.43, which provides savings of 67.45 MWh of electricity or 5.4%, on an annualized basis (assuming only waste heat is used). Additional advantages of such a cycle include increased accu-racy and stability of maintaining the water temperature at the absorption chiller evaporator due to more flexible adjustment of the temperature of the lithium bromide solution in the high-temperature generator.

Revisiting the relationships between energy consumption, economic development and urban size: A global perspective using remote sensing data

Existing methods of measuring energy consumption require complex statistics and computing. A real-time and globally applicable approach for comparing energy consumption across different cities is still lacking. Additionally, the nonlinear relationships and varying thresholds of energy consumption in relation to economic activities and urbanization remain unconfirmed. This study aims to fill these gaps by utilizing Suomi National Polar-orbiting Partnership Visible Infrared Imaging Radiometer Suite (NPP-VIIRS) nighttime light data in 2015 and a top-down approach based on a multiple regression model to examine energy consumption in global cities employing a redefined urban boundary. It also explores the accurate relationship between energy consumption, population density (as a proxy of urbanization), and per capita gross domestic product (GDP) across different regions and urban sizes using generalized additive models and regression models. High-resolution gridded population and GDP datasets covering the entire planet are utilized for this purpose. The study also estimates the development potentiality. The study yields followings outcomes: Firstly, the top 30 cities with the highest per capita energy consumption account for over 0.66% of the total per capita energy consumption of all cities. Secondly, in East Asia (EA) and Southeast Asia (SEA), the per capita energy consumption decreases when per capita GDP reaches $40,000 and $75,000, respectively, while it remains stable in cities located in Western Europe (WE) and North America (NA) as per capita GDP increases. Thirdly, the per capita energy consumption declines with increasing urban population density until reaching 10,000 person/km2, 22,000 person/km2, and 4000 person/km2 in EA, SEA, and NA, respectively. Fourthly, in Central Asia (CA), megacities can save over 100 Mbtu/population when per capita GDP increases by $1000 compared to big cities. This pioneering study provides a comparable investigation of energy consumption at the global city level, exploring its relationship with urbanization and economy by employing a unified calculation standard. It will facilitate long-term energy-saving policies and urban planning strategies.

Unsupervised deep learning with convolutional neural networks for static parallel transmit design: A retrospective study.

To mitigate inhomogeneity at 7T for multi-channel transmit arrays using unsupervised deep learning with convolutional neural networks (CNNs). Deep learning parallel transmit (pTx) pulse design has received attention, but such methods have relied on supervised training and did not use CNNs for multi-channel maps. In this work, we introduce an alternative approach that facilitates the use of CNNs with multi-channel maps while performing unsupervised training. The multi-channel maps are concatenated along the spatial dimension to enable shift-equivariant processing amenable to CNNs. Training is performed in an unsupervised manner using a physics-driven loss function that minimizes the discrepancy of the Bloch simulation with the target magnetization, which eliminates the calculation of reference transmit RF weights. The training database comprises 3824 2D sagittal, multi-channel maps of the healthy human brain from 143 subjects. data were acquired at 7T using an 8Tx/32Rx head coil. The proposed method is compared to the unregularized magnitude least-squares (MLS) solution for the target magnetization in static pTx design. The proposed method outperformed the unregularized MLS solution for RMS error and coefficient-of-variation and had comparable energy consumption. Additionally, the proposed method did not show local phase singularities leading to distinct holes in the resulting magnetization unlike the unregularized MLS solution. Proposed unsupervised deep learning with CNNs performs better than unregularized MLS in static pTx for speed and robustness.

Energy consumption comparison of two cooling systems equipped with the heat exchangers in different agricultural postharvest storage conditions

In a hot, humid, and fluctuating climate due to global climate change, agricultural postharvest relies prominently on refrigerating systems. To enhance thermal performance, such as in refrigerating systems, heat exchangers can be used. This work focused on expressing the air temperature, air relative humidity, and energy consumption (EC) profiles of two refrigerating storages using the HFC-32 fixed- and variable-speed compressor (FSC and VSC) systems in four experimental investigations. The profiles were recorded before and after the double-pipe heat exchanger (DPHEx) installations. Both storages had heaters, humidifiers, and hot water pots to generate heat and humidity at 18 °C and 22 °C, a storage temperature range for many postharvest products. From the results, both systems performances in reducing the EC of the FSC and VSC systems were enhanced by using the DPHExs. The EC of the FSC and VSC systems were reduced by 52.33 % and 17.19 % at 18 °C and 50.63 % and 20.00 % at 22 °C, respectively. All experiments with storage using the FSC system resulted in fluctuating profiles. This research information provides basic information for preliminary decisions about using DPHExs in postharvest refrigerating systems and selecting systems targeting the FSC and VSC systems in different situations. The power demand and operating cost relating to agricultural product storage can be calculated by using the EC correlation of each cooling system. Product freshness and abundance depend on fluctuating conditions, postharvest storage conditions, temperature, and relative humidity. The VSC system, coupled with the DPHEx, demonstrated enhancements on the EC and stable conditions.

Comparison of Energy Consumption to Economic Growth in Developing Asian and Developed Asian Countries

This study will analyze the comparative use of Economic Stability Comparisons from the Consumption of Fossil and New and Sustainable Energy: Developed and Developing Countries in Asia, including developing countries Indonesia, Malaysia and Thailand and developed countries Japan, the United Arab Emirates and South Korea. This study uses a panel cross-section/observation form of 6 Asian countries by taking the category of 3 developing countries and 3 developed countries. The time series takes the period 2005-2021, using the ordinary least squares (OLS) method. The results of a study of 3 developing Asian countries namely Indonesia, Malaysia and Thailand GDP Per Unit Energy Use and consumption of sustainable energy have a positive and significant influence and consumption of fossil energy has no effect on growth. In the equation model of 3 developed Asian countries, namely Japan, the United Arab Emirates and South Korea, GDP per Unit Energy Use has a positive and significant influence, sustainable energy consumption has no effect on economic growth, fossil energy consumption has a positive and significant influence in region 3 developed Asian countries during 2005-2021.

Well-to-wheel Energy Consumption and CO2 Emission Comparison of Electric and Fossil Fuel Buses: Tehran Case Study

Well-to-wheel Energy Consumption and CO2 Emission Comparison of Electric and Fossil Fuel Buses: Tehran Case Study

An interface design for comparison of energy consumption of penumatic and ball screw-driven linear actuators

Today, engineers use many computer programs and applications to model and analyze engineering problems. However, the demand for user-friendly interfaces and web-based applications is increasing daily to select the appropriate system components according to different working conditions and to evaluate the results comparatively. Also, most of these interfaces calculate the actuators' size and are mostly developed by foreign manufacturers. Nowadays, with the increase in energy costs, the demand for the use of energy-saving products is also increasing. Therefore, examining and comparing the energy consumption of the actuator elements used in the systems depending on the work done is necessary.
 In this study, the authors discussed the issue of developing an interface that can define the appropriate size of actuators for the different operating conditions, such as different loads, slopes, friction, opposite load, and speed, and enable comparative energy consumption according to these elements for electro-pneumatic and servo motor driven ball screw shaft driven actuator types.

Improving Energy Management in Deep-Level Mines by Integrating Advanced M&V with Operational Changes

Advanced measurement and verification (M&V) is a process where the impact of an energy initiative is determined in real time. Data prediction models can be used to predict and compare energy consumption with a predetermined baseline. Deep-level mines can benefit from advanced M&V as the impact of operational changes can be identified in real time. Ultimately, this can ensure that informed decisions are made regarding energy management based on the impact and severity of the occurrence.Previous studies on advanced M&V do not account for operational changes to the model’s baseline. These changes can significantly impact the performance of both the mine and related activities. The aim of this study is to propose a method that can accurately predict the energy consumption of a deep-level mine regardless of operational changes. To achieve this objective, nine different data predictive modelling techniques were considered.The proposed method is based on the Moving Average (MA) modelling technique due to its simplicity, flexibility, and rapid development time. The coefficient of variation for the root mean square error (CV(RMSE)) was used to statistically analyse the modelling error. If the predictions exhibit an unsatisfactory CV(RMSE), the model dynamically adjusts to reduce the prediction error.The model was developed to adapt to operational changes in scenarios where the standard model becomes irrelevant. The method developed in this study was able to predict the future energy consumption of deep-level mines with an accuracy of 99%, improving the mine’s energy and finance management.

Intensification proposals for the downstream separation of the methanol-to-olefins process

The Methanol-to-Olefins (MTO) process presents a sustainable alternative for producing light olefins from environmentally friendlier sources compared to traditional petroleum-derived methods. However, industrial implementation remains cost-intensive, especially in the recovery section which uses multiple distillation columns. This study introduces two intensified sequences for MTO downstream. Intensified Process 1 uses four columns, including a Dividing-Wall Column (DWC), while Intensified Process 2 uses two conventional columns and two DWCs. When comparing energy consumption, costs, and CO2 emissions to traditional configurations, the sequence with two DWCs outperformed, saving up to 15.56% energy in the reboiler and reducing total annual costs by 7.68%. It also reduced daily CO2 emissions by 11.33 tons, marking a 14.19% decrease compared to the conventional method.

Comparison of human health, energy consumption, and carbon emission with virgin and recycled filament in Fused deposition modeling printing

Fused deposition modeling (FDM) three-dimensional (3D) printing is commonly used by small factories, entrants, and families owing to its ease of use and speed. However, certain studies have shown that during the manufacturing process, particulate matter (PM) and volatile organic compounds (VOCs) are harmful to the respiratory system, and that carbon emissions associated with energy consumption can contribute to global warming. These studies considered only virgin filaments and not recycled filaments. Considering the importance of plastic recycling for achieving circular economy targets, the sustainability of recycled filaments much be investigated. This study used grey relational analysis to determine the multi-objective optimal printing parameters for virgin and recycled filaments on the human health and carbon emissions impacts and thus provide a reference for the “circularization” of filament materials. The experimental results indicate that the orientation angle, layer height, and heatbed temperature are the three most important parameters affecting human health and carbon emissions in recycled filaments. The optimal printing parameters showed an improvement of 20.24 % for all objectives, and the PM reached 54.02 %. Furthermore, based on a life-cycle assessment, the use of optimal printing parameters can decrease lifecycle emissions by 21.7 %.

PED: Probabilistic Energy-efficient Deadline-aware scheduler for heterogeneous SoCs

Heterogeneous systems-on-chip (SoCs) integrate diverse cores with different performance and energy tradeoffs. Scheduling applications with soft deadline constraints is highly complex in such heterogeneous platforms, and the complexity is further exacerbated by the streaming jobs generated by applications from domains such as communication and radar systems. Existing deadline-aware schedulers typically first translate the job deadlines to task-level slacks before scheduling, which is the time available for a processing element (PE) to execute a specific task. Task-level slacks are critically dependent on the task-to-PE allocation of all other tasks from the same job (intra-job) or concurrent jobs (inter-job). However, this allocation is usually unknown before the start of the scheduling process. To address the problem, we propose PED, a probabilistic energy-efficient deadline-aware scheduler for heterogeneous SoCs. PED minimizes the average tardiness of streaming jobs with the least energy consumption by accurately predicting the task-to-PE allocation using Neural Network and considering intra- and inter-job contentions when scheduling tasks. Our extensive experimental results in a domain-specific SoC (DSSoC) designed for radar and communication domains show that PED can reduce tardiness by 6.9× with comparable energy consumption; and reduce energy consumption by 14% without any loss in tardiness, when compared with state-of-the-art schedulers.

Air purifier or fresh air system? A comparison of energy consumption and cost in urban China residential buildings

Air purifier or fresh air system? A comparison of energy consumption and cost in urban China residential buildings

Discussion on the Effectiveness of JGJ 26-2018 "Energy Efficiency Design Standard for Residential Buildings in Severe Cold and Cold Areas"

Building energy consumption is a substantial part of total energy consumption and is rising in the context of energy crises and environmental issues. To maximize energy savings and limit carbon emissions, the government recommends updating construction requirements. The Ministry of Housing and Urban-Rural Development of China proposed JGJ 26-2018 "Energy Saving Design Standard for Residential Structures in Extreme Cold and Cold Regions" in accordance to national policy. Several reports noted that some Chinese design requirements just stack energy-saving materials and technology without actually reducing energy consumption. This study proves the JGJ 26-2018's legitimacy. This essay first selects three major variables that have the largest impact on the energy consumption of buildings in extreme cold and cold areasexterior walls, roofs, doors, and windowsand then gathers four cases of housing restoration of these three essential components according to JGJ 26-2018. The partial success of the strategy is proven by comparing energy consumption before and after building renovations, which provides a reference for energy-saving residential building design in severe cold and cold regions.

Comparison of Primary Energy Consumption Between Additive Manufacturing Processes and CNC Machining Applied to Components in the Oil and Gas Sector

This work elucidates the environmental impact on the production of components in the oil and gas sector by analyzing two different production routes. To this end, a life cycle assessment of the CNC machining process and additive manufacturing (AM) was carried out using Multi Jet Fusion (MJF) technology. Life cycle inventories were prepared for both processes, using the Open LCA software and information from the Ecoinvent database to develop the life cycle, with Cumulative Energy Demand (CED) being considered as the impact method. From the analysis, it was found that the machining process presented an energy demand of 7177 MJ. In contrast, the MJF presented 3214 MJ, less than half of the primary energy required to produce one unit of the studied component, thus indicating that manufacturing by MJF presents greater environmental sustainability than the Oil and Gasconventional machining process.

A compliance control strategy of lower‐limb exoskeletons for energy‐efficient stance‐squat transitions with a payload

AbstractThis paper proposes an admittance control algorithm for lower‐limb exoskeletons to assist able‐bodied wearers in performing energy‐efficient stance‐squat transitions while carrying a payload of up to 20 kg. A two‐degree‐of‐freedom (DOF) model dedicated to the stance‐squat transition is derived, which takes into account the wearer's torso inclination angle and the vertical displacement of the hip joint. The torso inclination angle is obtained from an inertial measurement unit (IMU) located at the backpack of the exoskeleton. In addition, the moment caused by the torso plus the payload with respect to the hip joint is estimated. Then a model‐based disturbance observer (DOB) is used to estimate the wearer's joint torque as an indication of the motion intention, and the exoskeleton complies with the intention by following the desired joint angular velocity generated from the estimated wearer's joint torque through an admittance function. Experiments with different admittance parameters are conducted, and the energy consumption of the wearer is evaluated in terms of the normalized energy consumption index (NECI) and the physiological cost index (PCI). Furthermore, experimental comparisons of energy consumption are made for a subject carrying a payload of up to 20 kg and performing repeated stance‐squat transitions with and without the exoskeleton. The results show that a 50% reduction of energy consumption (in terms of PCI) is achieved by the exoskeleton with the proposed admittance control strategy.

Comparative Energy Consumption Analysis of the Hybrid Diesel Train and the Hybrid Fuel Cell Train

Comparative Energy Consumption Analysis of the Hybrid Diesel Train and the Hybrid Fuel Cell Train

Proton-blocking tadpole-type anion exchange membranes for acid recovery by electrodialysis

Three kinds of long-side-chain-modified tadpole-type anion exchange membranes (AEMs) named QPEK-DMODAs with microphase separated structures designed for electrodialysis (ED) acid recovery were fabricated from N,N-dimethyloctadecylamine (DMODA) as quaternization agent and poly(arylene ether ketone) (PEK) as skeleton, which is the copolymer of 2,2′,6,6′-tetramethyl biphenol (TMBP) and 4,4′-difluorobenzophenone (DFBP). QPEK-DMODAs were characterized systematically including basic structures and properties, ED recovery performance of H2SO4 solutions without or with metal impurities, and corrosive acid stability. The well-defined microphase separation structure of QPEK-DMODA-3 is formed by the suitable distribution of tadpole ionic groups at the highest IEC of 2.09 mmol g−1. The aggregate structure offers the membrane competent mechanical stability, ion conductivity and permselectivity, as well as low energy consumption and water transport ratio at the ED process. QPEK-DMODA-3 exhibits higher current efficiency (54.58 %) and recovery H+ concentration (1.74 M) than those of QPEK-DMODA-1, QPEK-DMODA-2 and commercial AMX with comparable energy consumption to that of AMX under the ED conditions of Fe2+ absence. Moreover, the Fe2+ removal rate (88.74 %) and ion selectivity (S = 57.32) of QPEK-DMODA-3 are remarkably higher than those of AMX (67.10 % and 17.32) without the scarce of recovery efficiencies in the ED recovery tests of 0.50 M H2SO4 solution containing 0.10 M of Fe2+. The combination of the comparable tolerance to strong acid to that of AMX and the confirmed good ED recovery performances declares a strong potential of tadpole-type QPEK-DMODA-3 in waste acid recovery by electrodialysis.

Building brick wall thermal management optimization and temperature control based on phase change materials integration. Case study of the city of Bechar, Algeria

Energy is a critical component of modern human life, and life without energy-consuming sectors is unthinkable for twenty-first-century humans. The building sector is a significant consumer of energy. A significant portion of human energy consumption is used to maintain comfortable building conditions. This work investigates three types of brick cavities (square, polygon, and circle cavities) filled with various phase change materials (PCMs). PCMs include RT24, RT42, n-Eicosane, and Capric acid. In Algerias hot climate, the effects of PCM type and cavity forms on the thermal performance of brick walls are discussed. In addition, an energy consumption comparison was performed between the new wall brick and the traditional brick. According to the findings, the utilization of PCM within the brick wall leads to a decrease in the indoor heat transfer and generates an indoor wall temperature more in line with the desired indoor air temperature. Furthermore, when square cavities are filled with capric acid as PCM, the outcome is a maximum temperature of 27.8 °C. Moreover, it leads to a reduction of 67.84 % in peak indoor heat flux and a decrease of 61.8 % in energy consumption.

A feasibility study of HFO refrigerants for onboard BOG liquefaction processes

As the global demand for natural gas continues to increase, the production of liquefied natural gas (LNG) and the demand for LNG carriers are also on the rise. Following the advent of LNG propulsion engines, there has been widespread adoption of systems that use LNG or boil-off gas (BOG) as fuel, and subsequently re-liquefy remaining gas thorough the re-liquefaction system. In this study, we investigated the feasibility of hydrofluro-olefins (HFO) refrigerants, the newly developed refrigerants having low flammability and low global warming potential (GWP), in BOG re-liquefaction systems for liquefied natural gas carriers. Simulations of BOG re-liquefaction process were conducted and optimized to minimize energy consumption. Then, the explosion risk and global warming potential during the lifespan of the re-liquefaction processes are also analyzed. The optimization results indicate that using HFO refrigerants in the re-liquefaction process yields comparable energy consumption to the conventional hydrocarbon refrigerants. Additionally, the use of HFO refrigerants can contribute to reducing explosion risk of liquefaction process. However, despite HFO refrigerants being considered an environmentally friendly refrigerant, it is important to note that global warming impact has not decreased as significantly as expected. This is primarily due to the fact that the GWP of the system is heavily influenced by energy consumption.