Related Energy Consumption Research Articles

Impact of mechanical ventilation control strategies based on non-steady-state and steady-state Wells-Riley models on airborne transmission and building energy consumption.

Ventilation is an effective solution for improving indoor air quality and reducing airborne transmission. Buildings need sufficient ventilation to maintain a low infection risk but also need to avoid an excessive ventilation rate, which may lead to high energy consumption. The Wells-Riley (WR) model is widely used to predict infection risk and control the ventilation rate. However, few studies compared the non-steady-state (NSS) and steady-state (SS) WR models that are used for ventilation control. To fill in this research gap, this study investigates the effects of the mechanical ventilation control strategies based on NSS/SS WR models on the required ventilation rates to prevent airborne transmission and related energy consumption. The modified NSS/SS WR models were proposed by considering many parameters that were ignored before, such as the initial quantum concentration. Based on the NSS/SS WR models, two new ventilation control strategies were proposed. A real building in Canada is used as the case study. The results indicate that under a high initial quantum concentration (e.g., 0.3 q/m3) and no protective measures, SS WR control underestimates the required ventilation rate. The ventilation energy consumption of NSS control is up to 2.5 times as high as that of the SS control.

Association between Body Mass Index with Sugar-Sweetened and Dairy Beverages Consumption in Children from the Mexico-USA Border.

The consumption of sugar-sweetened beverages has been associated with the onset of cardiometabolic diseases. The aim of this study was to describe consumption patterns of sugar-sweetened and dairy beverages and to evaluate their correlation with the body mass index in children residing at the Mexico–USA border. A total of 722 (370 girls, 352 boys) elementary school children aged 9 to 12 years from Tijuana, Mexico, participated in the study. Anthropometric measures were recorded, and a beverage intake questionnaire was completed by the children’s parents. Significant age by sex interactions were found on body mass index Z-scores (p < 0.01). Boys showed higher sugar intake (p < 0.05) and total relative energy consumption from sugar (p < 0.05) than girls. The energy consumption from sugar-sweetened and dairy beverages was similar between sexes (p > 0.05). Sugar intake from beverages was higher than the limit recommended by the World Health Organization in boys (66%) and girls (44%). A high frequency of consumption of sugar-sweetened beverages and similar intake of dairy beverages were found in children from the Mexico–USA border. The high consumption of sugar exceeds international recommendations and should be carefully monitored.

Hydrodynamics of gas-solid fluidization at ultra-high temperatures

The interest in processing granular materials in fluidized beds at ultra-high temperatures has grown recently to reduce energy consumption and CO2 emissions in relation to numerous high-temperature solid-state reactions. The present research focuses on understanding the hydrodynamics of gas-solid fluidization at temperatures up to 1650 °C to aid the development of ultra-high temperature fluidized bed reactors. Experiments are conducted in a fluidized bed of 30 mm diameter at temperatures up to 1650 °C with corundum and magnesite oxide particles. The fluidization stability is examined based on bed pressure drop measurements using a non-isothermal experimental method. The results demonstrate that stable fluidization of these particles at ultra-high temperatures can be attained by using particles of large and broad size distribution and operating at sufficiently high gas velocities. This article also discusses the bed pressure drop fluctuation, minimum fluidization velocity, and pressure drop offset at ultra-high temperatures.

Low carbon and high efficiency limestone-calcined clay as supplementary cementitious materials (SCMs): Multi-indicator comparison with conventional SCMs

The increasing shortage of conventional supplementary cementitious materials, including fly ash (FA) and ground granulated blast furnace slag (GGBS), further obliterates the sustainability potential of Portland cement. Fortunately, recent studies have proved that limestone-calcined clay (LC2) is a feasible substitute. In this study, LC2 was used as SCM to study the properties of blended cement, and compared with FA and GGBS, the relevant mechanisms leading to the unique properties of LC2 were also explained. The evaluation indexes related to energy consumption and carbon emission were proposed. Results show that, contrary to the positive effects of FA and GGBS, LC2 has a negative effect on normal consistency and workability. LC2 slightly shorten the setting time at normal consistency, but at large content, the setting time was significantly prolonged due to the increase of consistency. LC2 diminished drying shrinkage and is superior to FA and GGBS. LC2 has higher cementing efficiency than FA and GGBS, and it is more obvious at early age. The environmental impact analysis also showed that LC2 reduced the relative energy consumption and carbon emission of cement, and reduces by about half at the substitution rate of 45 ∼ 60%.

The Impacts of Carbon Emissions and Energy Consumption on Life Satisfaction: Evidence From China

This study investigates how carbon emissions and energy consumption related to the life satisfaction of Chinese households over the 2010–2018 period. The China Family Panel Studies (CFPS) data from 25 Chinese provinces shows that the effect of provincial carbon emissions on life satisfaction is positive, and increases in fuel and electricity consumption also predict a higher life satisfaction level. Fuel consumption, especially, has a greater impact on life satisfaction among older people with lower income or education levels. In addition, an increase in relative energy consumption negatively affects Chinese households’ life satisfaction. Heterogeneity analysis demonstrates that the relative fuel consumption change has a larger negative life satisfaction effect for younger, less educated or rural people. In developed regions (including Beijing and Shanghai), a strong inverse relationship between carbon emissions and the residents’ life satisfaction exists in China, but the effects of residents’ own and relative energy consumption are insignificant or slight.

Combined experimental and computational study on the promising monoethanolamine + 2-(ethylamino)ethanol + sulfolane biphasic aqueous solution for CO2 absorption

To reduce the regeneration energy consumption for CO2 capture, an advanced monoethanolamine (MEA) + 2-(ethylamino)ethanol (EAE) + sulfolane biphasic aqueous solution was developed, and the phase separation mechanism was explored. The effects of the concentration ratio on the phase separation behavior, CO2 absorption performance, CO2 loading at the phase separation point, and CO2 desorption performance of MEA + EAE + sulfolane solutions were investigated comprehensively in experiments. The 3 M MEA + 2 M EAE + 5 M sulfolane showed the best properties with a large CO2 loading of 0.32 mol/mol at the phase separation point and the relative low regeneration energy consumption, which is comparable to 5 M MEA in absorption with an improved desorption performance. The molecular mechanism of phase separation was revealed by molecular dynamics simulations, illustrating that strong hydrogen bonding between amine products and water and enhanced intermolecular interaction among amine products, would promote an aggregation of amine products. This study provides a promising candidate for energy-efficient CO2 capture with molecular insights into a liquid–liquid phase separation.

Asymptotic theory of a flapping wing of a circular cross-section

The paper is devoted to the study of the propulsive motion of a flapping wing of a circular cross-section performing translational–rotational oscillations in a viscous incompressible fluid. To describe the flow past the wing, the unsteady Navier–Stokes equation is solved. Using the method of asymptotic expansions for the case of small amplitudes of oscillations, an analytical solution of the problem is constructed in the first two terms. It is shown that the nonlinear interaction of time harmonics of translational and rotational oscillations causes secondary flows (steady streaming) that make the wing move in the direction perpendicular to the axis of translational oscillations. For the case of cruising motion, when the average hydrodynamic force acting on the wing is equal to zero, the dependence of the average speed on the dimensionless oscillation parameters is found. The results show that for relatively large angles of rotation the cruising speed of a flapping wing can be as high as the velocity amplitude of translational oscillations. The limits of applicability of the asymptotic theory are investigated using direct numerical simulations. Numerical data demonstrate that the theory well describes the flow past the wing in a wide range of dimensionless amplitudes, frequencies and angles of rotation. In conclusion, the efficiency of the propulsion system is evaluated. It is shown that in terms of relative energy consumption, a cylindrical flapping wing can be attributed to the most efficient propulsors in the range of Reynolds numbers $Re \sim 10^2\text {--}10^3$ .

Energy Consumption and CO2 Emissions Related to Wine Production: The Case Study of a Winery in Douro Wine Region-Portugal

Water use and its associated energy consumption in wine processes are often unnoticed in best practice. Many proprietors are insensitive to how water is used within their winery procedures. Key areas of environmental concern currently faced by the wine industry include water and energy use and the production of greenhouse effect gas emissions, among others. This review revealed that the practice within wine organizations tends to be largely unexplored and inadequate. To address the present needs for accurate water and energy resources control, it is vital to develop research on how water and energy are related and used in wine production to increase the effective use of these resources, minimizing the related environmental impact. The main aim of this paper was to find the relationship between energy and water utilization and subsequent CO2 emissions from a winery located in the Douro Valley, contributing to its sustainability in terms of resources consumption. A two-year monitoring plan on water use was implemented, and the related energy consumption and CO2 emissions were calculated. The results showed high values of energy (148.5 kWh/day) as well as related CO2 emissions (54 kg CO2/day) associated with high water consumption (that ranged from 16.20 to 27.66 m3 water/day). This information is very important and contributes to enlarging the database of environmental parameters related to wine production in the Douro wine region, creating opportunities for environmental improvement.

Energy cost minimization of a multifarious water heating system with energy recovery: A case of a healthcare institution

The energy usage intensity of healthcare institutions is extensive. The recorded relative typical energy consumption of hospitals has been noted to be in the range of 43 to 93 kWh/bed/day. Currently, with the global COVID 19 pandemic, the overall energy consumption of these hospitals has proportionally increased with these higher patient occupancy rates. The demand for hot water is directly proportional to occupancy rates and contributes to a large proportion of the energy consumed. Reducing the energy and associated costs of water heating processes may prove highly beneficial to the currently severely overstrained healthcare sector.In this paper the operation of a multifarious water heating system with energy recovery was optimized in order to minimize the grid energy costs based on the ToU tariff and maximum demand charges from the utility, while the required hot water temperature was maintained.A life cycle cost analysis between two baseline systems, consisting of the multifarious water heating system with and without energy recovery was compared to the optimal control approach. The results indicate that the energy recovery system with optimal control in 5.3 years. Retrospectively, the proposed initiatives may result in a potential saving of 68.23%, over a 20 year project lifetime.

Energy consumption in relation to the number of stacked packages in forced air pre‐cooling of apples

AbstractTo better investigate the effect of the number of stacked packages on the seven‐eights cooling time and the specific fan energy consumption in forced air pre‐cooling (FAC), a three‐dimensional model of FAC in the stacked packages was developed. The predicted total pressure loss was less than the product of the number of stacked packages and the pressure loss of a single package. This was due to the pressure loss of the cold air flowing through the openings in the adjacent packages accounting for the dominant proportion of the stacked packages. The difference was used to prove the overestimation of the specific fan energy consumption calculated in terms of the product of the number of stacked packages and the pressure loss of a single package. In terms of the required parameters in the pre‐cooling industry, the optimal condition of three stacked packages at the air velocity of 1.0 m/s was suggested. Compared with the other complied conditions, the specific fan energy consumption of the optimal condition was reduced by more than 50% and 0.0289–0.975$ t−1, respectively.Practical applicationsForced air pre‐cooling was an effective way to retain freshness and to improve the economic benefit of horticultural products. The quantitative relationships among the number of stacked packages, the pressure loss, and the fan energy consumption were obtained by computational fluid dynamics (CFD) simulation. Based on the results, the optimal condition in forced air pre‐cooling of apples was suggested.

Internet of Things in Industry: Research Profiling, Application, Challenges and Opportunities—A Review

The fourth industrial revolution taking place in the industrial sector is related to the increasing digitization and linkage of goods, products, value chains and business models. Industry 4.0 is based on the global connection of people, things and machines. By connecting devices and sensors to the internet, we are entering a new era of data analysis, connectivity and automation. This gives great opportunities for innovation and progress, previously unattainable in such a dimension. The term Internet of Things (IoT) has spread along with the vision of a world instrumented with intelligent inputs and outputs able to communicate with each other through internet data and technologies. IoT is being implemented in various areas of the modern economy, for example, healthcare, quality control, logistics, energy, agriculture and production. The Industrial Internet of Things (IIoT) blazes the trail to a better understanding of the manufacturing process, thus enabling efficient and sustainable production. The paper explains the concepts of IoT, IIoT and Industry 4.0. It highlights the accompanying opportunities, threats and challenges related to their implementation. Additionally, it presents an outline of computing architecture in IoT and related energy consumption issues. Moreover, it provides examples of application and IIoT research profiling.

Performance test of medium-temperature chiller with induction air-conditioning system

Abstract In this paper, medium-temperature chiller with induction air-conditioning system is introduced. Several onsite measurements were carried out on temperature and relative humidity distribution and energy consumption in summer 2020 in order to study the potential performance when applied in hot summer cold winter zone. The performance test results show that (1) the indoor temperature and humidity both comply with the range of design parameters; (2) the corresponding indoor air dew point temperature is much lower than the supply air temperature of air inductive unit, which implies no condensed water or dew on surface of air inductive unit; (3) the performance of the circulation pump, extensive type air handling unit fan; and medium-temperature chiller has exceeded the requirements of national standards.

Assessing the effects of emissions trading systems on energy consumption and energy mix

The carbon emissions trading system (ETS) is expected to achieve energy transition and carbon-neutrality goals by theoretically reducing energy consumption and adjusting the energy mix. This study aims to provide firm-level evidence on these effects by adopting the distribution dynamics approach, which could reveal historical transition probabilities and predict long-term evolutions. By using the unique dataset from the Hubei ETS pilot in China, this study can serve as an example for promoting ETS. The results indicate that: (1) Most firms converge to a lower relative energy consumption under ETS, resulting in reduced total energy consumption. However, it would take a long time to achieve energy transition. (2) The primary peak of the relative coal consumption distribution reduces from 0.07 to 0.02 under ETS, implying a decline in coal use. Meanwhile, the share of electricity consumption increases, indicating a switch from coal to electricity. (3) ETS would place a limit on fossil energy, and an even stricter limit on coal for firms with high energy consumption. (4) Both the total and share of energy-induced carbon emissions also decrease, implying that ETS might realize the decoupling of economic growth from fossil energy and carbon emissions.

CO2 Emissions Forecast and Emissions Peak Analysis in Shanxi Province, China: An Application of the LEAP Model

Shanxi Province, an important source of coal resources in China, has consumed a large amount of fossil fuels in the past few decades. The CO2 emissions of Shanxi Province have been increasing annually, reaching 541.8 million tons in 2018, 54.6% higher than the national mean. This will have a negative impact on China’s ability to meet its target of peaking CO2 emissions by 2030. To assist China to achieve this target and reduce CO2 emissions in Shanxi Province, this study used the Long-range Energy Alternatives Planning (LEAP) model to analyze the CO2 emissions and peaks in Shanxi Province from 2019 to 2035 under different scenarios. Furthermore, this study analyzed the time to peak CO2 emissions under different emission reduction measures through a sensitivity analysis. The results show that in the absence of other mitigation policy interventions, CO2 emissions in Shanxi Province will increase annually, reaching 1646.2 million tons by 2035. Furthermore, this study shows that if shares of industrial gross domestic product (GDP) in Shanxi, energy intensity reduction in the industrial and transport sectors compared to the base scenario, thermal power, and relative clean energy consumption reach 25%, 30%, 50%, and 50%, respectively, by 2035, then CO2 emissions of Shanxi would peak at 801.2 million tons in 2029 and GDP per capita would increase to USD 2000 by 2035. Finally, according to the results of this study, we have made some recommendations for emission reduction in Shanxi Province. The limitation of this study was that the implementation cost of the abatement policy was not considered.

Recovery of ammonia from simulated membrane contactor effluent using bipolar membrane electrodialysis

Abundant in municipal, agricultural, and industrial wastewaters, ammonia is a versatile chemical, which can be used as fertilizer or as a hydrogen carrier for the hydrogen economy. Membrane contactors (MCs) are an effective membrane process for selectively recovering ammonia from a wastewater stream, but the system’s continuous acid consumption and the residual acidity in the produced stream remain a major hurdle. In this study, we propose a chemical-free, electrified process that combines MC with bipolar membrane electrodialysis (BMED) to produce ammonia as a gas from wastewater. We devise three different BMED configurations, and identify the most suitable configuration by examining the impact of different operating conditions including pH, initial ammonia concentration, and relative volume ratios on the ammonia recovery and BMED energy consumption. We demonstrate up to ∼68% recovery of theoretically recoverable ammonia, and attribute the unrecovered fraction primarily to the diffusion of neutral ammonia through membranes. While the system is sub-optimal, the relative energy consumption of the system is comparable to the Haber-Bosch process for conventional ammonia production, with potentially lower energy consumption and higher ammonia recovery through higher initial ammonia concentrations, higher relative volume ratios or alternate BMED configurations.

Expression of glucose transporter-2 in murine retina: Evidence for glucose transport from horizontal cells to photoreceptor synapses.

The retina has the highest relative energy consumption of any tissue, depending on a steady supply of glucose from the bloodstream. Glucose uptake is mediated by specific transporters whose regulation and expression are critical for the pathogenesis of many diseases, including diabetes and diabetic retinopathy. Here, we used immunofluorescence to show that glucose transporter-2 (GLUT2) is expressed in horizontal cells of the mouse neuroretina in proximity to inner retinal capillaries. To study the function of GLUT2 in the murine retina, we used organotypic retinal explants, cultivated under entirely controlled, serum-free conditions and exposed them to streptozotocin, a cytotoxic drug transported exclusively by GLUT2. Contrary to our expectations, streptozotocin did not measurably affect horizontal cell viability, while it ablated rod and cone photoreceptors in a concentration-dependent manner. Staining for poly-ADP-ribose (PAR) indicated that the detrimental effect of streptozotocin on photoreceptors may be associated with DNA damage. The negative effect of streptozotocin on the viability of rod photoreceptors was counteracted by co-administration of either the inhibitor of connexin-formed hemi-channels meclofenamic acid or the blocker of clathrin-mediated endocytosis dynasore. Remarkably, cone photoreceptors were not protected from streptozotocin-induced degeneration by neither of the two drugs. Overall, these data suggest the existence of a GLUT2-dependent glucose transport shuttle, from horizontal cells into photoreceptor synapses. Moreover, our study points at different glucose uptake mechanisms in rod and cone photoreceptors.

Design optimization of multi-functional building envelope for thermal insulation and exhaust air heat recovery in different climates

Exhaust air insulation wall (EAIW) utilizes the exfiltration process of low-grade exhaust air within porous material to improve the thermal insulation of wall. Previous studies tend to neglect the pressure loss of exfiltration process and its impact on optimal design of EAIW. This paper quantitatively estimates the pressure loss of exfiltration process and proposes a methodology to determine the optimal design for maximizing energy saving potential of EAIW. In this study, a network heat transfer model was validated and used to calculate the hourly cooling and heating load of EAIW. The pressure loss of exfiltration process and its related energy consumption was estimated by Darcy's law . The optimal design was identified for minimizing the overall annual energy consumption of EAIW in different climates. Influences of exfiltration velocity and porous material selection on the optimal design of EAIW were investigated. The results demonstrate the pressure loss of exfiltration process significantly affects the overall energy performance and optimal design of EAIW. The optimal thickness of porous material component are 40 mm, 50 mm, and 50 mm for three climate zones, which correspond to a minimum annual overall energy consumption of 0.51 kWh/m 2 , 0.48 kWh/m 2 , and 0.49 kWh/m 2 , respectively. The porous materials with high permeability and thermal resistance are recommended as air-permeable component of EAIW. The optimal design can achieve a trade-off between cooling/heating energy consumption and fan power consumption for maximizing the energy saving potential of EAIW. • Optimal design of exhaust air insulation wall in three climates was investigated. • Pressure loss of exfiltration process through porous material was identified. • Optimal design achieves a trade-off for maximizing energy saving potential. • Permeability of porous material significantly affects the optimal design of wall.

Enhanced ammonium removal and recovery from municipal wastewater by asymmetric CDI cell equipped with oxygen functionalized carbon electrode

Following the concept of sustainable development and circular economy, the Capacitive Deionization (CDI) was examined for the removal and recovery of ammonium (NH4+) ions from municipal wastewater towards prevention of eutrophication and obtaining a valuable component for fertilizers production. The electrosorption study was conducted in the symmetric CDI cell, composed of activated carbon (AC) electrodes, and an asymmetric CDI cell, equipped with oxygen functionalized AC (AC-ox) cathode. The asymmetric CDI cell was demonstrated the enhanced performance in terms of the removal efficiency towards ammonium ions (83%) and the related energy consumption (and 0.085 kWh/mmol NH4+), compared to the symmetric one with the following results: 30% removal of NH4+ ions and 0.215 kWh/mmol NH4+. The beneficial performance of the AC-ox electrode also has been observed in terms of NH4+ recovery: 20% recovered NH4+ ions, compared to 9% NH4+ recovered ions by AC pristine electrode. The presence of competitive ions hindered the electrosorption efficiency. Nevertheless, the time-dependent selectivity of the AC-ox electrode towards NH4+ ions was observed. The specific capacities of the symmetric and asymmetric cells at 5 mV/s were calculated to be 10.4 F/g and 18.3 F/g, respectively. Material characterization of AC before and after oxidation explained the enhanced CDI performance of the AC-ox electrode due to the increased hydrophilicity and additional oxygen functionalities on the electrode surface.

Evaluating performance metrics in non-homogeneous cutting processes using a random-grid based digital image correlation (DIC) method

The mechanics of chip formation is widely known to be a robust indicator of cutting performance. While chips have been studied and classified for several decades, a direct quantitative correlation between chip morphology and properties of the resulting machined surface is yet to be established. In this work, we develop and demonstrate a digital image correlation (DIC) technique that specifically addresses this issue. Our technique is a departure from standard DIC methods in that it uses an iterative technique on multiple independent random grids, allowing us to obtain accurate full-field deformation measurements during chip formation. The method works especially well at or near free surfaces (e.g., machined surface) and interfaces (e.g., tool-chip contact) and when deformation is temporally unsteady and spatially non-homogeneous. Given that these are central features of nearly all cutting processes, we show how our technique can quantify unsteady, non-uniform flow fields, residual surface and near-surface strains, as well as the amount of redundant deformation during chip formation. These results suggest the use of a simple heuristic test to evaluate critical process performance metrics, such as part surface quality, sub-surface damage and relative energy consumption during machining.

Quality of Life and Relative Household Energy Consumption in China

AbstractIncreasing household energy consumption, mainly due to consumption upgrading, will create tough challenges for China if that country is to achieve peak carbon emissions in 2030 and carbon neutrality in 2060. However, this critical issue has not been explored comprehensively in the literature. Using China Family Panel Studies data and the distribution dynamics approach, this article is the first study to examine the relationship between quality of life (QOL) (proxied by consumption upgrading) and relative household energy consumption (RHEC). The results show that convergence clubs exist in all QOL groups for the RHEC, but they are more evident in the groups with lower middle and low QOL. This is encouraging because they suggest that an improvement in QOL does not necessarily lead to a higher level of energy consumption. The dataset was then divided into rural‐urban and regional subgroups to further explore the impacts of these different characteristics on energy consumption. Significant disparities are found among the same QOL groups between urban and rural households and among different regions. The results derived from this study lead to pragmatic policy suggestions in areas including energy saving, emissions reduction, and particularly alleviation of inequality.