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Records with Keyword: Energy Efficiency
Showing records 1 to 25 of 51. [First] Page: 1 2 3 Last
Process Drive Sizing Methodology and Multi-Level Modeling Linking MATLAB® and Aspen Plus® Environment
Patrik Furda, Miroslav Variny, Zuzana Labovská, Tomáš Cibulka
June 2, 2021 (v1)
Keywords: Energy Efficiency, heat pump, pressure and heat losses, process steam drive, propane–propylene separation, software linking, steam network
Optimal steam process drive sizing is crucial for efficient and sustainable operation of energy-intense industries. Recent years have brought several methods assessing this problem, which differ in complexity and user-friendliness. In this paper, a novel complex method was developed and presented and its superiority over other approaches was documented on an industrial case study. Both the process-side and steam-side characteristics were analyzed to obtain correct model input data: Driven equipment performance and efficiency maps were considered, off-design and seasonal operation was studied, and steam network topology was included. Operational data processing and sizing calculations were performed in a linked MATLAB®−Aspen Plus® environment, exploiting the strong sides of both software tools. The case study aimed to replace a condensing steam turbine by a backpressure one, revealing that: 1. Simpler methods neglecting frictional pressure losses and off-design turbine operation efficie... [more]
Improving the Energy Efficiency of Industrial Refrigeration Systems by Means of Data-Driven Load Management
Josep Cirera, Jesus A. Carino, Daniel Zurita, Juan A. Ortega
March 1, 2021 (v1)
Keywords: Compressors, data-driven, energy disaggregation, Energy Efficiency, load management, multi-layer perceptron, NILM, Optimization, partial load ratio, refrigeration systems
A common denominator in the vast majority of processes in the food industry is refrigeration. Such systems guarantee the quality and the requisites of the final product at the expense of high amounts of energy. In this regard, the new Industry 4.0 framework provides the required data to develop new data-based methodologies to reduce such energy expenditure concern. Focusing in this issue, this paper proposes a data-driven methodology which improves the efficiency of the refrigeration systems acting on the load side. The solution approaches the problem with a novel load management methodology that considers the estimation of the individual load consumption and the necessary robustness to be applicable in highly variable industrial environments. Thus, the refrigeration system efficiency can be enhanced while maintaining the product in the desired conditions. The experimental results of the methodology demonstrate the ability to reduce the electrical consumption of the compressors by 17%... [more]
Modification of Conventional Sugar Juice Evaporation Process for Increasing Energy Efficiency and Decreasing Sucrose Inversion Loss
Somchart Chantasiriwan
October 6, 2020 (v1)
Keywords: Energy Efficiency, heat exchanger, inversion loss, mass transfer, mathematical model, process design
The evaporation process, boiler, and turbine are the main components of the cogeneration system of the sugar factory. In the conventional process, the evaporator requires extracted steam from the turbine, and bled vapor from the evaporator is supplied to the juice heater and the pan stage. The evaporation process may be modified by using extracted steam for the heating duty in the pan stage. This paper is aimed at the investigation of the effects of this process modification. Mathematical models of the conventional and modified processes were developed for this purpose. It was found that, under the conditions that the total evaporator area is 13,000 m2, and the inlet juice flow rate is 125 kg/s, the optimum modified evaporation process requires extracted steam at a pressure of 157.0 kPa. Under the condition that the fuel consumption rate is 21 kg/s, the cogeneration system that uses the optimum modified evaporation process yields 2.3% more power output than the cogeneration system that... [more]
A Data-Driven-Based Industrial Refrigeration Optimization Method Considering Demand Forecasting
Josep Cirera, Jesus A. Carino, Daniel Zurita, Juan A. Ortega
July 17, 2020 (v1)
Keywords: Compressors, data-driven, Energy Efficiency, industrial process modelling, multi-layer perceptron, partial load ratio, refrigeration systems, self-organizing maps
One of the main concerns of industry is energy efficiency, in which the paradigm of Industry 4.0 opens new possibilities by facing optimization approaches using data-driven methodologies. In this regard, increasing the efficiency of industrial refrigeration systems is an important challenge, since this type of process consume a huge amount of electricity that can be reduced with an optimal compressor configuration. In this paper, a novel data-driven methodology is presented, which employs self-organizing maps (SOM) and multi-layer perceptron (MLP) to deal with the (PLR) issue of refrigeration systems. The proposed methodology takes into account the variables that influence the system performance to develop a discrete model of the operating conditions. The aforementioned model is used to find the best PLR of the compressors for each operating condition of the system. Furthermore, to overcome the limitations of the historical performance, various scenarios are artificially created to fin... [more]
Energy Efficiency Evaluation of Dynamic Partial Reconfiguration in Field Programmable Gate Arrays: An Experimental Case Study
Vincenzo Conti, Leonardo Rundo, Giuseppe Dario Billeci, Carmelo Militello, Salvatore Vitabile
June 23, 2020 (v1)
Keywords: digital signal processing, dynamic partial reconfiguration, Energy Efficiency, Field Programmable Gate Array, video filtering
Both computational performances and energy efficiency are required for the development of any mobile or embedded information processing system. The Internet of Things (IoT) is the latest evolution of these systems, paving the way for advancements in ubiquitous computing. In a context in which a large amount of data is often analyzed and processed, it is mandatory to adapt node logic and processing capabilities with respect to the available energy resources. This paper investigates under which conditions a partially reconfigurable hardware accelerator can provide energy saving in complex processing tasks. The paper also presents a useful analysis of how the dynamic partial reconfiguration technique can be used to enable energy efficiency in a generic IoT node that exploits a Field Programmable Gate Array (FPGA) device. Furthermore, this work introduces a hardware infrastructure and new energy metrics tailored for the energy efficiency evaluation of the dynamic partial reconfiguration pr... [more]
Identification and Evaluation of Cases for Excess Heat Utilisation Using GIS
Fabian Bühler, Stefan Petrović, Torben Ommen, Fridolin Müller Holm, Henrik Pieper, Brian Elmegaard
June 23, 2020 (v1)
Keywords: district heating, Energy Efficiency, excess heat, heat recovery, industry, power generation, utility
Excess heat is present in many sectors, and its utilization could reduce the primary energy use and emission of greenhouse gases. This work presents a geographical mapping of excess heat, in which excess heat from the industry and utility sector was distributed to specific geographical locations in Denmark. Based on this mapping, a systematic approach for identifying cases for the utilization of excess heat is proposed, considering the production of district heat and process heat, as well as power generation. The technical and economic feasibility of this approach was evaluated for six cases. Special focus was placed on the challenges for the connection of excess heat sources to heat users. To account for uncertainties in the model input, different methods were applied to determine the uncertainty of the results and the most important model parameters. The results show how the spatial mapping of excess heat sources can be used to identify their utilization potentials. The identified ca... [more]
Increased Energy Efficiency of a Backward-Feed Multiple-Effect Evaporator Compared with a Forward-Feed Multiple-Effect Evaporator in the Cogeneration System of a Sugar Factory
Somchart Chantasiriwan
May 22, 2020 (v1)
Keywords: counter-current, Energy Efficiency, heat exchanger, mathematical model
The cogeneration system of a sugar factory consists of boiler, steam turbine, and sugar juice evaporation process. The multiple-effect evaporator used for the conventional sugar juice evaporation process is the forward-feed multiple-effect evaporator, in which steam and sugar juice flow in the same direction. The main objective of this paper is to investigate the energy efficiency of the backward-feed multiple-effect evaporator, in which steam and sugar juice flow in opposite directions, compared with that of the forward-feed multiple-effect evaporator. Mathematical models are developed for both multiple-effect evaporators, and used to compare the performances of two cogeneration systems that use the forward-feed and backward-feed multiple-effect evaporators. The forward-feed multiple-effect evaporator requires extracted steam from a turbine at one pressure, whereas the backward-feed multiple-effect evaporator requires steam extraction at two pressures. Both evaporators have the same t... [more]
Analyses for Synthesis Gas from Municipal Solid Waste Gasification under Medium Temperatures
Qinyang Gu, Wei Wu, Baosheng Jin, Zheng Zhou
February 12, 2020 (v1)
Keywords: Energy Efficiency, oxygen content, syngas evolution, syngas quality
Municipal solid waste (MSW) gasification could be a novel method that shows the various advantages over traditional MSW treatments in China. Other research concluded that MSW gasification was operating by the assistant heat, and the gasification may occur under medium temperature. So, this study is aimed to investigate MSW gasification and pyrolysis behavior and analyze the syngas evolution and reaction mechanism. The MSW samples were collected in daily life and the experiments were carried out in a fixed tubular reactor below 650 °C. The effects of medium temperature and oxygen content on syngas quality were elucidated in depth. The results have shown that temperature can promote the syngas quality in the range of 550−650 °C, because the increasing temperature strengthens the reaction rate. The oxygen content should be controlled in a certain range, or oxidation reactions will be more prominent during gasification. The optimal gasification condition in this study was obtained at 650 °... [more]
The Energy Saving Potential of Occupancy-Based Lighting Control Strategies in Open-Plan Offices: The Influence of Occupancy Patterns
Christel de Bakker, Tom van de Voort, Alexander Rosemann
January 23, 2020 (v1)
Keywords: convergence analysis, Energy Efficiency, individual occupancy, occupancy sensors, occupancy spread, office buildings, smart lighting, stochastic modeling
Occupancy-based lighting control strategies have been proven to be effective in diminishing offices’ energy consumption. These strategies have typically worked by controlling lighting at the room level but, recently, lighting systems have begun to be equipped with sensors on a more fine-grained level, enabling lighting control at the desk level. For some office cases, however, the savings gained using this strategy may not outweigh the costs and design efforts compared to room control. This is because, in some offices, individual occupancy patterns are similar, hence the difference in savings between desk and room control would be minimal. This study examined the influence of occupancy pattern variance within an office space on the relative energy savings of control strategies with different control zone sizes. We applied stochastic modeling to estimate the occupancy patterns, as this method can account for uncertainty. To validate our model, simulation results were compared to earlier... [more]
A Data-Driven Learning-Based Continuous-Time Estimation and Simulation Method for Energy Efficiency and Coulombic Efficiency of Lithium Ion Batteries
Yuechen Liu, Linjing Zhang, Jiuchun Jiang, Shaoyuan Wei, Sijia Liu, Weige Zhang
December 10, 2019 (v1)
Keywords: back propagation (BP) neural network, continuous-time efficiency estimation, coulombic efficiency, Energy Efficiency, lithium titanate battery
Lithium ion (Li-ion) batteries work as the basic energy storage components in modern railway systems, hence estimating and improving battery efficiency is a critical issue in optimizing the energy usage strategy. However, it is difficult to estimate the efficiency of lithium ion batteries accurately since it varies continuously under working conditions and is unmeasurable via experiments. This paper offers a learning-based simulation method that employs experimental data to estimate the continuous-time energy efficiency and coulombic efficiency of lithium ion batteries, taking lithium titanate batteries as an example. The state of charge (SOC) regions and discharge current rates are considered as the main variables that may affect the efficiencies. Over eight million empirical datasets are collected during a series of experiments performed to investigate the efficiency variation. A back propagation (BP) neural network efficiency estimation and simulation model is proposed to estimate t... [more]
Numerical Investigation of Periodic Fluctuations in Energy Efficiency in Centrifugal Pumps at Different Working Points
Hehui Zhang, Shengxiang Deng, Yingjie Qu
December 10, 2019 (v1)
Keywords: centrifugal pump, Computational Fluid Dynamics, Energy Efficiency, fluctuation
In order to simulate the energy efficiency fluctuation behavior of an industrial centrifugal pump with a six-blade impeller, a full-scale three-dimensional (3D) an unsteady state computational fluid dynamics (CFD) model was used. Five operational points with different flow fluxes were numerically investigated by using the Navier⁻Stokes code with shear-stress transport (SST) k-ω turbulence model. The predicted performance curves agreed well with the test data. A sine function was fitted to the transient calculation results and the results show that the efficiency fluctuates mainly on the blade passing frequency, while the fluctuation level varies with flow rate. Furthermore, high efficiency is not necessarily associated with low fluctuation level. The efficiency fluctuation level is high at part-load points, and becomes relatively low when flow rate exceeds the design value. The effect of change in torque is greater than that of the head lift with respect to fluctuations of efficiency.... [more]
Optimization of External Envelope Insulation Thickness: A Parametric Study
Eleftheria Touloupaki, Theodoros Theodosiou
December 10, 2019 (v1)
Subject: Optimization
Keywords: cost-optimal, Energy Efficiency, energy performance of buildings (EPBD) recast, energy policy, insulation thickness, nearly zero energy buildings (nZEBs)
Almost four years after the implementation deadline of the energy performance of buildings Directive recast (2010/31/EU) and after being referred to the Court of Justice of the EU by the European Commission, Greece has not yet proceeded with the necessary calculations and legislative measures on the minimum, cost-optimal energy performance requirements for buildings. This paper aims to identify the optimal thickness of insulation that is cost-effective to apply in urban multi-family domestic buildings in the four climate zones of Greece. A reference building is selected in order to perform calculations over ten scenarios of external insulation thickness for each climate zone on a basic and three sensitivity analysis calculations according to the EU comparative methodology framework. The resulting energy savings for each insulation scenario are calculated, and then the cost-effectiveness of the measure is examined in financial and macroeconomic perspective for an economic lifecycle of 3... [more]
An Economic Model-Based Predictive Control to Manage the Users’ Thermal Comfort in a Building
Yaser Imad Alamin, María del Mar Castilla, José Domingo Álvarez, Antonio Ruano
December 10, 2019 (v1)
Keywords: economic MPC, Energy Efficiency, Predicted Mean Vote index, thermal comfort
The goal of maintaining users’ thermal comfort conditions in indoor environments may require complex regulation procedures and a proper energy management. This problem is being widely analyzed, since it has a direct effect on users’ productivity. This paper presents an economic model-based predictive control (MPC) whose main strength is the use of the day-ahead price (DAP) in order to predict the energy consumption associated with the heating, ventilation and air conditioning (HVAC). In this way, the control system is able to maintain a high thermal comfort level by optimizing the use of the HVAC system and to reduce, at the same time, the energy consumption associated with it, as much as possible. Later, the performance of the proposed control system is tested through simulations with a non-linear model of a bioclimatic building room. Several simulation scenarios are considered as a test-bed. From the obtained results, it is possible to conclude that the control system has a good beha... [more]
A Methodological Approach to Assess the Impact of Smarting Action on Electricity Transmission and Distribution Networks Related to Europe 2020 Targets
Andrea Bonfiglio, Federico Delfino, Marco Invernizzi, Renato Procopio
December 10, 2019 (v1)
Keywords: electricity transmission and distribution, Energy Efficiency, environmental impact, power systems, renewable generation integration
The achievement of the so-called 2020 targets requested by the European Union (EU) has determined a significant growth of proposals of solutions and of technical projects aiming at reducing the CO₂ emissions and increasing the energy efficiency, as well as the penetration of Renewable Energy Sources (RES) in the electric network. As many of them ask for funding from the EU itself, there is the necessity to define a methodology to rank them and decide which projects should be sponsored to obtain the maximum effect on the EU 2020 targets. The present paper aims at (i) defining a set of Key Performance Indicators (KPIs) to compare different proposals, (ii) proposing an analytical methodology to evaluate the defined KPIs and (iii) evaluating the maximum impact that the considered action is capable of producing. The proposed methodology is applied to a set of possible interventions performed on a benchmark transmission network test case, in order to show that the defined indicators can be e... [more]
A Review on Energy Consumption, Energy Efficiency and Energy Saving of Metal Forming Processes from Different Hierarchies
Mengdi Gao, Kang He, Lei Li, Qingyang Wang, Conghu Liu
August 8, 2019 (v1)
Subject: Energy Policy
Keywords: energy consumption, Energy Efficiency, energy-saving, metal forming process, press
Energy efficiency improvement and environmental impact reduction are emerging issues in the manufacturing industry. Aside from cutting, metal forming is also an important process in manufacturing. Metal forming is energy intensive because of the low energy efficiency of the used metal forming press. Although many literature reviews focused on the energy reduction and energy efficiency of machine tools, a comprehensive literature review of metal forming processes remains lacking because of the great difference between cutting machines and forming equipment. In addition, methods for energy efficiency and energy-saving still need to be promoted in metal forming. In this review, a novel hierarchy of the metal forming system was presented to describe the relationship among the equipment, process, and manufacturing system, providing a guideline of methods for energy efficiency and saving in metal forming. Then, existing energy consumption modeling and estimation theories and methods were dis... [more]
Measuring Energy Efficiency and Environmental Performance: A Case of South Asia
Yumei Hou, Wasim Iqbal, Ghulam Muhammad Shaikh, Nadeem Iqbal, Yasir Ahmad Solangi, Arooj Fatima
August 5, 2019 (v1)
Subject: Energy Policy
Keywords: Energy Efficiency, energy efficiency indicators, environmental performance, South Asia region
When assessing energy efficiency, most studies have frequently ignored environmental aspects even though the concept has been widely used in the past. This study evaluates the energy efficiency and environmental performance of South Asia by using DEA (data envelopment analysis) like mathematical composite indicator. We construct a comprehensive set of indicators, including an energy self-sufficiency ratio, energy production over consumption ratio, energy imports, diversification index of energy imports, energy reserve ratio, GDP productivity, energy intensity, per capita energy consumption index, carbon emission index, carbon emission index per unit of energy consumption and share of renewable energy in order to develop an energy efficiency and environmental performance index. Unlike other studies, this study first examines each indicator and then estimates a combined score for each country. The results reveal that Bhutan as a more secure country and Pakistan showed a decreasing trend,... [more]
A Composite Evaluation Model of Sustainable Manufacturing in Machining Process for Typical Machine Tools
Lishu Lv, Zhaohui Deng, Tao Liu, Linlin Wan, Wenliang Huang, Hui Yin, Tao Zhao
July 29, 2019 (v1)
Keywords: carbon efficiency, energy conservation and emission reduction, Energy Efficiency, green degree, typical machine tools
Machine tool is the basic manufacturing equipment in today’s mechanical manufacturing industry. A considerable amount of energy and carbon emission are consumed in machining processes, the realization of sustainable manufacturing of machine tools have become an urgent problem to be solved in the field of industry and academia. Therefore, five types of machine tools were selected for the typical machining processes (turning, milling, planning, grinding and drilling). Then the model of the energy efficiency, carbon efficiency and green degree model were established in this paper which considers the theory and experiment with the resource, energy and emission modeling method. The head frame spindle and head frame box were selected to verify the feasibility and practicability of the proposed model, based on the orthogonal experiment case of the key machining process. In addition, the influence rules of machining parameters were explored and the energy efficiency and green degree of the mac... [more]
Particle Swarm Optimization for Outdoor Lighting Design
Ana Castillo-Martinez, Jose Ramon Almagro, Alberto Gutierrez-Escolar, Antonio del Corte, José Luis Castillo-Sequera, José Manuel Gómez-Pulido, José-María Gutiérrez-Martínez
July 26, 2019 (v1)
Keywords: Energy Efficiency, lighting design, lighting optimization, particle swarm optimization (PSO)
Outdoor lighting is an essential service for modern life. However, the high influence of this type of facility on energy consumption makes it necessary to take extra care in the design phase. Therefore, this manuscript describes an algorithm to help light designers to get, in an easy way, the best configuration parameters and to improve energy efficiency, while ensuring a minimum level of overall uniformity. To make this possible, we used a particle swarm optimization (PSO) algorithm. These algorithms are well established, and are simple and effective to solve optimization problems. To take into account the most influential parameters on lighting and energy efficiency, 500 simulations were performed using DIALux software (, DIAL, Ludenscheid, Germany). Next, the relation between these parameters was studied using to data mining software. Subsequently, we conducted two experiments for setting parameters that enabled the best configuration algorithm in order to improve efficiency... [more]
Assessment of the Governance System Regarding Adoption of Energy Efficient Appliances by Households in Nigeria
James A. Gana, Thomas Hoppe
July 26, 2019 (v1)
Subject: Energy Policy
Keywords: Energy Efficiency, governance, household electrical appliances, Nigeria, policy
The adoption of energy efficient electrical appliances by households has a great potential to reduce electricity consumption in Nigeria. A well-formulated and implemented policy (mix) to spur adoption is said to be required to drive this process. This article presents an assessment of policies that aim to spur adoption among households, and the related governance system. The analytical framework used for this analysis is the Governance Assessment Tool (GAT). Data collection involved semi-structured interviews, a review of policy documents, and secondary quantitative data. The results show that policies in Nigeria had little effect in meeting pre-set goals. The governance system was found to be weakly developed due to a lack of policy, the overlapping work of different governmental organizations, a lack of appropriate resources, and a lack of householders’ involvement in agenda-setting and decision-making processes. Current actions mostly depend on local programmes that run via donor ai... [more]
Characterization and Analysis of Energy Demand Patterns in Airports
Sergio Ortega Alba, Mario Manana
July 26, 2019 (v1)
Keywords: airports, electric charges, electric load profile, energy consumption, energy demand patterns, Energy Efficiency, energy modeling, infrastructure energy conservation, loads
Airports in general have high-energy consumption. Influenced by many factors, the characteristics of airport energy consumption are stochastic, nonlinear and dynamic. In recent years, airport managers have made huge efforts to harmonize airport operation with environmental sustainability by minimizing the environmental impact, with energy conservation and energy efficiency as one of their pillars. A key factor in order to reduce energy consumption at airports is to understand the energy use and consumption behavior, due to the multiple parameters and singularities that are involved. In this article, a 3-step methodology based on monitoring methods is proposed to characterize and analyze energy demand patterns in airports through their electric load profiles, and is applied to the Seve Ballesteros-Santander Airport (Santander, Spain). This methodology can be also used in airports in order to determine the way energy is used, to establish the classification of the electrical charges base... [more]
Barriers to Energy Efficiency in Swedish Non-Energy-Intensive Micro- and Small-Sized Enterprises—A Case Study of a Local Energy Program
Fredrik Backman
July 26, 2019 (v1)
Subject: Energy Policy
Keywords: barriers, Energy Efficiency, municipal, Swedish local enterprises
Improved energy efficiency has become a strategic issue and represents a priority for European competitiveness. Countries adopt various energy policies on local and national levels where energy audit programs are the most common energy end-use efficiency policy for industrial small- and medium-sized enterprises (SMEs). However, studies indicate that cost-efficient energy conservation measures are not always implemented, which can be explained by the existence of barriers to energy efficiency. This paper investigates how Swedish municipalities can support local micro- and small-sized enterprises with improved energy efficiency and the existence of different barriers to the implementation of energy efficiency. Relating this empirical case study to the theoretical barriers outlined in the text, this study found that the major explanatory factors related to non-implementation of cost-effective energy efficiency measures among micro- and small-sized industrial enterprises were bounded ratio... [more]
Energy Rebound as a Potential Threat to a Low-Carbon Future: Findings from a New Exergy-Based National-Level Rebound Approach
Paul E. Brockway, Harry Saunders, Matthew K. Heun, Timothy J. Foxon, Julia K. Steinberger, John R. Barrett, Steve Sorrell
July 26, 2019 (v1)
Keywords: aggregate production function (APF), constant elasticity of substitution (CES) function, Energy Efficiency, energy policy, energy rebound, Exergy, Exergy Efficiency, macroeconomic rebound
150 years ago, Stanley Jevons introduced the concept of energy rebound: that anticipated energy efficiency savings may be “taken back” by behavioural responses. This is an important issue today because, if energy rebound is significant, this would hamper the effectiveness of energy efficiency policies aimed at reducing energy use and associated carbon emissions. However, empirical studies which estimate national energy rebound are rare and, perhaps as a result, rebound is largely ignored in energy-economy models and associated policy. A significant difficulty lies in the components of energy rebound assessed in empirical studies: most examine direct and indirect rebound in the static economy, excluding potentially significant rebound of the longer term structural response of the national economy. In response, we develop a novel exergy-based approach to estimate national energy rebound for the UK and US (1980⁻2010) and China (1981⁻2010). Exergy—as “available energy”—allows a consistent,... [more]
Improving Flexibility and Energy Efficiency of Post-Combustion CO₂ Capture Plants Using Economic Model Predictive Control
Benjamin Decardi-Nelson, Su Liu, Jinfeng Liu
April 8, 2019 (v1)
Keywords: Energy Efficiency, optimal control, post-combustion CO2 capture, time-varying operation
To reduce CO 2 emissions from power plants, electricity companies have diversified their generation sources. Fossil fuels, however, still remain an integral energy generation source as they are more reliable compared to the renewable energy sources. This diversification as well as changing electricity demand could hinder effective economical operation of an amine-based post-combustion CO 2 capture (PCC) plant attached to the power plant to reduce CO 2 emissions. This is as a result of large fluctuations in the flue gas flow rate and unavailability of steam from the power plant. To tackle this problem, efficient control algorithms are necessary. In this work, tracking and economic model predictive controllers are applied to a PCC plant and their economic performance is compared under different scenarios. The results show that economic model predictive control has a potential to improve the economic performance and energy efficiency of the amine-based PCC process up... [more]
Bioenergy from Low-Intensity Agricultural Systems: An Energy Efficiency Analysis
Oludunsin Arodudu, Katharina Helming, Hubert Wiggering, Alexey Voinov
March 26, 2019 (v1)
Subject: Biosystems
Keywords: bioenergy, biofuel, Energy Efficiency, EROEI, high-intensity industrialized agricultural production systems, low-intensity eco-agricultural production systems, NEG
In light of possible future restrictions on the use of fossil fuel, due to climate change obligations and continuous depletion of global fossil fuel reserves, the search for alternative renewable energy sources is expected to be an issue of great concern for policy stakeholders. This study assessed the feasibility of bioenergy production under relatively low-intensity conservative, eco-agricultural settings (as opposed to those produced under high-intensity, fossil fuel based industrialized agriculture). Estimates of the net energy gain (NEG) and the energy return on energy invested (EROEI) obtained from a life cycle inventory of the energy inputs and outputs involved reveal that the energy efficiency of bioenergy produced in low-intensity eco-agricultural systems could be as much as much as 448.5⁻488.3 GJ·ha−1 of NEG and an EROEI of 5.4⁻5.9 for maize ethanol production systems, and as much as 155.0⁻283.9 GJ·ha−1 of NEG and an EROEI of 14.7⁻22.4 for maize biogas production systems. Thi... [more]
Development of a Numerical Weather Analysis Tool for Assessing the Precooling Potential at Any Location
Dimitris Lazos, Merlinde Kay, Alistair Sproul
March 26, 2019 (v1)
Keywords: climate effects, Energy Efficiency, precooling, weather analysis
Precooling a building overnight during the summer is a low cost practice that may provide significant help in decreasing energy demand and shaving peak loads in buildings. The effectiveness of precooling depends on the weather patterns at the location, however research in this field is predominantly focused in the building thermal response alone. This paper proposes an analytical tool for assessing the precooling potential through simulations from real data in a numerical weather prediction platform. Three dimensionless ratios are developed based on the meteorological analysis and the concept of degree hours that provide an understanding of the precooling potential, utilization and theoretical value. Simulations were carried out for five sites within the Sydney (Australia) metro area and it was found that they have different responses to precooling, depending on their proximity to the ocean, vegetation coverage, and urban density. These effects cannot be detected when typical meteorolo... [more]
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