scholarly journals Water–Energy Nexus in Typical Industrial Water Circuits

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 699 ◽  
Author(s):  
Miguel C. Oliveira ◽  
Muriel Iten ◽  
Henrique A. Matos ◽  
Jochen Michels

Water–energy nexus has been recognized as an important and challenging issue, namely in industry. This is due to industry reforms, increasing demand, and climate change. This concept focuses on the link between energy and water infrastructure. Overall, there is limited understanding of the nature of this link, as it is assumed that water is not a threat to the energy sector or an influence of the electricity to the water resources. This work aims to present and evaluate case studies related to typical industrial water circuits. These circuits represent some of the most relevant industrial sectors in terms of water–energy nexus such as: steel industry, chemical industry, paper and pulp industry, and food industry. Moreover, these sectors also cover typical industrial water circuits, namely: cooling circuit, gas washing circuit, water treatment circuit, transportation circuit, and quenching circuit. The circuits have firstly been assembled in OpenModelica software considering the equipment and physical layout of each circuit. According to their actual operation conditions, the energy and water consumption have been estimated. Furthermore, water and energy efficiency improvement measures have been proposed and implemented into the assembled models. This enabled a techno-economic assessment based on the implementation of the improvement measures. In order to contextualise these results into the industrial trends, the achieved water and energy savings are projected into potential national and sectorial savings considering the current levels of water and energy demand for each sector.

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 223 ◽  
Author(s):  
Muriel Iten ◽  
Miguel Oliveira ◽  
Diogo Costa ◽  
Jochen Michels

Industrial water circuits (IWC) are frequently neglected as they are auxiliary circuits of industrial processes, leading to a missing awareness of their energy- and water-saving potential. Industrial sectors such as steel, chemicals, paper and food processing are notable in their water-related energy requirements. Improvement of energy efficiency in industrial processes saves resources and reduces manufacturing costs. The paper presents a cooling IWC of a steel wire processing plant in which steel billets are transformed into wire. The circuit was built in object-oriented language in OpenModelica and validated with real plant data. Several improvement measures have been identified and an optimisation methodology has been proposed. A techno-economic analysis has been carried out to estimate the energy savings and payback time for the proposed improvement measures. The suggested measures allow energy savings up to 29% in less than 3 years’ payback time and water consumption savings of approximately 7.5%.


Author(s):  
Yangping Yu ◽  
Yulei Xie ◽  
Ling Ji ◽  
Jinbo Zhang ◽  
Yanpeng Cai ◽  
...  

Abstract In this study, a new concept concerning comprehensive characteristics of water resources utilization as an index for risk modeling within the water allocation management model is proposed to explore the tolerance of unbalanced allocation problem under water–energy nexus. The model is integrated with interval two-stage stochastic programming for reflecting system uncertainties. These uncertainties are associated with the industrial production feature and the decision-making process. With respect to water–energy nexus, energy proposed is mainly focused on the consumption intensity of water purification and transportation from different water sources. The developed model is applied for industrial water resources allocation management in Henan province, China. Multiple scenarios related to disparate energy consumption control and the comprehensive risk levels are simulated to obtain a reasonable trade-off among system profit, comprehensive risk, and energy consumption. The results indicated that the strict comprehensive risk management or energy consumption control measures could cause damage to system benefit owing to decreasing the flexibility of industrial water resources distributions, and the preliminary energy consumption or the comprehensive risk control would be beneficial to moderate the conflict between industrial sectors and water resources, and accelerate industrial structure transformation in the future.


Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1012
Author(s):  
Francesco Calise ◽  
Francesco L. Cappiello ◽  
Maria Vicidomini ◽  
Jian Song ◽  
Antonio M. Pantaleo ◽  
...  

In this research, a technoeconomic comparison of energy efficiency options for energy districts located in different climatic areas (Naples, Italy and Fayoum, Egypt) is presented. A dynamic simulation model based on TRNSYS is developed to evaluate the different energy efficiency options, which includes different buildings of conceived districts. The TRNSYS model is integrated with the plug-in Google SketchUp TRNSYS3d to estimate the thermal load of the buildings and the temporal variation. The model considers the unsteady state energy balance and includes all the features of the building’s envelope. For the considered climatic zones and for the different energy efficiency measures, primary energy savings, pay back periods and reduced CO2 emissions are evaluated. The proposed energy efficiency options include a district heating system for hot water supply, air-to-air conventional heat pumps for both cooling and space heating of the buildings and the integration of photovoltaic and solar thermal systems. The energy actions are compared to baseline scenarios, where the hot water and space heating demand is satisfied by conventional natural gas boilers, the cooling demand is met by conventional air-to-air vapor compression heat pumps and the electric energy demand is satisfied by the power grid. The simulation results provide valuable guidance for selecting the optimal designs and system configurations, as well as suggest guidelines to policymakers to define decarbonization targets in different scenarios. The scenario of Fayoum offers a savings of 67% in primary energy, but the associated payback period extends to 23 years due to the lower cost of energy in comparison to Naples.


2020 ◽  
Vol 10 (12) ◽  
pp. 4061 ◽  
Author(s):  
Naoto Takatsu ◽  
Hooman Farzaneh

After the Great East Japan Earthquake, energy security and vulnerability have become critical issues facing the Japanese energy system. The integration of renewable energy sources to meet specific regional energy demand is a promising scenario to overcome these challenges. To this aim, this paper proposes a novel hydrogen-based hybrid renewable energy system (HRES), in which hydrogen fuel can be produced using both the methods of solar electrolysis and supercritical water gasification (SCWG) of biomass feedstock. The produced hydrogen is considered to function as an energy storage medium by storing renewable energy until the fuel cell converts it to electricity. The proposed HRES is used to meet the electricity demand load requirements for a typical household in a selected residential area located in Shinchi-machi in Fukuoka prefecture, Japan. The techno-economic assessment of deploying the proposed systems was conducted, using an integrated simulation-optimization modeling framework, considering two scenarios: (1) minimization of the total cost of the system in an off-grid mode and (2) maximization of the total profit obtained from using renewable electricity and selling surplus solar electricity to the grid, considering the feed-in-tariff (FiT) scheme in a grid-tied mode. As indicated by the model results, the proposed HRES can generate about 47.3 MWh of electricity in all scenarios, which is needed to meet the external load requirement in the selected study area. The levelized cost of energy (LCOE) of the system in scenarios 1 and 2 was estimated at 55.92 JPY/kWh and 56.47 JPY/kWh, respectively.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1226
Author(s):  
Beatriz Fraga-De Cal ◽  
Antonio Garrido-Marijuan ◽  
Olaia Eguiarte ◽  
Beñat Arregi ◽  
Ander Romero-Amorrortu ◽  
...  

Prefabricated solutions incorporating thermal insulation are increasingly adopted as an energy conservation measure for building renovation. The InnoWEE European project developed three technologies from Construction and Demolition Waste (CDW) materials through a manufacturing process that supports the circular economy strategy of the European Union. Two of them consisted of geopolymer panels incorporated into an External Thermal Insulation Composite System (ETICS) and a ventilated façade. This study evaluates their thermal performance by means of monitoring data from three pilot case studies in Greece, Italy, and Romania, and calibrated building simulation models enabling the reliable prediction of energy savings in different climates and use scenarios. Results showed a reduction in energy demand for all demo buildings, with annual energy savings up to 25% after placing the novel insulation solutions. However, savings are highly dependent on weather conditions since the panels affect cooling and heating loads differently. Finally, a parametric assessment is performed to assess the impact of insulation thickness through an energy performance prediction and a cash flow analysis.


Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 156
Author(s):  
Paige Wenbin Tien ◽  
Shuangyu Wei ◽  
John Calautit

Because of extensive variations in occupancy patterns around office space environments and their use of electrical equipment, accurate occupants’ behaviour detection is valuable for reducing the building energy demand and carbon emissions. Using the collected occupancy information, building energy management system can automatically adjust the operation of heating, ventilation and air-conditioning (HVAC) systems to meet the actual demands in different conditioned spaces in real-time. Existing and commonly used ‘fixed’ schedules for HVAC systems are not sufficient and cannot adjust based on the dynamic changes in building environments. This study proposes a vision-based occupancy and equipment usage detection method based on deep learning for demand-driven control systems. A model based on region-based convolutional neural network (R-CNN) was developed, trained and deployed to a camera for real-time detection of occupancy activities and equipment usage. Experiments tests within a case study office room suggested an overall accuracy of 97.32% and 80.80%. In order to predict the energy savings that can be attained using the proposed approach, the case study building was simulated. The simulation results revealed that the heat gains could be over or under predicted when using static or fixed profiles. Based on the set conditions, the equipment and occupancy gains were 65.75% and 32.74% lower when using the deep learning approach. Overall, the study showed the capabilities of the proposed approach in detecting and recognising multiple occupants’ activities and equipment usage and providing an alternative to estimate the internal heat emissions.


Environments ◽  
2018 ◽  
Vol 5 (11) ◽  
pp. 119 ◽  
Author(s):  
Alessia Arteconi ◽  
Luca Del Zotto ◽  
Roberto Tascioni ◽  
Khamid Mahkamov ◽  
Chris Underwood ◽  
...  

In this paper, the smart management of buildings energy use by means of an innovative renewable micro-cogeneration system is investigated. The system consists of a concentrated linear Fresnel reflectors solar field coupled with a phase change material thermal energy storage tank and a 2 kWe/18 kWth organic Rankine cycle (ORC) system. The microsolar ORC was designed to supply both electricity and thermal energy demand to residential dwellings to reduce their primary energy use. In this analysis, the achievable energy and operational cost savings through the proposed plant with respect to traditional technologies (i.e., condensing boilers and electricity grid) were assessed by means of simulations. The influence of the climate and latitude of the installation was taken into account to assess the performance and the potential of such system across Europe and specifically in Spain, Italy, France, Germany, U.K., and Sweden. Results show that the proposed plant can satisfy about 80% of the overall energy demand of a 100 m2 dwelling in southern Europe, while the energy demand coverage drops to 34% in the worst scenario in northern Europe. The corresponding operational cost savings amount to 87% for a dwelling in the south and at 33% for one in the north.


Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2530 ◽  
Author(s):  
Luigi Cimorelli ◽  
Carmine Covelli ◽  
Bruno Molino ◽  
Domenico Pianese

Greenhouse gas emission is one of the main environmental issues of today, and energy savings in all industries contribute to reducing energy demand, implying, in turn, less carbon emissions into the atmosphere. In this framework, water pumping systems are one of the most energy-consuming activities. The optimal regulation of pumping systems with the use of variable speed drives is gaining the attention of designers and managing authorities. However, optimal management and operation of pumping systems is often performed, employing variable speed drives without considering if the energy savings are enough to justify their purchasing and installation costs. In this paper, the authors compare two optimal pump scheduling techniques, optimal regulation of constant speed pumps by an optimal ON/OFF sequence and optimal regulation with a variable speed pump. Much of the attention is devoted to the analysis of the costs involved in a hypothetical managing authority for the water distribution system in order to determine whether the savings in operating costs is enough to justify the employment of variable speed drives.


2017 ◽  
Vol 742 ◽  
pp. 593-601
Author(s):  
Michael Dieterle ◽  
Elisa Seiler ◽  
Tobias Viere

The purpose of this paper is to evaluate the eco-efficiency of three different recycling technologies for carbon fiber reinforced plastic (CFRP) waste, and to identify the preferable and most efficient solution. Recycling via mechanical shredding, microwave pyrolysis and subcritical solvolysis is compared and comprehensive primary data on energy demand and process throughput are examined. Following an ecological and economic assessment, the results are normalized and summarized into three single-score indicators. To decide which solution is most efficient, economic and ecological data are plotted on an eco-efficiency portfolio. The achieved results demonstrate that the eco-efficiency of the recycling technologies investigated is entirely positive on an industrial scale, and that the efficient use of CFRPs across the entire life cycle is possible. The material recycling of CFRP waste is consequently a promising topic for future development. The use of recycled material as conductivity additives in secondary applications can be considered as a valuable option for all three technologies, although the benefits of recycling are strongly dependent on the quality and quantity of the recycled material. Depending on the resources substituted in a secondary application, different recycling technologies offer considerable advantages. To ensure a consistently high quality of output materials on an industrial scale, specific process parameters have to be identified, for which, further research is necessary.


2018 ◽  
Author(s):  
Noah M. Sachs

In this Article, I demonstrate that the regulatory strategy for energy efficiency is working. Although information disclosure, financial incentives, and other softer alternatives to regulation play a vital role in reducing energy demand, these should be viewed as complements to efficiency regulation, rather than replacements. The regulatory approach has led to substantial cost and energy savings in the past, it has enjoyed bipartisan political support, and it targets products and behaviors that are difficult to address through other policy tools. Given the politics of climate change in the United States, which make federal carbon taxes or a cap-and-trade system infeasible, the regulatory option should be expanded, not abandoned.


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