Energies

2024

Jump to: 2023, 2022

23 pages, 2046 KiB

Open AccessArticle

Energy and Ecological Concept of a Zero-Emission Building Using Renewable Energy Sources—Case Study in Poland

by Anna Barwińska-Małajowicz, Marian Banaś, Teresa Piecuch, Radosław Pyrek, Krzysztof Szczotka and Jakub Szymiczek

Energies 2024, 17(23), 5817; https://doi.org/10.3390/en17235817 - 21 Nov 2024

Viewed by 281

Abstract

Zero-emission buildings, which do not emit CO₂ or other greenhouse gases throughout their entire life cycle, play a crucial role in sustainable development and the fight against climate change. Achieving carbon neutrality in construction requires considering emissions associated with material production, construction, [...] Read more.

Zero-emission buildings, which do not emit CO₂ or other greenhouse gases throughout their entire life cycle, play a crucial role in sustainable development and the fight against climate change. Achieving carbon neutrality in construction requires considering emissions associated with material production, construction, operation, as well as demolition and disposal. These buildings utilize energy-efficient technologies, renewable energy sources, and low-carbon materials, minimizing their environmental impact. The building sector accounts for a significant percentage of global greenhouse gas emissions, making it a key area for climate action. In Poland, where aging and energy-inefficient buildings prevail, the need for a transition towards zero-emission buildings is particularly urgent. This paper assesses the feasibility and hurdles of retrofitting existing buildings to achieve zero emissions by utilizing renewable energy systems like solar photovoltaic and heat pump technologies. The publication discusses the technical, economic, and legal aspects of this transformation, with particular emphasis on the Polish context and available support programs. The purpose of this publication is to disseminate practical knowledge and foster innovation among architects, investors, and decision-makers engaged in the development of a sustainable built environment. A key example is Net Zero Energy Buildings (NZEBs), which generate as much energy as they consume over a year through technologies such as photovoltaic panels, solar collectors, and heat pumps. NZEBs combine effective insulation, energy-efficient systems, and smart energy management to minimize consumption, and may even produce excess energy that feeds back into the grid. Despite challenges in construction and maintenance, the increasing adoption of zero-emission and NZEBs worldwide reflects their long-term ecological, economic, and health benefits. The focus of this publication is to analyze the potential for transforming standard buildings, as defined by current regulations, into zero-emission buildings powered entirely by renewable energy sources. This case study analyzes the energy potential of a residential building located in Krakow, Poland. The building’s energy efficiency potential was assessed through computer simulations using Audytor OZC software (version 7.0 Pro, Sankom), taking into account local climate conditions and building standards. The study analyzed the impact of various strategies, such as upgrading thermal insulation, using energy-efficient windows, and installing photovoltaic panels, on energy consumption and CO₂ emissions. Full article

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29 pages, 15770 KiB

Open AccessArticle

A Periodic Horizontal Shell-And-Tube Structure as an Efficient Latent Heat Thermal Energy Storage Unit

by Jerzy Wołoszyn and Krystian Szopa

Energies 2024, 17(22), 5760; https://doi.org/10.3390/en17225760 - 18 Nov 2024

Viewed by 402

Abstract

Thermal energy storage systems utilising phase change materials offer significantly higher energy densities compared to traditional solutions, and are therefore attracting growing interest in both research and application fields. However, the further development of this technology requires effective methods to enhance thermal efficiency. [...] Read more.

Thermal energy storage systems utilising phase change materials offer significantly higher energy densities compared to traditional solutions, and are therefore attracting growing interest in both research and application fields. However, the further development of this technology requires effective methods to enhance thermal efficiency. We propose a horizontal periodic shell-and-tube structure as an efficient latent heat thermal energy storage unit. This research aims to analyse heat transfer not only between the tube containing the heat transfer fluid and the phase change material but also between adjacent shell-and-tube units. The results obtained for a single cell within the periodic structure are compared with those of reference single shell-and-tube units with insulated adiabatic and highly conductive shells. The enthalpy–porosity approach, combined with the Boussinesq approximation, is applied to address the heat transfer challenges encountered during melting and solidification. The periodic horizontal shell-and-tube structure proves to be an efficient latent heat thermal energy storage unit with short melting and solidification times. In contrast, the non-periodic case with neglected conduction in the shell increases the melting and solidification times by 213.8% and 21%, respectively. The shortest melting and solidification times were recorded for the case with a periodic horizontal shell-and-tube structure and shell aspect ratios of 0.44 and 1, respectively. Full article

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20 pages, 11693 KiB

Open AccessArticle

Quantitative and Qualitative Experimental Assessment of Water Vapor Condensation in Atmospheric Air Transonic Flows in Convergent–Divergent Nozzles

by Mirosław Majkut, Sławomir Dykas, Krystian Smołka, Tim Wittmann, Axel Kuhlmann and Florian Thorey

Energies 2024, 17(21), 5459; https://doi.org/10.3390/en17215459 - 31 Oct 2024

Viewed by 486

Abstract

Atmospheric air, being also a moist gas, is present as a working medium in various areas of technology, including the areas of airframe aerodynamics and turbomachinery. Issues related to the condensation of water vapor contained in atmospheric air have been intensively studied analytically, [...] Read more.

Atmospheric air, being also a moist gas, is present as a working medium in various areas of technology, including the areas of airframe aerodynamics and turbomachinery. Issues related to the condensation of water vapor contained in atmospheric air have been intensively studied analytically, experimentally and numerically since the 1950s. An effort is made in this paper to present new, unique and complementary results of the experimental testing of moist air expansion in the de Laval nozzle. The results of the measurements, apart from the static pressure distribution on the nozzle wall and the images obtained using the Schlieren technique, additionally contain information regarding the quantity and quality of the condensate formed due to spontaneous condensation at the transition from the subsonic to the supersonic flow in the nozzle. The liquid phase was identified using the light extinction method (LEM). The experiments were performed for three geometries of convergent–divergent nozzles with different expansion rates of 3000, 2500 and 2000 s⁻¹. It is shown that as the expansion rate increases, the phenomenon of water vapor spontaneous condensation appears closer to the critical cross-section of the nozzle. A study was performed of the impact of the air relative humidity and pollution on the process of condensation of the water vapor contained in the air. As indicated by the results, both these parameters have a significant effect on the flow field and the pressure distribution in the nozzle. The results of the experimental analyses show that in the case of the atmospheric air flow, in addition to the pressure, temperature and velocity, other parameters must also be taken into account as boundary parameters for possible numerical analyses. Omitting information about the air humidity and pollution can lead to incorrect results in numerical simulations of transonic flows of atmospheric air. The presented results of the measurements of the moist air transonic flow field are original and fill the research gap in the field of experimental studies on the phenomenon of water vapor spontaneous condensation. Full article

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23 pages, 4391 KiB

Open AccessArticle

Computational Methods for Verifying the Normative Requirements Regarding the Lateral Correction Force of a Powered Roof Support

by Stanisław Szweda, Marek Szyguła, Michał Szelka, Marian Banaś and Krzysztof Kołodziejczyk

Energies 2024, 17(21), 5433; https://doi.org/10.3390/en17215433 - 31 Oct 2024

Viewed by 397

Abstract

The article discusses laboratory methods and the corresponding computational methods verifying compliance with the normative requirements regarding the lateral correction force of the powered roof support. The currently used flat model only allows for checking the normative requirement in relation to the sum [...] Read more.

The article discusses laboratory methods and the corresponding computational methods verifying compliance with the normative requirements regarding the lateral correction force of the powered roof support. The currently used flat model only allows for checking the normative requirement in relation to the sum of active forces of the correction cylinders installed in the roof support. Determining the required value of the active force of each cylinder is possible due to the simplified FEM model of a powered roof support, described in the research work, treated as a uniform weightless elastic body loaded with a concentrated force recreating the weight of the roof support located on an inclined longwall panel. The third analysed computational method involves determining the reaction in the four correction cylinders of the roof support, creating a spatial, statically indeterminate system of forces. It enables determining the range of variability of the response in the correction cylinders as a function of the distribution of floor pressure on the roof support base. The discussed computational methods were used to determine, for example, the lateral correction force of one of the types of powered supports used in a longwall panel inclined at an angle of 35°. The usefulness of the discussed calculation methods at various stages of the designing process of the powered support and its certification has been confirmed. Full article

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21 pages, 5904 KiB

Open AccessArticle

Air Pollutant Emissions of Passenger Cars in Poland in Terms of Their Environmental Impact and Type of Energy Consumption

by Piotr Pryciński, Piotr Pielecha, Jarosław Korzeb, Jacek Pielecha, Mariusz Kostrzewski and Ahmed Eliwa

Energies 2024, 17(21), 5357; https://doi.org/10.3390/en17215357 - 28 Oct 2024

Viewed by 559

Abstract

The increasing number of vehicles operating in Poland, especially passenger vehicles, justifies the need to conduct air pollution emission tests in the context of the impact of vehicles on the natural environment. Firstly, this article reviews the publications related to air pollutant emissions [...] Read more.

The increasing number of vehicles operating in Poland, especially passenger vehicles, justifies the need to conduct air pollution emission tests in the context of the impact of vehicles on the natural environment. Firstly, this article reviews the publications related to air pollutant emissions and passenger vehicles traveling on Polish roads. However, it presents a special method using advanced research equipment to determine air pollutant emissions. The above research methods are justified in implementing clean transport zones. Real Driving Emissions represent an essential procedure in the implementation of clean transport zones in Poland, verifying the actual emissions of air pollutants and modeling this phenomenon using the results of real air pollutant emissions. The results of this research state that establishing a link between a vehicle’s air pollutant emissions and its age can support making transport or delivery planning more sustainable and choosing less carbon-intensive means of transport to reduce the negative impact of transport on the environment. The scientific novelty of the proposed solutions is the verification of the actual emissions of Euro 6 vehicles and the modeling of air pollutant emissions as a function of speed and acceleration. The research results are included in this article and will become input data for further analysis in examining the impact of vehicle operating age on air pollution emissions. Consequently, the novelty of the present research also lies in its focus on the verification of the impact of operating age, particularly in the context of vehicles exceeding 15 years of age, on air pollutant emissions. By establishing a correlation between a vehicle’s air pollutant emissions and its operating age, it becomes possible to make transport or delivery planning more sustainable. Furthermore, the selection of less carbon-intensive means of transport can contribute to reducing the negative impact of transport on the environment. Full article

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9 pages, 240 KiB

Open AccessArticle

Methodology of Multiple-Criteria Decision Making for Selecting a Refrigerant to Be Used in Commercial Refrigeration Equipment

by Tomasz Bernat and Krzysztof Bieńczak

Energies 2024, 17(20), 5150; https://doi.org/10.3390/en17205150 - 16 Oct 2024

Viewed by 545

Abstract

This paper presents the application of the multiple-criteria decision-making (SAW) method for selecting the optimum refrigerant for the refrigeration systems of commercial cooling equipment used in gastronomy furniture, which is paramount in storing food under optimal conditions. The analysis focused on comparing different [...] Read more.

This paper presents the application of the multiple-criteria decision-making (SAW) method for selecting the optimum refrigerant for the refrigeration systems of commercial cooling equipment used in gastronomy furniture, which is paramount in storing food under optimal conditions. The analysis focused on comparing different refrigerants, including natural refrigerants such as R744 (carbon dioxide) and R290 (propane) and synthetic refrigerants such as R455A, R449A, and R452A. As a result of the analysis using the SAW method, the refrigerant R455A was found to be the best solution. This choice resulted from the consideration of various decision criteria, such as energy efficiency, environmental impact, operating costs, and technology availability. R455A stands out as a synthetic refrigerant that provides high energy efficiency with minimal environmental impact. Its use supports sustainability goals by reducing greenhouse gas emissions and electricity consumption, which is crucial given the modern regulatory requirements and environmental standards. This study offers a practical decision-making tool for commercial refrigeration equipment designers and manufacturers, supporting them while selecting the optimal technological solutions. The choice of refrigerant R455A addresses the need to integrate energy efficiency, environmental protection, and cost-effectiveness in the process of designing modern refrigeration systems for catering furniture. Full article

16 pages, 7972 KiB

Open AccessArticle

Visualization of Injected Fuel Vaporization Using Background-Oriented Schlieren Method

by Jungkoo Lee, Youngkun Kim, Woongil Kim and Kihyung Lee

Energies 2024, 17(19), 4867; https://doi.org/10.3390/en17194867 - 27 Sep 2024

Viewed by 457

Abstract

In this experimental study, ethanol, an eco-friendly fuel used to reduce harmful exhaust emissions from internal combustion engines, was blended with gasoline. To optimize the combustion and the shape of the combustion chamber, the spray development and spray behavior of ethanol and gasoline [...] Read more.

In this experimental study, ethanol, an eco-friendly fuel used to reduce harmful exhaust emissions from internal combustion engines, was blended with gasoline. To optimize the combustion and the shape of the combustion chamber, the spray development and spray behavior of ethanol and gasoline were visualized and compared. Droplets of injected fuel were visualized using a high-speed camera. Because it is difficult to experimentally observe fuel vaporization using only high-speed cameras, the vaporization characteristics of the spray were compared and analyzed by using the background-oriented schlieren (BOS) method with density variation and image displacement in the spray flow field to visualize the vaporized fuel. The experimental results indicate that the fuel vaporization phenomenon could be observed during the spray development and that more fuel vaporization occurred at higher ambient temperatures and lower ambient pressures. Additionally, the dependence of the differences in the vaporization characteristics of the fuel and the wall-wetting phenomenon caused by the vaporized fuel was analyzed. Full article

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14 pages, 1729 KiB

Open AccessArticle

Mine Water as a Source of Energy—Case Study from Poland

by Magdalena Starczewska, Anna Sowiżdżał, Kajetan d’Obyrn and Damian Cień

Energies 2024, 17(19), 4808; https://doi.org/10.3390/en17194808 - 25 Sep 2024

Viewed by 687

Abstract

The energy sector in Poland is primarily based on fossil fuels, mainly coal. Hard coal mining is one of the most important industries in Poland. Hard coal deposits in Poland are found in three basins, but mining is currently carried out in the [...] Read more.

The energy sector in Poland is primarily based on fossil fuels, mainly coal. Hard coal mining is one of the most important industries in Poland. Hard coal deposits in Poland are found in three basins, but mining is currently carried out in the Upper Silesian Coal Basin (USCB) and the Lublin Coal Basin (LCB). The Upper Silesian Coal Basin is Poland’s central hard coal basin, with the most significant coal production extending across Poland and the Czech Republic. Approximately 80% of proven hard coal resources in Poland are found in the Upper Silesian Coal Basin (USCB). There is a tremendous amount of water in active and abandoned hard coal mines, which must be drained daily. Relatively high temperatures characterize mine water. This study analyzed the geological and hydrogeological conditions of the Upper Silesian Coal Basin and determined the potential for the use of mine waters for energy purposes. Depending on the location of the mine, the volume of mine water inflow ranges from 1 to 60 m³/min. The temperature of the pumped water is between 13 and 25 °C. In Poland, several such pilot installations have already been created; it is worth taking a closer look at the following examples. Heat recovery from mine drainage water can significantly reduce atmospheric emissions, which is particularly important in mining areas affected by low emissions. Therefore, Poland must raise the issue of using mined water for energy purposes, especially when making decisions related to decommissioning mines and developing post-mining areas. Full article

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33 pages, 1181 KiB

Open AccessFeature PaperReview

Municipal Solid Waste as a Renewable Energy Source: Advances in Thermochemical Conversion Technologies and Environmental Impacts

by Sławomir Kasiński and Marcin Dębowski

Energies 2024, 17(18), 4704; https://doi.org/10.3390/en17184704 - 21 Sep 2024

Cited by 1 | Viewed by 2062

Abstract

This review examines the potential of municipal solid waste (MSW) as a renewable energy source, focusing on recent advances in thermochemical conversion technologies and their environmental impacts. The exponential growth of urban populations has led to a surge in MSW, necessitating sustainable waste [...] Read more.

This review examines the potential of municipal solid waste (MSW) as a renewable energy source, focusing on recent advances in thermochemical conversion technologies and their environmental impacts. The exponential growth of urban populations has led to a surge in MSW, necessitating sustainable waste management solutions. Traditional disposal methods, such as landfilling and incineration, have significant environmental drawbacks. However, advancements in waste-to-energy (WtE) technologies, including incineration, pyrolysis, and gasification, offer promising alternatives for energy recovery and resource utilization. This review explores the composition of MSW, its classification as a renewable resource, and the thermochemical conversion technologies that transform waste into energy. The environmental impacts of these technologies, particularly emissions and air quality concerns, are critically analyzed. The review highlights the evolving regulatory landscape and the implementation of advanced emission reduction systems. The findings underscore the importance of integrating innovative waste management strategies to promote a circular economy and achieve sustainable development goals. Full article

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19 pages, 7761 KiB

Open AccessArticle

Forecasting of Daily Heat Production in a District Heating Plant Using a Neural Network

by Adam Maryniak, Marian Banaś, Piotr Michalak and Jakub Szymiczek

Energies 2024, 17(17), 4369; https://doi.org/10.3390/en17174369 - 1 Sep 2024

Cited by 1 | Viewed by 791

Abstract

Artificial neural networks (ANNs) can be used for accurate heat load forecasting in district heating systems (DHSs). This paper presents an application of a shallow ANN with two hidden layers in the case of a local DHS. The developed model was used to [...] Read more.

Artificial neural networks (ANNs) can be used for accurate heat load forecasting in district heating systems (DHSs). This paper presents an application of a shallow ANN with two hidden layers in the case of a local DHS. The developed model was used to write a simple application in Python 3.10 that can be used in the operation of a district heating plant to carry out a preliminary analysis of heat demand, taking into account the ambient temperature on a given day. The model was trained using the real data from the period 2019–2022. The training was sufficient for the number of 150 epochs. The prediction effectiveness indicator was proposed. In the considered case, the effectiveness of the trained network was 85% and was better in comparison to five different regression models. The developed tool was based on an open-source programming environment and proved its ability to predict heating load. Full article

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19 pages, 2537 KiB

Open AccessArticle

Energy Efficiency Analysis of Waste-to-Energy Plants in Poland

by Marian Banaś, Tadeusz Pająk, Jakub Bator, Wojciech Wróbel and Józef Ciuła

Energies 2024, 17(10), 2390; https://doi.org/10.3390/en17102390 - 16 May 2024

Cited by 2 | Viewed by 1511

Abstract

The issue of enhancing energy recovery efficiency is a key concern within the European Union’s climate protection efforts. In particular, it applies to all processes and plants for the harvesting, gathering, and conversion of energy. The abandonment of fossil fuels in favour of [...] Read more.

The issue of enhancing energy recovery efficiency is a key concern within the European Union’s climate protection efforts. In particular, it applies to all processes and plants for the harvesting, gathering, and conversion of energy. The abandonment of fossil fuels in favour of alternative energy sources, and the increasing of energy efficiency and its recovery, is now a widely accepted direction of energy development. This study focuses on facilities that recover and process energy from municipal waste left after recycling processes, known as waste-to-energy (WtE) plants. These plants’ energy recovery efficiency is governed by the R1 Formula in EU countries. This report is based on an analysis of four years of operational data from selected Polish municipal waste incinerators, supplemented by a discussion of various studies on energy recovery efficiency. The primary objective of this report is to evaluate the effectiveness of these plants in contributing to sustainable waste management and energy recovery. The main effect of the developed report is the set of results of the energy recovery efficiency factor values, determined based on the R1 formula valid in the EU legislation, tabulated and graphically illustrated, and calculated for five selected Polish waste-to-energy plants. The presented results, with their graphical interpretation, discussion, and conclusions, provide insights into several factors influencing the value of the R1 efficiency factor. They can be a valuable contribution to operators of waste-to-energy plants, especially those operating in countries outside the EU. Full article

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10 pages, 948 KiB

Open AccessArticle

R455A Refrigerant as a Prospective Working Fluid in Refrigeration Systems for Gastronomy Furnishings

by Tomasz Bernat and Krzysztof Bieńczak

Energies 2024, 17(10), 2361; https://doi.org/10.3390/en17102361 - 14 May 2024

Cited by 1 | Viewed by 956

Abstract

The general development of technology and universal access means that gastronomy furnishings can be found in every corner of the world. Therefore, it is important to develop these devices and the machines that constitute them. We are talking about refrigeration systems located inside [...] Read more.

The general development of technology and universal access means that gastronomy furnishings can be found in every corner of the world. Therefore, it is important to develop these devices and the machines that constitute them. We are talking about refrigeration systems located inside gastronomy furnishings. The R404A refrigerant, popular in recent years, is being withdrawn from use due to its harmful impact on the environment. Modern synthetic refrigerants or natural refrigerants can be used as alternative substances. In modern solutions, it is expected that devices and all cooperating elements have the lowest possible harmful impact on the environment and the user while, at the same time, having the highest possible energy efficiency. First, tests were carried out with the R404A refrigerant. Then, the working medium was replaced without changing any element of the refrigeration system with the modern R455A refrigerant. The system was tested in terms of the operating parameters achieved and in terms of electricity consumption. It was found that there is an alternative R455A refrigerant operating in the refrigeration system of catering furnishings, which provides the system with an average of 34% better energy efficiency than the reference refrigerant R404A. It was also found that the time needed to achieve the set working conditions decreased. An alternative refrigerant allows a refrigeration system to be built based on components available on the market or one that can be used as a direct replacement for the old refrigerant. Full article

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14 pages, 2234 KiB

Open AccessArticle

Efficiency of Photosynthetic Microbial Fuel Cells (pMFC) Depending on the Type of Microorganisms Inhabiting the Cathode Chamber

by Marcin Zieliński, Paulina Rusanowska, Magda Dudek, Adam Starowicz, Łukasz Barczak and Marcin Dębowski

Energies 2024, 17(10), 2296; https://doi.org/10.3390/en17102296 - 10 May 2024

Cited by 1 | Viewed by 1140

Abstract

Photosynthetic microbial fuel cells (pMFCs) are hybrid systems that enable simultaneous wastewater treatment under anaerobic conditions and the generation of electricity by utilizing the potential difference in the anaerobic anode chamber and the oxygenated cathode chamber. Dairy wastewater with a concentration of 2000 [...] Read more.

Photosynthetic microbial fuel cells (pMFCs) are hybrid systems that enable simultaneous wastewater treatment under anaerobic conditions and the generation of electricity by utilizing the potential difference in the anaerobic anode chamber and the oxygenated cathode chamber. Dairy wastewater with a concentration of 2000 mg COD/L was treated in the anode of a batch pMFC. In the cathode chamber, Chlorella vulgaris or Arthrospira platensis was cultivated in synthetic medium, and next in diluted effluent from the anode chamber. The highest power density of 91 mW/m² was generated by the pMFC with the cultivation of Arthrospira platensis. Higher values of dissolved oxygen remained during the dark phase in the cathodic medium with Arthrospira platensis cultivation than with Chlorella vulgaris. This depletion of oxygen significantly decreased voltage generation, which during the light phase increased again to the maximum values. The COD removal achieved in the anodic chamber was 87%. The efficiency of nitrogen removal in the cathode chamber during the cultivation of Arthrospira platensis and Chlorella vulgaris was about 78% and 69%, respectively. The efficiency of phosphorus removal in the cathode chamber with the cultivation of Arthrospira plantensis and Chlorella vulgaris was 58% and 43%, respectively. This study has shown that the introduction of Arthrospira platensis into the cathode chamber is more effective than that of Chlorella vulgaris. Full article

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26 pages, 9370 KiB

Open AccessArticle

The Impact of Vehicle Technology, Size Class, and Driving Style on the GHG and Pollutant Emissions of Passenger Cars

by Martin Opetnik, Stefan Hausberger, Claus Uwe Matzer, Silke Lipp, Lukas Landl, Konstantin Weller and Miriam Elser

Energies 2024, 17(9), 2052; https://doi.org/10.3390/en17092052 - 26 Apr 2024

Cited by 1 | Viewed by 1024

Abstract

Although technical improvements to engines and aftertreatment systems have the greatest impact on pollutant emissions, there is also potential for reducing emissions through driver behavior. This potential can be realized in the very short term, while better emission-control technologies only take effect once [...] Read more.

Although technical improvements to engines and aftertreatment systems have the greatest impact on pollutant emissions, there is also potential for reducing emissions through driver behavior. This potential can be realized in the very short term, while better emission-control technologies only take effect once they have penetrated the market. In addition to a change in driving style, the vehicle owner’s choice of vehicle technology and size class will also have an impact on the future emissions of the vehicle fleet. The effects of different driving styles, the tire choice, the vehicle size class, and propulsion technologies on energy consumption and tailpipe and non-exhaust emissions are analyzed in this paper for different traffic situations and start temperatures for cars with petrol and diesel combustion engines and for battery electric vehicles. The analysis is completed with the corresponding upstream emissions from fuel and electricity production. The analysis is based on a vehicle simulation using the Passenger car and Heavy-duty Emission Model (PHEM), which is based on a large database of vehicles created using measurements of real driving conditions. For the assessment of the driving style, a novel method was developed in an H2020 project, which reproduces a measured trip with a virtual eco-driver. Carbon dioxide equivalent emissions (CO_2eq) increase with increasing vehicle size, but can be reduced by around 20% for conventional vehicles and 17% for battery electric vehicles (BEVs) through an environmentally conscious driving style. On average, BEVs have around 50% lower CO_2eq emissions than conventional vehicles, if the emissions from vehicle production are also taken into account. On an average journey of 35 km, the cold start of modern diesel vehicles accounts for around half of the total NO_x emissions, while the proportion of cold starts for petrol vehicles is around 25%. Tire and brake wear together generate a similar amount of PN23 emissions as the exhaust gases from new cars. Full article

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22 pages, 4017 KiB

Open AccessArticle

Influence of the TABS Material, Design, and Operating Factors on an Office Room’s Thermal Performance

by Mikołaj Bobula, Piotr Michalak and Jerzy Wołoszyn

Energies 2024, 17(8), 1951; https://doi.org/10.3390/en17081951 - 19 Apr 2024

Viewed by 819

Abstract

Reducing energy consumption in residential and commercial buildings is an important research topic. Thermally activated building systems are a promising technology for significantly reducing energy consumption. The high thermal inertia, large surfaces, and radiative nature are advantages of these systems, but, on the [...] Read more.

Reducing energy consumption in residential and commercial buildings is an important research topic. Thermally activated building systems are a promising technology for significantly reducing energy consumption. The high thermal inertia, large surfaces, and radiative nature are advantages of these systems, but, on the other hand, this makes the system control and design complex. A transient simulation is also required to address the dynamic behavior of the system. The influence of 19 factors (material, design, and operating parameters) on the air temperature and mean radiant temperature inside the room as well as the required cooling equipment power were analyzed to better understand the system. The screening experiment was conducted using the random balance design method, and measurement data were used to validate the resistance–capacitance model. The analysis was performed using the Plackett–Burman design and a design with randomly selected points from a full factorial experiment. The results show that internal heat gains and the inlet water temperature have a significant influence on the system, and the influence of the screed’s properties is insignificant compared to other parameters. It should be borne in mind that the obtained results and conclusions are valid for the assumed range of factors’ variability. Full article

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16 pages, 18544 KiB

Open AccessArticle

Research on the Monitoring of Overlying Aquifer Water Richness in Coal Mining by the Time-Lapse Electrical Method

by Chenyang Zhu, Guowei Zhu, Yufei Gong and Lei Zhang

Energies 2024, 17(8), 1946; https://doi.org/10.3390/en17081946 - 19 Apr 2024

Viewed by 719

Abstract

To study the influence of coal mining on the water richness overlying strata in the mining area using time-lapse electrical monitoring technology, four dataset acquisitions were completed with the same acquisition method, equipment, parameters, and processing flow. According to the characteristics of the [...] Read more.

To study the influence of coal mining on the water richness overlying strata in the mining area using time-lapse electrical monitoring technology, four dataset acquisitions were completed with the same acquisition method, equipment, parameters, and processing flow. According to the characteristics of the data, major problems such as topographic correction, high-precision denoising, spatial and temporal normalization, and resistivity data inversion have been solved. Precise tomographic imaging was achieved through high-precision data processing and difference inversion. The results show that the electrical stratification characteristics of the overlying soil and rock layers are clear, the resistivity from the surface down gradually increases, and the electrical layers are not uniform locally. During mining, the overlying strata are affected by mining, the electrical resistivity of the underlying aquifers increased to varying degrees, and the fluctuation of electrical resistivity increased while the aquifer’s water content decreased. After mining, the overlying aquifer has the phenomenon of ‘reduced resistivity and water recovery’. After a period of time, the overlying soil disturbance and overlying rock failure zone will gradually tend to be stable. Meanwhile, the aquifer structure and water content will also gradually recover. Our results could provide guidance for water resources protection in this region. Full article

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2023

Jump to: 2024, 2022

23 pages, 6695 KiB

Open AccessArticle

Modelling of Automated Store Energy Consumption

by Konrad Gac, Grzegorz Góra, Maciej Petko, Joanna Iwaniec, Adam Martowicz and Artur Kowalski

Energies 2023, 16(24), 7969; https://doi.org/10.3390/en16247969 - 8 Dec 2023

Viewed by 878

Abstract

Over the last decade, a constantly growing trend of the popularization of self-service automated stores has been observed. Vending machines have been expanded into fully automated stores, the offer of which is comparable to small, conventional stores. One of the basic reasons for [...] Read more.

Over the last decade, a constantly growing trend of the popularization of self-service automated stores has been observed. Vending machines have been expanded into fully automated stores, the offer of which is comparable to small, conventional stores. One of the basic reasons for the popularization of modern automated stores is the reduction in a store’s energy consumption while ensuring a comparable range of products offered. The research into possibilities of reducing greenhouse gases emission is important in terms of the environment and climate protection. The research presented in the paper concerns the development of a model for determining electricity consumption, operating costs and CO₂ emission of an automated store designed and developed by Delfin company. In the developed model, the potential location of the store, prevailing climatic conditions and expected product sales are taken into account. Estimated energy demand for the store is the information of key importance for the potential investors and the manufacturer of the automated store. It is worth emphasizing that the average annual electrical energy consumption evaluated for a grocery store of an area of 70 m² amounted to approximately 38.4 MWh, while for an automated store of an area of 9 m² and a comparable product range, the electricity consumption was approximately 10.1 MWh, i.e., 74% smaller. Full article

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26 pages, 28505 KiB

Open AccessFeature PaperArticle

Shell Shape Influence on Latent Heat Thermal Energy Storage Performance during Melting and Solidification

by Jerzy Wołoszyn and Krystian Szopa

Energies 2023, 16(23), 7822; https://doi.org/10.3390/en16237822 - 28 Nov 2023

Cited by 4 | Viewed by 1219

Abstract

Phase-change materials have various applications across industries from thermal energy storage through automotive battery temperature management systems to thermal stabilisation. Many of these applications are shell and tube structures with different shell shapes. However, it is not yet known how the shape of [...] Read more.

Phase-change materials have various applications across industries from thermal energy storage through automotive battery temperature management systems to thermal stabilisation. Many of these applications are shell and tube structures with different shell shapes. However, it is not yet known how the shape of the shell affects the melting, solidification times, and heat transport processes in such structures. To fill this research gap, seventeen shell shapes/orientations were compared using a simulation study. The well-known and validated enthalpy porosity algorithm implemented in the Fluent 2021R2 software was used. The numerical calculations were preceded by the measurement of thermal conductivity, phase change enthalpy, and specific heat during melting and solidification of the phase-change material. The shortest melting time was achieved for a semi-circular shell shape in the downward position, which was 44% shorter than the reference circular case. The shortest solidification times were recorded for an isosceles trapezium in an upward orientation relative to the reference circular case. Therefore, it is possible to significantly reduce the melting time in shell-and-tube systems as a result of the appropriate selection of the shell shape. Full article

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15 pages, 3181 KiB

Open AccessArticle

Performance and Energy Utilization Efficiency of an Expanded Granular Sludge Bed Reactor in the Treatment of Cassava Alcohol Wastewater

by Guoqin Xu, Junlin Ji, Zhanyao Zheng, Hongchuan Song, Hong Yang, Jing Liu, Fang Yin, Wudi Zhang and Shumei Hao

Energies 2023, 16(22), 7496; https://doi.org/10.3390/en16227496 - 8 Nov 2023

Cited by 1 | Viewed by 1088

Abstract

In recent years, expanded granular sludge blanket (EGSB) reactor has been widely used in the treatment of high-concentration organic wastewater, but its research mainly focused on treatment efficiency and microbial community composition. There were few studies on the relationship of operation conditions and [...] Read more.

In recent years, expanded granular sludge blanket (EGSB) reactor has been widely used in the treatment of high-concentration organic wastewater, but its research mainly focused on treatment efficiency and microbial community composition. There were few studies on the relationship of operation conditions and energy utilization efficiency. Therefore, the methanogenic characteristics and energy utilization efficiency of EGSB reactor were studied by using cassava alcohol wastewater (CAW) as a raw material at (36 ± 1) °C. The results show that the degradation of volatile fatty acids (VFAs) is an important step affecting methane generation compared to the hydrolysis stage. When organic load rate (OLR) was 12.73 gCOD/L·d, the chemical oxygen demand (COD) removal rate was above 95%, the methane production efficiency of raw material was 202.73 mLCH₄/ gCOD·d, the four-stage conversion efficiency was the highest, and the energy utilization efficiency was 62.26%, which was the optimal stage for EGSB reactor to treat CAW. These findings support high-efficiency bioenergy recovery from CAW in practice and highlight the potential wide application of high-performance anaerobic reactors for CAW. Full article

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14 pages, 2831 KiB

Open AccessArticle

Research on the Whole Lifecycle Emission Reduction Effect of Buildings with Different Structures in Severely Cold Regions—A Case Study in China

by Han Yang, Koki Kikuta and Motoya Hayashi

Energies 2023, 16(14), 5285; https://doi.org/10.3390/en16145285 - 10 Jul 2023

Cited by 6 | Viewed by 1381

Abstract

Since the construction industry is one of China’s high carbon emission industries, to achieve China’s carbon neutrality target by 2060, CO₂ emissions in cold regions must be reduced. At the same time, forests have excellent carbon sequestration abilities, so this paper takes [...] Read more.

Since the construction industry is one of China’s high carbon emission industries, to achieve China’s carbon neutrality target by 2060, CO₂ emissions in cold regions must be reduced. At the same time, forests have excellent carbon sequestration abilities, so this paper takes residential buildings in severely cold regions as the object of carbon emission reduction research. A model of a two-story building in Changchun was constructed, and the life-cycle carbon emissions of reinforced concrete and wood structures were measured using the life-cycle evaluation method as the basis for calculation and simulation with DesignBuilderVer.7 software. The results show that the life-cycle carbon emission of a wood structure house is 61.46 t less than that of a reinforced concrete house, and the life-cycle carbon emission reduction rate of a wood structure house is 43.39%. Based on the data, it has been proven that wooden structures effectively reduce carbon dioxide emissions during the building life cycle while enhancing building performance, given the same structural conditions. Full article

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24 pages, 5363 KiB

Open AccessArticle

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

by Krzysztof Szczotka, Anna Barwińska-Małajowicz, Jakub Szymiczek and Radosław Pyrek

Energies 2023, 16(13), 5026; https://doi.org/10.3390/en16135026 - 28 Jun 2023

Cited by 4 | Viewed by 1191

Abstract

Improving energy efficiency indicators and reasonable use of energy resources in the context of the increasing demand for energy are sectors that must definitely be paid attention to. The fight against climate change must start in the construction sector, as buildings are the [...] Read more.

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

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21 pages, 3961 KiB

Open AccessArticle

Audit-Based Energy Performance Analysis of Multifamily Buildings in South-East Poland

by Piotr Michalak, Krzysztof Szczotka and Jakub Szymiczek

Energies 2023, 16(12), 4828; https://doi.org/10.3390/en16124828 - 20 Jun 2023

Cited by 5 | Viewed by 1400

Abstract

Multifamily buildings account for about half of all residential buildings in Poland and about 70% of the urban population live in them. Most of them require thermal refurbishment. Evaluation of a building’s energy performance with the use of correlation models has been very [...] Read more.

Multifamily buildings account for about half of all residential buildings in Poland and about 70% of the urban population live in them. Most of them require thermal refurbishment. Evaluation of a building’s energy performance with the use of correlation models has been very rarely used in relation to buildings in Poland. This method is simple, fast and can improve the decision process on thermal modernisation. It is especially important at the pre-design stage of planned investments. This paper presents an attempt to develop correlations that could be used in the energy assessment of multifamily buildings. For this purpose a dataset containing of 29 audits of multifamily buildings was used. The statistical analysis was performed for buildings before and after planned refurbishment. Obtained relationships showed strong correlation between thermal demand for space heating or domestic hot water and ventilation airflow and thermal transmittance of windows (R² > 0.6). After designed modernisation the number of strong correlations decreased. Energy for domestic hot water was correlated with the number of inhabitants (R² = 0.6). Energy for space heating was correlated with the number of users and heated volume of a building. Full article

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26 pages, 42862 KiB

Open AccessArticle

The Efficiency Improvement of the Device Based on the Example of a High Building Facade Washer in the Area of Industry 4.0

by Witold Żołna, Przemysław Jura, Marian Banaś and Krzysztof Szczotka

Energies 2023, 16(10), 4246; https://doi.org/10.3390/en16104246 - 22 May 2023

Viewed by 1212

Abstract

The publication analyzes aspects of energy efficiency of various types and several technological concepts of facade washing devices. The conducted analyses and tests answered the most essential question of this stage: which, from the technical point of view of solving the problem of [...] Read more.

The publication analyzes aspects of energy efficiency of various types and several technological concepts of facade washing devices. The conducted analyses and tests answered the most essential question of this stage: which, from the technical point of view of solving the problem of stabilizing the track of the washing machine, gives the highest guarantee of effective stabilization of this track in unfavorable wind conditions. The literature analysis showed several solutions to the problem of track stabilization of facade washing machines on the market, of which suction cups stabilize the machine device, a system not attached to the wall of the building, and fans or propellers have been commercialized. However, it pointed out that there are no universal solutions. Detailed analysis of solutions under many criteria led to finding the solution with the fewest defects at this stage of analysis and potentially the greatest chance of success. Thanks to the results of work and research on the effectiveness of technology, it was possible to implement a number of solutions leading to the improvement of work efficiency, safety, and the development of Industry 4.0. Full article

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21 pages, 1615 KiB

Open AccessArticle

Enhancing Hydrogen Production from Biogas through Catalyst Rearrangements

by Marcin Pajak, Grzegorz Brus, Shinji Kimijima and Janusz S. Szmyd

Energies 2023, 16(10), 4058; https://doi.org/10.3390/en16104058 - 12 May 2023

Cited by 3 | Viewed by 1709

Abstract

Recent trends in hydrogen production include using renewable energy sources, e.g., biogas as feedstocks for steam reforming. Crucial to the field is minimizing existing reforming reactors for their applications to fuel cell systems. Here, we present a novel design of a steam reforming [...] Read more.

Recent trends in hydrogen production include using renewable energy sources, e.g., biogas as feedstocks for steam reforming. Crucial to the field is minimizing existing reforming reactors for their applications to fuel cell systems. Here, we present a novel design of a steam reforming reactor for an efficient biogas conversion to hydrogen. The design includes a radial division of the catalytic insert into individual segments and substituting parts of the catalytic material with metallic foam. The segment configuration is optimized using a genetic algorithm to maximize the efficiency of the reactor. Changes in the catalytic insert design influence the thermal conditions inside the reactor, leading to moderation of the reaction rate. This article presents a promising approach to producing hydrogen from renewable sources via steam reforming. A significant enhancement in the reforming process effectiveness is achieved with a notable decrease in the amount of the catalyst used. The final results demonstrate the capability for acquiring a similar level of biogas conversion with a 41% reduction of the catalytic material applied. Full article

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21 pages, 2718 KiB

Open AccessArticle

Improving the Energy Efficiency of Public Utility Buildings in Poland through Thermomodernization and Renewable Energy Sources—A Case Study

by Anna Barwińska-Małajowicz, Radosław Pyrek, Krzysztof Szczotka, Jakub Szymiczek and Teresa Piecuch

Energies 2023, 16(10), 4021; https://doi.org/10.3390/en16104021 - 11 May 2023

Cited by 9 | Viewed by 2991

Abstract

Economical and efficient use of energy is promoted around the world as a model of conscious care for the environment in which we live. A mere change of habits in the use of energy can reduce its costs by 5% to 15%, and [...] Read more.

Economical and efficient use of energy is promoted around the world as a model of conscious care for the environment in which we live. A mere change of habits in the use of energy can reduce its costs by 5% to 15%, and investments in energy-saving technologies can pay for themselves after just a few years. This case study shows how significant steps can be taken in saving energy in the building of public utility buildings through deep thermomodernization using renewable energy sources—compressor heat pumps and photovoltaics. The article presents a comprehensive thermomodernization of a school building made according to Polish regulations. A detailed description of the tested object is given, and the calculation procedure is described. Next, the optimal investment variant and ex post analysis are described. The implementation of these projects significantly improved the energy efficiency of the building and generated final energy savings of 80%, which will significantly reduce the school’s operating costs. Thanks to the applied improvements, it was possible to save 72.30% of thermal energy in the building, which directly translates into lowering the building’s operating costs. The improvement of energy efficiency indicators ranges from 66% for usable energy to almost 85% for non-renewable primary energy. Furthermore, by reducing the demand for energy used in the building by nearly 74%, we see a reduction in CO₂ emissions. The methods used were desk research and an extended case study of Poland, a country facing a number of problems related to energy prices during the energy crisis. In this article, we identify the challenges faced by Poland due to its geopolitical situation, and the solutions introduced to the difficult situation in the energy market come in the form of the thermomodernization of buildings. It was on this basis that Poland was selected as a case study. Full article

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12 pages, 1185 KiB

Open AccessPerspective

Balance and Energy Use of Biogas in Poland: Prospects and Directions of Development for the Circular Economy

by Józef Ciuła, Iwona Wiewiórska, Marian Banaś, Tadeusz Pająk and Piotr Szewczyk

Energies 2023, 16(9), 3910; https://doi.org/10.3390/en16093910 - 5 May 2023

Cited by 12 | Viewed by 1883

Abstract

The production of biogas from biodegradable waste generated in all sectors of the economy in Poland is a key issue for the diversification of energy sources and climate neutrality. The biogas balances presented in the literature based on bio-waste often contain overly optimistic [...] Read more.

The production of biogas from biodegradable waste generated in all sectors of the economy in Poland is a key issue for the diversification of energy sources and climate neutrality. The biogas balances presented in the literature based on bio-waste often contain overly optimistic data, which in reality only represent the theoretical potential of biogas in Poland. The pragmatic approach presented in this study fills a gap in research by presenting a technical balance of biogas (real potential) that can be realistically achieved. The objective of the work was to perform a biogas balance in the context of electricity and heat generation in cogeneration units. The tests made it possible to estimate the technical potential of biogas, depending on the source of its generation, the possibility of its conversion to biomethane and biohydrogen and the methods of its use. The research results showed a 30% increase in biogas potential on an annual basis compared to the current state, resulting in a 29% increase in electricity production and a 28% increase in heat production. The technical potential of biogas was estimated at 2186.62 million m³, which would allow for the production of 4627.06 GWh of electricity and 1869.64 TG of heat. The technical balance of biogas and the potential energy production can serve as input material for developing plans and strategies for the development of renewable energy sources in Poland. The work is consistent with the issues of balancing the renewable energy resources from biogas and the methods of conversion into other energy carriers using sustainable energy transformations in order to optimise energy production processes. Full article

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24 pages, 3644 KiB

Open AccessArticle

Wave Energy Generation in Brazil: A Georeferenced Oscillating Water Column Inventory

by Adriano Silva Bastos, Tâmara Rita Costa de Souza, Dieimys Santos Ribeiro, Mirian de Lourdes Noronha Motta Melo and Carlos Barreira Martinez

Energies 2023, 16(8), 3409; https://doi.org/10.3390/en16083409 - 13 Apr 2023

Cited by 3 | Viewed by 2846

Abstract

Seas and oceans offer great potential as a widely available source of clean and renewable energy near high energy consumption centers. This source of energy is a valuable option in the energy transition and in energy matrix decarbonization. Wave energy and an oscillating [...] Read more.

Seas and oceans offer great potential as a widely available source of clean and renewable energy near high energy consumption centers. This source of energy is a valuable option in the energy transition and in energy matrix decarbonization. Wave energy and an oscillating water column (OWC) device stand out as the types of ocean energy with the most potential. An onshore OWC requires locations with rocky outcrops and steeper slopes as the device needs to be physically installed and has lower energy dissipation due to friction with the seabed. However, Brazil has approximately 7490 km of coastlines, with various shoreline geometries and geomorphologies, some of which are very suitable for OWC implementation. Some authors have estimated that the Brazilian coast has a total potential of 114 GW, distributed between wave and tidal energy, with a great possibility of contributing to global decarbonization efforts. This study aimed to identify and quantify the potential of locations suitable for implementing wave energy farms equipped with onshore OWC. For this, a prospect was carried out using the georeferencing software QGIS, resulting in a georeferenced map with a dataset of 319 locations, and determining a power capacity of exploitation of 9.84 GW and an estimated energy of 83,689 GWh/year in ten of the seventeen coastal states. This energy corresponds to twice the energy consumption of the state of Rio de Janeiro, which has a population of approximately 17.5 million people. If the same amount of wave energy as gas-fired thermal generation energy were to be consumed, the use of wave energy would reduce emissions by approximately 44.52 million tons of CO₂ annually. This result suggests that wave energy generation should be included in future studies on the expansion of Brazilian electric systems as an accelerating factor in the energy transition. Full article

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20 pages, 10756 KiB

Open AccessArticle

Acceleration-Insensitive Pressure Sensor for Aerodynamic Analysis

by Zygmunt Szczerba, Piotr Szczerba, Kamil Szczerba and Krzysztof Pytel

Energies 2023, 16(7), 3040; https://doi.org/10.3390/en16073040 - 27 Mar 2023

Cited by 1 | Viewed by 1605

Abstract

This paper presents a method for preparing a pressure sensor that is insensitive to acceleration along with experimental evidence of its efficacy in aerodynamic analysis. A literature review and preliminary studies revealed the undesirable effect of acceleration on sensors that are located on [...] Read more.

This paper presents a method for preparing a pressure sensor that is insensitive to acceleration along with experimental evidence of its efficacy in aerodynamic analysis. A literature review and preliminary studies revealed the undesirable effect of acceleration on sensors that are located on moving elements, as evidenced by deviations from actual pressure values for piezoresistive pressure sensors that are made using MEMS technology. To address this, the authors developed a double-membrane sensor geometry that eliminated this imperfection; a method of implementing two solo pressure sensors as a new geometry-designed sensor was also proposed. Experimental tests of this suggested solution were conducted; these measurements are presented here. The results indicated that this new sensor concept could be used to measure the dynamic pressures of rotating and moving objects in order to obtain measurement results that are more reliable and closer to the true values that are derived from aerodynamic analyses. The published results confirm the reliability of the proposed device. Full article

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16 pages, 8271 KiB

Open AccessArticle

Design and Implementation of a Particulate Matter Measurement System for Energy-Efficient Searching of Air Pollution Sources Using a Multirotor Robot

by Grzegorz Suchanek, Roman Filipek and Andrzej Gołaś

Energies 2023, 16(7), 2959; https://doi.org/10.3390/en16072959 - 23 Mar 2023

Cited by 4 | Viewed by 1505

Abstract

Analyzing air pollutants is of key importance for the environmental protection goals. High concentrations of particulate matter (PM) have a particularly negative impact on human life and health. The use of an autonomous multirotor flying robot (drone) for the purposes of locating PM [...] Read more.

Analyzing air pollutants is of key importance for the environmental protection goals. High concentrations of particulate matter (PM) have a particularly negative impact on human life and health. The use of an autonomous multirotor flying robot (drone) for the purposes of locating PM sources requires the design of a dedicated measurement system from scratch. The aim of this study was to make the most important design decision, which is the correct localization of the inlet of the measurement system, taking into account disturbances in the flow field caused by the rotors. To achieve this, a computational model was built with the use of a finite-volume method in Ansys Fluent software. Based on its results, a novel criterion was proposed and applied. In addition to the trivial position outside the rotors on the extended arm, it gave the second location in the space limited by the rotors below the robot. Finally, a robot prototype was built, and a series of verification experiments were carried out, first indoors and then outdoors, at different levels of ambient PM concentrations with and without a pollution source. The field results were compiled as histograms and scatter plots and clearly demonstrated the validity of the adopted criterion. The determination coefficient between measured concentrations showed a stronger relationship when the rotors were operating. Furthermore, in cases with a present pollution source, higher concentrations were observed around the internal sensor, making it more suitable for the studied application. Full article

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15 pages, 3879 KiB

Open AccessArticle

Energy Costs Reduction for Dispersion Using a Jet-Slot Type Milk Homogenizer

by Kyrylo Samoichuk, Alexandr Kovalyov, Natalia Fuchadzhy, Taras Hutsol, Michał Jurczyk, Tadeusz Pająk, Marian Banaś, Olena Bezaltychna and Alona Shevtsova

Energies 2023, 16(5), 2211; https://doi.org/10.3390/en16052211 - 24 Feb 2023

Cited by 4 | Viewed by 1729

Abstract

The priority task of the milk processing industry is in reducing the specific energy consumption of milk fat dispersion while simultaneously ensuring a high dispersion of milk emulsion. One of the possible ways to solve this problem is by developing and implementing a [...] Read more.

The priority task of the milk processing industry is in reducing the specific energy consumption of milk fat dispersion while simultaneously ensuring a high dispersion of milk emulsion. One of the possible ways to solve this problem is by developing and implementing a little-studied jet milk homogenizer of the slot type. In it, homogenization occurs by implementing the method of the separate feeding of cream, which allows creating the maximum difference between the speeds of skim milk and cream, which is a necessary condition for effective dispersion. Analytical dependences have been found that relate power and specific energy consumption to the performance of a milk homogenizer with the separate cream supply, the diameter of the annular gap, the fat content of normalized milk and cream, and the cream supply speed. The rational value of the fat content of the cream used for homogenization is analytically substantiated; in order to reduce the specific energy consumption of the process, their fat content should be higher than 20%. The most significant increase in the energy costs of dispersion is observed when processing milk with a fat content of less than 3–4%, while the use of cream with a fat content of less than 20% leads to a multiple increase in the energy costs of the process. The research results indicate the hyperbolic nature of the dependence of the homogenizer power on its productivity. Supplying the cream through an annular gap of small diameter allows reducing the main component of dispersion energy costs by eight times. The obtained data indicate the existence of a deviation within 5–10% of the experimental power values from the analytical ones, which is explained by the influence of the efficiency of pumps, drives, and losses in the connecting fittings. Full article

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21 pages, 3869 KiB

Open AccessArticle

Energy Efficiency Analysis of Pumping Systems Impacted by the Golden Mussel: A Case Study in the Brazilian Amazon

by Tâmara Rita Costa de Souza, Jennifer Thayane Melo de Andrade, Rodrigo Otávio Peréa Serrano, Teofânia Heloísa Dutra Amorim Vidigal, Edna Maria de Faria Viana, Adriano Silva Bastos and Carlos Barreira Martinez

Energies 2023, 16(4), 1858; https://doi.org/10.3390/en16041858 - 13 Feb 2023

Cited by 1 | Viewed by 1812

Abstract

Pumping systems, especially those used in the water supply sector and in industrial and hydroelectric facilities, are commonly infested by the golden mussel. This causes an increase in maintenance operations (e.g., system shutdowns for cleaning) that can generate an increased energy cost. The [...] Read more.

Pumping systems, especially those used in the water supply sector and in industrial and hydroelectric facilities, are commonly infested by the golden mussel. This causes an increase in maintenance operations (e.g., system shutdowns for cleaning) that can generate an increased energy cost. The geographical expansion of the golden mussel in Latin America presents an economic risk, not only to the ecosystem in general, but also to the energy sector. The imminence of its spread in the Amazon region, one of the main river basins in South America, is cause for concern with regard to the problems that bioinvasion of this species can cause. Given the absence of studies on the loss of energy efficiency in pumping systems impacted by the golden mussel, this study proposes a methodology to estimate the increase in energy consumption and costs of pumping under such bioinfestation. For the standardization of the methodology and development of mathematical calculations (both novel and improved equations), data from the literature (the growth of the golden mussel as a function of infestation time) and an analysis of the dimensions (length and height) of a sample of mussels available in the laboratory were considered. These data were used to calculate the roughness generated by the mussel infestation in the pumping suction and discharger pipe, which was necessary to determine the loss of energy efficiency (load loss, power consumption, and cost of pumping) resulting from the increase in energy consumption for pumping. This methodology was applied to a pumping station representative of the Brazilian Amazon as a case study. The results show an average increase in economic indicators (consumption and cost of pumping) after the system undergoes bioinfestation. This total increase corresponded to 19% and 44% in the first and second years, respectively, achieving a stabilization of the increase in the cost of pumping at 46%, in the 30 months of operation. Our results demonstrate the pioneering nature of the proposal, since these are the first quantitative data on the energy efficiency of pumping systems associated with bioinfestation by the golden mussel. These results can also be used to estimate the increase in costs caused by golden mussel bioinfestation in the raw water pumping systems of other facilities. Full article

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15 pages, 3293 KiB

Open AccessArticle

A System of Improving Energy and Ecological Efficiency, Using the Example of Fuel Oil Combustion in Power Plant Boilers

by Wilhelm Jan Tic and Joanna Guziałowska-Tic

Energies 2023, 16(3), 1107; https://doi.org/10.3390/en16031107 - 19 Jan 2023

Cited by 2 | Viewed by 1447

Abstract

Most climatic changes are not just the result of human activity, but also of business models that harm the environment. An attempt to attain an ecological balance is an answer to the challenge posed by this situation. The combustion of liquid fuels results [...] Read more.

Most climatic changes are not just the result of human activity, but also of business models that harm the environment. An attempt to attain an ecological balance is an answer to the challenge posed by this situation. The combustion of liquid fuels results in the atmospheric emissions of pollutants, such as nitrogen oxides (NOx), sulfur dioxide and hydrocarbons. To reduce emissions of these pollutants and at the same time attain an ecological balance, specific modifiers are applied. This paper presents an analysis of the energy efficiency and ecological efficiency of fuel oil combustion in power plant boilers based on the results of tests carried out by the present authors, in which a Fe/Mg/Ce modifier was used. The tests were carried out for system capacities ranging from 1 to 5 MW. It was found that savings on fuel, which resulted from the implementation of a system for the control and supervision of power plant operation, were in the range of 4 to 6%, and those resulting from the use of the combustion modifier were from 2 to 4%. Moreover, it was found that the system designed to improve efficiency also provided the extra result of reducing CO₂ emission and equivalent emission (SO₂, NO₂, and particulate matter). Full article

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15 pages, 5794 KiB

Open AccessArticle

Study of the Blade Shape Impact on the Improvement of Fan Efficiency Based on State-of-the-Art Prototyping Methods

by Michał Szelka, Andrzej Drwięga, Jarosław Tokarczyk, Marek Szyguła, Kamil Szewerda, Marian Banaś, Krzysztof Kołodziejczyk and Krzysztof Kędzia

Energies 2023, 16(1), 542; https://doi.org/10.3390/en16010542 - 3 Jan 2023

Cited by 2 | Viewed by 3014

Abstract

The article discusses the process of designing and testing as well as their results, carried out in order to increase the efficiency of axial fans, implemented as part of the European project INESI. Modifications of existing solutions based on rapid prototyping methods were [...] Read more.

The article discusses the process of designing and testing as well as their results, carried out in order to increase the efficiency of axial fans, implemented as part of the European project INESI. Modifications of existing solutions based on rapid prototyping methods were presented. Scanning, FEM and CFD numerical calculations and 3D printing were used for that purpose. Rapid prototyping involved the use of a steel blade base and 3D-printed complex aerodynamic shapes that were bonded to create completely new blades. After their installation on the new rotor, enabling the angle of attack adjusting, a number of verifying tests of the fan were carried out. The solution was successfully tested and the results are discussed in the article. Full article

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2022

Jump to: 2024, 2023

24 pages, 10860 KiB

Open AccessArticle

Influence of the Longitudinal and Tree-Shaped Fin Parameters on the Shell-and-Tube LHTES Energy Efficiency

by Grzegorz Czerwiński and Jerzy Wołoszyn

Energies 2023, 16(1), 268; https://doi.org/10.3390/en16010268 - 26 Dec 2022

Cited by 5 | Viewed by 1672

Abstract

Changes in the energy sector, associated with the move away from fossil fuels, pose a challenge for appropriate thermal energy management in residential buildings. The important element to deal with the variability of renewable energy in thermal systems is latent heat thermal energy [...] Read more.

Changes in the energy sector, associated with the move away from fossil fuels, pose a challenge for appropriate thermal energy management in residential buildings. The important element to deal with the variability of renewable energy in thermal systems is latent heat thermal energy storage. Due to the low thermal conductivity of phase change materials, a number of techniques are proposed to enhance the heat transfer process. In this research, the global sensitivity of fin geometrical parameters on the melting and solidification times and energy efficiency of these processes was investigated. The computational model of the phase change was developed using the finite volume method with the enthalpy-porosity model and Boussinesq approximation. Numerical simulations were carried out according to the design of experiments technique. The multi-dimensional response surface was developed, and the multi-objective optimisation was done. The research shows that the melting process is most influenced by the position of the top fin (

α

angle) and the solidification process by the position of the bottom fin (

γ

angle). The angle of the tree fin (

β

) has a different effect on both processes, with the energy efficiency decreasing during melting and increasing during solidification. Maximum values for the energy efficiencies of melting (

η_{m} = 0.973

) and solidification (

η_{s} = 0.988

) were obtained for

α = 18 . 2^{°}

,

β = 89 . 0^{°}

,

L = 10.7

mm and

γ = 21 . 0^{°}

. Full article

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