Search Results (2,444)

Optimizing chiller load (OCL) distribution in multi-chiller HVAC systems is critical for energy efficiency, yet existing algorithms often struggle with accuracy and convergence. This challenge is compounded by the fact that existing research predominantly focuses on chiller-centric optimization, often neglecting the significant energy consumption of auxiliary components. To address this gap, this study proposes a novel method utilizing Modelica/Simulink co-simulation to accurately model the entire refrigeration system, including chillers, pumps and cooling towers, thereby eliminating complex mathematical derivations and enhancing real-world applicability. To solve this holistic optimization problem, an Improved Particle Swarm Optimization (IPSO) algorithm is developed, which integrates a Phased Adaptive Decreasing Inertia Weight (PADIW) strategy, adaptive learning factors, and a mutation operator to enhance its global search capability and robustness. A case study of a shopping mall demonstrates the approach’s efficacy: over a six-month period, the optimization method reduces total refrigeration system consumption by 25.5% compared to the strategy of distributing the load equally and 15.5% compared to the human experience strategy. Notably, this case revealed that the water pumps, while accounting for less than 20% of total consumption, held a disproportionately large energy-saving potential of over 25%. Comparative experiments and Monte Carlo simulations further confirm the proposed IPSO’s superior convergence and robustness over standard PSO and other common metaheuristics. This study demonstrates that the synergy of Modelica/Simulink co-simulation and the IPSO algorithm is crucial for realizing the full energy-saving potential of the entire system, particularly from previously overlooked components like the water pumps. Full article

The research process was based on an analysis of an existing building equipped with a heat pump on which photovoltaic panels were installed; then, based on energy consumption, the investment profitability was evaluated. In this research, using the available data, the coefficient of self-consumption of energy from the PV installation, the potential index of the installation’s own needs coverage, and the index of energy use from photovoltaic modules were determined, which in practice is equated with the energy efficiency of the PV installation. The entire investment was subjected to simulation and field tests to determine the energy demand of a single-family building. The main aim of this work was to check whether a system equipped with a heat pump combined with a PV installation is an effective technical solution in the analysed climatic conditions in one of the countries of Central and Eastern Europe. In addition, both positive and negative aspects of renewable energy sources were analysed, including long-term financial savings, energy independence, and reductions in greenhouse gas emissions. It has been shown that the described solution is characterised by high initial costs depending on weather conditions. The installation presented would allow us to avoid 1891 kg/year of CO₂ emissions, which means that with this solution, we contribute to environmental protection activities. Full article

The objective of this work was to evaluate the potential of PEF application on the decrease in orange peel air-drying time and temperature, resulting in energy savings. Orange peel waste (by-product of squeezable orange juice typical production, with a moisture content of 70%) was PEF pretreated (1.0–5.0 kV/cm electric field strength, frequency of 20 Hz, pulse width 15 μs, >1000 pulses), achieving a cell disintegration index Z ranging from 0.1 to 0.8. Drying experiments of PEF-treated orange peels were carried out at mild temperatures (40–70 °C). The moisture diffusion coefficients D_eff and the air-drying energy consumed of all samples were estimated and compared. At low drying temperatures (<55 °C), PEF treatment led to increased effective moisture diffusivity D_eff by up to 25%, resulting in reduced drying time and energy savings up to 15 MJ/kg, compared to untreated samples. More intense PEF conditions resulted in higher drying rates, while, for temperatures > 60 °C, there was no significant effect on the moisture diffusion coefficient for PEF pretreated samples. PEF treatment did not lead to changes in the antioxidant activity of dried samples. The results showed the potential of PEF pretreatment to accelerate the drying process of orange peel waste minimizing energy consumption. Full article

This study explores the feasibility of constructing a microwave kiln for artisanal ceramics using accessible materials and homemade susceptors. Two modified microwave ovens (18 L and 50 L) were equipped with insulation and susceptors to achieve temperatures up to 1280 °C. Susceptors were fabricated from silicon carbide (SiC) and magnetite (Fe₃O₄) powders via microwave-assisted reactive sintering. Magnetite-poor susceptors (SiC/Fe₃O₄ > 2 by weight) demonstrated excellent durability, maintaining stable thermal performance over multiple cycles. In contrast, magnetite-rich susceptors (SiC/Fe₃O₄ ∼ 1) exhibited high initial efficiency and the ability to control redox conditions but degraded significantly after 10–15 cycles due to partial melting. The microwave kiln achieved significant time savings, completing the ramp-up of the firing cycles in 1 h, compared to 8–10 h in conventional kilns. Energy consumption per litre was comparable to large electric kilns but significantly lower than small ones. The fired ceramics, including porcelain and earthenware, showed excellent mechanical and aesthetic qualities, with glazes performing well even at lower temperatures than recommended. The study highlights the advantages of microwave heating, such as faster processing, energy efficiency, and the ability to control redox conditions, which mimic traditional gas-fired kilns. The developed susceptors are cost-effective and easy to manufacture, making this approach accessible to craftspeople and amateurs. While magnetite-rich susceptors enable redox control, their limited lifespan requires further optimisation. This work demonstrates the potential of microwave kilns for artisanal ceramics, offering flexibility, efficiency, and quality comparable to traditional methods, with promising applications for unique or small-scale production. Future research should focus on refining susceptors durability and validating redox control effects on ceramic glazes. Full article

Buildings consume energy and are responsible for a significant portion of greenhouse gas emissions in Australia. Increased standards are being set for building thermal performance. Given the rising demand for energy-efficient housing solutions, this work explores the potential application of innovative technologies to enhance the thermal performance. Since modular construction is attracting popularity owing to numerous advantages, including its efficiency and cost-effectiveness, optimising the thermal performance is a way to further improve its popularity, particularly in diverse Australian climates. Smart materials are unique and have desirable properties when subjected to a change in the external environment. Integration of smart insulation materials in prefabricated buildings forecasts a potential to expand the horizon of thermal performance of prefabricated buildings and subsequently lead towards an enhanced energy performance. This work investigates the effects of aerogel, phase change materials (PCMs), and electrochromic glazing. To assess their potential to improve the thermal performance of a modular house, building energy performance simulations were conducted for three different climatic conditions in Australia. Individual implementation of innovative technologies and their combined effects were also quantified. The combination of the three innovative technologies has yielded total annual energy savings of 15.6%, 11.2%, and 6.1% for Melbourne, Perth, and Brisbane, respectively. Full article

Fouling has been a major concern in membrane processing, requiring frequent cleaning, increasing the time of processing, and reducing the lifespan of membranes. As a strategy to improve membrane filtration processes, our study investigates the impact of nanobubbles (NBs) on the whey ultrafiltration (UF) process and provides insights into the resulting changes in permeation flux, concentration factor, composition, particle charge and size, viscosity, and protein secondary structures. NBs led to significantly enhanced permeation flux up to 60 min (p < 0.05), leading to a higher concentration factor with time, as indicated at 120 min compared to the control. There was a significant increase in protein and total solids concentrations (33 ± 10% and 28 ± 5%) in the final retentate at 120 min for NB-treated cheese whey (NBW) as compared to the control (p < 0.05). While particle size is relatively unchanged with and without NB treatment, increased viscosity in NBW is caused by the increased concentration factors achieved with higher flux for the NBW by the end of UF. FTIR and SDS-PAGE reveal no significant alterations in whey protein secondary structures and fractions, respectively. Overall, membrane efficiency was enhanced by significantly increasing peak flux and concentration factor (34 ± 5% and 40 ± 4%) for NBW compared to CW. Our study presents an innovative approach to reach the targeted total solids/protein for cheese whey concentration in significantly less processing time (28.27% ± 2.33 reduction), with potential energy savings. Therefore, nanobubble technology shows promising potential to improve membrane filtration in the dairy industry with higher permeation flux, reduced fouling, and improved membrane processing efficiency. Full article

Sewage sludge management remains a critical environmental and economic challenge due to high volumes, transport requirements, and landfill restrictions. Pyrolysis offers a promising alternative by reducing sludge mass and producing biochar with potential for soil fertility enhancement and long-term carbon sequestration. This study integrates physicochemical characterization of Portuguese wastewater treatment plant sludges with experimental drying data and literature-based pyrolysis yields to estimate mass reduction, energy requirements, and carbon retention. A simplified life cycle comparison highlights potential reductions in greenhouse gas emissions, human toxicity, and land use, while also suggesting significant economic savings from avoided transport and landfill disposal. Full article

The energy sector is currently under enormous transition, moving from fossil fuels to renewable energies and integrating energy efficiency measures. This transition can hold opportunities for new and innovative energy systems. This study presents an energetic and economic assessment of an innovative tri-generation unit working with a two-phase thermodynamic cycle. The tri-generation unit is driven by heat and is capable of providing heat at lower level, cold, and electricity to end users. The use cases—residential, day-use offices, commercial retail, and manufacturing industry—are integrated in a dynamic simulation model, indicating the operation mode of the unit. The results show that the tri-generation unit is able to provide heat and cold with an Energy Utilization Factor of 35% to 68%, depending on the use case. Solar thermal has a limited to potential to supply the unit with heat, due to the high temperature of 180 °C and the required unit operation at nighttime. The economic comparison indicates that the driving heat must be as low as possible and that savings through self-consumption is most relevant. Full article

As an important basic material for modern industry, the performance and production energy consumption of medium and thick plates have an important impact on engineering quality, industry technological progress and economic benefits. However, traditional process parameter adjustment relies on manual experience, which is difficult to meet the dual needs of efficient production and energy conservation and emission reduction. This paper focuses on the energy consumption optimization problem in the production process of medium and thick plates. Under the premise of meeting the mechanical property constraints, a data-driven process parameter optimization method is proposed. Firstly, a comprehensive energy consumption prediction model for medium and thick plates is established. Secondly, based on historical data and knowledge, a data set covering chemical composition, physical parameters and process parameters is constructed, and a mechanical property prediction model is developed to achieve the prediction of actual performance. On this basis, the energy consumption minimization problem that satisfies mechanical property constraints is modeled as a constrained optimization problem, and a data-inspired initialized particle swarm optimization algorithm is designed to improve the global search capability and local convergence efficiency. Experimental results confirm that the proposed model provides more stable and accurate prediction of mechanical properties than conventional Random Forest and XGBoost models. Furthermore, compared with standard PSO, GA, SA, and ACO algorithms, the data-inspired initialized particle swarm optimization shows faster convergence and better energy-saving performance, demonstrating the overall effectiveness and practical potential of the proposed framework. Full article

One of the main processes of shoe-sole production is injection molding, in which the desired shape is achieved by injecting a heated thermoplastic polymer in a highly plastic state under high pressure into the mold cavity. The study shows the energy analysis and share of electricity costs in the process of injection into the mold cavity to achieve the desired shape and describe the production process of PVC. Although fairly accurate energy-consumption comparison in the injection-molding process is almost unachievable since it depends on the type of machine, feedstock and molded product, it is still crucial for optimizing energy efficiency. The analysis showed that the basic process requirements of shoe-sole injection molding requires electrical energy in the amount of 5.76 kWh per pair of produced soles, while an increase in energy efficiency and environmental pollution reduction can be achieved by the return of process condensate, with a return share of Y = 80%. The price of electricity per pair of manufactured shoe soles is calculated, and given the fluctuations regarding fossil fuel market, the heat recovery potential leading to fossil-fuel savings in PVC production is analyzed. Full article

Previous research shows that thin-ply composite materials offer superior static and fatigue characteristics to standard laminates used in aviation. Therefore, they are expected to be capable of significantly contributing to a mass reduction needed to improve the energy-efficiency of future aircraft. However, so far, thin-ply composites have only been employed in special applications. Quantitative full-scale assessments of the benefits on the level of global aircraft structures are missing. This study employs a parametric, finite element-based tool chain with a fully-stressed design methodology to investigate potential benefits from the use of thin plies, which may result from increased strength, an extended design freedom and stability considerations, in a generic wing structure of a conceptual medium-range aircraft in order to reduce this research gap. The methodology is validated using an academic test case. Naturally, mass reductions from strength enhancements are limited by buckling constraints in thin-walled structures. However, for the wing examined in this study, an increase in strength of 10% still yields up to a 7.9% reduction in global wing mass, while an increase of 20% results in mass savings of up to 13.4%. The use of thin-ply composites may allow for reducing minimum wall thickness constraints. Associated mass savings of up to 3.1% found in this study on global wing level when alleviating the requirement from 2.4 $\mathrm{m}$$\mathrm{m}$ to 1.2 $\mathrm{m}$$\mathrm{m}$ are, however, restricted to rib mass and may better be achieved by different means such as topology optimisation. In contrast, mass penalties from the application of a simplified manufacturing constraint are reduced significantly from beyond 10% on global wing level for plies with a thickness of 0.175 $\mathrm{m}$$\mathrm{m}$ to approximately 1.5% with a ply thickness of 0.05 $\mathrm{m}$$\mathrm{m}$. Full article

This paper investigates how the existing pellet plant of the Energy Community of Karditsa (ESEK) can be leveraged to strengthen RESCoop operations by integrating a variety of biomass feedstocks as (i) urban residual biomass, (ii) forest residues, and (iii) alternative sources such as spent coffee grounds (SCGs). The RESCoop envisions an extended role as an Energy Service Company (ESCO) by installing and operating biomass boilers in local public buildings. The paper provides an overview of the technical and business support that was provided to the RESCoop for the development of such new business activities and aggregates the lessons learned from engaging the rural society towards sustainable bioenergy production. More specifically, the study covers the logistical aspects of the new RESCoop value chains, including availability, collection, transportation, and processing of the feedstocks along with their costs. A base case scenario investigates the feasibility of installing biomass boilers in municipal buildings through a detailed financial viability study examining capital and operational expenses, revenues, and key financial indicators. Further, the environmental and socio-economic impacts of the new RESCoop activities are evaluated in terms of CO₂ equivalent savings compared to fossil fuel solutions and new job creation, respectively. This detailed analysis highlights the potential for sustainable bioenergy integration and provides valuable insights for similar initiatives aiming to diversify and enhance sustainable energy practices in local communities. Full article

The construction industry faces urgent challenges in reducing its carbon footprint, particularly in geotechnical engineering where conventional methods often involve high-emission materials. Artificial Ground Freezing (AGF) presents a sustainable, material-saving alternative for stabilizing water-rich strata, but its efficiency relies on accurate characterization of frozen soil behavior under in situ conditions. This study advances the understanding of AGF’s sustainability by investigating the directional shear behavior of pressurized frozen saturated medium sand (Fujian ISO standard sand) at −10 °C using a novel hollow cylinder apparatus. Through systematic testing under varying mean principal stresses (p = 0.5–6 MPa) with fixed intermediate principal stress coefficient (b = 0.5) and principal stress direction (α = 30°), we demonstrate that pressurized freezing creates a fundamentally different soil–ice composite compared to conventional unpressurized freezing. Key findings reveal (1) a linear strength increase described by the failure criterion q_f = 1.17p + 3.77 (R² = 0.98) without pressure melting effects within the tested range; (2) a distinct brittle-to-ductile transition at p ≈ 4 MPa, with associated failure mode changes from localized shear bands to homogeneous plastic flow; (3) a stable peak stress ratio (q/p ≈ 1.8) for p ≥ 4 MPa. These findings enable more reliable and potentially less conservative frozen wall design, directly contributing to reduced energy consumption in AGF operations. The research provides mechanical insights and practical parameters that enhance AGF’s viability as a low-carbon ground stabilization technology, supporting the construction industry’s transition toward sustainable underground development. Full article

To achieve net-zero targets globally, industrial decarbonisation is a major priority. This paper examines lost energy resources in a wastewater treatment plant (WWTP) and the deployment of novel wastewater heat recovery (WWHR) technology in the food and beverage processing industry. Four industrial WWTPs were monitored in Ireland to quantify the available embedded energy. Post monitoring, WWHR technology was developed to be integrated within existing infrastructure without compromising the primary function, and evaluated in real operating conditions. On average, 1.11–2.55 GWh/a of embedded energy was measured within the wastewater. The direct WWHR pilot plant resulted in a projected recovery rate of 10.89 MWh/a, leading to substantial economic savings and emission reductions. Incorporating a water-to-water heat pump incurred energy savings of 13.5 MWh/a. Nationally, the energy recovery potential was assessed to be 82.1 GWh/a in Ireland and 476.9 GWh/a in the UK. A large proportion of the energy embedded in this wastewater remains to be recovered and, based on the monitoring campaign, could amount to 118.5 TWh/a and 20.4 TWh/a for the UK and Ireland, respectively. WWHR could serve a prominent role in increasing operational energy efficiency of manufacturing processes by enacting energy, economic and emission savings, thus leading to industrial decarbonisation. Full article

Integration of renewable energy sources into existing residential and communal district heating systems requires technical adjustments and corrections. Measures aimed at reducing heat consumption at the points of delivery have a similar impact. This study aims, through simplified partial models (in heating mode), to present the relationships between these modifications and their potential effects on operational problems and deficiencies. The main parameters assessed in the design and correction of systems are temperature differentials, derived flow rates, pumping work, and control methods. Within the chain of heat source–primary distribution–secondary distribution–consumers, the analysis focuses on secondary circuits with consumers. A simplified multi-building network model was used to compare static and dynamic control strategies under temperature regimes of 70/50 °C, 60/40 °C, and 40/30 °C. The results show that dynamic control based on variable-frequency pumps, weather-compensated supply regulation, and optimized temperature differences between supply and return lines (ΔT) reduces pumping energy by 30–40% and increases heat delivery efficiency by up to 10%. A significant reduction in CO₂ emissions is also observed due to decreased pumping work, reduced heat losses in the distribution network, and the integration of renewable energy sources. The savings depend on the type and extent of RES utilization. The implementation of dynamic control in these systems significantly improves exergy efficiency, operational stability, and the potential for low-temperature operation, thus providing a practical framework for the modernization of district heating networks. Full article