SOx and NOx emissions originating from the combustion of fuels during the operation of industrial boilers are one of the primary contributors to regional and local air pollution, which have major effects on human well-being and ecosystems. As governmental bodies attempt to regulate and enforce emission norms, the industries operating the boilers are presented with an opportunity to optimise their fuel mix configurations to achieve a reduction in SOx, NOx, and CO2 emissions while ensuring the financial sustainability of plant operations. In this study, a System Dynamic simulation model is constructed from the perspective of an individual plant to facilitate the analysis of SOx, NOx, and CO2 emissions and the expenditure incurred through energy use and pollution control systems under different fuel-mix configurations, market conditions, and policy scenarios. The model facilitates the identification of alternative fuel-mix configurations to replace existing single-fuel firing systems whil... [more]

The evaluation and analysis of the procedures for determining the dependability of WF wind farm equipment employed in a few publications are this article’s main problems. The publications chosen for review specifically mention investigations into the dependability of WF wind farm machinery. The following topics were the authors’ main areas of analysis: description and review of the techniques used to represent how technical items operate and the selection of the weight of the theoretical ideas of reliability that were used to gauge the dependability of the wind farm equipment under study. The authors of the studied works set out to address a number of significant problems pertaining to the modernization of the management of the WF equipment renewal process. The subjects of the studied works suggest that the established models of the technical object’s operational process are particularly significant in both the theory and practice of the reliability of technical objects. Using Kolmogor... [more]

There are several massive deposits around the world with different geological characteristics. Thus, different mining methods and strategies are applied based on the particularity of each method and mine experience. Particularly, in this work, we review and summarize the underground exploitation of some world-class base metal deposits based on Poland and Chilean experiences. Here, the main geological and mining parameters of Poland and Chilean mines applied in massive deposits are reported and analyzed. In Poland, mainly room and pillar methods (and variants) have been applied in massive deposits. Here, back-filling is required to maintain the mine’s stability due to the large deposit size and open areas. In Chile, the block caving method is commonly used in massive underground deposits where less development is required. Here, the cave is naturally filled with broken material and a large subsidence zone is generated. In this review, it has been observed that different underground meth... [more]

This article focuses on residents’ perception of smart and sustainable transport in the city, and on local and central government policy towards sustainable and smart mobility transition, using Lodz, a city in Poland, as an example. Its purpose is to examine residents’ opinions about the development of a sustainable, intelligent transportation system (ITS) for the city and learn about their awareness of the benefits of ITS development. The article discusses findings of a survey conducted in 2022 on a sample of 250 residents of Lodz. The data obtained from the survey were subjected to statistical analyses: correlation, exploratory factor analysis, and linear regression. The results suggest there is a correlation between the assessment of a sustainable and intelligent transportation system and residents’ perception of benefits that it offers. In addition, government, regional, and municipal transportation strategies were qualitatively analysed to identify the preferred trends featuring i... [more]

The high penetration of electric vehicles (EVs) will burden the existing power delivery infrastructure if their charging and discharging are not adequately coordinated. Dynamic pricing is a special form of demand response that can encourage EV owners to participate in scheduling programs. Therefore, EV charging and discharging scheduling and its dynamic pricing model are important fields of study. Many researchers have focused on artificial intelligence-based EV charging demand forecasting and scheduling models and suggested that artificial intelligence techniques perform better than conventional optimization methods such as linear, exponential, and multinomial logit models. However, only a few research studies focused on EV discharging scheduling (i.e., vehicle-to-grid, V2G) because the concept of EV discharging electricity back to the power grid is relatively new and evolving. Therefore, a review of existing EV charging and discharging-related studies is needed to understand the rese... [more]

This paper investigates magnet demagnetization characteristics of the modular permanent magnet machine. The influence of flux gaps on magnet flux density, losses distribution, torque and demagnetization are analyzed for different operating conditions. The magnet demagnetizations caused by three sources, such as the PM field, the armature field, and the magnet temperature rise, are individually investigated using the frozen permeability method. Furthermore, coupled electromagnetic (EM)-thermal modelling is also adopted in this paper to fully reveal the advantages of the modular machine in improving machine EM performances. This is essential due to the temperature-dependent properties of the machines, such as the magnet remanence, coercivity, and copper resistivity. For comparison propose, the EM performances with a particular focus on the demagnetization withstand capability for both the modular and non-modular machines are investigated based on the EM-thermal coupling. It is found that... [more]

To meet future goals of energy sustainability and carbon neutrality, disruptive changes to the current energy mix will be required, and it is expected that renewable fuels, such as hydrotreated vegetable oil (HVO), will play a significant role. To determine how these fuels can transition from pilot scale to the commercial marketplace, extensive research remains needed within the transportation sector. It is well-known that cold engine thermal states, which represent an inevitable portion of a vehicle journey, have significant drawbacks, such as increased incomplete combustion emissions and higher fuel consumption. In view of a more widespread HVO utilization, it is crucial to evaluate its performance under these conditions. In the literature, detailed studies upon these topics are rarely found, especially when HVO is dealt with. Consequently, the aim of this study is to investigate performance and exhaust pollutant emissions of a compression ignition engine running on either regular (p... [more]

Predictive current control (PCC) is an advanced control strategy for permanent magnet synchronous motors (PMSM). When the motor drive system is undisturbed, predictive current control exhibits a good dynamic response speed and steady−state performance, but the conventional PCC control performance of PMSM that depends on the motor body model is vulnerable to parameter perturbation. Aiming at this problem, an improved model−free predictive current control (IMFPCC) strategy based on a high−gain disturbance observer (HGDO) is proposed in this paper. The proposed strategy is introduced with the idea of model−free control, relying only on the system input and output to build an ultra−local current prediction model, which gets rid of the constraints of the motor body parameters. In the paper, the ultra−local structure is optimized by comparing and analyzing the equation of the state of the classical ultra−local structure and PMSM system. The system’s current state variables are incorporated i... [more]

Current and future trends in the world population lead to the continuous growth of municipal waste volumes. Only in the EU-28 approx. 86 million tons of biowaste is produced yearly. On the other hand, the recent energy crisis calls for a fast transition towards more local and renewable energy sources. Most of this stream could be recycled through anaerobic digestion (AD) to produce energy and high-quality fertilizers. This paper presents a balance of dry anaerobic digestion of municipal biowaste based on three years of system monitoring in an industrial-scale AD plant. The results indicate that the average biogas production rate of 120 Nm3/ton of fresh waste can be achieved. Biogas utilization in combined heat and power (CHP) units leads to an overall positive energy balance at significantly reduced CO2 emissions. The overall CO2 emission reduction of 25.3−26.6% was achieved, considering that biogas utilization is environmentally neutral. Moreover, biowaste conversion allows digestate... [more]

Using high charge dilution low temperature combustion (LTC) strategies in a diesel engine offers low emissions of nitrogen oxides (NOx). These strategies are limited to part-load conditions and involve high levels of charge dilution, typically achieved through the use of recirculated exhaust gases (EGR). The slow response of the gas handling system, compared to load demand and fuelling, can lead to conditions where dilution levels are higher or lower than expected, impacting emissions and combustion stability. This article reports on the sensitivity of high-dilution LTC to variations in EGR rate and fuel injection timing. Impacts on engine efficiency, combustion stability and emissions are assessed in a single-cylinder engine and compared to in-cylinder flame temperatures measured using a borescope-based two-colour pyrometer. The work focuses on low-load conditions (300 kPa gross indicated mean effective pressure) and includes an EGR sweep from conventional diesel mode to high-dilution... [more]

Nuclear magnetic resonance (NMR) is widely used to characterize the pore structure of rock. The nanoscale pores and fractures are well developed in a shale gas reservoir. The closure of nanopores caused by the increase in effective stress during the gas production process could induce stress sensitivity in shale nanopores, which has a great impact on the single-well productivity in the middle−late development stage. In this paper, shale samples from the Longmaxi Formation were taken to investigate the nanopore stress sensitivity via an NMR method. Samples with different degrees of pore and fracture development were selected and NMR experiments under different effective stress conditions were carried out. The results show that: (1) As the effective stress increases, the pore space in shale is continuously compressed, and the cumulative pore volume of shale decreases; (2) There is a more pronounced decrease in the cumulative pore volume of samples containing larger pores with the increas... [more]

The use of energy from waste can be a key means of reducing the consumption of fossil fuels and thus reduction of greenhouse gas emissions. Waste energy can be a worthy alternative to conventional energy sources in construction. This paper presents data on energy consumption for the preparation of domestic hot water in residential buildings. A review of the literature sources and inventions in the area of waste energy recovery from grey water was carried out. It also presents the results of research on prototypes of devices used to receive energy deposited in wastewater, published in recent years. The benefits of using drain water heat recovery systems for preheating utility water in residential buildings are presented. An analysis of technical solutions for grey water energy collection units was made, revealing their advantages and disadvantages. Great importance was attached to the review of patent sources as well as devices available on the market. According to the authors, the resu... [more]

It is difficult to measure the concentrated solar radiation flux (CSRF) inside a cavity receiver directly due to the complex geometry of cavity receivers. At present, most reports measure the CSRF at the aperture plane (generally coinciding with the focal plane of solar concentrators) of the cavity receiver instead of at the absorber wall, which would result in serious aberration because of the obvious difference in configuration between the aperture plane and the absorber wall. To obtain the CSRF at the absorber wall with complex geometry, the vector characteristics (consisting of both directional distributions and spatial distributions) of the CSRF at the focal plane were measured using developed double water-cooled Lambertian targets together with a CCD (charge-coupled device) camera. Then the CSRF images at the absorber wall of a hemisphere cavity receiver were carried out by applying MCRTM (Monte Carlo ray-tracing method) in combination with the measured vector results of the CSRF... [more]

In the case of cogeneration, the allocation of operation costs has a particularity specific to the joint production of heat and electricity from the same primary energy source. The cost allocation is also influenced by the demand conditions faced by the joint products, and prices must be sufficient for both products to remain profitable and competitive with other power generation alternatives in the respective markets. Therefore, the choice of cost allocation methodology is influenced by market conditions. The paper presents an algorithm for determining the prices of energy and heat produced in cogeneration according to demand and market conditions. The economic market method was extended with an algorithm based on duality theory for verifying allocation methods and establishing forecasting strategies. An example is provided for a cogeneration plant (1.287 MWe; 5.386 MWth) based on ORC (Organic Rankine Cycle) technology and biomass fuel. The fuel cost has a major influence on the total... [more]

Presently, among the global ocean energy technologies, the most conventional one is the wave energy power generation device based on the oscillating water column (OWC) wave energy converter. Given the fluctuation and randomness of waves and the complexity of the current power grid, the dynamic response of grid connections must be considered. Furthermore, considering the characteristics of the wave energy converter, this paper proposed an adaptive intelligent controller (AIC) for the permanent magnet synchronous generator (PMSG) in an OWC. The proposed controller includes a grey predictor, a recurrent wavelet-based Elman neural network (RWENN), and an adaptive critical network (ACN) to improve the stability of OWC power generation. This scheme can increase the maximum power output and improve dynamic performance when a transient occurs under the operating conditions of random wave changes. The proposed AIC for the PMSG based on OWC has a faster response speed, a smaller overshoot, and b... [more]

The traditional ampere-hour (Ah) integration method ignores the influence of battery health (SOH) and considers that the battery capacity will not change over time. To solve the above problem, we proposed a joint SOH-SOC estimation model based on the GWO-BP neural network to optimize the Ah integration method. The method completed SOH estimation through the GWO-BP neural network and introduced SOH into the Ah integration method to correct battery capacity and improve the accuracy of state of charge (SOC) estimation. In addition, the method also predicted the SOH of the battery, so the driver could have a clearer understanding of the battery aging level. In this paper, the stability of the joint SOH-SOC estimation model was verified by using different battery data from different sources. Comparative experimental results showed that the estimation error of the joint SOH-SOC estimation model could be stabilized within 5%, which was smaller compared with the traditional ampere integration... [more]

In order to explore the hydrogen source term characteristics under severe accidents of marine pressurized water reactors (PWR) and effectively assess the hydrogen risk, the best estimation program SCDAP/RELAP5/MOD3.2 is used to establish the marine reactor severe accident analysis model. Based on the Latin Hypercube sampling (LHS) method and the Wilks sampling theory, a set of methods for the uncertainty analysis of severe accidents is developed. This method can be applied to the uncertainty and sensitivity analysis of different target parameters. The phenomenon identification and ranking table (PIRT) under the severe accident induced by the break are established, and 14 uncertain parameters are selected as input variables. The established PIRT fills the gap in the uncertainty and sensitivity analysis of severe accidents of marine reactors and provides a reference for subsequent research. The quantitative uncertainty analysis of the calculation results is carried out, and the uncertain... [more]

Electric Vehicles are becoming increasingly popular due to their environment friendly operation. As the demand for electric vehicles increases, it has become quite important to explore their charging strategies. Since charging and traction do not normally occur simultaneously and the power electronics converters for both operations have some similarities, the practice of integrating both charging and traction systems is becoming popular. These types of chargers are termed ‘Integrated Chargers’. The aim of this paper is to review the available literature on the integrated chargers and present a critical analysis of the pros and cons of different integrated charging architectures. Integrated chargers for electric vehicles with three-phase permanent magnet synchronous machines, multi-phase machines and switched reluctance machines were compared. The challenges with the published integrated chargers and the future aspect of the work were been discussed.

Polymer electrolyte membrane fuel cells are considered one of the alternatives to fossil energy sources. The slow kinetics of the oxygen reduction reaction (ORR) at the cathode and the high price of Pt-based catalysts remain one of the key challenges for the commercial viability of proton exchange membrane fuel cells. However, their high cost and susceptibility to poisoning severely limit their use for large-scale commercial applications in fuel cells. Heteroatom-doped porous carbon has attracted extensive attention from scientists due to its advantages such as high specific surface area and the properties conferred by heteroatom doping. On the one hand, we discuss a variety of current methods for the preparation of heteroatom-doped porous carbons, including the template method and the activation method. On the other hand, we discuss the application of heteroatom-doped porous carbon in Pt catalysts, transition metal catalysts and metal-free catalysts. Finally, we also present the pre-e... [more]

The key to ensuring the economic feasibility of EGS mainly includes two points. On the one hand, it is necessary to ensure the connectivity of the artificial fracture network; on the other hand, it is necessary to determine the most efficient geothermal energy exploitation mode. Most previous studies have only focused on one of the points. To restitute the entire geothermal energy development process, the two parts should be combined to conduct research. In this study, a random fractured medium model was established based on the TOUGH2-BIOT simulation program and the whole process of reservoir stimulation was analyzed. According to the results of reservoir stimulation, different geothermal energy exploitation schemes are set up, and the heat transfer efficiency of the conventional double vertical wells, the horizontal wells, and the double-pipe heat exchange system are comparatively analyzed. The results show that reservoir reconstruction is mainly divided into three stages: In the fir... [more]

This study aims at investigating the improvement in the thermal performance of energy storage for a hydronic system when it is equipped with evacuated tubes integrated within a hot water tank. The PCM shell in the bottom section is thicker than at the top to maintain a uniform, minimal water temperature difference of 5 °C between the top and bottom sections of the hot water tank. The thermal performance of the system was analyzed in diverse months when the ambient temperature fluctuated. The results have revealed that the thermal performance in December, March, and June was 80%, 81%, and 84%, respectively, meaning that the thermal performance is optimal in warm weather. The results confirmed that the system had boosted the presence of hot water throughout the whole day, including the time of the sun’s absence, due to the release of stored PCM latent heat. The designed system solves the overheating problem and expands the availability of hot water through the cold weather. The system is... [more]

Driven by the excessive consumption of fossil resources and environmental pollution concerns, a large amount of biorefinery research efforts have been made for converting lignocellulosic biomass into fuels and chemicals. Recently, a strategy termed “lignin-first,” which allows for realizing high-yield and high-selectivity aromatic monomers, is regarded as one of the best prospective strategies. This review summarizes recent research advances in lignin-first biorefinery, starting from the raw lignocellulose through lignin-first processing and moving to downstream processing pathways for intermediate compounds. In particular, for the core purpose of producing liquid fuels, the corresponding downstream processing strategies are discussed in detail. These are based on the structural properties of the intermediates derived from lignin-first biorefinery, including the catalytic conversion of lignin and its derivatives (aqueous phase system and pyrolysis system) and the cascade utilization of... [more]

With the increasing constraints on energy and resource markets and the non-decreasing trend in energy demand, the need for relevant clean energy generation and storage solutions is growing and is gradually reaching the individual home. However, small-scale energy storage is still an expensive investment in 2022 and the risk/reward ratio is not yet attractive enough for individual homeowners. One solution is for homeowners not to store excess clean energy individually but to produce hydrogen for mutual use. In this paper, a collective production of hydrogen for a daily filling of a bus is considered. Following our previous work on the subject, the investigation consists of finding an optimal buy/sell rule to the grid, and the use of the energy with an additional objective: mobility. The dominant technique in the energy community is reinforcement learning, which however is difficult to use when the learning data is limited, as in our study. We chose a less data-intensive and yet technica... [more]

The performance degradation issue caused by carbon deposition has limited the commercial application of natural-gas-fueled solid oxide fuel cells. Most previous corresponding studies are based on thermodynamic equilibrium analyses, while long-term transient evaluation work is lacking. Therefore, a transient multi-physics numerical model is developed in present work. The corresponding long-term performance degradation evaluation is then conducted. The results show that, for a direct internal reforming solid oxide fuel cell, the increase in carbon deposition and deterioration of performance degradation were concentrated in the first 180 days of steady−state operation and slowed down at the later stage. The electrode inlet rapidly developed a high concentration of carbon deposition after 180 days of steady−state operation. The deposited carbon deteriorated the gas transport and decayed reaction activity within the porous electrode, eventually inducing a deactivation zone with 0 current de... [more]

The application of residential rooftop PV systems increased significantly in the last 10 years in many countries and became a major source of clean energy in dwellings besides traditional solar hot water technology. To optimise the performance of these green energy systems, the incorporation of PV/thermal hybrid systems is a future option for sustainable residential building designs. In this work, a novel design of PV/Thermal (PVT) hybrid panels, using heat pipe technology, is proposed with the aim of fulfilling the hot water and electricity demand of a house in Sydney. The heat pipe system is integrated into a traditional PV panel to transfer the heat stored within the PV panel material to a header that is connected to the household hot water cycle. A preliminary analysis of the test results for the proposed PVT system design under different weather conditions in Sydney is conducted, where the transient variation of the output water temperature as well as power production is investiga... [more]