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Degradation is an inevitable companion in the operation of solid oxide fuel cell (SOFC) systems since it directly deteriorates the reliability of the system's operation and the system's durability. Both are seen as barriers that limit the extensive commercial use of SOFC systems. Therefore, diagnosis and prognosis are valuable tools that can contribute to raising the reliability of the system operation, efficient health management, increased durability and implementation of predictive maintenance techniques. Remaining useful life (RUL) prediction has been extensively studied in many areas like batteries and proton-exchange membrane fuel cell (PEM) systems, and a range of different approaches has been proposed. On the other hand, results available in the domain of SOFC systems are still relatively limited. Moreover, methods relying on detailed process models and models of degradation turned out to have limited applicability for in-field applications. Therefore, in this paper, we propose an effective, data-driven approach to predicting RUL where the trend of the health index is modeled by an adaptive linear model, which is updated at all times during the system operation. This allows for a closed-form solution of the probability distribution of the RUL, which is the main novelty of this paper. Such a solution requires no computational load and is as such very convenient for the application in ordinary low-cost control systems. The performance of the approach is demonstrated first on the simulated case studies and then on the data obtained from a long-term experiment on a laboratory SOFC system. From the tests conducted so far, it turns out that the quality of the RUL prediction is usually rather low at the beginning of the system operation, but then gradually improves while the system is approaching the end-of-life (EOL), making it a viable tool for prognosis. [ABSTRACT FROM AUTHOR]

Solid oxide fuel cell power generation systems are devices that utilize solid electrolytes to transfer ions for electrochemical energy conversion. A wide range of gases can be used as fuel gas, including hydrogen, natural gas, and carbon monoxide. Considering the high cost of pure hydrogen, hydrogen production from natural gas reforming has become a hot research area. In this study, the 4F-LCA method was employed to construct an evaluation framework, with a particular emphasis on the cost analysis of solid oxide fuel cell power generation systems, and uses a bottom-up approach to build a system economic analysis model to visualize the major costs involved in the system. An economic benefit analysis and sensitivity analysis were carried out for the 2 kW natural gas solid oxide fuel cell as a case by taking the financial net present value (NPV), internal rate of return (IRR) and payback period into account. In this study, the investment cost and payback period of a 2 kW solid oxide fuel cell system are obtained, which can provide a reference for the project construction and operation of solid oxide fuel cell systems. [ABSTRACT FROM AUTHOR]

Ejector-based proton exchange membrane fuel cells (PEMFCs) are of great interest due to their simplicity and feasibility. Thus, proton exchange membrane fuel cells are considered the most suitable technology for in-vehicle systems, industrial applications, etc. Despite the passive characteristics of the ejector, active control of the hydrogen supply system is needed to ensure sufficient hydrogen, maintain the stack pressure, and ensure effective entrainment. In this research, a novel semi-empirical model is proposed to accurately predict the entrainment performance of the ejector with an 80 kW fuel cell system. According to the precise semi-empirical model, the hydrogen supply system and the anode channel are modeled. Then, a fuzzy logic controller (FLC) is developed to supply sufficient and adequate gas flow and maintain the rapid dynamic response. Compared to the conventional proportional–integral–derivative controller, the fuzzy logic controller could reduce the anode pressure variability by 5% during a stepped case and 2% during a dynamic case. [ABSTRACT FROM AUTHOR]

In road transport, varying fuel flow rates make it hard to maintain a consistent water ratio in non-surfactant emulsion fuels using the Real-Time Non-Surfactant Emulsion Fuel Supply System (RTES). Thus, it becomes more reasonable to establish an appropriate range of water content tailored to a road condition. Therefore, this study aims to evaluate fuel consumption and exhaust emissions of non-surfactant emulsion fuel in light-duty trucks equipped with RTES, focusing specifically on urban conditions. On-road testing and 300-s idling tests were used as the urban conditions to compare diesel with non-surfactant Water-in-Diesel Emulsion (WiDE) fuel with water percentages from low to high concentrations of water, namely WiDE low%, WiDE med%, and WiDE high%. During idling tests, all emulsion variants reduce fuel consumption. WiDE high% exhibits the most substantial NOx reduction of 9.2%. On-road testing reveals comparable WiDE and diesel fuel consumption, despite the RTES increased electrical load. WiDE high% shows an increment for NOx and CO emissions by 11.71% and 202.19%. In conclusion, a 7.4% to 21.1% water content range was suggested for non-surfactant emulsion fuel in urban road conditions. [ABSTRACT FROM AUTHOR]

The Chebyshev Rational Approximation Method (CRAM) has become one of the dominant methods for solving the Bateman equations for nuclear fuel depletion analysis. Since its introduction over a decade ago, several improvements have been made to CRAM improving its accuracy and reducing its run time. We analyzed its run time using two previously published methods for solving the CRAM system of equations, direct matrix inversion (DMI) and sparse Gaussian elimination (SGE), for depletion systems of varying numbers of nuclides to see how the two methods perform relative to one another. In addition to these two methods, we introduced the Gauss-Seidel (GS) method for solving the CRAM system of equations and compared its performance relative to DMI and SGE for depletion systems with varying numbers of nuclides. We demonstrated that for practical purposes, GS is faster than SGE and DMI and achieves a practical level of accuracy. All testing was performed using the CRAM implementation in the Griffin reactor physics analysis application. [ABSTRACT FROM AUTHOR]

The objective of this study is to experimentally investigate cyclic combustion variabilities in a four-cylinder automotive common-rail diesel engine at different engine speeds, including 1600, 1800, and 2000 rpm. The investigation evaluates the relative effects of speeds on the cyclic discrepancies in a modern diesel engine. 1000 cyclic combustion data including peak combustion pressure (Pmax), peak pressure rise rate (PRRmax) and indicated mean effective pressure (IMEP) were analyzed in the experimental study. It was found that the cyclic fluctuations in combustion pressure in each engine speed were minor, but detailed comparison of Pmax, PRRmax, and IMEP revealed noteworthy differences in the studied cycles. Higher cylinder temperatures and air movement improved combustion. Therefore, not only coefficient of variations COVs of IMEP and Pmax decreased, but also mean Pmax and PRRmax increased with increasing engine speed. On the other hand, the friction effect of the intake air reduced the positive effects of improved combustion with increasing engine speed and as a result mean IMEP decreased. COVs of IMEP and Pmax remained below 1% at all speeds, thus stable and regular combustion was maintained even in a numerous range of the cycle numbers. Pre-injection phase of fuel injection system was recognized to be effective in formation of the first peak of the combustion pressure in individual cycles. It was concluded from this study that the common-rail diesel engine generated minor cyclic discrepancies under different engine speeds. [ABSTRACT FROM AUTHOR]

A new afterburner installation is proposed, fueled with pure hydrogen (100%H2) or hydrogen–methane mixtures (60% H2 + 40% CH4, 80% H2 + 20% CH4) for use in cogeneration applications. Two prototypes (P1 and P2) with the same expansion angle (45 degrees) were developed and tested. P1 was manufactured by the classic method and P2 by additive manufacturing. Both prototypes were manufactured from Inconel 625. During the tests, analysis of flue gas (CO2, CO, and NO concentration), PIV measurements, and noise measurements were conducted. The flue gas analysis emphasizes that the behavior of the two tested prototypes was very similar. For all three fuels used, the CO2 concentration levels were slightly lower in the case of the additive-manufactured prototype P2. The CO concentration levels were significantly higher in the case of the additive-manufactured prototype P2 when 60% H2/40% CH4 and 80% H2/20% CH4 mixtures were used as fuel. When pure H2 was used as fuel, the measured data suggest that no additional CO was produced during the combustion process, and the level of CO was similar to that from the Garrett micro gas turbine in all five measuring points. The NO emissions gradually decreased as the percentage of H2 in the fuel mixture increased. The NO concentration was significantly lower in the case of the additive-manufactured prototype (P2) in comparison with the classic manufactured prototype (P1). Examining the data obtained from the PIV measurements of the flow within the mixing region shows that the highest axial velocity component value on the centerline was measured for the P1 prototype. The acoustic measurements showed that a higher H2 concentration led to a reduction in noise of approximately 1.5 dB for both afterburner prototypes. The outcomes reveal that the examined V-gutter flame holder prototype flow was smooth, without any perpendicular oscillations, without chaotic motions or turbulent oscillations to the flow direction, across all tested conditions, keeping constant thermal power. [ABSTRACT FROM AUTHOR]

An ultra-high-speed centrifugal pump plays a crucial role as part of an aircraft engine's fuel supply system. This paper focuses on the coupled vibration and optimization of a parallel double-stage ultra-high-speed centrifugal pump considering fluid–structure interaction (FSI). The accuracy of the numerical calculation is verified and compared with the experimental results. The steady and transient characteristics of the rotor system are analyzed to ensure the operational reliability of the rotor system. Moreover, an orthogonal test is conducted to explore the transient structural characteristics of the rotor system. The existing cross-support structure meets high-speed stability requirements and there is no resonance in the cantilevered rotor system. The maximum and minimum errors for the head of Pump 2 are 4% and 0.7%, respectively. The minimum values for maximum average deformation and maximum average stress are less than 0.31 mm and 245 MPa, respectively, at design conditions. The position of Bearing 1 near the multi-stage impeller has the greatest impact on the deformation and stress of the rotor system, and the deformation and stress increase as the distance increases. The results of this study can provide a valuable reference for the design of ultra-high-speed centrifugal pump rotor systems. [ABSTRACT FROM AUTHOR]

This paper provides a comprehensive analysis of a grid-connected hybrid microgrid system that seamlessly integrates renewable energy sources, encompassing wind generators, solar arrays, and Fuel Cells (FCs). Emphasis is placed on the pivotal role of power electronic converters in optimizing control and energy management strategies for these diverse sources. The wind and solar subsystems employ Perturb and Observe (P&O) controllers to achieve Maximum Power Point Tracking (MPPT). Additionally, the study delves into the analysis and control design of the grid-connected hybrid system inverter, employing a Proportional-Integral (PI) control technique in the synchronous d-q frame to maximize the output voltage response and active power. In managing renewable grid energy based on artificial neural networks (ANNs), the main goal is to address grid availability concerns by prioritizing renewable sources. The hybrid system acts as a backup during grid unavailability and simultaneously produces hydrogen via electrolysis. The excess energy is seamlessly supplied to the grid upon filling the hydrogen tank. The proposed solution shows great promise for use in renewable energy management systems that combine hybrid technologies. [ABSTRACT FROM AUTHOR]

In a fuel cell system, the performance of the ejector is limited when it operates under off-design conditions. To improve the performance of the ejector under all operating conditions in the fuel cell system, this study employs a multi-response optimization approach to optimize the structural parameters of the ejector. The optimization objectives are the entrainment ratio under low-power and high-power operating conditions, with the optimization variables including the mixing tube diameter (Dm), primary nozzle exit position (Lnxp), and mixing tube length (Lm). A quadratic polynomial model is proposed to correlate the key structural parameters of the ejector with the entrainment ratio using the response surface methodology based on the Box-Behnken design. The optimal structural parameters of the ejector are obtained using the desirability function approach. The results demonstrate that this optimization approach significantly improves the ejector performance under off-design conditions while the performance remains essentially unchanged under high-power operating conditions. [ABSTRACT FROM AUTHOR]

Fuel cells have been studied for use in stationary power generation and vehicle propulsion systems. The fuel cell thermal management subsystem is coupled and nonlinear, posing challenges for modeling and temperature control. This paper aims to integrate the physical models of the fuel cell stack, pump, thermostat, and other components combined with intelligent algorithms into an efficient system-level thermal management model framework and develop a model predictive controller to solve the temperature control problem. First, a physics-based nonlinear model of the fuel cell system is developed and used as a basis to identify the linearized model for different operating points. Then, the global model is obtained by fusing the local models with Gaussian validity functions using the local linear model tree method. Third, a multi-step prediction model is derived based on the local model networks, and a parameterized linear state space form is obtained and used for controller design. Furthermore, an online correction method is developed to reduce the model discrepancy. Finally, the accuracy of the system model and the performance of the proposed controller are verified by open-loop experimental data and a series of closed-loop simulation cases. [ABSTRACT FROM AUTHOR]

Fuel cell systems, particularly in stationary power and transport applications, are becoming increasingly prevalent for hydrogen utilization. However, designing reliable and leak-tight hydrogen fuel cell vehicles and infrastructure presents significant challenges due to the small molecule nature of hydrogen, which can easily permeate through even the smallest fissures. Proton exchange membrane fuel cells (PEMFCs) operate at low temperatures and pressures, necessitating precise fuel flow control for optimal performance. Thus, the performance of fittings in high-pressure hydrogen fuel systems is crucial. This paper explores design considerations to ensure safety and efficiency in fuel cell systems, focusing on components and materials in fuel piping, while adhering to relevant standards and regulations. A proposed fluid system solution is also presented. [ABSTRACT FROM AUTHOR]

The present power generation corporations are working on Renewable Power Systems (RPS) for supplying electrical power to the automotive power industries. There are several categories of RPSs available in the atmosphere. Among all of the RPSs, the most general power network used for Electric Vehicles (EVs) is hydrogen fuel which is available in nature. The H2 fuel is fed to the Proton Exchange Membrane Fuel Stack (PEMFS) for producing electricity for the EV stations. The advantages of this selected fuel system are more power conversion efficiency, environmentally friendly, low carbon emissions, more power density, less starting time, plus able to work at very low-temperature values. However, this fuel stack faces the issue of a nonlinear power density curve. Due to this nonlinear power supply from the fuel stack, the functioning point of the overall network changes from one position of the I–V curve to another position. So, the peak voltage extraction from the fuel stack is not possible. In this article, there are various metaheuristic optimization-based Maximum Power Point Tracking (MPPT) methodologies are studied along with the conventional methods for obtaining the Maximum Power Point (MPP) position of the PEMFS. From the simulative investigation, the Continuous Different Slope Value-based Cuckoo Search Method (CDSV with CSM) provides better efficiency with more output power. Also, for all the MPPT methods comprehensive analysis has been made by utilizing the simulation results. [ABSTRACT FROM AUTHOR]

The hydrogen recirculation ejector, known for its low cost and simple structure, has garnered widespread attention in PEM fuel cell applications. As a fluid-driven passive component, the fluid dynamics inside the ejector play a pivotal role in determining its entrainment performance. This study explores the impact of the primary flow temperature on phase change characteristics based on the Euler-Lagrange model. Results indicate that at a primary flow temperature of −40 °C, the mass flow rate of droplets at the outlet reaches 285.2 mg/s, representing a condensation efficiency of 24.1%. Concurrently, condensation elevates the outlet temperature by 31.2 °C, resulting in an 8.8% reduction in the entrainment ratio. The mass flow rate of droplets decreases significantly as the primary flow temperature increases. As the temperature rises to 60 °C, homogeneous droplets vanish entirely. Simultaneously, foreign heterogeneous droplets evaporate by 42.0%, attributed to the negative subcooling degree at the diffuser and outlet pipe. This study emphasizes the significance of controlling the primary flow temperature for the hydrogen recirculation ejector. [Display omitted] • Condensation efficiency increases with decreasing primary flow temperature. • 24.1% of the water vapor condenses at a primary flow temperature of −40 °C. • Condensation reduces the entrainment ratio and enhances outlet temperature. • Evaporation occurs when the primary flow temperature rises to 60 °C. [ABSTRACT FROM AUTHOR]

The conventional startup and shutdown methods were unsuitable for idle situations such as waiting at traffic lights or roadside parking, especially when the FCV battery capacity is small and cannot withstand high-power charging. This study presented the water state in PEMFC during a shutdown purging process, and a test was conducted on the mature vehicle FCS consisting of 350 single cells. A conventional start-stop test was studied firstly, and the result reported an OCV time of 0.3 s during the conventional startup process, and the normal shutdown process took approximately 1 min. Then, a voltage maintenance strategy was explored by starting the air compressor and opening the cathode inlet stop valve at intervals to maintain the anode pressure at 20 kPag, but the high voltage in some stages needed further optimized. Finally, the start-stop test embedded with a voltage maintenance strategy were carried out to analyze the feasibility of optimizing the processes. By increasing the discharge process during the idle voltage maintenance, the average cell voltage is maintained at a range of 0.72–0.8 V, which can potentially minimize the damage to the lifespan during the start and stop processes, ultimately improving the durability of the fuel cell system. During the voltage maintenance stage, the energy consumption of the system was 0.33 kWh. A new control strategy was proposed for fuel cell voltage maintenance during the idle startup and shutdown processes and effectively reduced issues related to frequent purging, extended downtime, and power battery charging in dry and wet cycles. • Water state in PEMFC during a shutdown purging process were summarized. • Three different tests were performed to study the start-stop process of FCS. • A new voltage control strategy during start-stop process was proposed. • Average cell voltage is maintained at 0.72–0.8 V during startup and shutdown. [ABSTRACT FROM AUTHOR]

In order to reduce carbon emissions, which are currently a problem in the shipping and offshore plant sectors, the international community is strengthening regulations such as the Energy Efficiency Design Index (EEDI) and Energy Efficiency Existing Ship Index (EEXI). To cope with this, eco-friendly fuel propulsion technology is being developed, and the development of an ammonia fuel supply system is in progress. Among them, fuel valve train (FVT) technology was researched for the final supply and cutoff of fuel and purging through nitrogen for ammonia engines. In this paper, we analyzed the change in ammonia supply due to FVT opening and the change in nitrogen supply due to closure. In addition, a plan to minimize risk factors was presented by applying a control method to remove residual fuel in FVT. According to the presented FVT model, the difference in the flow rate of supplied fuel was as much as 17.8 kg/s. Additionally, by opening the gas bleed valve at intervals during the closing process and purging about 0.28 kg of nitrogen, the internal fuel could be completely discharged. This is expected to have an impact on improving the marine environment through the application of eco-friendly fuels and the development of fuel supply system technology. [ABSTRACT FROM AUTHOR]

The environmental and societal challenges of our contemporary society are leading us to reconsider our approaches to vehicle design. The aim of this article is to provide the reader with the essential knowledge needed to responsibly design a vehicle equipped with a hydrogen fuel cell system. Two pivotal aspects of hydrogen-electric powertrain eco-design are examined. First, the global warming potential is assessed for both PEMFC systems and Type IV hydrogen tanks, accounting for material extraction, production, and end-of-life considerations. The usage phase was omitted from the study in order to facilitate data adaptation for each type of use. PEMFC exhibits a global warming potential of about 29.2 kgCO 2eq /kW, while the tank records 12.4 kgCO 2eq /kWh, with transportation factors considered. Secondly, the societal and governmental impacts are scrutinized, with the carbon-intensive hydrogen tank emerging as having the most significant societal and governmental risks. In fact, on a scale of 1–5, with 5 representing the highest level of risk, the PEMFC system has a societal impact and governance risk of 2.98. The Type IV tank has a societal impact and governance risk of 3.31. Although uncertainties persist regarding the results presented in this study, the values obtained provide an overview of the societal and governmental impacts of the hydrogen ecosystem in the transportation sector. The next step will be to compare, for the same usage, which solution between hydrogen-electric and 100% battery is more respectful of humans and the environment. • Platinum accounts for less than 0.01% of the mass in a fuel cell system. • A type IV hydrogen tank mass consists of over two-thirds carbon fiber one. • The societal impact of the tank is higher than that of the fuel cell system. • The global warming potential of the tank exceeds that of the fuel cell system. • Assessing societal impacts and governance risks involves inherent uncertainties. [ABSTRACT FROM AUTHOR]

Inter-shaft fuel supply systems (ISFSSs) consisting of a shaft annulus and a fuel slinger are usually used in micro turbojet engines to pump the fuel to the combustor, aiming at reducing engine's size and weight. Differing from the configuration with stationary fuel pipework, the fast-rotating shaft in the annulus would induce significant drag jeopardizing the fuel supply during engine acceleration. This study investigates the flow physics inside a micro turbojet engine ISFSS. Air–fuel two-phase flow is found in the slinger cavity and the shaft annulus, with main gas path air ingress into the ISFSS under disk pumping of the slinger, and the ingress is enhanced by introducing blades on the slinger disk. Results show that the axial flow drag in the shaft annulus is reduced as air being ingested in. Further investigation indicates that the best supplied fuel volume fraction is 0.8, and this can reduce the axial drag in the shaft annulus by ∼63%, compared with the single-phase fuel flow. Therefore, two-phase air–fuel mixture is proposed for the ISFSS drag reduction. [ABSTRACT FROM AUTHOR]

Triphenyl phosphane (TPP) and an epoxide as a fuel system transiently transformed a non-catalytic six-component turnstile into a four-component catalytic rotor releasing N-methyl pyrrolidine and a copper(I) complex. The two latter compounds acted synergistically as catalysts to perform first a Michael addition and then a 5-exo-dig cyclization, giving rise to dissipative sequential catalysis. [ABSTRACT FROM AUTHOR]

Fuel level gauging in aircraft presents a significant flight mechanics challenge due to the influence of aircraft movements on measurements. Moreover, it constitutes a multidimensional problem where various sensors distributed within the tank must converge to yield a precise and single measurement, independent of the aircraft's attitude. Furthermore, fuel distribution across multiple tanks of irregular geometries complicates the readings even further. These issues critically impact safety and economy, as gauging errors may compromise flight security and lead to carrying excess weight. In response to these challenges, this research introduces a multi-stage project in aircraft fuel gauging systems, as a continuum of studies, where this first article presents a computational tool designed to simulate aircraft fuel sensor data readings as a function of fuel level, fuel tank geometry, sensor location, and aircraft attitude. Developed in an open-source environment, the tool aims to support the statistical inference required for accurate modeling in which synthetic data generation becomes a crucial component. A discretization procedure accurately maps fuel tank geometries and their mass properties. The tool, then, intersects these geometries with fuel-level planes and calculates each new volume. It integrates descriptive geometry to intersect these fuel planes with representative capacitive level-sensing probes and computes the sensor readings for the simulated flight conditions. The method is validated against geometries with analytical solutions. This process yields detailed fuel measurement responses for each sensor inside the tank, and for different analyzed fuel levels, providing insights into the sensors' signals' non-linear behavior at each analyzed aircraft attitude. The non-linear behavior is also influenced by the sensor saturation readings at 0 when above the fuel level and at 1 when submerged. The synthetic fuel sensor readings lay the baseline for a better understanding on how to compute the true fuel level from multiple sensor readings, and ultimately optimizing the amount of used sensors and their placement. The tool's design offers significant improvements in aircraft fuel gauging accuracy, directly impacting aerostructures and instrumentation, and it is a key aspect of flight safety, fuel management, and navigation in aerospace technology. [ABSTRACT FROM AUTHOR]

This paper proposes a novel approach to identify the presence of a latent factor in the co-movements of gasoline and diesel prices in the three major European Union economies, (France, Germany, and Italy) using daily data from January 3, 2005, to June 28, 2021. More precisely, we advance an artificial neural networks algorithm estimated through a machine learning experiment through the backpropagation system to show that the neural signal is altered by an element that could coincide with a latent factor in the fuel price co-movements. We consider the role of the fuel tax systems and the connection between gasoline and diesel prices in these countries. The estimations indicate the presence of an unobservable component (the latent factor) in the fuel price co-movements, capable of influencing NN. This result validates the previous findings reported in the literature, indicating an excess co-movement in fuel prices. It also has implications in terms of fuel price forecasts in the short run. [ABSTRACT FROM AUTHOR]

Hydrogen fuel cell tractors are emerging as a new power source for tractors. Currently, there is no mature energy management control method available. Existing methods mostly rely on engineers' experience to determine the output power of the fuel cell and the power battery, resulting in relatively low energy utilization efficiency of the energy system. To address the aforementioned problems, a power optimization method for the energy system of hydrogen fuel cell wheel-driven electric tractor was proposed. A dynamic model of tractor ploughing conditions was established based on the system dynamics theory. From this, based on the equivalent hydrogen consumption theory, the charging and discharging of the power battery were equivalent to the fuel consumption of the hydrogen fuel cell, forming an equivalent hydrogen consumption model for the tractor. Using the state of charge (SOC) of the power battery as a constraint, and with the minimum equivalent hydrogen consumption as the objective function, an instantaneously optimized power allocation method based on load demand in the energy system is proposed by using a traversal algorithm. The optimization method was simulated and tested based on the MATLAB simulation platform, and the results showed under ploughing conditions, compared with the rule-based control strategy, the proposed energy system power optimization method optimized the power output of hydrogen fuel cells and power batteries, allowing the energy system to work in a high-efficiency range, reducing the equivalent hydrogen consumption of the tractor by 7.79%, and solving the energy system power distribution problem. [ABSTRACT FROM AUTHOR]

Fuel cell systems (FCSs) have been widely used for niche applications in the market. Furthermore, the research community has worked on using FCSs for different sectors, such as transportation, stationary power generation, marine and maritime, aerospace, military and defense, telecommunications, and material handling. The reformation of various fuels, such as methanol, methane, and diesel can be utilized to generate hydrogen for FCSs. This study introduces an advanced convolutional neural network (CNN) model designed to accurately forecast hydrogen yield and carbon monoxide volume percentages during the reformation processes of methane, methanol, and diesel. Moreover, the CNN model has been tailored to accurately estimate methane conversion rates in methane reforming processes. The proposed CNN models are created by combining the 3D-CNN and 2D-CNN models. The Keras Tuner approach in Python is employed in this study to find the ideal values for different hyperparameters such as batch size, learning rate, time steps, and optimization method selection. The accuracy of the proposed CNN model is evaluated by using the root mean square error (RMSE), mean absolute percentage error (MAE), mean absolute error (MAE), and R2. The results indicate that the proposed CNN model is better than other artificial intelligence (AI) techniques and standard CNN for performance estimation of reforming processes of methane, diesel, and methanol. The results also show that the suggested CNN model can be used to accurately estimate critical output parameters for reforming various fuels. The proposed method performs better in CO prediction than the support vector machine (SVM), with an R2 of 0.9989 against 0.9827. This novel methodology not only improves performance estimation for reforming processes but also provides a valuable tool for accurately estimating output parameters across various fuel types. [ABSTRACT FROM AUTHOR]

This research showcases the seamless integration of solid oxide fuel cells (SOFC) with waste heat recovery systems, utilizing liquefied petroleum gas (LPG) as the primary fuel source. The focus of the study is on efficiently harnessing the cold energy from the LPG supply to produce substantial power for the entire system. To optimize energy utilization, a gas turbine (GT) and steam Rankine cycle (SRC) are integrated to effectively convert waste heat from the system into useful work and power. Additionally, a waste heat boiler (WHB) is incorporated to provide superheated vapor steam for seafarer accommodation. A detailed thermodynamic analysis and investigation of the proposed integrated system are performed. The simulations and optimizations of combined system are conducted using ASPEN HYSYS V12.1. Thermodynamic equations based on the fundamental laws of thermodynamics are employed to estimate system performance indicators, and the exergy destruction in major components is assessed to optimize the system's design and operation. The proposed system exhibits impressive energy and exergy efficiencies, calculated at 52.65% and 51.10%, respectively. Moreover, the waste heat recovery combined cycles contribute an additional 1,759.73 kW, equivalent to 31.65% of the total system output. The innovative models are validated against experimental data from the literature, demonstrating strong agreement. Furthermore, a comprehensive parametric study investigates the influence of varying the current density from 900 to 1,950 A/m2, leading to a total energy efficiency variation of 41.59%, ranging from 82.45% to 40.86%. The organic Rankine cycle (ORC) performs exceptionally well, capitalizing on both cold energy and high-temperature waste heat to achieve high energy recovery efficiency. The WHB is capable of providing 8,200 kg/h of superheated vapor stream at 151°C and 499 kPa for seafarer accommodation and heating purposes. The economic viability analysis is conducted to assess the potential for investment, maintenance costs, and the payback period associated with the proposed system. [ABSTRACT FROM AUTHOR]

Pumps are important components in aviation fuel hydraulic systems, and thanks to the development of sensor technology and industrial intelligence technology, it is possible to achieve efficient state monitoring of pumps. However, when data quality is poor or the amount of data is small, a single data-driven model may not be able to meet diagnostic accuracy. A condition monitoring method for hydraulic gear pumps based on mechanism-data fusion is proposed. The method combines a mechanism model based on the volumetric efficiency formula with a data-driven model based on vibration signals. First, the parameters of volumetric efficiency are solved by fitting the pressure–flow relationship. Subsequently, a multichannel fusion and multikernel function-weighted ensemble support vector classification (MCMK-SVC) is developed, to establish a data-driven model. Finally, through data-level fusion, feature-level fusion, and decision-level fusion, a condition monitoring model based on mechanism-data fusion is built. Experimental verification shows that the accuracy of the three levels of fusion models exceeds 96.9%. Compared to the single data-driven model or other traditional data-driven models, the accuracy of the proposed method has improved by 3% to 33%, demonstrating the effectiveness of the mechanism-data fusion model. [ABSTRACT FROM AUTHOR]

Medium-sized 5- and 6-membered ring lactams are molecules with remarkable stability, in contrast to smaller β-lactams. As monomers, they grant access to nylon-4 and nylon-5, which are alternative polyamides to widespread caprolactam-based nylon-6. Chemical hydrolysis of monocyclic γ- and δ-lactams to the corresponding amino acids requires harsh reaction conditions and up to now, no mild (enzymatic) protocol has been reported. Herein, the biocatalytic potential of a pair of heterologously expressed bacterial ATP-dependent oxoprolinases – OplA and OplB – was exploited. Strong activity in the presence of excess of ATP was monitored on δ-valerolactam and derivatives thereof, while trace activity was detected on γ-butyrolactam. An ATP recycling system based on cheap Graham's salt (sodium metaphosphate) and a polyphosphate kinase allowed the use of catalytic amounts of ATP, leading to up to full conversion of 10 mM δ-valerolactam at 30 °C in aqueous medium. Further improvements were obtained by co-expressing OplA and OplB using the pETDuet1 vector, a strategy which enhanced the soluble expression yield and the protein stability. Finally, a range of phosphodonors was investigated in place of ATP. With acetyl phosphate and carbamoyl phosphate, turnover numbers up to 176 were reached, providing hints on a possible mechanism, which was studied by 31P-NMR. [ABSTRACT FROM AUTHOR]

Durability is one of the technical bottlenecks restricting fuel cell electric vehicle development. As a result, significant time and resources have been invested in research related to this area worldwide. Current durability research mainly focuses on the single cell and stack levels, which is quite different from the usage scenarios of actual vehicles. There is almost no research on developing durability test cycles on the fuel cell system level. This paper proposes a universal model for developing a durability test cycle for fuel cell system based on the China automotive test cycle. Large-scale comparison tests of the fuel cell systems are conducted. After 1000 h test, the output performance degradation of three mass-produced fuel cell system is 14.49%, 9.59%, and 4.21%, respectively. The test results show that the durability test cycle proposed in this paper can effectively accelerate the durability test of the fuel cell system and evaluate the durability performance of the fuel cell system. Moreover, the methodology proposed in this paper could be used in any other test cycles such as NEDC (New European Driving Cycle), WLTC (Worldwide Harmonized Light Vehicles Test Procedure), etc. And it has comprehensive application value and are significant for reducing the cost of durability testing of fuel cell systems and promoting the industrialization of fuel cell electric vehicles. [ABSTRACT FROM AUTHOR]

The ejector-driven hydrogen recirculation system plays an important role in enhancing efficiency of the PEM fuel cell. It's necessary to have deep knowledge of dynamic characteristic of the ejector for optimizing system state, but until now related research is not adequate. In this paper, dynamic characteristic of the ejector for the hydrogen recirculation system of the PEM fuel cell is studied using active periodic pressure excitation. Test plant is set up and active periodic pressure excitation with small amplitude is superimposed on steady pressure at the ejector primary flow inlet. Experiment result shows that in frequency domain, amplitude ratio of dynamic pressure at primary flow inlet to the dynamic delta-pressure, equal to pressure at mixing outlet minus that at backflow inlet, is independent of excitation frequency for each steady operating point. In the complex coordinate, vector of dynamic pressure at primary flow inlet is in parallel with that of dynamic delta-pressure, for all frequencies and for all stable operating points. Furthermore, amplitude ratio of dynamic pressure at primary flow inlet to dynamic delta-pressure exhibits linearity with entrainment ratio of the ejector for all stable operating points. Experiment on the 120 kW fuel cell system validates the same dynamic characteristic. • Dynamic characteristic of ejector studied using active periodic pressure excitation. • Ratio of dynamic primary-flow pressure to delta pressure independent of frequency. • Vector of primary-flow pressure in parallel with that of the dynamic delta-pressure. • Ratio of primary-flow pressure to delta pressure in linearity with entrainment ratio. [ABSTRACT FROM AUTHOR]

Diesel is consistently a very popular fuel for internal combustion engines. Its consumption in the European Union has been rising over recent years, as has the number of engines increasingly sensitive to fuel contamination. One of the most important parameters affecting diesel quality is water content. Its exceedance of the standard's permissible amount carries the risk of serious damage to expensive, modern fuel injection systems. Current methods of measuring water content require both specialised personnel and equipment, as well as transporting the sample to a suitable laboratory. Analysing the properties of diesel is challenging, mainly because many types of the fuel are sold, the chemical composition of which is always a well-guarded manufacturer's secret. The research presented in this paper is aimed at verifying whether it is possible to test the moisture content of diesel using impedance spectroscopy. To date, it is the first such attempt with commercially available diesel using this method, which, once refined, could be used in situ. The authors propose and apply a novel technique that is able to be used when the electrical properties of tested oils are unknown. The experimental results obtained show that it is possible to use impedance spectroscopy to estimate the water content of different types of diesel fuel. The measurement accuracy achieved makes it possible to detect approaching or exceeding the permissible water content. [ABSTRACT FROM AUTHOR]

Electrical Distribution Grid (EDG) will be required to further enhance PQ while also providing higher-efficiency electrical technology. The relationship between the elements of EDG and Hydrogen Fuel Cell Systems (HFCS) was thoroughly examined in this study. This investigation, emphasizes the controller techniques of DVR technology and HFCS interface, as well as the connected converter topology such as multi-input single-output dc-dc converters topology, voltage double boost converters topology, and high step-up coupled inductor converter topology, could contribute to decreasing the danger of EDG by limiting the consumption of fossil fuels for power-generation, reducing the emission of hazardous. Moreover, according to what the research discussed HFCS with EDG interfacing is based on DVR technology. The article delivers several novel contributions to the realm of electrical engineering and renewable energy integration. It presents a pioneering integration of hydrogen fuel cells with DVR technology to enhance power delivery reliability and efficiency within electrical distribution grids. This work introduces advanced optimization algorithms aimed at im-proving the operational efficiency, lifespan, and cost-effectiveness of hydrogen fuel cells. Furthermore, it develops robust control strategies for dynamic voltage restoration, crucial for maintaining stable voltage levels under variable loads. The article also includes detailed simulation models to provide empirical support for the proposed strategies and assesses both the environmental impacts and scalability aspects of the system. These innovative elements ensure that the article contributes significantly to the existing body of knowledge, providing practical solutions and theoretical insights that could influence future research and development in the integration of renewable energy technologies within electrical distribution systems. [ABSTRACT FROM AUTHOR]

A new type of bioelectrochemical system features a constructed wetland (CW) coupled with a microbial fuel cell (MFC) to treat Cr(VI) wastewater while generating electricity. The optimal operating parameters for treating wastewater containing Cr(VI) are discussed. The results show that the CW-MFC system is more effective in the treatment of Cr(VI)-containing wastewater and generating electricity. A COD concentration of 300 mg/dm³ corresponded to the greatest COD and Cr(VI) removal rates with a maximum power density of 505.62 mW/m³, whereas a Cr(VI) concentration of 80 mg/dm³ yielded the greatest COD removal rate, with a maximum power density of 484.43 mW/m³. A hydraulic retention time (HRT) of 3 days yielded the largest pollutant removal rates with a maximum power density of 479.21 mW/m³. Considering that the comprehensive operating conditions of CW-MFC are based on planting plants, the COD concentration is 300 mg/dm³, the Cr(VI) concentration is 80 mg/dm³, and the HRT is 3 days. The abundance of electrogenic bacteria Geobacter and metal dissimilatory reducing bacteria Acinetobacter in CW-MFC is higher than that in the control group. The results of this study provide theoretical guidance for determining the optimal operating conditions and energy recovery of the CW-MFC system for treating chromium wastewater. [ABSTRACT FROM AUTHOR]

The hydrogen circulation pump (HCP) is an important power component of the hydrogen fuel system, used to recover the unconsumed hydrogen from the anode and transport it back to the inlet of the battery stack to improve the hydrogen utilization efficiency. In this paper, to determine the optimal parameter configuration of the HCP, a multifactor and multi-objective optimization design method is proposed, and the influences of various design parameters on the performance of the HCP are analyzed based on the verified overset grid simulation method. The research results show that the proposed coupling design method can effectively achieve the optimal parameter configuration of the HCP, with diameter-to-pitch ratio κ = 1.47, rotor blade number Z = 3, and helix angle φ = 60°, which is validated using another model with significant performance advantages. In the process of studying the influence of design parameters, it is found that the average flow rate of the HCP is directly proportional to the diameter-to-pitch ratio and the blade number, gradually decreases in the range of helix angle from 0° to 22.5°, and increases in the range of helix angle from 22.5° to 60°. The flow pulsation value and pressure pulsation value of the HCP are less affected by the diameter-to-pitch ratio, decrease with the increase of the blade number, and show a trend of first increasing and then decreasing with the increase of the helix angle. [ABSTRACT FROM AUTHOR]

Featured Application: The multi-stack fuel cell system proposed in this paper can be applied to high-power generation, transport, and other engineering fields. A multi-stack fuel cell system (MFCS) is a promising solution for high-power PEM fuel cell applications. This paper proposes an optimized stack allocation approach for power allocation, considering economy and dynamics to establish integrated subsystems with added functional components. The results show that an MFCS with target powers of 20 kW, 70 kW, and 120 kW satisfies lifetime and efficiency factors. The common rail buffer at the air supply subsystem inlet stabilizes pressure, buffers, and diverts. By adjusting the volume of the common rail buffer, it is possible to reduce the maximum instantaneous power and consumption of the air compressor. The integrated hydrogen supply subsystem improves hydrogen utilization and reduces parasitic power consumption. However, the integrated thermal subsystem does not have the advantages of integrated gas supply subsystems, and its thermal management performance is worse than that of a distributed thermal subsystem. This MFCS provides a solution for high-power non-average distribution PEM fuel cell systems. [ABSTRACT FROM AUTHOR]

The environmental impact of fossil fuel combustion is driving the search for efficiency and sustainable propulsion systems. Questions remain on what source can meet the high energy requirements for heavy-duty propulsion and standalone systems. The recuperated split cycle engine (SCE) has shown potential for a step change in efficiency compared to conventional compression ignition heavy-duty engines. Combining this engine with hydrogen fuel would also reduce dependence on fossil fuels. This study uses Chemkin-Pro multizone homogeneous charge compression ignition (MZ HCCI) engine model to determine the feasibility of a hydrogen fuelled SCE. The MZ HCCI model represents the expansion cylinder of the SCE and is used to compare hydrogen and diesel in terms of performance and compatibility with the SCE at various valve timings. Results show that, though the IMEP generated by hydrogen is lower than diesel due to lower fuel mass density at higher initial temperatures, it delivers comparable thermal efficiency, with values approaching 60 %. Also, hydrogen shows characteristics well suited to the SCE architecture, indicating that hydrogen and the SCE is a feasible alternative to diesel CI heavy-duty propulsion systems. • Multizone Chemkin-Pro model of split cycle engine. • Indicated thermal efficiency approaching 60% for hydrogen. • Hydrogen low volumetric energy density requires tailoring of fuel injection systems. • Beneficial characteristics of hydrogen fuel in split cycle engine architecture. [ABSTRACT FROM AUTHOR]

Breed and Burn (B&B) fuel cycle in molten salt reactors (MSRs) qualifies this reactor type as one of the best candidates to be developed for the Gen-IV R&D program. This feature can be approached by employing a closed fuel cycle and application of a molten salt reactor as a spent nuclear fuel burner; the features promise sustainable and clean energy in the future. In this study, a complete package has been developed to calculate core inventory, fuel burnup, and salt clean-up systems of molten salt reactors during their lifetime. To achieve this, the iMAGINE-3BIC package ("iMAGINE 3D-Reg Burnup & Inventory Calculator package") has been developed in MATLAB R2023a by employing a CINDER90 module of MCNPX 2.7 for burnup-calculation and multi-linear regression method (MLR). The package can estimate the core inventory (concentration of 25 actinides and 245 non-actinides elements) and the burnup of the reactor core during MSR lifetime (up to 100 years) while optimizing the computational resources (time, CPU and RAM), and it can even be hassle-freely executed on standalone PCs in an appropriate time due to its generous database. In addition, the salt clean-up module of the iMAGINE-3BIC package can be employed to evaluate the effects of the salt clean-up system on the above parameters over the MSRs' lifetime. Finally, the iMAGINE-3BIC package has been applied to an iMAGINE reactor core design (University of Liverpool, UK—chloride-based salt fuel system) and an EVOL reactor core design (CNRS, Grenoble, France, fluoride-based salt fuel system) to evaluate and compare the performance of chloride/fluoride-based salt fuel MSRs from the point of burnup, core inventory, and salt clean-up systems. The results confirm that while a chloride-based salt fuel system has some advantages in less dependency on the salt clean-up system and fewer poisoning elements inventory, the fluoride-based system can achieve higher burnup during the reactor lifetime. The outcome of this study, along with the first part of this article, provides evidence to support the neutronic decision matrix as well as the pros and cons of employing chloride- or fluoride-based fuel systems in MSR cores. [ABSTRACT FROM AUTHOR]

We introduce a mathematical model of cultural evolution to study cultural traits that shape how individuals exchange information. Current theory focuses on traits that influence the reception of information (receiver traits), such as evaluating whether information represents the majority or stems from a trusted source. Our model shifts the focus from the receiver to the sender of cultural information and emphasizes the role of sender traits, such as communicability or persuasiveness. Here, we show that sender traits are probably a stronger driving force in cultural evolution than receiver traits. While receiver traits evolve to curb cultural transmission, sender traits can amplify it and fuel the self-organization of systems of mutually supporting cultural traits, including traits that cannot be maintained on their own. Such systems can reach arbitrary complexity, potentially explaining uniquely human practical and mental skills, goals, knowledge and creativity, independent of innate factors. Our model incorporates social and individual learning throughout the lifespan, thus connecting cultural evolutionary theory with developmental psychology. This approach provides fresh insights into the trait-individual duality, that is, how cultural transmission of single traits is influenced by individuals, who are each represented as an acquired system of cultural traits. [ABSTRACT FROM AUTHOR]

Recently, micro gas turbine (MGT) systems for combined heat and power (CHP) plants have attracted much attention due to their high combined energy efficiencies and low carbon emissions. Therefore, this study has focused on the performance and fuel flexibility analysis of a 5.5 kW MGT-CHP system coupled with a proton exchange membrane (PEM) electrolysis cell and a fuel cell unit for domestic applications. The simulation study includes an MGT unit that produces both heat and electricity, a low-temperature PEM electrolysis of H 2 O to produce H 2 fuel for the combustor, and a PEM fuel cell to generate electricity during system initialisation. The MGT unit in this study uses H 2 , hythane (20% H 2 + 80% C H 4), natural gas (NG) and methane (C H 4) fuels to investigate the thermal and electrical efficiency and C O 2 emission avoidance for each fuel utilisation. The result shows that the combustion of H 2 and hythane in the MGT combustor produces almost the same amount of nitrogen oxides (NOx) due to the lower reaction temperature of the combustor. Nearly 7% of C O 2 and C O emissions were avoided by replacing NG with hythane. C O 2 and C O emissions were avoided by burning H 2 instead of other fuels. Higher thermal efficiency was seen on the H 2 -fuelled MGT system. However, higher end-use costs were observed for the MGT system running on both H 2 and hythane fuels due to the higher purchase price of both fuels. The addition of a recuperator promoted lean combustion, which improved the overall efficiency of the proposed system. The outcome of the studied work achieved an efficiency of 82% for PEM electrolysis of H 2 O and an MGT-CHP combined efficiency of 96%. [Display omitted] • NG, CH 4 , hythane and H 2 fuelled MGT-CHP systems are introduced. • The electrolysis of H 2 O and H 2 fuel cell systems are proposed. • The hybrid system recorded low NOx and reduced carbon emissions. • The proposed system achieved an efficiency of 96% for the MGT unit. [ABSTRACT FROM AUTHOR]

This study compared the fuel consumption and exhaust emissions of a sparkignition engine using a carburetor fuel system, an injection fuel system, and an ultrasonic fuel system. When using gasoline only, the ultrasonic fuel system showed a 31% decrease in fuel consumption compared to the carburetor system and a 15% decrease compared to the injection system. When adding 10% bioethanol to the gasoline, fuel consumption increased in all three systems, with the ultrasonic system showing the largest increase of 10%. Exhaust emissions were also measured, and the ultrasonic system showed a significant decrease in CO, HC, and NOx compared to the carburetor and injection systems, with the largest decrease in CO emissions. The addition of bioethanol to the fuel resulted in reducing exhaust emission values in all three systems, with the ultrasonic system showing the largest decrease in CO and HC emissions compared to the carburetor and injection systems, but with an increase in NOx emissions compared to the injection system. When comparing three fuel systems, it was observed that injection fuel systems have the highest CO2 values. Although the addition of alcohol to the fuel does not cause a significant change in CO2 emission values for injection and ultrasonic fuel systems, an increase is observed in the carburetor fuel system. Overall, the ultrasonic fuel system showed promising results for reducing fuel consumption and improving exhaust emissions. [ABSTRACT FROM AUTHOR]

The advancement of contemporary internal combustion engine technologies necessitates not only design enhancements but also the exploration of alternative fuels or fuel catalysts. These endeavors are integral to curbing the emission of hazardous substances in exhaust gases. Most contemporary catalyst additives are of complex chemical origins, introduced into the fuel during the fuel preparation stage. Nonetheless, none of these additives yield a significant reduction in fuel consumption. The research endeavors to develop the fuel system of a primary marine diesel engine to facilitate the incorporation of pure hydrogen additives into diesel fuel. Notably, this study introduces a pioneering approach, employing compressed gaseous hydrogen up to 5 MPa as an additive to the principal diesel fuel. This method obviates the need for extensive modifications to the ship engine fuel equipment and is adaptable to modern marine power plants. With the introduction of modest quantities of hydrogen into the primary fuel, observable shifts in the behavior of the fuel equipment become apparent, aligning with the calculations outlined in the methodology. The innovative outcomes of the experimental study affirm that the mass consumption of hydrogen is contingent upon the hydrogen supply pressure, the settings of the fuel equipment, and the structural attributes of the fuel delivery system. The modulation of engine load exerts a particularly pronounced influence on the mass admixture of hydrogen. The proportion of mass addition of hydrogen in relation to the pressure of supply (ranging from 4-12 MPa) adheres to a geometric progression (within the range of 0.04-0.1%). The application of this technology allows for a reduction in the specific fuel consumption of the engine by 2-5%, contingent upon the type of fuel system in use, and concurrently permits an augmentation in engine power by up to 5%. The resultant economic benefits are estimated at 1.5-4.2% of the total fuel expenses. This technology is applicable across marine, automotive, tractor, and stationary diesel engines. Its implementation necessitates no intricate modifications to the engine design, and its utilization demands no specialized skills. It is worth noting that, in addition to hydrogen, other combustible gases can be employed. [ABSTRACT FROM AUTHOR]

• Limited research on the role of the adaptive immune system (IS) in Alzheimer's disease (AD). • We show a detrimental impact of the adaptive IS on AD in mildly peripherally inflamed App NL-G-F mice. • The lack of an adaptive IS positively affects the performance of complex cognitive tasks. • This is associated with reduced Aβ pathology, less glial activation, and better neuronal networks. Alzheimer's disease (AD) is a devastating neurodegenerative disorder characterized by a concerning rise in prevalence. It is projected that the number of affected individuals will reach a staggering 150 million by 2050. While recent advancements in monoclonal antibodies targeting Aβ have shown some clinical effects, there is an urgent need for improved therapies to effectively address the impeding surge of AD patients worldwide. To achieve this, a deeper understanding of the intricate mechanisms underlying the disease is crucial. In recent years, mounting evidence has underscored the vital role of the innate immune system in AD pathology. However, limited findings persist regarding the involvement of the adaptive immune system. Here, we report on the impact of the adaptive immune system on various aspects of AD by using AppNL-G-F mice crossed into a Rag2−/− background lacking mature adaptive immune cells. In addition, to simulate the continuous exposure to various challenges such as infections that is commonly observed in humans, the innate immune system was activated through the repetitive induction of peripheral inflammation. We observed a remarkably improved performance on complex cognitive tasks when a mature adaptive immune system is absent. Notably, this observation is pathologically associated with lower Aβ plaque accumulation, reduced glial activation, and better-preserved neuronal networks in the mice lacking a mature adaptive immune system. Collectively, these findings highlight the detrimental role of the adaptive immune system in AD and underscore the need for effective strategies to modulate it for therapeutic purposes. [ABSTRACT FROM AUTHOR]

This paper presents a combined heating, power, and hydrogen system production by utilizing biogas energy. A novel methodology is proposed to identify thermodynamic cycle conditions and reform processes by using biogas as the energy source. Biogas steam and dry reforming methods are considered based on equilibrium data employing the EES program. It is found that biogas has two principal roles for combustion and reforming processes simultaneously. The thermal energy from the combustion of biogas causes its reforming and improves the efficiency of the system by 74%. The exergy efficiency, the overall exergy destruction, and hydrogen efficiency are calculated for various electric powers ranging from 5 to 40 MW. It is found that the combustion chamber has the maximum exergy destruction of about 51%. The parametric study of the system is performed to assess the optimum conditions for producing hydrogen. The optimal condition corresponds to CO 2 /CH 4 = 0.50–0.66, H 2 O/CH 4 = 2–3.6, and the reforming temperature range of 965–1036 K. The conversion of methane and carbon dioxide shows the reduction of the greenhouse gases. [Display omitted] • A combined heating, power, and hydrogen system production is proposed by utilizing biogas energy. • Biogas steam and dry reforming methods are considered. • The combustion of biogas improves the efficiency of the system by 74%. • The optimal condition corresponds to CO 2 /CH 4 = 0.50-0.66, H 2 O/CH 4 = 2-3.6, and the reforming temperature range of 965-1036 K. [ABSTRACT FROM AUTHOR]

The fuel injection performance and spray characteristics of the high‐pressure common rail (HPCR) system at low temperatures are investigated with experiment. The effects of environmental temperature, common rail pressure, and fuel injection pulse width on the injection quantity and spray characteristics are discussed. The fuel injection quantity at −30°C decreases by about 10% compared to the target fuel quantity. For the different target fuel quantity, the decrease of fuel injection quantity with temperature is the same under different rail pressures. The impact of temperature change on fuel injection quantity is relatively greater when the fuel injection pulse width is small. At the same common rail pressure and injector control pulse width, the injection quantity of −35# diesel is greater than that of −10# diesel for the same temperature condition. The low‐temperature fluidity can ensure normal diesel supply and injection in the fuel supply system. When the viscosity of diesel fuel rises and fluidity deteriorates in a low‐temperature environment, the spray beam produced by the same spray pressure becomes difficult to spread, and the spray penetration distance and cone angle decrease. The spray penetration distance differs by about 2.2 mm between the two temperatures. At low temperatures, the viscosity of diesel fuel rises and the fluidity deteriorates. The minimum injection pressure of the spray increases, and the spray angle is relatively small. [ABSTRACT FROM AUTHOR]