Search

The traditional 70 MPa liquid hydrogen (LH 2) refueling stations (HRSs) require LH 2 pumps with high outlet pressures, leading to high initial investment, energy consumption, and difficulty in developing an LH 2 pump meeting requirements. Existing LH 2 HRSs using thermal compression eliminate the need for pressurization equipment but result in significant waste due to low-pressure hydrogen venting. Therefore, we have pioneered a novel pump-thermal synergistic pressurization process for an efficient LH 2 HRS system. The process utilizes a 45 MPa LH 2 pump and an electric heating method, allowing easily controllable heat input. This study constructs a thermodynamic model for this system that includes the dynamic operational processes of all core components. Based on the established model, the outlet parameters of the LH 2 pump, characteristic parameters of the pressure vessel, the refueling process, and the operation of the entire system are investigated. By dynamic simulation of the whole HRS system with pump and thermal compression, it is found that the specific energy consumption for hydrogen refueling is reduced to 0.55 kWh/kg, with the pump consuming 0.2 kWh/kg while thermal compression consuming 0.35 kWh/kg. After optimizing control strategies, the cycle venting of the pressure vessel and the residual hydrogen gas after re-heating and pressurization account for only 11.6%, and further utilization through the pump pressurization cycle can achieve high utilization with no residuals. This system effectively reduces the initial investment and energy consumption for LH 2 HRSs. It simplifies the structure, facilitating the retrofit of existing stations and promoting the construction and application of HRSs. [Display omitted] • An advanced hydrogen refueling station with pump and thermal compression is proposed. • A simulation model is developed for HRS with pump and thermal compression. • Thermodynamic analysis of HRS with pump and thermal compression is conducted. [ABSTRACT FROM AUTHOR]

• A traditional R134a and a novel R744 cooling units are compared over their lifetime. • Dynamic numerical simulations are used to assess the performance during operation. • The total carbon footprint of the units is evaluated from a life cycle perspective. • On annual basis, the R744 unit COP is 27.5 % higher than the R134a unit. • The lifetime carbon footprint of the R744 unit is 34.8 % lower than the R134a unit. In recent years, the temperature-controlled transport sector has experienced a substantial growth, and this trend is expected to accelerate in the coming years. However, as the sector expands, it becomes imperative to address and mitigate the carbon footprint of transport refrigeration systems. The carbon footprint of a refrigeration system comprises both direct emissions from refrigerant leakage and indirect emissions derived from energy consumption. In this study, dynamic numerical simulations are used to evaluate the annual performance of a conventional HFC (R134a) transport refrigeration unit and of a newly developed natural refrigerant (R744) one employed in a multi-drop delivery mission in urban environment. Additionally, a simplified life cycle approach is used to compare the carbon footprint of these cooling units across various stages of the system supply chain, including refrigerant production and recycling, unit manufacturing, operation and disposal. Results show that the R744 unit presents significantly higher COP for high ambient temperatures, while its performance is degraded for low ambient temperatures due to low duty cycle. On annual basis, the R744 unit COP is 27.5 % higher than the R134a one. However, the increased weight of the R744 unit results in significantly higher emissions associated with fuel consumption required to transport the unit weight, leading to slightly higher fuel related emissions (+9.3 %) for the R744 unit. Nevertheless, the high GWP of R134a contributes to substantial direct emissions due to refrigerant leakages, resulting in an overall 31.9 % reduction in the lifetime CO 2 equivalent emissions for the R744 unit when considering the total emissions. [ABSTRACT FROM AUTHOR]

The integration of offshore wind energy into Power‐to‐X (PtX) process chains offers opportunities for the efficient use of renewable energy. This article analyzes different PtX process chain configurations and their adaptation to the offshore environment. However, direct coupling of PtX platforms with fluctuating electrical energy poses major challenges. Dynamic process simulation is presented for analysis of different plant configurations and operating strategies. The article emphasizes the need for interdisciplinary research to consider technological as well as economic and environmental aspects. [ABSTRACT FROM AUTHOR]

The South African mining sector depends on intensive energy usage to extract minerals. Most of this energy is used to enhance underground working conditions through cooling. Electricity costs have been on the rise, reducing the profitability of mines. Mines must invest in management systems that optimise energy usage while maintaining underground conditions. Dynamic simulation models are critical for systems analysis, optimal management, and improved decision-making. This paper presents an integrated dynamic simulation model for deeplevel mine cooling systems. The model was developed using Process ToolBox simulation software, and a Mean Average Percentage Error of 3.53% was achieved. The impact of load curtailment on underground services was simulated. Eight working areas exceeded the legal limit of 32.5 °C, and the steady state simulation underestimated the impact, as only three working areas were affected. The simulation was sensitive to the ambient conditions; high temperatures were noted in the working areas when the ambient temperatures peaked. [ABSTRACT FROM AUTHOR]

In order to reduce global energy consumption, energy-efficient, green and smart buildings should be built. In addition to the application of other energy efficiency measures, effective management of heating, ventilation and air conditioning (HVAC) systems are also required. High-quality management and control of those systems ensures optimal occupant comfort, proper operation, rational energy consumption, and a positive impact on the environment. This is especially important for large buildings with complex systems such as hotels. As a contribution to the creation of appropriate tools for the management and control of HVAC systems in smart buildings, this paper presents the results of the development of a detailed dynamic simulation model based on data collected from a smart room system in a hotel in Zagreb, Croatia. The smart room system provides historical data on a set and actual room temperatures, occupancy schedule, windows openings, fan coil unit (FCU) operating status, fan speed, control valve opening, and heating or cooling modes with a time step of 5 minutes. The simulation model based on TRNSYS software uses part of the available data and predicts the room temperatures. A comparison of the predicted and measured temperatures at each time step shows that the deviations of the manually calibrated model are within acceptable standardized limits. The developed model has been applied to identify major anomalies in the operation of the FCU system, yielding promising results. [ABSTRACT FROM AUTHOR]

As the urgency to mitigate climate change intensifies, the achievement of zero carbon targets in the built environment has become a critical objective. Building retrofitting plays a vital role in reducing energy consumption and carbon emissions in existing buildings. This paper presents an approach that combines Building Information Modeling (BIM) with multiple domains to strive for zero carbon targets in building retrofit projects. The proposed approach is based on a dynamic multi-parameter analysis that integrates indoor comfort, energy savings, CO2eq reduction, and the social cost of carbon while considering investment costs. Renewable energy technologies, such as photovoltaic panels and solar thermal systems, are emphasized to achieve the desired zero-carbon outcomes. Real-time monitoring mechanisms enable continuous performance evaluation and adaptive retrofit strategies for further energy savings. This approach is validated through a case study of an existing thermal bath building, known as "Terme Lucane", located in southern Italy. The results of the study demonstrate significant reductions in energy consumption and carbon emissions, highlighting the potential of the proposed approach to achieve zero carbon targets through the integration of multi-data BIM implementation. These findings offer a promising pathway for building retrofit projects aiming for zero carbon targets through multi-data BIM modeling. [ABSTRACT FROM AUTHOR]

Building a reliable energy model for old residential buildings with insufficient documentation and user assistance is a challenging and time-consuming task. Nevertheless, the ambitious European decarbonization targets require this building stock to be renovated, making energy assessment a key priority. In line with this goal, the following study explores a more simplified and automatic framework to generate a residential building energy model (BEM). The paper's approach is based on the concept of urban building energy modelling (UBEM) archetypes or building prototypes and is customized according to the principles of dynamic simulations performed in the existing BEM software, Integrated Environmental Solutions Virtual Environment IES VE, and Solemma Open Studio. Therefore, based on three real starting inputs, a prototype database (DB) of assigned inputs is generated, i.e., an input matrix, using Google Maps as a geometry source. Other data are drawn from tabular DB. The proposed approach is evaluated by benchmarking the simulation results with precise models and monitoring the data that come from the Horizon2020 project REZBUILD. Nevertheless, a level of simplification is introduced that creates less accurate results for total or system-level energy consumption; this is compensated for using a set of simple calibration steps. The approach gives promising results for daily indoor temperature, making it a suitable indicator for evaluating further retrofitting alternatives. [ABSTRACT FROM AUTHOR]

Parabolic Trough Solar Receiver-Reactor (PTSRR) of Methanol Decomposition Reaction process (MDR), which can achieve chemical storage and efficient utilization of solar energy, has gained increasing attention recently. To comprehensively study the performance of PTSRR of MDR under off-design conditions and during dynamic processes, a model of PTSRR-MDR is developed and validated. Detailed energy and exergy analysis model are developed to figure out the irreversibility distribution. Results indicate that exergy destructions caused by solar concentrating and thermochemical reaction processes limit the improvement of exergy efficiency, which account 39.32% and 18.32%, respectively, under 800 DNI. When DNI step decreases from 800 to 400 W m−2, the methanol conversion rate decreases from 90.0% to 40.9% in ∼400 s. The solar-to-chemical exergy efficiency increases from 16.39% to 32.80% immediately, then decreases to the lowest value in 30 s, and rises to 11.23%. The efficiency is lower than the stable value transiently because the exergy stored in solid phase is partly destructed when converted to chemical exergy. Then, dynamic performance under DNI step increase is studied. Due to thermal inertia, additional chemical energy and exergy are gained or lost, compared to the ideal process. The results may provide some guidance for further efficient operation control. [ABSTRACT FROM AUTHOR]

Aedes aegypti (A. aegypti) is the principal vector for several diseases and despite having synthetic repellents to curb its feeding and transmission, they pose a threat to humans upon chronic use. Therefore, this study explores natural alternative thymol, via both structural and molecular binding properties against whole proteome targets of A. using a multi-target approach. Properties of thymol were studied using ProTox-II to determine the toxicity class. A preliminary screening of the proteome of A. aegypti was performed using existing microarray data analysis, conserved domain studies and protein modelling to narrow down the target categories. RaptorX standalone high-computing server was utilised for 309 protein structure modelling. Molecular docking was performed for 20 shortlisted protein categories against thymol, and top three docked complexes were simulated at 100 ns. Results showed that thymol belonged to class 4 low-toxicity, and molecular docking and 100 ns simulations in dynamic environment revealed stable complexes of thymol with glutathione-S-transferase (GST), octopamine receptor and glutamate-gated chloride channels (GGCC). Free energy binding via molecular mechanics revealed thymol with GST and GGCC to be stable. Our multi-target study presents insights into the molecular binding events that take place when thymol binds to newly identified A. aegypti targets. [ABSTRACT FROM AUTHOR]

The building sector greatly contributes to energy consumption and Greenhouse Gas emissions, relating to the whole building life cycle. Boasting a huge building heritage of historical and architectural value, Europe faces challenging retrofit perspectives, as the potential for high energy efficiency has to be exploited while preserving the buildings' original characteristics. The present work aims to feature the influence of a passive strategy on a heritage building in a mild climate. As historical its façade cannot be modified, its large glazing areas involve multiple issues, such as an increase in the heating ( Q H) and cooling ( Q C ) energy demands and the risk of thermal discomfort. Thus, window replacement was proposed for retrofitting. A dynamic simulation model in TRNSYS was validated with experimental data collected by the continuous monitoring of walls of different thicknesses and orientations. Solutions from replacement with Double Glazing Units (DGUs) with improved thermal insulation, to internal shading activation were applied. All configurations were compared in terms of Q H , Q C , thermal performance of the building and user comfort (Fanger). Low-e DGU enabled the saving of up to 14% of the annual energy demand, and shading also offered good results in summer, reducing Q C by 19%. In summer, DGU involved a maximum PPD reduction of 10 units. [ABSTRACT FROM AUTHOR]

The railway sector's energy impact is increasing, and this trend is expected to persist over the next decade. Particularly, the energy consumption of Heating Ventilation, and Air Conditioning (HVAC) systems is significant among various services provided on board (30 % of total energy requirements) due to the rising attention to passengers' thermal comfort. In this framework, this research proposes an innovative method for enhancing indoor thermal comfort while also studying the associated energy consequences. It consists of an advanced passenger-centric-control framework for HVAC systems that prioritizes comfort, utilising optimized indoor air setpoints, which surpasses the rule-based control logic proposed by the existing standards. To analyse the proposed control framework, a novel mathematical model for the energy, economic, and environmental performance analyses of train HVAC systems, which can incorporate weather data associated with actual railway paths, is developed and validated. To prove the potential of the proposed method, a proof-of-concept analysis is conducted. In particular, for an existing railway coach operating in Italy, the standard and the innovative control logic are tested and compared. The results show an interesting thermal comfort hours increase (≃+1000 h) and energy savings (−27 % yearly), proving the benefits potentially achievable by adopting the proposed method. • Train cars' energy and thermal comfort assessment through dynamic simulation. • Investigation on railway carriages' indoor thermal comfort enhancement. • Development of an innovative passenger-centric HVAC system control framework. • Improved thermal comfort (+1000 h) and energy efficiency (−2.5MWh el) are achieved. [ABSTRACT FROM AUTHOR]

Gas–electricity integrated energy systems (GE-IES) offers a promising solution for enhancing energy efficiency and accommodating renewable energy sources. Accurate dynamic simulation is essential for optimizing and controlling GE-IES. However, the presence of various local controllers introduces prominent discrete characteristics, posing challenges for the dynamic simulation of the GE-IES. This paper investigates the dynamic simulation method in GE-IES with discrete characteristics. Firstly, we propose an adaptive step size simulation method based on quantized state system theory. This method maintains the event-driven characteristics of the quantized state integration algorithms, while enhancing computational speed through adaptive step size adjustments. Secondly, we establish an event-driven simulation framework that facilitates interactions of different subsystems during the dynamic simulation, improving the compatibility with various models and solving algorithms. Finally, we validate the accuracy, efficiency, and scalability of the proposed method and the framework using two typical GE-IES cases with different scales. Simulation results demonstrate the effectiveness on the dynamic simulation of GE-IES and highlight the feasibility of natural gas networks in consuming and storing surplus renewable energy. • An adaptive step size, 2nd/3rd-order quantized state system simulation method is proposed. • A comprehensive event-driven simulation framework incorporating both state-discretized and time-discretized methods is established. • Improved performance is achieved in simulating gas–electricity integrated energy systems with discrete characteristics. • The effectiveness in analyzing operation strategy and fault dynamics is verified. [ABSTRACT FROM AUTHOR]

• The steady state and dynamic BOG re-liquefaction techniques are analyzed and compared in this research. • The existing steady-state simulation techniques are summarized and analyzed from three aspects: structure, parameters and optimization methods. • This paper analyzes the technology of dynamic simulation and points out the opportunities and difficulties in the future development of BOG dynamic simulation. • The existing system evaluation parameters are summarized and the system is analyzed from the comprehensive point of view. Over the past few years, liquefied natural gas (LNG) evaporated gas re-liquefaction technology has rapidly developed. This technology is particularly useful in trans -oceanic LNG trade, which has grown to be a hot sector in the world's energy trade. And there are several limitations on board. Reducing energy consumption, improving efficiency, and lowering costs are crucial factors in the BOG re-liquefaction process. This review provides a comprehensive review of the recent advancements in the design and optimization of BOG re-liquefaction processes. It includes a detailed analysis and comparison of existing BOG re-liquefaction technologies, and specifically discusses two types of re-liquefaction processes: dynamic and steady-state. Furthermore, this review examines different perspectives and directions for improving these two re-liquefaction technologies. Finally, the challenges faced by the BOG re-liquefaction process for LNG carriers are presented, along with future directions for addressing these challenges. [ABSTRACT FROM AUTHOR]

Residential buildings account for 84 % of Italy's built environment, playing a pivotal role in the EU's aim to cut GHG emissions by 55 % through enhanced energy efficiency and climate adaptation. This necessitates comprehensive energy retrofit initiatives, especially in sectors like social housing, which has been relatively overlooked in terms of energy efficiency strategies. This study focuses on a multi-story building from the 1980s in Rome, implementing an innovative energy system proposed by the RESHeat European project. This system, aimed at standardizing energy retrofits for late 20th-century social housing, leverages the underexplored potential of water-source heat pump (WSHP) systems. The novelty of this research extends to its examination of multi-family housing, a sector that has seen less attention compared to public spaces and smaller residential buildings. Through experimental validation and annual dynamic simulations using TRNSYS and Simulink, the research compares the existing heating system with a proposed upgrade that includes a WSHP and Photovoltaic-Thermal (PVT) panels. This upgrade demonstrated a significant efficiency improvement, achieving an annual COP of 6.1 for the WSHP and a 36 % Primary Energy Savings (PES) from the PVT panels, showcasing the effectiveness of these technologies in enhancing the energy profile of multi-family residential buildings. [Display omitted] • A multi-energy system for a 1980s social housing in mild climate is presented. • A dynamic model based on a water-source HP and cooled PV panels was set. • Experimental validation of building and plant components were conducted. • Combining heat pump and PVT panels a seasonal COP of 5.4 can be achieved in heating. • Solar fraction of 0.98 ensured by PVT contributes to a Primary Energy Saving of 36 %. [ABSTRACT FROM AUTHOR]

In this study, two processes of predictive model combining dynamic simulation and regression model were presented. First, (1) the demand forecasting process defined in this study is a method of predicting energy consumption based on the simulated energy consumption of a target building, and (2) the energy saving process is a method of setting an energy reduction target based on the predicted energy consumption and providing energy saving measures to achieve the target. Specifically, there are two functions based on the regression models which are predicting actual energy consumption by inputting the energy consumption simulation data, and inversely inputting the actual energy consumption and deriving the corresponding simulation conditions. As a result of predicting building energy consumption through the demand forecasting process, the performance in the heating season showed CV-RMSE was 14.622%, and in the cooling season CV-RMSE was 5.877%. In addition, in the case study using the energy saving process, it was possible to derive the heating and cooling set temperature for 5% energy saving as an energy saving method by using weather forecast data. • Demand forecasting and energy saving of buildings. • Regression model-based process between simulation-based predictions and actual energy consumption. • Two processes combining TRNSYS and DNN model to ensure building energy management efficiency. [ABSTRACT FROM AUTHOR]

• The heat and mass transfer in DED was simulated by dynamic coupling. • The interactions between the multiphase flow and heat transfer were established. • The relationship between the powder features and the melt pool size was studied. Powder flow can affect the temperature variations in directed energy deposition (DED). However, the direct coupling mechanism remains unknown. To solve this problem, the heat and mass transfer in additive manufacturing was simulated using dynamic coupling. The interactions between the multiphase flow and heat transfer were established. A comparison with experiment shows that the accuracy of the predictions of the numerical simulation regarding powder size distributions and temperature increases is higher than 95 %. The average temperature increase of the metal powders with different weight functions was highly consistent in the simulation process. As the powder size increases, the average temperature of the powder on the printing plane decreases. This was the reason for the formation of a deeper melt pool in the case of smaller particles in the experiment. The different curvatures between the particle surface and melt pool surface lead to a decreased energy absorption efficiency in DED. The relationship between the powder features and the melt pool size was studied. A decrease in the powder flow rate increased the temperature, leading to a larger melt depth. [Display omitted] [ABSTRACT FROM AUTHOR]

Thermal bridges constitute a significant share in the overall heat losses through building partitions. This is an important issue not only in traditional but also ecological buildings, where the load-bearing structure is often a wooden frame. In partitions insulated with hemp-lime composite, the skeleton is usually hidden in the insulation. However, in some nodes or jambs, wooden elements may be exposed or have a large cross-section, intensifying the heat transfer. This work presents simulations of energy demand in a single-family building insulated with hemp-lime composite, using the BSim dynamic simulation program. The calculations take into account the linear thermal transmittance of structural nodes modeled in the THERM program. The energy demand for heating and the share of thermal bridges in the heat loss of the entire building were calculated for different locations of the structural framework in the walls, as well as the size and number of windows. The share of thermal bridges in heat losses was about 10%, and the differences in energy demand for heating using various frame locations in the wall were negligible. [ABSTRACT FROM AUTHOR]

The large net torque fluctuations in the reducer output shafts of conventional beam pumping units and the existence of negative torque are the decisive factors that lead to their low efficiency and high energy consumption. This study developed a positive torque modulation scheme for conventional beam pumping units, which was based on the principle of the follow-up secondary balance of the connecting rod. The CYJ10-4.2-53HF conventional beam pumping unit was selected as the research object. The kinematic and dynamic simulation analysis of the modified pumping unit was carried out using ADAMS software. The results showed that secondary balance torque curves could realize the function of "peak cutting and valley filling" for the curves after the primary balance and that the modified pumping unit could achieve a full-cycle positive value for the reducer output shaft and verify the feasibility of our modulation scheme. A secondary balance offset angle of 315° was the best choice as the amplitude of the torque curve clearly increased and the phase remained basically the same when the radius of the mass center of the secondary balance increased. Therefore, when the offset angle value of the secondary balance weight was determined, the radius of the mass center could be changed by adjusting the position of the secondary balance weight to achieve the balance adjustment. [ABSTRACT FROM AUTHOR]

In this study, a practical fuel cell vehicle considering the Heating, Ventilation, and Air conditioning system is considered to analyze hydrogen consumption under different working conditions. As a prevalent hydrogen-fueled vehicle, Toyota Mirai has been meticulously modeled in Simecenter Amesim software. The simulated model covers all of the vehicle's components with a concentration on Heating, Ventilation, and Air conditioning system. Since the air temperature and 'weather conditions can significantly impact the vehicle's overall performance, various environmental conditions, including temperature variations, humidity, and varied solar fluxes, are taken into account. Furthermore, New York City is chosen as a densely populated megacity to simulate the dynamic behavior of the fuel cell vehicle under actual driving circumstances. The results illustrate that the Heating, Ventilation, and Air conditioning system can notably alter hydrogen consumption under real driving conditions. In this regard, turning on the Heating, Ventilation, and Air Conditioning system results in a 19% increase in fuel consumption. Moreover, the degradation phenomenon, which is a typical result of using fuel cell vehicles under urban driving conditions, impacts the vehicle's mileage and hydrogen consumption. The simulation results indicate that a fresh fuel cell stack consumes 80 g of hydrogen, while for 2500 and 5500 working hours fuel cells, the stack consumes 89.6 and 107 g of hydrogen, respectively. Based on the obtained results, a 33.75% increase in fuel consumption occurs by implementing a degraded fuel cell stack under real driving conditions. • Toyota Mirai hydrogen-fueled vehicle is modeled precisely in Simcenter Amesim software considering Heating, Ventilation, and Air conditioning system. • Various climate conditions, including temperature changes, humidity differences, different solar powers, and four different vehicle's colors are considered. • Vehicle performance under real driving conditions in New York City is analyzed to model the overall vehicle's performance dynamically. • Hydrogen consumption under different climate conditions is recorded, and the results have been discussed. [ABSTRACT FROM AUTHOR]

Solar energy systems are an effective way to meet the needs of zone heating, cooling, electricity, and domestic hot water. However, to reach sustainability, and energy storage unit should be considered for installation. In this study, two combined cooling, heating and power (CCHP) systems are simulated and studied using TRNSYS software; both using natural gas engine generators and photovoltaics as prime movers and a hydrogen fuel cell/electrolyzer storage unit, one with absorption chiller and another with compression chiller cooling. For the study, a residential building is modeled for three major populated climate zones of the United States of America, namely, Hot-humid, mixed-humid and cold using DesignBuilder and EnergyPlus software. The energy demand for its HVAC operation and domestic electricity is obtained and used for system simulation in TRNSYS software. Due to choosing actual equipment for the CCHP arrangement, precise economic and environmental models are designed to further evaluate the possibility of execution of the system. The results show that absorption chiller-equipped CCHP has better performance both environmentally and economically. In addition, the outcome shows that the suggested systems show less favorability to be utilized in hot humid climate zones. • Design a multi objective optimization system with TRNSYS simulator. • Various geographical location is considered for study the proposed system. • Designed system with chiller in colder climates has less Carbon-dioxide emission. • Hot climate leads to a higher energy consumption in the designed unit. [ABSTRACT FROM AUTHOR]

Revealing the long-term development trajectory and peak scenarios of the urban residential building sector is crucial for formulating targeted emission reduction strategies and contributing to achieving the "Dual carbon" target. Given that, significant variables affecting carbon emissions from urban residential buildings (URBCE) at both macro and end-use building levels are identified in this study. Furthermore, an innovative dynamic simulation model is developed by integrating the Monte Carlo simulation model with the Kaya identity model, taking into account the uncertainties of the variables. Subsequently, the long-term evolution trajectories, potential emission peaks, and peak time of the URBCE close to 2060 in China's hot summer and cold winter (HSCW) zone are simulated. Results indicate that URBCE is expected to reach its peak of 272.43 Mt CO 2 in 2040 under the baseline scenario. Through the dynamic simulation, the probable peak time of energy consumption in the HSCW zone is 2044 (±1.85), with a peak of 145.42 (±6.91) Mtce, and the possible peak time of carbon emissions is probably 2039 (±1.60), with a peak of 271.93 (±13.40) Mt CO 2. According to dynamic sensitivity analysis, carbon emission factor, per capita residential space, and heating energy intensity can promote the peak size and timing. These findings lay a robust foundation for the formulation of regionally specific carbon reduction targets and initiatives. Dynamic simulation results of peaking time and peak value of URBEC and URBCE. [Display omitted] [ABSTRACT FROM AUTHOR]

• Optimal operation of a large-scale gas sweetening plant was conducted by application of self-optimizing control and model predictive control. • Optimization of the process was performed using surrogate models based on neural networks. • Performance analysis of the proposed control structure using traditional PIDs and modern multivariable MPCs was carried out using dynamic simulation. The most common method of removing acid gases from natural gas is through the use of solvent-based gas sweetening plants, which are energy-intensive. The present study aims to establish a plant-wide structure to operate natural gas sweetening plants optimally. Thus, a steady-state simulation of the Khangiran plant was carried out, and a 17% reduction in energy usage was achieved as a result of the optimization by the application of surrogate models. The self-optimizing method was applied to find the best set of controlled variables (CVs). There was found one unconstrained degree of freedom (DOF). The best CV for the remaining DOF was found to be the top stage temperature of the regenerator. Aspen Plus Dynamics was used to examine the performance of the proposed control structure utilizing simple traditional PIDs and compare it to modern feedback and feedforward MPCs. [Display omitted] [ABSTRACT FROM AUTHOR]

One of the strategies for achieving sustainable development goals is to close the gap between environmental vulnerability and economic progress (SDGs). The significance of renewable energy in harmonizing environmental and economic conditions is becoming a touchy subject in current debates. Against this backdrop, the major objective of this paper is to assess whether economic growth and environmental sustainability can promote renewable energy consumption in the Indian economy by using ARDL and Novel Dynamic ARDL estimation techniques. The results obtained from both the methodology shows that rising efficiency in the economic growth coupled with environmental sustainability leads to an increase in renewable energy consumption. We also find, from the frequency domain causality test, that there is a unidirectional causality between renewable energy consumption and economic growth & renewable energy consumption and environmental sustainability in both the short- and long run. The former causation validating the conservation hypothesis for the Indian economy. [ABSTRACT FROM AUTHOR]

The industrial sector is one of the biggest oil consumers in Cyprus, corresponding to 20% of the fuel consumption. A parabolic trough collector (PTC) system seems the best option to produce clean thermal energy at higher temperatures than those that can be achieved from the already widely used flat plate collectors on the island. This paper presents a simulation model built to investigate the performance of the first industrial PTC system in Cyprus, installed at the Cyprus biggest soft drinks factory. The simulation model is built in TRNSYS and is validated using data from the real PTC system installed at the factory. The results show a very good fitting between the operating parameters and the power output of the Solar Field (SF), Concrete Thermal Storage System (CTES), and the Steam Generator (SG). The average percentage relative error of the system's contribution to the process is less than 6.32% for the daily steam production and during a week did not exceed 6.45%. The novelty of this study is the development of a design tool that can be used by potential interested industries to identify the suitable system that fits their needs. All data are provided in the form of graphs and allow anyone to use as input data the thermal energy demand and required steam temperature of the industry to retrieve information about the size of a suitable system which satisfies these requirements depending on each case. The payback period for all cases examined varies from 2 to 6 years, depending on the size of the system. • Validated dynamic simulation model of a PTC system working under various operation modes for Industrial Process Heat application. • Evaluation of the operation modes and strategies developed to make the PTC system dispatchable. • A scaled up model for of the validated dynamic simulation model. • Development of a tool for potential interested industries in Cyprus for PTC systems. [ABSTRACT FROM AUTHOR]

Sensible thermal energy storage is the most common solution for small-to-medium solar process heat systems. Hence, it is vital to enhance the thermal stratification and energy utilization of stratified tanks. In this study, four process heat systems are dynamically simulated: 1) S0 with a single outlet port to the load, 2) S1 with a single port and a thermostatic mixing valve, 3) M0 with multiple ports, and 4) M1 with multiple ports and a mixing valve. Two novel models are proposed for the compound parabolic collectors and the stratified tanks. System M1, with annual system efficiency of 47.3% and solar fraction of 0.57, was found to be the best-performing one, followed by S1, M0, and S0. System M1 also reduced the annual energy consumption of the backup heater in S0 by 16.45%. The thermostatic mixing valve reduced the thermocline thickness. The incorporation of both mixing valve and multiple ports delayed the startup of the heater, reduced the system's thermal losses, and slightly improved the collectors' efficiencies. The proposed tank model can be a viable tool for solar energy designers to optimize the number and relative positions of the inlet and outlet ports for maximized system efficiency and solar coverage. [Display omitted] [ABSTRACT FROM AUTHOR]

Thailand's Nationally Determined Contribution (NDC) intends to minimize CO2 emissions by 20–25%. Similarly, to focus on achieving the Paris Agreement's long-term target of remaining well below 2 °C, aggressive mitigation steps are necessary beyond 2030. Given the importance, the study examines the impact of energy depletion rate, renewable energy consumption, depletion rate of non-renewable energy, and GDP on CO2 emissions in Thailand from 1980 to 2018. The research using a novel dynamic ARDL simulations model [1] and frequency domain causality (FDC) test. The empirical outcomes indicate that the pace of depletion has a significant adverse impact on CO2 emissions both in the long run and short run. Additionally, we found that renewable energy has a negative and statistically significant impact on CO2 emissions in the short run. However, the depletion rate of non-renewable energy and GDP revealed a positive and statistically substantial effects on CO2 emissions in the short and long run. Also, the FDC test confirmed the short, medium, and long-run causality among DR, RE, DRNRE, and CO2 emission. The findings show that without a radical shift in Thailand's economic environment and energy infrastructure, the nation will have to face high costs in decreasing its CO2 emission. • Examines relationship between DR, RE, DRNRE, and GDP with CO2 emission. • The time series data collected from 1980 to 2018 in Thailand. • The study employed novel dynamic Autoregressive Distributed lag (ARDL) model. • We found depletion rate (DR) significant impact on CO2 emissions in long and short run. • Also, DRNRE and GDP revealed significant effect on CO2 emissions in long and short run. [ABSTRACT FROM AUTHOR]

In top coal caving mining, common impact occurs between coal gangue particles and tail beam. Little attention has been paid to the effects of coal gangue particles failure on impact force and tail beam response theoretically, numerically, and experimentally. This paper aims to reveal the influence of coal gangue particles failure on the impact effect of tail beam. First, this paper incorporates the theory of rock failure and energy consumption to assess the impact process of coal gangue particles on the tail beam. A new model to simulate the actual failure conditions of rock particles was developed: the brittle damage-fracture particle model. By comparing damage phenomena and simulation data, the brittle damage-fracture particle model was proved to be correct. Based on this model, a dynamic simulation of brittle coal gangue particles impacting the tail beam was conducted. Then, the dynamic responses of the particles and tail beam were analyzed. The results show that particle failure significantly affects the impact force and dynamic response of the tail beam. The impact effects of coal and gangue particles on the tail beam and their failure energy consumption also differed significantly. This paper stresses the importance of coal gangue particle failure conditions for research on top coal caving mining. Theoretical support is provided for the research of coal gangue identification technology based on the tail beam vibration signal. [ABSTRACT FROM AUTHOR]

This study aims to investigate the effect of demand response (DR) on power and energy flexibilities with three types of district heated buildings (apartment building, cultural center, and office building) in Finland and Germany. A rule-based control algorithm was applied for the DR control with two country-specific dynamic district heating (DH) prices, the more fluctuating Finnish synthetic DH price and the flatter German synthetic DH price. This research was implemented with the validated dynamic building simulation tool IDA ICE. Set-point smoothing of the indoor air temperature was applied to minimize the rebound effect. Nighttime set-back was adopted in the cultural center and the office building. The results show that the DR control without smoothing creates additional peaks in power demand, while the set-point smoothing significantly decreases the peak power demand. The DR control can significantly shape the heating power demand of the buildings and increase energy flexibility. The range of the resultant seasonal energy flexibility factors is from 3 to 26% for charging and from −6 to −31% for discharging, depending on the building types and countries. Cases with nighttime set-back have higher power and energy flexibilities, while this causes additional peaks, which is detrimental to DH systems. [ABSTRACT FROM AUTHOR]

The theme of the energy requalification of historic buildings is addressed considering the Palaeontology Museum of Naples (Southern Italy). It is assessed whether, through non-invasive methods and without intervening on the building envelope, it is possible to obtain internal hygrothermal parameters suitable to allow both occupants' thermal comfort and satisfactory conservation conditions for the archaeological finds. In addition, a relevant reduction of energy requirements and CO2 equivalent emissions is required. Dynamic energy simulations are conducted regarding both the current configuration and the various possible modifications concerning the air conditioning system; the model is calibrated by comparison with real energy consumption data. The electric and primary energy are compared for the various cases. Furthermore, the internal hygrothermal conditions for occupants' thermal comfort and for conservation of the archaeological finds are analysed. Finally, the possibility of inserting a suitable and minimally invasive photovoltaic system is evaluated and an almost 'Double Plus-Zero Energy Building' is obtained. [ABSTRACT FROM AUTHOR]

This study investigates the influence of glazing characteristics and shading device configuration on energy use and cost, daylighting performance and visual comfort. A typical patient room from a hospital design in Belgium is used as a baseline scenario and different window design alternatives are explored through parametric modeling. Based on the comparative analysis, the article discusses potential design options that allow for energy efficient and daylit patient rooms with higher visual comfort. The methodology combines dynamic energy simulations, daylighting and glare analysis. The results show that glazing characteristics and shading device configuration have a major impact on energy use/cost, daylighting and visual comfort and to achieve an overall good performance, selecting the right window configuration is essential. The findings indicate that pairing windows with suitable louvers configuration leads to a 40–80% reduction in cooling loads while maintaining sufficient daylighting levels (sDA300/50%>55) and reducing the UDI>3000lux values ca. 70%. The results suggest that the ASE metric may not provide a realistic picture regarding glare probability when we are aiming at controlling glare in specific locations within the room. This study emphasizes the need for integrated performance analysis in order to obtain a correct insight into the window systems performance. The proposed integrated approach can hence support design decisions regarding the most preferred window system to better fulfill the project objectives. [ABSTRACT FROM AUTHOR]

This paper discusses the effects of vegetation shading on the energy consumption of a detached passive building with a sunspace in winter and summer conditions. The presented study was conducted by means of a dynamic simulation using EnergyPlus software for a created MODEL building with a sunspace. Nine different subvariants of vegetation planting adjacent to the building were established in order to determine the effects of vegetation shading on the energy required for heating and cooling. The subvariants comprise vegetation planted 5 m and 10 m away from the south-, east, and west-facing façades. The simulation results for different vegetation subvariants and for window-to-wall ratios WWR=20%, WWR=40%, and WWR=60%, showed that tree placement does affect a buildings’ energy performance. It was also determined that vegetation placement should be such as to make the south-facing façade shade-free while providing maximum shading of the east- and westfacing façades. The energy savings for cooling reached up to 15%, while the savings for total annual heating and cooling energy consumption reached up to 9.40%. [ABSTRACT FROM AUTHOR]

This paper reports a study on the static and dynamic behavior of pneumatic actuation systems, resulting in a comprehensive view of the influence of the system parameters on the energy efficiency and dynamic performance. The operating point approach based on the steady-state analysis of a pneumatic actuation system is used for developing analytical expressions to describe the relationship between the piston diameter and the system performance, including displacement time, stroke end velocity, and energy efficiency. The validity of the proposed equations is demonstrated by comparison with results from a test rig. Sensitivity analysis using a nonlinear dynamic simulation model indicated that a specific operating region exists, where good energy efficiency and the maximum dynamic performance are achieved. Moreover, the results show that an oversized system becomes more inefficient in both energetic and dynamic aspects. The results obtained provide a very consistent foundation for developing a method for pneumatic system sizing. [ABSTRACT FROM AUTHOR]

A nuclear heating system integrated with a heat storage tank (HST-NHS) is a promising technical solution for countries with large-scale heating demand. HST-NHS can greatly curtail carbon dioxide emissions and contribute to sustainable development. Appropriate control strategies are not only crucial to realize the real-time matching between HST-NHS heat supply and heat demand, but also ensure the stable and safe operation of HST-NHS. Until now, control strategies for HST-NHS have received limited attention. A refined dynamic simulation model for HST-NHS is established based on APROS software. The verification of the built model in steady state and transient state is completed. Two basic control strategies for the primary heating network (PHN) of HST-NHS, constant supply water temperature and variable flow rate (CT-VF) and variable supply water temperature and constant flow rate (VT-CF) are presented in detail. Based on various typical working conditions of a central heating region in Liaoyuan City, the control effects of two control strategies are investigated. Additionally, a comprehensive performance comparison between the two strategies is explored. Simulation results indicated that under the two control strategies, the indoor temperature can be effectively controlled at a high comfort level. During the same typical day, the total energy consumption cost under the VT-CF control strategy is 0.5 × 105 yuan lower than that under the CT-VF control strategy. • Dynamic model of nuclear heating system with heat storage is developed. • The verification of the built model in steady and transient state is completed. • Control effects of two basic control strategies during typical days are evaluated. • A performance comparison of two basic control strategies is conducted. [ABSTRACT FROM AUTHOR]

In the field of mines, there are dozens of methods concerned with the optimization of ventilation system in underground mines and how bad ventilation system is playing a major effect on miners and mine's activities. The ventilation system is considered very important because it consumed high energy of mines of total power consumption. This paper is a review of previous studies, which have been done before on design of ventilation system and its optimization methods like, using of software tools to simulate the numerical equations based on the pressure, temperature, flow rate, and other effected parameters, which are recorded by various ways of surveying. It has observed that Ventsim software is widely used because of its flexibility in dynamic simulation based on various parameters included deep, fan position and flow rate. [ABSTRACT FROM AUTHOR]

The high share of global energy costs to create an indoor climate has been of increasing interest to the global community for several decades and is increasingly the focus of policy. This paper analyses the energy performance gap between actual energy consumption and energy demand obtained during the dynamic energy simulation and building certification. To identify the energy performance gap, an existing office of energy efficiency class B was selected as a case study. The simulation program IDA Indoor Climate and Energy was used to create a dynamic energy model, based on the designed documentation and the actual indoor climate parameters recorded by the building management system. The results of the case study showed that the accuracy and reliability of the results presented by the dynamic energy model of the building directly depend on the assumptions. The correct values of the internal heat gains, indoor climate parameters, human behavior, air quality levels at different times of the day and season, HVAC system operation parameters and operation modes, specific fan powers of ventilation systems, the seasonal energy efficiency of cooling equipment and characteristics of sun protection measures have to be selected. [ABSTRACT FROM AUTHOR]

Solar biomass steam gasification using concentrated sunlight offers an efficient means of storing intermittent solar energy into renewable solar fuels while upgrading the carbonaceous feedstock. Such solar-driven (allothermal) processes have demonstrated the ability and the effectiveness for the production of high quality hydrogen-rich syngas, but they suffer from inherent barriers related to the variability of solar energy caused by cloud passages and shut off at night. The concept of hybrid solar/autothermal gasification appears promising to meet the requirement for stable and continuous operation under fluctuating or intermittent solar irradiation. To date, dynamic modelling to simulate coupled solar/combustion heating and steam gasification using real solar irradiation data has never been proposed and could be used to predict the annual performance of large-scale solar gasification plants. In this study, a dynamic mathematical model of a scaled-up solar gasification reactor was developed. The model was composed of a system of differential equations that were derived from unsteady mass and energy conservation equations. After an experimental validation step with the results from a lab-scale solar reactor, the dynamic model was applied at large scale to determine the reactor temperature and syngas production evolution during continuous day and night operation in both solar-only (allothermal) and hybrid solar/autothermal modes. Different reactants feeding management strategies were proposed and compared with the aim of achieving enhanced syngas productivity and optimized use of solar energy during solar-aided steam gasification. It was shown that the hybrid mode with partial oxy-combustion of the feedstock and dynamic feeding control results in the most stable process operation upon fluctuating solar power input, while ensuring continuous production of H 2 and CO at night and during cloudy periods. • A dynamic model is proposed to study the dynamic response of MW-scale solar gasifier. • The model is validated against experimental data for a lab-scale solar reactor. • The temperature and syngas production evolutions are determined using representative solar data. • Three feeding management strategies are proposed for controlled and optimized biomass conversion. • The hybrid control mode results in the highest syngas yield and continuous day and night production. [ABSTRACT FROM AUTHOR]

A micro gas turbine (MGT) is a potential option for distributed energy systems driven by fuel and solar energy. The dynamic characteristics of a solar-hybrid microturbine system are essential to its control development and performance assessment. In this paper, a dynamic model is proposed, including an MGT (T100), a tubular air receiver and a sensible thermal energy storage system, which are experimentally validated well. Based on the developed model, the dynamic responses of a solar-hybrid microturbine system in stand-alone mode are studied considering load and Direct Normal Irradiance (DNI) changes. Results show that the fuel consumption is greatly reduced by integrating solar energy, which comes at the cost of system instability; if the investigated system experiences a significant load decrease, heliostats must be oriented away from the air receiver to ensure a stable operation, whereas the load must be increased incrementally to avoid a compressor surge in the case of a significant load increase. Compared to load change, DNI change will cause smaller overshoots of the MGT's rotational speed and surge margin. The system is simulated with measured DNI and shows that the thermal energy storage can reduce the fluctuation of combustor inlet temperature from 130.8 °C to 12.8 °C. • A dynamic model including micro gas turbine, solar receiver and thermal energy storage sub-models is experimentally validated. • Dynamic performance of a solar-hybrid microturbine system is investigated with changing load or solar irradiation. • Control strates are proposed for the investigated system. • The maximum share of solar energy reaches 64.7% for the system with an electrical efficiency of 24.1%. [ABSTRACT FROM AUTHOR]

• An interdisciplinary methodology is applied on a recently restored church. • Multi-objective analysis performed for artwork conservation, thermal comfort, energy efficiency. • The experimental campaign highlighted the improvable artwork conservation conditions. • A calibrated dynamic simulation model was used to hypothesize HVAC systems. • The joint objective of artworks conservations and thermal comfort is obtainable only with high energy consumption. Indoor microclimate and energy performance analyses of historic buildings require tailored methodologies, because of their complexities, e.g. presence of artworks, lack of documents or project data and employed structure and materials. Given such difficulties, there are a few interdisciplinary methodologies, capable of carrying out multi-objective analyses for this kind of buildings, and they are often based on in situ monitoring that, however, may not be able to predict the effects deriving from different conceivable technologies and control strategies. In this work, an interdisciplinary methodology is employed for evaluating cultural heritage conservation conditions, occupants 'thermal comfort and energy performance of a specific historic building category, such as churches, on the basis of experimental and numerical approach. The methodology was applied to the case study of an ancient Italian church, recently restored following the earthquake that hit L'Aquila in 2009. After the refurbishment of the church, the statistical analysis of temperature and relative humidity experimental data allowed to observe that the conservation conditions of artistic heritage just restored may be non-correct, due to remarkable thermo-hygrometric fluctuations of the indoor microclimate. Therefore, starting from the current condition of absence of HVAC system, calibrated dynamic simulation models of the church allowed to hypothesize different technological solutions able to control the indoor microclimate and to evaluate the effects on artworks preservation, thermal comfort, and energy performance. The results of the multi-scenario analysis showed that suitable conservation conditions (PIs > 90%) and thermal comfort can be obtained by employing a complex heating/cooling and humidification/dehumidification system which determines a significant increase in energy consumption. [ABSTRACT FROM AUTHOR]

This study concerns MC Formula and the table-based protocol hydrogen fueling methods described in SAE J2601 2016 edition fueling protocols for light duty gaseous hydrogen surface vehicles. It considers the overall efficiency and performance of the two methods. This is achieved by dynamic simulations, using the Dymola hydrogen fueling station library. The MC formula and table-based methods are implemented in the library and different simulations are performed, to evaluate the performance of the two different fueling methods under various conditions. The efficiency is evaluated according to; fueling time, State of Charge levels and total energy consumption. The MC formula is up to 26% faster. The state of charge levels are similar between the table-based and MC formula. The energy consumption for the MC formula is up to 6.9% higher than for the table-based method. Comparing consecutive fuelings without recharging the station, the table-based method is able to fill 7 vehicles and the MC formula 5 vehicles. • Comparison between the average pressure ramp rate and MC hydrogen fueling methods. • Different fueling conditions are compared with respect to time end energy consumption. • Description of the methodology and equations used to implement the MC method. • The effect on consecutive fuelings depending on the fueling method. [ABSTRACT FROM AUTHOR]

This paper presents the design and testing of a full-scale 330-kV, 210-MVA transformer tank designed to withstand the pressure effects of a 20 MJ, three-cycle low-impedance fault in oil, and fail at its cover in a safe and controlled manner above that amount of energy. The transformer tank, equipped with a mockup active part, was designed for arc resistance using nonlinear static finite-element analysis and a specific rupture criterion. It was then tested using an experimental methodology based on injecting pressurized air into the water-filled tank. To adequately reproduce the effects of an arc in oil, the test parameters were determined using explicit dynamic simulations. The transformer tank performed as predicted by the finite-element and explicit dynamic simulations. The energy levels used in the tests here are, to our knowledge, the largest ever reported. This study demonstrates that it is feasible to design a power transformer to safely withstand high-energy low-impedance faults of short duration. [ABSTRACT FROM AUTHOR]

The object of this research work is the comparison of the annual primary energy consumption of different types of heating systems, using two different calculation methods. The TRNSYS 18 software makes use of dynamic simulation, while the WinWatt software calculates according to the Hungarian implementation of EPBD (Decree No. 7/2006). There were differences in results which could be caused by the more precise calculation of the TRNSYS software. Differences were shown also in the weather data used by the two computer tools that had one of the most important effects on the results according this investigation. The number of heating degree days used by TRNSYS is 10% less, than that the Hungarian decree provides. Using the yearly measured energy consumption data given by the inhabitant of the investigated family house, the validation of the developed dynamic building energy simulation model by TRNSYS could be also achieved with good agreement. [ABSTRACT FROM AUTHOR]

Energy certification of buildings in Serbia was introduced in 2011 and energy label depends on energy need for heating per unit floor area of heated space, calculated by the fully prescribed monthly quasi-steady-state method defined by ISO 13790. In the Republic of Serbia, most of families live in single-family houses built before the energy certification of buildings was introduced. Therefore, the estimation of energy performance of the existing buildings is important for labeling, and evaluation of energy saving measures and energy strategies to be implemented. This paper examines the applicability of monthly method defined by National legislation on the existing buildings stock in Serbia, by comparing it to the more accurate dynamic simulation method. Typical singlefamily houses are taken as a test case, since they are responsible for about 76% of energy consumption for heating. The results show that the dynamic simulation method estimates 21% to 54% higher energy need for heating, compared to the monthly method. Also, the monthly method estimates up to 13% higher savings by typical building envelope energy saving measures, compared to the dynamic simulation. This paper recommends improvement in procedures for calculation of building energy performance index to better assess energy consumption, effects of energy saving measures, and create solid background for developing and implementing of energy saving strategies. [ABSTRACT FROM AUTHOR]

The temperature has a significant effect on the lifespan and the safety of the batteries which are one of the core components of electric vehicles. A well-designed battery thermal management system is required to adjust the temperature of the batteries within an appropriate range for thermal safety, and further minimize the energy consumption for energy savings. However, these two goals form a tradeoff. Typically, increased energy consumption for cooling results in safer batteries thermally. To examine this tradeoff, firstly, a linear electro-thermal model is built to evaluate the thermal dynamics of the operating battery-cooling module. The linear model accounts for the heat generation based on internal resistance, and the heat transfer based on a resistance–capacitance model. Such linear model reduces the computation of the model simulation to dynamically catch up with the change of temperatures and to implement control strategies on the cooling system in a short time. Based on this model, a model predictive control (MPC) framework is proposed to design thermal control methods, which considers both thermal safety and energy saving. The weight of these two goals can be adjusted to explore the tradeoff between them. Finally, we investigate the performance of the MPC framework by applying the Urban Dynamometer Driving Schedule (UDDS) to the battery module. The simulation results show that the electro-thermal model is effective for battery thermal dynamics evaluation. Additionally, the tradeoff between the two goals is demonstrated by the simulation. • A fast temperature prediction and closed-loop thermal control framework is proposed. • An electro-thermal model of an active-liquid-cooling battery module is developed. • A thermal prevention control strategy is proposed. [ABSTRACT FROM AUTHOR]

In this paper a novel dynamic simulation model for enhancing the sustainability of transportation systems equipped with diesel co-generators is presented. In each simulation time step of the carried out energy performance analyses, the best operation/combination of generators as well as their optimal part load ratio are determined with the aim to achieve the minimum fuel consumption. Input to the model are: size of each installed diesel generator; number of engines; required power profile; route scheduling and hourly weather data. The developed simulation model is implemented in TRNSYS environment. Here, a new in-house TRNSYS type written in Fortran is also included. With the presented approach - especially helpful for cruise ship designers, manufacturers and owners - new design criteria and useful technical results can be obtained. To show the capability of the tool a novel case study is presented. It concerns on an existing cruise ship to be refurbished from the energy point of view. Here, four diesel generators are installed on-board. The ship energy system includes five electric chillers, two auxiliary boilers, two reverse osmosis and two multi-stage flash desalination devices (driven by the diesel generators waste heat recoveries). Simulation results show remarkable energy savings obtained through the proposed optimization approach. Specifically, a maximum primary energy saving of about 15 GWh/y is obtained compared to the initial reference scenario. It corresponds to a fuel consumption reduction of 2.5 kt/y (-1.6 M$/y) and to an avoided CO 2 emission of 8.0 kt/y. • Proposed model improves sustainability of ships through unit commitment approach. • Optimization of the generators operating sequence increases a ship's energy efficiency. • The model dynamically adapts waste heat recovery to different operating conditions. • A novel algorithm identifies the best running sequence for on-board generators. • Primary energy saving of 1.92% and fuel consumption reduction of 1.73% are obtained. [ABSTRACT FROM AUTHOR]

Among the various heating technologies that can be applied to urban areas district heating is recognized to allow significant reduction in primary energy consumption, provided that the system is properly designed and operated. Thermo-fluid dynamic simulation tools can be of extreme importance in order to achieve this objective. This paper aims at presenting a thermo fluid dynamic model for the detailed simulation of large district heating network and showing how it can be usefully applied to examine options for the reduction of primary energy consumption. The model is tested using experimental data and then applied for analyzing transient operations of the Turin district heating network, which is the largest network in Italy and one of the largest in Europe. A comparison between simulations and experimental results shows that the model is able to predict the temperature in the nodes of the network with good accuracy. The thermal power required to each plant is also calculated with a good level of accuracy. The model can be used for the simulation of operational strategies, thus representing a versatile and important tool for the implementation of advanced management such as the installation of local storage units or the variation of user request schedules. • A thermo-fluid dynamic model for the detailed simulation of large DHNs is proposed. • The model receives data from the substations as the input. • The transient simulation of the Turin DHN is compared with measurements. • The model can be applied to implement advanced management strategies. [ABSTRACT FROM AUTHOR]

• A novel reversible solid oxide fuel cells system for grid stabilization. • A two-staged methanation subsystem utilizes the H 2 from SOEC operating and CO 2. • A control strategy of 7 modes (M1 – M7) operation is proposed. • M2 and M6 are optimal in terms of energy efficiency and system risk. • Dynamic simulations are conducted to investigate the system. The power to gas concept is promising for the next generation of electrochemical energy storage and grid stabilization technologies. The fuel produced from electricity-driven fuel production can be an efficient energy carrier for excessive grid power. Here, a reversible solid oxide cell(s) system integrated with methane synthesis (ReSOC-MS) is proposed for the grid stabilization application at Mega Watts class. CH 4 can be synthesized at grid surplus conditions and can be a transportation friendly energy carrier. A control strategy is proposed for this combined system, based on the grid state and H 2 tank state of the system for the normal solid oxide fuel cell (SOFC) mode and solid oxide electrolysis cell (SOEC) mode. Simulation results of these two operational modes demonstrate that the ReSOC-MS can achieve 85.34% power to gas efficiency in SOEC mode and 46.95% gas to power efficiency in SOFC mode. Dynamic simulations of stepping grid state for 5000 s operation show that the power to gas efficiency can be higher than 70%, thereby successfully demonstrating the capability of grid-balancing and methane production. [ABSTRACT FROM AUTHOR]

• A novel road description using stochastic models in a hierarchical structure. • A method for how to generate data possible to simulate in a dynamic model. • Hilliness and stop intensity are the most prominent properties in the chosen range. • The statistical method is compared with real log data and the results match well. • Ideas discussed on how to make realistic predictions of CO 2 emissions from vehicles. We propose a novel statistical description of the physical properties of road transport operations by using stochastic models arranged in a hierarchical structure. The description includes speed signs, stops, speed bumps, curvature, topography, road roughness and ground type, with a road type introduced at the top of the hierarchy to group characteristics that are often connected. Methods are described how to generate data on a form (the operating cycle format) that can be used in dynamic simulations to estimate energy usage and CO 2 emissions. To showcase the behaviour of the description, two examples are presented using a modular vehicle model for a heavy-duty truck: a sensitivity study on impacts from changes in the environment, and a comparison study on a real goods transport operation with respect to energy usage. It is found that the stop intensity and topography amplitude have the greatest impact in the sensitivity study (8.3% and 9.5% respectively), and the comparison study implies that the statistical description is capable of capturing properties of the road that are significant for vehicular energy usage. Moreover, it is discussed how the statistical description can be used in a vehicle design process, and how the mean CO 2 emissions and its variation can be estimated for a vehicle specification. [ABSTRACT FROM AUTHOR]