Explore the vast range of titles available.

This study presents a sophisticated numerical simulation model for a forced circulation solar water heating system (FC-SWHs), specifically designed for the unique climatic conditions of Algeria. The model aims to cater to the hot water needs of single-family houses, with a daily consumption of 246 L. Utilizing a dynamic approach based on TRNSYS modeling, the system’s performance in Ain Temouchent’s climate was scrutinized. The model’s validation was conducted against literature results for the collector outlet temperature. Key findings include a maximum monthly average outlet temperature of 38 °C in September and a peak cumulative useful energy gain of 250 W in August. The auxiliary heating system displayed seasonal energy consumption variations, with the highest rate of 500 kJ/hr in May to maintain the water temperature at 60 °C. The energy input at the storage tank’s inlet and the consistent high-level energy output at the hot water outlet were analyzed, with the former peaking at 500 W in May. The system ensured an average water tank temperature (hot, middle and bottom) and water temperature after the mixer, suitable for consumption, ranging between 55 °C and 57 °C. For applications requiring cooler water, the mixer’s exit temperature was maintained at 47 °C. The study’s key findings reveal that the TRNSYS model predicts equal inlet and outlet flow rates for the tank, a condition that is particularly significant when the system operates with high-temperature water, starting at 55 °C. The flow rate at this temperature is lower, at 7 kg/hr, while the water mass flow rate exiting the mixer is higher, at 10.5 kg/hr. In terms of thermal performance, the system’s solar fraction (SF) and thermal efficiency were evaluated. The results indicate that the lowest average SF of 54% occurs in July, while the highest average SF of over 84% is observed in September. Throughout the other months, the SF consistently stays above 60%. The thermal efficiency of the system varies, ranging from 49 to 73% in January, 43–62% in April, 48–66% in July, and 53–69% in October. The novelty of this research lies in its climate-specific design, which addresses Algeria’s solar heating needs and challenges. Major contributions include a thorough analysis of energy efficiency metrics, seasonal auxiliary heating demands, and optimal system operation for residential applications, supporting Algeria’s goal of sustainable energy independence.

Solar energy‐based heating systems, which are capable of providing space heating as well as domestic hot water heating, are a promising alternative to conventional systems to achieve the status of reducing fossil energy consumption in residential buildings. Determining how suitable such systems are performing in Canada and which station is the most suitable in terms of energy‐economic‐environmental parameters are issues that have not been investigated so far. Considering that such results are very important for energy decision‐makers and investors, therefore, in the present work, the provision of space heating and hot water heating on a residential scale in 10 Canadian provinces was done by Valentin TSOL v2021 R3 software. Then nine software output parameters along with three parameters of land price, the population of each station, and the natural disaster index were weighted using the AHP method. Finally, the results of the stations were ranked using five MCDM methods including AHP, TOPSIS, WASPAS, CRITIC, and GRA. The results of numerical simulations showed that the CO 2 emissions avoided parameter has the most weight, and the parameters solar contribution to DHW and boiler energy to DHW has the least weight. Also, the final ranking of each station showed that the most suitable station is Regina and the most unsuitable station is Victoria. By examining and analyzing the results, it was found that only based on the outputs of the Valentin TSOL v2021 R3 software, it is not possible to comment on finding appropriate and inappropriate stations, and the necessity of using ranking methods was observed more than before.

End-use efficiency, demand response and coupling of different energy vectors are important aspects of future renewable energy systems. Growth in the number of data centres is leading to an increase in electricity demand and the emergence of a new electricity-intensive industry. Studies on data centres and energy use have so far focused mainly on energy efficiency. This paper contributes with an assessment of the potential for energy system integration of data centres via demand response and waste heat utilization, and with a review of EU policies relevant to this. Waste heat utilization is mainly an option for data centres that are close to district heating systems. Flexible electricity demand can be achieved through temporal and spatial scheduling of data centre operations. This could provide more than 10 GW of demand response in the European electricity system in 2030. Most data centres also have auxiliary power systems employing batteries and stand-by diesel generators, which could potentially be used in power system balancing. These potentials have received little attention so far and have not yet been considered in policies concerning energy or data centres. Policies are needed to capture the potential societal benefits of energy system integration of data centres. In the EU, such policies are in their nascent phase and mainly focused on energy efficiency through the voluntary Code of Conduct and criteria under the EU Ecodesign Directive. Some research and development in the field of energy efficiency and integration is also supported through the EU Horizon 2020 programme. Our analysis shows that there is considerable potential for demand response and energy system integration. This motivates greater efforts in developing future policies, policy coordination, and changes in regulation, taxation and electricity market design.

China has the world’s largest machine tool consumer market, and its proportion of annual output of machine tools is still gradually increasing. As basic equipment of the manufacturing industry, the energy consumption of machine tools is significant. A lot of research has been done to model the cutting power, spindle power, and feed power of machine tools. However, many studies have shown that the fixed energy consumption of machine tools (generated by standby and auxiliary devices) accounts for a high proportion. This paper solves the problem of standby and auxiliary power modeling. The following work is done: (1) a new standby power empirical model is proposed, which distinguishes the standby power of CNC machine tool in weak and strong current states. Meanwhile, the new model reveals the influence of the intermittent working characteristics of the lubrication cooling device on the standby power, through deriving the power equations of the lubrication and cooling system (three stages are considered namely preheating, minimum theoretical oil supply period, and non-oil interval). (2) The new standby model is verified by experiments performed on a lathe, milling machine, and machining centers. Comparing with the existing standby power model, the new model is confirmed to be closer to the actual measurement curve of standby power, and avoids the standby energy consumption prediction error caused by using a single constant power value. (3) Through the analysis of the working principle and energy consumption of auxiliary functional components, the theory and empirical power equations of lighting, cutting fluid device, tool changer device, chip removal device power, and air blowing device are deduced, and also have been verified by experiments on three machine tools.

The coordinated use of electricity and a heat energy system can effectively improve the energy structure during winter heating in the northern part of China and improve the environmental pollution problem. In this paper, an economic scheduling model of an electric–thermal integrated energy system, including a wind turbine, regenerative electric boiler, solar heat collection system, biomass boiler, ground source heat pump and battery is proposed, and a biomass boiler was selected as the auxiliary heat source of the solar heat collection system. A mixed integer linear programming model was established to take the operating cost of the whole system as the target. A day-ahead optimization scheduling strategy considering the demand side response and improving new energy consumption is proposed. In order to verify the influence of the coordinated utilization of the flexible load and energy storage equipment on the optimal scheduling in the model built, three scenarios were set up. Scenario 3 contains energy storage and a flexible load. Compared with scenario 1, the total cost of scenario 3 was reduced by 51.5%, and the abandonment cost of wind energy was reduced by 43.3%. The use of a flexible load and energy storage can effectively reduce the cost and improve new energy consumption. By increasing the capacity of the energy-storage device, the wind power is completely absorbed, but the operation and maintenance cost is increased, so the capacity of energy storage equipment is allocated reasonably according to the actual situation.

The horizontal well technology was successfully applied in the Chinese second natural gas hydrate (NGH) field test in the Shenhu area of the South China Sea in 2020. However, the results show that the threshold for commercial exploitation has not been broken, judging from daily gas production and cumulative gas production. Consequently, the paper presents the effects of dual horizontal well systems for exploitation in this area. The NGH reservoir model in the Shenhu area was established with CMG software. The influence of various layout options and various spacing of dual horizontal well systems on the production capacity was investigated. Further, we simulated the production effect of dual horizontal well systems joint auxiliary measures, such as well wall heating, heat injection, etc. The results show that the production capacity of dual horizontal well systems increased by about 1.27~2.67 times compared with that of a single horizontal well. The daily gas production will drop significantly, no matter which method was used, when exploitation lasts for about 200 d. Meanwhile, well wall heating and heat injection have limited effects on promoting production capacity. In conclusion, attention was drawn to the fact that the synergistic effect could be fully exerted to accelerate NGH dissociation when dual horizontal well systems are applied. The NGH reservoirs in the Shenhu area may be more suitable for short-term exploitation. The research results of this paper can provide a reference for the exploitation of the Shenhu area.

The findings in application of laser diagnostic systems for the investigation of wet steam flows in flow paths of steam turbines, specifically, in channels of various configurations, are reviewed. The experimental results accumulated over more than a decade enabled the authors to generalize and formulate the essential features of the movement of coarse erosion-hazardous droplets downstream of turbine cascades and in interblade channels. The regions with liquid phase particles are found using the data of visual analysis. The results of application of the particle image velocimetry/particle tracking velocity (PIV/PTV) methods, which implement algorithms for determining vector fields of particle velocities, are presented. The features of the distribution of kinematic characteristics of the liquid phase in various regions of turbine cascades, which affect the erosion wear rate, are discussed. Data are presented on the effect of the blade profile on the formation of trajectories of droplet flows, and methods for improving the separation ability of a blade operating in a wet stem flow are proposed. Using the experimental database on liquid phase velocity fields in turbine channels of various configurations, a semiempirical model of the flow of large erosive-dangerous droplets is formulated. It describes their movement in a cocurrent steam flow and interaction with the walls of the interblade channels. A review is presented of engineering solutions that were obtained on the basis of theoretical and experimental studies of wet steam flows using laser diagnostic systems. The concept of blade surface heating, heating steam jet injection, and optimization of the in-channel separation system is examined. The principles are formulated for the development of approaches based on laser flow diagnostic systems in the field of application of neural networks, which should considerably extend the capabilities of experimental studies since they offer the potential for increasing the amount of data obtained by implementing such experimental methods.

As the first full superconducting tokamak in the world, the equipment and the experimental level on EAST have been constantly improved. A large number of experimental data are produced, and then the high-quality discharge has great significance to EAST project. In order to improve the experimental level of EAST and guide the high-quality discharge, this paper selected the high-quality discharge shots from the historical experimental data of EAST, and statistically analyzed the key physical parameters of this shots. Finally, the standard of high-quality discharge shots has been conclude, so as to guide the experimenter to obtain the optimal parameter configuration and improve the experimental level of EAST.

At present, based on the features of Pulse Step Modulator (PSM) technology in high voltage power supply (HVPS) is applied to drive the auxiliary heating system in domestic and foreign Tokomak facility. Before design of PSM HVPS, it is necessary to consider the effect of stray parameter existed in HVPS on the dynamic process of HVPS and load. In this paper, based on PSM technology 50 kV HVPS have been completed which is built for EAST auxiliary heating system and the relationship between the stray capacitance and leakage impedance respectively existed in the oil isolation transformer and dry multi-secondary winding transformer is discussed. Finally a stray parameters electrical circuit model of HVPS is presented. At last, from the results of experiment,it is consistent with the results of simulation.

Based on the natural environment of Gansu YuMen oilfield in china, aiming at the winter heating requirements for oil field duty room, using the solar heating system that make solar energy storage and auxiliary electric heating, selection of flat plate collector, tacking double working medium for heat exchange indirectly, use the antifreeze liquid as the hot working medium, use the water as the energy storage and heating medium. According to the room temperature and medium temperature, intelligent control system adjust and control the double medium circulation loop, automatic regulating the intermittent work time for auxiliary electric heating system, the problem of antifreeze and sand prevention be solved effectively in the extreme temperatures. Compared to the electric heater heating, it can realize energy saving and environmental protection, the energy saving effect more than 46%, having remarkable economic and social benefits.