We propose new Li2CO3-doped dark CaCO3 pellets. The solar full-spectrum absorption of the new pellets can be as high as 73.25%. After 60 cycles, the energy storage density of the new CaCO3 pellets is still as high as 1671 kJ/kg, and the decay rate of the energy storage density decreased from 56.73% to 4.24% compared with pure CaCO3 pellets. At the same temperature, the average decomposition rate of the new CaCO3 pellets in the first cycle is 2.1 times that of the ordinary dark CaCO3 pellets. Therefore, this new CaCO3 pellets can simultaneously achieve the characteristics of fast heat storage, excellent cyclic stability and high solar absorptance.
A global performance analysis with weather conditions from 20 cities is conducted on a solar-driven indoor air carbon capture model to uncover the influence of solar irradiance and ambient temperature on the novel systemâ€™s carbon capture performance and cooling energy-saving performance. Results show that solar irradiance significantly affects collected CO2 mass while temperature affects energy-saving amounts. Specifically, for a 40 m^2Ã—2.8 m room with 39 occupants, the proposed system can capture 37.2-41.03 kg CO2 per day and achieves an energy-saving performance between 23.95%-50.66% in different cities. This study sheds light on effectively and renewably capturing CO2 from indoor air worldwide.
As a growing need for reducing carbon emissions, the renewable energy-based electric vehicle (EV) system has been studied. Extensive research has investigated the optimal sites for EV charging stations (EVCS) powered by photovoltaic (PV) plants. However, feasible ranges of applying EVCS powered by PV can be varied by different land use. This paper presents the effective approaches for siting and sizing EV charging stations using the geo-spatial clustering method on Geographic Information System (GIS). This study explores the optimization of site selection for charging stations depending on parcel maps and conducts an economy and environment analysis through the evaluation of potential electricity which can be generated in the study area.
The development of thermoacoustic refrigeration technology has been held back by low power density and high required temperatures. The present work proposes and simulates a compact, multi-stage loop thermoacoustic refrigeration system with integrated stages connected by a short thermal buffer tube at the heating-cooling section interface. This arrangement improves power density and reduces friction losses. Designed to operate at a cooling temperature between 200 and 290 K, and powered by low-grade heat input at around 450 to 600 K at 2.0 MPa mean pressure and 293 K ambient temperature, the system can achieve relatively high power density and low onset temperature. Simulation results show a four-stage system can produce a maximum cooling power output of around 5 to 10 kW with an overall axial length of less than 12 m. The system also requires a low onset temperature difference at approximately 35 K between heat input and ambient for the system to sustain limit cycle oscillations.
Microwave irradiation, as a heating source, has potential applications in mining industry. Microwave irradiation makes physical impacts on brittle rock particles that transform its power draw trend during comminution. This potentially improves the raw material supply. In this research, an instantaneous power draw analysis is applied to detect the microwave heating impact on the particle breakage mechanism during single-roll crushing. Microwave energy is reducing the duration of high resistance zone of crushing trend, which provides shorter crushing time as well as lower crushing energy saving.
Partial shaded conditions (PSC) significantly affect the performance of photovoltaic (PV) systems. Understanding and mitigating PSC effects require an accurate model with the ability to simulate the PV operating in both forward and reverse biased regions. Herein, a high-resolution approach is presented to address this issue. The reversed biased effects of PSC are fully considered at the cell level using an enhanced single diode model. Based on this, the electrical characteristic of the PV module can be accurately calculated. Good agreement is obtained between the simulation and measurement with a maximum relative error of 6.1%. This approach provides a useful tool for comprehensive modeling of the PV system.
This paper presented an energy hub model considering the impact of transformer efficiencies, by taking the difference in transformer efficiency based on the load demand. This can be achieved by taking the transformer efficiency as a dynamic value according to the transformer loading efficiency curve, as the transformer efficiency differs due to the copper losses. The following energy hub model was solved using Mixed Integer Linear Programming (MILP) with a CPLEX solver in GAMS software. Final findings showed that there is only a slight difference in the final overall when taking transformer efficiency variety into consideration for one transformer
This work presents a revolutionary design of a Smart Hybrid Solar Chimney Power Plant (SHSCPP) with a target of maximizing the power capacity and reducing the operation cost. The design combines a classic Solar Chimney Power Plant (SCPP) structure with a Cooling Tower (CT) configuration. The chimney and a bidirectional turbine are shared components of the SCPP and CT. The SHSCPP system operates as a typical CT throughout the night. However, during the daytime, the system switches back and forth between the CT and the SCPP to produce the maximum amount of electricity depending on predicted weather data. Additionally, the SHSCPP produces distilled water while the system is working as an SCPP. Aqaba city which is located in Jordan has been selected to assess the performance of the SHSCPP due to its geographical area, and weather variations. The main results showed that the SHSCPP produces 651.7 MW/year of electricity compared to 368.4 MW/year when operating as a traditional SCPP.
In recent years, the cross-regional interconnection of power grid is gradually strengthened, and this large-scale network interconnection ensures electricity But it increases the complexity of the dynamic process of the power grid, and small local faults may occur in chain The response was extended to the entire power grid. Traditional linkage fault analysis methods usually use differential equations, and their solving process is very simple In some defects, complex network theory opens up new ideas and methods for the study of grid chain faults. This paper introduces the basic concepts, parameters and models of complex networks, and analyzes the characteristics and modes of each parameter The characteristics of each type. The degree is taken as the index to identify the vulnerability of the line, and two methods are used: random attack and deliberate destruction In this paper, a new load loss ratio index is established to evaluate the impact of faults on the power grid and analyze the linkage Temporal and spatial characteristics of fault propagation. A 1029 node system of Zhejiang Provincial Power grid and a 197 node system of Northwest Power Grid were built by matpower The validity of the study is guaranteed. Through the analysis, the random attack pattern is obtained for the power grid when the attack proportion is low The extent of the impact is small, while the mode of deliberately destroying several nodes and lines is adopted, although the proportion of attacks is relatively high Low, the power grid could still suffer significant impacts. This shows that the high-degree nodes and the high-degree lines are on the grid The safe and stable operation plays an important role.
This study presents a novel approach to measuring energy sufficiency, which can identify whether people really satisfy an adequate level of domestic energy services, considering their diverse energy needs. The result, applying the method to the case of Japan, clarifies the characteristics of people in energy sufficiency, and those of the energy poor and energy extravagant. The study also demonstrates that reducing inequalities in access to low-carbon energy or technology is a major challenge in engendering an inclusive low-carbon energy transition.