Parameters Optimizing of Ammonia-Recovery System in the Modified Equipment of Flax Fiber

A detailed analysis of operational process and principle of ammonia-recovery system in the modified equipment of flax fiber,which will be applied to parameters optimizing of the ammoniarecovery system as a foundational principle,is presented. According to the principle,an ammonia compressor,whose working conditions are based on key operational parameters of the whole ammoniarecovery system, is the mainly energy-consumption part of ammonia-recovery system in the modified equipment of flax fiber. A generally mathematical model based on work efficiency of an ammonia compressor is founded,which is available to rate effective work and energy consumption of the ammonia compressor. The optimum operation-efficiency of the ammonia compressor is chosen as the goal to analyze and calculate the key operational parameters of the ammonia-recovery system. In the above analyzing and calculating,a mathematical model on ammonia flowing from the reactor to the register 1 is developed,in order to provide further understanding of the principle of an ammonia-recovery system. At the meantime,the ammonia flow regime in the pipeline and the process of ammonia inflation and deflation from the reactor to the register 1 are taken separately into account in the model. An iterative method is for obtaining parametric solutions of the mathematical model on ammonia flowing from the reactor to the register 1 and the key operational parameters of the ammoniarecovery system. A parametric analysis is put forward to complete showing the ammonia velocity or the state of the reactor and the register 1. The key optimized parameters will be achieved in term of the minimum efficiency after comparing the work efficiencies of an ammonia compressor at different working conditions.

Revisiting the electrode manufacturing: A look into electrode rheology and active material microenvironment

The microstructures on electrode level are crucial for battery performance, but the ambiguous understanding of both electrode microstructures and their structuring process causes critical challenges in controlling and evaluating the electrode quality during fabrication. In this review, analogous to the cell microenvironment well-known in biology, we introduce the concept of ‘‘active material microenvironment”(ME@AM)that is built by the ion/electron transport structures surrounding the AMs, for better understanding the significance of the electrode microstructures. Further, the scientific significance of electrode processing for electrode quality control is highlighted by its strong links to the structuring and quality control of ME@AM. Meanwhile, the roles of electrode rheology in both electrode structuring and structural characterizations involved in the entire electrode manufacturing process(i.e., slurry preparation, coating/printing/extrusion, drying and calendering) are specifically detailed. The advantages of electrode rheology testing on in-situ characterizations of the electrode qualities/structures are emphasized. This review provides a glimpse of the electrode rheology engaged in electrode manufacturing process and new insights into the understanding and effective regulation of electrode microstructures for future high-performance batteries.

Highly efficient charging and discharging of three-level quantum batteries through shortcuts to adiabaticity

Quantum batteries are energy storage devices that satisfy quantum mechanical principles.How to improve the battery’s performance such as stored energy and power is a crucial element in the quantum battery.Here,we investigate the charging and discharging dynamics of a three-level counterdiabatic stimulated Raman adiabatic passage quantum battery via shortcuts to adiabaticity,which can compensate for undesired transitions to realize a fast adiabatic evolution through the application of an additional control field to an initial Hamiltonian.The scheme can significantly speed up the charging and discharging processes of a three-level quantum battery and obtain more stored energy and higher power compared with the original stimulated Raman adiabatic passage.We explore the effect of both the amplitude and the delay time of driving fields on the performances of the quantum battery.Possible experimental implementation in superconducting circuit and nitrogen–vacancy center is also discussed.

Sensitivity analysis of borehole thermal energy storage: examining key factors for system optimization

Borehole thermal energy storage(BTES)systems have garnered significant attention owing to their efficacy in storing thermal energy for heating and cooling applications.Accurate modeling is paramount for ensuring the precise design and operation of BTES systems.This study conducts a sensitivity analysis of BTES modeling by employing a comparative investigation of five distinct parameters on a wedge-shaped model,with implications extendable to a cylindrical configuration.The parameters examined included two design factors(well spacing and grout thermal conductivity),two operational variables(charging and discharging rates),and one geological attribute(soil thermal conductivity).Finite element simulations were carried out for the sensitivity analysis to evaluate the round-trip efficiency,both on a per-cycle basis and cumulatively over three years of operation,serving as performance metrics.The results showed varying degrees of sensitivity across different models to changes in these parameters.In particular,the round-trip efficiency exhibited a greater sensitivity to changes in spacing and volumetric flow rate.Furthermore,this study underscores the importance of considering the impact of the soil and grout-material thermal conductivities on the BTES-system performance over time.An optimized scenario is modelled and compared with the base case,over a comparative assessment based on a 10-year simulation.The analysis revealed that,at the end of the 10-year period,the optimized BTES model achieved a cycle efficiency of 83.4%.This sensitivity analysis provides valuable insights into the merits and constraints of diverse BTES modeling methodologies,aiding in the selection of appropriate modeling tools for BTES system design and operation.

To Improve the Accuracy of Laser Pulse Range Finding by Time Scale-Up

A method of improving the accuracy of laser pulse range finding from ±10 m to ±1 m inexpensively by means of time scale up is described. Time scale up can stretch the entire flight time by a factor of 1 000 and then the stretched result is counted to calculate the distance. The use of this technique decreases the resolution of counting from nanosecond to microsecond, therefore a separate counting oscillator followed by an interpolation operation is unnecessary. This technique can improve the accuracy of laser pulse range finding inexpensively and effectively.

Flow-rate Characteristics Measurement of Regulators Based on the Pressure Response in an Isothermal Tank

Regulators are important components in pneumatic system, and their flow-rate characteristics are the key parameters for designers. According to the correlatively international standard and national standard of China, which describe the flow-rate characteristics measurement method of pneumatic regulators, the pressure and the flow are measured point by point, and then the flow-rate characteristics curve is plotted point to point. This method has some disadvantages, such as equipment complexity, much air consumption, and low efficiency. To settle the problems presented above, this paper puts forward a new high efficient and energy saving flow-rate characteristics measurement method of regulators, which is based on the pressure response when charging and discharging to an isothermal tank without any flow meters. The measurement principle, the system and the steps are introduced. And the tracking differentiator is used for the data processing of the pressure difference. Two typical kinds of regulators were experimentally investigated, and their flow-rate characteristics curves were obtained with the new and the conventional method, respectively. Comparatively, it＇s proved that this new method is feasible because it is not only able to meet the demand of the measurement precision, but also to save energy and improve efficiency. Compared to the conventional method, the new method takes only about 1/10 amount of time and consumes about only 1/30 amount of air. Hopefully it will be able to serve as an international standard of flow-rate characteristics measurement method of regulators.

Analytical model for describing ion guiding through capillaries in insulating polymers

An analytical description for guiding of ions through nanocapillaries is given on the basis of previous work. The current entering into the capillary is assumed to be divided into a current fraction transmitted through the capillary, a current fraction flowing away via the capillary conductivity and a current fraction remaining within the capillary, which is responsible for its charge-up. The discharging current is assumed to be governed by the Frenkel–Poole process. At higher conductivities the analytical model shows a blocking of the ion transmission, which is in agreement with recent simulations.Also, it is shown that ion blocking observed in experiments is well reproduced by the analytical formula. Furthermore, the asymptotic fraction of transmitted ions is determined. Apart from the key controlling parameter(charge-to-energy ratio), the ratio of the capillary conductivity to the incident current is included in the model. Differences resulting from the nonlinear and linear limits of the Frenkel–Poole discharge are pointed out.

Experimental research on charging characteristics of a pressure-controlled VRLA battery in high-temperature environments

Valve-regulated-lead-acid (VRLA) battery charging performed in high-temperature environments is extremely risky under overcharge conditions, and may lead to a subsequent thermal runaway. A new pressure-controlled charging method was adopted and the charging characteristics of the pressure-controlled VRLA battery in high-temperature environments were ex-perimentally studied. The concept was tested in a large temperature gradient to obtain more details about the effects of users' accustomed charging and discharging modes on battery capacity. The premature capacity loss (PCL) phenomenon under high temperature exposure was analyzed. The results showed that the capacity loss could be recovered by charging using a large current.

TIME AND POLING HISTORY DEPENDENT ENERGY STORAGE AND DISCHARGE BEHAVIORS IN POLY(VINYLIDENE FLUORIDE-CO-HEXAFLUOROPROPYLENE) RANDOM COPOLYMERS

We studied cycle time （0.01-10 s with triangular input waves） and poling history （continuous versus fresh poling） dependent electric energy storage and discharge behaviors in poly（vinylidene fluoride-co-hexafluoropropylene） [P（VDF- HFP）] films using the electric displacement -- the electric field （D-E） hysteresis loop measurements. Since the permanent dipoles in PVDF are orientational in nature, it is generally considered that both charging and discharging processes should be time and poling history dependent. Intriguingly, our experimental results showed that the charging process depended heavily on the cycle time and the prior poling history, and thus the D-E hysteresis loops had different shapes accordingly. However, the discharged energy density did not change no matter how the D-E loop shape varied due to different measurements. This experimental result could be explained in terms of reversible and irreversible polarizations. The reversible polarization could be charged and discharged fairly quickly （〈 5 ms for each process）, while the irreversible polarization depended heavily on the poling time and the prior poling history. This study suggests that it is only meaningful to compare the discharged energy density for PVDF and its copolymer films when different cycle times and poling histories are used.

Microgrid economic operation considering plug-in hybrid electric vehicles integration

In this paper,the microgrid economic scheduling mathematical model considering the integration of plug-in hybrid electric vehicles(PHEVs)is presented and the influence of different charging and discharging modes on microgrid economic operation is analyzed.The generic algorithm is used to find an economically optimal solution for the microgrid and PHEV owners.The scheduling of PHEVs and the microgrid are optimized to reduce daily electricity cost and the potential benefits of controlled charging/discharging are explored systematically.Constraints caused by vehicle utilization as well as technical limitations of distributed generation and energy storage system are taken into account.The proposed economic scheduling is evaluated through a simulation by using a typical grid-connected microgrid model.