削峰填谷背景下的民用楼房供暖策略研究

本研究回顾了中国在削峰填谷和电采暖领域的研究,分析了储能技术和光储协同系统的进展。基于对个体居民与社区供暖系统的详细建模,提出了优化控制策略。研究表明,通过合理的温度控制和功率调节,供暖系统能有效降低能耗并提升经济效益,削峰时段的电能节省优于填谷时段的电能增加,为节能减排提供了重要参考。

3D modeling for effect of tool eccentricity on coupled thermal and material flow characteristics during friction stir welding

A novel three-dimensional numerical model is proposed to investigate the effect of tool eccentricity on the coupled thermal and material flow characteristics in friction stir welding(FSW) process.An asymmetrical boundary condition at the tool-workpiece interface,and the dynamic mesh technique are both employed for the consideration of the tool eccentricity during tool rotating.It is found that tool eccentricity induces the periodical variation of the heat densities both at the tool-workpiece interface and inside the shear layer,but the fluctuation amplitudes of the heat density variations are limited.However,it is demonstrated that tool eccentricity results in significant variation of the material flow behavior in one tool rotating period.Moreover,the material velocity variation at the retreating side is particularly important for the formation of the periodic characteristics in FSW.The modeling result is found to be in good agreement with the experimental one.

Modeling of metadynamic recrystallization kinetics after hot deformation of low-alloy steel Q345B

Based on the steady-state strain measured by single-pass hot compression tests,the method by a double-pass hot compression testing was developed to measure the metadynamic-recrystallization kinetics.The metadynamic recrystallization behavior of low-alloy steel Q345B during hot compression deformation was investigated in the temperature range of 1 000-1 100℃,the strain rate range of 0.01-0.10 s -1 and the interpass time range of 0.5-50 s on a Gleeble-3500 thermo-simulation machine.The results show that metadynamic recrystallization during the interpass time can be observed.As the deformation temperature and strain rate increase,softening caused by metadynamic recrystallization is obvious.According to the data of thermo-simulation,the metadynamic recrystallization activation energy is obtained to be Qmd=100.674 kJ/mol and metadynamic recrystallization kinetics model is set up.Finally,the error analysis of metadynamic recrystallization kinetics model proves that the model has high accuracy(correlation coefficient R=0.988 6).

Effect of thermodynamic parameters on prediction of phase behavior and process design of extractive distillation

Extractive distillation was investigated for separation of the minimum azeotrope of n-propanol/water, via the Aspen Plus simulation platform. Experimental data of n-propanol/water, which could pass the thermodynamic consistency test, were regressed to get suitable binary interaction parameters(BIPs) by the UNIQUAC thermodynamic model. The azeotrope system was heterogeneous in the simulation with built-in BIPs, which was contrary to the experimental data. The study focused on the effect of thermodynamic parameters on the prediction of phase behavior, and process design of extractive distillation. N-methyl-2-pyrrolidone(NMP) and ethylene glycol were used as solvents to implement the separation. Processes with built-in and regressed BIPs were explored,based on the minimum total annual cost(TAC). There were significant differences in the phase behavior simulation using different thermodynamic parameters, which showed the importance of BIPs in the design and optimization of extractive distillation.

Corrosion Behavior of TP316L of Superheater in Biomass Boiler with Simulated Atmosphere and Deposit

Corrosion behavior of TP316L was investigated with simulated atmosphere and ash deposition for the superheater in biomass boiler.Corrosion dynamic curves were plotted by mass gain.The results showed that the corrosion was dependent on temperature and was greatly accelerated by ash deposition.The mass gain was distinctly reduced in the presence of SO2 with and without ash deposition on the specimens.Corrosion rates with ash deposit at different temperatures were calculated.Two feasible methods were provided to avoid serious high-temperature corrosion in the biomass boiler.

Equation oriented method for Rectisol wash modeling and analysis

Rectisol process is more efficient in comparison with other physical or chemical absorption methods for gas purification. To implement a real time simulation of Rectisol process, thermodynamic model and simulation strategy are needed. In this paper, a method of modified statistical associated fluid theory with perturbation theory is used to predict thermodynamic behavior of process. As Rectisol process is a highly heat-integrated process with many loops, a method of equation oriented strategy, sequential quadratic programming, is used as the solver and the process converges perfectly. Then analyses are conducted with this simulator.

Simulation of thermomechanical behavior during continuous casting process based on MiLE method

A new method called mixed Lagrangian and Eulerian method （MILE method） was used to simulate the thermomechanical behavior during continuous casting process of steel YF45MnV. The simulation results are basically in agreement with the measured data. The delaying period at the beginning of solidification is about 0.1. in square root of solidification time which is agreement with the data in literatures, and shell thickness increases in linear relation to square root of solidification time. The bloom surface temperature decreases gradually as the casting proceeds. The effective stress in the comer is much larger than that in the mid-face. The comer area is the dangerous zone of cracking. The effects of mold flux break temperature on the air gap and hot tearing indicator were also modeled. The model predicts that the bloom surface temperature increases with the increase of the mold flux break temperature, but the heat flux decreases with the increase of the mold flux break temperature. ,The hot tearing indicator is much smaller when the mold flux break temperature is higher.

Modeling and Simulation of Heat Transfer through an Electric Wire

This paper illustrates the use of a general purpose differential equation （DE） solver called FlexPDE for the solution heat transfer problems in electric wire. FlexPDE uses the finite element method for the solution of boundary and initial value problems. A flexible input of the governing DE＇s and of material properties functions allows the simulation of non-linear variable behavior quickly and inexpensively. A modeling of temperature distribution in one-dimensional problem, a cross section of an electric wire was simulated. Comparison of those results obtained by FlexPDE with analytical and numerical solutions are done. The results compared well with those obtained from the analytical and numerical methods. The adaptability of the FlexPDE software for solving a variety of problem types was clearly demonstrated.