利用平面编码器测量巨型转轴转矩的原理研究

利用平面编码器的二维微位移测量功能,组建一组测量体系,用于测量巨型转轴的转矩。综述了转轴扭矩测量的原理、发展和运用技术。在两截面处用四组平面编码器测量两截面的相对位移,通过对相对位移运算,得到两截面的相对转角。进而实现转矩的测量。实现大型机械设备主传动的动力监测。为设备自动化、智能化奠定基础。     

基于ADAMS的新型振动采种机的仿真分析

分析了目前国内林木采种机的特点,提出了一种适用于我国东北地区红松采种作业的新型振动采种机,对其总体结构进行了设计,并用Pro/E4.0软件进行了三维实体造型。该机的主要特点是能自动修剪障碍树枝、采种效率高、体积小、作业时对母树的破坏小。并用ADAMS 2010对振动采种机激振部分进行了动力学分析,分析了振动采种机轮和树干的速度、受力等动力学参数,再通过对各参数的分析为物理样机提供了理论参考依据。     

新型不等距抛光机磨头创新设计及动力学分析

为了研究大规格瓷砖加工设备,提出一种新型不等距抛光机磨头。从结构原理上进行了创新设计,并继承了摆动式抛光磨头的优势,弥补了存在的缺陷。以新型不等距抛光磨头为研究对象,建立磨块距方程和磨头动力学模型。得出不等距磨块的分布规律改变了各个磨块切出磨削状态的隔间时间,同时分析得出不等距磨头垂直方向的磨削力平稳,振动减小。     

Dynamics of CO2 adsorption on sodium oxide promoted alumina in a packed-bed reactor

CO₂ adsorption in packed-bed reactors has potential applications in flue gas CO₂ capture and adsorption enhanced reaction processes. This work focuses on CO₂ adsorption dynamics on sodium oxide promoted alumina in a packed-bed reactor. A comprehensive model is developed to describe the coupled transport phenomena and is solved using orthogonal collocation on finite elements. The model predicted breakthrough curve matches very well with experimental data obtained from a pilot-scale packed-bed reactor. Several dimensionless parameters are also derived to explain the shape of the breakthrough curve.     

汽包炉单元机组协调控制系统的设计与投运

本文着重简述了炉跟机直接能量平衡协调控制系统的设计思想，燃烧对象的动态特性和部分回路的整定过程，并介绍了使用热量信号实现主汽压力自动调节的现场经验，有一定的推广价值。     

一种新型液压能量回收装置的动力学研究

分析了自由活塞式液压能量回收机的活塞运动、设计示功图，活塞力图，主要零部件及基础的受力状态，为该类机械动力学研究和设计计算提供了理论论据。     

CFD predictions for hazardous area classification

This study aimed to describe a Computational Fluid Dynamics(CFD) procedure using the ANSYS CFX software 16.1 and Design of Experiments for the determination of volume and extension of explosive atmospheres due to fugitive emissions of flammable gases.The multidimensional statistical sampling technique Latin Hypercube was used, which defined 100 simulations of random methane gas leak conditions.The CFD model proved to be robust in predicting the extension and volume of the explosive atmosphere for orifice diameters from 0.1 to2.5 mm, pressure from 0.1 MPa to 12 MPa and temperatures from 0 ℃ to 400 ℃.It was found that the calculation domain must be parameterized 8 m in length for each millimeter of the diameter of the source of release to ensure the predictions.In order not to lose precision for very small diameters, the mesh was parameterized with 50 elements along the orifice diameter.It was proved that gravity does not influence the extension and volume of the explosive atmosphere at sonic emissions.The deviation from the ideal gas behavior in the reservoir,achieved by applying the Soave–Redlich–Kwong equation of state, also has not significantly influenced the extension and volume of the explosive atmosphere.The results showed that the size of the explosive atmosphere varies directly with the diameter of the source emission and reservoir pressure, and inversely with the temperature of the reservoir.The diameter of the source is the parameter that has the major effect on the extension of the explosive atmosphere, followed by the pressure and lastly the temperature of the reservoir.     

Adsorption of Uranium from Dilute Aqueous Solution on Inorganic Adsorbents

Abstract

The adsorption of uranium from a dilute aqueous solution by a large number of inorganic adsorbents has been investigated. A mixture of aluminum hydroxide, ferric hydroxide, and activated carbon in the weight ratio 1:3:4 has shown a high adsorbability for uranium. The separation of uranium from a dilute aqueous solution by this mixed adsorbent under various temperatures and pH values has been studied. The adsorbability was found to exhibit a maximum at pH 4.0 to 5.5 and to decrease with increasing temperature. A number of eluting solutions for the desorption of uranium from the mixed adsorbent were also tested; 1 N (NH₄)₂ CO ₃ was found to be the most suitable eluting solution (93% recovery of uranium).     

CFD study of non-premixed swirling burners: Effect of turbulence models

This research investigates a numerical simulation of swirling turbulent non-premixed combustion. The effects on the combustion characteristics are examined with three turbulence models: namely as the Reynolds stress model, spectral turbulence analysis and Re-Normalization Group. In addition, the P-1 and discrete ordinate (DO) models are used to simulate the radiative heat transfer in this model. The governing equations associated with the required boundary conditions are solved using the numerical model. The accuracy of this model is validated with the published experimental data and the comparison elucidates that there is a reasonable agreement between the obtained values from this model and the corresponding experimental quantities. Among different models proposed in this research, the Reynolds stress model with the Probability Density Function (PDF) approach is more accurate (nearly up to 50%) than other turbulent models for a swirling flow field. Regarding the effect of radiative heat transfer model, it is observed that the discrete ordinate model is more precise than the P-1 model in anticipating the experimental behavior. This model is able to simulate the subcritical nature of the isothermal flow as well as the size and shape of the internal recirculation induced by the swirl due to combustion.