新型陶瓷与熔融盐复合蓄热材料优化组合的数值模拟

将高温熔融盐相变蓄热材料和陶瓷固相蓄热材料进行复合 ,成功地研制成了能快速吸热和放热且蓄热密度高、蓄热量大的新型复合蓄热材料。分别以Al2 O3 ,MgO ,SiC为代表的陶瓷材料与 6 0LiF 40NaF ,5 0LiF 5 0KF ,6 0 .1NaCl 39.9MgCl2 ,LiH等为代表的 10余种高温熔融盐材料为复合研究对象 ,对复合蓄热材料的蓄热密度等与温度、复合材料中熔融盐的含量、材料种类间的关系进行了数值模拟研究 ,得到了对复合材料的优化设计具有指导意义的结论     

Al-Mg-Li系1420合金

对运输制造业和航空结构上应用的材料,密度和比弹性模量像强度一样都是重要的性能指标。为了降低铝的密度和提高它的比弹性模量添加锂和镁。因此,研究出含5.0～6.0％Mg,1.9～2.3％Li,0.09～0.15％Zr,0.1～0.3％Si;≤0.3％Fe,0.1％Ti,0.3％Mn,0.005％Na的铝基1420合金。该合金的强度与Al-     

高温钎料PdCu-Ti在氧化铝陶瓷上的润湿性及界面反应

本文采用座滴法试验研究了合金系统ＰｄＣｕ－Ｔｉ在Ａｌ２Ｏ３上润湿性的变化规律，探讨了界面冶金及结合等行为，运用热力学理论对结果进行了分析，随Ｔｉ含量的增加及Ｐｄ含量的减少润湿角逐渐降低，Ｔｉ的加入使界面发生了一个双重变化；液相侧富氧，钛吸收层的生成及随后的固相侧氧化钛的生成，只有界面上生成一氧化钛，才能有较好的润湿行为和较强的结合力。     

CrMoV钢时效前热处理对磷在晶界偏析的影响

含有0.04wt-％P的汽轮机转子用CrMoV钢,时效前在较高温度(600和570℃)进行预时效处理,然后在480℃时效,元素磷偏析到晶界的速度比没有经过预时效处理的钢快得多。这与预时效过程中碳化物析出,基体成分改变有关。Mo可抑制磷的偏析,但因时效过程中富Mo碳化物的生成和长大,使基体中Mo的含量降低,因此,磷从Mo的“束缚”下“解放”出来并偏析到晶界,使脆性转变温度升高,此外,碳化物的粗化也可能导致脆性转变温度升高。     

用氩气和氯气吹洗的方法从Al—Mg合金中除去钠

用5■公斤批量熔体研究了从Al—Mg合金中除钠,使之降到1ppm水平。采用了不同的方法:用叶轮机械搅拌;叶轮搅拌+MgCl_2盐覆盖;叶轮搅拌+惰性气体(氩气)吹洗,同时用盐覆盖或不用盐覆盖;叶轮搅拌,惰性气体+2％Cl_2吹洗。叶轮有一个单一的气体入口与空心轴相通。本试验给出了Na-时间关系曲线,它是用Na+1/2Cl_2=NaCl反应的化学计算法简单确定的。其理由是气泡熔体的接触面积足够大。在各个试验中发现镁都没有明显的去掉。如果接触面积不够大,除钠应该是由熔体中质量迁移起支配作用。文中也处理了这种情况的动力学。根据各种实验室的试验确定了顶部表面的质量迁移系数。在除去溶解氧的水模型试验中,测定了叶轮不同转速和气体不同流量下的接触面积。这些结果与带有多孔装置的化学工程系统有比较好的一致性。然而,不知道这些结果能否满意地推广到工业规模的装置上。     

CVD反应器传输过程的三维数学模型

提出了一个同时表示CVD过程的气体流动、温度分布和物质传输的三维数学模型。应用这个模型预报了在含有SiCl_4的氢气流中沉积出Si的锥台式反应器中的速度场、温度场和浓度场。所得的结果有助于增进对这类反应器中的传输过程的认识,模型亦可用于设计参数的最优化,诸如入口流量,锥台倾角等。     

Operational optimization of a building-level integrated energy system considering additional potential benefits of energy storage

As a key component of an integrated energy system (IES), energy storage can effectively alleviate the problem of the times between energy production and consumption. Exploiting the benefits of energy storage can improve the competitiveness of multi-energy systems. This paper proposes a method for day-ahead operation optimization of a building-level integrated energy system (BIES) considering additional potential benefits of energy storage. Based on the characteristics of peak-shaving and valley-filling of energy storage, and further consideration of the changes in the system’s load and real-time electricity price, a model of additional potential benefits of energy storage is developed. Aiming at the lowest total operating cost, a bi-level optimal operational model for day-ahead operation of BIES is developed. A case analysis of different dispatch strategies verifies that the addition of the proposed battery scheduling strategy improves economic operation. The results demonstrate that the model can exploit energy storage’s potential, further optimize the power output of BIES and reduce the economic cost.     

Impact of communication time delays on combined LFC and AVR of a multi-area hybrid system with IPFC-RFBs coordinated control strategy

In this paper, the impact of communication time delays (CTDs) on combined load frequency control (LFC) and automatic voltage regulation (AVR) of a multi-area system with hybrid generation units is addressed. Investigation reveals that CTDs have significant effect on system performance. A classical PID controller is employed as a secondary regulator and its parametric gains are optimized with a differential evolution - artificial electric field algorithm (DE-AEFA). The superior performance of the presented algorithm is established by comparing with various optimization algorithms reported in the literature. The investigation is further extended to integration of redox flow batteries (RFBs) and interline power flow controller (IPFC) with tie-lines. Analysis reveals that IPFC and RFBs coordinated control enhances system dynamic performance. Finally, the robustness of the proposed control methodology is validated by sensitivity analysis during wide variations of system parameters and load.     

细磨活化对白钨矿浸取行为的影响SCIEI

本文研究了细磨活化对白钨矿浸取行为的影响.实验结果表明,细磨活化后白钨矿在HCl-Na_3PO_4介质中的浸出速率显著加快,钨的浸出率由原来的约8％提高到99％以上.红外光谱和X射线分析结果表明,细磨除了使白钨矿比表面积显著增大外,还在固体的表面和内部产生缺陷结构,增加了矿物表面的反应活性,改善了白钨矿的分解,使得白钨矿的浸出能在较低的温度顺利进行。     

Simulation of polycrystalline aluminum tensile test with crystal plasticity finite element method

The crystal plasticity was implemented in the finite element method（FEM） software ABAQUS through the user subroutine UMAT. By means of discretizing the space at the grain level with the Voronoi diagram method, a polycrystal model was built and used in the FEM analysis. The initial orientation of each grain was generated based on the orientation distribution function（ODF）. The developed model was successfully applied in simulation of polycrystalline aluminium samples deformed by the tensile tests. The theoretical strain--stress relation was in good agreement with the experimental result. The simulation results show that the grain size has significant effect on the deformation behavior. The initial plastic deformation usually occurs at grain boundaries, and multiple slip often results in an enhanced local hardening at grain boundaries.