漆包机烘炉加热失效原因探究及处理

针对漆包机烘炉加热失效形式及产生原因,进行了深入的研究和分析。结果表明,影响烘炉加热失效的主要原因是加热管损坏及装配异常、催化剂表面粘有金属化合物等颗粒杂质、排废风机转速设定不合理,并对加热管、催化剂、排废风机提出了合理实用的技术措施,为降低烘炉加热失效提高加热效果提供帮助。     

Molecular structure and granule morphology of native and heat‐moisture‐treated pinhão starch

Pinhão seed is an unconventional source of starch and the pines grow up in native forests of southern Latin America. In this study, pinhão starch was adjusted at 15, 20 and 25% moisture content and heated to 100, 110 and 120 °C for 1 h. A decrease in λ max (starch/iodine complex) was observed as a result of increase in temperature and moisture content of HMT. The ratio of crystalline to amorphous phase in pinhão starch was determined via Fourier transform infra red by taking 1045/1022 band ratio. A decrease in crystallinity occurred as a result of HMT. Polarised light microscopy indicated a loss of birefringence of starch granules under 120 °C at 25% moisture content. Granule size distribution was further confirmed via scanning electron microscopy which showed the HMT effects. These results increased the understanding on molecular and structural properties of HMT pinhão starch and broadened its food and nonfood industrial applications.     

水泥窑余热发电系统用耐磨材料的研制与应用

本研究针对水泥窑余热发电系统的工作条件,根据耐磨材料的损毁机理,采用高铝矾土、煅烧氧化铝粉、黏土、硅微粉等为原料,以磷酸二氢铝为结合剂,以铝酸钙水泥为促硬剂,通过添加掩蔽剂和优化配料工艺,制备了水泥窑余热发电系统用耐磨材料,并对不同处理温度对耐磨材料的性能影响进行了分析。结果表明增强骨料与基质的结合能力有利于耐磨性的提高,磷酸及磷酸盐与氧化铝之间会随着温度的升高生成不同的磷酸铝相,都能够起到结合作用,比采用水泥结合更有利于提高材料在不同温度下的强度和耐磨性。使用结果表明,制备的耐磨材料施工性能优良,凝结硬化时间适当,强度高,抗冲刷性能好,在水泥窑余热发电系统中取得了良好的使用效果。     

Mechanical properties and microstructure of Yb2SiO5 environmental barrier coatings under isothermal heat treatment

Yb₂SiO₅ (ytterbium monosilicate) top coatings and Si bond coat layer were deposited by air plasma spray method as a protection layer on SiC substrates for environmental barrier coatings (EBCs) application. The Yb₂SiO₅-coated specimens were subjected to isothermal heat treatment at 1400 °C on air for 0, 1, 10, and 50 h. The Yb₂SiO₅ phase of the top coat layer reacted with Si from the bonding layer and O₂ from atmosphere formed to the Yb₂Si₂O₇ phase upon heat treatment at 1400 °C. The oxygen penetrated into the cracks to form SiO₂ phase of thermally grown oxide (TGO) in the bond coat and the interface of specimens during heat treatment. Horizontal cracks were also observed, due to a mismatch of the coefficient of thermal expansion (CTE) between the top coat and bond coat. The isothermal heat treatment improves the hardness and elastic modulus of Yb₂SiO₅ coatings; however, these properties in the Si bond coat were a little bit decreased.     

换能器结构参数对聚合物超声塑化黏弹生热的影响

为研究超声换能器结构参数对聚合物超声塑化过程黏弹性生热的影响，首先确定超声黏弹性生热系统的组成，进行纵振超声换能器结构设计；然后分析超声黏弹性生热过程及超声黏弹性生热原理；最后采用单一变量法分析超声换能器的主要结构参数对其纵振频率及工具头前端质点最大振幅的影响，将其实际输出的纵振激励加载于熔融聚合物，研究其结构参数对聚合物超声黏弹性生热过程及达到聚合物玻璃化转变温度所用时间的影响。结果表明，随纵振激励作用时间的增加，聚合物温度非线性升高；放大比对聚合物温度变化影响最大，前盖板厚度和工具头长度次之，影响最小的是变幅杆长度。     

AP1000稳压器波动管竖直管段空气-水CCFL实验研究

使用竖直管代替波动管模型开展稳压器波动管竖直管段内空气-水两相逆流限制（CCFL）特性可视化实验研究。实验现象表明:竖直管与上容器接口处的局部CCFL决定了进入竖直管内的液相流量；竖直管内的局部CCFL决定了从竖直管流出的液相流量；两处局部CCFL均随空气流量的增大而增强。在较低气量情况，进入竖直管内的液相能够完全或大部分流出，竖直管内的局部CCFL较弱，上容器和竖直管接口处的局部CCFL在整体CCFL中占主导地位，整体CCFL程度随着上容器液位升高而略有增强。在高气量情况，从上容器进入竖直管的液相大部分或者完全被限制而不能向下流出，竖直管内的局部CCFL强烈，在整体CCFL中占主导地位，整体CCFL特性不受上容器液位变化的影响。通过实验数据拟合得到了新的稳压器竖直管CCFL模型。稳压器波动管CCFL数据和稳压器竖直管CCFL数据基本重合，表明波动管CCFL主要由CCFL-U决定。      

不同折流板结构螺旋折流板换热器传热性能的比较(英文)

Numerical simulations were performed on flow and heat transfer performances of heat exchangers having six helical baffles of different baffle shapes and assembly configurations, i.e., two trisection baffle schemes, two quadrant baffle schemes, and two continuous helical baffle schemes. The temperature contour or the pressure contour and velocity contour plots with superimposed velocity vectors on meridian, transverse and unfolded concentric hexagonal slices are presented to obtain a full angular view. For the six helix baffled heat exchangers, the different patterns of the single vortex secondary flow and the shortcut leakage flow were depicted as wel as the heat transfer properties were compared. The results show that the optimum scheme among the six configurations is a circumferential overlap trisection helix baffled heat exchanger with a baffle incline angle of 20° (20°TCO) scheme with an anti-shortcut baffle structure, which exhibits the second highest pressure dropΔpo, the highest overal heat transfer coefficient K, shel-side heat transfer coefficient ho and shel-side average comprehensive index ho/Δpo.     

新型低GWP高温热泵工质HFO-1234ze(Z)的研究进展

高温热泵可以有效回收工业余热，达到节能减排和保护环境的目的。目前，有关高温热泵技术的研究热点在于寻找一种全球变暖潜能值(GWP)低、使用性能良好的工质，以替代现有CFC-114、HFC-245fa工质。对新型环境友好型工质HFO-1234ze(Z)进行了综述，其GWP＜1，临界温度高于423 K，是一种潜在的高温热泵替代工质。总结了近年来国内外学者对HFO-1234ze(Z)的合成技术、热力学性质、输运性质、传热性能等方面的研究，并分析了HFO-1234ze(Z)在高温热泵系统中应用的可行性，认为HFO-1234ze(Z)在高温热泵中具有较好的工作性能和发展前景。     

环形通道内液态铅铋合金流动换热特性实验研究

通过对环形通道内液态铅铋合金的流动换热特性进行实验研究，得到了气泡泵注气对液态金属流动的影响，并拟合出环形通道内液态铅铋合金的摩擦系数关系式和换热特性关系式。结果表明：采用气泡泵注气能有效提升铅铋合金的质量流速；相同Reynolds数下环形通道内液态铅铋合金的摩擦系数大于由布拉休斯公式计算得到的摩擦系数；液态铅铋合金对流换热过程中，导热项占主导地位，并且Nusselt数随Peclet数的增大而增大。     

基于(火用)效率目标的环冷机余热回收系统操作参数优化

摘要：针对烧结环冷机余热回收利用率不高的难题，采用分析法建立了评价某钢铁厂烧结环冷机余热回收系统运行效率的效率模型。基于多孔介质模型、局部非热平衡方程、真实气体SRK方程建立环冷机内气固两相换热模型。通过CFD仿真模拟，探究料层高度、循环风机输入烟气温度、烧结矿底部入口风速三项可控环冷机运行工艺参数对系统效率的影响规律。结果表明，料层厚度在1～1.5 m区间每增加0.1 m，效率增加0.8%～1.1%；循环风温在100～140℃之间每增加10℃，效率增加1.4%～1.5%；烧结矿底部入口风速在0.9～1.9 m/s之间每增加0.1 m/s，效率降低0.18%～0.24%。在此基础上，基于工业运行数据建立效率正交试验优化模型，提高了该余热回收系统3.42%的效率。