磷酸铵生产中高温冷凝水密闭循环回收与应用

针对目前磷酸铵生产排出的高温冷凝水的热能未得到充分利用及由此产生的热污染，介绍了一种把排出的高温冷凝水密闭循环回收利用技术，可使蒸汽热力系统的运行效率提高10％以上。分析了该技术的特点和运行状况，认为采用该技术对蒸汽能力系统进行改造，投资少、见效快，投资回收期短、经济效益好，又消除了热污染现象，在磷酸铵生产中有推广价值。     

［Bmim］BF4-H2O-Na2CO3离子液体双水相体系液液相平衡数据的测定与关联

用浊点法测定了四氟硼酸1-丁基-3-甲基咪唑—水—碳酸钠体系在常压30℃下的溶解度曲线及密度曲线，并用经验方程进行了关联。用浊点—密度法测定了该体系的液液相平衡数据，绘制了相应的相图。结果表明：双水相体系一相以离子液体和水为主，碳酸钠的含量很少，另一相以碳酸钠和水为主，离子液体的含量很少。该体系既可作为萃取分离体系，也可作为从水溶液中分离回收离子液体的初步体系。用Othmer-Tobias+Bancroft经验方程对相平衡数据进行关联，最大相对误差为94.99%， 最大平均相对误差为15.69%，关联结果不理想。提出用Othmer-Tobias经验方程+溶解度方程对其进行关联，最大相对误差为4.52%，最大平均相对误差为2.77%，关联精度较高，该方法可适用于有一组分含量较低的体系的液液相平衡的关联计算。     

CONDENSING HEAT TRANSFER IN AN ADVANCED TWO-PHASE CLOSED THERMOSYPHON

1 INTRODUCTIONClosed thermosyphon has been developed to enhance heat transfer and recover wasteheat in various process industries [1,2].Stimulated by this success,a new type oftwo-phase closed thermosyphon was designed by inserting respectively two inner tubesinto the thermosyphon,one in the boiling section and the other in the condensing sec-tion.The two-phase flow boiling heat transfer coefficient was calculated successfully onthe basis of Chen's dual-mechanism [3].A boiling heat transfer model for thetwo-phase closed thermosyphon with an inner tube in the boiling section was pro-     

旋风分离器两相流研究综述

综述了旋风分离器内部流场、颗粒运动和数值计算模型的理论研究发展历程。     

等离子体煤气化反应器内部流动数值模拟及设计优化的初步研究

本文对一种等离子体煤气化反应器内部湍流、两相流动和燃烧化学反应等复杂流动现象进行了三维数值模拟 ,得出了其内部的温度分布、速度分布和组分浓度分布 ,在对计算结果进行分析的基础上 ,提出了等离子体煤气化反应器的一种优化设计方案 ,并对此方案进行了不同等离子体流速下的数值模拟和比较分析 ,以确定气流参数的最佳匹配 ;数值分析结果表明 :改进的设计方案和气流参数匹配提高了等离子体热源利用的效率和煤气转化的效率     

水平管气液两相弹状流液弹频率的水动力学新模型

The prediction of slug frequency has important significance on gas-liquid two-phase flow. A hydrodynamic model was put forward to evaluate slug frequency for horizontal two-phase flow, based on the dependence of slug frequency on the frequency of unstable interfacial wave. Using air and water, experimental verification of the model was carried out in a large range of flow parameters. Six electrical probes were installed at different positions of a horizontal plexiglass pipe to detect slug frequency development. The pipe is 30 m long and its inner diameter is 24 ram. It is observed experimentally that the interracial wave frequency at the inlet is about i to 3 times the frequency of stable slug. The slug frequencies predicted by the model fit well with Tronconi (1990) model and the experimental data. The combination of the hydrodynamic model and the experimental data results in a conclusion that the frequency of equilibrium liquid slug is approximately half the minimum frequency of interfacial wave.     

垂直管道中塞状流的模拟

运用简化的硬球模型模拟垂直管道中的塞状流. 固相行为通过跟踪离散颗粒的运动轨迹处理,气相运动由局部平均的Navier–Stokes方程处理,气固两相间的耦合作用服从牛顿第三定律. 每个颗粒的运动过程被分解为颗粒间相互碰撞的过程及流体对其悬浮的过程. 该模型定性地模拟了垂直管道中的塞状流,即在细而长的管道中,颗粒形成沿管道运动的塞状物,且塞状物的运动速度独立于塞状物的长度,但随着气体速度的增加而增加.     

鼓泡床内气泡-液体两相湍流代数应力模型的数值模拟

现有的气泡 -液体两相流动的数值模拟中 ,或者不考虑湍流 ,或者仅仅考虑液体湍流 ,但是直接模拟和PIV测量结果都表明气泡由于尾迹的作用有强烈的湍流脉动 .本文首次推导和封闭了同时模拟气泡湍流脉动和液体湍流脉动的二阶矩输运方程两相湍流模型 ,并在此基础上建立了代数应力气泡 -液体两相湍流模型 .用代数应力模型模拟了二维矩形断面鼓泡床内气泡 -液体两相流动 .预报结果给出了气泡和液体两相速度场、两相Reynolds应力及湍动能分布和气泡体积分数分布 .模拟结果与PIV测量结果符合很好 ,表明了模型的合理性 .研究结果表明 ,原先静止的液体在气泡因浮力而产生的上升运动的作用下产生回流流动 ,而气泡则只有上升运动 .气泡速度始终大于液体速度 .在床内气泡湍流脉动确实始终很强烈 .液体则由于气泡的作用以及自身速度梯度产生的双重作用而发生湍流脉动 .气泡的脉动显著地大于液体的脉动 .两相湍流脉动都是各向异性的 ,而且气泡湍流脉动的各向异性比液体的更强烈     

A Numerical Sirnulation of Gas-Particle Two-Phase Flow in a Suspension Bed Using DifFusion Flux Model

A mathematical modei of two-dimensional turbulent gas-particle twophase flow based on the modified diffusion flux modei (DFM) and a numerical simulation method to analyze the gas-particle flow structures are developed. The modified diffusion flux modei, in which the acceleration due to various forces is taken into account for the calculation of the diffusion velocity of particles, is applicable to the analysis of multi-dimensional gas-particle two-phase turbulent flow. In order to verify its accuracy and efficiency, the numerical simulation by DFM is compared with experimental studies and the prediction by k-ε-kp two-fluid modei, which shows a reasonable agreement. It is confirmed that the modified diffusion flux modei is suitable for simulating the multi-dimensional gas-particle two-phase flow.     

高矣物的特性对双水相相图和头孢氨苄及7-ADCA分配行为的影响

A series of ethylene oxide(EO)-propylene oxide (PO) random co-polymers (EOPO) were used to form aqueous two-phase systems (ATPS) with ammonium sulfate.Effects of EOPO′s properties on the phase separation behaviors and on the partition of cephalexin and 7-aminodesacetoxicephalosporanic acid(7-ADCA) in ATPS were investigated.Both the molar mass and molar ratio of EO to PO of EOPO could greatly influence partition behaviors of cephalexin and 7-ADCA as well as the binodal curve of ATPS. With the increase of molar mass of co-polymer or the decrease of molar ratio of EO to PO,the critical point of ATPS decreased,the binodal curve became more asymmetry,and both cephalexin and 7-ADCA followed the same tendency to partition into the polymer-poor bottom phase.The experimental results shows that it is feasible to partition cephalexin and 7-ADCA in either the polymer-rich top phase or the polymer-poor bottom phase by choosing a specific phase-forming EOPO.