多组元分批精馏中各种设计参数对回流比的影响

考察了恒回流比分批精馏过程中各种设计参数对回流比的影响,并用分离难度系数关联了各参数,研究中权衡了生产中的操作费用和设备投资,结果表明：分批精馏设计中适宜的分离难度系数应介于0.4～0．6．对于一般情况可取0．5,视具体情况可调整该值的大小、该研究结果为分批精馏塔的简捷设计奠定了基础。     

基于拓展移相调制的双有源桥回流功率优化策略

在光伏直流汇聚与消纳领域,针对双有源桥DC-DC变换器由于回流功率导致效率降低的问题,在扩展移相调制的基础上,提出一种基于移相比坐标变换的回流功率优化调制策略.所提策略简化了不同模式下的传输功率数学模型,给出了回流功率分段优化运行轨迹,保证了传输功率与坐标变换后外移相比的单调性,根据坐标变换后的外移相比寻求最优移相比组...     

Supercritical carbon dioxide separation of fish oil ethyl esters by means of a continuous countercurrent process with an internal reflux

The continuous countercurrent fractionation of fish oil ethyl esters using supercritical carbon dioxide is studied, modelling a process with internal reflux generated by a thermal gradient at the top stage. A methodology for process design is proposed and applied to determine the relationships between the temperature at the top stage (T₁), the number of theoretical stages (N), and the solvent to feed ratio (S/F), with the aim of providing a quantitative comparison with the external reflux process. The internal reflux process is viable and, for stated process specifications (mass fraction and recovery of C20 + C22 ethyl esters of 95%), provides comparable or better results than the external reflux process. For example, operating at 13.3 MPa and 50 °C, and keeping T₁ in the range (66–70) °C, the specifications are attained with N and S/F in the range 16–30 and 88–120, respectively.     

A fresh look at thermal cycling absorption process for hydrogen isotopes separation by dynamic simulation: Initial feeding process and total reflux mode

Thermal Cycling Absorption Process (TCAP) is an important method to separate hydrogen isotopes for the production and engineering application of tritium. There are so many influencing factors that it is difficult to fully understand the influence mechanisms only through experiments. A new simulation model of TCAP was developed. Using the simulation model, the influencing trend and optimized value of parameters of initial feeding process and total reflux mode in TCAP are obtained as follows. (1) The temperatures of initial feeding and the cold cycle are not the lower the better as commonly assumed but exists an optimal value of 30 °C in initial feeding and -20 °C in the cold cycle. (2) The heating rate and cooling rate also exist optimal values of 45 ^°C/min and 55 ^°C/min (3) Lower feeding rate is conducive to a better separation effect of hydrogen isotopes. (4) Increasing the reflux ratio benefits the enrichment of heavy hydrogen isotope at the product side but not the light hydrogen isotope at the tail side. (5) It needs more cycles to achieve the same isotope abundance in D/T separation than H/D separation and the separation degree of hydrogen isotopes exists a maximum value after multiple cycles. The findings can provide references for the process optimization and the device design of TCAP, and also can shed new light on the understanding of the basic physical and chemical process of TCAP.     

计及灰水负荷预测的区域型热补偿系统调控策略

传统供暖手段以热电联产机组作为主要热源，由于热电联产机组具有电热耦合的特性，因此运行时会产生热电负荷不匹配问题。为缓解这一问题，提出了一种集中供暖与区域型热补偿系统共同参与的供暖手段。对用户侧的灰水生产情况进行灰水生产活动预测，量化预计可回收热能，并结合光热电站的余热，将二者一同作为集中供暖的补偿热源。根据用户侧的热负荷特性以及光热电站和灰水热能回流系统的供热特性，构建区域型热补偿系统的运行优化模型，使用模型预测控制方法制定系统模型的调控策略。最后，通过设置算例仿真对比可知，所提出的调控策略能够回收利用原本废弃的热能，在实现供暖目标的同时保证了系统的经济性和环保性。     

黑磷的液相法制备研究进展

黑磷因其独特的结构和优异的性能在许多领域展现出很好的应用前景。目前黑磷的应用仍受限于其制备方法及剥离方法。液相法是在液相条件下合成黑磷的方法,主要包括汞回流法、铋熔化法和溶剂热法。液相法可以一步制备出纳米黑磷,具有操作简单、反应条件温和、可控性强等优点,是目前最有可能实现纳米黑磷的低成本、可控制备的方法。综述了液相法制备黑磷的研究现状,分析并讨论了该方法的优点和不足之处。针对液相法制备出的黑磷存在晶型差、产率低且不稳定的问题,提出选择合适的溶剂、调控反应温度有望制备出新型结构的纳米黑磷基材料并提高黑磷的结晶性及产率,同时在制备过程中实现原位掺杂或形成复合材料有望提升黑磷的稳定性,进而拓宽黑磷的应用领域并提升黑磷的性能。     

设平衡孔时气液混输泵内部流动及轴向力分析

本文采用两相混合模型进行数值模拟计算，探究了不同进口含气率条件下，设置平衡孔对气液混输泵外特性、内部流动及轴向力的影响。研究发现：各工况条件下，设置平衡孔后该混输泵的轴向力均明显减小；从平衡系统回流的高压流体对转轮内部流动状态产生扰动，同时能破坏和夹带转轮流道内聚集的气泡；综合考虑对混输泵的性能和轴向力的影响，在较低进口含气率时采用平衡孔方法平衡混输泵轴向力的方法是可行的；平衡系统进出口压力系数随比面积系数增大而非线性减小，平衡孔的直径过大会导致混输泵的容积损失问题，因此平衡孔直径设计存在最佳值；对比发现平衡孔设在转轮叶片吸力面时转轮的轴向力幅值和脉动相对较小。研究结论可为后期多级气液混输泵平衡孔平衡轴向力系统的设计和优化提供思路和借鉴。