换热器网络在非设计工况下的运行

所有的换热器网络(HENs)都是在给定的运行工况下进行设计的.但有时它们并非在设计工况下运行,即某些过程流体进口参数与其设计值存在着偏差,因而其他过程流体进口参数需要进行调节以维持过程流体的出口参数设计值.换热器网络在非设计工况下的运行问题可以分为3种情况:调节参数的个数大于、等于或小于出口目标参数的个数,如果进口参数偏差处于换热器网络的可行域内,那么将可能分别存在一种、多种调节方案,或者不存在调节方案.对于存在多种调节方案的情形,最优的方案需要确定.     

上海市房地局建造一批鸳鸯楼作为结婚过渡用房

建造年大结婚过渡用房是上海市房地局为缓和居住困难的应急措施之一。自82年下半年以来,各区房管部门研究方案,落实基地,积极筹建,至目前为止,普陀区已竣323,140平方米交付使用,可解决132对结婚户用户。最近已有115户年大青年新婚夫妇乔     

固定床颗粒亲合吸附研究

颗粒亲合吸附方法在回收有用化合物的工程中具有广泛的应用前景.在颗粒吸附被处理物质的过程中,被处理物质在颗粒的孔隙中不断扩散,并被颗粒孔隙壁面所吸附.本文对固定床内硅胶(XWP-P005)颗粒对流动液中的乙醇脱氢酶(Y-ADH)的吸附过程进行了理论模型的数值计算及实验研究,对固定床的设计具有参考意义.     

BaTiO3纳米线的制备及其复合物介电和储能性能研究

采用两步水热法合成钛酸钡(BaTiO₃)纳米线, 并以此为填充物, 聚偏氟乙烯六氟丙烯(P(VDF-HFP))为聚合物基体制备介电复合物, 研究不同含量BaTiO₃纳米线对复合物的介电及储能性能的影响。采用X射线衍射仪、扫描电镜、透射电镜、阻抗分析仪和铁电工作站等表征BaTiO₃纳米线及其复合物的物相、微观结构、介电和储能性能。结果表明: BaTiO₃纳米线具有典型的四方相, 且在聚合物基体中具有良好的分散性与相容性。相同频率下, 复合物的介电常数随着BaTiO₃纳米线含量的增加而增加。含量为20vol%的复合物, 在1 kHz频率下其介电常数取得最 大值30.69。含量为5vol%的复合物, 在场强为240 kV/mm时, 获得了最大的储能密度与放电能量密度, 分别为4.89和2.58 J/cm³。     

基于温度和热容流率同时变化的有分流换热网络弹性设计的研究

A new superstructure model of heat exchanger networks (HEN) with stream splits based on rangers of streams supply temperatures and heat capacity flow rates is presented. The simultaneous optimal mathematical model of flexible HEN synthesis is established too. Firstly, the streams with rangers of supply temperatures and/or the streams with the rangers of heat capacity flow rates are pretreated; Secondly, several rules are proposed to establish the superstructure model of HEN with splits and the simultaneous optimal mathematical model of flexible HEN; Thirdly, the improving genetic algorithm is applied to solve the mathematical model established at the second step effectively, and the original optimal structure of HEN based on the maximum operation limiting condition can be obtained easily; Finally, the rules of heat exchange unit merged and the heat load of heat exchanger relaxed are presented, the flexible configuration of HEN satisfied the operation condition between the upper and down bounds of supply temperature and heat capacity flow rates can be obtained based on the original optimal structure of HEN by means of these rules. A case study demonstrates the method presented in this paper is effective