大面积、超补偿的干坞地基变形研究——上海外环隧道的浦东干坞开挖工程

对一个大型干坞沉管制作的珍贵沉降监测资料进行分析,同时,运用20多年来对回弹与再压缩研究成果,采用综合分析方法,从不同角度分析,进一步运用有关理论与经验的综合,对本课题进行深入分析,得出有益的结论,以期填补上海地区该类岩土工程问题的空白,为类似工程积累宝贵的经验。     

进料组成对中部蒸汽压缩两段式精馏塔节能与经济效益的影响

提出一种中部蒸汽压缩两段式新型精馏塔,并以丙烯和丙烷分离过程为例,对中部蒸汽压缩两段式精馏塔与常规精馏塔的性能进行比较。通过使用Aspen Plus模拟软件对流程建模及优化,探讨了丙烯和丙烷在不同配比进料条件情况下对中部蒸汽压缩两段式精馏塔的节能效果、全局有效能损失和经济效益的影响。结果发现,中部蒸汽压缩两段式精馏塔相比于常规精馏塔有着良好的节能效果,在丙烯和丙烷比例为3∶1时节能效果最为显著。中部蒸汽压缩两段式精馏塔比常规精馏塔全局有效能损失明显减少,并且受进料组成配比的影响不大。在经济投资方面,中部蒸汽压缩两段式精馏塔有着良好的经济效益,最后的年总投资节省率受进料组成配比的影响不大。说明该中部蒸汽压缩两段式精馏塔在进料组成配比上具有良好的适应性。     

色度域亮度域信息融合的监控视频重压缩取证

为解决当前视频重压缩取证方法没有考虑色度域信息、取证准确度低的问题,提出一种面向最新多用途视频编码(versatile video coding, VVC)标准色度域亮度域信息融合的监控视频重压缩取证方法(CLF-SVRF)。基于VVC标准的编码原理,从监控视频的色度域和亮度域维度分析并确定VVC视频码流中与压缩次数密切相关的基础码流特征;基础码流特征包括色度域和亮度域编码单元(coding unit, CU)的划分类型及预测模式;结合拉格朗日率失真优化技术分析随着压缩次数的增加,色度域亮度域CU划分类型和预测模式的变化;进一步确定色度域亮度域CU划分类型和预测模式可以作为检测视频压缩次数的基础码流特征;接着考虑视频监控应用对重压缩取证方法低复杂度的需求,基于色度域亮度域CU划分类型和预测模式构建低复杂度高级码流特征;将高级码流特征输入支持向量机完成监控视频的重压缩取证。实验结果表明,与当前先进方法相比,CLF-SVRF方法的监控视频重压缩取证准确度平均提升了13.53%,同时可以大幅度地降低重压缩取证耗时,重压缩取证时间平均减少了47.42%。     

基于多级蒸汽机械再压缩热泵的稀N,N-二甲基甲酰胺水溶液蒸馏浓缩工艺

分析了蒸汽机械再压缩(MVR)热泵蒸馏浓缩工艺的特点和适用工况,以稀N,N-二甲基甲酰胺水溶液的浓缩过程为研究对象,提出了三级MVR热泵蒸馏浓缩工艺。采用Aspen Plus化工流程模拟软件中的严格精馏模块和压缩机模块,以能耗最低为目标函数,对三级MVR热泵蒸馏浓缩工艺和三效蒸馏浓缩工艺分别进行了模拟与优化,得到了合适的工艺操作参数。模拟结果表明,与三效蒸馏浓缩工艺相比,三级MVR热泵蒸馏浓缩工艺节能约83.2%,其平均能效比(压缩机制热量与压缩机输入功率的比)为0.834;多级MVR热泵蒸馏浓缩工艺具有较大的经济优势。     

机械蒸汽再压缩系统的设计及其在食品工业中的应用

从热力学的角度对MVR系统进行了分析,并主要对蒸发器、蒸汽压缩机、预热器进行数学模型的构建。综述MVR技术在国内外食品工业上的应用。     

沉管隧道离心模型试验及数值模拟

沉管隧道在开挖及回填过程中基底应力分布特征及其与沉管结构的变形特性分析在隧道工程中占重要地位。通过以港-珠-澳沉管隧道天然地基段某一横断面为研究对象,对整个施工过程进行不同垫层厚度的离心模型试验及有限元计算模拟,揭示沉管隧道天然地基开挖回弹及回填再压缩应力分布及变形特征、沉管结构的应变特征及垫层厚度对其影响,为沉管隧道的施工及地基处理方案设计提供参考。结果表明,开挖卸荷使基底产生拱形分布回弹。回填后基底应力呈马鞍形分布,仅中间部分应力随时间及回淤增加而增大;沉管底板应变呈马鞍形分布,工后应变量变化不大。垫层厚度变薄使基底应力分布匀化效果差,回填再压缩量及工后沉降量变大。     

A novel multistage vapor recompression reactive distillation system with intermediate reboilers

Most of the published studies have focused on the thermal integration of nonreactive distillation columns. The key limitation of reactive distillation (RD) technology is that the necessary conditions (such as pressure and temperature) for the reaction must match those of distillation. Owing to this constraint, the reaction conversion may be adversely affected at the elevated pressure in the reactive section of an internally heat integrated distillation column (HIDiC). This fact forces us to adopt an external heat integration approach for an industrial heterogeneously catalyzed ethyl tert‐butyl ether (ETBE) RD column. The direct vapor recompression column (VRC) is an external heat integration scheme that is successfully used as an energy efficient scheme for separating a close‐boiling mixture. Interestingly, there exists a large temperature difference between the two ends of the representative ETBE column, and it makes the external heat integration more challenging. Aiming to improve the thermal efficiency of the ETBE column under the VRC framework, various heat pump arrangements with intermediate reboiler(s) (IR(s)) are explored and analyzed with performing a comparative study in terms of energy consumption and economics. To improve further the thermal efficiency, in this contribution, a novel multistage vapor recompression RD column with IRs is introduced addressing a number of practical concerns. An algorithm for the proposed column is formulated showing the sequential steps involved in heat integration. It is inspected that the proposed multistage vapor recompression RD system appears overwhelmingly superior to the classical vapor recompression RD and its conventional stand alone column providing a significant savings in energy as well as cost. © 2012 American Institute of Chemical Engineers AIChE J, 59: 761–771, 2013     

蒸汽再压缩式蒸发器

介绍了新型热泵蒸发装置—蒸汽再压缩式蒸发器的工作原理及工艺流程，并与双效蒸发、双效蒸发加喷射泵两种蒸发方式的运行费用进行了对比，体现其明显的节能效果，生产能力8万t／a的烧碱蒸发工序耗蒸汽及电力总费用为88万元／a。     

Introducing vapor recompression mechanism in heat‐integrated distillation column: Impact of internal energy driven intermediate and bottom reboiler

A novel combination of internally heat‐integrated distillation column (HIDiC) and vapor recompression column (VRC) with intermediate reboiler (IR) is proposed. Supplying heat at the highest temperature point (i.e., column bottom) of the VRC scheme is not thermodynamically favorable and, therefore, we aim to install the IR for better distribution of heat along the column length, thereby reducing the compressor work. Introducing IR in the combined HIDiC‐VRC system formulates an open‐loop variable manipulation policy to evaluate the comparative impact of internal and external heat sources on bottom liquid reboiling. With internal energy driven bottom reboiler, we further investigate the hybrid HIDiC‐VRCIR column with proposing the two modes of compressor arrangement, namely parallel and series. Finally, a multicomponent distillation system is exampled to show the promising potential of the proposed HIDiC‐VRCIR configurations in improving the energetic and economic performance over the HIDiC‐alone and HIDiC‐VRC schemes with reference to a conventional standalone column. © 2014 American Institute of Chemical Engineers AIChE J, 61: 118–131, 2015     

机械蒸汽再压缩蒸发结晶系统模拟分析

提出了一种升膜(或降膜)蒸发器与强制循环蒸发器并用的机械蒸汽再压缩蒸发结晶系统,溶液在升膜(或降膜)蒸发器中蒸发至接近饱和,再进入强制循环蒸发器中蒸发结晶,可减少溶液循环功耗。并以处理量为1 t/h,质量浓度为10%碳酸钠水溶液为例,模拟分析了蒸发温度、压缩机压缩比对制热能效比COP等的影响规律,并以年总费用为目标函数进行优化计算。结果表明:(1)COP随蒸发温度升高稍有下降,随压缩比增大大幅减小,本模拟条件范围内的COP达15~50;(2)本优化条件下,年总费用随压缩比的增大先减小后增加,压缩比在1.3~1.4之间年总费用最低。